1 #include <linux/kernel.h> 2 #include <linux/init.h> 3 #include <linux/ipv6.h> 4 #include <linux/netfilter.h> 5 #include <linux/netfilter_ipv6.h> 6 #include <net/dst.h> 7 #include <net/ipv6.h> 8 #include <net/ip6_route.h> 9 #include <net/xfrm.h> 10 #include <net/ip6_checksum.h> 11 #include <net/netfilter/nf_queue.h> 12 13 int ip6_route_me_harder(struct sk_buff *skb) 14 { 15 struct ipv6hdr *iph = ipv6_hdr(skb); 16 struct dst_entry *dst; 17 struct flowi fl = { 18 .oif = skb->sk ? skb->sk->sk_bound_dev_if : 0, 19 .mark = skb->mark, 20 .nl_u = 21 { .ip6_u = 22 { .daddr = iph->daddr, 23 .saddr = iph->saddr, } }, 24 }; 25 26 dst = ip6_route_output(skb->sk, &fl); 27 28 #ifdef CONFIG_XFRM 29 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && 30 xfrm_decode_session(skb, &fl, AF_INET6) == 0) 31 if (xfrm_lookup(&skb->dst, &fl, skb->sk, 0)) 32 return -1; 33 #endif 34 35 if (dst->error) { 36 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 37 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); 38 dst_release(dst); 39 return -EINVAL; 40 } 41 42 /* Drop old route. */ 43 dst_release(skb->dst); 44 45 skb->dst = dst; 46 return 0; 47 } 48 EXPORT_SYMBOL(ip6_route_me_harder); 49 50 /* 51 * Extra routing may needed on local out, as the QUEUE target never 52 * returns control to the table. 53 */ 54 55 struct ip6_rt_info { 56 struct in6_addr daddr; 57 struct in6_addr saddr; 58 }; 59 60 static void nf_ip6_saveroute(const struct sk_buff *skb, 61 struct nf_queue_entry *entry) 62 { 63 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 64 65 if (entry->hook == NF_INET_LOCAL_OUT) { 66 struct ipv6hdr *iph = ipv6_hdr(skb); 67 68 rt_info->daddr = iph->daddr; 69 rt_info->saddr = iph->saddr; 70 } 71 } 72 73 static int nf_ip6_reroute(struct sk_buff *skb, 74 const struct nf_queue_entry *entry) 75 { 76 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 77 78 if (entry->hook == NF_INET_LOCAL_OUT) { 79 struct ipv6hdr *iph = ipv6_hdr(skb); 80 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 81 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr)) 82 return ip6_route_me_harder(skb); 83 } 84 return 0; 85 } 86 87 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 88 { 89 *dst = ip6_route_output(NULL, fl); 90 return (*dst)->error; 91 } 92 93 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 94 unsigned int dataoff, u_int8_t protocol) 95 { 96 struct ipv6hdr *ip6h = ipv6_hdr(skb); 97 __sum16 csum = 0; 98 99 switch (skb->ip_summed) { 100 case CHECKSUM_COMPLETE: 101 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 102 break; 103 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 104 skb->len - dataoff, protocol, 105 csum_sub(skb->csum, 106 skb_checksum(skb, 0, 107 dataoff, 0)))) { 108 skb->ip_summed = CHECKSUM_UNNECESSARY; 109 break; 110 } 111 /* fall through */ 112 case CHECKSUM_NONE: 113 skb->csum = ~csum_unfold( 114 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 115 skb->len - dataoff, 116 protocol, 117 csum_sub(0, 118 skb_checksum(skb, 0, 119 dataoff, 0)))); 120 csum = __skb_checksum_complete(skb); 121 } 122 return csum; 123 } 124 125 EXPORT_SYMBOL(nf_ip6_checksum); 126 127 static const struct nf_afinfo nf_ip6_afinfo = { 128 .family = AF_INET6, 129 .checksum = nf_ip6_checksum, 130 .route = nf_ip6_route, 131 .saveroute = nf_ip6_saveroute, 132 .reroute = nf_ip6_reroute, 133 .route_key_size = sizeof(struct ip6_rt_info), 134 }; 135 136 int __init ipv6_netfilter_init(void) 137 { 138 return nf_register_afinfo(&nf_ip6_afinfo); 139 } 140 141 /* This can be called from inet6_init() on errors, so it cannot 142 * be marked __exit. -DaveM 143 */ 144 void ipv6_netfilter_fini(void) 145 { 146 nf_unregister_afinfo(&nf_ip6_afinfo); 147 } 148