[vlc-devel] [PATCH] added handling of wrong MIME boundary separator to mjpeg demux

[Sergey Radionov]

2012/8/28 Hugo Beauzée-Luyssen <hugo at beauzee.fr>:
> On Tue, Aug 28, 2012 at 10:45 AM, Sergey Radionov <rsatom at gmail.com> wrote:
>> 2012/8/26 Sergey Radionov <rsatom at gmail.com>:
>>> ---
>>>  modules/demux/mjpeg.c |   83 ++++++++++++++++++++++++++++++++++++++++++++----
>>>  1 files changed, 76 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/modules/demux/mjpeg.c b/modules/demux/mjpeg.c
>>> index a057db3..055a908 100644
>>> --- a/modules/demux/mjpeg.c
>>> +++ b/modules/demux/mjpeg.c
>>> @@ -200,10 +200,10 @@ static bool CheckMimeHeader( demux_t *p_demux, int *p_header_size )
>>>              char *content_type = stream_ContentType( p_demux->s );
>>>              if ( content_type == NULL )
>>>                  return false;
>>> -            const char* boundary = strstr( content_type, "boundary=--" );
>>> +            const char* boundary = strstr( content_type, "boundary=" );
>>>              if ( boundary != NULL )
>>>              {
>>> -                p_sys->psz_separator = strdup( boundary + strlen( "boundary=--" ) );
>>> +                p_sys->psz_separator = strdup( boundary + sizeof("boundary=") - 1 );
>>>                  msg_Dbg( p_demux, "Video boundary extracted from Content-Type: %s", p_sys->psz_separator );
>>>                  free( content_type );
>>>                  /* Skip to HTTP header parsing as there's no boundary to extract
>>> @@ -223,7 +223,8 @@ static bool CheckMimeHeader( demux_t *p_demux, int *p_header_size )
>>>      }
>>>      else
>>>      {
>>> -        i_pos = *p_sys->p_peek == '-' ? 2 : 4;
>>> +        i_pos = *p_sys->p_peek == '-' ? 0 : 2;//skip "\r\n" if exist
>>> +        int i_pos_save = i_pos;//to allow restore after missing "\r\n"...
>>>          psz_line = GetLine( p_demux, &i_pos );
>>>          if( NULL == psz_line )
>>>          {
>>> @@ -235,13 +236,77 @@ static bool CheckMimeHeader( demux_t *p_demux, int *p_header_size )
>>>          /* Read the separator and remember it if not yet stored */
>>>          if( p_sys->psz_separator == NULL )
>>>          {
>>> -            p_sys->psz_separator = psz_line;
>>> -            msg_Dbg( p_demux, "Multipart MIME detected, using separator: %s",
>>> -                     p_sys->psz_separator );
>>> +            char *content_type = stream_ContentType( p_demux->s );
>>> +            char* boundary = NULL;
>>> +            if ( content_type != NULL )
>>> +            {
>>> +                boundary = strstr( content_type, "boundary=" );
>>> +                if( boundary ) boundary += sizeof("boundary=") - 1;
>>> +            }
>>> +
>>> +            //some vendors add "--" at boundary begin and end in ContentType declaration,
>>> +            //and don't add additional "--" in the body - it's incorrect...
>>> +            //some other vendors, forget to add "\r\n" after boundary - it's incorrect too...
>>> +            //and some else vendors, forget to add "\r\n" and forget to add "--" both
>>> +            //(or add excess "--" to ContentType, which is the same)...
>>> +
>>> +            size_t bl = boundary ? strlen(boundary) : 0;
>>> +            //if used boundary without additional "--"
>>> +            //(i.e. used same string was declared in ContentType), then
>>> +            if( boundary && !strncmp( psz_line, boundary, bl ) )
>>> +            {
>>> +                //if boundary identical to psz_line, then
>>> +                if( (psz_line + bl) == '\0' )
>>> +                {
>>> +                    //just use whole line as separator
>>> +                    p_sys->psz_separator = psz_line;
>>> +                }
>>> +                else
>>> +                {
>>> +                    //restore buffer position to right place
>>> +                    i_pos = i_pos_save + bl;
>>> +                    p_sys->psz_separator = strdup( boundary );
>>> +                    free( psz_line );
>>> +                }
>>> +            }
>>> +
>>> +            //if used boundary with additional "--"
>>> +            if( !p_sys->psz_separator && boundary &&
>>> +                !strncmp( psz_line + sizeof("--") - 1, boundary, bl ) )
>>> +            {
>>> +                char* s = psz_line + sizeof("--") - 1 + bl;
>>> +                if( !strncmp( s , "--", 2 ) ) //skip "--" if boundary is last
>>> +                    s += 2;
>>> +
>>> +                //"\r\n" is forgotten
>>> +                if ( s != '\0' ) {
>>> +                    //restore buffer position to right place
>>> +                    i_pos = i_pos_save + bl;
>>> +                }
>>> +
>>> +                p_sys->psz_separator = strdup( boundary );
>>> +                free( psz_line );
>>> +            }
>>> +
>>> +            if( !p_sys->psz_separator )
>>> +            {
>>> +                //separator was not found, then just use whole line
>>> +                //FIXME: don't sure it's right
>>> +                p_sys->psz_separator = psz_line;
>>> +            }
>>> +
>>> +            if ( p_sys->psz_separator ) {
>>> +                msg_Dbg( p_demux, "Multipart MIME detected, using separator: %s",
>>> +                         p_sys->psz_separator );
>>> +            }
>>> +
>>> +            free( content_type );
>>>          }
>>>          else
>>>          {
>>> -            if( strcmp( psz_line, p_sys->psz_separator ) )
>>> +            size_t sl = strlen(p_sys->psz_separator);
>>> +            if( strncmp( psz_line + sizeof("--") - 1, p_sys->psz_separator, sl ) &&
>>> +                strncmp( psz_line, p_sys->psz_separator, sl ) )
>>>              {
>>>                  msg_Warn( p_demux, "separator %s does not match %s", psz_line,
>>>                            p_sys->psz_separator );
>>> @@ -527,7 +592,11 @@ static int MimeDemux( demux_t *p_demux )
>>>              }
>>>          }
>>>
>>> +        //some vendors use as separator same string which was defined in ContentType
>>> +        //without additional "--"
>>>          if( !strncmp( p_sys->psz_separator, (char *)(p_sys->p_peek + i + 2),
>>> +                      strlen( p_sys->psz_separator ) ) ||
>>> +            !strncmp( p_sys->psz_separator, (char *)(p_sys->p_peek + i),
>>>                        strlen( p_sys->psz_separator ) ) )
>>>          {
>>>              break;
>>> --
>>> 1.7.7.1.msysgit.0
>>>
>>
>> don't forget please....
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>
> I'll review it soon(ish).
Thanks!

> Do you have some sample stream to test your patch with?
Send to your email.

>
> Regards
>
> --
> Hugo Beauzée-Luyssen
> mail: hugo at beauzee.fr
> skype: beauze.h
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