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

Ganesh Ajjanagadde gajjanag at mit.edu
Thu Aug 20 23:38:58 CEST 2015


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.

>
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