Adding upstream version 1.52.0.upstream/1.52.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1008 insertions, 0 deletions

diff --git a/src/shrpx_log.cc b/src/shrpx_log.cc
new file mode 100644
index 0000000..de5e09f
--- /dev/null
+++ b/src/shrpx_log.cc
@@ -0,0 +1,1008 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2012 Tatsuhiro Tsujikawa
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "shrpx_log.h"
+
+#ifdef HAVE_SYSLOG_H
+#  include <syslog.h>
+#endif // HAVE_SYSLOG_H
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif // HAVE_UNISTD_H
+#ifdef HAVE_INTTYPES_H
+#  include <inttypes.h>
+#endif // HAVE_INTTYPES_H
+#include <sys/types.h>
+#include <sys/stat.h>
+#ifdef HAVE_FCNTL_H
+#  include <fcntl.h>
+#endif // HAVE_FCNTL_H
+#include <sys/wait.h>
+
+#include <cerrno>
+#include <cstdio>
+#include <cstring>
+#include <ctime>
+#include <iostream>
+#include <iomanip>
+
+#include "shrpx_config.h"
+#include "shrpx_downstream.h"
+#include "shrpx_worker.h"
+#include "util.h"
+#include "template.h"
+
+using namespace nghttp2;
+
+namespace shrpx {
+
+namespace {
+constexpr StringRef SEVERITY_STR[] = {
+    StringRef::from_lit("INFO"), StringRef::from_lit("NOTICE"),
+    StringRef::from_lit("WARN"), StringRef::from_lit("ERROR"),
+    StringRef::from_lit("FATAL")};
+} // namespace
+
+namespace {
+constexpr const char *SEVERITY_COLOR[] = {
+    "\033[1;32m", // INFO
+    "\033[1;36m", // NOTICE
+    "\033[1;33m", // WARN
+    "\033[1;31m", // ERROR
+    "\033[1;35m", // FATAL
+};
+} // namespace
+
+#ifndef NOTHREADS
+#  ifdef HAVE_THREAD_LOCAL
+namespace {
+thread_local LogBuffer logbuf_;
+} // namespace
+
+namespace {
+LogBuffer *get_logbuf() { return &logbuf_; }
+} // namespace
+#  else  // !HAVE_THREAD_LOCAL
+namespace {
+pthread_key_t lckey;
+pthread_once_t lckey_once = PTHREAD_ONCE_INIT;
+} // namespace
+
+namespace {
+void make_key() { pthread_key_create(&lckey, nullptr); }
+} // namespace
+
+LogBuffer *get_logbuf() {
+  pthread_once(&lckey_once, make_key);
+  auto buf = static_cast<LogBuffer *>(pthread_getspecific(lckey));
+  if (!buf) {
+    buf = new LogBuffer();
+    pthread_setspecific(lckey, buf);
+  }
+  return buf;
+}
+#  endif // !HAVE_THREAD_LOCAL
+#else    // NOTHREADS
+namespace {
+LogBuffer *get_logbuf() {
+  static LogBuffer logbuf;
+  return &logbuf;
+}
+} // namespace
+#endif   // NOTHREADS
+
+int Log::severity_thres_ = NOTICE;
+
+void Log::set_severity_level(int severity) { severity_thres_ = severity; }
+
+int Log::get_severity_level_by_name(const StringRef &name) {
+  for (size_t i = 0, max = array_size(SEVERITY_STR); i < max; ++i) {
+    if (name == SEVERITY_STR[i]) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+int severity_to_syslog_level(int severity) {
+  switch (severity) {
+  case (INFO):
+    return LOG_INFO;
+  case (NOTICE):
+    return LOG_NOTICE;
+  case (WARN):
+    return LOG_WARNING;
+  case (ERROR):
+    return LOG_ERR;
+  case (FATAL):
+    return LOG_CRIT;
+  default:
+    return -1;
+  }
+}
+
+Log::Log(int severity, const char *filename, int linenum)
+    : buf_(*get_logbuf()),
+      begin_(buf_.data()),
+      end_(begin_ + buf_.size()),
+      last_(begin_),
+      filename_(filename),
+      flags_(0),
+      severity_(severity),
+      linenum_(linenum),
+      full_(false) {}
+
+Log::~Log() {
+  int rv;
+  auto config = get_config();
+
+  if (!config) {
+    return;
+  }
+
+  auto lgconf = log_config();
+
+  auto &errorconf = config->logging.error;
+
+  if (!log_enabled(severity_) ||
+      (lgconf->errorlog_fd == -1 && !errorconf.syslog)) {
+    return;
+  }
+
+  if (errorconf.syslog) {
+    if (severity_ == NOTICE) {
+      syslog(severity_to_syslog_level(severity_), "[%s] %.*s",
+             SEVERITY_STR[severity_].c_str(), static_cast<int>(rleft()),
+             begin_);
+    } else {
+      syslog(severity_to_syslog_level(severity_), "[%s] %.*s (%s:%d)",
+             SEVERITY_STR[severity_].c_str(), static_cast<int>(rleft()), begin_,
+             filename_, linenum_);
+    }
+
+    return;
+  }
+
+  char buf[4_k];
+  auto tty = lgconf->errorlog_tty;
+
+  lgconf->update_tstamp_millis(std::chrono::system_clock::now());
+
+  // Error log format: <datetime> <main-pid> <current-pid>
+  // <thread-id> <level> (<filename>:<line>) <msg>
+  rv = snprintf(buf, sizeof(buf), "%s %d %d %s %s%s%s (%s:%d) %.*s\n",
+                lgconf->tstamp->time_iso8601.c_str(), config->pid, lgconf->pid,
+                lgconf->thread_id.c_str(), tty ? SEVERITY_COLOR[severity_] : "",
+                SEVERITY_STR[severity_].c_str(), tty ? "\033[0m" : "",
+                filename_, linenum_, static_cast<int>(rleft()), begin_);
+
+  if (rv < 0) {
+    return;
+  }
+
+  auto nwrite = std::min(static_cast<size_t>(rv), sizeof(buf) - 1);
+
+  while (write(lgconf->errorlog_fd, buf, nwrite) == -1 && errno == EINTR)
+    ;
+}
+
+Log &Log::operator<<(const std::string &s) {
+  write_seq(std::begin(s), std::end(s));
+  return *this;
+}
+
+Log &Log::operator<<(const StringRef &s) {
+  write_seq(std::begin(s), std::end(s));
+  return *this;
+}
+
+Log &Log::operator<<(const char *s) {
+  write_seq(s, s + strlen(s));
+  return *this;
+}
+
+Log &Log::operator<<(const ImmutableString &s) {
+  write_seq(std::begin(s), std::end(s));
+  return *this;
+}
+
+Log &Log::operator<<(long long n) {
+  if (n >= 0) {
+    return *this << static_cast<uint64_t>(n);
+  }
+
+  if (flags_ & fmt_hex) {
+    write_hex(n);
+    return *this;
+  }
+
+  if (full_) {
+    return *this;
+  }
+
+  n *= -1;
+
+  size_t nlen = 0;
+  for (auto t = n; t; t /= 10, ++nlen)
+    ;
+  if (wleft() < 1 /* sign */ + nlen) {
+    full_ = true;
+    return *this;
+  }
+  *last_++ = '-';
+  last_ += nlen;
+  update_full();
+
+  auto p = last_ - 1;
+  for (; n; n /= 10) {
+    *p-- = (n % 10) + '0';
+  }
+  return *this;
+}
+
+Log &Log::operator<<(unsigned long long n) {
+  if (flags_ & fmt_hex) {
+    write_hex(n);
+    return *this;
+  }
+
+  if (full_) {
+    return *this;
+  }
+
+  if (n == 0) {
+    *last_++ = '0';
+    update_full();
+    return *this;
+  }
+  size_t nlen = 0;
+  for (auto t = n; t; t /= 10, ++nlen)
+    ;
+  if (wleft() < nlen) {
+    full_ = true;
+    return *this;
+  }
+
+  last_ += nlen;
+  update_full();
+
+  auto p = last_ - 1;
+  for (; n; n /= 10) {
+    *p-- = (n % 10) + '0';
+  }
+  return *this;
+}
+
+Log &Log::operator<<(double n) {
+  if (full_) {
+    return *this;
+  }
+
+  auto left = wleft();
+  auto rv = snprintf(reinterpret_cast<char *>(last_), left, "%.9f", n);
+  if (rv > static_cast<int>(left)) {
+    full_ = true;
+    return *this;
+  }
+
+  last_ += rv;
+  update_full();
+
+  return *this;
+}
+
+Log &Log::operator<<(long double n) {
+  if (full_) {
+    return *this;
+  }
+
+  auto left = wleft();
+  auto rv = snprintf(reinterpret_cast<char *>(last_), left, "%.9Lf", n);
+  if (rv > static_cast<int>(left)) {
+    full_ = true;
+    return *this;
+  }
+
+  last_ += rv;
+  update_full();
+
+  return *this;
+}
+
+Log &Log::operator<<(bool n) {
+  if (full_) {
+    return *this;
+  }
+
+  *last_++ = n ? '1' : '0';
+  update_full();
+
+  return *this;
+}
+
+Log &Log::operator<<(const void *p) {
+  if (full_) {
+    return *this;
+  }
+
+  write_hex(reinterpret_cast<uintptr_t>(p));
+
+  return *this;
+}
+
+namespace log {
+void hex(Log &log) { log.set_flags(Log::fmt_hex); };
+
+void dec(Log &log) { log.set_flags(Log::fmt_dec); };
+} // namespace log
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator> copy(const char *src, size_t srclen,
+                                               OutputIterator d_first,
+                                               OutputIterator d_last) {
+  auto nwrite =
+      std::min(static_cast<size_t>(std::distance(d_first, d_last)), srclen);
+  return std::make_pair(std::copy_n(src, nwrite, d_first), d_last);
+}
+} // namespace
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator>
+copy(const char *src, OutputIterator d_first, OutputIterator d_last) {
+  return copy(src, strlen(src), d_first, d_last);
+}
+} // namespace
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator>
+copy(const StringRef &src, OutputIterator d_first, OutputIterator d_last) {
+  return copy(src.c_str(), src.size(), d_first, d_last);
+}
+} // namespace
+
+namespace {
+template <size_t N, typename OutputIterator>
+std::pair<OutputIterator, OutputIterator>
+copy_l(const char (&src)[N], OutputIterator d_first, OutputIterator d_last) {
+  return copy(src, N - 1, d_first, d_last);
+}
+} // namespace
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator> copy(char c, OutputIterator d_first,
+                                               OutputIterator d_last) {
+  if (d_first == d_last) {
+    return std::make_pair(d_last, d_last);
+  }
+  *d_first++ = c;
+  return std::make_pair(d_first, d_last);
+}
+} // namespace
+
+namespace {
+constexpr char LOWER_XDIGITS[] = "0123456789abcdef";
+} // namespace
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator>
+copy_hex_low(const uint8_t *src, size_t srclen, OutputIterator d_first,
+             OutputIterator d_last) {
+  auto nwrite = std::min(static_cast<size_t>(std::distance(d_first, d_last)),
+                         srclen * 2) /
+                2;
+  for (size_t i = 0; i < nwrite; ++i) {
+    *d_first++ = LOWER_XDIGITS[src[i] >> 4];
+    *d_first++ = LOWER_XDIGITS[src[i] & 0xf];
+  }
+  return std::make_pair(d_first, d_last);
+}
+} // namespace
+
+namespace {
+template <typename OutputIterator, typename T>
+std::pair<OutputIterator, OutputIterator> copy(T n, OutputIterator d_first,
+                                               OutputIterator d_last) {
+  if (static_cast<size_t>(std::distance(d_first, d_last)) <
+      NGHTTP2_MAX_UINT64_DIGITS) {
+    return std::make_pair(d_last, d_last);
+  }
+  return std::make_pair(util::utos(d_first, n), d_last);
+}
+} // namespace
+
+namespace {
+// 1 means that character must be escaped as "\xNN", where NN is ascii
+// code of the character in hex notation.
+constexpr uint8_t ESCAPE_TBL[] = {
+    1 /* NUL  */, 1 /* SOH  */, 1 /* STX  */, 1 /* ETX  */, 1 /* EOT  */,
+    1 /* ENQ  */, 1 /* ACK  */, 1 /* BEL  */, 1 /* BS   */, 1 /* HT   */,
+    1 /* LF   */, 1 /* VT   */, 1 /* FF   */, 1 /* CR   */, 1 /* SO   */,
+    1 /* SI   */, 1 /* DLE  */, 1 /* DC1  */, 1 /* DC2  */, 1 /* DC3  */,
+    1 /* DC4  */, 1 /* NAK  */, 1 /* SYN  */, 1 /* ETB  */, 1 /* CAN  */,
+    1 /* EM   */, 1 /* SUB  */, 1 /* ESC  */, 1 /* FS   */, 1 /* GS   */,
+    1 /* RS   */, 1 /* US   */, 0 /* SPC  */, 0 /* !    */, 1 /* "    */,
+    0 /* #    */, 0 /* $    */, 0 /* %    */, 0 /* &    */, 0 /* '    */,
+    0 /* (    */, 0 /* )    */, 0 /* *    */, 0 /* +    */, 0 /* ,    */,
+    0 /* -    */, 0 /* .    */, 0 /* /    */, 0 /* 0    */, 0 /* 1    */,
+    0 /* 2    */, 0 /* 3    */, 0 /* 4    */, 0 /* 5    */, 0 /* 6    */,
+    0 /* 7    */, 0 /* 8    */, 0 /* 9    */, 0 /* :    */, 0 /* ;    */,
+    0 /* <    */, 0 /* =    */, 0 /* >    */, 0 /* ?    */, 0 /* @    */,
+    0 /* A    */, 0 /* B    */, 0 /* C    */, 0 /* D    */, 0 /* E    */,
+    0 /* F    */, 0 /* G    */, 0 /* H    */, 0 /* I    */, 0 /* J    */,
+    0 /* K    */, 0 /* L    */, 0 /* M    */, 0 /* N    */, 0 /* O    */,
+    0 /* P    */, 0 /* Q    */, 0 /* R    */, 0 /* S    */, 0 /* T    */,
+    0 /* U    */, 0 /* V    */, 0 /* W    */, 0 /* X    */, 0 /* Y    */,
+    0 /* Z    */, 0 /* [    */, 1 /* \    */, 0 /* ]    */, 0 /* ^    */,
+    0 /* _    */, 0 /* `    */, 0 /* a    */, 0 /* b    */, 0 /* c    */,
+    0 /* d    */, 0 /* e    */, 0 /* f    */, 0 /* g    */, 0 /* h    */,
+    0 /* i    */, 0 /* j    */, 0 /* k    */, 0 /* l    */, 0 /* m    */,
+    0 /* n    */, 0 /* o    */, 0 /* p    */, 0 /* q    */, 0 /* r    */,
+    0 /* s    */, 0 /* t    */, 0 /* u    */, 0 /* v    */, 0 /* w    */,
+    0 /* x    */, 0 /* y    */, 0 /* z    */, 0 /* {    */, 0 /* |    */,
+    0 /* }    */, 0 /* ~    */, 1 /* DEL  */, 1 /* 0x80 */, 1 /* 0x81 */,
+    1 /* 0x82 */, 1 /* 0x83 */, 1 /* 0x84 */, 1 /* 0x85 */, 1 /* 0x86 */,
+    1 /* 0x87 */, 1 /* 0x88 */, 1 /* 0x89 */, 1 /* 0x8a */, 1 /* 0x8b */,
+    1 /* 0x8c */, 1 /* 0x8d */, 1 /* 0x8e */, 1 /* 0x8f */, 1 /* 0x90 */,
+    1 /* 0x91 */, 1 /* 0x92 */, 1 /* 0x93 */, 1 /* 0x94 */, 1 /* 0x95 */,
+    1 /* 0x96 */, 1 /* 0x97 */, 1 /* 0x98 */, 1 /* 0x99 */, 1 /* 0x9a */,
+    1 /* 0x9b */, 1 /* 0x9c */, 1 /* 0x9d */, 1 /* 0x9e */, 1 /* 0x9f */,
+    1 /* 0xa0 */, 1 /* 0xa1 */, 1 /* 0xa2 */, 1 /* 0xa3 */, 1 /* 0xa4 */,
+    1 /* 0xa5 */, 1 /* 0xa6 */, 1 /* 0xa7 */, 1 /* 0xa8 */, 1 /* 0xa9 */,
+    1 /* 0xaa */, 1 /* 0xab */, 1 /* 0xac */, 1 /* 0xad */, 1 /* 0xae */,
+    1 /* 0xaf */, 1 /* 0xb0 */, 1 /* 0xb1 */, 1 /* 0xb2 */, 1 /* 0xb3 */,
+    1 /* 0xb4 */, 1 /* 0xb5 */, 1 /* 0xb6 */, 1 /* 0xb7 */, 1 /* 0xb8 */,
+    1 /* 0xb9 */, 1 /* 0xba */, 1 /* 0xbb */, 1 /* 0xbc */, 1 /* 0xbd */,
+    1 /* 0xbe */, 1 /* 0xbf */, 1 /* 0xc0 */, 1 /* 0xc1 */, 1 /* 0xc2 */,
+    1 /* 0xc3 */, 1 /* 0xc4 */, 1 /* 0xc5 */, 1 /* 0xc6 */, 1 /* 0xc7 */,
+    1 /* 0xc8 */, 1 /* 0xc9 */, 1 /* 0xca */, 1 /* 0xcb */, 1 /* 0xcc */,
+    1 /* 0xcd */, 1 /* 0xce */, 1 /* 0xcf */, 1 /* 0xd0 */, 1 /* 0xd1 */,
+    1 /* 0xd2 */, 1 /* 0xd3 */, 1 /* 0xd4 */, 1 /* 0xd5 */, 1 /* 0xd6 */,
+    1 /* 0xd7 */, 1 /* 0xd8 */, 1 /* 0xd9 */, 1 /* 0xda */, 1 /* 0xdb */,
+    1 /* 0xdc */, 1 /* 0xdd */, 1 /* 0xde */, 1 /* 0xdf */, 1 /* 0xe0 */,
+    1 /* 0xe1 */, 1 /* 0xe2 */, 1 /* 0xe3 */, 1 /* 0xe4 */, 1 /* 0xe5 */,
+    1 /* 0xe6 */, 1 /* 0xe7 */, 1 /* 0xe8 */, 1 /* 0xe9 */, 1 /* 0xea */,
+    1 /* 0xeb */, 1 /* 0xec */, 1 /* 0xed */, 1 /* 0xee */, 1 /* 0xef */,
+    1 /* 0xf0 */, 1 /* 0xf1 */, 1 /* 0xf2 */, 1 /* 0xf3 */, 1 /* 0xf4 */,
+    1 /* 0xf5 */, 1 /* 0xf6 */, 1 /* 0xf7 */, 1 /* 0xf8 */, 1 /* 0xf9 */,
+    1 /* 0xfa */, 1 /* 0xfb */, 1 /* 0xfc */, 1 /* 0xfd */, 1 /* 0xfe */,
+    1 /* 0xff */,
+};
+} // namespace
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator>
+copy_escape(const char *src, size_t srclen, OutputIterator d_first,
+            OutputIterator d_last) {
+  auto safe_first = src;
+  for (auto p = src; p != src + srclen && d_first != d_last; ++p) {
+    unsigned char c = *p;
+    if (!ESCAPE_TBL[c]) {
+      continue;
+    }
+
+    auto n =
+        std::min(std::distance(d_first, d_last), std::distance(safe_first, p));
+    d_first = std::copy_n(safe_first, n, d_first);
+    if (std::distance(d_first, d_last) < 4) {
+      return std::make_pair(d_first, d_last);
+    }
+    *d_first++ = '\\';
+    *d_first++ = 'x';
+    *d_first++ = LOWER_XDIGITS[c >> 4];
+    *d_first++ = LOWER_XDIGITS[c & 0xf];
+    safe_first = p + 1;
+  }
+
+  auto n = std::min(std::distance(d_first, d_last),
+                    std::distance(safe_first, src + srclen));
+  return std::make_pair(std::copy_n(safe_first, n, d_first), d_last);
+}
+} // namespace
+
+namespace {
+template <typename OutputIterator>
+std::pair<OutputIterator, OutputIterator> copy_escape(const StringRef &src,
+                                                      OutputIterator d_first,
+                                                      OutputIterator d_last) {
+  return copy_escape(src.c_str(), src.size(), d_first, d_last);
+}
+} // namespace
+
+namespace {
+// Construct absolute request URI from |Request|, mainly to log
+// request URI for proxy request (HTTP/2 proxy or client proxy).  This
+// is mostly same routine found in
+// HttpDownstreamConnection::push_request_headers(), but vastly
+// simplified since we only care about absolute URI.
+StringRef construct_absolute_request_uri(BlockAllocator &balloc,
+                                         const Request &req) {
+  if (req.authority.empty()) {
+    return req.path;
+  }
+
+  auto len = req.authority.size() + req.path.size();
+  if (req.scheme.empty()) {
+    len += str_size("http://");
+  } else {
+    len += req.scheme.size() + str_size("://");
+  }
+
+  auto iov = make_byte_ref(balloc, len + 1);
+  auto p = iov.base;
+
+  if (req.scheme.empty()) {
+    // We may have to log the request which lacks scheme (e.g.,
+    // http/1.1 with origin form).
+    p = util::copy_lit(p, "http://");
+  } else {
+    p = std::copy(std::begin(req.scheme), std::end(req.scheme), p);
+    p = util::copy_lit(p, "://");
+  }
+  p = std::copy(std::begin(req.authority), std::end(req.authority), p);
+  p = std::copy(std::begin(req.path), std::end(req.path), p);
+  *p = '\0';
+
+  return StringRef{iov.base, p};
+}
+} // namespace
+
+void upstream_accesslog(const std::vector<LogFragment> &lfv,
+                        const LogSpec &lgsp) {
+  auto config = get_config();
+  auto lgconf = log_config();
+  auto &accessconf = get_config()->logging.access;
+
+  if (lgconf->accesslog_fd == -1 && !accessconf.syslog) {
+    return;
+  }
+
+  std::array<char, 4_k> buf;
+
+  auto downstream = lgsp.downstream;
+
+  const auto &req = downstream->request();
+  const auto &resp = downstream->response();
+  const auto &tstamp = req.tstamp;
+  auto &balloc = downstream->get_block_allocator();
+
+  auto downstream_addr = downstream->get_addr();
+  auto method = req.method == -1 ? StringRef::from_lit("<unknown>")
+                                 : http2::to_method_string(req.method);
+  auto path =
+      req.method == HTTP_CONNECT ? req.authority
+      : config->http2_proxy      ? construct_absolute_request_uri(balloc, req)
+      : req.path.empty() ? req.method == HTTP_OPTIONS ? StringRef::from_lit("*")
+                                                      : StringRef::from_lit("-")
+                         : req.path;
+  auto path_without_query =
+      req.method == HTTP_CONNECT
+          ? path
+          : StringRef{std::begin(path),
+                      std::find(std::begin(path), std::end(path), '?')};
+
+  auto p = std::begin(buf);
+  auto last = std::end(buf) - 2;
+
+  for (auto &lf : lfv) {
+    switch (lf.type) {
+    case LogFragmentType::LITERAL:
+      std::tie(p, last) = copy(lf.value, p, last);
+      break;
+    case LogFragmentType::REMOTE_ADDR:
+      std::tie(p, last) = copy(lgsp.remote_addr, p, last);
+      break;
+    case LogFragmentType::TIME_LOCAL:
+      std::tie(p, last) = copy(tstamp->time_local, p, last);
+      break;
+    case LogFragmentType::TIME_ISO8601:
+      std::tie(p, last) = copy(tstamp->time_iso8601, p, last);
+      break;
+    case LogFragmentType::REQUEST:
+      std::tie(p, last) = copy(method, p, last);
+      std::tie(p, last) = copy(' ', p, last);
+      std::tie(p, last) = copy_escape(path, p, last);
+      std::tie(p, last) = copy_l(" HTTP/", p, last);
+      std::tie(p, last) = copy(req.http_major, p, last);
+      if (req.http_major < 2) {
+        std::tie(p, last) = copy('.', p, last);
+        std::tie(p, last) = copy(req.http_minor, p, last);
+      }
+      break;
+    case LogFragmentType::METHOD:
+      std::tie(p, last) = copy(method, p, last);
+      break;
+    case LogFragmentType::PATH:
+      std::tie(p, last) = copy_escape(path, p, last);
+      break;
+    case LogFragmentType::PATH_WITHOUT_QUERY:
+      std::tie(p, last) = copy_escape(path_without_query, p, last);
+      break;
+    case LogFragmentType::PROTOCOL_VERSION:
+      std::tie(p, last) = copy_l("HTTP/", p, last);
+      std::tie(p, last) = copy(req.http_major, p, last);
+      if (req.http_major < 2) {
+        std::tie(p, last) = copy('.', p, last);
+        std::tie(p, last) = copy(req.http_minor, p, last);
+      }
+      break;
+    case LogFragmentType::STATUS:
+      std::tie(p, last) = copy(resp.http_status, p, last);
+      break;
+    case LogFragmentType::BODY_BYTES_SENT:
+      std::tie(p, last) = copy(downstream->response_sent_body_length, p, last);
+      break;
+    case LogFragmentType::HTTP: {
+      auto hd = req.fs.header(lf.value);
+      if (hd) {
+        std::tie(p, last) = copy_escape((*hd).value, p, last);
+        break;
+      }
+
+      std::tie(p, last) = copy('-', p, last);
+
+      break;
+    }
+    case LogFragmentType::AUTHORITY:
+      if (!req.authority.empty()) {
+        std::tie(p, last) = copy(req.authority, p, last);
+        break;
+      }
+
+      std::tie(p, last) = copy('-', p, last);
+
+      break;
+    case LogFragmentType::REMOTE_PORT:
+      std::tie(p, last) = copy(lgsp.remote_port, p, last);
+      break;
+    case LogFragmentType::SERVER_PORT:
+      std::tie(p, last) = copy(lgsp.server_port, p, last);
+      break;
+    case LogFragmentType::REQUEST_TIME: {
+      auto t = std::chrono::duration_cast<std::chrono::milliseconds>(
+                   lgsp.request_end_time - downstream->get_request_start_time())
+                   .count();
+      std::tie(p, last) = copy(t / 1000, p, last);
+      std::tie(p, last) = copy('.', p, last);
+      auto frac = t % 1000;
+      if (frac < 100) {
+        auto n = frac < 10 ? 2 : 1;
+        std::tie(p, last) = copy("000", n, p, last);
+      }
+      std::tie(p, last) = copy(frac, p, last);
+      break;
+    }
+    case LogFragmentType::PID:
+      std::tie(p, last) = copy(lgsp.pid, p, last);
+      break;
+    case LogFragmentType::ALPN:
+      std::tie(p, last) = copy_escape(lgsp.alpn, p, last);
+      break;
+    case LogFragmentType::TLS_CIPHER:
+      if (!lgsp.ssl) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy(SSL_get_cipher_name(lgsp.ssl), p, last);
+      break;
+    case LogFragmentType::TLS_PROTOCOL:
+      if (!lgsp.ssl) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) =
+          copy(nghttp2::tls::get_tls_protocol(lgsp.ssl), p, last);
+      break;
+    case LogFragmentType::TLS_SESSION_ID: {
+      auto session = SSL_get_session(lgsp.ssl);
+      if (!session) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      unsigned int session_id_length = 0;
+      auto session_id = SSL_SESSION_get_id(session, &session_id_length);
+      if (session_id_length == 0) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy_hex_low(session_id, session_id_length, p, last);
+      break;
+    }
+    case LogFragmentType::TLS_SESSION_REUSED:
+      if (!lgsp.ssl) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) =
+          copy(SSL_session_reused(lgsp.ssl) ? 'r' : '.', p, last);
+      break;
+    case LogFragmentType::TLS_SNI:
+      if (lgsp.sni.empty()) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy_escape(lgsp.sni, p, last);
+      break;
+    case LogFragmentType::TLS_CLIENT_FINGERPRINT_SHA1:
+    case LogFragmentType::TLS_CLIENT_FINGERPRINT_SHA256: {
+      if (!lgsp.ssl) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+#if OPENSSL_3_0_0_API
+      auto x = SSL_get0_peer_certificate(lgsp.ssl);
+#else  // !OPENSSL_3_0_0_API
+      auto x = SSL_get_peer_certificate(lgsp.ssl);
+#endif // !OPENSSL_3_0_0_API
+      if (!x) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::array<uint8_t, 32> buf;
+      auto len = tls::get_x509_fingerprint(
+          buf.data(), buf.size(), x,
+          lf.type == LogFragmentType::TLS_CLIENT_FINGERPRINT_SHA256
+              ? EVP_sha256()
+              : EVP_sha1());
+#if !OPENSSL_3_0_0_API
+      X509_free(x);
+#endif // !OPENSSL_3_0_0_API
+      if (len <= 0) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy_hex_low(buf.data(), len, p, last);
+      break;
+    }
+    case LogFragmentType::TLS_CLIENT_ISSUER_NAME:
+    case LogFragmentType::TLS_CLIENT_SUBJECT_NAME: {
+      if (!lgsp.ssl) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+#if OPENSSL_3_0_0_API
+      auto x = SSL_get0_peer_certificate(lgsp.ssl);
+#else  // !OPENSSL_3_0_0_API
+      auto x = SSL_get_peer_certificate(lgsp.ssl);
+#endif // !OPENSSL_3_0_0_API
+      if (!x) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      auto name = lf.type == LogFragmentType::TLS_CLIENT_ISSUER_NAME
+                      ? tls::get_x509_issuer_name(balloc, x)
+                      : tls::get_x509_subject_name(balloc, x);
+#if !OPENSSL_3_0_0_API
+      X509_free(x);
+#endif // !OPENSSL_3_0_0_API
+      if (name.empty()) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy(name, p, last);
+      break;
+    }
+    case LogFragmentType::TLS_CLIENT_SERIAL: {
+      if (!lgsp.ssl) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+#if OPENSSL_3_0_0_API
+      auto x = SSL_get0_peer_certificate(lgsp.ssl);
+#else  // !OPENSSL_3_0_0_API
+      auto x = SSL_get_peer_certificate(lgsp.ssl);
+#endif // !OPENSSL_3_0_0_API
+      if (!x) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      auto sn = tls::get_x509_serial(balloc, x);
+#if !OPENSSL_3_0_0_API
+      X509_free(x);
+#endif // !OPENSSL_3_0_0_API
+      if (sn.empty()) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy(sn, p, last);
+      break;
+    }
+    case LogFragmentType::BACKEND_HOST:
+      if (!downstream_addr) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy(downstream_addr->host, p, last);
+      break;
+    case LogFragmentType::BACKEND_PORT:
+      if (!downstream_addr) {
+        std::tie(p, last) = copy('-', p, last);
+        break;
+      }
+      std::tie(p, last) = copy(downstream_addr->port, p, last);
+      break;
+    case LogFragmentType::NONE:
+      break;
+    default:
+      break;
+    }
+  }
+
+  *p = '\0';
+
+  if (accessconf.syslog) {
+    syslog(LOG_INFO, "%s", buf.data());
+
+    return;
+  }
+
+  *p++ = '\n';
+
+  auto nwrite = std::distance(std::begin(buf), p);
+  while (write(lgconf->accesslog_fd, buf.data(), nwrite) == -1 &&
+         errno == EINTR)
+    ;
+}
+
+int reopen_log_files(const LoggingConfig &loggingconf) {
+  int res = 0;
+  int new_accesslog_fd = -1;
+  int new_errorlog_fd = -1;
+
+  auto lgconf = log_config();
+  auto &accessconf = loggingconf.access;
+  auto &errorconf = loggingconf.error;
+
+  if (!accessconf.syslog && !accessconf.file.empty()) {
+    new_accesslog_fd = open_log_file(accessconf.file.c_str());
+
+    if (new_accesslog_fd == -1) {
+      LOG(ERROR) << "Failed to open accesslog file " << accessconf.file;
+      res = -1;
+    }
+  }
+
+  if (!errorconf.syslog && !errorconf.file.empty()) {
+    new_errorlog_fd = open_log_file(errorconf.file.c_str());
+
+    if (new_errorlog_fd == -1) {
+      if (lgconf->errorlog_fd != -1) {
+        LOG(ERROR) << "Failed to open errorlog file " << errorconf.file;
+      } else {
+        std::cerr << "Failed to open errorlog file " << errorconf.file
+                  << std::endl;
+      }
+
+      res = -1;
+    }
+  }
+
+  close_log_file(lgconf->accesslog_fd);
+  close_log_file(lgconf->errorlog_fd);
+
+  lgconf->accesslog_fd = new_accesslog_fd;
+  lgconf->errorlog_fd = new_errorlog_fd;
+  lgconf->errorlog_tty =
+      (new_errorlog_fd == -1) ? false : isatty(new_errorlog_fd);
+
+  return res;
+}
+
+void log_chld(pid_t pid, int rstatus, const char *msg) {
+  std::string signalstr;
+  if (WIFSIGNALED(rstatus)) {
+    signalstr += "; signal ";
+    auto sig = WTERMSIG(rstatus);
+    auto s = strsignal(sig);
+    if (s) {
+      signalstr += s;
+      signalstr += '(';
+    } else {
+      signalstr += "UNKNOWN(";
+    }
+    signalstr += util::utos(sig);
+    signalstr += ')';
+  }
+
+  LOG(NOTICE) << msg << ": [" << pid << "] exited "
+              << (WIFEXITED(rstatus) ? "normally" : "abnormally")
+              << " with status " << log::hex << rstatus << log::dec
+              << "; exit status "
+              << (WIFEXITED(rstatus) ? WEXITSTATUS(rstatus) : 0)
+              << (signalstr.empty() ? "" : signalstr.c_str());
+}
+
+void redirect_stderr_to_errorlog(const LoggingConfig &loggingconf) {
+  auto lgconf = log_config();
+  auto &errorconf = loggingconf.error;
+
+  if (errorconf.syslog || lgconf->errorlog_fd == -1) {
+    return;
+  }
+
+  dup2(lgconf->errorlog_fd, STDERR_FILENO);
+}
+
+namespace {
+int STDERR_COPY = -1;
+int STDOUT_COPY = -1;
+} // namespace
+
+void store_original_fds() {
+  // consider dup'ing stdout too
+  STDERR_COPY = dup(STDERR_FILENO);
+  STDOUT_COPY = STDOUT_FILENO;
+  // no race here, since it is called early
+  util::make_socket_closeonexec(STDERR_COPY);
+}
+
+void restore_original_fds() { dup2(STDERR_COPY, STDERR_FILENO); }
+
+void close_log_file(int &fd) {
+  if (fd != STDERR_COPY && fd != STDOUT_COPY && fd != -1) {
+    close(fd);
+  }
+  fd = -1;
+}
+
+int open_log_file(const char *path) {
+
+  if (strcmp(path, "/dev/stdout") == 0 ||
+      strcmp(path, "/proc/self/fd/1") == 0) {
+    return STDOUT_COPY;
+  }
+
+  if (strcmp(path, "/dev/stderr") == 0 ||
+      strcmp(path, "/proc/self/fd/2") == 0) {
+    return STDERR_COPY;
+  }
+#ifdef O_CLOEXEC
+
+  auto fd = open(path, O_WRONLY | O_APPEND | O_CREAT | O_CLOEXEC,
+                 S_IRUSR | S_IWUSR | S_IRGRP);
+#else // !O_CLOEXEC
+
+  auto fd =
+      open(path, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP);
+
+  // We get race condition if execve is called at the same time.
+  if (fd != -1) {
+    util::make_socket_closeonexec(fd);
+  }
+
+#endif // !O_CLOEXEC
+
+  if (fd == -1) {
+    return -1;
+  }
+
+  return fd;
+}
+
+} // namespace shrpx