diff options
| -rw-r--r-- | src/gsm/lapd_core.c | 10 | ||||
| -rw-r--r-- | tests/lapd/lapd_test.c | 76 | ||||
| -rw-r--r-- | tests/lapd/lapd_test.ok | 3 |
3 files changed, 87 insertions, 2 deletions
diff --git a/src/gsm/lapd_core.c b/src/gsm/lapd_core.c index b33cf6eb..f351308d 100644 --- a/src/gsm/lapd_core.c +++ b/src/gsm/lapd_core.c @@ -820,7 +820,12 @@ static int lapd_rx_u(struct msgb *msg, struct lapd_msg_ctx *lctx) "frame established state\n"); /* If link is lost on the remote side, we start over * and send DL-ESTABLISH indication again. */ - if (dl->v_send != dl->v_recv) { + /* Additionally, continue in case of content resoltion + * (GSM network). This happens, if the mobile has not + * yet received UA or another mobile (collision) tries + * to establish connection. The mobile must receive + * UA again. */ + if (!dl->cont_res && dl->v_send != dl->v_recv) { LOGP(DLLAPD, LOGL_INFO, "Remote reestablish\n"); mdl_error(MDL_CAUSE_SABM_MF, lctx); break; @@ -831,7 +836,8 @@ static int lapd_rx_u(struct msgb *msg, struct lapd_msg_ctx *lctx) #ifdef TEST_CONTENT_RESOLUTION_NETWORK dl->cont_res->data[0] ^= 0x01; #endif - if (memcmp(dl->cont_res, msg->data, length)) { + if (memcmp(dl->cont_res->data, msg->data, + length)) { LOGP(DLLAPD, LOGL_INFO, "Another SABM " "with diffrent content - " "ignoring!\n"); diff --git a/tests/lapd/lapd_test.c b/tests/lapd/lapd_test.c index a60c45d4..49b7eefa 100644 --- a/tests/lapd/lapd_test.c +++ b/tests/lapd/lapd_test.c @@ -67,6 +67,12 @@ static const uint8_t cm_padded[] = { 0x2b, 0x2b, 0x2b, 0x2b }; +static const uint8_t ua[] = { + 0x01, 0x73, 0x41, 0x05, 0x24, 0x31, 0x03, 0x50, + 0x18, 0x93, 0x08, 0x29, 0x47, 0x80, 0x00, 0x00, + 0x00, 0x00, 0x80, 0x2b, 0x2b, 0x2b, 0x2b +}; + static const uint8_t mm[] = { 0x00, 0x0c, 0x00, 0x03, 0x01, 0x01, 0x20, 0x02, 0x00, 0x0b, 0x00, 0x03, 0x05, 0x04, 0x0d @@ -153,6 +159,32 @@ static int send(struct msgb *in_msg, struct lapdm_channel *chan) return 0; } +static int send_sabm(struct lapdm_channel *chan, int second_ms) +{ + struct osmo_phsap_prim pp; + struct msgb *msg; + int rc; + + msg = msgb_alloc_headroom(128, 64, "PH-DATA.ind"); + osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_DATA, + PRIM_OP_INDICATION, msg); + /* copy over actual MAC block */ + msg->l2h = msgb_put(msg, 23); + msg->l2h[0] = 0x01; + msg->l2h[1] = 0x3f; + msg->l2h[2] = 0x01 | (sizeof(cm) << 2); + memcpy(msg->l2h + 3, cm_padded, sizeof(cm_padded)); + msg->l2h[3] += second_ms; /* alter message, for second mobile */ + + /* LAPDm requires those... */ + pp.u.data.chan_nr = 0; + pp.u.data.link_id = 0; + /* feed into the LAPDm code of libosmogsm */ + rc = lapdm_phsap_up(&pp.oph, &chan->lapdm_dcch); + OSMO_ASSERT(rc == 0 || rc == -EBUSY); + return 0; +} + /* * I get called from the LAPDm code when something was sent my way... */ @@ -348,12 +380,56 @@ static void test_lapdm_early_release() lapdm_channel_exit(&bts_to_ms_channel); } +static void test_lapdm_contention_resolution() +{ + printf("I test contention resultion by having two mobiles collide and " + "first mobile repeating SABM.\n"); + + int rc; + struct lapdm_polling_state test_state; + struct osmo_phsap_prim pp; + + /* Configure LAPDm on both sides */ + struct lapdm_channel bts_to_ms_channel; + memset(&bts_to_ms_channel, 0, sizeof(bts_to_ms_channel)); + + memset(&test_state, 0, sizeof(test_state)); + test_state.bts = &bts_to_ms_channel; + + /* BTS to MS in polling mode */ + lapdm_channel_init(&bts_to_ms_channel, LAPDM_MODE_BTS); + lapdm_channel_set_flags(&bts_to_ms_channel, LAPDM_ENT_F_POLLING_ONLY); + lapdm_channel_set_l1(&bts_to_ms_channel, NULL, &test_state); + lapdm_channel_set_l3(&bts_to_ms_channel, bts_to_ms_tx_cb, &test_state); + + /* Send SABM MS 1, we must get UA */ + send_sabm(&bts_to_ms_channel, 0); + rc = lapdm_phsap_dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp); + CHECK_RC(rc); + OSMO_ASSERT(memcmp(pp.oph.msg->l2h, ua, ARRAY_SIZE(ua)) == 0); + + /* Send SABM MS 2, we must get nothing, due to collision */ + send_sabm(&bts_to_ms_channel, 1); + rc = lapdm_phsap_dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp); + OSMO_ASSERT(rc == -ENODEV); + + /* Send SABM MS 1 again, we must get UA gain */ + send_sabm(&bts_to_ms_channel, 0); + rc = lapdm_phsap_dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp); + CHECK_RC(rc); + OSMO_ASSERT(memcmp(pp.oph.msg->l2h, ua, ARRAY_SIZE(ua)) == 0); + + /* clean up */ + lapdm_channel_exit(&bts_to_ms_channel); +} + int main(int argc, char **argv) { osmo_init_logging(&info); test_lapdm_polling(); test_lapdm_early_release(); + test_lapdm_contention_resolution(); printf("Success.\n"); return 0; diff --git a/tests/lapd/lapd_test.ok b/tests/lapd/lapd_test.ok index f1b990ea..aa927088 100644 --- a/tests/lapd/lapd_test.ok +++ b/tests/lapd/lapd_test.ok @@ -18,4 +18,7 @@ ms_to_bts_l1_cb: MS(us) -> BTS prim message bts_to_ms_tx_cb: MS->BTS(us) message 14 BTS: Verifying dummy message. I test RF channel release of an unestablished channel. +I test contention resultion by having two mobiles collide and first mobile repeating SABM. +bts_to_ms_tx_cb: MS->BTS(us) message 29 +BTS: Verifying CM request. Success. |