1 files changed, 22 insertions, 21 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 591d18785285..429dbb064240 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -83,8 +83,7 @@
 #define L2TP_SLFLAG_S	   0x40000000
 #define L2TP_SL_SEQ_MASK   0x00ffffff
 
-#define L2TP_HDR_SIZE_SEQ		10
-#define L2TP_HDR_SIZE_NOSEQ		6
+#define L2TP_HDR_SIZE_MAX		14
 
 /* Default trace flags */
 #define L2TP_DEFAULT_DEBUG_FLAGS	0
@@ -705,11 +704,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 				 "%s: recv data ns=%u, session nr=%u\n",
 				 session->name, ns, session->nr);
 		}
+		ptr += 4;
 	}
 
-	/* Advance past L2-specific header, if present */
-	ptr += session->l2specific_len;
-
 	if (L2TP_SKB_CB(skb)->has_seq) {
 		/* Received a packet with sequence numbers. If we're the LNS,
 		 * check if we sre sending sequence numbers and if not,
@@ -860,7 +857,7 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 	__skb_pull(skb, sizeof(struct udphdr));
 
 	/* Short packet? */
-	if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) {
+	if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) {
 		l2tp_info(tunnel, L2TP_MSG_DATA,
 			  "%s: recv short packet (len=%d)\n",
 			  tunnel->name, skb->len);
@@ -933,6 +930,10 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 		goto error;
 	}
 
+	if (tunnel->version == L2TP_HDR_VER_3 &&
+	    l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
+		goto error;
+
 	l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook);
 
 	return 0;
@@ -1031,21 +1032,20 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf)
 		memcpy(bufp, &session->cookie[0], session->cookie_len);
 		bufp += session->cookie_len;
 	}
-	if (session->l2specific_len) {
-		if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) {
-			u32 l2h = 0;
-			if (session->send_seq) {
-				l2h = 0x40000000 | session->ns;
-				session->ns++;
-				session->ns &= 0xffffff;
-				l2tp_dbg(session, L2TP_MSG_SEQ,
-					 "%s: updated ns to %u\n",
-					 session->name, session->ns);
-			}
+	if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) {
+		u32 l2h = 0;
 
-			*((__be32 *) bufp) = htonl(l2h);
+		if (session->send_seq) {
+			l2h = 0x40000000 | session->ns;
+			session->ns++;
+			session->ns &= 0xffffff;
+			l2tp_dbg(session, L2TP_MSG_SEQ,
+				 "%s: updated ns to %u\n",
+				 session->name, session->ns);
 		}
-		bufp += session->l2specific_len;
+
+		*((__be32 *)bufp) = htonl(l2h);
+		bufp += 4;
 	}
 	if (session->offset)
 		bufp += session->offset;
@@ -1724,7 +1724,7 @@ int l2tp_session_delete(struct l2tp_session *session)
 EXPORT_SYMBOL_GPL(l2tp_session_delete);
 
 /* We come here whenever a session's send_seq, cookie_len or
- * l2specific_len parameters are set.
+ * l2specific_type parameters are set.
  */
 void l2tp_session_set_header_len(struct l2tp_session *session, int version)
 {
@@ -1733,7 +1733,8 @@ void l2tp_session_set_header_len(struct l2tp_session *session, int version)
 		if (session->send_seq)
 			session->hdr_len += 4;
 	} else {
-		session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset;
+		session->hdr_len = 4 + session->cookie_len + session->offset;
+		session->hdr_len += l2tp_get_l2specific_len(session);
 		if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP)
 			session->hdr_len += 4;
 	}