Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / net / ipv4 / xfrm4_input.c

diff --git a/kernel/net/ipv4/xfrm4_input.c b/kernel/net/ipv4/xfrm4_input.c
new file mode 100644 (file)
index 0000000..60b032f
--- /dev/null
+++ b/kernel/net/ipv4/xfrm4_input.c
@@ -0,0 +1,158 @@
+/*
+ * xfrm4_input.c
+ *
+ * Changes:
+ *     YOSHIFUJI Hideaki @USAGI
+ *             Split up af-specific portion
+ *     Derek Atkins <derek@ihtfp.com>
+ *             Add Encapsulation support
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+
+int xfrm4_extract_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+       return xfrm4_extract_header(skb);
+}
+
+static inline int xfrm4_rcv_encap_finish(struct sock *sk, struct sk_buff *skb)
+{
+       if (!skb_dst(skb)) {
+               const struct iphdr *iph = ip_hdr(skb);
+
+               if (ip_route_input_noref(skb, iph->daddr, iph->saddr,
+                                        iph->tos, skb->dev))
+                       goto drop;
+       }
+       return dst_input(skb);
+drop:
+       kfree_skb(skb);
+       return NET_RX_DROP;
+}
+
+int xfrm4_transport_finish(struct sk_buff *skb, int async)
+{
+       struct iphdr *iph = ip_hdr(skb);
+
+       iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
+
+#ifndef CONFIG_NETFILTER
+       if (!async)
+               return -iph->protocol;
+#endif
+
+       __skb_push(skb, skb->data - skb_network_header(skb));
+       iph->tot_len = htons(skb->len);
+       ip_send_check(iph);
+
+       NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, NULL, skb,
+               skb->dev, NULL,
+               xfrm4_rcv_encap_finish);
+       return 0;
+}
+
+/* If it's a keepalive packet, then just eat it.
+ * If it's an encapsulated packet, then pass it to the
+ * IPsec xfrm input.
+ * Returns 0 if skb passed to xfrm or was dropped.
+ * Returns >0 if skb should be passed to UDP.
+ * Returns <0 if skb should be resubmitted (-ret is protocol)
+ */
+int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
+{
+       struct udp_sock *up = udp_sk(sk);
+       struct udphdr *uh;
+       struct iphdr *iph;
+       int iphlen, len;
+
+       __u8 *udpdata;
+       __be32 *udpdata32;
+       __u16 encap_type = up->encap_type;
+
+       /* if this is not encapsulated socket, then just return now */
+       if (!encap_type)
+               return 1;
+
+       /* If this is a paged skb, make sure we pull up
+        * whatever data we need to look at. */
+       len = skb->len - sizeof(struct udphdr);
+       if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
+               return 1;
+
+       /* Now we can get the pointers */
+       uh = udp_hdr(skb);
+       udpdata = (__u8 *)uh + sizeof(struct udphdr);
+       udpdata32 = (__be32 *)udpdata;
+
+       switch (encap_type) {
+       default:
+       case UDP_ENCAP_ESPINUDP:
+               /* Check if this is a keepalive packet.  If so, eat it. */
+               if (len == 1 && udpdata[0] == 0xff) {
+                       goto drop;
+               } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
+                       /* ESP Packet without Non-ESP header */
+                       len = sizeof(struct udphdr);
+               } else
+                       /* Must be an IKE packet.. pass it through */
+                       return 1;
+               break;
+       case UDP_ENCAP_ESPINUDP_NON_IKE:
+               /* Check if this is a keepalive packet.  If so, eat it. */
+               if (len == 1 && udpdata[0] == 0xff) {
+                       goto drop;
+               } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
+                          udpdata32[0] == 0 && udpdata32[1] == 0) {
+
+                       /* ESP Packet with Non-IKE marker */
+                       len = sizeof(struct udphdr) + 2 * sizeof(u32);
+               } else
+                       /* Must be an IKE packet.. pass it through */
+                       return 1;
+               break;
+       }
+
+       /* At this point we are sure that this is an ESPinUDP packet,
+        * so we need to remove 'len' bytes from the packet (the UDP
+        * header and optional ESP marker bytes) and then modify the
+        * protocol to ESP, and then call into the transform receiver.
+        */
+       if (skb_unclone(skb, GFP_ATOMIC))
+               goto drop;
+
+       /* Now we can update and verify the packet length... */
+       iph = ip_hdr(skb);
+       iphlen = iph->ihl << 2;
+       iph->tot_len = htons(ntohs(iph->tot_len) - len);
+       if (skb->len < iphlen + len) {
+               /* packet is too small!?! */
+               goto drop;
+       }
+
+       /* pull the data buffer up to the ESP header and set the
+        * transport header to point to ESP.  Keep UDP on the stack
+        * for later.
+        */
+       __skb_pull(skb, len);
+       skb_reset_transport_header(skb);
+
+       /* process ESP */
+       return xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, encap_type);
+
+drop:
+       kfree_skb(skb);
+       return 0;
+}
+
+int xfrm4_rcv(struct sk_buff *skb)
+{
+       return xfrm4_rcv_spi(skb, ip_hdr(skb)->protocol, 0);
+}
+EXPORT_SYMBOL(xfrm4_rcv);