254d0d24e3
Beet mode looks for the beet pseudo header after the outer IP header, which is wrong since that is followed by the ESP header. Additionally it needs to adjust the packet length after removing the pseudo header and point the data pointer to the real data location. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
144 lines
3.5 KiB
C
144 lines
3.5 KiB
C
/*
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* xfrm4_mode_beet.c - BEET mode encapsulation for IPv4.
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*
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* Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
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* Miika Komu <miika@iki.fi>
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* Herbert Xu <herbert@gondor.apana.org.au>
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* Abhinav Pathak <abhinav.pathak@hiit.fi>
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* Jeff Ahrenholz <ahrenholz@gmail.com>
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*/
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#include <linux/init.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/stringify.h>
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#include <net/dst.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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/* Add encapsulation header.
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*
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* The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
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* The following fields in it shall be filled in by x->type->output:
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* tot_len
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* check
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*
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* On exit, skb->h will be set to the start of the payload to be processed
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* by x->type->output and skb->nh will be set to the top IP header.
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*/
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static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct iphdr *iph, *top_iph = NULL;
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int hdrlen, optlen;
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iph = skb->nh.iph;
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skb->h.ipiph = iph;
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hdrlen = 0;
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optlen = iph->ihl * 4 - sizeof(*iph);
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if (unlikely(optlen))
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hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
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skb->nh.raw = skb_push(skb, x->props.header_len + hdrlen);
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top_iph = skb->nh.iph;
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skb->h.raw += sizeof(*iph) - hdrlen;
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memmove(top_iph, iph, sizeof(*iph));
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if (unlikely(optlen)) {
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struct ip_beet_phdr *ph;
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BUG_ON(optlen < 0);
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ph = (struct ip_beet_phdr *)skb->h.raw;
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ph->padlen = 4 - (optlen & 4);
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ph->hdrlen = (optlen + ph->padlen + sizeof(*ph)) / 8;
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ph->nexthdr = top_iph->protocol;
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if (ph->padlen)
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memset(ph + 1, IPOPT_NOP, ph->padlen);
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top_iph->protocol = IPPROTO_BEETPH;
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top_iph->ihl = sizeof(struct iphdr) / 4;
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}
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top_iph->saddr = x->props.saddr.a4;
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top_iph->daddr = x->id.daddr.a4;
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return 0;
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}
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static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct iphdr *iph = skb->nh.iph;
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int phlen = 0;
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int optlen = 0;
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__u8 ph_nexthdr = 0, protocol = 0;
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int err = -EINVAL;
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protocol = iph->protocol;
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if (unlikely(iph->protocol == IPPROTO_BEETPH)) {
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struct ip_beet_phdr *ph;
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if (!pskb_may_pull(skb, sizeof(*ph)))
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goto out;
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ph = (struct ip_beet_phdr *)(skb->h.ipiph + 1);
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phlen = sizeof(*ph) + ph->padlen;
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optlen = ph->hdrlen * 8 - phlen;
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if (optlen < 0 || optlen & 3 || optlen > 250)
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goto out;
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if (!pskb_may_pull(skb, phlen + optlen))
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goto out;
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skb->len -= phlen + optlen;
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ph_nexthdr = ph->nexthdr;
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}
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skb->nh.raw = skb->data + (phlen - sizeof(*iph));
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memmove(skb->nh.raw, iph, sizeof(*iph));
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skb->h.raw = skb->data + (phlen + optlen);
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skb->data = skb->h.raw;
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iph = skb->nh.iph;
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iph->ihl = (sizeof(*iph) + optlen) / 4;
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iph->tot_len = htons(skb->len + iph->ihl * 4);
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iph->daddr = x->sel.daddr.a4;
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iph->saddr = x->sel.saddr.a4;
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if (ph_nexthdr)
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iph->protocol = ph_nexthdr;
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else
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iph->protocol = protocol;
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iph->check = 0;
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iph->check = ip_fast_csum(skb->nh.raw, iph->ihl);
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err = 0;
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out:
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return err;
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}
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static struct xfrm_mode xfrm4_beet_mode = {
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.input = xfrm4_beet_input,
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.output = xfrm4_beet_output,
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.owner = THIS_MODULE,
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.encap = XFRM_MODE_BEET,
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};
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static int __init xfrm4_beet_init(void)
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{
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return xfrm_register_mode(&xfrm4_beet_mode, AF_INET);
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}
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static void __exit xfrm4_beet_exit(void)
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{
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int err;
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err = xfrm_unregister_mode(&xfrm4_beet_mode, AF_INET);
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BUG_ON(err);
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}
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module_init(xfrm4_beet_init);
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module_exit(xfrm4_beet_exit);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_BEET);
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