[LEDE-DEV] [PATCH] netifd: Add option to configure locktime for each device

[Alin Nastac]

The UCI parameter neighlocktime allows to control the hardware
address to IP mapping lock time in the IPv4 neighbour table.

The IPv6 lock time was not set because it is not used at all in any
kernel versions, hardware address override being controlled in this case
by the override flag present in the NA packet.

Signed-off-by: Alin Nastac <alin.nastac at gmail.com>
---
 device.c       | 10 ++++++++++
 device.h       |  3 +++
 system-linux.c | 20 ++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/device.c b/device.c
index 43881e5..306496c 100644
--- a/device.c
+++ b/device.c
@@ -59,6 +59,7 @@ static const struct blobmsg_policy dev_attrs[__DEV_ATTR_MAX] = {
 	[DEV_ATTR_LEARNING] = { .name ="learning", .type = BLOBMSG_TYPE_BOOL },
 	[DEV_ATTR_UNICAST_FLOOD] = { .name ="unicast_flood", .type = BLOBMSG_TYPE_BOOL },
 	[DEV_ATTR_SENDREDIRECTS] = { .name = "sendredirects", .type = BLOBMSG_TYPE_BOOL },
+	[DEV_ATTR_NEIGHLOCKTIME] = { .name = "neighlocktime", .type = BLOBMSG_TYPE_INT32 },
 };
 
 const struct uci_blob_param_list device_attr_list = {
@@ -217,6 +218,8 @@ device_merge_settings(struct device *dev, struct device_settings *n)
 		s->neigh4gcstaletime : os->neigh4gcstaletime;
 	n->neigh6gcstaletime = s->flags & DEV_OPT_NEIGHGCSTALETIME ?
 		s->neigh6gcstaletime : os->neigh6gcstaletime;
+	n->neigh4locktime = s->flags & DEV_OPT_NEIGHLOCKTIME ?
+		s->neigh4locktime : os->neigh4locktime;
 	n->dadtransmits = s->flags & DEV_OPT_DADTRANSMITS ?
 		s->dadtransmits : os->dadtransmits;
 	n->multicast = s->flags & DEV_OPT_MULTICAST ?
@@ -314,6 +317,11 @@ device_init_settings(struct device *dev, struct blob_attr **tb)
 		s->flags |= DEV_OPT_NEIGHGCSTALETIME;
 	}
 
+	if ((cur = tb[DEV_ATTR_NEIGHLOCKTIME])) {
+		s->neigh4locktime = blobmsg_get_u32(cur);
+		s->flags |= DEV_OPT_NEIGHLOCKTIME;
+	}
+
 	if ((cur = tb[DEV_ATTR_RPS])) {
 		s->rps = blobmsg_get_bool(cur);
 		s->flags |= DEV_OPT_RPS;
@@ -1044,6 +1052,8 @@ device_dump_status(struct blob_buf *b, struct device *dev)
 			blobmsg_add_u32(b, "neigh4gcstaletime", st.neigh4gcstaletime);
 			blobmsg_add_u32(b, "neigh6gcstaletime", st.neigh6gcstaletime);
 		}
+		if (st.flags & DEV_OPT_NEIGHLOCKTIME)
+			blobmsg_add_u32(b, "neigh4locktime", st.neigh4locktime);
 		if (st.flags & DEV_OPT_DADTRANSMITS)
 			blobmsg_add_u32(b, "dadtransmits", st.dadtransmits);
 		if (st.flags & DEV_OPT_MULTICAST_TO_UNICAST)
diff --git a/device.h b/device.h
index 87236d4..feb865f 100644
--- a/device.h
+++ b/device.h
@@ -51,6 +51,7 @@ enum {
 	DEV_ATTR_UNICAST_FLOOD,
 	DEV_ATTR_NEIGHGCSTALETIME,
 	DEV_ATTR_SENDREDIRECTS,
+	DEV_ATTR_NEIGHLOCKTIME,
 	__DEV_ATTR_MAX,
 };
 
@@ -103,6 +104,7 @@ enum {
 	DEV_OPT_NEIGHGCSTALETIME	= (1 << 19),
 	DEV_OPT_MULTICAST_FAST_LEAVE	= (1 << 20),
 	DEV_OPT_SENDREDIRECTS		= (1 << 21),
+	DEV_OPT_NEIGHLOCKTIME		= (1 << 22),
 };
 
 /* events broadcasted to all users of a device */
@@ -160,6 +162,7 @@ struct device_settings {
 	unsigned int neigh6reachabletime;
 	unsigned int neigh4gcstaletime;
 	unsigned int neigh6gcstaletime;
+	unsigned int neigh4locktime;
 	bool rps;
 	bool xps;
 	unsigned int dadtransmits;
diff --git a/system-linux.c b/system-linux.c
index 2f15bf1..a77ff5f 100644
--- a/system-linux.c
+++ b/system-linux.c
@@ -316,6 +316,11 @@ static void system_set_neigh6gcstaletime(struct device *dev, const char *val)
 	system_set_dev_sysctl("/proc/sys/net/ipv6/neigh/%s/gc_stale_time", dev->ifname, val);
 }
 
+static void system_set_neigh4locktime(struct device *dev, const char *val)
+{
+	system_set_dev_sysctl("/proc/sys/net/ipv4/neigh/%s/locktime", dev->ifname, val);
+}
+
 static void system_set_dadtransmits(struct device *dev, const char *val)
 {
 	system_set_dev_sysctl("/proc/sys/net/ipv6/conf/%s/dad_transmits", dev->ifname, val);
@@ -484,6 +489,12 @@ static int system_get_neigh6gcstaletime(struct device *dev, char *buf, const siz
 			dev->ifname, buf, buf_sz);
 }
 
+static int system_get_neigh4locktime(struct device *dev, char *buf, const size_t buf_sz)
+{
+	return system_get_dev_sysctl("/proc/sys/net/ipv4/neigh/%s/locktime",
+			dev->ifname, buf, buf_sz);
+}
+
 static int system_get_dadtransmits(struct device *dev, char *buf, const size_t buf_sz)
 {
 	return system_get_dev_sysctl("/proc/sys/net/ipv6/conf/%s/dad_transmits",
@@ -1285,6 +1296,11 @@ system_if_get_settings(struct device *dev, struct device_settings *s)
 		s->flags |= DEV_OPT_NEIGHREACHABLETIME;
 	}
 
+	if (!system_get_neigh4locktime(dev, buf, sizeof(buf))) {
+		s->neigh4locktime = strtoul(buf, NULL, 0);
+		s->flags |= DEV_OPT_NEIGHLOCKTIME;
+	}
+
 	if (!system_get_neigh4gcstaletime(dev, buf, sizeof(buf))) {
 		s->neigh4gcstaletime = strtoul(buf, NULL, 0);
 		s->flags |= DEV_OPT_NEIGHGCSTALETIME;
@@ -1394,6 +1410,10 @@ system_if_apply_settings(struct device *dev, struct device_settings *s, unsigned
 		snprintf(buf, sizeof(buf), "%d", s->neigh6reachabletime);
 		system_set_neigh6reachabletime(dev, buf);
 	}
+	if (s->flags & DEV_OPT_NEIGHLOCKTIME & apply_mask) {
+		snprintf(buf, sizeof(buf), "%d", s->neigh4locktime);
+		system_set_neigh4locktime(dev, buf);
+	}
 	if (s->flags & DEV_OPT_NEIGHGCSTALETIME & apply_mask) {
 		snprintf(buf, sizeof(buf), "%d", s->neigh4gcstaletime);
 		system_set_neigh4gcstaletime(dev, buf);
-- 
1.7.12.4