libsoup/soup-content-decoder.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2 /*
   3  * soup-content-decoder.c
   4  *
   5  * Copyright (C) 2009 Red Hat, Inc.
   6  */
   7
   8 #ifdef HAVE_CONFIG_H
   9 #include <config.h>
  10 #endif
  11
  12 #include <string.h>
  13 #include <gio/gio.h>
  14
  15 #include "soup-content-decoder.h"
  16 #include "soup-enum-types.h"
  17 #include "soup-message.h"
  18 #include "soup-message-private.h"
  19 #include "soup-session-feature.h"
  20 #include "soup-uri.h"
  21
  22 /**
  23  * SECTION:soup-content-decoder
  24  * @short_description: Content-Encoding handler
  25  *
  26  * #SoupContentDecoder handles the "Accept-Encoding" header on
  27  * outgoing messages, and the "Content-Encoding" header on incoming
  28  * ones. If you add it to a session with soup_session_add_feature() or
  29  * soup_session_add_feature_by_type(), the session will automatically
  30  * use Content-Encoding as appropriate.
  31  *
  32  * (Note that currently there is no way to (automatically) use
  33  * Content-Encoding when sending a request body, or to pick specific
  34  * encoding types to support.)
  35  *
  36  * If #SoupContentDecoder successfully decodes the Content-Encoding,
  37  * it will set the %SOUP_MESSAGE_CONTENT_DECODED flag on the message,
  38  * and the message body and the chunks in the #SoupMessage::got_chunk
  39  * signals will contain the decoded data; however, the message headers
  40  * will be unchanged (and so "Content-Encoding" will still be present,
  41  * "Content-Length" will describe the original encoded length, etc).
  42  *
  43  * If "Content-Encoding" contains any encoding types that
  44  * #SoupContentDecoder doesn't recognize, then none of the encodings
  45  * will be decoded (and the %SOUP_MESSAGE_CONTENT_DECODED flag will
  46  * not be set).
  47  *
  48  * Since: 2.28.2
  49  **/
  50
  51 struct _SoupContentDecoderPrivate {
  52         GHashTable *decoders;
  53 };
  54
  55 typedef GConverter * (*SoupContentDecoderCreator) (void);
  56
  57 static void soup_content_decoder_session_feature_init (SoupSessionFeatureInterface *feature_interface, gpointer interface_data);
  58
  59 G_DEFINE_TYPE_WITH_CODE (SoupContentDecoder, soup_content_decoder, G_TYPE_OBJECT,
  60                          G_IMPLEMENT_INTERFACE (SOUP_TYPE_SESSION_FEATURE,
  61                                                 soup_content_decoder_session_feature_init))
  62
  63 /* This is constant for now */
  64 #define ACCEPT_ENCODING_HEADER "gzip, deflate"
  65
  66 static GConverter *
  67 gzip_decoder_creator (void)
  68 {
  69         return (GConverter *)g_zlib_decompressor_new (G_ZLIB_COMPRESSOR_FORMAT_GZIP);
  70 }
  71
  72 static GConverter *
  73 zlib_decoder_creator (void)
  74 {
  75         return (GConverter *)g_zlib_decompressor_new (G_ZLIB_COMPRESSOR_FORMAT_ZLIB);
  76 }
  77
  78 static void
  79 soup_content_decoder_init (SoupContentDecoder *decoder)
  80 {
  81         decoder->priv = G_TYPE_INSTANCE_GET_PRIVATE (decoder,
  82                                                      SOUP_TYPE_CONTENT_DECODER,
  83                                                      SoupContentDecoderPrivate);
  84
  85         decoder->priv->decoders = g_hash_table_new (g_str_hash, g_str_equal);
  86         /* Hardcoded for now */
  87         g_hash_table_insert (decoder->priv->decoders, "gzip",
  88                              gzip_decoder_creator);
  89         g_hash_table_insert (decoder->priv->decoders, "x-gzip",
  90                              gzip_decoder_creator);
  91         g_hash_table_insert (decoder->priv->decoders, "deflate",
  92                              zlib_decoder_creator);
  93 }
  94
  95 static void
  96 soup_content_decoder_finalize (GObject *object)
  97 {
  98         SoupContentDecoder *decoder = SOUP_CONTENT_DECODER (object);
  99
 100         g_hash_table_destroy (decoder->priv->decoders);
 101
 102         G_OBJECT_CLASS (soup_content_decoder_parent_class)->finalize (object);
 103 }
 104
 105 static void
 106 soup_content_decoder_class_init (SoupContentDecoderClass *decoder_class)
 107 {
 108         GObjectClass *object_class = G_OBJECT_CLASS (decoder_class);
 109
 110         g_type_class_add_private (decoder_class, sizeof (SoupContentDecoderPrivate));
 111
 112         object_class->finalize = soup_content_decoder_finalize;
 113 }
 114
 115 static void
 116 soup_content_decoder_got_headers_cb (SoupMessage *msg, SoupContentDecoder *decoder)
 117 {
 118         SoupMessagePrivate *msgpriv = SOUP_MESSAGE_GET_PRIVATE (msg);
 119         const char *header;
 120         GSList *encodings, *e;
 121         SoupContentDecoderCreator converter_creator;
 122         GConverter *converter;
 123
 124         header = soup_message_headers_get_list (msg->response_headers,
 125                                                 "Content-Encoding");
 126         if (!header)
 127                 return;
 128
 129         /* Workaround for an apache bug (bgo 613361) */
 130         if (!g_ascii_strcasecmp (header, "gzip") ||
 131             !g_ascii_strcasecmp (header, "x-gzip")) {
 132                 const char *content_type = soup_message_headers_get_content_type (msg->response_headers, NULL);
 133
 134                 if (content_type &&
 135                     (!g_ascii_strcasecmp (content_type, "application/gzip") ||
 136                      !g_ascii_strcasecmp (content_type, "application/x-gzip")))
 137                         return;
 138         }
 139
 140         /* OK, really, no one is ever going to use more than one
 141          * encoding, but we'll be robust.
 142          */
 143         encodings = soup_header_parse_list (header);
 144         if (!encodings)
 145                 return;
 146
 147         for (e = encodings; e; e = e->next) {
 148                 if (!g_hash_table_lookup (decoder->priv->decoders, e->data)) {
 149                         soup_header_free_list (encodings);
 150                         return;
 151                 }
 152         }
 153
 154         /* msgpriv->decoders should be empty at this point anyway, but
 155          * clean it up if it's not.
 156          */
 157         g_slist_free_full (msgpriv->decoders, g_object_unref);
 158
 159         for (e = encodings; e; e = e->next) {
 160                 converter_creator = g_hash_table_lookup (decoder->priv->decoders, e->data);
 161                 converter = converter_creator ();
 162
 163                 /* Content-Encoding lists the codings in the order
 164                  * they were applied in, so we put decoders in reverse
 165                  * order so the last-applied will be the first
 166                  * decoded.
 167                  */
 168                 msgpriv->decoders = g_slist_prepend (msgpriv->decoders, converter);
 169         }
 170         soup_header_free_list (encodings);
 171 }
 172
 173 static void
 174 soup_content_decoder_request_queued (SoupSessionFeature *feature,
 175                                      SoupSession *session,
 176                                      SoupMessage *msg)
 177 {
 178         SoupContentDecoder *decoder = SOUP_CONTENT_DECODER (feature);
 179
 180         if (!soup_message_headers_get_one (msg->request_headers,
 181                                            "Accept-Encoding")) {
 182                 soup_message_headers_append (msg->request_headers,
 183                                              "Accept-Encoding",
 184                                              ACCEPT_ENCODING_HEADER);
 185         }
 186
 187         g_signal_connect (msg, "got-headers",
 188                           G_CALLBACK (soup_content_decoder_got_headers_cb),
 189                           decoder);
 190 }
 191
 192 static void
 193 soup_content_decoder_request_unqueued (SoupSessionFeature *feature,
 194                                        SoupSession *session,
 195                                        SoupMessage *msg)
 196 {
 197         g_signal_handlers_disconnect_by_func (msg, soup_content_decoder_got_headers_cb, feature);
 198 }
 199
 200 static void
 201 soup_content_decoder_session_feature_init (SoupSessionFeatureInterface *feature_interface,
 202                                            gpointer interface_data)
 203 {
 204         feature_interface->request_queued = soup_content_decoder_request_queued;
 205         feature_interface->request_unqueued = soup_content_decoder_request_unqueued;
 206 }