[FFmpeg-devel] [PATCH v2] avformat/hls: clean up duplicate option fields

Steven Liu lq at chinaffmpeg.org
Tue Apr 17 09:42:42 EEST 2018



> On 17 Apr 2018, at 03:02, Richard Shaffer <rshaffer at tunein.com> wrote:
> 
> On Fri, Apr 13, 2018 at 5:14 PM, <rshaffer at tunein.com> wrote:
> 
>> From: Richard Shaffer <rshaffer at tunein.com>
>> 
>> The HLSContext struct contains fields which duplicate the data stored in
>> the
>> avio_opts field. This change removes those fields in favor of avio_opts,
>> and
>> updates the code accordingly.
>> ---
>> The original patch caused the buffer pointed to by new_cookies in open_url
>> to be
>> leaked. The only thing that buffer is used for is to store the value until
>> it
>> can be passed to av_dict_set. To fix the leak, v2 of the patch simply calls
>> av_dict_set with the AV_DICT_DONT_STRDUP_VAL flag, so that the dictionary
>> takes
>> ownership of the memory instead of copying it again.
>> 
>> libavformat/hls.c | 74 +++++++-----------------------
>> -------------------------
>> 1 file changed, 9 insertions(+), 65 deletions(-)
>> 
>> diff --git a/libavformat/hls.c b/libavformat/hls.c
>> index 1257cd101c..d6158c0ada 100644
>> --- a/libavformat/hls.c
>> +++ b/libavformat/hls.c
>> @@ -202,11 +202,6 @@ typedef struct HLSContext {
>>     int64_t first_timestamp;
>>     int64_t cur_timestamp;
>>     AVIOInterruptCB *interrupt_callback;
>> -    char *referer;                       ///< holds HTTP referer set as
>> an AVOption to the HTTP protocol context
>> -    char *user_agent;                    ///< holds HTTP user agent set
>> as an AVOption to the HTTP protocol context
>> -    char *cookies;                       ///< holds HTTP cookie values
>> set in either the initial response or as an AVOption to the HTTP protocol
>> context
>> -    char *headers;                       ///< holds HTTP headers set as
>> an AVOption to the HTTP protocol context
>> -    char *http_proxy;                    ///< holds the address of the
>> HTTP proxy server
>>     AVDictionary *avio_opts;
>>     int strict_std_compliance;
>>     char *allowed_extensions;
>> @@ -267,10 +262,6 @@ static void free_playlist_list(HLSContext *c)
>>         av_free(pls);
>>     }
>>     av_freep(&c->playlists);
>> -    av_freep(&c->cookies);
>> -    av_freep(&c->user_agent);
>> -    av_freep(&c->headers);
>> -    av_freep(&c->http_proxy);
>>     c->n_playlists = 0;
>> }
>> 
>> @@ -593,14 +584,6 @@ static int ensure_playlist(HLSContext *c, struct
>> playlist **pls, const char *url
>>     return 0;
>> }
>> 
>> -static void update_options(char **dest, const char *name, void *src)
>> -{
>> -    av_freep(dest);
>> -    av_opt_get(src, name, AV_OPT_SEARCH_CHILDREN, (uint8_t**)dest);
>> -    if (*dest && !strlen(*dest))
>> -        av_freep(dest);
>> -}
>> -
>> static int open_url_keepalive(AVFormatContext *s, AVIOContext **pb,
>>                               const char *url)
>> {
>> @@ -684,12 +667,8 @@ static int open_url(AVFormatContext *s, AVIOContext
>> **pb, const char *url,
>>         if (!(s->flags & AVFMT_FLAG_CUSTOM_IO))
>>             av_opt_get(*pb, "cookies", AV_OPT_SEARCH_CHILDREN,
>> (uint8_t**)&new_cookies);
>> 
>> -        if (new_cookies) {
>> -            av_free(c->cookies);
>> -            c->cookies = new_cookies;
>> -        }
>> -
>> -        av_dict_set(&opts, "cookies", c->cookies, 0);
>> +        if (new_cookies)
>> +            av_dict_set(&opts, "cookies", new_cookies,
>> AV_DICT_DONT_STRDUP_VAL);
>>     }
>> 
>>     av_dict_free(&tmp);
>> @@ -736,14 +715,7 @@ static int parse_playlist(HLSContext *c, const char
>> *url,
>> 
>>     if (!in) {
>>         AVDictionary *opts = NULL;
>> -        /* Some HLS servers don't like being sent the range header */
>> -        av_dict_set(&opts, "seekable", "0", 0);
>> -
>> -        // broker prior HTTP options that should be consistent across
>> requests
>> -        av_dict_set(&opts, "user_agent", c->user_agent, 0);
>> -        av_dict_set(&opts, "cookies", c->cookies, 0);
>> -        av_dict_set(&opts, "headers", c->headers, 0);
>> -        av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
>> +        av_dict_copy(&opts, c->avio_opts, 0);
>> 
>>         if (c->http_persistent)
>>             av_dict_set(&opts, "multiple_requests", "1", 0);
>> @@ -1169,14 +1141,6 @@ static int open_input(HLSContext *c, struct
>> playlist *pls, struct segment *seg,
>>     int ret;
>>     int is_http = 0;
>> 
>> -    // broker prior HTTP options that should be consistent across requests
>> -    av_dict_set(&opts, "user_agent", c->user_agent, 0);
>> -    av_dict_set(&opts, "referer", c->referer, 0);
>> -    av_dict_set(&opts, "cookies", c->cookies, 0);
>> -    av_dict_set(&opts, "headers", c->headers, 0);
>> -    av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
>> -    av_dict_set(&opts, "seekable", "0", 0);
>> -
>>     if (c->http_persistent)
>>         av_dict_set(&opts, "multiple_requests", "1", 0);
>> 
>> @@ -1193,7 +1157,6 @@ static int open_input(HLSContext *c, struct playlist
>> *pls, struct segment *seg,
>>     if (seg->key_type == KEY_NONE) {
>>         ret = open_url(pls->parent, in, seg->url, c->avio_opts, opts,
>> &is_http);
>>     } else if (seg->key_type == KEY_AES_128) {
>> -        AVDictionary *opts2 = NULL;
>>         char iv[33], key[33], url[MAX_URL_SIZE];
>>         if (strcmp(seg->key, pls->key_url)) {
>>             AVIOContext *pb = NULL;
>> @@ -1218,14 +1181,10 @@ static int open_input(HLSContext *c, struct
>> playlist *pls, struct segment *seg,
>>         else
>>             snprintf(url, sizeof(url), "crypto:%s", seg->url);
>> 
>> -        av_dict_copy(&opts2, c->avio_opts, 0);
>> -        av_dict_set(&opts2, "key", key, 0);
>> -        av_dict_set(&opts2, "iv", iv, 0);
>> -
>> -        ret = open_url(pls->parent, in, url, opts2, opts, &is_http);
>> -
>> -        av_dict_free(&opts2);
>> +        av_dict_set(&opts, "key", key, 0);
>> +        av_dict_set(&opts, "iv", iv, 0);
>> 
>> +        ret = open_url(pls->parent, in, url, c->avio_opts, opts,
>> &is_http);
>>         if (ret < 0) {
>>             goto cleanup;
>>         }
>> @@ -1781,7 +1740,6 @@ static int hls_close(AVFormatContext *s)
>> 
>> static int hls_read_header(AVFormatContext *s)
>> {
>> -    void *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb;
>>     HLSContext *c = s->priv_data;
>>     int ret = 0, i;
>>     int highest_cur_seq_no = 0;
>> @@ -1794,29 +1752,15 @@ static int hls_read_header(AVFormatContext *s)
>>     c->first_timestamp = AV_NOPTS_VALUE;
>>     c->cur_timestamp = AV_NOPTS_VALUE;
>> 
>> -    if (u) {
>> -        // get the previous user agent & set back to null if string size
>> is zero
>> -        update_options(&c->user_agent, "user_agent", u);
>> -
>> -        // get the previous cookies & set back to null if string size is
>> zero
>> -        update_options(&c->cookies, "cookies", u);
>> -
>> -        // get the previous headers & set back to null if string size is
>> zero
>> -        update_options(&c->headers, "headers", u);
>> -
>> -        // get the previous http proxt & set back to null if string size
>> is zero
>> -        update_options(&c->http_proxy, "http_proxy", u);
>> -    }
>> -
>> -    if ((ret = parse_playlist(c, s->url, NULL, s->pb)) < 0)
>> -        goto fail;
>> -
>>     if ((ret = save_avio_options(s)) < 0)
>>         goto fail;
>> 
>>     /* Some HLS servers don't like being sent the range header */
>>     av_dict_set(&c->avio_opts, "seekable", "0", 0);
>> 
>> +    if ((ret = parse_playlist(c, s->url, NULL, s->pb)) < 0)
>> +        goto fail;
>> +
>>     if (c->n_variants == 0) {
>>         av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
>>         ret = AVERROR_EOF;
>> --
>> 2.15.1 (Apple Git-101)
>> 
>> 
> Just wanted to send a reminder about this patch. The original version was
> sent about a week ago. If anyone has time to review and either comment or
> merge, that would be really great.

Pushed
> 
> -Richard
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Thanks
Steven







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