Linux sandbox: add a new low-level broker process mechanism.

base/posix/unix_domain_socket.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/posix/unix_domain_socket.h"
 
 #include <errno.h>
 #include <unistd.h>
 #include <sys/uio.h>
 #include <sys/socket.h>
@@ skipping 25 matching lines @@
     msg.msg_control = control_buffer;
     msg.msg_controllen = control_len;
     cmsg = CMSG_FIRSTHDR(&msg);
     cmsg->cmsg_level = SOL_SOCKET;
     cmsg->cmsg_type = SCM_RIGHTS;
     cmsg->cmsg_len = CMSG_LEN(sizeof(int) * fds.size());
     memcpy(CMSG_DATA(cmsg), &fds[0], sizeof(int) * fds.size());
     msg.msg_controllen = cmsg->cmsg_len;
   }
 
-  const ssize_t r = HANDLE_EINTR(sendmsg(fd, &msg, 0));
+  // When available, take advantage of MSG_NOSIGNAL to avoid
+  // a SIGPIPE if the other end breaks the connection.
+#if defined(MSG_NOSIGNAL)
+  const int flags = MSG_NOSIGNAL;
+#else
+  const int flags = 0;
+#endif
+  const ssize_t r = HANDLE_EINTR(sendmsg(fd, &msg, flags));
   const bool ret = static_cast<ssize_t>(length) == r;
   delete[] control_buffer;
   return ret;
 }
 
 // static
 ssize_t UnixDomainSocket::RecvMsg(int fd,
                                   void* buf,
                                   size_t length,
                                   std::vector<int>* fds) {
@@ skipping 80 matching lines @@
     NOTREACHED();
 
     return -1;
   }
 
   if (result_fd)
     *result_fd = fd_vector.empty() ? -1 : fd_vector[0];
 
   return reply_len;
 }