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/unix_domain_socket_posix.h" 6 7 #include <errno.h> 8 #include <unistd.h> 9 #include <sys/uio.h> 10 #include <sys/socket.h> 11 12 #include "base/eintr_wrapper.h" 13 #include "base/logging.h" 14 #include "base/pickle.h" 15 16 namespace base { 17 18 bool SendMsg(int fd, const void* buf, size_t length, std::vector<int>& fds) { 19 struct msghdr msg; 20 memset(&msg, 0, sizeof(msg)); 21 struct iovec iov = {const_cast<void*>(buf), length}; 22 msg.msg_iov = &iov; 23 msg.msg_iovlen = 1; 24 25 char* control_buffer = NULL; 26 if (fds.size()) { 27 const unsigned control_len = CMSG_SPACE(sizeof(int) * fds.size()); 28 control_buffer = new char[control_len]; 29 if (!control_buffer) 30 return false; 31 32 struct cmsghdr *cmsg; 33 34 msg.msg_control = control_buffer; 35 msg.msg_controllen = control_len; 36 cmsg = CMSG_FIRSTHDR(&msg); 37 cmsg->cmsg_level = SOL_SOCKET; 38 cmsg->cmsg_type = SCM_RIGHTS; 39 cmsg->cmsg_len = CMSG_LEN(sizeof(int) * fds.size()); 40 memcpy(CMSG_DATA(cmsg), &fds[0], sizeof(int) * fds.size()); 41 msg.msg_controllen = cmsg->cmsg_len; 42 } 43 44 const ssize_t r = HANDLE_EINTR(sendmsg(fd, &msg, 0)); 45 const bool ret = static_cast<ssize_t>(length) == r; 46 delete[] control_buffer; 47 return ret; 48 } 49 50 ssize_t RecvMsg(int fd, void* buf, size_t length, std::vector<int>* fds) { 51 static const unsigned kMaxDescriptors = 16; 52 53 fds->clear(); 54 55 struct msghdr msg; 56 memset(&msg, 0, sizeof(msg)); 57 struct iovec iov = {buf, length}; 58 msg.msg_iov = &iov; 59 msg.msg_iovlen = 1; 60 61 char control_buffer[CMSG_SPACE(sizeof(int) * kMaxDescriptors)]; 62 msg.msg_control = control_buffer; 63 msg.msg_controllen = sizeof(control_buffer); 64 65 const ssize_t r = HANDLE_EINTR(recvmsg(fd, &msg, 0)); 66 if (r == -1) 67 return -1; 68 69 int* wire_fds = NULL; 70 unsigned wire_fds_len = 0; 71 72 if (msg.msg_controllen > 0) { 73 struct cmsghdr* cmsg; 74 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { 75 if (cmsg->cmsg_level == SOL_SOCKET && 76 cmsg->cmsg_type == SCM_RIGHTS) { 77 const unsigned payload_len = cmsg->cmsg_len - CMSG_LEN(0); 78 DCHECK(payload_len % sizeof(int) == 0); 79 wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg)); 80 wire_fds_len = payload_len / sizeof(int); 81 break; 82 } 83 } 84 } 85 86 if (msg.msg_flags & MSG_TRUNC || msg.msg_flags & MSG_CTRUNC) { 87 for (unsigned i = 0; i < wire_fds_len; ++i) 88 close(wire_fds[i]); 89 errno = EMSGSIZE; 90 return -1; 91 } 92 93 fds->resize(wire_fds_len); 94 memcpy(&(*fds)[0], wire_fds, sizeof(int) * wire_fds_len); 95 96 return r; 97 } 98 99 ssize_t SendRecvMsg(int fd, uint8_t* reply, unsigned max_reply_len, int* result_fd, 100 const Pickle& request) { 101 int fds[2]; 102 103 // This socketpair is only used for the IPC and is cleaned up before 104 // returning. 105 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, fds) == -1) 106 return false; 107 108 std::vector<int> fd_vector; 109 fd_vector.push_back(fds[1]); 110 if (!SendMsg(fd, request.data(), request.size(), fd_vector)) { 111 close(fds[0]); 112 close(fds[1]); 113 return -1; 114 } 115 close(fds[1]); 116 117 fd_vector.clear(); 118 const ssize_t reply_len = RecvMsg(fds[0], reply, max_reply_len, &fd_vector); 119 close(fds[0]); 120 if (reply_len == -1) 121 return -1; 122 123 if ((fd_vector.size() > 0 && result_fd == NULL) || fd_vector.size() > 1) { 124 for (std::vector<int>::const_iterator 125 i = fd_vector.begin(); i != fd_vector.end(); ++i) { 126 close(*i); 127 } 128 129 NOTREACHED(); 130 131 return -1; 132 } 133 134 if (result_fd) { 135 if (fd_vector.size() == 0) { 136 *result_fd = -1; 137 } else { 138 *result_fd = fd_vector[0]; 139 } 140 } 141 142 return reply_len; 143 } 144 145 } // namespace base 146
