| /* |
| * IPv6 specific functions of netfilter core |
| * |
| * Rusty Russell (C) 2000 -- This code is GPL. |
| * Patrick McHardy (C) 2006-2012 |
| */ |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/ipv6.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_ipv6.h> |
| #include <linux/export.h> |
| #include <net/addrconf.h> |
| #include <net/dst.h> |
| #include <net/ipv6.h> |
| #include <net/ip6_route.h> |
| #include <net/xfrm.h> |
| #include <net/netfilter/nf_queue.h> |
| #include <net/netfilter/nf_conntrack_bridge.h> |
| #include <net/netfilter/ipv6/nf_defrag_ipv6.h> |
| #include "../bridge/br_private.h" |
| |
| int ip6_route_me_harder(struct net *net, struct sk_buff *skb) |
| { |
| const struct ipv6hdr *iph = ipv6_hdr(skb); |
| struct sock *sk = sk_to_full_sk(skb->sk); |
| unsigned int hh_len; |
| struct dst_entry *dst; |
| int strict = (ipv6_addr_type(&iph->daddr) & |
| (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); |
| struct flowi6 fl6 = { |
| .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if : |
| strict ? skb_dst(skb)->dev->ifindex : 0, |
| .flowi6_mark = skb->mark, |
| .flowi6_uid = sock_net_uid(net, sk), |
| .daddr = iph->daddr, |
| .saddr = iph->saddr, |
| }; |
| int err; |
| |
| dst = ip6_route_output(net, sk, &fl6); |
| err = dst->error; |
| if (err) { |
| IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); |
| net_dbg_ratelimited("ip6_route_me_harder: No more route\n"); |
| dst_release(dst); |
| return err; |
| } |
| |
| /* Drop old route. */ |
| skb_dst_drop(skb); |
| |
| skb_dst_set(skb, dst); |
| |
| #ifdef CONFIG_XFRM |
| if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && |
| xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) { |
| skb_dst_set(skb, NULL); |
| dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
| if (IS_ERR(dst)) |
| return PTR_ERR(dst); |
| skb_dst_set(skb, dst); |
| } |
| #endif |
| |
| /* Change in oif may mean change in hh_len. */ |
| hh_len = skb_dst(skb)->dev->hard_header_len; |
| if (skb_headroom(skb) < hh_len && |
| pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)), |
| 0, GFP_ATOMIC)) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(ip6_route_me_harder); |
| |
| static int nf_ip6_reroute(struct sk_buff *skb, |
| const struct nf_queue_entry *entry) |
| { |
| struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); |
| |
| if (entry->state.hook == NF_INET_LOCAL_OUT) { |
| const struct ipv6hdr *iph = ipv6_hdr(skb); |
| if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || |
| !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || |
| skb->mark != rt_info->mark) |
| return ip6_route_me_harder(entry->state.net, skb); |
| } |
| return 0; |
| } |
| |
| int __nf_ip6_route(struct net *net, struct dst_entry **dst, |
| struct flowi *fl, bool strict) |
| { |
| static const struct ipv6_pinfo fake_pinfo; |
| static const struct inet_sock fake_sk = { |
| /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */ |
| .sk.sk_bound_dev_if = 1, |
| .pinet6 = (struct ipv6_pinfo *) &fake_pinfo, |
| }; |
| const void *sk = strict ? &fake_sk : NULL; |
| struct dst_entry *result; |
| int err; |
| |
| result = ip6_route_output(net, sk, &fl->u.ip6); |
| err = result->error; |
| if (err) |
| dst_release(result); |
| else |
| *dst = result; |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(__nf_ip6_route); |
| |
| int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
| struct nf_bridge_frag_data *data, |
| int (*output)(struct net *, struct sock *sk, |
| const struct nf_bridge_frag_data *data, |
| struct sk_buff *)) |
| { |
| int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; |
| struct ip6_frag_state state; |
| u8 *prevhdr, nexthdr = 0; |
| unsigned int mtu, hlen; |
| int hroom, err = 0; |
| __be32 frag_id; |
| |
| err = ip6_find_1stfragopt(skb, &prevhdr); |
| if (err < 0) |
| goto blackhole; |
| hlen = err; |
| nexthdr = *prevhdr; |
| |
| mtu = skb->dev->mtu; |
| if (frag_max_size > mtu || |
| frag_max_size < IPV6_MIN_MTU) |
| goto blackhole; |
| |
| mtu = frag_max_size; |
| if (mtu < hlen + sizeof(struct frag_hdr) + 8) |
| goto blackhole; |
| mtu -= hlen + sizeof(struct frag_hdr); |
| |
| frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, |
| &ipv6_hdr(skb)->saddr); |
| |
| if (skb->ip_summed == CHECKSUM_PARTIAL && |
| (err = skb_checksum_help(skb))) |
| goto blackhole; |
| |
| hroom = LL_RESERVED_SPACE(skb->dev); |
| if (skb_has_frag_list(skb)) { |
| unsigned int first_len = skb_pagelen(skb); |
| struct ip6_fraglist_iter iter; |
| struct sk_buff *frag2; |
| |
| if (first_len - hlen > mtu || |
| skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) |
| goto blackhole; |
| |
| if (skb_cloned(skb)) |
| goto slow_path; |
| |
| skb_walk_frags(skb, frag2) { |
| if (frag2->len > mtu || |
| skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr))) |
| goto blackhole; |
| |
| /* Partially cloned skb? */ |
| if (skb_shared(frag2)) |
| goto slow_path; |
| } |
| |
| err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, |
| &iter); |
| if (err < 0) |
| goto blackhole; |
| |
| for (;;) { |
| /* Prepare header of the next frame, |
| * before previous one went down. |
| */ |
| if (iter.frag) |
| ip6_fraglist_prepare(skb, &iter); |
| |
| err = output(net, sk, data, skb); |
| if (err || !iter.frag) |
| break; |
| |
| skb = ip6_fraglist_next(&iter); |
| } |
| |
| kfree(iter.tmp_hdr); |
| if (!err) |
| return 0; |
| |
| kfree_skb_list(iter.frag); |
| return err; |
| } |
| slow_path: |
| /* This is a linearized skbuff, the original geometry is lost for us. |
| * This may also be a clone skbuff, we could preserve the geometry for |
| * the copies but probably not worth the effort. |
| */ |
| ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom, |
| LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id, |
| &state); |
| |
| while (state.left > 0) { |
| struct sk_buff *skb2; |
| |
| skb2 = ip6_frag_next(skb, &state); |
| if (IS_ERR(skb2)) { |
| err = PTR_ERR(skb2); |
| goto blackhole; |
| } |
| |
| err = output(net, sk, data, skb2); |
| if (err) |
| goto blackhole; |
| } |
| consume_skb(skb); |
| return err; |
| |
| blackhole: |
| kfree_skb(skb); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(br_ip6_fragment); |
| |
| static const struct nf_ipv6_ops ipv6ops = { |
| #if IS_MODULE(CONFIG_IPV6) |
| .chk_addr = ipv6_chk_addr, |
| .route_me_harder = ip6_route_me_harder, |
| .dev_get_saddr = ipv6_dev_get_saddr, |
| .route = __nf_ip6_route, |
| #if IS_ENABLED(CONFIG_SYN_COOKIES) |
| .cookie_init_sequence = __cookie_v6_init_sequence, |
| .cookie_v6_check = __cookie_v6_check, |
| #endif |
| #endif |
| .route_input = ip6_route_input, |
| .fragment = ip6_fragment, |
| .reroute = nf_ip6_reroute, |
| #if IS_MODULE(CONFIG_IPV6) && IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) |
| .br_defrag = nf_ct_frag6_gather, |
| #endif |
| #if IS_MODULE(CONFIG_IPV6) |
| .br_fragment = br_ip6_fragment, |
| #endif |
| }; |
| |
| int __init ipv6_netfilter_init(void) |
| { |
| RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops); |
| return 0; |
| } |
| |
| /* This can be called from inet6_init() on errors, so it cannot |
| * be marked __exit. -DaveM |
| */ |
| void ipv6_netfilter_fini(void) |
| { |
| RCU_INIT_POINTER(nf_ipv6_ops, NULL); |
| } |