sync_socket_win.cc revision c7f5f8508d98d5952d42ed7648c2a8f30a4da156 
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#include <limits.h>
7#include <stdio.h>
8#include <windows.h>
9#include <sys/types.h>
10#include "base/atomicops.h"
11#include "base/logging.h"
12
13
14namespace base {
15
16namespace {
17// This prefix used to be appended to pipe names for pipes
18// created in CreatePair.
19const wchar_t kPipePrefix[] = L"\\\\.\\pipe\\chrome.sync.";
20const size_t kPipePrefixSize = arraysize(kPipePrefix);
21const size_t kPathMax = 28;  // print length of process id + pair count.
22const size_t kPipePathMax = kPipePrefixSize + kPathMax + 1;
23
24// To avoid users sending negative message lengths to Send/Receive
25// we clamp message lengths, which are size_t, to no more than INT_MAX.
26const size_t kMaxMessageLength = static_cast<size_t>(INT_MAX);
27
28const int kOutBufferSize = 4096;
29const int kInBufferSize = 4096;
30const int kDefaultTimeoutMilliSeconds = 1000;
31
32static const SyncSocket::Handle kInvalidHandle = INVALID_HANDLE_VALUE;
33
34}  // namespace
35
36bool SyncSocket::CreatePair(SyncSocket* pair[2]) {
37  Handle handles[2];
38  SyncSocket* tmp_sockets[2];
39
40  // Create the two SyncSocket objects first to avoid ugly cleanup issues.
41  tmp_sockets[0] = new SyncSocket(kInvalidHandle);
42  if (tmp_sockets[0] == NULL) {
43    return false;
44  }
45  tmp_sockets[1] = new SyncSocket(kInvalidHandle);
46  if (tmp_sockets[1] == NULL) {
47    delete tmp_sockets[0];
48    return false;
49  }
50
51  wchar_t name[kPipePathMax];
52  do {
53    unsigned int rnd_name;
54    if (rand_s(&rnd_name) != 0)
55      return false;
56    swprintf(name, kPipePathMax, L"%s%u.%lu",
57             kPipePrefix, GetCurrentProcessId(),
58             rnd_name);
59    handles[0] = CreateNamedPipeW(
60        name,
61        PIPE_ACCESS_DUPLEX | FILE_FLAG_FIRST_PIPE_INSTANCE,
62        PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
63        1,
64        kOutBufferSize,
65        kInBufferSize,
66        kDefaultTimeoutMilliSeconds,
67        NULL);
68    if (handles[0] == INVALID_HANDLE_VALUE &&
69        GetLastError() != ERROR_ACCESS_DENIED &&
70        GetLastError() != ERROR_PIPE_BUSY) {
71      return false;
72    }
73  } while (handles[0] == INVALID_HANDLE_VALUE);
74  handles[1] = CreateFileW(name,
75                           GENERIC_READ | GENERIC_WRITE,
76                           0,              // no sharing.
77                           NULL,           // default security attributes.
78                           OPEN_EXISTING,  // opens existing pipe.
79                           SECURITY_SQOS_PRESENT | SECURITY_ANONYMOUS,
80                                           // no impersonation.
81                           NULL);          // no template file.
82  if (handles[1] == INVALID_HANDLE_VALUE) {
83    CloseHandle(handles[0]);
84    return false;
85  }
86  if (ConnectNamedPipe(handles[0], NULL) == FALSE) {
87    DWORD error = GetLastError();
88    if (error != ERROR_PIPE_CONNECTED) {
89      CloseHandle(handles[0]);
90      CloseHandle(handles[1]);
91      return false;
92    }
93  }
94  // Copy the handles out for successful return.
95  tmp_sockets[0]->handle_ = handles[0];
96  pair[0] = tmp_sockets[0];
97  tmp_sockets[1]->handle_ = handles[1];
98  pair[1] = tmp_sockets[1];
99  return true;
100}
101
102bool SyncSocket::Close() {
103  if (handle_ == kInvalidHandle) {
104    return false;
105  }
106  BOOL retval = CloseHandle(handle_);
107  handle_ = kInvalidHandle;
108  return retval ? true : false;
109}
110
111size_t SyncSocket::Send(const void* buffer, size_t length) {
112  DCHECK(length <= kMaxMessageLength);
113  size_t count = 0;
114  while (count < length) {
115    DWORD len;
116    // The following statement is for 64 bit portability.
117    DWORD chunk = static_cast<DWORD>(
118      ((length - count) <= UINT_MAX) ? (length - count) : UINT_MAX);
119    if (WriteFile(handle_, static_cast<const char*>(buffer) + count,
120                  chunk, &len, NULL) == FALSE) {
121      return (0 < count) ? count : 0;
122    }
123    count += len;
124  }
125  return count;
126}
127
128size_t SyncSocket::Receive(void* buffer, size_t length) {
129  DCHECK(length <= kMaxMessageLength);
130  size_t count = 0;
131  while (count < length) {
132    DWORD len;
133    DWORD chunk = static_cast<DWORD>(
134      ((length - count) <= UINT_MAX) ? (length - count) : UINT_MAX);
135    if (ReadFile(handle_, static_cast<char*>(buffer) + count,
136                 chunk, &len, NULL) == FALSE) {
137      return (0 < count) ? count : 0;
138    }
139    count += len;
140  }
141  return count;
142}
143
144size_t SyncSocket::Peek() {
145  DWORD available = 0;
146  PeekNamedPipe(handle_, NULL, 0, NULL, &available, NULL);
147  return available;
148}
149
150}  // namespace base
151