diff options
| author | Andreas Eversberg <jolly@eversberg.eu> | 2013-02-06 14:13:21 +0100 |
|---|---|---|
| committer | Holger Hans Peter Freyther <zecke@selfish.org> | 2013-04-06 23:23:52 +0200 |
| commit | 6e182087f4ef6cc73f245e0fbc5db11916651ba0 (patch) | |
| tree | 03e38be814962e4d7a00040e3fbf1f273039befd /src | |
| parent | b64b2b031344b354b7a59f1eb4c1f97d457613f3 (diff) | |
Fix: LAPDm contention resoltion must acknowledge subsequent SABM
After reception of SABM, the network responds with UA and enters the
establised multiframe state. If UA is not received by mobile, the SABM
is transmitted again, and the network must respond with UA again, unless
it is from a different mobile.
Add LAPDm collision test (contention resolution on network side).
Diffstat (limited to 'src')
| -rw-r--r-- | src/gsm/lapd_core.c | 10 |
1 files changed, 8 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"); |