Change in osmo-sgsn[master]: gprs_llc: remove the FCS from the msgb by trim'ing the msgb

[lynxis lazus]

lynxis lazus has submitted this change and it was merged. ( https://gerrit.osmocom.org/11022 )

Change subject: gprs_llc: remove the FCS from the msgb by trim'ing the msgb
......................................................................

gprs_llc: remove the FCS from the msgb by trim'ing the msgb

After checking the FCS, it's no use. The FCS should also not
appear on `hexdump(msgb_l3(MSG), msgb_l3len(MSG))`.

Change-Id: I27e061ead86395a336b67c7aead93d305a0f2ae8
---
M src/gprs/gprs_llc.c
M src/gprs/gprs_sndcp.c
2 files changed, 4 insertions(+), 2 deletions(-)

Approvals:
  Harald Welte: Looks good to me, approved
  Jenkins Builder: Verified



diff --git a/src/gprs/gprs_llc.c b/src/gprs/gprs_llc.c
index 6c92f83..abbb742 100644
--- a/src/gprs/gprs_llc.c
+++ b/src/gprs/gprs_llc.c
@@ -945,6 +945,9 @@
 		LOGP(DLLC, LOGL_INFO, "Dropping frame with invalid FCS\n");
 		return -EIO;
 	}
+	/* set l3 layer & remove the fcs */
+	msg->l3h = llhp.data;
+	msgb_l3trim(msg, llhp.data_len);
 
 	/* Update LLE's (BVCI, NSEI) tuple */
 	lle->llme->bvci = msgb_bvci(msg);
@@ -960,7 +963,6 @@
 
 	/* llhp.data is only set when we need to send LL_[UNIT]DATA_IND up */
 	if (llhp.cmd == GPRS_LLC_UI && llhp.data && llhp.data_len) {
-		msgb_gmmh(msg) = llhp.data;
 		switch (llhp.sapi) {
 		case GPRS_SAPI_GMM:
 			/* send LL_UNITDATA_IND to GMM */
diff --git a/src/gprs/gprs_sndcp.c b/src/gprs/gprs_sndcp.c
index 77f8ca6..52eeb75 100644
--- a/src/gprs/gprs_sndcp.c
+++ b/src/gprs/gprs_sndcp.c
@@ -792,7 +792,7 @@
 
 	npdu_num = (suh->npdu_high << 8) | suh->npdu_low;
 	npdu = (uint8_t *)suh + sizeof(*suh);
-	npdu_len = (msg->data + msg->len) - npdu - 3;	/* -3 'removes' the FCS */
+	npdu_len = (msg->data + msg->len) - npdu;
 
 	if (npdu_len <= 0) {
 		LOGP(DSNDCP, LOGL_ERROR, "Short SNDCP N-PDU: %d\n", npdu_len);

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Gerrit-Project: osmo-sgsn
Gerrit-Branch: master
Gerrit-MessageType: merged
Gerrit-Change-Id: I27e061ead86395a336b67c7aead93d305a0f2ae8
Gerrit-Change-Number: 11022
Gerrit-PatchSet: 3
Gerrit-Owner: lynxis lazus <lynxis at fe80.eu>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder (1000002)
Gerrit-Reviewer: lynxis lazus <lynxis at fe80.eu>
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