PPPoE patch for connection problems

[Paul Galbraith <paul_(_at_)_paulgalbraith_(_dot_)_net>]

I've been running this little patch for several weeks and it's been a
real life saver.  My ppp connection kept cycling through a never-ending
connect-disconnect cycle, constantly reporting 'connection reset by
peer'.  Some investigation showed that my DSL provider (or more likely,
Bell Canada) keeps sending PPPoE PADT tags immediately after a
connection is established.

This patch allows you to play along and keep your connection up by
ignoring the disconnect request...
? pppoe
? pppoe.cat8
Index: client.c
===================================================================
RCS file: /cvs/src/usr.sbin/pppoe/client.c,v
retrieving revision 1.20
diff -u -b -r1.20 client.c
--- client.c	3 Sep 2004 06:37:14 -0000	1.20
+++ client.c	1 May 2005 03:13:10 -0000
@@ -495,6 +495,9 @@
     struct ether_header *eh, struct pppoe_header *ph,
     u_long len, u_int8_t *pkt)
 {
+	if (ignorepadt)
+		return (0);
+
 	if (bcmp(&eh->ether_shost[0], rmea, ETHER_ADDR_LEN))
 		return (0);
 
Index: debug.c
===================================================================
RCS file: /cvs/src/usr.sbin/pppoe/debug.c,v
retrieving revision 1.2
diff -u -b -r1.2 debug.c
Index: pppoe.8
===================================================================
RCS file: /cvs/src/usr.sbin/pppoe/pppoe.8,v
retrieving revision 1.18
diff -u -b -r1.18 pppoe.8
--- pppoe.8	18 Feb 2005 12:19:22 -0000	1.18
+++ pppoe.8	1 May 2005 03:13:10 -0000
@@ -33,7 +33,7 @@
 .Nd PPP Over Ethernet translator
 .Sh SYNOPSIS
 .Nm pppoe
-.Op Fl sv
+.Op Fl stv
 .Op Fl i Ar interface
 .Op Fl n Ar service
 .Op Fl p Ar system
@@ -74,6 +74,14 @@
 Otherwise,
 .Nm
 runs as a client.
+.It Fl t
+Instruct 
+.Nm
+to ignore PADT packets.  If you observe numerous
+"connection reset by peer" error messages and constantly
+lose connection soon after establishing one, it may because
+of spurious PADT tags being sent from the peer.  Ignoring them 
+may alleviate the problem. 
 .It Fl v
 For each use of the flag, the verbosity of
 .Nm pppoe
Index: pppoe.c
===================================================================
RCS file: /cvs/src/usr.sbin/pppoe/pppoe.c,v
retrieving revision 1.15
diff -u -b -r1.15 pppoe.c
--- pppoe.c	20 Sep 2004 17:51:07 -0000	1.15
+++ pppoe.c	1 May 2005 03:13:10 -0000
@@ -53,6 +53,7 @@
 #include "pppoe.h"
 
 int option_verbose = 0;
+int ignorepadt = 0;
 u_char etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
 int main(int, char **);
@@ -78,7 +79,7 @@
 	if ((pw = getpwnam("_ppp")) == NULL)
 		err(EX_CONFIG, "getpwnam(\"_ppp\")");
 
-	while ((c = getopt(argc, argv, "svi:n:p:")) != -1) {
+	while ((c = getopt(argc, argv, "stvi:n:p:")) != -1) {
 		switch (c) {
 		case 'i':
 			if (ifname != NULL) {
@@ -108,6 +109,13 @@
 			}
 			smode = 1;
 			break;
+		case 't':
+			if (ignorepadt) {
+				usage();
+				return (EX_USAGE);
+			}	
+			ignorepadt = 1;
+			break;
 		case 'v':
 			option_verbose++;
 			break;
@@ -463,7 +471,7 @@
 {
 	extern char *__progname;
 
-	fprintf(stderr,"%s [-sv] [-i interface] [-n service] [-p system]\n",
+	fprintf(stderr,"%s [-stv] [-i interface] [-n service] [-p system]\n",
 	    __progname);
 }
 
Index: pppoe.h
===================================================================
RCS file: /cvs/src/usr.sbin/pppoe/pppoe.h,v
retrieving revision 1.7
diff -u -b -r1.7 pppoe.h
--- pppoe.h	6 May 2004 20:29:04 -0000	1.7
+++ pppoe.h	1 May 2005 03:13:10 -0000
@@ -81,6 +81,7 @@
 #define	PPPOE_TAG_GENERIC_ERROR		0x0203	/* Generic Error */
 
 extern int option_verbose;
+extern int ignorepadt;
 extern u_char etherbroadcastaddr[];
 
 void server_mode(int, u_int8_t *, u_int8_t *, struct ether_addr *);