| /* |
| * Handle firewalling |
| * Linux ethernet bridge |
| * |
| * Authors: |
| * Lennert Buytenhek <buytenh@gnu.org> |
| * Bart De Schuymer <bart.de.schuymer@pandora.be> |
| * |
| * $Id: br_netfilter.c,v 1.3 2002/10/19 14:33:23 bdschuym Exp $ |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Lennert dedicates this file to Kerstin Wurdinger. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/ip.h> |
| #include <linux/netdevice.h> |
| #include <linux/skbuff.h> |
| #include <linux/if_ether.h> |
| #include <linux/netfilter_bridge.h> |
| #include <linux/netfilter_ipv4.h> |
| #include <linux/in_route.h> |
| #include <net/ip.h> |
| #include <asm/uaccess.h> |
| #include <asm/checksum.h> |
| #include "br_private.h" |
| |
| |
| #define skb_origaddr(skb) (((struct bridge_skb_cb *) \ |
| (skb->cb))->daddr.ipv4) |
| #define store_orig_dstaddr(skb) (skb_origaddr(skb) = (skb)->nh.iph->daddr) |
| #define dnat_took_place(skb) (skb_origaddr(skb) != (skb)->nh.iph->daddr) |
| #define clear_cb(skb) (memset(&skb_origaddr(skb), 0, \ |
| sizeof(struct bridge_skb_cb))) |
| |
| #define has_bridge_parent(device) ((device)->br_port != NULL) |
| #define bridge_parent(device) (&((device)->br_port->br->dev)) |
| |
| /* We need these fake structures to make netfilter happy -- |
| * lots of places assume that skb->dst != NULL, which isn't |
| * all that unreasonable. |
| * |
| * Currently, we fill in the PMTU entry because netfilter |
| * refragmentation needs it, and the rt_flags entry because |
| * ipt_REJECT needs it. Future netfilter modules might |
| * require us to fill additional fields. |
| */ |
| static struct net_device __fake_net_device = { |
| hard_header_len: ETH_HLEN |
| }; |
| |
| static struct rtable __fake_rtable = { |
| u: { |
| dst: { |
| __refcnt: ATOMIC_INIT(1), |
| dev: &__fake_net_device, |
| pmtu: 1500 |
| } |
| }, |
| |
| rt_flags: 0 |
| }; |
| |
| |
| /* PF_BRIDGE/PRE_ROUTING *********************************************/ |
| static void __br_dnat_complain(void) |
| { |
| static unsigned long last_complaint = 0; |
| |
| if (jiffies - last_complaint >= 5 * HZ) { |
| printk(KERN_WARNING "Performing cross-bridge DNAT requires IP " |
| "forwarding to be enabled\n"); |
| last_complaint = jiffies; |
| } |
| } |
| |
| |
| /* 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. |
| * |
| * There are two cases to consider: |
| * 1. The packet was DNAT'ed to a device in the same bridge |
| * port group as it was received on. We can still bridge |
| * the packet. |
| * 2. The packet was DNAT'ed to a different device, either |
| * a non-bridged device or another bridge port group. |
| * The packet will need to be routed. |
| * |
| * The correct way of distinguishing between these two cases is to |
| * 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. We then call |
| * skb->dst->output() 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. |
| * |
| * 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. |
| * |
| * Let us now consider the case that ip_route_input() fails: |
| * |
| * After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input() |
| * will fail, while ip_route_output() will return success. The source |
| * address for ip_route_output() is set to zero, so ip_route_output() |
| * 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) |
| */ |
| |
| static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) |
| { |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug |= (1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_FORWARD); |
| #endif |
| |
| if (skb->pkt_type == PACKET_OTHERHOST) { |
| skb->pkt_type = PACKET_HOST; |
| skb->nf_bridge->mask |= BRNF_PKT_TYPE; |
| } |
| |
| skb->dev = bridge_parent(skb->dev); |
| skb->dst->output(skb); |
| return 0; |
| } |
| |
| static int br_nf_pre_routing_finish(struct sk_buff *skb) |
| { |
| struct net_device *dev = skb->dev; |
| struct iphdr *iph = skb->nh.iph; |
| struct nf_bridge_info *nf_bridge = skb->nf_bridge; |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug ^= (1 << NF_BR_PRE_ROUTING); |
| #endif |
| |
| if (nf_bridge->mask & BRNF_PKT_TYPE) { |
| skb->pkt_type = PACKET_OTHERHOST; |
| nf_bridge->mask ^= BRNF_PKT_TYPE; |
| } |
| |
| if (dnat_took_place(skb)) { |
| if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, |
| dev)) { |
| struct rtable *rt; |
| |
| if (!ip_route_output(&rt, iph->daddr, 0, iph->tos, 0)) { |
| /* Bridged-and-DNAT'ed traffic doesn't |
| * require ip_forwarding. |
| */ |
| if (((struct dst_entry *)rt)->dev == dev) { |
| skb->dst = (struct dst_entry *)rt; |
| goto bridged_dnat; |
| } |
| __br_dnat_complain(); |
| dst_release((struct dst_entry *)rt); |
| } |
| kfree_skb(skb); |
| return 0; |
| } else { |
| if (skb->dst->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; |
| clear_cb(skb); |
| NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, |
| skb, skb->dev, NULL, |
| br_nf_pre_routing_finish_bridge, |
| 1); |
| return 0; |
| } |
| memcpy(skb->mac.ethernet->h_dest, dev->dev_addr, |
| ETH_ALEN); |
| } |
| } else { |
| skb->dst = (struct dst_entry *)&__fake_rtable; |
| dst_hold(skb->dst); |
| } |
| |
| clear_cb(skb); |
| skb->dev = nf_bridge->physindev; |
| NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
| br_handle_frame_finish, 1); |
| |
| return 0; |
| } |
| |
| /* Replicate the checks that IPv4 does on packet reception. |
| * Set skb->dev to the bridge device (i.e. parent of the |
| * 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 **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| struct iphdr *iph; |
| __u32 len; |
| struct sk_buff *skb; |
| struct nf_bridge_info *nf_bridge; |
| |
| if ((*pskb)->protocol != __constant_htons(ETH_P_IP)) |
| return NF_ACCEPT; |
| |
| if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL) |
| goto out; |
| |
| if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
| goto inhdr_error; |
| |
| iph = skb->nh.iph; |
| if (iph->ihl < 5 || iph->version != 4) |
| goto inhdr_error; |
| |
| if (!pskb_may_pull(skb, 4*iph->ihl)) |
| goto inhdr_error; |
| |
| iph = skb->nh.iph; |
| 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; |
| |
| if (skb->len > len) { |
| __pskb_trim(skb, len); |
| if (skb->ip_summed == CHECKSUM_HW) |
| skb->ip_summed = CHECKSUM_NONE; |
| } |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug ^= (1 << NF_IP_PRE_ROUTING); |
| #endif |
| |
| nf_bridge = skb->nf_bridge; |
| if (skb->pkt_type == PACKET_OTHERHOST) { |
| skb->pkt_type = PACKET_HOST; |
| nf_bridge->mask |= BRNF_PKT_TYPE; |
| } |
| |
| nf_bridge->physindev = skb->dev; |
| skb->dev = bridge_parent(skb->dev); |
| store_orig_dstaddr(skb); |
| |
| NF_HOOK(PF_INET, NF_IP_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; |
| } |
| |
| |
| /* PF_BRIDGE/LOCAL_IN ************************************************/ |
| /* The packet is locally destined, which requires a real |
| * dst_entry, so detach the fake one. On the way up, the |
| * packet would pass through PRE_ROUTING again (which already |
| * 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 **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| struct sk_buff *skb = *pskb; |
| |
| if (skb->protocol != __constant_htons(ETH_P_IP)) |
| return NF_ACCEPT; |
| |
| if (skb->dst == (struct dst_entry *)&__fake_rtable) { |
| dst_release(skb->dst); |
| skb->dst = NULL; |
| } |
| |
| return NF_ACCEPT; |
| } |
| |
| |
| /* PF_BRIDGE/FORWARD *************************************************/ |
| static int br_nf_forward_finish(struct sk_buff *skb) |
| { |
| struct nf_bridge_info *nf_bridge = skb->nf_bridge; |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug ^= (1 << NF_BR_FORWARD); |
| #endif |
| |
| if (nf_bridge->mask & BRNF_PKT_TYPE) { |
| skb->pkt_type = PACKET_OTHERHOST; |
| nf_bridge->mask ^= BRNF_PKT_TYPE; |
| } |
| |
| NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, nf_bridge->physindev, |
| skb->dev, br_forward_finish, 1); |
| |
| return 0; |
| } |
| |
| /* This is the 'purely bridged' case. 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 another bit of the bridge-nf patch overloads the |
| * '-i' and '-o' iptables interface checks to take |
| * skb->phys{in,out}dev into account as well (so both the real |
| * device and the bridge device will match). |
| */ |
| static unsigned int br_nf_forward(unsigned int hook, struct sk_buff **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| struct sk_buff *skb = *pskb; |
| struct nf_bridge_info *nf_bridge; |
| |
| if (skb->protocol != __constant_htons(ETH_P_IP)) |
| return NF_ACCEPT; |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug ^= (1 << NF_BR_FORWARD); |
| #endif |
| |
| nf_bridge = skb->nf_bridge; |
| if (skb->pkt_type == PACKET_OTHERHOST) { |
| skb->pkt_type = PACKET_HOST; |
| nf_bridge->mask |= BRNF_PKT_TYPE; |
| } |
| |
| nf_bridge->physoutdev = skb->dev; |
| |
| NF_HOOK(PF_INET, NF_IP_FORWARD, skb, bridge_parent(nf_bridge->physindev), |
| bridge_parent(skb->dev), br_nf_forward_finish); |
| |
| return NF_STOLEN; |
| } |
| |
| |
| /* PF_BRIDGE/LOCAL_OUT ***********************************************/ |
| static int br_nf_local_out_finish(struct sk_buff *skb) |
| { |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug &= ~(1 << NF_BR_LOCAL_OUT); |
| #endif |
| |
| NF_HOOK_THRESH(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
| br_forward_finish, NF_BR_PRI_FIRST + 1); |
| |
| return 0; |
| } |
| |
| |
| /* 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. |
| * For the sake of interface transparency (i.e. properly |
| * overloading the '-o' option), we steal packets destined to |
| * a bridge device away from the PF_INET/FORWARD and PF_INET/OUTPUT hook |
| * functions, and give them back later, when we have determined the real |
| * output device. This is done in here. |
| * |
| * 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. |
| * Otherwise, if nf_bridge->physindev is NULL, the bridge-nf code never touched |
| * this packet before, and so the packet was locally originated. We fake |
| * the PF_INET/LOCAL_OUT hook. |
| * Finally, if nf_bridge->physindev isn't NULL, then the packet was IP routed, |
| * so we fake the PF_INET/FORWARD hook. ipv4_sabotage_out() makes sure |
| * even routed packets that didn't arrive on a bridge interface have their |
| * nf_bridge->physindev set. |
| */ |
| |
| static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*_okfn)(struct sk_buff *)) |
| { |
| int (*okfn)(struct sk_buff *skb); |
| struct net_device *realindev; |
| struct sk_buff *skb = *pskb; |
| struct nf_bridge_info *nf_bridge; |
| |
| if (skb->protocol != __constant_htons(ETH_P_IP)) |
| return NF_ACCEPT; |
| |
| /* Sometimes we get packets with NULL ->dst here (for example, |
| * running a dhcp client daemon triggers this). |
| */ |
| if (skb->dst == NULL) |
| return NF_ACCEPT; |
| |
| nf_bridge = skb->nf_bridge; |
| nf_bridge->physoutdev = skb->dev; |
| |
| realindev = nf_bridge->physindev; |
| |
| /* Bridged, take PF_BRIDGE/FORWARD. |
| * (see big note in front of br_nf_pre_routing_finish) |
| */ |
| if (nf_bridge->mask & BRNF_BRIDGED_DNAT) { |
| okfn = br_forward_finish; |
| |
| if (nf_bridge->mask & BRNF_PKT_TYPE) { |
| skb->pkt_type = PACKET_OTHERHOST; |
| nf_bridge->mask ^= BRNF_PKT_TYPE; |
| } |
| |
| NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, realindev, |
| skb->dev, okfn); |
| } else { |
| okfn = br_nf_local_out_finish; |
| /* IP forwarded traffic has a physindev, locally |
| * generated traffic hasn't. |
| */ |
| if (realindev != NULL) { |
| if (((nf_bridge->mask & BRNF_DONT_TAKE_PARENT) == 0) && |
| has_bridge_parent(realindev)) |
| realindev = bridge_parent(realindev); |
| |
| NF_HOOK_THRESH(PF_INET, NF_IP_FORWARD, skb, realindev, |
| bridge_parent(skb->dev), okfn, |
| NF_IP_PRI_BRIDGE_SABOTAGE_FORWARD + 1); |
| } else { |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug ^= (1 << NF_IP_LOCAL_OUT); |
| #endif |
| |
| NF_HOOK_THRESH(PF_INET, NF_IP_LOCAL_OUT, skb, realindev, |
| bridge_parent(skb->dev), okfn, |
| NF_IP_PRI_BRIDGE_SABOTAGE_LOCAL_OUT + 1); |
| } |
| } |
| |
| return NF_STOLEN; |
| } |
| |
| |
| /* PF_BRIDGE/POST_ROUTING ********************************************/ |
| static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| struct sk_buff *skb = *pskb; |
| struct nf_bridge_info *nf_bridge = (*pskb)->nf_bridge; |
| |
| /* Be very paranoid. */ |
| if (skb->mac.raw < skb->head || skb->mac.raw + ETH_HLEN > skb->data) { |
| printk(KERN_CRIT "br_netfilter: Argh!! br_nf_post_routing: " |
| "bad mac.raw pointer."); |
| if (skb->dev != NULL) { |
| printk("[%s]", skb->dev->name); |
| if (has_bridge_parent(skb->dev)) |
| printk("[%s]", bridge_parent(skb->dev)->name); |
| } |
| printk("\n"); |
| return NF_ACCEPT; |
| } |
| |
| if (skb->protocol != __constant_htons(ETH_P_IP)) |
| return NF_ACCEPT; |
| |
| /* Sometimes we get packets with NULL ->dst here (for example, |
| * running a dhcp client daemon triggers this). |
| */ |
| if (skb->dst == NULL) |
| return NF_ACCEPT; |
| |
| #ifdef CONFIG_NETFILTER_DEBUG |
| skb->nf_debug ^= (1 << NF_IP_POST_ROUTING); |
| #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) { |
| skb->pkt_type = PACKET_HOST; |
| nf_bridge->mask |= BRNF_PKT_TYPE; |
| } |
| |
| memcpy(nf_bridge->hh, skb->data - 16, 16); |
| nf_bridge->mask |= BRNF_COPY_HEADER; |
| |
| NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, |
| bridge_parent(skb->dev), br_dev_queue_push_xmit); |
| |
| return NF_STOLEN; |
| } |
| |
| |
| /* IPv4/SABOTAGE *****************************************************/ |
| |
| /* Don't hand locally destined packets to PF_INET/PRE_ROUTING |
| * for the second time. |
| */ |
| static unsigned int ipv4_sabotage_in(unsigned int hook, struct sk_buff **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| if (in->hard_start_xmit == br_dev_xmit && |
| okfn != br_nf_pre_routing_finish) { |
| okfn(*pskb); |
| return NF_STOLEN; |
| } |
| |
| return NF_ACCEPT; |
| } |
| |
| /* Postpone execution of PF_INET/FORWARD, PF_INET/LOCAL_OUT |
| * and PF_INET/POST_ROUTING until we have done the forwarding |
| * decision in the bridge code and have determined skb->physoutdev. |
| */ |
| static unsigned int ipv4_sabotage_out(unsigned int hook, struct sk_buff **pskb, |
| const struct net_device *in, const struct net_device *out, |
| int (*okfn)(struct sk_buff *)) |
| { |
| if (out->hard_start_xmit == br_dev_xmit && |
| okfn != br_nf_forward_finish && |
| okfn != br_nf_local_out_finish && |
| okfn != br_dev_queue_push_xmit) { |
| struct sk_buff *skb = *pskb; |
| struct nf_bridge_info *nf_bridge; |
| |
| if (!skb->nf_bridge) |
| nf_bridge_alloc(skb); |
| |
| nf_bridge = skb->nf_bridge; |
| |
| /* This frame will arrive on PF_BRIDGE/LOCAL_OUT and we |
| * will need the indev then. For a brouter, the real indev |
| * can be a bridge port, so we make sure br_nf_local_out() |
| * doesn't use the bridge parent of the indev by using |
| * the BRNF_DONT_TAKE_PARENT mask. |
| */ |
| if (hook == NF_IP_FORWARD && nf_bridge->physindev == NULL) { |
| nf_bridge->mask &= BRNF_DONT_TAKE_PARENT; |
| nf_bridge->physindev = (struct net_device *)in; |
| } |
| okfn(skb); |
| return NF_STOLEN; |
| } |
| |
| 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. |
| */ |
| static struct nf_hook_ops br_nf_ops[] = { |
| { { NULL, NULL }, br_nf_pre_routing, PF_BRIDGE, NF_BR_PRE_ROUTING, NF_BR_PRI_BRNF }, |
| { { NULL, NULL }, br_nf_local_in, PF_BRIDGE, NF_BR_LOCAL_IN, NF_BR_PRI_BRNF }, |
| { { NULL, NULL }, br_nf_forward, PF_BRIDGE, NF_BR_FORWARD, NF_BR_PRI_BRNF }, |
| { { NULL, NULL }, br_nf_local_out, PF_BRIDGE, NF_BR_LOCAL_OUT, NF_BR_PRI_FIRST }, |
| { { NULL, NULL }, br_nf_post_routing, PF_BRIDGE, NF_BR_POST_ROUTING, NF_BR_PRI_LAST }, |
| { { NULL, NULL }, ipv4_sabotage_in, PF_INET, NF_IP_PRE_ROUTING, NF_IP_PRI_FIRST }, |
| { { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_FORWARD, NF_IP_PRI_BRIDGE_SABOTAGE_FORWARD }, |
| { { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_LOCAL_OUT, NF_IP_PRI_BRIDGE_SABOTAGE_LOCAL_OUT }, |
| { { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_POST_ROUTING, NF_IP_PRI_FIRST } |
| }; |
| |
| #define NUMHOOKS (sizeof(br_nf_ops)/sizeof(br_nf_ops[0])) |
| |
| int br_netfilter_init(void) |
| { |
| int i; |
| |
| for (i = 0; i < NUMHOOKS; i++) { |
| int ret; |
| |
| if ((ret = nf_register_hook(&br_nf_ops[i])) >= 0) |
| continue; |
| |
| while (i--) |
| nf_unregister_hook(&br_nf_ops[i]); |
| |
| return ret; |
| } |
| |
| printk(KERN_NOTICE "Bridge firewalling registered\n"); |
| |
| return 0; |
| } |
| |
| void br_netfilter_fini(void) |
| { |
| int i; |
| |
| for (i = NUMHOOKS - 1; i >= 0; i--) |
| nf_unregister_hook(&br_nf_ops[i]); |
| } |