1  /*
       2   * Check decoding of SCM_PIDFD control messages.
       3   *
       4   * Copyright (c) 2023 Dmitry V. Levin <ldv@strace.io>
       5   * All rights reserved.
       6   *
       7   * SPDX-License-Identifier: GPL-2.0-or-later
       8   */
       9  
      10  #include "tests.h"
      11  #include "scno.h"
      12  
      13  #include <assert.h>
      14  #include <stdio.h>
      15  #include <string.h>
      16  #include <unistd.h>
      17  #include <sys/socket.h>
      18  
      19  #define XLAT_MACROS_ONLY
      20  # include "xlat/scmvals.h"
      21  #undef XLAT_MACROS_ONLY
      22  
      23  int
      24  main(void)
      25  {
      26  	skip_if_unavailable("/proc/self/fd/");
      27  
      28  	int pv[2];
      29  	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pv))
      30                  perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
      31  	if (close(pv[1]))
      32  		perror_msg_and_fail("close");
      33  
      34  	int sv[2];
      35  	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
      36                  perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
      37  	if (close(sv[1]))
      38  		perror_msg_and_fail("close");
      39  
      40  	unsigned int cmsg_size = CMSG_SPACE(sizeof(pv[0]));
      41  	struct cmsghdr *cmsg = tail_alloc(cmsg_size);
      42  	cmsg->cmsg_len = cmsg_size;
      43  	cmsg->cmsg_level = SOL_SOCKET;
      44  	cmsg->cmsg_type = SCM_PIDFD;
      45  	memcpy(CMSG_DATA(cmsg), pv, sizeof(pv[0]));
      46  
      47  	char sym = 'A';
      48  	struct iovec iov = {
      49  		.iov_base = &sym,
      50  		.iov_len = sizeof(sym)
      51  	};
      52  	struct msghdr mh = {
      53  		.msg_iov = &iov,
      54  		.msg_iovlen = 1,
      55  		.msg_control = cmsg,
      56  		.msg_controllen = cmsg_size
      57  	};
      58  
      59  	recvmsg(sv[0], &mh, 0);
      60  
      61  	printf("recvmsg(%d<socket:[%lu]>, {msg_name=NULL, msg_namelen=0"
      62  	       ", msg_iov=[{iov_base=\"A\", iov_len=1}], msg_iovlen=1"
      63  	       ", msg_control=[{cmsg_len=%u, cmsg_level=SOL_SOCKET"
      64  	       ", cmsg_type=SCM_PIDFD, cmsg_data=%d<socket:[%lu]>}]"
      65  	       ", msg_controllen=%u, msg_flags=0}, 0) = 1 (INJECTED)\n",
      66  	       sv[0], inode_of_sockfd(sv[0]), cmsg_size,
      67  	       pv[0], inode_of_sockfd(pv[0]), cmsg_size);
      68  
      69  	puts("+++ exited with 0 +++");
      70  	return 0;
      71  }