From 4394542ca4ec9f28c3c8405063d200b1e7c347d7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 15 Apr 2013 17:03:24 +0000 Subject: [PATCH] bonding: fix l23 and l34 load balancing in forwarding path Since commit 6b923cb7188d46 (bonding: support for IPv6 transmit hashing) bonding doesn't properly hash traffic in forwarding setups. Vitaly V. Bursov diagnosed that skb_network_header_len() returned 0 in this case. More generally, the transport header might not be in the skb head. Use pskb_may_pull() & skb_header_pointer() to get it right, and use proto_ports_offset() in bond_xmit_hash_policy_l34() to get support for more protocols than TCP and UDP. Reported-by: Vitaly V. Bursov Signed-off-by: Eric Dumazet Cc: Jay Vosburgh Cc: Andy Gospodarek Cc: John Eaglesham Tested-by: Vitaly V. Bursov Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 55 ++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 25 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index a61a760484f7..dea8ce20fea4 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3296,20 +3296,22 @@ static int bond_xmit_hash_policy_l2(struct sk_buff *skb, int count) */ static int bond_xmit_hash_policy_l23(struct sk_buff *skb, int count) { - struct ethhdr *data = (struct ethhdr *)skb->data; - struct iphdr *iph; - struct ipv6hdr *ipv6h; + const struct ethhdr *data; + const struct iphdr *iph; + const struct ipv6hdr *ipv6h; u32 v6hash; - __be32 *s, *d; + const __be32 *s, *d; if (skb->protocol == htons(ETH_P_IP) && - skb_network_header_len(skb) >= sizeof(*iph)) { + pskb_network_may_pull(skb, sizeof(*iph))) { iph = ip_hdr(skb); + data = (struct ethhdr *)skb->data; return ((ntohl(iph->saddr ^ iph->daddr) & 0xffff) ^ (data->h_dest[5] ^ data->h_source[5])) % count; } else if (skb->protocol == htons(ETH_P_IPV6) && - skb_network_header_len(skb) >= sizeof(*ipv6h)) { + pskb_network_may_pull(skb, sizeof(*ipv6h))) { ipv6h = ipv6_hdr(skb); + data = (struct ethhdr *)skb->data; s = &ipv6h->saddr.s6_addr32[0]; d = &ipv6h->daddr.s6_addr32[0]; v6hash = (s[1] ^ d[1]) ^ (s[2] ^ d[2]) ^ (s[3] ^ d[3]); @@ -3328,33 +3330,36 @@ static int bond_xmit_hash_policy_l23(struct sk_buff *skb, int count) static int bond_xmit_hash_policy_l34(struct sk_buff *skb, int count) { u32 layer4_xor = 0; - struct iphdr *iph; - struct ipv6hdr *ipv6h; - __be32 *s, *d; - __be16 *layer4hdr; + const struct iphdr *iph; + const struct ipv6hdr *ipv6h; + const __be32 *s, *d; + const __be16 *l4 = NULL; + __be16 _l4[2]; + int noff = skb_network_offset(skb); + int poff; if (skb->protocol == htons(ETH_P_IP) && - skb_network_header_len(skb) >= sizeof(*iph)) { + pskb_may_pull(skb, noff + sizeof(*iph))) { iph = ip_hdr(skb); - if (!ip_is_fragment(iph) && - (iph->protocol == IPPROTO_TCP || - iph->protocol == IPPROTO_UDP) && - (skb_headlen(skb) - skb_network_offset(skb) >= - iph->ihl * sizeof(u32) + sizeof(*layer4hdr) * 2)) { - layer4hdr = (__be16 *)((u32 *)iph + iph->ihl); - layer4_xor = ntohs(*layer4hdr ^ *(layer4hdr + 1)); + poff = proto_ports_offset(iph->protocol); + + if (!ip_is_fragment(iph) && poff >= 0) { + l4 = skb_header_pointer(skb, noff + (iph->ihl << 2) + poff, + sizeof(_l4), &_l4); + if (l4) + layer4_xor = ntohs(l4[0] ^ l4[1]); } return (layer4_xor ^ ((ntohl(iph->saddr ^ iph->daddr)) & 0xffff)) % count; } else if (skb->protocol == htons(ETH_P_IPV6) && - skb_network_header_len(skb) >= sizeof(*ipv6h)) { + pskb_may_pull(skb, noff + sizeof(*ipv6h))) { ipv6h = ipv6_hdr(skb); - if ((ipv6h->nexthdr == IPPROTO_TCP || - ipv6h->nexthdr == IPPROTO_UDP) && - (skb_headlen(skb) - skb_network_offset(skb) >= - sizeof(*ipv6h) + sizeof(*layer4hdr) * 2)) { - layer4hdr = (__be16 *)(ipv6h + 1); - layer4_xor = ntohs(*layer4hdr ^ *(layer4hdr + 1)); + poff = proto_ports_offset(ipv6h->nexthdr); + if (poff >= 0) { + l4 = skb_header_pointer(skb, noff + sizeof(*ipv6h) + poff, + sizeof(_l4), &_l4); + if (l4) + layer4_xor = ntohs(l4[0] ^ l4[1]); } s = &ipv6h->saddr.s6_addr32[0]; d = &ipv6h->daddr.s6_addr32[0]; -- 2.30.2