kernel-gtp: support IPv6 on inner layer

Related: OS#6096
Change-Id: I3df47b6c209f1e2f8254ba139581d6e622c6b35f

3 files changed, 70 insertions, 43 deletions

diff --git a/TODO-RELEASE b/TODO-RELEASE
index d8cc3af..22cfd1d 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -8,3 +8,4 @@
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what		description / commit summary line
 libgtp		REMOVE		remove GTP cause defines of reserved values
+libgtpnl > 1.2.5		gtp_tunnel_set_family()
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index cec043d..db906ea 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -202,11 +202,6 @@ int apn_start(struct apn_ctx *apn)
 		break;
 	case APN_GTPU_MODE_KERNEL_GTP:
 		LOGPAPN(LOGL_INFO, apn, "Opening Kernel GTP device %s\n", apn->tun.cfg.dev_name);
-		if (apn->cfg.apn_type_mask & (APN_TYPE_IPv6|APN_TYPE_IPv4v6)) {
-			LOGPAPN(LOGL_ERROR, apn, "Kernel GTP currently supports only IPv4\n");
-			apn_stop(apn);
-			return -1;
-		}
 		if (gsn == NULL) {
 			/* skip bringing up the APN now if the GSN is not initialized yet.
 			 * This happens during initial load of the config file, as the
@@ -536,8 +531,7 @@ int create_context_ind(struct pdp_t *pdp)
 
 	in46a_to_eua(addr, num_addr, &pdp->eua);
 
-	if (apn->cfg.gtpu_mode == APN_GTPU_MODE_KERNEL_GTP && apn_supports_ipv4(apn)) {
-		/* TODO: In IPv6, EUA doesn't contain the actual IP addr/prefix! */
+	if (apn->cfg.gtpu_mode == APN_GTPU_MODE_KERNEL_GTP) {
 		if (gtp_kernel_tunnel_add(pdp, apn->tun.cfg.dev_name) < 0) {
 			LOGPPDP(LOGL_ERROR, pdp, "Cannot add tunnel to kernel: %s\n", strerror(errno));
 			gtp_create_context_resp(gsn, pdp, GTPCAUSE_SYS_FAIL);
diff --git a/lib/gtp-kernel.c b/lib/gtp-kernel.c
index 2a731e6..9bfb380 100644
--- a/lib/gtp-kernel.c
+++ b/lib/gtp-kernel.c
@@ -104,61 +104,93 @@ void gtp_kernel_stop(const char *devname)
 
 int gtp_kernel_tunnel_add(struct pdp_t *pdp, const char *devname)
 {
-	struct in_addr ms, sgsn;
+	int ms_addr_count;
+	struct in46_addr ms[2];
+	struct in46_addr sgsn;
 	struct gtp_tunnel *t;
 	int ret;
 
 	pdp_debug(__func__, devname, pdp);
 
-	t = gtp_tunnel_alloc();
-	if (t == NULL)
-		return -1;
-
-	memcpy(&ms, &pdp->eua.v[2], sizeof(struct in_addr));
-	memcpy(&sgsn, &pdp->gsnrc.v[0], sizeof(struct in_addr));
-
-	gtp_tunnel_set_ifidx(t, if_nametoindex(devname));
-	gtp_tunnel_set_version(t, pdp->version);
-	gtp_tunnel_set_ms_ip4(t, &ms);
-	gtp_tunnel_set_sgsn_ip4(t, &sgsn);
-	if (pdp->version == 0) {
-		gtp_tunnel_set_tid(t, pdp_gettid(pdp->imsi, pdp->nsapi));
-		gtp_tunnel_set_flowid(t, pdp->flru);
-	} else {
-		gtp_tunnel_set_i_tei(t, pdp->teid_own);
-		/* use the TEI advertised by SGSN when sending packets
-		 * towards the SGSN */
-		gtp_tunnel_set_o_tei(t, pdp->teid_gn);
+	in46a_from_gsna(&pdp->gsnrc, &sgsn);
+
+	ms_addr_count = in46a_from_eua(&pdp->eua, ms);
+
+	for (int i = 0; i < ms_addr_count; i++) {
+		t = gtp_tunnel_alloc();
+		if (t == NULL)
+			return -1;
+
+		gtp_tunnel_set_ifidx(t, if_nametoindex(devname));
+		gtp_tunnel_set_version(t, pdp->version);
+
+		if (in46a_to_af(&ms[i]) == AF_INET)
+			gtp_tunnel_set_ms_ip4(t, &ms[i].v4);
+		else {
+			/* In IPv6, EUA doesn't contain the actual IP
+			 * addr/prefix. Set higher bits to 0 to get the 64 bit
+			 * netmask. */
+			memset(((void *)&ms[i].v6) + 8, 0, 8);
+			gtp_tunnel_set_ms_ip6(t, &ms[i].v6);
+		}
+
+		if (in46a_to_af(&sgsn) == AF_INET)
+			gtp_tunnel_set_sgsn_ip4(t, &sgsn.v4);
+		else
+			gtp_tunnel_set_sgsn_ip6(t, &sgsn.v6);
+
+		if (pdp->version == 0) {
+			gtp_tunnel_set_tid(t, pdp_gettid(pdp->imsi, pdp->nsapi));
+			gtp_tunnel_set_flowid(t, pdp->flru);
+		} else {
+			gtp_tunnel_set_i_tei(t, pdp->teid_own);
+			/* use the TEI advertised by SGSN when sending packets
+			 * towards the SGSN */
+			gtp_tunnel_set_o_tei(t, pdp->teid_gn);
+		}
+
+		ret = gtp_add_tunnel(gtp_nl.genl_id, gtp_nl.nl, t);
+		gtp_tunnel_free(t);
+
+		if (ret != 0)
+			break;
 	}
 
-	ret = gtp_add_tunnel(gtp_nl.genl_id, gtp_nl.nl, t);
-	gtp_tunnel_free(t);
-
 	return ret;
 }
 
 int gtp_kernel_tunnel_del(struct pdp_t *pdp, const char *devname)
 {
+	int ms_addr_count;
+	struct in46_addr ms[2];
 	struct gtp_tunnel *t;
 	int ret;
 
 	pdp_debug(__func__, devname, pdp);
 
-	t = gtp_tunnel_alloc();
-	if (t == NULL)
-		return -1;
+	ms_addr_count = in46a_from_eua(&pdp->eua, ms);
 
-	gtp_tunnel_set_ifidx(t, if_nametoindex(devname));
-	gtp_tunnel_set_version(t, pdp->version);
-	if (pdp->version == 0) {
-		gtp_tunnel_set_tid(t, pdp_gettid(pdp->imsi, pdp->nsapi));
-		gtp_tunnel_set_flowid(t, pdp->flru);
-	} else {
-		gtp_tunnel_set_i_tei(t, pdp->teid_own);
-	}
+	for (int i = 0; i < ms_addr_count; i++) {
+		t = gtp_tunnel_alloc();
+		if (t == NULL)
+			return -1;
+
+		gtp_tunnel_set_ifidx(t, if_nametoindex(devname));
+		gtp_tunnel_set_family(t, in46a_to_af(&ms[i]));
+		gtp_tunnel_set_version(t, pdp->version);
+		if (pdp->version == 0) {
+			gtp_tunnel_set_tid(t, pdp_gettid(pdp->imsi, pdp->nsapi));
+			gtp_tunnel_set_flowid(t, pdp->flru);
+		} else {
+			gtp_tunnel_set_i_tei(t, pdp->teid_own);
+		}
 
-	ret = gtp_del_tunnel(gtp_nl.genl_id, gtp_nl.nl, t);
-	gtp_tunnel_free(t);
+		ret = gtp_del_tunnel(gtp_nl.genl_id, gtp_nl.nl, t);
+		gtp_tunnel_free(t);
+
+		if (ret != 0)
+			break;
+	}
 
 	return ret;
 }