diff options
Diffstat (limited to 'net/bridge/br_netfilter.c')
| -rw-r--r-- | net/bridge/br_netfilter.c | 676 |
1 files changed, 360 insertions, 316 deletions
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 268e2e72588..a615264cf01 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -3,15 +3,8 @@ * Linux ethernet bridge * * Authors: - * Lennert Buytenhek <buytenh@gnu.org> - * Bart De Schuymer (maintainer) <bdschuym@pandora.be> - * - * Changes: - * Apr 29 2003: physdev module support (bdschuym) - * Jun 19 2003: let arptables see bridged ARP traffic (bdschuym) - * Oct 06 2003: filter encapsulated IP/ARP VLAN traffic on untagged bridge - * (bdschuym) - * Sep 01 2004: add IPv6 filtering (bdschuym) + * Lennert Buytenhek <buytenh@gnu.org> + * Bart De Schuymer <bdschuym@pandora.be> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -23,6 +16,7 @@ #include <linux/module.h> #include <linux/kernel.h> +#include <linux/slab.h> #include <linux/ip.h> #include <linux/netdevice.h> #include <linux/skbuff.h> @@ -60,29 +54,45 @@ static int brnf_call_ip6tables __read_mostly = 1; static int brnf_call_arptables __read_mostly = 1; static int brnf_filter_vlan_tagged __read_mostly = 0; static int brnf_filter_pppoe_tagged __read_mostly = 0; +static int brnf_pass_vlan_indev __read_mostly = 0; #else +#define brnf_call_iptables 1 +#define brnf_call_ip6tables 1 +#define brnf_call_arptables 1 #define brnf_filter_vlan_tagged 0 #define brnf_filter_pppoe_tagged 0 +#define brnf_pass_vlan_indev 0 #endif +#define IS_IP(skb) \ + (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IP)) + +#define IS_IPV6(skb) \ + (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6)) + +#define IS_ARP(skb) \ + (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_ARP)) + static inline __be16 vlan_proto(const struct sk_buff *skb) { - return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto; + if (vlan_tx_tag_present(skb)) + return skb->protocol; + else if (skb->protocol == htons(ETH_P_8021Q)) + return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto; + else + return 0; } #define IS_VLAN_IP(skb) \ - (skb->protocol == htons(ETH_P_8021Q) && \ - vlan_proto(skb) == htons(ETH_P_IP) && \ + (vlan_proto(skb) == htons(ETH_P_IP) && \ brnf_filter_vlan_tagged) #define IS_VLAN_IPV6(skb) \ - (skb->protocol == htons(ETH_P_8021Q) && \ - vlan_proto(skb) == htons(ETH_P_IPV6) &&\ + (vlan_proto(skb) == htons(ETH_P_IPV6) && \ brnf_filter_vlan_tagged) #define IS_VLAN_ARP(skb) \ - (skb->protocol == htons(ETH_P_8021Q) && \ - vlan_proto(skb) == htons(ETH_P_ARP) && \ + (vlan_proto(skb) == htons(ETH_P_ARP) && \ brnf_filter_vlan_tagged) static inline __be16 pppoe_proto(const struct sk_buff *skb) @@ -101,15 +111,41 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb) pppoe_proto(skb) == htons(PPP_IPV6) && \ brnf_filter_pppoe_tagged) -static void fake_update_pmtu(struct dst_entry *dst, u32 mtu) +static void fake_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu) +{ +} + +static void fake_redirect(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb) +{ +} + +static u32 *fake_cow_metrics(struct dst_entry *dst, unsigned long old) +{ + return NULL; +} + +static struct neighbour *fake_neigh_lookup(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr) { + return NULL; +} + +static unsigned int fake_mtu(const struct dst_entry *dst) +{ + return dst->dev->mtu; } static struct dst_ops fake_dst_ops = { .family = AF_INET, .protocol = cpu_to_be16(ETH_P_IP), .update_pmtu = fake_update_pmtu, - .entries = ATOMIC_INIT(0), + .redirect = fake_redirect, + .cow_metrics = fake_cow_metrics, + .neigh_lookup = fake_neigh_lookup, + .mtu = fake_mtu, }; /* @@ -119,29 +155,35 @@ static struct dst_ops fake_dst_ops = { * ipt_REJECT needs it. Future netfilter modules might * require us to fill additional fields. */ +static const u32 br_dst_default_metrics[RTAX_MAX] = { + [RTAX_MTU - 1] = 1500, +}; + void br_netfilter_rtable_init(struct net_bridge *br) { struct rtable *rt = &br->fake_rtable; - atomic_set(&rt->u.dst.__refcnt, 1); - rt->u.dst.dev = br->dev; - rt->u.dst.path = &rt->u.dst; - rt->u.dst.metrics[RTAX_MTU - 1] = 1500; - rt->u.dst.flags = DST_NOXFRM; - rt->u.dst.ops = &fake_dst_ops; + atomic_set(&rt->dst.__refcnt, 1); + rt->dst.dev = br->dev; + rt->dst.path = &rt->dst; + dst_init_metrics(&rt->dst, br_dst_default_metrics, true); + rt->dst.flags = DST_NOXFRM | DST_FAKE_RTABLE; + rt->dst.ops = &fake_dst_ops; } static inline struct rtable *bridge_parent_rtable(const struct net_device *dev) { - struct net_bridge_port *port = rcu_dereference(dev->br_port); + struct net_bridge_port *port; + port = br_port_get_rcu(dev); return port ? &port->br->fake_rtable : NULL; } static inline struct net_device *bridge_parent(const struct net_device *dev) { - struct net_bridge_port *port = rcu_dereference(dev->br_port); + struct net_bridge_port *port; + port = br_port_get_rcu(dev); return port ? port->br->dev : NULL; } @@ -164,8 +206,8 @@ static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb) if (tmp) { memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info)); atomic_set(&tmp->use, 1); - nf_bridge_put(nf_bridge); } + nf_bridge_put(nf_bridge); nf_bridge = tmp; } return nf_bridge; @@ -203,15 +245,91 @@ static inline void nf_bridge_save_header(struct sk_buff *skb) skb->nf_bridge->data, header_size); } -/* - * When forwarding bridge frames, we save a copy of the original - * header before processing. +static inline 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); +} + +/* When handing a packet over to the IP layer + * check whether we have a skb that is in the + * expected format + */ + +static int br_parse_ip_options(struct sk_buff *skb) +{ + struct ip_options *opt; + const struct iphdr *iph; + struct net_device *dev = skb->dev; + u32 len; + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto inhdr_error; + + iph = ip_hdr(skb); + opt = &(IPCB(skb)->opt); + + /* Basic sanity checks */ + if (iph->ihl < 5 || iph->version != 4) + goto inhdr_error; + + if (!pskb_may_pull(skb, iph->ihl*4)) + goto inhdr_error; + + iph = ip_hdr(skb); + if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) + goto inhdr_error; + + len = ntohs(iph->tot_len); + if (skb->len < len) { + IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS); + goto drop; + } else if (len < (iph->ihl*4)) + goto inhdr_error; + + if (pskb_trim_rcsum(skb, len)) { + IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS); + goto drop; + } + + memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); + if (iph->ihl == 5) + return 0; + + opt->optlen = iph->ihl*4 - sizeof(struct iphdr); + if (ip_options_compile(dev_net(dev), opt, skb)) + goto inhdr_error; + + /* Check correct handling of SRR option */ + if (unlikely(opt->srr)) { + struct in_device *in_dev = __in_dev_get_rcu(dev); + if (in_dev && !IN_DEV_SOURCE_ROUTE(in_dev)) + goto drop; + + if (ip_options_rcv_srr(skb)) + goto drop; + } + + return 0; + +inhdr_error: + IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS); +drop: + return -1; +} + +/* Fill in the header for fragmented IP packets handled by + * the IPv4 connection tracking code. */ int nf_bridge_copy_header(struct sk_buff *skb) { int err; - int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb); + 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 err; @@ -241,31 +359,63 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) kfree_skb(skb); return 0; } - dst_hold(&rt->u.dst); - skb_dst_set(skb, &rt->u.dst); + skb_dst_set_noref(skb, &rt->dst); skb->dev = nf_bridge->physindev; + nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, br_handle_frame_finish, 1); return 0; } -static void __br_dnat_complain(void) +/* Obtain the correct destination MAC address, while preserving the original + * source MAC address. If we already know this address, we just copy it. If we + * 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 unsigned long last_complaint; + struct nf_bridge_info *nf_bridge = skb->nf_bridge; + struct neighbour *neigh; + struct dst_entry *dst; - if (jiffies - last_complaint >= 5 * HZ) { - printk(KERN_WARNING "Performing cross-bridge DNAT requires IP " - "forwarding to be enabled\n"); - last_complaint = jiffies; + skb->dev = bridge_parent(skb->dev); + if (!skb->dev) + goto free_skb; + dst = skb_dst(skb); + neigh = dst_neigh_lookup_skb(dst, skb); + if (neigh) { + int ret; + + if (neigh->hh.hh_len) { + neigh_hh_bridge(&neigh->hh, skb); + skb->dev = nf_bridge->physindev; + ret = br_handle_frame_finish(skb); + } else { + /* the neighbour function below overwrites the complete + * MAC header, so we save the Ethernet source address and + * protocol number. + */ + skb_copy_from_linear_data_offset(skb, + -(ETH_HLEN-ETH_ALEN), + skb->nf_bridge->data, + ETH_HLEN-ETH_ALEN); + /* tell br_dev_xmit to continue with forwarding */ + nf_bridge->mask |= BRNF_BRIDGED_DNAT; + ret = neigh->output(neigh, skb); + } + neigh_release(neigh); + return ret; } +free_skb: + kfree_skb(skb); + return 0; } /* This requires some explaining. If DNAT has taken place, - * we will need to fix up the destination Ethernet address, - * and this is a tricky process. + * we will need to fix up the destination Ethernet address. * * There are two cases to consider: * 1. The packet was DNAT'ed to a device in the same bridge @@ -279,62 +429,29 @@ static void __br_dnat_complain(void) * call ip_route_input() and to look at skb->dst->dev, which is * changed to the destination device if ip_route_input() succeeds. * - * Let us first consider the case that ip_route_input() succeeds: - * - * If skb->dst->dev equals the logical bridge device the packet - * came in on, we can consider this bridging. The packet is passed - * through the neighbour output function to build a new destination - * MAC address, which will make the packet enter br_nf_local_out() - * not much later. In that function it is assured that the iptables - * FORWARD chain is traversed for the packet. + * Let's first consider the case that ip_route_input() succeeds: * + * If the output device equals the logical bridge device the packet + * came in on, we can consider this bridging. The corresponding MAC + * address will be obtained in br_nf_pre_routing_finish_bridge. * Otherwise, the packet is considered to be routed and we just * change the destination MAC address so that the packet will * later be passed up to the IP stack to be routed. For a redirected * packet, ip_route_input() will give back the localhost as output device, * which differs from the bridge device. * - * Let us now consider the case that ip_route_input() fails: + * Let's now consider the case that ip_route_input() fails: * * This can be because the destination address is martian, in which case * the packet will be dropped. - * After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input() - * will fail, while __ip_route_output_key() will return success. The source - * address for __ip_route_output_key() is set to zero, so __ip_route_output_key + * If IP forwarding is disabled, ip_route_input() will fail, while + * ip_route_output_key() can return success. The source + * address for ip_route_output_key() is set to zero, so ip_route_output_key() * thinks we're handling a locally generated packet and won't care - * if IP forwarding is allowed. We send a warning message to the users's - * log telling her to put IP forwarding on. - * - * ip_route_input() will also fail if there is no route available. - * In that case we just drop the packet. - * - * --Lennert, 20020411 - * --Bart, 20020416 (updated) - * --Bart, 20021007 (updated) - * --Bart, 20062711 (updated) */ -static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) -{ - if (skb->pkt_type == PACKET_OTHERHOST) { - skb->pkt_type = PACKET_HOST; - skb->nf_bridge->mask |= BRNF_PKT_TYPE; - } - skb->nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; - - skb->dev = bridge_parent(skb->dev); - if (skb->dev) { - struct dst_entry *dst = skb_dst(skb); - - nf_bridge_pull_encap_header(skb); - - if (dst->hh) - return neigh_hh_output(dst->hh, skb); - else if (dst->neighbour) - return dst->neighbour->output(skb); - } - kfree_skb(skb); - return 0; -} - + * if IP forwarding is enabled. If the output device equals the logical bridge + * 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) { struct net_device *dev = skb->dev; @@ -350,15 +467,6 @@ static int br_nf_pre_routing_finish(struct sk_buff *skb) nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; if (dnat_took_place(skb)) { if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { - struct flowi fl = { - .nl_u = { - .ip4_u = { - .daddr = iph->daddr, - .saddr = 0, - .tos = RT_TOS(iph->tos) }, - }, - .proto = 0, - }; struct in_device *in_dev = __in_dev_get_rcu(dev); /* If err equals -EHOSTUNREACH the error is due to a @@ -371,19 +479,16 @@ static int br_nf_pre_routing_finish(struct sk_buff *skb) if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev)) goto free_skb; - if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { + rt = ip_route_output(dev_net(dev), iph->daddr, 0, + RT_TOS(iph->tos), 0); + if (!IS_ERR(rt)) { /* - Bridged-and-DNAT'ed traffic doesn't * require ip_forwarding. */ - if (((struct dst_entry *)rt)->dev == dev) { - skb_dst_set(skb, (struct dst_entry *)rt); + if (rt->dst.dev == dev) { + skb_dst_set(skb, &rt->dst); goto bridged_dnat; } - /* we are sure that forwarding is disabled, so printing - * this message is no problem. Note that the packet could - * still have a martian destination address, in which case - * the packet could be dropped even if forwarding were enabled */ - __br_dnat_complain(); - dst_release((struct dst_entry *)rt); + ip_rt_put(rt); } free_skb: kfree_skb(skb); @@ -391,18 +496,17 @@ free_skb: } else { if (skb_dst(skb)->dev == dev) { bridged_dnat: - /* Tell br_nf_local_out this is a - * bridged frame */ - nf_bridge->mask |= BRNF_BRIDGED_DNAT; skb->dev = nf_bridge->physindev; + nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, + NF_HOOK_THRESH(NFPROTO_BRIDGE, + NF_BR_PRE_ROUTING, skb, skb->dev, NULL, br_nf_pre_routing_finish_bridge, 1); return 0; } - memcpy(eth_hdr(skb)->h_dest, dev->dev_addr, ETH_ALEN); + ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr); skb->pkt_type = PACKET_HOST; } } else { @@ -411,18 +515,32 @@ bridged_dnat: kfree_skb(skb); return 0; } - dst_hold(&rt->u.dst); - skb_dst_set(skb, &rt->u.dst); + skb_dst_set_noref(skb, &rt->dst); } skb->dev = nf_bridge->physindev; + nf_bridge_update_protocol(skb); nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, br_handle_frame_finish, 1); return 0; } +static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev) +{ + struct net_device *vlan, *br; + + br = bridge_parent(dev); + if (brnf_pass_vlan_indev == 0 || !vlan_tx_tag_present(skb)) + return br; + + vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto, + vlan_tx_tag_get(skb) & VLAN_VID_MASK); + + return vlan ? vlan : br; +} + /* Some common code for IPv4/IPv6 */ static struct net_device *setup_pre_routing(struct sk_buff *skb) { @@ -435,8 +553,14 @@ static struct net_device *setup_pre_routing(struct sk_buff *skb) nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING; nf_bridge->physindev = skb->dev; - skb->dev = bridge_parent(skb->dev); - + skb->dev = brnf_get_logical_dev(skb, skb->dev); + if (skb->protocol == htons(ETH_P_8021Q)) + nf_bridge->mask |= BRNF_8021Q; + else if (skb->protocol == htons(ETH_P_PPP_SES)) + nf_bridge->mask |= BRNF_PPPoE; + + /* Must drop socket now because of tproxy. */ + skb_orphan(skb); return skb->dev; } @@ -459,7 +583,7 @@ static int check_hbh_len(struct sk_buff *skb) int optlen = nh[off + 1] + 2; switch (nh[off]) { - case IPV6_TLV_PAD0: + case IPV6_TLV_PAD1: optlen = 1; break; @@ -497,36 +621,36 @@ bad: /* Replicate the checks that IPv6 does on packet reception and pass the packet * to ip6tables, which doesn't support NAT, so things are fairly simple. */ -static unsigned int br_nf_pre_routing_ipv6(unsigned int hook, +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 *)) { - struct ipv6hdr *hdr; + const struct ipv6hdr *hdr; u32 pkt_len; if (skb->len < sizeof(struct ipv6hdr)) - goto inhdr_error; + return NF_DROP; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) - goto inhdr_error; + return NF_DROP; hdr = ipv6_hdr(skb); if (hdr->version != 6) - goto inhdr_error; + return NF_DROP; pkt_len = ntohs(hdr->payload_len); if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { if (pkt_len + sizeof(struct ipv6hdr) > skb->len) - goto inhdr_error; + return NF_DROP; if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) - goto inhdr_error; + return NF_DROP; } if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb)) - goto inhdr_error; + return NF_DROP; nf_bridge_put(skb->nf_bridge); if (!nf_bridge_alloc(skb)) @@ -534,13 +658,11 @@ static unsigned int br_nf_pre_routing_ipv6(unsigned int hook, if (!setup_pre_routing(skb)) return NF_DROP; - NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, + skb->protocol = htons(ETH_P_IPV6); + NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, br_nf_pre_routing_finish_ipv6); return NF_STOLEN; - -inhdr_error: - return NF_DROP; } /* Direct IPv6 traffic to br_nf_pre_routing_ipv6. @@ -549,56 +671,42 @@ inhdr_error: * receiving device) to make netfilter happy, the REDIRECT * target in particular. Save the original destination IP * address to be able to detect DNAT afterwards. */ -static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff *skb, +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 *)) { - struct iphdr *iph; + struct net_bridge_port *p; + struct net_bridge *br; __u32 len = nf_bridge_encap_header_len(skb); if (unlikely(!pskb_may_pull(skb, len))) - goto out; + return NF_DROP; - if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || - IS_PPPOE_IPV6(skb)) { -#ifdef CONFIG_SYSCTL - if (!brnf_call_ip6tables) + p = br_port_get_rcu(in); + if (p == NULL) + return NF_DROP; + br = p->br; + + if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) { + if (!brnf_call_ip6tables && !br->nf_call_ip6tables) return NF_ACCEPT; -#endif + nf_bridge_pull_encap_header_rcsum(skb); - return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn); + return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn); } -#ifdef CONFIG_SYSCTL - if (!brnf_call_iptables) + + if (!brnf_call_iptables && !br->nf_call_iptables) return NF_ACCEPT; -#endif - if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb) && - !IS_PPPOE_IP(skb)) + if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb)) return NF_ACCEPT; nf_bridge_pull_encap_header_rcsum(skb); - if (!pskb_may_pull(skb, sizeof(struct iphdr))) - goto inhdr_error; - - iph = ip_hdr(skb); - if (iph->ihl < 5 || iph->version != 4) - goto inhdr_error; - - if (!pskb_may_pull(skb, 4 * iph->ihl)) - goto inhdr_error; - - iph = ip_hdr(skb); - if (ip_fast_csum((__u8 *) iph, iph->ihl) != 0) - goto inhdr_error; - - len = ntohs(iph->tot_len); - if (skb->len < len || len < 4 * iph->ihl) - goto inhdr_error; - - pskb_trim_rcsum(skb, len); + if (br_parse_ip_options(skb)) + return NF_DROP; nf_bridge_put(skb->nf_bridge); if (!nf_bridge_alloc(skb)) @@ -606,16 +714,12 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff *skb, if (!setup_pre_routing(skb)) return NF_DROP; store_orig_dstaddr(skb); + skb->protocol = htons(ETH_P_IP); - NF_HOOK(PF_INET, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, + NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, br_nf_pre_routing_finish); return NF_STOLEN; - -inhdr_error: -// IP_INC_STATS_BH(IpInHdrErrors); -out: - return NF_DROP; } @@ -626,16 +730,13 @@ out: * took place when the packet entered the bridge), but we * register an IPv4 PRE_ROUTING 'sabotage' hook that will * prevent this from happening. */ -static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff *skb, +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 *)) { - struct rtable *rt = skb_rtable(skb); - - if (rt && rt == bridge_parent_rtable(in)) - skb_dst_drop(skb); - + br_drop_fake_rtable(skb); return NF_ACCEPT; } @@ -645,27 +746,31 @@ static int br_nf_forward_finish(struct sk_buff *skb) struct nf_bridge_info *nf_bridge = skb->nf_bridge; struct net_device *in; - if (skb->protocol != htons(ETH_P_ARP) && !IS_VLAN_ARP(skb)) { + if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) { in = nf_bridge->physindev; if (nf_bridge->mask & BRNF_PKT_TYPE) { skb->pkt_type = PACKET_OTHERHOST; nf_bridge->mask ^= BRNF_PKT_TYPE; } + nf_bridge_update_protocol(skb); } else { in = *((struct net_device **)(skb->cb)); } nf_bridge_push_encap_header(skb); - NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, in, + + NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in, skb->dev, br_forward_finish, 1); return 0; } + /* This is the 'purely bridged' case. For IP, we pass the packet to * netfilter with indev and outdev set to the bridge device, * but we are still able to filter on the 'real' indev/outdev * because of the physdev module. For ARP, indev and outdev are the * bridge ports. */ -static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb, +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 *)) @@ -686,12 +791,10 @@ static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb, if (!parent) return NF_DROP; - if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) || - IS_PPPOE_IP(skb)) - pf = PF_INET; - else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || - IS_PPPOE_IPV6(skb)) - pf = PF_INET6; + if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) + pf = NFPROTO_IPV4; + else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) + pf = NFPROTO_IPV6; else return NF_ACCEPT; @@ -703,29 +806,42 @@ static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb, nf_bridge->mask |= BRNF_PKT_TYPE; } + if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb)) + return NF_DROP; + /* 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, bridge_parent(in), parent, + NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent, br_nf_forward_finish); return NF_STOLEN; } -static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb, +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 *)) { + struct net_bridge_port *p; + struct net_bridge *br; struct net_device **d = (struct net_device **)(skb->cb); -#ifdef CONFIG_SYSCTL - if (!brnf_call_arptables) + p = br_port_get_rcu(out); + if (p == NULL) + return NF_ACCEPT; + br = p->br; + + if (!brnf_call_arptables && !br->nf_call_arptables) return NF_ACCEPT; -#endif - if (skb->protocol != htons(ETH_P_ARP)) { + if (!IS_ARP(skb)) { if (!IS_VLAN_ARP(skb)) return NF_ACCEPT; nf_bridge_pull_encap_header(skb); @@ -743,64 +859,22 @@ static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb, return NF_STOLEN; } -/* PF_BRIDGE/LOCAL_OUT *********************************************** - * - * This function sees both locally originated IP packets and forwarded - * IP packets (in both cases the destination device is a bridge - * device). It also sees bridged-and-DNAT'ed packets. - * - * If (nf_bridge->mask & BRNF_BRIDGED_DNAT) then the packet is bridged - * and we fake the PF_BRIDGE/FORWARD hook. The function br_nf_forward() - * will then fake the PF_INET/FORWARD hook. br_nf_local_out() has priority - * NF_BR_PRI_FIRST, so no relevant PF_BRIDGE/INPUT functions have been nor - * will be executed. - */ -static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) +static int br_nf_dev_queue_xmit(struct sk_buff *skb) { - struct net_device *realindev; - struct nf_bridge_info *nf_bridge; - - if (!skb->nf_bridge) - return NF_ACCEPT; - - /* Need exclusive nf_bridge_info since we might have multiple - * different physoutdevs. */ - if (!nf_bridge_unshare(skb)) - return NF_DROP; - - nf_bridge = skb->nf_bridge; - if (!(nf_bridge->mask & BRNF_BRIDGED_DNAT)) - return NF_ACCEPT; - - /* Bridged, take PF_BRIDGE/FORWARD. - * (see big note in front of br_nf_pre_routing_finish) */ - nf_bridge->physoutdev = skb->dev; - realindev = nf_bridge->physindev; - - if (nf_bridge->mask & BRNF_PKT_TYPE) { - skb->pkt_type = PACKET_OTHERHOST; - nf_bridge->mask ^= BRNF_PKT_TYPE; - } - nf_bridge_push_encap_header(skb); + int ret; - NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, realindev, skb->dev, - br_forward_finish); - return NF_STOLEN; -} + if (skb->protocol == htons(ETH_P_IP) && + skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu && + !skb_is_gso(skb)) { + if (br_parse_ip_options(skb)) + /* Drop invalid packet */ + return NF_DROP; + ret = ip_fragment(skb, br_dev_queue_push_xmit); + } else + ret = br_dev_queue_push_xmit(skb); -#if defined(CONFIG_NF_CONNTRACK_IPV4) || defined(CONFIG_NF_CONNTRACK_IPV4_MODULE) -static int br_nf_dev_queue_xmit(struct sk_buff *skb) -{ - if (skb->nfct != NULL && - (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb)) && - skb->len > skb->dev->mtu && - !skb_is_gso(skb)) - return ip_fragment(skb, br_dev_queue_push_xmit); - else - return br_dev_queue_push_xmit(skb); + return ret; } #else static int br_nf_dev_queue_xmit(struct sk_buff *skb) @@ -810,7 +884,8 @@ static int br_nf_dev_queue_xmit(struct sk_buff *skb) #endif /* PF_BRIDGE/POST_ROUTING ********************************************/ -static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb, +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 *)) @@ -819,42 +894,19 @@ static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb, struct net_device *realoutdev = bridge_parent(skb->dev); u_int8_t pf; -#ifdef CONFIG_NETFILTER_DEBUG - /* Be very paranoid. This probably won't happen anymore, but let's - * keep the check just to be sure... */ - if (skb_mac_header(skb) < skb->head || - skb_mac_header(skb) + ETH_HLEN > skb->data) { - printk(KERN_CRIT "br_netfilter: Argh!! br_nf_post_routing: " - "bad mac.raw pointer.\n"); - goto print_error; - } -#endif - - if (!nf_bridge) - return NF_ACCEPT; - - if (!(nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT))) + if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED)) return NF_ACCEPT; if (!realoutdev) return NF_DROP; - if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) || - IS_PPPOE_IP(skb)) - pf = PF_INET; - else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || - IS_PPPOE_IPV6(skb)) - pf = PF_INET6; + if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) + pf = NFPROTO_IPV4; + else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) + pf = NFPROTO_IPV6; else return NF_ACCEPT; -#ifdef CONFIG_NETFILTER_DEBUG - if (skb_dst(skb) == NULL) { - printk(KERN_INFO "br_netfilter post_routing: skb->dst == NULL\n"); - goto print_error; - } -#endif - /* We assume any code from br_dev_queue_push_xmit onwards doesn't care * about the value of skb->pkt_type. */ if (skb->pkt_type == PACKET_OTHERHOST) { @@ -864,30 +916,22 @@ static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb, 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, br_nf_dev_queue_xmit); return NF_STOLEN; - -#ifdef CONFIG_NETFILTER_DEBUG -print_error: - if (skb->dev != NULL) { - printk("[%s]", skb->dev->name); - if (realoutdev) - printk("[%s]", realoutdev->name); - } - printk(" head:%p, raw:%p, data:%p\n", skb->head, skb_mac_header(skb), - skb->data); - dump_stack(); - return NF_ACCEPT; -#endif } /* IP/SABOTAGE *****************************************************/ /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING * for the second time. */ -static unsigned int ip_sabotage_in(unsigned int hook, struct sk_buff *skb, +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 *)) @@ -900,64 +944,55 @@ static unsigned int ip_sabotage_in(unsigned int hook, struct sk_buff *skb, return NF_ACCEPT; } -/* For br_nf_local_out we need (prio = NF_BR_PRI_FIRST), to insure that innocent - * PF_BRIDGE/NF_BR_LOCAL_OUT functions don't get bridged traffic as input. - * For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because - * ip_refrag() can return NF_STOLEN. */ +/* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because + * br_dev_queue_push_xmit is called afterwards */ static struct nf_hook_ops br_nf_ops[] __read_mostly = { { .hook = br_nf_pre_routing, .owner = THIS_MODULE, - .pf = PF_BRIDGE, + .pf = NFPROTO_BRIDGE, .hooknum = NF_BR_PRE_ROUTING, .priority = NF_BR_PRI_BRNF, }, { .hook = br_nf_local_in, .owner = THIS_MODULE, - .pf = PF_BRIDGE, + .pf = NFPROTO_BRIDGE, .hooknum = NF_BR_LOCAL_IN, .priority = NF_BR_PRI_BRNF, }, { .hook = br_nf_forward_ip, .owner = THIS_MODULE, - .pf = PF_BRIDGE, + .pf = NFPROTO_BRIDGE, .hooknum = NF_BR_FORWARD, .priority = NF_BR_PRI_BRNF - 1, }, { .hook = br_nf_forward_arp, .owner = THIS_MODULE, - .pf = PF_BRIDGE, + .pf = NFPROTO_BRIDGE, .hooknum = NF_BR_FORWARD, .priority = NF_BR_PRI_BRNF, }, { - .hook = br_nf_local_out, - .owner = THIS_MODULE, - .pf = PF_BRIDGE, - .hooknum = NF_BR_LOCAL_OUT, - .priority = NF_BR_PRI_FIRST, - }, - { .hook = br_nf_post_routing, .owner = THIS_MODULE, - .pf = PF_BRIDGE, + .pf = NFPROTO_BRIDGE, .hooknum = NF_BR_POST_ROUTING, .priority = NF_BR_PRI_LAST, }, { .hook = ip_sabotage_in, .owner = THIS_MODULE, - .pf = PF_INET, + .pf = NFPROTO_IPV4, .hooknum = NF_INET_PRE_ROUTING, .priority = NF_IP_PRI_FIRST, }, { .hook = ip_sabotage_in, .owner = THIS_MODULE, - .pf = PF_INET6, + .pf = NFPROTO_IPV6, .hooknum = NF_INET_PRE_ROUTING, .priority = NF_IP6_PRI_FIRST, }, @@ -965,8 +1000,8 @@ static struct nf_hook_ops br_nf_ops[] __read_mostly = { #ifdef CONFIG_SYSCTL static -int brnf_sysctl_call_tables(ctl_table * ctl, int write, - void __user * buffer, size_t * lenp, loff_t * ppos) +int brnf_sysctl_call_tables(struct ctl_table *ctl, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; @@ -977,7 +1012,7 @@ int brnf_sysctl_call_tables(ctl_table * ctl, int write, return ret; } -static ctl_table brnf_table[] = { +static struct ctl_table brnf_table[] = { { .procname = "bridge-nf-call-arptables", .data = &brnf_call_arptables, @@ -1013,12 +1048,13 @@ static ctl_table brnf_table[] = { .mode = 0644, .proc_handler = brnf_sysctl_call_tables, }, - { } -}; - -static struct ctl_path brnf_path[] = { - { .procname = "net", }, - { .procname = "bridge", }, + { + .procname = "bridge-nf-pass-vlan-input-dev", + .data = &brnf_pass_vlan_indev, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = brnf_sysctl_call_tables, + }, { } }; #endif @@ -1027,15 +1063,22 @@ int __init br_netfilter_init(void) { int ret; - ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); + ret = dst_entries_init(&fake_dst_ops); if (ret < 0) return ret; + + ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); + if (ret < 0) { + dst_entries_destroy(&fake_dst_ops); + return ret; + } #ifdef CONFIG_SYSCTL - brnf_sysctl_header = register_sysctl_paths(brnf_path, brnf_table); + brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table); if (brnf_sysctl_header == NULL) { printk(KERN_WARNING "br_netfilter: can't register to sysctl.\n"); nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); + dst_entries_destroy(&fake_dst_ops); return -ENOMEM; } #endif @@ -1047,6 +1090,7 @@ void br_netfilter_fini(void) { nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); #ifdef CONFIG_SYSCTL - unregister_sysctl_table(brnf_sysctl_header); + unregister_net_sysctl_table(brnf_sysctl_header); #endif + dst_entries_destroy(&fake_dst_ops); } |