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 #include "config_components.h"
  28
  29 #include "libavutil/avstring.h"
  30 #include "avformat.h"
  31 #include "internal.h"
  32 #include "network.h"
  33 #include "url.h"
  34
  35 typedef struct GopherContext {
  36     URLContext *hd;
  37 } GopherContext;
  38
  39 static int gopher_write(URLContext *h, const uint8_t *buf, int size)
  40 {
  41     GopherContext *s = h->priv_data;
  42     return ffurl_write(s->hd, buf, size);
  43 }
  44
  45 static int gopher_connect(URLContext *h, const char *path)
  46 {
  47     char buffer[1024];
  48
  49     if (!*path) return AVERROR(EINVAL);
  50     switch (*++path) {
  51         case ';':
  52         case '<':
  53         case '5':
  54         case '9':
  55         case 's':
  56             path = strchr(path, '/');
  57             if (!path) return AVERROR(EINVAL);
  58             break;
  59         default:
  60             av_log(h, AV_LOG_WARNING,
  61                    "Gopher protocol type '%c' not supported yet!\n",
  62                    *path);
  63             return AVERROR(EINVAL);
  64     }
  65
  66     /* send gopher sector */
  67     snprintf(buffer, sizeof(buffer), "%s\r\n", path);
  68
  69     if (gopher_write(h, buffer, strlen(buffer)) < 0)
  70         return AVERROR(EIO);
  71
  72     return 0;
  73 }
  74
  75 static int gopher_close(URLContext *h)
  76 {
  77     GopherContext *s = h->priv_data;
  78     ffurl_closep(&s->hd);
  79     return 0;
  80 }
  81
  82 static int gopher_open(URLContext *h, const char *uri, int flags)
  83 {
  84     GopherContext *s = h->priv_data;
  85     char proto[10], hostname[1024], auth[1024], path[1024], buf[1024];
  86     int port, err;
  87     const char *lower_proto = "tcp";
  88
  89     h->is_streamed = 1;
  90
  91     /* needed in any case to build the host string */
  92     av_url_split(proto, sizeof(proto), auth, sizeof(auth),
  93                  hostname, sizeof(hostname), &port, path, sizeof(path), uri);
  94
  95     if (port < 0)
  96         port = 70;
  97
  98     if (!strcmp(proto, "gophers"))
  99         lower_proto = "tls";
 100
 101     ff_url_join(buf, sizeof(buf), lower_proto, NULL, hostname, port, NULL);
 102
 103     s->hd = NULL;
 104     err = ffurl_open_whitelist(&s->hd, buf, AVIO_FLAG_READ_WRITE,
 105                                &h->interrupt_callback, NULL, h->protocol_whitelist, h->protocol_blacklist, h);
 106     if (err < 0)
 107         goto fail;
 108
 109     if ((err = gopher_connect(h, path)) < 0)
 110         goto fail;
 111     return 0;
 112  fail:
 113     gopher_close(h);
 114     return err;
 115 }
 116
 117 static int gopher_read(URLContext *h, uint8_t *buf, int size)
 118 {
 119     GopherContext *s = h->priv_data;
 120     int len = ffurl_read(s->hd, buf, size);
 121     return len;
 122 }
 123
 124 #if CONFIG_GOPHER_PROTOCOL
 125 const URLProtocol ff_gopher_protocol = {
 126     .name              = "gopher",
 127     .url_open          = gopher_open,
 128     .url_read          = gopher_read,
 129     .url_write         = gopher_write,
 130     .url_close         = gopher_close,
 131     .priv_data_size    = sizeof(GopherContext),
 132     .flags             = URL_PROTOCOL_FLAG_NETWORK,
 133     .default_whitelist = "gopher,tcp"
 134 };
 135 #endif /* CONFIG_GOPHER_PROTOCOL */
 136
 137 #if CONFIG_GOPHERS_PROTOCOL
 138 const URLProtocol ff_gophers_protocol = {
 139     .name              = "gophers",
 140     .url_open          = gopher_open,
 141     .url_read          = gopher_read,
 142     .url_write         = gopher_write,
 143     .url_close         = gopher_close,
 144     .priv_data_size    = sizeof(GopherContext),
 145     .flags             = URL_PROTOCOL_FLAG_NETWORK,
 146     .default_whitelist = "gopher,gophers,tcp,tls"
 147 };
 148 #endif /* CONFIG_GOPHERS_PROTOCOL */