[Bluez-devel] confusion about libs/sdp.c - sdp_service_search_req()

[Bluez-devel] confusion about libs/sdp.c - sdp_service_search_req()

[Albert Huang]

the documentation for sdp_service_search_req() states that it outputs
an sdp_list_t * of sdp_record_t * (list of sdp service records)

reading through the code, it appears that it actually returns a list
of uint32_t * data structures.

line 2721:
        extract_record_handle_seq(pdata, rsp, rec_count, &scanned);


line 2523:
static void extract_record_handle_seq(char *pdu, sdp_list_t **seq, int
count, int *scanned)
{
    sdp_list_t *pSeq = *seq;
    char *pdata = pdu;
    int n;
 
    for (n = 0; n < count; n++) {
        uint32_t *pSvcRec = (uint32_t *) malloc(sizeof(uint32_t));
        *pSvcRec = ntohl(bt_get_unaligned((uint32_t *) pdata));
        pSeq = sdp_list_append(pSeq, pSvcRec);
        pdata += sizeof(uint32_t);
        *scanned += sizeof(uint32_t);
    }
    *seq = pSeq;
}

I think this will cause segfaults when you try to sdp_record_free the
records in the list (it does for me).

perhaps it shold read something more like:
        sdp_record_t *pSvcRec = (sdp_record_t*) malloc(sizeof(sdp_record_t));
        pSvcRec->attrlist = pSvcRec->pattern = 0;
        pSvcRec->handle = ntohl(bt_get_unaligned((uint32_t *) pdata));
        pSeq = sdp_list_append(pSeq, pSvcRec);

Regards,
-albert


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Re: [Bluez-devel] confusion about libs/sdp.c - sdp_service_search_req()

[Marcel Holtmann]

Hi Albert,

> the documentation for sdp_service_search_req() states that it outputs
> an sdp_list_t * of sdp_record_t * (list of sdp service records)
> 
> reading through the code, it appears that it actually returns a list
> of uint32_t * data structures.
> 
> line 2721:
>         extract_record_handle_seq(pdata, rsp, rec_count, &scanned);
> 
> 
> line 2523:
> static void extract_record_handle_seq(char *pdu, sdp_list_t **seq, int
> count, int *scanned)
> {
>     sdp_list_t *pSeq = *seq;
>     char *pdata = pdu;
>     int n;
>  
>     for (n = 0; n < count; n++) {
>         uint32_t *pSvcRec = (uint32_t *) malloc(sizeof(uint32_t));
>         *pSvcRec = ntohl(bt_get_unaligned((uint32_t *) pdata));
>         pSeq = sdp_list_append(pSeq, pSvcRec);
>         pdata += sizeof(uint32_t);
>         *scanned += sizeof(uint32_t);
>     }
>     *seq = pSeq;
> }
> 
> I think this will cause segfaults when you try to sdp_record_free the
> records in the list (it does for me).
> 
> perhaps it shold read something more like:
>         sdp_record_t *pSvcRec = (sdp_record_t*) malloc(sizeof(sdp_record_t));
>         pSvcRec->attrlist = pSvcRec->pattern = 0;
>         pSvcRec->handle = ntohl(bt_get_unaligned((uint32_t *) pdata));
>         pSeq = sdp_list_append(pSeq, pSvcRec);

Steve, any thoughts on this one?

Regards

Marcel




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Re: [Bluez-devel] confusion about libs/sdp.c - sdp_service_search_req()

[Stephen Crane]

Hi Albert, Marcel,

The documentation is incorrect: the correct behaviour of
sdp_service_search_req() is that it returns a list of service record
handles --- you then use sdp_search_attr_req() to fetch attributes of
interest. Alternatively, you can use sdp_search_attr_req() to perform a
combined search.

I have fixed the comment in CVS.

Thanks,
Steve

On Mon, 2005-02-28 at 09:34 +0100, Marcel Holtmann wrote:
> Hi Albert,
> 
> > the documentation for sdp_service_search_req() states that it outputs
> > an sdp_list_t * of sdp_record_t * (list of sdp service records)
> > 
> > reading through the code, it appears that it actually returns a list
> > of uint32_t * data structures.
> > 
> > line 2721:
> >         extract_record_handle_seq(pdata, rsp, rec_count, &scanned);
> > 
> > 
> > line 2523:
> > static void extract_record_handle_seq(char *pdu, sdp_list_t **seq, int
> > count, int *scanned)
> > {
> >     sdp_list_t *pSeq = *seq;
> >     char *pdata = pdu;
> >     int n;
> >  
> >     for (n = 0; n < count; n++) {
> >         uint32_t *pSvcRec = (uint32_t *) malloc(sizeof(uint32_t));
> >         *pSvcRec = ntohl(bt_get_unaligned((uint32_t *) pdata));
> >         pSeq = sdp_list_append(pSeq, pSvcRec);
> >         pdata += sizeof(uint32_t);
> >         *scanned += sizeof(uint32_t);
> >     }
> >     *seq = pSeq;
> > }
> > 
> > I think this will cause segfaults when you try to sdp_record_free the
> > records in the list (it does for me).
> > 
> > perhaps it shold read something more like:
> >         sdp_record_t *pSvcRec = (sdp_record_t*) malloc(sizeof(sdp_record_t));
> >         pSvcRec->attrlist = pSvcRec->pattern = 0;
> >         pSvcRec->handle = ntohl(bt_get_unaligned((uint32_t *) pdata));
> >         pSeq = sdp_list_append(pSeq, pSvcRec);
> 
> Steve, any thoughts on this one?
> 
> Regards
> 
> Marcel
> 
> 

Re: [Bluez-devel] confusion about libs/sdp.c - sdp_service_search_req()

[Albert Huang]

it appears that the internal documentation for sdp_record_register is
also incorrect.

libs/src/sdp.c:2288
 *
 * Returns a non-null value (a pointer) to a service
 * record if successful, else -1 setting errno
 */

I think it should read something like:
 *
 * Returns zero if successful, also setting rec->handle 
 * else -1 setting erro
 */

You may also want to update libs/include/sdp_lib.h to indicate the
behavior of sdp_record_register

Regards,
Albert

On Mon, 28 Feb 2005 12:20:38 +0000, Stephen Crane
<steve.crane@rococosoft.com> wrote:
> Hi Albert, Marcel,
> 
> The documentation is incorrect: the correct behaviour of
> sdp_service_search_req() is that it returns a list of service record
> handles --- you then use sdp_search_attr_req() to fetch attributes of
> interest. Alternatively, you can use sdp_search_attr_req() to perform a
> combined search.
> 
> I have fixed the comment in CVS.
> 
> Thanks,
> Steve
> 
> On Mon, 2005-02-28 at 09:34 +0100, Marcel Holtmann wrote:
> > Hi Albert,
> >
> > > the documentation for sdp_service_search_req() states that it outputs
> > > an sdp_list_t * of sdp_record_t * (list of sdp service records)
> > >
> > > reading through the code, it appears that it actually returns a list
> > > of uint32_t * data structures.
> > >
> > > line 2721:
> > >         extract_record_handle_seq(pdata, rsp, rec_count, &scanned);
> > >
> > >
> > > line 2523:
> > > static void extract_record_handle_seq(char *pdu, sdp_list_t **seq, int
> > > count, int *scanned)
> > > {
> > >     sdp_list_t *pSeq = *seq;
> > >     char *pdata = pdu;
> > >     int n;
> > >
> > >     for (n = 0; n < count; n++) {
> > >         uint32_t *pSvcRec = (uint32_t *) malloc(sizeof(uint32_t));
> > >         *pSvcRec = ntohl(bt_get_unaligned((uint32_t *) pdata));
> > >         pSeq = sdp_list_append(pSeq, pSvcRec);
> > >         pdata += sizeof(uint32_t);
> > >         *scanned += sizeof(uint32_t);
> > >     }
> > >     *seq = pSeq;
> > > }
> > >
> > > I think this will cause segfaults when you try to sdp_record_free the
> > > records in the list (it does for me).
> > >
> > > perhaps it shold read something more like:
> > >         sdp_record_t *pSvcRec = (sdp_record_t*) malloc(sizeof(sdp_record_t));
> > >         pSvcRec->attrlist = pSvcRec->pattern = 0;
> > >         pSvcRec->handle = ntohl(bt_get_unaligned((uint32_t *) pdata));
> > >         pSeq = sdp_list_append(pSeq, pSvcRec);
> >
> > Steve, any thoughts on this one?
> >
> > Regards
> >
> > Marcel
> >
> >
> 
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Re: [Bluez-devel] confusion about libs/sdp.c - sdp_service_search_req()

[Stephen Crane]

[-- Attachment #1: Type: text/plain, Size: 3469 bytes --]

Hi Albert,
I have made the changes as you suggest. In future, it would probably be
just as easy for you to send patches, right?

Thanks,
Steve

On Wed, 2005-03-02 at 03:48 -0500, Albert Huang wrote:
> it appears that the internal documentation for sdp_record_register is
> also incorrect.
> 
> libs/src/sdp.c:2288
>  *
>  * Returns a non-null value (a pointer) to a service
>  * record if successful, else -1 setting errno
>  */
> 
> I think it should read something like:
>  *
>  * Returns zero if successful, also setting rec->handle 
>  * else -1 setting erro
>  */
> 
> You may also want to update libs/include/sdp_lib.h to indicate the
> behavior of sdp_record_register
> 
> Regards,
> Albert
> 
> On Mon, 28 Feb 2005 12:20:38 +0000, Stephen Crane
> <steve.crane@rococosoft.com> wrote:
> > Hi Albert, Marcel,
> > 
> > The documentation is incorrect: the correct behaviour of
> > sdp_service_search_req() is that it returns a list of service record
> > handles --- you then use sdp_search_attr_req() to fetch attributes of
> > interest. Alternatively, you can use sdp_search_attr_req() to perform a
> > combined search.
> > 
> > I have fixed the comment in CVS.
> > 
> > Thanks,
> > Steve
> > 
> > On Mon, 2005-02-28 at 09:34 +0100, Marcel Holtmann wrote:
> > > Hi Albert,
> > >
> > > > the documentation for sdp_service_search_req() states that it outputs
> > > > an sdp_list_t * of sdp_record_t * (list of sdp service records)
> > > >
> > > > reading through the code, it appears that it actually returns a list
> > > > of uint32_t * data structures.
> > > >
> > > > line 2721:
> > > >         extract_record_handle_seq(pdata, rsp, rec_count, &scanned);
> > > >
> > > >
> > > > line 2523:
> > > > static void extract_record_handle_seq(char *pdu, sdp_list_t **seq, int
> > > > count, int *scanned)
> > > > {
> > > >     sdp_list_t *pSeq = *seq;
> > > >     char *pdata = pdu;
> > > >     int n;
> > > >
> > > >     for (n = 0; n < count; n++) {
> > > >         uint32_t *pSvcRec = (uint32_t *) malloc(sizeof(uint32_t));
> > > >         *pSvcRec = ntohl(bt_get_unaligned((uint32_t *) pdata));
> > > >         pSeq = sdp_list_append(pSeq, pSvcRec);
> > > >         pdata += sizeof(uint32_t);
> > > >         *scanned += sizeof(uint32_t);
> > > >     }
> > > >     *seq = pSeq;
> > > > }
> > > >
> > > > I think this will cause segfaults when you try to sdp_record_free the
> > > > records in the list (it does for me).
> > > >
> > > > perhaps it shold read something more like:
> > > >         sdp_record_t *pSvcRec = (sdp_record_t*) malloc(sizeof(sdp_record_t));
> > > >         pSvcRec->attrlist = pSvcRec->pattern = 0;
> > > >         pSvcRec->handle = ntohl(bt_get_unaligned((uint32_t *) pdata));
> > > >         pSeq = sdp_list_append(pSeq, pSvcRec);
> > >
> > > Steve, any thoughts on this one?
> > >
> > > Regards
> > >
> > > Marcel
> > >
> > >
> > 
> > -------------------------------------------------------
> > SF email is sponsored by - The IT Product Guide
> > Read honest & candid reviews on hundreds of IT Products from real users.
> > Discover which products truly live up to the hype. Start reading now.
> > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> > _______________________________________________
> > Bluez-devel mailing list
> > Bluez-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/bluez-devel
> >

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