Nikolay Aleksandrov
2018-Nov-22 04:29 UTC
[Bridge] [PATCH net-next 0/2] net: bridge: add an option to disabe linklocal learning
Hi, This set adds a new bridge option which can control learning from link-local packets, by default learning is on to be consistent and avoid breaking users expectations. If the new no_linklocal_learn option is enabled then the bridge will stop learning from link-local packets. In order to save space for future boolean options, patch 01 adds a new bool option API that uses a bitmask to control boolean options. The bridge is by far the largest netlink attr user and we keep adding simple boolean options which waste nl attr ids and space. We're not directly mapping these to the in-kernel bridge flags because some might require more complex configuration changes (e.g. if we were to add the per port vlan stats now, it'd require multiple checks before changing value). Any new bool option needs to be handled by both br_boolopt_toggle and get in order to be able to retrieve its state later. All such options are automatically exported via netlink. The behaviour of setting such options is consistent with netlink option handling when a missing option is being set (silently ignored), e.g. when a newer iproute2 is used on older kernel. Thanks, Nik Nikolay Aleksandrov (2): net: bridge: add support for user-controlled bool options net: bridge: add no_linklocal_learn bool option include/uapi/linux/if_bridge.h | 21 ++++++++++ include/uapi/linux/if_link.h | 1 + net/bridge/br.c | 72 ++++++++++++++++++++++++++++++++++ net/bridge/br_input.c | 4 +- net/bridge/br_netlink.c | 17 +++++++- net/bridge/br_private.h | 7 ++++ net/bridge/br_sysfs_br.c | 22 +++++++++++ net/core/rtnetlink.c | 2 +- 8 files changed, 143 insertions(+), 3 deletions(-) -- 2.17.2
Nikolay Aleksandrov
2018-Nov-22 04:29 UTC
[Bridge] [PATCH net-next 1/2] net: bridge: add support for user-controlled bool options
We have been adding many new bridge options, a big number of which are
boolean but still take up netlink attribute ids and waste space in the skb.
Recently we discussed learning from link-local packets[1] and decided
yet another new boolean option will be needed, thus introducing this API
to save some bridge nl space.
The API supports changing the value of multiple boolean options at once
via the br_boolopt_multi struct which has an optmask (which options to
set, bit per opt) and optval (options' new values). Future boolean
options will only be added to the br_boolopt_id enum and then will have
to be handled in br_boolopt_toggle/get. The API will automatically
add the ability to change and export them via netlink, sysfs can use the
single boolopt function versions to do the same. The behaviour with
failing/succeeding is the same as with normal netlink option changing.
If an option requires mapping to internal kernel flag or needs special
configuration to be enabled then it should be handled in
br_boolopt_toggle. It should also be able to retrieve an option's current
state via br_boolopt_get.
[1] https://www.spinics.net/lists/netdev/msg532698.html
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
include/uapi/linux/if_bridge.h | 18 +++++++++
include/uapi/linux/if_link.h | 1 +
net/bridge/br.c | 68 ++++++++++++++++++++++++++++++++++
net/bridge/br_netlink.c | 17 ++++++++-
net/bridge/br_private.h | 6 +++
net/core/rtnetlink.c | 2 +-
6 files changed, 110 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index e41eda3c71f1..6dc02c03bdf8 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -292,4 +292,22 @@ struct br_mcast_stats {
__u64 mcast_bytes[BR_MCAST_DIR_SIZE];
__u64 mcast_packets[BR_MCAST_DIR_SIZE];
};
+
+/* bridge boolean options
+ * IMPORTANT: if adding a new option do not forget to handle
+ * it in br_boolopt_toggle/get and bridge sysfs
+ */
+enum br_boolopt_id {
+ BR_BOOLOPT_MAX
+};
+
+/* struct br_boolopt_multi - change multiple bridge boolean options
+ *
+ * @optval: new option values (bit per option)
+ * @optmask: options to change (bit per option)
+ */
+struct br_boolopt_multi {
+ __u32 optval;
+ __u32 optmask;
+};
#endif /* _UAPI_LINUX_IF_BRIDGE_H */
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index f42c069d81db..d6533828123a 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -288,6 +288,7 @@ enum {
IFLA_BR_MCAST_IGMP_VERSION,
IFLA_BR_MCAST_MLD_VERSION,
IFLA_BR_VLAN_STATS_PER_PORT,
+ IFLA_BR_MULTI_BOOLOPT,
__IFLA_BR_MAX,
};
diff --git a/net/bridge/br.c b/net/bridge/br.c
index 360ad66c21e9..290b0adbf6d6 100644
--- a/net/bridge/br.c
+++ b/net/bridge/br.c
@@ -175,6 +175,74 @@ static struct notifier_block br_switchdev_notifier = {
.notifier_call = br_switchdev_event,
};
+/* br_boolopt_toggle - change user-controlled boolean option
+ *
+ * @br: bridge device
+ * @opt: id of the option to change
+ * @on: new option value
+ *
+ * Changes the value of the respective boolean option to @on taking care of
+ * any internal option value mapping and configuration.
+ */
+int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on)
+{
+ int err = -ENOENT;
+
+ switch (opt) {
+ default:
+ break;
+ }
+
+ return err;
+}
+
+int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
+{
+ int optval = 0;
+
+ switch (opt) {
+ default:
+ break;
+ }
+
+ return optval;
+}
+
+int br_boolopt_multi_toggle(struct net_bridge *br,
+ struct br_boolopt_multi *bm)
+{
+ unsigned long bitmap = bm->optmask;
+ int err = 0;
+ int opt_id;
+
+ for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
+ bool on = !!(bm->optval & BIT(opt_id));
+
+ err = br_boolopt_toggle(br, opt_id, on);
+ if (err) {
+ br_debug(br, "boolopt multi-toggle error: option: %d current: %d new:
%d error: %d\n",
+ opt_id, br_boolopt_get(br, opt_id), on, err);
+ break;
+ }
+ }
+
+ return err;
+}
+
+void br_boolopt_multi_get(const struct net_bridge *br,
+ struct br_boolopt_multi *bm)
+{
+ u32 optval = 0;
+ int opt_id;
+
+ for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
+ optval |= (br_boolopt_get(br, opt_id) << opt_id);
+
+ bm->optval = optval;
+ bm->optmask = 0;
+}
+
+/* private bridge options, controlled by the kernel */
void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
{
bool cur = !!br_opt_get(br, opt);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 3345f1984542..11325dc2e90a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1035,6 +1035,8 @@ static const struct nla_policy br_policy[IFLA_BR_MAX + 1]
= {
[IFLA_BR_MCAST_IGMP_VERSION] = { .type = NLA_U8 },
[IFLA_BR_MCAST_MLD_VERSION] = { .type = NLA_U8 },
[IFLA_BR_VLAN_STATS_PER_PORT] = { .type = NLA_U8 },
+ [IFLA_BR_MULTI_BOOLOPT] = { .type = NLA_EXACT_LEN,
+ .len = sizeof(struct br_boolopt_multi) },
};
static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
@@ -1296,6 +1298,15 @@ static int br_changelink(struct net_device *brdev, struct
nlattr *tb[],
}
#endif
+ if (data[IFLA_BR_MULTI_BOOLOPT]) {
+ struct br_boolopt_multi *bm;
+
+ bm = nla_data(data[IFLA_BR_MULTI_BOOLOPT]);
+ err = br_boolopt_multi_toggle(br, bm);
+ if (err)
+ return err;
+ }
+
return 0;
}
@@ -1374,6 +1385,7 @@ static size_t br_get_size(const struct net_device *brdev)
nla_total_size(sizeof(u8)) + /* IFLA_BR_NF_CALL_IP6TABLES */
nla_total_size(sizeof(u8)) + /* IFLA_BR_NF_CALL_ARPTABLES */
#endif
+ nla_total_size(sizeof(struct br_boolopt_multi)) + /*
IFLA_BR_MULTI_BOOLOPT */
0;
}
@@ -1387,6 +1399,7 @@ static int br_fill_info(struct sk_buff *skb, const struct
net_device *brdev)
u32 stp_enabled = br->stp_enabled;
u16 priority = (br->bridge_id.prio[0] << 8) |
br->bridge_id.prio[1];
u8 vlan_enabled = br_vlan_enabled(br->dev);
+ struct br_boolopt_multi bm;
u64 clockval;
clockval = br_timer_value(&br->hello_timer);
@@ -1403,6 +1416,7 @@ static int br_fill_info(struct sk_buff *skb, const struct
net_device *brdev)
if (nla_put_u64_64bit(skb, IFLA_BR_GC_TIMER, clockval, IFLA_BR_PAD))
return -EMSGSIZE;
+ br_boolopt_multi_get(br, &bm);
if (nla_put_u32(skb, IFLA_BR_FORWARD_DELAY, forward_delay) ||
nla_put_u32(skb, IFLA_BR_HELLO_TIME, hello_time) ||
nla_put_u32(skb, IFLA_BR_MAX_AGE, age_time) ||
@@ -1420,7 +1434,8 @@ static int br_fill_info(struct sk_buff *skb, const struct
net_device *brdev)
nla_put_u8(skb, IFLA_BR_TOPOLOGY_CHANGE, br->topology_change) ||
nla_put_u8(skb, IFLA_BR_TOPOLOGY_CHANGE_DETECTED,
br->topology_change_detected) ||
- nla_put(skb, IFLA_BR_GROUP_ADDR, ETH_ALEN, br->group_addr))
+ nla_put(skb, IFLA_BR_GROUP_ADDR, ETH_ALEN, br->group_addr) ||
+ nla_put(skb, IFLA_BR_MULTI_BOOLOPT, sizeof(bm), &bm))
return -EMSGSIZE;
#ifdef CONFIG_BRIDGE_VLAN_FILTERING
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index bc2653738fc3..0f051730ed4f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -507,6 +507,12 @@ static inline int br_opt_get(const struct net_bridge *br,
return test_bit(opt, &br->options);
}
+int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on);
+int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt);
+int br_boolopt_multi_toggle(struct net_bridge *br,
+ struct br_boolopt_multi *bm);
+void br_boolopt_multi_get(const struct net_bridge *br,
+ struct br_boolopt_multi *bm);
void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on);
/* br_device.c */
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 86f2d9cbdae3..a498bb41c9aa 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -59,7 +59,7 @@
#include <net/rtnetlink.h>
#include <net/net_namespace.h>
-#define RTNL_MAX_TYPE 49
+#define RTNL_MAX_TYPE 50
#define RTNL_SLAVE_MAX_TYPE 36
struct rtnl_link {
--
2.17.2
Nikolay Aleksandrov
2018-Nov-22 04:29 UTC
[Bridge] [PATCH net-next 2/2] net: bridge: add no_linklocal_learn bool option
Use the new boolopt API to add an option which disables learning from
link-local packets. The default is kept as before and learning is
enabled. This is a simple map from a boolopt bit to a bridge private
flag that is tested before learning.
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
include/uapi/linux/if_bridge.h | 3 +++
net/bridge/br.c | 10 +++++++---
net/bridge/br_input.c | 4 +++-
net/bridge/br_private.h | 1 +
net/bridge/br_sysfs_br.c | 22 ++++++++++++++++++++++
5 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index 6dc02c03bdf8..773e476a8e54 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -294,10 +294,13 @@ struct br_mcast_stats {
};
/* bridge boolean options
+ * BR_BOOLOPT_NO_LL_LEARN - disable learning from link-local packets
+ *
* IMPORTANT: if adding a new option do not forget to handle
* it in br_boolopt_toggle/get and bridge sysfs
*/
enum br_boolopt_id {
+ BR_BOOLOPT_NO_LL_LEARN,
BR_BOOLOPT_MAX
};
diff --git a/net/bridge/br.c b/net/bridge/br.c
index 290b0adbf6d6..5b78a6385bd6 100644
--- a/net/bridge/br.c
+++ b/net/bridge/br.c
@@ -189,6 +189,10 @@ int br_boolopt_toggle(struct net_bridge *br, enum
br_boolopt_id opt, bool on)
int err = -ENOENT;
switch (opt) {
+ case BR_BOOLOPT_NO_LL_LEARN:
+ err = 0;
+ br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
+ break;
default:
break;
}
@@ -198,14 +202,14 @@ int br_boolopt_toggle(struct net_bridge *br, enum
br_boolopt_id opt, bool on)
int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
{
- int optval = 0;
-
switch (opt) {
+ case BR_BOOLOPT_NO_LL_LEARN:
+ return br_opt_get(br, BROPT_NO_LL_LEARN);
default:
break;
}
- return optval;
+ return 0;
}
int br_boolopt_multi_toggle(struct net_bridge *br,
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 3ddca11f44c2..5ea7e56119c1 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -188,7 +188,9 @@ static void __br_handle_local_finish(struct sk_buff *skb)
u16 vid = 0;
/* check if vlan is allowed, to avoid spoofing */
- if (p->flags & BR_LEARNING && br_should_learn(p, skb,
&vid))
+ if ((p->flags & BR_LEARNING) &&
+ !br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
+ br_should_learn(p, skb, &vid))
br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
}
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 0f051730ed4f..390848acff08 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -328,6 +328,7 @@ enum net_bridge_opts {
BROPT_NEIGH_SUPPRESS_ENABLED,
BROPT_MTU_SET_BY_USER,
BROPT_VLAN_STATS_PER_PORT,
+ BROPT_NO_LL_LEARN,
};
struct net_bridge {
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 60182bef6341..5a03033ccd27 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -328,6 +328,27 @@ static ssize_t flush_store(struct device *d,
}
static DEVICE_ATTR_WO(flush);
+static ssize_t no_linklocal_learn_show(struct device *d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct net_bridge *br = to_bridge(d);
+ return sprintf(buf, "%d\n", br_boolopt_get(br,
BR_BOOLOPT_NO_LL_LEARN));
+}
+
+static int set_no_linklocal_learn(struct net_bridge *br, unsigned long val)
+{
+ return br_boolopt_toggle(br, BR_BOOLOPT_NO_LL_LEARN, !!val);
+}
+
+static ssize_t no_linklocal_learn_store(struct device *d,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ return store_bridge_parm(d, buf, len, set_no_linklocal_learn);
+}
+static DEVICE_ATTR_RW(no_linklocal_learn);
+
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
static ssize_t multicast_router_show(struct device *d,
struct device_attribute *attr, char *buf)
@@ -841,6 +862,7 @@ static struct attribute *bridge_attrs[] = {
&dev_attr_gc_timer.attr,
&dev_attr_group_addr.attr,
&dev_attr_flush.attr,
+ &dev_attr_no_linklocal_learn.attr,
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
&dev_attr_multicast_router.attr,
&dev_attr_multicast_snooping.attr,
--
2.17.2