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/***************************************************************************
* libancillary - black magic on Unix domain sockets
* (C) Nicolas George
* fd_send.c - receiving file descriptors
***************************************************************************/
/*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _XPG4_2 /* Solaris sucks */
# define _XPG4_2
#endif
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <assert.h>
#if defined(__FreeBSD__)
# include <sys/param.h> /* FreeBSD sucks */
#endif
#include "ancillary.h"
int
ancil_recv_fds_with_buffer(int sock, int *fds, unsigned n_fds, void *buffer)
{
struct msghdr msghdr;
char nothing;
struct iovec nothing_ptr;
struct cmsghdr *cmsg;
int i;
nothing_ptr.iov_base = ¬hing;
nothing_ptr.iov_len = 1;
msghdr.msg_name = NULL;
msghdr.msg_namelen = 0;
msghdr.msg_iov = ¬hing_ptr;
msghdr.msg_iovlen = 1;
msghdr.msg_flags = 0;
msghdr.msg_control = buffer;
msghdr.msg_controllen = sizeof(struct cmsghdr) + sizeof(int) * n_fds;
cmsg = CMSG_FIRSTHDR(&msghdr);
cmsg->cmsg_len = msghdr.msg_controllen;
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
for(i = 0; i < n_fds; i++)
((int *)CMSG_DATA(cmsg))[i] = -1;
if(recvmsg(sock, &msghdr, 0) < 0)
return(-1);
for(i = 0; i < n_fds; i++)
fds[i] = ((int *)CMSG_DATA(cmsg))[i];
n_fds = (cmsg->cmsg_len - sizeof(struct cmsghdr)) / sizeof(int);
return(n_fds);
}
#ifndef SPARE_RECV_FDS
int
ancil_recv_fds(int sock, int *fd, unsigned n_fds)
{
ANCIL_FD_BUFFER(ANCIL_MAX_N_FDS) buffer;
assert(n_fds <= ANCIL_MAX_N_FDS);
return(ancil_recv_fds_with_buffer(sock, fd, n_fds, &buffer));
}
#endif /* SPARE_RECV_FDS */
#ifndef SPARE_RECV_FD
int
ancil_recv_fd(int sock, int *fd)
{
ANCIL_FD_BUFFER(1) buffer;
return(ancil_recv_fds_with_buffer(sock, fd, 1, &buffer) == 1 ? 0 : -1);
}
#endif /* SPARE_RECV_FD */
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