Return-Path: MIME-Version: 1.0 In-Reply-To: <001f01d0108c$2041e680$60c5b380$@samsung.com> References: <1417608081-27926-1-git-send-email-gowtham.ab@samsung.com> <000501d01078$707a0830$516e1890$@samsung.com> <1762326.kKINeE8oQE@uw000953> <000601d0107c$32fcecd0$98f6c670$@samsung.com> <001f01d0108c$2041e680$60c5b380$@samsung.com> Date: Fri, 5 Dec 2014 15:07:34 +0200 Message-ID: Subject: Re: [PATCH v1 2/5] monitor/rfcomm: Add support for RPN frame decoding From: Luiz Augusto von Dentz To: Gowtham Anandha Babu Cc: Szymon Janc , "linux-bluetooth@vger.kernel.org" , Dmitry Kasatkin , Bharat Panda , cpgs@samsung.com Content-Type: text/plain; charset=UTF-8 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Gowtham, On Fri, Dec 5, 2014 at 3:04 PM, Gowtham Anandha Babu wrote: > Hi Luiz, > >> -----Original Message----- >> From: linux-bluetooth-owner@vger.kernel.org [mailto:linux-bluetooth- >> owner@vger.kernel.org] On Behalf Of Luiz Augusto von Dentz >> Sent: Friday, December 05, 2014 5:18 PM >> To: Gowtham Anandha Babu >> Cc: Szymon Janc; linux-bluetooth@vger.kernel.org; Dmitry Kasatkin; Bharat >> Panda; cpgs@samsung.com >> Subject: Re: [PATCH v1 2/5] monitor/rfcomm: Add support for RPN frame >> decoding >> >> Hi Gowtham, >> >> On Fri, Dec 5, 2014 at 1:10 PM, Gowtham Anandha Babu >> wrote: >> > Hi Szymon, >> > >> >> -----Original Message----- >> >> From: linux-bluetooth-owner@vger.kernel.org [mailto:linux-bluetooth- >> >> owner@vger.kernel.org] On Behalf Of Szymon Janc >> >> Sent: Friday, December 05, 2014 4:33 PM >> >> To: Gowtham Anandha Babu >> >> Cc: 'Szymon Janc'; linux-bluetooth@vger.kernel.org; >> >> d.kasatkin@samsung.com; bharat.panda@samsung.com; >> cpgs@samsung.com >> >> Subject: Re: [PATCH v1 2/5] monitor/rfcomm: Add support for RPN frame >> >> decoding >> >> >> >> Hi Gowtham, >> >> >> >> On Friday 05 of December 2014 16:14:20 Gowtham Anandha Babu wrote: >> >> > Hi Szymon, >> >> > >> >> > > -----Original Message----- >> >> > > From: linux-bluetooth-owner@vger.kernel.org >> >> > > [mailto:linux-bluetooth- owner@vger.kernel.org] On Behalf Of >> >> > > Szymon Janc >> >> > > Sent: Thursday, December 04, 2014 8:48 PM >> >> > > To: Gowtham Anandha Babu >> >> > > Cc: linux-bluetooth@vger.kernel.org; d.kasatkin@samsung.com; >> >> > > bharat.panda@samsung.com; cpgs@samsung.com >> >> > > Subject: Re: [PATCH v1 2/5] monitor/rfcomm: Add support for RPN >> >> > > frame decoding >> >> > > >> >> > > Hi Gowtham, >> >> > > >> >> > > On Wed, Dec 3, 2014 at 1:01 PM, Gowtham Anandha Babu >> >> > > wrote: >> >> > > > Changes made to decode RPN frame in RFCOMM for btmon. >> >> > > > >> >> > > > RFCOMM: Unnumbered Info with Header Check (UIH)(0xef) >> >> > > > Address: 0x03 cr 1 dlci 0x00 >> >> > > > Control: 0xef poll/final 0 >> >> > > > Length: 10 >> >> > > > FCS: 0x70 >> >> > > > MCC Message type: Remote Port Negotiation Command >> >> CMD(0x24) >> >> > > > Length: 8 >> >> > > > dlci 32 >> >> > > > br 3 db 2 sb 0 p 0 pt 0 xi 0 xo 0 >> >> > > > rtri 0 rtro 0 rtci 0 rtco 0 xon 17 xoff 19 >> >> > > > pm 0x3f7f >> >> > > > --- >> >> > > > monitor/rfcomm.c | 73 >> >> > > > >> >> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> >> > > > 1 file changed, 73 insertions(+) >> >> > > > >> >> > > > diff --git a/monitor/rfcomm.c b/monitor/rfcomm.c index >> >> > > > cd50c8c..62b52cc 100644 >> >> > > > --- a/monitor/rfcomm.c >> >> > > > +++ b/monitor/rfcomm.c >> >> > > > @@ -63,6 +63,18 @@ static char *cr_str[] = { >> >> > > > #define GET_V24_IC(sigs) ((sigs & 0x40) >> 6) >> >> > > > #define GET_V24_DV(sigs) ((sigs & 0x80) >> 7) >> >> > > > >> >> > > > +/* RPN macros */ >> >> > > > +#define GET_RPN_DB(parity) (parity & 0x03) >> >> > > > +#define GET_RPN_SB(parity) ((parity & 0x04) >> 2) >> >> > > > +#define GET_RPN_PARITY(parity) ((parity & 0x08) >> 3) #define >> >> > > > +GET_RPN_PTYPE(parity) ((parity & 0x03) >> 3) >> >> > > > +#define GET_RPN_XIN(io) (io & 0x01) >> >> > > > +#define GET_RPN_XOUT(io) ((io & 0x02) >> 1) >> >> > > > +#define GET_RPN_RTRI(io) ((io & 0x04) >> 2) >> >> > > > +#define GET_RPN_RTRO(io) ((io & 0x08) >> 3) >> >> > > > +#define GET_RPN_RTCI(io) ((io & 0x10) >> 4) >> >> > > > +#define GET_RPN_RTCO(io) ((io & 0x20) >> 5) >> >> > > > + >> >> > > > struct rfcomm_lhdr { >> >> > > > uint8_t address; >> >> > > > uint8_t control; >> >> > > > @@ -77,6 +89,16 @@ struct rfcomm_lmsc { >> >> > > > uint8_t break_sig; >> >> > > > } __attribute__((packed)); >> >> > > > >> >> > > > +struct rfcomm_rpn { >> >> > > > + uint8_t dlci; >> >> > > > + uint8_t bit_rate; >> >> > > > + uint8_t parity; >> >> > > > + uint8_t io; >> >> > > > + uint8_t xon; >> >> > > > + uint8_t xoff; >> >> > > > + uint16_t pm; >> >> > > > +} __attribute__ ((packed)); >> >> > > > + >> >> > > > struct rfcomm_lmcc { >> >> > > > uint8_t type; >> >> > > > uint16_t length; >> >> > > > @@ -138,6 +160,55 @@ done: >> >> > > > return true; >> >> > > > } >> >> > > > >> >> > > > +static inline bool mcc_rpn(struct rfcomm_frame *rfcomm_frame, >> >> > > > +uint8_t >> >> > > > +indent) { >> >> > > > + struct l2cap_frame *frame = &rfcomm_frame->l2cap_frame; >> >> > > > + struct rfcomm_rpn rpn; >> >> > > > + >> >> > > > + if (!l2cap_frame_get_u8(frame, &rpn.dlci)) >> >> > > > + return false; >> >> > > > + >> >> > > > + print_field("%*cdlci %d", indent, ' ', >> >> > > > + RFCOMM_GET_DLCI(rpn.dlci)); >> >> > > > + >> >> > > > + if (frame->size < 7) >> >> > > > + goto done; >> >> > > > + >> >> > > > + /* port value octets (optional) */ >> >> > > > + >> >> > > > + if (!l2cap_frame_get_u8(frame, &rpn.bit_rate)) >> >> > > > + return false; >> >> > > > + >> >> > > > + if (!l2cap_frame_get_u8(frame, &rpn.parity)) >> >> > > > + return false; >> >> > > > + >> >> > > > + if (!l2cap_frame_get_u8(frame, &rpn.io)) >> >> > > > + return false; >> >> > > > + >> >> > > > + print_field("%*cbr %d db %d sb %d p %d pt %d xi %d xo >> >> > > > + %d", >> >> > indent, ' >> >> > > ', >> >> > > > + rpn.bit_rate, GET_RPN_DB(rpn.parity), >> >> > GET_RPN_SB(rpn.parity), >> >> > > > + GET_RPN_PARITY(rpn.parity), GET_RPN_PTYPE(rpn.parity), >> >> > > > + GET_RPN_XIN(rpn.io), GET_RPN_XOUT(rpn.io)); >> >> > > > + >> >> > > > + if (!l2cap_frame_get_u8(frame, &rpn.xon)) >> >> > > > + return false; >> >> > > > + >> >> > > > + if (!l2cap_frame_get_u8(frame, &rpn.xoff)) >> >> > > > + return false; >> >> > > > + >> >> > > > + print_field("%*crtri %d rtro %d rtci %d rtco %d xon %d xoff %d", >> >> > > > + indent, ' ', GET_RPN_RTRI(rpn.io), GET_RPN_RTRO(rpn.io), >> >> > > > + GET_RPN_RTCI(rpn.io), GET_RPN_RTCO(rpn.io), rpn.xon, >> >> > > > + rpn.xoff); >> >> > > > + >> >> > > > + if (!l2cap_frame_get_be16(frame, &rpn.pm)) >> >> > > > + return false; >> >> > > > + >> >> > > > + print_field("%*cpm 0x%04x", indent, ' ', >> >> > > > + __bswap_16(rpn.pm)); >> >> > > >> >> > > This __bswap_16 is invalid since rpn.pm was already converted to >> >> > > host >> >> > order >> >> > > by l2cap_frame_get_be16(). (It wouldn't work correctly on BE arch >> >> anyway). >> >> > > >> >> > > Also this was causing build problems under Android. If you are >> >> > > able to >> >> > build- >> >> > > test under Android please do so. If not then at least point this >> >> > > in cover >> >> > letter >> >> > > or patch comment that code was tested only under Linux). >> >> > > >> >> > > I've fixed this myself but please pay attention to this with any >> >> > > future submission. >> >> > > >> >> > >> >> > Sure I will mention the tested platform details for future submission. >> >> > >> >> > Btw without __bswap_16(), rpn.pm and pn.mtu will be different from >> >> > the hcidump logs. >> >> > >> >> > This is captured by removing __bswap_16(). >> >> > >> >> > Btmon log: >> >> > RFCOMM: Unnumbered Info with Header Check (UIH)(0xef) >> >> > Address: 0x03 cr 1 dlci 0x00 >> >> > Control: 0xef poll/final 0 >> >> > Length: 10 >> >> > FCS: 0x70 >> >> > MCC Message type: DLC Parameter Negotiation CMD(0x20) >> >> > Length: 8 >> >> > dlci 6 frame_type 0 credit_flow 15 pri 3 >> >> > ack_timer 0 frame_size 32256 max_retrans 0 credits 1 >> >> > >> >> > Hcidump log: >> >> > RFCOMM(s): PN CMD: cr 1 dlci 0 pf 0 ilen 10 fcs 0x70 mcc_len 8 >> >> > dlci 6 frame_type 0 credit_flow 15 pri 3 ack_timer 0 >> >> > frame_size 126 max_retrans 0 credits 1 >> >> > >> >> > The rpn.pm is fine. That may be printed without doing __bswap_16() >> also. >> >> > >> >> > But in the above PN frame, frame_size is different from actual >> >> > hcidump trace. >> >> > I cross checked with PTS logs, it was same as the hcidump trace. >> >> > So, if it is causing build problems under Android, use >> >> > l2cap_frame_get_le16() >> >> > Instead of l2cap_frame_get_be16() for pn.mtu. >> >> > >> >> > If we are consistent with hcidump, then replace the be16() by >> >> > le16() for both pn.mtu and rpn.pm. >> >> > >> >> > After replacing the le16() function: >> >> > Btmon logs looks like: >> >> > >> >> > RFCOMM: Unnumbered Info with Header Check (UIH)(0xef) >> >> > Address: 0x03 cr 1 dlci 0x00 >> >> > Control: 0xef poll/final 0 >> >> > Length: 10 >> >> > FCS: 0x70 >> >> > MCC Message type: DLC Parameter Negotiation CMD(0x20) >> >> > Length: 8 >> >> > dlci 6 frame_type 0 credit_flow 15 pri 3 >> >> > ack_timer 0 frame_size 126 max_retrans 0 credits 1 >> >> > >> >> > What do you think ? >> >> >> >> If value is LE then l2cap_frame_get_le16() should be used. >> >> (Same issue affects rpn.pm mcc_rpn(), right?) >> >> >> > >> > Yes you are right. We have to use l2cap_frame_get_le16() for fetching both >> rpn.pm and pn.mtu. >> > I hope it will not cause any Android build problem. >> >> Actually you need to check what endianess for the protocol, the kernel >> seems to treat RFCOMM as little endian which I suppose is the correct byte >> order otherwise we would not be able to qualify or even interoperate with >> other devices. >> > > I checked it, the correct byte ordering for RFCOMM protocol is LE only. Then we need to replace every l2cap_frame_get_be* with l2cap_frame_get_le*. > >> >> > >> >> > > > + >> >> > > > +done: >> >> > > > + return true; >> >> > > > +} >> >> > > > + >> >> > > > struct mcc_data { >> >> > > > uint8_t type; >> >> > > > const char *str; >> >> > > > @@ -201,6 +272,8 @@ static inline bool mcc_frame(struct >> >> > > > rfcomm_frame >> >> > > *rfcomm_frame, uint8_t indent) >> >> > > > switch (type) { >> >> > > > case RFCOMM_MSC: >> >> > > > return mcc_msc(rfcomm_frame, indent+2); >> >> > > > + case RFCOMM_RPN: >> >> > > > + return mcc_rpn(rfcomm_frame, indent+2); >> >> > > > default: >> >> > > > packet_hexdump(frame->data, frame->size); >> >> > > > } >> >> > > > -- >> >> > > > 1.9.1 >> >> > > > >> >> > > > -- >> >> > > > To unsubscribe from this list: send the line "unsubscribe >> >> > > > linux-bluetooth" in the body of a message to >> >> > > > majordomo@vger.kernel.org More majordomo info at >> >> > > > http://vger.kernel.org/majordomo-info.html >> >> > > >> >> > > >> >> > > >> >> > > -- >> >> > > pozdrawiam >> >> > > Szymon K. Janc >> >> > > szymon.janc@gmail.com >> >> > > -- >> >> > > To unsubscribe from this list: send the line "unsubscribe linux- >> bluetooth" >> >> > in >> >> > > the body of a message to majordomo@vger.kernel.org More >> majordomo >> >> > > info at http://vger.kernel.org/majordomo-info.html >> >> > >> >> > >> >> > Regards, >> >> > Gowtham Anandha Babu >> >> > >> >> > -- >> >> > To unsubscribe from this list: send the line "unsubscribe >> >> > linux-bluetooth" in the body of a message to >> >> > majordomo@vger.kernel.org More majordomo info at >> >> > http://vger.kernel.org/majordomo-info.html >> >> >> >> -- >> >> Best regards, >> >> Szymon Janc >> >> -- >> >> To unsubscribe from this list: send the line "unsubscribe >> >> linux-bluetooth" in the body of a message to >> >> majordomo@vger.kernel.org More majordomo info at >> >> http://vger.kernel.org/majordomo-info.html >> > >> > Regards, >> > Gowtham Anandha Babu >> > >> > -- >> > To unsubscribe from this list: send the line "unsubscribe >> > linux-bluetooth" in the body of a message to majordomo@vger.kernel.org >> > More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> >> >> -- >> Luiz Augusto von Dentz >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in >> the body of a message to majordomo@vger.kernel.org More majordomo >> info at http://vger.kernel.org/majordomo-info.html > > > Regards, > Gowtham Anandha Babu > -- Luiz Augusto von Dentz