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 ipv6hdr *iph = ipv6_hdr(skb); 16 struct dst_entry *dst; 17 struct flowi fl = { 18 .oif = skb->sk ? skb->sk->sk_bound_dev_if : 0, 19 .mark = skb->mark, 20 .nl_u = 21 { .ip6_u = 22 { .daddr = iph->daddr, 23 .saddr = iph->saddr, } }, 24 }; 25 26 dst = ip6_route_output(&init_net, skb->sk, &fl); 27 28 #ifdef CONFIG_XFRM 29 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && 30 xfrm_decode_session(skb, &fl, AF_INET6) == 0) 31 if (xfrm_lookup(&skb->dst, &fl, skb->sk, 0)) 32 return -1; 33 #endif 34 35 if (dst->error) { 36 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 37 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); 38 dst_release(dst); 39 return -EINVAL; 40 } 41 42 /* Drop old route. */ 43 dst_release(skb->dst); 44 45 skb->dst = dst; 46 return 0; 47 } 48 EXPORT_SYMBOL(ip6_route_me_harder); 49 50 /* 51 * Extra routing may needed on local out, as the QUEUE target never 52 * returns control to the table. 53 */ 54 55 struct ip6_rt_info { 56 struct in6_addr daddr; 57 struct in6_addr saddr; 58 }; 59 60 static void nf_ip6_saveroute(const struct sk_buff *skb, 61 struct nf_queue_entry *entry) 62 { 63 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 64 65 if (entry->hook == NF_INET_LOCAL_OUT) { 66 struct ipv6hdr *iph = ipv6_hdr(skb); 67 68 rt_info->daddr = iph->daddr; 69 rt_info->saddr = iph->saddr; 70 } 71 } 72 73 static int nf_ip6_reroute(struct sk_buff *skb, 74 const struct nf_queue_entry *entry) 75 { 76 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); 77 78 if (entry->hook == NF_INET_LOCAL_OUT) { 79 struct ipv6hdr *iph = ipv6_hdr(skb); 80 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || 81 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr)) 82 return ip6_route_me_harder(skb); 83 } 84 return 0; 85 } 86 87 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) 88 { 89 *dst = ip6_route_output(&init_net, NULL, fl); 90 return (*dst)->error; 91 } 92 93 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, 94 unsigned int dataoff, u_int8_t protocol) 95 { 96 struct ipv6hdr *ip6h = ipv6_hdr(skb); 97 __sum16 csum = 0; 98 99 switch (skb->ip_summed) { 100 case CHECKSUM_COMPLETE: 101 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) 102 break; 103 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 104 skb->len - dataoff, protocol, 105 csum_sub(skb->csum, 106 skb_checksum(skb, 0, 107 dataoff, 0)))) { 108 skb->ip_summed = CHECKSUM_UNNECESSARY; 109 break; 110 } 111 /* fall through */ 112 case CHECKSUM_NONE: 113 skb->csum = ~csum_unfold( 114 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, 115 skb->len - dataoff, 116 protocol, 117 csum_sub(0, 118 skb_checksum(skb, 0, 119 dataoff, 0)))); 120 csum = __skb_checksum_complete(skb); 121 } 122 return csum; 123 } 124 EXPORT_SYMBOL(nf_ip6_checksum); 125 126 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, 127 unsigned int dataoff, unsigned int len, 128 u_int8_t protocol) 129 { 130 struct ipv6hdr *ip6h = ipv6_hdr(skb); 131 __wsum hsum; 132 __sum16 csum = 0; 133 134 switch (skb->ip_summed) { 135 case CHECKSUM_COMPLETE: 136 if (len == skb->len - dataoff) 137 return nf_ip6_checksum(skb, hook, dataoff, protocol); 138 /* fall through */ 139 case CHECKSUM_NONE: 140 hsum = skb_checksum(skb, 0, dataoff, 0); 141 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, 142 &ip6h->daddr, 143 skb->len - dataoff, 144 protocol, 145 csum_sub(0, hsum))); 146 skb->ip_summed = CHECKSUM_NONE; 147 csum = __skb_checksum_complete_head(skb, dataoff + len); 148 if (!csum) 149 skb->ip_summed = CHECKSUM_UNNECESSARY; 150 } 151 return csum; 152 }; 153 154 static const struct nf_afinfo nf_ip6_afinfo = { 155 .family = AF_INET6, 156 .checksum = nf_ip6_checksum, 157 .checksum_partial = nf_ip6_checksum_partial, 158 .route = nf_ip6_route, 159 .saveroute = nf_ip6_saveroute, 160 .reroute = nf_ip6_reroute, 161 .route_key_size = sizeof(struct ip6_rt_info), 162 }; 163 164 int __init ipv6_netfilter_init(void) 165 { 166 return nf_register_afinfo(&nf_ip6_afinfo); 167 } 168 169 /* This can be called from inet6_init() on errors, so it cannot 170 * be marked __exit. -DaveM 171 */ 172 void ipv6_netfilter_fini(void) 173 { 174 nf_unregister_afinfo(&nf_ip6_afinfo); 175 } 176