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-rw-r--r--tcps_sess.c421
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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 <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <ctype.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#include "rsyslog.h"
+#include "syslogd.h"
+#include "module-template.h"
+#include "net.h"
+#include "tcps_sess.h"
+#include "obj.h"
+
+
+/* static data */
+DEFobjStaticHelpers
+
+/* Standard-Constructor
+ */
+BEGINobjConstruct(tcps_sess) /* be sure to specify the object type also in END macro! */
+ pThis->sock = -1; /* no sock */
+ pThis->iMsg = 0; /* just make sure... */
+ pThis->bAtStrtOfFram = 1; /* indicate frame header expected */
+ pThis->eFraming = TCP_FRAMING_OCTET_STUFFING; /* just make sure... */
+ if(pThis->pOnTCPSessConstruct != NULL) {
+ // TODO: return value! Supply user pointer or whole
+ // object?
+ pThis->pOnTCPSessConstruct(pThis->pUsr);
+ }
+ENDobjConstruct(tcps_sess)
+
+
+/* ConstructionFinalizer
+ */
+static rsRetVal
+tcps_sessConstructFinalize(tcps_sess_t __attribute__((unused)) *pThis)
+{
+ DEFiRet;
+ ISOBJ_TYPE_assert(pThis, tcps_sess);
+ if(pThis->pOnTCPSessConstructFinalize != NULL) {
+ // TODO: return value! Supply user pointer or whole
+ // object?
+ pThis->pOnTCPSessConstructFinalize(pThis->pUsr);
+ }
+ 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->pOnTCPSessDestruct != NULL) {
+ // TODO: return value! Supply user pointer or whole
+ // object?
+ pThis->pOnTCPSessDestruct(pThis->pUsr);
+ }
+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 */
+static rsRetVal
+SetHost(tcps_sess_t *pThis, uchar *pszHost)
+{
+ DEFiRet;
+
+ ISOBJ_TYPE_assert(pThis, tcps_sess);
+
+RUNLOG_VAR("%p", pThis->fromHost);
+ if(pThis->fromHost != NULL) {
+ free(pThis->fromHost);
+ pThis->fromHost = NULL;
+ }
+
+RUNLOG;
+ if((pThis->fromHost = strdup((char*)pszHost)) == NULL)
+ ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
+
+RUNLOG;
+finalize_it:
+ RETiRet;
+}
+
+static rsRetVal
+SetSock(tcps_sess_t *pThis, int sock)
+{
+ DEFiRet;
+ ISOBJ_TYPE_assert(pThis, tcps_sess);
+ pThis->sock = sock;
+ RETiRet;
+}
+
+static rsRetVal
+SetMsgIdx(tcps_sess_t *pThis, int idx)
+{
+ DEFiRet;
+ ISOBJ_TYPE_assert(pThis, tcps_sess);
+ pThis->iMsg = idx;
+ 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.
+ */
+ logerrorInt("Incomplete frame at end of stream in session %d - "
+ "ignoring extra data (a message may be lost).\n",
+ pThis->sock);
+ /* 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->msg,
+ pThis->iMsg, MSG_PARSE_HOSTNAME);
+ pThis->bAtStrtOfFram = 1;
+ }
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* Closes a TCP session and marks its slot in the session
+ * table as unused. 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);
+ close(pThis->sock);
+ pThis->sock = -1;
+ free(pThis->fromHost);
+ pThis->fromHost = NULL; /* not really needed, but... */
+
+ 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
+ * Changed this functions interface. We now return a status of
+ * what shall happen with the session. This is information for
+ * the caller. If 1 is returned, the session should remain open
+ * and additional data be accepted. If we return 0, the TCP
+ * session is to be closed by the caller. This functionality is
+ * needed in order to support framing errors, from which there
+ * is no recovery possible other than session termination and
+ * re-establishment. The need for this functionality thus is
+ * primarily rooted in support for -transport-tls I-D framing.
+ * rgerhards, 2006-12-07
+ * 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;
+ register int iMsg;
+ char *pMsg;
+ char *pEnd;
+
+ ISOBJ_TYPE_assert(pThis, tcps_sess);
+ assert(pData != NULL);
+ assert(iLen > 0);
+
+ /* We now copy the message to the session buffer. As
+ * it looks, we need to do this in any case because
+ * we might run into multiple messages inside a single
+ * buffer. Of course, we could think about optimizations,
+ * but as this code is to be replaced by liblogging, it
+ * probably doesn't make so much sense...
+ * rgerhards 2005-07-04
+ *
+ * Algo:
+ * - copy message to buffer until the first LF is found
+ * - printline() the buffer
+ * - continue with copying
+ */
+ iMsg = pThis->iMsg; /* copy for speed */
+ pMsg = pThis->msg; /* just a shortcut */
+ pEnd = pData + iLen; /* this is one off, which is intensional */
+
+ while(pData < pEnd) {
+ /* Check if we are at a new frame */
+ if(pThis->bAtStrtOfFram) {
+ /* we need to look at the message and detect
+ * the framing mode used
+ *//*
+ * Contrary to -transport-tls, we accept leading zeros in the message
+ * length. We do this in the spirit of "Be liberal in what you accept,
+ * and conservative in what you send". We expect that including leading
+ * zeros could be a common coding error.
+ * rgerhards, 2006-12-07
+ * The chairs of the IETF syslog-sec WG have announced that it is
+ * consensus to do the octet count on the SYSLOG-MSG part only. I am
+ * now changing the code to reflect this. Hopefully, it will not change
+ * once again (there can no compatibility layer programmed for this).
+ * To be on the save side, I just comment the code out. I mark these
+ * comments with "IETF20061218".
+ * rgerhards, 2006-12-19
+ */
+ if(isdigit((int) *pData)) {
+ int iCnt; /* the frame count specified */
+ pThis->eFraming = TCP_FRAMING_OCTET_COUNTING;
+ /* in this mode, we have OCTET-COUNT SP MSG - so we now need
+ * to extract the OCTET-COUNT and the SP and then extract
+ * the msg.
+ */
+ iCnt = 0;
+ /* IETF20061218 int iNbrOctets = 0; / * number of octets already consumed */
+ while(isdigit((int) *pData)) {
+ iCnt = iCnt * 10 + *pData - '0';
+ /* IETF20061218 ++iNbrOctets; */
+ ++pData;
+ }
+ dbgprintf("TCP Message with octet-counter, size %d.\n", iCnt);
+ if(*pData == ' ') {
+ ++pData; /* skip over SP */
+ /* IETF20061218 ++iNbrOctets; */
+ } else {
+ /* TODO: handle "invalid frame" case */
+ logerrorInt("Framing Error in received TCP message: "
+ "delimiter is not SP but has ASCII value %d.\n",
+ *pData);
+ return(0); /* unconditional error exit */
+ }
+ /* IETF20061218 pThis->iOctetsRemain = iCnt - iNbrOctets; */
+ pThis->iOctetsRemain = iCnt;
+ if(pThis->iOctetsRemain < 1) {
+ /* TODO: handle the case where the octet count is 0 or negative! */
+ dbgprintf("Framing Error: invalid octet count\n");
+ logerrorInt("Framing Error in received TCP message: "
+ "invalid octet count %d.\n",
+ pThis->iOctetsRemain);
+ return(0); /* unconditional error exit */
+ }
+ } else {
+ pThis->eFraming = TCP_FRAMING_OCTET_STUFFING;
+ /* No need to do anything else here in this case */
+ }
+ pThis->bAtStrtOfFram = 0; /* done frame header */
+ }
+
+ /* now copy message until end of record */
+
+ if(iMsg >= MAXLINE) {
+ /* emergency, we now need to flush, no matter if
+ * we are at end of message or not...
+ */
+ parseAndSubmitMessage(pThis->fromHost, pMsg, iMsg, MSG_PARSE_HOSTNAME);
+ 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(*pData == '\n' &&
+ pThis->eFraming == TCP_FRAMING_OCTET_STUFFING) { /* record delemiter? */
+ parseAndSubmitMessage(pThis->fromHost, pMsg, iMsg, MSG_PARSE_HOSTNAME);
+ iMsg = 0;
+ pThis->bAtStrtOfFram = 1;
+ ++pData;
+ } else {
+ /* IMPORTANT: here we copy the actual frame content to the message! */
+ *(pMsg + iMsg++) = *pData++;
+ }
+
+ 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, pMsg, iMsg, MSG_PARSE_HOSTNAME);
+ iMsg = 0;
+ pThis->bAtStrtOfFram = 1;
+ }
+ }
+ }
+
+ pThis->iMsg = iMsg; /* persist value */
+
+ return(1); /* successful return */
+ 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->SetHost = SetHost;
+ pIf->SetSock = SetSock;
+ pIf->SetMsgIdx = SetMsgIdx;
+finalize_it:
+ENDobjQueryInterface(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_LOADABLE_MODULE) /* class, version - CHANGE class also in END MACRO! */
+BEGINObjClassInit(tcps_sess, 1, OBJ_IS_CORE_MODULE) /* class, version - CHANGE class also in END MACRO! */
+ /* request objects we use */
+ //CHKiRet(objUse(expr, CORE_COMPONENT));
+
+ /* set our own handlers */
+ OBJSetMethodHandler(objMethod_DEBUGPRINT, tcps_sessDebugPrint);
+ OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, tcps_sessConstructFinalize);
+ENDObjClassInit(tcps_sess)
+
+
+
+/* vim:set ai:
+ */
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