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