Merge branch 'bridge-mcast-preparations-for-evpn-extensions'

Ido Schimmel says:

====================
bridge: mcast: Preparations for EVPN extensions

This patchset was split from [1] and includes non-functional changes
aimed at making it easier to add additional netlink attributes later on.
Future extensions are available here [2].

The idea behind these patches is to create an MDB configuration
structure into which netlink messages are parsed into. The structure is
then passed in the entry creation / deletion call chain instead of
passing the netlink attributes themselves. The same pattern is used by
other rtnetlink objects such as routes and nexthops.

I initially tried to extend the current code, but it proved to be too
difficult, which is why I decided to refactor it to the extensible and
familiar pattern used by other rtnetlink objects.

Tested using existing selftests and using a new selftest that will be
submitted together with the planned extensions.

[1] https://lore.kernel.org/netdev/20221018120420.561846-1-idosch@nvidia.com/
[2] https://github.com/idosch/linux/commits/submit/mdb_v1
====================

Link: https://lore.kernel.org/r/20221206105809.363767-1-idosch@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/bridge/br_mdb.c

@@ -754,73 +754,6 @@ static const struct nla_policy br_mdbe_attrs_pol[MDBE_ATTR_MAX + 1] = {
 					      sizeof(struct in6_addr)),
 };
 
-static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
-			struct net_device **pdev, struct br_mdb_entry **pentry,
-			struct nlattr **mdb_attrs, struct netlink_ext_ack *extack)
-{
-	struct net *net = sock_net(skb->sk);
-	struct br_mdb_entry *entry;
-	struct br_port_msg *bpm;
-	struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
-	struct net_device *dev;
-	int err;
-
-	err = nlmsg_parse_deprecated(nlh, sizeof(*bpm), tb,
-				     MDBA_SET_ENTRY_MAX, NULL, NULL);
-	if (err < 0)
-		return err;
-
-	bpm = nlmsg_data(nlh);
-	if (bpm->ifindex == 0) {
-		NL_SET_ERR_MSG_MOD(extack, "Invalid bridge ifindex");
-		return -EINVAL;
-	}
-
-	dev = __dev_get_by_index(net, bpm->ifindex);
-	if (dev == NULL) {
-		NL_SET_ERR_MSG_MOD(extack, "Bridge device doesn't exist");
-		return -ENODEV;
-	}
-
-	if (!netif_is_bridge_master(dev)) {
-		NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge");
-		return -EOPNOTSUPP;
-	}
-
-	*pdev = dev;
-
-	if (!tb[MDBA_SET_ENTRY]) {
-		NL_SET_ERR_MSG_MOD(extack, "Missing MDBA_SET_ENTRY attribute");
-		return -EINVAL;
-	}
-	if (nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
-		NL_SET_ERR_MSG_MOD(extack, "Invalid MDBA_SET_ENTRY attribute length");
-		return -EINVAL;
-	}
-
-	entry = nla_data(tb[MDBA_SET_ENTRY]);
-	if (!is_valid_mdb_entry(entry, extack))
-		return -EINVAL;
-	*pentry = entry;
-
-	if (tb[MDBA_SET_ENTRY_ATTRS]) {
-		err = nla_parse_nested(mdb_attrs, MDBE_ATTR_MAX,
-				       tb[MDBA_SET_ENTRY_ATTRS],
-				       br_mdbe_attrs_pol, extack);
-		if (err)
-			return err;
-		if (mdb_attrs[MDBE_ATTR_SOURCE] &&
-		    !is_valid_mdb_source(mdb_attrs[MDBE_ATTR_SOURCE],
-					 entry->addr.proto, extack))
-			return -EINVAL;
-	} else {
-		memset(mdb_attrs, 0,
-		       sizeof(struct nlattr *) * (MDBE_ATTR_MAX + 1));
-	}
-
-	return 0;
-}
-
 static struct net_bridge_mcast *
 __br_mdb_choose_context(struct net_bridge *br,
 			const struct br_mdb_entry *entry,
@@ -853,44 +786,26 @@ __br_mdb_choose_context(struct net_bridge *br,
 	return brmctx;
 }
 
-static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
-			    struct br_mdb_entry *entry,
-			    struct nlattr **mdb_attrs,
+static int br_mdb_add_group(const struct br_mdb_config *cfg,
 			    struct netlink_ext_ack *extack)
 {
 	struct net_bridge_mdb_entry *mp, *star_mp;
 	struct net_bridge_port_group __rcu **pp;
+	struct br_mdb_entry *entry = cfg->entry;
+	struct net_bridge_port *port = cfg->p;
+	struct net_bridge *br = cfg->br;
 	struct net_bridge_port_group *p;
 	struct net_bridge_mcast *brmctx;
-	struct br_ip group, star_group;
+	struct br_ip group = cfg->group;
 	unsigned long now = jiffies;
 	unsigned char flags = 0;
+	struct br_ip star_group;
 	u8 filter_mode;
 
-	__mdb_entry_to_br_ip(entry, &group, mdb_attrs);
-
 	brmctx = __br_mdb_choose_context(br, entry, extack);
 	if (!brmctx)
 		return -EINVAL;
 
-	/* host join errors which can happen before creating the group */
-	if (!port && !br_group_is_l2(&group)) {
-		/* don't allow any flags for host-joined IP groups */
-		if (entry->state) {
-			NL_SET_ERR_MSG_MOD(extack, "Flags are not allowed for host groups");
-			return -EINVAL;
-		}
-		if (!br_multicast_is_star_g(&group)) {
-			NL_SET_ERR_MSG_MOD(extack, "Groups with sources cannot be manually host joined");
-			return -EINVAL;
-		}
-	}
-
-	if (br_group_is_l2(&group) && entry->state != MDB_PERMANENT) {
-		NL_SET_ERR_MSG_MOD(extack, "Only permanent L2 entries allowed");
-		return -EINVAL;
-	}
-
 	mp = br_multicast_new_group(br, &group);
 	if (IS_ERR(mp))
 		return PTR_ERR(mp);
@@ -959,107 +874,197 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 	return 0;
 }
 
-static int __br_mdb_add(struct net *net, struct net_bridge *br,
-			struct net_bridge_port *p,
-			struct br_mdb_entry *entry,
-			struct nlattr **mdb_attrs,
+static int __br_mdb_add(const struct br_mdb_config *cfg,
 			struct netlink_ext_ack *extack)
 {
 	int ret;
 
-	spin_lock_bh(&br->multicast_lock);
-	ret = br_mdb_add_group(br, p, entry, mdb_attrs, extack);
-	spin_unlock_bh(&br->multicast_lock);
+	spin_lock_bh(&cfg->br->multicast_lock);
+	ret = br_mdb_add_group(cfg, extack);
+	spin_unlock_bh(&cfg->br->multicast_lock);
 
 	return ret;
 }
 
-static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
-		      struct netlink_ext_ack *extack)
+static int br_mdb_config_attrs_init(struct nlattr *set_attrs,
+				    struct br_mdb_config *cfg,
+				    struct netlink_ext_ack *extack)
 {
 	struct nlattr *mdb_attrs[MDBE_ATTR_MAX + 1];
-	struct net *net = sock_net(skb->sk);
-	struct net_bridge_vlan_group *vg;
-	struct net_bridge_port *p = NULL;
-	struct net_device *dev, *pdev;
-	struct br_mdb_entry *entry;
-	struct net_bridge_vlan *v;
-	struct net_bridge *br;
 	int err;
 
-	err = br_mdb_parse(skb, nlh, &dev, &entry, mdb_attrs, extack);
-	if (err < 0)
+	err = nla_parse_nested(mdb_attrs, MDBE_ATTR_MAX, set_attrs,
+			       br_mdbe_attrs_pol, extack);
+	if (err)
 		return err;
 
-	br = netdev_priv(dev);
+	if (mdb_attrs[MDBE_ATTR_SOURCE] &&
+	    !is_valid_mdb_source(mdb_attrs[MDBE_ATTR_SOURCE],
+				 cfg->entry->addr.proto, extack))
+		return -EINVAL;
+
+	__mdb_entry_to_br_ip(cfg->entry, &cfg->group, mdb_attrs);
 
-	if (!netif_running(br->dev)) {
+	return 0;
+}
+
+static int br_mdb_config_init(struct net *net, const struct nlmsghdr *nlh,
+			      struct br_mdb_config *cfg,
+			      struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[MDBA_SET_ENTRY_MAX + 1];
+	struct br_port_msg *bpm;
+	struct net_device *dev;
+	int err;
+
+	err = nlmsg_parse_deprecated(nlh, sizeof(*bpm), tb,
+				     MDBA_SET_ENTRY_MAX, NULL, extack);
+	if (err)
+		return err;
+
+	memset(cfg, 0, sizeof(*cfg));
+
+	bpm = nlmsg_data(nlh);
+	if (!bpm->ifindex) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid bridge ifindex");
+		return -EINVAL;
+	}
+
+	dev = __dev_get_by_index(net, bpm->ifindex);
+	if (!dev) {
+		NL_SET_ERR_MSG_MOD(extack, "Bridge device doesn't exist");
+		return -ENODEV;
+	}
+
+	if (!netif_is_bridge_master(dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge");
+		return -EOPNOTSUPP;
+	}
+
+	cfg->br = netdev_priv(dev);
+
+	if (!netif_running(cfg->br->dev)) {
 		NL_SET_ERR_MSG_MOD(extack, "Bridge device is not running");
 		return -EINVAL;
 	}
 
-	if (!br_opt_get(br, BROPT_MULTICAST_ENABLED)) {
+	if (!br_opt_get(cfg->br, BROPT_MULTICAST_ENABLED)) {
 		NL_SET_ERR_MSG_MOD(extack, "Bridge's multicast processing is disabled");
 		return -EINVAL;
 	}
 
-	if (entry->ifindex != br->dev->ifindex) {
-		pdev = __dev_get_by_index(net, entry->ifindex);
+	if (NL_REQ_ATTR_CHECK(extack, NULL, tb, MDBA_SET_ENTRY)) {
+		NL_SET_ERR_MSG_MOD(extack, "Missing MDBA_SET_ENTRY attribute");
+		return -EINVAL;
+	}
+	if (nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid MDBA_SET_ENTRY attribute length");
+		return -EINVAL;
+	}
+
+	cfg->entry = nla_data(tb[MDBA_SET_ENTRY]);
+	if (!is_valid_mdb_entry(cfg->entry, extack))
+		return -EINVAL;
+
+	if (cfg->entry->ifindex != cfg->br->dev->ifindex) {
+		struct net_device *pdev;
+
+		pdev = __dev_get_by_index(net, cfg->entry->ifindex);
 		if (!pdev) {
 			NL_SET_ERR_MSG_MOD(extack, "Port net device doesn't exist");
 			return -ENODEV;
 		}
 
-		p = br_port_get_rtnl(pdev);
-		if (!p) {
+		cfg->p = br_port_get_rtnl(pdev);
+		if (!cfg->p) {
 			NL_SET_ERR_MSG_MOD(extack, "Net device is not a bridge port");
 			return -EINVAL;
 		}
 
-		if (p->br != br) {
+		if (cfg->p->br != cfg->br) {
 			NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device");
 			return -EINVAL;
 		}
-		if (p->state == BR_STATE_DISABLED && entry->state != MDB_PERMANENT) {
+	}
+
+	if (tb[MDBA_SET_ENTRY_ATTRS])
+		return br_mdb_config_attrs_init(tb[MDBA_SET_ENTRY_ATTRS], cfg,
+						extack);
+	else
+		__mdb_entry_to_br_ip(cfg->entry, &cfg->group, NULL);
+
+	return 0;
+}
+
+static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
+		      struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct net_bridge_vlan_group *vg;
+	struct net_bridge_vlan *v;
+	struct br_mdb_config cfg;
+	int err;
+
+	err = br_mdb_config_init(net, nlh, &cfg, extack);
+	if (err)
+		return err;
+
+	/* host join errors which can happen before creating the group */
+	if (!cfg.p && !br_group_is_l2(&cfg.group)) {
+		/* don't allow any flags for host-joined IP groups */
+		if (cfg.entry->state) {
+			NL_SET_ERR_MSG_MOD(extack, "Flags are not allowed for host groups");
+			return -EINVAL;
+		}
+		if (!br_multicast_is_star_g(&cfg.group)) {
+			NL_SET_ERR_MSG_MOD(extack, "Groups with sources cannot be manually host joined");
+			return -EINVAL;
+		}
+	}
+
+	if (br_group_is_l2(&cfg.group) && cfg.entry->state != MDB_PERMANENT) {
+		NL_SET_ERR_MSG_MOD(extack, "Only permanent L2 entries allowed");
+		return -EINVAL;
+	}
+
+	if (cfg.p) {
+		if (cfg.p->state == BR_STATE_DISABLED && cfg.entry->state != MDB_PERMANENT) {
 			NL_SET_ERR_MSG_MOD(extack, "Port is in disabled state and entry is not permanent");
 			return -EINVAL;
 		}
-		vg = nbp_vlan_group(p);
+		vg = nbp_vlan_group(cfg.p);
 	} else {
-		vg = br_vlan_group(br);
+		vg = br_vlan_group(cfg.br);
 	}
 
 	/* If vlan filtering is enabled and VLAN is not specified
 	 * install mdb entry on all vlans configured on the port.
 	 */
-	if (br_vlan_enabled(br->dev) && vg && entry->vid == 0) {
+	if (br_vlan_enabled(cfg.br->dev) && vg && cfg.entry->vid == 0) {
 		list_for_each_entry(v, &vg->vlan_list, vlist) {
-			entry->vid = v->vid;
-			err = __br_mdb_add(net, br, p, entry, mdb_attrs, extack);
+			cfg.entry->vid = v->vid;
+			cfg.group.vid = v->vid;
+			err = __br_mdb_add(&cfg, extack);
 			if (err)
 				break;
 		}
 	} else {
-		err = __br_mdb_add(net, br, p, entry, mdb_attrs, extack);
+		err = __br_mdb_add(&cfg, extack);
 	}
 
 	return err;
 }
 
-static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry,
-			struct nlattr **mdb_attrs)
+static int __br_mdb_del(const struct br_mdb_config *cfg)
 {
+	struct br_mdb_entry *entry = cfg->entry;
+	struct net_bridge *br = cfg->br;
 	struct net_bridge_mdb_entry *mp;
 	struct net_bridge_port_group *p;
 	struct net_bridge_port_group __rcu **pp;
-	struct br_ip ip;
+	struct br_ip ip = cfg->group;
 	int err = -EINVAL;
 
-	if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
-		return -EINVAL;
-
-	__mdb_entry_to_br_ip(entry, &ip, mdb_attrs);
-
 	spin_lock_bh(&br->multicast_lock);
 	mp = br_mdb_ip_get(br, &ip);
 	if (!mp)
@@ -1094,51 +1099,32 @@ static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry,
 static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 		      struct netlink_ext_ack *extack)
 {
-	struct nlattr *mdb_attrs[MDBE_ATTR_MAX + 1];
 	struct net *net = sock_net(skb->sk);
 	struct net_bridge_vlan_group *vg;
-	struct net_bridge_port *p = NULL;
-	struct net_device *dev, *pdev;
-	struct br_mdb_entry *entry;
 	struct net_bridge_vlan *v;
-	struct net_bridge *br;
+	struct br_mdb_config cfg;
 	int err;
 
-	err = br_mdb_parse(skb, nlh, &dev, &entry, mdb_attrs, extack);
-	if (err < 0)
+	err = br_mdb_config_init(net, nlh, &cfg, extack);
+	if (err)
 		return err;
 
-	br = netdev_priv(dev);
-
-	if (entry->ifindex != br->dev->ifindex) {
-		pdev = __dev_get_by_index(net, entry->ifindex);
-		if (!pdev)
-			return -ENODEV;
-
-		p = br_port_get_rtnl(pdev);
-		if (!p) {
-			NL_SET_ERR_MSG_MOD(extack, "Net device is not a bridge port");
-			return -EINVAL;
-		}
-		if (p->br != br) {
-			NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device");
-			return -EINVAL;
-		}
-		vg = nbp_vlan_group(p);
-	} else {
-		vg = br_vlan_group(br);
-	}
+	if (cfg.p)
+		vg = nbp_vlan_group(cfg.p);
+	else
+		vg = br_vlan_group(cfg.br);
 
 	/* If vlan filtering is enabled and VLAN is not specified
 	 * delete mdb entry on all vlans configured on the port.
 	 */
-	if (br_vlan_enabled(br->dev) && vg && entry->vid == 0) {
+	if (br_vlan_enabled(cfg.br->dev) && vg && cfg.entry->vid == 0) {
 		list_for_each_entry(v, &vg->vlan_list, vlist) {
-			entry->vid = v->vid;
-			err = __br_mdb_del(br, entry, mdb_attrs);
+			cfg.entry->vid = v->vid;
+			cfg.group.vid = v->vid;
+			err = __br_mdb_del(&cfg);
 		}
 	} else {
-		err = __br_mdb_del(br, entry, mdb_attrs);
+		err = __br_mdb_del(&cfg);
 	}
 
 	return err;

net/bridge/br_multicast.c

@@ -1273,7 +1273,7 @@ br_multicast_new_group_src(struct net_bridge_port_group *pg, struct br_ip *src_i
 
 struct net_bridge_port_group *br_multicast_new_port_group(
 			struct net_bridge_port *port,
-			struct br_ip *group,
+			const struct br_ip *group,
 			struct net_bridge_port_group __rcu *next,
 			unsigned char flags,
 			const unsigned char *src,

net/bridge/br_private.h

@@ -92,6 +92,13 @@ struct bridge_mcast_stats {
 	struct br_mcast_stats mstats;
 	struct u64_stats_sync syncp;
 };
+
+struct br_mdb_config {
+	struct net_bridge		*br;
+	struct net_bridge_port		*p;
+	struct br_mdb_entry		*entry;
+	struct br_ip			group;
+};
 #endif
 
 /* net_bridge_mcast_port must be always defined due to forwarding stubs */
@@ -934,7 +941,8 @@ br_mdb_ip_get(struct net_bridge *br, struct br_ip *dst);
 struct net_bridge_mdb_entry *
 br_multicast_new_group(struct net_bridge *br, struct br_ip *group);
 struct net_bridge_port_group *
-br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group,
+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);