1 #include <linux/errno.h> 2 #include <linux/ip.h> 3 #include <linux/kernel.h> 4 #include <linux/module.h> 5 #include <linux/skbuff.h> 6 #include <linux/socket.h> 7 #include <linux/types.h> 8 #include <net/checksum.h> 9 #include <net/ip.h> 10 #include <net/ip6_fib.h> 11 #include <net/lwtunnel.h> 12 #include <net/protocol.h> 13 #include <uapi/linux/ila.h> 14 #include "ila.h" 15 16 static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p) 17 { 18 if (*(__be64 *)&ip6h->daddr == p->locator_match) 19 return p->csum_diff; 20 else 21 return compute_csum_diff8((__be32 *)&ip6h->daddr, 22 (__be32 *)&p->locator); 23 } 24 25 void update_ipv6_locator(struct sk_buff *skb, struct ila_params *p) 26 { 27 __wsum diff; 28 struct ipv6hdr *ip6h = ipv6_hdr(skb); 29 size_t nhoff = sizeof(struct ipv6hdr); 30 31 /* First update checksum */ 32 switch (ip6h->nexthdr) { 33 case NEXTHDR_TCP: 34 if (likely(pskb_may_pull(skb, nhoff + sizeof(struct tcphdr)))) { 35 struct tcphdr *th = (struct tcphdr *) 36 (skb_network_header(skb) + nhoff); 37 38 diff = get_csum_diff(ip6h, p); 39 inet_proto_csum_replace_by_diff(&th->check, skb, 40 diff, true); 41 } 42 break; 43 case NEXTHDR_UDP: 44 if (likely(pskb_may_pull(skb, nhoff + sizeof(struct udphdr)))) { 45 struct udphdr *uh = (struct udphdr *) 46 (skb_network_header(skb) + nhoff); 47 48 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) { 49 diff = get_csum_diff(ip6h, p); 50 inet_proto_csum_replace_by_diff(&uh->check, skb, 51 diff, true); 52 if (!uh->check) 53 uh->check = CSUM_MANGLED_0; 54 } 55 } 56 break; 57 case NEXTHDR_ICMP: 58 if (likely(pskb_may_pull(skb, 59 nhoff + sizeof(struct icmp6hdr)))) { 60 struct icmp6hdr *ih = (struct icmp6hdr *) 61 (skb_network_header(skb) + nhoff); 62 63 diff = get_csum_diff(ip6h, p); 64 inet_proto_csum_replace_by_diff(&ih->icmp6_cksum, skb, 65 diff, true); 66 } 67 break; 68 } 69 70 /* Now change destination address */ 71 *(__be64 *)&ip6h->daddr = p->locator; 72 } 73 74 static int __init ila_init(void) 75 { 76 int ret; 77 78 ret = ila_lwt_init(); 79 80 if (ret) 81 goto fail_lwt; 82 83 ret = ila_xlat_init(); 84 if (ret) 85 goto fail_xlat; 86 87 return 0; 88 fail_xlat: 89 ila_lwt_fini(); 90 fail_lwt: 91 return ret; 92 } 93 94 static void __exit ila_fini(void) 95 { 96 ila_xlat_fini(); 97 ila_lwt_fini(); 98 } 99 100 module_init(ila_init); 101 module_exit(ila_fini); 102 MODULE_ALIAS_RTNL_LWT(ILA); 103 MODULE_AUTHOR("Tom Herbert <tom@herbertland.com>"); 104 MODULE_LICENSE("GPL"); 105