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erspan: auto detect truncated ipv6 packets.

PATCH Applied William Tu 2 participants 2 messages May 11, 2018

Subsystems (3)
Networking Network drivers IPv4/IPv6
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Share & tools
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William Tu

author
#0 lore raw

PATCH 1/1 erspan: auto detect truncated ipv6 packets.

Currently the truncated bit is set only when 1) the mirrored packet is larger than mtu and 2) the ipv4 packet tot_len is larger than the actual skb->len. This patch adds another case for detecting whether ipv6 packet is truncated or not, by checking the ipv6 header payload_len and the skb->len.

Reported-by Xiaoyan Jin <[email protected]>
Signed-off-by William Tu <[email protected]>
---
 net/ipv4/ip_gre.c  | 6 ++++++
 net/ipv6/ip6_gre.c | 6 ++++++
 2 files changed, 12 insertions(+)
net/ipv4/ip_gre.c +6 -0
index dfe5b22f6ed4..2409e648454d 100644
@@ -579,6 +579,7 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 	int version;
 	__be16 df;
 	int nhoff;
+	int thoff;
 
 	tun_info = skb_tunnel_info(skb);
 	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

@@ -611,6 +612,11 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
 		truncate = true;
 
+	thoff = skb_transport_header(skb) - skb_mac_header(skb);
+	if (skb->protocol == htons(ETH_P_IPV6) &&
+	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
+		truncate = true;
+
 	if (version == 1) {
 		erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
 				    ntohl(md->u.index), truncate, true);
net/ipv6/ip6_gre.c +6 -0
index b511818b268c..bede77f24784 100644
@@ -897,6 +897,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 	int err = -EINVAL;
 	__u32 mtu;
 	int nhoff;
+	int thoff;
 
 	if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
 		goto tx_err;

@@ -914,6 +915,11 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
 	    (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
 		truncate = true;
 
+	thoff = skb_transport_header(skb) - skb_mac_header(skb);
+	if (skb->protocol == htons(ETH_P_IPV6) &&
+	    (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
+		truncate = true;
+
 	if (skb_cow_head(skb, dev->needed_headroom))
 		goto tx_err;
Signature · 1 line
2.7.4
maintainer Applied
#1 lore raw

From: William Tu <[email protected]>
Date: Fri, 11 May 2018 05:49:47 -0700

Quoted 8 lines

Currently the truncated bit is set only when 1) the mirrored packet is larger than mtu and 2) the ipv4 packet tot_len is larger than the actual skb->len. This patch adds another case for detecting whether ipv6 packet is truncated or not, by checking the ipv6 header payload_len and the skb->len.

Reported-by Xiaoyan Jin <[email protected]>
Signed-off-by William Tu <[email protected]>

Applied, thanks William.