ipv6pool: added gw-ip6-address option and special handling for /128 prefixes

If pool specified with /128 prefix length, then initialize intf_id by gw_ip6_address and peer_intf_id by generated pool address.

3 files changed, 23 insertions, 4 deletions

diff --git a/accel-pppd/accel-ppp.conf b/accel-pppd/accel-ppp.conf
index 1da9dc3f..edab749e 100644
--- a/accel-pppd/accel-ppp.conf
+++ b/accel-pppd/accel-ppp.conf
@@ -262,6 +262,7 @@ burst=3
 timeout=60
 
 [ipv6-pool]
+#gw-ip6-address=fc00:0:1::1
 fc00:0:1::/48,64
 delegate=fc00:1::/36,48
 
diff --git a/accel-pppd/accel-ppp.conf.5 b/accel-pppd/accel-ppp.conf.5
index c69c5ed0..ce4550d1 100644
--- a/accel-pppd/accel-ppp.conf.5
+++ b/accel-pppd/accel-ppp.conf.5
@@ -873,6 +873,8 @@ fc00:0:1:ffff::/64
 .BI "delegate=" ipv6prefix/mask,prefix_len
 Specifies range of prefixes to delegate to clients through DHCPv6 prefix delegation (rfc3633).
 Format is same as described above.
+.BI "gw-ip6-address=" ipv6address
+Specifies gateway address (used only for /128 prefixes)
 .SH [connlimit]
 .br
 This module limits connection rate from single source.
diff --git a/accel-pppd/extra/ipv6pool.c b/accel-pppd/extra/ipv6pool.c
index 6887ea32..6fa5cc53 100644
--- a/accel-pppd/extra/ipv6pool.c
+++ b/accel-pppd/extra/ipv6pool.c
@@ -32,6 +32,7 @@ static LIST_HEAD(ippool);
 static LIST_HEAD(dppool);
 static spinlock_t pool_lock;
 static struct ipdb_t ipdb;
+static struct in6_addr conf_gw_addr;
 
 static void in6_addr_add(struct in6_addr *res, const struct in6_addr *arg)
 {
@@ -182,18 +183,30 @@ err:
 static struct ipv6db_item_t *get_ip(struct ap_session *ses)
 {
 	struct ippool_item_t *it;
+	struct ipv6db_addr_t *a;
 
 	spin_lock(&pool_lock);
 	if (!list_empty(&ippool)) {
 		it = list_entry(ippool.next, typeof(*it), entry);
 		list_del(&it->entry);
-		it->it.intf_id = 0;
-		it->it.peer_intf_id = 0;
 	} else
 		it = NULL;
 	spin_unlock(&pool_lock);
 
-	return it ? &it->it : NULL;
+	if (it) {
+		a = list_entry(it->it.addr_list.next, typeof(*a), entry);
+		if (a->prefix_len == 128) {
+			memcpy(&it->it.intf_id, conf_gw_addr.s6_addr + 8, 8);
+			memcpy(&it->it.peer_intf_id, a->addr.s6_addr + 8, 8);
+		} else {
+			it->it.intf_id = 0;
+			it->it.peer_intf_id = 0;
+		}
+
+		return &it->it;
+	}
+
+	return NULL;
 }
 
 static void put_ip(struct ap_session *ses, struct ipv6db_item_t *it)
@@ -247,7 +260,10 @@ static void ippool_init(void)
 		return;
 
 	list_for_each_entry(opt, &s->items, entry) {
-		if (!strcmp(opt->name, "delegate"))
+		if (!strcmp(opt->name, "gw-ip6-address")) {
+			if (inet_pton(AF_INET6, opt->val, &conf_gw_addr) == 0)
+				log_error("ipv6_pool: failed to parse gw-ip6-address\n");
+		} else if (!strcmp(opt->name, "delegate"))
 			add_prefix(1, opt->val);
 		else
 			add_prefix(0, opt->name);