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 .nl_u = 22 { .ip6_u = 23 { .daddr = iph->daddr, 24 .saddr = iph->saddr, } }, 25 }; 26 27 dst = ip6_route_output(net, skb->sk, &fl); 28 if (dst->error) { 29 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 30 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); 31 dst_release(dst); 32 return -EINVAL; 33 } 34 35 /* Drop old route. */ 36 skb_dst_drop(skb); 37 38 skb_dst_set(skb, dst); 39 40 #ifdef CONFIG_XFRM 41 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && 42 xfrm_decode_session(skb, &fl, AF_INET6) == 0) { 43 skb_dst_set(skb, NULL); 44 if (xfrm_lookup(net, &dst, &fl, skb->sk, 0)) 45 return -1; 46 skb_dst_set(skb, dst); 47 } 48 #endif 49 50 return 0; 51 } 52 EXPORT_SYMBOL(ip6_route_me_harder); 53 54 /* 55 * Extra routing may needed on local out, as the QUEUE target never 56 * returns control to the table. 57 */ 58 59 struct ip6_rt_info { 60 struct in6_addr daddr; 61 struct in6_addr saddr; 62 u_int32_t mark; 63 }; 64 65 static void nf_ip6_saveroute(const struct sk_buff *skb, 66 struct nf_queue_entry *entry) 67 { 68 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 69 70 if (entry->hook == NF_INET_LOCAL_OUT) { 71 struct ipv6hdr *iph = ipv6_hdr(skb); 72 73 rt_info->daddr = iph->daddr; 74 rt_info->saddr = iph->saddr; 75 rt_info->mark = skb->mark; 76 } 77 } 78 79 static int nf_ip6_reroute(struct sk_buff *skb, 80 const struct nf_queue_entry *entry) 81 { 82 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 83 84 if (entry->hook == NF_INET_LOCAL_OUT) { 85 struct ipv6hdr *iph = ipv6_hdr(skb); 86 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 87 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || 88 skb->mark != rt_info->mark) 89 return ip6_route_me_harder(skb); 90 } 91 return 0; 92 } 93 94 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 95 { 96 *dst = ip6_route_output(&init_net, NULL, fl); 97 return (*dst)->error; 98 } 99 100 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 101 unsigned int dataoff, u_int8_t protocol) 102 { 103 struct ipv6hdr *ip6h = ipv6_hdr(skb); 104 __sum16 csum = 0; 105 106 switch (skb->ip_summed) { 107 case CHECKSUM_COMPLETE: 108 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 109 break; 110 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 111 skb->len - dataoff, protocol, 112 csum_sub(skb->csum, 113 skb_checksum(skb, 0, 114 dataoff, 0)))) { 115 skb->ip_summed = CHECKSUM_UNNECESSARY; 116 break; 117 } 118 /* fall through */ 119 case CHECKSUM_NONE: 120 skb->csum = ~csum_unfold( 121 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 122 skb->len - dataoff, 123 protocol, 124 csum_sub(0, 125 skb_checksum(skb, 0, 126 dataoff, 0)))); 127 csum = __skb_checksum_complete(skb); 128 } 129 return csum; 130 } 131 EXPORT_SYMBOL(nf_ip6_checksum); 132 133 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 134 unsigned int dataoff, unsigned int len, 135 u_int8_t protocol) 136 { 137 struct ipv6hdr *ip6h = ipv6_hdr(skb); 138 __wsum hsum; 139 __sum16 csum = 0; 140 141 switch (skb->ip_summed) { 142 case CHECKSUM_COMPLETE: 143 if (len == skb->len - dataoff) 144 return nf_ip6_checksum(skb, hook, dataoff, protocol); 145 /* fall through */ 146 case CHECKSUM_NONE: 147 hsum = skb_checksum(skb, 0, dataoff, 0); 148 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 149 &ip6h->daddr, 150 skb->len - dataoff, 151 protocol, 152 csum_sub(0, hsum))); 153 skb->ip_summed = CHECKSUM_NONE; 154 return __skb_checksum_complete_head(skb, dataoff + len); 155 } 156 return csum; 157 }; 158 159 static const struct nf_afinfo nf_ip6_afinfo = { 160 .family = AF_INET6, 161 .checksum = nf_ip6_checksum, 162 .checksum_partial = nf_ip6_checksum_partial, 163 .route = nf_ip6_route, 164 .saveroute = nf_ip6_saveroute, 165 .reroute = nf_ip6_reroute, 166 .route_key_size = sizeof(struct ip6_rt_info), 167 }; 168 169 int __init ipv6_netfilter_init(void) 170 { 171 return nf_register_afinfo(&nf_ip6_afinfo); 172 } 173 174 /* This can be called from inet6_init() on errors, so it cannot 175 * be marked __exit. -DaveM 176 */ 177 void ipv6_netfilter_fini(void) 178 { 179 nf_unregister_afinfo(&nf_ip6_afinfo); 180 } 181