#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/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 sk_buff *skb) { struct net *net = dev_net(skb_dst(skb)->dev); const struct ipv6hdr *iph = ipv6_hdr(skb); struct dst_entry *dst; struct flowi6 fl6 = { .flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0, .flowi6_mark = skb->mark, .daddr = iph->daddr, .saddr = iph->saddr, }; dst = ip6_route_output(net, skb->sk, &fl6); if (dst->error) { IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); dst_release(dst); return -EINVAL; } /* 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), skb->sk, 0); if (IS_ERR(dst)) return -1; skb_dst_set(skb, dst); } #endif 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->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 sk_buff *skb, const struct nf_queue_entry *entry) { struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); if (entry->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(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_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) { 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) { nf_unregister_afinfo(&nf_ip6_afinfo); }