From: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: linux-bluetooth@vger.kernel.org
Subject: Re: [PATCH] Fix parser of AVRCP continuing messages
Date: Tue, 13 Sep 2011 17:40:55 +0300 [thread overview]
Message-ID: <CABBYNZJnJkBcKqe0SghJUhMYDar2Kg4mZMEi5VDepnDfevJAvg@mail.gmail.com> (raw)
In-Reply-To: <1315923685-30574-1-git-send-email-lucas.demarchi@profusion.mobi>
Hi Lucas,
On Tue, Sep 13, 2011 at 5:21 PM, Lucas De Marchi
<lucas.demarchi@profusion.mobi> wrote:
> If packet_type is not START or SINGLE, we have to continue where we
> stopped from previous packet. Therefore we must store where we left on
> previous packet due to packet size limit. We store both the number of
> attributes missing and the lenght of the last attribute that is missing.
>
> An example interaction for this implementation, obtained with PTS test
> TC_TG_MDI_BV_04_C (I reduced the MTU in order to reproduce it here and
> values between brackets I added now):
>
>> AVCTP: Command : pt 0x00 transaction 2 pid 0x110e
> AV/C: Status: address 0x48 opcode 0x00
> Subunit: Panel
> Opcode: Vendor Dependent
> Company ID: 0x001958
> AVRCP: GetElementAttributes: pt Single len 0x0009
> Identifier: 0x0 (PLAYING)
> AttributeCount: 0x00
> < AVCTP: Response : pt 0x00 transaction 2 pid 0x110e
> AV/C: Stable: address 0x48 opcode 0x00
> Subunit: Panel
> Opcode: Vendor Dependent
> Company ID: 0x001958
> AVRCP: GetElementAttributes: pt Start len 0x0118
> AttributeCount: 0x04
> Attribute: 0x00000001 (Title)
> CharsetID: 0x006a (UTF-8)
> AttributeValueLength: 0x001b
> AttributeValue: isso eh um titulo mei longo
> Attribute: 0x00000003 (Album)
> CharsetID: 0x006a (UTF-8)
> AttributeValueLength: 0x00fe
> AttributeValue: super-long-album-name super-long-album-name
> super-long-album-name super-long-album-name super-long-album
> super-long-album-name [... snip... ] super-long-album-name-1234
>> AVCTP: Command : pt 0x00 transaction 2 pid 0x110e
> AV/C: Control: address 0x48 opcode 0x00
> Subunit: Panel
> Opcode: Vendor Dependent
> Company ID: 0x001958
> AVRCP: RequestContinuingResponse: pt Single len 0x0001
> < AVCTP: Response : pt 0x00 transaction 2 pid 0x110e
> AV/C: Stable: address 0x48 opcode 0x00
> Subunit: Panel
> Opcode: Vendor Dependent
> Company ID: 0x001958
> AVRCP: GetElementAttributes: pt End len 0x002a
> ContinuingAttributeValue: 678900000000000000
> Attribute: 0x00000005 (Track Total)
> CharsetID: 0x006a (UTF-8)
> AttributeValueLength: 0x0002
> AttributeValue: 30
> Attribute: 0x00000006 (Genre)
> CharsetID: 0x006a (UTF-8)
> AttributeValueLength: 0x0006
> AttributeValue: Gospel
> ---
> parser/avrcp.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++---------
> 1 files changed, 79 insertions(+), 15 deletions(-)
>
> diff --git a/parser/avrcp.c b/parser/avrcp.c
> index 0b98a3e..65d3bda 100644
> --- a/parser/avrcp.c
> +++ b/parser/avrcp.c
> @@ -87,6 +87,12 @@
> #define AVC_PANEL_FORWARD 0x4b
> #define AVC_PANEL_BACKWARD 0x4c
>
> +/* Packet types */
> +#define AVRCP_PACKET_TYPE_SINGLE 0x00
> +#define AVRCP_PACKET_TYPE_START 0x01
> +#define AVRCP_PACKET_TYPE_CONTINUING 0x02
> +#define AVRCP_PACKET_TYPE_END 0x03
> +
> /* pdu ids */
> #define AVRCP_GET_CAPABILITIES 0x10
> #define AVRCP_LIST_PLAYER_ATTRIBUTES 0x11
> @@ -176,6 +182,11 @@
> #define AVRCP_PLAY_STATUS_REV_SEEK 0x04
> #define AVRCP_PLAY_STATUS_ERROR 0xFF
>
> +static struct avrcp_continuing {
> + uint16_t num;
> + uint16_t size;
> +} avrcp_continuing;
> +
> static const char *ctype2str(uint8_t ctype)
> {
> switch (ctype & 0x0f) {
> @@ -224,6 +235,22 @@ static const char *opcode2str(uint8_t opcode)
> }
> }
>
> +static const char *pt2str(uint8_t pt)
> +{
> + switch (pt) {
> + case AVRCP_PACKET_TYPE_SINGLE:
> + return "Single";
> + case AVRCP_PACKET_TYPE_START:
> + return "Start";
> + case AVRCP_PACKET_TYPE_CONTINUING:
> + return "Continuing";
> + case AVRCP_PACKET_TYPE_END:
> + return "End";
> + default:
> + return "Unknown";
> + }
> +}
> +
> static const char *pdu2str(uint8_t pduid)
> {
> switch (pduid) {
> @@ -917,7 +944,8 @@ static const char *mediattr2str(uint32_t attr)
> }
>
> static void avrcp_get_element_attributes_dump(int level, struct frame *frm,
> - uint8_t ctype, uint16_t len)
> + uint8_t ctype, uint16_t len,
> + uint8_t pt)
> {
> uint64_t id;
> uint8_t num;
> @@ -953,18 +981,45 @@ static void avrcp_get_element_attributes_dump(int level, struct frame *frm,
> return;
>
> response:
> - if (len < 1) {
> - printf("PDU Malformed\n");
> - raw_dump(level, frm);
> - return;
> - }
> + if (pt == AVRCP_PACKET_TYPE_SINGLE || pt == AVRCP_PACKET_TYPE_START) {
> + if (len < 1) {
> + printf("PDU Malformed\n");
> + raw_dump(level, frm);
> + return;
> + }
>
> - num = get_u8(frm);
> - printf("AttributeCount: 0x%02x\n", num);
> + num = get_u8(frm);
> + avrcp_continuing.num = num;
> + printf("AttributeCount: 0x%02x\n", num);
> + len--;
> + } else {
> + num = avrcp_continuing.num;
> +
> + if (avrcp_continuing.size > 0) {
> + uint16_t size;
> +
> + if (avrcp_continuing.size > len) {
> + size = len;
> + avrcp_continuing.size -= len;
> + } else {
> + size = avrcp_continuing.size;
> + avrcp_continuing.size = 0;
> + }
> +
> + printf("ContinuingAttributeValue: ");
> + for (; size > 0; size--) {
> + uint8_t c = get_u8(frm);
> + printf("%1c", isprint(c) ? c : '.');
> + }
> + printf("\n");
>
> - for (; num > 0; num--) {
> + len -= size;
> + }
> + }
> +
> + while (num > 0 && len > 0) {
> uint32_t attr;
> - uint16_t charset, len;
> + uint16_t charset, attrlen;
>
> p_indent(level, frm);
>
> @@ -978,19 +1033,26 @@ response:
> charset2str(charset));
>
> p_indent(level, frm);
> + attrlen = get_u16(frm);
> + printf("AttributeValueLength: 0x%04x\n", attrlen);
>
> - len = get_u16(frm);
> - printf("AttributeValueLength: 0x%04x\n", len);
> + len -= sizeof(attr) + sizeof(charset) + sizeof(attrlen);
> + num--;
>
> p_indent(level, frm);
>
> printf("AttributeValue: ");
> - for (; len > 0; len--) {
> + for (; attrlen > 0 && len > 0; attrlen--, len--) {
> uint8_t c = get_u8(frm);
> printf("%1c", isprint(c) ? c : '.');
> }
> printf("\n");
> +
> + if (attrlen > 0)
> + avrcp_continuing.size = attrlen;
> }
> +
> + avrcp_continuing.num = num;
> }
>
> static const char *playstatus2str(uint8_t status)
> @@ -1153,7 +1215,8 @@ static void avrcp_pdu_dump(int level, struct frame *frm, uint8_t ctype)
> pt = get_u8(frm);
> len = get_u16(frm);
>
> - printf("AVRCP: %s: pt 0x%02x len 0x%04x\n", pdu2str(pduid), pt, len);
> + printf("AVRCP: %s: pt %s len 0x%04x\n", pdu2str(pduid),
> + pt2str(pt), len);
>
> if (len != frm->len) {
> p_indent(level, frm);
> @@ -1198,7 +1261,8 @@ static void avrcp_pdu_dump(int level, struct frame *frm, uint8_t ctype)
> avrcp_ct_battery_status_dump(level + 1, frm, ctype, len);
> break;
> case AVRCP_GET_ELEMENT_ATTRIBUTES:
> - avrcp_get_element_attributes_dump(level + 1, frm, ctype, len);
> + avrcp_get_element_attributes_dump(level + 1, frm, ctype, len,
> + pt);
> break;
> case AVRCP_GET_PLAY_STATUS:
> avrcp_get_play_status_dump(level + 1, frm, ctype, len);
> --
> 1.7.6.1
Ack, please remember to add hcidump to prefix next time.
--
Luiz Augusto von Dentz
next prev parent reply other threads:[~2011-09-13 14:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-13 14:21 [PATCH] Fix parser of AVRCP continuing messages Lucas De Marchi
2011-09-13 14:40 ` Luiz Augusto von Dentz [this message]
2011-09-13 16:33 ` Lucas De Marchi
2011-09-27 9:58 ` Johan Hedberg
-- strict thread matches above, loose matches on Subject: below --
2011-09-09 17:40 Lucas De Marchi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CABBYNZJnJkBcKqe0SghJUhMYDar2Kg4mZMEi5VDepnDfevJAvg@mail.gmail.com \
--to=luiz.dentz@gmail.com \
--cc=linux-bluetooth@vger.kernel.org \
--cc=lucas.demarchi@profusion.mobi \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.