1 files changed, 441 insertions, 0 deletions
diff --git a/tcps_sess.c b/tcps_sess.c
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+/* tcps_sess.c
+ *
+ * This implements a session of the tcpsrv object. For general
+ * comments, see header of tcpsrv.c.
+ *
+ * NOTE: read comments in module-template.h to understand how this file
+ *       works!
+ *
+ * File begun on 2008-03-01 by RGerhards (extracted from tcpsrv.c)
+ *
+ * Copyright 2007, 2008 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This file is part of rsyslog.
+ *
+ * Rsyslog is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Rsyslog is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ */
+#include "config.h"
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include "rsyslog.h"
+#include "dirty.h"
+#include "module-template.h"
+#include "net.h"
+#include "tcpsrv.h"
+#include "tcps_sess.h"
+#include "obj.h"
+#include "errmsg.h"
+#include "netstrm.h"
+
+
+/* static data */
+DEFobjStaticHelpers
+DEFobjCurrIf(errmsg)
+DEFobjCurrIf(netstrm)
+
+/* forward definitions */
+static rsRetVal Close(tcps_sess_t *pThis);
+
+
+/* Standard-Constructor
+ */
+BEGINobjConstruct(tcps_sess) /* be sure to specify the object type also in END macro! */
+		pThis->iMsg = 0; /* just make sure... */
+		pThis->bAtStrtOfFram = 1; /* indicate frame header expected */
+		pThis->eFraming = TCP_FRAMING_OCTET_STUFFING; /* just make sure... */
+ENDobjConstruct(tcps_sess)
+
+
+/* ConstructionFinalizer
+ */
+static rsRetVal
+tcps_sessConstructFinalize(tcps_sess_t __attribute__((unused)) *pThis)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	if(pThis->pSrv->OnSessConstructFinalize != NULL) {
+		CHKiRet(pThis->pSrv->OnSessConstructFinalize(&pThis->pUsr));
+	}
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* destructor for the tcps_sess object */
+BEGINobjDestruct(tcps_sess) /* be sure to specify the object type also in END and CODESTART macros! */
+CODESTARTobjDestruct(tcps_sess)
+	if(pThis->pStrm != NULL)
+		netstrm.Destruct(&pThis->pStrm);
+
+	if(pThis->pSrv->pOnSessDestruct != NULL) {
+		pThis->pSrv->pOnSessDestruct(&pThis->pUsr);
+	}
+	/* now destruct our own properties */
+	if(pThis->fromHost != NULL)
+		free(pThis->fromHost);
+	if(pThis->fromHostIP != NULL)
+		free(pThis->fromHostIP);
+ENDobjDestruct(tcps_sess)
+
+
+/* debugprint for the tcps_sess object */
+BEGINobjDebugPrint(tcps_sess) /* be sure to specify the object type also in END and CODESTART macros! */
+CODESTARTobjDebugPrint(tcps_sess)
+ENDobjDebugPrint(tcps_sess)
+
+
+/* set property functions */
+/* set the hostname. Note that the caller *hands over* the string. That is,
+ * the caller no longer controls it once SetHost() has received it. Most importantly,
+ * the caller must not free it. -- rgerhards, 2008-04-24
+ */
+static rsRetVal
+SetHost(tcps_sess_t *pThis, uchar *pszHost)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+
+	if(pThis->fromHost != NULL) {
+		free(pThis->fromHost);
+	}
+	
+	pThis->fromHost = pszHost;
+
+	RETiRet;
+}
+
+/* set the remote host's IP. Note that the caller *hands over* the string. That is,
+ * the caller no longer controls it once SetHostIP() has received it. Most importantly,
+ * the caller must not free it. -- rgerhards, 2008-05-16
+ */
+static rsRetVal
+SetHostIP(tcps_sess_t *pThis, uchar *pszHostIP)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+
+	if(pThis->fromHostIP != NULL) {
+		free(pThis->fromHostIP);
+	}
+	
+	pThis->fromHostIP = pszHostIP;
+
+	RETiRet;
+}
+
+static rsRetVal
+SetStrm(tcps_sess_t *pThis, netstrm_t *pStrm)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	pThis->pStrm = pStrm;
+	RETiRet;
+}
+
+
+static rsRetVal
+SetMsgIdx(tcps_sess_t *pThis, int idx)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	pThis->iMsg = idx;
+	RETiRet;
+}
+
+
+/* set our parent, the tcpsrv object */
+static rsRetVal
+SetTcpsrv(tcps_sess_t *pThis, tcpsrv_t *pSrv)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	ISOBJ_TYPE_assert(pSrv, tcpsrv);
+	pThis->pSrv = pSrv;
+	RETiRet;
+}
+
+
+static rsRetVal
+SetUsrP(tcps_sess_t *pThis, void *pUsr)
+{
+	DEFiRet;
+	pThis->pUsr = pUsr;
+	RETiRet;
+}
+
+
+/* This should be called before a normal (non forced) close
+ * of a TCP session. This function checks if there is any unprocessed
+ * message left in the TCP stream. Such a message is probably a
+ * fragement. If evrything goes well, we must be right at the
+ * beginnig of a new frame without any data received from it. If
+ * not, there is some kind of a framing error. I think I remember that
+ * some legacy syslog/TCP implementations have non-LF terminated
+ * messages at the end of the stream. For now, we allow this behaviour.
+ * Later, it should probably become a configuration option.
+ * rgerhards, 2006-12-07
+ */
+static rsRetVal
+PrepareClose(tcps_sess_t *pThis)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	
+	if(pThis->bAtStrtOfFram == 1) {
+		/* this is how it should be. There is no unprocessed
+		 * data left and such we have nothing to do. For simplicity
+		 * reasons, we immediately return in that case.
+		 */
+		 FINALIZE;
+	}
+
+	/* we have some data left! */
+	if(pThis->eFraming == TCP_FRAMING_OCTET_COUNTING) {
+		/* In this case, we have an invalid frame count and thus
+		 * generate an error message and discard the frame.
+		 */
+		errmsg.LogError(0, NO_ERRCODE, "Incomplete frame at end of stream in session %p - "
+			    "ignoring extra data (a message may be lost).\n", pThis->pStrm);
+		/* nothing more to do */
+	} else { /* here, we have traditional framing. Missing LF at the end
+		 * of message may occur. As such, we process the message in
+		 * this case.
+		 */
+		dbgprintf("Extra data at end of stream in legacy syslog/tcp message - processing\n");
+		parseAndSubmitMessage(pThis->fromHost, pThis->fromHostIP, pThis->msg, pThis->iMsg, MSG_PARSE_HOSTNAME, NOFLAG, eFLOWCTL_LIGHT_DELAY);
+		pThis->bAtStrtOfFram = 1;
+	}
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* Closes a TCP session
+ * No attention is paid to the return code
+ * of close, so potential-double closes are not detected.
+ */
+static rsRetVal
+Close(tcps_sess_t *pThis)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	netstrm.Destruct(&pThis->pStrm);
+	free(pThis->fromHost);
+	pThis->fromHost = NULL; /* not really needed, but... */
+	free(pThis->fromHostIP);
+	pThis->fromHostIP = NULL; /* not really needed, but... */
+
+	RETiRet;
+}
+
+
+/* process the data received. As TCP is stream based, we need to process the
+ * data inside a state machine. The actual data received is passed in byte-by-byte
+ * from DataRcvd, and this function here compiles messages from them and submits
+ * the end result to the queue. Introducing this function fixes a long-term bug ;)
+ * rgerhards, 2008-03-14
+ */
+static rsRetVal
+processDataRcvd(tcps_sess_t *pThis, char c)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+
+	if(pThis->inputState == eAtStrtFram) {
+		if(isdigit((int) c)) {
+			pThis->inputState = eInOctetCnt;
+			pThis->iOctetsRemain = 0;
+			pThis->eFraming = TCP_FRAMING_OCTET_COUNTING;
+		} else {
+			pThis->inputState = eInMsg;
+			pThis->eFraming = TCP_FRAMING_OCTET_STUFFING;
+		}
+	}
+
+	if(pThis->inputState == eInOctetCnt) {
+		if(isdigit(c)) {
+			pThis->iOctetsRemain = pThis->iOctetsRemain * 10 + c - '0';
+		} else { /* done with the octet count, so this must be the SP terminator */
+			dbgprintf("TCP Message with octet-counter, size %d.\n", pThis->iOctetsRemain);
+			if(c != ' ') {
+				errmsg.LogError(0, NO_ERRCODE, "Framing Error in received TCP message: "
+					    "delimiter is not SP but has ASCII value %d.\n", c);
+			}
+			if(pThis->iOctetsRemain < 1) {
+				/* TODO: handle the case where the octet count is 0! */
+				dbgprintf("Framing Error: invalid octet count\n");
+				errmsg.LogError(0, NO_ERRCODE, "Framing Error in received TCP message: "
+					    "invalid octet count %d.\n", pThis->iOctetsRemain);
+			} else if(pThis->iOctetsRemain > MAXLINE) {
+				/* while we can not do anything against it, we can at least log an indication
+				 * that something went wrong) -- rgerhards, 2008-03-14
+				 */
+				dbgprintf("truncating message with %d octets - MAXLINE is %d\n",
+					  pThis->iOctetsRemain, MAXLINE);
+				errmsg.LogError(0, NO_ERRCODE, "received oversize message: size is %d bytes, "
+					        "MAXLINE is %d, truncating...\n", pThis->iOctetsRemain, MAXLINE);
+			}
+			pThis->inputState = eInMsg;
+		}
+	} else {
+		assert(pThis->inputState == eInMsg);
+		if(pThis->iMsg >= MAXLINE) {
+			/* emergency, we now need to flush, no matter if we are at end of message or not... */
+			dbgprintf("error: message received is larger than MAXLINE, we split it\n");
+			parseAndSubmitMessage(pThis->fromHost, pThis->fromHostIP, pThis->msg, pThis->iMsg, MSG_PARSE_HOSTNAME, NOFLAG, eFLOWCTL_LIGHT_DELAY);
+			pThis->iMsg = 0;
+			/* we might think if it is better to ignore the rest of the
+			 * message than to treat it as a new one. Maybe this is a good
+			 * candidate for a configuration parameter...
+			 * rgerhards, 2006-12-04
+			 */
+		}
+
+		if(c == '\n' && pThis->eFraming == TCP_FRAMING_OCTET_STUFFING) { /* record delemiter? */
+			parseAndSubmitMessage(pThis->fromHost, pThis->fromHostIP, pThis->msg, pThis->iMsg, MSG_PARSE_HOSTNAME, NOFLAG, eFLOWCTL_LIGHT_DELAY);
+			pThis->iMsg = 0;
+			pThis->inputState = eAtStrtFram;
+		} else {
+			/* IMPORTANT: here we copy the actual frame content to the message - for BOTH framing modes!
+			 * If we have a message that is larger than MAXLINE, we truncate it. This is the best
+			 * we can do in light of what the engine supports. -- rgerhards, 2008-03-14
+			 */
+			if(pThis->iMsg < MAXLINE) {
+				*(pThis->msg + pThis->iMsg++) = c;
+			}
+		}
+
+		if(pThis->eFraming == TCP_FRAMING_OCTET_COUNTING) {
+			/* do we need to find end-of-frame via octet counting? */
+			pThis->iOctetsRemain--;
+			if(pThis->iOctetsRemain < 1) {
+				/* we have end of frame! */
+				parseAndSubmitMessage(pThis->fromHost, pThis->fromHostIP, pThis->msg, pThis->iMsg, MSG_PARSE_HOSTNAME, NOFLAG, eFLOWCTL_LIGHT_DELAY);
+				pThis->iMsg = 0;
+				pThis->inputState = eAtStrtFram;
+			}
+		}
+	}
+
+	RETiRet;
+}
+
+
+/* Processes the data received via a TCP session. If there
+ * is no other way to handle it, data is discarded.
+ * Input parameter data is the data received, iLen is its
+ * len as returned from recv(). iLen must be 1 or more (that
+ * is errors must be handled by caller!). iTCPSess must be
+ * the index of the TCP session that received the data.
+ * rgerhards 2005-07-04
+ * And another change while generalizing. We now return either
+ * RS_RET_OK, which means the session should be kept open
+ * or anything else, which means it must be closed.
+ * rgerhards, 2008-03-01
+ */
+static rsRetVal
+DataRcvd(tcps_sess_t *pThis, char *pData, size_t iLen)
+{
+	DEFiRet;
+	char *pEnd;
+
+	ISOBJ_TYPE_assert(pThis, tcps_sess);
+	assert(pData != NULL);
+	assert(iLen > 0);
+
+	 /* We now copy the message to the session buffer. */
+	pEnd = pData + iLen; /* this is one off, which is intensional */
+
+	while(pData < pEnd) {
+		CHKiRet(processDataRcvd(pThis, *pData++));
+	}
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* queryInterface function
+ * rgerhards, 2008-02-29
+ */
+BEGINobjQueryInterface(tcps_sess)
+CODESTARTobjQueryInterface(tcps_sess)
+	if(pIf->ifVersion != tcps_sessCURR_IF_VERSION) { /* check for current version, increment on each change */
+		ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED);
+	}
+
+	/* ok, we have the right interface, so let's fill it
+	 * Please note that we may also do some backwards-compatibility
+	 * work here (if we can support an older interface version - that,
+	 * of course, also affects the "if" above).
+	 */
+	pIf->DebugPrint = tcps_sessDebugPrint;
+	pIf->Construct = tcps_sessConstruct;
+	pIf->ConstructFinalize = tcps_sessConstructFinalize;
+	pIf->Destruct = tcps_sessDestruct;
+
+	pIf->PrepareClose = PrepareClose;
+	pIf->Close = Close;
+	pIf->DataRcvd = DataRcvd;
+
+	pIf->SetUsrP = SetUsrP;
+	pIf->SetTcpsrv = SetTcpsrv;
+	pIf->SetHost = SetHost;
+	pIf->SetHostIP = SetHostIP;
+	pIf->SetStrm = SetStrm;
+	pIf->SetMsgIdx = SetMsgIdx;
+finalize_it:
+ENDobjQueryInterface(tcps_sess)
+
+
+/* exit our class
+ * rgerhards, 2008-03-10
+ */
+BEGINObjClassExit(tcps_sess, OBJ_IS_LOADABLE_MODULE) /* CHANGE class also in END MACRO! */
+CODESTARTObjClassExit(tcps_sess)
+	/* release objects we no longer need */
+	objRelease(errmsg, CORE_COMPONENT);
+	objRelease(netstrm, LM_NETSTRMS_FILENAME);
+ENDObjClassExit(tcps_sess)
+
+
+/* Initialize our class. Must be called as the very first method
+ * before anything else is called inside this class.
+ * rgerhards, 2008-02-29
+ */
+BEGINObjClassInit(tcps_sess, 1, OBJ_IS_CORE_MODULE) /* class, version - CHANGE class also in END MACRO! */
+	/* request objects we use */
+	CHKiRet(objUse(errmsg, CORE_COMPONENT));
+	CHKiRet(objUse(netstrm, LM_NETSTRMS_FILENAME));
+
+	/* set our own handlers */
+	OBJSetMethodHandler(objMethod_DEBUGPRINT, tcps_sessDebugPrint);
+	OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, tcps_sessConstructFinalize);
+ENDObjClassInit(tcps_sess)
+
+
+
+/* vim:set ai:
+ */