diff options
Diffstat (limited to 'net/bridge/br_netfilter.c')
-rw-r--r-- | net/bridge/br_netfilter.c | 78 |
1 files changed, 74 insertions, 4 deletions
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 0ee453f..a8361c7 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -239,6 +239,14 @@ drop: return -1; } +static void nf_bridge_update_protocol(struct sk_buff *skb) +{ + if (skb->nf_bridge->mask & BRNF_8021Q) + skb->protocol = htons(ETH_P_8021Q); + else if (skb->nf_bridge->mask & BRNF_PPPoE) + skb->protocol = htons(ETH_P_PPP_SES); +} + /* PF_BRIDGE/PRE_ROUTING *********************************************/ /* Undo the changes made for ip6tables PREROUTING and continue the * bridge PRE_ROUTING hook. */ @@ -764,23 +772,53 @@ static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, } #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) +static bool nf_bridge_copy_header(struct sk_buff *skb) +{ + int err; + unsigned int header_size; + + nf_bridge_update_protocol(skb); + header_size = ETH_HLEN + nf_bridge_encap_header_len(skb); + err = skb_cow_head(skb, header_size); + if (err) + return false; + + skb_copy_to_linear_data_offset(skb, -header_size, + skb->nf_bridge->data, header_size); + __skb_push(skb, nf_bridge_encap_header_len(skb)); + return true; +} + +static int br_nf_push_frag_xmit(struct sk_buff *skb) +{ + if (!nf_bridge_copy_header(skb)) { + kfree_skb(skb); + return 0; + } + + return br_dev_queue_push_xmit(skb); +} + static int br_nf_dev_queue_xmit(struct sk_buff *skb) { int ret; int frag_max_size; + unsigned int mtu_reserved; + if (skb_is_gso(skb) || skb->protocol != htons(ETH_P_IP)) + return br_dev_queue_push_xmit(skb); + + mtu_reserved = nf_bridge_mtu_reduction(skb); /* This is wrong! We should preserve the original fragment * boundaries by preserving frag_list rather than refragmenting. */ - if (skb->protocol == htons(ETH_P_IP) && - skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu && - !skb_is_gso(skb)) { + if (skb->len + mtu_reserved > skb->dev->mtu) { frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; if (br_parse_ip_options(skb)) /* Drop invalid packet */ return NF_DROP; IPCB(skb)->frag_max_size = frag_max_size; - ret = ip_fragment(skb, br_dev_queue_push_xmit); + ret = ip_fragment(skb, br_nf_push_frag_xmit); } else ret = br_dev_queue_push_xmit(skb); @@ -854,6 +892,38 @@ static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops, return NF_ACCEPT; } +/* This is called when br_netfilter has called into iptables/netfilter, + * and DNAT has taken place on a bridge-forwarded packet. + * + * neigh->output has created a new MAC header, with local br0 MAC + * as saddr. + * + * This restores the original MAC saddr of the bridged packet + * before invoking bridge forward logic to transmit the packet. + */ +static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) +{ + struct nf_bridge_info *nf_bridge = skb->nf_bridge; + + skb_pull(skb, ETH_HLEN); + nf_bridge->mask &= ~BRNF_BRIDGED_DNAT; + + skb_copy_to_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN), + skb->nf_bridge->data, ETH_HLEN-ETH_ALEN); + skb->dev = nf_bridge->physindev; + br_handle_frame_finish(skb); +} + +int br_nf_prerouting_finish_bridge(struct sk_buff *skb) +{ + if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { + br_nf_pre_routing_finish_bridge_slow(skb); + return 1; + } + return 0; +} +EXPORT_SYMBOL_GPL(br_nf_prerouting_finish_bridge); + void br_netfilter_enable(void) { } |