007f0211a8
Current the x->mode->output functions store the IPv6 nh pointer in the skb network header. This is inconvenient because the network header then has to be fixed up before the packet can leave the IPsec stack. The mac header field is unused on output so we can use that to store this instead. This patch does that and removes the network header fix-up in xfrm_output. It also uses ipv6_hdr where appropriate in the x->type->output functions. There is also a minor clean-up in esp4 to make it use the same code as esp6 to help any subsequent effort to merge the two. Lastly it kills two redundant skb_set_* statements in BEET that were simply copied over from transport mode. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
149 lines
4.1 KiB
C
149 lines
4.1 KiB
C
/*
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* xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
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*
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* Copyright (C) 2002 USAGI/WIDE Project
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* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
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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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static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
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{
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struct ipv6hdr *outer_iph = ipv6_hdr(skb);
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struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
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if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
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IP6_ECN_set_ce(inner_iph);
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}
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static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
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{
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if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6_hdr(skb))))
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IP_ECN_set_ce(ipip_hdr(skb));
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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 RFC 2401. The following fields
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* in it shall be filled in by x->type->output:
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* payload_len
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*
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* On exit, skb->h will be set to the start of the encapsulation header to be
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* filled in by x->type->output and the mac header will be set to the
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* nextheader field of the extension header directly preceding the
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* encapsulation header, or in its absence, that of the top IP header.
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* The value of skb->data and the network header will always point to the
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* top IP header.
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*/
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static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct dst_entry *dst = skb->dst;
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struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
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struct ipv6hdr *iph, *top_iph;
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int dsfield;
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skb_push(skb, x->props.header_len);
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iph = ipv6_hdr(skb);
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skb_set_mac_header(skb, offsetof(struct ipv6hdr, nexthdr));
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skb_reset_network_header(skb);
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skb_set_transport_header(skb, sizeof(struct ipv6hdr));
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top_iph = ipv6_hdr(skb);
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top_iph->version = 6;
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if (xdst->route->ops->family == AF_INET6) {
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top_iph->priority = iph->priority;
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top_iph->flow_lbl[0] = iph->flow_lbl[0];
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top_iph->flow_lbl[1] = iph->flow_lbl[1];
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top_iph->flow_lbl[2] = iph->flow_lbl[2];
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top_iph->nexthdr = IPPROTO_IPV6;
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} else {
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top_iph->priority = 0;
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top_iph->flow_lbl[0] = 0;
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top_iph->flow_lbl[1] = 0;
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top_iph->flow_lbl[2] = 0;
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top_iph->nexthdr = IPPROTO_IPIP;
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}
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dsfield = ipv6_get_dsfield(top_iph);
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dsfield = INET_ECN_encapsulate(dsfield, dsfield);
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if (x->props.flags & XFRM_STATE_NOECN)
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dsfield &= ~INET_ECN_MASK;
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ipv6_change_dsfield(top_iph, 0, dsfield);
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top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
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ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
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ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
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skb->protocol = htons(ETH_P_IPV6);
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return 0;
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}
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static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err = -EINVAL;
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const unsigned char *old_mac;
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const unsigned char *nh = skb_network_header(skb);
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if (nh[IP6CB(skb)->nhoff] != IPPROTO_IPV6 &&
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nh[IP6CB(skb)->nhoff] != IPPROTO_IPIP)
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goto out;
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if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
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goto out;
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if (skb_cloned(skb) &&
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(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
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goto out;
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nh = skb_network_header(skb);
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if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
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if (x->props.flags & XFRM_STATE_DECAP_DSCP)
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ipv6_copy_dscp(ipv6_hdr(skb), ipipv6_hdr(skb));
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if (!(x->props.flags & XFRM_STATE_NOECN))
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ipip6_ecn_decapsulate(skb);
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} else {
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if (!(x->props.flags & XFRM_STATE_NOECN))
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ip6ip_ecn_decapsulate(skb);
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skb->protocol = htons(ETH_P_IP);
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}
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old_mac = skb_mac_header(skb);
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skb_set_mac_header(skb, -skb->mac_len);
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memmove(skb_mac_header(skb), old_mac, skb->mac_len);
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skb_reset_network_header(skb);
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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 xfrm6_tunnel_mode = {
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.input = xfrm6_tunnel_input,
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.output = xfrm6_tunnel_output,
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.owner = THIS_MODULE,
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.encap = XFRM_MODE_TUNNEL,
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};
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static int __init xfrm6_tunnel_init(void)
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{
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return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
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}
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static void __exit xfrm6_tunnel_exit(void)
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{
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int err;
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err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
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BUG_ON(err);
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}
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module_init(xfrm6_tunnel_init);
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module_exit(xfrm6_tunnel_exit);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
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