170 lines
3.3 KiB
C
170 lines
3.3 KiB
C
/*
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* xfrm4_input.c
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*
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* Changes:
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* YOSHIFUJI Hideaki @USAGI
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* Split up af-specific portion
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* Derek Atkins <derek@ihtfp.com>
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* Add Encapsulation support
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*
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*/
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv4.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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int xfrm4_rcv(struct sk_buff *skb)
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{
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return xfrm4_rcv_encap(skb, 0);
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}
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EXPORT_SYMBOL(xfrm4_rcv);
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static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
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{
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switch (nexthdr) {
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case IPPROTO_IPIP:
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case IPPROTO_IPV6:
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*spi = ip_hdr(skb)->saddr;
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*seq = 0;
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return 0;
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}
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return xfrm_parse_spi(skb, nexthdr, spi, seq);
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}
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#ifdef CONFIG_NETFILTER
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static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb)
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{
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if (skb->dst == NULL) {
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const struct iphdr *iph = ip_hdr(skb);
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if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
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skb->dev))
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goto drop;
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}
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return dst_input(skb);
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drop:
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kfree_skb(skb);
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return NET_RX_DROP;
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}
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#endif
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int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
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{
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__be32 spi, seq;
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struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
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struct xfrm_state *x;
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int xfrm_nr = 0;
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int decaps = 0;
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int err = xfrm4_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq);
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if (err != 0)
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goto drop;
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do {
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const struct iphdr *iph = ip_hdr(skb);
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if (xfrm_nr == XFRM_MAX_DEPTH)
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goto drop;
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x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi,
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iph->protocol != IPPROTO_IPV6 ? iph->protocol : IPPROTO_IPIP, AF_INET);
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if (x == NULL)
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goto drop;
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spin_lock(&x->lock);
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if (unlikely(x->km.state != XFRM_STATE_VALID))
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goto drop_unlock;
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if ((x->encap ? x->encap->encap_type : 0) != encap_type)
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goto drop_unlock;
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if (x->props.replay_window && xfrm_replay_check(x, seq))
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goto drop_unlock;
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if (xfrm_state_check_expire(x))
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goto drop_unlock;
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if (x->type->input(x, skb))
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goto drop_unlock;
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/* only the first xfrm gets the encap type */
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encap_type = 0;
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if (x->props.replay_window)
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xfrm_replay_advance(x, seq);
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x->curlft.bytes += skb->len;
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x->curlft.packets++;
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spin_unlock(&x->lock);
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xfrm_vec[xfrm_nr++] = x;
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if (x->mode->input(x, skb))
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goto drop;
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if (x->props.mode == XFRM_MODE_TUNNEL) {
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decaps = 1;
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break;
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}
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err = xfrm_parse_spi(skb, ip_hdr(skb)->protocol, &spi, &seq);
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if (err < 0)
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goto drop;
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} while (!err);
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/* Allocate new secpath or COW existing one. */
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if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
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struct sec_path *sp;
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sp = secpath_dup(skb->sp);
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if (!sp)
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goto drop;
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if (skb->sp)
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secpath_put(skb->sp);
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skb->sp = sp;
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}
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if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
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goto drop;
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memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec,
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xfrm_nr * sizeof(xfrm_vec[0]));
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skb->sp->len += xfrm_nr;
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nf_reset(skb);
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if (decaps) {
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dst_release(skb->dst);
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skb->dst = NULL;
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netif_rx(skb);
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return 0;
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} else {
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#ifdef CONFIG_NETFILTER
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__skb_push(skb, skb->data - skb_network_header(skb));
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ip_hdr(skb)->tot_len = htons(skb->len);
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ip_send_check(ip_hdr(skb));
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NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
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xfrm4_rcv_encap_finish);
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return 0;
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#else
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return -ip_hdr(skb)->protocol;
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#endif
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}
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drop_unlock:
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spin_unlock(&x->lock);
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xfrm_state_put(x);
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drop:
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while (--xfrm_nr >= 0)
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xfrm_state_put(xfrm_vec[xfrm_nr]);
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kfree_skb(skb);
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return 0;
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}
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