From 689c5ad56338b4a9ed81ac9a58d13689a24ba955 Mon Sep 17 00:00:00 2001
From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Thu, 7 May 2015 08:57:58 +0200
Subject: [PATCH] allow specifying a subnet id

---
 src/config.c        | 4 ++++
 src/ocserv-args.def | 5 +++++
 src/vpn.h           | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/src/config.c b/src/config.c
index cdaea4cd..e1a0a74d 100644
--- a/src/config.c
+++ b/src/config.c
@@ -163,6 +163,7 @@ static struct cfg_options available_options[] = {
 
 	{ .name = "ipv6-network", .type = OPTION_STRING, .mandatory = 0 },
 	{ .name = "ipv6-prefix", .type = OPTION_NUMERIC, .mandatory = 0 },
+	{ .name = "ipv6-subnet-id-length", .type = OPTION_NUMERIC, .mandatory = 0 },
 	{ .name = "route-add-cmd", .type = OPTION_STRING, .mandatory = 0 },
 	{ .name = "route-del-cmd", .type = OPTION_STRING, .mandatory = 0 },
 	{ .name = "config-per-user", .type = OPTION_STRING, .mandatory = 0 },
@@ -886,6 +887,9 @@ unsigned urlfw_size = 0;
 	}
 
 	READ_STRING("ipv6-network", config->network.ipv6);
+	READ_NUMERIC("ipv6-subnet-id-length", config->network.ipv6_subnet_id_length);
+	if (config->network.ipv6_subnet_id_length == 0)
+		config->network.ipv6_subnet_id_length = DEFAULT_SUBNET_ID_LENGTH;
 
 	prefix = extract_prefix(config->network.ipv6);
 	if (prefix == 0) {
diff --git a/src/ocserv-args.def b/src/ocserv-args.def
index 0cb99965..beb9cfb2 100644
--- a/src/ocserv-args.def
+++ b/src/ocserv-args.def
@@ -450,6 +450,11 @@ ipv4-netmask = 255.255.255.0
 # The IPv6 subnet that leases will be given from.
 #ipv6-network = fda9:4efe:7e3b:03ea::/64
 
+# The length, in bits, of the subnet id to give addresses to clients.
+# This also defines the maximum number of clients the server can handle,
+# i.e., 2^(length).
+#ipv6-subnet-id-length = 16
+
 # The advertized DNS server. Use multiple lines for
 # multiple servers.
 # dns = fc00::4be0
diff --git a/src/vpn.h b/src/vpn.h
index 66876b42..78f19522 100644
--- a/src/vpn.h
+++ b/src/vpn.h
@@ -66,6 +66,7 @@ typedef enum {
 #define DEFAULT_KKDCP_POINTS 1
 #define DEFAULT_MAX_BAN_SCORE (MAX_PASSWORD_TRIES*DEFAULT_PASSWORD_POINTS)
 #define DEFAULT_BAN_RESET_TIME 300
+#define DEFAULT_SUBNET_ID_LENGTH 16
 
 #define MIN_NO_COMPRESS_LIMIT 64
 #define DEFAULT_NO_COMPRESS_LIMIT 256
@@ -218,6 +219,7 @@ struct vpn_st {
 
 	char *ipv6;
 	char *ipv6_local; /* local IPv6 address */
+	unsigned ipv6_subnet_id_length;
 	unsigned int mtu;
 
 	char **routes;