@@ -3072,6 +3072,76 @@
}
/**
+ * This methods checks if a client instance is allowed to use an address
+ *
+ * Reasons for disallowing a specific address are that a client might be
+ * already using that address. In that case the method needs to decide
+ * if this instance can kick out the other instance.
+ *
+ * The method will then terminate the other instance if that check was
+ * positive.
+ */
+static bool
+multi_check_dest_addr_allowed(struct multi_context *m, struct multi_instance *mi, struct mroute_addr *real)
+{
+ struct hash *hash = m->hash;
+ const uint64_t hv = hash_value(hash, real);
+ struct hash_bucket *bucket = hash_bucket(hash, hv);
+
+ /* make sure that we don't assign the client to an address taken by
+ * another client */
+ struct hash_element *he = hash_lookup_fast(hash, bucket, real, hv);
+ if (!he)
+ {
+ /* Address is not taken, everything is fine. */
+ return true;
+ }
+
+ struct multi_instance *ex_mi = he->value;
+
+ struct tls_multi *m1 = mi->context.c2.tls_multi;
+ struct tls_multi *m2 = ex_mi->context.c2.tls_multi;
+
+ struct gc_arena gc = gc_new();
+ int ret = false;
+
+ /* do not allow if target address is taken by client with another cert */
+ if (!cert_hash_compare(m1->locked_cert_hash_set, m2->locked_cert_hash_set))
+ {
+ msg(D_MULTI_LOW, "Disallow float to an address taken by another client %s",
+ multi_instance_string(ex_mi, false, &gc));
+
+ mi->context.c2.buf.len = 0;
+ goto done;
+ }
+
+ /* It doesn't make sense to let a peer float to the address it already
+ * has, so we disallow it. This can happen if a DCO netlink notification
+ * gets lost and we miss a floating step.
+ */
+ if (m1->rx_peer_id == m2->rx_peer_id)
+ {
+ msg(M_WARN,
+ "disallowing peer %" PRIu32 " (%s) from floating to "
+ "its own address (%s)",
+ m1->rx_peer_id, tls_common_name(mi->context.c2.tls_multi, false),
+ mroute_addr_print(&mi->real, &gc));
+ goto done;
+ }
+
+ msg(D_MULTI_LOW,
+ "closing instance %s due to float collision with %s "
+ "using the same certificate",
+ multi_instance_string(ex_mi, false, &gc), multi_instance_string(mi, false, &gc));
+ multi_close_instance(m, ex_mi, false);
+ ret = true;
+
+done:
+ gc_free(&gc);
+ return ret;
+}
+
+/**
* Handles peer floating.
*
* If peer is floated to a taken address, either drops packet
@@ -3083,8 +3153,6 @@
multi_process_float(struct multi_context *m, struct multi_instance *mi, struct link_socket *sock)
{
struct mroute_addr real = { 0 };
- struct hash *hash = m->hash;
- struct gc_arena gc = gc_new();
if (mi->real.type & MR_WITH_PROTO)
{
@@ -3094,53 +3162,16 @@
if (!mroute_extract_openvpn_sockaddr(&real, &m->top.c2.from.dest, true))
{
- goto done;
+ return;
}
- const uint64_t hv = hash_value(hash, &real);
- struct hash_bucket *bucket = hash_bucket(hash, hv);
-
- /* make sure that we don't float to an address taken by another client */
- struct hash_element *he = hash_lookup_fast(hash, bucket, &real, hv);
- if (he)
+ if (!multi_check_dest_addr_allowed(m, mi, &real))
{
- struct multi_instance *ex_mi = (struct multi_instance *)he->value;
-
- struct tls_multi *m1 = mi->context.c2.tls_multi;
- struct tls_multi *m2 = ex_mi->context.c2.tls_multi;
-
- /* do not float if target address is taken by client with another cert */
- if (!cert_hash_compare(m1->locked_cert_hash_set, m2->locked_cert_hash_set))
- {
- msg(D_MULTI_LOW, "Disallow float to an address taken by another client %s",
- multi_instance_string(ex_mi, false, &gc));
-
- mi->context.c2.buf.len = 0;
-
- goto done;
- }
-
- /* It doesn't make sense to let a peer float to the address it already
- * has, so we disallow it. This can happen if a DCO netlink notification
- * gets lost and we miss a floating step.
- */
- if (m1->rx_peer_id == m2->rx_peer_id)
- {
- msg(M_WARN,
- "disallowing peer %" PRIu32 " (%s) from floating to "
- "its own address (%s)",
- m1->rx_peer_id, tls_common_name(mi->context.c2.tls_multi, false),
- mroute_addr_print(&mi->real, &gc));
- goto done;
- }
-
- msg(D_MULTI_LOW,
- "closing instance %s due to float collision with %s "
- "using the same certificate",
- multi_instance_string(ex_mi, false, &gc), multi_instance_string(mi, false, &gc));
- multi_close_instance(m, ex_mi, false);
+ return;
}
+ struct gc_arena gc = gc_new();
+
msg(D_MULTI_MEDIUM, "peer %" PRIu32 " (%s) floated from %s to %s",
mi->context.c2.tls_multi->rx_peer_id,
tls_common_name(mi->context.c2.tls_multi, false),
@@ -3169,7 +3200,6 @@
ASSERT(hash_add(m->cid_hash, &mi->context.c2.mda_context.cid, mi, true));
#endif
-done:
gc_free(&gc);
}