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-rw-r--r--net/ipv4/xfrm4_input.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
new file mode 100644
index 0000000..2d3849c
--- /dev/null
+++ b/net/ipv4/xfrm4_input.c
@@ -0,0 +1,160 @@
+/*
+ * xfrm4_input.c
+ *
+ * Changes:
+ * YOSHIFUJI Hideaki @USAGI
+ * Split up af-specific portion
+ * Derek Atkins <derek@ihtfp.com>
+ * Add Encapsulation support
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <net/inet_ecn.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+
+int xfrm4_rcv(struct sk_buff *skb)
+{
+ return xfrm4_rcv_encap(skb, 0);
+}
+
+EXPORT_SYMBOL(xfrm4_rcv);
+
+static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
+{
+ struct iphdr *outer_iph = skb->nh.iph;
+ struct iphdr *inner_iph = skb->h.ipiph;
+
+ if (INET_ECN_is_ce(outer_iph->tos))
+ IP_ECN_set_ce(inner_iph);
+}
+
+static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq)
+{
+ switch (nexthdr) {
+ case IPPROTO_IPIP:
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ return -EINVAL;
+ *spi = skb->nh.iph->saddr;
+ *seq = 0;
+ return 0;
+ }
+
+ return xfrm_parse_spi(skb, nexthdr, spi, seq);
+}
+
+int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
+{
+ int err;
+ u32 spi, seq;
+ struct sec_decap_state xfrm_vec[XFRM_MAX_DEPTH];
+ struct xfrm_state *x;
+ int xfrm_nr = 0;
+ int decaps = 0;
+
+ if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0)
+ goto drop;
+
+ do {
+ struct iphdr *iph = skb->nh.iph;
+
+ if (xfrm_nr == XFRM_MAX_DEPTH)
+ goto drop;
+
+ x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, iph->protocol, AF_INET);
+ if (x == NULL)
+ goto drop;
+
+ spin_lock(&x->lock);
+ if (unlikely(x->km.state != XFRM_STATE_VALID))
+ goto drop_unlock;
+
+ if (x->props.replay_window && xfrm_replay_check(x, seq))
+ goto drop_unlock;
+
+ if (xfrm_state_check_expire(x))
+ goto drop_unlock;
+
+ xfrm_vec[xfrm_nr].decap.decap_type = encap_type;
+ if (x->type->input(x, &(xfrm_vec[xfrm_nr].decap), skb))
+ goto drop_unlock;
+
+ /* only the first xfrm gets the encap type */
+ encap_type = 0;
+
+ if (x->props.replay_window)
+ xfrm_replay_advance(x, seq);
+
+ x->curlft.bytes += skb->len;
+ x->curlft.packets++;
+
+ spin_unlock(&x->lock);
+
+ xfrm_vec[xfrm_nr++].xvec = x;
+
+ iph = skb->nh.iph;
+
+ if (x->props.mode) {
+ if (iph->protocol != IPPROTO_IPIP)
+ goto drop;
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ goto drop;
+ if (skb_cloned(skb) &&
+ pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ goto drop;
+ if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+ ipv4_copy_dscp(iph, skb->h.ipiph);
+ if (!(x->props.flags & XFRM_STATE_NOECN))
+ ipip_ecn_decapsulate(skb);
+ skb->mac.raw = memmove(skb->data - skb->mac_len,
+ skb->mac.raw, skb->mac_len);
+ skb->nh.raw = skb->data;
+ memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
+ decaps = 1;
+ break;
+ }
+
+ if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) < 0)
+ goto drop;
+ } while (!err);
+
+ /* Allocate new secpath or COW existing one. */
+
+ if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
+ struct sec_path *sp;
+ sp = secpath_dup(skb->sp);
+ if (!sp)
+ goto drop;
+ if (skb->sp)
+ secpath_put(skb->sp);
+ skb->sp = sp;
+ }
+ if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
+ goto drop;
+
+ memcpy(skb->sp->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state));
+ skb->sp->len += xfrm_nr;
+
+ if (decaps) {
+ if (!(skb->dev->flags&IFF_LOOPBACK)) {
+ dst_release(skb->dst);
+ skb->dst = NULL;
+ }
+ netif_rx(skb);
+ return 0;
+ } else {
+ return -skb->nh.iph->protocol;
+ }
+
+drop_unlock:
+ spin_unlock(&x->lock);
+ xfrm_state_put(x);
+drop:
+ while (--xfrm_nr >= 0)
+ xfrm_state_put(xfrm_vec[xfrm_nr].xvec);
+
+ kfree_skb(skb);
+ return 0;
+}
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