diff options
| author | Andreas.Eversberg <jolly@eversberg.eu> | 2011-11-06 20:46:30 +0100 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2011-11-12 23:23:36 +0100 |
| commit | 816e178e99510267475a5f8948677a24e43a2863 (patch) | |
| tree | 9e6fc88577a1a478c855e100106891ca7bc33648 | |
| parent | f1f80de007aeefb7757d469dcc3869b6c5a89a9a (diff) | |
gsm/lapdm: Fix UI frames from BTS->MS have length (B4 format)
This is part of a set of commit to fix LAPDm to handle datalink
connection on ACCH (SAPI 3)
This is required to transfer SMS on SACCH of TCH/f or SDCCH/8 (4).
Written-by: Andreas Eversberg <jolly@eversberg.eu>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
| -rw-r--r-- | src/gsm/lapdm.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/src/gsm/lapdm.c b/src/gsm/lapdm.c index aac203e2..3e33e00f 100644 --- a/src/gsm/lapdm.c +++ b/src/gsm/lapdm.c @@ -520,8 +520,10 @@ static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, if (mctx.link_id & 0x40) { /* It was received from network on SACCH */ - /* If sent by BTS, lapdm_fmt must be B4 */ - if (le->mode == LAPDM_MODE_MS) { + /* If UI on SACCH sent by BTS, lapdm_fmt must be B4 */ + if (le->mode == LAPDM_MODE_MS + && LAPDm_CTRL_is_U(msg->l2h[3]) + && LAPDm_CTRL_U_BITS(msg->l2h[3]) == 0) { mctx.lapdm_fmt = LAPDm_FMT_B4; n201 = N201_B4; LOGP(DLLAPD, LOGL_INFO, "fmt=B4\n"); @@ -802,6 +804,8 @@ static int rslms_rx_rll_est_req(struct msgb *msg, struct lapdm_datalink *dl) /* L3 requests transfer of unnumbered information */ static int rslms_rx_rll_udata_req(struct msgb *msg, struct lapdm_datalink *dl) { + struct lapdm_entity *le = dl->entity; + int ui_bts = (le->mode == LAPDM_MODE_BTS); struct abis_rsl_rll_hdr *rllh = msgb_l2(msg); uint8_t chan_nr = rllh->chan_nr; uint8_t link_id = rllh->link_id; @@ -828,9 +832,9 @@ static int rslms_rx_rll_udata_req(struct msgb *msg, struct lapdm_datalink *dl) msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO); length = TLVP_LEN(&tv, RSL_IE_L3_INFO); /* check if the layer3 message length exceeds N201 */ - if (length + 5 > 23) { /* FIXME: do we know the channel N201? */ + if (length + 4 + !ui_bts > 23) { LOGP(DLLAPD, LOGL_ERROR, "frame too large: %d > N201(%d) " - "(discarding)\n", length + 5, 23); + "(discarding)\n", length, 18 + ui_bts); msgb_free(msg); return -EIO; } @@ -844,13 +848,13 @@ static int rslms_rx_rll_udata_req(struct msgb *msg, struct lapdm_datalink *dl) msg->tail = msg->data + length; /* Push L1 + LAPDm header on msgb */ - msg->l2h = msgb_push(msg, 2 + 3); + msg->l2h = msgb_push(msg, 4 + !ui_bts); msg->l2h[0] = le->tx_power; msg->l2h[1] = le->ta; msg->l2h[2] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, dl->dl.cr.loc2rem.cmd); msg->l2h[3] = LAPDm_CTRL_U(LAPDm_U_UI, 0); - msg->l2h[4] = LAPDm_LEN(length); - // FIXME: short L2 header support + if (!ui_bts) + msg->l2h[4] = LAPDm_LEN(length); /* Tramsmit */ return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, 23); |