net: bridge: mdb: use extack in br_mdb_add() and br_mdb_add_group()

Pass and use extack all the way down to br_mdb_add_group().

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 92ab736..1df62d8 100644 (file)
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -723,7 +723,8 @@ static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
 }
 
 static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
-                           struct br_ip *group, struct br_mdb_entry *entry)
+                           struct br_ip *group, struct br_mdb_entry *entry,
+                           struct netlink_ext_ack *extack)
 {
        struct net_bridge_mdb_entry *mp;
        struct net_bridge_port_group *p;
@@ -742,10 +743,14 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
        /* host join */
        if (!port) {
                /* don't allow any flags for host-joined groups */
-               if (entry->state)
+               if (entry->state) {
+                       NL_SET_ERR_MSG_MOD(extack, "Flags are not allowed for host groups");
                        return -EINVAL;
-               if (mp->host_joined)
+               }
+               if (mp->host_joined) {
+                       NL_SET_ERR_MSG_MOD(extack, "Group is already joined by host");
                        return -EEXIST;
+               }
 
                br_multicast_host_join(mp, false);
                br_mdb_notify(br->dev, mp, NULL, RTM_NEWMDB);
@@ -756,16 +761,20 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
        for (pp = &mp->ports;
             (p = mlock_dereference(*pp, br)) != NULL;
             pp = &p->next) {
-               if (p->port == port)
+               if (p->port == port) {
+                       NL_SET_ERR_MSG_MOD(extack, "Group is already joined by port");
                        return -EEXIST;
+               }
                if ((unsigned long)p->port < (unsigned long)port)
                        break;
        }
 
        p = br_multicast_new_port_group(port, group, *pp, entry->state, NULL,
                                        MCAST_EXCLUDE);
-       if (unlikely(!p))
+       if (unlikely(!p)) {
+               NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new port group");
                return -ENOMEM;
+       }
        rcu_assign_pointer(*pp, p);
        if (entry->state == MDB_TEMPORARY)
                mod_timer(&p->timer, now + br->multicast_membership_interval);
@@ -776,7 +785,8 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 
 static int __br_mdb_add(struct net *net, struct net_bridge *br,
                        struct net_bridge_port *p,
-                       struct br_mdb_entry *entry)
+                       struct br_mdb_entry *entry,
+                       struct netlink_ext_ack *extack)
 {
        struct br_ip ip;
        int ret;
@@ -784,7 +794,7 @@ static int __br_mdb_add(struct net *net, struct net_bridge *br,
        __mdb_entry_to_br_ip(entry, &ip);
 
        spin_lock_bh(&br->multicast_lock);
-       ret = br_mdb_add_group(br, p, &ip, entry);
+       ret = br_mdb_add_group(br, p, &ip, entry, extack);
        spin_unlock_bh(&br->multicast_lock);
 
        return ret;
@@ -808,17 +818,37 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 
        br = netdev_priv(dev);
 
-       if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
+       if (!netif_running(br->dev)) {
+               NL_SET_ERR_MSG_MOD(extack, "Bridge device is not running");
                return -EINVAL;
+       }
+
+       if (!br_opt_get(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 (!pdev)
+               if (!pdev) {
+                       NL_SET_ERR_MSG_MOD(extack, "Port net device doesn't exist");
                        return -ENODEV;
+               }
 
                p = br_port_get_rtnl(pdev);
-               if (!p || p->br != br || p->state == BR_STATE_DISABLED)
+               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;
+               }
+               if (p->state == BR_STATE_DISABLED) {
+                       NL_SET_ERR_MSG_MOD(extack, "Port is in disabled state");
+                       return -EINVAL;
+               }
                vg = nbp_vlan_group(p);
        } else {
                vg = br_vlan_group(br);
@@ -830,12 +860,12 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
        if (br_vlan_enabled(br->dev) && vg && entry->vid == 0) {
                list_for_each_entry(v, &vg->vlan_list, vlist) {
                        entry->vid = v->vid;
-                       err = __br_mdb_add(net, br, p, entry);
+                       err = __br_mdb_add(net, br, p, entry, extack);
                        if (err)
                                break;
                }
        } else {
-               err = __br_mdb_add(net, br, p, entry);
+               err = __br_mdb_add(net, br, p, entry, extack);
        }
 
        return err;