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 net *net = dev_net(skb_dst(skb)->dev); 16 struct ipv6hdr *iph = ipv6_hdr(skb); 17 struct dst_entry *dst; 18 struct flowi fl = { 19 .oif = skb->sk ? skb->sk->sk_bound_dev_if : 0, 20 .mark = skb->mark, 21 .fl6_dst = iph->daddr, 22 .fl6_src = iph->saddr, 23 }; 24 25 dst = ip6_route_output(net, skb->sk, &fl); 26 if (dst->error) { 27 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 28 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); 29 dst_release(dst); 30 return -EINVAL; 31 } 32 33 /* Drop old route. */ 34 skb_dst_drop(skb); 35 36 skb_dst_set(skb, dst); 37 38 #ifdef CONFIG_XFRM 39 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && 40 xfrm_decode_session(skb, &fl, AF_INET6) == 0) { 41 skb_dst_set(skb, NULL); 42 if (xfrm_lookup(net, &dst, &fl, skb->sk, 0)) 43 return -1; 44 skb_dst_set(skb, dst); 45 } 46 #endif 47 48 return 0; 49 } 50 EXPORT_SYMBOL(ip6_route_me_harder); 51 52 /* 53 * Extra routing may needed on local out, as the QUEUE target never 54 * returns control to the table. 55 */ 56 57 struct ip6_rt_info { 58 struct in6_addr daddr; 59 struct in6_addr saddr; 60 u_int32_t mark; 61 }; 62 63 static void nf_ip6_saveroute(const struct sk_buff *skb, 64 struct nf_queue_entry *entry) 65 { 66 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 67 68 if (entry->hook == NF_INET_LOCAL_OUT) { 69 struct ipv6hdr *iph = ipv6_hdr(skb); 70 71 rt_info->daddr = iph->daddr; 72 rt_info->saddr = iph->saddr; 73 rt_info->mark = skb->mark; 74 } 75 } 76 77 static int nf_ip6_reroute(struct sk_buff *skb, 78 const struct nf_queue_entry *entry) 79 { 80 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 81 82 if (entry->hook == NF_INET_LOCAL_OUT) { 83 struct ipv6hdr *iph = ipv6_hdr(skb); 84 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 85 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || 86 skb->mark != rt_info->mark) 87 return ip6_route_me_harder(skb); 88 } 89 return 0; 90 } 91 92 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 93 { 94 *dst = ip6_route_output(&init_net, NULL, fl); 95 return (*dst)->error; 96 } 97 98 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 99 unsigned int dataoff, u_int8_t protocol) 100 { 101 struct ipv6hdr *ip6h = ipv6_hdr(skb); 102 __sum16 csum = 0; 103 104 switch (skb->ip_summed) { 105 case CHECKSUM_COMPLETE: 106 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 107 break; 108 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 109 skb->len - dataoff, protocol, 110 csum_sub(skb->csum, 111 skb_checksum(skb, 0, 112 dataoff, 0)))) { 113 skb->ip_summed = CHECKSUM_UNNECESSARY; 114 break; 115 } 116 /* fall through */ 117 case CHECKSUM_NONE: 118 skb->csum = ~csum_unfold( 119 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 120 skb->len - dataoff, 121 protocol, 122 csum_sub(0, 123 skb_checksum(skb, 0, 124 dataoff, 0)))); 125 csum = __skb_checksum_complete(skb); 126 } 127 return csum; 128 } 129 EXPORT_SYMBOL(nf_ip6_checksum); 130 131 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 132 unsigned int dataoff, unsigned int len, 133 u_int8_t protocol) 134 { 135 struct ipv6hdr *ip6h = ipv6_hdr(skb); 136 __wsum hsum; 137 __sum16 csum = 0; 138 139 switch (skb->ip_summed) { 140 case CHECKSUM_COMPLETE: 141 if (len == skb->len - dataoff) 142 return nf_ip6_checksum(skb, hook, dataoff, protocol); 143 /* fall through */ 144 case CHECKSUM_NONE: 145 hsum = skb_checksum(skb, 0, dataoff, 0); 146 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 147 &ip6h->daddr, 148 skb->len - dataoff, 149 protocol, 150 csum_sub(0, hsum))); 151 skb->ip_summed = CHECKSUM_NONE; 152 return __skb_checksum_complete_head(skb, dataoff + len); 153 } 154 return csum; 155 }; 156 157 static const struct nf_afinfo nf_ip6_afinfo = { 158 .family = AF_INET6, 159 .checksum = nf_ip6_checksum, 160 .checksum_partial = nf_ip6_checksum_partial, 161 .route = nf_ip6_route, 162 .saveroute = nf_ip6_saveroute, 163 .reroute = nf_ip6_reroute, 164 .route_key_size = sizeof(struct ip6_rt_info), 165 }; 166 167 int __init ipv6_netfilter_init(void) 168 { 169 return nf_register_afinfo(&nf_ip6_afinfo); 170 } 171 172 /* This can be called from inet6_init() on errors, so it cannot 173 * be marked __exit. -DaveM 174 */ 175 void ipv6_netfilter_fini(void) 176 { 177 nf_unregister_afinfo(&nf_ip6_afinfo); 178 } 179