added support for SCM_CREDENTIALS to imuxsock (now fully working)

3 files changed, 107 insertions, 105 deletions

diff --git a/ChangeLog b/ChangeLog
index 9696f398..6622b67c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,11 @@
 ---------------------------------------------------------------------------
+Version 5.7.1  [V5-DEVEL] (rgerhards), 2010-09-??
+- imuxsock now optionally use SCM_CREDENTIALS to pull the pid from the log
+  socket itself (thanks to Lennart Poettering for the suggestion)
+- added new config statements
+  * $InputUnixListenSocketUsePIDFromSystem 
+  * $SystemLogUsePIDFromSystem 
+---------------------------------------------------------------------------
 Version 5.7.0  [V5-DEVEL] (rgerhards), 2010-09-16
 - added module impstat to emit periodic statistics on rsyslog counters
 - support for systemd officially added
diff --git a/doc/imuxsock.html b/doc/imuxsock.html
index 381374d2..4af2c030 100644
--- a/doc/imuxsock.html
+++ b/doc/imuxsock.html
@@ -40,12 +40,20 @@ the implications. Note that for many systems, turning on flow control does not h
 <br>Ignore timestamps included in the message. Applies to the next socket being added.</li>
 <li><b>$InputUnixListenSocketFlowControl</b> [on/<b>off</b>] - specifies if flow control should be applied
 to the next socket.</li>
+<li><b>$InputUnixListenSocketUsePIDFromSystem</b> [on/<b>off</b>] - specifies if the pid being logged shall
+be obtained from the log socket itself. If so, the TAG part of the message is rewritten.
+It is recommended to turn this option on, but the default is "off" to keep compatible
+with earlier versions of rsyslog. This option was introduced in 5.7.0.</li>
 <li><b>$SystemLogSocketIgnoreMsgTimestamp</b> [<b>on</b>/off]<br>
 Ignore timestamps included in the messages, applies to messages received via the system log socket.</li>
 <li><b>$OmitLocalLogging</b> (imuxsock) [on/<b>off</b>] -- former -o option</li>
 <li><b>$SystemLogSocketName</b> &lt;name-of-socket&gt; -- former -p option</li>
 <li><b>$SystemLogFlowControl</b> [on/<b>off</b>] - specifies if flow control should be applied
 to the system log socket.</li>
+<li><b>$SystemLogUsePIDFromSystem</b> [on/<b>off</b>] - specifies if the pid being logged shall
+be obtained from the log socket itself. If so, the TAG part of the message is rewritten.
+It is recommended to turn this option on, but the default is "off" to keep compatible
+with earlier versions of rsyslog. This option was introduced in 5.7.0.</li>
 <li><b>$InputUnixListenSocketCreatePath</b> [on/<b>off</b>] - create directories in the socket path
 if they do not already exist. They are created with 0755 permissions with the owner being the process under
 which rsyslogd runs. The default is not to create directories. Keep in mind, though, that rsyslogd always
diff --git a/plugins/imuxsock/imuxsock.c b/plugins/imuxsock/imuxsock.c
index 493f11c4..df2b8efc 100644
--- a/plugins/imuxsock/imuxsock.c
+++ b/plugins/imuxsock/imuxsock.c
@@ -83,7 +83,7 @@ statsobj_t *modStats;
 STATSCOUNTER_DEF(ctrSubmit, mutCtrSubmit)
 
 /* structure to describe a specific listener */
-struct lstn_s {
+typedef struct lstn_s {
 	uchar *sockName; /* read-only after startup */
 	prop_t *hostName; /* host-name override - if set, use this instead of actual name */
 	int fd; /* read-only after startup */
@@ -91,9 +91,9 @@ struct lstn_s {
 	int flowCtl; /* flow control settings for this socket */
 	sbool bParseHost; /* should parser parse host name?  read-only after startup */
 	sbool bUseCreds;
-	sbool bCreateSockPath; /* auto-creation of socket directory? */
-};
-static struct lstn_s listeners[MAXFUNIX];
+	sbool bCreatePath; /* auto-creation of socket directory? */
+} lstn_t;
+static lstn_t listeners[MAXFUNIX];
 
 static prop_t *pLocalHostIP = NULL;	/* there is only one global IP for all internally-generated messages */
 static prop_t *pInputName = NULL;	/* our inputName currently is always "imudp", and this will hold it */
@@ -108,10 +108,11 @@ static int bOmitLocalLogging = 0;
 static uchar *pLogSockName = NULL;
 static uchar *pLogHostName = NULL;	/* host name to use with this socket */
 static int bUseFlowCtl = 0;		/* use flow control or not (if yes, only LIGHT is used! */
-static int bIgnoreTimestamp = 1; /* ignore timestamps present in the incoming message? */
-static int bUseCreds = 0;	/* use credentials from recvmsg() and fixup PID in TAG */
-#define DFLT_bCreateSockPath 0
-static int bCreateSockPath = DFLT_bCreateSockPath; /* auto-create socket path? */
+static int bIgnoreTimestamp = 1;	 /* ignore timestamps present in the incoming message? */
+static int bUseCreds = 0;		/* use credentials from recvmsg() and fixup PID in TAG */
+static int bUseCredsSysSock = 0;	/* use credentials from recvmsg() and fixup PID in TAG */
+#define DFLT_bCreatePath 0
+static int bCreatePath = DFLT_bCreatePath; /* auto-create socket path? */
 
 
 /* set the timestamp ignore / not ignore option for the system
@@ -165,7 +166,7 @@ addLstnSocketName(void __attribute__((unused)) *pVal, uchar *pNewVal)
 		CHKiRet(prop.ConstructFinalize(listeners[nfd].hostName));
 		listeners[nfd].flowCtl = bUseFlowCtl ? eFLOWCTL_LIGHT_DELAY : eFLOWCTL_NO_DELAY;
 		listeners[nfd].flags = bIgnoreTimestamp ? IGNDATE : NOFLAG;
-		listeners[nfd].bCreateSockPath = bCreateSockPath;
+		listeners[nfd].bCreatePath = bCreatePath;
 		listeners[nfd].sockName = pNewVal;
 		listeners[nfd].bUseCreds = bUseCreds;
 		nfd++;
@@ -204,24 +205,25 @@ static rsRetVal discardFunixn(void)
 /* used to create a log socket if NOT passed in via systemd. 
  */
 static inline rsRetVal
-createLogSocket(const char *path, int bCreatePath, int *fd)
+createLogSocket(lstn_t *pLstn)
 {
 	struct sockaddr_un sunx;
 	DEFiRet;
 
-	unlink(path);
+	unlink((char*)pLstn->sockName);
 	memset(&sunx, 0, sizeof(sunx));
 	sunx.sun_family = AF_UNIX;
-	if(bCreatePath) {
-		makeFileParentDirs((uchar*)path, strlen(path), 0755, -1, -1, 0);
+	if(pLstn->bCreatePath) {
+		makeFileParentDirs((uchar*)pLstn->sockName, ustrlen(pLstn->sockName), 0755, -1, -1, 0);
 	}
-	strncpy(sunx.sun_path, path, sizeof(sunx.sun_path));
-	*fd = socket(AF_UNIX, SOCK_DGRAM, 0);
-	if(*fd < 0 || bind(*fd, (struct sockaddr *) &sunx, SUN_LEN(&sunx)) < 0 ||
-	    chmod(path, 0666) < 0) {
-		errmsg.LogError(errno, NO_ERRCODE, "connot create '%s'", path);
-		dbgprintf("cannot create %s (%d).\n", path, errno);
-		close(*fd);
+	strncpy(sunx.sun_path, (char*)pLstn->sockName, sizeof(sunx.sun_path));
+	pLstn->fd = socket(AF_UNIX, SOCK_DGRAM, 0);
+	if(pLstn->fd < 0 || bind(pLstn->fd, (struct sockaddr *) &sunx, SUN_LEN(&sunx)) < 0 ||
+	    chmod((char*)pLstn->sockName, 0666) < 0) {
+		errmsg.LogError(errno, NO_ERRCODE, "connot create '%s'", pLstn->sockName);
+		dbgprintf("cannot create %s (%d).\n", pLstn->sockName, errno);
+		close(pLstn->fd);
+		pLstn->fd = -1;
 		ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
 	}
 finalize_it:
@@ -230,16 +232,15 @@ finalize_it:
 
 
 static inline rsRetVal
-openLogSocket(const char *path, int bCreatePath, int *pfd)
+openLogSocket(lstn_t *pLstn)
 {
 	DEFiRet;
-	int fd;
 	int one;
 
-	if (path[0] == '\0')
+	if(pLstn->sockName[0] == '\0')
 		return -1;
 
-       if (strcmp(path, _PATH_LOG) == 0) {
+       if (ustrcmp(pLstn->sockName, UCHAR_CONSTANT(_PATH_LOG)) == 0) {
                int r;
 
                /* System log socket code. Check whether an FD was passed in from systemd. If
@@ -257,8 +258,8 @@ openLogSocket(const char *path, int bCreatePath, int *pfd)
                }
 
                if (r == 1) {
-                       fd = SD_LISTEN_FDS_START;
-                       r = sd_is_socket_unix(fd, SOCK_DGRAM, -1, _PATH_LOG, 0);
+                       pLstn->fd = SD_LISTEN_FDS_START;
+                       r = sd_is_socket_unix(pLstn->fd, SOCK_DGRAM, -1, _PATH_LOG, 0);
                        if (r < 0) {
                                errmsg.LogError(-r, NO_ERRCODE, "Failed to verify systemd socket type");
 				ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
@@ -269,42 +270,39 @@ openLogSocket(const char *path, int bCreatePath, int *pfd)
 				ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
                        }
 		} else {
-			CHKiRet(createLogSocket(path, bCreatePath, &fd));
+			CHKiRet(createLogSocket(pLstn));
 		}
 	} else {
-		CHKiRet(createLogSocket(path, bCreatePath, &fd));
+		CHKiRet(createLogSocket(pLstn));
 	}
 
-	one = 1;
-	if(setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, (socklen_t) sizeof(one)) != 0) {
-		errmsg.LogError(errno, NO_ERRCODE, "set SCM_CREDENTIALS '%s'", path);
-		close(fd);
-		ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
-	}
-	if(setsockopt(fd, SOL_SOCKET, SCM_CREDENTIALS, &one, sizeof(one)) != 0) {
-		errmsg.LogError(errno, NO_ERRCODE, "set SCM_CREDENTIALS '%s'", path);
-		close(fd);
-		ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
+	if(pLstn->bUseCreds) {
+		one = 1;
+		if(setsockopt(pLstn->fd, SOL_SOCKET, SO_PASSCRED, &one, (socklen_t) sizeof(one)) != 0) {
+			errmsg.LogError(errno, NO_ERRCODE, "set SO_PASSCRED failed on '%s'", pLstn->sockName);
+			pLstn->bUseCreds = 0;
+		}
+		if(setsockopt(pLstn->fd, SOL_SOCKET, SCM_CREDENTIALS, &one, sizeof(one)) != 0) {
+			errmsg.LogError(errno, NO_ERRCODE, "set SCM_CREDENTIALS failed on '%s'", pLstn->sockName);
+			pLstn->bUseCreds = 0;
+		}
 	}
+
+#if 0
+	// SO_TIMESTAMP currently does not work for an unknown reason. Any help is appreciated!
 	one = 1;
-	if(setsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one)) != 0) {
-		errmsg.LogError(errno, NO_ERRCODE, "set SO_TIMESTAMP '%s'", path);
-		close(fd);
+	if(setsockopt(pLstn->fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one)) != 0) {
+		errmsg.LogError(errno, NO_ERRCODE, "set SO_TIMESTAMP '%s'", pLstn->sockName);
 		ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
 	}
+#endif
 
-
-
-static socklen_t two =sizeof(one);
-	if(getsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, &one,&two) != 0) {
-		errmsg.LogError(errno, NO_ERRCODE, "set SO_TIMESTAMP '%s'", path);
-		close(fd);
-		ABORT_FINALIZE(RS_RET_ERR_CRE_AFUX);
+finalize_it:
+	if(iRet != RS_RET_OK) {
+		close(pLstn->fd);
+		pLstn->fd = -1;
 	}
-dbgprintf("imuxsock: SO_TIMESTAMP is %d\n", one);
 
-	*pfd = fd;
-finalize_it:
 	RETiRet;
 }
 
@@ -321,7 +319,7 @@ fixPID(uchar *bufTAG, int *lenTag, struct ucred *cred)
 	if(cred == NULL)
 		return;
 	
-	lenPID = snprintf(bufPID, sizeof(bufPID), "[%u]:", (unsigned) cred->pid);
+	lenPID = snprintf(bufPID, sizeof(bufPID), "[%lu]:", (unsigned long) cred->pid);
 
 	for(i = *lenTag ; i >= 0  && bufTAG[i] != '[' ; --i)
 		/*JUST SKIP*/;
@@ -342,7 +340,7 @@ fixPID(uchar *bufTAG, int *lenTag, struct ucred *cred)
  * can also mangle it if necessary.
  */
 static inline rsRetVal
-SubmitMsg(uchar *pRcv, int lenRcv, int iSock, struct ucred *cred)
+SubmitMsg(uchar *pRcv, int lenRcv, lstn_t *pLstn, struct ucred *cred)
 {
 	msg_t *pMsg;
 	int lenMsg;
@@ -356,7 +354,7 @@ SubmitMsg(uchar *pRcv, int lenRcv, int iSock, struct ucred *cred)
 	CHKiRet(msgConstruct(&pMsg));
 	MsgSetRawMsg(pMsg, (char*)pRcv, lenRcv);
 	MsgSetInputName(pMsg, pInputName);
-	MsgSetFlowControlType(pMsg, listeners[iSock].flowCtl);
+	MsgSetFlowControlType(pMsg, pLstn->flowCtl);
 
 // TODO: handle format errors
 	parse = pRcv;
@@ -372,17 +370,14 @@ SubmitMsg(uchar *pRcv, int lenRcv, int iSock, struct ucred *cred)
 	pMsg->iFacility = LOG_FAC(pri);
 	pMsg->iSeverity = LOG_PRI(pri);
 	MsgSetAfterPRIOffs(pMsg, lenRcv - lenMsg);
-dbgprintf("imuxsock: submit: facil %d, sever %d\n", pMsg->iFacility, pMsg->iSeverity);
 
 	parse++; lenMsg--; /* '>' */
 
-dbgprintf("imuxsock: submit: stage 2\n");
 	if(datetime.ParseTIMESTAMP3164(&(pMsg->tTIMESTAMP), &parse, &lenMsg) != RS_RET_OK) {
 		dbgprintf("we have a problem, invalid timestamp in msg!\n");
 	}
 
 	/* pull tag */
-dbgprintf("imuxsock: submit: stage 3\n");
 
 	i = 0;
 	while(lenMsg > 0 && *parse != ' ' && i < CONF_TAG_MAXSIZE) {
@@ -395,19 +390,13 @@ dbgprintf("imuxsock: submit: stage 3\n");
 
 	MsgSetMSGoffs(pMsg, lenRcv - lenMsg);
 
-	// TODO: here we need to mangle the raw message if we need to
-	// "fix up" the user pid. In the long term, it may make more sense
-	// to add this (somehow) to the message object (problem: at this stage,
-	// it is not fully available, eg no structured data). Alternatively, we
-	// may use a custom parser for our messages, but that doesn't play too well
-	// with the rest of the system.
-	if(listeners[iSock].bParseHost) {
-		pMsg->msgFlags  = listeners[iSock].flags | PARSE_HOSTNAME;
+	if(pLstn->bParseHost) {
+		pMsg->msgFlags  = pLstn->flags | PARSE_HOSTNAME;
 	} else {
-		pMsg->msgFlags  = listeners[iSock].flags;
+		pMsg->msgFlags  = pLstn->flags;
 	}
 
-	MsgSetRcvFrom(pMsg, listeners[iSock].hostName);
+	MsgSetRcvFrom(pMsg, pLstn->hostName);
 	CHKiRet(MsgSetRcvFromIP(pMsg, pLocalHostIP));
 	CHKiRet(submitMsg(pMsg));
 
@@ -424,21 +413,20 @@ finalize_it:
  * of the socket which is to be processed. This eases access to the
  * growing number of properties. -- rgerhards, 2008-08-01
  */
-static rsRetVal readSocket(int fd, int iSock)
+static rsRetVal readSocket(lstn_t *pLstn)
 {
 	DEFiRet;
 	int iRcvd;
 	int iMaxLine;
 	struct msghdr msgh;
 	struct iovec msgiov;
-	static int ratelimitErrmsg = 0; // TODO: atomic OPS
 	struct cmsghdr *cm;
 	struct ucred *cred;
 	uchar bufRcv[4096+1];
-	char aux[1024];
+	char aux[128];
 	uchar *pRcv = NULL; /* receive buffer */
 
-	assert(iSock >= 0);
+	assert(pLstn->fd >= 0);
 
 	iMaxLine = glbl.GetMaxLine();
 
@@ -456,38 +444,34 @@ static rsRetVal readSocket(int fd, int iSock)
 
 	memset(&msgh, 0, sizeof(msgh));
 	memset(&msgiov, 0, sizeof(msgiov));
-	memset(&aux, 0, sizeof(aux));
+	if(pLstn->bUseCreds) {
+		memset(&aux, 0, sizeof(aux));
+		msgh.msg_control = aux;
+		msgh.msg_controllen = sizeof(aux);
+	}
 	msgiov.iov_base = pRcv;
 	msgiov.iov_len = iMaxLine;
 	msgh.msg_iov = &msgiov;
 	msgh.msg_iovlen = 1;
-	msgh.msg_control = aux;
-	msgh.msg_controllen = sizeof(aux);
-	iRcvd = recvmsg(fd, &msgh, MSG_DONTWAIT);
-/*	iRcvd = recv(fd, pRcv, iMaxLine, 0);
- */
+	iRcvd = recvmsg(pLstn->fd, &msgh, MSG_DONTWAIT);
  
-	dbgprintf("Message from UNIX socket: #%d\n", fd);
-	if (iRcvd > 0) {
-		ratelimitErrmsg = 0;
-
-
-dbgprintf("XXX: pre CM loop, length of control message %d\n", (int) msgh.msg_controllen);
-	cred = NULL;
-        for (cm = CMSG_FIRSTHDR(&msgh); cm; cm = CMSG_NXTHDR(&msgh, cm)) {
-dbgprintf("XXX: in CM loop, %d, %d\n", cm->cmsg_level, cm->cmsg_type);
-            if (cm->cmsg_level == SOL_SOCKET && cm->cmsg_type == SCM_CREDENTIALS) {
-	    	cred = (struct ucred*) CMSG_DATA(cm);
-	    	dbgprintf("XXX: got credentials pid %d\n", (int) cred->pid);
-                //break;
-            }
-	 }
-dbgprintf("XXX: post CM loop\n");
-
-
-
-		CHKiRet(SubmitMsg(pRcv, iRcvd, iSock, cred));
-	} else if (iRcvd < 0 && errno != EINTR && ratelimitErrmsg++ < 100) {
+	dbgprintf("Message from UNIX socket: #%d\n", pLstn->fd);
+	if(iRcvd > 0) {
+		cred = NULL;
+		if(pLstn->bUseCreds) {
+			dbgprintf("XXX: pre CM loop, length of control message %d\n", (int) msgh.msg_controllen);
+			for (cm = CMSG_FIRSTHDR(&msgh); cm; cm = CMSG_NXTHDR(&msgh, cm)) {
+				dbgprintf("XXX: in CM loop, %d, %d\n", cm->cmsg_level, cm->cmsg_type);
+				if (cm->cmsg_level == SOL_SOCKET && cm->cmsg_type == SCM_CREDENTIALS) {
+					cred = (struct ucred*) CMSG_DATA(cm);
+					dbgprintf("XXX: got credentials pid %d\n", (int) cred->pid);
+					//break;
+				}
+			}
+			dbgprintf("XXX: post CM loop\n");
+		}
+		CHKiRet(SubmitMsg(pRcv, iRcvd, pLstn, cred));
+	} else if(iRcvd < 0 && errno != EINTR) {
 		char errStr[1024];
 		rs_strerror_r(errno, errStr, sizeof(errStr));
 		dbgprintf("UNIX socket error: %d = %s.\n", errno, errStr);
@@ -555,7 +539,7 @@ CODESTARTrunInput
 			if(glbl.GetGlobalInputTermState() == 1)
 				ABORT_FINALIZE(RS_RET_FORCE_TERM); /* terminate input! */
 			if ((fd = listeners[i].fd) != -1 && FD_ISSET(fd, pReadfds)) {
-				readSocket(fd, i);
+				readSocket(&(listeners[i]));
 				--nfds; /* indicate we have processed one */
 			}
 		}
@@ -585,12 +569,12 @@ CODESTARTwillRun
 #	endif
 	if(pLogSockName != NULL)
 		listeners[0].sockName = pLogSockName;
+	listeners[0].bUseCreds = bUseCredsSysSock;
 
 	/* initialize and return if will run or not */
 	actSocks = 0;
 	for (i = startIndexUxLocalSockets ; i < nfd ; i++) {
-		if(openLogSocket((char*) listeners[i].sockName, listeners[i].bCreateSockPath,
-			&(listeners[i].fd)) == RS_RET_OK) {
+		if(openLogSocket(&(listeners[i])) == RS_RET_OK) {
 			++actSocks;
 			dbgprintf("Opened UNIX socket '%s' (fd %d).\n", listeners[i].sockName, listeners[i].fd);
 			}
@@ -682,7 +666,8 @@ static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __a
 	bIgnoreTimestamp = 1;
 	bUseFlowCtl = 0;
 	bUseCreds = 0;
-	bCreateSockPath = DFLT_bCreateSockPath;
+	bUseCredsSysSock = 0;
+	bCreatePath = DFLT_bCreatePath;
 
 	return RS_RET_OK;
 }
@@ -709,7 +694,7 @@ CODEmodInit_QueryRegCFSLineHdlr
 	listeners[0].fd = -1;
 	listeners[0].bParseHost = 0;
 	listeners[0].bUseCreds = 0;
-	listeners[0].bCreateSockPath = 0;
+	listeners[0].bCreatePath = 0;
 
 	/* initialize socket names */
 	for(i = 1 ; i < MAXFUNIX ; ++i) {
@@ -738,9 +723,11 @@ CODEmodInit_QueryRegCFSLineHdlr
 	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputunixlistensocketflowcontrol", 0, eCmdHdlrBinary,
 		NULL, &bUseFlowCtl, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputunixlistensocketcreatepath", 0, eCmdHdlrBinary,
-		NULL, &bCreateSockPath, STD_LOADABLE_MODULE_ID));
-	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputunixlistensocketusespidfromsystem", 0, eCmdHdlrBinary,
+		NULL, &bCreatePath, STD_LOADABLE_MODULE_ID));
+	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputunixlistensocketusepidfromsystem", 0, eCmdHdlrBinary,
 		NULL, &bUseCreds, STD_LOADABLE_MODULE_ID));
+	CHKiRet(omsdRegCFSLineHdlr((uchar *)"systemlogusepidfromsystem", 0, eCmdHdlrBinary,
+		NULL, &bUseCredsSysSock, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr((uchar *)"addunixlistensocket", 0, eCmdHdlrGetWord,
 		addLstnSocketName, NULL, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,