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bridge: Limit number of MDB entries per port, port-vlan

PATCH Applied Petr Machata 4 participants 24 messages Feb 2, 2023 – Feb 6, 2023

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#0 lore raw

v3 cover bridge: Limit number of MDB entries per port, port-vlan

The MDB maintained by the bridge is limited. When the bridge is configured for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its capacity. In SW datapath, the capacity is configurable through the IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a similar limit exists in the HW datapath for purposes of offloading.

In order to prevent the issue of unilateral exhaustion of MDB resources, introduce two parameters in each of two contexts:

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled) per-port-VLAN number of MDB entries that the port is member in.

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled) per-port-VLAN maximum permitted number of MDB entries, or 0 for no limit.

Per-port number of entries keeps track of the total number of MDB entries configured on a given port. The per-port-VLAN value then keeps track of the subset of MDB entries configured specifically for the given VLAN, on that port. The number is adjusted as port_groups are created and deleted, and therefore under multicast lock.

A maximum value, if non-zero, then places a limit on the number of entries that can be configured in a given context. Attempts to add entries above the maximum are rejected.

Rejection reason of netlink-based requests to add MDB entries is communicated through extack. This channel is unavailable for rejections triggered from the control path. To address this lack of visibility, the patchset adds a tracepoint, bridge:br_mdb_full:

	# perf record -e bridge:br_mdb_full &
	# [...]
	# perf script | cut -d: -f4-
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 0
	 dev v2 af 10 src :: grp ff0e::112/00:00:00:00:00:00 vid 0
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 10
	 dev v2 af 10 src 2001:db8:1::1 grp ff0e::1/00:00:00:00:00:00 vid 10
	 dev v2 af 2 src ::ffff:192.0.2.1 grp ::ffff:239.1.1.1/00:00:00:00:00:00 vid 10

Another option to consume the tracepoint is e.g. through the bpftrace tool:

	# bpftrace -e ' tracepoint:bridge:br_mdb_full /args->af != 0/ {
			    printf("dev %s src %s grp %s vid %u\n",
				   str(args->dev), ntop(args->src),
				   ntop(args->grp), args->vid);
			}
			tracepoint:bridge:br_mdb_full /args->af == 0/ {
			    printf("dev %s grp %s vid %u\n",
				   str(args->dev),
				   macaddr(args->grpmac), args->vid);
			}'

This tracepoint is triggered for mcast_hash_max exhaustions as well.

The following is an example of how the feature is used. A more extensive example is available in patch #8:

	# bridge vlan set dev v1 vid 1 mcast_max_groups 1
	# bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1
	# bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1
	Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1.

The patchset progresses as follows:

- In patch #1, set strict_start_type at two bridge-related policies. The reason is we are adding a new attribute to one of these, and want the new attribute to be parsed strictly. The other was adjusted for completeness' sake.

- In patches #2 to #5, br_mdb and br_multicast code is adjusted to make the following additions smoother.

- In patch #6, add the tracepoint.

- In patch #7, the code to maintain number of MDB entries is added as struct net_bridge_mcast_port::mdb_n_entries. The maximum is added, too, as struct net_bridge_mcast_port::mdb_max_entries, however at this point there is no way to set the value yet, and since 0 is treated as "no limit", the functionality doesn't change at this point. Note however, that mcast_hash_max violations already do trigger at this point.

- In patch #8, netlink plumbing is added: reading of number of entries, and reading and writing of maximum.

The per-port values are passed through RTM_NEWLINK / RTM_GETLINK messages in IFLA_BRPORT_MCAST_N_GROUPS and _MAX_GROUPS, inside IFLA_PROTINFO nest.

The per-port-vlan values are passed through RTM_GETVLAN / RTM_NEWVLAN messages in BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS, _MAX_GROUPS, inside BRIDGE_VLANDB_ENTRY.

The following patches deal with the selftest:

- Patches #9 and #10 clean up and move around some selftest code.

- Patches #11 to #14 add helpers and generalize the existing IGMP / MLD support to allow generating packets with configurable group addresses and varying source lists for (S,G) memberships.

- Patch #15 adds code to generate IGMP leave and MLD done packets.

- Patch #16 finally adds the selftest itself.

v3:
- Patch #7:
- Access mdb_max_/_n_entries through READ_/WRITE_ONCE
- Move extack setting to br_multicast_port_ngroups_inc_one(). Since we use NL_SET_ERR_MSG_FMT_MOD, the correct context (port / port-vlan) can be passed through an argument. This also removes the need for more READ/WRITE_ONCE's at the extack-setting site.
- Patch #8:
- Move the br_multicast_port_ctx_vlan_disabled() check out to the _vlan_ helpers callers. Thus these helpers cannot fail, which makes them very similar to the _port_ helpers. Have them take the MC context directly and unify them.

v2:
- Cover letter:
- Add an example of a bpftrace-based probe script
- Patch #6:
- Report IPv4 as an IPv6-mapped address through the IPv6 buffer as well, to save ring buffer space.
- Patch #7:
- In br_multicast_port_ngroups_inc_one(), bounce
if n>=max, not if n==max
- Adjust extack messages to mention ngroups, now that the bounces appear when n>=max, not n==max
- In __br_multicast_enable_port_ctx(), do not reset max to 0. Also do not count number of entries by going through _inc, as that would end up incorrectly bouncing the entries.
- Patch #8:
- Drop locks around accesses in br_multicast_{port,vlan}_ngroups_{get,set_max}(),
- Drop bounces due to max<n in br_multicast_{port,vlan}_ngroups_set_max().
- Patch #12:
- In the comment at payload_template_calc_checksum(), s/%#02x/%02x/, that's the mausezahn payload format.
- Patch #16:
- Adjust the tests that check setting max below n and reset of max on VLAN snooping enablement
- Make test naming uniform
- Enable testing of control path (IGMP/MLD) in mcast_vlan_snooping bridge
- Reorganize the code so that test instances (per bridge type and configuration type) always come right after the test, in order of {d,q,qvs}{4,6}{cfg,ctl}. Then groups of selftests are at the end of the file. Similarly adjust invocation order of the tests.

Petr Machata (16):
net: bridge: Set strict_start_type at two policies
net: bridge: Add extack to br_multicast_new_port_group()
net: bridge: Move extack-setting to br_multicast_new_port_group()
net: bridge: Add br_multicast_del_port_group()
net: bridge: Change a cleanup in br_multicast_new_port_group() to goto
net: bridge: Add a tracepoint for MDB overflows
net: bridge: Maintain number of MDB entries in net_bridge_mcast_port
net: bridge: Add netlink knobs for number / maximum MDB entries
selftests: forwarding: Move IGMP- and MLD-related functions to lib
selftests: forwarding: bridge_mdb: Fix a typo
selftests: forwarding: lib: Add helpers for IP address handling
selftests: forwarding: lib: Add helpers for checksum handling
selftests: forwarding: lib: Parameterize IGMPv3/MLDv2 generation
selftests: forwarding: lib: Allow list of IPs for IGMPv3/MLDv2
selftests: forwarding: lib: Add helpers to build IGMP/MLD leave
packets
selftests: forwarding: bridge_mdb_max: Add a new selftest

 include/trace/events/bridge.h                 |   58 +
 include/uapi/linux/if_bridge.h                |    2 +
 include/uapi/linux/if_link.h                  |    2 +
 net/bridge/br_mdb.c                           |   17 +-
 net/bridge/br_multicast.c                     |  179 ++-
 net/bridge/br_netlink.c                       |   19 +-
 net/bridge/br_netlink_tunnel.c                |    3 +
 net/bridge/br_private.h                       |   12 +-
 net/bridge/br_vlan.c                          |   11 +-
 net/bridge/br_vlan_options.c                  |   27 +-
 net/core/net-traces.c                         |    1 +
 net/core/rtnetlink.c                          |    2 +-
 .../testing/selftests/net/forwarding/Makefile |    1 +
 .../selftests/net/forwarding/bridge_mdb.sh    |   60 +-
 .../net/forwarding/bridge_mdb_max.sh          | 1336 +++++++++++++++++
 tools/testing/selftests/net/forwarding/lib.sh |  216 +++
 16 files changed, 1867 insertions(+), 79 deletions(-)
 create mode 100755 tools/testing/selftests/net/forwarding/bridge_mdb_max.sh
Signature · 1 line
2.39.0
#1 lore raw

PATCH v3 1/16 net: bridge: Set strict_start_type at two policies

Make any attributes newly-added to br_port_policy or vlan_tunnel_policy parsed strictly, to prevent userspace from passing garbage. Note that this patchset only touches the former policy. The latter was adjusted for completeness' sake. There do not appear to be other _deprecated calls with non-NULL policies.

---
 net/bridge/br_netlink.c        | 2 ++
 net/bridge/br_netlink_tunnel.c | 3 +++
 2 files changed, 5 insertions(+)
net/bridge/br_netlink.c +2 -0
index 4316cc82ae17..a6133d469885 100644
@@ -858,6 +858,8 @@ static int br_afspec(struct net_bridge *br,
 }
 
 static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = {
+	[IFLA_BRPORT_UNSPEC]	= { .strict_start_type =
+					IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT + 1 },
 	[IFLA_BRPORT_STATE]	= { .type = NLA_U8 },
 	[IFLA_BRPORT_COST]	= { .type = NLA_U32 },
 	[IFLA_BRPORT_PRIORITY]	= { .type = NLA_U16 },
net/bridge/br_netlink_tunnel.c +3 -0
index 8914290c75d4..17abf092f7ca 100644
@@ -188,6 +188,9 @@ int br_fill_vlan_tunnel_info(struct sk_buff *skb,
 }
 
 static const struct nla_policy vlan_tunnel_policy[IFLA_BRIDGE_VLAN_TUNNEL_MAX + 1] = {
+	[IFLA_BRIDGE_VLAN_TUNNEL_UNSPEC] = {
+		.strict_start_type = IFLA_BRIDGE_VLAN_TUNNEL_FLAGS + 1
+	},
 	[IFLA_BRIDGE_VLAN_TUNNEL_ID] = { .type = NLA_U32 },
 	[IFLA_BRIDGE_VLAN_TUNNEL_VID] = { .type = NLA_U16 },
 	[IFLA_BRIDGE_VLAN_TUNNEL_FLAGS] = { .type = NLA_U16 },
Signature · 1 line
2.39.0
#2 lore raw

PATCH v3 2/16 net: bridge: Add extack to br_multicast_new_port_group()

In reply to Petr Machata

Make it possible to set an extack in br_multicast_new_port_group(). Eventually, this function will check for per-port and per-port-vlan MDB maximums, and will use the extack to communicate the reason for the bounce.

---
 net/bridge/br_mdb.c       | 5 +++--
 net/bridge/br_multicast.c | 5 +++--
 net/bridge/br_private.h   | 3 ++-
 3 files changed, 8 insertions(+), 5 deletions(-)
net/bridge/br_mdb.c +3 -2
index 00e5743647b0..069061366541 100644
@@ -849,7 +849,7 @@ static int br_mdb_add_group_sg(const struct br_mdb_config *cfg,
 	}
 
 	p = br_multicast_new_port_group(cfg->p, &cfg->group, *pp, flags, NULL,
-					MCAST_INCLUDE, cfg->rt_protocol);
+					MCAST_INCLUDE, cfg->rt_protocol, extack);
 	if (unlikely(!p)) {
 		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new (S, G) port group");
 		return -ENOMEM;
@@ -1075,7 +1075,8 @@ static int br_mdb_add_group_star_g(const struct br_mdb_config *cfg,
 	}
 
 	p = br_multicast_new_port_group(cfg->p, &cfg->group, *pp, flags, NULL,
-					cfg->filter_mode, cfg->rt_protocol);
+					cfg->filter_mode, cfg->rt_protocol,
+					extack);
 	if (unlikely(!p)) {
 		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new (*, G) port group");
 		return -ENOMEM;
net/bridge/br_multicast.c +3 -2
index dea1ee1bd095..de67d176838f 100644
@@ -1284,7 +1284,8 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 			unsigned char flags,
 			const unsigned char *src,
 			u8 filter_mode,
-			u8 rt_protocol)
+			u8 rt_protocol,
+			struct netlink_ext_ack *extack)
 {
 	struct net_bridge_port_group *p;
 
@@ -1387,7 +1388,7 @@ __br_multicast_add_group(struct net_bridge_mcast *brmctx,
 	}
 
 	p = br_multicast_new_port_group(pmctx->port, group, *pp, 0, src,
-					filter_mode, RTPROT_KERNEL);
+					filter_mode, RTPROT_KERNEL, NULL);
 	if (unlikely(!p)) {
 		p = ERR_PTR(-ENOMEM);
 		goto out;
net/bridge/br_private.h +2 -1
index 15ef7fd508ee..1805c468ae03 100644
@@ -956,7 +956,8 @@ br_multicast_new_port_group(struct net_bridge_port *port,
 			    const struct br_ip *group,
 			    struct net_bridge_port_group __rcu *next,
 			    unsigned char flags, const unsigned char *src,
-			    u8 filter_mode, u8 rt_protocol);
+			    u8 filter_mode, u8 rt_protocol,
+			    struct netlink_ext_ack *extack);
 int br_mdb_hash_init(struct net_bridge *br);
 void br_mdb_hash_fini(struct net_bridge *br);
 void br_mdb_notify(struct net_device *dev, struct net_bridge_mdb_entry *mp,
Signature · 1 line
2.39.0
#3 lore raw

PATCH v3 3/16 net: bridge: Move extack-setting to br_multicast_new_port_group()

In reply to Petr Machata

Now that br_multicast_new_port_group() takes an extack argument, move setting the extack there. The downside is that the error messages end up being less specific (the function cannot distinguish between (S,G) and (*,G) groups). However, the alternative is to check in the caller whether the callee set the extack, and if it didn't, set it. But that is only done when the callee is not exactly known. (E.g. in case of a notifier invocation.)

---
 net/bridge/br_mdb.c       | 9 +++------
 net/bridge/br_multicast.c | 5 ++++-
 2 files changed, 7 insertions(+), 7 deletions(-)
net/bridge/br_mdb.c +3 -6
index 069061366541..139de8ac532c 100644
@@ -850,10 +850,9 @@ static int br_mdb_add_group_sg(const struct br_mdb_config *cfg,
 
 	p = br_multicast_new_port_group(cfg->p, &cfg->group, *pp, flags, NULL,
 					MCAST_INCLUDE, cfg->rt_protocol, extack);
-	if (unlikely(!p)) {
-		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new (S, G) port group");
+	if (unlikely(!p))
 		return -ENOMEM;
-	}
+
 	rcu_assign_pointer(*pp, p);
 	if (!(flags & MDB_PG_FLAGS_PERMANENT) && !cfg->src_entry)
 		mod_timer(&p->timer,
@@ -1077,10 +1076,8 @@ static int br_mdb_add_group_star_g(const struct br_mdb_config *cfg,
 	p = br_multicast_new_port_group(cfg->p, &cfg->group, *pp, flags, NULL,
 					cfg->filter_mode, cfg->rt_protocol,
 					extack);
-	if (unlikely(!p)) {
-		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new (*, G) port group");
+	if (unlikely(!p))
 		return -ENOMEM;
-	}
 
 	err = br_mdb_add_group_srcs(cfg, p, brmctx, extack);
 	if (err)
net/bridge/br_multicast.c +4 -1
index de67d176838f..f9f4d54226fd 100644
@@ -1290,8 +1290,10 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 	struct net_bridge_port_group *p;
 
 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
-	if (unlikely(!p))
+	if (unlikely(!p)) {
+		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new port group");
 		return NULL;
+	}
 
 	p->key.addr = *group;
 	p->key.port = port;
@@ -1306,6 +1308,7 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 	if (!br_multicast_is_star_g(group) &&
 	    rhashtable_lookup_insert_fast(&port->br->sg_port_tbl, &p->rhnode,
 					  br_sg_port_rht_params)) {
+		NL_SET_ERR_MSG_MOD(extack, "Couldn't insert new port group");
 		kfree(p);
 		return NULL;
 	}
Signature · 1 line
2.39.0
#4 lore raw

PATCH v3 4/16 net: bridge: Add br_multicast_del_port_group()

In reply to Petr Machata

Since cleaning up the effects of br_multicast_new_port_group() just consists of delisting and freeing the memory, the function br_mdb_add_group_star_g() inlines the corresponding code. In the following patches, number of per-port and per-port-VLAN MDB entries is going to be maintained, and that counter will have to be updated. Because that logic is going to be hidden in the br_multicast module, introduce a new hook intended to again remove a newly-created group.

---
 net/bridge/br_mdb.c       |  3 +--
 net/bridge/br_multicast.c | 11 +++++++++++
 net/bridge/br_private.h   |  1 +
 3 files changed, 13 insertions(+), 2 deletions(-)
net/bridge/br_mdb.c +1 -2
index 139de8ac532c..9f22ebfdc518 100644
@@ -1099,8 +1099,7 @@ static int br_mdb_add_group_star_g(const struct br_mdb_config *cfg,
 	return 0;
 
 err_del_port_group:
-	hlist_del_init(&p->mglist);
-	kfree(p);
+	br_multicast_del_port_group(p);
 	return err;
 }
 
net/bridge/br_multicast.c +11 -0
index f9f4d54226fd..08da724ebfdd 100644
@@ -1326,6 +1326,17 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 	return p;
 }
 
+void br_multicast_del_port_group(struct net_bridge_port_group *p)
+{
+	struct net_bridge_port *port = p->key.port;
+
+	hlist_del_init(&p->mglist);
+	if (!br_multicast_is_star_g(&p->key.addr))
+		rhashtable_remove_fast(&port->br->sg_port_tbl, &p->rhnode,
+				       br_sg_port_rht_params);
+	kfree(p);
+}
+
 void br_multicast_host_join(const struct net_bridge_mcast *brmctx,
 			    struct net_bridge_mdb_entry *mp, bool notify)
 {
net/bridge/br_private.h +1 -0
index 1805c468ae03..e4069e27b5c6 100644
@@ -958,6 +958,7 @@ br_multicast_new_port_group(struct net_bridge_port *port,
 			    unsigned char flags, const unsigned char *src,
 			    u8 filter_mode, u8 rt_protocol,
 			    struct netlink_ext_ack *extack);
+void br_multicast_del_port_group(struct net_bridge_port_group *p);
 int br_mdb_hash_init(struct net_bridge *br);
 void br_mdb_hash_fini(struct net_bridge *br);
 void br_mdb_notify(struct net_device *dev, struct net_bridge_mdb_entry *mp,
Signature · 1 line
2.39.0
#5 lore raw

PATCH v3 5/16 net: bridge: Change a cleanup in br_multicast_new_port_group() to goto

In reply to Petr Machata

This function is getting more to clean up in the following patches. Structuring the cleanups in one labeled block will allow reusing the same cleanup from several places.

---
 net/bridge/br_multicast.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
net/bridge/br_multicast.c +5 -2
index 08da724ebfdd..51b622afdb67 100644
@@ -1309,8 +1309,7 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 	    rhashtable_lookup_insert_fast(&port->br->sg_port_tbl, &p->rhnode,
 					  br_sg_port_rht_params)) {
 		NL_SET_ERR_MSG_MOD(extack, "Couldn't insert new port group");
-		kfree(p);
-		return NULL;
+		goto free_out;
 	}
 
 	rcu_assign_pointer(p->next, next);
@@ -1324,6 +1323,10 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 		eth_broadcast_addr(p->eth_addr);
 
 	return p;
+
+free_out:
+	kfree(p);
+	return NULL;
 }
 
 void br_multicast_del_port_group(struct net_bridge_port_group *p)
Signature · 1 line
2.39.0
#6 lore raw

PATCH v3 6/16 net: bridge: Add a tracepoint for MDB overflows

In reply to Petr Machata

The following patch will add two more maximum MDB allowances to the global one, mcast_hash_max, that exists today. In all these cases, attempts to add MDB entries above the configured maximums through netlink, fail noisily and obviously. Such visibility is missing when adding entries through the control plane traffic, by IGMP or MLD packets.

To improve visibility in those cases, add a trace point that reports the violation, including the relevant netdevice (be it a slave or the bridge itself), and the MDB entry parameters:

	# perf record -e bridge:br_mdb_full &
	# [...]
	# perf script | cut -d: -f4-
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 0
	 dev v2 af 10 src :: grp ff0e::112/00:00:00:00:00:00 vid 0
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 10
	 dev v2 af 10 src 2001:db8:1::1 grp ff0e::1/00:00:00:00:00:00 vid 10
	 dev v2 af 2 src ::ffff:192.0.2.1 grp ::ffff:239.1.1.1/00:00:00:00:00:00 vid 10

---

Notes:
v2:
- Report IPv4 as an IPv6-mapped address through the IPv6 buffer as well, to save ring buffer space.

 include/trace/events/bridge.h | 58 +++++++++++++++++++++++++++++++++++
 net/core/net-traces.c         |  1 +
 2 files changed, 59 insertions(+)
include/trace/events/bridge.h +58 -0
index 6b200059c2c5..a6b3a4e409f0 100644
@@ -122,6 +122,64 @@ TRACE_EVENT(br_fdb_update,
 		  __entry->flags)
 );
 
+TRACE_EVENT(br_mdb_full,
+
+	TP_PROTO(const struct net_device *dev,
+		 const struct br_ip *group),
+
+	TP_ARGS(dev, group),
+
+	TP_STRUCT__entry(
+		__string(dev, dev->name)
+		__field(int, af)
+		__field(u16, vid)
+		__array(__u8, src, 16)
+		__array(__u8, grp, 16)
+		__array(__u8, grpmac, ETH_ALEN) /* For af == 0. */
+	),
+
+	TP_fast_assign(
+		struct in6_addr *in6;
+
+		__assign_str(dev, dev->name);
+		__entry->vid = group->vid;
+
+		if (!group->proto) {
+			__entry->af = 0;
+
+			memset(__entry->src, 0, sizeof(__entry->src));
+			memset(__entry->grp, 0, sizeof(__entry->grp));
+			memcpy(__entry->grpmac, group->dst.mac_addr, ETH_ALEN);
+		} else if (group->proto == htons(ETH_P_IP)) {
+			__entry->af = AF_INET;
+
+			in6 = (struct in6_addr *)__entry->src;
+			ipv6_addr_set_v4mapped(group->src.ip4, in6);
+
+			in6 = (struct in6_addr *)__entry->grp;
+			ipv6_addr_set_v4mapped(group->dst.ip4, in6);
+
+			memset(__entry->grpmac, 0, ETH_ALEN);
+
+#if IS_ENABLED(CONFIG_IPV6)
+		} else {
+			__entry->af = AF_INET6;
+
+			in6 = (struct in6_addr *)__entry->src;
+			*in6 = group->src.ip6;
+
+			in6 = (struct in6_addr *)__entry->grp;
+			*in6 = group->dst.ip6;
+
+			memset(__entry->grpmac, 0, ETH_ALEN);
+#endif
+		}
+	),
+
+	TP_printk("dev %s af %u src %pI6c grp %pI6c/%pM vid %u",
+		  __get_str(dev), __entry->af, __entry->src, __entry->grp,
+		  __entry->grpmac, __entry->vid)
+);
 
 #endif /* _TRACE_BRIDGE_H */
 
net/core/net-traces.c +1 -0
index c40cd8dd75c7..c6820ad2183f 100644
@@ -41,6 +41,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_add);
 EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_external_learn_add);
 EXPORT_TRACEPOINT_SYMBOL_GPL(fdb_delete);
 EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_update);
+EXPORT_TRACEPOINT_SYMBOL_GPL(br_mdb_full);
 #endif
 
 #if IS_ENABLED(CONFIG_PAGE_POOL)
Signature · 1 line
2.39.0
maintainer Acked-by on v3 6/16
#7 lore raw

Re: [PATCH net-next v3 06/16] net: bridge: Add a tracepoint for MDB overflows

Quoted 25 lines · Petr Machata

The following patch will add two more maximum MDB allowances to the global one, mcast_hash_max, that exists today. In all these cases, attempts to add MDB entries above the configured maximums through netlink, fail noisily and obviously. Such visibility is missing when adding entries through the control plane traffic, by IGMP or MLD packets.

To improve visibility in those cases, add a trace point that reports the violation, including the relevant netdevice (be it a slave or the bridge itself), and the MDB entry parameters:

	# perf record -e bridge:br_mdb_full &
	# [...]
	# perf script | cut -d: -f4-
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 0
	 dev v2 af 10 src :: grp ff0e::112/00:00:00:00:00:00 vid 0
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 10
	 dev v2 af 10 src 2001:db8:1::1 grp ff0e::1/00:00:00:00:00:00 vid 10
	 dev v2 af 2 src ::ffff:192.0.2.1 grp ::ffff:239.1.1.1/00:00:00:00:00:00 vid 10

---

Quoted 9 lines

Notes:
v2:
- Report IPv4 as an IPv6-mapped address through the IPv6 buffer as well, to save ring buffer space.

 include/trace/events/bridge.h | 58 +++++++++++++++++++++++++++++++++++
 net/core/net-traces.c         |  1 +
 2 files changed, 59 insertions(+)
#8 lore raw

PATCH v3 7/16 net: bridge: Maintain number of MDB entries in net_bridge_mcast_port

In reply to Petr Machata

The MDB maintained by the bridge is limited. When the bridge is configured for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its capacity. In SW datapath, the capacity is configurable through the IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a similar limit exists in the HW datapath for purposes of offloading.

In order to prevent the issue of unilateral exhaustion of MDB resources, introduce two parameters in each of two contexts:

- Per-port and per-port-VLAN number of MDB entries that the port is member in.

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled) per-port-VLAN maximum permitted number of MDB entries, or 0 for no limit.

The per-port multicast context is used for tracking of MDB entries for the port as a whole. This is available for all bridges.

The per-port-VLAN multicast context is then only available on VLAN-filtering bridges on VLANs that have multicast snooping on.

With these changes in place, it will be possible to configure MDB limit for bridge as a whole, or any one port as a whole, or any single port-VLAN.

Note that unlike the global limit, exhaustion of the per-port and per-port-VLAN maximums does not cause disablement of multicast snooping. It is also permitted to configure the local limit larger than hash_max, even though that is not useful.

In this patch, introduce only the accounting for number of entries, and the max field itself, but not the means to toggle the max. The next patch introduces the netlink APIs to toggle and read the values.

---

Notes:
v3:
- Access mdb_max_/_n_entries through READ_/WRITE_ONCE
- Move extack setting to br_multicast_port_ngroups_inc_one(). Since we use NL_SET_ERR_MSG_FMT_MOD, the correct context (port / port-vlan) can be passed through an argument. This also removes the need for more READ/WRITE_ONCE's at the extack-setting site.

v2:
- In br_multicast_port_ngroups_inc_one(), bounce if n>=max, not if n==max
- Adjust extack messages to mention ngroups, now that the bounces appear when n>=max, not n==max
- In __br_multicast_enable_port_ctx(), do not reset max to 0. Also do not count number of entries by going through _inc, as that would end up incorrectly bouncing the entries.

 net/bridge/br_multicast.c | 136 +++++++++++++++++++++++++++++++++++++-
 net/bridge/br_private.h   |   2 +
 2 files changed, 137 insertions(+), 1 deletion(-)
net/bridge/br_multicast.c +135 -1
index 51b622afdb67..b6aa0bad5817 100644
@@ -31,6 +31,7 @@
 #include <net/ip6_checksum.h>
 #include <net/addrconf.h>
 #endif
+#include <trace/events/bridge.h>
 
 #include "br_private.h"
 #include "br_private_mcast_eht.h"
@@ -234,6 +235,29 @@ br_multicast_pg_to_port_ctx(const struct net_bridge_port_group *pg)
 	return pmctx;
 }
 
+static struct net_bridge_mcast_port *
+br_multicast_port_vid_to_port_ctx(struct net_bridge_port *port, u16 vid)
+{
+	struct net_bridge_mcast_port *pmctx = NULL;
+	struct net_bridge_vlan *vlan;
+
+	lockdep_assert_held_once(&port->br->multicast_lock);
+
+	if (!br_opt_get(port->br, BROPT_MCAST_VLAN_SNOOPING_ENABLED))
+		return NULL;
+
+	/* Take RCU to access the vlan. */
+	rcu_read_lock();
+
+	vlan = br_vlan_find(nbp_vlan_group_rcu(port), vid);
+	if (vlan && !br_multicast_port_ctx_vlan_disabled(&vlan->port_mcast_ctx))
+		pmctx = &vlan->port_mcast_ctx;
+
+	rcu_read_unlock();
+
+	return pmctx;
+}
+
 /* when snooping we need to check if the contexts should be used
  * in the following order:
  * - if pmctx is non-NULL (port), check if it should be used
@@ -668,6 +692,86 @@ void br_multicast_del_group_src(struct net_bridge_group_src *src,
 	__br_multicast_del_group_src(src);
 }
 
+static int
+br_multicast_port_ngroups_inc_one(struct net_bridge_mcast_port *pmctx,
+				  struct netlink_ext_ack *extack,
+				  const char *what)
+{
+	u32 max = READ_ONCE(pmctx->mdb_max_entries);
+	u32 n = READ_ONCE(pmctx->mdb_n_entries);
+
+	if (max && n >= max) {
+		NL_SET_ERR_MSG_FMT_MOD(extack, "%s is already in %u groups, and mcast_max_groups=%u",
+				       what, n, max);
+		return -E2BIG;
+	}
+
+	WRITE_ONCE(pmctx->mdb_n_entries, n + 1);
+	return 0;
+}
+
+static void br_multicast_port_ngroups_dec_one(struct net_bridge_mcast_port *pmctx)
+{
+	u32 n = READ_ONCE(pmctx->mdb_n_entries);
+
+	WARN_ON_ONCE(n == 0);
+	WRITE_ONCE(pmctx->mdb_n_entries, n - 1);
+}
+
+static int br_multicast_port_ngroups_inc(struct net_bridge_port *port,
+					 const struct br_ip *group,
+					 struct netlink_ext_ack *extack)
+{
+	struct net_bridge_mcast_port *pmctx;
+	int err;
+
+	lockdep_assert_held_once(&port->br->multicast_lock);
+
+	/* Always count on the port context. */
+	err = br_multicast_port_ngroups_inc_one(&port->multicast_ctx, extack,
+						"Port");
+	if (err) {
+		trace_br_mdb_full(port->dev, group);
+		return err;
+	}
+
+	/* Only count on the VLAN context if VID is given, and if snooping on
+	 * that VLAN is enabled.
+	 */
+	if (!group->vid)
+		return 0;
+
+	pmctx = br_multicast_port_vid_to_port_ctx(port, group->vid);
+	if (!pmctx)
+		return 0;
+
+	err = br_multicast_port_ngroups_inc_one(pmctx, extack, "Port-VLAN");
+	if (err) {
+		trace_br_mdb_full(port->dev, group);
+		goto dec_one_out;
+	}
+
+	return 0;
+
+dec_one_out:
+	br_multicast_port_ngroups_dec_one(&port->multicast_ctx);
+	return err;
+}
+
+static void br_multicast_port_ngroups_dec(struct net_bridge_port *port, u16 vid)
+{
+	struct net_bridge_mcast_port *pmctx;
+
+	lockdep_assert_held_once(&port->br->multicast_lock);
+
+	if (vid) {
+		pmctx = br_multicast_port_vid_to_port_ctx(port, vid);
+		if (pmctx)
+			br_multicast_port_ngroups_dec_one(pmctx);
+	}
+	br_multicast_port_ngroups_dec_one(&port->multicast_ctx);
+}
+
 static void br_multicast_destroy_port_group(struct net_bridge_mcast_gc *gc)
 {
 	struct net_bridge_port_group *pg;
@@ -702,6 +806,7 @@ void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
 	} else {
 		br_multicast_star_g_handle_mode(pg, MCAST_INCLUDE);
 	}
+	br_multicast_port_ngroups_dec(pg->key.port, pg->key.addr.vid);
 	hlist_add_head(&pg->mcast_gc.gc_node, &br->mcast_gc_list);
 	queue_work(system_long_wq, &br->mcast_gc_work);
 
@@ -1165,6 +1270,7 @@ struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,
 		return mp;
 
 	if (atomic_read(&br->mdb_hash_tbl.nelems) >= br->hash_max) {
+		trace_br_mdb_full(br->dev, group);
 		br_mc_disabled_update(br->dev, false, NULL);
 		br_opt_toggle(br, BROPT_MULTICAST_ENABLED, false);
 		return ERR_PTR(-E2BIG);
@@ -1288,11 +1394,16 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 			struct netlink_ext_ack *extack)
 {
 	struct net_bridge_port_group *p;
+	int err;
+
+	err = br_multicast_port_ngroups_inc(port, group, extack);
+	if (err)
+		return NULL;
 
 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
 	if (unlikely(!p)) {
 		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new port group");
-		return NULL;
+		goto dec_out;
 	}
 
 	p->key.addr = *group;
@@ -1326,18 +1437,22 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 
 free_out:
 	kfree(p);
+dec_out:
+	br_multicast_port_ngroups_dec(port, group->vid);
 	return NULL;
 }
 
 void br_multicast_del_port_group(struct net_bridge_port_group *p)
 {
 	struct net_bridge_port *port = p->key.port;
+	__u16 vid = p->key.addr.vid;
 
 	hlist_del_init(&p->mglist);
 	if (!br_multicast_is_star_g(&p->key.addr))
 		rhashtable_remove_fast(&port->br->sg_port_tbl, &p->rhnode,
 				       br_sg_port_rht_params);
 	kfree(p);
+	br_multicast_port_ngroups_dec(port, vid);
 }
 
 void br_multicast_host_join(const struct net_bridge_mcast *brmctx,
@@ -1951,6 +2066,25 @@ static void __br_multicast_enable_port_ctx(struct net_bridge_mcast_port *pmctx)
 		br_ip4_multicast_add_router(brmctx, pmctx);
 		br_ip6_multicast_add_router(brmctx, pmctx);
 	}
+
+	if (br_multicast_port_ctx_is_vlan(pmctx)) {
+		struct net_bridge_port_group *pg;
+		u32 n = 0;
+
+		/* The mcast_n_groups counter might be wrong. First,
+		 * BR_VLFLAG_MCAST_ENABLED is toggled before temporary entries
+		 * are flushed, thus mcast_n_groups after the toggle does not
+		 * reflect the true values. And second, permanent entries added
+		 * while BR_VLFLAG_MCAST_ENABLED was disabled, are not reflected
+		 * either. Thus we have to refresh the counter.
+		 */
+
+		hlist_for_each_entry(pg, &pmctx->port->mglist, mglist) {
+			if (pg->key.addr.vid == pmctx->vlan->vid)
+				n++;
+		}
+		WRITE_ONCE(pmctx->mdb_n_entries, n);
+	}
 }
 
 void br_multicast_enable_port(struct net_bridge_port *port)
net/bridge/br_private.h +2 -0
index e4069e27b5c6..49f411a0a1f1 100644
@@ -126,6 +126,8 @@ struct net_bridge_mcast_port {
 	struct hlist_node		ip6_rlist;
 #endif /* IS_ENABLED(CONFIG_IPV6) */
 	unsigned char			multicast_router;
+	u32				mdb_n_entries;
+	u32				mdb_max_entries;
 #endif /* CONFIG_BRIDGE_IGMP_SNOOPING */
 };
 
Signature · 1 line
2.39.0
maintainer Acked-by on v3 7/16
#9 lore raw

Re: [PATCH net-next v3 07/16] net: bridge: Maintain number of MDB entries in net_bridge_mcast_port

Quoted 56 lines · Petr Machata

The MDB maintained by the bridge is limited. When the bridge is configured for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its capacity. In SW datapath, the capacity is configurable through the IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a similar limit exists in the HW datapath for purposes of offloading.

In order to prevent the issue of unilateral exhaustion of MDB resources, introduce two parameters in each of two contexts:

- Per-port and per-port-VLAN number of MDB entries that the port is member in.

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled) per-port-VLAN maximum permitted number of MDB entries, or 0 for no limit.

The per-port multicast context is used for tracking of MDB entries for the port as a whole. This is available for all bridges.

The per-port-VLAN multicast context is then only available on VLAN-filtering bridges on VLANs that have multicast snooping on.

With these changes in place, it will be possible to configure MDB limit for bridge as a whole, or any one port as a whole, or any single port-VLAN.

Note that unlike the global limit, exhaustion of the per-port and per-port-VLAN maximums does not cause disablement of multicast snooping. It is also permitted to configure the local limit larger than hash_max, even though that is not useful.

In this patch, introduce only the accounting for number of entries, and the max field itself, but not the means to toggle the max. The next patch introduces the netlink APIs to toggle and read the values.

---

Notes:
v3:
- Access mdb_max_/_n_entries through READ_/WRITE_ONCE
- Move extack setting to br_multicast_port_ngroups_inc_one(). Since we use NL_SET_ERR_MSG_FMT_MOD, the correct context (port / port-vlan) can be passed through an argument. This also removes the need for more READ/WRITE_ONCE's at the extack-setting site.

v2:
- In br_multicast_port_ngroups_inc_one(), bounce if n>=max, not if n==max
- Adjust extack messages to mention ngroups, now that the bounces appear when n>=max, not n==max
- In __br_multicast_enable_port_ctx(), do not reset max to 0. Also do not count number of entries by going through _inc, as that would end up incorrectly bouncing the entries.

Quoted 3 lines
 net/bridge/br_multicast.c | 136 +++++++++++++++++++++++++++++++++++++-
 net/bridge/br_private.h   |   2 +
 2 files changed, 137 insertions(+), 1 deletion(-)
maintainer Reviewed-by on v3 7/16
#10 lore raw

Re: [PATCH net-next v3 07/16] net: bridge: Maintain number of MDB entries in net_bridge_mcast_port

In reply to Petr Machata
Quoted 30 lines · Petr Machata

The MDB maintained by the bridge is limited. When the bridge is configured for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its capacity. In SW datapath, the capacity is configurable through the IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a similar limit exists in the HW datapath for purposes of offloading.

In order to prevent the issue of unilateral exhaustion of MDB resources, introduce two parameters in each of two contexts:

- Per-port and per-port-VLAN number of MDB entries that the port is member in.

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled) per-port-VLAN maximum permitted number of MDB entries, or 0 for no limit.

The per-port multicast context is used for tracking of MDB entries for the port as a whole. This is available for all bridges.

The per-port-VLAN multicast context is then only available on VLAN-filtering bridges on VLANs that have multicast snooping on.

With these changes in place, it will be possible to configure MDB limit for bridge as a whole, or any one port as a whole, or any single port-VLAN.

Note that unlike the global limit, exhaustion of the per-port and per-port-VLAN maximums does not cause disablement of multicast snooping. It is also permitted to configure the local limit larger than hash_max, even though that is not useful.

Quoted 5 lines

In this patch, introduce only the accounting for number of entries, and the max field itself, but not the means to toggle the max. The next patch introduces the netlink APIs to toggle and read the values.

#11 lore raw

PATCH v3 8/16 net: bridge: Add netlink knobs for number / maximum MDB entries

In reply to Petr Machata

The previous patch added accounting for number of MDB entries per port and per port-VLAN, and the logic to verify that these values stay within configured bounds. However it didn't provide means to actually configure those bounds or read the occupancy. This patch does that.

Two new netlink attributes are added for the MDB occupancy:
IFLA_BRPORT_MCAST_N_GROUPS for the per-port occupancy and BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS for the per-port-VLAN occupancy. And another two for the maximum number of MDB entries:
IFLA_BRPORT_MCAST_MAX_GROUPS for the per-port maximum, and BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS for the per-port-VLAN one.

Note that the two new IFLA_BRPORT_ attributes prompt bumping of RTNL_SLAVE_MAX_TYPE to size the slave attribute tables large enough.

The new attributes are used like this:

 # ip link add name br up type bridge vlan_filtering 1 mcast_snooping 1 \
                                      mcast_vlan_snooping 1 mcast_querier 1
 # ip link set dev v1 master br
 # bridge vlan add dev v1 vid 2
 # bridge vlan set dev v1 vid 1 mcast_max_groups 1
 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1
 # bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1
 Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1.
 # bridge link set dev v1 mcast_max_groups 1
 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 2
 Error: bridge: Port is already in 1 groups, and mcast_max_groups=1.
 # bridge -d link show
 5: v1@v2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br [...]
     [...] mcast_n_groups 1 mcast_max_groups 1
 # bridge -d vlan show
 port              vlan-id
 br                1 PVID Egress Untagged
                     state forwarding mcast_router 1
 v1                1 PVID Egress Untagged
                     [...] mcast_n_groups 1 mcast_max_groups 1
                   2
                     [...] mcast_n_groups 0 mcast_max_groups 0

---

Notes:
v3:
- Move the br_multicast_port_ctx_vlan_disabled() check out to the _vlan_ helpers callers. Thus these helpers cannot fail, which makes them very similar to the _port_ helpers. Have them take the MC context directly and unify them.

v2:
- Drop locks around accesses in br_multicast_{port,vlan}_ngroups_{get,set_max}(),
- Drop bounces due to max<n in br_multicast_{port,vlan}_ngroups_set_max().

 include/uapi/linux/if_bridge.h |  2 ++
 include/uapi/linux/if_link.h   |  2 ++
 net/bridge/br_multicast.c      | 15 +++++++++++++++
 net/bridge/br_netlink.c        | 17 ++++++++++++++++-
 net/bridge/br_private.h        |  6 +++++-
 net/bridge/br_vlan.c           | 11 +++++++----
 net/bridge/br_vlan_options.c   | 27 ++++++++++++++++++++++++++-
 net/core/rtnetlink.c           |  2 +-
 8 files changed, 74 insertions(+), 8 deletions(-)
include/uapi/linux/if_bridge.h +2 -0
index d9de241d90f9..d60c456710b3 100644
@@ -523,6 +523,8 @@ enum {
 	BRIDGE_VLANDB_ENTRY_TUNNEL_INFO,
 	BRIDGE_VLANDB_ENTRY_STATS,
 	BRIDGE_VLANDB_ENTRY_MCAST_ROUTER,
+	BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS,
+	BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS,
 	__BRIDGE_VLANDB_ENTRY_MAX,
 };
 #define BRIDGE_VLANDB_ENTRY_MAX (__BRIDGE_VLANDB_ENTRY_MAX - 1)
include/uapi/linux/if_link.h +2 -0
index 1021a7e47a86..1bed3a72939c 100644
@@ -564,6 +564,8 @@ enum {
 	IFLA_BRPORT_MCAST_EHT_HOSTS_CNT,
 	IFLA_BRPORT_LOCKED,
 	IFLA_BRPORT_MAB,
+	IFLA_BRPORT_MCAST_N_GROUPS,
+	IFLA_BRPORT_MCAST_MAX_GROUPS,
 	__IFLA_BRPORT_MAX
 };
 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)
net/bridge/br_multicast.c +15 -0
index b6aa0bad5817..96d1fc78dd39 100644
@@ -772,6 +772,21 @@ static void br_multicast_port_ngroups_dec(struct net_bridge_port *port, u16 vid)
 	br_multicast_port_ngroups_dec_one(&port->multicast_ctx);
 }
 
+u32 br_multicast_ngroups_get(const struct net_bridge_mcast_port *pmctx)
+{
+	return READ_ONCE(pmctx->mdb_n_entries);
+}
+
+void br_multicast_ngroups_set_max(struct net_bridge_mcast_port *pmctx, u32 max)
+{
+	WRITE_ONCE(pmctx->mdb_max_entries, max);
+}
+
+u32 br_multicast_ngroups_get_max(const struct net_bridge_mcast_port *pmctx)
+{
+	return READ_ONCE(pmctx->mdb_max_entries);
+}
+
 static void br_multicast_destroy_port_group(struct net_bridge_mcast_gc *gc)
 {
 	struct net_bridge_port_group *pg;
net/bridge/br_netlink.c +16 -1
index a6133d469885..9173e52b89e2 100644
@@ -202,6 +202,8 @@ static inline size_t br_port_info_size(void)
 		+ nla_total_size_64bit(sizeof(u64)) /* IFLA_BRPORT_HOLD_TIMER */
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 		+ nla_total_size(sizeof(u8))	/* IFLA_BRPORT_MULTICAST_ROUTER */
+		+ nla_total_size(sizeof(u32))	/* IFLA_BRPORT_MCAST_N_GROUPS */
+		+ nla_total_size(sizeof(u32))	/* IFLA_BRPORT_MCAST_MAX_GROUPS */
 #endif
 		+ nla_total_size(sizeof(u16))	/* IFLA_BRPORT_GROUP_FWD_MASK */
 		+ nla_total_size(sizeof(u8))	/* IFLA_BRPORT_MRP_RING_OPEN */
@@ -298,7 +300,11 @@ static int br_port_fill_attrs(struct sk_buff *skb,
 	    nla_put_u32(skb, IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT,
 			p->multicast_eht_hosts_limit) ||
 	    nla_put_u32(skb, IFLA_BRPORT_MCAST_EHT_HOSTS_CNT,
-			p->multicast_eht_hosts_cnt))
+			p->multicast_eht_hosts_cnt) ||
+	    nla_put_u32(skb, IFLA_BRPORT_MCAST_N_GROUPS,
+			br_multicast_ngroups_get(&p->multicast_ctx)) ||
+	    nla_put_u32(skb, IFLA_BRPORT_MCAST_MAX_GROUPS,
+			br_multicast_ngroups_get_max(&p->multicast_ctx)))
 		return -EMSGSIZE;
 #endif
 
@@ -883,6 +889,8 @@ static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = {
 	[IFLA_BRPORT_MAB] = { .type = NLA_U8 },
 	[IFLA_BRPORT_BACKUP_PORT] = { .type = NLA_U32 },
 	[IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT] = { .type = NLA_U32 },
+	[IFLA_BRPORT_MCAST_N_GROUPS] = { .type = NLA_REJECT },
+	[IFLA_BRPORT_MCAST_MAX_GROUPS] = { .type = NLA_U32 },
 };
 
 /* Change the state of the port and notify spanning tree */
@@ -1017,6 +1025,13 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[],
 		if (err)
 			return err;
 	}
+
+	if (tb[IFLA_BRPORT_MCAST_MAX_GROUPS]) {
+		u32 max_groups;
+
+		max_groups = nla_get_u32(tb[IFLA_BRPORT_MCAST_MAX_GROUPS]);
+		br_multicast_ngroups_set_max(&p->multicast_ctx, max_groups);
+	}
 #endif
 
 	if (tb[IFLA_BRPORT_GROUP_FWD_MASK]) {
net/bridge/br_private.h +5 -1
index 49f411a0a1f1..cef5f6ea850c 100644
@@ -978,6 +978,9 @@ void br_multicast_uninit_stats(struct net_bridge *br);
 void br_multicast_get_stats(const struct net_bridge *br,
 			    const struct net_bridge_port *p,
 			    struct br_mcast_stats *dest);
+u32 br_multicast_ngroups_get(const struct net_bridge_mcast_port *pmctx);
+void br_multicast_ngroups_set_max(struct net_bridge_mcast_port *pmctx, u32 max);
+u32 br_multicast_ngroups_get_max(const struct net_bridge_mcast_port *pmctx);
 void br_mdb_init(void);
 void br_mdb_uninit(void);
 void br_multicast_host_join(const struct net_bridge_mcast *brmctx,
@@ -1761,7 +1764,8 @@ static inline u16 br_vlan_flags(const struct net_bridge_vlan *v, u16 pvid)
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 bool br_vlan_opts_eq_range(const struct net_bridge_vlan *v_curr,
 			   const struct net_bridge_vlan *range_end);
-bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v);
+bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v,
+		       const struct net_bridge_port *p);
 size_t br_vlan_opts_nl_size(void);
 int br_vlan_process_options(const struct net_bridge *br,
 			    const struct net_bridge_port *p,
net/bridge/br_vlan.c +7 -4
index bc75fa1e4666..8a3dbc09ba38 100644
@@ -1816,6 +1816,7 @@ static bool br_vlan_stats_fill(struct sk_buff *skb,
 /* v_opts is used to dump the options which must be equal in the whole range */
 static bool br_vlan_fill_vids(struct sk_buff *skb, u16 vid, u16 vid_range,
 			      const struct net_bridge_vlan *v_opts,
+			      const struct net_bridge_port *p,
 			      u16 flags,
 			      bool dump_stats)
 {
@@ -1842,7 +1843,7 @@ static bool br_vlan_fill_vids(struct sk_buff *skb, u16 vid, u16 vid_range,
 		goto out_err;
 
 	if (v_opts) {
-		if (!br_vlan_opts_fill(skb, v_opts))
+		if (!br_vlan_opts_fill(skb, v_opts, p))
 			goto out_err;
 
 		if (dump_stats && !br_vlan_stats_fill(skb, v_opts))
@@ -1925,7 +1926,7 @@ void br_vlan_notify(const struct net_bridge *br,
 		goto out_kfree;
 	}
 
-	if (!br_vlan_fill_vids(skb, vid, vid_range, v, flags, false))
+	if (!br_vlan_fill_vids(skb, vid, vid_range, v, p, flags, false))
 		goto out_err;
 
 	nlmsg_end(skb, nlh);
@@ -2030,7 +2031,7 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 
 			if (!br_vlan_fill_vids(skb, range_start->vid,
 					       range_end->vid, range_start,
-					       vlan_flags, dump_stats)) {
+					       p, vlan_flags, dump_stats)) {
 				err = -EMSGSIZE;
 				break;
 			}
@@ -2056,7 +2057,7 @@ static int br_vlan_dump_dev(const struct net_device *dev,
 		else if (!dump_global &&
 			 !br_vlan_fill_vids(skb, range_start->vid,
 					    range_end->vid, range_start,
-					    br_vlan_flags(range_start, pvid),
+					    p, br_vlan_flags(range_start, pvid),
 					    dump_stats))
 			err = -EMSGSIZE;
 	}
@@ -2131,6 +2132,8 @@ static const struct nla_policy br_vlan_db_policy[BRIDGE_VLANDB_ENTRY_MAX + 1] =
 	[BRIDGE_VLANDB_ENTRY_STATE]	= { .type = NLA_U8 },
 	[BRIDGE_VLANDB_ENTRY_TUNNEL_INFO] = { .type = NLA_NESTED },
 	[BRIDGE_VLANDB_ENTRY_MCAST_ROUTER]	= { .type = NLA_U8 },
+	[BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS]	= { .type = NLA_REJECT },
+	[BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS]	= { .type = NLA_U32 },
 };
 
 static int br_vlan_rtm_process_one(struct net_device *dev,
net/bridge/br_vlan_options.c +26 -1
index a2724d03278c..e378c2f3a9e2 100644
@@ -48,7 +48,8 @@ bool br_vlan_opts_eq_range(const struct net_bridge_vlan *v_curr,
 	       curr_mc_rtr == range_mc_rtr;
 }
 
-bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v)
+bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v,
+		       const struct net_bridge_port *p)
 {
 	if (nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_STATE, br_vlan_get_state(v)) ||
 	    !__vlan_tun_put(skb, v))
@@ -58,6 +59,12 @@ bool br_vlan_opts_fill(struct sk_buff *skb, const struct net_bridge_vlan *v)
 	if (nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_MCAST_ROUTER,
 		       br_vlan_multicast_router(v)))
 		return false;
+	if (p && !br_multicast_port_ctx_vlan_disabled(&v->port_mcast_ctx) &&
+	    (nla_put_u32(skb, BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS,
+			 br_multicast_ngroups_get(&v->port_mcast_ctx)) ||
+	     nla_put_u32(skb, BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS,
+			 br_multicast_ngroups_get_max(&v->port_mcast_ctx))))
+		return false;
 #endif
 
 	return true;
@@ -70,6 +77,8 @@ size_t br_vlan_opts_nl_size(void)
 	       + nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_TINFO_ID */
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 	       + nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_ENTRY_MCAST_ROUTER */
+	       + nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS */
+	       + nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS */
 #endif
 	       + 0;
 }
@@ -212,6 +221,22 @@ static int br_vlan_process_one_opts(const struct net_bridge *br,
 			return err;
 		*changed = true;
 	}
+	if (tb[BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS]) {
+		u32 val;
+
+		if (!p) {
+			NL_SET_ERR_MSG_MOD(extack, "Can't set mcast_max_groups for non-port vlans");
+			return -EINVAL;
+		}
+		if (br_multicast_port_ctx_vlan_disabled(&v->port_mcast_ctx)) {
+			NL_SET_ERR_MSG_MOD(extack, "Multicast snooping disabled on this VLAN");
+			return -EINVAL;
+		}
+
+		val = nla_get_u32(tb[BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS]);
+		br_multicast_ngroups_set_max(&v->port_mcast_ctx, val);
+		*changed = true;
+	}
 #endif
 
 	return 0;
net/core/rtnetlink.c +1 -1
index 64289bc98887..e786255a8360 100644
@@ -58,7 +58,7 @@
 #include "dev.h"
 
 #define RTNL_MAX_TYPE		50
-#define RTNL_SLAVE_MAX_TYPE	40
+#define RTNL_SLAVE_MAX_TYPE	42
 
 struct rtnl_link {
 	rtnl_doit_func		doit;
Signature · 1 line
2.39.0
maintainer Acked-by on v3 8/16
#12 lore raw

Re: [PATCH net-next v3 08/16] net: bridge: Add netlink knobs for number / maximum MDB entries

Quoted 61 lines · Petr Machata

The previous patch added accounting for number of MDB entries per port and per port-VLAN, and the logic to verify that these values stay within configured bounds. However it didn't provide means to actually configure those bounds or read the occupancy. This patch does that.

Two new netlink attributes are added for the MDB occupancy:
IFLA_BRPORT_MCAST_N_GROUPS for the per-port occupancy and BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS for the per-port-VLAN occupancy. And another two for the maximum number of MDB entries:
IFLA_BRPORT_MCAST_MAX_GROUPS for the per-port maximum, and BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS for the per-port-VLAN one.

Note that the two new IFLA_BRPORT_ attributes prompt bumping of RTNL_SLAVE_MAX_TYPE to size the slave attribute tables large enough.

The new attributes are used like this:

 # ip link add name br up type bridge vlan_filtering 1 mcast_snooping 1 \
                                      mcast_vlan_snooping 1 mcast_querier 1
 # ip link set dev v1 master br
 # bridge vlan add dev v1 vid 2
 # bridge vlan set dev v1 vid 1 mcast_max_groups 1
 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1
 # bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1
 Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1.
 # bridge link set dev v1 mcast_max_groups 1
 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 2
 Error: bridge: Port is already in 1 groups, and mcast_max_groups=1.
 # bridge -d link show
 5: v1@v2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br [...]
     [...] mcast_n_groups 1 mcast_max_groups 1
 # bridge -d vlan show
 port              vlan-id
 br                1 PVID Egress Untagged
                     state forwarding mcast_router 1
 v1                1 PVID Egress Untagged
                     [...] mcast_n_groups 1 mcast_max_groups 1
                   2
                     [...] mcast_n_groups 0 mcast_max_groups 0

---

Notes:
v3:
- Move the br_multicast_port_ctx_vlan_disabled() check out to the _vlan_ helpers callers. Thus these helpers cannot fail, which makes them very similar to the _port_ helpers. Have them take the MC context directly and unify them.

v2:
- Drop locks around accesses in br_multicast_{port,vlan}_ngroups_{get,set_max}(),
- Drop bounces due to max<n in br_multicast_{port,vlan}_ngroups_set_max().

Quoted 10 lines
 include/uapi/linux/if_bridge.h |  2 ++
 include/uapi/linux/if_link.h   |  2 ++
 net/bridge/br_multicast.c      | 15 +++++++++++++++
 net/bridge/br_netlink.c        | 17 ++++++++++++++++-
 net/bridge/br_private.h        |  6 +++++-
 net/bridge/br_vlan.c           | 11 +++++++----
 net/bridge/br_vlan_options.c   | 27 ++++++++++++++++++++++++++-
 net/core/rtnetlink.c           |  2 +-
 8 files changed, 74 insertions(+), 8 deletions(-)
maintainer Reviewed-by on v3 8/16
#13 lore raw

Re: [PATCH net-next v3 08/16] net: bridge: Add netlink knobs for number / maximum MDB entries

In reply to Petr Machata
Quoted 44 lines · Petr Machata

The previous patch added accounting for number of MDB entries per port and per port-VLAN, and the logic to verify that these values stay within configured bounds. However it didn't provide means to actually configure those bounds or read the occupancy. This patch does that.

Two new netlink attributes are added for the MDB occupancy:
IFLA_BRPORT_MCAST_N_GROUPS for the per-port occupancy and BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS for the per-port-VLAN occupancy. And another two for the maximum number of MDB entries:
IFLA_BRPORT_MCAST_MAX_GROUPS for the per-port maximum, and BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS for the per-port-VLAN one.

Note that the two new IFLA_BRPORT_ attributes prompt bumping of RTNL_SLAVE_MAX_TYPE to size the slave attribute tables large enough.

The new attributes are used like this:

 # ip link add name br up type bridge vlan_filtering 1 mcast_snooping 1 \
                                      mcast_vlan_snooping 1 mcast_querier 1
 # ip link set dev v1 master br
 # bridge vlan add dev v1 vid 2
 # bridge vlan set dev v1 vid 1 mcast_max_groups 1
 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1
 # bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1
 Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1.
 # bridge link set dev v1 mcast_max_groups 1
 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 2
 Error: bridge: Port is already in 1 groups, and mcast_max_groups=1.
 # bridge -d link show
 5: v1@v2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br [...]
     [...] mcast_n_groups 1 mcast_max_groups 1
 # bridge -d vlan show
 port              vlan-id
 br                1 PVID Egress Untagged
                     state forwarding mcast_router 1
 v1                1 PVID Egress Untagged
                     [...] mcast_n_groups 1 mcast_max_groups 1
                   2
                     [...] mcast_n_groups 0 mcast_max_groups 0
Quoted 1 line
#14 lore raw

PATCH v3 9/16 selftests: forwarding: Move IGMP- and MLD-related functions to lib

In reply to Petr Machata

These functions will be helpful for other testsuites as well. Extract them to a common place.

---
 .../selftests/net/forwarding/bridge_mdb.sh    | 49 -------------------
 tools/testing/selftests/net/forwarding/lib.sh | 49 +++++++++++++++++++
 2 files changed, 49 insertions(+), 49 deletions(-)
tools/testing/selftests/net/forwarding/bridge_mdb.sh +0 -49
index 2fa5973c0c28..51f2b0d77067 100755
@@ -1018,26 +1018,6 @@ fwd_test()
 	ip -6 address del fe80::1/64 dev br0
 }
 
-igmpv3_is_in_get()
-{
-	local igmpv3
-
-	igmpv3=$(:
-		)"22:"$(			: Type - Membership Report
-		)"00:"$(			: Reserved
-		)"2a:f8:"$(			: Checksum
-		)"00:00:"$(			: Reserved
-		)"00:01:"$(			: Number of Group Records
-		)"01:"$(			: Record Type - IS_IN
-		)"00:"$(			: Aux Data Len
-		)"00:01:"$(			: Number of Sources
-		)"ef:01:01:01:"$(		: Multicast Address - 239.1.1.1
-		)"c0:00:02:02"$(		: Source Address - 192.0.2.2
-		)
-
-	echo $igmpv3
-}
-
 ctrl_igmpv3_is_in_test()
 {
 	RET=0
@@ -1077,35 +1057,6 @@ ctrl_igmpv3_is_in_test()
 	log_test "IGMPv3 MODE_IS_INCLUE tests"
 }
 
-mldv2_is_in_get()
-{
-	local hbh
-	local icmpv6
-
-	hbh=$(:
-		)"3a:"$(			: Next Header - ICMPv6
-		)"00:"$(			: Hdr Ext Len
-		)"00:00:00:00:00:00:"$(		: Options and Padding
-		)
-
-	icmpv6=$(:
-		)"8f:"$(			: Type - MLDv2 Report
-		)"00:"$(			: Code
-		)"45:39:"$(			: Checksum
-		)"00:00:"$(			: Reserved
-		)"00:01:"$(			: Number of Group Records
-		)"01:"$(			: Record Type - IS_IN
-		)"00:"$(			: Aux Data Len
-		)"00:01:"$(			: Number of Sources
-		)"ff:0e:00:00:00:00:00:00:"$(	: Multicast address - ff0e::1
-		)"00:00:00:00:00:00:00:01:"$(	:
-		)"20:01:0d:b8:00:01:00:00:"$(	: Source Address - 2001:db8:1::2
-		)"00:00:00:00:00:00:00:02:"$(	:
-		)
-
-	echo ${hbh}${icmpv6}
-}
-
 ctrl_mldv2_is_in_test()
 {
 	RET=0
tools/testing/selftests/net/forwarding/lib.sh +49 -0

52 lines not on this page · raw message

Signature · 1 line
2.39.0
#15 lore raw

PATCH v3 10/16 selftests: forwarding: bridge_mdb: Fix a typo

In reply to Petr Machata

Add the letter missing from the word "INCLUDE".

---
 tools/testing/selftests/net/forwarding/bridge_mdb.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
tools/testing/selftests/net/forwarding/bridge_mdb.sh +1 -1
index 51f2b0d77067..4e16677f02ba 100755
@@ -1054,7 +1054,7 @@ ctrl_igmpv3_is_in_test()
 
 	bridge mdb del dev br0 port $swp1 grp 239.1.1.1 vid 10
 
-	log_test "IGMPv3 MODE_IS_INCLUE tests"
+	log_test "IGMPv3 MODE_IS_INCLUDE tests"
 }
 
 ctrl_mldv2_is_in_test()
Signature · 1 line
2.39.0
#16 lore raw

PATCH v3 11/16 selftests: forwarding: lib: Add helpers for IP address handling

In reply to Petr Machata

In order to generate IGMPv3 and MLDv2 packets on the fly, we will need helpers to expand IPv4 and IPv6 addresses given as parameters in mausezahn payload notation. Add helpers that do it.

---
 tools/testing/selftests/net/forwarding/lib.sh | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)
tools/testing/selftests/net/forwarding/lib.sh +37 -0
index 0cfa0b699803..409ff3799b55 100755
@@ -1693,6 +1693,43 @@ hw_stats_monitor_test()
 	log_test "${type}_stats notifications"
 }
 
+ipv4_to_bytes()
+{
+	local IP=$1; shift
+
+	printf '%02x:' ${IP//./ } |
+	    sed 's/:$//'
+}
+
+# Convert a given IPv6 address, `IP' such that the :: token, if present, is
+# expanded, and each 16-bit group is padded with zeroes to be 4 hexadecimal
+# digits. An optional `BYTESEP' parameter can be given to further separate
+# individual bytes of each 16-bit group.
+expand_ipv6()
+{
+	local IP=$1; shift
+	local bytesep=$1; shift
+
+	local cvt_ip=${IP/::/_}
+	local colons=${cvt_ip//[^:]/}
+	local allcol=:::::::
+	# IP where :: -> the appropriate number of colons:
+	local allcol_ip=${cvt_ip/_/${allcol:${#colons}}}
+
+	echo $allcol_ip | tr : '\n' |
+	    sed s/^/0000/ |
+	    sed 's/.*\(..\)\(..\)/\1'"$bytesep"'\2/' |
+	    tr '\n' : |
+	    sed 's/:$//'
+}
+
+ipv6_to_bytes()
+{
+	local IP=$1; shift
+
+	expand_ipv6 "$IP" :
+}
+
 igmpv3_is_in_get()
 {
 	local igmpv3
Signature · 1 line
2.39.0
#17 lore raw

PATCH v3 12/16 selftests: forwarding: lib: Add helpers for checksum handling

In reply to Petr Machata

In order to generate IGMPv3 and MLDv2 packets on the fly, we will need helpers to calculate the packet checksum.

The approach presented in this patch revolves around payload templates for mausezahn. These are mausezahn-like payload strings (01:23:45:...) with possibly one 2-byte sequence replaced with the word PAYLOAD. The main function is payload_template_calc_checksum(), which calculates RFC 1071 checksum of the message. There are further helpers to then convert the checksum to the payload format, and to expand it.

For IPv6, MLDv2 message checksum is computed using a pseudoheader that differs from the header used in the payload itself. The fact that the two messages are different means that the checksum needs to be returned as a separate quantity, instead of being expanded in-place in the payload itself. Furthermore, the pseudoheader includes a length of the message. Much like the checksum, this needs to be expanded in mausezahn format. And likewise for number of addresses for (S,G) entries. Thus we have several places where a computed quantity needs to be presented in the payload format. Add a helper u16_to_bytes(), which will be used in all these cases.

---

Notes:

    v2:
    - In the comment at payload_template_calc_checksum(),
      s/%#02x/%02x/, that's the mausezahn payload format.
 tools/testing/selftests/net/forwarding/lib.sh | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
tools/testing/selftests/net/forwarding/lib.sh +56 -0
index 409ff3799b55..b10c903d9abd 100755
@@ -1730,6 +1730,62 @@ ipv6_to_bytes()
 	expand_ipv6 "$IP" :
 }
 
+u16_to_bytes()
+{
+	local u16=$1; shift
+
+	printf "%04x" $u16 | sed 's/^/000/;s/^.*\(..\)\(..\)$/\1:\2/'
+}
+
+# Given a mausezahn-formatted payload (colon-separated bytes given as %02x),
+# possibly with a keyword CHECKSUM stashed where a 16-bit checksum should be,
+# calculate checksum as per RFC 1071, assuming the CHECKSUM field (if any)
+# stands for 00:00.
+payload_template_calc_checksum()
+{
+	local payload=$1; shift
+
+	(
+	    # Set input radix.
+	    echo "16i"
+	    # Push zero for the initial checksum.
+	    echo 0
+
+	    # Pad the payload with a terminating 00: in case we get an odd
+	    # number of bytes.
+	    echo "${payload%:}:00:" |
+		sed 's/CHECKSUM/00:00/g' |
+		tr '[:lower:]' '[:upper:]' |
+		# Add the word to the checksum.
+		sed 's/\(..\):\(..\):/\1\2+\n/g' |
+		# Strip the extra odd byte we pushed if left unconverted.
+		sed 's/\(..\):$//'
+
+	    echo "10000 ~ +"	# Calculate and add carry.
+	    echo "FFFF r - p"	# Bit-flip and print.
+	) |
+	    dc |
+	    tr '[:upper:]' '[:lower:]'
+}
+
+payload_template_expand_checksum()
+{
+	local payload=$1; shift
+	local checksum=$1; shift
+
+	local ckbytes=$(u16_to_bytes $checksum)
+
+	echo "$payload" | sed "s/CHECKSUM/$ckbytes/g"
+}
+
+payload_template_nbytes()
+{
+	local payload=$1; shift
+
+	payload_template_expand_checksum "${payload%:}" 0 |
+		sed 's/:/\n/g' | wc -l
+}
+
 igmpv3_is_in_get()
 {
 	local igmpv3
Signature · 1 line
2.39.0
#18 lore raw

PATCH v3 13/16 selftests: forwarding: lib: Parameterize IGMPv3/MLDv2 generation

In reply to Petr Machata

In order to generate IGMPv3 and MLDv2 packets on the fly, the functions that generate these packets need to be able to generate packets for different groups and different sources. Generating MLDv2 packets further needs the source address of the packet for purposes of checksum calculation. Add the necessary parameters, and generate the payload accordingly by dispatching to helpers added in the previous patches.

Adjust the sole client, bridge_mdb.sh, as well.

---
 .../selftests/net/forwarding/bridge_mdb.sh    |  9 ++---
 tools/testing/selftests/net/forwarding/lib.sh | 36 +++++++++++++------
 2 files changed, 31 insertions(+), 14 deletions(-)
tools/testing/selftests/net/forwarding/bridge_mdb.sh +5 -4
index 4e16677f02ba..b48867d8cadf 100755
@@ -1029,7 +1029,7 @@ ctrl_igmpv3_is_in_test()
 
 	# IS_IN ( 192.0.2.2 )
 	$MZ $h1.10 -c 1 -A 192.0.2.1 -B 239.1.1.1 \
-		-t ip proto=2,p=$(igmpv3_is_in_get) -q
+		-t ip proto=2,p=$(igmpv3_is_in_get 239.1.1.1 192.0.2.2) -q
 
 	bridge -d mdb show dev br0 vid 10 | grep 239.1.1.1 | grep -q 192.0.2.2
 	check_fail $? "Permanent entry affected by IGMP packet"
@@ -1042,7 +1042,7 @@ ctrl_igmpv3_is_in_test()
 
 	# IS_IN ( 192.0.2.2 )
 	$MZ $h1.10 -c 1 -A 192.0.2.1 -B 239.1.1.1 \
-		-t ip proto=2,p=$(igmpv3_is_in_get) -q
+		-t ip proto=2,p=$(igmpv3_is_in_get 239.1.1.1 192.0.2.2) -q
 
 	bridge -d mdb show dev br0 vid 10 | grep 239.1.1.1 | grep -v "src" | \
 		grep -q 192.0.2.2
@@ -1067,8 +1067,9 @@ ctrl_mldv2_is_in_test()
 		filter_mode include source_list 2001:db8:1::1
 
 	# IS_IN ( 2001:db8:1::2 )
+	local p=$(mldv2_is_in_get fe80::1 ff0e::1 2001:db8:1::2)
 	$MZ -6 $h1.10 -c 1 -A fe80::1 -B ff0e::1 \
-		-t ip hop=1,next=0,p=$(mldv2_is_in_get) -q
+		-t ip hop=1,next=0,p="$p" -q
 
 	bridge -d mdb show dev br0 vid 10 | grep ff0e::1 | \
 		grep -q 2001:db8:1::2
@@ -1082,7 +1083,7 @@ ctrl_mldv2_is_in_test()
 
 	# IS_IN ( 2001:db8:1::2 )
 	$MZ -6 $h1.10 -c 1 -A fe80::1 -B ff0e::1 \
-		-t ip hop=1,next=0,p=$(mldv2_is_in_get) -q
+		-t ip hop=1,next=0,p="$p" -q
 
 	bridge -d mdb show dev br0 vid 10 | grep ff0e::1 | grep -v "src" | \
 		grep -q 2001:db8:1::2
tools/testing/selftests/net/forwarding/lib.sh +26 -10
index b10c903d9abd..190e49e60508 100755
@@ -1788,26 +1788,35 @@ payload_template_nbytes()
 
 igmpv3_is_in_get()
 {
+	local GRP=$1; shift
+	local IP=$1; shift
+
 	local igmpv3
 
+	# IS_IN ( $IP )
 	igmpv3=$(:
 		)"22:"$(			: Type - Membership Report
 		)"00:"$(			: Reserved
-		)"2a:f8:"$(			: Checksum
+		)"CHECKSUM:"$(			: Checksum
 		)"00:00:"$(			: Reserved
 		)"00:01:"$(			: Number of Group Records
 		)"01:"$(			: Record Type - IS_IN
 		)"00:"$(			: Aux Data Len
 		)"00:01:"$(			: Number of Sources
-		)"ef:01:01:01:"$(		: Multicast Address - 239.1.1.1
-		)"c0:00:02:02"$(		: Source Address - 192.0.2.2
+		)"$(ipv4_to_bytes $GRP):"$(	: Multicast Address
+		)"$(ipv4_to_bytes $IP)"$(	: Source Address
 		)
+	local checksum=$(payload_template_calc_checksum "$igmpv3")
 
-	echo $igmpv3
+	payload_template_expand_checksum "$igmpv3" $checksum
 }
 
 mldv2_is_in_get()
 {
+	local SIP=$1; shift
+	local GRP=$1; shift
+	local IP=$1; shift
+
 	local hbh
 	local icmpv6
 
@@ -1820,17 +1829,24 @@ mldv2_is_in_get()
 	icmpv6=$(:
 		)"8f:"$(			: Type - MLDv2 Report
 		)"00:"$(			: Code
-		)"45:39:"$(			: Checksum
+		)"CHECKSUM:"$(			: Checksum
 		)"00:00:"$(			: Reserved
 		)"00:01:"$(			: Number of Group Records
 		)"01:"$(			: Record Type - IS_IN
 		)"00:"$(			: Aux Data Len
 		)"00:01:"$(			: Number of Sources
-		)"ff:0e:00:00:00:00:00:00:"$(	: Multicast address - ff0e::1
-		)"00:00:00:00:00:00:00:01:"$(	:
-		)"20:01:0d:b8:00:01:00:00:"$(	: Source Address - 2001:db8:1::2
-		)"00:00:00:00:00:00:00:02:"$(	:
+		)"$(ipv6_to_bytes $GRP):"$(	: Multicast address
+		)"$(ipv6_to_bytes $IP):"$(	: Source Address
 		)
 
-	echo ${hbh}${icmpv6}
+	local len=$(u16_to_bytes $(payload_template_nbytes $icmpv6))
+	local sudohdr=$(:
+		)"$(ipv6_to_bytes $SIP):"$(	: SIP
+		)"$(ipv6_to_bytes $GRP):"$(	: DIP is multicast address
+	        )"${len}:"$(			: Upper-layer length
+	        )"00:3a:"$(			: Zero and next-header
+	        )
+	local checksum=$(payload_template_calc_checksum ${sudohdr}${icmpv6})
+
+	payload_template_expand_checksum "$hbh$icmpv6" $checksum
 }
Signature · 1 line
2.39.0
#19 lore raw

PATCH v3 14/16 selftests: forwarding: lib: Allow list of IPs for IGMPv3/MLDv2

In reply to Petr Machata

The testsuite that checks for mcast_max_groups functionality will need to generate IGMP and MLD packets with configurable number of (S,G) addresses. To that end, further extend igmpv3_is_in_get() and mldv2_is_in_get() to allow a list of IP addresses instead of one address.

---
 tools/testing/selftests/net/forwarding/lib.sh | 22 +++++++++++++------
 1 file changed, 15 insertions(+), 7 deletions(-)
tools/testing/selftests/net/forwarding/lib.sh +15 -7
index 190e49e60508..12ef34ebcbbf 100755
@@ -1789,11 +1789,12 @@ payload_template_nbytes()
 igmpv3_is_in_get()
 {
 	local GRP=$1; shift
-	local IP=$1; shift
+	local sources=("$@")
 
 	local igmpv3
+	local nsources=$(u16_to_bytes ${#sources[@]})
 
-	# IS_IN ( $IP )
+	# IS_IN ( $sources )
 	igmpv3=$(:
 		)"22:"$(			: Type - Membership Report
 		)"00:"$(			: Reserved
@@ -1802,9 +1803,12 @@ igmpv3_is_in_get()
 		)"00:01:"$(			: Number of Group Records
 		)"01:"$(			: Record Type - IS_IN
 		)"00:"$(			: Aux Data Len
-		)"00:01:"$(			: Number of Sources
+		)"${nsources}:"$(		: Number of Sources
 		)"$(ipv4_to_bytes $GRP):"$(	: Multicast Address
-		)"$(ipv4_to_bytes $IP)"$(	: Source Address
+		)"$(for src in "${sources[@]}"; do
+			ipv4_to_bytes $src
+			echo -n :
+		    done)"$(			: Source Addresses
 		)
 	local checksum=$(payload_template_calc_checksum "$igmpv3")
 
@@ -1815,10 +1819,11 @@ mldv2_is_in_get()
 {
 	local SIP=$1; shift
 	local GRP=$1; shift
-	local IP=$1; shift
+	local sources=("$@")
 
 	local hbh
 	local icmpv6
+	local nsources=$(u16_to_bytes ${#sources[@]})
 
 	hbh=$(:
 		)"3a:"$(			: Next Header - ICMPv6
@@ -1834,9 +1839,12 @@ mldv2_is_in_get()
 		)"00:01:"$(			: Number of Group Records
 		)"01:"$(			: Record Type - IS_IN
 		)"00:"$(			: Aux Data Len
-		)"00:01:"$(			: Number of Sources
+		)"${nsources}:"$(		: Number of Sources
 		)"$(ipv6_to_bytes $GRP):"$(	: Multicast address
-		)"$(ipv6_to_bytes $IP):"$(	: Source Address
+		)"$(for src in "${sources[@]}"; do
+			ipv6_to_bytes $src
+			echo -n :
+		    done)"$(			: Source Addresses
 		)
 
 	local len=$(u16_to_bytes $(payload_template_nbytes $icmpv6))
Signature · 1 line
2.39.0
#20 lore raw

PATCH v3 15/16 selftests: forwarding: lib: Add helpers to build IGMP/MLD leave packets

In reply to Petr Machata

The testsuite that checks for mcast_max_groups functionality will need to wipe the added groups as well. Add helpers to build an IGMP or MLD packets announcing that host is leaving a given group.

---
 tools/testing/selftests/net/forwarding/lib.sh | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
tools/testing/selftests/net/forwarding/lib.sh +50 -0
index 12ef34ebcbbf..969e570f609e 100755
@@ -1815,6 +1815,21 @@ igmpv3_is_in_get()
 	payload_template_expand_checksum "$igmpv3" $checksum
 }
 
+igmpv2_leave_get()
+{
+	local GRP=$1; shift
+
+	local payload=$(:
+		)"17:"$(			: Type - Leave Group
+		)"00:"$(			: Max Resp Time - not meaningful
+		)"CHECKSUM:"$(			: Checksum
+		)"$(ipv4_to_bytes $GRP)"$(	: Group Address
+		)
+	local checksum=$(payload_template_calc_checksum "$payload")
+
+	payload_template_expand_checksum "$payload" $checksum
+}
+
 mldv2_is_in_get()
 {
 	local SIP=$1; shift
@@ -1858,3 +1873,38 @@ mldv2_is_in_get()
 
 	payload_template_expand_checksum "$hbh$icmpv6" $checksum
 }
+
+mldv1_done_get()
+{
+	local SIP=$1; shift
+	local GRP=$1; shift
+
+	local hbh
+	local icmpv6
+
+	hbh=$(:
+		)"3a:"$(			: Next Header - ICMPv6
+		)"00:"$(			: Hdr Ext Len
+		)"00:00:00:00:00:00:"$(		: Options and Padding
+		)
+
+	icmpv6=$(:
+		)"84:"$(			: Type - MLDv1 Done
+		)"00:"$(			: Code
+		)"CHECKSUM:"$(			: Checksum
+		)"00:00:"$(			: Max Resp Delay - not meaningful
+		)"00:00:"$(			: Reserved
+		)"$(ipv6_to_bytes $GRP):"$(	: Multicast address
+		)
+
+	local len=$(u16_to_bytes $(payload_template_nbytes $icmpv6))
+	local sudohdr=$(:
+		)"$(ipv6_to_bytes $SIP):"$(	: SIP
+		)"$(ipv6_to_bytes $GRP):"$(	: DIP is multicast address
+	        )"${len}:"$(			: Upper-layer length
+	        )"00:3a:"$(			: Zero and next-header
+	        )
+	local checksum=$(payload_template_calc_checksum ${sudohdr}${icmpv6})
+
+	payload_template_expand_checksum "$hbh$icmpv6" $checksum
+}
Signature · 1 line
2.39.0
#21 lore raw

PATCH v3 16/16 selftests: forwarding: bridge_mdb_max: Add a new selftest

In reply to Petr Machata

Add a suite covering mcast_n_groups and mcast_max_groups bridge features.

---

Notes:
v2:
- Adjust the tests that check setting max below n and reset of max on VLAN snooping enablement
- Make test naming uniform
- Enable testing of control path (IGMP/MLD) in mcast_vlan_snooping bridge
- Reorganize the code so that test instances (per bridge type and configuration type) always come right after the test, in order of {d,q,qvs}{4,6}{cfg,ctl}. Then groups of selftests are at the end of the file. Similarly adjust invocation order of the tests.

 .../testing/selftests/net/forwarding/Makefile |    1 +
 .../net/forwarding/bridge_mdb_max.sh          | 1336 +++++++++++++++++
 2 files changed, 1337 insertions(+)
 create mode 100755 tools/testing/selftests/net/forwarding/bridge_mdb_max.sh
tools/testing/selftests/net/forwarding/Makefile +1 -0
index 453ae006fbcf..91201ab3c4fc 100644
@@ -4,6 +4,7 @@ TEST_PROGS = bridge_igmp.sh \
 	bridge_locked_port.sh \
 	bridge_mdb.sh \
 	bridge_mdb_host.sh \
+	bridge_mdb_max.sh \
 	bridge_mdb_port_down.sh \
 	bridge_mld.sh \
 	bridge_port_isolation.sh \
tools/testing/selftests/net/forwarding/bridge_mdb_max.sh new file +1336 -0

1,336 lines not on this page · raw message

Signature · 1 line
2.39.0
maintainer Acked-by on v3 16/16
#22 lore raw

Re: [PATCH net-next v3 16/16] selftests: forwarding: bridge_mdb_max: Add a new selftest

Quoted 18 lines · Petr Machata

Add a suite covering mcast_n_groups and mcast_max_groups bridge features.

---

Notes:
v2:
- Adjust the tests that check setting max below n and reset of max on VLAN snooping enablement
- Make test naming uniform
- Enable testing of control path (IGMP/MLD) in mcast_vlan_snooping bridge
- Reorganize the code so that test instances (per bridge type and configuration type) always come right after the test, in order of {d,q,qvs}{4,6}{cfg,ctl}. Then groups of selftests are at the end of the file. Similarly adjust invocation order of the tests.

Quoted 5 lines
 .../testing/selftests/net/forwarding/Makefile |    1 +
 .../net/forwarding/bridge_mdb_max.sh          | 1336 +++++++++++++++++
 2 files changed, 1337 insertions(+)
 create mode 100755 tools/testing/selftests/net/forwarding/bridge_mdb_max.sh
#23 lore raw
In reply to Petr Machata
This series was applied to netdev/net-next.git (master) by David S. Miller <[email protected]>:

Hello:

This series was applied to netdev/net-next.git (master) by David S. Miller <[email protected]>:

Quoted 10 lines · On Thu, 2 Feb 2023 18:59:18 +0100 you wrote:

The MDB maintained by the bridge is limited. When the bridge is configured for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its capacity. In SW datapath, the capacity is configurable through the IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a similar limit exists in the HW datapath for purposes of offloading.

In order to prevent the issue of unilateral exhaustion of MDB resources, introduce two parameters in each of two contexts:

[...]

Here is the summary with links:
- [net-next,v3,01/16] net: bridge: Set strict_start_type at two policies

    https://git.kernel.org/netdev/net-next/c/c00041cf1cb8
  - [net-next,v3,02/16] net: bridge: Add extack to br_multicast_new_port_group()
    https://git.kernel.org/netdev/net-next/c/60977a0c6337
  - [net-next,v3,03/16] net: bridge: Move extack-setting to br_multicast_new_port_group()
    https://git.kernel.org/netdev/net-next/c/1c85b80b20a1
  - [net-next,v3,04/16] net: bridge: Add br_multicast_del_port_group()
    https://git.kernel.org/netdev/net-next/c/976b3858dd14
  - [net-next,v3,05/16] net: bridge: Change a cleanup in br_multicast_new_port_group() to goto
    https://git.kernel.org/netdev/net-next/c/eceb30854f6b
  - [net-next,v3,06/16] net: bridge: Add a tracepoint for MDB overflows
    https://git.kernel.org/netdev/net-next/c/d47230a3480a
  - [net-next,v3,07/16] net: bridge: Maintain number of MDB entries in net_bridge_mcast_port
    https://git.kernel.org/netdev/net-next/c/b57e8d870d52
  - [net-next,v3,08/16] net: bridge: Add netlink knobs for number / maximum MDB entries
    https://git.kernel.org/netdev/net-next/c/a1aee20d5db2
  - [net-next,v3,09/16] selftests: forwarding: Move IGMP- and MLD-related functions to lib
    https://git.kernel.org/netdev/net-next/c/344dd2c9e743
  - [net-next,v3,10/16] selftests: forwarding: bridge_mdb: Fix a typo
    https://git.kernel.org/netdev/net-next/c/f7ccf60c4ada
  - [net-next,v3,11/16] selftests: forwarding: lib: Add helpers for IP address handling
    https://git.kernel.org/netdev/net-next/c/fcf4927632ee
  - [net-next,v3,12/16] selftests: forwarding: lib: Add helpers for checksum handling
    https://git.kernel.org/netdev/net-next/c/952e0ee38c72
  - [net-next,v3,13/16] selftests: forwarding: lib: Parameterize IGMPv3/MLDv2 generation
    https://git.kernel.org/netdev/net-next/c/506a1ac9d32b
  - [net-next,v3,14/16] selftests: forwarding: lib: Allow list of IPs for IGMPv3/MLDv2
    https://git.kernel.org/netdev/net-next/c/705d4bc7b6b6
  - [net-next,v3,15/16] selftests: forwarding: lib: Add helpers to build IGMP/MLD leave packets
    https://git.kernel.org/netdev/net-next/c/9ae854697317
  - [net-next,v3,16/16] selftests: forwarding: bridge_mdb_max: Add a new selftest
    https://git.kernel.org/netdev/net-next/c/3446dcd7df05

You are awesome, thank you!

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