summaryrefslogtreecommitdiffstats
path: root/src/net/port.go
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:18:25 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:18:25 +0000
commit109be507377fe7f6e8819ac94041d3fdcdf6fd2f (patch)
tree2806a689f8fab4a2ec9fc949830ef270a91d667d /src/net/port.go
parentInitial commit. (diff)
downloadgolang-1.19-109be507377fe7f6e8819ac94041d3fdcdf6fd2f.tar.xz
golang-1.19-109be507377fe7f6e8819ac94041d3fdcdf6fd2f.zip
Adding upstream version 1.19.8.upstream/1.19.8upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/net/port.go')
-rw-r--r--src/net/port.go62
1 files changed, 62 insertions, 0 deletions
diff --git a/src/net/port.go b/src/net/port.go
new file mode 100644
index 0000000..32e7628
--- /dev/null
+++ b/src/net/port.go
@@ -0,0 +1,62 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package net
+
+// parsePort parses service as a decimal integer and returns the
+// corresponding value as port. It is the caller's responsibility to
+// parse service as a non-decimal integer when needsLookup is true.
+//
+// Some system resolvers will return a valid port number when given a number
+// over 65536 (see https://golang.org/issues/11715). Alas, the parser
+// can't bail early on numbers > 65536. Therefore reasonably large/small
+// numbers are parsed in full and rejected if invalid.
+func parsePort(service string) (port int, needsLookup bool) {
+ if service == "" {
+ // Lock in the legacy behavior that an empty string
+ // means port 0. See golang.org/issue/13610.
+ return 0, false
+ }
+ const (
+ max = uint32(1<<32 - 1)
+ cutoff = uint32(1 << 30)
+ )
+ neg := false
+ if service[0] == '+' {
+ service = service[1:]
+ } else if service[0] == '-' {
+ neg = true
+ service = service[1:]
+ }
+ var n uint32
+ for _, d := range service {
+ if '0' <= d && d <= '9' {
+ d -= '0'
+ } else {
+ return 0, true
+ }
+ if n >= cutoff {
+ n = max
+ break
+ }
+ n *= 10
+ nn := n + uint32(d)
+ if nn < n || nn > max {
+ n = max
+ break
+ }
+ n = nn
+ }
+ if !neg && n >= cutoff {
+ port = int(cutoff - 1)
+ } else if neg && n > cutoff {
+ port = int(cutoff)
+ } else {
+ port = int(n)
+ }
+ if neg {
+ port = -port
+ }
+ return port, false
+}