diff options
Diffstat (limited to '')
| -rw-r--r-- | src/net/http/h2_bundle.go | 11303 |
1 files changed, 11303 insertions, 0 deletions
diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go new file mode 100644 index 0000000..e719b5d --- /dev/null +++ b/src/net/http/h2_bundle.go @@ -0,0 +1,11303 @@ +//go:build !nethttpomithttp2 +// +build !nethttpomithttp2 + +// Code generated by golang.org/x/tools/cmd/bundle. DO NOT EDIT. +// $ bundle -o=h2_bundle.go -prefix=http2 -tags=!nethttpomithttp2 golang.org/x/net/http2 + +// Package http2 implements the HTTP/2 protocol. +// +// This package is low-level and intended to be used directly by very +// few people. Most users will use it indirectly through the automatic +// use by the net/http package (from Go 1.6 and later). +// For use in earlier Go versions see ConfigureServer. (Transport support +// requires Go 1.6 or later) +// +// See https://http2.github.io/ for more information on HTTP/2. +// +// See https://http2.golang.org/ for a test server running this code. +// + +package http + +import ( + "bufio" + "bytes" + "compress/gzip" + "context" + "crypto/rand" + "crypto/tls" + "encoding/binary" + "errors" + "fmt" + "io" + "io/fs" + "log" + "math" + mathrand "math/rand" + "net" + "net/http/httptrace" + "net/textproto" + "net/url" + "os" + "reflect" + "runtime" + "sort" + "strconv" + "strings" + "sync" + "sync/atomic" + "time" + + "golang.org/x/net/http/httpguts" + "golang.org/x/net/http2/hpack" + "golang.org/x/net/idna" +) + +// The HTTP protocols are defined in terms of ASCII, not Unicode. This file +// contains helper functions which may use Unicode-aware functions which would +// otherwise be unsafe and could introduce vulnerabilities if used improperly. + +// asciiEqualFold is strings.EqualFold, ASCII only. It reports whether s and t +// are equal, ASCII-case-insensitively. +func http2asciiEqualFold(s, t string) bool { + if len(s) != len(t) { + return false + } + for i := 0; i < len(s); i++ { + if http2lower(s[i]) != http2lower(t[i]) { + return false + } + } + return true +} + +// lower returns the ASCII lowercase version of b. +func http2lower(b byte) byte { + if 'A' <= b && b <= 'Z' { + return b + ('a' - 'A') + } + return b +} + +// isASCIIPrint returns whether s is ASCII and printable according to +// https://tools.ietf.org/html/rfc20#section-4.2. +func http2isASCIIPrint(s string) bool { + for i := 0; i < len(s); i++ { + if s[i] < ' ' || s[i] > '~' { + return false + } + } + return true +} + +// asciiToLower returns the lowercase version of s if s is ASCII and printable, +// and whether or not it was. +func http2asciiToLower(s string) (lower string, ok bool) { + if !http2isASCIIPrint(s) { + return "", false + } + return strings.ToLower(s), true +} + +// A list of the possible cipher suite ids. Taken from +// https://www.iana.org/assignments/tls-parameters/tls-parameters.txt + +const ( + http2cipher_TLS_NULL_WITH_NULL_NULL uint16 = 0x0000 + http2cipher_TLS_RSA_WITH_NULL_MD5 uint16 = 0x0001 + http2cipher_TLS_RSA_WITH_NULL_SHA uint16 = 0x0002 + http2cipher_TLS_RSA_EXPORT_WITH_RC4_40_MD5 uint16 = 0x0003 + http2cipher_TLS_RSA_WITH_RC4_128_MD5 uint16 = 0x0004 + http2cipher_TLS_RSA_WITH_RC4_128_SHA uint16 = 0x0005 + http2cipher_TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 uint16 = 0x0006 + http2cipher_TLS_RSA_WITH_IDEA_CBC_SHA uint16 = 0x0007 + http2cipher_TLS_RSA_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0008 + http2cipher_TLS_RSA_WITH_DES_CBC_SHA uint16 = 0x0009 + http2cipher_TLS_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x000A + http2cipher_TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x000B + http2cipher_TLS_DH_DSS_WITH_DES_CBC_SHA uint16 = 0x000C + http2cipher_TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA uint16 = 0x000D + http2cipher_TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x000E + http2cipher_TLS_DH_RSA_WITH_DES_CBC_SHA uint16 = 0x000F + http2cipher_TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x0010 + http2cipher_TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0011 + http2cipher_TLS_DHE_DSS_WITH_DES_CBC_SHA uint16 = 0x0012 + http2cipher_TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA uint16 = 0x0013 + http2cipher_TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0014 + http2cipher_TLS_DHE_RSA_WITH_DES_CBC_SHA uint16 = 0x0015 + http2cipher_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x0016 + http2cipher_TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 uint16 = 0x0017 + http2cipher_TLS_DH_anon_WITH_RC4_128_MD5 uint16 = 0x0018 + http2cipher_TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0019 + http2cipher_TLS_DH_anon_WITH_DES_CBC_SHA uint16 = 0x001A + http2cipher_TLS_DH_anon_WITH_3DES_EDE_CBC_SHA uint16 = 0x001B + // Reserved uint16 = 0x001C-1D + http2cipher_TLS_KRB5_WITH_DES_CBC_SHA uint16 = 0x001E + http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_SHA uint16 = 0x001F + http2cipher_TLS_KRB5_WITH_RC4_128_SHA uint16 = 0x0020 + http2cipher_TLS_KRB5_WITH_IDEA_CBC_SHA uint16 = 0x0021 + http2cipher_TLS_KRB5_WITH_DES_CBC_MD5 uint16 = 0x0022 + http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_MD5 uint16 = 0x0023 + http2cipher_TLS_KRB5_WITH_RC4_128_MD5 uint16 = 0x0024 + http2cipher_TLS_KRB5_WITH_IDEA_CBC_MD5 uint16 = 0x0025 + http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA uint16 = 0x0026 + http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA uint16 = 0x0027 + http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_SHA uint16 = 0x0028 + http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5 uint16 = 0x0029 + http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5 uint16 = 0x002A + http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_MD5 uint16 = 0x002B + http2cipher_TLS_PSK_WITH_NULL_SHA uint16 = 0x002C + http2cipher_TLS_DHE_PSK_WITH_NULL_SHA uint16 = 0x002D + http2cipher_TLS_RSA_PSK_WITH_NULL_SHA uint16 = 0x002E + http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA uint16 = 0x002F + http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA uint16 = 0x0030 + http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA uint16 = 0x0031 + http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA uint16 = 0x0032 + http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA uint16 = 0x0033 + http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA uint16 = 0x0034 + http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0035 + http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA uint16 = 0x0036 + http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0037 + http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA uint16 = 0x0038 + http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0039 + http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA uint16 = 0x003A + http2cipher_TLS_RSA_WITH_NULL_SHA256 uint16 = 0x003B + http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003C + http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x003D + http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA256 uint16 = 0x003E + http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003F + http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 uint16 = 0x0040 + http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0041 + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0042 + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0043 + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0044 + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0045 + http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0046 + // Reserved uint16 = 0x0047-4F + // Reserved uint16 = 0x0050-58 + // Reserved uint16 = 0x0059-5C + // Unassigned uint16 = 0x005D-5F + // Reserved uint16 = 0x0060-66 + http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x0067 + http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA256 uint16 = 0x0068 + http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x0069 + http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 uint16 = 0x006A + http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x006B + http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA256 uint16 = 0x006C + http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA256 uint16 = 0x006D + // Unassigned uint16 = 0x006E-83 + http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0084 + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0085 + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0086 + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0087 + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0088 + http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0089 + http2cipher_TLS_PSK_WITH_RC4_128_SHA uint16 = 0x008A + http2cipher_TLS_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0x008B + http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA uint16 = 0x008C + http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA uint16 = 0x008D + http2cipher_TLS_DHE_PSK_WITH_RC4_128_SHA uint16 = 0x008E + http2cipher_TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0x008F + http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA uint16 = 0x0090 + http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA uint16 = 0x0091 + http2cipher_TLS_RSA_PSK_WITH_RC4_128_SHA uint16 = 0x0092 + http2cipher_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0x0093 + http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA uint16 = 0x0094 + http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA uint16 = 0x0095 + http2cipher_TLS_RSA_WITH_SEED_CBC_SHA uint16 = 0x0096 + http2cipher_TLS_DH_DSS_WITH_SEED_CBC_SHA uint16 = 0x0097 + http2cipher_TLS_DH_RSA_WITH_SEED_CBC_SHA uint16 = 0x0098 + http2cipher_TLS_DHE_DSS_WITH_SEED_CBC_SHA uint16 = 0x0099 + http2cipher_TLS_DHE_RSA_WITH_SEED_CBC_SHA uint16 = 0x009A + http2cipher_TLS_DH_anon_WITH_SEED_CBC_SHA uint16 = 0x009B + http2cipher_TLS_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009C + http2cipher_TLS_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009D + http2cipher_TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009E + http2cipher_TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009F + http2cipher_TLS_DH_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x00A0 + http2cipher_TLS_DH_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x00A1 + http2cipher_TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 uint16 = 0x00A2 + http2cipher_TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 uint16 = 0x00A3 + http2cipher_TLS_DH_DSS_WITH_AES_128_GCM_SHA256 uint16 = 0x00A4 + http2cipher_TLS_DH_DSS_WITH_AES_256_GCM_SHA384 uint16 = 0x00A5 + http2cipher_TLS_DH_anon_WITH_AES_128_GCM_SHA256 uint16 = 0x00A6 + http2cipher_TLS_DH_anon_WITH_AES_256_GCM_SHA384 uint16 = 0x00A7 + http2cipher_TLS_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0x00A8 + http2cipher_TLS_PSK_WITH_AES_256_GCM_SHA384 uint16 = 0x00A9 + http2cipher_TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0x00AA + http2cipher_TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 uint16 = 0x00AB + http2cipher_TLS_RSA_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0x00AC + http2cipher_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384 uint16 = 0x00AD + http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0x00AE + http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0x00AF + http2cipher_TLS_PSK_WITH_NULL_SHA256 uint16 = 0x00B0 + http2cipher_TLS_PSK_WITH_NULL_SHA384 uint16 = 0x00B1 + http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0x00B2 + http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0x00B3 + http2cipher_TLS_DHE_PSK_WITH_NULL_SHA256 uint16 = 0x00B4 + http2cipher_TLS_DHE_PSK_WITH_NULL_SHA384 uint16 = 0x00B5 + http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0x00B6 + http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0x00B7 + http2cipher_TLS_RSA_PSK_WITH_NULL_SHA256 uint16 = 0x00B8 + http2cipher_TLS_RSA_PSK_WITH_NULL_SHA384 uint16 = 0x00B9 + http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BA + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BB + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BC + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BD + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BE + http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BF + http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C0 + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C1 + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C2 + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C3 + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C4 + http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C5 + // Unassigned uint16 = 0x00C6-FE + http2cipher_TLS_EMPTY_RENEGOTIATION_INFO_SCSV uint16 = 0x00FF + // Unassigned uint16 = 0x01-55,* + http2cipher_TLS_FALLBACK_SCSV uint16 = 0x5600 + // Unassigned uint16 = 0x5601 - 0xC000 + http2cipher_TLS_ECDH_ECDSA_WITH_NULL_SHA uint16 = 0xC001 + http2cipher_TLS_ECDH_ECDSA_WITH_RC4_128_SHA uint16 = 0xC002 + http2cipher_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC003 + http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA uint16 = 0xC004 + http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA uint16 = 0xC005 + http2cipher_TLS_ECDHE_ECDSA_WITH_NULL_SHA uint16 = 0xC006 + http2cipher_TLS_ECDHE_ECDSA_WITH_RC4_128_SHA uint16 = 0xC007 + http2cipher_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC008 + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA uint16 = 0xC009 + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA uint16 = 0xC00A + http2cipher_TLS_ECDH_RSA_WITH_NULL_SHA uint16 = 0xC00B + http2cipher_TLS_ECDH_RSA_WITH_RC4_128_SHA uint16 = 0xC00C + http2cipher_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC00D + http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA uint16 = 0xC00E + http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA uint16 = 0xC00F + http2cipher_TLS_ECDHE_RSA_WITH_NULL_SHA uint16 = 0xC010 + http2cipher_TLS_ECDHE_RSA_WITH_RC4_128_SHA uint16 = 0xC011 + http2cipher_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC012 + http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA uint16 = 0xC013 + http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA uint16 = 0xC014 + http2cipher_TLS_ECDH_anon_WITH_NULL_SHA uint16 = 0xC015 + http2cipher_TLS_ECDH_anon_WITH_RC4_128_SHA uint16 = 0xC016 + http2cipher_TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA uint16 = 0xC017 + http2cipher_TLS_ECDH_anon_WITH_AES_128_CBC_SHA uint16 = 0xC018 + http2cipher_TLS_ECDH_anon_WITH_AES_256_CBC_SHA uint16 = 0xC019 + http2cipher_TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC01A + http2cipher_TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC01B + http2cipher_TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA uint16 = 0xC01C + http2cipher_TLS_SRP_SHA_WITH_AES_128_CBC_SHA uint16 = 0xC01D + http2cipher_TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA uint16 = 0xC01E + http2cipher_TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA uint16 = 0xC01F + http2cipher_TLS_SRP_SHA_WITH_AES_256_CBC_SHA uint16 = 0xC020 + http2cipher_TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA uint16 = 0xC021 + http2cipher_TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA uint16 = 0xC022 + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC023 + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC024 + http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC025 + http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC026 + http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC027 + http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC028 + http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC029 + http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC02A + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC02B + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC02C + http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC02D + http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC02E + http2cipher_TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC02F + http2cipher_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC030 + http2cipher_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC031 + http2cipher_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC032 + http2cipher_TLS_ECDHE_PSK_WITH_RC4_128_SHA uint16 = 0xC033 + http2cipher_TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0xC034 + http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA uint16 = 0xC035 + http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA uint16 = 0xC036 + http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0xC037 + http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0xC038 + http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA uint16 = 0xC039 + http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA256 uint16 = 0xC03A + http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA384 uint16 = 0xC03B + http2cipher_TLS_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC03C + http2cipher_TLS_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC03D + http2cipher_TLS_DH_DSS_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC03E + http2cipher_TLS_DH_DSS_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC03F + http2cipher_TLS_DH_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC040 + http2cipher_TLS_DH_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC041 + http2cipher_TLS_DHE_DSS_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC042 + http2cipher_TLS_DHE_DSS_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC043 + http2cipher_TLS_DHE_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC044 + http2cipher_TLS_DHE_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC045 + http2cipher_TLS_DH_anon_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC046 + http2cipher_TLS_DH_anon_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC047 + http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC048 + http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC049 + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC04A + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC04B + http2cipher_TLS_ECDHE_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC04C + http2cipher_TLS_ECDHE_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC04D + http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC04E + http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC04F + http2cipher_TLS_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC050 + http2cipher_TLS_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC051 + http2cipher_TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC052 + http2cipher_TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC053 + http2cipher_TLS_DH_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC054 + http2cipher_TLS_DH_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC055 + http2cipher_TLS_DHE_DSS_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC056 + http2cipher_TLS_DHE_DSS_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC057 + http2cipher_TLS_DH_DSS_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC058 + http2cipher_TLS_DH_DSS_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC059 + http2cipher_TLS_DH_anon_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC05A + http2cipher_TLS_DH_anon_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC05B + http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC05C + http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC05D + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC05E + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC05F + http2cipher_TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC060 + http2cipher_TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC061 + http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC062 + http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC063 + http2cipher_TLS_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC064 + http2cipher_TLS_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC065 + http2cipher_TLS_DHE_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC066 + http2cipher_TLS_DHE_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC067 + http2cipher_TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC068 + http2cipher_TLS_RSA_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC069 + http2cipher_TLS_PSK_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC06A + http2cipher_TLS_PSK_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC06B + http2cipher_TLS_DHE_PSK_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC06C + http2cipher_TLS_DHE_PSK_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC06D + http2cipher_TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC06E + http2cipher_TLS_RSA_PSK_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC06F + http2cipher_TLS_ECDHE_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC070 + http2cipher_TLS_ECDHE_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC071 + http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC072 + http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC073 + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC074 + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC075 + http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC076 + http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC077 + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC078 + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC079 + http2cipher_TLS_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC07A + http2cipher_TLS_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC07B + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC07C + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC07D + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC07E + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC07F + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC080 + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC081 + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC082 + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC083 + http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC084 + http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC085 + http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC086 + http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC087 + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC088 + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC089 + http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC08A + http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC08B + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC08C + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC08D + http2cipher_TLS_PSK_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC08E + http2cipher_TLS_PSK_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC08F + http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC090 + http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC091 + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC092 + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC093 + http2cipher_TLS_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC094 + http2cipher_TLS_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC095 + http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC096 + http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC097 + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC098 + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC099 + http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC09A + http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC09B + http2cipher_TLS_RSA_WITH_AES_128_CCM uint16 = 0xC09C + http2cipher_TLS_RSA_WITH_AES_256_CCM uint16 = 0xC09D + http2cipher_TLS_DHE_RSA_WITH_AES_128_CCM uint16 = 0xC09E + http2cipher_TLS_DHE_RSA_WITH_AES_256_CCM uint16 = 0xC09F + http2cipher_TLS_RSA_WITH_AES_128_CCM_8 uint16 = 0xC0A0 + http2cipher_TLS_RSA_WITH_AES_256_CCM_8 uint16 = 0xC0A1 + http2cipher_TLS_DHE_RSA_WITH_AES_128_CCM_8 uint16 = 0xC0A2 + http2cipher_TLS_DHE_RSA_WITH_AES_256_CCM_8 uint16 = 0xC0A3 + http2cipher_TLS_PSK_WITH_AES_128_CCM uint16 = 0xC0A4 + http2cipher_TLS_PSK_WITH_AES_256_CCM uint16 = 0xC0A5 + http2cipher_TLS_DHE_PSK_WITH_AES_128_CCM uint16 = 0xC0A6 + http2cipher_TLS_DHE_PSK_WITH_AES_256_CCM uint16 = 0xC0A7 + http2cipher_TLS_PSK_WITH_AES_128_CCM_8 uint16 = 0xC0A8 + http2cipher_TLS_PSK_WITH_AES_256_CCM_8 uint16 = 0xC0A9 + http2cipher_TLS_PSK_DHE_WITH_AES_128_CCM_8 uint16 = 0xC0AA + http2cipher_TLS_PSK_DHE_WITH_AES_256_CCM_8 uint16 = 0xC0AB + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CCM uint16 = 0xC0AC + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CCM uint16 = 0xC0AD + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 uint16 = 0xC0AE + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 uint16 = 0xC0AF + // Unassigned uint16 = 0xC0B0-FF + // Unassigned uint16 = 0xC1-CB,* + // Unassigned uint16 = 0xCC00-A7 + http2cipher_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCA8 + http2cipher_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCA9 + http2cipher_TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAA + http2cipher_TLS_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAB + http2cipher_TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAC + http2cipher_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAD + http2cipher_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAE +) + +// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec. +// References: +// https://tools.ietf.org/html/rfc7540#appendix-A +// Reject cipher suites from Appendix A. +// "This list includes those cipher suites that do not +// offer an ephemeral key exchange and those that are +// based on the TLS null, stream or block cipher type" +func http2isBadCipher(cipher uint16) bool { + switch cipher { + case http2cipher_TLS_NULL_WITH_NULL_NULL, + http2cipher_TLS_RSA_WITH_NULL_MD5, + http2cipher_TLS_RSA_WITH_NULL_SHA, + http2cipher_TLS_RSA_EXPORT_WITH_RC4_40_MD5, + http2cipher_TLS_RSA_WITH_RC4_128_MD5, + http2cipher_TLS_RSA_WITH_RC4_128_SHA, + http2cipher_TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5, + http2cipher_TLS_RSA_WITH_IDEA_CBC_SHA, + http2cipher_TLS_RSA_EXPORT_WITH_DES40_CBC_SHA, + http2cipher_TLS_RSA_WITH_DES_CBC_SHA, + http2cipher_TLS_RSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_DES_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_DES_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_DES_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_DES_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_DH_anon_EXPORT_WITH_RC4_40_MD5, + http2cipher_TLS_DH_anon_WITH_RC4_128_MD5, + http2cipher_TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_DES_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_KRB5_WITH_DES_CBC_SHA, + http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_KRB5_WITH_RC4_128_SHA, + http2cipher_TLS_KRB5_WITH_IDEA_CBC_SHA, + http2cipher_TLS_KRB5_WITH_DES_CBC_MD5, + http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_MD5, + http2cipher_TLS_KRB5_WITH_RC4_128_MD5, + http2cipher_TLS_KRB5_WITH_IDEA_CBC_MD5, + http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA, + http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA, + http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_SHA, + http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5, + http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5, + http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_MD5, + http2cipher_TLS_PSK_WITH_NULL_SHA, + http2cipher_TLS_DHE_PSK_WITH_NULL_SHA, + http2cipher_TLS_RSA_PSK_WITH_NULL_SHA, + http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA, + http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA, + http2cipher_TLS_RSA_WITH_NULL_SHA256, + http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA256, + http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA256, + http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA256, + http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA256, + http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, + http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA256, + http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA, + http2cipher_TLS_PSK_WITH_RC4_128_SHA, + http2cipher_TLS_PSK_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA, + http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA, + http2cipher_TLS_DHE_PSK_WITH_RC4_128_SHA, + http2cipher_TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA, + http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA, + http2cipher_TLS_RSA_PSK_WITH_RC4_128_SHA, + http2cipher_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA, + http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA, + http2cipher_TLS_RSA_WITH_SEED_CBC_SHA, + http2cipher_TLS_DH_DSS_WITH_SEED_CBC_SHA, + http2cipher_TLS_DH_RSA_WITH_SEED_CBC_SHA, + http2cipher_TLS_DHE_DSS_WITH_SEED_CBC_SHA, + http2cipher_TLS_DHE_RSA_WITH_SEED_CBC_SHA, + http2cipher_TLS_DH_anon_WITH_SEED_CBC_SHA, + http2cipher_TLS_RSA_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_RSA_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_DH_RSA_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_DH_RSA_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_DH_DSS_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_DH_DSS_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_DH_anon_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_DH_anon_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_PSK_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_PSK_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_RSA_PSK_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_PSK_WITH_NULL_SHA256, + http2cipher_TLS_PSK_WITH_NULL_SHA384, + http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_DHE_PSK_WITH_NULL_SHA256, + http2cipher_TLS_DHE_PSK_WITH_NULL_SHA384, + http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_RSA_PSK_WITH_NULL_SHA256, + http2cipher_TLS_RSA_PSK_WITH_NULL_SHA384, + http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256, + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA256, + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA256, + http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256, + http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256, + http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256, + http2cipher_TLS_EMPTY_RENEGOTIATION_INFO_SCSV, + http2cipher_TLS_ECDH_ECDSA_WITH_NULL_SHA, + http2cipher_TLS_ECDH_ECDSA_WITH_RC4_128_SHA, + http2cipher_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_ECDHE_ECDSA_WITH_NULL_SHA, + http2cipher_TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, + http2cipher_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_ECDH_RSA_WITH_NULL_SHA, + http2cipher_TLS_ECDH_RSA_WITH_RC4_128_SHA, + http2cipher_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_ECDHE_RSA_WITH_NULL_SHA, + http2cipher_TLS_ECDHE_RSA_WITH_RC4_128_SHA, + http2cipher_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_ECDH_anon_WITH_NULL_SHA, + http2cipher_TLS_ECDH_anon_WITH_RC4_128_SHA, + http2cipher_TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_ECDH_anon_WITH_AES_128_CBC_SHA, + http2cipher_TLS_ECDH_anon_WITH_AES_256_CBC_SHA, + http2cipher_TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_SRP_SHA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA, + http2cipher_TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA, + http2cipher_TLS_SRP_SHA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA, + http2cipher_TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA, + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256, + http2cipher_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384, + http2cipher_TLS_ECDHE_PSK_WITH_RC4_128_SHA, + http2cipher_TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA, + http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA, + http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA, + http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256, + http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384, + http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA, + http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA256, + http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA384, + http2cipher_TLS_RSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_RSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_DH_DSS_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_DH_DSS_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_DH_RSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_DH_RSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_DHE_DSS_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_DHE_DSS_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_DHE_RSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_DHE_RSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_DH_anon_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_DH_anon_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_ECDHE_RSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_ECDHE_RSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_RSA_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_RSA_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_DH_RSA_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_DH_RSA_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_DH_DSS_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_DH_DSS_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_DH_anon_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_DH_anon_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_PSK_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_PSK_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_DHE_PSK_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_DHE_PSK_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_RSA_PSK_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_PSK_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_PSK_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256, + http2cipher_TLS_RSA_PSK_WITH_ARIA_256_GCM_SHA384, + http2cipher_TLS_ECDHE_PSK_WITH_ARIA_128_CBC_SHA256, + http2cipher_TLS_ECDHE_PSK_WITH_ARIA_256_CBC_SHA384, + http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_RSA_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_RSA_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_PSK_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_PSK_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_GCM_SHA256, + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_GCM_SHA384, + http2cipher_TLS_PSK_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_PSK_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_128_CBC_SHA256, + http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_256_CBC_SHA384, + http2cipher_TLS_RSA_WITH_AES_128_CCM, + http2cipher_TLS_RSA_WITH_AES_256_CCM, + http2cipher_TLS_RSA_WITH_AES_128_CCM_8, + http2cipher_TLS_RSA_WITH_AES_256_CCM_8, + http2cipher_TLS_PSK_WITH_AES_128_CCM, + http2cipher_TLS_PSK_WITH_AES_256_CCM, + http2cipher_TLS_PSK_WITH_AES_128_CCM_8, + http2cipher_TLS_PSK_WITH_AES_256_CCM_8: + return true + default: + return false + } +} + +// ClientConnPool manages a pool of HTTP/2 client connections. +type http2ClientConnPool interface { + // GetClientConn returns a specific HTTP/2 connection (usually + // a TLS-TCP connection) to an HTTP/2 server. On success, the + // returned ClientConn accounts for the upcoming RoundTrip + // call, so the caller should not omit it. If the caller needs + // to, ClientConn.RoundTrip can be called with a bogus + // new(http.Request) to release the stream reservation. + GetClientConn(req *Request, addr string) (*http2ClientConn, error) + MarkDead(*http2ClientConn) +} + +// clientConnPoolIdleCloser is the interface implemented by ClientConnPool +// implementations which can close their idle connections. +type http2clientConnPoolIdleCloser interface { + http2ClientConnPool + closeIdleConnections() +} + +var ( + _ http2clientConnPoolIdleCloser = (*http2clientConnPool)(nil) + _ http2clientConnPoolIdleCloser = http2noDialClientConnPool{} +) + +// TODO: use singleflight for dialing and addConnCalls? +type http2clientConnPool struct { + t *http2Transport + + mu sync.Mutex // TODO: maybe switch to RWMutex + // TODO: add support for sharing conns based on cert names + // (e.g. share conn for googleapis.com and appspot.com) + conns map[string][]*http2ClientConn // key is host:port + dialing map[string]*http2dialCall // currently in-flight dials + keys map[*http2ClientConn][]string + addConnCalls map[string]*http2addConnCall // in-flight addConnIfNeeded calls +} + +func (p *http2clientConnPool) GetClientConn(req *Request, addr string) (*http2ClientConn, error) { + return p.getClientConn(req, addr, http2dialOnMiss) +} + +const ( + http2dialOnMiss = true + http2noDialOnMiss = false +) + +func (p *http2clientConnPool) getClientConn(req *Request, addr string, dialOnMiss bool) (*http2ClientConn, error) { + // TODO(dneil): Dial a new connection when t.DisableKeepAlives is set? + if http2isConnectionCloseRequest(req) && dialOnMiss { + // It gets its own connection. + http2traceGetConn(req, addr) + const singleUse = true + cc, err := p.t.dialClientConn(req.Context(), addr, singleUse) + if err != nil { + return nil, err + } + return cc, nil + } + for { + p.mu.Lock() + for _, cc := range p.conns[addr] { + if cc.ReserveNewRequest() { + // When a connection is presented to us by the net/http package, + // the GetConn hook has already been called. + // Don't call it a second time here. + if !cc.getConnCalled { + http2traceGetConn(req, addr) + } + cc.getConnCalled = false + p.mu.Unlock() + return cc, nil + } + } + if !dialOnMiss { + p.mu.Unlock() + return nil, http2ErrNoCachedConn + } + http2traceGetConn(req, addr) + call := p.getStartDialLocked(req.Context(), addr) + p.mu.Unlock() + <-call.done + if http2shouldRetryDial(call, req) { + continue + } + cc, err := call.res, call.err + if err != nil { + return nil, err + } + if cc.ReserveNewRequest() { + return cc, nil + } + } +} + +// dialCall is an in-flight Transport dial call to a host. +type http2dialCall struct { + _ http2incomparable + p *http2clientConnPool + // the context associated with the request + // that created this dialCall + ctx context.Context + done chan struct{} // closed when done + res *http2ClientConn // valid after done is closed + err error // valid after done is closed +} + +// requires p.mu is held. +func (p *http2clientConnPool) getStartDialLocked(ctx context.Context, addr string) *http2dialCall { + if call, ok := p.dialing[addr]; ok { + // A dial is already in-flight. Don't start another. + return call + } + call := &http2dialCall{p: p, done: make(chan struct{}), ctx: ctx} + if p.dialing == nil { + p.dialing = make(map[string]*http2dialCall) + } + p.dialing[addr] = call + go call.dial(call.ctx, addr) + return call +} + +// run in its own goroutine. +func (c *http2dialCall) dial(ctx context.Context, addr string) { + const singleUse = false // shared conn + c.res, c.err = c.p.t.dialClientConn(ctx, addr, singleUse) + + c.p.mu.Lock() + delete(c.p.dialing, addr) + if c.err == nil { + c.p.addConnLocked(addr, c.res) + } + c.p.mu.Unlock() + + close(c.done) +} + +// addConnIfNeeded makes a NewClientConn out of c if a connection for key doesn't +// already exist. It coalesces concurrent calls with the same key. +// This is used by the http1 Transport code when it creates a new connection. Because +// the http1 Transport doesn't de-dup TCP dials to outbound hosts (because it doesn't know +// the protocol), it can get into a situation where it has multiple TLS connections. +// This code decides which ones live or die. +// The return value used is whether c was used. +// c is never closed. +func (p *http2clientConnPool) addConnIfNeeded(key string, t *http2Transport, c *tls.Conn) (used bool, err error) { + p.mu.Lock() + for _, cc := range p.conns[key] { + if cc.CanTakeNewRequest() { + p.mu.Unlock() + return false, nil + } + } + call, dup := p.addConnCalls[key] + if !dup { + if p.addConnCalls == nil { + p.addConnCalls = make(map[string]*http2addConnCall) + } + call = &http2addConnCall{ + p: p, + done: make(chan struct{}), + } + p.addConnCalls[key] = call + go call.run(t, key, c) + } + p.mu.Unlock() + + <-call.done + if call.err != nil { + return false, call.err + } + return !dup, nil +} + +type http2addConnCall struct { + _ http2incomparable + p *http2clientConnPool + done chan struct{} // closed when done + err error +} + +func (c *http2addConnCall) run(t *http2Transport, key string, tc *tls.Conn) { + cc, err := t.NewClientConn(tc) + + p := c.p + p.mu.Lock() + if err != nil { + c.err = err + } else { + cc.getConnCalled = true // already called by the net/http package + p.addConnLocked(key, cc) + } + delete(p.addConnCalls, key) + p.mu.Unlock() + close(c.done) +} + +// p.mu must be held +func (p *http2clientConnPool) addConnLocked(key string, cc *http2ClientConn) { + for _, v := range p.conns[key] { + if v == cc { + return + } + } + if p.conns == nil { + p.conns = make(map[string][]*http2ClientConn) + } + if p.keys == nil { + p.keys = make(map[*http2ClientConn][]string) + } + p.conns[key] = append(p.conns[key], cc) + p.keys[cc] = append(p.keys[cc], key) +} + +func (p *http2clientConnPool) MarkDead(cc *http2ClientConn) { + p.mu.Lock() + defer p.mu.Unlock() + for _, key := range p.keys[cc] { + vv, ok := p.conns[key] + if !ok { + continue + } + newList := http2filterOutClientConn(vv, cc) + if len(newList) > 0 { + p.conns[key] = newList + } else { + delete(p.conns, key) + } + } + delete(p.keys, cc) +} + +func (p *http2clientConnPool) closeIdleConnections() { + p.mu.Lock() + defer p.mu.Unlock() + // TODO: don't close a cc if it was just added to the pool + // milliseconds ago and has never been used. There's currently + // a small race window with the HTTP/1 Transport's integration + // where it can add an idle conn just before using it, and + // somebody else can concurrently call CloseIdleConns and + // break some caller's RoundTrip. + for _, vv := range p.conns { + for _, cc := range vv { + cc.closeIfIdle() + } + } +} + +func http2filterOutClientConn(in []*http2ClientConn, exclude *http2ClientConn) []*http2ClientConn { + out := in[:0] + for _, v := range in { + if v != exclude { + out = append(out, v) + } + } + // If we filtered it out, zero out the last item to prevent + // the GC from seeing it. + if len(in) != len(out) { + in[len(in)-1] = nil + } + return out +} + +// noDialClientConnPool is an implementation of http2.ClientConnPool +// which never dials. We let the HTTP/1.1 client dial and use its TLS +// connection instead. +type http2noDialClientConnPool struct{ *http2clientConnPool } + +func (p http2noDialClientConnPool) GetClientConn(req *Request, addr string) (*http2ClientConn, error) { + return p.getClientConn(req, addr, http2noDialOnMiss) +} + +// shouldRetryDial reports whether the current request should +// retry dialing after the call finished unsuccessfully, for example +// if the dial was canceled because of a context cancellation or +// deadline expiry. +func http2shouldRetryDial(call *http2dialCall, req *Request) bool { + if call.err == nil { + // No error, no need to retry + return false + } + if call.ctx == req.Context() { + // If the call has the same context as the request, the dial + // should not be retried, since any cancellation will have come + // from this request. + return false + } + if !errors.Is(call.err, context.Canceled) && !errors.Is(call.err, context.DeadlineExceeded) { + // If the call error is not because of a context cancellation or a deadline expiry, + // the dial should not be retried. + return false + } + // Only retry if the error is a context cancellation error or deadline expiry + // and the context associated with the call was canceled or expired. + return call.ctx.Err() != nil +} + +// Buffer chunks are allocated from a pool to reduce pressure on GC. +// The maximum wasted space per dataBuffer is 2x the largest size class, +// which happens when the dataBuffer has multiple chunks and there is +// one unread byte in both the first and last chunks. We use a few size +// classes to minimize overheads for servers that typically receive very +// small request bodies. +// +// TODO: Benchmark to determine if the pools are necessary. The GC may have +// improved enough that we can instead allocate chunks like this: +// make([]byte, max(16<<10, expectedBytesRemaining)) +var ( + http2dataChunkSizeClasses = []int{ + 1 << 10, + 2 << 10, + 4 << 10, + 8 << 10, + 16 << 10, + } + http2dataChunkPools = [...]sync.Pool{ + {New: func() interface{} { return make([]byte, 1<<10) }}, + {New: func() interface{} { return make([]byte, 2<<10) }}, + {New: func() interface{} { return make([]byte, 4<<10) }}, + {New: func() interface{} { return make([]byte, 8<<10) }}, + {New: func() interface{} { return make([]byte, 16<<10) }}, + } +) + +func http2getDataBufferChunk(size int64) []byte { + i := 0 + for ; i < len(http2dataChunkSizeClasses)-1; i++ { + if size <= int64(http2dataChunkSizeClasses[i]) { + break + } + } + return http2dataChunkPools[i].Get().([]byte) +} + +func http2putDataBufferChunk(p []byte) { + for i, n := range http2dataChunkSizeClasses { + if len(p) == n { + http2dataChunkPools[i].Put(p) + return + } + } + panic(fmt.Sprintf("unexpected buffer len=%v", len(p))) +} + +// dataBuffer is an io.ReadWriter backed by a list of data chunks. +// Each dataBuffer is used to read DATA frames on a single stream. +// The buffer is divided into chunks so the server can limit the +// total memory used by a single connection without limiting the +// request body size on any single stream. +type http2dataBuffer struct { + chunks [][]byte + r int // next byte to read is chunks[0][r] + w int // next byte to write is chunks[len(chunks)-1][w] + size int // total buffered bytes + expected int64 // we expect at least this many bytes in future Write calls (ignored if <= 0) +} + +var http2errReadEmpty = errors.New("read from empty dataBuffer") + +// Read copies bytes from the buffer into p. +// It is an error to read when no data is available. +func (b *http2dataBuffer) Read(p []byte) (int, error) { + if b.size == 0 { + return 0, http2errReadEmpty + } + var ntotal int + for len(p) > 0 && b.size > 0 { + readFrom := b.bytesFromFirstChunk() + n := copy(p, readFrom) + p = p[n:] + ntotal += n + b.r += n + b.size -= n + // If the first chunk has been consumed, advance to the next chunk. + if b.r == len(b.chunks[0]) { + http2putDataBufferChunk(b.chunks[0]) + end := len(b.chunks) - 1 + copy(b.chunks[:end], b.chunks[1:]) + b.chunks[end] = nil + b.chunks = b.chunks[:end] + b.r = 0 + } + } + return ntotal, nil +} + +func (b *http2dataBuffer) bytesFromFirstChunk() []byte { + if len(b.chunks) == 1 { + return b.chunks[0][b.r:b.w] + } + return b.chunks[0][b.r:] +} + +// Len returns the number of bytes of the unread portion of the buffer. +func (b *http2dataBuffer) Len() int { + return b.size +} + +// Write appends p to the buffer. +func (b *http2dataBuffer) Write(p []byte) (int, error) { + ntotal := len(p) + for len(p) > 0 { + // If the last chunk is empty, allocate a new chunk. Try to allocate + // enough to fully copy p plus any additional bytes we expect to + // receive. However, this may allocate less than len(p). + want := int64(len(p)) + if b.expected > want { + want = b.expected + } + chunk := b.lastChunkOrAlloc(want) + n := copy(chunk[b.w:], p) + p = p[n:] + b.w += n + b.size += n + b.expected -= int64(n) + } + return ntotal, nil +} + +func (b *http2dataBuffer) lastChunkOrAlloc(want int64) []byte { + if len(b.chunks) != 0 { + last := b.chunks[len(b.chunks)-1] + if b.w < len(last) { + return last + } + } + chunk := http2getDataBufferChunk(want) + b.chunks = append(b.chunks, chunk) + b.w = 0 + return chunk +} + +// An ErrCode is an unsigned 32-bit error code as defined in the HTTP/2 spec. +type http2ErrCode uint32 + +const ( + http2ErrCodeNo http2ErrCode = 0x0 + http2ErrCodeProtocol http2ErrCode = 0x1 + http2ErrCodeInternal http2ErrCode = 0x2 + http2ErrCodeFlowControl http2ErrCode = 0x3 + http2ErrCodeSettingsTimeout http2ErrCode = 0x4 + http2ErrCodeStreamClosed http2ErrCode = 0x5 + http2ErrCodeFrameSize http2ErrCode = 0x6 + http2ErrCodeRefusedStream http2ErrCode = 0x7 + http2ErrCodeCancel http2ErrCode = 0x8 + http2ErrCodeCompression http2ErrCode = 0x9 + http2ErrCodeConnect http2ErrCode = 0xa + http2ErrCodeEnhanceYourCalm http2ErrCode = 0xb + http2ErrCodeInadequateSecurity http2ErrCode = 0xc + http2ErrCodeHTTP11Required http2ErrCode = 0xd +) + +var http2errCodeName = map[http2ErrCode]string{ + http2ErrCodeNo: "NO_ERROR", + http2ErrCodeProtocol: "PROTOCOL_ERROR", + http2ErrCodeInternal: "INTERNAL_ERROR", + http2ErrCodeFlowControl: "FLOW_CONTROL_ERROR", + http2ErrCodeSettingsTimeout: "SETTINGS_TIMEOUT", + http2ErrCodeStreamClosed: "STREAM_CLOSED", + http2ErrCodeFrameSize: "FRAME_SIZE_ERROR", + http2ErrCodeRefusedStream: "REFUSED_STREAM", + http2ErrCodeCancel: "CANCEL", + http2ErrCodeCompression: "COMPRESSION_ERROR", + http2ErrCodeConnect: "CONNECT_ERROR", + http2ErrCodeEnhanceYourCalm: "ENHANCE_YOUR_CALM", + http2ErrCodeInadequateSecurity: "INADEQUATE_SECURITY", + http2ErrCodeHTTP11Required: "HTTP_1_1_REQUIRED", +} + +func (e http2ErrCode) String() string { + if s, ok := http2errCodeName[e]; ok { + return s + } + return fmt.Sprintf("unknown error code 0x%x", uint32(e)) +} + +func (e http2ErrCode) stringToken() string { + if s, ok := http2errCodeName[e]; ok { + return s + } + return fmt.Sprintf("ERR_UNKNOWN_%d", uint32(e)) +} + +// ConnectionError is an error that results in the termination of the +// entire connection. +type http2ConnectionError http2ErrCode + +func (e http2ConnectionError) Error() string { + return fmt.Sprintf("connection error: %s", http2ErrCode(e)) +} + +// StreamError is an error that only affects one stream within an +// HTTP/2 connection. +type http2StreamError struct { + StreamID uint32 + Code http2ErrCode + Cause error // optional additional detail +} + +// errFromPeer is a sentinel error value for StreamError.Cause to +// indicate that the StreamError was sent from the peer over the wire +// and wasn't locally generated in the Transport. +var http2errFromPeer = errors.New("received from peer") + +func http2streamError(id uint32, code http2ErrCode) http2StreamError { + return http2StreamError{StreamID: id, Code: code} +} + +func (e http2StreamError) Error() string { + if e.Cause != nil { + return fmt.Sprintf("stream error: stream ID %d; %v; %v", e.StreamID, e.Code, e.Cause) + } + return fmt.Sprintf("stream error: stream ID %d; %v", e.StreamID, e.Code) +} + +// 6.9.1 The Flow Control Window +// "If a sender receives a WINDOW_UPDATE that causes a flow control +// window to exceed this maximum it MUST terminate either the stream +// or the connection, as appropriate. For streams, [...]; for the +// connection, a GOAWAY frame with a FLOW_CONTROL_ERROR code." +type http2goAwayFlowError struct{} + +func (http2goAwayFlowError) Error() string { return "connection exceeded flow control window size" } + +// connError represents an HTTP/2 ConnectionError error code, along +// with a string (for debugging) explaining why. +// +// Errors of this type are only returned by the frame parser functions +// and converted into ConnectionError(Code), after stashing away +// the Reason into the Framer's errDetail field, accessible via +// the (*Framer).ErrorDetail method. +type http2connError struct { + Code http2ErrCode // the ConnectionError error code + Reason string // additional reason +} + +func (e http2connError) Error() string { + return fmt.Sprintf("http2: connection error: %v: %v", e.Code, e.Reason) +} + +type http2pseudoHeaderError string + +func (e http2pseudoHeaderError) Error() string { + return fmt.Sprintf("invalid pseudo-header %q", string(e)) +} + +type http2duplicatePseudoHeaderError string + +func (e http2duplicatePseudoHeaderError) Error() string { + return fmt.Sprintf("duplicate pseudo-header %q", string(e)) +} + +type http2headerFieldNameError string + +func (e http2headerFieldNameError) Error() string { + return fmt.Sprintf("invalid header field name %q", string(e)) +} + +type http2headerFieldValueError string + +func (e http2headerFieldValueError) Error() string { + return fmt.Sprintf("invalid header field value for %q", string(e)) +} + +var ( + http2errMixPseudoHeaderTypes = errors.New("mix of request and response pseudo headers") + http2errPseudoAfterRegular = errors.New("pseudo header field after regular") +) + +// flow is the flow control window's size. +type http2flow struct { + _ http2incomparable + + // n is the number of DATA bytes we're allowed to send. + // A flow is kept both on a conn and a per-stream. + n int32 + + // conn points to the shared connection-level flow that is + // shared by all streams on that conn. It is nil for the flow + // that's on the conn directly. + conn *http2flow +} + +func (f *http2flow) setConnFlow(cf *http2flow) { f.conn = cf } + +func (f *http2flow) available() int32 { + n := f.n + if f.conn != nil && f.conn.n < n { + n = f.conn.n + } + return n +} + +func (f *http2flow) take(n int32) { + if n > f.available() { + panic("internal error: took too much") + } + f.n -= n + if f.conn != nil { + f.conn.n -= n + } +} + +// add adds n bytes (positive or negative) to the flow control window. +// It returns false if the sum would exceed 2^31-1. +func (f *http2flow) add(n int32) bool { + sum := f.n + n + if (sum > n) == (f.n > 0) { + f.n = sum + return true + } + return false +} + +const http2frameHeaderLen = 9 + +var http2padZeros = make([]byte, 255) // zeros for padding + +// A FrameType is a registered frame type as defined in +// https://httpwg.org/specs/rfc7540.html#rfc.section.11.2 +type http2FrameType uint8 + +const ( + http2FrameData http2FrameType = 0x0 + http2FrameHeaders http2FrameType = 0x1 + http2FramePriority http2FrameType = 0x2 + http2FrameRSTStream http2FrameType = 0x3 + http2FrameSettings http2FrameType = 0x4 + http2FramePushPromise http2FrameType = 0x5 + http2FramePing http2FrameType = 0x6 + http2FrameGoAway http2FrameType = 0x7 + http2FrameWindowUpdate http2FrameType = 0x8 + http2FrameContinuation http2FrameType = 0x9 +) + +var http2frameName = map[http2FrameType]string{ + http2FrameData: "DATA", + http2FrameHeaders: "HEADERS", + http2FramePriority: "PRIORITY", + http2FrameRSTStream: "RST_STREAM", + http2FrameSettings: "SETTINGS", + http2FramePushPromise: "PUSH_PROMISE", + http2FramePing: "PING", + http2FrameGoAway: "GOAWAY", + http2FrameWindowUpdate: "WINDOW_UPDATE", + http2FrameContinuation: "CONTINUATION", +} + +func (t http2FrameType) String() string { + if s, ok := http2frameName[t]; ok { + return s + } + return fmt.Sprintf("UNKNOWN_FRAME_TYPE_%d", uint8(t)) +} + +// Flags is a bitmask of HTTP/2 flags. +// The meaning of flags varies depending on the frame type. +type http2Flags uint8 + +// Has reports whether f contains all (0 or more) flags in v. +func (f http2Flags) Has(v http2Flags) bool { + return (f & v) == v +} + +// Frame-specific FrameHeader flag bits. +const ( + // Data Frame + http2FlagDataEndStream http2Flags = 0x1 + http2FlagDataPadded http2Flags = 0x8 + + // Headers Frame + http2FlagHeadersEndStream http2Flags = 0x1 + http2FlagHeadersEndHeaders http2Flags = 0x4 + http2FlagHeadersPadded http2Flags = 0x8 + http2FlagHeadersPriority http2Flags = 0x20 + + // Settings Frame + http2FlagSettingsAck http2Flags = 0x1 + + // Ping Frame + http2FlagPingAck http2Flags = 0x1 + + // Continuation Frame + http2FlagContinuationEndHeaders http2Flags = 0x4 + + http2FlagPushPromiseEndHeaders http2Flags = 0x4 + http2FlagPushPromisePadded http2Flags = 0x8 +) + +var http2flagName = map[http2FrameType]map[http2Flags]string{ + http2FrameData: { + http2FlagDataEndStream: "END_STREAM", + http2FlagDataPadded: "PADDED", + }, + http2FrameHeaders: { + http2FlagHeadersEndStream: "END_STREAM", + http2FlagHeadersEndHeaders: "END_HEADERS", + http2FlagHeadersPadded: "PADDED", + http2FlagHeadersPriority: "PRIORITY", + }, + http2FrameSettings: { + http2FlagSettingsAck: "ACK", + }, + http2FramePing: { + http2FlagPingAck: "ACK", + }, + http2FrameContinuation: { + http2FlagContinuationEndHeaders: "END_HEADERS", + }, + http2FramePushPromise: { + http2FlagPushPromiseEndHeaders: "END_HEADERS", + http2FlagPushPromisePadded: "PADDED", + }, +} + +// a frameParser parses a frame given its FrameHeader and payload +// bytes. The length of payload will always equal fh.Length (which +// might be 0). +type http2frameParser func(fc *http2frameCache, fh http2FrameHeader, countError func(string), payload []byte) (http2Frame, error) + +var http2frameParsers = map[http2FrameType]http2frameParser{ + http2FrameData: http2parseDataFrame, + http2FrameHeaders: http2parseHeadersFrame, + http2FramePriority: http2parsePriorityFrame, + http2FrameRSTStream: http2parseRSTStreamFrame, + http2FrameSettings: http2parseSettingsFrame, + http2FramePushPromise: http2parsePushPromise, + http2FramePing: http2parsePingFrame, + http2FrameGoAway: http2parseGoAwayFrame, + http2FrameWindowUpdate: http2parseWindowUpdateFrame, + http2FrameContinuation: http2parseContinuationFrame, +} + +func http2typeFrameParser(t http2FrameType) http2frameParser { + if f := http2frameParsers[t]; f != nil { + return f + } + return http2parseUnknownFrame +} + +// A FrameHeader is the 9 byte header of all HTTP/2 frames. +// +// See https://httpwg.org/specs/rfc7540.html#FrameHeader +type http2FrameHeader struct { + valid bool // caller can access []byte fields in the Frame + + // Type is the 1 byte frame type. There are ten standard frame + // types, but extension frame types may be written by WriteRawFrame + // and will be returned by ReadFrame (as UnknownFrame). + Type http2FrameType + + // Flags are the 1 byte of 8 potential bit flags per frame. + // They are specific to the frame type. + Flags http2Flags + + // Length is the length of the frame, not including the 9 byte header. + // The maximum size is one byte less than 16MB (uint24), but only + // frames up to 16KB are allowed without peer agreement. + Length uint32 + + // StreamID is which stream this frame is for. Certain frames + // are not stream-specific, in which case this field is 0. + StreamID uint32 +} + +// Header returns h. It exists so FrameHeaders can be embedded in other +// specific frame types and implement the Frame interface. +func (h http2FrameHeader) Header() http2FrameHeader { return h } + +func (h http2FrameHeader) String() string { + var buf bytes.Buffer + buf.WriteString("[FrameHeader ") + h.writeDebug(&buf) + buf.WriteByte(']') + return buf.String() +} + +func (h http2FrameHeader) writeDebug(buf *bytes.Buffer) { + buf.WriteString(h.Type.String()) + if h.Flags != 0 { + buf.WriteString(" flags=") + set := 0 + for i := uint8(0); i < 8; i++ { + if h.Flags&(1<<i) == 0 { + continue + } + set++ + if set > 1 { + buf.WriteByte('|') + } + name := http2flagName[h.Type][http2Flags(1<<i)] + if name != "" { + buf.WriteString(name) + } else { + fmt.Fprintf(buf, "0x%x", 1<<i) + } + } + } + if h.StreamID != 0 { + fmt.Fprintf(buf, " stream=%d", h.StreamID) + } + fmt.Fprintf(buf, " len=%d", h.Length) +} + +func (h *http2FrameHeader) checkValid() { + if !h.valid { + panic("Frame accessor called on non-owned Frame") + } +} + +func (h *http2FrameHeader) invalidate() { h.valid = false } + +// frame header bytes. +// Used only by ReadFrameHeader. +var http2fhBytes = sync.Pool{ + New: func() interface{} { + buf := make([]byte, http2frameHeaderLen) + return &buf + }, +} + +// ReadFrameHeader reads 9 bytes from r and returns a FrameHeader. +// Most users should use Framer.ReadFrame instead. +func http2ReadFrameHeader(r io.Reader) (http2FrameHeader, error) { + bufp := http2fhBytes.Get().(*[]byte) + defer http2fhBytes.Put(bufp) + return http2readFrameHeader(*bufp, r) +} + +func http2readFrameHeader(buf []byte, r io.Reader) (http2FrameHeader, error) { + _, err := io.ReadFull(r, buf[:http2frameHeaderLen]) + if err != nil { + return http2FrameHeader{}, err + } + return http2FrameHeader{ + Length: (uint32(buf[0])<<16 | uint32(buf[1])<<8 | uint32(buf[2])), + Type: http2FrameType(buf[3]), + Flags: http2Flags(buf[4]), + StreamID: binary.BigEndian.Uint32(buf[5:]) & (1<<31 - 1), + valid: true, + }, nil +} + +// A Frame is the base interface implemented by all frame types. +// Callers will generally type-assert the specific frame type: +// *HeadersFrame, *SettingsFrame, *WindowUpdateFrame, etc. +// +// Frames are only valid until the next call to Framer.ReadFrame. +type http2Frame interface { + Header() http2FrameHeader + + // invalidate is called by Framer.ReadFrame to make this + // frame's buffers as being invalid, since the subsequent + // frame will reuse them. + invalidate() +} + +// A Framer reads and writes Frames. +type http2Framer struct { + r io.Reader + lastFrame http2Frame + errDetail error + + // countError is a non-nil func that's called on a frame parse + // error with some unique error path token. It's initialized + // from Transport.CountError or Server.CountError. + countError func(errToken string) + + // lastHeaderStream is non-zero if the last frame was an + // unfinished HEADERS/CONTINUATION. + lastHeaderStream uint32 + + maxReadSize uint32 + headerBuf [http2frameHeaderLen]byte + + // TODO: let getReadBuf be configurable, and use a less memory-pinning + // allocator in server.go to minimize memory pinned for many idle conns. + // Will probably also need to make frame invalidation have a hook too. + getReadBuf func(size uint32) []byte + readBuf []byte // cache for default getReadBuf + + maxWriteSize uint32 // zero means unlimited; TODO: implement + + w io.Writer + wbuf []byte + + // AllowIllegalWrites permits the Framer's Write methods to + // write frames that do not conform to the HTTP/2 spec. This + // permits using the Framer to test other HTTP/2 + // implementations' conformance to the spec. + // If false, the Write methods will prefer to return an error + // rather than comply. + AllowIllegalWrites bool + + // AllowIllegalReads permits the Framer's ReadFrame method + // to return non-compliant frames or frame orders. + // This is for testing and permits using the Framer to test + // other HTTP/2 implementations' conformance to the spec. + // It is not compatible with ReadMetaHeaders. + AllowIllegalReads bool + + // ReadMetaHeaders if non-nil causes ReadFrame to merge + // HEADERS and CONTINUATION frames together and return + // MetaHeadersFrame instead. + ReadMetaHeaders *hpack.Decoder + + // MaxHeaderListSize is the http2 MAX_HEADER_LIST_SIZE. + // It's used only if ReadMetaHeaders is set; 0 means a sane default + // (currently 16MB) + // If the limit is hit, MetaHeadersFrame.Truncated is set true. + MaxHeaderListSize uint32 + + // TODO: track which type of frame & with which flags was sent + // last. Then return an error (unless AllowIllegalWrites) if + // we're in the middle of a header block and a + // non-Continuation or Continuation on a different stream is + // attempted to be written. + + logReads, logWrites bool + + debugFramer *http2Framer // only use for logging written writes + debugFramerBuf *bytes.Buffer + debugReadLoggerf func(string, ...interface{}) + debugWriteLoggerf func(string, ...interface{}) + + frameCache *http2frameCache // nil if frames aren't reused (default) +} + +func (fr *http2Framer) maxHeaderListSize() uint32 { + if fr.MaxHeaderListSize == 0 { + return 16 << 20 // sane default, per docs + } + return fr.MaxHeaderListSize +} + +func (f *http2Framer) startWrite(ftype http2FrameType, flags http2Flags, streamID uint32) { + // Write the FrameHeader. + f.wbuf = append(f.wbuf[:0], + 0, // 3 bytes of length, filled in in endWrite + 0, + 0, + byte(ftype), + byte(flags), + byte(streamID>>24), + byte(streamID>>16), + byte(streamID>>8), + byte(streamID)) +} + +func (f *http2Framer) endWrite() error { + // Now that we know the final size, fill in the FrameHeader in + // the space previously reserved for it. Abuse append. + length := len(f.wbuf) - http2frameHeaderLen + if length >= (1 << 24) { + return http2ErrFrameTooLarge + } + _ = append(f.wbuf[:0], + byte(length>>16), + byte(length>>8), + byte(length)) + if f.logWrites { + f.logWrite() + } + + n, err := f.w.Write(f.wbuf) + if err == nil && n != len(f.wbuf) { + err = io.ErrShortWrite + } + return err +} + +func (f *http2Framer) logWrite() { + if f.debugFramer == nil { + f.debugFramerBuf = new(bytes.Buffer) + f.debugFramer = http2NewFramer(nil, f.debugFramerBuf) + f.debugFramer.logReads = false // we log it ourselves, saying "wrote" below + // Let us read anything, even if we accidentally wrote it + // in the wrong order: + f.debugFramer.AllowIllegalReads = true + } + f.debugFramerBuf.Write(f.wbuf) + fr, err := f.debugFramer.ReadFrame() + if err != nil { + f.debugWriteLoggerf("http2: Framer %p: failed to decode just-written frame", f) + return + } + f.debugWriteLoggerf("http2: Framer %p: wrote %v", f, http2summarizeFrame(fr)) +} + +func (f *http2Framer) writeByte(v byte) { f.wbuf = append(f.wbuf, v) } + +func (f *http2Framer) writeBytes(v []byte) { f.wbuf = append(f.wbuf, v...) } + +func (f *http2Framer) writeUint16(v uint16) { f.wbuf = append(f.wbuf, byte(v>>8), byte(v)) } + +func (f *http2Framer) writeUint32(v uint32) { + f.wbuf = append(f.wbuf, byte(v>>24), byte(v>>16), byte(v>>8), byte(v)) +} + +const ( + http2minMaxFrameSize = 1 << 14 + http2maxFrameSize = 1<<24 - 1 +) + +// SetReuseFrames allows the Framer to reuse Frames. +// If called on a Framer, Frames returned by calls to ReadFrame are only +// valid until the next call to ReadFrame. +func (fr *http2Framer) SetReuseFrames() { + if fr.frameCache != nil { + return + } + fr.frameCache = &http2frameCache{} +} + +type http2frameCache struct { + dataFrame http2DataFrame +} + +func (fc *http2frameCache) getDataFrame() *http2DataFrame { + if fc == nil { + return &http2DataFrame{} + } + return &fc.dataFrame +} + +// NewFramer returns a Framer that writes frames to w and reads them from r. +func http2NewFramer(w io.Writer, r io.Reader) *http2Framer { + fr := &http2Framer{ + w: w, + r: r, + countError: func(string) {}, + logReads: http2logFrameReads, + logWrites: http2logFrameWrites, + debugReadLoggerf: log.Printf, + debugWriteLoggerf: log.Printf, + } + fr.getReadBuf = func(size uint32) []byte { + if cap(fr.readBuf) >= int(size) { + return fr.readBuf[:size] + } + fr.readBuf = make([]byte, size) + return fr.readBuf + } + fr.SetMaxReadFrameSize(http2maxFrameSize) + return fr +} + +// SetMaxReadFrameSize sets the maximum size of a frame +// that will be read by a subsequent call to ReadFrame. +// It is the caller's responsibility to advertise this +// limit with a SETTINGS frame. +func (fr *http2Framer) SetMaxReadFrameSize(v uint32) { + if v > http2maxFrameSize { + v = http2maxFrameSize + } + fr.maxReadSize = v +} + +// ErrorDetail returns a more detailed error of the last error +// returned by Framer.ReadFrame. For instance, if ReadFrame +// returns a StreamError with code PROTOCOL_ERROR, ErrorDetail +// will say exactly what was invalid. ErrorDetail is not guaranteed +// to return a non-nil value and like the rest of the http2 package, +// its return value is not protected by an API compatibility promise. +// ErrorDetail is reset after the next call to ReadFrame. +func (fr *http2Framer) ErrorDetail() error { + return fr.errDetail +} + +// ErrFrameTooLarge is returned from Framer.ReadFrame when the peer +// sends a frame that is larger than declared with SetMaxReadFrameSize. +var http2ErrFrameTooLarge = errors.New("http2: frame too large") + +// terminalReadFrameError reports whether err is an unrecoverable +// error from ReadFrame and no other frames should be read. +func http2terminalReadFrameError(err error) bool { + if _, ok := err.(http2StreamError); ok { + return false + } + return err != nil +} + +// ReadFrame reads a single frame. The returned Frame is only valid +// until the next call to ReadFrame. +// +// If the frame is larger than previously set with SetMaxReadFrameSize, the +// returned error is ErrFrameTooLarge. Other errors may be of type +// ConnectionError, StreamError, or anything else from the underlying +// reader. +func (fr *http2Framer) ReadFrame() (http2Frame, error) { + fr.errDetail = nil + if fr.lastFrame != nil { + fr.lastFrame.invalidate() + } + fh, err := http2readFrameHeader(fr.headerBuf[:], fr.r) + if err != nil { + return nil, err + } + if fh.Length > fr.maxReadSize { + return nil, http2ErrFrameTooLarge + } + payload := fr.getReadBuf(fh.Length) + if _, err := io.ReadFull(fr.r, payload); err != nil { + return nil, err + } + f, err := http2typeFrameParser(fh.Type)(fr.frameCache, fh, fr.countError, payload) + if err != nil { + if ce, ok := err.(http2connError); ok { + return nil, fr.connError(ce.Code, ce.Reason) + } + return nil, err + } + if err := fr.checkFrameOrder(f); err != nil { + return nil, err + } + if fr.logReads { + fr.debugReadLoggerf("http2: Framer %p: read %v", fr, http2summarizeFrame(f)) + } + if fh.Type == http2FrameHeaders && fr.ReadMetaHeaders != nil { + return fr.readMetaFrame(f.(*http2HeadersFrame)) + } + return f, nil +} + +// connError returns ConnectionError(code) but first +// stashes away a public reason to the caller can optionally relay it +// to the peer before hanging up on them. This might help others debug +// their implementations. +func (fr *http2Framer) connError(code http2ErrCode, reason string) error { + fr.errDetail = errors.New(reason) + return http2ConnectionError(code) +} + +// checkFrameOrder reports an error if f is an invalid frame to return +// next from ReadFrame. Mostly it checks whether HEADERS and +// CONTINUATION frames are contiguous. +func (fr *http2Framer) checkFrameOrder(f http2Frame) error { + last := fr.lastFrame + fr.lastFrame = f + if fr.AllowIllegalReads { + return nil + } + + fh := f.Header() + if fr.lastHeaderStream != 0 { + if fh.Type != http2FrameContinuation { + return fr.connError(http2ErrCodeProtocol, + fmt.Sprintf("got %s for stream %d; expected CONTINUATION following %s for stream %d", + fh.Type, fh.StreamID, + last.Header().Type, fr.lastHeaderStream)) + } + if fh.StreamID != fr.lastHeaderStream { + return fr.connError(http2ErrCodeProtocol, + fmt.Sprintf("got CONTINUATION for stream %d; expected stream %d", + fh.StreamID, fr.lastHeaderStream)) + } + } else if fh.Type == http2FrameContinuation { + return fr.connError(http2ErrCodeProtocol, fmt.Sprintf("unexpected CONTINUATION for stream %d", fh.StreamID)) + } + + switch fh.Type { + case http2FrameHeaders, http2FrameContinuation: + if fh.Flags.Has(http2FlagHeadersEndHeaders) { + fr.lastHeaderStream = 0 + } else { + fr.lastHeaderStream = fh.StreamID + } + } + + return nil +} + +// A DataFrame conveys arbitrary, variable-length sequences of octets +// associated with a stream. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.1 +type http2DataFrame struct { + http2FrameHeader + data []byte +} + +func (f *http2DataFrame) StreamEnded() bool { + return f.http2FrameHeader.Flags.Has(http2FlagDataEndStream) +} + +// Data returns the frame's data octets, not including any padding +// size byte or padding suffix bytes. +// The caller must not retain the returned memory past the next +// call to ReadFrame. +func (f *http2DataFrame) Data() []byte { + f.checkValid() + return f.data +} + +func http2parseDataFrame(fc *http2frameCache, fh http2FrameHeader, countError func(string), payload []byte) (http2Frame, error) { + if fh.StreamID == 0 { + // DATA frames MUST be associated with a stream. If a + // DATA frame is received whose stream identifier + // field is 0x0, the recipient MUST respond with a + // connection error (Section 5.4.1) of type + // PROTOCOL_ERROR. + countError("frame_data_stream_0") + return nil, http2connError{http2ErrCodeProtocol, "DATA frame with stream ID 0"} + } + f := fc.getDataFrame() + f.http2FrameHeader = fh + + var padSize byte + if fh.Flags.Has(http2FlagDataPadded) { + var err error + payload, padSize, err = http2readByte(payload) + if err != nil { + countError("frame_data_pad_byte_short") + return nil, err + } + } + if int(padSize) > len(payload) { + // If the length of the padding is greater than the + // length of the frame payload, the recipient MUST + // treat this as a connection error. + // Filed: https://github.com/http2/http2-spec/issues/610 + countError("frame_data_pad_too_big") + return nil, http2connError{http2ErrCodeProtocol, "pad size larger than data payload"} + } + f.data = payload[:len(payload)-int(padSize)] + return f, nil +} + +var ( + http2errStreamID = errors.New("invalid stream ID") + http2errDepStreamID = errors.New("invalid dependent stream ID") + http2errPadLength = errors.New("pad length too large") + http2errPadBytes = errors.New("padding bytes must all be zeros unless AllowIllegalWrites is enabled") +) + +func http2validStreamIDOrZero(streamID uint32) bool { + return streamID&(1<<31) == 0 +} + +func http2validStreamID(streamID uint32) bool { + return streamID != 0 && streamID&(1<<31) == 0 +} + +// WriteData writes a DATA frame. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility not to violate the maximum frame size +// and to not call other Write methods concurrently. +func (f *http2Framer) WriteData(streamID uint32, endStream bool, data []byte) error { + return f.WriteDataPadded(streamID, endStream, data, nil) +} + +// WriteDataPadded writes a DATA frame with optional padding. +// +// If pad is nil, the padding bit is not sent. +// The length of pad must not exceed 255 bytes. +// The bytes of pad must all be zero, unless f.AllowIllegalWrites is set. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility not to violate the maximum frame size +// and to not call other Write methods concurrently. +func (f *http2Framer) WriteDataPadded(streamID uint32, endStream bool, data, pad []byte) error { + if !http2validStreamID(streamID) && !f.AllowIllegalWrites { + return http2errStreamID + } + if len(pad) > 0 { + if len(pad) > 255 { + return http2errPadLength + } + if !f.AllowIllegalWrites { + for _, b := range pad { + if b != 0 { + // "Padding octets MUST be set to zero when sending." + return http2errPadBytes + } + } + } + } + var flags http2Flags + if endStream { + flags |= http2FlagDataEndStream + } + if pad != nil { + flags |= http2FlagDataPadded + } + f.startWrite(http2FrameData, flags, streamID) + if pad != nil { + f.wbuf = append(f.wbuf, byte(len(pad))) + } + f.wbuf = append(f.wbuf, data...) + f.wbuf = append(f.wbuf, pad...) + return f.endWrite() +} + +// A SettingsFrame conveys configuration parameters that affect how +// endpoints communicate, such as preferences and constraints on peer +// behavior. +// +// See https://httpwg.org/specs/rfc7540.html#SETTINGS +type http2SettingsFrame struct { + http2FrameHeader + p []byte +} + +func http2parseSettingsFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (http2Frame, error) { + if fh.Flags.Has(http2FlagSettingsAck) && fh.Length > 0 { + // When this (ACK 0x1) bit is set, the payload of the + // SETTINGS frame MUST be empty. Receipt of a + // SETTINGS frame with the ACK flag set and a length + // field value other than 0 MUST be treated as a + // connection error (Section 5.4.1) of type + // FRAME_SIZE_ERROR. + countError("frame_settings_ack_with_length") + return nil, http2ConnectionError(http2ErrCodeFrameSize) + } + if fh.StreamID != 0 { + // SETTINGS frames always apply to a connection, + // never a single stream. The stream identifier for a + // SETTINGS frame MUST be zero (0x0). If an endpoint + // receives a SETTINGS frame whose stream identifier + // field is anything other than 0x0, the endpoint MUST + // respond with a connection error (Section 5.4.1) of + // type PROTOCOL_ERROR. + countError("frame_settings_has_stream") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + if len(p)%6 != 0 { + countError("frame_settings_mod_6") + // Expecting even number of 6 byte settings. + return nil, http2ConnectionError(http2ErrCodeFrameSize) + } + f := &http2SettingsFrame{http2FrameHeader: fh, p: p} + if v, ok := f.Value(http2SettingInitialWindowSize); ok && v > (1<<31)-1 { + countError("frame_settings_window_size_too_big") + // Values above the maximum flow control window size of 2^31 - 1 MUST + // be treated as a connection error (Section 5.4.1) of type + // FLOW_CONTROL_ERROR. + return nil, http2ConnectionError(http2ErrCodeFlowControl) + } + return f, nil +} + +func (f *http2SettingsFrame) IsAck() bool { + return f.http2FrameHeader.Flags.Has(http2FlagSettingsAck) +} + +func (f *http2SettingsFrame) Value(id http2SettingID) (v uint32, ok bool) { + f.checkValid() + for i := 0; i < f.NumSettings(); i++ { + if s := f.Setting(i); s.ID == id { + return s.Val, true + } + } + return 0, false +} + +// Setting returns the setting from the frame at the given 0-based index. +// The index must be >= 0 and less than f.NumSettings(). +func (f *http2SettingsFrame) Setting(i int) http2Setting { + buf := f.p + return http2Setting{ + ID: http2SettingID(binary.BigEndian.Uint16(buf[i*6 : i*6+2])), + Val: binary.BigEndian.Uint32(buf[i*6+2 : i*6+6]), + } +} + +func (f *http2SettingsFrame) NumSettings() int { return len(f.p) / 6 } + +// HasDuplicates reports whether f contains any duplicate setting IDs. +func (f *http2SettingsFrame) HasDuplicates() bool { + num := f.NumSettings() + if num == 0 { + return false + } + // If it's small enough (the common case), just do the n^2 + // thing and avoid a map allocation. + if num < 10 { + for i := 0; i < num; i++ { + idi := f.Setting(i).ID + for j := i + 1; j < num; j++ { + idj := f.Setting(j).ID + if idi == idj { + return true + } + } + } + return false + } + seen := map[http2SettingID]bool{} + for i := 0; i < num; i++ { + id := f.Setting(i).ID + if seen[id] { + return true + } + seen[id] = true + } + return false +} + +// ForeachSetting runs fn for each setting. +// It stops and returns the first error. +func (f *http2SettingsFrame) ForeachSetting(fn func(http2Setting) error) error { + f.checkValid() + for i := 0; i < f.NumSettings(); i++ { + if err := fn(f.Setting(i)); err != nil { + return err + } + } + return nil +} + +// WriteSettings writes a SETTINGS frame with zero or more settings +// specified and the ACK bit not set. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WriteSettings(settings ...http2Setting) error { + f.startWrite(http2FrameSettings, 0, 0) + for _, s := range settings { + f.writeUint16(uint16(s.ID)) + f.writeUint32(s.Val) + } + return f.endWrite() +} + +// WriteSettingsAck writes an empty SETTINGS frame with the ACK bit set. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WriteSettingsAck() error { + f.startWrite(http2FrameSettings, http2FlagSettingsAck, 0) + return f.endWrite() +} + +// A PingFrame is a mechanism for measuring a minimal round trip time +// from the sender, as well as determining whether an idle connection +// is still functional. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.7 +type http2PingFrame struct { + http2FrameHeader + Data [8]byte +} + +func (f *http2PingFrame) IsAck() bool { return f.Flags.Has(http2FlagPingAck) } + +func http2parsePingFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), payload []byte) (http2Frame, error) { + if len(payload) != 8 { + countError("frame_ping_length") + return nil, http2ConnectionError(http2ErrCodeFrameSize) + } + if fh.StreamID != 0 { + countError("frame_ping_has_stream") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + f := &http2PingFrame{http2FrameHeader: fh} + copy(f.Data[:], payload) + return f, nil +} + +func (f *http2Framer) WritePing(ack bool, data [8]byte) error { + var flags http2Flags + if ack { + flags = http2FlagPingAck + } + f.startWrite(http2FramePing, flags, 0) + f.writeBytes(data[:]) + return f.endWrite() +} + +// A GoAwayFrame informs the remote peer to stop creating streams on this connection. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.8 +type http2GoAwayFrame struct { + http2FrameHeader + LastStreamID uint32 + ErrCode http2ErrCode + debugData []byte +} + +// DebugData returns any debug data in the GOAWAY frame. Its contents +// are not defined. +// The caller must not retain the returned memory past the next +// call to ReadFrame. +func (f *http2GoAwayFrame) DebugData() []byte { + f.checkValid() + return f.debugData +} + +func http2parseGoAwayFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (http2Frame, error) { + if fh.StreamID != 0 { + countError("frame_goaway_has_stream") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + if len(p) < 8 { + countError("frame_goaway_short") + return nil, http2ConnectionError(http2ErrCodeFrameSize) + } + return &http2GoAwayFrame{ + http2FrameHeader: fh, + LastStreamID: binary.BigEndian.Uint32(p[:4]) & (1<<31 - 1), + ErrCode: http2ErrCode(binary.BigEndian.Uint32(p[4:8])), + debugData: p[8:], + }, nil +} + +func (f *http2Framer) WriteGoAway(maxStreamID uint32, code http2ErrCode, debugData []byte) error { + f.startWrite(http2FrameGoAway, 0, 0) + f.writeUint32(maxStreamID & (1<<31 - 1)) + f.writeUint32(uint32(code)) + f.writeBytes(debugData) + return f.endWrite() +} + +// An UnknownFrame is the frame type returned when the frame type is unknown +// or no specific frame type parser exists. +type http2UnknownFrame struct { + http2FrameHeader + p []byte +} + +// Payload returns the frame's payload (after the header). It is not +// valid to call this method after a subsequent call to +// Framer.ReadFrame, nor is it valid to retain the returned slice. +// The memory is owned by the Framer and is invalidated when the next +// frame is read. +func (f *http2UnknownFrame) Payload() []byte { + f.checkValid() + return f.p +} + +func http2parseUnknownFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (http2Frame, error) { + return &http2UnknownFrame{fh, p}, nil +} + +// A WindowUpdateFrame is used to implement flow control. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.9 +type http2WindowUpdateFrame struct { + http2FrameHeader + Increment uint32 // never read with high bit set +} + +func http2parseWindowUpdateFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (http2Frame, error) { + if len(p) != 4 { + countError("frame_windowupdate_bad_len") + return nil, http2ConnectionError(http2ErrCodeFrameSize) + } + inc := binary.BigEndian.Uint32(p[:4]) & 0x7fffffff // mask off high reserved bit + if inc == 0 { + // A receiver MUST treat the receipt of a + // WINDOW_UPDATE frame with an flow control window + // increment of 0 as a stream error (Section 5.4.2) of + // type PROTOCOL_ERROR; errors on the connection flow + // control window MUST be treated as a connection + // error (Section 5.4.1). + if fh.StreamID == 0 { + countError("frame_windowupdate_zero_inc_conn") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + countError("frame_windowupdate_zero_inc_stream") + return nil, http2streamError(fh.StreamID, http2ErrCodeProtocol) + } + return &http2WindowUpdateFrame{ + http2FrameHeader: fh, + Increment: inc, + }, nil +} + +// WriteWindowUpdate writes a WINDOW_UPDATE frame. +// The increment value must be between 1 and 2,147,483,647, inclusive. +// If the Stream ID is zero, the window update applies to the +// connection as a whole. +func (f *http2Framer) WriteWindowUpdate(streamID, incr uint32) error { + // "The legal range for the increment to the flow control window is 1 to 2^31-1 (2,147,483,647) octets." + if (incr < 1 || incr > 2147483647) && !f.AllowIllegalWrites { + return errors.New("illegal window increment value") + } + f.startWrite(http2FrameWindowUpdate, 0, streamID) + f.writeUint32(incr) + return f.endWrite() +} + +// A HeadersFrame is used to open a stream and additionally carries a +// header block fragment. +type http2HeadersFrame struct { + http2FrameHeader + + // Priority is set if FlagHeadersPriority is set in the FrameHeader. + Priority http2PriorityParam + + headerFragBuf []byte // not owned +} + +func (f *http2HeadersFrame) HeaderBlockFragment() []byte { + f.checkValid() + return f.headerFragBuf +} + +func (f *http2HeadersFrame) HeadersEnded() bool { + return f.http2FrameHeader.Flags.Has(http2FlagHeadersEndHeaders) +} + +func (f *http2HeadersFrame) StreamEnded() bool { + return f.http2FrameHeader.Flags.Has(http2FlagHeadersEndStream) +} + +func (f *http2HeadersFrame) HasPriority() bool { + return f.http2FrameHeader.Flags.Has(http2FlagHeadersPriority) +} + +func http2parseHeadersFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (_ http2Frame, err error) { + hf := &http2HeadersFrame{ + http2FrameHeader: fh, + } + if fh.StreamID == 0 { + // HEADERS frames MUST be associated with a stream. If a HEADERS frame + // is received whose stream identifier field is 0x0, the recipient MUST + // respond with a connection error (Section 5.4.1) of type + // PROTOCOL_ERROR. + countError("frame_headers_zero_stream") + return nil, http2connError{http2ErrCodeProtocol, "HEADERS frame with stream ID 0"} + } + var padLength uint8 + if fh.Flags.Has(http2FlagHeadersPadded) { + if p, padLength, err = http2readByte(p); err != nil { + countError("frame_headers_pad_short") + return + } + } + if fh.Flags.Has(http2FlagHeadersPriority) { + var v uint32 + p, v, err = http2readUint32(p) + if err != nil { + countError("frame_headers_prio_short") + return nil, err + } + hf.Priority.StreamDep = v & 0x7fffffff + hf.Priority.Exclusive = (v != hf.Priority.StreamDep) // high bit was set + p, hf.Priority.Weight, err = http2readByte(p) + if err != nil { + countError("frame_headers_prio_weight_short") + return nil, err + } + } + if len(p)-int(padLength) < 0 { + countError("frame_headers_pad_too_big") + return nil, http2streamError(fh.StreamID, http2ErrCodeProtocol) + } + hf.headerFragBuf = p[:len(p)-int(padLength)] + return hf, nil +} + +// HeadersFrameParam are the parameters for writing a HEADERS frame. +type http2HeadersFrameParam struct { + // StreamID is the required Stream ID to initiate. + StreamID uint32 + // BlockFragment is part (or all) of a Header Block. + BlockFragment []byte + + // EndStream indicates that the header block is the last that + // the endpoint will send for the identified stream. Setting + // this flag causes the stream to enter one of "half closed" + // states. + EndStream bool + + // EndHeaders indicates that this frame contains an entire + // header block and is not followed by any + // CONTINUATION frames. + EndHeaders bool + + // PadLength is the optional number of bytes of zeros to add + // to this frame. + PadLength uint8 + + // Priority, if non-zero, includes stream priority information + // in the HEADER frame. + Priority http2PriorityParam +} + +// WriteHeaders writes a single HEADERS frame. +// +// This is a low-level header writing method. Encoding headers and +// splitting them into any necessary CONTINUATION frames is handled +// elsewhere. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WriteHeaders(p http2HeadersFrameParam) error { + if !http2validStreamID(p.StreamID) && !f.AllowIllegalWrites { + return http2errStreamID + } + var flags http2Flags + if p.PadLength != 0 { + flags |= http2FlagHeadersPadded + } + if p.EndStream { + flags |= http2FlagHeadersEndStream + } + if p.EndHeaders { + flags |= http2FlagHeadersEndHeaders + } + if !p.Priority.IsZero() { + flags |= http2FlagHeadersPriority + } + f.startWrite(http2FrameHeaders, flags, p.StreamID) + if p.PadLength != 0 { + f.writeByte(p.PadLength) + } + if !p.Priority.IsZero() { + v := p.Priority.StreamDep + if !http2validStreamIDOrZero(v) && !f.AllowIllegalWrites { + return http2errDepStreamID + } + if p.Priority.Exclusive { + v |= 1 << 31 + } + f.writeUint32(v) + f.writeByte(p.Priority.Weight) + } + f.wbuf = append(f.wbuf, p.BlockFragment...) + f.wbuf = append(f.wbuf, http2padZeros[:p.PadLength]...) + return f.endWrite() +} + +// A PriorityFrame specifies the sender-advised priority of a stream. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.3 +type http2PriorityFrame struct { + http2FrameHeader + http2PriorityParam +} + +// PriorityParam are the stream prioritzation parameters. +type http2PriorityParam struct { + // StreamDep is a 31-bit stream identifier for the + // stream that this stream depends on. Zero means no + // dependency. + StreamDep uint32 + + // Exclusive is whether the dependency is exclusive. + Exclusive bool + + // Weight is the stream's zero-indexed weight. It should be + // set together with StreamDep, or neither should be set. Per + // the spec, "Add one to the value to obtain a weight between + // 1 and 256." + Weight uint8 +} + +func (p http2PriorityParam) IsZero() bool { + return p == http2PriorityParam{} +} + +func http2parsePriorityFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), payload []byte) (http2Frame, error) { + if fh.StreamID == 0 { + countError("frame_priority_zero_stream") + return nil, http2connError{http2ErrCodeProtocol, "PRIORITY frame with stream ID 0"} + } + if len(payload) != 5 { + countError("frame_priority_bad_length") + return nil, http2connError{http2ErrCodeFrameSize, fmt.Sprintf("PRIORITY frame payload size was %d; want 5", len(payload))} + } + v := binary.BigEndian.Uint32(payload[:4]) + streamID := v & 0x7fffffff // mask off high bit + return &http2PriorityFrame{ + http2FrameHeader: fh, + http2PriorityParam: http2PriorityParam{ + Weight: payload[4], + StreamDep: streamID, + Exclusive: streamID != v, // was high bit set? + }, + }, nil +} + +// WritePriority writes a PRIORITY frame. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WritePriority(streamID uint32, p http2PriorityParam) error { + if !http2validStreamID(streamID) && !f.AllowIllegalWrites { + return http2errStreamID + } + if !http2validStreamIDOrZero(p.StreamDep) { + return http2errDepStreamID + } + f.startWrite(http2FramePriority, 0, streamID) + v := p.StreamDep + if p.Exclusive { + v |= 1 << 31 + } + f.writeUint32(v) + f.writeByte(p.Weight) + return f.endWrite() +} + +// A RSTStreamFrame allows for abnormal termination of a stream. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.4 +type http2RSTStreamFrame struct { + http2FrameHeader + ErrCode http2ErrCode +} + +func http2parseRSTStreamFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (http2Frame, error) { + if len(p) != 4 { + countError("frame_rststream_bad_len") + return nil, http2ConnectionError(http2ErrCodeFrameSize) + } + if fh.StreamID == 0 { + countError("frame_rststream_zero_stream") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + return &http2RSTStreamFrame{fh, http2ErrCode(binary.BigEndian.Uint32(p[:4]))}, nil +} + +// WriteRSTStream writes a RST_STREAM frame. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WriteRSTStream(streamID uint32, code http2ErrCode) error { + if !http2validStreamID(streamID) && !f.AllowIllegalWrites { + return http2errStreamID + } + f.startWrite(http2FrameRSTStream, 0, streamID) + f.writeUint32(uint32(code)) + return f.endWrite() +} + +// A ContinuationFrame is used to continue a sequence of header block fragments. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.10 +type http2ContinuationFrame struct { + http2FrameHeader + headerFragBuf []byte +} + +func http2parseContinuationFrame(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (http2Frame, error) { + if fh.StreamID == 0 { + countError("frame_continuation_zero_stream") + return nil, http2connError{http2ErrCodeProtocol, "CONTINUATION frame with stream ID 0"} + } + return &http2ContinuationFrame{fh, p}, nil +} + +func (f *http2ContinuationFrame) HeaderBlockFragment() []byte { + f.checkValid() + return f.headerFragBuf +} + +func (f *http2ContinuationFrame) HeadersEnded() bool { + return f.http2FrameHeader.Flags.Has(http2FlagContinuationEndHeaders) +} + +// WriteContinuation writes a CONTINUATION frame. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WriteContinuation(streamID uint32, endHeaders bool, headerBlockFragment []byte) error { + if !http2validStreamID(streamID) && !f.AllowIllegalWrites { + return http2errStreamID + } + var flags http2Flags + if endHeaders { + flags |= http2FlagContinuationEndHeaders + } + f.startWrite(http2FrameContinuation, flags, streamID) + f.wbuf = append(f.wbuf, headerBlockFragment...) + return f.endWrite() +} + +// A PushPromiseFrame is used to initiate a server stream. +// See https://httpwg.org/specs/rfc7540.html#rfc.section.6.6 +type http2PushPromiseFrame struct { + http2FrameHeader + PromiseID uint32 + headerFragBuf []byte // not owned +} + +func (f *http2PushPromiseFrame) HeaderBlockFragment() []byte { + f.checkValid() + return f.headerFragBuf +} + +func (f *http2PushPromiseFrame) HeadersEnded() bool { + return f.http2FrameHeader.Flags.Has(http2FlagPushPromiseEndHeaders) +} + +func http2parsePushPromise(_ *http2frameCache, fh http2FrameHeader, countError func(string), p []byte) (_ http2Frame, err error) { + pp := &http2PushPromiseFrame{ + http2FrameHeader: fh, + } + if pp.StreamID == 0 { + // PUSH_PROMISE frames MUST be associated with an existing, + // peer-initiated stream. The stream identifier of a + // PUSH_PROMISE frame indicates the stream it is associated + // with. If the stream identifier field specifies the value + // 0x0, a recipient MUST respond with a connection error + // (Section 5.4.1) of type PROTOCOL_ERROR. + countError("frame_pushpromise_zero_stream") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + // The PUSH_PROMISE frame includes optional padding. + // Padding fields and flags are identical to those defined for DATA frames + var padLength uint8 + if fh.Flags.Has(http2FlagPushPromisePadded) { + if p, padLength, err = http2readByte(p); err != nil { + countError("frame_pushpromise_pad_short") + return + } + } + + p, pp.PromiseID, err = http2readUint32(p) + if err != nil { + countError("frame_pushpromise_promiseid_short") + return + } + pp.PromiseID = pp.PromiseID & (1<<31 - 1) + + if int(padLength) > len(p) { + // like the DATA frame, error out if padding is longer than the body. + countError("frame_pushpromise_pad_too_big") + return nil, http2ConnectionError(http2ErrCodeProtocol) + } + pp.headerFragBuf = p[:len(p)-int(padLength)] + return pp, nil +} + +// PushPromiseParam are the parameters for writing a PUSH_PROMISE frame. +type http2PushPromiseParam struct { + // StreamID is the required Stream ID to initiate. + StreamID uint32 + + // PromiseID is the required Stream ID which this + // Push Promises + PromiseID uint32 + + // BlockFragment is part (or all) of a Header Block. + BlockFragment []byte + + // EndHeaders indicates that this frame contains an entire + // header block and is not followed by any + // CONTINUATION frames. + EndHeaders bool + + // PadLength is the optional number of bytes of zeros to add + // to this frame. + PadLength uint8 +} + +// WritePushPromise writes a single PushPromise Frame. +// +// As with Header Frames, This is the low level call for writing +// individual frames. Continuation frames are handled elsewhere. +// +// It will perform exactly one Write to the underlying Writer. +// It is the caller's responsibility to not call other Write methods concurrently. +func (f *http2Framer) WritePushPromise(p http2PushPromiseParam) error { + if !http2validStreamID(p.StreamID) && !f.AllowIllegalWrites { + return http2errStreamID + } + var flags http2Flags + if p.PadLength != 0 { + flags |= http2FlagPushPromisePadded + } + if p.EndHeaders { + flags |= http2FlagPushPromiseEndHeaders + } + f.startWrite(http2FramePushPromise, flags, p.StreamID) + if p.PadLength != 0 { + f.writeByte(p.PadLength) + } + if !http2validStreamID(p.PromiseID) && !f.AllowIllegalWrites { + return http2errStreamID + } + f.writeUint32(p.PromiseID) + f.wbuf = append(f.wbuf, p.BlockFragment...) + f.wbuf = append(f.wbuf, http2padZeros[:p.PadLength]...) + return f.endWrite() +} + +// WriteRawFrame writes a raw frame. This can be used to write +// extension frames unknown to this package. +func (f *http2Framer) WriteRawFrame(t http2FrameType, flags http2Flags, streamID uint32, payload []byte) error { + f.startWrite(t, flags, streamID) + f.writeBytes(payload) + return f.endWrite() +} + +func http2readByte(p []byte) (remain []byte, b byte, err error) { + if len(p) == 0 { + return nil, 0, io.ErrUnexpectedEOF + } + return p[1:], p[0], nil +} + +func http2readUint32(p []byte) (remain []byte, v uint32, err error) { + if len(p) < 4 { + return nil, 0, io.ErrUnexpectedEOF + } + return p[4:], binary.BigEndian.Uint32(p[:4]), nil +} + +type http2streamEnder interface { + StreamEnded() bool +} + +type http2headersEnder interface { + HeadersEnded() bool +} + +type http2headersOrContinuation interface { + http2headersEnder + HeaderBlockFragment() []byte +} + +// A MetaHeadersFrame is the representation of one HEADERS frame and +// zero or more contiguous CONTINUATION frames and the decoding of +// their HPACK-encoded contents. +// +// This type of frame does not appear on the wire and is only returned +// by the Framer when Framer.ReadMetaHeaders is set. +type http2MetaHeadersFrame struct { + *http2HeadersFrame + + // Fields are the fields contained in the HEADERS and + // CONTINUATION frames. The underlying slice is owned by the + // Framer and must not be retained after the next call to + // ReadFrame. + // + // Fields are guaranteed to be in the correct http2 order and + // not have unknown pseudo header fields or invalid header + // field names or values. Required pseudo header fields may be + // missing, however. Use the MetaHeadersFrame.Pseudo accessor + // method access pseudo headers. + Fields []hpack.HeaderField + + // Truncated is whether the max header list size limit was hit + // and Fields is incomplete. The hpack decoder state is still + // valid, however. + Truncated bool +} + +// PseudoValue returns the given pseudo header field's value. +// The provided pseudo field should not contain the leading colon. +func (mh *http2MetaHeadersFrame) PseudoValue(pseudo string) string { + for _, hf := range mh.Fields { + if !hf.IsPseudo() { + return "" + } + if hf.Name[1:] == pseudo { + return hf.Value + } + } + return "" +} + +// RegularFields returns the regular (non-pseudo) header fields of mh. +// The caller does not own the returned slice. +func (mh *http2MetaHeadersFrame) RegularFields() []hpack.HeaderField { + for i, hf := range mh.Fields { + if !hf.IsPseudo() { + return mh.Fields[i:] + } + } + return nil +} + +// PseudoFields returns the pseudo header fields of mh. +// The caller does not own the returned slice. +func (mh *http2MetaHeadersFrame) PseudoFields() []hpack.HeaderField { + for i, hf := range mh.Fields { + if !hf.IsPseudo() { + return mh.Fields[:i] + } + } + return mh.Fields +} + +func (mh *http2MetaHeadersFrame) checkPseudos() error { + var isRequest, isResponse bool + pf := mh.PseudoFields() + for i, hf := range pf { + switch hf.Name { + case ":method", ":path", ":scheme", ":authority": + isRequest = true + case ":status": + isResponse = true + default: + return http2pseudoHeaderError(hf.Name) + } + // Check for duplicates. + // This would be a bad algorithm, but N is 4. + // And this doesn't allocate. + for _, hf2 := range pf[:i] { + if hf.Name == hf2.Name { + return http2duplicatePseudoHeaderError(hf.Name) + } + } + } + if isRequest && isResponse { + return http2errMixPseudoHeaderTypes + } + return nil +} + +func (fr *http2Framer) maxHeaderStringLen() int { + v := fr.maxHeaderListSize() + if uint32(int(v)) == v { + return int(v) + } + // They had a crazy big number for MaxHeaderBytes anyway, + // so give them unlimited header lengths: + return 0 +} + +// readMetaFrame returns 0 or more CONTINUATION frames from fr and +// merge them into the provided hf and returns a MetaHeadersFrame +// with the decoded hpack values. +func (fr *http2Framer) readMetaFrame(hf *http2HeadersFrame) (*http2MetaHeadersFrame, error) { + if fr.AllowIllegalReads { + return nil, errors.New("illegal use of AllowIllegalReads with ReadMetaHeaders") + } + mh := &http2MetaHeadersFrame{ + http2HeadersFrame: hf, + } + var remainSize = fr.maxHeaderListSize() + var sawRegular bool + + var invalid error // pseudo header field errors + hdec := fr.ReadMetaHeaders + hdec.SetEmitEnabled(true) + hdec.SetMaxStringLength(fr.maxHeaderStringLen()) + hdec.SetEmitFunc(func(hf hpack.HeaderField) { + if http2VerboseLogs && fr.logReads { + fr.debugReadLoggerf("http2: decoded hpack field %+v", hf) + } + if !httpguts.ValidHeaderFieldValue(hf.Value) { + // Don't include the value in the error, because it may be sensitive. + invalid = http2headerFieldValueError(hf.Name) + } + isPseudo := strings.HasPrefix(hf.Name, ":") + if isPseudo { + if sawRegular { + invalid = http2errPseudoAfterRegular + } + } else { + sawRegular = true + if !http2validWireHeaderFieldName(hf.Name) { + invalid = http2headerFieldNameError(hf.Name) + } + } + + if invalid != nil { + hdec.SetEmitEnabled(false) + return + } + + size := hf.Size() + if size > remainSize { + hdec.SetEmitEnabled(false) + mh.Truncated = true + return + } + remainSize -= size + + mh.Fields = append(mh.Fields, hf) + }) + // Lose reference to MetaHeadersFrame: + defer hdec.SetEmitFunc(func(hf hpack.HeaderField) {}) + + var hc http2headersOrContinuation = hf + for { + frag := hc.HeaderBlockFragment() + if _, err := hdec.Write(frag); err != nil { + return nil, http2ConnectionError(http2ErrCodeCompression) + } + + if hc.HeadersEnded() { + break + } + if f, err := fr.ReadFrame(); err != nil { + return nil, err + } else { + hc = f.(*http2ContinuationFrame) // guaranteed by checkFrameOrder + } + } + + mh.http2HeadersFrame.headerFragBuf = nil + mh.http2HeadersFrame.invalidate() + + if err := hdec.Close(); err != nil { + return nil, http2ConnectionError(http2ErrCodeCompression) + } + if invalid != nil { + fr.errDetail = invalid + if http2VerboseLogs { + log.Printf("http2: invalid header: %v", invalid) + } + return nil, http2StreamError{mh.StreamID, http2ErrCodeProtocol, invalid} + } + if err := mh.checkPseudos(); err != nil { + fr.errDetail = err + if http2VerboseLogs { + log.Printf("http2: invalid pseudo headers: %v", err) + } + return nil, http2StreamError{mh.StreamID, http2ErrCodeProtocol, err} + } + return mh, nil +} + +func http2summarizeFrame(f http2Frame) string { + var buf bytes.Buffer + f.Header().writeDebug(&buf) + switch f := f.(type) { + case *http2SettingsFrame: + n := 0 + f.ForeachSetting(func(s http2Setting) error { + n++ + if n == 1 { + buf.WriteString(", settings:") + } + fmt.Fprintf(&buf, " %v=%v,", s.ID, s.Val) + return nil + }) + if n > 0 { + buf.Truncate(buf.Len() - 1) // remove trailing comma + } + case *http2DataFrame: + data := f.Data() + const max = 256 + if len(data) > max { + data = data[:max] + } + fmt.Fprintf(&buf, " data=%q", data) + if len(f.Data()) > max { + fmt.Fprintf(&buf, " (%d bytes omitted)", len(f.Data())-max) + } + case *http2WindowUpdateFrame: + if f.StreamID == 0 { + buf.WriteString(" (conn)") + } + fmt.Fprintf(&buf, " incr=%v", f.Increment) + case *http2PingFrame: + fmt.Fprintf(&buf, " ping=%q", f.Data[:]) + case *http2GoAwayFrame: + fmt.Fprintf(&buf, " LastStreamID=%v ErrCode=%v Debug=%q", + f.LastStreamID, f.ErrCode, f.debugData) + case *http2RSTStreamFrame: + fmt.Fprintf(&buf, " ErrCode=%v", f.ErrCode) + } + return buf.String() +} + +func http2traceHasWroteHeaderField(trace *httptrace.ClientTrace) bool { + return trace != nil && trace.WroteHeaderField != nil +} + +func http2traceWroteHeaderField(trace *httptrace.ClientTrace, k, v string) { + if trace != nil && trace.WroteHeaderField != nil { + trace.WroteHeaderField(k, []string{v}) + } +} + +func http2traceGot1xxResponseFunc(trace *httptrace.ClientTrace) func(int, textproto.MIMEHeader) error { + if trace != nil { + return trace.Got1xxResponse + } + return nil +} + +// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS +// connection. +func (t *http2Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) { + dialer := &tls.Dialer{ + Config: cfg, + } + cn, err := dialer.DialContext(ctx, network, addr) + if err != nil { + return nil, err + } + tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed + return tlsCn, nil +} + +func http2tlsUnderlyingConn(tc *tls.Conn) net.Conn { + return tc.NetConn() +} + +var http2DebugGoroutines = os.Getenv("DEBUG_HTTP2_GOROUTINES") == "1" + +type http2goroutineLock uint64 + +func http2newGoroutineLock() http2goroutineLock { + if !http2DebugGoroutines { + return 0 + } + return http2goroutineLock(http2curGoroutineID()) +} + +func (g http2goroutineLock) check() { + if !http2DebugGoroutines { + return + } + if http2curGoroutineID() != uint64(g) { + panic("running on the wrong goroutine") + } +} + +func (g http2goroutineLock) checkNotOn() { + if !http2DebugGoroutines { + return + } + if http2curGoroutineID() == uint64(g) { + panic("running on the wrong goroutine") + } +} + +var http2goroutineSpace = []byte("goroutine ") + +func http2curGoroutineID() uint64 { + bp := http2littleBuf.Get().(*[]byte) + defer http2littleBuf.Put(bp) + b := *bp + b = b[:runtime.Stack(b, false)] + // Parse the 4707 out of "goroutine 4707 [" + b = bytes.TrimPrefix(b, http2goroutineSpace) + i := bytes.IndexByte(b, ' ') + if i < 0 { + panic(fmt.Sprintf("No space found in %q", b)) + } + b = b[:i] + n, err := http2parseUintBytes(b, 10, 64) + if err != nil { + panic(fmt.Sprintf("Failed to parse goroutine ID out of %q: %v", b, err)) + } + return n +} + +var http2littleBuf = sync.Pool{ + New: func() interface{} { + buf := make([]byte, 64) + return &buf + }, +} + +// parseUintBytes is like strconv.ParseUint, but using a []byte. +func http2parseUintBytes(s []byte, base int, bitSize int) (n uint64, err error) { + var cutoff, maxVal uint64 + + if bitSize == 0 { + bitSize = int(strconv.IntSize) + } + + s0 := s + switch { + case len(s) < 1: + err = strconv.ErrSyntax + goto Error + + case 2 <= base && base <= 36: + // valid base; nothing to do + + case base == 0: + // Look for octal, hex prefix. + switch { + case s[0] == '0' && len(s) > 1 && (s[1] == 'x' || s[1] == 'X'): + base = 16 + s = s[2:] + if len(s) < 1 { + err = strconv.ErrSyntax + goto Error + } + case s[0] == '0': + base = 8 + default: + base = 10 + } + + default: + err = errors.New("invalid base " + strconv.Itoa(base)) + goto Error + } + + n = 0 + cutoff = http2cutoff64(base) + maxVal = 1<<uint(bitSize) - 1 + + for i := 0; i < len(s); i++ { + var v byte + d := s[i] + switch { + case '0' <= d && d <= '9': + v = d - '0' + case 'a' <= d && d <= 'z': + v = d - 'a' + 10 + case 'A' <= d && d <= 'Z': + v = d - 'A' + 10 + default: + n = 0 + err = strconv.ErrSyntax + goto Error + } + if int(v) >= base { + n = 0 + err = strconv.ErrSyntax + goto Error + } + + if n >= cutoff { + // n*base overflows + n = 1<<64 - 1 + err = strconv.ErrRange + goto Error + } + n *= uint64(base) + + n1 := n + uint64(v) + if n1 < n || n1 > maxVal { + // n+v overflows + n = 1<<64 - 1 + err = strconv.ErrRange + goto Error + } + n = n1 + } + + return n, nil + +Error: + return n, &strconv.NumError{Func: "ParseUint", Num: string(s0), Err: err} +} + +// Return the first number n such that n*base >= 1<<64. +func http2cutoff64(base int) uint64 { + if base < 2 { + return 0 + } + return (1<<64-1)/uint64(base) + 1 +} + +var ( + http2commonBuildOnce sync.Once + http2commonLowerHeader map[string]string // Go-Canonical-Case -> lower-case + http2commonCanonHeader map[string]string // lower-case -> Go-Canonical-Case +) + +func http2buildCommonHeaderMapsOnce() { + http2commonBuildOnce.Do(http2buildCommonHeaderMaps) +} + +func http2buildCommonHeaderMaps() { + common := []string{ + "accept", + "accept-charset", + "accept-encoding", + "accept-language", + "accept-ranges", + "age", + "access-control-allow-credentials", + "access-control-allow-headers", + "access-control-allow-methods", + "access-control-allow-origin", + "access-control-expose-headers", + "access-control-max-age", + "access-control-request-headers", + "access-control-request-method", + "allow", + "authorization", + "cache-control", + "content-disposition", + "content-encoding", + "content-language", + "content-length", + "content-location", + "content-range", + "content-type", + "cookie", + "date", + "etag", + "expect", + "expires", + "from", + "host", + "if-match", + "if-modified-since", + "if-none-match", + "if-unmodified-since", + "last-modified", + "link", + "location", + "max-forwards", + "origin", + "proxy-authenticate", + "proxy-authorization", + "range", + "referer", + "refresh", + "retry-after", + "server", + "set-cookie", + "strict-transport-security", + "trailer", + "transfer-encoding", + "user-agent", + "vary", + "via", + "www-authenticate", + "x-forwarded-for", + "x-forwarded-proto", + } + http2commonLowerHeader = make(map[string]string, len(common)) + http2commonCanonHeader = make(map[string]string, len(common)) + for _, v := range common { + chk := CanonicalHeaderKey(v) + http2commonLowerHeader[chk] = v + http2commonCanonHeader[v] = chk + } +} + +func http2lowerHeader(v string) (lower string, ascii bool) { + http2buildCommonHeaderMapsOnce() + if s, ok := http2commonLowerHeader[v]; ok { + return s, true + } + return http2asciiToLower(v) +} + +func http2canonicalHeader(v string) string { + http2buildCommonHeaderMapsOnce() + if s, ok := http2commonCanonHeader[v]; ok { + return s + } + return CanonicalHeaderKey(v) +} + +var ( + http2VerboseLogs bool + http2logFrameWrites bool + http2logFrameReads bool + http2inTests bool +) + +func init() { + e := os.Getenv("GODEBUG") + if strings.Contains(e, "http2debug=1") { + http2VerboseLogs = true + } + if strings.Contains(e, "http2debug=2") { + http2VerboseLogs = true + http2logFrameWrites = true + http2logFrameReads = true + } +} + +const ( + // ClientPreface is the string that must be sent by new + // connections from clients. + http2ClientPreface = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n" + + // SETTINGS_MAX_FRAME_SIZE default + // https://httpwg.org/specs/rfc7540.html#rfc.section.6.5.2 + http2initialMaxFrameSize = 16384 + + // NextProtoTLS is the NPN/ALPN protocol negotiated during + // HTTP/2's TLS setup. + http2NextProtoTLS = "h2" + + // https://httpwg.org/specs/rfc7540.html#SettingValues + http2initialHeaderTableSize = 4096 + + http2initialWindowSize = 65535 // 6.9.2 Initial Flow Control Window Size + + http2defaultMaxReadFrameSize = 1 << 20 +) + +var ( + http2clientPreface = []byte(http2ClientPreface) +) + +type http2streamState int + +// HTTP/2 stream states. +// +// See http://tools.ietf.org/html/rfc7540#section-5.1. +// +// For simplicity, the server code merges "reserved (local)" into +// "half-closed (remote)". This is one less state transition to track. +// The only downside is that we send PUSH_PROMISEs slightly less +// liberally than allowable. More discussion here: +// https://lists.w3.org/Archives/Public/ietf-http-wg/2016JulSep/0599.html +// +// "reserved (remote)" is omitted since the client code does not +// support server push. +const ( + http2stateIdle http2streamState = iota + http2stateOpen + http2stateHalfClosedLocal + http2stateHalfClosedRemote + http2stateClosed +) + +var http2stateName = [...]string{ + http2stateIdle: "Idle", + http2stateOpen: "Open", + http2stateHalfClosedLocal: "HalfClosedLocal", + http2stateHalfClosedRemote: "HalfClosedRemote", + http2stateClosed: "Closed", +} + +func (st http2streamState) String() string { + return http2stateName[st] +} + +// Setting is a setting parameter: which setting it is, and its value. +type http2Setting struct { + // ID is which setting is being set. + // See https://httpwg.org/specs/rfc7540.html#SettingFormat + ID http2SettingID + + // Val is the value. + Val uint32 +} + +func (s http2Setting) String() string { + return fmt.Sprintf("[%v = %d]", s.ID, s.Val) +} + +// Valid reports whether the setting is valid. +func (s http2Setting) Valid() error { + // Limits and error codes from 6.5.2 Defined SETTINGS Parameters + switch s.ID { + case http2SettingEnablePush: + if s.Val != 1 && s.Val != 0 { + return http2ConnectionError(http2ErrCodeProtocol) + } + case http2SettingInitialWindowSize: + if s.Val > 1<<31-1 { + return http2ConnectionError(http2ErrCodeFlowControl) + } + case http2SettingMaxFrameSize: + if s.Val < 16384 || s.Val > 1<<24-1 { + return http2ConnectionError(http2ErrCodeProtocol) + } + } + return nil +} + +// A SettingID is an HTTP/2 setting as defined in +// https://httpwg.org/specs/rfc7540.html#iana-settings +type http2SettingID uint16 + +const ( + http2SettingHeaderTableSize http2SettingID = 0x1 + http2SettingEnablePush http2SettingID = 0x2 + http2SettingMaxConcurrentStreams http2SettingID = 0x3 + http2SettingInitialWindowSize http2SettingID = 0x4 + http2SettingMaxFrameSize http2SettingID = 0x5 + http2SettingMaxHeaderListSize http2SettingID = 0x6 +) + +var http2settingName = map[http2SettingID]string{ + http2SettingHeaderTableSize: "HEADER_TABLE_SIZE", + http2SettingEnablePush: "ENABLE_PUSH", + http2SettingMaxConcurrentStreams: "MAX_CONCURRENT_STREAMS", + http2SettingInitialWindowSize: "INITIAL_WINDOW_SIZE", + http2SettingMaxFrameSize: "MAX_FRAME_SIZE", + http2SettingMaxHeaderListSize: "MAX_HEADER_LIST_SIZE", +} + +func (s http2SettingID) String() string { + if v, ok := http2settingName[s]; ok { + return v + } + return fmt.Sprintf("UNKNOWN_SETTING_%d", uint16(s)) +} + +// validWireHeaderFieldName reports whether v is a valid header field +// name (key). See httpguts.ValidHeaderName for the base rules. +// +// Further, http2 says: +// +// "Just as in HTTP/1.x, header field names are strings of ASCII +// characters that are compared in a case-insensitive +// fashion. However, header field names MUST be converted to +// lowercase prior to their encoding in HTTP/2. " +func http2validWireHeaderFieldName(v string) bool { + if len(v) == 0 { + return false + } + for _, r := range v { + if !httpguts.IsTokenRune(r) { + return false + } + if 'A' <= r && r <= 'Z' { + return false + } + } + return true +} + +func http2httpCodeString(code int) string { + switch code { + case 200: + return "200" + case 404: + return "404" + } + return strconv.Itoa(code) +} + +// from pkg io +type http2stringWriter interface { + WriteString(s string) (n int, err error) +} + +// A gate lets two goroutines coordinate their activities. +type http2gate chan struct{} + +func (g http2gate) Done() { g <- struct{}{} } + +func (g http2gate) Wait() { <-g } + +// A closeWaiter is like a sync.WaitGroup but only goes 1 to 0 (open to closed). +type http2closeWaiter chan struct{} + +// Init makes a closeWaiter usable. +// It exists because so a closeWaiter value can be placed inside a +// larger struct and have the Mutex and Cond's memory in the same +// allocation. +func (cw *http2closeWaiter) Init() { + *cw = make(chan struct{}) +} + +// Close marks the closeWaiter as closed and unblocks any waiters. +func (cw http2closeWaiter) Close() { + close(cw) +} + +// Wait waits for the closeWaiter to become closed. +func (cw http2closeWaiter) Wait() { + <-cw +} + +// bufferedWriter is a buffered writer that writes to w. +// Its buffered writer is lazily allocated as needed, to minimize +// idle memory usage with many connections. +type http2bufferedWriter struct { + _ http2incomparable + w io.Writer // immutable + bw *bufio.Writer // non-nil when data is buffered +} + +func http2newBufferedWriter(w io.Writer) *http2bufferedWriter { + return &http2bufferedWriter{w: w} +} + +// bufWriterPoolBufferSize is the size of bufio.Writer's +// buffers created using bufWriterPool. +// +// TODO: pick a less arbitrary value? this is a bit under +// (3 x typical 1500 byte MTU) at least. Other than that, +// not much thought went into it. +const http2bufWriterPoolBufferSize = 4 << 10 + +var http2bufWriterPool = sync.Pool{ + New: func() interface{} { + return bufio.NewWriterSize(nil, http2bufWriterPoolBufferSize) + }, +} + +func (w *http2bufferedWriter) Available() int { + if w.bw == nil { + return http2bufWriterPoolBufferSize + } + return w.bw.Available() +} + +func (w *http2bufferedWriter) Write(p []byte) (n int, err error) { + if w.bw == nil { + bw := http2bufWriterPool.Get().(*bufio.Writer) + bw.Reset(w.w) + w.bw = bw + } + return w.bw.Write(p) +} + +func (w *http2bufferedWriter) Flush() error { + bw := w.bw + if bw == nil { + return nil + } + err := bw.Flush() + bw.Reset(nil) + http2bufWriterPool.Put(bw) + w.bw = nil + return err +} + +func http2mustUint31(v int32) uint32 { + if v < 0 || v > 2147483647 { + panic("out of range") + } + return uint32(v) +} + +// bodyAllowedForStatus reports whether a given response status code +// permits a body. See RFC 7230, section 3.3. +func http2bodyAllowedForStatus(status int) bool { + switch { + case status >= 100 && status <= 199: + return false + case status == 204: + return false + case status == 304: + return false + } + return true +} + +type http2httpError struct { + _ http2incomparable + msg string + timeout bool +} + +func (e *http2httpError) Error() string { return e.msg } + +func (e *http2httpError) Timeout() bool { return e.timeout } + +func (e *http2httpError) Temporary() bool { return true } + +var http2errTimeout error = &http2httpError{msg: "http2: timeout awaiting response headers", timeout: true} + +type http2connectionStater interface { + ConnectionState() tls.ConnectionState +} + +var http2sorterPool = sync.Pool{New: func() interface{} { return new(http2sorter) }} + +type http2sorter struct { + v []string // owned by sorter +} + +func (s *http2sorter) Len() int { return len(s.v) } + +func (s *http2sorter) Swap(i, j int) { s.v[i], s.v[j] = s.v[j], s.v[i] } + +func (s *http2sorter) Less(i, j int) bool { return s.v[i] < s.v[j] } + +// Keys returns the sorted keys of h. +// +// The returned slice is only valid until s used again or returned to +// its pool. +func (s *http2sorter) Keys(h Header) []string { + keys := s.v[:0] + for k := range h { + keys = append(keys, k) + } + s.v = keys + sort.Sort(s) + return keys +} + +func (s *http2sorter) SortStrings(ss []string) { + // Our sorter works on s.v, which sorter owns, so + // stash it away while we sort the user's buffer. + save := s.v + s.v = ss + sort.Sort(s) + s.v = save +} + +// validPseudoPath reports whether v is a valid :path pseudo-header +// value. It must be either: +// +// - a non-empty string starting with '/' +// - the string '*', for OPTIONS requests. +// +// For now this is only used a quick check for deciding when to clean +// up Opaque URLs before sending requests from the Transport. +// See golang.org/issue/16847 +// +// We used to enforce that the path also didn't start with "//", but +// Google's GFE accepts such paths and Chrome sends them, so ignore +// that part of the spec. See golang.org/issue/19103. +func http2validPseudoPath(v string) bool { + return (len(v) > 0 && v[0] == '/') || v == "*" +} + +// incomparable is a zero-width, non-comparable type. Adding it to a struct +// makes that struct also non-comparable, and generally doesn't add +// any size (as long as it's first). +type http2incomparable [0]func() + +// pipe is a goroutine-safe io.Reader/io.Writer pair. It's like +// io.Pipe except there are no PipeReader/PipeWriter halves, and the +// underlying buffer is an interface. (io.Pipe is always unbuffered) +type http2pipe struct { + mu sync.Mutex + c sync.Cond // c.L lazily initialized to &p.mu + b http2pipeBuffer // nil when done reading + unread int // bytes unread when done + err error // read error once empty. non-nil means closed. + breakErr error // immediate read error (caller doesn't see rest of b) + donec chan struct{} // closed on error + readFn func() // optional code to run in Read before error +} + +type http2pipeBuffer interface { + Len() int + io.Writer + io.Reader +} + +// setBuffer initializes the pipe buffer. +// It has no effect if the pipe is already closed. +func (p *http2pipe) setBuffer(b http2pipeBuffer) { + p.mu.Lock() + defer p.mu.Unlock() + if p.err != nil || p.breakErr != nil { + return + } + p.b = b +} + +func (p *http2pipe) Len() int { + p.mu.Lock() + defer p.mu.Unlock() + if p.b == nil { + return p.unread + } + return p.b.Len() +} + +// Read waits until data is available and copies bytes +// from the buffer into p. +func (p *http2pipe) Read(d []byte) (n int, err error) { + p.mu.Lock() + defer p.mu.Unlock() + if p.c.L == nil { + p.c.L = &p.mu + } + for { + if p.breakErr != nil { + return 0, p.breakErr + } + if p.b != nil && p.b.Len() > 0 { + return p.b.Read(d) + } + if p.err != nil { + if p.readFn != nil { + p.readFn() // e.g. copy trailers + p.readFn = nil // not sticky like p.err + } + p.b = nil + return 0, p.err + } + p.c.Wait() + } +} + +var http2errClosedPipeWrite = errors.New("write on closed buffer") + +// Write copies bytes from p into the buffer and wakes a reader. +// It is an error to write more data than the buffer can hold. +func (p *http2pipe) Write(d []byte) (n int, err error) { + p.mu.Lock() + defer p.mu.Unlock() + if p.c.L == nil { + p.c.L = &p.mu + } + defer p.c.Signal() + if p.err != nil { + return 0, http2errClosedPipeWrite + } + if p.breakErr != nil { + p.unread += len(d) + return len(d), nil // discard when there is no reader + } + return p.b.Write(d) +} + +// CloseWithError causes the next Read (waking up a current blocked +// Read if needed) to return the provided err after all data has been +// read. +// +// The error must be non-nil. +func (p *http2pipe) CloseWithError(err error) { p.closeWithError(&p.err, err, nil) } + +// BreakWithError causes the next Read (waking up a current blocked +// Read if needed) to return the provided err immediately, without +// waiting for unread data. +func (p *http2pipe) BreakWithError(err error) { p.closeWithError(&p.breakErr, err, nil) } + +// closeWithErrorAndCode is like CloseWithError but also sets some code to run +// in the caller's goroutine before returning the error. +func (p *http2pipe) closeWithErrorAndCode(err error, fn func()) { p.closeWithError(&p.err, err, fn) } + +func (p *http2pipe) closeWithError(dst *error, err error, fn func()) { + if err == nil { + panic("err must be non-nil") + } + p.mu.Lock() + defer p.mu.Unlock() + if p.c.L == nil { + p.c.L = &p.mu + } + defer p.c.Signal() + if *dst != nil { + // Already been done. + return + } + p.readFn = fn + if dst == &p.breakErr { + if p.b != nil { + p.unread += p.b.Len() + } + p.b = nil + } + *dst = err + p.closeDoneLocked() +} + +// requires p.mu be held. +func (p *http2pipe) closeDoneLocked() { + if p.donec == nil { + return + } + // Close if unclosed. This isn't racy since we always + // hold p.mu while closing. + select { + case <-p.donec: + default: + close(p.donec) + } +} + +// Err returns the error (if any) first set by BreakWithError or CloseWithError. +func (p *http2pipe) Err() error { + p.mu.Lock() + defer p.mu.Unlock() + if p.breakErr != nil { + return p.breakErr + } + return p.err +} + +// Done returns a channel which is closed if and when this pipe is closed +// with CloseWithError. +func (p *http2pipe) Done() <-chan struct{} { + p.mu.Lock() + defer p.mu.Unlock() + if p.donec == nil { + p.donec = make(chan struct{}) + if p.err != nil || p.breakErr != nil { + // Already hit an error. + p.closeDoneLocked() + } + } + return p.donec +} + +const ( + http2prefaceTimeout = 10 * time.Second + http2firstSettingsTimeout = 2 * time.Second // should be in-flight with preface anyway + http2handlerChunkWriteSize = 4 << 10 + http2defaultMaxStreams = 250 // TODO: make this 100 as the GFE seems to? + http2maxQueuedControlFrames = 10000 +) + +var ( + http2errClientDisconnected = errors.New("client disconnected") + http2errClosedBody = errors.New("body closed by handler") + http2errHandlerComplete = errors.New("http2: request body closed due to handler exiting") + http2errStreamClosed = errors.New("http2: stream closed") +) + +var http2responseWriterStatePool = sync.Pool{ + New: func() interface{} { + rws := &http2responseWriterState{} + rws.bw = bufio.NewWriterSize(http2chunkWriter{rws}, http2handlerChunkWriteSize) + return rws + }, +} + +// Test hooks. +var ( + http2testHookOnConn func() + http2testHookGetServerConn func(*http2serverConn) + http2testHookOnPanicMu *sync.Mutex // nil except in tests + http2testHookOnPanic func(sc *http2serverConn, panicVal interface{}) (rePanic bool) +) + +// Server is an HTTP/2 server. +type http2Server struct { + // MaxHandlers limits the number of http.Handler ServeHTTP goroutines + // which may run at a time over all connections. + // Negative or zero no limit. + // TODO: implement + MaxHandlers int + + // MaxConcurrentStreams optionally specifies the number of + // concurrent streams that each client may have open at a + // time. This is unrelated to the number of http.Handler goroutines + // which may be active globally, which is MaxHandlers. + // If zero, MaxConcurrentStreams defaults to at least 100, per + // the HTTP/2 spec's recommendations. + MaxConcurrentStreams uint32 + + // MaxDecoderHeaderTableSize optionally specifies the http2 + // SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It + // informs the remote endpoint of the maximum size of the header compression + // table used to decode header blocks, in octets. If zero, the default value + // of 4096 is used. + MaxDecoderHeaderTableSize uint32 + + // MaxEncoderHeaderTableSize optionally specifies an upper limit for the + // header compression table used for encoding request headers. Received + // SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero, + // the default value of 4096 is used. + MaxEncoderHeaderTableSize uint32 + + // MaxReadFrameSize optionally specifies the largest frame + // this server is willing to read. A valid value is between + // 16k and 16M, inclusive. If zero or otherwise invalid, a + // default value is used. + MaxReadFrameSize uint32 + + // PermitProhibitedCipherSuites, if true, permits the use of + // cipher suites prohibited by the HTTP/2 spec. + PermitProhibitedCipherSuites bool + + // IdleTimeout specifies how long until idle clients should be + // closed with a GOAWAY frame. PING frames are not considered + // activity for the purposes of IdleTimeout. + IdleTimeout time.Duration + + // MaxUploadBufferPerConnection is the size of the initial flow + // control window for each connections. The HTTP/2 spec does not + // allow this to be smaller than 65535 or larger than 2^32-1. + // If the value is outside this range, a default value will be + // used instead. + MaxUploadBufferPerConnection int32 + + // MaxUploadBufferPerStream is the size of the initial flow control + // window for each stream. The HTTP/2 spec does not allow this to + // be larger than 2^32-1. If the value is zero or larger than the + // maximum, a default value will be used instead. + MaxUploadBufferPerStream int32 + + // NewWriteScheduler constructs a write scheduler for a connection. + // If nil, a default scheduler is chosen. + NewWriteScheduler func() http2WriteScheduler + + // CountError, if non-nil, is called on HTTP/2 server errors. + // It's intended to increment a metric for monitoring, such + // as an expvar or Prometheus metric. + // The errType consists of only ASCII word characters. + CountError func(errType string) + + // Internal state. This is a pointer (rather than embedded directly) + // so that we don't embed a Mutex in this struct, which will make the + // struct non-copyable, which might break some callers. + state *http2serverInternalState +} + +func (s *http2Server) initialConnRecvWindowSize() int32 { + if s.MaxUploadBufferPerConnection >= http2initialWindowSize { + return s.MaxUploadBufferPerConnection + } + return 1 << 20 +} + +func (s *http2Server) initialStreamRecvWindowSize() int32 { + if s.MaxUploadBufferPerStream > 0 { + return s.MaxUploadBufferPerStream + } + return 1 << 20 +} + +func (s *http2Server) maxReadFrameSize() uint32 { + if v := s.MaxReadFrameSize; v >= http2minMaxFrameSize && v <= http2maxFrameSize { + return v + } + return http2defaultMaxReadFrameSize +} + +func (s *http2Server) maxConcurrentStreams() uint32 { + if v := s.MaxConcurrentStreams; v > 0 { + return v + } + return http2defaultMaxStreams +} + +func (s *http2Server) maxDecoderHeaderTableSize() uint32 { + if v := s.MaxDecoderHeaderTableSize; v > 0 { + return v + } + return http2initialHeaderTableSize +} + +func (s *http2Server) maxEncoderHeaderTableSize() uint32 { + if v := s.MaxEncoderHeaderTableSize; v > 0 { + return v + } + return http2initialHeaderTableSize +} + +// maxQueuedControlFrames is the maximum number of control frames like +// SETTINGS, PING and RST_STREAM that will be queued for writing before +// the connection is closed to prevent memory exhaustion attacks. +func (s *http2Server) maxQueuedControlFrames() int { + // TODO: if anybody asks, add a Server field, and remember to define the + // behavior of negative values. + return http2maxQueuedControlFrames +} + +type http2serverInternalState struct { + mu sync.Mutex + activeConns map[*http2serverConn]struct{} +} + +func (s *http2serverInternalState) registerConn(sc *http2serverConn) { + if s == nil { + return // if the Server was used without calling ConfigureServer + } + s.mu.Lock() + s.activeConns[sc] = struct{}{} + s.mu.Unlock() +} + +func (s *http2serverInternalState) unregisterConn(sc *http2serverConn) { + if s == nil { + return // if the Server was used without calling ConfigureServer + } + s.mu.Lock() + delete(s.activeConns, sc) + s.mu.Unlock() +} + +func (s *http2serverInternalState) startGracefulShutdown() { + if s == nil { + return // if the Server was used without calling ConfigureServer + } + s.mu.Lock() + for sc := range s.activeConns { + sc.startGracefulShutdown() + } + s.mu.Unlock() +} + +// ConfigureServer adds HTTP/2 support to a net/http Server. +// +// The configuration conf may be nil. +// +// ConfigureServer must be called before s begins serving. +func http2ConfigureServer(s *Server, conf *http2Server) error { + if s == nil { + panic("nil *http.Server") + } + if conf == nil { + conf = new(http2Server) + } + conf.state = &http2serverInternalState{activeConns: make(map[*http2serverConn]struct{})} + if h1, h2 := s, conf; h2.IdleTimeout == 0 { + if h1.IdleTimeout != 0 { + h2.IdleTimeout = h1.IdleTimeout + } else { + h2.IdleTimeout = h1.ReadTimeout + } + } + s.RegisterOnShutdown(conf.state.startGracefulShutdown) + + if s.TLSConfig == nil { + s.TLSConfig = new(tls.Config) + } else if s.TLSConfig.CipherSuites != nil && s.TLSConfig.MinVersion < tls.VersionTLS13 { + // If they already provided a TLS 1.0–1.2 CipherSuite list, return an + // error if it is missing ECDHE_RSA_WITH_AES_128_GCM_SHA256 or + // ECDHE_ECDSA_WITH_AES_128_GCM_SHA256. + haveRequired := false + for _, cs := range s.TLSConfig.CipherSuites { + switch cs { + case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, + // Alternative MTI cipher to not discourage ECDSA-only servers. + // See http://golang.org/cl/30721 for further information. + tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256: + haveRequired = true + } + } + if !haveRequired { + return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)") + } + } + + // Note: not setting MinVersion to tls.VersionTLS12, + // as we don't want to interfere with HTTP/1.1 traffic + // on the user's server. We enforce TLS 1.2 later once + // we accept a connection. Ideally this should be done + // during next-proto selection, but using TLS <1.2 with + // HTTP/2 is still the client's bug. + + s.TLSConfig.PreferServerCipherSuites = true + + if !http2strSliceContains(s.TLSConfig.NextProtos, http2NextProtoTLS) { + s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, http2NextProtoTLS) + } + if !http2strSliceContains(s.TLSConfig.NextProtos, "http/1.1") { + s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "http/1.1") + } + + if s.TLSNextProto == nil { + s.TLSNextProto = map[string]func(*Server, *tls.Conn, Handler){} + } + protoHandler := func(hs *Server, c *tls.Conn, h Handler) { + if http2testHookOnConn != nil { + http2testHookOnConn() + } + // The TLSNextProto interface predates contexts, so + // the net/http package passes down its per-connection + // base context via an exported but unadvertised + // method on the Handler. This is for internal + // net/http<=>http2 use only. + var ctx context.Context + type baseContexter interface { + BaseContext() context.Context + } + if bc, ok := h.(baseContexter); ok { + ctx = bc.BaseContext() + } + conf.ServeConn(c, &http2ServeConnOpts{ + Context: ctx, + Handler: h, + BaseConfig: hs, + }) + } + s.TLSNextProto[http2NextProtoTLS] = protoHandler + return nil +} + +// ServeConnOpts are options for the Server.ServeConn method. +type http2ServeConnOpts struct { + // Context is the base context to use. + // If nil, context.Background is used. + Context context.Context + + // BaseConfig optionally sets the base configuration + // for values. If nil, defaults are used. + BaseConfig *Server + + // Handler specifies which handler to use for processing + // requests. If nil, BaseConfig.Handler is used. If BaseConfig + // or BaseConfig.Handler is nil, http.DefaultServeMux is used. + Handler Handler + + // UpgradeRequest is an initial request received on a connection + // undergoing an h2c upgrade. The request body must have been + // completely read from the connection before calling ServeConn, + // and the 101 Switching Protocols response written. + UpgradeRequest *Request + + // Settings is the decoded contents of the HTTP2-Settings header + // in an h2c upgrade request. + Settings []byte + + // SawClientPreface is set if the HTTP/2 connection preface + // has already been read from the connection. + SawClientPreface bool +} + +func (o *http2ServeConnOpts) context() context.Context { + if o != nil && o.Context != nil { + return o.Context + } + return context.Background() +} + +func (o *http2ServeConnOpts) baseConfig() *Server { + if o != nil && o.BaseConfig != nil { + return o.BaseConfig + } + return new(Server) +} + +func (o *http2ServeConnOpts) handler() Handler { + if o != nil { + if o.Handler != nil { + return o.Handler + } + if o.BaseConfig != nil && o.BaseConfig.Handler != nil { + return o.BaseConfig.Handler + } + } + return DefaultServeMux +} + +// ServeConn serves HTTP/2 requests on the provided connection and +// blocks until the connection is no longer readable. +// +// ServeConn starts speaking HTTP/2 assuming that c has not had any +// reads or writes. It writes its initial settings frame and expects +// to be able to read the preface and settings frame from the +// client. If c has a ConnectionState method like a *tls.Conn, the +// ConnectionState is used to verify the TLS ciphersuite and to set +// the Request.TLS field in Handlers. +// +// ServeConn does not support h2c by itself. Any h2c support must be +// implemented in terms of providing a suitably-behaving net.Conn. +// +// The opts parameter is optional. If nil, default values are used. +func (s *http2Server) ServeConn(c net.Conn, opts *http2ServeConnOpts) { + baseCtx, cancel := http2serverConnBaseContext(c, opts) + defer cancel() + + sc := &http2serverConn{ + srv: s, + hs: opts.baseConfig(), + conn: c, + baseCtx: baseCtx, + remoteAddrStr: c.RemoteAddr().String(), + bw: http2newBufferedWriter(c), + handler: opts.handler(), + streams: make(map[uint32]*http2stream), + readFrameCh: make(chan http2readFrameResult), + wantWriteFrameCh: make(chan http2FrameWriteRequest, 8), + serveMsgCh: make(chan interface{}, 8), + wroteFrameCh: make(chan http2frameWriteResult, 1), // buffered; one send in writeFrameAsync + bodyReadCh: make(chan http2bodyReadMsg), // buffering doesn't matter either way + doneServing: make(chan struct{}), + clientMaxStreams: math.MaxUint32, // Section 6.5.2: "Initially, there is no limit to this value" + advMaxStreams: s.maxConcurrentStreams(), + initialStreamSendWindowSize: http2initialWindowSize, + maxFrameSize: http2initialMaxFrameSize, + serveG: http2newGoroutineLock(), + pushEnabled: true, + sawClientPreface: opts.SawClientPreface, + } + + s.state.registerConn(sc) + defer s.state.unregisterConn(sc) + + // The net/http package sets the write deadline from the + // http.Server.WriteTimeout during the TLS handshake, but then + // passes the connection off to us with the deadline already set. + // Write deadlines are set per stream in serverConn.newStream. + // Disarm the net.Conn write deadline here. + if sc.hs.WriteTimeout != 0 { + sc.conn.SetWriteDeadline(time.Time{}) + } + + if s.NewWriteScheduler != nil { + sc.writeSched = s.NewWriteScheduler() + } else { + sc.writeSched = http2NewPriorityWriteScheduler(nil) + } + + // These start at the RFC-specified defaults. If there is a higher + // configured value for inflow, that will be updated when we send a + // WINDOW_UPDATE shortly after sending SETTINGS. + sc.flow.add(http2initialWindowSize) + sc.inflow.add(http2initialWindowSize) + sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf) + sc.hpackEncoder.SetMaxDynamicTableSizeLimit(s.maxEncoderHeaderTableSize()) + + fr := http2NewFramer(sc.bw, c) + if s.CountError != nil { + fr.countError = s.CountError + } + fr.ReadMetaHeaders = hpack.NewDecoder(s.maxDecoderHeaderTableSize(), nil) + fr.MaxHeaderListSize = sc.maxHeaderListSize() + fr.SetMaxReadFrameSize(s.maxReadFrameSize()) + sc.framer = fr + + if tc, ok := c.(http2connectionStater); ok { + sc.tlsState = new(tls.ConnectionState) + *sc.tlsState = tc.ConnectionState() + // 9.2 Use of TLS Features + // An implementation of HTTP/2 over TLS MUST use TLS + // 1.2 or higher with the restrictions on feature set + // and cipher suite described in this section. Due to + // implementation limitations, it might not be + // possible to fail TLS negotiation. An endpoint MUST + // immediately terminate an HTTP/2 connection that + // does not meet the TLS requirements described in + // this section with a connection error (Section + // 5.4.1) of type INADEQUATE_SECURITY. + if sc.tlsState.Version < tls.VersionTLS12 { + sc.rejectConn(http2ErrCodeInadequateSecurity, "TLS version too low") + return + } + + if sc.tlsState.ServerName == "" { + // Client must use SNI, but we don't enforce that anymore, + // since it was causing problems when connecting to bare IP + // addresses during development. + // + // TODO: optionally enforce? Or enforce at the time we receive + // a new request, and verify the ServerName matches the :authority? + // But that precludes proxy situations, perhaps. + // + // So for now, do nothing here again. + } + + if !s.PermitProhibitedCipherSuites && http2isBadCipher(sc.tlsState.CipherSuite) { + // "Endpoints MAY choose to generate a connection error + // (Section 5.4.1) of type INADEQUATE_SECURITY if one of + // the prohibited cipher suites are negotiated." + // + // We choose that. In my opinion, the spec is weak + // here. It also says both parties must support at least + // TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 so there's no + // excuses here. If we really must, we could allow an + // "AllowInsecureWeakCiphers" option on the server later. + // Let's see how it plays out first. + sc.rejectConn(http2ErrCodeInadequateSecurity, fmt.Sprintf("Prohibited TLS 1.2 Cipher Suite: %x", sc.tlsState.CipherSuite)) + return + } + } + + if opts.Settings != nil { + fr := &http2SettingsFrame{ + http2FrameHeader: http2FrameHeader{valid: true}, + p: opts.Settings, + } + if err := fr.ForeachSetting(sc.processSetting); err != nil { + sc.rejectConn(http2ErrCodeProtocol, "invalid settings") + return + } + opts.Settings = nil + } + + if hook := http2testHookGetServerConn; hook != nil { + hook(sc) + } + + if opts.UpgradeRequest != nil { + sc.upgradeRequest(opts.UpgradeRequest) + opts.UpgradeRequest = nil + } + + sc.serve() +} + +func http2serverConnBaseContext(c net.Conn, opts *http2ServeConnOpts) (ctx context.Context, cancel func()) { + ctx, cancel = context.WithCancel(opts.context()) + ctx = context.WithValue(ctx, LocalAddrContextKey, c.LocalAddr()) + if hs := opts.baseConfig(); hs != nil { + ctx = context.WithValue(ctx, ServerContextKey, hs) + } + return +} + +func (sc *http2serverConn) rejectConn(err http2ErrCode, debug string) { + sc.vlogf("http2: server rejecting conn: %v, %s", err, debug) + // ignoring errors. hanging up anyway. + sc.framer.WriteGoAway(0, err, []byte(debug)) + sc.bw.Flush() + sc.conn.Close() +} + +type http2serverConn struct { + // Immutable: + srv *http2Server + hs *Server + conn net.Conn + bw *http2bufferedWriter // writing to conn + handler Handler + baseCtx context.Context + framer *http2Framer + doneServing chan struct{} // closed when serverConn.serve ends + readFrameCh chan http2readFrameResult // written by serverConn.readFrames + wantWriteFrameCh chan http2FrameWriteRequest // from handlers -> serve + wroteFrameCh chan http2frameWriteResult // from writeFrameAsync -> serve, tickles more frame writes + bodyReadCh chan http2bodyReadMsg // from handlers -> serve + serveMsgCh chan interface{} // misc messages & code to send to / run on the serve loop + flow http2flow // conn-wide (not stream-specific) outbound flow control + inflow http2flow // conn-wide inbound flow control + tlsState *tls.ConnectionState // shared by all handlers, like net/http + remoteAddrStr string + writeSched http2WriteScheduler + + // Everything following is owned by the serve loop; use serveG.check(): + serveG http2goroutineLock // used to verify funcs are on serve() + pushEnabled bool + sawClientPreface bool // preface has already been read, used in h2c upgrade + sawFirstSettings bool // got the initial SETTINGS frame after the preface + needToSendSettingsAck bool + unackedSettings int // how many SETTINGS have we sent without ACKs? + queuedControlFrames int // control frames in the writeSched queue + clientMaxStreams uint32 // SETTINGS_MAX_CONCURRENT_STREAMS from client (our PUSH_PROMISE limit) + advMaxStreams uint32 // our SETTINGS_MAX_CONCURRENT_STREAMS advertised the client + curClientStreams uint32 // number of open streams initiated by the client + curPushedStreams uint32 // number of open streams initiated by server push + curHandlers uint32 // number of running handler goroutines + maxClientStreamID uint32 // max ever seen from client (odd), or 0 if there have been no client requests + maxPushPromiseID uint32 // ID of the last push promise (even), or 0 if there have been no pushes + streams map[uint32]*http2stream + unstartedHandlers []http2unstartedHandler + initialStreamSendWindowSize int32 + maxFrameSize int32 + peerMaxHeaderListSize uint32 // zero means unknown (default) + canonHeader map[string]string // http2-lower-case -> Go-Canonical-Case + canonHeaderKeysSize int // canonHeader keys size in bytes + writingFrame bool // started writing a frame (on serve goroutine or separate) + writingFrameAsync bool // started a frame on its own goroutine but haven't heard back on wroteFrameCh + needsFrameFlush bool // last frame write wasn't a flush + inGoAway bool // we've started to or sent GOAWAY + inFrameScheduleLoop bool // whether we're in the scheduleFrameWrite loop + needToSendGoAway bool // we need to schedule a GOAWAY frame write + goAwayCode http2ErrCode + shutdownTimer *time.Timer // nil until used + idleTimer *time.Timer // nil if unused + + // Owned by the writeFrameAsync goroutine: + headerWriteBuf bytes.Buffer + hpackEncoder *hpack.Encoder + + // Used by startGracefulShutdown. + shutdownOnce sync.Once +} + +func (sc *http2serverConn) maxHeaderListSize() uint32 { + n := sc.hs.MaxHeaderBytes + if n <= 0 { + n = DefaultMaxHeaderBytes + } + // http2's count is in a slightly different unit and includes 32 bytes per pair. + // So, take the net/http.Server value and pad it up a bit, assuming 10 headers. + const perFieldOverhead = 32 // per http2 spec + const typicalHeaders = 10 // conservative + return uint32(n + typicalHeaders*perFieldOverhead) +} + +func (sc *http2serverConn) curOpenStreams() uint32 { + sc.serveG.check() + return sc.curClientStreams + sc.curPushedStreams +} + +// stream represents a stream. This is the minimal metadata needed by +// the serve goroutine. Most of the actual stream state is owned by +// the http.Handler's goroutine in the responseWriter. Because the +// responseWriter's responseWriterState is recycled at the end of a +// handler, this struct intentionally has no pointer to the +// *responseWriter{,State} itself, as the Handler ending nils out the +// responseWriter's state field. +type http2stream struct { + // immutable: + sc *http2serverConn + id uint32 + body *http2pipe // non-nil if expecting DATA frames + cw http2closeWaiter // closed wait stream transitions to closed state + ctx context.Context + cancelCtx func() + + // owned by serverConn's serve loop: + bodyBytes int64 // body bytes seen so far + declBodyBytes int64 // or -1 if undeclared + flow http2flow // limits writing from Handler to client + inflow http2flow // what the client is allowed to POST/etc to us + state http2streamState + resetQueued bool // RST_STREAM queued for write; set by sc.resetStream + gotTrailerHeader bool // HEADER frame for trailers was seen + wroteHeaders bool // whether we wrote headers (not status 100) + readDeadline *time.Timer // nil if unused + writeDeadline *time.Timer // nil if unused + closeErr error // set before cw is closed + + trailer Header // accumulated trailers + reqTrailer Header // handler's Request.Trailer +} + +func (sc *http2serverConn) Framer() *http2Framer { return sc.framer } + +func (sc *http2serverConn) CloseConn() error { return sc.conn.Close() } + +func (sc *http2serverConn) Flush() error { return sc.bw.Flush() } + +func (sc *http2serverConn) HeaderEncoder() (*hpack.Encoder, *bytes.Buffer) { + return sc.hpackEncoder, &sc.headerWriteBuf +} + +func (sc *http2serverConn) state(streamID uint32) (http2streamState, *http2stream) { + sc.serveG.check() + // http://tools.ietf.org/html/rfc7540#section-5.1 + if st, ok := sc.streams[streamID]; ok { + return st.state, st + } + // "The first use of a new stream identifier implicitly closes all + // streams in the "idle" state that might have been initiated by + // that peer with a lower-valued stream identifier. For example, if + // a client sends a HEADERS frame on stream 7 without ever sending a + // frame on stream 5, then stream 5 transitions to the "closed" + // state when the first frame for stream 7 is sent or received." + if streamID%2 == 1 { + if streamID <= sc.maxClientStreamID { + return http2stateClosed, nil + } + } else { + if streamID <= sc.maxPushPromiseID { + return http2stateClosed, nil + } + } + return http2stateIdle, nil +} + +// setConnState calls the net/http ConnState hook for this connection, if configured. +// Note that the net/http package does StateNew and StateClosed for us. +// There is currently no plan for StateHijacked or hijacking HTTP/2 connections. +func (sc *http2serverConn) setConnState(state ConnState) { + if sc.hs.ConnState != nil { + sc.hs.ConnState(sc.conn, state) + } +} + +func (sc *http2serverConn) vlogf(format string, args ...interface{}) { + if http2VerboseLogs { + sc.logf(format, args...) + } +} + +func (sc *http2serverConn) logf(format string, args ...interface{}) { + if lg := sc.hs.ErrorLog; lg != nil { + lg.Printf(format, args...) + } else { + log.Printf(format, args...) + } +} + +// errno returns v's underlying uintptr, else 0. +// +// TODO: remove this helper function once http2 can use build +// tags. See comment in isClosedConnError. +func http2errno(v error) uintptr { + if rv := reflect.ValueOf(v); rv.Kind() == reflect.Uintptr { + return uintptr(rv.Uint()) + } + return 0 +} + +// isClosedConnError reports whether err is an error from use of a closed +// network connection. +func http2isClosedConnError(err error) bool { + if err == nil { + return false + } + + // TODO: remove this string search and be more like the Windows + // case below. That might involve modifying the standard library + // to return better error types. + str := err.Error() + if strings.Contains(str, "use of closed network connection") { + return true + } + + // TODO(bradfitz): x/tools/cmd/bundle doesn't really support + // build tags, so I can't make an http2_windows.go file with + // Windows-specific stuff. Fix that and move this, once we + // have a way to bundle this into std's net/http somehow. + if runtime.GOOS == "windows" { + if oe, ok := err.(*net.OpError); ok && oe.Op == "read" { + if se, ok := oe.Err.(*os.SyscallError); ok && se.Syscall == "wsarecv" { + const WSAECONNABORTED = 10053 + const WSAECONNRESET = 10054 + if n := http2errno(se.Err); n == WSAECONNRESET || n == WSAECONNABORTED { + return true + } + } + } + } + return false +} + +func (sc *http2serverConn) condlogf(err error, format string, args ...interface{}) { + if err == nil { + return + } + if err == io.EOF || err == io.ErrUnexpectedEOF || http2isClosedConnError(err) || err == http2errPrefaceTimeout { + // Boring, expected errors. + sc.vlogf(format, args...) + } else { + sc.logf(format, args...) + } +} + +// maxCachedCanonicalHeadersKeysSize is an arbitrarily-chosen limit on the size +// of the entries in the canonHeader cache. +// This should be larger than the size of unique, uncommon header keys likely to +// be sent by the peer, while not so high as to permit unreasonable memory usage +// if the peer sends an unbounded number of unique header keys. +const http2maxCachedCanonicalHeadersKeysSize = 2048 + +func (sc *http2serverConn) canonicalHeader(v string) string { + sc.serveG.check() + http2buildCommonHeaderMapsOnce() + cv, ok := http2commonCanonHeader[v] + if ok { + return cv + } + cv, ok = sc.canonHeader[v] + if ok { + return cv + } + if sc.canonHeader == nil { + sc.canonHeader = make(map[string]string) + } + cv = CanonicalHeaderKey(v) + size := 100 + len(v)*2 // 100 bytes of map overhead + key + value + if sc.canonHeaderKeysSize+size <= http2maxCachedCanonicalHeadersKeysSize { + sc.canonHeader[v] = cv + sc.canonHeaderKeysSize += size + } + return cv +} + +type http2readFrameResult struct { + f http2Frame // valid until readMore is called + err error + + // readMore should be called once the consumer no longer needs or + // retains f. After readMore, f is invalid and more frames can be + // read. + readMore func() +} + +// readFrames is the loop that reads incoming frames. +// It takes care to only read one frame at a time, blocking until the +// consumer is done with the frame. +// It's run on its own goroutine. +func (sc *http2serverConn) readFrames() { + gate := make(http2gate) + gateDone := gate.Done + for { + f, err := sc.framer.ReadFrame() + select { + case sc.readFrameCh <- http2readFrameResult{f, err, gateDone}: + case <-sc.doneServing: + return + } + select { + case <-gate: + case <-sc.doneServing: + return + } + if http2terminalReadFrameError(err) { + return + } + } +} + +// frameWriteResult is the message passed from writeFrameAsync to the serve goroutine. +type http2frameWriteResult struct { + _ http2incomparable + wr http2FrameWriteRequest // what was written (or attempted) + err error // result of the writeFrame call +} + +// writeFrameAsync runs in its own goroutine and writes a single frame +// and then reports when it's done. +// At most one goroutine can be running writeFrameAsync at a time per +// serverConn. +func (sc *http2serverConn) writeFrameAsync(wr http2FrameWriteRequest) { + err := wr.write.writeFrame(sc) + sc.wroteFrameCh <- http2frameWriteResult{wr: wr, err: err} +} + +func (sc *http2serverConn) closeAllStreamsOnConnClose() { + sc.serveG.check() + for _, st := range sc.streams { + sc.closeStream(st, http2errClientDisconnected) + } +} + +func (sc *http2serverConn) stopShutdownTimer() { + sc.serveG.check() + if t := sc.shutdownTimer; t != nil { + t.Stop() + } +} + +func (sc *http2serverConn) notePanic() { + // Note: this is for serverConn.serve panicking, not http.Handler code. + if http2testHookOnPanicMu != nil { + http2testHookOnPanicMu.Lock() + defer http2testHookOnPanicMu.Unlock() + } + if http2testHookOnPanic != nil { + if e := recover(); e != nil { + if http2testHookOnPanic(sc, e) { + panic(e) + } + } + } +} + +func (sc *http2serverConn) serve() { + sc.serveG.check() + defer sc.notePanic() + defer sc.conn.Close() + defer sc.closeAllStreamsOnConnClose() + defer sc.stopShutdownTimer() + defer close(sc.doneServing) // unblocks handlers trying to send + + if http2VerboseLogs { + sc.vlogf("http2: server connection from %v on %p", sc.conn.RemoteAddr(), sc.hs) + } + + sc.writeFrame(http2FrameWriteRequest{ + write: http2writeSettings{ + {http2SettingMaxFrameSize, sc.srv.maxReadFrameSize()}, + {http2SettingMaxConcurrentStreams, sc.advMaxStreams}, + {http2SettingMaxHeaderListSize, sc.maxHeaderListSize()}, + {http2SettingHeaderTableSize, sc.srv.maxDecoderHeaderTableSize()}, + {http2SettingInitialWindowSize, uint32(sc.srv.initialStreamRecvWindowSize())}, + }, + }) + sc.unackedSettings++ + + // Each connection starts with initialWindowSize inflow tokens. + // If a higher value is configured, we add more tokens. + if diff := sc.srv.initialConnRecvWindowSize() - http2initialWindowSize; diff > 0 { + sc.sendWindowUpdate(nil, int(diff)) + } + + if err := sc.readPreface(); err != nil { + sc.condlogf(err, "http2: server: error reading preface from client %v: %v", sc.conn.RemoteAddr(), err) + return + } + // Now that we've got the preface, get us out of the + // "StateNew" state. We can't go directly to idle, though. + // Active means we read some data and anticipate a request. We'll + // do another Active when we get a HEADERS frame. + sc.setConnState(StateActive) + sc.setConnState(StateIdle) + + if sc.srv.IdleTimeout != 0 { + sc.idleTimer = time.AfterFunc(sc.srv.IdleTimeout, sc.onIdleTimer) + defer sc.idleTimer.Stop() + } + + go sc.readFrames() // closed by defer sc.conn.Close above + + settingsTimer := time.AfterFunc(http2firstSettingsTimeout, sc.onSettingsTimer) + defer settingsTimer.Stop() + + loopNum := 0 + for { + loopNum++ + select { + case wr := <-sc.wantWriteFrameCh: + if se, ok := wr.write.(http2StreamError); ok { + sc.resetStream(se) + break + } + sc.writeFrame(wr) + case res := <-sc.wroteFrameCh: + sc.wroteFrame(res) + case res := <-sc.readFrameCh: + // Process any written frames before reading new frames from the client since a + // written frame could have triggered a new stream to be started. + if sc.writingFrameAsync { + select { + case wroteRes := <-sc.wroteFrameCh: + sc.wroteFrame(wroteRes) + default: + } + } + if !sc.processFrameFromReader(res) { + return + } + res.readMore() + if settingsTimer != nil { + settingsTimer.Stop() + settingsTimer = nil + } + case m := <-sc.bodyReadCh: + sc.noteBodyRead(m.st, m.n) + case msg := <-sc.serveMsgCh: + switch v := msg.(type) { + case func(int): + v(loopNum) // for testing + case *http2serverMessage: + switch v { + case http2settingsTimerMsg: + sc.logf("timeout waiting for SETTINGS frames from %v", sc.conn.RemoteAddr()) + return + case http2idleTimerMsg: + sc.vlogf("connection is idle") + sc.goAway(http2ErrCodeNo) + case http2shutdownTimerMsg: + sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr()) + return + case http2gracefulShutdownMsg: + sc.startGracefulShutdownInternal() + case http2handlerDoneMsg: + sc.handlerDone() + default: + panic("unknown timer") + } + case *http2startPushRequest: + sc.startPush(v) + case func(*http2serverConn): + v(sc) + default: + panic(fmt.Sprintf("unexpected type %T", v)) + } + } + + // If the peer is causing us to generate a lot of control frames, + // but not reading them from us, assume they are trying to make us + // run out of memory. + if sc.queuedControlFrames > sc.srv.maxQueuedControlFrames() { + sc.vlogf("http2: too many control frames in send queue, closing connection") + return + } + + // Start the shutdown timer after sending a GOAWAY. When sending GOAWAY + // with no error code (graceful shutdown), don't start the timer until + // all open streams have been completed. + sentGoAway := sc.inGoAway && !sc.needToSendGoAway && !sc.writingFrame + gracefulShutdownComplete := sc.goAwayCode == http2ErrCodeNo && sc.curOpenStreams() == 0 + if sentGoAway && sc.shutdownTimer == nil && (sc.goAwayCode != http2ErrCodeNo || gracefulShutdownComplete) { + sc.shutDownIn(http2goAwayTimeout) + } + } +} + +func (sc *http2serverConn) awaitGracefulShutdown(sharedCh <-chan struct{}, privateCh chan struct{}) { + select { + case <-sc.doneServing: + case <-sharedCh: + close(privateCh) + } +} + +type http2serverMessage int + +// Message values sent to serveMsgCh. +var ( + http2settingsTimerMsg = new(http2serverMessage) + http2idleTimerMsg = new(http2serverMessage) + http2shutdownTimerMsg = new(http2serverMessage) + http2gracefulShutdownMsg = new(http2serverMessage) + http2handlerDoneMsg = new(http2serverMessage) +) + +func (sc *http2serverConn) onSettingsTimer() { sc.sendServeMsg(http2settingsTimerMsg) } + +func (sc *http2serverConn) onIdleTimer() { sc.sendServeMsg(http2idleTimerMsg) } + +func (sc *http2serverConn) onShutdownTimer() { sc.sendServeMsg(http2shutdownTimerMsg) } + +func (sc *http2serverConn) sendServeMsg(msg interface{}) { + sc.serveG.checkNotOn() // NOT + select { + case sc.serveMsgCh <- msg: + case <-sc.doneServing: + } +} + +var http2errPrefaceTimeout = errors.New("timeout waiting for client preface") + +// readPreface reads the ClientPreface greeting from the peer or +// returns errPrefaceTimeout on timeout, or an error if the greeting +// is invalid. +func (sc *http2serverConn) readPreface() error { + if sc.sawClientPreface { + return nil + } + errc := make(chan error, 1) + go func() { + // Read the client preface + buf := make([]byte, len(http2ClientPreface)) + if _, err := io.ReadFull(sc.conn, buf); err != nil { + errc <- err + } else if !bytes.Equal(buf, http2clientPreface) { + errc <- fmt.Errorf("bogus greeting %q", buf) + } else { + errc <- nil + } + }() + timer := time.NewTimer(http2prefaceTimeout) // TODO: configurable on *Server? + defer timer.Stop() + select { + case <-timer.C: + return http2errPrefaceTimeout + case err := <-errc: + if err == nil { + if http2VerboseLogs { + sc.vlogf("http2: server: client %v said hello", sc.conn.RemoteAddr()) + } + } + return err + } +} + +var http2errChanPool = sync.Pool{ + New: func() interface{} { return make(chan error, 1) }, +} + +var http2writeDataPool = sync.Pool{ + New: func() interface{} { return new(http2writeData) }, +} + +// writeDataFromHandler writes DATA response frames from a handler on +// the given stream. +func (sc *http2serverConn) writeDataFromHandler(stream *http2stream, data []byte, endStream bool) error { + ch := http2errChanPool.Get().(chan error) + writeArg := http2writeDataPool.Get().(*http2writeData) + *writeArg = http2writeData{stream.id, data, endStream} + err := sc.writeFrameFromHandler(http2FrameWriteRequest{ + write: writeArg, + stream: stream, + done: ch, + }) + if err != nil { + return err + } + var frameWriteDone bool // the frame write is done (successfully or not) + select { + case err = <-ch: + frameWriteDone = true + case <-sc.doneServing: + return http2errClientDisconnected + case <-stream.cw: + // If both ch and stream.cw were ready (as might + // happen on the final Write after an http.Handler + // ends), prefer the write result. Otherwise this + // might just be us successfully closing the stream. + // The writeFrameAsync and serve goroutines guarantee + // that the ch send will happen before the stream.cw + // close. + select { + case err = <-ch: + frameWriteDone = true + default: + return http2errStreamClosed + } + } + http2errChanPool.Put(ch) + if frameWriteDone { + http2writeDataPool.Put(writeArg) + } + return err +} + +// writeFrameFromHandler sends wr to sc.wantWriteFrameCh, but aborts +// if the connection has gone away. +// +// This must not be run from the serve goroutine itself, else it might +// deadlock writing to sc.wantWriteFrameCh (which is only mildly +// buffered and is read by serve itself). If you're on the serve +// goroutine, call writeFrame instead. +func (sc *http2serverConn) writeFrameFromHandler(wr http2FrameWriteRequest) error { + sc.serveG.checkNotOn() // NOT + select { + case sc.wantWriteFrameCh <- wr: + return nil + case <-sc.doneServing: + // Serve loop is gone. + // Client has closed their connection to the server. + return http2errClientDisconnected + } +} + +// writeFrame schedules a frame to write and sends it if there's nothing +// already being written. +// +// There is no pushback here (the serve goroutine never blocks). It's +// the http.Handlers that block, waiting for their previous frames to +// make it onto the wire +// +// If you're not on the serve goroutine, use writeFrameFromHandler instead. +func (sc *http2serverConn) writeFrame(wr http2FrameWriteRequest) { + sc.serveG.check() + + // If true, wr will not be written and wr.done will not be signaled. + var ignoreWrite bool + + // We are not allowed to write frames on closed streams. RFC 7540 Section + // 5.1.1 says: "An endpoint MUST NOT send frames other than PRIORITY on + // a closed stream." Our server never sends PRIORITY, so that exception + // does not apply. + // + // The serverConn might close an open stream while the stream's handler + // is still running. For example, the server might close a stream when it + // receives bad data from the client. If this happens, the handler might + // attempt to write a frame after the stream has been closed (since the + // handler hasn't yet been notified of the close). In this case, we simply + // ignore the frame. The handler will notice that the stream is closed when + // it waits for the frame to be written. + // + // As an exception to this rule, we allow sending RST_STREAM after close. + // This allows us to immediately reject new streams without tracking any + // state for those streams (except for the queued RST_STREAM frame). This + // may result in duplicate RST_STREAMs in some cases, but the client should + // ignore those. + if wr.StreamID() != 0 { + _, isReset := wr.write.(http2StreamError) + if state, _ := sc.state(wr.StreamID()); state == http2stateClosed && !isReset { + ignoreWrite = true + } + } + + // Don't send a 100-continue response if we've already sent headers. + // See golang.org/issue/14030. + switch wr.write.(type) { + case *http2writeResHeaders: + wr.stream.wroteHeaders = true + case http2write100ContinueHeadersFrame: + if wr.stream.wroteHeaders { + // We do not need to notify wr.done because this frame is + // never written with wr.done != nil. + if wr.done != nil { + panic("wr.done != nil for write100ContinueHeadersFrame") + } + ignoreWrite = true + } + } + + if !ignoreWrite { + if wr.isControl() { + sc.queuedControlFrames++ + // For extra safety, detect wraparounds, which should not happen, + // and pull the plug. + if sc.queuedControlFrames < 0 { + sc.conn.Close() + } + } + sc.writeSched.Push(wr) + } + sc.scheduleFrameWrite() +} + +// startFrameWrite starts a goroutine to write wr (in a separate +// goroutine since that might block on the network), and updates the +// serve goroutine's state about the world, updated from info in wr. +func (sc *http2serverConn) startFrameWrite(wr http2FrameWriteRequest) { + sc.serveG.check() + if sc.writingFrame { + panic("internal error: can only be writing one frame at a time") + } + + st := wr.stream + if st != nil { + switch st.state { + case http2stateHalfClosedLocal: + switch wr.write.(type) { + case http2StreamError, http2handlerPanicRST, http2writeWindowUpdate: + // RFC 7540 Section 5.1 allows sending RST_STREAM, PRIORITY, and WINDOW_UPDATE + // in this state. (We never send PRIORITY from the server, so that is not checked.) + default: + panic(fmt.Sprintf("internal error: attempt to send frame on a half-closed-local stream: %v", wr)) + } + case http2stateClosed: + panic(fmt.Sprintf("internal error: attempt to send frame on a closed stream: %v", wr)) + } + } + if wpp, ok := wr.write.(*http2writePushPromise); ok { + var err error + wpp.promisedID, err = wpp.allocatePromisedID() + if err != nil { + sc.writingFrameAsync = false + wr.replyToWriter(err) + return + } + } + + sc.writingFrame = true + sc.needsFrameFlush = true + if wr.write.staysWithinBuffer(sc.bw.Available()) { + sc.writingFrameAsync = false + err := wr.write.writeFrame(sc) + sc.wroteFrame(http2frameWriteResult{wr: wr, err: err}) + } else { + sc.writingFrameAsync = true + go sc.writeFrameAsync(wr) + } +} + +// errHandlerPanicked is the error given to any callers blocked in a read from +// Request.Body when the main goroutine panics. Since most handlers read in the +// main ServeHTTP goroutine, this will show up rarely. +var http2errHandlerPanicked = errors.New("http2: handler panicked") + +// wroteFrame is called on the serve goroutine with the result of +// whatever happened on writeFrameAsync. +func (sc *http2serverConn) wroteFrame(res http2frameWriteResult) { + sc.serveG.check() + if !sc.writingFrame { + panic("internal error: expected to be already writing a frame") + } + sc.writingFrame = false + sc.writingFrameAsync = false + + wr := res.wr + + if http2writeEndsStream(wr.write) { + st := wr.stream + if st == nil { + panic("internal error: expecting non-nil stream") + } + switch st.state { + case http2stateOpen: + // Here we would go to stateHalfClosedLocal in + // theory, but since our handler is done and + // the net/http package provides no mechanism + // for closing a ResponseWriter while still + // reading data (see possible TODO at top of + // this file), we go into closed state here + // anyway, after telling the peer we're + // hanging up on them. We'll transition to + // stateClosed after the RST_STREAM frame is + // written. + st.state = http2stateHalfClosedLocal + // Section 8.1: a server MAY request that the client abort + // transmission of a request without error by sending a + // RST_STREAM with an error code of NO_ERROR after sending + // a complete response. + sc.resetStream(http2streamError(st.id, http2ErrCodeNo)) + case http2stateHalfClosedRemote: + sc.closeStream(st, http2errHandlerComplete) + } + } else { + switch v := wr.write.(type) { + case http2StreamError: + // st may be unknown if the RST_STREAM was generated to reject bad input. + if st, ok := sc.streams[v.StreamID]; ok { + sc.closeStream(st, v) + } + case http2handlerPanicRST: + sc.closeStream(wr.stream, http2errHandlerPanicked) + } + } + + // Reply (if requested) to unblock the ServeHTTP goroutine. + wr.replyToWriter(res.err) + + sc.scheduleFrameWrite() +} + +// scheduleFrameWrite tickles the frame writing scheduler. +// +// If a frame is already being written, nothing happens. This will be called again +// when the frame is done being written. +// +// If a frame isn't being written and we need to send one, the best frame +// to send is selected by writeSched. +// +// If a frame isn't being written and there's nothing else to send, we +// flush the write buffer. +func (sc *http2serverConn) scheduleFrameWrite() { + sc.serveG.check() + if sc.writingFrame || sc.inFrameScheduleLoop { + return + } + sc.inFrameScheduleLoop = true + for !sc.writingFrameAsync { + if sc.needToSendGoAway { + sc.needToSendGoAway = false + sc.startFrameWrite(http2FrameWriteRequest{ + write: &http2writeGoAway{ + maxStreamID: sc.maxClientStreamID, + code: sc.goAwayCode, + }, + }) + continue + } + if sc.needToSendSettingsAck { + sc.needToSendSettingsAck = false + sc.startFrameWrite(http2FrameWriteRequest{write: http2writeSettingsAck{}}) + continue + } + if !sc.inGoAway || sc.goAwayCode == http2ErrCodeNo { + if wr, ok := sc.writeSched.Pop(); ok { + if wr.isControl() { + sc.queuedControlFrames-- + } + sc.startFrameWrite(wr) + continue + } + } + if sc.needsFrameFlush { + sc.startFrameWrite(http2FrameWriteRequest{write: http2flushFrameWriter{}}) + sc.needsFrameFlush = false // after startFrameWrite, since it sets this true + continue + } + break + } + sc.inFrameScheduleLoop = false +} + +// startGracefulShutdown gracefully shuts down a connection. This +// sends GOAWAY with ErrCodeNo to tell the client we're gracefully +// shutting down. The connection isn't closed until all current +// streams are done. +// +// startGracefulShutdown returns immediately; it does not wait until +// the connection has shut down. +func (sc *http2serverConn) startGracefulShutdown() { + sc.serveG.checkNotOn() // NOT + sc.shutdownOnce.Do(func() { sc.sendServeMsg(http2gracefulShutdownMsg) }) +} + +// After sending GOAWAY with an error code (non-graceful shutdown), the +// connection will close after goAwayTimeout. +// +// If we close the connection immediately after sending GOAWAY, there may +// be unsent data in our kernel receive buffer, which will cause the kernel +// to send a TCP RST on close() instead of a FIN. This RST will abort the +// connection immediately, whether or not the client had received the GOAWAY. +// +// Ideally we should delay for at least 1 RTT + epsilon so the client has +// a chance to read the GOAWAY and stop sending messages. Measuring RTT +// is hard, so we approximate with 1 second. See golang.org/issue/18701. +// +// This is a var so it can be shorter in tests, where all requests uses the +// loopback interface making the expected RTT very small. +// +// TODO: configurable? +var http2goAwayTimeout = 1 * time.Second + +func (sc *http2serverConn) startGracefulShutdownInternal() { + sc.goAway(http2ErrCodeNo) +} + +func (sc *http2serverConn) goAway(code http2ErrCode) { + sc.serveG.check() + if sc.inGoAway { + if sc.goAwayCode == http2ErrCodeNo { + sc.goAwayCode = code + } + return + } + sc.inGoAway = true + sc.needToSendGoAway = true + sc.goAwayCode = code + sc.scheduleFrameWrite() +} + +func (sc *http2serverConn) shutDownIn(d time.Duration) { + sc.serveG.check() + sc.shutdownTimer = time.AfterFunc(d, sc.onShutdownTimer) +} + +func (sc *http2serverConn) resetStream(se http2StreamError) { + sc.serveG.check() + sc.writeFrame(http2FrameWriteRequest{write: se}) + if st, ok := sc.streams[se.StreamID]; ok { + st.resetQueued = true + } +} + +// processFrameFromReader processes the serve loop's read from readFrameCh from the +// frame-reading goroutine. +// processFrameFromReader returns whether the connection should be kept open. +func (sc *http2serverConn) processFrameFromReader(res http2readFrameResult) bool { + sc.serveG.check() + err := res.err + if err != nil { + if err == http2ErrFrameTooLarge { + sc.goAway(http2ErrCodeFrameSize) + return true // goAway will close the loop + } + clientGone := err == io.EOF || err == io.ErrUnexpectedEOF || http2isClosedConnError(err) + if clientGone { + // TODO: could we also get into this state if + // the peer does a half close + // (e.g. CloseWrite) because they're done + // sending frames but they're still wanting + // our open replies? Investigate. + // TODO: add CloseWrite to crypto/tls.Conn first + // so we have a way to test this? I suppose + // just for testing we could have a non-TLS mode. + return false + } + } else { + f := res.f + if http2VerboseLogs { + sc.vlogf("http2: server read frame %v", http2summarizeFrame(f)) + } + err = sc.processFrame(f) + if err == nil { + return true + } + } + + switch ev := err.(type) { + case http2StreamError: + sc.resetStream(ev) + return true + case http2goAwayFlowError: + sc.goAway(http2ErrCodeFlowControl) + return true + case http2ConnectionError: + sc.logf("http2: server connection error from %v: %v", sc.conn.RemoteAddr(), ev) + sc.goAway(http2ErrCode(ev)) + return true // goAway will handle shutdown + default: + if res.err != nil { + sc.vlogf("http2: server closing client connection; error reading frame from client %s: %v", sc.conn.RemoteAddr(), err) + } else { + sc.logf("http2: server closing client connection: %v", err) + } + return false + } +} + +func (sc *http2serverConn) processFrame(f http2Frame) error { + sc.serveG.check() + + // First frame received must be SETTINGS. + if !sc.sawFirstSettings { + if _, ok := f.(*http2SettingsFrame); !ok { + return sc.countError("first_settings", http2ConnectionError(http2ErrCodeProtocol)) + } + sc.sawFirstSettings = true + } + + // Discard frames for streams initiated after the identified last + // stream sent in a GOAWAY, or all frames after sending an error. + // We still need to return connection-level flow control for DATA frames. + // RFC 9113 Section 6.8. + if sc.inGoAway && (sc.goAwayCode != http2ErrCodeNo || f.Header().StreamID > sc.maxClientStreamID) { + + if f, ok := f.(*http2DataFrame); ok { + if sc.inflow.available() < int32(f.Length) { + return sc.countError("data_flow", http2streamError(f.Header().StreamID, http2ErrCodeFlowControl)) + } + sc.sendWindowUpdate(nil, int(f.Length)) // conn-level + } + return nil + } + + switch f := f.(type) { + case *http2SettingsFrame: + return sc.processSettings(f) + case *http2MetaHeadersFrame: + return sc.processHeaders(f) + case *http2WindowUpdateFrame: + return sc.processWindowUpdate(f) + case *http2PingFrame: + return sc.processPing(f) + case *http2DataFrame: + return sc.processData(f) + case *http2RSTStreamFrame: + return sc.processResetStream(f) + case *http2PriorityFrame: + return sc.processPriority(f) + case *http2GoAwayFrame: + return sc.processGoAway(f) + case *http2PushPromiseFrame: + // A client cannot push. Thus, servers MUST treat the receipt of a PUSH_PROMISE + // frame as a connection error (Section 5.4.1) of type PROTOCOL_ERROR. + return sc.countError("push_promise", http2ConnectionError(http2ErrCodeProtocol)) + default: + sc.vlogf("http2: server ignoring frame: %v", f.Header()) + return nil + } +} + +func (sc *http2serverConn) processPing(f *http2PingFrame) error { + sc.serveG.check() + if f.IsAck() { + // 6.7 PING: " An endpoint MUST NOT respond to PING frames + // containing this flag." + return nil + } + if f.StreamID != 0 { + // "PING frames are not associated with any individual + // stream. If a PING frame is received with a stream + // identifier field value other than 0x0, the recipient MUST + // respond with a connection error (Section 5.4.1) of type + // PROTOCOL_ERROR." + return sc.countError("ping_on_stream", http2ConnectionError(http2ErrCodeProtocol)) + } + sc.writeFrame(http2FrameWriteRequest{write: http2writePingAck{f}}) + return nil +} + +func (sc *http2serverConn) processWindowUpdate(f *http2WindowUpdateFrame) error { + sc.serveG.check() + switch { + case f.StreamID != 0: // stream-level flow control + state, st := sc.state(f.StreamID) + if state == http2stateIdle { + // Section 5.1: "Receiving any frame other than HEADERS + // or PRIORITY on a stream in this state MUST be + // treated as a connection error (Section 5.4.1) of + // type PROTOCOL_ERROR." + return sc.countError("stream_idle", http2ConnectionError(http2ErrCodeProtocol)) + } + if st == nil { + // "WINDOW_UPDATE can be sent by a peer that has sent a + // frame bearing the END_STREAM flag. This means that a + // receiver could receive a WINDOW_UPDATE frame on a "half + // closed (remote)" or "closed" stream. A receiver MUST + // NOT treat this as an error, see Section 5.1." + return nil + } + if !st.flow.add(int32(f.Increment)) { + return sc.countError("bad_flow", http2streamError(f.StreamID, http2ErrCodeFlowControl)) + } + default: // connection-level flow control + if !sc.flow.add(int32(f.Increment)) { + return http2goAwayFlowError{} + } + } + sc.scheduleFrameWrite() + return nil +} + +func (sc *http2serverConn) processResetStream(f *http2RSTStreamFrame) error { + sc.serveG.check() + + state, st := sc.state(f.StreamID) + if state == http2stateIdle { + // 6.4 "RST_STREAM frames MUST NOT be sent for a + // stream in the "idle" state. If a RST_STREAM frame + // identifying an idle stream is received, the + // recipient MUST treat this as a connection error + // (Section 5.4.1) of type PROTOCOL_ERROR. + return sc.countError("reset_idle_stream", http2ConnectionError(http2ErrCodeProtocol)) + } + if st != nil { + st.cancelCtx() + sc.closeStream(st, http2streamError(f.StreamID, f.ErrCode)) + } + return nil +} + +func (sc *http2serverConn) closeStream(st *http2stream, err error) { + sc.serveG.check() + if st.state == http2stateIdle || st.state == http2stateClosed { + panic(fmt.Sprintf("invariant; can't close stream in state %v", st.state)) + } + st.state = http2stateClosed + if st.readDeadline != nil { + st.readDeadline.Stop() + } + if st.writeDeadline != nil { + st.writeDeadline.Stop() + } + if st.isPushed() { + sc.curPushedStreams-- + } else { + sc.curClientStreams-- + } + delete(sc.streams, st.id) + if len(sc.streams) == 0 { + sc.setConnState(StateIdle) + if sc.srv.IdleTimeout != 0 { + sc.idleTimer.Reset(sc.srv.IdleTimeout) + } + if http2h1ServerKeepAlivesDisabled(sc.hs) { + sc.startGracefulShutdownInternal() + } + } + if p := st.body; p != nil { + // Return any buffered unread bytes worth of conn-level flow control. + // See golang.org/issue/16481 + sc.sendWindowUpdate(nil, p.Len()) + + p.CloseWithError(err) + } + if e, ok := err.(http2StreamError); ok { + if e.Cause != nil { + err = e.Cause + } else { + err = http2errStreamClosed + } + } + st.closeErr = err + st.cw.Close() // signals Handler's CloseNotifier, unblocks writes, etc + sc.writeSched.CloseStream(st.id) +} + +func (sc *http2serverConn) processSettings(f *http2SettingsFrame) error { + sc.serveG.check() + if f.IsAck() { + sc.unackedSettings-- + if sc.unackedSettings < 0 { + // Why is the peer ACKing settings we never sent? + // The spec doesn't mention this case, but + // hang up on them anyway. + return sc.countError("ack_mystery", http2ConnectionError(http2ErrCodeProtocol)) + } + return nil + } + if f.NumSettings() > 100 || f.HasDuplicates() { + // This isn't actually in the spec, but hang up on + // suspiciously large settings frames or those with + // duplicate entries. + return sc.countError("settings_big_or_dups", http2ConnectionError(http2ErrCodeProtocol)) + } + if err := f.ForeachSetting(sc.processSetting); err != nil { + return err + } + // TODO: judging by RFC 7540, Section 6.5.3 each SETTINGS frame should be + // acknowledged individually, even if multiple are received before the ACK. + sc.needToSendSettingsAck = true + sc.scheduleFrameWrite() + return nil +} + +func (sc *http2serverConn) processSetting(s http2Setting) error { + sc.serveG.check() + if err := s.Valid(); err != nil { + return err + } + if http2VerboseLogs { + sc.vlogf("http2: server processing setting %v", s) + } + switch s.ID { + case http2SettingHeaderTableSize: + sc.hpackEncoder.SetMaxDynamicTableSize(s.Val) + case http2SettingEnablePush: + sc.pushEnabled = s.Val != 0 + case http2SettingMaxConcurrentStreams: + sc.clientMaxStreams = s.Val + case http2SettingInitialWindowSize: + return sc.processSettingInitialWindowSize(s.Val) + case http2SettingMaxFrameSize: + sc.maxFrameSize = int32(s.Val) // the maximum valid s.Val is < 2^31 + case http2SettingMaxHeaderListSize: + sc.peerMaxHeaderListSize = s.Val + default: + // Unknown setting: "An endpoint that receives a SETTINGS + // frame with any unknown or unsupported identifier MUST + // ignore that setting." + if http2VerboseLogs { + sc.vlogf("http2: server ignoring unknown setting %v", s) + } + } + return nil +} + +func (sc *http2serverConn) processSettingInitialWindowSize(val uint32) error { + sc.serveG.check() + // Note: val already validated to be within range by + // processSetting's Valid call. + + // "A SETTINGS frame can alter the initial flow control window + // size for all current streams. When the value of + // SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST + // adjust the size of all stream flow control windows that it + // maintains by the difference between the new value and the + // old value." + old := sc.initialStreamSendWindowSize + sc.initialStreamSendWindowSize = int32(val) + growth := int32(val) - old // may be negative + for _, st := range sc.streams { + if !st.flow.add(growth) { + // 6.9.2 Initial Flow Control Window Size + // "An endpoint MUST treat a change to + // SETTINGS_INITIAL_WINDOW_SIZE that causes any flow + // control window to exceed the maximum size as a + // connection error (Section 5.4.1) of type + // FLOW_CONTROL_ERROR." + return sc.countError("setting_win_size", http2ConnectionError(http2ErrCodeFlowControl)) + } + } + return nil +} + +func (sc *http2serverConn) processData(f *http2DataFrame) error { + sc.serveG.check() + id := f.Header().StreamID + + data := f.Data() + state, st := sc.state(id) + if id == 0 || state == http2stateIdle { + // Section 6.1: "DATA frames MUST be associated with a + // stream. If a DATA frame is received whose stream + // identifier field is 0x0, the recipient MUST respond + // with a connection error (Section 5.4.1) of type + // PROTOCOL_ERROR." + // + // Section 5.1: "Receiving any frame other than HEADERS + // or PRIORITY on a stream in this state MUST be + // treated as a connection error (Section 5.4.1) of + // type PROTOCOL_ERROR." + return sc.countError("data_on_idle", http2ConnectionError(http2ErrCodeProtocol)) + } + + // "If a DATA frame is received whose stream is not in "open" + // or "half closed (local)" state, the recipient MUST respond + // with a stream error (Section 5.4.2) of type STREAM_CLOSED." + if st == nil || state != http2stateOpen || st.gotTrailerHeader || st.resetQueued { + // This includes sending a RST_STREAM if the stream is + // in stateHalfClosedLocal (which currently means that + // the http.Handler returned, so it's done reading & + // done writing). Try to stop the client from sending + // more DATA. + + // But still enforce their connection-level flow control, + // and return any flow control bytes since we're not going + // to consume them. + if sc.inflow.available() < int32(f.Length) { + return sc.countError("data_flow", http2streamError(id, http2ErrCodeFlowControl)) + } + // Deduct the flow control from inflow, since we're + // going to immediately add it back in + // sendWindowUpdate, which also schedules sending the + // frames. + sc.inflow.take(int32(f.Length)) + sc.sendWindowUpdate(nil, int(f.Length)) // conn-level + + if st != nil && st.resetQueued { + // Already have a stream error in flight. Don't send another. + return nil + } + return sc.countError("closed", http2streamError(id, http2ErrCodeStreamClosed)) + } + if st.body == nil { + panic("internal error: should have a body in this state") + } + + // Sender sending more than they'd declared? + if st.declBodyBytes != -1 && st.bodyBytes+int64(len(data)) > st.declBodyBytes { + if sc.inflow.available() < int32(f.Length) { + return sc.countError("data_flow", http2streamError(id, http2ErrCodeFlowControl)) + } + sc.inflow.take(int32(f.Length)) + sc.sendWindowUpdate(nil, int(f.Length)) // conn-level + + st.body.CloseWithError(fmt.Errorf("sender tried to send more than declared Content-Length of %d bytes", st.declBodyBytes)) + // RFC 7540, sec 8.1.2.6: A request or response is also malformed if the + // value of a content-length header field does not equal the sum of the + // DATA frame payload lengths that form the body. + return sc.countError("send_too_much", http2streamError(id, http2ErrCodeProtocol)) + } + if f.Length > 0 { + // Check whether the client has flow control quota. + if st.inflow.available() < int32(f.Length) { + return sc.countError("flow_on_data_length", http2streamError(id, http2ErrCodeFlowControl)) + } + st.inflow.take(int32(f.Length)) + + if len(data) > 0 { + wrote, err := st.body.Write(data) + if err != nil { + sc.sendWindowUpdate(nil, int(f.Length)-wrote) + return sc.countError("body_write_err", http2streamError(id, http2ErrCodeStreamClosed)) + } + if wrote != len(data) { + panic("internal error: bad Writer") + } + st.bodyBytes += int64(len(data)) + } + + // Return any padded flow control now, since we won't + // refund it later on body reads. + if pad := int32(f.Length) - int32(len(data)); pad > 0 { + sc.sendWindowUpdate32(nil, pad) + sc.sendWindowUpdate32(st, pad) + } + } + if f.StreamEnded() { + st.endStream() + } + return nil +} + +func (sc *http2serverConn) processGoAway(f *http2GoAwayFrame) error { + sc.serveG.check() + if f.ErrCode != http2ErrCodeNo { + sc.logf("http2: received GOAWAY %+v, starting graceful shutdown", f) + } else { + sc.vlogf("http2: received GOAWAY %+v, starting graceful shutdown", f) + } + sc.startGracefulShutdownInternal() + // http://tools.ietf.org/html/rfc7540#section-6.8 + // We should not create any new streams, which means we should disable push. + sc.pushEnabled = false + return nil +} + +// isPushed reports whether the stream is server-initiated. +func (st *http2stream) isPushed() bool { + return st.id%2 == 0 +} + +// endStream closes a Request.Body's pipe. It is called when a DATA +// frame says a request body is over (or after trailers). +func (st *http2stream) endStream() { + sc := st.sc + sc.serveG.check() + + if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes { + st.body.CloseWithError(fmt.Errorf("request declared a Content-Length of %d but only wrote %d bytes", + st.declBodyBytes, st.bodyBytes)) + } else { + st.body.closeWithErrorAndCode(io.EOF, st.copyTrailersToHandlerRequest) + st.body.CloseWithError(io.EOF) + } + st.state = http2stateHalfClosedRemote +} + +// copyTrailersToHandlerRequest is run in the Handler's goroutine in +// its Request.Body.Read just before it gets io.EOF. +func (st *http2stream) copyTrailersToHandlerRequest() { + for k, vv := range st.trailer { + if _, ok := st.reqTrailer[k]; ok { + // Only copy it over it was pre-declared. + st.reqTrailer[k] = vv + } + } +} + +// onReadTimeout is run on its own goroutine (from time.AfterFunc) +// when the stream's ReadTimeout has fired. +func (st *http2stream) onReadTimeout() { + // Wrap the ErrDeadlineExceeded to avoid callers depending on us + // returning the bare error. + st.body.CloseWithError(fmt.Errorf("%w", os.ErrDeadlineExceeded)) +} + +// onWriteTimeout is run on its own goroutine (from time.AfterFunc) +// when the stream's WriteTimeout has fired. +func (st *http2stream) onWriteTimeout() { + st.sc.writeFrameFromHandler(http2FrameWriteRequest{write: http2StreamError{ + StreamID: st.id, + Code: http2ErrCodeInternal, + Cause: os.ErrDeadlineExceeded, + }}) +} + +func (sc *http2serverConn) processHeaders(f *http2MetaHeadersFrame) error { + sc.serveG.check() + id := f.StreamID + // http://tools.ietf.org/html/rfc7540#section-5.1.1 + // Streams initiated by a client MUST use odd-numbered stream + // identifiers. [...] An endpoint that receives an unexpected + // stream identifier MUST respond with a connection error + // (Section 5.4.1) of type PROTOCOL_ERROR. + if id%2 != 1 { + return sc.countError("headers_even", http2ConnectionError(http2ErrCodeProtocol)) + } + // A HEADERS frame can be used to create a new stream or + // send a trailer for an open one. If we already have a stream + // open, let it process its own HEADERS frame (trailers at this + // point, if it's valid). + if st := sc.streams[f.StreamID]; st != nil { + if st.resetQueued { + // We're sending RST_STREAM to close the stream, so don't bother + // processing this frame. + return nil + } + // RFC 7540, sec 5.1: If an endpoint receives additional frames, other than + // WINDOW_UPDATE, PRIORITY, or RST_STREAM, for a stream that is in + // this state, it MUST respond with a stream error (Section 5.4.2) of + // type STREAM_CLOSED. + if st.state == http2stateHalfClosedRemote { + return sc.countError("headers_half_closed", http2streamError(id, http2ErrCodeStreamClosed)) + } + return st.processTrailerHeaders(f) + } + + // [...] The identifier of a newly established stream MUST be + // numerically greater than all streams that the initiating + // endpoint has opened or reserved. [...] An endpoint that + // receives an unexpected stream identifier MUST respond with + // a connection error (Section 5.4.1) of type PROTOCOL_ERROR. + if id <= sc.maxClientStreamID { + return sc.countError("stream_went_down", http2ConnectionError(http2ErrCodeProtocol)) + } + sc.maxClientStreamID = id + + if sc.idleTimer != nil { + sc.idleTimer.Stop() + } + + // http://tools.ietf.org/html/rfc7540#section-5.1.2 + // [...] Endpoints MUST NOT exceed the limit set by their peer. An + // endpoint that receives a HEADERS frame that causes their + // advertised concurrent stream limit to be exceeded MUST treat + // this as a stream error (Section 5.4.2) of type PROTOCOL_ERROR + // or REFUSED_STREAM. + if sc.curClientStreams+1 > sc.advMaxStreams { + if sc.unackedSettings == 0 { + // They should know better. + return sc.countError("over_max_streams", http2streamError(id, http2ErrCodeProtocol)) + } + // Assume it's a network race, where they just haven't + // received our last SETTINGS update. But actually + // this can't happen yet, because we don't yet provide + // a way for users to adjust server parameters at + // runtime. + return sc.countError("over_max_streams_race", http2streamError(id, http2ErrCodeRefusedStream)) + } + + initialState := http2stateOpen + if f.StreamEnded() { + initialState = http2stateHalfClosedRemote + } + st := sc.newStream(id, 0, initialState) + + if f.HasPriority() { + if err := sc.checkPriority(f.StreamID, f.Priority); err != nil { + return err + } + sc.writeSched.AdjustStream(st.id, f.Priority) + } + + rw, req, err := sc.newWriterAndRequest(st, f) + if err != nil { + return err + } + st.reqTrailer = req.Trailer + if st.reqTrailer != nil { + st.trailer = make(Header) + } + st.body = req.Body.(*http2requestBody).pipe // may be nil + st.declBodyBytes = req.ContentLength + + handler := sc.handler.ServeHTTP + if f.Truncated { + // Their header list was too long. Send a 431 error. + handler = http2handleHeaderListTooLong + } else if err := http2checkValidHTTP2RequestHeaders(req.Header); err != nil { + handler = http2new400Handler(err) + } + + // The net/http package sets the read deadline from the + // http.Server.ReadTimeout during the TLS handshake, but then + // passes the connection off to us with the deadline already + // set. Disarm it here after the request headers are read, + // similar to how the http1 server works. Here it's + // technically more like the http1 Server's ReadHeaderTimeout + // (in Go 1.8), though. That's a more sane option anyway. + if sc.hs.ReadTimeout != 0 { + sc.conn.SetReadDeadline(time.Time{}) + if st.body != nil { + st.readDeadline = time.AfterFunc(sc.hs.ReadTimeout, st.onReadTimeout) + } + } + + return sc.scheduleHandler(id, rw, req, handler) +} + +func (sc *http2serverConn) upgradeRequest(req *Request) { + sc.serveG.check() + id := uint32(1) + sc.maxClientStreamID = id + st := sc.newStream(id, 0, http2stateHalfClosedRemote) + st.reqTrailer = req.Trailer + if st.reqTrailer != nil { + st.trailer = make(Header) + } + rw := sc.newResponseWriter(st, req) + + // Disable any read deadline set by the net/http package + // prior to the upgrade. + if sc.hs.ReadTimeout != 0 { + sc.conn.SetReadDeadline(time.Time{}) + } + + // This is the first request on the connection, + // so start the handler directly rather than going + // through scheduleHandler. + sc.curHandlers++ + go sc.runHandler(rw, req, sc.handler.ServeHTTP) +} + +func (st *http2stream) processTrailerHeaders(f *http2MetaHeadersFrame) error { + sc := st.sc + sc.serveG.check() + if st.gotTrailerHeader { + return sc.countError("dup_trailers", http2ConnectionError(http2ErrCodeProtocol)) + } + st.gotTrailerHeader = true + if !f.StreamEnded() { + return sc.countError("trailers_not_ended", http2streamError(st.id, http2ErrCodeProtocol)) + } + + if len(f.PseudoFields()) > 0 { + return sc.countError("trailers_pseudo", http2streamError(st.id, http2ErrCodeProtocol)) + } + if st.trailer != nil { + for _, hf := range f.RegularFields() { + key := sc.canonicalHeader(hf.Name) + if !httpguts.ValidTrailerHeader(key) { + // TODO: send more details to the peer somehow. But http2 has + // no way to send debug data at a stream level. Discuss with + // HTTP folk. + return sc.countError("trailers_bogus", http2streamError(st.id, http2ErrCodeProtocol)) + } + st.trailer[key] = append(st.trailer[key], hf.Value) + } + } + st.endStream() + return nil +} + +func (sc *http2serverConn) checkPriority(streamID uint32, p http2PriorityParam) error { + if streamID == p.StreamDep { + // Section 5.3.1: "A stream cannot depend on itself. An endpoint MUST treat + // this as a stream error (Section 5.4.2) of type PROTOCOL_ERROR." + // Section 5.3.3 says that a stream can depend on one of its dependencies, + // so it's only self-dependencies that are forbidden. + return sc.countError("priority", http2streamError(streamID, http2ErrCodeProtocol)) + } + return nil +} + +func (sc *http2serverConn) processPriority(f *http2PriorityFrame) error { + if err := sc.checkPriority(f.StreamID, f.http2PriorityParam); err != nil { + return err + } + sc.writeSched.AdjustStream(f.StreamID, f.http2PriorityParam) + return nil +} + +func (sc *http2serverConn) newStream(id, pusherID uint32, state http2streamState) *http2stream { + sc.serveG.check() + if id == 0 { + panic("internal error: cannot create stream with id 0") + } + + ctx, cancelCtx := context.WithCancel(sc.baseCtx) + st := &http2stream{ + sc: sc, + id: id, + state: state, + ctx: ctx, + cancelCtx: cancelCtx, + } + st.cw.Init() + st.flow.conn = &sc.flow // link to conn-level counter + st.flow.add(sc.initialStreamSendWindowSize) + st.inflow.conn = &sc.inflow // link to conn-level counter + st.inflow.add(sc.srv.initialStreamRecvWindowSize()) + if sc.hs.WriteTimeout != 0 { + st.writeDeadline = time.AfterFunc(sc.hs.WriteTimeout, st.onWriteTimeout) + } + + sc.streams[id] = st + sc.writeSched.OpenStream(st.id, http2OpenStreamOptions{PusherID: pusherID}) + if st.isPushed() { + sc.curPushedStreams++ + } else { + sc.curClientStreams++ + } + if sc.curOpenStreams() == 1 { + sc.setConnState(StateActive) + } + + return st +} + +func (sc *http2serverConn) newWriterAndRequest(st *http2stream, f *http2MetaHeadersFrame) (*http2responseWriter, *Request, error) { + sc.serveG.check() + + rp := http2requestParam{ + method: f.PseudoValue("method"), + scheme: f.PseudoValue("scheme"), + authority: f.PseudoValue("authority"), + path: f.PseudoValue("path"), + } + + isConnect := rp.method == "CONNECT" + if isConnect { + if rp.path != "" || rp.scheme != "" || rp.authority == "" { + return nil, nil, sc.countError("bad_connect", http2streamError(f.StreamID, http2ErrCodeProtocol)) + } + } else if rp.method == "" || rp.path == "" || (rp.scheme != "https" && rp.scheme != "http") { + // See 8.1.2.6 Malformed Requests and Responses: + // + // Malformed requests or responses that are detected + // MUST be treated as a stream error (Section 5.4.2) + // of type PROTOCOL_ERROR." + // + // 8.1.2.3 Request Pseudo-Header Fields + // "All HTTP/2 requests MUST include exactly one valid + // value for the :method, :scheme, and :path + // pseudo-header fields" + return nil, nil, sc.countError("bad_path_method", http2streamError(f.StreamID, http2ErrCodeProtocol)) + } + + rp.header = make(Header) + for _, hf := range f.RegularFields() { + rp.header.Add(sc.canonicalHeader(hf.Name), hf.Value) + } + if rp.authority == "" { + rp.authority = rp.header.Get("Host") + } + + rw, req, err := sc.newWriterAndRequestNoBody(st, rp) + if err != nil { + return nil, nil, err + } + bodyOpen := !f.StreamEnded() + if bodyOpen { + if vv, ok := rp.header["Content-Length"]; ok { + if cl, err := strconv.ParseUint(vv[0], 10, 63); err == nil { + req.ContentLength = int64(cl) + } else { + req.ContentLength = 0 + } + } else { + req.ContentLength = -1 + } + req.Body.(*http2requestBody).pipe = &http2pipe{ + b: &http2dataBuffer{expected: req.ContentLength}, + } + } + return rw, req, nil +} + +type http2requestParam struct { + method string + scheme, authority, path string + header Header +} + +func (sc *http2serverConn) newWriterAndRequestNoBody(st *http2stream, rp http2requestParam) (*http2responseWriter, *Request, error) { + sc.serveG.check() + + var tlsState *tls.ConnectionState // nil if not scheme https + if rp.scheme == "https" { + tlsState = sc.tlsState + } + + needsContinue := rp.header.Get("Expect") == "100-continue" + if needsContinue { + rp.header.Del("Expect") + } + // Merge Cookie headers into one "; "-delimited value. + if cookies := rp.header["Cookie"]; len(cookies) > 1 { + rp.header.Set("Cookie", strings.Join(cookies, "; ")) + } + + // Setup Trailers + var trailer Header + for _, v := range rp.header["Trailer"] { + for _, key := range strings.Split(v, ",") { + key = CanonicalHeaderKey(textproto.TrimString(key)) + switch key { + case "Transfer-Encoding", "Trailer", "Content-Length": + // Bogus. (copy of http1 rules) + // Ignore. + default: + if trailer == nil { + trailer = make(Header) + } + trailer[key] = nil + } + } + } + delete(rp.header, "Trailer") + + var url_ *url.URL + var requestURI string + if rp.method == "CONNECT" { + url_ = &url.URL{Host: rp.authority} + requestURI = rp.authority // mimic HTTP/1 server behavior + } else { + var err error + url_, err = url.ParseRequestURI(rp.path) + if err != nil { + return nil, nil, sc.countError("bad_path", http2streamError(st.id, http2ErrCodeProtocol)) + } + requestURI = rp.path + } + + body := &http2requestBody{ + conn: sc, + stream: st, + needsContinue: needsContinue, + } + req := &Request{ + Method: rp.method, + URL: url_, + RemoteAddr: sc.remoteAddrStr, + Header: rp.header, + RequestURI: requestURI, + Proto: "HTTP/2.0", + ProtoMajor: 2, + ProtoMinor: 0, + TLS: tlsState, + Host: rp.authority, + Body: body, + Trailer: trailer, + } + req = req.WithContext(st.ctx) + + rw := sc.newResponseWriter(st, req) + return rw, req, nil +} + +func (sc *http2serverConn) newResponseWriter(st *http2stream, req *Request) *http2responseWriter { + rws := http2responseWriterStatePool.Get().(*http2responseWriterState) + bwSave := rws.bw + *rws = http2responseWriterState{} // zero all the fields + rws.conn = sc + rws.bw = bwSave + rws.bw.Reset(http2chunkWriter{rws}) + rws.stream = st + rws.req = req + return &http2responseWriter{rws: rws} +} + +type http2unstartedHandler struct { + streamID uint32 + rw *http2responseWriter + req *Request + handler func(ResponseWriter, *Request) +} + +// scheduleHandler starts a handler goroutine, +// or schedules one to start as soon as an existing handler finishes. +func (sc *http2serverConn) scheduleHandler(streamID uint32, rw *http2responseWriter, req *Request, handler func(ResponseWriter, *Request)) error { + sc.serveG.check() + maxHandlers := sc.advMaxStreams + if sc.curHandlers < maxHandlers { + sc.curHandlers++ + go sc.runHandler(rw, req, handler) + return nil + } + if len(sc.unstartedHandlers) > int(4*sc.advMaxStreams) { + return sc.countError("too_many_early_resets", http2ConnectionError(http2ErrCodeEnhanceYourCalm)) + } + sc.unstartedHandlers = append(sc.unstartedHandlers, http2unstartedHandler{ + streamID: streamID, + rw: rw, + req: req, + handler: handler, + }) + return nil +} + +func (sc *http2serverConn) handlerDone() { + sc.serveG.check() + sc.curHandlers-- + i := 0 + maxHandlers := sc.advMaxStreams + for ; i < len(sc.unstartedHandlers); i++ { + u := sc.unstartedHandlers[i] + if sc.streams[u.streamID] == nil { + // This stream was reset before its goroutine had a chance to start. + continue + } + if sc.curHandlers >= maxHandlers { + break + } + sc.curHandlers++ + go sc.runHandler(u.rw, u.req, u.handler) + sc.unstartedHandlers[i] = http2unstartedHandler{} // don't retain references + } + sc.unstartedHandlers = sc.unstartedHandlers[i:] + if len(sc.unstartedHandlers) == 0 { + sc.unstartedHandlers = nil + } +} + +// Run on its own goroutine. +func (sc *http2serverConn) runHandler(rw *http2responseWriter, req *Request, handler func(ResponseWriter, *Request)) { + defer sc.sendServeMsg(http2handlerDoneMsg) + didPanic := true + defer func() { + rw.rws.stream.cancelCtx() + if req.MultipartForm != nil { + req.MultipartForm.RemoveAll() + } + if didPanic { + e := recover() + sc.writeFrameFromHandler(http2FrameWriteRequest{ + write: http2handlerPanicRST{rw.rws.stream.id}, + stream: rw.rws.stream, + }) + // Same as net/http: + if e != nil && e != ErrAbortHandler { + const size = 64 << 10 + buf := make([]byte, size) + buf = buf[:runtime.Stack(buf, false)] + sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf) + } + return + } + rw.handlerDone() + }() + handler(rw, req) + didPanic = false +} + +func http2handleHeaderListTooLong(w ResponseWriter, r *Request) { + // 10.5.1 Limits on Header Block Size: + // .. "A server that receives a larger header block than it is + // willing to handle can send an HTTP 431 (Request Header Fields Too + // Large) status code" + const statusRequestHeaderFieldsTooLarge = 431 // only in Go 1.6+ + w.WriteHeader(statusRequestHeaderFieldsTooLarge) + io.WriteString(w, "<h1>HTTP Error 431</h1><p>Request Header Field(s) Too Large</p>") +} + +// called from handler goroutines. +// h may be nil. +func (sc *http2serverConn) writeHeaders(st *http2stream, headerData *http2writeResHeaders) error { + sc.serveG.checkNotOn() // NOT on + var errc chan error + if headerData.h != nil { + // If there's a header map (which we don't own), so we have to block on + // waiting for this frame to be written, so an http.Flush mid-handler + // writes out the correct value of keys, before a handler later potentially + // mutates it. + errc = http2errChanPool.Get().(chan error) + } + if err := sc.writeFrameFromHandler(http2FrameWriteRequest{ + write: headerData, + stream: st, + done: errc, + }); err != nil { + return err + } + if errc != nil { + select { + case err := <-errc: + http2errChanPool.Put(errc) + return err + case <-sc.doneServing: + return http2errClientDisconnected + case <-st.cw: + return http2errStreamClosed + } + } + return nil +} + +// called from handler goroutines. +func (sc *http2serverConn) write100ContinueHeaders(st *http2stream) { + sc.writeFrameFromHandler(http2FrameWriteRequest{ + write: http2write100ContinueHeadersFrame{st.id}, + stream: st, + }) +} + +// A bodyReadMsg tells the server loop that the http.Handler read n +// bytes of the DATA from the client on the given stream. +type http2bodyReadMsg struct { + st *http2stream + n int +} + +// called from handler goroutines. +// Notes that the handler for the given stream ID read n bytes of its body +// and schedules flow control tokens to be sent. +func (sc *http2serverConn) noteBodyReadFromHandler(st *http2stream, n int, err error) { + sc.serveG.checkNotOn() // NOT on + if n > 0 { + select { + case sc.bodyReadCh <- http2bodyReadMsg{st, n}: + case <-sc.doneServing: + } + } +} + +func (sc *http2serverConn) noteBodyRead(st *http2stream, n int) { + sc.serveG.check() + sc.sendWindowUpdate(nil, n) // conn-level + if st.state != http2stateHalfClosedRemote && st.state != http2stateClosed { + // Don't send this WINDOW_UPDATE if the stream is closed + // remotely. + sc.sendWindowUpdate(st, n) + } +} + +// st may be nil for conn-level +func (sc *http2serverConn) sendWindowUpdate(st *http2stream, n int) { + sc.serveG.check() + // "The legal range for the increment to the flow control + // window is 1 to 2^31-1 (2,147,483,647) octets." + // A Go Read call on 64-bit machines could in theory read + // a larger Read than this. Very unlikely, but we handle it here + // rather than elsewhere for now. + const maxUint31 = 1<<31 - 1 + for n > maxUint31 { + sc.sendWindowUpdate32(st, maxUint31) + n -= maxUint31 + } + sc.sendWindowUpdate32(st, int32(n)) +} + +// st may be nil for conn-level +func (sc *http2serverConn) sendWindowUpdate32(st *http2stream, n int32) { + sc.serveG.check() + if n == 0 { + return + } + if n < 0 { + panic("negative update") + } + var streamID uint32 + if st != nil { + streamID = st.id + } + sc.writeFrame(http2FrameWriteRequest{ + write: http2writeWindowUpdate{streamID: streamID, n: uint32(n)}, + stream: st, + }) + var ok bool + if st == nil { + ok = sc.inflow.add(n) + } else { + ok = st.inflow.add(n) + } + if !ok { + panic("internal error; sent too many window updates without decrements?") + } +} + +// requestBody is the Handler's Request.Body type. +// Read and Close may be called concurrently. +type http2requestBody struct { + _ http2incomparable + stream *http2stream + conn *http2serverConn + closeOnce sync.Once // for use by Close only + sawEOF bool // for use by Read only + pipe *http2pipe // non-nil if we have a HTTP entity message body + needsContinue bool // need to send a 100-continue +} + +func (b *http2requestBody) Close() error { + b.closeOnce.Do(func() { + if b.pipe != nil { + b.pipe.BreakWithError(http2errClosedBody) + } + }) + return nil +} + +func (b *http2requestBody) Read(p []byte) (n int, err error) { + if b.needsContinue { + b.needsContinue = false + b.conn.write100ContinueHeaders(b.stream) + } + if b.pipe == nil || b.sawEOF { + return 0, io.EOF + } + n, err = b.pipe.Read(p) + if err == io.EOF { + b.sawEOF = true + } + if b.conn == nil && http2inTests { + return + } + b.conn.noteBodyReadFromHandler(b.stream, n, err) + return +} + +// responseWriter is the http.ResponseWriter implementation. It's +// intentionally small (1 pointer wide) to minimize garbage. The +// responseWriterState pointer inside is zeroed at the end of a +// request (in handlerDone) and calls on the responseWriter thereafter +// simply crash (caller's mistake), but the much larger responseWriterState +// and buffers are reused between multiple requests. +type http2responseWriter struct { + rws *http2responseWriterState +} + +// Optional http.ResponseWriter interfaces implemented. +var ( + _ CloseNotifier = (*http2responseWriter)(nil) + _ Flusher = (*http2responseWriter)(nil) + _ http2stringWriter = (*http2responseWriter)(nil) +) + +type http2responseWriterState struct { + // immutable within a request: + stream *http2stream + req *Request + conn *http2serverConn + + // TODO: adjust buffer writing sizes based on server config, frame size updates from peer, etc + bw *bufio.Writer // writing to a chunkWriter{this *responseWriterState} + + // mutated by http.Handler goroutine: + handlerHeader Header // nil until called + snapHeader Header // snapshot of handlerHeader at WriteHeader time + trailers []string // set in writeChunk + status int // status code passed to WriteHeader + wroteHeader bool // WriteHeader called (explicitly or implicitly). Not necessarily sent to user yet. + sentHeader bool // have we sent the header frame? + handlerDone bool // handler has finished + dirty bool // a Write failed; don't reuse this responseWriterState + + sentContentLen int64 // non-zero if handler set a Content-Length header + wroteBytes int64 + + closeNotifierMu sync.Mutex // guards closeNotifierCh + closeNotifierCh chan bool // nil until first used +} + +type http2chunkWriter struct{ rws *http2responseWriterState } + +func (cw http2chunkWriter) Write(p []byte) (n int, err error) { + n, err = cw.rws.writeChunk(p) + if err == http2errStreamClosed { + // If writing failed because the stream has been closed, + // return the reason it was closed. + err = cw.rws.stream.closeErr + } + return n, err +} + +func (rws *http2responseWriterState) hasTrailers() bool { return len(rws.trailers) > 0 } + +func (rws *http2responseWriterState) hasNonemptyTrailers() bool { + for _, trailer := range rws.trailers { + if _, ok := rws.handlerHeader[trailer]; ok { + return true + } + } + return false +} + +// declareTrailer is called for each Trailer header when the +// response header is written. It notes that a header will need to be +// written in the trailers at the end of the response. +func (rws *http2responseWriterState) declareTrailer(k string) { + k = CanonicalHeaderKey(k) + if !httpguts.ValidTrailerHeader(k) { + // Forbidden by RFC 7230, section 4.1.2. + rws.conn.logf("ignoring invalid trailer %q", k) + return + } + if !http2strSliceContains(rws.trailers, k) { + rws.trailers = append(rws.trailers, k) + } +} + +// writeChunk writes chunks from the bufio.Writer. But because +// bufio.Writer may bypass its chunking, sometimes p may be +// arbitrarily large. +// +// writeChunk is also responsible (on the first chunk) for sending the +// HEADER response. +func (rws *http2responseWriterState) writeChunk(p []byte) (n int, err error) { + if !rws.wroteHeader { + rws.writeHeader(200) + } + + if rws.handlerDone { + rws.promoteUndeclaredTrailers() + } + + isHeadResp := rws.req.Method == "HEAD" + if !rws.sentHeader { + rws.sentHeader = true + var ctype, clen string + if clen = rws.snapHeader.Get("Content-Length"); clen != "" { + rws.snapHeader.Del("Content-Length") + if cl, err := strconv.ParseUint(clen, 10, 63); err == nil { + rws.sentContentLen = int64(cl) + } else { + clen = "" + } + } + if clen == "" && rws.handlerDone && http2bodyAllowedForStatus(rws.status) && (len(p) > 0 || !isHeadResp) { + clen = strconv.Itoa(len(p)) + } + _, hasContentType := rws.snapHeader["Content-Type"] + // If the Content-Encoding is non-blank, we shouldn't + // sniff the body. See Issue golang.org/issue/31753. + ce := rws.snapHeader.Get("Content-Encoding") + hasCE := len(ce) > 0 + if !hasCE && !hasContentType && http2bodyAllowedForStatus(rws.status) && len(p) > 0 { + ctype = DetectContentType(p) + } + var date string + if _, ok := rws.snapHeader["Date"]; !ok { + // TODO(bradfitz): be faster here, like net/http? measure. + date = time.Now().UTC().Format(TimeFormat) + } + + for _, v := range rws.snapHeader["Trailer"] { + http2foreachHeaderElement(v, rws.declareTrailer) + } + + // "Connection" headers aren't allowed in HTTP/2 (RFC 7540, 8.1.2.2), + // but respect "Connection" == "close" to mean sending a GOAWAY and tearing + // down the TCP connection when idle, like we do for HTTP/1. + // TODO: remove more Connection-specific header fields here, in addition + // to "Connection". + if _, ok := rws.snapHeader["Connection"]; ok { + v := rws.snapHeader.Get("Connection") + delete(rws.snapHeader, "Connection") + if v == "close" { + rws.conn.startGracefulShutdown() + } + } + + endStream := (rws.handlerDone && !rws.hasTrailers() && len(p) == 0) || isHeadResp + err = rws.conn.writeHeaders(rws.stream, &http2writeResHeaders{ + streamID: rws.stream.id, + httpResCode: rws.status, + h: rws.snapHeader, + endStream: endStream, + contentType: ctype, + contentLength: clen, + date: date, + }) + if err != nil { + rws.dirty = true + return 0, err + } + if endStream { + return 0, nil + } + } + if isHeadResp { + return len(p), nil + } + if len(p) == 0 && !rws.handlerDone { + return 0, nil + } + + // only send trailers if they have actually been defined by the + // server handler. + hasNonemptyTrailers := rws.hasNonemptyTrailers() + endStream := rws.handlerDone && !hasNonemptyTrailers + if len(p) > 0 || endStream { + // only send a 0 byte DATA frame if we're ending the stream. + if err := rws.conn.writeDataFromHandler(rws.stream, p, endStream); err != nil { + rws.dirty = true + return 0, err + } + } + + if rws.handlerDone && hasNonemptyTrailers { + err = rws.conn.writeHeaders(rws.stream, &http2writeResHeaders{ + streamID: rws.stream.id, + h: rws.handlerHeader, + trailers: rws.trailers, + endStream: true, + }) + if err != nil { + rws.dirty = true + } + return len(p), err + } + return len(p), nil +} + +// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys +// that, if present, signals that the map entry is actually for +// the response trailers, and not the response headers. The prefix +// is stripped after the ServeHTTP call finishes and the values are +// sent in the trailers. +// +// This mechanism is intended only for trailers that are not known +// prior to the headers being written. If the set of trailers is fixed +// or known before the header is written, the normal Go trailers mechanism +// is preferred: +// +// https://golang.org/pkg/net/http/#ResponseWriter +// https://golang.org/pkg/net/http/#example_ResponseWriter_trailers +const http2TrailerPrefix = "Trailer:" + +// promoteUndeclaredTrailers permits http.Handlers to set trailers +// after the header has already been flushed. Because the Go +// ResponseWriter interface has no way to set Trailers (only the +// Header), and because we didn't want to expand the ResponseWriter +// interface, and because nobody used trailers, and because RFC 7230 +// says you SHOULD (but not must) predeclare any trailers in the +// header, the official ResponseWriter rules said trailers in Go must +// be predeclared, and then we reuse the same ResponseWriter.Header() +// map to mean both Headers and Trailers. When it's time to write the +// Trailers, we pick out the fields of Headers that were declared as +// trailers. That worked for a while, until we found the first major +// user of Trailers in the wild: gRPC (using them only over http2), +// and gRPC libraries permit setting trailers mid-stream without +// predeclaring them. So: change of plans. We still permit the old +// way, but we also permit this hack: if a Header() key begins with +// "Trailer:", the suffix of that key is a Trailer. Because ':' is an +// invalid token byte anyway, there is no ambiguity. (And it's already +// filtered out) It's mildly hacky, but not terrible. +// +// This method runs after the Handler is done and promotes any Header +// fields to be trailers. +func (rws *http2responseWriterState) promoteUndeclaredTrailers() { + for k, vv := range rws.handlerHeader { + if !strings.HasPrefix(k, http2TrailerPrefix) { + continue + } + trailerKey := strings.TrimPrefix(k, http2TrailerPrefix) + rws.declareTrailer(trailerKey) + rws.handlerHeader[CanonicalHeaderKey(trailerKey)] = vv + } + + if len(rws.trailers) > 1 { + sorter := http2sorterPool.Get().(*http2sorter) + sorter.SortStrings(rws.trailers) + http2sorterPool.Put(sorter) + } +} + +func (w *http2responseWriter) SetReadDeadline(deadline time.Time) error { + st := w.rws.stream + if !deadline.IsZero() && deadline.Before(time.Now()) { + // If we're setting a deadline in the past, reset the stream immediately + // so writes after SetWriteDeadline returns will fail. + st.onReadTimeout() + return nil + } + w.rws.conn.sendServeMsg(func(sc *http2serverConn) { + if st.readDeadline != nil { + if !st.readDeadline.Stop() { + // Deadline already exceeded, or stream has been closed. + return + } + } + if deadline.IsZero() { + st.readDeadline = nil + } else if st.readDeadline == nil { + st.readDeadline = time.AfterFunc(deadline.Sub(time.Now()), st.onReadTimeout) + } else { + st.readDeadline.Reset(deadline.Sub(time.Now())) + } + }) + return nil +} + +func (w *http2responseWriter) SetWriteDeadline(deadline time.Time) error { + st := w.rws.stream + if !deadline.IsZero() && deadline.Before(time.Now()) { + // If we're setting a deadline in the past, reset the stream immediately + // so writes after SetWriteDeadline returns will fail. + st.onWriteTimeout() + return nil + } + w.rws.conn.sendServeMsg(func(sc *http2serverConn) { + if st.writeDeadline != nil { + if !st.writeDeadline.Stop() { + // Deadline already exceeded, or stream has been closed. + return + } + } + if deadline.IsZero() { + st.writeDeadline = nil + } else if st.writeDeadline == nil { + st.writeDeadline = time.AfterFunc(deadline.Sub(time.Now()), st.onWriteTimeout) + } else { + st.writeDeadline.Reset(deadline.Sub(time.Now())) + } + }) + return nil +} + +func (w *http2responseWriter) Flush() { + w.FlushError() +} + +func (w *http2responseWriter) FlushError() error { + rws := w.rws + if rws == nil { + panic("Header called after Handler finished") + } + var err error + if rws.bw.Buffered() > 0 { + err = rws.bw.Flush() + } else { + // The bufio.Writer won't call chunkWriter.Write + // (writeChunk with zero bytes, so we have to do it + // ourselves to force the HTTP response header and/or + // final DATA frame (with END_STREAM) to be sent. + _, err = http2chunkWriter{rws}.Write(nil) + if err == nil { + select { + case <-rws.stream.cw: + err = rws.stream.closeErr + default: + } + } + } + return err +} + +func (w *http2responseWriter) CloseNotify() <-chan bool { + rws := w.rws + if rws == nil { + panic("CloseNotify called after Handler finished") + } + rws.closeNotifierMu.Lock() + ch := rws.closeNotifierCh + if ch == nil { + ch = make(chan bool, 1) + rws.closeNotifierCh = ch + cw := rws.stream.cw + go func() { + cw.Wait() // wait for close + ch <- true + }() + } + rws.closeNotifierMu.Unlock() + return ch +} + +func (w *http2responseWriter) Header() Header { + rws := w.rws + if rws == nil { + panic("Header called after Handler finished") + } + if rws.handlerHeader == nil { + rws.handlerHeader = make(Header) + } + return rws.handlerHeader +} + +// checkWriteHeaderCode is a copy of net/http's checkWriteHeaderCode. +func http2checkWriteHeaderCode(code int) { + // Issue 22880: require valid WriteHeader status codes. + // For now we only enforce that it's three digits. + // In the future we might block things over 599 (600 and above aren't defined + // at http://httpwg.org/specs/rfc7231.html#status.codes). + // But for now any three digits. + // + // We used to send "HTTP/1.1 000 0" on the wire in responses but there's + // no equivalent bogus thing we can realistically send in HTTP/2, + // so we'll consistently panic instead and help people find their bugs + // early. (We can't return an error from WriteHeader even if we wanted to.) + if code < 100 || code > 999 { + panic(fmt.Sprintf("invalid WriteHeader code %v", code)) + } +} + +func (w *http2responseWriter) WriteHeader(code int) { + rws := w.rws + if rws == nil { + panic("WriteHeader called after Handler finished") + } + rws.writeHeader(code) +} + +func (rws *http2responseWriterState) writeHeader(code int) { + if rws.wroteHeader { + return + } + + http2checkWriteHeaderCode(code) + + // Handle informational headers + if code >= 100 && code <= 199 { + // Per RFC 8297 we must not clear the current header map + h := rws.handlerHeader + + _, cl := h["Content-Length"] + _, te := h["Transfer-Encoding"] + if cl || te { + h = h.Clone() + h.Del("Content-Length") + h.Del("Transfer-Encoding") + } + + if rws.conn.writeHeaders(rws.stream, &http2writeResHeaders{ + streamID: rws.stream.id, + httpResCode: code, + h: h, + endStream: rws.handlerDone && !rws.hasTrailers(), + }) != nil { + rws.dirty = true + } + + return + } + + rws.wroteHeader = true + rws.status = code + if len(rws.handlerHeader) > 0 { + rws.snapHeader = http2cloneHeader(rws.handlerHeader) + } +} + +func http2cloneHeader(h Header) Header { + h2 := make(Header, len(h)) + for k, vv := range h { + vv2 := make([]string, len(vv)) + copy(vv2, vv) + h2[k] = vv2 + } + return h2 +} + +// The Life Of A Write is like this: +// +// * Handler calls w.Write or w.WriteString -> +// * -> rws.bw (*bufio.Writer) -> +// * (Handler might call Flush) +// * -> chunkWriter{rws} +// * -> responseWriterState.writeChunk(p []byte) +// * -> responseWriterState.writeChunk (most of the magic; see comment there) +func (w *http2responseWriter) Write(p []byte) (n int, err error) { + return w.write(len(p), p, "") +} + +func (w *http2responseWriter) WriteString(s string) (n int, err error) { + return w.write(len(s), nil, s) +} + +// either dataB or dataS is non-zero. +func (w *http2responseWriter) write(lenData int, dataB []byte, dataS string) (n int, err error) { + rws := w.rws + if rws == nil { + panic("Write called after Handler finished") + } + if !rws.wroteHeader { + w.WriteHeader(200) + } + if !http2bodyAllowedForStatus(rws.status) { + return 0, ErrBodyNotAllowed + } + rws.wroteBytes += int64(len(dataB)) + int64(len(dataS)) // only one can be set + if rws.sentContentLen != 0 && rws.wroteBytes > rws.sentContentLen { + // TODO: send a RST_STREAM + return 0, errors.New("http2: handler wrote more than declared Content-Length") + } + + if dataB != nil { + return rws.bw.Write(dataB) + } else { + return rws.bw.WriteString(dataS) + } +} + +func (w *http2responseWriter) handlerDone() { + rws := w.rws + dirty := rws.dirty + rws.handlerDone = true + w.Flush() + w.rws = nil + if !dirty { + // Only recycle the pool if all prior Write calls to + // the serverConn goroutine completed successfully. If + // they returned earlier due to resets from the peer + // there might still be write goroutines outstanding + // from the serverConn referencing the rws memory. See + // issue 20704. + http2responseWriterStatePool.Put(rws) + } +} + +// Push errors. +var ( + http2ErrRecursivePush = errors.New("http2: recursive push not allowed") + http2ErrPushLimitReached = errors.New("http2: push would exceed peer's SETTINGS_MAX_CONCURRENT_STREAMS") +) + +var _ Pusher = (*http2responseWriter)(nil) + +func (w *http2responseWriter) Push(target string, opts *PushOptions) error { + st := w.rws.stream + sc := st.sc + sc.serveG.checkNotOn() + + // No recursive pushes: "PUSH_PROMISE frames MUST only be sent on a peer-initiated stream." + // http://tools.ietf.org/html/rfc7540#section-6.6 + if st.isPushed() { + return http2ErrRecursivePush + } + + if opts == nil { + opts = new(PushOptions) + } + + // Default options. + if opts.Method == "" { + opts.Method = "GET" + } + if opts.Header == nil { + opts.Header = Header{} + } + wantScheme := "http" + if w.rws.req.TLS != nil { + wantScheme = "https" + } + + // Validate the request. + u, err := url.Parse(target) + if err != nil { + return err + } + if u.Scheme == "" { + if !strings.HasPrefix(target, "/") { + return fmt.Errorf("target must be an absolute URL or an absolute path: %q", target) + } + u.Scheme = wantScheme + u.Host = w.rws.req.Host + } else { + if u.Scheme != wantScheme { + return fmt.Errorf("cannot push URL with scheme %q from request with scheme %q", u.Scheme, wantScheme) + } + if u.Host == "" { + return errors.New("URL must have a host") + } + } + for k := range opts.Header { + if strings.HasPrefix(k, ":") { + return fmt.Errorf("promised request headers cannot include pseudo header %q", k) + } + // These headers are meaningful only if the request has a body, + // but PUSH_PROMISE requests cannot have a body. + // http://tools.ietf.org/html/rfc7540#section-8.2 + // Also disallow Host, since the promised URL must be absolute. + if http2asciiEqualFold(k, "content-length") || + http2asciiEqualFold(k, "content-encoding") || + http2asciiEqualFold(k, "trailer") || + http2asciiEqualFold(k, "te") || + http2asciiEqualFold(k, "expect") || + http2asciiEqualFold(k, "host") { + return fmt.Errorf("promised request headers cannot include %q", k) + } + } + if err := http2checkValidHTTP2RequestHeaders(opts.Header); err != nil { + return err + } + + // The RFC effectively limits promised requests to GET and HEAD: + // "Promised requests MUST be cacheable [GET, HEAD, or POST], and MUST be safe [GET or HEAD]" + // http://tools.ietf.org/html/rfc7540#section-8.2 + if opts.Method != "GET" && opts.Method != "HEAD" { + return fmt.Errorf("method %q must be GET or HEAD", opts.Method) + } + + msg := &http2startPushRequest{ + parent: st, + method: opts.Method, + url: u, + header: http2cloneHeader(opts.Header), + done: http2errChanPool.Get().(chan error), + } + + select { + case <-sc.doneServing: + return http2errClientDisconnected + case <-st.cw: + return http2errStreamClosed + case sc.serveMsgCh <- msg: + } + + select { + case <-sc.doneServing: + return http2errClientDisconnected + case <-st.cw: + return http2errStreamClosed + case err := <-msg.done: + http2errChanPool.Put(msg.done) + return err + } +} + +type http2startPushRequest struct { + parent *http2stream + method string + url *url.URL + header Header + done chan error +} + +func (sc *http2serverConn) startPush(msg *http2startPushRequest) { + sc.serveG.check() + + // http://tools.ietf.org/html/rfc7540#section-6.6. + // PUSH_PROMISE frames MUST only be sent on a peer-initiated stream that + // is in either the "open" or "half-closed (remote)" state. + if msg.parent.state != http2stateOpen && msg.parent.state != http2stateHalfClosedRemote { + // responseWriter.Push checks that the stream is peer-initiated. + msg.done <- http2errStreamClosed + return + } + + // http://tools.ietf.org/html/rfc7540#section-6.6. + if !sc.pushEnabled { + msg.done <- ErrNotSupported + return + } + + // PUSH_PROMISE frames must be sent in increasing order by stream ID, so + // we allocate an ID for the promised stream lazily, when the PUSH_PROMISE + // is written. Once the ID is allocated, we start the request handler. + allocatePromisedID := func() (uint32, error) { + sc.serveG.check() + + // Check this again, just in case. Technically, we might have received + // an updated SETTINGS by the time we got around to writing this frame. + if !sc.pushEnabled { + return 0, ErrNotSupported + } + // http://tools.ietf.org/html/rfc7540#section-6.5.2. + if sc.curPushedStreams+1 > sc.clientMaxStreams { + return 0, http2ErrPushLimitReached + } + + // http://tools.ietf.org/html/rfc7540#section-5.1.1. + // Streams initiated by the server MUST use even-numbered identifiers. + // A server that is unable to establish a new stream identifier can send a GOAWAY + // frame so that the client is forced to open a new connection for new streams. + if sc.maxPushPromiseID+2 >= 1<<31 { + sc.startGracefulShutdownInternal() + return 0, http2ErrPushLimitReached + } + sc.maxPushPromiseID += 2 + promisedID := sc.maxPushPromiseID + + // http://tools.ietf.org/html/rfc7540#section-8.2. + // Strictly speaking, the new stream should start in "reserved (local)", then + // transition to "half closed (remote)" after sending the initial HEADERS, but + // we start in "half closed (remote)" for simplicity. + // See further comments at the definition of stateHalfClosedRemote. + promised := sc.newStream(promisedID, msg.parent.id, http2stateHalfClosedRemote) + rw, req, err := sc.newWriterAndRequestNoBody(promised, http2requestParam{ + method: msg.method, + scheme: msg.url.Scheme, + authority: msg.url.Host, + path: msg.url.RequestURI(), + header: http2cloneHeader(msg.header), // clone since handler runs concurrently with writing the PUSH_PROMISE + }) + if err != nil { + // Should not happen, since we've already validated msg.url. + panic(fmt.Sprintf("newWriterAndRequestNoBody(%+v): %v", msg.url, err)) + } + + sc.curHandlers++ + go sc.runHandler(rw, req, sc.handler.ServeHTTP) + return promisedID, nil + } + + sc.writeFrame(http2FrameWriteRequest{ + write: &http2writePushPromise{ + streamID: msg.parent.id, + method: msg.method, + url: msg.url, + h: msg.header, + allocatePromisedID: allocatePromisedID, + }, + stream: msg.parent, + done: msg.done, + }) +} + +// foreachHeaderElement splits v according to the "#rule" construction +// in RFC 7230 section 7 and calls fn for each non-empty element. +func http2foreachHeaderElement(v string, fn func(string)) { + v = textproto.TrimString(v) + if v == "" { + return + } + if !strings.Contains(v, ",") { + fn(v) + return + } + for _, f := range strings.Split(v, ",") { + if f = textproto.TrimString(f); f != "" { + fn(f) + } + } +} + +// From http://httpwg.org/specs/rfc7540.html#rfc.section.8.1.2.2 +var http2connHeaders = []string{ + "Connection", + "Keep-Alive", + "Proxy-Connection", + "Transfer-Encoding", + "Upgrade", +} + +// checkValidHTTP2RequestHeaders checks whether h is a valid HTTP/2 request, +// per RFC 7540 Section 8.1.2.2. +// The returned error is reported to users. +func http2checkValidHTTP2RequestHeaders(h Header) error { + for _, k := range http2connHeaders { + if _, ok := h[k]; ok { + return fmt.Errorf("request header %q is not valid in HTTP/2", k) + } + } + te := h["Te"] + if len(te) > 0 && (len(te) > 1 || (te[0] != "trailers" && te[0] != "")) { + return errors.New(`request header "TE" may only be "trailers" in HTTP/2`) + } + return nil +} + +func http2new400Handler(err error) HandlerFunc { + return func(w ResponseWriter, r *Request) { + Error(w, err.Error(), StatusBadRequest) + } +} + +// h1ServerKeepAlivesDisabled reports whether hs has its keep-alives +// disabled. See comments on h1ServerShutdownChan above for why +// the code is written this way. +func http2h1ServerKeepAlivesDisabled(hs *Server) bool { + var x interface{} = hs + type I interface { + doKeepAlives() bool + } + if hs, ok := x.(I); ok { + return !hs.doKeepAlives() + } + return false +} + +func (sc *http2serverConn) countError(name string, err error) error { + if sc == nil || sc.srv == nil { + return err + } + f := sc.srv.CountError + if f == nil { + return err + } + var typ string + var code http2ErrCode + switch e := err.(type) { + case http2ConnectionError: + typ = "conn" + code = http2ErrCode(e) + case http2StreamError: + typ = "stream" + code = http2ErrCode(e.Code) + default: + return err + } + codeStr := http2errCodeName[code] + if codeStr == "" { + codeStr = strconv.Itoa(int(code)) + } + f(fmt.Sprintf("%s_%s_%s", typ, codeStr, name)) + return err +} + +const ( + // transportDefaultConnFlow is how many connection-level flow control + // tokens we give the server at start-up, past the default 64k. + http2transportDefaultConnFlow = 1 << 30 + + // transportDefaultStreamFlow is how many stream-level flow + // control tokens we announce to the peer, and how many bytes + // we buffer per stream. + http2transportDefaultStreamFlow = 4 << 20 + + // transportDefaultStreamMinRefresh is the minimum number of bytes we'll send + // a stream-level WINDOW_UPDATE for at a time. + http2transportDefaultStreamMinRefresh = 4 << 10 + + http2defaultUserAgent = "Go-http-client/2.0" + + // initialMaxConcurrentStreams is a connections maxConcurrentStreams until + // it's received servers initial SETTINGS frame, which corresponds with the + // spec's minimum recommended value. + http2initialMaxConcurrentStreams = 100 + + // defaultMaxConcurrentStreams is a connections default maxConcurrentStreams + // if the server doesn't include one in its initial SETTINGS frame. + http2defaultMaxConcurrentStreams = 1000 +) + +// Transport is an HTTP/2 Transport. +// +// A Transport internally caches connections to servers. It is safe +// for concurrent use by multiple goroutines. +type http2Transport struct { + // DialTLSContext specifies an optional dial function with context for + // creating TLS connections for requests. + // + // If DialTLSContext and DialTLS is nil, tls.Dial is used. + // + // If the returned net.Conn has a ConnectionState method like tls.Conn, + // it will be used to set http.Response.TLS. + DialTLSContext func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) + + // DialTLS specifies an optional dial function for creating + // TLS connections for requests. + // + // If DialTLSContext and DialTLS is nil, tls.Dial is used. + // + // Deprecated: Use DialTLSContext instead, which allows the transport + // to cancel dials as soon as they are no longer needed. + // If both are set, DialTLSContext takes priority. + DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error) + + // TLSClientConfig specifies the TLS configuration to use with + // tls.Client. If nil, the default configuration is used. + TLSClientConfig *tls.Config + + // ConnPool optionally specifies an alternate connection pool to use. + // If nil, the default is used. + ConnPool http2ClientConnPool + + // DisableCompression, if true, prevents the Transport from + // requesting compression with an "Accept-Encoding: gzip" + // request header when the Request contains no existing + // Accept-Encoding value. If the Transport requests gzip on + // its own and gets a gzipped response, it's transparently + // decoded in the Response.Body. However, if the user + // explicitly requested gzip it is not automatically + // uncompressed. + DisableCompression bool + + // AllowHTTP, if true, permits HTTP/2 requests using the insecure, + // plain-text "http" scheme. Note that this does not enable h2c support. + AllowHTTP bool + + // MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to + // send in the initial settings frame. It is how many bytes + // of response headers are allowed. Unlike the http2 spec, zero here + // means to use a default limit (currently 10MB). If you actually + // want to advertise an unlimited value to the peer, Transport + // interprets the highest possible value here (0xffffffff or 1<<32-1) + // to mean no limit. + MaxHeaderListSize uint32 + + // MaxReadFrameSize is the http2 SETTINGS_MAX_FRAME_SIZE to send in the + // initial settings frame. It is the size in bytes of the largest frame + // payload that the sender is willing to receive. If 0, no setting is + // sent, and the value is provided by the peer, which should be 16384 + // according to the spec: + // https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2. + // Values are bounded in the range 16k to 16M. + MaxReadFrameSize uint32 + + // MaxDecoderHeaderTableSize optionally specifies the http2 + // SETTINGS_HEADER_TABLE_SIZE to send in the initial settings frame. It + // informs the remote endpoint of the maximum size of the header compression + // table used to decode header blocks, in octets. If zero, the default value + // of 4096 is used. + MaxDecoderHeaderTableSize uint32 + + // MaxEncoderHeaderTableSize optionally specifies an upper limit for the + // header compression table used for encoding request headers. Received + // SETTINGS_HEADER_TABLE_SIZE settings are capped at this limit. If zero, + // the default value of 4096 is used. + MaxEncoderHeaderTableSize uint32 + + // StrictMaxConcurrentStreams controls whether the server's + // SETTINGS_MAX_CONCURRENT_STREAMS should be respected + // globally. If false, new TCP connections are created to the + // server as needed to keep each under the per-connection + // SETTINGS_MAX_CONCURRENT_STREAMS limit. If true, the + // server's SETTINGS_MAX_CONCURRENT_STREAMS is interpreted as + // a global limit and callers of RoundTrip block when needed, + // waiting for their turn. + StrictMaxConcurrentStreams bool + + // ReadIdleTimeout is the timeout after which a health check using ping + // frame will be carried out if no frame is received on the connection. + // Note that a ping response will is considered a received frame, so if + // there is no other traffic on the connection, the health check will + // be performed every ReadIdleTimeout interval. + // If zero, no health check is performed. + ReadIdleTimeout time.Duration + + // PingTimeout is the timeout after which the connection will be closed + // if a response to Ping is not received. + // Defaults to 15s. + PingTimeout time.Duration + + // WriteByteTimeout is the timeout after which the connection will be + // closed no data can be written to it. The timeout begins when data is + // available to write, and is extended whenever any bytes are written. + WriteByteTimeout time.Duration + + // CountError, if non-nil, is called on HTTP/2 transport errors. + // It's intended to increment a metric for monitoring, such + // as an expvar or Prometheus metric. + // The errType consists of only ASCII word characters. + CountError func(errType string) + + // t1, if non-nil, is the standard library Transport using + // this transport. Its settings are used (but not its + // RoundTrip method, etc). + t1 *Transport + + connPoolOnce sync.Once + connPoolOrDef http2ClientConnPool // non-nil version of ConnPool +} + +func (t *http2Transport) maxHeaderListSize() uint32 { + if t.MaxHeaderListSize == 0 { + return 10 << 20 + } + if t.MaxHeaderListSize == 0xffffffff { + return 0 + } + return t.MaxHeaderListSize +} + +func (t *http2Transport) maxFrameReadSize() uint32 { + if t.MaxReadFrameSize == 0 { + return 0 // use the default provided by the peer + } + if t.MaxReadFrameSize < http2minMaxFrameSize { + return http2minMaxFrameSize + } + if t.MaxReadFrameSize > http2maxFrameSize { + return http2maxFrameSize + } + return t.MaxReadFrameSize +} + +func (t *http2Transport) disableCompression() bool { + return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression) +} + +func (t *http2Transport) pingTimeout() time.Duration { + if t.PingTimeout == 0 { + return 15 * time.Second + } + return t.PingTimeout + +} + +// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2. +// It returns an error if t1 has already been HTTP/2-enabled. +// +// Use ConfigureTransports instead to configure the HTTP/2 Transport. +func http2ConfigureTransport(t1 *Transport) error { + _, err := http2ConfigureTransports(t1) + return err +} + +// ConfigureTransports configures a net/http HTTP/1 Transport to use HTTP/2. +// It returns a new HTTP/2 Transport for further configuration. +// It returns an error if t1 has already been HTTP/2-enabled. +func http2ConfigureTransports(t1 *Transport) (*http2Transport, error) { + return http2configureTransports(t1) +} + +func http2configureTransports(t1 *Transport) (*http2Transport, error) { + connPool := new(http2clientConnPool) + t2 := &http2Transport{ + ConnPool: http2noDialClientConnPool{connPool}, + t1: t1, + } + connPool.t = t2 + if err := http2registerHTTPSProtocol(t1, http2noDialH2RoundTripper{t2}); err != nil { + return nil, err + } + if t1.TLSClientConfig == nil { + t1.TLSClientConfig = new(tls.Config) + } + if !http2strSliceContains(t1.TLSClientConfig.NextProtos, "h2") { + t1.TLSClientConfig.NextProtos = append([]string{"h2"}, t1.TLSClientConfig.NextProtos...) + } + if !http2strSliceContains(t1.TLSClientConfig.NextProtos, "http/1.1") { + t1.TLSClientConfig.NextProtos = append(t1.TLSClientConfig.NextProtos, "http/1.1") + } + upgradeFn := func(authority string, c *tls.Conn) RoundTripper { + addr := http2authorityAddr("https", authority) + if used, err := connPool.addConnIfNeeded(addr, t2, c); err != nil { + go c.Close() + return http2erringRoundTripper{err} + } else if !used { + // Turns out we don't need this c. + // For example, two goroutines made requests to the same host + // at the same time, both kicking off TCP dials. (since protocol + // was unknown) + go c.Close() + } + return t2 + } + if m := t1.TLSNextProto; len(m) == 0 { + t1.TLSNextProto = map[string]func(string, *tls.Conn) RoundTripper{ + "h2": upgradeFn, + } + } else { + m["h2"] = upgradeFn + } + return t2, nil +} + +func (t *http2Transport) connPool() http2ClientConnPool { + t.connPoolOnce.Do(t.initConnPool) + return t.connPoolOrDef +} + +func (t *http2Transport) initConnPool() { + if t.ConnPool != nil { + t.connPoolOrDef = t.ConnPool + } else { + t.connPoolOrDef = &http2clientConnPool{t: t} + } +} + +// ClientConn is the state of a single HTTP/2 client connection to an +// HTTP/2 server. +type http2ClientConn struct { + t *http2Transport + tconn net.Conn // usually *tls.Conn, except specialized impls + tconnClosed bool + tlsState *tls.ConnectionState // nil only for specialized impls + reused uint32 // whether conn is being reused; atomic + singleUse bool // whether being used for a single http.Request + getConnCalled bool // used by clientConnPool + + // readLoop goroutine fields: + readerDone chan struct{} // closed on error + readerErr error // set before readerDone is closed + + idleTimeout time.Duration // or 0 for never + idleTimer *time.Timer + + mu sync.Mutex // guards following + cond *sync.Cond // hold mu; broadcast on flow/closed changes + flow http2flow // our conn-level flow control quota (cs.flow is per stream) + inflow http2flow // peer's conn-level flow control + doNotReuse bool // whether conn is marked to not be reused for any future requests + closing bool + closed bool + seenSettings bool // true if we've seen a settings frame, false otherwise + wantSettingsAck bool // we sent a SETTINGS frame and haven't heard back + goAway *http2GoAwayFrame // if non-nil, the GoAwayFrame we received + goAwayDebug string // goAway frame's debug data, retained as a string + streams map[uint32]*http2clientStream // client-initiated + streamsReserved int // incr by ReserveNewRequest; decr on RoundTrip + nextStreamID uint32 + pendingRequests int // requests blocked and waiting to be sent because len(streams) == maxConcurrentStreams + pings map[[8]byte]chan struct{} // in flight ping data to notification channel + br *bufio.Reader + lastActive time.Time + lastIdle time.Time // time last idle + // Settings from peer: (also guarded by wmu) + maxFrameSize uint32 + maxConcurrentStreams uint32 + peerMaxHeaderListSize uint64 + peerMaxHeaderTableSize uint32 + initialWindowSize uint32 + + // reqHeaderMu is a 1-element semaphore channel controlling access to sending new requests. + // Write to reqHeaderMu to lock it, read from it to unlock. + // Lock reqmu BEFORE mu or wmu. + reqHeaderMu chan struct{} + + // wmu is held while writing. + // Acquire BEFORE mu when holding both, to avoid blocking mu on network writes. + // Only acquire both at the same time when changing peer settings. + wmu sync.Mutex + bw *bufio.Writer + fr *http2Framer + werr error // first write error that has occurred + hbuf bytes.Buffer // HPACK encoder writes into this + henc *hpack.Encoder +} + +// clientStream is the state for a single HTTP/2 stream. One of these +// is created for each Transport.RoundTrip call. +type http2clientStream struct { + cc *http2ClientConn + + // Fields of Request that we may access even after the response body is closed. + ctx context.Context + reqCancel <-chan struct{} + + trace *httptrace.ClientTrace // or nil + ID uint32 + bufPipe http2pipe // buffered pipe with the flow-controlled response payload + requestedGzip bool + isHead bool + + abortOnce sync.Once + abort chan struct{} // closed to signal stream should end immediately + abortErr error // set if abort is closed + + peerClosed chan struct{} // closed when the peer sends an END_STREAM flag + donec chan struct{} // closed after the stream is in the closed state + on100 chan struct{} // buffered; written to if a 100 is received + + respHeaderRecv chan struct{} // closed when headers are received + res *Response // set if respHeaderRecv is closed + + flow http2flow // guarded by cc.mu + inflow http2flow // guarded by cc.mu + bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read + readErr error // sticky read error; owned by transportResponseBody.Read + + reqBody io.ReadCloser + reqBodyContentLength int64 // -1 means unknown + reqBodyClosed chan struct{} // guarded by cc.mu; non-nil on Close, closed when done + + // owned by writeRequest: + sentEndStream bool // sent an END_STREAM flag to the peer + sentHeaders bool + + // owned by clientConnReadLoop: + firstByte bool // got the first response byte + pastHeaders bool // got first MetaHeadersFrame (actual headers) + pastTrailers bool // got optional second MetaHeadersFrame (trailers) + num1xx uint8 // number of 1xx responses seen + readClosed bool // peer sent an END_STREAM flag + readAborted bool // read loop reset the stream + + trailer Header // accumulated trailers + resTrailer *Header // client's Response.Trailer +} + +var http2got1xxFuncForTests func(int, textproto.MIMEHeader) error + +// get1xxTraceFunc returns the value of request's httptrace.ClientTrace.Got1xxResponse func, +// if any. It returns nil if not set or if the Go version is too old. +func (cs *http2clientStream) get1xxTraceFunc() func(int, textproto.MIMEHeader) error { + if fn := http2got1xxFuncForTests; fn != nil { + return fn + } + return http2traceGot1xxResponseFunc(cs.trace) +} + +func (cs *http2clientStream) abortStream(err error) { + cs.cc.mu.Lock() + defer cs.cc.mu.Unlock() + cs.abortStreamLocked(err) +} + +func (cs *http2clientStream) abortStreamLocked(err error) { + cs.abortOnce.Do(func() { + cs.abortErr = err + close(cs.abort) + }) + if cs.reqBody != nil { + cs.closeReqBodyLocked() + } + // TODO(dneil): Clean up tests where cs.cc.cond is nil. + if cs.cc.cond != nil { + // Wake up writeRequestBody if it is waiting on flow control. + cs.cc.cond.Broadcast() + } +} + +func (cs *http2clientStream) abortRequestBodyWrite() { + cc := cs.cc + cc.mu.Lock() + defer cc.mu.Unlock() + if cs.reqBody != nil && cs.reqBodyClosed == nil { + cs.closeReqBodyLocked() + cc.cond.Broadcast() + } +} + +func (cs *http2clientStream) closeReqBodyLocked() { + if cs.reqBodyClosed != nil { + return + } + cs.reqBodyClosed = make(chan struct{}) + reqBodyClosed := cs.reqBodyClosed + go func() { + cs.reqBody.Close() + close(reqBodyClosed) + }() +} + +type http2stickyErrWriter struct { + conn net.Conn + timeout time.Duration + err *error +} + +func (sew http2stickyErrWriter) Write(p []byte) (n int, err error) { + if *sew.err != nil { + return 0, *sew.err + } + for { + if sew.timeout != 0 { + sew.conn.SetWriteDeadline(time.Now().Add(sew.timeout)) + } + nn, err := sew.conn.Write(p[n:]) + n += nn + if n < len(p) && nn > 0 && errors.Is(err, os.ErrDeadlineExceeded) { + // Keep extending the deadline so long as we're making progress. + continue + } + if sew.timeout != 0 { + sew.conn.SetWriteDeadline(time.Time{}) + } + *sew.err = err + return n, err + } +} + +// noCachedConnError is the concrete type of ErrNoCachedConn, which +// needs to be detected by net/http regardless of whether it's its +// bundled version (in h2_bundle.go with a rewritten type name) or +// from a user's x/net/http2. As such, as it has a unique method name +// (IsHTTP2NoCachedConnError) that net/http sniffs for via func +// isNoCachedConnError. +type http2noCachedConnError struct{} + +func (http2noCachedConnError) IsHTTP2NoCachedConnError() {} + +func (http2noCachedConnError) Error() string { return "http2: no cached connection was available" } + +// isNoCachedConnError reports whether err is of type noCachedConnError +// or its equivalent renamed type in net/http2's h2_bundle.go. Both types +// may coexist in the same running program. +func http2isNoCachedConnError(err error) bool { + _, ok := err.(interface{ IsHTTP2NoCachedConnError() }) + return ok +} + +var http2ErrNoCachedConn error = http2noCachedConnError{} + +// RoundTripOpt are options for the Transport.RoundTripOpt method. +type http2RoundTripOpt struct { + // OnlyCachedConn controls whether RoundTripOpt may + // create a new TCP connection. If set true and + // no cached connection is available, RoundTripOpt + // will return ErrNoCachedConn. + OnlyCachedConn bool +} + +func (t *http2Transport) RoundTrip(req *Request) (*Response, error) { + return t.RoundTripOpt(req, http2RoundTripOpt{}) +} + +// authorityAddr returns a given authority (a host/IP, or host:port / ip:port) +// and returns a host:port. The port 443 is added if needed. +func http2authorityAddr(scheme string, authority string) (addr string) { + host, port, err := net.SplitHostPort(authority) + if err != nil { // authority didn't have a port + port = "443" + if scheme == "http" { + port = "80" + } + host = authority + } + if a, err := idna.ToASCII(host); err == nil { + host = a + } + // IPv6 address literal, without a port: + if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") { + return host + ":" + port + } + return net.JoinHostPort(host, port) +} + +var http2retryBackoffHook func(time.Duration) *time.Timer + +func http2backoffNewTimer(d time.Duration) *time.Timer { + if http2retryBackoffHook != nil { + return http2retryBackoffHook(d) + } + return time.NewTimer(d) +} + +// RoundTripOpt is like RoundTrip, but takes options. +func (t *http2Transport) RoundTripOpt(req *Request, opt http2RoundTripOpt) (*Response, error) { + if !(req.URL.Scheme == "https" || (req.URL.Scheme == "http" && t.AllowHTTP)) { + return nil, errors.New("http2: unsupported scheme") + } + + addr := http2authorityAddr(req.URL.Scheme, req.URL.Host) + for retry := 0; ; retry++ { + cc, err := t.connPool().GetClientConn(req, addr) + if err != nil { + t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err) + return nil, err + } + reused := !atomic.CompareAndSwapUint32(&cc.reused, 0, 1) + http2traceGotConn(req, cc, reused) + res, err := cc.RoundTrip(req) + if err != nil && retry <= 6 { + if req, err = http2shouldRetryRequest(req, err); err == nil { + // After the first retry, do exponential backoff with 10% jitter. + if retry == 0 { + t.vlogf("RoundTrip retrying after failure: %v", err) + continue + } + backoff := float64(uint(1) << (uint(retry) - 1)) + backoff += backoff * (0.1 * mathrand.Float64()) + d := time.Second * time.Duration(backoff) + timer := http2backoffNewTimer(d) + select { + case <-timer.C: + t.vlogf("RoundTrip retrying after failure: %v", err) + continue + case <-req.Context().Done(): + timer.Stop() + err = req.Context().Err() + } + } + } + if err != nil { + t.vlogf("RoundTrip failure: %v", err) + return nil, err + } + return res, nil + } +} + +// CloseIdleConnections closes any connections which were previously +// connected from previous requests but are now sitting idle. +// It does not interrupt any connections currently in use. +func (t *http2Transport) CloseIdleConnections() { + if cp, ok := t.connPool().(http2clientConnPoolIdleCloser); ok { + cp.closeIdleConnections() + } +} + +var ( + http2errClientConnClosed = errors.New("http2: client conn is closed") + http2errClientConnUnusable = errors.New("http2: client conn not usable") + http2errClientConnGotGoAway = errors.New("http2: Transport received Server's graceful shutdown GOAWAY") +) + +// shouldRetryRequest is called by RoundTrip when a request fails to get +// response headers. It is always called with a non-nil error. +// It returns either a request to retry (either the same request, or a +// modified clone), or an error if the request can't be replayed. +func http2shouldRetryRequest(req *Request, err error) (*Request, error) { + if !http2canRetryError(err) { + return nil, err + } + // If the Body is nil (or http.NoBody), it's safe to reuse + // this request and its Body. + if req.Body == nil || req.Body == NoBody { + return req, nil + } + + // If the request body can be reset back to its original + // state via the optional req.GetBody, do that. + if req.GetBody != nil { + body, err := req.GetBody() + if err != nil { + return nil, err + } + newReq := *req + newReq.Body = body + return &newReq, nil + } + + // The Request.Body can't reset back to the beginning, but we + // don't seem to have started to read from it yet, so reuse + // the request directly. + if err == http2errClientConnUnusable { + return req, nil + } + + return nil, fmt.Errorf("http2: Transport: cannot retry err [%v] after Request.Body was written; define Request.GetBody to avoid this error", err) +} + +func http2canRetryError(err error) bool { + if err == http2errClientConnUnusable || err == http2errClientConnGotGoAway { + return true + } + if se, ok := err.(http2StreamError); ok { + if se.Code == http2ErrCodeProtocol && se.Cause == http2errFromPeer { + // See golang/go#47635, golang/go#42777 + return true + } + return se.Code == http2ErrCodeRefusedStream + } + return false +} + +func (t *http2Transport) dialClientConn(ctx context.Context, addr string, singleUse bool) (*http2ClientConn, error) { + host, _, err := net.SplitHostPort(addr) + if err != nil { + return nil, err + } + tconn, err := t.dialTLS(ctx, "tcp", addr, t.newTLSConfig(host)) + if err != nil { + return nil, err + } + return t.newClientConn(tconn, singleUse) +} + +func (t *http2Transport) newTLSConfig(host string) *tls.Config { + cfg := new(tls.Config) + if t.TLSClientConfig != nil { + *cfg = *t.TLSClientConfig.Clone() + } + if !http2strSliceContains(cfg.NextProtos, http2NextProtoTLS) { + cfg.NextProtos = append([]string{http2NextProtoTLS}, cfg.NextProtos...) + } + if cfg.ServerName == "" { + cfg.ServerName = host + } + return cfg +} + +func (t *http2Transport) dialTLS(ctx context.Context, network, addr string, tlsCfg *tls.Config) (net.Conn, error) { + if t.DialTLSContext != nil { + return t.DialTLSContext(ctx, network, addr, tlsCfg) + } else if t.DialTLS != nil { + return t.DialTLS(network, addr, tlsCfg) + } + + tlsCn, err := t.dialTLSWithContext(ctx, network, addr, tlsCfg) + if err != nil { + return nil, err + } + state := tlsCn.ConnectionState() + if p := state.NegotiatedProtocol; p != http2NextProtoTLS { + return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, http2NextProtoTLS) + } + if !state.NegotiatedProtocolIsMutual { + return nil, errors.New("http2: could not negotiate protocol mutually") + } + return tlsCn, nil +} + +// disableKeepAlives reports whether connections should be closed as +// soon as possible after handling the first request. +func (t *http2Transport) disableKeepAlives() bool { + return t.t1 != nil && t.t1.DisableKeepAlives +} + +func (t *http2Transport) expectContinueTimeout() time.Duration { + if t.t1 == nil { + return 0 + } + return t.t1.ExpectContinueTimeout +} + +func (t *http2Transport) maxDecoderHeaderTableSize() uint32 { + if v := t.MaxDecoderHeaderTableSize; v > 0 { + return v + } + return http2initialHeaderTableSize +} + +func (t *http2Transport) maxEncoderHeaderTableSize() uint32 { + if v := t.MaxEncoderHeaderTableSize; v > 0 { + return v + } + return http2initialHeaderTableSize +} + +func (t *http2Transport) NewClientConn(c net.Conn) (*http2ClientConn, error) { + return t.newClientConn(c, t.disableKeepAlives()) +} + +func (t *http2Transport) newClientConn(c net.Conn, singleUse bool) (*http2ClientConn, error) { + cc := &http2ClientConn{ + t: t, + tconn: c, + readerDone: make(chan struct{}), + nextStreamID: 1, + maxFrameSize: 16 << 10, // spec default + initialWindowSize: 65535, // spec default + maxConcurrentStreams: http2initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings. + peerMaxHeaderListSize: 0xffffffffffffffff, // "infinite", per spec. Use 2^64-1 instead. + streams: make(map[uint32]*http2clientStream), + singleUse: singleUse, + wantSettingsAck: true, + pings: make(map[[8]byte]chan struct{}), + reqHeaderMu: make(chan struct{}, 1), + } + if d := t.idleConnTimeout(); d != 0 { + cc.idleTimeout = d + cc.idleTimer = time.AfterFunc(d, cc.onIdleTimeout) + } + if http2VerboseLogs { + t.vlogf("http2: Transport creating client conn %p to %v", cc, c.RemoteAddr()) + } + + cc.cond = sync.NewCond(&cc.mu) + cc.flow.add(int32(http2initialWindowSize)) + + // TODO: adjust this writer size to account for frame size + + // MTU + crypto/tls record padding. + cc.bw = bufio.NewWriter(http2stickyErrWriter{ + conn: c, + timeout: t.WriteByteTimeout, + err: &cc.werr, + }) + cc.br = bufio.NewReader(c) + cc.fr = http2NewFramer(cc.bw, cc.br) + if t.maxFrameReadSize() != 0 { + cc.fr.SetMaxReadFrameSize(t.maxFrameReadSize()) + } + if t.CountError != nil { + cc.fr.countError = t.CountError + } + maxHeaderTableSize := t.maxDecoderHeaderTableSize() + cc.fr.ReadMetaHeaders = hpack.NewDecoder(maxHeaderTableSize, nil) + cc.fr.MaxHeaderListSize = t.maxHeaderListSize() + + cc.henc = hpack.NewEncoder(&cc.hbuf) + cc.henc.SetMaxDynamicTableSizeLimit(t.maxEncoderHeaderTableSize()) + cc.peerMaxHeaderTableSize = http2initialHeaderTableSize + + if t.AllowHTTP { + cc.nextStreamID = 3 + } + + if cs, ok := c.(http2connectionStater); ok { + state := cs.ConnectionState() + cc.tlsState = &state + } + + initialSettings := []http2Setting{ + {ID: http2SettingEnablePush, Val: 0}, + {ID: http2SettingInitialWindowSize, Val: http2transportDefaultStreamFlow}, + } + if max := t.maxFrameReadSize(); max != 0 { + initialSettings = append(initialSettings, http2Setting{ID: http2SettingMaxFrameSize, Val: max}) + } + if max := t.maxHeaderListSize(); max != 0 { + initialSettings = append(initialSettings, http2Setting{ID: http2SettingMaxHeaderListSize, Val: max}) + } + if maxHeaderTableSize != http2initialHeaderTableSize { + initialSettings = append(initialSettings, http2Setting{ID: http2SettingHeaderTableSize, Val: maxHeaderTableSize}) + } + + cc.bw.Write(http2clientPreface) + cc.fr.WriteSettings(initialSettings...) + cc.fr.WriteWindowUpdate(0, http2transportDefaultConnFlow) + cc.inflow.add(http2transportDefaultConnFlow + http2initialWindowSize) + cc.bw.Flush() + if cc.werr != nil { + cc.Close() + return nil, cc.werr + } + + go cc.readLoop() + return cc, nil +} + +func (cc *http2ClientConn) healthCheck() { + pingTimeout := cc.t.pingTimeout() + // We don't need to periodically ping in the health check, because the readLoop of ClientConn will + // trigger the healthCheck again if there is no frame received. + ctx, cancel := context.WithTimeout(context.Background(), pingTimeout) + defer cancel() + cc.vlogf("http2: Transport sending health check") + err := cc.Ping(ctx) + if err != nil { + cc.vlogf("http2: Transport health check failure: %v", err) + cc.closeForLostPing() + } else { + cc.vlogf("http2: Transport health check success") + } +} + +// SetDoNotReuse marks cc as not reusable for future HTTP requests. +func (cc *http2ClientConn) SetDoNotReuse() { + cc.mu.Lock() + defer cc.mu.Unlock() + cc.doNotReuse = true +} + +func (cc *http2ClientConn) setGoAway(f *http2GoAwayFrame) { + cc.mu.Lock() + defer cc.mu.Unlock() + + old := cc.goAway + cc.goAway = f + + // Merge the previous and current GoAway error frames. + if cc.goAwayDebug == "" { + cc.goAwayDebug = string(f.DebugData()) + } + if old != nil && old.ErrCode != http2ErrCodeNo { + cc.goAway.ErrCode = old.ErrCode + } + last := f.LastStreamID + for streamID, cs := range cc.streams { + if streamID > last { + cs.abortStreamLocked(http2errClientConnGotGoAway) + } + } +} + +// CanTakeNewRequest reports whether the connection can take a new request, +// meaning it has not been closed or received or sent a GOAWAY. +// +// If the caller is going to immediately make a new request on this +// connection, use ReserveNewRequest instead. +func (cc *http2ClientConn) CanTakeNewRequest() bool { + cc.mu.Lock() + defer cc.mu.Unlock() + return cc.canTakeNewRequestLocked() +} + +// ReserveNewRequest is like CanTakeNewRequest but also reserves a +// concurrent stream in cc. The reservation is decremented on the +// next call to RoundTrip. +func (cc *http2ClientConn) ReserveNewRequest() bool { + cc.mu.Lock() + defer cc.mu.Unlock() + if st := cc.idleStateLocked(); !st.canTakeNewRequest { + return false + } + cc.streamsReserved++ + return true +} + +// ClientConnState describes the state of a ClientConn. +type http2ClientConnState struct { + // Closed is whether the connection is closed. + Closed bool + + // Closing is whether the connection is in the process of + // closing. It may be closing due to shutdown, being a + // single-use connection, being marked as DoNotReuse, or + // having received a GOAWAY frame. + Closing bool + + // StreamsActive is how many streams are active. + StreamsActive int + + // StreamsReserved is how many streams have been reserved via + // ClientConn.ReserveNewRequest. + StreamsReserved int + + // StreamsPending is how many requests have been sent in excess + // of the peer's advertised MaxConcurrentStreams setting and + // are waiting for other streams to complete. + StreamsPending int + + // MaxConcurrentStreams is how many concurrent streams the + // peer advertised as acceptable. Zero means no SETTINGS + // frame has been received yet. + MaxConcurrentStreams uint32 + + // LastIdle, if non-zero, is when the connection last + // transitioned to idle state. + LastIdle time.Time +} + +// State returns a snapshot of cc's state. +func (cc *http2ClientConn) State() http2ClientConnState { + cc.wmu.Lock() + maxConcurrent := cc.maxConcurrentStreams + if !cc.seenSettings { + maxConcurrent = 0 + } + cc.wmu.Unlock() + + cc.mu.Lock() + defer cc.mu.Unlock() + return http2ClientConnState{ + Closed: cc.closed, + Closing: cc.closing || cc.singleUse || cc.doNotReuse || cc.goAway != nil, + StreamsActive: len(cc.streams), + StreamsReserved: cc.streamsReserved, + StreamsPending: cc.pendingRequests, + LastIdle: cc.lastIdle, + MaxConcurrentStreams: maxConcurrent, + } +} + +// clientConnIdleState describes the suitability of a client +// connection to initiate a new RoundTrip request. +type http2clientConnIdleState struct { + canTakeNewRequest bool +} + +func (cc *http2ClientConn) idleState() http2clientConnIdleState { + cc.mu.Lock() + defer cc.mu.Unlock() + return cc.idleStateLocked() +} + +func (cc *http2ClientConn) idleStateLocked() (st http2clientConnIdleState) { + if cc.singleUse && cc.nextStreamID > 1 { + return + } + var maxConcurrentOkay bool + if cc.t.StrictMaxConcurrentStreams { + // We'll tell the caller we can take a new request to + // prevent the caller from dialing a new TCP + // connection, but then we'll block later before + // writing it. + maxConcurrentOkay = true + } else { + maxConcurrentOkay = int64(len(cc.streams)+cc.streamsReserved+1) <= int64(cc.maxConcurrentStreams) + } + + st.canTakeNewRequest = cc.goAway == nil && !cc.closed && !cc.closing && maxConcurrentOkay && + !cc.doNotReuse && + int64(cc.nextStreamID)+2*int64(cc.pendingRequests) < math.MaxInt32 && + !cc.tooIdleLocked() + return +} + +func (cc *http2ClientConn) canTakeNewRequestLocked() bool { + st := cc.idleStateLocked() + return st.canTakeNewRequest +} + +// tooIdleLocked reports whether this connection has been been sitting idle +// for too much wall time. +func (cc *http2ClientConn) tooIdleLocked() bool { + // The Round(0) strips the monontonic clock reading so the + // times are compared based on their wall time. We don't want + // to reuse a connection that's been sitting idle during + // VM/laptop suspend if monotonic time was also frozen. + return cc.idleTimeout != 0 && !cc.lastIdle.IsZero() && time.Since(cc.lastIdle.Round(0)) > cc.idleTimeout +} + +// onIdleTimeout is called from a time.AfterFunc goroutine. It will +// only be called when we're idle, but because we're coming from a new +// goroutine, there could be a new request coming in at the same time, +// so this simply calls the synchronized closeIfIdle to shut down this +// connection. The timer could just call closeIfIdle, but this is more +// clear. +func (cc *http2ClientConn) onIdleTimeout() { + cc.closeIfIdle() +} + +func (cc *http2ClientConn) closeConn() { + t := time.AfterFunc(250*time.Millisecond, cc.forceCloseConn) + defer t.Stop() + cc.tconn.Close() +} + +// A tls.Conn.Close can hang for a long time if the peer is unresponsive. +// Try to shut it down more aggressively. +func (cc *http2ClientConn) forceCloseConn() { + tc, ok := cc.tconn.(*tls.Conn) + if !ok { + return + } + if nc := http2tlsUnderlyingConn(tc); nc != nil { + nc.Close() + } +} + +func (cc *http2ClientConn) closeIfIdle() { + cc.mu.Lock() + if len(cc.streams) > 0 || cc.streamsReserved > 0 { + cc.mu.Unlock() + return + } + cc.closed = true + nextID := cc.nextStreamID + // TODO: do clients send GOAWAY too? maybe? Just Close: + cc.mu.Unlock() + + if http2VerboseLogs { + cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, nextID-2) + } + cc.closeConn() +} + +func (cc *http2ClientConn) isDoNotReuseAndIdle() bool { + cc.mu.Lock() + defer cc.mu.Unlock() + return cc.doNotReuse && len(cc.streams) == 0 +} + +var http2shutdownEnterWaitStateHook = func() {} + +// Shutdown gracefully closes the client connection, waiting for running streams to complete. +func (cc *http2ClientConn) Shutdown(ctx context.Context) error { + if err := cc.sendGoAway(); err != nil { + return err + } + // Wait for all in-flight streams to complete or connection to close + done := make(chan struct{}) + cancelled := false // guarded by cc.mu + go func() { + cc.mu.Lock() + defer cc.mu.Unlock() + for { + if len(cc.streams) == 0 || cc.closed { + cc.closed = true + close(done) + break + } + if cancelled { + break + } + cc.cond.Wait() + } + }() + http2shutdownEnterWaitStateHook() + select { + case <-done: + cc.closeConn() + return nil + case <-ctx.Done(): + cc.mu.Lock() + // Free the goroutine above + cancelled = true + cc.cond.Broadcast() + cc.mu.Unlock() + return ctx.Err() + } +} + +func (cc *http2ClientConn) sendGoAway() error { + cc.mu.Lock() + closing := cc.closing + cc.closing = true + maxStreamID := cc.nextStreamID + cc.mu.Unlock() + if closing { + // GOAWAY sent already + return nil + } + + cc.wmu.Lock() + defer cc.wmu.Unlock() + // Send a graceful shutdown frame to server + if err := cc.fr.WriteGoAway(maxStreamID, http2ErrCodeNo, nil); err != nil { + return err + } + if err := cc.bw.Flush(); err != nil { + return err + } + // Prevent new requests + return nil +} + +// closes the client connection immediately. In-flight requests are interrupted. +// err is sent to streams. +func (cc *http2ClientConn) closeForError(err error) { + cc.mu.Lock() + cc.closed = true + for _, cs := range cc.streams { + cs.abortStreamLocked(err) + } + cc.cond.Broadcast() + cc.mu.Unlock() + cc.closeConn() +} + +// Close closes the client connection immediately. +// +// In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead. +func (cc *http2ClientConn) Close() error { + err := errors.New("http2: client connection force closed via ClientConn.Close") + cc.closeForError(err) + return nil +} + +// closes the client connection immediately. In-flight requests are interrupted. +func (cc *http2ClientConn) closeForLostPing() { + err := errors.New("http2: client connection lost") + if f := cc.t.CountError; f != nil { + f("conn_close_lost_ping") + } + cc.closeForError(err) +} + +// errRequestCanceled is a copy of net/http's errRequestCanceled because it's not +// exported. At least they'll be DeepEqual for h1-vs-h2 comparisons tests. +var http2errRequestCanceled = errors.New("net/http: request canceled") + +func http2commaSeparatedTrailers(req *Request) (string, error) { + keys := make([]string, 0, len(req.Trailer)) + for k := range req.Trailer { + k = http2canonicalHeader(k) + switch k { + case "Transfer-Encoding", "Trailer", "Content-Length": + return "", fmt.Errorf("invalid Trailer key %q", k) + } + keys = append(keys, k) + } + if len(keys) > 0 { + sort.Strings(keys) + return strings.Join(keys, ","), nil + } + return "", nil +} + +func (cc *http2ClientConn) responseHeaderTimeout() time.Duration { + if cc.t.t1 != nil { + return cc.t.t1.ResponseHeaderTimeout + } + // No way to do this (yet?) with just an http2.Transport. Probably + // no need. Request.Cancel this is the new way. We only need to support + // this for compatibility with the old http.Transport fields when + // we're doing transparent http2. + return 0 +} + +// checkConnHeaders checks whether req has any invalid connection-level headers. +// per RFC 7540 section 8.1.2.2: Connection-Specific Header Fields. +// Certain headers are special-cased as okay but not transmitted later. +func http2checkConnHeaders(req *Request) error { + if v := req.Header.Get("Upgrade"); v != "" { + return fmt.Errorf("http2: invalid Upgrade request header: %q", req.Header["Upgrade"]) + } + if vv := req.Header["Transfer-Encoding"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && vv[0] != "chunked") { + return fmt.Errorf("http2: invalid Transfer-Encoding request header: %q", vv) + } + if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !http2asciiEqualFold(vv[0], "close") && !http2asciiEqualFold(vv[0], "keep-alive")) { + return fmt.Errorf("http2: invalid Connection request header: %q", vv) + } + return nil +} + +// actualContentLength returns a sanitized version of +// req.ContentLength, where 0 actually means zero (not unknown) and -1 +// means unknown. +func http2actualContentLength(req *Request) int64 { + if req.Body == nil || req.Body == NoBody { + return 0 + } + if req.ContentLength != 0 { + return req.ContentLength + } + return -1 +} + +func (cc *http2ClientConn) decrStreamReservations() { + cc.mu.Lock() + defer cc.mu.Unlock() + cc.decrStreamReservationsLocked() +} + +func (cc *http2ClientConn) decrStreamReservationsLocked() { + if cc.streamsReserved > 0 { + cc.streamsReserved-- + } +} + +func (cc *http2ClientConn) RoundTrip(req *Request) (*Response, error) { + ctx := req.Context() + cs := &http2clientStream{ + cc: cc, + ctx: ctx, + reqCancel: req.Cancel, + isHead: req.Method == "HEAD", + reqBody: req.Body, + reqBodyContentLength: http2actualContentLength(req), + trace: httptrace.ContextClientTrace(ctx), + peerClosed: make(chan struct{}), + abort: make(chan struct{}), + respHeaderRecv: make(chan struct{}), + donec: make(chan struct{}), + } + go cs.doRequest(req) + + waitDone := func() error { + select { + case <-cs.donec: + return nil + case <-ctx.Done(): + return ctx.Err() + case <-cs.reqCancel: + return http2errRequestCanceled + } + } + + handleResponseHeaders := func() (*Response, error) { + res := cs.res + if res.StatusCode > 299 { + // On error or status code 3xx, 4xx, 5xx, etc abort any + // ongoing write, assuming that the server doesn't care + // about our request body. If the server replied with 1xx or + // 2xx, however, then assume the server DOES potentially + // want our body (e.g. full-duplex streaming: + // golang.org/issue/13444). If it turns out the server + // doesn't, they'll RST_STREAM us soon enough. This is a + // heuristic to avoid adding knobs to Transport. Hopefully + // we can keep it. + cs.abortRequestBodyWrite() + } + res.Request = req + res.TLS = cc.tlsState + if res.Body == http2noBody && http2actualContentLength(req) == 0 { + // If there isn't a request or response body still being + // written, then wait for the stream to be closed before + // RoundTrip returns. + if err := waitDone(); err != nil { + return nil, err + } + } + return res, nil + } + + for { + select { + case <-cs.respHeaderRecv: + return handleResponseHeaders() + case <-cs.abort: + select { + case <-cs.respHeaderRecv: + // If both cs.respHeaderRecv and cs.abort are signaling, + // pick respHeaderRecv. The server probably wrote the + // response and immediately reset the stream. + // golang.org/issue/49645 + return handleResponseHeaders() + default: + waitDone() + return nil, cs.abortErr + } + case <-ctx.Done(): + err := ctx.Err() + cs.abortStream(err) + return nil, err + case <-cs.reqCancel: + cs.abortStream(http2errRequestCanceled) + return nil, http2errRequestCanceled + } + } +} + +// doRequest runs for the duration of the request lifetime. +// +// It sends the request and performs post-request cleanup (closing Request.Body, etc.). +func (cs *http2clientStream) doRequest(req *Request) { + err := cs.writeRequest(req) + cs.cleanupWriteRequest(err) +} + +// writeRequest sends a request. +// +// It returns nil after the request is written, the response read, +// and the request stream is half-closed by the peer. +// +// It returns non-nil if the request ends otherwise. +// If the returned error is StreamError, the error Code may be used in resetting the stream. +func (cs *http2clientStream) writeRequest(req *Request) (err error) { + cc := cs.cc + ctx := cs.ctx + + if err := http2checkConnHeaders(req); err != nil { + return err + } + + // Acquire the new-request lock by writing to reqHeaderMu. + // This lock guards the critical section covering allocating a new stream ID + // (requires mu) and creating the stream (requires wmu). + if cc.reqHeaderMu == nil { + panic("RoundTrip on uninitialized ClientConn") // for tests + } + select { + case cc.reqHeaderMu <- struct{}{}: + case <-cs.reqCancel: + return http2errRequestCanceled + case <-ctx.Done(): + return ctx.Err() + } + + cc.mu.Lock() + if cc.idleTimer != nil { + cc.idleTimer.Stop() + } + cc.decrStreamReservationsLocked() + if err := cc.awaitOpenSlotForStreamLocked(cs); err != nil { + cc.mu.Unlock() + <-cc.reqHeaderMu + return err + } + cc.addStreamLocked(cs) // assigns stream ID + if http2isConnectionCloseRequest(req) { + cc.doNotReuse = true + } + cc.mu.Unlock() + + // TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere? + if !cc.t.disableCompression() && + req.Header.Get("Accept-Encoding") == "" && + req.Header.Get("Range") == "" && + !cs.isHead { + // Request gzip only, not deflate. Deflate is ambiguous and + // not as universally supported anyway. + // See: https://zlib.net/zlib_faq.html#faq39 + // + // Note that we don't request this for HEAD requests, + // due to a bug in nginx: + // http://trac.nginx.org/nginx/ticket/358 + // https://golang.org/issue/5522 + // + // We don't request gzip if the request is for a range, since + // auto-decoding a portion of a gzipped document will just fail + // anyway. See https://golang.org/issue/8923 + cs.requestedGzip = true + } + + continueTimeout := cc.t.expectContinueTimeout() + if continueTimeout != 0 { + if !httpguts.HeaderValuesContainsToken(req.Header["Expect"], "100-continue") { + continueTimeout = 0 + } else { + cs.on100 = make(chan struct{}, 1) + } + } + + // Past this point (where we send request headers), it is possible for + // RoundTrip to return successfully. Since the RoundTrip contract permits + // the caller to "mutate or reuse" the Request after closing the Response's Body, + // we must take care when referencing the Request from here on. + err = cs.encodeAndWriteHeaders(req) + <-cc.reqHeaderMu + if err != nil { + return err + } + + hasBody := cs.reqBodyContentLength != 0 + if !hasBody { + cs.sentEndStream = true + } else { + if continueTimeout != 0 { + http2traceWait100Continue(cs.trace) + timer := time.NewTimer(continueTimeout) + select { + case <-timer.C: + err = nil + case <-cs.on100: + err = nil + case <-cs.abort: + err = cs.abortErr + case <-ctx.Done(): + err = ctx.Err() + case <-cs.reqCancel: + err = http2errRequestCanceled + } + timer.Stop() + if err != nil { + http2traceWroteRequest(cs.trace, err) + return err + } + } + + if err = cs.writeRequestBody(req); err != nil { + if err != http2errStopReqBodyWrite { + http2traceWroteRequest(cs.trace, err) + return err + } + } else { + cs.sentEndStream = true + } + } + + http2traceWroteRequest(cs.trace, err) + + var respHeaderTimer <-chan time.Time + var respHeaderRecv chan struct{} + if d := cc.responseHeaderTimeout(); d != 0 { + timer := time.NewTimer(d) + defer timer.Stop() + respHeaderTimer = timer.C + respHeaderRecv = cs.respHeaderRecv + } + // Wait until the peer half-closes its end of the stream, + // or until the request is aborted (via context, error, or otherwise), + // whichever comes first. + for { + select { + case <-cs.peerClosed: + return nil + case <-respHeaderTimer: + return http2errTimeout + case <-respHeaderRecv: + respHeaderRecv = nil + respHeaderTimer = nil // keep waiting for END_STREAM + case <-cs.abort: + return cs.abortErr + case <-ctx.Done(): + return ctx.Err() + case <-cs.reqCancel: + return http2errRequestCanceled + } + } +} + +func (cs *http2clientStream) encodeAndWriteHeaders(req *Request) error { + cc := cs.cc + ctx := cs.ctx + + cc.wmu.Lock() + defer cc.wmu.Unlock() + + // If the request was canceled while waiting for cc.mu, just quit. + select { + case <-cs.abort: + return cs.abortErr + case <-ctx.Done(): + return ctx.Err() + case <-cs.reqCancel: + return http2errRequestCanceled + default: + } + + // Encode headers. + // + // we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is + // sent by writeRequestBody below, along with any Trailers, + // again in form HEADERS{1}, CONTINUATION{0,}) + trailers, err := http2commaSeparatedTrailers(req) + if err != nil { + return err + } + hasTrailers := trailers != "" + contentLen := http2actualContentLength(req) + hasBody := contentLen != 0 + hdrs, err := cc.encodeHeaders(req, cs.requestedGzip, trailers, contentLen) + if err != nil { + return err + } + + // Write the request. + endStream := !hasBody && !hasTrailers + cs.sentHeaders = true + err = cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs) + http2traceWroteHeaders(cs.trace) + return err +} + +// cleanupWriteRequest performs post-request tasks. +// +// If err (the result of writeRequest) is non-nil and the stream is not closed, +// cleanupWriteRequest will send a reset to the peer. +func (cs *http2clientStream) cleanupWriteRequest(err error) { + cc := cs.cc + + if cs.ID == 0 { + // We were canceled before creating the stream, so return our reservation. + cc.decrStreamReservations() + } + + // TODO: write h12Compare test showing whether + // Request.Body is closed by the Transport, + // and in multiple cases: server replies <=299 and >299 + // while still writing request body + cc.mu.Lock() + mustCloseBody := false + if cs.reqBody != nil && cs.reqBodyClosed == nil { + mustCloseBody = true + cs.reqBodyClosed = make(chan struct{}) + } + bodyClosed := cs.reqBodyClosed + cc.mu.Unlock() + if mustCloseBody { + cs.reqBody.Close() + close(bodyClosed) + } + if bodyClosed != nil { + <-bodyClosed + } + + if err != nil && cs.sentEndStream { + // If the connection is closed immediately after the response is read, + // we may be aborted before finishing up here. If the stream was closed + // cleanly on both sides, there is no error. + select { + case <-cs.peerClosed: + err = nil + default: + } + } + if err != nil { + cs.abortStream(err) // possibly redundant, but harmless + if cs.sentHeaders { + if se, ok := err.(http2StreamError); ok { + if se.Cause != http2errFromPeer { + cc.writeStreamReset(cs.ID, se.Code, err) + } + } else { + cc.writeStreamReset(cs.ID, http2ErrCodeCancel, err) + } + } + cs.bufPipe.CloseWithError(err) // no-op if already closed + } else { + if cs.sentHeaders && !cs.sentEndStream { + cc.writeStreamReset(cs.ID, http2ErrCodeNo, nil) + } + cs.bufPipe.CloseWithError(http2errRequestCanceled) + } + if cs.ID != 0 { + cc.forgetStreamID(cs.ID) + } + + cc.wmu.Lock() + werr := cc.werr + cc.wmu.Unlock() + if werr != nil { + cc.Close() + } + + close(cs.donec) +} + +// awaitOpenSlotForStream waits until len(streams) < maxConcurrentStreams. +// Must hold cc.mu. +func (cc *http2ClientConn) awaitOpenSlotForStreamLocked(cs *http2clientStream) error { + for { + cc.lastActive = time.Now() + if cc.closed || !cc.canTakeNewRequestLocked() { + return http2errClientConnUnusable + } + cc.lastIdle = time.Time{} + if int64(len(cc.streams)) < int64(cc.maxConcurrentStreams) { + return nil + } + cc.pendingRequests++ + cc.cond.Wait() + cc.pendingRequests-- + select { + case <-cs.abort: + return cs.abortErr + default: + } + } +} + +// requires cc.wmu be held +func (cc *http2ClientConn) writeHeaders(streamID uint32, endStream bool, maxFrameSize int, hdrs []byte) error { + first := true // first frame written (HEADERS is first, then CONTINUATION) + for len(hdrs) > 0 && cc.werr == nil { + chunk := hdrs + if len(chunk) > maxFrameSize { + chunk = chunk[:maxFrameSize] + } + hdrs = hdrs[len(chunk):] + endHeaders := len(hdrs) == 0 + if first { + cc.fr.WriteHeaders(http2HeadersFrameParam{ + StreamID: streamID, + BlockFragment: chunk, + EndStream: endStream, + EndHeaders: endHeaders, + }) + first = false + } else { + cc.fr.WriteContinuation(streamID, endHeaders, chunk) + } + } + cc.bw.Flush() + return cc.werr +} + +// internal error values; they don't escape to callers +var ( + // abort request body write; don't send cancel + http2errStopReqBodyWrite = errors.New("http2: aborting request body write") + + // abort request body write, but send stream reset of cancel. + http2errStopReqBodyWriteAndCancel = errors.New("http2: canceling request") + + http2errReqBodyTooLong = errors.New("http2: request body larger than specified content length") +) + +// frameScratchBufferLen returns the length of a buffer to use for +// outgoing request bodies to read/write to/from. +// +// It returns max(1, min(peer's advertised max frame size, +// Request.ContentLength+1, 512KB)). +func (cs *http2clientStream) frameScratchBufferLen(maxFrameSize int) int { + const max = 512 << 10 + n := int64(maxFrameSize) + if n > max { + n = max + } + if cl := cs.reqBodyContentLength; cl != -1 && cl+1 < n { + // Add an extra byte past the declared content-length to + // give the caller's Request.Body io.Reader a chance to + // give us more bytes than they declared, so we can catch it + // early. + n = cl + 1 + } + if n < 1 { + return 1 + } + return int(n) // doesn't truncate; max is 512K +} + +var http2bufPool sync.Pool // of *[]byte + +func (cs *http2clientStream) writeRequestBody(req *Request) (err error) { + cc := cs.cc + body := cs.reqBody + sentEnd := false // whether we sent the final DATA frame w/ END_STREAM + + hasTrailers := req.Trailer != nil + remainLen := cs.reqBodyContentLength + hasContentLen := remainLen != -1 + + cc.mu.Lock() + maxFrameSize := int(cc.maxFrameSize) + cc.mu.Unlock() + + // Scratch buffer for reading into & writing from. + scratchLen := cs.frameScratchBufferLen(maxFrameSize) + var buf []byte + if bp, ok := http2bufPool.Get().(*[]byte); ok && len(*bp) >= scratchLen { + defer http2bufPool.Put(bp) + buf = *bp + } else { + buf = make([]byte, scratchLen) + defer http2bufPool.Put(&buf) + } + + var sawEOF bool + for !sawEOF { + n, err := body.Read(buf) + if hasContentLen { + remainLen -= int64(n) + if remainLen == 0 && err == nil { + // The request body's Content-Length was predeclared and + // we just finished reading it all, but the underlying io.Reader + // returned the final chunk with a nil error (which is one of + // the two valid things a Reader can do at EOF). Because we'd prefer + // to send the END_STREAM bit early, double-check that we're actually + // at EOF. Subsequent reads should return (0, EOF) at this point. + // If either value is different, we return an error in one of two ways below. + var scratch [1]byte + var n1 int + n1, err = body.Read(scratch[:]) + remainLen -= int64(n1) + } + if remainLen < 0 { + err = http2errReqBodyTooLong + return err + } + } + if err != nil { + cc.mu.Lock() + bodyClosed := cs.reqBodyClosed != nil + cc.mu.Unlock() + switch { + case bodyClosed: + return http2errStopReqBodyWrite + case err == io.EOF: + sawEOF = true + err = nil + default: + return err + } + } + + remain := buf[:n] + for len(remain) > 0 && err == nil { + var allowed int32 + allowed, err = cs.awaitFlowControl(len(remain)) + if err != nil { + return err + } + cc.wmu.Lock() + data := remain[:allowed] + remain = remain[allowed:] + sentEnd = sawEOF && len(remain) == 0 && !hasTrailers + err = cc.fr.WriteData(cs.ID, sentEnd, data) + if err == nil { + // TODO(bradfitz): this flush is for latency, not bandwidth. + // Most requests won't need this. Make this opt-in or + // opt-out? Use some heuristic on the body type? Nagel-like + // timers? Based on 'n'? Only last chunk of this for loop, + // unless flow control tokens are low? For now, always. + // If we change this, see comment below. + err = cc.bw.Flush() + } + cc.wmu.Unlock() + } + if err != nil { + return err + } + } + + if sentEnd { + // Already sent END_STREAM (which implies we have no + // trailers) and flushed, because currently all + // WriteData frames above get a flush. So we're done. + return nil + } + + // Since the RoundTrip contract permits the caller to "mutate or reuse" + // a request after the Response's Body is closed, verify that this hasn't + // happened before accessing the trailers. + cc.mu.Lock() + trailer := req.Trailer + err = cs.abortErr + cc.mu.Unlock() + if err != nil { + return err + } + + cc.wmu.Lock() + defer cc.wmu.Unlock() + var trls []byte + if len(trailer) > 0 { + trls, err = cc.encodeTrailers(trailer) + if err != nil { + return err + } + } + + // Two ways to send END_STREAM: either with trailers, or + // with an empty DATA frame. + if len(trls) > 0 { + err = cc.writeHeaders(cs.ID, true, maxFrameSize, trls) + } else { + err = cc.fr.WriteData(cs.ID, true, nil) + } + if ferr := cc.bw.Flush(); ferr != nil && err == nil { + err = ferr + } + return err +} + +// awaitFlowControl waits for [1, min(maxBytes, cc.cs.maxFrameSize)] flow +// control tokens from the server. +// It returns either the non-zero number of tokens taken or an error +// if the stream is dead. +func (cs *http2clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) { + cc := cs.cc + ctx := cs.ctx + cc.mu.Lock() + defer cc.mu.Unlock() + for { + if cc.closed { + return 0, http2errClientConnClosed + } + if cs.reqBodyClosed != nil { + return 0, http2errStopReqBodyWrite + } + select { + case <-cs.abort: + return 0, cs.abortErr + case <-ctx.Done(): + return 0, ctx.Err() + case <-cs.reqCancel: + return 0, http2errRequestCanceled + default: + } + if a := cs.flow.available(); a > 0 { + take := a + if int(take) > maxBytes { + + take = int32(maxBytes) // can't truncate int; take is int32 + } + if take > int32(cc.maxFrameSize) { + take = int32(cc.maxFrameSize) + } + cs.flow.take(take) + return take, nil + } + cc.cond.Wait() + } +} + +var http2errNilRequestURL = errors.New("http2: Request.URI is nil") + +// requires cc.wmu be held. +func (cc *http2ClientConn) encodeHeaders(req *Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) { + cc.hbuf.Reset() + if req.URL == nil { + return nil, http2errNilRequestURL + } + + host := req.Host + if host == "" { + host = req.URL.Host + } + host, err := httpguts.PunycodeHostPort(host) + if err != nil { + return nil, err + } + + var path string + if req.Method != "CONNECT" { + path = req.URL.RequestURI() + if !http2validPseudoPath(path) { + orig := path + path = strings.TrimPrefix(path, req.URL.Scheme+"://"+host) + if !http2validPseudoPath(path) { + if req.URL.Opaque != "" { + return nil, fmt.Errorf("invalid request :path %q from URL.Opaque = %q", orig, req.URL.Opaque) + } else { + return nil, fmt.Errorf("invalid request :path %q", orig) + } + } + } + } + + // Check for any invalid headers and return an error before we + // potentially pollute our hpack state. (We want to be able to + // continue to reuse the hpack encoder for future requests) + for k, vv := range req.Header { + if !httpguts.ValidHeaderFieldName(k) { + return nil, fmt.Errorf("invalid HTTP header name %q", k) + } + for _, v := range vv { + if !httpguts.ValidHeaderFieldValue(v) { + // Don't include the value in the error, because it may be sensitive. + return nil, fmt.Errorf("invalid HTTP header value for header %q", k) + } + } + } + + enumerateHeaders := func(f func(name, value string)) { + // 8.1.2.3 Request Pseudo-Header Fields + // The :path pseudo-header field includes the path and query parts of the + // target URI (the path-absolute production and optionally a '?' character + // followed by the query production (see Sections 3.3 and 3.4 of + // [RFC3986]). + f(":authority", host) + m := req.Method + if m == "" { + m = MethodGet + } + f(":method", m) + if req.Method != "CONNECT" { + f(":path", path) + f(":scheme", req.URL.Scheme) + } + if trailers != "" { + f("trailer", trailers) + } + + var didUA bool + for k, vv := range req.Header { + if http2asciiEqualFold(k, "host") || http2asciiEqualFold(k, "content-length") { + // Host is :authority, already sent. + // Content-Length is automatic, set below. + continue + } else if http2asciiEqualFold(k, "connection") || + http2asciiEqualFold(k, "proxy-connection") || + http2asciiEqualFold(k, "transfer-encoding") || + http2asciiEqualFold(k, "upgrade") || + http2asciiEqualFold(k, "keep-alive") { + // Per 8.1.2.2 Connection-Specific Header + // Fields, don't send connection-specific + // fields. We have already checked if any + // are error-worthy so just ignore the rest. + continue + } else if http2asciiEqualFold(k, "user-agent") { + // Match Go's http1 behavior: at most one + // User-Agent. If set to nil or empty string, + // then omit it. Otherwise if not mentioned, + // include the default (below). + didUA = true + if len(vv) < 1 { + continue + } + vv = vv[:1] + if vv[0] == "" { + continue + } + } else if http2asciiEqualFold(k, "cookie") { + // Per 8.1.2.5 To allow for better compression efficiency, the + // Cookie header field MAY be split into separate header fields, + // each with one or more cookie-pairs. + for _, v := range vv { + for { + p := strings.IndexByte(v, ';') + if p < 0 { + break + } + f("cookie", v[:p]) + p++ + // strip space after semicolon if any. + for p+1 <= len(v) && v[p] == ' ' { + p++ + } + v = v[p:] + } + if len(v) > 0 { + f("cookie", v) + } + } + continue + } + + for _, v := range vv { + f(k, v) + } + } + if http2shouldSendReqContentLength(req.Method, contentLength) { + f("content-length", strconv.FormatInt(contentLength, 10)) + } + if addGzipHeader { + f("accept-encoding", "gzip") + } + if !didUA { + f("user-agent", http2defaultUserAgent) + } + } + + // Do a first pass over the headers counting bytes to ensure + // we don't exceed cc.peerMaxHeaderListSize. This is done as a + // separate pass before encoding the headers to prevent + // modifying the hpack state. + hlSize := uint64(0) + enumerateHeaders(func(name, value string) { + hf := hpack.HeaderField{Name: name, Value: value} + hlSize += uint64(hf.Size()) + }) + + if hlSize > cc.peerMaxHeaderListSize { + return nil, http2errRequestHeaderListSize + } + + trace := httptrace.ContextClientTrace(req.Context()) + traceHeaders := http2traceHasWroteHeaderField(trace) + + // Header list size is ok. Write the headers. + enumerateHeaders(func(name, value string) { + name, ascii := http2lowerHeader(name) + if !ascii { + // Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header + // field names have to be ASCII characters (just as in HTTP/1.x). + return + } + cc.writeHeader(name, value) + if traceHeaders { + http2traceWroteHeaderField(trace, name, value) + } + }) + + return cc.hbuf.Bytes(), nil +} + +// shouldSendReqContentLength reports whether the http2.Transport should send +// a "content-length" request header. This logic is basically a copy of the net/http +// transferWriter.shouldSendContentLength. +// The contentLength is the corrected contentLength (so 0 means actually 0, not unknown). +// -1 means unknown. +func http2shouldSendReqContentLength(method string, contentLength int64) bool { + if contentLength > 0 { + return true + } + if contentLength < 0 { + return false + } + // For zero bodies, whether we send a content-length depends on the method. + // It also kinda doesn't matter for http2 either way, with END_STREAM. + switch method { + case "POST", "PUT", "PATCH": + return true + default: + return false + } +} + +// requires cc.wmu be held. +func (cc *http2ClientConn) encodeTrailers(trailer Header) ([]byte, error) { + cc.hbuf.Reset() + + hlSize := uint64(0) + for k, vv := range trailer { + for _, v := range vv { + hf := hpack.HeaderField{Name: k, Value: v} + hlSize += uint64(hf.Size()) + } + } + if hlSize > cc.peerMaxHeaderListSize { + return nil, http2errRequestHeaderListSize + } + + for k, vv := range trailer { + lowKey, ascii := http2lowerHeader(k) + if !ascii { + // Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header + // field names have to be ASCII characters (just as in HTTP/1.x). + continue + } + // Transfer-Encoding, etc.. have already been filtered at the + // start of RoundTrip + for _, v := range vv { + cc.writeHeader(lowKey, v) + } + } + return cc.hbuf.Bytes(), nil +} + +func (cc *http2ClientConn) writeHeader(name, value string) { + if http2VerboseLogs { + log.Printf("http2: Transport encoding header %q = %q", name, value) + } + cc.henc.WriteField(hpack.HeaderField{Name: name, Value: value}) +} + +type http2resAndError struct { + _ http2incomparable + res *Response + err error +} + +// requires cc.mu be held. +func (cc *http2ClientConn) addStreamLocked(cs *http2clientStream) { + cs.flow.add(int32(cc.initialWindowSize)) + cs.flow.setConnFlow(&cc.flow) + cs.inflow.add(http2transportDefaultStreamFlow) + cs.inflow.setConnFlow(&cc.inflow) + cs.ID = cc.nextStreamID + cc.nextStreamID += 2 + cc.streams[cs.ID] = cs + if cs.ID == 0 { + panic("assigned stream ID 0") + } +} + +func (cc *http2ClientConn) forgetStreamID(id uint32) { + cc.mu.Lock() + slen := len(cc.streams) + delete(cc.streams, id) + if len(cc.streams) != slen-1 { + panic("forgetting unknown stream id") + } + cc.lastActive = time.Now() + if len(cc.streams) == 0 && cc.idleTimer != nil { + cc.idleTimer.Reset(cc.idleTimeout) + cc.lastIdle = time.Now() + } + // Wake up writeRequestBody via clientStream.awaitFlowControl and + // wake up RoundTrip if there is a pending request. + cc.cond.Broadcast() + + closeOnIdle := cc.singleUse || cc.doNotReuse || cc.t.disableKeepAlives() || cc.goAway != nil + if closeOnIdle && cc.streamsReserved == 0 && len(cc.streams) == 0 { + if http2VerboseLogs { + cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, cc.nextStreamID-2) + } + cc.closed = true + defer cc.closeConn() + } + + cc.mu.Unlock() +} + +// clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop. +type http2clientConnReadLoop struct { + _ http2incomparable + cc *http2ClientConn +} + +// readLoop runs in its own goroutine and reads and dispatches frames. +func (cc *http2ClientConn) readLoop() { + rl := &http2clientConnReadLoop{cc: cc} + defer rl.cleanup() + cc.readerErr = rl.run() + if ce, ok := cc.readerErr.(http2ConnectionError); ok { + cc.wmu.Lock() + cc.fr.WriteGoAway(0, http2ErrCode(ce), nil) + cc.wmu.Unlock() + } +} + +// GoAwayError is returned by the Transport when the server closes the +// TCP connection after sending a GOAWAY frame. +type http2GoAwayError struct { + LastStreamID uint32 + ErrCode http2ErrCode + DebugData string +} + +func (e http2GoAwayError) Error() string { + return fmt.Sprintf("http2: server sent GOAWAY and closed the connection; LastStreamID=%v, ErrCode=%v, debug=%q", + e.LastStreamID, e.ErrCode, e.DebugData) +} + +func http2isEOFOrNetReadError(err error) bool { + if err == io.EOF { + return true + } + ne, ok := err.(*net.OpError) + return ok && ne.Op == "read" +} + +func (rl *http2clientConnReadLoop) cleanup() { + cc := rl.cc + cc.t.connPool().MarkDead(cc) + defer cc.closeConn() + defer close(cc.readerDone) + + if cc.idleTimer != nil { + cc.idleTimer.Stop() + } + + // Close any response bodies if the server closes prematurely. + // TODO: also do this if we've written the headers but not + // gotten a response yet. + err := cc.readerErr + cc.mu.Lock() + if cc.goAway != nil && http2isEOFOrNetReadError(err) { + err = http2GoAwayError{ + LastStreamID: cc.goAway.LastStreamID, + ErrCode: cc.goAway.ErrCode, + DebugData: cc.goAwayDebug, + } + } else if err == io.EOF { + err = io.ErrUnexpectedEOF + } + cc.closed = true + + for _, cs := range cc.streams { + select { + case <-cs.peerClosed: + // The server closed the stream before closing the conn, + // so no need to interrupt it. + default: + cs.abortStreamLocked(err) + } + } + cc.cond.Broadcast() + cc.mu.Unlock() +} + +// countReadFrameError calls Transport.CountError with a string +// representing err. +func (cc *http2ClientConn) countReadFrameError(err error) { + f := cc.t.CountError + if f == nil || err == nil { + return + } + if ce, ok := err.(http2ConnectionError); ok { + errCode := http2ErrCode(ce) + f(fmt.Sprintf("read_frame_conn_error_%s", errCode.stringToken())) + return + } + if errors.Is(err, io.EOF) { + f("read_frame_eof") + return + } + if errors.Is(err, io.ErrUnexpectedEOF) { + f("read_frame_unexpected_eof") + return + } + if errors.Is(err, http2ErrFrameTooLarge) { + f("read_frame_too_large") + return + } + f("read_frame_other") +} + +func (rl *http2clientConnReadLoop) run() error { + cc := rl.cc + gotSettings := false + readIdleTimeout := cc.t.ReadIdleTimeout + var t *time.Timer + if readIdleTimeout != 0 { + t = time.AfterFunc(readIdleTimeout, cc.healthCheck) + defer t.Stop() + } + for { + f, err := cc.fr.ReadFrame() + if t != nil { + t.Reset(readIdleTimeout) + } + if err != nil { + cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err) + } + if se, ok := err.(http2StreamError); ok { + if cs := rl.streamByID(se.StreamID); cs != nil { + if se.Cause == nil { + se.Cause = cc.fr.errDetail + } + rl.endStreamError(cs, se) + } + continue + } else if err != nil { + cc.countReadFrameError(err) + return err + } + if http2VerboseLogs { + cc.vlogf("http2: Transport received %s", http2summarizeFrame(f)) + } + if !gotSettings { + if _, ok := f.(*http2SettingsFrame); !ok { + cc.logf("protocol error: received %T before a SETTINGS frame", f) + return http2ConnectionError(http2ErrCodeProtocol) + } + gotSettings = true + } + + switch f := f.(type) { + case *http2MetaHeadersFrame: + err = rl.processHeaders(f) + case *http2DataFrame: + err = rl.processData(f) + case *http2GoAwayFrame: + err = rl.processGoAway(f) + case *http2RSTStreamFrame: + err = rl.processResetStream(f) + case *http2SettingsFrame: + err = rl.processSettings(f) + case *http2PushPromiseFrame: + err = rl.processPushPromise(f) + case *http2WindowUpdateFrame: + err = rl.processWindowUpdate(f) + case *http2PingFrame: + err = rl.processPing(f) + default: + cc.logf("Transport: unhandled response frame type %T", f) + } + if err != nil { + if http2VerboseLogs { + cc.vlogf("http2: Transport conn %p received error from processing frame %v: %v", cc, http2summarizeFrame(f), err) + } + return err + } + } +} + +func (rl *http2clientConnReadLoop) processHeaders(f *http2MetaHeadersFrame) error { + cs := rl.streamByID(f.StreamID) + if cs == nil { + // We'd get here if we canceled a request while the + // server had its response still in flight. So if this + // was just something we canceled, ignore it. + return nil + } + if cs.readClosed { + rl.endStreamError(cs, http2StreamError{ + StreamID: f.StreamID, + Code: http2ErrCodeProtocol, + Cause: errors.New("protocol error: headers after END_STREAM"), + }) + return nil + } + if !cs.firstByte { + if cs.trace != nil { + // TODO(bradfitz): move first response byte earlier, + // when we first read the 9 byte header, not waiting + // until all the HEADERS+CONTINUATION frames have been + // merged. This works for now. + http2traceFirstResponseByte(cs.trace) + } + cs.firstByte = true + } + if !cs.pastHeaders { + cs.pastHeaders = true + } else { + return rl.processTrailers(cs, f) + } + + res, err := rl.handleResponse(cs, f) + if err != nil { + if _, ok := err.(http2ConnectionError); ok { + return err + } + // Any other error type is a stream error. + rl.endStreamError(cs, http2StreamError{ + StreamID: f.StreamID, + Code: http2ErrCodeProtocol, + Cause: err, + }) + return nil // return nil from process* funcs to keep conn alive + } + if res == nil { + // (nil, nil) special case. See handleResponse docs. + return nil + } + cs.resTrailer = &res.Trailer + cs.res = res + close(cs.respHeaderRecv) + if f.StreamEnded() { + rl.endStream(cs) + } + return nil +} + +// may return error types nil, or ConnectionError. Any other error value +// is a StreamError of type ErrCodeProtocol. The returned error in that case +// is the detail. +// +// As a special case, handleResponse may return (nil, nil) to skip the +// frame (currently only used for 1xx responses). +func (rl *http2clientConnReadLoop) handleResponse(cs *http2clientStream, f *http2MetaHeadersFrame) (*Response, error) { + if f.Truncated { + return nil, http2errResponseHeaderListSize + } + + status := f.PseudoValue("status") + if status == "" { + return nil, errors.New("malformed response from server: missing status pseudo header") + } + statusCode, err := strconv.Atoi(status) + if err != nil { + return nil, errors.New("malformed response from server: malformed non-numeric status pseudo header") + } + + regularFields := f.RegularFields() + strs := make([]string, len(regularFields)) + header := make(Header, len(regularFields)) + res := &Response{ + Proto: "HTTP/2.0", + ProtoMajor: 2, + Header: header, + StatusCode: statusCode, + Status: status + " " + StatusText(statusCode), + } + for _, hf := range regularFields { + key := http2canonicalHeader(hf.Name) + if key == "Trailer" { + t := res.Trailer + if t == nil { + t = make(Header) + res.Trailer = t + } + http2foreachHeaderElement(hf.Value, func(v string) { + t[http2canonicalHeader(v)] = nil + }) + } else { + vv := header[key] + if vv == nil && len(strs) > 0 { + // More than likely this will be a single-element key. + // Most headers aren't multi-valued. + // Set the capacity on strs[0] to 1, so any future append + // won't extend the slice into the other strings. + vv, strs = strs[:1:1], strs[1:] + vv[0] = hf.Value + header[key] = vv + } else { + header[key] = append(vv, hf.Value) + } + } + } + + if statusCode >= 100 && statusCode <= 199 { + if f.StreamEnded() { + return nil, errors.New("1xx informational response with END_STREAM flag") + } + cs.num1xx++ + const max1xxResponses = 5 // arbitrary bound on number of informational responses, same as net/http + if cs.num1xx > max1xxResponses { + return nil, errors.New("http2: too many 1xx informational responses") + } + if fn := cs.get1xxTraceFunc(); fn != nil { + if err := fn(statusCode, textproto.MIMEHeader(header)); err != nil { + return nil, err + } + } + if statusCode == 100 { + http2traceGot100Continue(cs.trace) + select { + case cs.on100 <- struct{}{}: + default: + } + } + cs.pastHeaders = false // do it all again + return nil, nil + } + + res.ContentLength = -1 + if clens := res.Header["Content-Length"]; len(clens) == 1 { + if cl, err := strconv.ParseUint(clens[0], 10, 63); err == nil { + res.ContentLength = int64(cl) + } else { + // TODO: care? unlike http/1, it won't mess up our framing, so it's + // more safe smuggling-wise to ignore. + } + } else if len(clens) > 1 { + // TODO: care? unlike http/1, it won't mess up our framing, so it's + // more safe smuggling-wise to ignore. + } else if f.StreamEnded() && !cs.isHead { + res.ContentLength = 0 + } + + if cs.isHead { + res.Body = http2noBody + return res, nil + } + + if f.StreamEnded() { + if res.ContentLength > 0 { + res.Body = http2missingBody{} + } else { + res.Body = http2noBody + } + return res, nil + } + + cs.bufPipe.setBuffer(&http2dataBuffer{expected: res.ContentLength}) + cs.bytesRemain = res.ContentLength + res.Body = http2transportResponseBody{cs} + + if cs.requestedGzip && http2asciiEqualFold(res.Header.Get("Content-Encoding"), "gzip") { + res.Header.Del("Content-Encoding") + res.Header.Del("Content-Length") + res.ContentLength = -1 + res.Body = &http2gzipReader{body: res.Body} + res.Uncompressed = true + } + return res, nil +} + +func (rl *http2clientConnReadLoop) processTrailers(cs *http2clientStream, f *http2MetaHeadersFrame) error { + if cs.pastTrailers { + // Too many HEADERS frames for this stream. + return http2ConnectionError(http2ErrCodeProtocol) + } + cs.pastTrailers = true + if !f.StreamEnded() { + // We expect that any headers for trailers also + // has END_STREAM. + return http2ConnectionError(http2ErrCodeProtocol) + } + if len(f.PseudoFields()) > 0 { + // No pseudo header fields are defined for trailers. + // TODO: ConnectionError might be overly harsh? Check. + return http2ConnectionError(http2ErrCodeProtocol) + } + + trailer := make(Header) + for _, hf := range f.RegularFields() { + key := http2canonicalHeader(hf.Name) + trailer[key] = append(trailer[key], hf.Value) + } + cs.trailer = trailer + + rl.endStream(cs) + return nil +} + +// transportResponseBody is the concrete type of Transport.RoundTrip's +// Response.Body. It is an io.ReadCloser. +type http2transportResponseBody struct { + cs *http2clientStream +} + +func (b http2transportResponseBody) Read(p []byte) (n int, err error) { + cs := b.cs + cc := cs.cc + + if cs.readErr != nil { + return 0, cs.readErr + } + n, err = b.cs.bufPipe.Read(p) + if cs.bytesRemain != -1 { + if int64(n) > cs.bytesRemain { + n = int(cs.bytesRemain) + if err == nil { + err = errors.New("net/http: server replied with more than declared Content-Length; truncated") + cs.abortStream(err) + } + cs.readErr = err + return int(cs.bytesRemain), err + } + cs.bytesRemain -= int64(n) + if err == io.EOF && cs.bytesRemain > 0 { + err = io.ErrUnexpectedEOF + cs.readErr = err + return n, err + } + } + if n == 0 { + // No flow control tokens to send back. + return + } + + cc.mu.Lock() + var connAdd, streamAdd int32 + // Check the conn-level first, before the stream-level. + if v := cc.inflow.available(); v < http2transportDefaultConnFlow/2 { + connAdd = http2transportDefaultConnFlow - v + cc.inflow.add(connAdd) + } + if err == nil { // No need to refresh if the stream is over or failed. + // Consider any buffered body data (read from the conn but not + // consumed by the client) when computing flow control for this + // stream. + v := int(cs.inflow.available()) + cs.bufPipe.Len() + if v < http2transportDefaultStreamFlow-http2transportDefaultStreamMinRefresh { + streamAdd = int32(http2transportDefaultStreamFlow - v) + cs.inflow.add(streamAdd) + } + } + cc.mu.Unlock() + + if connAdd != 0 || streamAdd != 0 { + cc.wmu.Lock() + defer cc.wmu.Unlock() + if connAdd != 0 { + cc.fr.WriteWindowUpdate(0, http2mustUint31(connAdd)) + } + if streamAdd != 0 { + cc.fr.WriteWindowUpdate(cs.ID, http2mustUint31(streamAdd)) + } + cc.bw.Flush() + } + return +} + +var http2errClosedResponseBody = errors.New("http2: response body closed") + +func (b http2transportResponseBody) Close() error { + cs := b.cs + cc := cs.cc + + unread := cs.bufPipe.Len() + if unread > 0 { + cc.mu.Lock() + // Return connection-level flow control. + if unread > 0 { + cc.inflow.add(int32(unread)) + } + cc.mu.Unlock() + + // TODO(dneil): Acquiring this mutex can block indefinitely. + // Move flow control return to a goroutine? + cc.wmu.Lock() + // Return connection-level flow control. + if unread > 0 { + cc.fr.WriteWindowUpdate(0, uint32(unread)) + } + cc.bw.Flush() + cc.wmu.Unlock() + } + + cs.bufPipe.BreakWithError(http2errClosedResponseBody) + cs.abortStream(http2errClosedResponseBody) + + select { + case <-cs.donec: + case <-cs.ctx.Done(): + // See golang/go#49366: The net/http package can cancel the + // request context after the response body is fully read. + // Don't treat this as an error. + return nil + case <-cs.reqCancel: + return http2errRequestCanceled + } + return nil +} + +func (rl *http2clientConnReadLoop) processData(f *http2DataFrame) error { + cc := rl.cc + cs := rl.streamByID(f.StreamID) + data := f.Data() + if cs == nil { + cc.mu.Lock() + neverSent := cc.nextStreamID + cc.mu.Unlock() + if f.StreamID >= neverSent { + // We never asked for this. + cc.logf("http2: Transport received unsolicited DATA frame; closing connection") + return http2ConnectionError(http2ErrCodeProtocol) + } + // We probably did ask for this, but canceled. Just ignore it. + // TODO: be stricter here? only silently ignore things which + // we canceled, but not things which were closed normally + // by the peer? Tough without accumulating too much state. + + // But at least return their flow control: + if f.Length > 0 { + cc.mu.Lock() + cc.inflow.add(int32(f.Length)) + cc.mu.Unlock() + + cc.wmu.Lock() + cc.fr.WriteWindowUpdate(0, uint32(f.Length)) + cc.bw.Flush() + cc.wmu.Unlock() + } + return nil + } + if cs.readClosed { + cc.logf("protocol error: received DATA after END_STREAM") + rl.endStreamError(cs, http2StreamError{ + StreamID: f.StreamID, + Code: http2ErrCodeProtocol, + }) + return nil + } + if !cs.firstByte { + cc.logf("protocol error: received DATA before a HEADERS frame") + rl.endStreamError(cs, http2StreamError{ + StreamID: f.StreamID, + Code: http2ErrCodeProtocol, + }) + return nil + } + if f.Length > 0 { + if cs.isHead && len(data) > 0 { + cc.logf("protocol error: received DATA on a HEAD request") + rl.endStreamError(cs, http2StreamError{ + StreamID: f.StreamID, + Code: http2ErrCodeProtocol, + }) + return nil + } + // Check connection-level flow control. + cc.mu.Lock() + if cs.inflow.available() >= int32(f.Length) { + cs.inflow.take(int32(f.Length)) + } else { + cc.mu.Unlock() + return http2ConnectionError(http2ErrCodeFlowControl) + } + // Return any padded flow control now, since we won't + // refund it later on body reads. + var refund int + if pad := int(f.Length) - len(data); pad > 0 { + refund += pad + } + + didReset := false + var err error + if len(data) > 0 { + if _, err = cs.bufPipe.Write(data); err != nil { + // Return len(data) now if the stream is already closed, + // since data will never be read. + didReset = true + refund += len(data) + } + } + + if refund > 0 { + cc.inflow.add(int32(refund)) + if !didReset { + cs.inflow.add(int32(refund)) + } + } + cc.mu.Unlock() + + if refund > 0 { + cc.wmu.Lock() + cc.fr.WriteWindowUpdate(0, uint32(refund)) + if !didReset { + cc.fr.WriteWindowUpdate(cs.ID, uint32(refund)) + } + cc.bw.Flush() + cc.wmu.Unlock() + } + + if err != nil { + rl.endStreamError(cs, err) + return nil + } + } + + if f.StreamEnded() { + rl.endStream(cs) + } + return nil +} + +func (rl *http2clientConnReadLoop) endStream(cs *http2clientStream) { + // TODO: check that any declared content-length matches, like + // server.go's (*stream).endStream method. + if !cs.readClosed { + cs.readClosed = true + // Close cs.bufPipe and cs.peerClosed with cc.mu held to avoid a + // race condition: The caller can read io.EOF from Response.Body + // and close the body before we close cs.peerClosed, causing + // cleanupWriteRequest to send a RST_STREAM. + rl.cc.mu.Lock() + defer rl.cc.mu.Unlock() + cs.bufPipe.closeWithErrorAndCode(io.EOF, cs.copyTrailers) + close(cs.peerClosed) + } +} + +func (rl *http2clientConnReadLoop) endStreamError(cs *http2clientStream, err error) { + cs.readAborted = true + cs.abortStream(err) +} + +func (rl *http2clientConnReadLoop) streamByID(id uint32) *http2clientStream { + rl.cc.mu.Lock() + defer rl.cc.mu.Unlock() + cs := rl.cc.streams[id] + if cs != nil && !cs.readAborted { + return cs + } + return nil +} + +func (cs *http2clientStream) copyTrailers() { + for k, vv := range cs.trailer { + t := cs.resTrailer + if *t == nil { + *t = make(Header) + } + (*t)[k] = vv + } +} + +func (rl *http2clientConnReadLoop) processGoAway(f *http2GoAwayFrame) error { + cc := rl.cc + cc.t.connPool().MarkDead(cc) + if f.ErrCode != 0 { + // TODO: deal with GOAWAY more. particularly the error code + cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode) + if fn := cc.t.CountError; fn != nil { + fn("recv_goaway_" + f.ErrCode.stringToken()) + } + } + cc.setGoAway(f) + return nil +} + +func (rl *http2clientConnReadLoop) processSettings(f *http2SettingsFrame) error { + cc := rl.cc + // Locking both mu and wmu here allows frame encoding to read settings with only wmu held. + // Acquiring wmu when f.IsAck() is unnecessary, but convenient and mostly harmless. + cc.wmu.Lock() + defer cc.wmu.Unlock() + + if err := rl.processSettingsNoWrite(f); err != nil { + return err + } + if !f.IsAck() { + cc.fr.WriteSettingsAck() + cc.bw.Flush() + } + return nil +} + +func (rl *http2clientConnReadLoop) processSettingsNoWrite(f *http2SettingsFrame) error { + cc := rl.cc + cc.mu.Lock() + defer cc.mu.Unlock() + + if f.IsAck() { + if cc.wantSettingsAck { + cc.wantSettingsAck = false + return nil + } + return http2ConnectionError(http2ErrCodeProtocol) + } + + var seenMaxConcurrentStreams bool + err := f.ForeachSetting(func(s http2Setting) error { + switch s.ID { + case http2SettingMaxFrameSize: + cc.maxFrameSize = s.Val + case http2SettingMaxConcurrentStreams: + cc.maxConcurrentStreams = s.Val + seenMaxConcurrentStreams = true + case http2SettingMaxHeaderListSize: + cc.peerMaxHeaderListSize = uint64(s.Val) + case http2SettingInitialWindowSize: + // Values above the maximum flow-control + // window size of 2^31-1 MUST be treated as a + // connection error (Section 5.4.1) of type + // FLOW_CONTROL_ERROR. + if s.Val > math.MaxInt32 { + return http2ConnectionError(http2ErrCodeFlowControl) + } + + // Adjust flow control of currently-open + // frames by the difference of the old initial + // window size and this one. + delta := int32(s.Val) - int32(cc.initialWindowSize) + for _, cs := range cc.streams { + cs.flow.add(delta) + } + cc.cond.Broadcast() + + cc.initialWindowSize = s.Val + case http2SettingHeaderTableSize: + cc.henc.SetMaxDynamicTableSize(s.Val) + cc.peerMaxHeaderTableSize = s.Val + default: + cc.vlogf("Unhandled Setting: %v", s) + } + return nil + }) + if err != nil { + return err + } + + if !cc.seenSettings { + if !seenMaxConcurrentStreams { + // This was the servers initial SETTINGS frame and it + // didn't contain a MAX_CONCURRENT_STREAMS field so + // increase the number of concurrent streams this + // connection can establish to our default. + cc.maxConcurrentStreams = http2defaultMaxConcurrentStreams + } + cc.seenSettings = true + } + + return nil +} + +func (rl *http2clientConnReadLoop) processWindowUpdate(f *http2WindowUpdateFrame) error { + cc := rl.cc + cs := rl.streamByID(f.StreamID) + if f.StreamID != 0 && cs == nil { + return nil + } + + cc.mu.Lock() + defer cc.mu.Unlock() + + fl := &cc.flow + if cs != nil { + fl = &cs.flow + } + if !fl.add(int32(f.Increment)) { + return http2ConnectionError(http2ErrCodeFlowControl) + } + cc.cond.Broadcast() + return nil +} + +func (rl *http2clientConnReadLoop) processResetStream(f *http2RSTStreamFrame) error { + cs := rl.streamByID(f.StreamID) + if cs == nil { + // TODO: return error if server tries to RST_STREAM an idle stream + return nil + } + serr := http2streamError(cs.ID, f.ErrCode) + serr.Cause = http2errFromPeer + if f.ErrCode == http2ErrCodeProtocol { + rl.cc.SetDoNotReuse() + } + if fn := cs.cc.t.CountError; fn != nil { + fn("recv_rststream_" + f.ErrCode.stringToken()) + } + cs.abortStream(serr) + + cs.bufPipe.CloseWithError(serr) + return nil +} + +// Ping sends a PING frame to the server and waits for the ack. +func (cc *http2ClientConn) Ping(ctx context.Context) error { + c := make(chan struct{}) + // Generate a random payload + var p [8]byte + for { + if _, err := rand.Read(p[:]); err != nil { + return err + } + cc.mu.Lock() + // check for dup before insert + if _, found := cc.pings[p]; !found { + cc.pings[p] = c + cc.mu.Unlock() + break + } + cc.mu.Unlock() + } + errc := make(chan error, 1) + go func() { + cc.wmu.Lock() + defer cc.wmu.Unlock() + if err := cc.fr.WritePing(false, p); err != nil { + errc <- err + return + } + if err := cc.bw.Flush(); err != nil { + errc <- err + return + } + }() + select { + case <-c: + return nil + case err := <-errc: + return err + case <-ctx.Done(): + return ctx.Err() + case <-cc.readerDone: + // connection closed + return cc.readerErr + } +} + +func (rl *http2clientConnReadLoop) processPing(f *http2PingFrame) error { + if f.IsAck() { + cc := rl.cc + cc.mu.Lock() + defer cc.mu.Unlock() + // If ack, notify listener if any + if c, ok := cc.pings[f.Data]; ok { + close(c) + delete(cc.pings, f.Data) + } + return nil + } + cc := rl.cc + cc.wmu.Lock() + defer cc.wmu.Unlock() + if err := cc.fr.WritePing(true, f.Data); err != nil { + return err + } + return cc.bw.Flush() +} + +func (rl *http2clientConnReadLoop) processPushPromise(f *http2PushPromiseFrame) error { + // We told the peer we don't want them. + // Spec says: + // "PUSH_PROMISE MUST NOT be sent if the SETTINGS_ENABLE_PUSH + // setting of the peer endpoint is set to 0. An endpoint that + // has set this setting and has received acknowledgement MUST + // treat the receipt of a PUSH_PROMISE frame as a connection + // error (Section 5.4.1) of type PROTOCOL_ERROR." + return http2ConnectionError(http2ErrCodeProtocol) +} + +func (cc *http2ClientConn) writeStreamReset(streamID uint32, code http2ErrCode, err error) { + // TODO: map err to more interesting error codes, once the + // HTTP community comes up with some. But currently for + // RST_STREAM there's no equivalent to GOAWAY frame's debug + // data, and the error codes are all pretty vague ("cancel"). + cc.wmu.Lock() + cc.fr.WriteRSTStream(streamID, code) + cc.bw.Flush() + cc.wmu.Unlock() +} + +var ( + http2errResponseHeaderListSize = errors.New("http2: response header list larger than advertised limit") + http2errRequestHeaderListSize = errors.New("http2: request header list larger than peer's advertised limit") +) + +func (cc *http2ClientConn) logf(format string, args ...interface{}) { + cc.t.logf(format, args...) +} + +func (cc *http2ClientConn) vlogf(format string, args ...interface{}) { + cc.t.vlogf(format, args...) +} + +func (t *http2Transport) vlogf(format string, args ...interface{}) { + if http2VerboseLogs { + t.logf(format, args...) + } +} + +func (t *http2Transport) logf(format string, args ...interface{}) { + log.Printf(format, args...) +} + +var http2noBody io.ReadCloser = http2noBodyReader{} + +type http2noBodyReader struct{} + +func (http2noBodyReader) Close() error { return nil } + +func (http2noBodyReader) Read([]byte) (int, error) { return 0, io.EOF } + +type http2missingBody struct{} + +func (http2missingBody) Close() error { return nil } + +func (http2missingBody) Read([]byte) (int, error) { return 0, io.ErrUnexpectedEOF } + +func http2strSliceContains(ss []string, s string) bool { + for _, v := range ss { + if v == s { + return true + } + } + return false +} + +type http2erringRoundTripper struct{ err error } + +func (rt http2erringRoundTripper) RoundTripErr() error { return rt.err } + +func (rt http2erringRoundTripper) RoundTrip(*Request) (*Response, error) { return nil, rt.err } + +// gzipReader wraps a response body so it can lazily +// call gzip.NewReader on the first call to Read +type http2gzipReader struct { + _ http2incomparable + body io.ReadCloser // underlying Response.Body + zr *gzip.Reader // lazily-initialized gzip reader + zerr error // sticky error +} + +func (gz *http2gzipReader) Read(p []byte) (n int, err error) { + if gz.zerr != nil { + return 0, gz.zerr + } + if gz.zr == nil { + gz.zr, err = gzip.NewReader(gz.body) + if err != nil { + gz.zerr = err + return 0, err + } + } + return gz.zr.Read(p) +} + +func (gz *http2gzipReader) Close() error { + if err := gz.body.Close(); err != nil { + return err + } + gz.zerr = fs.ErrClosed + return nil +} + +type http2errorReader struct{ err error } + +func (r http2errorReader) Read(p []byte) (int, error) { return 0, r.err } + +// isConnectionCloseRequest reports whether req should use its own +// connection for a single request and then close the connection. +func http2isConnectionCloseRequest(req *Request) bool { + return req.Close || httpguts.HeaderValuesContainsToken(req.Header["Connection"], "close") +} + +// registerHTTPSProtocol calls Transport.RegisterProtocol but +// converting panics into errors. +func http2registerHTTPSProtocol(t *Transport, rt http2noDialH2RoundTripper) (err error) { + defer func() { + if e := recover(); e != nil { + err = fmt.Errorf("%v", e) + } + }() + t.RegisterProtocol("https", rt) + return nil +} + +// noDialH2RoundTripper is a RoundTripper which only tries to complete the request +// if there's already has a cached connection to the host. +// (The field is exported so it can be accessed via reflect from net/http; tested +// by TestNoDialH2RoundTripperType) +type http2noDialH2RoundTripper struct{ *http2Transport } + +func (rt http2noDialH2RoundTripper) RoundTrip(req *Request) (*Response, error) { + res, err := rt.http2Transport.RoundTrip(req) + if http2isNoCachedConnError(err) { + return nil, ErrSkipAltProtocol + } + return res, err +} + +func (t *http2Transport) idleConnTimeout() time.Duration { + if t.t1 != nil { + return t.t1.IdleConnTimeout + } + return 0 +} + +func http2traceGetConn(req *Request, hostPort string) { + trace := httptrace.ContextClientTrace(req.Context()) + if trace == nil || trace.GetConn == nil { + return + } + trace.GetConn(hostPort) +} + +func http2traceGotConn(req *Request, cc *http2ClientConn, reused bool) { + trace := httptrace.ContextClientTrace(req.Context()) + if trace == nil || trace.GotConn == nil { + return + } + ci := httptrace.GotConnInfo{Conn: cc.tconn} + ci.Reused = reused + cc.mu.Lock() + ci.WasIdle = len(cc.streams) == 0 && reused + if ci.WasIdle && !cc.lastActive.IsZero() { + ci.IdleTime = time.Since(cc.lastActive) + } + cc.mu.Unlock() + + trace.GotConn(ci) +} + +func http2traceWroteHeaders(trace *httptrace.ClientTrace) { + if trace != nil && trace.WroteHeaders != nil { + trace.WroteHeaders() + } +} + +func http2traceGot100Continue(trace *httptrace.ClientTrace) { + if trace != nil && trace.Got100Continue != nil { + trace.Got100Continue() + } +} + +func http2traceWait100Continue(trace *httptrace.ClientTrace) { + if trace != nil && trace.Wait100Continue != nil { + trace.Wait100Continue() + } +} + +func http2traceWroteRequest(trace *httptrace.ClientTrace, err error) { + if trace != nil && trace.WroteRequest != nil { + trace.WroteRequest(httptrace.WroteRequestInfo{Err: err}) + } +} + +func http2traceFirstResponseByte(trace *httptrace.ClientTrace) { + if trace != nil && trace.GotFirstResponseByte != nil { + trace.GotFirstResponseByte() + } +} + +// writeFramer is implemented by any type that is used to write frames. +type http2writeFramer interface { + writeFrame(http2writeContext) error + + // staysWithinBuffer reports whether this writer promises that + // it will only write less than or equal to size bytes, and it + // won't Flush the write context. + staysWithinBuffer(size int) bool +} + +// writeContext is the interface needed by the various frame writer +// types below. All the writeFrame methods below are scheduled via the +// frame writing scheduler (see writeScheduler in writesched.go). +// +// This interface is implemented by *serverConn. +// +// TODO: decide whether to a) use this in the client code (which didn't +// end up using this yet, because it has a simpler design, not +// currently implementing priorities), or b) delete this and +// make the server code a bit more concrete. +type http2writeContext interface { + Framer() *http2Framer + Flush() error + CloseConn() error + // HeaderEncoder returns an HPACK encoder that writes to the + // returned buffer. + HeaderEncoder() (*hpack.Encoder, *bytes.Buffer) +} + +// writeEndsStream reports whether w writes a frame that will transition +// the stream to a half-closed local state. This returns false for RST_STREAM, +// which closes the entire stream (not just the local half). +func http2writeEndsStream(w http2writeFramer) bool { + switch v := w.(type) { + case *http2writeData: + return v.endStream + case *http2writeResHeaders: + return v.endStream + case nil: + // This can only happen if the caller reuses w after it's + // been intentionally nil'ed out to prevent use. Keep this + // here to catch future refactoring breaking it. + panic("writeEndsStream called on nil writeFramer") + } + return false +} + +type http2flushFrameWriter struct{} + +func (http2flushFrameWriter) writeFrame(ctx http2writeContext) error { + return ctx.Flush() +} + +func (http2flushFrameWriter) staysWithinBuffer(max int) bool { return false } + +type http2writeSettings []http2Setting + +func (s http2writeSettings) staysWithinBuffer(max int) bool { + const settingSize = 6 // uint16 + uint32 + return http2frameHeaderLen+settingSize*len(s) <= max + +} + +func (s http2writeSettings) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WriteSettings([]http2Setting(s)...) +} + +type http2writeGoAway struct { + maxStreamID uint32 + code http2ErrCode +} + +func (p *http2writeGoAway) writeFrame(ctx http2writeContext) error { + err := ctx.Framer().WriteGoAway(p.maxStreamID, p.code, nil) + ctx.Flush() // ignore error: we're hanging up on them anyway + return err +} + +func (*http2writeGoAway) staysWithinBuffer(max int) bool { return false } // flushes + +type http2writeData struct { + streamID uint32 + p []byte + endStream bool +} + +func (w *http2writeData) String() string { + return fmt.Sprintf("writeData(stream=%d, p=%d, endStream=%v)", w.streamID, len(w.p), w.endStream) +} + +func (w *http2writeData) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WriteData(w.streamID, w.endStream, w.p) +} + +func (w *http2writeData) staysWithinBuffer(max int) bool { + return http2frameHeaderLen+len(w.p) <= max +} + +// handlerPanicRST is the message sent from handler goroutines when +// the handler panics. +type http2handlerPanicRST struct { + StreamID uint32 +} + +func (hp http2handlerPanicRST) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WriteRSTStream(hp.StreamID, http2ErrCodeInternal) +} + +func (hp http2handlerPanicRST) staysWithinBuffer(max int) bool { return http2frameHeaderLen+4 <= max } + +func (se http2StreamError) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WriteRSTStream(se.StreamID, se.Code) +} + +func (se http2StreamError) staysWithinBuffer(max int) bool { return http2frameHeaderLen+4 <= max } + +type http2writePingAck struct{ pf *http2PingFrame } + +func (w http2writePingAck) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WritePing(true, w.pf.Data) +} + +func (w http2writePingAck) staysWithinBuffer(max int) bool { + return http2frameHeaderLen+len(w.pf.Data) <= max +} + +type http2writeSettingsAck struct{} + +func (http2writeSettingsAck) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WriteSettingsAck() +} + +func (http2writeSettingsAck) staysWithinBuffer(max int) bool { return http2frameHeaderLen <= max } + +// splitHeaderBlock splits headerBlock into fragments so that each fragment fits +// in a single frame, then calls fn for each fragment. firstFrag/lastFrag are true +// for the first/last fragment, respectively. +func http2splitHeaderBlock(ctx http2writeContext, headerBlock []byte, fn func(ctx http2writeContext, frag []byte, firstFrag, lastFrag bool) error) error { + // For now we're lazy and just pick the minimum MAX_FRAME_SIZE + // that all peers must support (16KB). Later we could care + // more and send larger frames if the peer advertised it, but + // there's little point. Most headers are small anyway (so we + // generally won't have CONTINUATION frames), and extra frames + // only waste 9 bytes anyway. + const maxFrameSize = 16384 + + first := true + for len(headerBlock) > 0 { + frag := headerBlock + if len(frag) > maxFrameSize { + frag = frag[:maxFrameSize] + } + headerBlock = headerBlock[len(frag):] + if err := fn(ctx, frag, first, len(headerBlock) == 0); err != nil { + return err + } + first = false + } + return nil +} + +// writeResHeaders is a request to write a HEADERS and 0+ CONTINUATION frames +// for HTTP response headers or trailers from a server handler. +type http2writeResHeaders struct { + streamID uint32 + httpResCode int // 0 means no ":status" line + h Header // may be nil + trailers []string // if non-nil, which keys of h to write. nil means all. + endStream bool + + date string + contentType string + contentLength string +} + +func http2encKV(enc *hpack.Encoder, k, v string) { + if http2VerboseLogs { + log.Printf("http2: server encoding header %q = %q", k, v) + } + enc.WriteField(hpack.HeaderField{Name: k, Value: v}) +} + +func (w *http2writeResHeaders) staysWithinBuffer(max int) bool { + // TODO: this is a common one. It'd be nice to return true + // here and get into the fast path if we could be clever and + // calculate the size fast enough, or at least a conservative + // upper bound that usually fires. (Maybe if w.h and + // w.trailers are nil, so we don't need to enumerate it.) + // Otherwise I'm afraid that just calculating the length to + // answer this question would be slower than the ~2µs benefit. + return false +} + +func (w *http2writeResHeaders) writeFrame(ctx http2writeContext) error { + enc, buf := ctx.HeaderEncoder() + buf.Reset() + + if w.httpResCode != 0 { + http2encKV(enc, ":status", http2httpCodeString(w.httpResCode)) + } + + http2encodeHeaders(enc, w.h, w.trailers) + + if w.contentType != "" { + http2encKV(enc, "content-type", w.contentType) + } + if w.contentLength != "" { + http2encKV(enc, "content-length", w.contentLength) + } + if w.date != "" { + http2encKV(enc, "date", w.date) + } + + headerBlock := buf.Bytes() + if len(headerBlock) == 0 && w.trailers == nil { + panic("unexpected empty hpack") + } + + return http2splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock) +} + +func (w *http2writeResHeaders) writeHeaderBlock(ctx http2writeContext, frag []byte, firstFrag, lastFrag bool) error { + if firstFrag { + return ctx.Framer().WriteHeaders(http2HeadersFrameParam{ + StreamID: w.streamID, + BlockFragment: frag, + EndStream: w.endStream, + EndHeaders: lastFrag, + }) + } else { + return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag) + } +} + +// writePushPromise is a request to write a PUSH_PROMISE and 0+ CONTINUATION frames. +type http2writePushPromise struct { + streamID uint32 // pusher stream + method string // for :method + url *url.URL // for :scheme, :authority, :path + h Header + + // Creates an ID for a pushed stream. This runs on serveG just before + // the frame is written. The returned ID is copied to promisedID. + allocatePromisedID func() (uint32, error) + promisedID uint32 +} + +func (w *http2writePushPromise) staysWithinBuffer(max int) bool { + // TODO: see writeResHeaders.staysWithinBuffer + return false +} + +func (w *http2writePushPromise) writeFrame(ctx http2writeContext) error { + enc, buf := ctx.HeaderEncoder() + buf.Reset() + + http2encKV(enc, ":method", w.method) + http2encKV(enc, ":scheme", w.url.Scheme) + http2encKV(enc, ":authority", w.url.Host) + http2encKV(enc, ":path", w.url.RequestURI()) + http2encodeHeaders(enc, w.h, nil) + + headerBlock := buf.Bytes() + if len(headerBlock) == 0 { + panic("unexpected empty hpack") + } + + return http2splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock) +} + +func (w *http2writePushPromise) writeHeaderBlock(ctx http2writeContext, frag []byte, firstFrag, lastFrag bool) error { + if firstFrag { + return ctx.Framer().WritePushPromise(http2PushPromiseParam{ + StreamID: w.streamID, + PromiseID: w.promisedID, + BlockFragment: frag, + EndHeaders: lastFrag, + }) + } else { + return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag) + } +} + +type http2write100ContinueHeadersFrame struct { + streamID uint32 +} + +func (w http2write100ContinueHeadersFrame) writeFrame(ctx http2writeContext) error { + enc, buf := ctx.HeaderEncoder() + buf.Reset() + http2encKV(enc, ":status", "100") + return ctx.Framer().WriteHeaders(http2HeadersFrameParam{ + StreamID: w.streamID, + BlockFragment: buf.Bytes(), + EndStream: false, + EndHeaders: true, + }) +} + +func (w http2write100ContinueHeadersFrame) staysWithinBuffer(max int) bool { + // Sloppy but conservative: + return 9+2*(len(":status")+len("100")) <= max +} + +type http2writeWindowUpdate struct { + streamID uint32 // or 0 for conn-level + n uint32 +} + +func (wu http2writeWindowUpdate) staysWithinBuffer(max int) bool { return http2frameHeaderLen+4 <= max } + +func (wu http2writeWindowUpdate) writeFrame(ctx http2writeContext) error { + return ctx.Framer().WriteWindowUpdate(wu.streamID, wu.n) +} + +// encodeHeaders encodes an http.Header. If keys is not nil, then (k, h[k]) +// is encoded only if k is in keys. +func http2encodeHeaders(enc *hpack.Encoder, h Header, keys []string) { + if keys == nil { + sorter := http2sorterPool.Get().(*http2sorter) + // Using defer here, since the returned keys from the + // sorter.Keys method is only valid until the sorter + // is returned: + defer http2sorterPool.Put(sorter) + keys = sorter.Keys(h) + } + for _, k := range keys { + vv := h[k] + k, ascii := http2lowerHeader(k) + if !ascii { + // Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header + // field names have to be ASCII characters (just as in HTTP/1.x). + continue + } + if !http2validWireHeaderFieldName(k) { + // Skip it as backup paranoia. Per + // golang.org/issue/14048, these should + // already be rejected at a higher level. + continue + } + isTE := k == "transfer-encoding" + for _, v := range vv { + if !httpguts.ValidHeaderFieldValue(v) { + // TODO: return an error? golang.org/issue/14048 + // For now just omit it. + continue + } + // TODO: more of "8.1.2.2 Connection-Specific Header Fields" + if isTE && v != "trailers" { + continue + } + http2encKV(enc, k, v) + } + } +} + +// WriteScheduler is the interface implemented by HTTP/2 write schedulers. +// Methods are never called concurrently. +type http2WriteScheduler interface { + // OpenStream opens a new stream in the write scheduler. + // It is illegal to call this with streamID=0 or with a streamID that is + // already open -- the call may panic. + OpenStream(streamID uint32, options http2OpenStreamOptions) + + // CloseStream closes a stream in the write scheduler. Any frames queued on + // this stream should be discarded. It is illegal to call this on a stream + // that is not open -- the call may panic. + CloseStream(streamID uint32) + + // AdjustStream adjusts the priority of the given stream. This may be called + // on a stream that has not yet been opened or has been closed. Note that + // RFC 7540 allows PRIORITY frames to be sent on streams in any state. See: + // https://tools.ietf.org/html/rfc7540#section-5.1 + AdjustStream(streamID uint32, priority http2PriorityParam) + + // Push queues a frame in the scheduler. In most cases, this will not be + // called with wr.StreamID()!=0 unless that stream is currently open. The one + // exception is RST_STREAM frames, which may be sent on idle or closed streams. + Push(wr http2FrameWriteRequest) + + // Pop dequeues the next frame to write. Returns false if no frames can + // be written. Frames with a given wr.StreamID() are Pop'd in the same + // order they are Push'd, except RST_STREAM frames. No frames should be + // discarded except by CloseStream. + Pop() (wr http2FrameWriteRequest, ok bool) +} + +// OpenStreamOptions specifies extra options for WriteScheduler.OpenStream. +type http2OpenStreamOptions struct { + // PusherID is zero if the stream was initiated by the client. Otherwise, + // PusherID names the stream that pushed the newly opened stream. + PusherID uint32 +} + +// FrameWriteRequest is a request to write a frame. +type http2FrameWriteRequest struct { + // write is the interface value that does the writing, once the + // WriteScheduler has selected this frame to write. The write + // functions are all defined in write.go. + write http2writeFramer + + // stream is the stream on which this frame will be written. + // nil for non-stream frames like PING and SETTINGS. + // nil for RST_STREAM streams, which use the StreamError.StreamID field instead. + stream *http2stream + + // done, if non-nil, must be a buffered channel with space for + // 1 message and is sent the return value from write (or an + // earlier error) when the frame has been written. + done chan error +} + +// StreamID returns the id of the stream this frame will be written to. +// 0 is used for non-stream frames such as PING and SETTINGS. +func (wr http2FrameWriteRequest) StreamID() uint32 { + if wr.stream == nil { + if se, ok := wr.write.(http2StreamError); ok { + // (*serverConn).resetStream doesn't set + // stream because it doesn't necessarily have + // one. So special case this type of write + // message. + return se.StreamID + } + return 0 + } + return wr.stream.id +} + +// isControl reports whether wr is a control frame for MaxQueuedControlFrames +// purposes. That includes non-stream frames and RST_STREAM frames. +func (wr http2FrameWriteRequest) isControl() bool { + return wr.stream == nil +} + +// DataSize returns the number of flow control bytes that must be consumed +// to write this entire frame. This is 0 for non-DATA frames. +func (wr http2FrameWriteRequest) DataSize() int { + if wd, ok := wr.write.(*http2writeData); ok { + return len(wd.p) + } + return 0 +} + +// Consume consumes min(n, available) bytes from this frame, where available +// is the number of flow control bytes available on the stream. Consume returns +// 0, 1, or 2 frames, where the integer return value gives the number of frames +// returned. +// +// If flow control prevents consuming any bytes, this returns (_, _, 0). If +// the entire frame was consumed, this returns (wr, _, 1). Otherwise, this +// returns (consumed, rest, 2), where 'consumed' contains the consumed bytes and +// 'rest' contains the remaining bytes. The consumed bytes are deducted from the +// underlying stream's flow control budget. +func (wr http2FrameWriteRequest) Consume(n int32) (http2FrameWriteRequest, http2FrameWriteRequest, int) { + var empty http2FrameWriteRequest + + // Non-DATA frames are always consumed whole. + wd, ok := wr.write.(*http2writeData) + if !ok || len(wd.p) == 0 { + return wr, empty, 1 + } + + // Might need to split after applying limits. + allowed := wr.stream.flow.available() + if n < allowed { + allowed = n + } + if wr.stream.sc.maxFrameSize < allowed { + allowed = wr.stream.sc.maxFrameSize + } + if allowed <= 0 { + return empty, empty, 0 + } + if len(wd.p) > int(allowed) { + wr.stream.flow.take(allowed) + consumed := http2FrameWriteRequest{ + stream: wr.stream, + write: &http2writeData{ + streamID: wd.streamID, + p: wd.p[:allowed], + // Even if the original had endStream set, there + // are bytes remaining because len(wd.p) > allowed, + // so we know endStream is false. + endStream: false, + }, + // Our caller is blocking on the final DATA frame, not + // this intermediate frame, so no need to wait. + done: nil, + } + rest := http2FrameWriteRequest{ + stream: wr.stream, + write: &http2writeData{ + streamID: wd.streamID, + p: wd.p[allowed:], + endStream: wd.endStream, + }, + done: wr.done, + } + return consumed, rest, 2 + } + + // The frame is consumed whole. + // NB: This cast cannot overflow because allowed is <= math.MaxInt32. + wr.stream.flow.take(int32(len(wd.p))) + return wr, empty, 1 +} + +// String is for debugging only. +func (wr http2FrameWriteRequest) String() string { + var des string + if s, ok := wr.write.(fmt.Stringer); ok { + des = s.String() + } else { + des = fmt.Sprintf("%T", wr.write) + } + return fmt.Sprintf("[FrameWriteRequest stream=%d, ch=%v, writer=%v]", wr.StreamID(), wr.done != nil, des) +} + +// replyToWriter sends err to wr.done and panics if the send must block +// This does nothing if wr.done is nil. +func (wr *http2FrameWriteRequest) replyToWriter(err error) { + if wr.done == nil { + return + } + select { + case wr.done <- err: + default: + panic(fmt.Sprintf("unbuffered done channel passed in for type %T", wr.write)) + } + wr.write = nil // prevent use (assume it's tainted after wr.done send) +} + +// writeQueue is used by implementations of WriteScheduler. +type http2writeQueue struct { + s []http2FrameWriteRequest +} + +func (q *http2writeQueue) empty() bool { return len(q.s) == 0 } + +func (q *http2writeQueue) push(wr http2FrameWriteRequest) { + q.s = append(q.s, wr) +} + +func (q *http2writeQueue) shift() http2FrameWriteRequest { + if len(q.s) == 0 { + panic("invalid use of queue") + } + wr := q.s[0] + // TODO: less copy-happy queue. + copy(q.s, q.s[1:]) + q.s[len(q.s)-1] = http2FrameWriteRequest{} + q.s = q.s[:len(q.s)-1] + return wr +} + +// consume consumes up to n bytes from q.s[0]. If the frame is +// entirely consumed, it is removed from the queue. If the frame +// is partially consumed, the frame is kept with the consumed +// bytes removed. Returns true iff any bytes were consumed. +func (q *http2writeQueue) consume(n int32) (http2FrameWriteRequest, bool) { + if len(q.s) == 0 { + return http2FrameWriteRequest{}, false + } + consumed, rest, numresult := q.s[0].Consume(n) + switch numresult { + case 0: + return http2FrameWriteRequest{}, false + case 1: + q.shift() + case 2: + q.s[0] = rest + } + return consumed, true +} + +type http2writeQueuePool []*http2writeQueue + +// put inserts an unused writeQueue into the pool. + +// put inserts an unused writeQueue into the pool. +func (p *http2writeQueuePool) put(q *http2writeQueue) { + for i := range q.s { + q.s[i] = http2FrameWriteRequest{} + } + q.s = q.s[:0] + *p = append(*p, q) +} + +// get returns an empty writeQueue. +func (p *http2writeQueuePool) get() *http2writeQueue { + ln := len(*p) + if ln == 0 { + return new(http2writeQueue) + } + x := ln - 1 + q := (*p)[x] + (*p)[x] = nil + *p = (*p)[:x] + return q +} + +// RFC 7540, Section 5.3.5: the default weight is 16. +const http2priorityDefaultWeight = 15 // 16 = 15 + 1 + +// PriorityWriteSchedulerConfig configures a priorityWriteScheduler. +type http2PriorityWriteSchedulerConfig struct { + // MaxClosedNodesInTree controls the maximum number of closed streams to + // retain in the priority tree. Setting this to zero saves a small amount + // of memory at the cost of performance. + // + // See RFC 7540, Section 5.3.4: + // "It is possible for a stream to become closed while prioritization + // information ... is in transit. ... This potentially creates suboptimal + // prioritization, since the stream could be given a priority that is + // different from what is intended. To avoid these problems, an endpoint + // SHOULD retain stream prioritization state for a period after streams + // become closed. The longer state is retained, the lower the chance that + // streams are assigned incorrect or default priority values." + MaxClosedNodesInTree int + + // MaxIdleNodesInTree controls the maximum number of idle streams to + // retain in the priority tree. Setting this to zero saves a small amount + // of memory at the cost of performance. + // + // See RFC 7540, Section 5.3.4: + // Similarly, streams that are in the "idle" state can be assigned + // priority or become a parent of other streams. This allows for the + // creation of a grouping node in the dependency tree, which enables + // more flexible expressions of priority. Idle streams begin with a + // default priority (Section 5.3.5). + MaxIdleNodesInTree int + + // ThrottleOutOfOrderWrites enables write throttling to help ensure that + // data is delivered in priority order. This works around a race where + // stream B depends on stream A and both streams are about to call Write + // to queue DATA frames. If B wins the race, a naive scheduler would eagerly + // write as much data from B as possible, but this is suboptimal because A + // is a higher-priority stream. With throttling enabled, we write a small + // amount of data from B to minimize the amount of bandwidth that B can + // steal from A. + ThrottleOutOfOrderWrites bool +} + +// NewPriorityWriteScheduler constructs a WriteScheduler that schedules +// frames by following HTTP/2 priorities as described in RFC 7540 Section 5.3. +// If cfg is nil, default options are used. +func http2NewPriorityWriteScheduler(cfg *http2PriorityWriteSchedulerConfig) http2WriteScheduler { + if cfg == nil { + // For justification of these defaults, see: + // https://docs.google.com/document/d/1oLhNg1skaWD4_DtaoCxdSRN5erEXrH-KnLrMwEpOtFY + cfg = &http2PriorityWriteSchedulerConfig{ + MaxClosedNodesInTree: 10, + MaxIdleNodesInTree: 10, + ThrottleOutOfOrderWrites: false, + } + } + + ws := &http2priorityWriteScheduler{ + nodes: make(map[uint32]*http2priorityNode), + maxClosedNodesInTree: cfg.MaxClosedNodesInTree, + maxIdleNodesInTree: cfg.MaxIdleNodesInTree, + enableWriteThrottle: cfg.ThrottleOutOfOrderWrites, + } + ws.nodes[0] = &ws.root + if cfg.ThrottleOutOfOrderWrites { + ws.writeThrottleLimit = 1024 + } else { + ws.writeThrottleLimit = math.MaxInt32 + } + return ws +} + +type http2priorityNodeState int + +const ( + http2priorityNodeOpen http2priorityNodeState = iota + http2priorityNodeClosed + http2priorityNodeIdle +) + +// priorityNode is a node in an HTTP/2 priority tree. +// Each node is associated with a single stream ID. +// See RFC 7540, Section 5.3. +type http2priorityNode struct { + q http2writeQueue // queue of pending frames to write + id uint32 // id of the stream, or 0 for the root of the tree + weight uint8 // the actual weight is weight+1, so the value is in [1,256] + state http2priorityNodeState // open | closed | idle + bytes int64 // number of bytes written by this node, or 0 if closed + subtreeBytes int64 // sum(node.bytes) of all nodes in this subtree + + // These links form the priority tree. + parent *http2priorityNode + kids *http2priorityNode // start of the kids list + prev, next *http2priorityNode // doubly-linked list of siblings +} + +func (n *http2priorityNode) setParent(parent *http2priorityNode) { + if n == parent { + panic("setParent to self") + } + if n.parent == parent { + return + } + // Unlink from current parent. + if parent := n.parent; parent != nil { + if n.prev == nil { + parent.kids = n.next + } else { + n.prev.next = n.next + } + if n.next != nil { + n.next.prev = n.prev + } + } + // Link to new parent. + // If parent=nil, remove n from the tree. + // Always insert at the head of parent.kids (this is assumed by walkReadyInOrder). + n.parent = parent + if parent == nil { + n.next = nil + n.prev = nil + } else { + n.next = parent.kids + n.prev = nil + if n.next != nil { + n.next.prev = n + } + parent.kids = n + } +} + +func (n *http2priorityNode) addBytes(b int64) { + n.bytes += b + for ; n != nil; n = n.parent { + n.subtreeBytes += b + } +} + +// walkReadyInOrder iterates over the tree in priority order, calling f for each node +// with a non-empty write queue. When f returns true, this function returns true and the +// walk halts. tmp is used as scratch space for sorting. +// +// f(n, openParent) takes two arguments: the node to visit, n, and a bool that is true +// if any ancestor p of n is still open (ignoring the root node). +func (n *http2priorityNode) walkReadyInOrder(openParent bool, tmp *[]*http2priorityNode, f func(*http2priorityNode, bool) bool) bool { + if !n.q.empty() && f(n, openParent) { + return true + } + if n.kids == nil { + return false + } + + // Don't consider the root "open" when updating openParent since + // we can't send data frames on the root stream (only control frames). + if n.id != 0 { + openParent = openParent || (n.state == http2priorityNodeOpen) + } + + // Common case: only one kid or all kids have the same weight. + // Some clients don't use weights; other clients (like web browsers) + // use mostly-linear priority trees. + w := n.kids.weight + needSort := false + for k := n.kids.next; k != nil; k = k.next { + if k.weight != w { + needSort = true + break + } + } + if !needSort { + for k := n.kids; k != nil; k = k.next { + if k.walkReadyInOrder(openParent, tmp, f) { + return true + } + } + return false + } + + // Uncommon case: sort the child nodes. We remove the kids from the parent, + // then re-insert after sorting so we can reuse tmp for future sort calls. + *tmp = (*tmp)[:0] + for n.kids != nil { + *tmp = append(*tmp, n.kids) + n.kids.setParent(nil) + } + sort.Sort(http2sortPriorityNodeSiblings(*tmp)) + for i := len(*tmp) - 1; i >= 0; i-- { + (*tmp)[i].setParent(n) // setParent inserts at the head of n.kids + } + for k := n.kids; k != nil; k = k.next { + if k.walkReadyInOrder(openParent, tmp, f) { + return true + } + } + return false +} + +type http2sortPriorityNodeSiblings []*http2priorityNode + +func (z http2sortPriorityNodeSiblings) Len() int { return len(z) } + +func (z http2sortPriorityNodeSiblings) Swap(i, k int) { z[i], z[k] = z[k], z[i] } + +func (z http2sortPriorityNodeSiblings) Less(i, k int) bool { + // Prefer the subtree that has sent fewer bytes relative to its weight. + // See sections 5.3.2 and 5.3.4. + wi, bi := float64(z[i].weight+1), float64(z[i].subtreeBytes) + wk, bk := float64(z[k].weight+1), float64(z[k].subtreeBytes) + if bi == 0 && bk == 0 { + return wi >= wk + } + if bk == 0 { + return false + } + return bi/bk <= wi/wk +} + +type http2priorityWriteScheduler struct { + // root is the root of the priority tree, where root.id = 0. + // The root queues control frames that are not associated with any stream. + root http2priorityNode + + // nodes maps stream ids to priority tree nodes. + nodes map[uint32]*http2priorityNode + + // maxID is the maximum stream id in nodes. + maxID uint32 + + // lists of nodes that have been closed or are idle, but are kept in + // the tree for improved prioritization. When the lengths exceed either + // maxClosedNodesInTree or maxIdleNodesInTree, old nodes are discarded. + closedNodes, idleNodes []*http2priorityNode + + // From the config. + maxClosedNodesInTree int + maxIdleNodesInTree int + writeThrottleLimit int32 + enableWriteThrottle bool + + // tmp is scratch space for priorityNode.walkReadyInOrder to reduce allocations. + tmp []*http2priorityNode + + // pool of empty queues for reuse. + queuePool http2writeQueuePool +} + +func (ws *http2priorityWriteScheduler) OpenStream(streamID uint32, options http2OpenStreamOptions) { + // The stream may be currently idle but cannot be opened or closed. + if curr := ws.nodes[streamID]; curr != nil { + if curr.state != http2priorityNodeIdle { + panic(fmt.Sprintf("stream %d already opened", streamID)) + } + curr.state = http2priorityNodeOpen + return + } + + // RFC 7540, Section 5.3.5: + // "All streams are initially assigned a non-exclusive dependency on stream 0x0. + // Pushed streams initially depend on their associated stream. In both cases, + // streams are assigned a default weight of 16." + parent := ws.nodes[options.PusherID] + if parent == nil { + parent = &ws.root + } + n := &http2priorityNode{ + q: *ws.queuePool.get(), + id: streamID, + weight: http2priorityDefaultWeight, + state: http2priorityNodeOpen, + } + n.setParent(parent) + ws.nodes[streamID] = n + if streamID > ws.maxID { + ws.maxID = streamID + } +} + +func (ws *http2priorityWriteScheduler) CloseStream(streamID uint32) { + if streamID == 0 { + panic("violation of WriteScheduler interface: cannot close stream 0") + } + if ws.nodes[streamID] == nil { + panic(fmt.Sprintf("violation of WriteScheduler interface: unknown stream %d", streamID)) + } + if ws.nodes[streamID].state != http2priorityNodeOpen { + panic(fmt.Sprintf("violation of WriteScheduler interface: stream %d already closed", streamID)) + } + + n := ws.nodes[streamID] + n.state = http2priorityNodeClosed + n.addBytes(-n.bytes) + + q := n.q + ws.queuePool.put(&q) + n.q.s = nil + if ws.maxClosedNodesInTree > 0 { + ws.addClosedOrIdleNode(&ws.closedNodes, ws.maxClosedNodesInTree, n) + } else { + ws.removeNode(n) + } +} + +func (ws *http2priorityWriteScheduler) AdjustStream(streamID uint32, priority http2PriorityParam) { + if streamID == 0 { + panic("adjustPriority on root") + } + + // If streamID does not exist, there are two cases: + // - A closed stream that has been removed (this will have ID <= maxID) + // - An idle stream that is being used for "grouping" (this will have ID > maxID) + n := ws.nodes[streamID] + if n == nil { + if streamID <= ws.maxID || ws.maxIdleNodesInTree == 0 { + return + } + ws.maxID = streamID + n = &http2priorityNode{ + q: *ws.queuePool.get(), + id: streamID, + weight: http2priorityDefaultWeight, + state: http2priorityNodeIdle, + } + n.setParent(&ws.root) + ws.nodes[streamID] = n + ws.addClosedOrIdleNode(&ws.idleNodes, ws.maxIdleNodesInTree, n) + } + + // Section 5.3.1: A dependency on a stream that is not currently in the tree + // results in that stream being given a default priority (Section 5.3.5). + parent := ws.nodes[priority.StreamDep] + if parent == nil { + n.setParent(&ws.root) + n.weight = http2priorityDefaultWeight + return + } + + // Ignore if the client tries to make a node its own parent. + if n == parent { + return + } + + // Section 5.3.3: + // "If a stream is made dependent on one of its own dependencies, the + // formerly dependent stream is first moved to be dependent on the + // reprioritized stream's previous parent. The moved dependency retains + // its weight." + // + // That is: if parent depends on n, move parent to depend on n.parent. + for x := parent.parent; x != nil; x = x.parent { + if x == n { + parent.setParent(n.parent) + break + } + } + + // Section 5.3.3: The exclusive flag causes the stream to become the sole + // dependency of its parent stream, causing other dependencies to become + // dependent on the exclusive stream. + if priority.Exclusive { + k := parent.kids + for k != nil { + next := k.next + if k != n { + k.setParent(n) + } + k = next + } + } + + n.setParent(parent) + n.weight = priority.Weight +} + +func (ws *http2priorityWriteScheduler) Push(wr http2FrameWriteRequest) { + var n *http2priorityNode + if wr.isControl() { + n = &ws.root + } else { + id := wr.StreamID() + n = ws.nodes[id] + if n == nil { + // id is an idle or closed stream. wr should not be a HEADERS or + // DATA frame. In other case, we push wr onto the root, rather + // than creating a new priorityNode. + if wr.DataSize() > 0 { + panic("add DATA on non-open stream") + } + n = &ws.root + } + } + n.q.push(wr) +} + +func (ws *http2priorityWriteScheduler) Pop() (wr http2FrameWriteRequest, ok bool) { + ws.root.walkReadyInOrder(false, &ws.tmp, func(n *http2priorityNode, openParent bool) bool { + limit := int32(math.MaxInt32) + if openParent { + limit = ws.writeThrottleLimit + } + wr, ok = n.q.consume(limit) + if !ok { + return false + } + n.addBytes(int64(wr.DataSize())) + // If B depends on A and B continuously has data available but A + // does not, gradually increase the throttling limit to allow B to + // steal more and more bandwidth from A. + if openParent { + ws.writeThrottleLimit += 1024 + if ws.writeThrottleLimit < 0 { + ws.writeThrottleLimit = math.MaxInt32 + } + } else if ws.enableWriteThrottle { + ws.writeThrottleLimit = 1024 + } + return true + }) + return wr, ok +} + +func (ws *http2priorityWriteScheduler) addClosedOrIdleNode(list *[]*http2priorityNode, maxSize int, n *http2priorityNode) { + if maxSize == 0 { + return + } + if len(*list) == maxSize { + // Remove the oldest node, then shift left. + ws.removeNode((*list)[0]) + x := (*list)[1:] + copy(*list, x) + *list = (*list)[:len(x)] + } + *list = append(*list, n) +} + +func (ws *http2priorityWriteScheduler) removeNode(n *http2priorityNode) { + for k := n.kids; k != nil; k = k.next { + k.setParent(n.parent) + } + n.setParent(nil) + delete(ws.nodes, n.id) +} + +// NewRandomWriteScheduler constructs a WriteScheduler that ignores HTTP/2 +// priorities. Control frames like SETTINGS and PING are written before DATA +// frames, but if no control frames are queued and multiple streams have queued +// HEADERS or DATA frames, Pop selects a ready stream arbitrarily. +func http2NewRandomWriteScheduler() http2WriteScheduler { + return &http2randomWriteScheduler{sq: make(map[uint32]*http2writeQueue)} +} + +type http2randomWriteScheduler struct { + // zero are frames not associated with a specific stream. + zero http2writeQueue + + // sq contains the stream-specific queues, keyed by stream ID. + // When a stream is idle, closed, or emptied, it's deleted + // from the map. + sq map[uint32]*http2writeQueue + + // pool of empty queues for reuse. + queuePool http2writeQueuePool +} + +func (ws *http2randomWriteScheduler) OpenStream(streamID uint32, options http2OpenStreamOptions) { + // no-op: idle streams are not tracked +} + +func (ws *http2randomWriteScheduler) CloseStream(streamID uint32) { + q, ok := ws.sq[streamID] + if !ok { + return + } + delete(ws.sq, streamID) + ws.queuePool.put(q) +} + +func (ws *http2randomWriteScheduler) AdjustStream(streamID uint32, priority http2PriorityParam) { + // no-op: priorities are ignored +} + +func (ws *http2randomWriteScheduler) Push(wr http2FrameWriteRequest) { + if wr.isControl() { + ws.zero.push(wr) + return + } + id := wr.StreamID() + q, ok := ws.sq[id] + if !ok { + q = ws.queuePool.get() + ws.sq[id] = q + } + q.push(wr) +} + +func (ws *http2randomWriteScheduler) Pop() (http2FrameWriteRequest, bool) { + // Control and RST_STREAM frames first. + if !ws.zero.empty() { + return ws.zero.shift(), true + } + // Iterate over all non-idle streams until finding one that can be consumed. + for streamID, q := range ws.sq { + if wr, ok := q.consume(math.MaxInt32); ok { + if q.empty() { + delete(ws.sq, streamID) + ws.queuePool.put(q) + } + return wr, true + } + } + return http2FrameWriteRequest{}, false +} |