3 files changed, 17 insertions, 6 deletions
diff --git a/accel-pppd/ctrl/l2tp/l2tp.c b/accel-pppd/ctrl/l2tp/l2tp.c
index 50523cfa..d8a98f8d 100644
--- a/accel-pppd/ctrl/l2tp/l2tp.c
+++ b/accel-pppd/ctrl/l2tp/l2tp.c
@@ -47,6 +47,7 @@
 #define STATE_CLOSE      0
 
 int conf_verbose = 0;
+int conf_avp_permissive = 0;
 static int conf_timeout = 60;
 static int conf_rtimeout = 5;
 static int conf_retransmit = 5;
@@ -1157,6 +1158,10 @@ static void load_config(void)
 	if (opt && atoi(opt) > 0)
 		conf_verbose = 1;
 
+	opt = conf_get_opt("l2tp", "avp_permissive");
+	if (opt && atoi(opt) > 0)
+		conf_avp_permissive = 1;
+
 	opt = conf_get_opt("l2tp", "hello-interval");
 	if (opt && atoi(opt) > 0)
 		conf_hello_interval = atoi(opt);
diff --git a/accel-pppd/ctrl/l2tp/l2tp.h b/accel-pppd/ctrl/l2tp/l2tp.h
index ac9b8e0b..8a8cffdd 100644
--- a/accel-pppd/ctrl/l2tp/l2tp.h
+++ b/accel-pppd/ctrl/l2tp/l2tp.h
@@ -66,6 +66,7 @@ struct l2tp_packet_t
 };
 
 extern int conf_verbose;
+extern int conf_avp_permissive;
 
 struct l2tp_dict_attr_t *l2tp_dict_find_attr_by_name(const char *name);
 struct l2tp_dict_attr_t *l2tp_dict_find_attr_by_id(int id);
diff --git a/accel-pppd/ctrl/l2tp/packet.c b/accel-pppd/ctrl/l2tp/packet.c
index d3121188..f8a46e7f 100644
--- a/accel-pppd/ctrl/l2tp/packet.c
+++ b/accel-pppd/ctrl/l2tp/packet.c
@@ -172,19 +172,22 @@ int l2tp_recv(int fd, struct l2tp_packet_t **p, struct in_pktinfo *pkt_info)
 		if (hdr->L == 0) {
 			if (conf_verbose)
 				log_warn("l2tp: incorrect message received (L=0)\n");
-			goto out_err_hdr;
+			if (!conf_avp_permissive)
+			    goto out_err_hdr;
 		}
 
 		if (hdr->S == 0) {
 			if (conf_verbose)
 				log_warn("l2tp: incorrect message received (S=0)\n");
-			goto out_err_hdr;
+			if (!conf_avp_permissive)
+			    goto out_err_hdr;
 		}
 
 		if (hdr->O == 1) {
 			if (conf_verbose)
 				log_warn("l2tp: incorrect message received (O=1)\n");
-			goto out_err_hdr;
+			if (!conf_avp_permissive)
+			    goto out_err_hdr;
 		}
 	} else if (hdr->ver != 3) {
 		if (conf_verbose)
@@ -222,19 +225,21 @@ int l2tp_recv(int fd, struct l2tp_packet_t **p, struct in_pktinfo *pkt_info)
 		if (!da) {
 			if (conf_verbose)
 				log_warn("l2tp: unknown avp received (type=%i, M=%u)\n", ntohs(avp->type), avp->M);
-			if (avp->M)
+			if (avp->M && !conf_avp_permissive)
 				goto out_err;
 		} else {
 			if (da->M != -1 && da->M != avp->M) {
 				if (conf_verbose)
 					log_warn("l2tp: incorrect avp received (type=%i, M=%i, must be %i)\n", ntohs(avp->type), avp->M, da->M);
-				goto out_err;
+				if (!conf_avp_permissive)
+				    goto out_err;
 			}
 
 			if (da->H != -1 && da->H != avp->H) {
 				if (conf_verbose)
 					log_warn("l2tp: incorrect avp received (type=%i, H=%i, must be %i)\n", ntohs(avp->type), avp->H, da->H);
-				goto out_err;
+				if (!conf_avp_permissive)
+				    goto out_err;
 			}
 
 			if (avp->H) {