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 flowi6 fl6 = { 19 .flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0, 20 .flowi6_mark = skb->mark, 21 .daddr = iph->daddr, 22 .saddr = iph->saddr, 23 }; 24 25 dst = ip6_route_output(net, skb->sk, &fl6); 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, flowi6_to_flowi(&fl6), AF_INET6) == 0) { 41 skb_dst_set(skb, NULL); 42 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0); 43 if (IS_ERR(dst)) 44 return -1; 45 skb_dst_set(skb, dst); 46 } 47 #endif 48 49 return 0; 50 } 51 EXPORT_SYMBOL(ip6_route_me_harder); 52 53 /* 54 * Extra routing may needed on local out, as the QUEUE target never 55 * returns control to the table. 56 */ 57 58 struct ip6_rt_info { 59 struct in6_addr daddr; 60 struct in6_addr saddr; 61 u_int32_t mark; 62 }; 63 64 static void nf_ip6_saveroute(const struct sk_buff *skb, 65 struct nf_queue_entry *entry) 66 { 67 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 68 69 if (entry->hook == NF_INET_LOCAL_OUT) { 70 struct ipv6hdr *iph = ipv6_hdr(skb); 71 72 rt_info->daddr = iph->daddr; 73 rt_info->saddr = iph->saddr; 74 rt_info->mark = skb->mark; 75 } 76 } 77 78 static int nf_ip6_reroute(struct sk_buff *skb, 79 const struct nf_queue_entry *entry) 80 { 81 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 82 83 if (entry->hook == NF_INET_LOCAL_OUT) { 84 struct ipv6hdr *iph = ipv6_hdr(skb); 85 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 86 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || 87 skb->mark != rt_info->mark) 88 return ip6_route_me_harder(skb); 89 } 90 return 0; 91 } 92 93 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 94 { 95 *dst = ip6_route_output(&init_net, NULL, &fl->u.ip6); 96 return (*dst)->error; 97 } 98 99 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 100 unsigned int dataoff, u_int8_t protocol) 101 { 102 struct ipv6hdr *ip6h = ipv6_hdr(skb); 103 __sum16 csum = 0; 104 105 switch (skb->ip_summed) { 106 case CHECKSUM_COMPLETE: 107 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 108 break; 109 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 110 skb->len - dataoff, protocol, 111 csum_sub(skb->csum, 112 skb_checksum(skb, 0, 113 dataoff, 0)))) { 114 skb->ip_summed = CHECKSUM_UNNECESSARY; 115 break; 116 } 117 /* fall through */ 118 case CHECKSUM_NONE: 119 skb->csum = ~csum_unfold( 120 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 121 skb->len - dataoff, 122 protocol, 123 csum_sub(0, 124 skb_checksum(skb, 0, 125 dataoff, 0)))); 126 csum = __skb_checksum_complete(skb); 127 } 128 return csum; 129 } 130 EXPORT_SYMBOL(nf_ip6_checksum); 131 132 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 133 unsigned int dataoff, unsigned int len, 134 u_int8_t protocol) 135 { 136 struct ipv6hdr *ip6h = ipv6_hdr(skb); 137 __wsum hsum; 138 __sum16 csum = 0; 139 140 switch (skb->ip_summed) { 141 case CHECKSUM_COMPLETE: 142 if (len == skb->len - dataoff) 143 return nf_ip6_checksum(skb, hook, dataoff, protocol); 144 /* fall through */ 145 case CHECKSUM_NONE: 146 hsum = skb_checksum(skb, 0, dataoff, 0); 147 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 148 &ip6h->daddr, 149 skb->len - dataoff, 150 protocol, 151 csum_sub(0, hsum))); 152 skb->ip_summed = CHECKSUM_NONE; 153 return __skb_checksum_complete_head(skb, dataoff + len); 154 } 155 return csum; 156 }; 157 158 static const struct nf_afinfo nf_ip6_afinfo = { 159 .family = AF_INET6, 160 .checksum = nf_ip6_checksum, 161 .checksum_partial = nf_ip6_checksum_partial, 162 .route = nf_ip6_route, 163 .saveroute = nf_ip6_saveroute, 164 .reroute = nf_ip6_reroute, 165 .route_key_size = sizeof(struct ip6_rt_info), 166 }; 167 168 int __init ipv6_netfilter_init(void) 169 { 170 return nf_register_afinfo(&nf_ip6_afinfo); 171 } 172 173 /* This can be called from inet6_init() on errors, so it cannot 174 * be marked __exit. -DaveM 175 */ 176 void ipv6_netfilter_fini(void) 177 { 178 nf_unregister_afinfo(&nf_ip6_afinfo); 179 } 180