linux/net/ipv6/ila/ila_common.c
Tom Herbert 7f00feaf10 ila: Add generic ILA translation facility
This patch implements an ILA tanslation table. This table can be
configured with identifier to locator mappings, and can be be queried
to resolve a mapping. Queries can be parameterized based on interface,
direction (incoming or outoing), and matching locator.  The table is
implemented using rhashtable and is configured via netlink (through
"ip ila .." in iproute).

The table may be used as alternative means to do do ILA tanslations
other than the lw tunnels

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-15 23:25:20 -05:00

104 lines
2.2 KiB
C

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