libavformat/gopher.c

   1 /*
   2  * Gopher protocol
   3  *
   4  * Copyright (c) 2009 Toshimitsu Kimura
   5  * Copyright (c) 2021 parazyd <parazyd@dyne.org>
   6  *
   7  * based on libavformat/http.c, Copyright (c) 2000, 2001 Fabrice Bellard
   8  *
   9  * This file is part of FFmpeg.
  10  *
  11  * FFmpeg is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2.1 of the License, or (at your option) any later version.
  15  *
  16  * FFmpeg is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with FFmpeg; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  24  */
  25
  26 #include "config.h"
  27
  28 #include "libavutil/avstring.h"
  29 #include "avformat.h"
  30 #include "internal.h"
  31 #include "network.h"
  32 #include "url.h"
  33
  34 typedef struct GopherContext {
  35     URLContext *hd;
  36 } GopherContext;
  37
  38 static int gopher_write(URLContext *h, const uint8_t *buf, int size)
  39 {
  40     GopherContext *s = h->priv_data;
  41     return ffurl_write(s->hd, buf, size);
  42 }
  43
  44 static int gopher_connect(URLContext *h, const char *path)
  45 {
  46     char buffer[1024];
  47
  48     if (!*path) return AVERROR(EINVAL);
  49     switch (*++path) {
  50         case '5':
  51         case '9':
  52             path = strchr(path, '/');
  53             if (!path) return AVERROR(EINVAL);
  54             break;
  55         default:
  56             av_log(h, AV_LOG_WARNING,
  57                    "Gopher protocol type '%c' not supported yet!\n",
  58                    *path);
  59             return AVERROR(EINVAL);
  60     }
  61
  62     /* send gopher sector */
  63     snprintf(buffer, sizeof(buffer), "%s\r\n", path);
  64
  65     if (gopher_write(h, buffer, strlen(buffer)) < 0)
  66         return AVERROR(EIO);
  67
  68     return 0;
  69 }
  70
  71 static int gopher_close(URLContext *h)
  72 {
  73     GopherContext *s = h->priv_data;
  74     ffurl_closep(&s->hd);
  75     return 0;
  76 }
  77
  78 static int gopher_open(URLContext *h, const char *uri, int flags)
  79 {
  80     GopherContext *s = h->priv_data;
  81     char proto[10], hostname[1024], auth[1024], path[1024], buf[1024];
  82     int port, err;
  83     const char *lower_proto = "tcp";
  84
  85     h->is_streamed = 1;
  86
  87     /* needed in any case to build the host string */
  88     av_url_split(proto, sizeof(proto), auth, sizeof(auth),
  89                  hostname, sizeof(hostname), &port, path, sizeof(path), uri);
  90
  91     if (port < 0)
  92         port = 70;
  93
  94     if (!strcmp(proto, "gophers"))
  95         lower_proto = "tls";
  96
  97     ff_url_join(buf, sizeof(buf), lower_proto, NULL, hostname, port, NULL);
  98
  99     s->hd = NULL;
 100     err = ffurl_open_whitelist(&s->hd, buf, AVIO_FLAG_READ_WRITE,
 101                                &h->interrupt_callback, NULL, h->protocol_whitelist, h->protocol_blacklist, h);
 102     if (err < 0)
 103         goto fail;
 104
 105     if ((err = gopher_connect(h, path)) < 0)
 106         goto fail;
 107     return 0;
 108  fail:
 109     gopher_close(h);
 110     return err;
 111 }
 112
 113 static int gopher_read(URLContext *h, uint8_t *buf, int size)
 114 {
 115     GopherContext *s = h->priv_data;
 116     int len = ffurl_read(s->hd, buf, size);
 117     return len;
 118 }
 119
 120 #if CONFIG_GOPHER_PROTOCOL
 121 const URLProtocol ff_gopher_protocol = {
 122     .name              = "gopher",
 123     .url_open          = gopher_open,
 124     .url_read          = gopher_read,
 125     .url_write         = gopher_write,
 126     .url_close         = gopher_close,
 127     .priv_data_size    = sizeof(GopherContext),
 128     .flags             = URL_PROTOCOL_FLAG_NETWORK,
 129     .default_whitelist = "gopher,tcp"
 130 };
 131 #endif /* CONFIG_GOPHER_PROTOCOL */
 132
 133 #if CONFIG_GOPHERS_PROTOCOL
 134 const URLProtocol ff_gophers_protocol = {
 135     .name              = "gophers",
 136     .url_open          = gopher_open,
 137     .url_read          = gopher_read,
 138     .url_write         = gopher_write,
 139     .url_close         = gopher_close,
 140     .priv_data_size    = sizeof(GopherContext),
 141     .flags             = URL_PROTOCOL_FLAG_NETWORK,
 142     .default_whitelist = "gopher,gophers,tcp,tls"
 143 };
 144 #endif /* CONFIG_GOPHERS_PROTOCOL */