Return-Path: MIME-Version: 1.0 In-Reply-To: <1417513057-16037-2-git-send-email-gowtham.ab@samsung.com> References: <1417513057-16037-1-git-send-email-gowtham.ab@samsung.com> <1417513057-16037-2-git-send-email-gowtham.ab@samsung.com> Date: Tue, 2 Dec 2014 12:51:37 +0200 Message-ID: Subject: Re: [PATCH 1/5] monitor/rfcomm.c: Add support for MSC frame decoding From: Luiz Augusto von Dentz To: Gowtham Anandha Babu Cc: "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 Tue, Dec 2, 2014 at 11:37 AM, Gowtham Anandha Babu wrote: > Changes made to decode MSC frame in RFCOMM for btmon. > > RFCOMM: Unnumbered Info with Header Check (UIH)(0xef) > Address: 0x01 cr 0 dlci 0x00 > Control: 0xef poll/final 0 > Length: 4 > FCS: 0xaa > MCC Message type: Modem Status Command CMD(0x38) > Length: 2 > dlci 32 > fc 0 rtc 1 rtr 1 ic 0 dv 1 > --- > monitor/rfcomm.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++------ > 1 file changed, 69 insertions(+), 7 deletions(-) > > diff --git a/monitor/rfcomm.c b/monitor/rfcomm.c > index b3db98b..969b29f 100644 > --- a/monitor/rfcomm.c > +++ b/monitor/rfcomm.c > @@ -49,11 +49,24 @@ static char *cr_str[] = { > "CMD" > }; > > -#define CR_STR(type) cr_str[GET_CR(type)] > -#define GET_LEN8(length) ((length & 0xfe) >> 1) > -#define GET_LEN16(length) ((length & 0xfffe) >> 1) > -#define GET_CR(type) ((type & 0x02) >> 1) > -#define GET_PF(ctr) (((ctr) >> 4) & 0x1) > +/* RFCOMM frame parsing macros */ > +#define CR_STR(type) cr_str[GET_CR(type)] > +#define GET_LEN8(length) ((length & 0xfe) >> 1) > +#define GET_LEN16(length) ((length & 0xfffe) >> 1) > +#define GET_CR(type) ((type & 0x02) >> 1) > +#define GET_PF(ctr) (((ctr) >> 4) & 0x1) > + > +/* MSC macros */ > +#define GET_V24_FC(sigs) ((sigs & 0x02) >> 1) > +#define GET_V24_RTC(sigs) ((sigs & 0x04) >> 2) > +#define GET_V24_RTR(sigs) ((sigs & 0x08) >> 3) > +#define GET_V24_IC(sigs) ((sigs & 0x40) >> 6) > +#define GET_V24_DV(sigs) ((sigs & 0x80) >> 7) > + > +#define GET_BRK_SIG1(sigs) ((sigs & 0x02) >> 1) > +#define GET_BRK_SIG2(sigs) ((sigs & 0x04) >> 2) > +#define GET_BRK_SIG3(sigs) ((sigs & 0x08) >> 3) > +#define GET_BRK_SIG_LEN(sigs) ((sigs & 0xf0) >> 4) > > struct rfcomm_lhdr { > uint8_t address; > @@ -63,6 +76,12 @@ struct rfcomm_lhdr { > uint8_t credits; /* only for UIH frame */ > } __attribute__((packed)); > > +struct rfcomm_lmsc { > + uint8_t dlci; > + uint8_t v24_sig; > + uint8_t break_sig; > +} __attribute__((packed)); > + > struct rfcomm_lmcc { > uint8_t type; > uint16_t length; > @@ -92,6 +111,43 @@ static void print_rfcomm_hdr(struct rfcomm_frame *rfcomm_frame, uint8_t indent) > print_field("%*cFCS: 0x%2.2x", indent, ' ', hdr.fcs); > } > > +static inline bool mcc_msc(struct rfcomm_frame *rfcomm_frame, uint8_t indent) > +{ > + struct l2cap_frame *frame = &rfcomm_frame->l2cap_frame; > + struct rfcomm_lmsc msc; > + > + if (!l2cap_frame_get_u8(frame, &msc.dlci)) > + return false; > + > + print_field("%*cdlci %d ", indent, ' ', RFCOMM_GET_DLCI(msc.dlci)); > + > + if (!l2cap_frame_get_u8(frame, &msc.v24_sig)) > + return false; > + > + /* v24 control signals */ > + print_field("%*cfc %d rtc %d rtr %d ic %d dv %d", indent, ' ', > + GET_V24_FC(msc.v24_sig), GET_V24_RTC(msc.v24_sig), > + GET_V24_RTR(msc.v24_sig), GET_V24_IC(msc.v24_sig), > + GET_V24_DV(msc.v24_sig)); > + > + if (frame->size < 2) > + goto done; > + > + /* break signals (optional) */ > + > + if (!l2cap_frame_get_u8(frame, &msc.break_sig)) > + return false; > + > + printf("%2.2x", msc.break_sig); Im very suspicious the printf above will break indentation, you better add a frame that does exercise this code to make sure it is not happening. > + print_field("%*cb1 %d b2 %d b3 %d len %d", indent, ' ', > + GET_BRK_SIG1(msc.break_sig), GET_BRK_SIG2(msc.break_sig), > + GET_BRK_SIG3(msc.break_sig), GET_BRK_SIG_LEN(msc.break_sig)); > + > +done: > + return true; > +} > + > struct mcc_data { > uint8_t type; > const char *str; > @@ -151,7 +207,13 @@ static inline bool mcc_frame(struct rfcomm_frame *rfcomm_frame, uint8_t indent) > print_field("%*cLength: %d", indent+2, ' ', mcc.length); > > rfcomm_frame->mcc = mcc; > - packet_hexdump(frame->data, frame->size); > + > + switch (type) { > + case RFCOMM_MSC: > + return mcc_msc(rfcomm_frame, indent+2); > + default: > + packet_hexdump(frame->data, frame->size); > + } > > return true; > } > @@ -225,7 +287,7 @@ void rfcomm_packet(const struct l2cap_frame *frame) > > l2cap_frame_pull(&tmp_frame, l2cap_frame, l2cap_frame->size-1); > > - if(!l2cap_frame_get_u8(&tmp_frame, &hdr.fcs)) > + if (!l2cap_frame_get_u8(&tmp_frame, &hdr.fcs)) > goto fail; > > /* Decoding frame type */ > -- > 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 -- Luiz Augusto von Dentz