src/fcntl/fcntl.c

   1 #define _GNU_SOURCE
   2 #include <fcntl.h>
   3 #include <stdarg.h>
   4 #include <errno.h>
   5 #include "syscall.h"
   6
   7 int fcntl(int fd, int cmd, ...)
   8 {
   9         unsigned long arg;
  10         va_list ap;
  11         va_start(ap, cmd);
  12         arg = va_arg(ap, unsigned long);
  13         va_end(ap);
  14         if (cmd == F_SETFL) arg |= O_LARGEFILE;
  15         if (cmd == F_SETLKW) return syscall_cp(SYS_fcntl, fd, cmd, (void *)arg);
  16         if (cmd == F_GETOWN) {
  17                 struct f_owner_ex ex;
  18                 int ret = __syscall(SYS_fcntl, fd, F_GETOWN_EX, &ex);
  19                 if (ret == -EINVAL) return __syscall(SYS_fcntl, fd, cmd, (void *)arg);
  20                 if (ret) return __syscall_ret(ret);
  21                 return ex.type == F_OWNER_PGRP ? -ex.pid : ex.pid;
  22         }
  23         if (cmd == F_DUPFD_CLOEXEC) {
  24                 int ret = __syscall(SYS_fcntl, fd, F_DUPFD_CLOEXEC, arg);
  25                 if (ret != -EINVAL) {
  26                         if (ret >= 0)
  27                                 __syscall(SYS_fcntl, ret, F_SETFD, FD_CLOEXEC);
  28                         return __syscall_ret(ret);
  29                 }
  30                 ret = __syscall(SYS_fcntl, fd, F_DUPFD_CLOEXEC, 0);
  31                 if (ret != -EINVAL) {
  32                         if (ret >= 0) __syscall(SYS_close, ret);
  33                         return __syscall_ret(-EINVAL);
  34                 }
  35                 ret = __syscall(SYS_fcntl, fd, F_DUPFD, arg);
  36                 if (ret >= 0) __syscall(SYS_fcntl, ret, F_SETFD, FD_CLOEXEC);
  37                 return __syscall_ret(ret);
  38         }
  39         switch (cmd) {
  40         case F_SETLK:
  41         case F_GETLK:
  42         case F_GETOWN_EX:
  43         case F_SETOWN_EX:
  44                 return syscall(SYS_fcntl, fd, cmd, (void *)arg);
  45         default:
  46                 return syscall(SYS_fcntl, fd, cmd, arg);
  47         }
  48 }