Support for sending messages to a custom port on remote server

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

README.md

@@ -59,6 +59,7 @@ Main differences from the original sysklogd package are:
 - Full [RFC3164][] and [RFC5424][] support
 - Includes timestamp and hostname, RFC3164 style, in remote logging
 - Support for sending RFC5424 style remote syslog messages
+- Support for sending messages to a custom port on a remote server
 - Includes a `logger` tool with RFC5424 capabilities (`msgid` etc.)
 - Includes a library and system header replacement for logging
 - FreeBSD socket receive buffer size patch

docs/TODO.org

@@ -3,7 +3,7 @@
 
 ** sysklogd v2.0
 
-*** TODO Add support for @host:port, i.e. custom remote port to send to
+*** DONE Add support for @host:port, i.e. custom remote port to send to
 *** DONE Add example application, test building and running it from Travis-CI
 *** DONE Check for memory/descriptor leaks, valgrind/Coverity
 

man/syslog.conf.5

@@ -49,7 +49,7 @@ RULE     := SELECTOR  ACTION  [;OPTION]
 SELECTOR := [SELECTOR;]facility[,facility].[!=]severity
 ACTION   := /path/to/file
          |= |/path/to/named/pipe
-	 |= @remote[.host.tld]
+	 |= @remote[.host.tld][:PORT]
 OPTION   := [OPTION,]
 	 |= RFC3164
 	 |= RFC5424
@@ -276,7 +276,9 @@ Full remote logging support is available in
 .Nm syslogd ,
 i.e. to send messages to a remote syslog server, and and to receive
 messages from remote hosts.  To forward messages to another host,
-prepend the hostname with the at sign ('@').
+prepend the hostname with the at sign ('@').  If a port number is added
+after a colon (':') then that port will be used as the destination port
+rather than the usual syslog port.
 .Pp
 This feature makes it possible to collect all syslog messages in a
 network on a central host.  This reduces administration needs and
@@ -488,13 +490,15 @@ command line option,
 *.*;kern.none               -/var/log/messages    ;rotate=100k:10
 .Ed
 .Ss Logging to Remote Syslog Server
-This rule redirects all messages to a remote host called
+This rule redirects all messages to one remote host called
-.Ql finlandia
+.Ql finlandia ,
-with RFC5424 style formatting.  This is useful especially in a cluster
+with RFC5424 style formatting, and another remote host called
-of machines where all syslog messages will be stored on only one
+.Ql sibelius ,
-machine.
+but on a non-standard port and with RFC3164 formatting (i.e.,
+including timestamp and hostname).
 .Bd -literal -offset indent
 *.*                          @finlandia           ;RFC5424
+*.*                          @sibelius:5514       ;RFC3164
 .Ed
 .Sh FILES
 .Bl -tag -compact -width /etc/syslog.d/*.conf

src/syslogd.c

@@ -1612,7 +1612,7 @@ void fprintlog(struct filed *f, struct buf_msg *buffer)
 			f->f_type = F_FORW;
 			goto f_forw;
 		} else {
-			logit(" %s\n", f->f_un.f_forw.f_hname);
+			logit(" %s:%s\n", f->f_un.f_forw.f_hname, f->f_un.f_forw.f_serv);
 			logit("Forwarding suspension not over, time left: %d.\n",
 			      INET_SUSPEND_TIME - fwd_suspend);
 		}
@@ -1627,15 +1627,16 @@ void fprintlog(struct filed *f, struct buf_msg *buffer)
 	 * is started after syslogd. 
 	 */
 	case F_FORW_UNKN:
-		logit(" %s\n", f->f_un.f_forw.f_hname);
+		logit(" %s:%s\n", f->f_un.f_forw.f_hname, f->f_un.f_forw.f_serv);
 		fwd_suspend = time(NULL) - f->f_time;
 		if (fwd_suspend >= INET_SUSPEND_TIME) {
-			char *host = f->f_un.f_forw.f_hname;;
+			char *host = f->f_un.f_forw.f_hname;
+			char *serv = f->f_un.f_forw.f_serv;
 
-			logit("Forwarding suspension to %s over, retrying\n", host);
+			logit("Forwarding suspension to %s:%s over, retrying\n", host, serv);
-			err = nslookup(host, service, &ai);
+			err = nslookup(host, serv, &ai);
 			if (err) {
-				logit("Failure resolving %s:%s: %s\n", host, service, gai_strerror(err));
+				logit("Failure resolving %s:%s: %s\n", host, serv, gai_strerror(err));
 				logit("Retries: %d\n", f->f_prevcount);
 				if (--f->f_prevcount < 0) {
 					flog(LOG_SYSLOG | LOG_WARN, "Still cannot find %s, "
@@ -1667,7 +1668,7 @@ void fprintlog(struct filed *f, struct buf_msg *buffer)
 		 * sent the message, we don't send it anyway)  -Joey
 		 */
 	f_forw:
-		logit(" %s\n", f->f_un.f_forw.f_hname);
+		logit(" %s:%s\n", f->f_un.f_forw.f_hname, f->f_un.f_forw.f_serv);
 		if (strcmp(buffer->hostname, LocalHostName) && NoHops)
 			logit("Not sending message to remote.\n");
 		else if (finet) {
@@ -2598,10 +2599,17 @@ static struct filed *cfline(char *line)
 	case '@':
 		cfopts(p, f);
 
-		strlcpy(f->f_un.f_forw.f_hname, ++p, sizeof(f->f_un.f_forw.f_hname));
+		bp = strchr(++p, ':');
-		logit("forwarding host: '%s'\n", p); /*ASP*/
+		if (bp)
+			*bp++ = 0;
+		else
+			bp = service;
 
-		err = nslookup(p, service, &ai);
+		strlcpy(f->f_un.f_forw.f_hname, p, sizeof(f->f_un.f_forw.f_hname));
+		strlcpy(f->f_un.f_forw.f_serv, bp, sizeof(f->f_un.f_forw.f_serv));
+		logit("forwarding host: '%s:%s'\n", p, bp);
+
+		err = nslookup(p, bp, &ai);
 		if (err) {
 			flog(LOG_SYSLOG | LOG_WARN, "Cannot find %s, "
 			     "will try again later: %s", p, gai_strerror(err));

src/syslogd.h

@@ -191,6 +191,7 @@ struct filed {
 		char f_uname[MAXUNAMES][UNAMESZ + 1];
 		struct {
 			char f_hname[MAXHOSTNAMELEN + 1];
+			char f_serv[20];
 			struct addrinfo *f_addr;
 		} f_forw; /* forwarding address */
 		char f_fname[MAXFNAME];