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(net, &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 u_int32_t mark; 60 }; 61 62 static void nf_ip6_saveroute(const struct sk_buff *skb, 63 struct nf_queue_entry *entry) 64 { 65 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 66 67 if (entry->hook == NF_INET_LOCAL_OUT) { 68 struct ipv6hdr *iph = ipv6_hdr(skb); 69 70 rt_info->daddr = iph->daddr; 71 rt_info->saddr = iph->saddr; 72 rt_info->mark = skb->mark; 73 } 74 } 75 76 static int nf_ip6_reroute(struct sk_buff *skb, 77 const struct nf_queue_entry *entry) 78 { 79 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 80 81 if (entry->hook == NF_INET_LOCAL_OUT) { 82 struct ipv6hdr *iph = ipv6_hdr(skb); 83 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 84 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || 85 skb->mark != rt_info->mark) 86 return ip6_route_me_harder(skb); 87 } 88 return 0; 89 } 90 91 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 92 { 93 *dst = ip6_route_output(&init_net, NULL, fl); 94 return (*dst)->error; 95 } 96 97 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 98 unsigned int dataoff, u_int8_t protocol) 99 { 100 struct ipv6hdr *ip6h = ipv6_hdr(skb); 101 __sum16 csum = 0; 102 103 switch (skb->ip_summed) { 104 case CHECKSUM_COMPLETE: 105 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 106 break; 107 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 108 skb->len - dataoff, protocol, 109 csum_sub(skb->csum, 110 skb_checksum(skb, 0, 111 dataoff, 0)))) { 112 skb->ip_summed = CHECKSUM_UNNECESSARY; 113 break; 114 } 115 /* fall through */ 116 case CHECKSUM_NONE: 117 skb->csum = ~csum_unfold( 118 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 119 skb->len - dataoff, 120 protocol, 121 csum_sub(0, 122 skb_checksum(skb, 0, 123 dataoff, 0)))); 124 csum = __skb_checksum_complete(skb); 125 } 126 return csum; 127 } 128 EXPORT_SYMBOL(nf_ip6_checksum); 129 130 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 131 unsigned int dataoff, unsigned int len, 132 u_int8_t protocol) 133 { 134 struct ipv6hdr *ip6h = ipv6_hdr(skb); 135 __wsum hsum; 136 __sum16 csum = 0; 137 138 switch (skb->ip_summed) { 139 case CHECKSUM_COMPLETE: 140 if (len == skb->len - dataoff) 141 return nf_ip6_checksum(skb, hook, dataoff, protocol); 142 /* fall through */ 143 case CHECKSUM_NONE: 144 hsum = skb_checksum(skb, 0, dataoff, 0); 145 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 146 &ip6h->daddr, 147 skb->len - dataoff, 148 protocol, 149 csum_sub(0, hsum))); 150 skb->ip_summed = CHECKSUM_NONE; 151 csum = __skb_checksum_complete_head(skb, dataoff + len); 152 if (!csum) 153 skb->ip_summed = CHECKSUM_UNNECESSARY; 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