base/sync_socket_posix.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/sync_socket.h"
   6
   7 #include <errno.h>
   8 #include <limits.h>
   9 #include <fcntl.h>
  10 #include <stdio.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/socket.h>
  13 #include <sys/types.h>
  14
  15 #if defined(OS_SOLARIS)
  16 #include <sys/filio.h>
  17 #endif
  18
  19 #include "base/file_util.h"
  20 #include "base/logging.h"
  21
  22
  23 namespace base {
  24
  25 namespace {
  26 // To avoid users sending negative message lengths to Send/Receive
  27 // we clamp message lengths, which are size_t, to no more than INT_MAX.
  28 const size_t kMaxMessageLength = static_cast<size_t>(INT_MAX);
  29
  30 }  // namespace
  31
  32 const SyncSocket::Handle SyncSocket::kInvalidHandle = -1;
  33
  34 SyncSocket::SyncSocket() : handle_(kInvalidHandle) {}
  35
  36 SyncSocket::~SyncSocket() {
  37   Close();
  38 }
  39
  40 // static
  41 bool SyncSocket::CreatePair(SyncSocket* socket_a, SyncSocket* socket_b) {
  42   DCHECK(socket_a != socket_b);
  43   DCHECK(socket_a->handle_ == kInvalidHandle);
  44   DCHECK(socket_b->handle_ == kInvalidHandle);
  45
  46 #if defined(OS_MACOSX)
  47   int nosigpipe = 1;
  48 #endif  // defined(OS_MACOSX)
  49
  50   Handle handles[2] = { kInvalidHandle, kInvalidHandle };
  51   if (socketpair(AF_UNIX, SOCK_STREAM, 0, handles) != 0)
  52     goto cleanup;
  53
  54 #if defined(OS_MACOSX)
  55   // On OSX an attempt to read or write to a closed socket may generate a
  56   // SIGPIPE rather than returning -1.  setsockopt will shut this off.
  57   if (0 != setsockopt(handles[0], SOL_SOCKET, SO_NOSIGPIPE,
  58                       &nosigpipe, sizeof nosigpipe) ||
  59       0 != setsockopt(handles[1], SOL_SOCKET, SO_NOSIGPIPE,
  60                       &nosigpipe, sizeof nosigpipe)) {
  61     goto cleanup;
  62   }
  63 #endif
  64
  65   // Copy the handles out for successful return.
  66   socket_a->handle_ = handles[0];
  67   socket_b->handle_ = handles[1];
  68
  69   return true;
  70
  71  cleanup:
  72   if (handles[0] != kInvalidHandle) {
  73     if (HANDLE_EINTR(close(handles[0])) < 0)
  74       DPLOG(ERROR) << "close";
  75   }
  76   if (handles[1] != kInvalidHandle) {
  77     if (HANDLE_EINTR(close(handles[1])) < 0)
  78       DPLOG(ERROR) << "close";
  79   }
  80
  81   return false;
  82 }
  83
  84 bool SyncSocket::Close() {
  85   if (handle_ == kInvalidHandle) {
  86     return false;
  87   }
  88   int retval = HANDLE_EINTR(close(handle_));
  89   if (retval < 0)
  90     DPLOG(ERROR) << "close";
  91   handle_ = kInvalidHandle;
  92   return (retval == 0);
  93 }
  94
  95 size_t SyncSocket::Send(const void* buffer, size_t length) {
  96   DCHECK_LE(length, kMaxMessageLength);
  97   const char* charbuffer = static_cast<const char*>(buffer);
  98   int len = file_util::WriteFileDescriptor(handle_, charbuffer, length);
  99
 100   return (len == -1) ? 0 : static_cast<size_t>(len);
 101 }
 102
 103 size_t SyncSocket::Receive(void* buffer, size_t length) {
 104   DCHECK_LE(length, kMaxMessageLength);
 105   char* charbuffer = static_cast<char*>(buffer);
 106   if (file_util::ReadFromFD(handle_, charbuffer, length))
 107     return length;
 108   return 0;
 109 }
 110
 111 size_t SyncSocket::Peek() {
 112   int number_chars;
 113   if (-1 == ioctl(handle_, FIONREAD, &number_chars)) {
 114     // If there is an error in ioctl, signal that the channel would block.
 115     return 0;
 116   }
 117   return (size_t) number_chars;
 118 }
 119
 120 CancelableSyncSocket::CancelableSyncSocket() {}
 121 CancelableSyncSocket::CancelableSyncSocket(Handle handle)
 122     : SyncSocket(handle) {
 123 }
 124
 125 bool CancelableSyncSocket::Shutdown() {
 126   return HANDLE_EINTR(shutdown(handle(), SHUT_RDWR)) >= 0;
 127 }
 128
 129 size_t CancelableSyncSocket::Send(const void* buffer, size_t length) {
 130   long flags = 0;
 131   flags = fcntl(handle_, F_GETFL, NULL);
 132   if (flags != -1 && (flags & O_NONBLOCK) == 0) {
 133     // Set the socket to non-blocking mode for sending if its original mode
 134     // is blocking.
 135     fcntl(handle_, F_SETFL, flags | O_NONBLOCK);
 136   }
 137
 138   size_t len = SyncSocket::Send(buffer, length);
 139
 140   if (flags != -1 && (flags & O_NONBLOCK) == 0) {
 141     // Restore the original flags.
 142     fcntl(handle_, F_SETFL, flags);
 143   }
 144
 145   return len;
 146 }
 147
 148 // static
 149 bool CancelableSyncSocket::CreatePair(CancelableSyncSocket* socket_a,
 150                                       CancelableSyncSocket* socket_b) {
 151   return SyncSocket::CreatePair(socket_a, socket_b);
 152 }
 153
 154 }  // namespace base