syscalls/tee.c

   1 /*
   2  * SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
   3  */
   4 #include <stdlib.h>
   5 #include "sanitise.h"
   6 #include "shm.h"
   7
   8 # define SPLICE_F_MOVE          1       /* Move pages instead of copying.  */
   9 # define SPLICE_F_NONBLOCK      2       /* Don't block on the pipe splicing
  10                                            (but we may still block on the fd
  11                                            we splice from/to).  */
  12 # define SPLICE_F_MORE          4       /* Expect more data.  */
  13 # define SPLICE_F_GIFT          8       /* Pages passed in are a gift.  */
  14
  15 static void sanitise_tee(int childno)
  16 {
  17         if ((rand() % 10) > 0) {
  18                 shm->syscall[childno].a1 = shm->pipe_fds[rand() % MAX_PIPE_FDS];
  19                 shm->syscall[childno].a2 = shm->pipe_fds[rand() % MAX_PIPE_FDS];
  20         }
  21 }
  22
  23 struct syscallentry syscall_tee = {
  24         .name = "tee",
  25         .num_args = 4,
  26         .arg1name = "fdin",
  27         .arg1type = ARG_FD,
  28         .arg2name = "fdout",
  29         .arg2type = ARG_FD,
  30         .arg3name = "len",
  31         .arg3type = ARG_LEN,
  32         .arg4name = "flags",
  33         .arg4type = ARG_LIST,
  34         .arg4list = {
  35                 .num = 4,
  36                 .values = { SPLICE_F_MOVE, SPLICE_F_NONBLOCK, SPLICE_F_MORE, SPLICE_F_GIFT },
  37         },
  38         .sanitise = sanitise_tee,
  39         .flags = NEED_ALARM,
  40 };