[FFmpeg-devel] [PATCH] lavf/http: implement directory listing callbacks for Apache

Ganesh Ajjanagadde gajjanag at mit.edu
Thu Aug 20 23:59:26 CEST 2015


On Thu, Aug 20, 2015 at 5:48 PM, Mariusz SzczepaƄczyk
<mszczepanczyk at gmail.com> wrote:
> On Thu, Aug 20, 2015 at 11:38 PM, Ganesh Ajjanagadde <gajjanag at mit.edu>
> wrote:
>
>> On Thu, Aug 20, 2015 at 5:32 PM, Mariusz SzczepaƄczyk
>> <mszczepanczyk at gmail.com> wrote:
>> > ---
>> >  configure          |   3 +
>> >  libavformat/http.c | 194
>> +++++++++++++++++++++++++++++++++++++++++++++++++++++
>> >  2 files changed, 197 insertions(+)
>> >
>> > diff --git a/configure b/configure
>> > index e67ddf6..401e041 100755
>> > --- a/configure
>> > +++ b/configure
>> > @@ -265,6 +265,7 @@ External library support:
>> >    --enable-libxcb-shm      enable X11 grabbing shm communication
>> [autodetect]
>> >    --enable-libxcb-xfixes   enable X11 grabbing mouse rendering
>> [autodetect]
>> >    --enable-libxcb-shape    enable X11 grabbing shape rendering
>> [autodetect]
>> > +  --enable-libxml2         enable HTML parsing via libxml2 [no]
>> >    --enable-libxvid         enable Xvid encoding via xvidcore,
>> >                             native MPEG-4/Xvid encoder exists [no]
>> >    --enable-libzmq          enable message passing via libzmq [no]
>> > @@ -1428,6 +1429,7 @@ EXTERNAL_LIBRARY_LIST="
>> >      libxcb_shm
>> >      libxcb_shape
>> >      libxcb_xfixes
>> > +    libxml2
>> >      libxvid
>> >      libzmq
>> >      libzvbi
>> > @@ -5309,6 +5311,7 @@ enabled libx265           && require_pkg_config
>> x265 x265.h x265_api_get &&
>> >                               { check_cpp_condition x265.h "X265_BUILD
>> >= 57" ||
>> >                                 die "ERROR: libx265 version must be >=
>> 57."; }
>> >  enabled libxavs           && require libxavs xavs.h xavs_encoder_encode
>> -lxavs
>> > +enabled libxml2           && require_pkg_config libxml-2.0
>> libxml/parser.h xmlInitParser
>> >  enabled libxvid           && require libxvid xvid.h xvid_global
>> -lxvidcore
>> >  enabled libzmq            && require_pkg_config libzmq zmq.h zmq_ctx_new
>> >  enabled libzvbi           && require libzvbi libzvbi.h vbi_decoder_new
>> -lzvbi
>> > diff --git a/libavformat/http.c b/libavformat/http.c
>> > index 1eb716b..df45958 100644
>> > --- a/libavformat/http.c
>> > +++ b/libavformat/http.c
>> > @@ -21,6 +21,10 @@
>> >
>> >  #include "config.h"
>> >
>> > +#if CONFIG_LIBXML2
>> > +#include <libxml/HTMLparser.h>
>> > +#endif /* CONFIG_LIBXML2 */
>> > +
>> >  #if CONFIG_ZLIB
>> >  #include <zlib.h>
>> >  #endif /* CONFIG_ZLIB */
>> > @@ -54,6 +58,16 @@ typedef enum {
>> >      FINISH
>> >  }HandshakeState;
>> >
>> > +typedef struct AVIODirEntryQueueNode {
>> > +    struct AVIODirEntry *entry;
>> > +    struct AVIODirEntryQueueNode *next;
>> > +} AVIODirEntryQueueNode;
>> > +
>> > +typedef struct AVIODirEntryQueue {
>> > +    struct AVIODirEntryQueueNode *front;
>> > +    struct AVIODirEntryQueueNode *rear;
>> > +} AVIODirEntryQueue;
>> > +
>> >  typedef struct HTTPContext {
>> >      const AVClass *class;
>> >      URLContext *hd;
>> > @@ -70,6 +84,7 @@ typedef struct HTTPContext {
>> >      char *mime_type;
>> >      char *user_agent;
>> >      char *content_type;
>> > +    char *server;
>> >      /* Set if the server correctly handles Connection: close and will
>> close
>> >       * the connection after feeding us the content. */
>> >      int willclose;
>> > @@ -111,6 +126,11 @@ typedef struct HTTPContext {
>> >      int is_multi_client;
>> >      HandshakeState handshake_step;
>> >      int is_connected_server;
>> > +#if CONFIG_LIBXML2
>> > +    htmlParserCtxtPtr html_parser;
>> > +    AVIODirEntryQueue *entry_queue;
>> > +    AVIODirEntry *entry;
>> > +#endif /* CONFIG_LIBXML2 */
>> >  } HTTPContext;
>> >
>> >  #define OFFSET(x) offsetof(HTTPContext, x)
>> > @@ -808,6 +828,8 @@ static int process_line(URLContext *h, char *line,
>> int line_count,
>> >              if (!strcmp(p, "close"))
>> >                  s->willclose = 1;
>> >          } else if (!av_strcasecmp(tag, "Server")) {
>> > +            av_free(s->server);
>> > +            s->server = av_strdup(p);
>> >              if (!av_strcasecmp(p, "AkamaiGHost")) {
>> >                  s->is_akamai = 1;
>> >              } else if (!av_strncasecmp(p, "MediaGateway", 12)) {
>> > @@ -1409,6 +1431,7 @@ static int http_close(URLContext *h)
>> >      if (s->hd)
>> >          ffurl_closep(&s->hd);
>> >      av_dict_free(&s->chained_options);
>> > +    av_freep(&s->server);
>> >      return ret;
>> >  }
>> >
>> > @@ -1471,6 +1494,167 @@ static int http_get_file_handle(URLContext *h)
>> >      return ffurl_get_file_handle(s->hd);
>> >  }
>> >
>> > +#if CONFIG_LIBXML2
>> > +static void avio_dir_entry_queue_push(AVIODirEntryQueue *queue,
>> AVIODirEntry *entry)
>> > +{
>> > +    AVIODirEntryQueueNode *node;
>> > +
>> > +    if (!queue)
>> > +        return;
>> > +
>> > +    node = av_mallocz(sizeof(AVIODirEntryQueueNode));
>> > +    node->entry = entry;
>> > +    if (!queue->front) {
>> > +        queue->front = queue->rear = node;
>> > +    } else {
>> > +        queue->rear->next = node;
>> > +        queue->rear = node;
>> > +    }
>> > +}
>> > +
>> > +static AVIODirEntry *avio_dir_entry_queue_pop(AVIODirEntryQueue *queue)
>> > +{
>> > +    AVIODirEntry *entry;
>> > +    AVIODirEntryQueueNode *tmp;
>> > +
>> > +    if (!queue || !queue->front)
>> > +        return NULL;
>> > +
>> > +    tmp = queue->front;
>> > +    entry = queue->front->entry;
>> > +    if (queue->front == queue->rear)
>> > +        queue->front = queue->rear = NULL;
>> > +    else
>> > +        queue->front = queue->front->next;
>> > +
>> > +    av_freep(&tmp);
>> > +
>> > +    return entry;
>> > +}
>> > +
>> > +static const char *get_attr(const xmlChar **attrs, const char *key)
>> > +{
>> > +    unsigned char i;
>> > +
>> > +    if (!attrs)
>> > +        return NULL;
>> > +
>> > +    for (i = 0; attrs[i] && i < UCHAR_MAX - 1; i += 2) {
>> > +        if (!strcmp(attrs[i], key))
>> > +            return attrs[i + 1];
>> > +    }
>> > +
>> > +    return NULL;
>> > +}
>> > +
>> > +static void parse_apache(void *ctx, const xmlChar *tag, const xmlChar
>> **attrs)
>> > +{
>> > +    URLContext *h = (URLContext *) ctx;
>> > +    HTTPContext *s = h->priv_data;
>> > +    const char *url, *alt, *src;
>> > +    if (!strcmp(tag, "img")) {
>> > +        av_freep(&s->entry);
>> > +        alt = get_attr(attrs, "alt");
>> > +        src = get_attr(attrs, "src");
>> > +        if (alt && alt[0] == '['
>> > +                && alt[strlen(alt) - 1] == ']'
>> > +                && strcmp(alt, "[PARENTDIR]")) {
>> > +            if (!src || strcmp(src, "/icons/back.gif")) {
>> > +                s->entry = ff_alloc_dir_entry();
>> > +                if (!strcmp(alt, "[DIR]"))
>> > +                    s->entry->type = AVIO_ENTRY_DIRECTORY;
>> > +                else
>> > +                    s->entry->type = AVIO_ENTRY_FILE;
>> > +            }
>> > +        }
>> > +    } else if (!strcmp(tag, "a")) {
>> > +        if (s->entry && (url = get_attr(attrs, "href"))
>> > +                && strcmp(url, "/")) {
>> > +            s->entry->name = av_strdup(url);
>> > +            if (s->entry->name[strlen(s->entry->name) - 1] == '/')
>> > +                s->entry->name[strlen(s->entry->name) - 1] = 0;
>> > +            avio_dir_entry_queue_push(s->entry_queue, s->entry);
>> > +            s->entry = NULL;
>> > +        } else
>> > +            av_freep(&s->entry);
>> > +    } else if (!strcmp(tag, "th") && s->entry) {
>> > +        av_freep(&s->entry);
>> > +    }
>> > +}
>> > +
>> > +static int http_open_dir(URLContext *h)
>> > +{
>> > +    HTTPContext *s = h->priv_data;
>> > +    xmlSAXHandler handlers = {};
>> > +    int ret;
>> > +
>> > +    if (ret = http_open(h, h->filename, 0, NULL) < 0)
>> > +        goto fail;
>> > +
>> > +    if (!s->mime_type || !strstr(s->mime_type, "text/html")) {
>> > +        ret = AVERROR(ENOSYS);
>> > +        goto fail;
>> > +    }
>> > +
>> > +    if (s->server && strstr(s->server, "Apache"))
>> > +        handlers.startElement = parse_apache;
>> > +
>> > +    if (!handlers.startElement) {
>> > +        ret = AVERROR(ENOSYS);
>> > +        goto fail;
>> > +    }
>> > +
>> > +    s->entry_queue = av_mallocz(sizeof(AVIODirEntryQueue));
>> > +    s->html_parser = htmlCreatePushParserCtxt(&handlers, h, NULL, 0,
>> h->filename, XML_CHAR_ENCODING_UTF8);
>> > +    if (!s->html_parser) {
>> > +        ret = AVERROR(EIO);
>> > +        goto fail;
>> > +    }
>> > +
>> > +    return 0;
>> > +
>> > +fail:
>> > +    http_close(h);
>> > +
>> > +    return ret;
>> > +}
>> > +
>> > +static int http_read_dir(URLContext *h, AVIODirEntry **next)
>> > +{
>> > +    HTTPContext *s = h->priv_data;
>> > +    int ret;
>> > +    char buf[BUFFER_SIZE];
>> > +
>> > +    if ((*next = avio_dir_entry_queue_pop(s->entry_queue)))
>> > +        return 0;
>> > +
>> > +    while ((ret = ffurl_read(h, (unsigned char *) buf, BUFFER_SIZE -
>> 1)) > 0) {
>> > +        htmlParseChunk(s->html_parser, (const char *) buf, ret, 0);
>> > +        if ((*next = avio_dir_entry_queue_pop(s->entry_queue)))
>> > +            return 0;
>> > +    }
>> > +
>> > +    if (ret < 0)
>> > +        return ret;
>> > +
>> > +    return 0;
>> > +}
>> > +
>> > +static int http_close_dir(URLContext *h)
>> > +{
>> > +    HTTPContext *s = h->priv_data;
>> > +    AVIODirEntry *entry;
>> > +    while (s->entry_queue && (entry =
>> avio_dir_entry_queue_pop(s->entry_queue)))
>> > +        av_freep(&entry);
>> > +    av_freep(&s->entry_queue);
>> > +    av_freep(&s->entry);
>> > +    htmlFreeParserCtxt(s->html_parser);
>> > +    s->html_parser = NULL;
>> > +    http_close(h);
>> > +    return 0;
>> > +}
>> > +#endif /* CONFIG_LIBXML2 */
>> > +
>> >  #define HTTP_CLASS(flavor)                          \
>> >  static const AVClass flavor ## _context_class = {   \
>> >      .class_name = # flavor,                         \
>> > @@ -1493,6 +1677,11 @@ URLProtocol ff_http_protocol = {
>> >      .url_close           = http_close,
>> >      .url_get_file_handle = http_get_file_handle,
>> >      .url_shutdown        = http_shutdown,
>> > +#if CONFIG_LIBXML2
>> > +    .url_open_dir        = http_open_dir,
>> > +    .url_read_dir        = http_read_dir,
>> > +    .url_close_dir       = http_close_dir,
>> > +#endif /* CONFIG_LIBXML2 */
>> >      .priv_data_size      = sizeof(HTTPContext),
>> >      .priv_data_class     = &http_context_class,
>> >      .flags               = URL_PROTOCOL_FLAG_NETWORK,
>> > @@ -1511,6 +1700,11 @@ URLProtocol ff_https_protocol = {
>> >      .url_close           = http_close,
>> >      .url_get_file_handle = http_get_file_handle,
>> >      .url_shutdown        = http_shutdown,
>> > +#if CONFIG_LIBXML2
>> > +    .url_open_dir        = http_open_dir,
>> > +    .url_read_dir        = http_read_dir,
>> > +    .url_close_dir       = http_close_dir,
>> > +#endif /* CONFIG_LIBXML2 */
>> >      .priv_data_size      = sizeof(HTTPContext),
>> >      .priv_data_class     = &https_context_class,
>> >      .flags               = URL_PROTOCOL_FLAG_NETWORK,
>> > --
>> > 2.4.6
>>
>> I don't like the commit message: this is not Apache.
>> Perhaps what you meant was "similar to Apache" or something like that.
>> Will check the actual patch later.
>>
>
> Actually that's what I meant - specifically for directory listing coming
> from Apache servers.

Thanks for clarifying; I still think commit message can be clearer.
How about this:

lavf/http: implement callbacks for directory listings from Apache

This is roughly of the same length and avoids the confusion.


> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel


More information about the ffmpeg-devel mailing list