 03606895cd
			
		
	
	
	03606895cd
	
	
	
		
			
			Niccolo Belli reported ipsec crashes in case we handle a frame without mac header (atm in his case) Before copying mac header, better make sure it is present. Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=42809 Reported-by: Niccolò Belli <darkbasic@linuxsystems.it> Tested-by: Niccolò Belli <darkbasic@linuxsystems.it> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			131 lines
		
	
	
	
		
			3.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			131 lines
		
	
	
	
		
			3.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
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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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| 
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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/dsfield.h>
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| #include <net/dst.h>
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| #include <net/inet_ecn.h>
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| #include <net/ipv6.h>
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| #include <net/xfrm.h>
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| 
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| static void xfrm6_beet_make_header(struct sk_buff *skb)
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| {
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| 	struct ipv6hdr *iph = ipv6_hdr(skb);
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| 
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| 	iph->version = 6;
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| 
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| 	memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
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| 	       sizeof(iph->flow_lbl));
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| 	iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
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| 
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| 	ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
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| 	iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
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| }
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| 
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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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|  */
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| static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
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| {
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| 	struct ipv6hdr *top_iph;
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| 	struct ip_beet_phdr *ph;
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| 	int optlen, hdr_len;
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| 
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| 	hdr_len = 0;
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| 	optlen = XFRM_MODE_SKB_CB(skb)->optlen;
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| 	if (unlikely(optlen))
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| 		hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
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| 
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| 	skb_set_network_header(skb, -x->props.header_len - hdr_len);
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| 	if (x->sel.family != AF_INET6)
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| 		skb->network_header += IPV4_BEET_PHMAXLEN;
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| 	skb->mac_header = skb->network_header +
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| 			  offsetof(struct ipv6hdr, nexthdr);
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| 	skb->transport_header = skb->network_header + sizeof(*top_iph);
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| 	ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);
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| 
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| 	xfrm6_beet_make_header(skb);
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| 
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| 	top_iph = ipv6_hdr(skb);
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| 	if (unlikely(optlen)) {
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| 
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| 		BUG_ON(optlen < 0);
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| 
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| 		ph->padlen = 4 - (optlen & 4);
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| 		ph->hdrlen = optlen / 8;
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| 		ph->nexthdr = top_iph->nexthdr;
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| 		if (ph->padlen)
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| 			memset(ph + 1, IPOPT_NOP, ph->padlen);
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| 
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| 		top_iph->nexthdr = IPPROTO_BEETPH;
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| 	}
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| 
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| 	top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
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| 	top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
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| 	return 0;
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| }
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| 
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| static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
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| {
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| 	struct ipv6hdr *ip6h;
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| 	int size = sizeof(struct ipv6hdr);
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| 	int err;
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| 
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| 	err = skb_cow_head(skb, size + skb->mac_len);
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| 	if (err)
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| 		goto out;
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| 
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| 	__skb_push(skb, size);
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| 	skb_reset_network_header(skb);
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| 	skb_mac_header_rebuild(skb);
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| 
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| 	xfrm6_beet_make_header(skb);
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| 
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| 	ip6h = ipv6_hdr(skb);
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| 	ip6h->payload_len = htons(skb->len - size);
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| 	ip6h->daddr = *(struct in6_addr *)&x->sel.daddr.a6;
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| 	ip6h->saddr = *(struct in6_addr *)&x->sel.saddr.a6;
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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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| 
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| static struct xfrm_mode xfrm6_beet_mode = {
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| 	.input2 = xfrm6_beet_input,
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| 	.input = xfrm_prepare_input,
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| 	.output2 = xfrm6_beet_output,
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| 	.output = xfrm6_prepare_output,
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| 	.owner = THIS_MODULE,
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| 	.encap = XFRM_MODE_BEET,
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| 	.flags = XFRM_MODE_FLAG_TUNNEL,
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| };
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| 
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| static int __init xfrm6_beet_init(void)
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| {
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| 	return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
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| }
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| 
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| static void __exit xfrm6_beet_exit(void)
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| {
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| 	int err;
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| 
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| 	err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
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| 	BUG_ON(err);
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| }
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| 
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| module_init(xfrm6_beet_init);
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| module_exit(xfrm6_beet_exit);
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| MODULE_LICENSE("GPL");
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| MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);
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