base/unix_domain_socket_posix.h

// Copyright (c) 2009 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.

#ifndef BASE_UNIX_DOMAIN_SOCKET_POSIX_H_
#define BASE_UNIX_DOMAIN_SOCKET_POSIX_H_

#include <stdint.h>
#include <sys/types.h>
#include <vector>

class Pickle;

namespace base {

// Use sendmsg to write the given msg and include a vector
// of file descriptors. Returns true iff successful.
bool SendMsg(int fd, const void* msg, size_t length,
             std::vector<int>& fds);
// Use recvmsg to read a message and an array of file descriptors. Returns
// -1 on failure. Note: will read, at most, 16 descriptors.
ssize_t RecvMsg(int fd, void* msg, size_t length, std::vector<int>* fds);
// Perform a sendmsg/recvmsg pair.
//   1. This process creates a UNIX DGRAM socketpair.
//   2. This proces writes a request to |fd| with an SCM_RIGHTS control message
//      containing on end of the fresh socket pair.
//   3. This process blocks reading from the other end of the fresh socketpair.
//   4. The target process receives the request, processes it and writes the
//      reply to the end of the socketpair contained in the request.
//   5. This process wakes up and continues.
//
//   fd: descriptor to send the request on
//   reply: buffer for the reply
//   reply_len: size of |reply|
//   result_fd: (may be NULL) the file descriptor returned in the reply (if any)
//   request: the bytes to send in the request
ssize_t SendRecvMsg(int fd, uint8_t* reply, unsigned reply_len, int* result_fd,
                    const Pickle& request);

}  // namespace base

#endif  // BASE_UNIX_DOMAIN_SOCKET_POSIX_H_