bridge: allow enabling or disabling the multicast querier independently of IGMP snooping

In larger networks, especially big batman-adv meshes, it may be desirable to
enable IGMP snooping on every bridge without enabling the multicast querier
to specifically put the querier on a well-connected node.

This patch adds a new UCI option 'multicast_querier' for bridges which allows
this. The default is still the value of the 'igmp_snooping' option to maintain
backwards compatiblity.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

3 files changed, 9 insertions, 2 deletions

diff --git a/bridge.c b/bridge.c
index 7076fd7..c5e17a4 100644
--- a/bridge.c
+++ b/bridge.c
@@ -32,6 +32,7 @@ enum {
 	BRIDGE_ATTR_HELLO_TIME,
 	BRIDGE_ATTR_MAX_AGE,
 	BRIDGE_ATTR_BRIDGE_EMPTY,
+	BRIDGE_ATTR_MULTICAST_QUERIER,
 	__BRIDGE_ATTR_MAX
 };
 
@@ -45,6 +46,7 @@ static const struct blobmsg_policy bridge_attrs[__BRIDGE_ATTR_MAX] = {
 	[BRIDGE_ATTR_MAX_AGE] = { "max_age", BLOBMSG_TYPE_INT32 },
 	[BRIDGE_ATTR_IGMP_SNOOP] = { "igmp_snooping", BLOBMSG_TYPE_BOOL },
 	[BRIDGE_ATTR_BRIDGE_EMPTY] = { "bridge_empty", BLOBMSG_TYPE_BOOL },
+	[BRIDGE_ATTR_MULTICAST_QUERIER] = { "multicast_querier", BLOBMSG_TYPE_BOOL },
 };
 
 static const struct uci_blob_param_info bridge_attr_info[__BRIDGE_ATTR_MAX] = {
@@ -548,6 +550,7 @@ bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 	cfg->stp = false;
 	cfg->forward_delay = 2;
 	cfg->igmp_snoop = true;
+	cfg->multicast_querier = true;
 	cfg->bridge_empty = false;
 	cfg->priority = 0x7FFF;
 
@@ -561,7 +564,10 @@ bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 		cfg->priority = blobmsg_get_u32(cur);
 
 	if ((cur = tb[BRIDGE_ATTR_IGMP_SNOOP]))
-		cfg->igmp_snoop = blobmsg_get_bool(cur);
+		cfg->multicast_querier = cfg->igmp_snoop = blobmsg_get_bool(cur);
+
+	if ((cur = tb[BRIDGE_ATTR_MULTICAST_QUERIER]))
+		cfg->multicast_querier = blobmsg_get_bool(cur);
 
 	if ((cur = tb[BRIDGE_ATTR_AGEING_TIME])) {
 		cfg->ageing_time = blobmsg_get_u32(cur);
diff --git a/system-linux.c b/system-linux.c
index 7a443ad..2b52cea 100644
--- a/system-linux.c
+++ b/system-linux.c
@@ -799,7 +799,7 @@ int system_bridge_addbr(struct device *bridge, struct bridge_config *cfg)
 		bridge->ifname, cfg->igmp_snoop ? "1" : "0");
 
 	system_set_dev_sysctl("/sys/devices/virtual/net/%s/bridge/multicast_querier",
-		bridge->ifname, cfg->igmp_snoop ? "1" : "0");
+		bridge->ifname, cfg->multicast_querier ? "1" : "0");
 
 	args[0] = BRCTL_SET_BRIDGE_PRIORITY;
 	args[1] = cfg->priority;
diff --git a/system.h b/system.h
index 9a2326b..94e0dd9 100644
--- a/system.h
+++ b/system.h
@@ -50,6 +50,7 @@ struct bridge_config {
 	enum bridge_opt flags;
 	bool stp;
 	bool igmp_snoop;
+	bool multicast_querier;
 	unsigned short priority;
 	int forward_delay;
 	bool bridge_empty;