Hi Arman,
> Added command for "Exchange MTU" request/response. Also added code for
> initiating an L2CAP connection over the ATT channel. Tested using a CSR
> uEnergy 1000 board with the following results:
>
> $ btatt -d 00:02:5B:00:15:10 -v exchange-mtu 50
> Going to set MTU to 16 bit value: 50
> att: ATT command 0x02
> att < 02 32 00
> att > 03 17 00
> Exchange MTU response: Server Rx MTU 23
> ---
> tools/btatt.c | 192 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 191 insertions(+), 1 deletion(-)
>
> diff --git a/tools/btatt.c b/tools/btatt.c
> index 476bb94..da1eb3d 100644
> --- a/tools/btatt.c
> +++ b/tools/btatt.c
> @@ -31,6 +31,7 @@
> #include <string.h>
>
> #include <bluetooth/bluetooth.h>
> +#include <bluetooth/l2cap.h>
>
> #include "monitor/mainloop.h"
> #include "src/shared/att.h"
> @@ -39,11 +40,153 @@
>
> static bool verbose = false;
>
> +static void handle_error(const void *param, uint16_t len)
> +{
> + const struct bt_att_error_rsp_param *rp = param;
> +
> + if (len != sizeof(*rp)) {
> + fprintf(stderr, "Invalid error response length (%u)\n", len);
> + return;
> + }
> +
> + printf("Request failed:\n\topcode:\t%u\n\thandle:\t%u\n\terror:\t%u\n",
> + rp->request_opcode, rp->handle, rp->error_code);
> +}
> +
> +static void exchange_mtu_cb(uint8_t opcode, const void *param,
> + uint16_t len, void *user_data)
> +{
> + const struct bt_att_exchange_mtu_rsp_param *rp;
> +
> + if (opcode == BT_ATT_OP_ERROR_RESP) {
> + handle_error(param, len);
> + goto done;
> + }
> +
> + if (opcode != BT_ATT_OP_EXCHANGE_MTU_RESP) {
> + fprintf(stderr, "Invalid response opcode (%u)\n", opcode);
> + goto done;
> + }
> +
> + rp = param;
> +
> + if (len != sizeof(*rp)) {
> + fprintf(stderr, "Invalid \"Exchange MTU\" response length "
> + "(%u)\n", len);
> + goto done;
> + }
> +
> + printf("Exchange MTU response: Server Rx MTU: %u\n", rp->server_rx_mtu);
> +
> +done:
> + mainloop_quit();
> +}
> +
> +static void mtu_usage(void)
> +{
> + printf("Usage: btatt exchange-mtu <ATT_MTU>\n");
> +}
> +
> +static struct option mtu_options[] = {
> + { "help", 0, 0, 'h'},
> + {}
> +};
> +
> +static void cmd_mtu(struct bt_att *att, int argc, char **argv)
> +{
> + struct bt_att_exchange_mtu_req_param param;
> + uint16_t mtu;
> + int opt;
> +
> + while ((opt = getopt_long(argc, argv, "+h", mtu_options,
> + NULL)) != -1) {
> + switch (opt) {
> + case 'h':
> + default:
> + mtu_usage();
> + exit(EXIT_SUCCESS);
> + }
> + }
these days I prefer the for (;;) style we are using in btmon and some newer tools.
> +
> + argc -= optind;
> + argv += optind;
> + optind = 0;
> +
> + if (argc < 1) {
> + mtu_usage();
> + exit(EXIT_FAILURE);
> + }
> +
> + mtu = atoi(argv[0]);
> +
> + if (verbose)
> + printf("Going to set MTU to 16 bit value: %u\n", mtu);
> +
> + memset(¶m, 0, sizeof(param));
> + param.client_rx_mtu = mtu;
> + if (bt_att_send_sequential(att, BT_ATT_OP_EXCHANGE_MTU_REQ,
> + ¶m, sizeof(param),
> + exchange_mtu_cb, NULL, NULL) == 0) {
> + fprintf(stderr, "Unable to send \"Exchange MTU\" request\n");
> + exit(EXIT_FAILURE);
> + }
> +}
> +
> +static int l2cap_le_att_connect(bdaddr_t *src, bdaddr_t *dst, uint8_t dst_type)
> +{
> + int sock;
> + struct sockaddr_l2 srcaddr, dstaddr;
> + char srcaddr_str[18], dstaddr_str[18];
> +
> + if (verbose) {
> + ba2str(src, srcaddr_str);
> + ba2str(dst, dstaddr_str);
> +
> + printf("Opening L2CAP LE connection on ATT channel: "
> + "src: %s dest: %s\n", srcaddr_str, dstaddr_str);
> + }
> +
> + sock = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
> + if (sock < 0) {
> + perror("Failed to create L2CAP socket");
> + return -1;
> + }
> +
> + /* Set up source address */
> + memset(&srcaddr, 0, sizeof(srcaddr));
> + srcaddr.l2_family = AF_BLUETOOTH;
> + bacpy(&srcaddr.l2_bdaddr, src);
> + srcaddr.l2_cid = htobs(ATT_CID);
> + srcaddr.l2_bdaddr_type = BDADDR_LE_PUBLIC;
> +
> + if (bind(sock, (struct sockaddr *) &srcaddr, sizeof(srcaddr)) < 0) {
> + perror("Failed to bind L2CAP socket");
> + close(sock);
> + return -1;
> + }
> +
> + /* Set up destination address */
> + memset(&dstaddr, 0, sizeof(dstaddr));
> + dstaddr.l2_family = AF_BLUETOOTH;
> + bacpy(&dstaddr.l2_bdaddr, dst);
> + dstaddr.l2_cid = htobs(ATT_CID);
> + dstaddr.l2_bdaddr_type = dst_type;
> +
> + if (connect(sock, (struct sockaddr *) &dstaddr, sizeof(dstaddr)) < 0) {
> + perror("Failed to connect");
> + close(sock);
> + return -1;
> + }
> +
> + return sock;
> +}
> +
> static struct {
> char *cmd;
> void (*func)(struct bt_att *att, int argc, char **argv);
> char *doc;
Make them const char * if they do not allow modifications.
> } command[] = {
> + { "exchange-mtu", cmd_mtu, "\"Exchange MTU\" request." },
> { }
> };
We have not done this in any tool before, but maybe consider including the struct option for the individual parameters in it. Play with it and see how it works out.
>
> @@ -80,6 +223,13 @@ static struct option main_options[] = {
> { 0, 0, 0, 0}
> };
>
> +static void att_debug(const char *str, void *user_data)
> +{
> + const char *prefix = user_data;
> +
> + printf("%s%s\n", prefix, str);
> +}
> +
> int main(int argc, char *argv[])
> {
> int opt, i;
> @@ -88,6 +238,8 @@ int main(int argc, char *argv[])
> uint8_t dest_type = BDADDR_LE_PUBLIC;
> bdaddr_t src_addr, dst_addr;
> int fd;
> + struct bt_att *att;
> + int exit_status;
>
> while ((opt = getopt_long(argc, argv, "+hvt:i:d:",
> main_options, NULL)) != -1) {
> @@ -148,5 +300,43 @@ int main(int argc, char *argv[])
> return EXIT_FAILURE;
> }
>
> - return 0;
> + mainloop_init();
> +
> + fd = l2cap_le_att_connect(&src_addr, &dst_addr, dest_type);
> +
These empty lines need to go away.
> + if (fd < 0)
> + return EXIT_FAILURE;
> +
> + att = bt_att_new(fd);
> +
> + if (!att) {
> + fprintf(stderr, "Failed to create bt_att.");
> + close(fd);
> + return EXIT_FAILURE;
> + }
> +
> + if (verbose)
> + bt_att_set_debug(att, att_debug, "att: ", NULL);
I wonder if the option should be just --debug and debug_enabled or something like that. And on a side not, make it ATT: here.
> +
> + bt_att_set_close_on_unref(att, true);
> +
> + for (i = 0; command[i].cmd; i++) {
> + if (strcmp(command[i].cmd, argv[0]) == 0)
Step by step we are moving away from strcmp() == 0. Use !strcmp().
> + break;
> + }
> +
> + if (command[i].cmd == NULL) {
Use if (!command[i].cmd) here.
> + fprintf(stderr, "Unknown command: %s\n", argv[0]);
> + bt_att_unref(att);
> + return EXIT_FAILURE;
I would set exit_status to EXIT_FAILURE and goto done;
> + }
> +
> + command[i].func(att, argc, argv);
> +
> + exit_status = mainloop_run();
> +
> + bt_att_cancel_all(att);
The cancel_all is a bit useless here. The att_unref should clean that out for you.
> + bt_att_unref(att);
> +
> + return exit_status;
> }
Regards
Marcel
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
