From 4497b0763cb1afae463f5e144c28b5d806e28b60 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 19 Jun 2008 16:22:28 -0700 Subject: [PATCH] net: Discard and warn about LRO'd skbs received for forwarding Add skb_warn_if_lro() to test whether an skb was received with LRO and warn if so. Change br_forward(), ip_forward() and ip6_forward() to call it) and discard the skb if it returns true. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- include/linux/skbuff.h | 14 ++++++++++++++ net/bridge/br_forward.c | 2 +- net/core/skbuff.c | 8 ++++++++ net/ipv4/ip_forward.c | 3 +++ net/ipv6/ip6_output.c | 3 +++ 5 files changed, 29 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 299ec4b3141..2220b9e2dab 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1702,6 +1702,20 @@ static inline int skb_is_gso_v6(const struct sk_buff *skb) return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; } +extern void __skb_warn_lro_forwarding(const struct sk_buff *skb); + +static inline bool skb_warn_if_lro(const struct sk_buff *skb) +{ + /* LRO sets gso_size but not gso_type, whereas if GSO is really + * wanted then gso_type will be set. */ + struct skb_shared_info *shinfo = skb_shinfo(skb); + if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) { + __skb_warn_lro_forwarding(skb); + return true; + } + return false; +} + static inline void skb_forward_csum(struct sk_buff *skb) { /* Unfortunately we don't support this one. Any brave souls? */ diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index 512645727f5..bdd9ccea17c 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -89,7 +89,7 @@ void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) /* called with rcu_read_lock */ void br_forward(const struct net_bridge_port *to, struct sk_buff *skb) { - if (should_deliver(to, skb)) { + if (!skb_warn_if_lro(skb) && should_deliver(to, skb)) { __br_forward(to, skb); return; } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3e18f8525e8..2df012be973 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2583,6 +2583,13 @@ bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off) return true; } +void __skb_warn_lro_forwarding(const struct sk_buff *skb) +{ + if (net_ratelimit()) + pr_warning("%s: received packets cannot be forwarded" + " while LRO is enabled\n", skb->dev->name); +} + EXPORT_SYMBOL(___pskb_trim); EXPORT_SYMBOL(__kfree_skb); EXPORT_SYMBOL(kfree_skb); @@ -2616,6 +2623,7 @@ EXPORT_SYMBOL(skb_seq_read); EXPORT_SYMBOL(skb_abort_seq_read); EXPORT_SYMBOL(skb_find_text); EXPORT_SYMBOL(skb_append_datato_frags); +EXPORT_SYMBOL(__skb_warn_lro_forwarding); EXPORT_SYMBOL_GPL(skb_to_sgvec); EXPORT_SYMBOL_GPL(skb_cow_data); diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 37d36a3f33c..da14725916d 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -56,6 +56,9 @@ int ip_forward(struct sk_buff *skb) struct rtable *rt; /* Route we use */ struct ip_options * opt = &(IPCB(skb)->opt); + if (skb_warn_if_lro(skb)) + goto drop; + if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb)) goto drop; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 40a2813a63d..fd7cd1bfe15 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -407,6 +407,9 @@ int ip6_forward(struct sk_buff *skb) if (ipv6_devconf.forwarding == 0) goto error; + if (skb_warn_if_lro(skb)) + goto drop; + if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); goto drop; -- 2.39.5