1 // Copyright (c) 2009 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 <stdio.h>
10 #include <sys/types.h>
11 #include <sys/ioctl.h>
12 #include <sys/socket.h>
13
14 #include "base/file_util.h"
15 #include "base/logging.h"
16
17
18 namespace base {
19
20 namespace {
21 // To avoid users sending negative message lengths to Send/Receive
22 // we clamp message lengths, which are size_t, to no more than INT_MAX.
23 const size_t kMaxMessageLength = static_cast<size_t>(INT_MAX);
24
25 static const SyncSocket::Handle kInvalidHandle = -1;
26
27 } // namespace
28
CreatePair(SyncSocket * pair[2])29 bool SyncSocket::CreatePair(SyncSocket* pair[2]) {
30 Handle handles[2] = { kInvalidHandle, kInvalidHandle };
31 SyncSocket* tmp_sockets[2] = { NULL, NULL };
32 #if defined(OS_MACOSX)
33 int nosigpipe = 1;
34 #endif // defined(OS_MACOSX)
35
36 // Create the two SyncSocket objects first to avoid ugly cleanup issues.
37 tmp_sockets[0] = new SyncSocket(kInvalidHandle);
38 if (tmp_sockets[0] == NULL) {
39 goto cleanup;
40 }
41 tmp_sockets[1] = new SyncSocket(kInvalidHandle);
42 if (tmp_sockets[1] == NULL) {
43 goto cleanup;
44 }
45 if (socketpair(AF_UNIX, SOCK_STREAM, 0, handles) != 0) {
46 goto cleanup;
47 }
48 #if defined(OS_MACOSX)
49 // On OSX an attempt to read or write to a closed socket may generate a
50 // SIGPIPE rather than returning -1. setsockopt will shut this off.
51 if (0 != setsockopt(handles[0], SOL_SOCKET, SO_NOSIGPIPE,
52 &nosigpipe, sizeof nosigpipe) ||
53 0 != setsockopt(handles[1], SOL_SOCKET, SO_NOSIGPIPE,
54 &nosigpipe, sizeof nosigpipe)) {
55 goto cleanup;
56 }
57 #endif
58 // Copy the handles out for successful return.
59 tmp_sockets[0]->handle_ = handles[0];
60 pair[0] = tmp_sockets[0];
61 tmp_sockets[1]->handle_ = handles[1];
62 pair[1] = tmp_sockets[1];
63 return true;
64
65 cleanup:
66 if (handles[0] != kInvalidHandle) {
67 if (HANDLE_EINTR(close(handles[0])) < 0)
68 PLOG(ERROR) << "close";
69 }
70 if (handles[1] != kInvalidHandle) {
71 if (HANDLE_EINTR(close(handles[1])) < 0)
72 PLOG(ERROR) << "close";
73 }
74 delete tmp_sockets[0];
75 delete tmp_sockets[1];
76 return false;
77 }
78
Close()79 bool SyncSocket::Close() {
80 if (handle_ == kInvalidHandle) {
81 return false;
82 }
83 int retval = HANDLE_EINTR(close(handle_));
84 if (retval < 0)
85 PLOG(ERROR) << "close";
86 handle_ = kInvalidHandle;
87 return (retval == 0);
88 }
89
Send(const void * buffer,size_t length)90 size_t SyncSocket::Send(const void* buffer, size_t length) {
91 DCHECK(length <= kMaxMessageLength);
92 const char* charbuffer = static_cast<const char*>(buffer);
93 int len = file_util::WriteFileDescriptor(handle_, charbuffer, length);
94 return static_cast<size_t>(len);
95 }
96
Receive(void * buffer,size_t length)97 size_t SyncSocket::Receive(void* buffer, size_t length) {
98 DCHECK(length <= kMaxMessageLength);
99 char* charbuffer = static_cast<char*>(buffer);
100 if (file_util::ReadFromFD(handle_, charbuffer, length)) {
101 return length;
102 } else {
103 return -1;
104 }
105 }
106
Peek()107 size_t SyncSocket::Peek() {
108 int number_chars;
109 if (-1 == ioctl(handle_, FIONREAD, &number_chars)) {
110 // If there is an error in ioctl, signal that the channel would block.
111 return 0;
112 }
113 return (size_t) number_chars;
114 }
115
116 } // namespace base
117