src/include/fexecve.c

   1 /* liblxcapi
   2  *
   3  * Copyright © 2019 Christian Brauner <christian.brauner@ubuntu.com>.
   4  * Copyright © 2019 Canonical Ltd.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this library; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #ifndef _GNU_SOURCE
  22 #define _GNU_SOURCE 1
  23 #endif
  24
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <unistd.h>
  28
  29 #include "config.h"
  30 #include "macro.h"
  31 #include "raw_syscalls.h"
  32
  33 int fexecve(int fd, char *const argv[], char *const envp[])
  34 {
  35         char procfd[LXC_PROC_PID_FD_LEN];
  36         int ret;
  37
  38         if (fd < 0 || !argv || !envp) {
  39                 errno = EINVAL;
  40                 return -1;
  41         }
  42
  43 #ifdef __NR_execveat
  44         lxc_raw_execveat(fd, "", argv, envp, AT_EMPTY_PATH);
  45         if (errno != ENOSYS)
  46                 return -1;
  47 #endif
  48
  49         ret = snprintf(procfd, sizeof(procfd), "/proc/self/fd/%d", fd);
  50         if (ret < 0 || (size_t)ret >= sizeof(procfd)) {
  51                 errno = ENAMETOOLONG;
  52                 return -1;
  53         }
  54
  55         execve(procfd, argv, envp);
  56         return -1;
  57 }