src/posix/getaddrinfo.c

   1 /*****************************************************************************
   2  * posix/getaddrinfo.c: interruptible DNS resolution for POSIX
   3  *****************************************************************************
   4  * Copyright (C) 2016 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU 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 program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <assert.h>
  26 #include <stdio.h>
  27 #include <netdb.h>
  28
  29 #include <vlc_common.h>
  30 #include <vlc_interrupt.h>
  31 #include <vlc_network.h>
  32
  33 struct vlc_gai_req
  34 {
  35     const char *name;
  36     const char *service;
  37     const struct addrinfo *hints;
  38     struct addrinfo *result;
  39     int error;
  40     vlc_sem_t done;
  41 };
  42
  43 static void *vlc_gai_thread(void *data)
  44 {
  45     struct vlc_gai_req *req = data;
  46
  47     req->error = EAI_SYSTEM;
  48     req->error = getaddrinfo(req->name, req->service, req->hints,
  49                              &req->result);
  50     vlc_sem_post(&req->done);
  51     return NULL;
  52 }
  53
  54 int vlc_getaddrinfo_i11e(const char *name, unsigned port,
  55                          const struct addrinfo *hints,
  56                          struct addrinfo **res)
  57 {
  58     struct vlc_gai_req req =
  59     {
  60         .name = name,
  61         .service = NULL,
  62         .hints = hints,
  63     };
  64     char portbuf[6];
  65     vlc_thread_t th;
  66
  67     if (port != 0)
  68     {
  69         if ((size_t)snprintf(portbuf, sizeof (portbuf), "%u",
  70                              port) >= sizeof (portbuf))
  71             return EAI_NONAME;
  72
  73         req.service = portbuf;
  74     }
  75
  76     vlc_sem_init(&req.done, 0);
  77
  78     if (vlc_clone(&th, vlc_gai_thread, &req, VLC_THREAD_PRIORITY_LOW))
  79     {
  80         vlc_sem_destroy(&req.done);
  81         return EAI_SYSTEM;
  82     }
  83
  84     vlc_sem_wait_i11e(&req.done);
  85
  86     vlc_cancel(th);
  87     vlc_join(th, NULL);
  88     vlc_sem_destroy(&req.done);
  89
  90     *res = req.result;
  91     return req.error;
  92 }