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