105 lines
2.3 KiB
C
105 lines
2.3 KiB
C
#include <linux/errno.h>
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#include <linux/ip.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/socket.h>
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#include <linux/types.h>
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#include <net/checksum.h>
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#include <net/ip.h>
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#include <net/ip6_fib.h>
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#include <net/lwtunnel.h>
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#include <net/protocol.h>
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#include <uapi/linux/ila.h>
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#include "ila.h"
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static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p)
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{
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if (*(__be64 *)&ip6h->daddr == p->locator_match)
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return p->csum_diff;
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else
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return compute_csum_diff8((__be32 *)&ip6h->daddr,
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(__be32 *)&p->locator);
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}
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void update_ipv6_locator(struct sk_buff *skb, struct ila_params *p)
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{
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__wsum diff;
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struct ipv6hdr *ip6h = ipv6_hdr(skb);
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size_t nhoff = sizeof(struct ipv6hdr);
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/* First update checksum */
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switch (ip6h->nexthdr) {
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case NEXTHDR_TCP:
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if (likely(pskb_may_pull(skb, nhoff + sizeof(struct tcphdr)))) {
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struct tcphdr *th = (struct tcphdr *)
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(skb_network_header(skb) + nhoff);
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diff = get_csum_diff(ip6h, p);
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inet_proto_csum_replace_by_diff(&th->check, skb,
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diff, true);
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}
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break;
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case NEXTHDR_UDP:
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if (likely(pskb_may_pull(skb, nhoff + sizeof(struct udphdr)))) {
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struct udphdr *uh = (struct udphdr *)
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(skb_network_header(skb) + nhoff);
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if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
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diff = get_csum_diff(ip6h, p);
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inet_proto_csum_replace_by_diff(&uh->check, skb,
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diff, true);
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if (!uh->check)
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uh->check = CSUM_MANGLED_0;
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}
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}
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break;
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case NEXTHDR_ICMP:
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if (likely(pskb_may_pull(skb,
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nhoff + sizeof(struct icmp6hdr)))) {
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struct icmp6hdr *ih = (struct icmp6hdr *)
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(skb_network_header(skb) + nhoff);
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diff = get_csum_diff(ip6h, p);
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inet_proto_csum_replace_by_diff(&ih->icmp6_cksum, skb,
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diff, true);
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}
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break;
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}
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/* Now change destination address */
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*(__be64 *)&ip6h->daddr = p->locator;
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}
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static int __init ila_init(void)
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{
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int ret;
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ret = ila_lwt_init();
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if (ret)
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goto fail_lwt;
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ret = ila_xlat_init();
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if (ret)
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goto fail_xlat;
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return 0;
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fail_xlat:
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ila_lwt_fini();
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fail_lwt:
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return ret;
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}
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static void __exit ila_fini(void)
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{
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ila_xlat_fini();
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ila_lwt_fini();
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}
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module_init(ila_init);
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module_exit(ila_fini);
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MODULE_ALIAS_RTNL_LWT(ILA);
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MODULE_AUTHOR("Tom Herbert <tom@herbertland.com>");
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MODULE_LICENSE("GPL");
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