added new config option $InputUnixListenSocketCreatePath

backport from v5-devel

3 files changed, 43 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index cbfb597b..34406f4a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 ---------------------------------------------------------------------------
 Version 4.7.0  [v4-devel] (rgerhards), 2009-09-??
+- added new config option $InputUnixListenSocketCreatePath
+  to permit the auto-creation of pathes to additional log sockets. This
+  turns out to be useful if they reside on temporary file systems and
+  rsyslogd starts up before the daemons that create these sockets
+  (rsyslogd always creates the socket itself if it does not exist).
 - added $LogRSyslogStatusMessages configuration directive
   permitting to turn off rsyslog start/stop/HUP messages. See Debian
   ticket http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=463793
diff --git a/doc/imuxsock.html b/doc/imuxsock.html
index 472470a0..15c365a6 100644
--- a/doc/imuxsock.html
+++ b/doc/imuxsock.html
@@ -46,6 +46,18 @@ Ignore timestamps included in the messages, applies to messages received via the
 <li><b>$SystemLogSocketName</b> &lt;name-of-socket&gt; -- former -p option</li>
 <li><b>$SystemLogFlowControl</b> [on/<b>off</b>] - specifies if flow control should be applied
 to the system log socket.</li>
+<li><b>$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
+creates the socket itself if it does not exist (just not the directories by default).
+<br>Note that this statement affects the
+next $AddUnixListenSocket directive that follows in sequence in the configuration file. It never works
+on the system log socket (where it is deemed unnecessary). Also note that it is automatically 
+being reset to &quot;off&quot; after the $AddUnixListenSocket directive, so if you would have it active
+for two additional listen sockets, you need to specify it in front of each one. This option is primarily considered
+useful for defining additional sockets that reside on non-permanent file systems. As rsyslogd probably starts
+up before the daemons that create these sockets, it is a vehicle to enable rsyslogd to listen to those
+sockets even though their directories do not yet exist. [available since 4.7.0 and 5.3.0]</li>
 <li><b>$AddUnixListenSocket</b> &lt;name-of-socket&gt; adds additional unix socket, default none -- former -a option</li>
 <li><b>$InputUnixListenSocketHostName</b> &lt;hostname&gt; permits to override the hostname that
 shall be used inside messages taken from the <b>next</b> $AddUnixListenSocket socket. Note that
@@ -57,20 +69,32 @@ that the local hostname can be overridden in cases where that is desired.</li>
 <br>
 This documentation is sparse and incomplete.
 <p><b>Sample:</b></p>
-<p>The following sample is the minimum setup required to accept syslog messages from applications running on the local system.<br>
+<p>The following sample is the minimum setup required to accept syslog messages from applications running
+on the local system.<br>
 </p>
 <textarea rows="2" cols="70">$ModLoad imuxsock # needs to be done just once
 $SystemLogSocketFlowControl on # enable flow control (use if needed)
 </textarea>
 <p>The following sample is a configuration where rsyslogd pulls logs from two
 jails, and assigns different hostnames to each of the jails: </p>
-<textarea rows="6" cols="60">$ModLoad imuxsock # needs to be done just once
+<textarea rows="6" cols="70">$ModLoad imuxsock # needs to be done just once
 
 $InputUnixListenSocketHostName jail1.example.net
 $AddUnixListenSocket /jail/1/dev/log
 $InputUnixListenSocketHostName jail2.example.net
 $AddUnixListenSocket /jail/2/dev/log
 </textarea>
+<p>The following sample is a configuration where rsyslogd reads the openssh log
+messages via a separate socket, but this socket is created on a temporary file
+system. As rsyslogd starts up before the sshd, it needs to create the socket
+directories, because it otherwise can not open the socket and thus not listen
+to openssh messages. Note that it is vital not to place any other socket between
+the $InputUnixListenSocketCreatePath and the $InputUnixListenSocketHostName.</p>
+<textarea rows="6" cols="70">$ModLoad imuxsock # needs to be done just once
+
+$InputUnixListenSocketCreatePath on # turn on for *next* socket
+$InputUnixListenSocketHostName /var/run/sshd/dev/log
+</textarea>
 <p>[<a href="rsyslog_conf.html">rsyslog.conf overview</a>]
 [<a href="manual.html">manual index</a>] [<a href="http://www.rsyslog.com/">rsyslog site</a>]</p>
 <p><font size="2">This documentation is part of the
diff --git a/plugins/imuxsock/imuxsock.c b/plugins/imuxsock/imuxsock.c
index 424d0904..c5fb0cc8 100644
--- a/plugins/imuxsock/imuxsock.c
+++ b/plugins/imuxsock/imuxsock.c
@@ -77,6 +77,7 @@ static int startIndexUxLocalSockets; /* process funix from that index on (used t
 				   */
 static int funixParseHost[MAXFUNIX] = { 0, }; /* should parser parse host name?  read-only after startup */
 static int funixFlags[MAXFUNIX] = { IGNDATE, }; /* should parser parse host name?  read-only after startup */
+static int funixCreateSockPath[MAXFUNIX] = { 0, }; /* auto-creation of socket directory? */
 static uchar *funixn[MAXFUNIX] = { (uchar*) _PATH_LOG }; /* read-only after startup */
 static uchar *funixHName[MAXFUNIX] = { NULL, }; /* host-name override - if set, use this instead of actual name */
 static int funixFlowCtl[MAXFUNIX] = { eFLOWCTL_NO_DELAY, }; /* flow control settings for this socket */
@@ -89,6 +90,8 @@ 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? */
+#define DFLT_bCreateSockPath 0
+static int bCreateSockPath = DFLT_bCreateSockPath; /* auto-create socket path? */
 
 
 /* set the timestamp ignore / not ignore option for the system
@@ -132,6 +135,7 @@ static rsRetVal addLstnSocketName(void __attribute__((unused)) *pVal, uchar *pNe
 		pLogHostName = NULL; /* re-init for next, not freed because funixHName[] now owns it */
 		funixFlowCtl[nfunix] = bUseFlowCtl ? eFLOWCTL_LIGHT_DELAY : eFLOWCTL_NO_DELAY;
 		funixFlags[nfunix] = bIgnoreTimestamp ? IGNDATE : NOFLAG;
+		funixCreateSockPath[nfunix] = bCreateSockPath;
 		funixn[nfunix++] = pNewVal;
 	}
 	else {
@@ -165,7 +169,7 @@ static rsRetVal discardFunixn(void)
 }
 
 
-static int create_unix_socket(const char *path)
+static int create_unix_socket(const char *path, int bCreatePath)
 {
 	struct sockaddr_un sunx;
 	int fd;
@@ -177,6 +181,9 @@ static int create_unix_socket(const char *path)
 
 	memset(&sunx, 0, sizeof(sunx));
 	sunx.sun_family = AF_UNIX;
+	if(bCreatePath) {
+		makeFileParentDirs((uchar*)path, strlen(path), 0755, -1, -1, 0);
+	}
 	(void) 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 ||
@@ -306,7 +313,7 @@ CODESTARTwillRun
 
 	/* initialize and return if will run or not */
 	for (i = startIndexUxLocalSockets ; i < nfunix ; i++) {
-		if ((funix[i] = create_unix_socket((char*) funixn[i])) != -1)
+		if ((funix[i] = create_unix_socket((char*) funixn[i], funixCreateSockPath[i])) != -1)
 			dbgprintf("Opened UNIX socket '%s' (fd %d).\n", funixn[i], funix[i]);
 	}
 
@@ -376,6 +383,7 @@ static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __a
 	nfunix = 1;
 	bIgnoreTimestamp = 1;
 	bUseFlowCtl = 0;
+	bCreateSockPath = DFLT_bCreateSockPath;
 
 	return RS_RET_OK;
 }
@@ -409,6 +417,8 @@ CODEmodInit_QueryRegCFSLineHdlr
 		NULL, &pLogHostName, STD_LOADABLE_MODULE_ID));
 	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 *)"addunixlistensocket", 0, eCmdHdlrGetWord,
 		addLstnSocketName, NULL, STD_LOADABLE_MODULE_ID));
 	CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,