From: Hans Dedecker <dedeckeh@gmail.com>
Date: Thu, 11 May 2017 13:34:27 +0000 (+0200)
Subject: config: make RA mtu configurable via UCI
X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fodhcpd.git;a=commitdiff_plain;h=9dd5316deae6402de68ddc8a08d1a6b496101828

config: make RA mtu configurable via UCI

Allow to specify the router advertisement mtu via the uci parameter
ra_mtu. In case the config parameter is not set the MTU is taken from
the interface as before.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
---

diff --git a/README b/README
index 9119071..3ad17f9 100644
--- a/README
+++ b/README
@@ -116,6 +116,8 @@ ra_lifetime	integer	1800			Value to be placed in Router
 ra_useleasetime	bool	0			Use configured leasetime as
 						limit for the preferred and
 						valid lifetime of a prefix
+ra_mtu		integer 0			MTU to be advertised in
+						RA messages
 ndproxy_routing	bool	1			Learn routes from NDP
 ndproxy_slave	bool	0			NDProxy external slave
 
diff --git a/src/config.c b/src/config.c
index acf30de..d6b4e81 100644
--- a/src/config.c
+++ b/src/config.c
@@ -50,6 +50,7 @@ enum {
 	IFACE_ATTR_RA_MAXINTERVAL,
 	IFACE_ATTR_RA_LIFETIME,
 	IFACE_ATTR_RA_USELEASETIME,
+	IFACE_ATTR_RA_MTU,
 	IFACE_ATTR_PD_MANAGER,
 	IFACE_ATTR_PD_CER,
 	IFACE_ATTR_NDPROXY_ROUTING,
@@ -88,6 +89,7 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
 	[IFACE_ATTR_RA_MAXINTERVAL] = { .name = "ra_maxinterval", .type = BLOBMSG_TYPE_INT32 },
 	[IFACE_ATTR_RA_LIFETIME] = { .name = "ra_lifetime", .type = BLOBMSG_TYPE_INT32 },
 	[IFACE_ATTR_RA_USELEASETIME] = { .name = "ra_useleasetime", .type = BLOBMSG_TYPE_BOOL },
+	[IFACE_ATTR_RA_MTU] = { .name = "ra_mtu", .type = BLOBMSG_TYPE_INT32 },
 	[IFACE_ATTR_NDPROXY_ROUTING] = { .name = "ndproxy_routing", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_NDPROXY_SLAVE] = { .name = "ndproxy_slave", .type = BLOBMSG_TYPE_BOOL },
 };
@@ -594,6 +596,12 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 	if ((c = tb[IFACE_ATTR_RA_MANAGEMENT]))
 		iface->managed = blobmsg_get_u32(c);
 
+	if ((c = tb[IFACE_ATTR_RA_MTU])) {
+		iface->ra_mtu = blobmsg_get_u32(c);
+		if (iface->ra_mtu < 1280)
+			goto err;
+	}
+
 	if ((c = tb[IFACE_ATTR_RA_OFFLINK]))
 		iface->ra_not_onlink = blobmsg_get_bool(c);
 
diff --git a/src/odhcpd.h b/src/odhcpd.h
index 334276e..50827a4 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -162,6 +162,7 @@ struct interface {
 	int ra_maxinterval;
 	int ra_mininterval;
 	int ra_lifetime;
+	uint32_t ra_mtu;
 
 	// DHCPv4
 	struct in_addr dhcpv4_start;
diff --git a/src/router.c b/src/router.c
index feae5c7..a31bf4e 100644
--- a/src/router.c
+++ b/src/router.c
@@ -259,9 +259,12 @@ static uint16_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
 static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
 {
 	time_t now = odhcpd_time();
-	int mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
+	uint32_t mtu = iface->ra_mtu;
 	int hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
 
+	if (mtu == 0)
+		 mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
+
 	if (mtu < 1280)
 		mtu = 1280;