[MERGED] osmo-ggsn[master]: ggsn: Avoid crash on wrong EUA type

[Harald Welte]

Harald Welte has submitted this change and it was merged.

Change subject: ggsn: Avoid crash on wrong EUA type
......................................................................


ggsn: Avoid crash on wrong EUA type

If the EUA in the Create PDP Context Request was not supported by
the given APN (e.g. IPv6 request for a v4-only APN), we crashed.

Avoid this and add proper handling of this error case.

Change-Id: I8d1f7ec727c5d2d4427232015f81ed57d3440dff
---
M ggsn/ggsn.c
1 file changed, 28 insertions(+), 0 deletions(-)

Approvals:
  Harald Welte: Looks good to me, approved
  Jenkins Builder: Verified



diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index 67d040f..29d8473 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -432,6 +432,20 @@
 	msgb_free(msg);
 }
 
+static bool apn_supports_ipv4(const struct apn_ctx *apn)
+{
+	if (apn->v4.cfg.static_prefix.addr.len  || apn->v4.cfg.dynamic_prefix.addr.len)
+		return true;
+	return false;
+}
+
+static bool apn_supports_ipv6(const struct apn_ctx *apn)
+{
+	if (apn->v6.cfg.static_prefix.addr.len  || apn->v6.cfg.dynamic_prefix.addr.len)
+		return true;
+	return false;
+}
+
 int create_context_ind(struct pdp_t *pdp)
 {
 	static char name_buf[256];
@@ -483,6 +497,10 @@
 	}
 
 	if (addr.len == sizeof(struct in_addr)) {
+		/* does this APN actually have an IPv4 pool? */
+		if (!apn_supports_ipv4(apn))
+			goto err_wrong_af;
+
 		rc = ippool_newip(apn->v4.pool, &member, &addr, 0);
 		if (rc < 0)
 			goto err_pool_full;
@@ -496,6 +514,11 @@
 		}
 	} else if (addr.len == sizeof(struct in6_addr)) {
 		struct in46_addr tmp;
+
+		/* does this APN actually have an IPv6 pool? */
+		if (!apn_supports_ipv6(apn))
+			goto err_wrong_af;
+
 		rc = ippool_newip(apn->v6.pool, &member, &addr, 0);
 		if (rc < 0)
 			goto err_pool_full;
@@ -534,6 +557,11 @@
 	LOGPPDP(LOGL_ERROR, pdp, "Cannot allocate IP address from pool (full!)\n");
 	gtp_create_context_resp(gsn, pdp, -rc);
 	return 0;	/* Already in use, or no more available */
+
+err_wrong_af:
+	LOGPPDP(LOGL_ERROR, pdp, "APN doesn't support requested EUA / AF type\n");
+	gtp_create_context_resp(gsn, pdp, GTPCAUSE_UNKNOWN_PDP);
+	return 0;
 }
 
 /* Internet-originated IP packet, needs to be sent via GTP towards MS */

-- 
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Gerrit-MessageType: merged
Gerrit-Change-Id: I8d1f7ec727c5d2d4427232015f81ed57d3440dff
Gerrit-PatchSet: 1
Gerrit-Project: osmo-ggsn
Gerrit-Branch: master
Gerrit-Owner: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder