granicus.if.org Git - strace/blob - tests/scm_rights.c

   1 #include <assert.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <errno.h>
   6 #include <fcntl.h>
   7 #include <sys/socket.h>
   8 #include <sys/wait.h>
   9
  10 int main(void)
  11 {
  12         int fd;
  13         int data = 0;
  14         struct iovec iov = {
  15                 .iov_base = &data,
  16                 .iov_len = sizeof(iov)
  17         };
  18
  19         while ((fd = open("/dev/null", O_RDWR)) < 3)
  20                 assert(fd >= 0);
  21         (void) close(3);
  22
  23         int sv[2];
  24         assert(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == 0);
  25         int one = 1;
  26         assert(setsockopt(sv[0], SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) == 0);
  27
  28         pid_t pid = fork();
  29         assert(pid >= 0);
  30
  31         if (pid) {
  32                 assert(close(sv[0]) == 0);
  33                 assert(dup2(sv[1], 1) == 1);
  34                 assert(close(sv[1]) == 0);
  35
  36                 int fds[2];
  37                 assert((fds[0] = open("/dev/null", O_RDWR)) == 3);
  38                 assert((fds[1] = open("/dev/zero", O_RDONLY)) == 4);
  39
  40                 union {
  41                         struct cmsghdr cmsg;
  42                         char buf[CMSG_LEN(sizeof(fds))];
  43                 } control = {
  44                         .cmsg = {
  45                                 .cmsg_level = SOL_SOCKET,
  46                                 .cmsg_type = SCM_RIGHTS,
  47                                 .cmsg_len = CMSG_LEN(sizeof(fds))
  48                         }
  49                 };
  50
  51                 memcpy(CMSG_DATA(&control.cmsg), fds, sizeof(fds));
  52
  53                 struct msghdr mh = {
  54                         .msg_iov = &iov,
  55                         .msg_iovlen = 1,
  56                         .msg_control = &control,
  57                         .msg_controllen = sizeof(control)
  58                 };
  59
  60                 assert(sendmsg(1, &mh, 0) == sizeof(iov));
  61                 assert(close(1) == 0);
  62
  63                 int status;
  64                 assert(waitpid(pid, &status, 0) == pid);
  65                 assert(status == 0);
  66         } else {
  67                 assert(close(sv[1]) == 0);
  68                 assert(dup2(sv[0], 0) == 0);
  69                 assert(close(sv[0]) == 0);
  70
  71                 struct cmsghdr control[4];
  72
  73                 struct msghdr mh = {
  74                         .msg_iov = &iov,
  75                         .msg_iovlen = 1,
  76                         .msg_control = control,
  77                         .msg_controllen = sizeof(control)
  78                 };
  79
  80                 assert(recvmsg(0, &mh, 0) == sizeof(iov));
  81                 assert(close(0) == 0);
  82         }
  83
  84         return 0;
  85 }