| Diego Beltrami | 0a69452 | 2006-10-03 23:47:05 -0700 | [diff] [blame] | 1 | /* |
| 2 | * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6. |
| 3 | * |
| 4 | * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com> |
| 5 | * Miika Komu <miika@iki.fi> |
| 6 | * Herbert Xu <herbert@gondor.apana.org.au> |
| 7 | * Abhinav Pathak <abhinav.pathak@hiit.fi> |
| 8 | * Jeff Ahrenholz <ahrenholz@gmail.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <linux/stringify.h> |
| 16 | #include <net/dsfield.h> |
| 17 | #include <net/dst.h> |
| 18 | #include <net/inet_ecn.h> |
| 19 | #include <net/ipv6.h> |
| 20 | #include <net/xfrm.h> |
| 21 | |
| 22 | /* Add encapsulation header. |
| 23 | * |
| 24 | * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt. |
| 25 | * The following fields in it shall be filled in by x->type->output: |
| 26 | * payload_len |
| 27 | * |
| 28 | * On exit, skb->h will be set to the start of the encapsulation header to be |
| 29 | * filled in by x->type->output and skb->nh will be set to the nextheader field |
| 30 | * of the extension header directly preceding the encapsulation header, or in |
| 31 | * its absence, that of the top IP header. The value of skb->data will always |
| 32 | * point to the top IP header. |
| 33 | */ |
| 34 | static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb) |
| 35 | { |
| 36 | struct ipv6hdr *iph, *top_iph; |
| 37 | u8 *prevhdr; |
| 38 | int hdr_len; |
| 39 | |
| 40 | skb_push(skb, x->props.header_len); |
| 41 | iph = skb->nh.ipv6h; |
| 42 | |
| 43 | hdr_len = ip6_find_1stfragopt(skb, &prevhdr); |
| 44 | skb->nh.raw = prevhdr - x->props.header_len; |
| 45 | skb->h.raw = skb->data + hdr_len; |
| 46 | memmove(skb->data, iph, hdr_len); |
| 47 | |
| 48 | skb->nh.raw = skb->data; |
| 49 | top_iph = skb->nh.ipv6h; |
| 50 | skb->nh.raw = &top_iph->nexthdr; |
| 51 | skb->h.ipv6h = top_iph + 1; |
| 52 | |
| 53 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); |
| 54 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); |
| 55 | |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb) |
| 60 | { |
| 61 | struct ipv6hdr *ip6h; |
| 62 | int size = sizeof(struct ipv6hdr); |
| 63 | int err = -EINVAL; |
| 64 | |
| 65 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| 66 | goto out; |
| 67 | |
| 68 | skb_push(skb, size); |
| 69 | memmove(skb->data, skb->nh.raw, size); |
| 70 | skb->nh.raw = skb->data; |
| 71 | |
| 72 | skb->mac.raw = memmove(skb->data - skb->mac_len, |
| 73 | skb->mac.raw, skb->mac_len); |
| 74 | |
| 75 | ip6h = skb->nh.ipv6h; |
| 76 | ip6h->payload_len = htons(skb->len - size); |
| 77 | ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6); |
| 78 | ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6); |
| 79 | err = 0; |
| 80 | out: |
| 81 | return err; |
| 82 | } |
| 83 | |
| 84 | static struct xfrm_mode xfrm6_beet_mode = { |
| 85 | .input = xfrm6_beet_input, |
| 86 | .output = xfrm6_beet_output, |
| 87 | .owner = THIS_MODULE, |
| 88 | .encap = XFRM_MODE_BEET, |
| 89 | }; |
| 90 | |
| 91 | static int __init xfrm6_beet_init(void) |
| 92 | { |
| 93 | return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6); |
| 94 | } |
| 95 | |
| 96 | static void __exit xfrm6_beet_exit(void) |
| 97 | { |
| 98 | int err; |
| 99 | |
| 100 | err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6); |
| 101 | BUG_ON(err); |
| 102 | } |
| 103 | |
| 104 | module_init(xfrm6_beet_init); |
| 105 | module_exit(xfrm6_beet_exit); |
| 106 | MODULE_LICENSE("GPL"); |
| 107 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET); |