ipvs: allow transmit of GRO aggregated skbs

Attempt at allowing LVS to transmit skbs of greater than MTU length that
have been aggregated by GRO and can thus be deaggregated by GSO.

Cc: Julian Anastasov <ja@ssi.bg>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Simon Horman <horms@verge.net.au>
(cherry picked from commit 8f1b03a4c18e8f3f0801447b62330faa8ed3bb37)
Signed-off-by: Willy Tarreau <w@1wt.eu>

1 files changed, 11 insertions, 10 deletions

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 30b3189bd29c..dd7da3c291a9 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -245,7 +245,8 @@ ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF))) {
+	if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF)) &&
+	    !skb_is_gso(skb)) {
 		ip_rt_put(rt);
 		icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -309,7 +310,7 @@ ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if (skb->len > mtu) {
+	if (skb->len > mtu && !skb_is_gso(skb)) {
 		dst_release(&rt->u.dst);
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -376,7 +377,7 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF))) {
+	if ((skb->len > mtu) && (iph->frag_off & htons(IP_DF)) && !skb_is_gso(skb)) {
 		ip_rt_put(rt);
 		icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
 		IP_VS_DBG_RL_PKT(0, pp, skb, 0, "ip_vs_nat_xmit(): frag needed for");
@@ -452,7 +453,7 @@ ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if (skb->len > mtu) {
+	if (skb->len > mtu && !skb_is_gso(skb)) {
 		dst_release(&rt->u.dst);
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 		IP_VS_DBG_RL_PKT(0, pp, skb, 0,
@@ -561,8 +562,8 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	df |= (old_iph->frag_off & htons(IP_DF));
 
-	if ((old_iph->frag_off & htons(IP_DF))
-	    && mtu < ntohs(old_iph->tot_len)) {
+	if ((old_iph->frag_off & htons(IP_DF) &&
+	    mtu < ntohs(old_iph->tot_len) && !skb_is_gso(skb))) {
 		icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
 		ip_rt_put(rt);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -671,7 +672,7 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 	if (skb_dst(skb))
 		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
 
-	if (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr)) {
+	if (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) && !skb_is_gso(skb)) {
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 		dst_release(&rt->u.dst);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -760,7 +761,7 @@ ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if ((iph->frag_off & htons(IP_DF)) && skb->len > mtu) {
+	if ((iph->frag_off & htons(IP_DF)) && skb->len > mtu && !skb_is_gso(skb)) {
 		icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
 		ip_rt_put(rt);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -888,7 +889,7 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if ((skb->len > mtu) && (ip_hdr(skb)->frag_off & htons(IP_DF))) {
+	if ((skb->len > mtu) && (ip_hdr(skb)->frag_off & htons(IP_DF)) && !skb_is_gso(skb)) {
 		ip_rt_put(rt);
 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -963,7 +964,7 @@ ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 
 	/* MTU checking */
 	mtu = dst_mtu(&rt->u.dst);
-	if (skb->len > mtu) {
+	if (skb->len > mtu && !skb_is_gso(skb)) {
 		dst_release(&rt->u.dst);
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);