[FFmpeg-devel] [PATCH v3] avformat/hls: change sequence number type to int64_t

"zhilizhao(赵志立)" quinkblack at foxmail.com
Fri Jan 22 15:22:24 EET 2021



> On Jan 22, 2021, at 4:10 PM, Steven Liu <lingjiujianke at gmail.com> wrote:
> 
> "zhilizhao(赵志立)" <quinkblack at foxmail.com> 于2021年1月22日周五 下午3:17写道:
>> 
>> Ping for review.
> 
> looks no objections?

Please help merge the patch, thanks!

>> 
>>> On Jan 16, 2021, at 11:40 AM, Zhao Zhili <quinkblack at foxmail.com> wrote:
>>> 
>>> Fix atoi() overflow for large EXT-X-MEDIA-SEQUENCE.
>>> 
>>> The spec says the type of sequence number is uint64_t. Use int64_t
>>> here since current implementation requires it to be signed integer,
>>> and hlsenc use int64_t too.
>>> ---
>>> v3:
>>> handle MEDIA-SEQUENCE higher than INT64_MAX
>>> 
>>> v2:
>>> AV_WB32 -> AV_WB64
>>> 
>>> libavformat/hls.c | 56 +++++++++++++++++++++++++++--------------------
>>> 1 file changed, 32 insertions(+), 24 deletions(-)
>>> 
>>> diff --git a/libavformat/hls.c b/libavformat/hls.c
>>> index 619e4800de..af2468ad9b 100644
>>> --- a/libavformat/hls.c
>>> +++ b/libavformat/hls.c
>>> @@ -112,13 +112,13 @@ struct playlist {
>>>    int finished;
>>>    enum PlaylistType type;
>>>    int64_t target_duration;
>>> -    int start_seq_no;
>>> +    int64_t start_seq_no;
>>>    int n_segments;
>>>    struct segment **segments;
>>>    int needed;
>>>    int broken;
>>> -    int cur_seq_no;
>>> -    int last_seq_no;
>>> +    int64_t cur_seq_no;
>>> +    int64_t last_seq_no;
>>>    int m3u8_hold_counters;
>>>    int64_t cur_seg_offset;
>>>    int64_t last_load_time;
>>> @@ -199,7 +199,7 @@ typedef struct HLSContext {
>>>    int n_renditions;
>>>    struct rendition **renditions;
>>> 
>>> -    int cur_seq_no;
>>> +    int64_t cur_seq_no;
>>>    int m3u8_hold_counters;
>>>    int live_start_index;
>>>    int first_packet;
>>> @@ -722,7 +722,7 @@ static int parse_playlist(HLSContext *c, const char *url,
>>>    int is_http = av_strstart(url, "http", NULL);
>>>    struct segment **prev_segments = NULL;
>>>    int prev_n_segments = 0;
>>> -    int prev_start_seq_no = -1;
>>> +    int64_t prev_start_seq_no = -1;
>>> 
>>>    if (is_http && !in && c->http_persistent && c->playlist_pb) {
>>>        in = c->playlist_pb;
>>> @@ -808,10 +808,17 @@ static int parse_playlist(HLSContext *c, const char *url,
>>>                goto fail;
>>>            pls->target_duration = strtoll(ptr, NULL, 10) * AV_TIME_BASE;
>>>        } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
>>> +            uint64_t seq_no;
>>>            ret = ensure_playlist(c, &pls, url);
>>>            if (ret < 0)
>>>                goto fail;
>>> -            pls->start_seq_no = atoi(ptr);
>>> +            seq_no = strtoull(ptr, NULL, 10);
>>> +            if (seq_no > INT64_MAX) {
>>> +                av_log(c->ctx, AV_LOG_DEBUG, "MEDIA-SEQUENCE higher than "
>>> +                        "INT64_MAX, mask out the highest bit\n");
>>> +                seq_no &= INT64_MAX;
>>> +            }
>>> +            pls->start_seq_no = seq_no;
>>>        } else if (av_strstart(line, "#EXT-X-PLAYLIST-TYPE:", &ptr)) {
>>>            ret = ensure_playlist(c, &pls, url);
>>>            if (ret < 0)
>>> @@ -832,9 +839,9 @@ static int parse_playlist(HLSContext *c, const char *url,
>>>            if (has_iv) {
>>>                memcpy(cur_init_section->iv, iv, sizeof(iv));
>>>            } else {
>>> -                int seq = pls->start_seq_no + pls->n_segments;
>>> +                int64_t seq = pls->start_seq_no + pls->n_segments;
>>>                memset(cur_init_section->iv, 0, sizeof(cur_init_section->iv));
>>> -                AV_WB32(cur_init_section->iv + 12, seq);
>>> +                AV_WB64(cur_init_section->iv + 8, seq);
>>>            }
>>> 
>>>            if (key_type != KEY_NONE) {
>>> @@ -889,9 +896,9 @@ static int parse_playlist(HLSContext *c, const char *url,
>>>                if (has_iv) {
>>>                    memcpy(seg->iv, iv, sizeof(iv));
>>>                } else {
>>> -                    int seq = pls->start_seq_no + pls->n_segments;
>>> +                    int64_t seq = pls->start_seq_no + pls->n_segments;
>>>                    memset(seg->iv, 0, sizeof(seg->iv));
>>> -                    AV_WB32(seg->iv + 12, seq);
>>> +                    AV_WB64(seg->iv + 8, seq);
>>>                }
>>> 
>>>                if (key_type != KEY_NONE) {
>>> @@ -954,16 +961,17 @@ static int parse_playlist(HLSContext *c, const char *url,
>>>    if (prev_segments) {
>>>        if (pls->start_seq_no > prev_start_seq_no && c->first_timestamp != AV_NOPTS_VALUE) {
>>>            int64_t prev_timestamp = c->first_timestamp;
>>> -            int i, diff = pls->start_seq_no - prev_start_seq_no;
>>> +            int i;
>>> +            int64_t diff = pls->start_seq_no - prev_start_seq_no;
>>>            for (i = 0; i < prev_n_segments && i < diff; i++) {
>>>                c->first_timestamp += prev_segments[i]->duration;
>>>            }
>>> -            av_log(c->ctx, AV_LOG_DEBUG, "Media sequence change (%d -> %d)"
>>> +            av_log(c->ctx, AV_LOG_DEBUG, "Media sequence change (%"PRId64" -> %"PRId64")"
>>>                   " reflected in first_timestamp: %"PRId64" -> %"PRId64"\n",
>>>                   prev_start_seq_no, pls->start_seq_no,
>>>                   prev_timestamp, c->first_timestamp);
>>>        } else if (pls->start_seq_no < prev_start_seq_no) {
>>> -            av_log(c->ctx, AV_LOG_WARNING, "Media sequence changed unexpectedly: %d -> %d\n",
>>> +            av_log(c->ctx, AV_LOG_WARNING, "Media sequence changed unexpectedly: %"PRId64" -> %"PRId64"\n",
>>>                   prev_start_seq_no, pls->start_seq_no);
>>>        }
>>>        free_segment_dynarray(prev_segments, prev_n_segments);
>>> @@ -991,7 +999,7 @@ static struct segment *current_segment(struct playlist *pls)
>>> 
>>> static struct segment *next_segment(struct playlist *pls)
>>> {
>>> -    int n = pls->cur_seq_no - pls->start_seq_no + 1;
>>> +    int64_t n = pls->cur_seq_no - pls->start_seq_no + 1;
>>>    if (n >= pls->n_segments)
>>>        return NULL;
>>>    return pls->segments[n];
>>> @@ -1457,7 +1465,7 @@ reload:
>>>        }
>>>        if (v->cur_seq_no < v->start_seq_no) {
>>>            av_log(v->parent, AV_LOG_WARNING,
>>> -                   "skipping %d segments ahead, expired from playlists\n",
>>> +                   "skipping %"PRId64" segments ahead, expired from playlists\n",
>>>                   v->start_seq_no - v->cur_seq_no);
>>>            v->cur_seq_no = v->start_seq_no;
>>>        }
>>> @@ -1503,7 +1511,7 @@ reload:
>>>        if (ret < 0) {
>>>            if (ff_check_interrupt(c->interrupt_callback))
>>>                return AVERROR_EXIT;
>>> -            av_log(v->parent, AV_LOG_WARNING, "Failed to open segment %d of playlist %d\n",
>>> +            av_log(v->parent, AV_LOG_WARNING, "Failed to open segment %"PRId64" of playlist %d\n",
>>>                   v->cur_seq_no,
>>>                   v->index);
>>>            v->cur_seq_no += 1;
>>> @@ -1528,7 +1536,7 @@ reload:
>>>        if (ret < 0) {
>>>            if (ff_check_interrupt(c->interrupt_callback))
>>>                return AVERROR_EXIT;
>>> -            av_log(v->parent, AV_LOG_WARNING, "Failed to open next segment %d of playlist %d\n",
>>> +            av_log(v->parent, AV_LOG_WARNING, "Failed to open segment %"PRId64" of playlist %d\n",
>>>                   v->cur_seq_no + 1,
>>>                   v->index);
>>>        } else {
>>> @@ -1625,7 +1633,7 @@ static void add_metadata_from_renditions(AVFormatContext *s, struct playlist *pl
>>> /* if timestamp was in valid range: returns 1 and sets seq_no
>>> * if not: returns 0 and sets seq_no to closest segment */
>>> static int find_timestamp_in_playlist(HLSContext *c, struct playlist *pls,
>>> -                                      int64_t timestamp, int *seq_no)
>>> +                                      int64_t timestamp, int64_t *seq_no)
>>> {
>>>    int i;
>>>    int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?
>>> @@ -1650,9 +1658,9 @@ static int find_timestamp_in_playlist(HLSContext *c, struct playlist *pls,
>>>    return 0;
>>> }
>>> 
>>> -static int select_cur_seq_no(HLSContext *c, struct playlist *pls)
>>> +static int64_t select_cur_seq_no(HLSContext *c, struct playlist *pls)
>>> {
>>> -    int seq_no;
>>> +    int64_t seq_no;
>>> 
>>>    if (!pls->finished && !c->first_packet &&
>>>        av_gettime_relative() - pls->last_load_time >= default_reload_interval(pls))
>>> @@ -1844,7 +1852,7 @@ static int hls_read_header(AVFormatContext *s)
>>> {
>>>    HLSContext *c = s->priv_data;
>>>    int ret = 0, i;
>>> -    int highest_cur_seq_no = 0;
>>> +    int64_t highest_cur_seq_no = 0;
>>> 
>>>    c->ctx                = s;
>>>    c->interrupt_callback = &s->interrupt_callback;
>>> @@ -2077,7 +2085,7 @@ static int recheck_discard_flags(AVFormatContext *s, int first)
>>>                pls->seek_flags = AVSEEK_FLAG_ANY;
>>>                pls->seek_stream_index = -1;
>>>            }
>>> -            av_log(s, AV_LOG_INFO, "Now receiving playlist %d, segment %d\n", i, pls->cur_seq_no);
>>> +            av_log(s, AV_LOG_INFO, "Now receiving playlist %d, segment %"PRId64"\n", i, pls->cur_seq_no);
>>>        } else if (first && !cur_needed && pls->needed) {
>>>            ff_format_io_close(pls->parent, &pls->input);
>>>            pls->input_read_done = 0;
>>> @@ -2274,10 +2282,10 @@ static int hls_read_seek(AVFormatContext *s, int stream_index,
>>> {
>>>    HLSContext *c = s->priv_data;
>>>    struct playlist *seek_pls = NULL;
>>> -    int i, seq_no;
>>> -    int j;
>>> +    int i, j;
>>>    int stream_subdemuxer_index;
>>>    int64_t first_timestamp, seek_timestamp, duration;
>>> +    int64_t seq_no;
>>> 
>>>    if ((flags & AVSEEK_FLAG_BYTE) || (c->ctx->ctx_flags & AVFMTCTX_UNSEEKABLE))
>>>        return AVERROR(ENOSYS);
>>> --
>>> 2.27.0
>>> 
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