[S] Change in libosmocore[master]: Add support for receiving Bter UI frames at lapdm.c

jolly has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/32934 ) Change subject: Add support for receiving Bter UI frames at lapdm.c ...................................................................... Add support for receiving Bter UI frames at lapdm.c Similar to support of sending Bter frame, the same rules apply when receiving them. Change-Id: If04115884743455c7bf2b2bc5f7e49e74b6ffb60 --- M src/gsm/lapdm.c 1 file changed, 31 insertions(+), 7 deletions(-) git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/34/32934/1 diff --git a/src/gsm/lapdm.c b/src/gsm/lapdm.c index aade046..ec2e661 100644 --- a/src/gsm/lapdm.c +++ b/src/gsm/lapdm.c @@ -57,6 +57,7 @@ #define LAPDm_ADDR_SAPI(addr) (((addr) >> 2) & 0x7) #define LAPDm_ADDR_CR(addr) (((addr) >> 1) & 0x1) #define LAPDm_ADDR_EA(addr) ((addr) & 0x1) +#define LAPDm_ADDR_SHORT_L2(addr) ((addr) & 0x3) /* TS 04.06 Table 3 / Section 3.4.3 */ #define LAPDm_CTRL_I(nr, ns, p) ((((nr) & 0x7) << 5) | (((p) & 0x1) << 4) | (((ns) & 0x7) << 1)) @@ -725,15 +726,23 @@ if (mctx.link_id & 0x40) { /* It was received from network on SACCH */ + /* A Short L3 header has both bits == 0. */ + if (LAPDm_ADDR_SHORT_L2(msg->l2h[2]) == 0x0) { + mctx.lapdm_fmt = LAPDm_FMT_Bter; + n201 = N201_Bter_SACCH; + sapi = 0; + } else /* 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; + sapi = (msg->l2h[0] >> 2) & 7; } else { mctx.lapdm_fmt = LAPDm_FMT_B; n201 = N201_AB_SACCH; + sapi = (msg->l2h[0] >> 2) & 7; } /* SACCH frames have a two-byte L1 header that * OsmocomBB L1 doesn't strip */ @@ -741,11 +750,17 @@ mctx.ta_ind = msg->l2h[1]; msgb_pull(msg, 2); msg->l2h += 2; - sapi = (msg->l2h[0] >> 2) & 7; } else { - mctx.lapdm_fmt = LAPDm_FMT_B; - n201 = N201_AB_SDCCH; - sapi = (msg->l2h[0] >> 2) & 7; + /* A Short L3 header has both bits == 0. */ + if (LAPDm_ADDR_SHORT_L2(msg->l2h[2]) == 0x0) { + mctx.lapdm_fmt = LAPDm_FMT_Bter; + n201 = N201_Bter_SDCCH; + sapi = 0; + } else { + mctx.lapdm_fmt = LAPDm_FMT_B; + n201 = N201_AB_SDCCH; + sapi = (msg->l2h[0] >> 2) & 7; + } } } @@ -838,9 +853,6 @@ rc = lapd_ph_data_ind(msg, &lctx); break; case LAPDm_FMT_Bter: - /* FIXME */ - msgb_free(msg); - break; case LAPDm_FMT_Bbis: /* directly pass up to layer3 */ msg->l3h = msg->l2h; -- To view, visit https://gerrit.osmocom.org/c/libosmocore/+/32934 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmocore Gerrit-Branch: master Gerrit-Change-Id: If04115884743455c7bf2b2bc5f7e49e74b6ffb60 Gerrit-Change-Number: 32934 Gerrit-PatchSet: 1 Gerrit-Owner: jolly &lt;andreas(a)eversberg.eu&gt; Gerrit-MessageType: newchange