diff mbox series

[net-next,6/6] erspan: make md work without TUNNEL_ERSPAN_OPT set

Message ID 90c2f6a1008b6a9e86bd7f427e28aedec902d552.1568617721.git.lucien.xin@gmail.com
State Deferred
Delegated to: David Miller
Headers show
Series net: add support for ip_tun_info options setting | expand

Commit Message

Xin Long Sept. 16, 2019, 7:10 a.m. UTC 
Now when a skb comes with ip_tun_info but with no TUNNEL_ERSPAN_OPT to
a md erspan device, it will be dropped.

This patch is to allow this skb to go through this erspan device, and
the options (version, index, hwid, dir, etc.) will be filled with
tunnel's params, which can be configured by users.

This can be verified by:

 # ip net a a; ip net a b
 # ip -n a l a eth0 type veth peer name eth0 netns b
 # ip -n a l s eth0 up; ip -n b link set eth0 up
 # ip -n a a a 10.1.0.1/24 dev eth0; ip -n b a a 10.1.0.2/24 dev eth0
 # ip -n b l a erspan1 type erspan key 1 seq local 10.1.0.2 remote 10.1.0.1
 # ip -n b a a 1.1.1.1/24 dev erspan1; ip -n b l s erspan1 up
 # ip -n b r a 2.1.1.0/24 dev erspan1
 # ip -n a l a erspan1 type erspan key 1 seq local 10.1.0.1 external
 # ip -n a a a 2.1.1.1/24 dev erspan1; ip -n a l s erspan1 up
 # ip -n a r a 1.1.1.0/24 encap ip id 1 dst 10.1.0.2 dev erspan1
 # ip net exec a ping 1.1.1.1 -c 1

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/ipv4/ip_gre.c  | 31 +++++++++++++------------------
 net/ipv6/ip6_gre.c | 35 +++++++++++++++++++----------------
 2 files changed, 32 insertions(+), 34 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index df7149c..ac4cbb8 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -491,15 +491,12 @@  static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct erspan_metadata *md = NULL;
 	struct ip_tunnel_info *tun_info;
 	const struct ip_tunnel_key *key;
-	struct erspan_metadata *md;
+	int version, nhoff, thoff;
 	bool truncate = false;
 	__be16 proto;
-	int tunnel_hlen;
-	int version;
-	int nhoff;
-	int thoff;
 
 	tun_info = skb_tunnel_info(skb);
 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
@@ -507,15 +504,11 @@  static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 		goto err_free_skb;
 
 	key = &tun_info->key;
-	if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
-		goto err_free_skb;
-	if (sizeof(*md) > tun_info->options_len)
-		goto err_free_skb;
-	md = ip_tunnel_info_opts(tun_info);
-
-	/* ERSPAN has fixed 8 byte GRE header */
-	version = md->version;
-	tunnel_hlen = 8 + erspan_hdr_len(version);
+	if (key->tun_flags & TUNNEL_ERSPAN_OPT) {
+		if (tun_info->options_len < sizeof(*md))
+			goto err_free_skb;
+		md = ip_tunnel_info_opts(tun_info);
+	}
 
 	if (skb_cow_head(skb, dev->needed_headroom))
 		goto err_free_skb;
@@ -538,15 +531,17 @@  static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
 		truncate = true;
 
+	version = md ? md->version : tunnel->erspan_ver;
 	if (version == 1) {
 		erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
-				    ntohl(md->u.index), truncate, true);
+				    md ? ntohl(md->u.index) : tunnel->index,
+				    truncate, true);
 		proto = htons(ETH_P_ERSPAN);
 	} else if (version == 2) {
 		erspan_build_header_v2(skb,
 				       ntohl(tunnel_id_to_key32(key->tun_id)),
-				       md->u.md2.dir,
-				       get_hwid(&md->u.md2),
+				       md ? md->u.md2.dir : tunnel->dir,
+				       md ? get_hwid(&md->u.md2) : tunnel->hwid,
 				       truncate, true);
 		proto = htons(ETH_P_ERSPAN2);
 	} else {
@@ -556,7 +551,7 @@  static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 	gre_build_header(skb, 8, TUNNEL_SEQ,
 			 proto, 0, htonl(tunnel->o_seqno++));
 
-	ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
+	ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, 8 + erspan_hdr_len(version));
 
 	return;
 
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 4aba9e0..a48cec3 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -959,10 +959,11 @@  static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
 	 */
 	if (t->parms.collect_md) {
+		struct erspan_metadata *md = NULL;
 		struct ip_tunnel_info *tun_info;
 		const struct ip_tunnel_key *key;
-		struct erspan_metadata *md;
 		__be32 tun_id;
+		int version;
 
 		tun_info = skb_tunnel_info(skb);
 		if (unlikely(!tun_info ||
@@ -978,23 +979,25 @@  static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 		fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
 
 		dsfield = key->tos;
-		if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
-			goto tx_err;
-		if (sizeof(*md) > tun_info->options_len)
-			goto tx_err;
-		md = ip_tunnel_info_opts(tun_info);
+		if (key->tun_flags & TUNNEL_ERSPAN_OPT) {
+			if (tun_info->options_len < sizeof(*md))
+				goto tx_err;
+			md = ip_tunnel_info_opts(tun_info);
+		}
 
 		tun_id = tunnel_id_to_key32(key->tun_id);
-		if (md->version == 1) {
-			erspan_build_header(skb,
-					    ntohl(tun_id),
-					    ntohl(md->u.index), truncate,
-					    false);
-		} else if (md->version == 2) {
-			erspan_build_header_v2(skb,
-					       ntohl(tun_id),
-					       md->u.md2.dir,
-					       get_hwid(&md->u.md2),
+		version = md ? md->version : t->parms.erspan_ver;
+		if (version == 1) {
+			erspan_build_header(skb, ntohl(tun_id),
+					    md ? ntohl(md->u.index)
+					       : t->parms.index,
+					    truncate, false);
+		} else if (version == 2) {
+			erspan_build_header_v2(skb, ntohl(tun_id),
+					       md ? md->u.md2.dir
+						  : t->parms.dir,
+					       md ? get_hwid(&md->u.md2)
+						  : t->parms.hwid,
 					       truncate, false);
 		} else {
 			goto tx_err;