Hi Gowtham,
On Tue, Dec 2, 2014 at 11:37 AM, Gowtham Anandha Babu
<gowtham.ab@xxxxxxxxxxx> 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
>
> --
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--
Luiz Augusto von Dentz
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