Hi Andrey,
On Wed, May 22, 2019 at 4:34 AM Andrey Smirnov <andrew.smirnov@xxxxxxxxx> wrote:
>
> Unknown options respose for Configure Respose packet has a different
> layout than that of unaccepted options, so it needs special code to
> handle it.
>
> Before:
>
> > ACL Data RX: Handle 12 flags 0x02 dlen 15
> L2CAP: Configure Response (0x05) ident 2 len 7
> Source CID: 64
> Flags: 0x0000
> Result: Failure - unknown options (0x0003)
> 04
>
> After:
>
> > ACL Data RX: Handle 12 flags 0x02 dlen 15
> L2CAP: Configure Response (0x05) ident 3 len 7
> Source CID: 65
> Flags: 0x0000
> Result: Failure - unknown options (0x0003)
> Option: Retransmission and Flow Control (0x04)
> ---
> monitor/l2cap.c | 56 ++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 44 insertions(+), 12 deletions(-)
>
> diff --git a/monitor/l2cap.c b/monitor/l2cap.c
> index 26719ac5e..6983f80f0 100644
> --- a/monitor/l2cap.c
> +++ b/monitor/l2cap.c
> @@ -705,6 +705,42 @@ static struct {
> { }
> };
>
> +static void lookup_option_by_type(uint8_t type, const char **str,
> + uint8_t *expect_len)
> +{
> + int i;
> +
> + for (i = 0; options_table[i].str; i++) {
> + if (options_table[i].type == type) {
> + *str = options_table[i].str;
> + if (expect_len)
> + *expect_len = options_table[i].len;
> + return;
> + }
> + }
> +
> + *str = "Unknown";
> + if (expect_len)
> + *expect_len = 0;
> +}
> +
> +static void print_unknown_options(const struct l2cap_frame *frame,
> + uint8_t offset)
> +{
> + const uint8_t *data = frame->data + offset;
> + uint16_t size = frame->size - offset;
> + uint16_t consumed = 0;
> +
> + while (size--) {
Id expected this to use l2cap_frame_get_u8 for fetching the type so
you don't have to create a custom code to iterate into the frame, the
offset can be handled with l2cap_frame_pull.
> + const char *str;
> + uint8_t type = data[consumed++] & 0x7f;
> +
> + lookup_option_by_type(type, &str, NULL);
> +
> + print_field("Option: %s (0x%2.2x)", str, type);
> + }
> +}
> +
> static void print_config_options(const struct l2cap_frame *frame,
> uint8_t offset, uint16_t cid, bool response)
> {
> @@ -713,24 +749,16 @@ static void print_config_options(const struct l2cap_frame *frame,
> uint16_t consumed = 0;
>
> while (consumed < size - 2) {
> - const char *str = "Unknown";
> + const char *str;
> uint8_t type = data[consumed] & 0x7f;
> uint8_t hint = data[consumed] & 0x80;
> uint8_t len = data[consumed + 1];
> - uint8_t expect_len = 0;
> - int i;
> + uint8_t expect_len;
>
> - for (i = 0; options_table[i].str; i++) {
> - if (options_table[i].type == type) {
> - str = options_table[i].str;
> - expect_len = options_table[i].len;
> - break;
> - }
> - }
> + lookup_option_by_type(type, &str, &expect_len);
>
> print_field("Option: %s (0x%2.2x) [%s]", str, type,
> hint ? "hint" : "mandatory");
> -
> if (expect_len == 0) {
> consumed += 2;
> break;
> @@ -1122,7 +1150,11 @@ static void sig_config_rsp(const struct l2cap_frame *frame)
> print_cid("Source", pdu->scid);
> print_config_flags(pdu->flags);
> print_config_result(pdu->result);
> - print_config_options(frame, 6, le16_to_cpu(pdu->scid), true);
> + if (pdu->result == 0x0003)
> + print_unknown_options(frame, 6);
> + else
> + print_config_options(frame, 6, le16_to_cpu(pdu->scid), true);
> +
> }
>
> static void sig_disconn_req(const struct l2cap_frame *frame)
> --
> 2.21.0
>
--
Luiz Augusto von Dentz
