IPv6 support for user IP

This patch enables the use of IPv6 PDP contexts.  The phone will
have to request an IPv6 End-user-Address, and the GGSN will have
to be configured for an IPv6 pool.

The outer transport-layer IP between SGSN and GGSN must still be
IPv4, it is not modified by this patch

Change-Id: I22c3bf32a98e5daf99d6eaeac8c9f95cc7574774

ggsn/ggsn.c

@@ -35,6 +35,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netinet/ip.h>
+#include <netinet/ip6.h>
 #include <arpa/inet.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
@@ -190,7 +191,7 @@ int create_context_ind(struct pdp_t *pdp)
 	memcpy(pdp->qos_neg.v, pdp->qos_req.v, pdp->qos_req.l);	/* TODO */
 	pdp->qos_neg.l = pdp->qos_req.l;
 
-	if (pdp_euaton(&pdp->eua, &addr.v4)) {
+	if (in46a_from_eua(&pdp->eua, &addr)) {
 		addr.v4.s_addr = 0;	/* Request dynamic */
 	}
 
@@ -199,7 +200,7 @@ int create_context_ind(struct pdp_t *pdp)
 		return 0;	/* Allready in use, or no more available */
 	}
 
-	pdp_ntoeua(&member->addr.v4, &pdp->eua);
+	in46a_to_eua(&member->addr, &pdp->eua);
 	pdp->peer = member;
 	pdp->ipif = tun;	/* TODO */
 	member->peer = pdp;
@@ -224,14 +225,18 @@ int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
 	struct ippoolm_t *ipm;
 	struct in46_addr dst;
 	struct iphdr *iph = (struct iphdr *)pack;
+	struct ip6_hdr *ip6h = (struct ip6_hdr *)pack;
 
 	if (iph->version == 4) {
 		if (len < sizeof(*iph) || len < 4*iph->ihl)
 			return -1;
 		dst.len = 4;
 		dst.v4.s_addr = iph->daddr;
+	} else if (iph->version == 6) {
+		dst.len = 16;
+		dst.v6 = ip6h->ip6_dst;
 	} else {
-		LOGP(DGGSN, LOGL_NOTICE, "non-IPv4 packet received from tun\n");
+		LOGP(DGGSN, LOGL_NOTICE, "non-IPv packet received from tun\n");
 		return -1;
 	}
 

lib/in46_addr.c

@@ -146,3 +146,63 @@ int in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net,
 		return 0;
 	}
 }
+
+/*! Convert given PDP End User Address to in46_addr
+ *  \returns 0 on success; negative on error */
+int in46a_to_eua(const struct in46_addr *src, struct ul66_t *eua)
+{
+	switch (src->len) {
+	case 4:
+		eua->l = 6;
+		eua->v[0] = 0xf1;	/* IETF */
+		eua->v[1] = 0x21;	/* IPv4 */
+		memcpy(&eua->v[2], &src->v4, 4);	/* Copy a 4 byte address */
+		break;
+	case 16:
+		eua->l = 18;
+		eua->v[0] = 0xf1;	/* IETF */
+		eua->v[1] = 0x57;	/* IPv6 */
+		memcpy(&eua->v[2], &src->v6, 16);	/* Copy a 16 byte address */
+		break;
+	default:
+		return -1;
+	}
+	return 0;
+}
+
+/*! Convert given in46_addr to PDP End User Address
+ *  \returns 0 on success; negative on error */
+int in46a_from_eua(const struct ul66_t *eua, struct in46_addr *dst)
+{
+	if (eua->l < 2)
+		goto default_to_dyn_v4;
+
+	if (eua->v[0] != 0xf1)
+		return -1;
+
+	switch (eua->v[1]) {
+	case 0x21:
+		dst->len = 4;
+		if (eua->l >= 6)
+			memcpy(&dst->v4, &eua->v[2], 4);	/* Copy a 4 byte address */
+		else
+			dst->v4.s_addr = 0;
+		break;
+	case 0x57:
+		dst->len = 16;
+		if (eua->l >= 18)
+			memcpy(&dst->v6, &eua->v[2], 16);	/* Copy a 16 byte address */
+		else
+			memset(&dst->v6, 0, 16);
+		break;
+	default:
+		return -1;
+	}
+	return 0;
+
+default_to_dyn_v4:
+	/* assume dynamic IPv4 by default */
+	dst->len = 4;
+	dst->v4.s_addr = 0;
+	return 0;
+}

lib/in46_addr.h

@@ -2,6 +2,8 @@
 #include <stdint.h>
 #include <netinet/in.h>
 
+#include "../gtp/pdp.h"
+
 /* a simple wrapper around an in6_addr to also contain the length of the address,
  * thereby implicitly indicating the address family of the address */
 struct in46_addr {
@@ -17,3 +19,6 @@ extern int in46a_to_sas(struct sockaddr_storage *out, const struct in46_addr *in
 extern const char *in46a_ntop(const struct in46_addr *in, char *dst, socklen_t dst_size);
 extern int in46a_equal(const struct in46_addr *a, const struct in46_addr *b);
 extern int in46a_within_mask(const struct in46_addr *addr, const struct in46_addr *net, size_t prefixlen);
+
+int in46a_to_eua(const struct in46_addr *src, struct ul66_t *eua);
+int in46a_from_eua(const struct ul66_t *eua, struct in46_addr *dst);

sgsnemu/sgsnemu.c

@@ -1329,7 +1329,7 @@ int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
 		return EOF;	/* Not what we expected */
 	}
 
-	if (pdp_euaton(&pdp->eua, &addr.v4)) {
+	if (in46a_from_eua(&pdp->eua, &addr)) {
 		printf
 		    ("Received create PDP context response. Cause value: %d\n",
 		     cause);