Adding upstream version 1.52.0.upstream/1.52.0upstream

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

1 files changed, 353 insertions, 0 deletions

diff --git a/src/shrpx_dns_resolver.cc b/src/shrpx_dns_resolver.cc
new file mode 100644
index 0000000..f83ecb7
--- /dev/null
+++ b/src/shrpx_dns_resolver.cc
@@ -0,0 +1,353 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2016 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_dns_resolver.h"
+
+#include <cstring>
+#include <sys/time.h>
+
+#include "shrpx_log.h"
+#include "shrpx_connection.h"
+#include "shrpx_config.h"
+
+namespace shrpx {
+
+namespace {
+void sock_state_cb(void *data, int s, int read, int write) {
+  auto resolv = static_cast<DNSResolver *>(data);
+
+  if (resolv->get_status(nullptr) != DNSResolverStatus::RUNNING) {
+    return;
+  }
+
+  if (read) {
+    resolv->start_rev(s);
+  } else {
+    resolv->stop_rev(s);
+  }
+  if (write) {
+    resolv->start_wev(s);
+  } else {
+    resolv->stop_wev(s);
+  }
+}
+} // namespace
+
+namespace {
+void host_cb(void *arg, int status, int timeouts, hostent *hostent) {
+  auto resolv = static_cast<DNSResolver *>(arg);
+  resolv->on_result(status, hostent);
+}
+} // namespace
+
+namespace {
+void process_result(DNSResolver *resolv) {
+  auto cb = resolv->get_complete_cb();
+  if (!cb) {
+    return;
+  }
+  Address result;
+  auto status = resolv->get_status(&result);
+  switch (status) {
+  case DNSResolverStatus::OK:
+  case DNSResolverStatus::ERROR:
+    cb(status, &result);
+    break;
+  default:
+    break;
+  }
+  // resolv may be deleted here.
+}
+} // namespace
+
+namespace {
+void readcb(struct ev_loop *loop, ev_io *w, int revents) {
+  auto resolv = static_cast<DNSResolver *>(w->data);
+  resolv->on_read(w->fd);
+  process_result(resolv);
+}
+} // namespace
+
+namespace {
+void writecb(struct ev_loop *loop, ev_io *w, int revents) {
+  auto resolv = static_cast<DNSResolver *>(w->data);
+  resolv->on_write(w->fd);
+  process_result(resolv);
+}
+} // namespace
+
+namespace {
+void timeoutcb(struct ev_loop *loop, ev_timer *w, int revents) {
+  auto resolv = static_cast<DNSResolver *>(w->data);
+  resolv->on_timeout();
+  process_result(resolv);
+}
+} // namespace
+
+namespace {
+void stop_ev(struct ev_loop *loop,
+             const std::vector<std::unique_ptr<ev_io>> &evs) {
+  for (auto &w : evs) {
+    ev_io_stop(loop, w.get());
+  }
+}
+} // namespace
+
+DNSResolver::DNSResolver(struct ev_loop *loop)
+    : result_{},
+      loop_(loop),
+      channel_(nullptr),
+      family_(AF_UNSPEC),
+      status_(DNSResolverStatus::IDLE) {
+  ev_timer_init(&timer_, timeoutcb, 0., 0.);
+  timer_.data = this;
+}
+
+DNSResolver::~DNSResolver() {
+  if (channel_) {
+    ares_destroy(channel_);
+  }
+
+  stop_ev(loop_, revs_);
+  stop_ev(loop_, wevs_);
+
+  ev_timer_stop(loop_, &timer_);
+}
+
+int DNSResolver::resolve(const StringRef &name, int family) {
+  if (status_ != DNSResolverStatus::IDLE) {
+    return -1;
+  }
+
+  if (LOG_ENABLED(INFO)) {
+    LOG(INFO) << "Start resolving host " << name << " in IPv"
+              << (family == AF_INET ? "4" : "6");
+  }
+
+  name_ = name;
+  family_ = family;
+
+  int rv;
+
+  auto &dnsconf = get_config()->dns;
+
+  ares_options opts{};
+  opts.sock_state_cb = sock_state_cb;
+  opts.sock_state_cb_data = this;
+  opts.timeout = static_cast<int>(dnsconf.timeout.lookup * 1000);
+  opts.tries = dnsconf.max_try;
+
+  auto optmask = ARES_OPT_SOCK_STATE_CB | ARES_OPT_TIMEOUTMS | ARES_OPT_TRIES;
+
+  ares_channel chan;
+  rv = ares_init_options(&chan, &opts, optmask);
+  if (rv != ARES_SUCCESS) {
+    if (LOG_ENABLED(INFO)) {
+      LOG(INFO) << "ares_init_options failed: " << ares_strerror(rv);
+    }
+    status_ = DNSResolverStatus::ERROR;
+    return -1;
+  }
+
+  channel_ = chan;
+  status_ = DNSResolverStatus::RUNNING;
+
+  ares_gethostbyname(channel_, name_.c_str(), family_, host_cb, this);
+  reset_timeout();
+
+  return 0;
+}
+
+int DNSResolver::on_read(int fd) { return handle_event(fd, ARES_SOCKET_BAD); }
+
+int DNSResolver::on_write(int fd) { return handle_event(ARES_SOCKET_BAD, fd); }
+
+int DNSResolver::on_timeout() {
+  return handle_event(ARES_SOCKET_BAD, ARES_SOCKET_BAD);
+}
+
+int DNSResolver::handle_event(int rfd, int wfd) {
+  if (status_ == DNSResolverStatus::IDLE) {
+    return -1;
+  }
+
+  ares_process_fd(channel_, rfd, wfd);
+
+  switch (status_) {
+  case DNSResolverStatus::RUNNING:
+    reset_timeout();
+    return 0;
+  case DNSResolverStatus::OK:
+    return 0;
+  case DNSResolverStatus::ERROR:
+    return -1;
+  default:
+    // Unreachable
+    assert(0);
+    abort();
+  }
+}
+
+void DNSResolver::reset_timeout() {
+  if (status_ != DNSResolverStatus::RUNNING) {
+    return;
+  }
+  timeval tvout;
+  auto tv = ares_timeout(channel_, nullptr, &tvout);
+  if (tv == nullptr) {
+    return;
+  }
+  // To avoid that timer_.repeat becomes 0, which makes ev_timer_again
+  // useless, add tiny fraction of time.
+  timer_.repeat = tv->tv_sec + tv->tv_usec / 1000000. + 1e-9;
+  ev_timer_again(loop_, &timer_);
+}
+
+DNSResolverStatus DNSResolver::get_status(Address *result) const {
+  if (status_ != DNSResolverStatus::OK) {
+    return status_;
+  }
+
+  if (result) {
+    memcpy(result, &result_, sizeof(result_));
+  }
+
+  return status_;
+}
+
+namespace {
+void start_ev(std::vector<std::unique_ptr<ev_io>> &evs, struct ev_loop *loop,
+              int fd, int event, IOCb cb, void *data) {
+  for (auto &w : evs) {
+    if (w->fd == fd) {
+      return;
+    }
+  }
+  for (auto &w : evs) {
+    if (w->fd == -1) {
+      ev_io_set(w.get(), fd, event);
+      ev_io_start(loop, w.get());
+      return;
+    }
+  }
+
+  auto w = std::make_unique<ev_io>();
+  ev_io_init(w.get(), cb, fd, event);
+  w->data = data;
+  ev_io_start(loop, w.get());
+  evs.emplace_back(std::move(w));
+}
+} // namespace
+
+namespace {
+void stop_ev(std::vector<std::unique_ptr<ev_io>> &evs, struct ev_loop *loop,
+             int fd, int event) {
+  for (auto &w : evs) {
+    if (w->fd == fd) {
+      ev_io_stop(loop, w.get());
+      ev_io_set(w.get(), -1, event);
+      return;
+    }
+  }
+}
+} // namespace
+
+void DNSResolver::start_rev(int fd) {
+  start_ev(revs_, loop_, fd, EV_READ, readcb, this);
+}
+
+void DNSResolver::stop_rev(int fd) { stop_ev(revs_, loop_, fd, EV_READ); }
+
+void DNSResolver::start_wev(int fd) {
+  start_ev(wevs_, loop_, fd, EV_WRITE, writecb, this);
+}
+
+void DNSResolver::stop_wev(int fd) { stop_ev(wevs_, loop_, fd, EV_WRITE); }
+
+void DNSResolver::on_result(int status, hostent *hostent) {
+  stop_ev(loop_, revs_);
+  stop_ev(loop_, wevs_);
+  ev_timer_stop(loop_, &timer_);
+
+  if (status != ARES_SUCCESS) {
+    if (LOG_ENABLED(INFO)) {
+      LOG(INFO) << "Name lookup for " << name_
+                << " failed: " << ares_strerror(status);
+    }
+    status_ = DNSResolverStatus::ERROR;
+    return;
+  }
+
+  auto ap = *hostent->h_addr_list;
+  if (!ap) {
+    if (LOG_ENABLED(INFO)) {
+      LOG(INFO) << "Name lookup for " << name_ << "failed: no address returned";
+    }
+    status_ = DNSResolverStatus::ERROR;
+    return;
+  }
+
+  switch (hostent->h_addrtype) {
+  case AF_INET:
+    status_ = DNSResolverStatus::OK;
+    result_.len = sizeof(result_.su.in);
+    result_.su.in = {};
+    result_.su.in.sin_family = AF_INET;
+#ifdef HAVE_SOCKADDR_IN_SIN_LEN
+    result_.su.in.sin_len = sizeof(result_.su.in);
+#endif // HAVE_SOCKADDR_IN_SIN_LEN
+    memcpy(&result_.su.in.sin_addr, ap, sizeof(result_.su.in.sin_addr));
+    break;
+  case AF_INET6:
+    status_ = DNSResolverStatus::OK;
+    result_.len = sizeof(result_.su.in6);
+    result_.su.in6 = {};
+    result_.su.in6.sin6_family = AF_INET6;
+#ifdef HAVE_SOCKADDR_IN6_SIN6_LEN
+    result_.su.in6.sin6_len = sizeof(result_.su.in6);
+#endif // HAVE_SOCKADDR_IN6_SIN6_LEN
+    memcpy(&result_.su.in6.sin6_addr, ap, sizeof(result_.su.in6.sin6_addr));
+    break;
+  default:
+    assert(0);
+  }
+
+  if (status_ == DNSResolverStatus::OK) {
+    if (LOG_ENABLED(INFO)) {
+      LOG(INFO) << "Name lookup succeeded: " << name_ << " -> "
+                << util::numeric_name(&result_.su.sa, result_.len);
+    }
+    return;
+  }
+
+  status_ = DNSResolverStatus::ERROR;
+}
+
+void DNSResolver::set_complete_cb(CompleteCb cb) {
+  completeCb_ = std::move(cb);
+}
+
+CompleteCb DNSResolver::get_complete_cb() const { return completeCb_; }
+
+} // namespace shrpx