memcheck/tests/sendmsg.c

   1 #include <netinet/ip.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <sys/types.h>
   6 #include <sys/socket.h>
   7
   8 #define PORT 12345
   9
  10 int
  11 main (int argc, char **argv)
  12 {
  13   int fd;
  14   struct sockaddr_in sa;
  15   struct msghdr msg;
  16   struct iovec iov[2];
  17
  18   fd = socket (AF_INET, SOCK_DGRAM, 0);
  19   if (fd == -1)
  20     {
  21       perror ("socket()");
  22       exit (EXIT_FAILURE);
  23     }
  24
  25   sa.sin_family = AF_INET;
  26   sa.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
  27   sa.sin_port = htons (PORT);
  28   if (connect (fd, (struct sockaddr *) &sa, sizeof (sa)) == -1)
  29     {
  30       perror ("connect ()");
  31       exit (EXIT_FAILURE);
  32     }
  33
  34   // Create msg_hdr. Oops, we forget to set msg_name...
  35   msg.msg_namelen = 0;
  36   iov[0].iov_base = "one";
  37   iov[0].iov_len = 3;
  38   iov[1].iov_base = "two";
  39   iov[1].iov_len = 3;
  40   msg.msg_iov = &iov[0];
  41   msg.msg_iovlen = 2;
  42   msg.msg_control = NULL;
  43   msg.msg_controllen = 0;
  44
  45   size_t s = sendmsg (fd, &msg, 0);
  46
  47   // Note how we now do set msg_name, but don't set msg_flags.
  48   // The msg_flags field is ignored by sendmsg.
  49   msg.msg_name = NULL;
  50
  51   fd = socket (AF_INET, SOCK_DGRAM, 0);
  52   if (fd == -1)
  53     {
  54       perror ("socket()");
  55       exit (EXIT_FAILURE);
  56     }
  57
  58   if (connect (fd, (struct sockaddr *) &sa, sizeof (sa)) == -1)
  59     {
  60       perror ("connect ()");
  61       exit (EXIT_FAILURE);
  62     }
  63
  64   s = sendmsg (fd, &msg, 0);
  65   if (s == -1)
  66     {
  67       perror ("sendmsg ()");
  68       exit (EXIT_FAILURE);
  69     }
  70   else
  71     fprintf (stderr, "sendmsg: %d\n", (int) s);
  72
  73   return 0;
  74 }