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