src/lxc/console.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <dlezcano at fr.ibm.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #include <stdio.h>
  25 #include <unistd.h>
  26 #include <errno.h>
  27 #include <sys/types.h>
  28 #include <sys/un.h>
  29
  30 #include "af_unix.h"
  31 #include "error.h"
  32
  33 #include <lxc/log.h>
  34
  35 lxc_log_define(lxc_console, lxc);
  36
  37 extern int lxc_console(const char *name, int ttynum, int *fd)
  38 {
  39         struct sockaddr_un addr = { 0 };
  40         int sock, ret = -LXC_ERROR_TTY_EAGAIN;
  41
  42         snprintf(addr.sun_path, sizeof(addr.sun_path), "@%s", name);
  43         addr.sun_path[0] = '\0';
  44
  45         sock = lxc_af_unix_connect(addr.sun_path);
  46         if (sock < 0) {
  47                 ERROR("failed to connect to the tty service");
  48                 goto out;
  49         }
  50
  51         ret = lxc_af_unix_send_credential(sock, &ttynum, sizeof(ttynum));
  52         if (ret < 0) {
  53                 SYSERROR("failed to send credentials");
  54                 goto out_close;
  55         }
  56
  57         ret = lxc_af_unix_recv_fd(sock, fd, &ttynum, sizeof(ttynum));
  58         if (ret < 0) {
  59                 ERROR("failed to connect to the tty");
  60                 goto out_close;
  61         }
  62
  63         INFO("tty %d allocated", ttynum);
  64
  65         if (!ret) {
  66                 ERROR("console denied by '%s'", name);
  67                 ret = -LXC_ERROR_TTY_DENIED;
  68                 goto out_close;
  69         }
  70
  71         ret = 0;
  72
  73 out:
  74         return ret;
  75 out_close:
  76         close(sock);
  77         goto out;
  78 }