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 29 #ifdef CONFIG_XFRM 30 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && 31 xfrm_decode_session(skb, &fl, AF_INET6) == 0) { 32 struct dst_entry *dst2 = skb_dst(skb); 33 34 if (xfrm_lookup(net, &dst2, &fl, skb->sk, 0)) { 35 skb_dst_set(skb, NULL); 36 return -1; 37 } 38 skb_dst_set(skb, dst2); 39 } 40 #endif 41 42 if (dst->error) { 43 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 44 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); 45 dst_release(dst); 46 return -EINVAL; 47 } 48 49 /* Drop old route. */ 50 skb_dst_drop(skb); 51 52 skb_dst_set(skb, dst); 53 return 0; 54 } 55 EXPORT_SYMBOL(ip6_route_me_harder); 56 57 /* 58 * Extra routing may needed on local out, as the QUEUE target never 59 * returns control to the table. 60 */ 61 62 struct ip6_rt_info { 63 struct in6_addr daddr; 64 struct in6_addr saddr; 65 u_int32_t mark; 66 }; 67 68 static void nf_ip6_saveroute(const struct sk_buff *skb, 69 struct nf_queue_entry *entry) 70 { 71 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 72 73 if (entry->hook == NF_INET_LOCAL_OUT) { 74 struct ipv6hdr *iph = ipv6_hdr(skb); 75 76 rt_info->daddr = iph->daddr; 77 rt_info->saddr = iph->saddr; 78 rt_info->mark = skb->mark; 79 } 80 } 81 82 static int nf_ip6_reroute(struct sk_buff *skb, 83 const struct nf_queue_entry *entry) 84 { 85 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 86 87 if (entry->hook == NF_INET_LOCAL_OUT) { 88 struct ipv6hdr *iph = ipv6_hdr(skb); 89 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 90 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || 91 skb->mark != rt_info->mark) 92 return ip6_route_me_harder(skb); 93 } 94 return 0; 95 } 96 97 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 98 { 99 *dst = ip6_route_output(&init_net, NULL, fl); 100 return (*dst)->error; 101 } 102 103 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 104 unsigned int dataoff, u_int8_t protocol) 105 { 106 struct ipv6hdr *ip6h = ipv6_hdr(skb); 107 __sum16 csum = 0; 108 109 switch (skb->ip_summed) { 110 case CHECKSUM_COMPLETE: 111 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 112 break; 113 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 114 skb->len - dataoff, protocol, 115 csum_sub(skb->csum, 116 skb_checksum(skb, 0, 117 dataoff, 0)))) { 118 skb->ip_summed = CHECKSUM_UNNECESSARY; 119 break; 120 } 121 /* fall through */ 122 case CHECKSUM_NONE: 123 skb->csum = ~csum_unfold( 124 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 125 skb->len - dataoff, 126 protocol, 127 csum_sub(0, 128 skb_checksum(skb, 0, 129 dataoff, 0)))); 130 csum = __skb_checksum_complete(skb); 131 } 132 return csum; 133 } 134 EXPORT_SYMBOL(nf_ip6_checksum); 135 136 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 137 unsigned int dataoff, unsigned int len, 138 u_int8_t protocol) 139 { 140 struct ipv6hdr *ip6h = ipv6_hdr(skb); 141 __wsum hsum; 142 __sum16 csum = 0; 143 144 switch (skb->ip_summed) { 145 case CHECKSUM_COMPLETE: 146 if (len == skb->len - dataoff) 147 return nf_ip6_checksum(skb, hook, dataoff, protocol); 148 /* fall through */ 149 case CHECKSUM_NONE: 150 hsum = skb_checksum(skb, 0, dataoff, 0); 151 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 152 &ip6h->daddr, 153 skb->len - dataoff, 154 protocol, 155 csum_sub(0, hsum))); 156 skb->ip_summed = CHECKSUM_NONE; 157 csum = __skb_checksum_complete_head(skb, dataoff + len); 158 if (!csum) 159 skb->ip_summed = CHECKSUM_UNNECESSARY; 160 } 161 return csum; 162 }; 163 164 static const struct nf_afinfo nf_ip6_afinfo = { 165 .family = AF_INET6, 166 .checksum = nf_ip6_checksum, 167 .checksum_partial = nf_ip6_checksum_partial, 168 .route = nf_ip6_route, 169 .saveroute = nf_ip6_saveroute, 170 .reroute = nf_ip6_reroute, 171 .route_key_size = sizeof(struct ip6_rt_info), 172 }; 173 174 int __init ipv6_netfilter_init(void) 175 { 176 return nf_register_afinfo(&nf_ip6_afinfo); 177 } 178 179 /* This can be called from inet6_init() on errors, so it cannot 180 * be marked __exit. -DaveM 181 */ 182 void ipv6_netfilter_fini(void) 183 { 184 nf_unregister_afinfo(&nf_ip6_afinfo); 185 } 186