[FFmpeg-devel] [PATCH v2] avformat/dashdec: fix memleak for commit commit e134c203

Steven Liu lq at chinaffmpeg.org
Fri Mar 20 14:17:24 EET 2020



> 2020年3月20日 下午7:19,Nicolas George <george at nsup.org> 写道:
> 
> Steven Liu (12020-03-20):
>> These member will be used for get more correct information of the MPD
>> 
>> Suggested-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
>> Suggested-by: Nicolas George <george at nsup.org>
>> Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
>> ---
>> libavformat/dashdec.c | 180 +++++++++++++++++++++++++++++++++++-------
>> 1 file changed, 151 insertions(+), 29 deletions(-)
>> 
>> diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
>> index 5bbe5d3985..df8f30dcb5 100644
>> --- a/libavformat/dashdec.c
>> +++ b/libavformat/dashdec.c
>> @@ -108,6 +108,7 @@ struct representation {
>>     int64_t cur_seg_offset;
>>     int64_t cur_seg_size;
>>     struct fragment *cur_seg;
>> +    char *lang;
>> 
>>     /* Currently active Media Initialization Section */
>>     struct fragment *init_section;
>> @@ -122,19 +123,17 @@ struct representation {
>> typedef struct DASHContext {
>>     const AVClass *class;
>>     char *base_url;
>> -    char *adaptionset_contenttype_val;
>> -    char *adaptionset_par_val;
>> -    char *adaptionset_lang_val;
>> -    char *adaptionset_minbw_val;
>> -    char *adaptionset_maxbw_val;
>> -    char *adaptionset_minwidth_val;
>> -    char *adaptionset_maxwidth_val;
>> -    char *adaptionset_minheight_val;
>> -    char *adaptionset_maxheight_val;
>> -    char *adaptionset_minframerate_val;
>> -    char *adaptionset_maxframerate_val;
>> -    char *adaptionset_segmentalignment_val;
>> -    char *adaptionset_bitstreamswitching_val;
>> +    char *adaptionset_lang;
>> +    uint64_t adaptionset_minbw;
>> +    uint64_t adaptionset_maxbw;
> 
>> +    uint64_t adaptionset_minwidth;
>> +    uint64_t adaptionset_maxwidth;
>> +    uint64_t adaptionset_minheight;
>> +    uint64_t adaptionset_maxheight;
> 
> Unused: remove. Add later if you have something to do with it.
> 
>> +    AVRational adaptionset_minframerate;
>> +    AVRational adaptionset_maxframerate;
> 
>> +    int adaptionset_segmentalignment;
>> +    int adaptionset_bitstreamswitching;
> 
> Unused: remove.
> 
>> 
>>     int n_videos;
>>     struct representation **videos;
>> @@ -169,6 +168,51 @@ typedef struct DASHContext {
>> 
>> } DASHContext;
>> 
> 
>> +#define DASH_GET_PROP_INT64(node, member, key)  \
> 
> No reason to make it a macro: make it a function.
> 
>> +{ \
> 
>> +    char *val = NULL; \
> 
> Useless initialization.
> 
>> +    char *end_ptr = NULL; \
>> +    val = xmlGetProp((node), (key)); \
> 
>> +    (member) = 0; \
> 
> This overwrites previous initializations, like "c->adaptionset_maxbw =
> INT64_MAX".
> 
>> +    if (val) { \
> 
>> +        (member) = strtoull(val, &end_ptr, 10); \
> 
> If the value is syntactically incorrect, the error return value of
> strtoull() will be stored in member, this is not good: use a temp
> variable.
> 
>> +        if (errno == ERANGE) \
>> +            av_log((s), AV_LOG_WARNING, "overflow/underflow when get value of %s\n", (key) ); \
> 
> And do nothing?
> 
>> +        if (end_ptr == val || end_ptr[0] != '\0') { \
>> +            av_log(s, AV_LOG_ERROR, "The %s field value is " \
>> +            "not a valid number: %s\n", (key), val); \
>> +            xmlFree(val); \
> 
>> +            return AVERROR(EINVAL); \
> 
> This is not an invalid value from the user, it's from a file:
> INVALIDDATA.
> 
> Also, sometimes you treat an invalid value as an error, sometimes as a
> warning: inconsistent.
> 
>> +        } \
>> +        xmlFree(val); \
>> +    } \
>> +}
>> +
> 
>> +#define DASH_GET_PROP_RATIO(node, member, key) \
> 
> No need to make it a macro.
> 
>> +{ \
>> +    char *val = NULL; \
>> +    val = xmlGetProp((node), (key)); \
> 
>> +    (member) = av_make_q(0, 0); \
> 
> Redundant init.
> 
>> +    if (val) { \
>> +        ret = get_ratio_from_string(&(member), val); \
>> +        if (ret < 0) \
>> +            av_log(s, AV_LOG_WARNING, "Ignoring invalid %s frame rate '%s'\n", (key), val); \
>> +        xmlFree(val); \
>> +    } \
> 
> Leak.
Which one leak? if xmlGetProp return null, val should null and dose not leak.

/**
 * xmlGetProp:
 * @node:  the node
 * @name:  the attribute name
 *
 * Search and get the value of an attribute associated to a node
 * This does the entity substitution.
 * This function looks in DTD attribute declaration for #FIXED or
 * default declaration values unless DTD use has been turned off.
 * NOTE: this function acts independently of namespaces associated
 *       to the attribute. Use xmlGetNsProp() or xmlGetNoNsProp()
 *       for namespace aware processing.
 *
 * Returns the attribute value or NULL if not found.
 *     It's up to the caller to free the memory with xmlFree().
 */
xmlChar *
xmlGetProp(const xmlNode *node, const xmlChar *name) {
    xmlAttrPtr prop;

    prop = xmlHasProp(node, name);
    if (prop == NULL)
    return(NULL);
    return(xmlGetPropNodeValueInternal(prop));
}


> 
>> +}
>> +
>> +#define DASH_GET_PROP_BOOL(node, member, key) \
> 
> No need to make it a macro.
> 
>> +{ \
>> +    char *val = NULL; \
>> +    val = xmlGetProp((node), (key)); \
>> +    (member) = 0; \
> 
> Redundant init.
> 
>> +    if (val) { \
>> +        if (!av_strcasecmp(val, "true")) \
>> +            (member) = 1; \
>> +        xmlFree(val); \
>> +    } \
> 
> Leak.
Ask same as above.
> 
>> +}
>> +
>> static int ishttp(char *url)
>> {
>>     const char *proto_name = avio_find_protocol_name(url);
>> @@ -406,6 +450,32 @@ static void free_subtitle_list(DASHContext *c)
>>     c->n_subtitles = 0;
>> }
>> 
>> +#define CHECK_STRTOL_RESULT(keystr, dest) \
>> +{ \
>> +    char *end_ptr = NULL; \
>> +    if ((keystr)) { \
>> +        (dest) = (int) strtol(keystr, &end_ptr, 10); \
>> +        if (errno == ERANGE) { \
>> +            return AVERROR(ERANGE); \
>> +        } \
>> +        if (end_ptr == keystr || end_ptr[0] != '\0') { \
>> +            return AVERROR(EINVAL); \
>> +        } \
>> +    } \
>> +}
>> +static int get_ratio_from_string(AVRational *dst, char *src)
>> +{
>> +    char *start = NULL;
>> +    char *end = NULL;
>> +
>> +    dst->den = 1;
> 
>> +    start = av_strtok(src, "/", &end);
>> +    CHECK_STRTOL_RESULT(start, dst->num)
>> +    CHECK_STRTOL_RESULT(end, dst->den)
> 
> end can be NULL. Don't use av_strtok(), it's not the proper function
> here. Use strtol(), it returns to you the end of the number. It's bad
> style to modify a string while parsing if it's not necessary.
The end can be null, there can only maxFrameRate=25, or maxFrameRate=60/2.

>> +
>> +    return 0;
>> +}
>> +
>> static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
>>                     AVDictionary *opts, AVDictionary *opts2, int *is_http)
>> {
>> @@ -885,6 +955,15 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
>>             ret = AVERROR(ENOMEM);
>>             goto end;
>>         }
>> +        if (c->adaptionset_lang) {
>> +            rep->lang = av_strdup(c->adaptionset_lang);
>> +            if (!rep->lang) {
>> +                av_log(s, AV_LOG_ERROR, "alloc language memory failure\n");
>> +                av_freep(&rep);
>> +                ret = AVERROR(ENOMEM);
>> +                goto end;
>> +            }
>> +        }
>>         rep->parent = s;
>>         representation_segmenttemplate_node = find_child_node_by_name(representation_node, "SegmentTemplate");
>>         representation_baseurl_node = find_child_node_by_name(representation_node, "BaseURL");
>> @@ -1073,12 +1152,25 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
>>             if (rep->fragment_duration > 0 && !rep->fragment_timescale)
>>                 rep->fragment_timescale = 1;
>>             rep->bandwidth = rep_bandwidth_val ? atoi(rep_bandwidth_val) : 0;
> 
>> +            if (rep->bandwidth > c->adaptionset_maxbw || rep->bandwidth < c->adaptionset_minbw)
>> +                av_log(s, AV_LOG_WARNING, "The bandwidth of representation %s id incorrect\n", rep_id_val);
>> +
> 
> This warning seems to be of dubious use: warnings should be useful to
> users; what can a user do here?
> 
>>             strncpy(rep->id, rep_id_val ? rep_id_val : "", sizeof(rep->id));
>>             rep->framerate = av_make_q(0, 0);
>>             if (type == AVMEDIA_TYPE_VIDEO && rep_framerate_val) {
>>                 ret = av_parse_video_rate(&rep->framerate, rep_framerate_val);
>>                 if (ret < 0)
>> -                    av_log(s, AV_LOG_VERBOSE, "Ignoring invalid frame rate '%s'\n", rep_framerate_val);
>> +                    av_log(s, AV_LOG_WARNING, "Ignoring invalid frame rate '%s'\n", rep_framerate_val);
> 
>> +                if (c->adaptionset_maxframerate.num > 0) {
>> +                    if (av_cmp_q(rep->framerate, c->adaptionset_maxframerate) == 1)
>> +                        av_log(s, AV_LOG_WARNING, "Ignoring frame rate of representation %s incorrect, "
>> +                        "higher than max framerate, you should check the mpd\n", rep_id_val);
>> +                }
>> +                if (c->adaptionset_minframerate.num > 0)
>> +                    if (av_cmp_q(rep->framerate, c->adaptionset_minframerate) == -1) {
>> +                        av_log(s, AV_LOG_WARNING, "Ignoring frame rate of representation %s incorrect, "
>> +                        "lower than min framerate, you should check the mpd\n", rep_id_val);
>> +                }
> 
> Ditto.
Just tell the user this value is incorrect in mpd, the result maybe does not accord with the expected result.
User should check the mpd file content is correct.
> 
>>             }
>> 
>>             switch (type) {
>> @@ -1116,6 +1208,34 @@ end:
>>     return ret;
>> }
>> 
>> +static int parse_manifest_adaptationset_attr(AVFormatContext *s, xmlNodePtr adaptionset_node)
>> +{
>> +    int ret = 0;
>> +    DASHContext *c = s->priv_data;
>> +
>> +    if (!adaptionset_node) {
>> +        av_log(s, AV_LOG_WARNING, "Cannot get AdaptionSet\n");
>> +        return AVERROR(EINVAL);
>> +    }
>> +    c->adaptionset_minframerate = av_make_q(0, 0);
>> +    c->adaptionset_maxbw = INT64_MAX;
>> +    c->adaptionset_minbw = 0;
>> +    c->adaptionset_lang = xmlGetProp(adaptionset_node, "lang");
>> +
>> +    DASH_GET_PROP_INT64(adaptionset_node, c->adaptionset_minbw, "minBandwidth")
>> +    DASH_GET_PROP_INT64(adaptionset_node, c->adaptionset_maxbw, "maxBandwidth")
>> +    DASH_GET_PROP_INT64(adaptionset_node, c->adaptionset_minwidth, "minWidth")
>> +    DASH_GET_PROP_INT64(adaptionset_node, c->adaptionset_maxwidth, "maxWidth")
>> +    DASH_GET_PROP_INT64(adaptionset_node, c->adaptionset_minheight, "minHeight")
>> +    DASH_GET_PROP_INT64(adaptionset_node, c->adaptionset_maxheight, "maxHeight")
>> +    DASH_GET_PROP_RATIO(adaptionset_node, c->adaptionset_minframerate, "minFrameRate")
>> +    DASH_GET_PROP_RATIO(adaptionset_node, c->adaptionset_maxframerate, "maxFrameRate")
>> +    DASH_GET_PROP_BOOL(adaptionset_node, c->adaptionset_segmentalignment, "segmentAlignment")
>> +    DASH_GET_PROP_BOOL(adaptionset_node, c->adaptionset_bitstreamswitching, "bitstreamSwitching")
>> +
>> +    return ret;
>> +}
>> +
>> static int parse_manifest_adaptationset(AVFormatContext *s, const char *url,
>>                                         xmlNodePtr adaptionset_node,
>>                                         xmlNodePtr mpd_baseurl_node,
>> @@ -1131,19 +1251,10 @@ static int parse_manifest_adaptationset(AVFormatContext *s, const char *url,
>>     xmlNodePtr adaptionset_segmentlist_node = NULL;
>>     xmlNodePtr adaptionset_supplementalproperty_node = NULL;
>>     xmlNodePtr node = NULL;
>> -    c->adaptionset_contenttype_val = xmlGetProp(adaptionset_node, "contentType");
>> -    c->adaptionset_par_val = xmlGetProp(adaptionset_node, "par");
>> -    c->adaptionset_lang_val = xmlGetProp(adaptionset_node, "lang");
>> -    c->adaptionset_minbw_val = xmlGetProp(adaptionset_node, "minBandwidth");
>> -    c->adaptionset_maxbw_val = xmlGetProp(adaptionset_node, "maxBandwidth");
>> -    c->adaptionset_minwidth_val = xmlGetProp(adaptionset_node, "minWidth");
>> -    c->adaptionset_maxwidth_val = xmlGetProp(adaptionset_node, "maxWidth");
>> -    c->adaptionset_minheight_val = xmlGetProp(adaptionset_node, "minHeight");
>> -    c->adaptionset_maxheight_val = xmlGetProp(adaptionset_node, "maxHeight");
>> -    c->adaptionset_minframerate_val = xmlGetProp(adaptionset_node, "minFrameRate");
>> -    c->adaptionset_maxframerate_val = xmlGetProp(adaptionset_node, "maxFrameRate");
>> -    c->adaptionset_segmentalignment_val = xmlGetProp(adaptionset_node, "segmentAlignment");
>> -    c->adaptionset_bitstreamswitching_val = xmlGetProp(adaptionset_node, "bitstreamSwitching");
>> +
>> +    ret = parse_manifest_adaptationset_attr(s, adaptionset_node);
>> +    if (ret < 0)
>> +        return ret;
>> 
>>     node = xmlFirstElementChild(adaptionset_node);
>>     while (node) {
>> @@ -1170,12 +1281,15 @@ static int parse_manifest_adaptationset(AVFormatContext *s, const char *url,
>>                                                 adaptionset_segmentlist_node,
>>                                                 adaptionset_supplementalproperty_node);
>>             if (ret < 0) {
>> -                return ret;
>> +                goto end;
>>             }
>>         }
>>         node = xmlNextElementSibling(node);
>>     }
>> -    return 0;
>> +
>> +end:
>> +    av_freep(&c->adaptionset_lang);
>> +    return ret;
>> }
>> 
>> static int parse_programinformation(AVFormatContext *s, xmlNodePtr node)
>> @@ -2148,6 +2262,10 @@ static int dash_read_header(AVFormatContext *s)
>>                 av_dict_set_int(&rep->assoc_stream->metadata, "variant_bitrate", rep->bandwidth, 0);
>>             if (rep->id[0])
>>                 av_dict_set(&rep->assoc_stream->metadata, "id", rep->id, 0);
>> +            if (rep->lang) {
>> +                av_dict_set(&rep->assoc_stream->metadata, "lang", rep->lang, 0);
>> +                av_freep(&rep->lang);
>> +            }
>>         }
>>         for (i = 0; i < c->n_subtitles; i++) {
>>             rep = c->subtitles[i];
>> @@ -2155,6 +2273,10 @@ static int dash_read_header(AVFormatContext *s)
>>             rep->assoc_stream = s->streams[rep->stream_index];
>>             if (rep->id[0])
>>                 av_dict_set(&rep->assoc_stream->metadata, "id", rep->id, 0);
>> +            if (rep->lang) {
>> +                av_dict_set(&rep->assoc_stream->metadata, "lang", rep->lang, 0);
>> +                av_freep(&rep->lang);
>> +            }
>>         }
>>     }
>> 
> 
> Regards,
> 
> -- 
>  Nicolas George

Thanks

Steven Liu



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