diff options
author | Dave Airlie <airlied@redhat.com> | 2015-04-20 11:32:26 +1000 |
---|---|---|
committer | Dave Airlie <airlied@redhat.com> | 2015-04-20 13:05:20 +1000 |
commit | 2c33ce009ca2389dbf0535d0672214d09738e35e (patch) | |
tree | 6186a6458c3c160385d794a23eaf07c786a9e61b /net/bridge/br_netfilter.c | |
parent | cec32a47010647e8b0603726ebb75b990a4057a4 (diff) | |
parent | 09d51602cf84a1264946711dd4ea0dddbac599a1 (diff) | |
download | linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.gz linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.bz2 linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.zip |
Merge Linus master into drm-next
The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.
I've included the patch into the merge to fix the build.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'net/bridge/br_netfilter.c')
-rw-r--r-- | net/bridge/br_netfilter.c | 319 |
1 files changed, 228 insertions, 91 deletions
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 0ee453fad3de..ab55e2472beb 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -37,17 +37,16 @@ #include <net/route.h> #include <net/netfilter/br_netfilter.h> +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif + #include <asm/uaccess.h> #include "br_private.h" #ifdef CONFIG_SYSCTL #include <linux/sysctl.h> #endif -#define skb_origaddr(skb) (((struct bridge_skb_cb *) \ - (skb->nf_bridge->data))->daddr.ipv4) -#define store_orig_dstaddr(skb) (skb_origaddr(skb) = ip_hdr(skb)->daddr) -#define dnat_took_place(skb) (skb_origaddr(skb) != ip_hdr(skb)->daddr) - #ifdef CONFIG_SYSCTL static struct ctl_table_header *brnf_sysctl_header; static int brnf_call_iptables __read_mostly = 1; @@ -112,6 +111,24 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb) pppoe_proto(skb) == htons(PPP_IPV6) && \ brnf_filter_pppoe_tagged) +/* largest possible L2 header, see br_nf_dev_queue_xmit() */ +#define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN) + +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) +struct brnf_frag_data { + char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH]; + u8 encap_size; + u8 size; +}; + +static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage); +#endif + +static struct nf_bridge_info *nf_bridge_info_get(const struct sk_buff *skb) +{ + return skb->nf_bridge; +} + static inline struct rtable *bridge_parent_rtable(const struct net_device *dev) { struct net_bridge_port *port; @@ -154,6 +171,18 @@ static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb) return nf_bridge; } +static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb) +{ + switch (skb->protocol) { + case __cpu_to_be16(ETH_P_8021Q): + return VLAN_HLEN; + case __cpu_to_be16(ETH_P_PPP_SES): + return PPPOE_SES_HLEN; + default: + return 0; + } +} + static inline void nf_bridge_push_encap_header(struct sk_buff *skb) { unsigned int len = nf_bridge_encap_header_len(skb); @@ -178,14 +207,6 @@ static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb) skb->network_header += len; } -static inline void nf_bridge_save_header(struct sk_buff *skb) -{ - int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb); - - skb_copy_from_linear_data_offset(skb, -header_size, - skb->nf_bridge->data, header_size); -} - /* When handing a packet over to the IP layer * check whether we have a skb that is in the * expected format @@ -239,17 +260,31 @@ drop: return -1; } +static void nf_bridge_update_protocol(struct sk_buff *skb) +{ + switch (skb->nf_bridge->orig_proto) { + case BRNF_PROTO_8021Q: + skb->protocol = htons(ETH_P_8021Q); + break; + case BRNF_PROTO_PPPOE: + skb->protocol = htons(ETH_P_PPP_SES); + break; + case BRNF_PROTO_UNCHANGED: + break; + } +} + /* PF_BRIDGE/PRE_ROUTING *********************************************/ /* Undo the changes made for ip6tables PREROUTING and continue the * bridge PRE_ROUTING hook. */ -static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) +static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb) { - struct nf_bridge_info *nf_bridge = skb->nf_bridge; + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); struct rtable *rt; - if (nf_bridge->mask & BRNF_PKT_TYPE) { + if (nf_bridge->pkt_otherhost) { skb->pkt_type = PACKET_OTHERHOST; - nf_bridge->mask ^= BRNF_PKT_TYPE; + nf_bridge->pkt_otherhost = false; } nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; @@ -263,7 +298,8 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) skb->dev = nf_bridge->physindev; nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb, + skb->dev, NULL, br_handle_frame_finish, 1); return 0; @@ -274,9 +310,8 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) * don't, we use the neighbour framework to find out. In both cases, we make * sure that br_handle_frame_finish() is called afterwards. */ -static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) +static int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb) { - struct nf_bridge_info *nf_bridge = skb->nf_bridge; struct neighbour *neigh; struct dst_entry *dst; @@ -286,12 +321,13 @@ static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) dst = skb_dst(skb); neigh = dst_neigh_lookup_skb(dst, skb); if (neigh) { + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); int ret; if (neigh->hh.hh_len) { neigh_hh_bridge(&neigh->hh, skb); skb->dev = nf_bridge->physindev; - ret = br_handle_frame_finish(skb); + ret = br_handle_frame_finish(sk, skb); } else { /* the neighbour function below overwrites the complete * MAC header, so we save the Ethernet source address and @@ -299,7 +335,7 @@ static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) */ skb_copy_from_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN), - skb->nf_bridge->data, + nf_bridge->neigh_header, ETH_HLEN-ETH_ALEN); /* tell br_dev_xmit to continue with forwarding */ nf_bridge->mask |= BRNF_BRIDGED_DNAT; @@ -314,6 +350,22 @@ free_skb: return 0; } +static bool dnat_took_place(const struct sk_buff *skb) +{ +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct || nf_ct_is_untracked(ct)) + return false; + + return test_bit(IPS_DST_NAT_BIT, &ct->status); +#else + return false; +#endif +} + /* This requires some explaining. If DNAT has taken place, * we will need to fix up the destination Ethernet address. * @@ -352,11 +404,11 @@ free_skb: * device, we proceed as if ip_route_input() succeeded. If it differs from the * logical bridge port or if ip_route_output_key() fails we drop the packet. */ -static int br_nf_pre_routing_finish(struct sk_buff *skb) +static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb) { struct net_device *dev = skb->dev; struct iphdr *iph = ip_hdr(skb); - struct nf_bridge_info *nf_bridge = skb->nf_bridge; + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); struct rtable *rt; int err; int frag_max_size; @@ -364,9 +416,9 @@ static int br_nf_pre_routing_finish(struct sk_buff *skb) frag_max_size = IPCB(skb)->frag_max_size; BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size; - if (nf_bridge->mask & BRNF_PKT_TYPE) { + if (nf_bridge->pkt_otherhost) { skb->pkt_type = PACKET_OTHERHOST; - nf_bridge->mask ^= BRNF_PKT_TYPE; + nf_bridge->pkt_otherhost = false; } nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; if (dnat_took_place(skb)) { @@ -405,7 +457,7 @@ bridged_dnat: nf_bridge_push_encap_header(skb); NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, - skb, skb->dev, NULL, + sk, skb, skb->dev, NULL, br_nf_pre_routing_finish_bridge, 1); return 0; @@ -425,7 +477,8 @@ bridged_dnat: skb->dev = nf_bridge->physindev; nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb, + skb->dev, NULL, br_handle_frame_finish, 1); return 0; @@ -448,20 +501,21 @@ static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct /* Some common code for IPv4/IPv6 */ static struct net_device *setup_pre_routing(struct sk_buff *skb) { - struct nf_bridge_info *nf_bridge = skb->nf_bridge; + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); if (skb->pkt_type == PACKET_OTHERHOST) { skb->pkt_type = PACKET_HOST; - nf_bridge->mask |= BRNF_PKT_TYPE; + nf_bridge->pkt_otherhost = true; } nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING; nf_bridge->physindev = skb->dev; skb->dev = brnf_get_logical_dev(skb, skb->dev); + if (skb->protocol == htons(ETH_P_8021Q)) - nf_bridge->mask |= BRNF_8021Q; + nf_bridge->orig_proto = BRNF_PROTO_8021Q; else if (skb->protocol == htons(ETH_P_PPP_SES)) - nf_bridge->mask |= BRNF_PPPoE; + nf_bridge->orig_proto = BRNF_PROTO_PPPOE; /* Must drop socket now because of tproxy. */ skb_orphan(skb); @@ -527,9 +581,7 @@ bad: * to ip6tables, which doesn't support NAT, so things are fairly simple. */ static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { const struct ipv6hdr *hdr; u32 pkt_len; @@ -563,7 +615,8 @@ static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, return NF_DROP; skb->protocol = htons(ETH_P_IPV6); - NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->sk, skb, + skb->dev, NULL, br_nf_pre_routing_finish_ipv6); return NF_STOLEN; @@ -577,9 +630,7 @@ static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, * address to be able to detect DNAT afterwards. */ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { struct net_bridge_port *p; struct net_bridge *br; @@ -588,7 +639,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, if (unlikely(!pskb_may_pull(skb, len))) return NF_DROP; - p = br_port_get_rcu(in); + p = br_port_get_rcu(state->in); if (p == NULL) return NF_DROP; br = p->br; @@ -598,7 +649,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, return NF_ACCEPT; nf_bridge_pull_encap_header_rcsum(skb); - return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn); + return br_nf_pre_routing_ipv6(ops, skb, state); } if (!brnf_call_iptables && !br->nf_call_iptables) @@ -617,10 +668,11 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, return NF_DROP; if (!setup_pre_routing(skb)) return NF_DROP; - store_orig_dstaddr(skb); + skb->protocol = htons(ETH_P_IP); - NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->sk, skb, + skb->dev, NULL, br_nf_pre_routing_finish); return NF_STOLEN; @@ -636,25 +688,30 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, * prevent this from happening. */ static unsigned int br_nf_local_in(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { br_drop_fake_rtable(skb); return NF_ACCEPT; } /* PF_BRIDGE/FORWARD *************************************************/ -static int br_nf_forward_finish(struct sk_buff *skb) +static int br_nf_forward_finish(struct sock *sk, struct sk_buff *skb) { - struct nf_bridge_info *nf_bridge = skb->nf_bridge; + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); struct net_device *in; if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) { + int frag_max_size; + + if (skb->protocol == htons(ETH_P_IP)) { + frag_max_size = IPCB(skb)->frag_max_size; + BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size; + } + in = nf_bridge->physindev; - if (nf_bridge->mask & BRNF_PKT_TYPE) { + if (nf_bridge->pkt_otherhost) { skb->pkt_type = PACKET_OTHERHOST; - nf_bridge->mask ^= BRNF_PKT_TYPE; + nf_bridge->pkt_otherhost = false; } nf_bridge_update_protocol(skb); } else { @@ -662,8 +719,8 @@ static int br_nf_forward_finish(struct sk_buff *skb) } nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in, - skb->dev, br_forward_finish, 1); + NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, sk, skb, + in, skb->dev, br_forward_finish, 1); return 0; } @@ -675,9 +732,7 @@ static int br_nf_forward_finish(struct sk_buff *skb) * bridge ports. */ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { struct nf_bridge_info *nf_bridge; struct net_device *parent; @@ -691,7 +746,11 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, if (!nf_bridge_unshare(skb)) return NF_DROP; - parent = bridge_parent(out); + nf_bridge = nf_bridge_info_get(skb); + if (!nf_bridge) + return NF_DROP; + + parent = bridge_parent(state->out); if (!parent) return NF_DROP; @@ -704,40 +763,42 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, nf_bridge_pull_encap_header(skb); - nf_bridge = skb->nf_bridge; if (skb->pkt_type == PACKET_OTHERHOST) { skb->pkt_type = PACKET_HOST; - nf_bridge->mask |= BRNF_PKT_TYPE; + nf_bridge->pkt_otherhost = true; } - if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb)) - return NF_DROP; + if (pf == NFPROTO_IPV4) { + int frag_max = BR_INPUT_SKB_CB(skb)->frag_max_size; + + if (br_parse_ip_options(skb)) + return NF_DROP; + + IPCB(skb)->frag_max_size = frag_max; + } - /* The physdev module checks on this */ - nf_bridge->mask |= BRNF_BRIDGED; nf_bridge->physoutdev = skb->dev; if (pf == NFPROTO_IPV4) skb->protocol = htons(ETH_P_IP); else skb->protocol = htons(ETH_P_IPV6); - NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent, - br_nf_forward_finish); + NF_HOOK(pf, NF_INET_FORWARD, NULL, skb, + brnf_get_logical_dev(skb, state->in), + parent, br_nf_forward_finish); return NF_STOLEN; } static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { struct net_bridge_port *p; struct net_bridge *br; struct net_device **d = (struct net_device **)(skb->cb); - p = br_port_get_rcu(out); + p = br_port_get_rcu(state->out); if (p == NULL) return NF_ACCEPT; br = p->br; @@ -756,55 +817,93 @@ static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, nf_bridge_push_encap_header(skb); return NF_ACCEPT; } - *d = (struct net_device *)in; - NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in, - (struct net_device *)out, br_nf_forward_finish); + *d = state->in; + NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, state->sk, skb, + state->in, state->out, br_nf_forward_finish); return NF_STOLEN; } #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) -static int br_nf_dev_queue_xmit(struct sk_buff *skb) +static int br_nf_push_frag_xmit(struct sock *sk, struct sk_buff *skb) +{ + struct brnf_frag_data *data; + int err; + + data = this_cpu_ptr(&brnf_frag_data_storage); + err = skb_cow_head(skb, data->size); + + if (err) { + kfree_skb(skb); + return 0; + } + + skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size); + __skb_push(skb, data->encap_size); + + return br_dev_queue_push_xmit(sk, skb); +} + +static int br_nf_dev_queue_xmit(struct sock *sk, 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(sk, 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) { + struct brnf_frag_data *data; + 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); - } else - ret = br_dev_queue_push_xmit(skb); + + nf_bridge_update_protocol(skb); + + data = this_cpu_ptr(&brnf_frag_data_storage); + data->encap_size = nf_bridge_encap_header_len(skb); + data->size = ETH_HLEN + data->encap_size; + + skb_copy_from_linear_data_offset(skb, -data->size, data->mac, + data->size); + + ret = ip_fragment(sk, skb, br_nf_push_frag_xmit); + } else { + ret = br_dev_queue_push_xmit(sk, skb); + } return ret; } #else -static int br_nf_dev_queue_xmit(struct sk_buff *skb) +static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb) { - return br_dev_queue_push_xmit(skb); + return br_dev_queue_push_xmit(sk, skb); } #endif /* PF_BRIDGE/POST_ROUTING ********************************************/ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { - struct nf_bridge_info *nf_bridge = skb->nf_bridge; + struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); struct net_device *realoutdev = bridge_parent(skb->dev); u_int8_t pf; - if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED)) + /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in + * on a bridge, but was delivered locally and is now being routed: + * + * POST_ROUTING was already invoked from the ip stack. + */ + if (!nf_bridge || !nf_bridge->physoutdev) return NF_ACCEPT; if (!realoutdev) @@ -821,17 +920,17 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, * about the value of skb->pkt_type. */ if (skb->pkt_type == PACKET_OTHERHOST) { skb->pkt_type = PACKET_HOST; - nf_bridge->mask |= BRNF_PKT_TYPE; + nf_bridge->pkt_otherhost = true; } nf_bridge_pull_encap_header(skb); - nf_bridge_save_header(skb); if (pf == NFPROTO_IPV4) skb->protocol = htons(ETH_P_IP); else skb->protocol = htons(ETH_P_IPV6); - NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev, + NF_HOOK(pf, NF_INET_POST_ROUTING, state->sk, skb, + NULL, realoutdev, br_nf_dev_queue_xmit); return NF_STOLEN; @@ -842,9 +941,7 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, * for the second time. */ static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) + const struct nf_hook_state *state) { if (skb->nf_bridge && !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) { @@ -854,6 +951,44 @@ 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 = nf_bridge_info_get(skb); + + skb_pull(skb, ETH_HLEN); + nf_bridge->mask &= ~BRNF_BRIDGED_DNAT; + + BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN)); + + skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN), + nf_bridge->neigh_header, + ETH_HLEN - ETH_ALEN); + skb->dev = nf_bridge->physindev; + br_handle_frame_finish(NULL, skb); +} + +static int br_nf_dev_xmit(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; +} + +static const struct nf_br_ops br_ops = { + .br_dev_xmit_hook = br_nf_dev_xmit, +}; + void br_netfilter_enable(void) { } @@ -991,12 +1126,14 @@ static int __init br_netfilter_init(void) return -ENOMEM; } #endif + RCU_INIT_POINTER(nf_br_ops, &br_ops); printk(KERN_NOTICE "Bridge firewalling registered\n"); return 0; } static void __exit br_netfilter_fini(void) { + RCU_INIT_POINTER(nf_br_ops, NULL); nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); #ifdef CONFIG_SYSCTL unregister_net_sysctl_table(brnf_sysctl_header); |