Coverage Report

Created: 2023-09-25 07:00

/src/pdns/pdns/dnsdistdist/channel.cc
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Source (jump to first uncovered line)
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/*
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 * This file is part of PowerDNS or dnsdist.
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 * Copyright -- PowerDNS.COM B.V. and its contributors
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of version 2 of the GNU General Public License as
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 * published by the Free Software Foundation.
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 *
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 * In addition, for the avoidance of any doubt, permission is granted to
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 * link this program with OpenSSL and to (re)distribute the binaries
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 * produced as the result of such linking.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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 */
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#include "channel.hh"
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namespace pdns::channel
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{
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Notifier::Notifier(FDWrapper&& descriptor) :
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  d_fd(std::move(descriptor))
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0
{
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0
}
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bool Notifier::notify() const
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{
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  char data = 'a';
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  while (true) {
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    auto sent = write(d_fd.getHandle(), &data, sizeof(data));
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    if (sent == 0) {
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      throw std::runtime_error("Unable to write to channel notifier pipe: remote end has been closed");
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    }
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    if (sent != sizeof(data)) {
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      if (errno == EINTR) {
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        continue;
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      }
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      if (errno == EAGAIN || errno == EWOULDBLOCK) {
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        return false;
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      }
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      throw std::runtime_error("Unable to write to channel notifier pipe: " + stringerror());
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    }
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    return true;
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  }
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}
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Waiter::Waiter(FDWrapper&& descriptor, bool throwOnEOF) :
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  d_fd(std::move(descriptor)), d_throwOnEOF(throwOnEOF)
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0
{
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}
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void Waiter::clear()
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0
{
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  ssize_t got{0};
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  do {
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    char data{0};
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    got = read(d_fd.getHandle(), &data, sizeof(data));
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    if (got == 0) {
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      d_closed = true;
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      if (!d_throwOnEOF) {
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        return;
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      }
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      throw std::runtime_error("EOF while clearing channel notifier pipe");
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    }
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    if (got == -1) {
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      if (errno == EINTR) {
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        continue;
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      }
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      if (errno == EAGAIN || errno == EWOULDBLOCK) {
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        break;
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      }
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      throw std::runtime_error("Error while clearing channel notifier pipe: " + stringerror());
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    }
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  } while (got > 0);
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}
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int Waiter::getDescriptor() const
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{
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  return d_fd.getHandle();
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}
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std::pair<Notifier, Waiter> createNotificationQueue(bool nonBlocking, size_t pipeBufferSize, bool throwOnEOF)
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{
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  std::array<int, 2> fds = {-1, -1};
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  if (pipe(fds.data()) < 0) {
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    throw std::runtime_error("Error creating notification channel pipe: " + stringerror());
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  }
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  FDWrapper sender(fds[1]);
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  FDWrapper receiver(fds[0]);
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  if (nonBlocking && !setNonBlocking(receiver.getHandle())) {
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    int err = errno;
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    throw std::runtime_error("Error making notification channel pipe non-blocking: " + stringerror(err));
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  }
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  if (nonBlocking && !setNonBlocking(sender.getHandle())) {
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    int err = errno;
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    throw std::runtime_error("Error making notification channel pipe non-blocking: " + stringerror(err));
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  }
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  if (pipeBufferSize > 0 && getPipeBufferSize(receiver.getHandle()) < pipeBufferSize) {
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    setPipeBufferSize(receiver.getHandle(), pipeBufferSize);
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  }
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  return {Notifier(std::move(sender)), Waiter(std::move(receiver), throwOnEOF)};
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}
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}