gdb/testsuite/gdb.reverse/recvmsg-reverse.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2008-2018 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #define _GNU_SOURCE
  19 #include <sys/socket.h>
  20 #include <sys/types.h>
  21 #include <sys/un.h>
  22 #include <unistd.h>
  23
  24 void
  25 marker1 (void)
  26 {
  27 }
  28
  29 void
  30 marker2 (void)
  31 {
  32 }
  33
  34 char wdata[] = "abcdef";
  35
  36 struct iovec wv[1] = {
  37   { wdata, 6 },
  38 };
  39
  40 char wc[CMSG_SPACE (sizeof (struct ucred)) + CMSG_SPACE (sizeof (int))];
  41
  42 struct msghdr wmsg = {
  43   0, 0,
  44   wv, 1,
  45   wc, sizeof wc,
  46   0,
  47 };
  48
  49 char rdata[5] = "xxxx";
  50
  51 struct iovec rv[2] = {
  52   {&rdata[2], 2},
  53   {&rdata[0], 2},
  54 };
  55
  56 char rc[CMSG_SPACE (sizeof (struct ucred)) + 7];
  57
  58 struct msghdr rmsg = {
  59   0, 0,
  60   rv, 2,
  61   rc, sizeof rc,
  62   0,
  63 };
  64
  65 int fds[2];
  66
  67 int
  68 main (void)
  69 {
  70   int itrue = 1;
  71   /* prepare cmsg to send */
  72   struct cmsghdr *cm1 = CMSG_FIRSTHDR (&wmsg);
  73   cm1->cmsg_len = CMSG_LEN (sizeof (struct ucred));
  74   cm1->cmsg_level = AF_UNIX;
  75   cm1->cmsg_type = SCM_CREDENTIALS;
  76   struct ucred *uc = (void *) CMSG_DATA (cm1);
  77   uc->pid = getpid ();
  78   uc->uid = getuid ();
  79   uc->gid = getgid ();
  80   struct cmsghdr *cm2 = CMSG_NXTHDR (&wmsg, cm1);
  81   cm2->cmsg_len = CMSG_LEN (sizeof (int));
  82   cm2->cmsg_level = AF_UNIX;
  83   cm2->cmsg_type = SCM_RIGHTS;
  84   int *pfd = (void *) CMSG_DATA (cm2);
  85   *pfd = 2;
  86   /* do the syscalls */
  87   marker1 ();
  88   socketpair (AF_UNIX, SOCK_DGRAM, 0, fds);
  89   setsockopt (fds[0], SOL_SOCKET, SO_PASSCRED, &itrue, sizeof itrue);
  90   sendmsg (fds[1], &wmsg, 0);
  91   recvmsg (fds[0], &rmsg, 0);
  92   marker2 ();
  93   return 0;
  94 }