1 #include <linux/errno.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>
10 #include <net/ip6_fib.h>
11 #include <net/lwtunnel.h>
12 #include <net/protocol.h>
13 #include <uapi/linux/ila.h>
16 static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p)
18 struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
20 if (p->locator_match.v64)
23 return compute_csum_diff8((__be32 *)&iaddr->loc,
24 (__be32 *)&p->locator);
27 static void ila_csum_do_neutral(struct ila_addr *iaddr,
30 __sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
33 /* Check if checksum adjust value has been cached */
34 if (p->locator_match.v64) {
37 diff = compute_csum_diff8((__be32 *)iaddr,
38 (__be32 *)&p->locator);
41 fval = (__force __wsum)(ila_csum_neutral_set(iaddr->ident) ?
42 ~CSUM_NEUTRAL_FLAG : CSUM_NEUTRAL_FLAG);
44 diff = csum_add(diff, fval);
46 *adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust)));
48 /* Flip the csum-neutral bit. Either we are doing a SIR->ILA
49 * translation with ILA_CSUM_NEUTRAL_MAP as the csum_method
50 * and the C-bit is not set, or we are doing an ILA-SIR
51 * tranlsation and the C-bit is set.
53 iaddr->ident.csum_neutral ^= 1;
56 static void ila_csum_adjust_transport(struct sk_buff *skb,
60 struct ipv6hdr *ip6h = ipv6_hdr(skb);
61 struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
62 size_t nhoff = sizeof(struct ipv6hdr);
64 switch (ip6h->nexthdr) {
66 if (likely(pskb_may_pull(skb, nhoff + sizeof(struct tcphdr)))) {
67 struct tcphdr *th = (struct tcphdr *)
68 (skb_network_header(skb) + nhoff);
70 diff = get_csum_diff(ip6h, p);
71 inet_proto_csum_replace_by_diff(&th->check, skb,
76 if (likely(pskb_may_pull(skb, nhoff + sizeof(struct udphdr)))) {
77 struct udphdr *uh = (struct udphdr *)
78 (skb_network_header(skb) + nhoff);
80 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
81 diff = get_csum_diff(ip6h, p);
82 inet_proto_csum_replace_by_diff(&uh->check, skb,
85 uh->check = CSUM_MANGLED_0;
90 if (likely(pskb_may_pull(skb,
91 nhoff + sizeof(struct icmp6hdr)))) {
92 struct icmp6hdr *ih = (struct icmp6hdr *)
93 (skb_network_header(skb) + nhoff);
95 diff = get_csum_diff(ip6h, p);
96 inet_proto_csum_replace_by_diff(&ih->icmp6_cksum, skb,
102 /* Now change destination address */
103 iaddr->loc = p->locator;
106 void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
108 struct ipv6hdr *ip6h = ipv6_hdr(skb);
109 struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
111 /* First deal with the transport checksum */
112 if (ila_csum_neutral_set(iaddr->ident)) {
113 /* C-bit is set in the locator indicating that this
114 * is a locator being translated to a SIR address.
115 * Perform (receiver) checksum-neutral translation.
117 ila_csum_do_neutral(iaddr, p);
119 switch (p->csum_mode) {
120 case ILA_CSUM_ADJUST_TRANSPORT:
121 ila_csum_adjust_transport(skb, p);
123 case ILA_CSUM_NEUTRAL_MAP:
124 ila_csum_do_neutral(iaddr, p);
126 case ILA_CSUM_NO_ACTION:
131 /* Now change destination address */
132 iaddr->loc = p->locator;
135 void ila_init_saved_csum(struct ila_params *p)
137 if (!p->locator_match.v64)
140 p->csum_diff = compute_csum_diff8(
141 (__be32 *)&p->locator_match,
142 (__be32 *)&p->locator);
145 static int __init ila_init(void)
149 ret = ila_lwt_init();
154 ret = ila_xlat_init();
165 static void __exit ila_fini(void)
171 module_init(ila_init);
172 module_exit(ila_fini);
173 MODULE_ALIAS_RTNL_LWT(ILA);
174 MODULE_AUTHOR("Tom Herbert <tom@herbertland.com>");
175 MODULE_LICENSE("GPL");