syscalls/fcntl.c

   1 /*
   2  * SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
   3  *
   4  * For a successful call, the return value depends on the operation:
   5  *
   6  *     F_DUPFD The new descriptor.
   7  *     F_GETFD Value of file descriptor flags.
   8  *     F_GETFL Value of file status flags.
   9  *     F_GETLEASE Type of lease held on file descriptor.
  10  *     F_GETOWN Value of descriptor owner.
  11  *     F_GETSIG Value of signal sent when read or write becomes possible, or zero for traditional SIGIO behavior.
  12  *     F_GETPIPE_SZ The pipe capacity.
  13  *
  14  *     All other commands
  15  *              Zero.
  16  *
  17  *     On error, -1 is returned, and errno is set appropriately.
  18  */
  19
  20 #include <fcntl.h>
  21 #include <signal.h>
  22 #include "random.h"
  23 #include "sanitise.h"
  24 #include "shm.h"
  25 #include "compat.h"
  26
  27 #if F_GETLK64 != F_GETLK
  28 #define HAVE_LK64
  29 #endif
  30
  31 static void sanitise_fcntl(int childno)
  32 {
  33         switch (shm->a2[childno]) {
  34         /* arg = fd */
  35         case F_DUPFD:
  36         case F_DUPFD_CLOEXEC:
  37         case F_SETLEASE:
  38                 shm->a3[childno] = (unsigned long) get_random_fd();
  39                 break;
  40
  41         /* no arg */
  42         case F_GETFD:
  43         case F_GETFL:
  44         case F_GETOWN:
  45         case F_GETSIG:
  46         case F_GETLEASE:
  47         case F_GETPIPE_SZ:
  48         case F_GETOWNER_UIDS:
  49                 break;
  50
  51         case F_SETFD:   /* arg = flags */
  52                 shm->a3[childno] = (unsigned int) rand32();
  53                 break;
  54
  55         case F_SETFL:
  56                 shm->a3[childno] = 0L;
  57                 if (rand_bool())
  58                         shm->a3[childno] |= O_APPEND;
  59                 if (rand_bool())
  60                         shm->a3[childno] |= O_ASYNC;
  61                 if (rand_bool())
  62                         shm->a3[childno] |= O_DIRECT;
  63                 if (rand_bool())
  64                         shm->a3[childno] |= O_NOATIME;
  65                 if (rand_bool())
  66                         shm->a3[childno] |= O_NONBLOCK;
  67                 break;
  68
  69         /* arg = (struct flock *) */
  70         case F_GETLK:
  71         case F_SETLK:
  72         case F_SETLKW:
  73                 break;
  74 #ifdef HAVE_LK64
  75         case F_GETLK64:
  76                 break;
  77         case F_SETLK64:
  78                 break;
  79         case F_SETLKW64:
  80                 break;
  81 #endif
  82
  83         case F_SETOWN:
  84                 shm->a3[childno] = (unsigned long) get_pid();
  85                 break;
  86
  87         /* arg = struct f_owner_ex *) */
  88         case F_GETOWN_EX:
  89         case F_SETOWN_EX:
  90                 break;
  91
  92         case F_SETSIG:
  93                 shm->a3[childno] = (unsigned long) rand32();
  94                 if (shm->a3[childno] == SIGINT)
  95                         shm->a3[childno] = 0; /* restore default (SIGIO) */
  96                 break;
  97
  98         case F_NOTIFY:
  99                 shm->a3[childno] = 0L;
 100                 if (rand_bool())
 101                         shm->a3[childno] |= DN_ACCESS;
 102                 if (rand_bool())
 103                         shm->a3[childno] |= DN_MODIFY;
 104                 if (rand_bool())
 105                         shm->a3[childno] |= DN_CREATE;
 106                 if (rand_bool())
 107                         shm->a3[childno] |= DN_DELETE;
 108                 if (rand_bool())
 109                         shm->a3[childno] |= DN_RENAME;
 110                 if (rand_bool())
 111                         shm->a3[childno] |= DN_ATTRIB;
 112                 break;
 113
 114         case F_SETPIPE_SZ:
 115                 shm->a3[childno] = rand32();
 116                 break;
 117
 118         default:
 119                 break;
 120         }
 121
 122 }
 123
 124 struct syscallentry syscall_fcntl = {
 125         .name = "fcntl",
 126         .num_args = 3,
 127         .arg1name = "fd",
 128         .arg1type = ARG_FD,
 129         .arg2name = "cmd",
 130         .arg2type = ARG_OP,
 131         .arg2list = {
 132 #ifndef HAVE_LK64
 133                 .num = 21,
 134 #else
 135                 .num = 24,
 136 #endif
 137                 .values = { F_DUPFD, F_DUPFD_CLOEXEC, F_GETFD, F_SETFD, F_GETFL, F_SETFL, F_GETLK, F_SETLK,
 138                   F_SETLKW, F_GETOWN, F_SETOWN, F_GETOWN_EX, F_SETOWN_EX, F_GETSIG, F_SETSIG, F_GETLEASE,
 139                   F_SETLEASE, F_NOTIFY, F_SETPIPE_SZ, F_GETPIPE_SZ, F_GETOWNER_UIDS,
 140 #ifdef HAVE_LK64
 141                   F_GETLK64, F_SETLK64, F_SETLKW64,
 142 #endif
 143                 },
 144         },
 145         .arg3name = "arg",
 146         .rettype = RET_FD,      //FIXME: Needs to mutate somehow depending on 'cmd'
 147         .flags = NEED_ALARM,
 148         .group = GROUP_VFS,
 149         .sanitise = sanitise_fcntl,
 150 };