by Gowtham Anandha Babu

[permalink] [raw]

Subject: [PATCH v1 3/5] monitor/rfcomm: Add support for RLS frame decoding

Changes made to decode RLS 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: 4
FCS: 0x70
MCC Message type: Remote Line Status CMD(0x14)
Length: 2
dlci 32 error: 5
---
monitor/rfcomm.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/monitor/rfcomm.c b/monitor/rfcomm.c
index 62b52cc..848bad7 100644
--- a/monitor/rfcomm.c
+++ b/monitor/rfcomm.c
@@ -75,6 +75,9 @@ static char *cr_str[] = {
#define GET_RPN_RTCI(io) ((io & 0x10) >> 4)
#define GET_RPN_RTCO(io) ((io & 0x20) >> 5)

+/* RLS macro */
+#define GET_ERROR(err) (err & 0x0f)
+
struct rfcomm_lhdr {
uint8_t address;
uint8_t control;
@@ -99,6 +102,11 @@ struct rfcomm_rpn {
uint16_t pm;
} __attribute__ ((packed));

+struct rfcomm_rls {
+ uint8_t dlci;
+ uint8_t error;
+} __attribute__((packed));
+
struct rfcomm_lmcc {
uint8_t type;
uint16_t length;
@@ -209,6 +217,23 @@ done:
return true;
}

+static inline bool mcc_rls(struct rfcomm_frame *rfcomm_frame, uint8_t indent)
+{
+ struct l2cap_frame *frame = &rfcomm_frame->l2cap_frame;
+ struct rfcomm_rls rls;
+
+ if (!l2cap_frame_get_u8(frame, &rls.dlci))
+ return false;
+
+ if (!l2cap_frame_get_u8(frame, &rls.error))
+ return false;
+
+ print_field("%*cdlci %d error: %d", indent, ' ',
+ RFCOMM_GET_DLCI(rls.dlci), GET_ERROR(rls.error));
+
+ return true;
+}
+
struct mcc_data {
uint8_t type;
const char *str;
@@ -274,6 +299,8 @@ static inline bool mcc_frame(struct rfcomm_frame *rfcomm_frame, uint8_t indent)
return mcc_msc(rfcomm_frame, indent+2);
case RFCOMM_RPN:
return mcc_rpn(rfcomm_frame, indent+2);
+ case RFCOMM_RLS:
+ return mcc_rls(rfcomm_frame, indent+2);
default:
packet_hexdump(frame->data, frame->size);
}
--
1.9.1

2014-12-03 12:01:17

by Gowtham Anandha Babu

[permalink] [raw]

Subject: [PATCH v1 1/5] monitor/rfcomm.c: Add support for MSC frame decoding

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 | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 59 insertions(+), 7 deletions(-)

diff --git a/monitor/rfcomm.c b/monitor/rfcomm.c
index b3db98b..cd50c8c 100644
--- a/monitor/rfcomm.c
+++ b/monitor/rfcomm.c
@@ -49,11 +49,19 @@ 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)

struct rfcomm_lhdr {
uint8_t address;
@@ -63,6 +71,12 @@ 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 +106,38 @@ 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;
+
+ /*
+ * TODO: Implement the break signals decoding.
+ */
+
+ packet_hexdump(frame->data, frame->size);
+
+done:
+ return true;
+}
+
struct mcc_data {
uint8_t type;
const char *str;
@@ -151,7 +197,13 @@ 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 +277,7 @@ 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