| /* |
| * 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/ip6_checksum.h> |
| #include <net/netfilter/nf_queue.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; |
| struct flowi6 fl6 = { |
| .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if : |
| rt6_need_strict(&iph->daddr) ? 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); |
| |
| /* |
| * Extra routing may needed on local out, as the QUEUE target never |
| * returns control to the table. |
| */ |
| |
| struct ip6_rt_info { |
| struct in6_addr daddr; |
| struct in6_addr saddr; |
| u_int32_t mark; |
| }; |
| |
| static void nf_ip6_saveroute(const struct sk_buff *skb, |
| 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); |
| |
| rt_info->daddr = iph->daddr; |
| rt_info->saddr = iph->saddr; |
| rt_info->mark = skb->mark; |
| } |
| } |
| |
| static int nf_ip6_reroute(struct net *net, 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(net, skb); |
| } |
| return 0; |
| } |
| |
| static 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; |
| } |
| |
| __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, |
| unsigned int dataoff, u_int8_t protocol) |
| { |
| const struct ipv6hdr *ip6h = ipv6_hdr(skb); |
| __sum16 csum = 0; |
| |
| switch (skb->ip_summed) { |
| case CHECKSUM_COMPLETE: |
| if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) |
| break; |
| if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, |
| skb->len - dataoff, protocol, |
| csum_sub(skb->csum, |
| skb_checksum(skb, 0, |
| dataoff, 0)))) { |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| break; |
| } |
| /* fall through */ |
| case CHECKSUM_NONE: |
| skb->csum = ~csum_unfold( |
| csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, |
| skb->len - dataoff, |
| protocol, |
| csum_sub(0, |
| skb_checksum(skb, 0, |
| dataoff, 0)))); |
| csum = __skb_checksum_complete(skb); |
| } |
| return csum; |
| } |
| EXPORT_SYMBOL(nf_ip6_checksum); |
| |
| static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, |
| unsigned int dataoff, unsigned int len, |
| u_int8_t protocol) |
| { |
| const struct ipv6hdr *ip6h = ipv6_hdr(skb); |
| __wsum hsum; |
| __sum16 csum = 0; |
| |
| switch (skb->ip_summed) { |
| case CHECKSUM_COMPLETE: |
| if (len == skb->len - dataoff) |
| return nf_ip6_checksum(skb, hook, dataoff, protocol); |
| /* fall through */ |
| case CHECKSUM_NONE: |
| hsum = skb_checksum(skb, 0, dataoff, 0); |
| skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, |
| &ip6h->daddr, |
| skb->len - dataoff, |
| protocol, |
| csum_sub(0, hsum))); |
| skb->ip_summed = CHECKSUM_NONE; |
| return __skb_checksum_complete_head(skb, dataoff + len); |
| } |
| return csum; |
| }; |
| |
| static const struct nf_ipv6_ops ipv6ops = { |
| .chk_addr = ipv6_chk_addr, |
| .route_input = ip6_route_input, |
| .fragment = ip6_fragment |
| }; |
| |
| static const struct nf_afinfo nf_ip6_afinfo = { |
| .family = AF_INET6, |
| .checksum = nf_ip6_checksum, |
| .checksum_partial = nf_ip6_checksum_partial, |
| .route = nf_ip6_route, |
| .saveroute = nf_ip6_saveroute, |
| .reroute = nf_ip6_reroute, |
| .route_key_size = sizeof(struct ip6_rt_info), |
| }; |
| |
| int __init ipv6_netfilter_init(void) |
| { |
| RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops); |
| return nf_register_afinfo(&nf_ip6_afinfo); |
| } |
| |
| /* 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); |
| nf_unregister_afinfo(&nf_ip6_afinfo); |
| } |