* Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
* a single port at the same time.
* Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
+ * James Chapman : Add L2TP encapsulation type.
*
*
* This program is free software; you can redistribute it and/or
return 0;
}
-/* return:
- * 1 if the UDP system should process it
- * 0 if we should drop this packet
- * -1 if it should get processed by xfrm4_rcv_encap
- */
-static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
-{
-#ifndef CONFIG_XFRM
- return 1;
-#else
- 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 we're overly short, let UDP handle it */
- len = skb->len - sizeof(struct udphdr);
- if (len <= 0)
- return 1;
-
- /* 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. */
- 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) {
- return 0;
- } 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) {
- return 0;
- } 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_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
- return 0;
-
- /* 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!?! */
- return 0;
- }
-
- /* 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);
-
- /* modify the protocol (it's ESP!) */
- iph->protocol = IPPROTO_ESP;
-
- /* and let the caller know to send this into the ESP processor... */
- return -1;
-#endif
-}
-
/* returns:
* -1: error
* 0: success
if (up->encap_type) {
/*
- * This is an encapsulation socket, so let's see if this is
- * an encapsulated packet.
- * If it's a keepalive packet, then just eat it.
- * If it's an encapsulateed packet, then pass it to the
- * IPsec xfrm input and return the response
- * appropriately. Otherwise, just fall through and
- * pass this up the UDP socket.
+ * This is an encapsulation socket so pass the skb to
+ * the socket's udp_encap_rcv() hook. Otherwise, just
+ * fall through and pass this up the UDP socket.
+ * up->encap_rcv() returns the following value:
+ * =0 if skb was successfully passed to the encap
+ * handler or was discarded by it.
+ * >0 if skb should be passed on to UDP.
+ * <0 if skb should be resubmitted as proto -N
*/
- int ret;
- ret = udp_encap_rcv(sk, skb);
- if (ret == 0) {
- /* Eat the packet .. */
- kfree_skb(skb);
- return 0;
- }
- if (ret < 0) {
- /* process the ESP packet */
- ret = xfrm4_rcv_encap(skb, up->encap_type);
- UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
- return -ret;
+ /* if we're overly short, let UDP handle it */
+ if (skb->len > sizeof(struct udphdr) &&
+ up->encap_rcv != NULL) {
+ int ret;
+
+ ret = (*up->encap_rcv)(sk, skb);
+ if (ret <= 0) {
+ UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
+ return -ret;
+ }
}
+
/* FALLTHROUGH -- it's a UDP Packet */
}
case 0:
case UDP_ENCAP_ESPINUDP:
case UDP_ENCAP_ESPINUDP_NON_IKE:
+ up->encap_rcv = xfrm4_udp_encap_rcv;
+ /* FALLTHROUGH */
+ case UDP_ENCAP_L2TPINUDP:
up->encap_type = val;
break;
default:
projects / linux-2.6 / blobdiff