From d5db21a3e6977dcb42cee3d16cd69901fa66510a Mon Sep 17 00:00:00 2001 From: William Tu Date: Fri, 11 May 2018 05:49:47 -0700 Subject: [PATCH] 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 Signed-off-by: William Tu Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 6 ++++++ net/ipv6/ip6_gre.c | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index dfe5b22f6ed4..2409e648454d 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -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); diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index b511818b268c..bede77f24784 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -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;