bugfix: imuxsock truncated head of received message

This happened only under some circumstances. Thanks to Marius
Tomaschwesky, Florian Piekert and Milan Bartos for their help in
solving this issue.

Note that Milan sent a patch, which solved the problem under some
conditions (can be found somewhat earlier in git history). However,
it did not handle the original root cause, and so did not fix the
problem always. The main reason was that the date parser modifies
the provided lenghts. That part of the API was not properly
used by the caller (who decremented the length once more).

2 files changed, 6 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 9574a84f..1edcb71f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 ---------------------------------------------------------------------------
 Version 5.10.1  [V5-STABLE], 2012-0?-??
+- bugfix: imuxsock truncated head of received message
+  This happened only under some circumstances. Thanks to Marius
+  Tomaschwesky, Florian Piekert and Milan Bartos for their help in
+  solving this issue.
 - enable DNS resolution in imrelp
   Thanks to Apollon Oikonomopoulos for the patch
 - bugfix: invalid property name in property-filter could cause abort
diff --git a/plugins/imuxsock/imuxsock.c b/plugins/imuxsock/imuxsock.c
index 2d9d4b5d..cbb09b62 100644
--- a/plugins/imuxsock/imuxsock.c
+++ b/plugins/imuxsock/imuxsock.c
@@ -722,7 +722,7 @@ SubmitMsg(uchar *pRcv, int lenRcv, lstn_t *pLstn, struct ucred *cred, struct tim
 	CHKiRet(msgConstructWithTime(&pMsg, &st, tt));
 	MsgSetRawMsg(pMsg, (char*)pRcv, lenRcv);
 	parser.SanitizeMsg(pMsg);
-	lenMsg = pMsg->iLenRawMsg - offs;
+	lenMsg = pMsg->iLenRawMsg - offs; /* SanitizeMsg() may have changed the size */
 	MsgSetInputName(pMsg, pInputName);
 	MsgSetFlowControlType(pMsg, pLstn->flowCtl);
 
@@ -752,7 +752,6 @@ SubmitMsg(uchar *pRcv, int lenRcv, lstn_t *pLstn, struct ucred *cred, struct tim
 			parse[15] = ' '; /* re-write \0 from fromatTimestamp3164 by SP */
 			/* update "counters" to reflect processed timestamp */
 			parse += 16;
-			lenMsg -= 16;
 		}
 	}
 
@@ -767,12 +766,7 @@ SubmitMsg(uchar *pRcv, int lenRcv, lstn_t *pLstn, struct ucred *cred, struct tim
 	if(pLstn->bWritePid)
 		fixPID(bufParseTAG, &i, cred);
 	MsgSetTAG(pMsg, bufParseTAG, i);
-
-	if (pLstn->bAnnotate) {
-		MsgSetMSGoffs(pMsg, pMsg->iLenRawMsg - lenMsg - 16);
-	} else {
-		MsgSetMSGoffs(pMsg, pMsg->iLenRawMsg - lenMsg);
-	}
+	MsgSetMSGoffs(pMsg, pMsg->iLenRawMsg - lenMsg);
 
 	if(pLstn->bParseHost) {
 		pMsg->msgFlags  = pLstn->flags | PARSE_HOSTNAME;