[B.A.T.M.A.N.] [RFC v4 11/19] batman-adv: Add gateway mesh genl configuration

Sven Eckelmann
2019-01-19T15:56:18Z

The mesh/soft-interface can optimize the handling of DHCP packets. Instead
of flooding them through the whole mesh, it can be forwarded as unicast to
a specific gateway server. The originator which injects the packets in the
mesh has to select (based on sel_class thresholds) a responsible gateway
server. This is done by switching this originator to the gw_mode client.
The servers announce their forwarding bandwidth (download/upload) when the
gw_mode server was selected.

The BATADV_CMD_SET_MESH/BATADV_CMD_GET_MESH commands allow to set/get the
configuration of this feature using the attributes:

* u8 BATADV_ATTR_GW_MODE (0 == off, 1 == client, 2 == server)
* u32 BATADV_ATTR_GW_BANDWIDTH_DOWN (in 100 kbit/s steps)
* u32 BATADV_ATTR_GW_BANDWIDTH_UP (in 100 kbit/s steps)
* u32 BATADV_ATTR_GW_SEL_CLASS

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Antonio Quartulli <a@unstable.cc>
---
include/uapi/linux/batman_adv.h | 40 ++++++++++++++
net/batman-adv/gateway_client.c | 1 -
net/batman-adv/gateway_common.c | 1 +
net/batman-adv/gateway_common.h | 6 ---
net/batman-adv/netlink.c | 92 +++++++++++++++++++++++++++++++++
net/batman-adv/soft-interface.c | 2 +-
net/batman-adv/sysfs.c | 1 +
7 files changed, 135 insertions(+), 8 deletions(-)

diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index 847841b8..165272be 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -139,6 +139,20 @@ enum batadv_mcast_flags_priv {
BATADV_MCAST_FLAGS_QUERIER_IPV6_SHADOWING = (1 << 4),
};

+/**
+ * enum batadv_gw_modes - gateway mode of node
+ */
+enum batadv_gw_modes {
+ /** @BATADV_GW_MODE_OFF: gw mode disabled */
+ BATADV_GW_MODE_OFF,
+
+ /** @BATADV_GW_MODE_CLIENT: send DHCP requests to gw servers */
+ BATADV_GW_MODE_CLIENT,
+
+ /** @BATADV_GW_MODE_SERVER: announce itself as gatway server */
+ BATADV_GW_MODE_SERVER,
+};
+
/**
* enum batadv_nl_attrs - batman-adv netlink attributes
*/
@@ -403,6 +417,32 @@ enum batadv_nl_attrs {
*/
BATADV_ATTR_FRAGMENTATION_ENABLED,

+ /**
+ * @BATADV_ATTR_GW_BANDWIDTH_DOWN: defines the download bandwidth which
+ * is propagated by this node if %BATADV_ATTR_GW_BANDWIDTH_MODE was set
+ * to 'server'.
+ */
+ BATADV_ATTR_GW_BANDWIDTH_DOWN,
+
+ /**
+ * @BATADV_ATTR_GW_BANDWIDTH_UP: defines the upload bandwidth which
+ * is propagated by this node if %BATADV_ATTR_GW_BANDWIDTH_MODE was set
+ * to 'server'.
+ */
+ BATADV_ATTR_GW_BANDWIDTH_UP,
+
+ /**
+ * @BATADV_ATTR_GW_MODE: defines the state of the gateway features.
+ * Possible values are specified in enum batadv_gw_modes
+ */
+ BATADV_ATTR_GW_MODE,
+
+ /**
+ * @BATADV_ATTR_GW_SEL_CLASS: defines the selection criteria this node
+ * will use to choose a gateway if gw_mode was set to 'client'.
+ */
+ BATADV_ATTR_GW_SEL_CLASS,
+
/* add attributes above here, update the policy in netlink.c */

/**
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 0a6b9b30..f5811f61 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -47,7 +47,6 @@
#include <uapi/linux/batadv_packet.h>
#include <uapi/linux/batman_adv.h>

-#include "gateway_common.h"
#include "hard-interface.h"
#include "log.h"
#include "netlink.h"
diff --git a/net/batman-adv/gateway_common.c b/net/batman-adv/gateway_common.c
index 53d03adc..e064de45 100644
--- a/net/batman-adv/gateway_common.c
+++ b/net/batman-adv/gateway_common.c
@@ -28,6 +28,7 @@
#include <linux/stddef.h>
#include <linux/string.h>
#include <uapi/linux/batadv_packet.h>
+#include <uapi/linux/batman_adv.h>

#include "gateway_client.h"
#include "log.h"
diff --git a/net/batman-adv/gateway_common.h b/net/batman-adv/gateway_common.h
index 89bae100..128467a0 100644
--- a/net/batman-adv/gateway_common.h
+++ b/net/batman-adv/gateway_common.h
@@ -25,12 +25,6 @@

struct net_device;

-enum batadv_gw_modes {
- BATADV_GW_MODE_OFF,
- BATADV_GW_MODE_CLIENT,
- BATADV_GW_MODE_SERVER,
-};
-
/**
* enum batadv_bandwidth_units - bandwidth unit types
*/
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 45f6aee5..8db3a2a4 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -51,6 +51,7 @@
#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "gateway_client.h"
+#include "gateway_common.h"
#include "hard-interface.h"
#include "multicast.h"
#include "originator.h"
@@ -147,6 +148,10 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED] = { .type = NLA_U8 },
[BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED] = { .type = NLA_U8 },
[BATADV_ATTR_FRAGMENTATION_ENABLED] = { .type = NLA_U8 },
+ [BATADV_ATTR_GW_BANDWIDTH_DOWN] = { .type = NLA_U32 },
+ [BATADV_ATTR_GW_BANDWIDTH_UP] = { .type = NLA_U32 },
+ [BATADV_ATTR_GW_MODE] = { .type = NLA_U8 },
+ [BATADV_ATTR_GW_SEL_CLASS] = { .type = NLA_U32 },
};

/**
@@ -303,6 +308,28 @@ static int batadv_netlink_mesh_put(struct sk_buff *msg,
!!atomic_read(&bat_priv->fragmentation)))
goto nla_put_failure;

+ if (nla_put_u32(msg, BATADV_ATTR_GW_BANDWIDTH_DOWN,
+ atomic_read(&bat_priv->gw.bandwidth_down)))
+ goto nla_put_failure;
+
+ if (nla_put_u32(msg, BATADV_ATTR_GW_BANDWIDTH_UP,
+ atomic_read(&bat_priv->gw.bandwidth_up)))
+ goto nla_put_failure;
+
+ if (nla_put_u8(msg, BATADV_ATTR_GW_MODE,
+ atomic_read(&bat_priv->gw.mode)))
+ goto nla_put_failure;
+
+ if (bat_priv->algo_ops->gw.get_best_gw_node &&
+ bat_priv->algo_ops->gw.is_eligible) {
+ /* GW selection class is not available if the routing algorithm
+ * in use does not implement the GW API
+ */
+ if (nla_put_u32(msg, BATADV_ATTR_GW_SEL_CLASS,
+ atomic_read(&bat_priv->gw.sel_class)))
+ goto nla_put_failure;
+ }
+
if (primary_if)
batadv_hardif_put(primary_if);

@@ -444,6 +471,71 @@ static int batadv_netlink_set_mesh(struct sk_buff *skb, struct genl_info *info)
batadv_update_min_mtu(bat_priv->soft_iface);
}

+ if (info->attrs[BATADV_ATTR_GW_BANDWIDTH_DOWN]) {
+ attr = info->attrs[BATADV_ATTR_GW_BANDWIDTH_DOWN];
+
+ atomic_set(&bat_priv->gw.bandwidth_down, nla_get_u32(attr));
+ batadv_gw_tvlv_container_update(bat_priv);
+ }
+
+ if (info->attrs[BATADV_ATTR_GW_BANDWIDTH_UP]) {
+ attr = info->attrs[BATADV_ATTR_GW_BANDWIDTH_UP];
+
+ atomic_set(&bat_priv->gw.bandwidth_up, nla_get_u32(attr));
+ batadv_gw_tvlv_container_update(bat_priv);
+ }
+
+ if (info->attrs[BATADV_ATTR_GW_MODE]) {
+ u8 gw_mode;
+
+ attr = info->attrs[BATADV_ATTR_GW_MODE];
+ gw_mode = nla_get_u8(attr);
+
+ if (gw_mode <= BATADV_GW_MODE_SERVER) {
+ /* Invoking batadv_gw_reselect() is not enough to really
+ * de-select the current GW. It will only instruct the
+ * gateway client code to perform a re-election the next
+ * time that this is needed.
+ *
+ * When gw client mode is being switched off the current
+ * GW must be de-selected explicitly otherwise no GW_ADD
+ * uevent is thrown on client mode re-activation. This
+ * is operation is performed in
+ * batadv_gw_check_client_stop().
+ */
+ batadv_gw_reselect(bat_priv);
+
+ /* always call batadv_gw_check_client_stop() before
+ * changing the gateway state
+ */
+ batadv_gw_check_client_stop(bat_priv);
+ atomic_set(&bat_priv->gw.mode, gw_mode);
+ batadv_gw_tvlv_container_update(bat_priv);
+ }
+ }
+
+ if (info->attrs[BATADV_ATTR_GW_SEL_CLASS] &&
+ bat_priv->algo_ops->gw.get_best_gw_node &&
+ bat_priv->algo_ops->gw.is_eligible) {
+ /* setting the GW selection class is allowed only if the routing
+ * algorithm in use implements the GW API
+ */
+
+ u32 sel_class_max = 0xffffffffu;
+ u32 sel_class;
+
+ attr = info->attrs[BATADV_ATTR_GW_SEL_CLASS];
+ sel_class = nla_get_u32(attr);
+
+ if (!bat_priv->algo_ops->gw.store_sel_class)
+ sel_class_max = BATADV_TQ_MAX_VALUE;
+
+ if (sel_class >= 1 && sel_class <= sel_class_max) {
+ atomic_set(&bat_priv->gw.sel_class, sel_class);
+ batadv_gw_reselect(bat_priv);
+ }
+ }
+
batadv_netlink_notify_mesh(bat_priv);

return 0;
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 5357dcae..d27a543f 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -50,13 +50,13 @@
#include <linux/string.h>
#include <linux/types.h>
#include <uapi/linux/batadv_packet.h>
+#include <uapi/linux/batman_adv.h>

#include "bat_algo.h"
#include "bridge_loop_avoidance.h"
#include "debugfs.h"
#include "distributed-arp-table.h"
#include "gateway_client.h"
-#include "gateway_common.h"
#include "hard-interface.h"
#include "multicast.h"
#include "network-coding.h"
diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c
index e1b81626..64fd5932 100644
--- a/net/batman-adv/sysfs.c
+++ b/net/batman-adv/sysfs.c
@@ -40,6 +40,7 @@
#include <linux/stringify.h>
#include <linux/workqueue.h>
#include <uapi/linux/batadv_packet.h>
+#include <uapi/linux/batman_adv.h>

#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
--
2.20.1