Minor adjustments regarding '-d' debug output

2 files changed, 81 insertions, 83 deletions

diff --git a/udp-broadcast-relay.c b/udp-broadcast-relay.c
index f3df27b..4010cf2 100644
--- a/udp-broadcast-relay.c
+++ b/udp-broadcast-relay.c
@@ -1,44 +1,41 @@
 /*
-******************************************************************
-udp-broadcast-relay
-	Relays UDP broadcasts to other networks, forging
-	the sender address.
-
-Copyright (c) 2003 Joachim Breitner <mail@joachim-breitner.de>
-
-Based upon:
-udp_broadcast_fw ; Forwards UDP broadcast packets to all local 
-	interfaces as though they originated from sender
-	
-Copyright (C) 2002  Nathan O'Sullivan
-
-This program 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 2
-of the License, or (at your option) any later version.
-
-This program 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.
-******************************************************************
-
-Thanks:
-
-Arny <cs6171@scitsc.wlv.ac.uk> 
-- public domain UDP spoofing code
-http://www.netfor2.com/ip.htm
-- IP/UDP packet formatting info
-
-*/
-
-#define MAXIFS	256
-#define DPRINT  if (debug) printf
-#define IPHEADER_LEN 20
-#define UDPHEADER_LEN 8
-#define HEADER_LEN (IPHEADER_LEN + UDPHEADER_LEN)
-#define TTL_ID_OFFSET 64
- 
+ * udp-broadcast-relay
+ *       Relays UDP broadcasts to other networks, forging
+ *       the sender address.
+ *
+ * Copyright (c) 2003 Joachim Breitner <mail@joachim-breitner.de>
+ *
+ * Based upon:
+ * udp_broadcast_fw ; Forwards UDP broadcast packets to all local
+ *	interfaces as though they originated from sender
+ *
+ * Copyright (C) 2002  Nathan O'Sullivan
+ *
+ * This program 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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.
+ */
+
+/* 
+ * Thanks to:
+ * Arny <cs6171@scitsc.wlv.ac.uk> - public domain UDP spoofing code
+ * http://www.netfor2.com/ip.htm - IP/UDP packet formatting info
+ */
+
+#define MAXIFS		256
+#define DPRINT		if (debug) printf
+#define IPHEADER_LEN	20
+#define UDPHEADER_LEN	8
+#define HEADER_LEN	(IPHEADER_LEN + UDPHEADER_LEN)
+#define TTL_ID_OFFSET	64
+#define MAX_ID		99
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in_systm.h>
@@ -77,7 +74,7 @@ int main(int argc,char **argv)
 {
 	/* Debugging, forking, other settings */
 	int debug, forking;
-	
+
 	u_int16_t port;
 	u_char id;
 	u_char ttl;
@@ -89,13 +86,13 @@ int main(int argc,char **argv)
 	/* Structure holds info on local interfaces */
 	struct ifreq reqbuf;
 	int maxifs;
-		
+
 	/* Address broadcast packet was sent from */
 	struct sockaddr_in rcv_addr;
 
         /* Spoofing source address of outgoing packets */
         in_addr_t spoof_addr = 0;
-	
+
 	/* Incoming message read via rcvsmsg */
 	struct msghdr rcv_msg;
 	struct iovec iov;
@@ -103,44 +100,46 @@ int main(int argc,char **argv)
 
 	/* various variables */
 	int x=1, len;
-	
+
 	struct cmsghdr *cmsg;
 	int *ttlptr=NULL;
 	int rcv_ifindex = 0;
 
-	iov.iov_base = gram+ HEADER_LEN; 
+	iov.iov_base = gram+ HEADER_LEN;
 	iov.iov_len = 4006 - HEADER_LEN - 1;
-	
+
 	rcv_msg.msg_name = &rcv_addr;
 	rcv_msg.msg_namelen = sizeof(rcv_addr);
 	rcv_msg.msg_iov = &iov;
 	rcv_msg.msg_iovlen = 1;
 	rcv_msg.msg_control = pkt_infos;
 	rcv_msg.msg_controllen = sizeof(pkt_infos);
-	
+
 	/* parsing the args */
 	if(argc < 5)
 	{
-		fprintf(stderr,"usage: %s [-d] [-f] [-s IP] id udp-port dev1 dev2 ...\n\n",*argv);
-		fprintf(stderr,"This program listens for broadcast  packets  on the  specified UDP port\n"
-			"and then forwards them to each other given interface.  Packets are sent\n"
+		fprintf(stderr,"usage: %s [-d] [-f] [-s IP] id port dev1 dev2 ...\n\n",*argv);
+		fprintf(stderr,"This program listens for broadcast  packets on the specified UDP port\n"
+			"and then forwards them to each other given interface. Packets are sent\n"
 			"such that they appear to have come from the original broadcaster, resp.\n"
-			"from the spoofing IP in case -s is used.  When using multiple instances\n"
+			"from the spoofing IP in case -s is used.\n"
+			"\n"
+			"One ID per UDP port is required. Maximum number of IDs: %i\n"
 			"for the same port on the same network, they must have a different id.\n\n"
 			"    -d      enables debugging\n"
 			"    -f      forces forking to background\n"
 			"    -s IP   sets the source IP of forwarded packets; otherwise the\n"
-			"            original sender's address is used\n\n");
+			"            original sender's address is used\n\n", MAX_ID);
 		exit(1);
 	};
-	
+
 	if ((debug = (strcmp(argv[1],"-d") == 0)))
 	{
 		argc--;
 		argv++;
 		DPRINT ("Debugging Mode enabled\n");
 	};
-	
+
 	if ((forking = (strcmp(argv[1],"-f") == 0)))
 	{
 		argc--;
@@ -171,9 +170,9 @@ int main(int argc,char **argv)
 	argc--;
 	argv++;
 
-	if (id < 1 || id > 99)
+	if (id < 1 || id > MAX_ID)
 	{
-		fprintf (stderr,"ID argument %i not between 1 and 99\n",id);
+		fprintf (stderr,"ID argument %i not between 1 and %d\n", id, MAX_ID);
 		exit(1);
 	}
 	ttl = id+TTL_ID_OFFSET;
@@ -181,7 +180,7 @@ int main(int argc,char **argv)
 	/* The id is used to detect packets we just sent, and is stored in the "ttl" field,
 	 * which is not used with broadcast packets. Beware when using this with
 	 * non-broadcast-packets */
-	
+
 	if ((port = atoi(argv[1])) == 0)
 	{
 		fprintf (stderr,"Port argument not valid\n");
@@ -189,7 +188,7 @@ int main(int argc,char **argv)
 	}
 	argc--;
 	argv++;
-	
+
 	DPRINT ("ID: %i (ttl: %i), Port %i\n",id,ttl,port);
 
 
@@ -204,7 +203,7 @@ int main(int argc,char **argv)
 	/* For each interface on the command line */
 	for (maxifs=0;argc>1;argc--,argv++)
 	{
-		int ioctl_request; 
+		int ioctl_request;
 
 		strncpy(reqbuf.ifr_name,argv[1],IFNAMSIZ);
 
@@ -213,10 +212,10 @@ int main(int argc,char **argv)
 			perror("ioctl(SIOCGIFINDEX)");
 			exit(1);
 		}
-		
-		/* Save the index for later use */	
+
+		/* Save the index for later use */
 		ifs[maxifs].ifindex = reqbuf.ifr_ifindex;
-		
+
 		/* Request flags for this interface */
 		if (ioctl(fd,SIOCGIFFLAGS, &reqbuf) < 0) {
 			perror("ioctl(SIOCGIFFLAGS)");
@@ -231,9 +230,9 @@ int main(int argc,char **argv)
 		/* find the address type we need */
 		if (reqbuf.ifr_flags & IFF_BROADCAST)
 			ioctl_request = SIOCGIFBRDADDR;
-		else 
+		else
 			ioctl_request = SIOCGIFDSTADDR;
-				
+
 
 		/* Request the broadcast/destination address for this interface */
   		if (ioctl(fd,ioctl_request, &reqbuf) < 0) {
@@ -287,7 +286,7 @@ int main(int argc,char **argv)
 	/* well, we want the max index, actually */
 	maxifs--;
 	DPRINT("found %i interfaces total\n",maxifs+1);
-	
+
 	/* Free our allocated buffer and close the socket */
 	close(fd);
 
@@ -328,16 +327,16 @@ int main(int argc,char **argv)
 	*(u_short*)(gram+22)=(u_short)htons(port);
 
  	/* Fork to background */
-  if (! debug) {
-    if (forking && fork())
-      exit(0);
+	if (! debug) {
+		if (forking && fork())
+		exit(0);
 
-    fclose(stdin);
-    fclose(stdout);
-    fclose(stderr);
-  }
+		fclose(stdin);
+		fclose(stdout);
+		fclose(stderr);
+	}
 
-  DPRINT("Done Initializing\n\n");
+	DPRINT("Done Initializing\n\n");
 
 	for (;;) /* endless loop */
 	{
@@ -365,16 +364,15 @@ int main(int argc,char **argv)
 			DPRINT ("Got local package (TTL %i) on interface %i\n",*ttlptr,rcv_ifindex);
 			continue;
 		}
-		
+
 
 		gram[HEADER_LEN + len] =0;
 		DPRINT("Got remote package:\n");
-		// DPRINT("Content:\t%s\n",gram+HEADER_LEN);
-		DPRINT("TTL:\t\t%i\n",*ttlptr);
-		DPRINT("Interface:\t%i\n",rcv_ifindex);
-		DPRINT("From:\t\t%s:%d\n",inet_ntoa(rcv_addr.sin_addr),rcv_addr.sin_port);
-	
-		/* copy sender's details into our datagram as the source addr */	
+		DPRINT("Interface %i, TTL %3i, from %s:%d\n", rcv_ifindex, *ttlptr,
+		       inet_ntoa(rcv_addr.sin_addr), rcv_addr.sin_port);
+		DPRINT("Content: %s\n", gram + HEADER_LEN);
+
+		/* copy sender's details into our datagram as the source addr */
 		if (spoof_addr)
 			rcv_addr.sin_addr.s_addr = spoof_addr;
 		bcopy(&(rcv_addr.sin_addr.s_addr),(gram+12),4);
@@ -390,13 +388,13 @@ int main(int argc,char **argv)
 			if (ifs[x].ifindex == rcv_ifindex) continue; /* no bounces, please */
 
 			/* Set destination addr ip - port is set already */
-			bcopy(&(ifs[x].dstaddr.sin_addr.s_addr),(gram+16),4);	
+			bcopy(&(ifs[x].dstaddr.sin_addr.s_addr),(gram+16),4);
 
 			DPRINT ("Sent to %s:%d on interface %i\n",
 				inet_ntoa(ifs[x].dstaddr.sin_addr), /* dst ip */
 				ntohs(*(u_short*)(gram+22)), /* dst port */
 				ifs[x].ifindex); /* interface number */
-				
+
 			/* Send the packet */
 			if (sendto(ifs[x].raw_socket,
 					&gram,
diff --git a/udp-broadcast-relay@.service b/udp-broadcast-relay@.service
index 90b37b7..229748c 100644
--- a/udp-broadcast-relay@.service
+++ b/udp-broadcast-relay@.service
@@ -7,7 +7,7 @@ RequiresMountsFor=/run
 Type=simple
 NotifyAccess=main
 EnvironmentFile=-/etc/default/udp-broadcast-relay%I
-ExecStart=/usr/sbin/udp-broadcast-relay %I $DAEMON_ARGS
+ExecStart=/usr/sbin/udp-broadcast-relay $DAEMON_ARGS
 Restart=on-failure
 
 [Install]