From 7bb90c3715a496c650b2e879225030f9dd9cfafb Mon Sep 17 00:00:00 2001 From: Toshiaki Makita Date: Thu, 4 Aug 2016 11:11:19 +0900 Subject: [PATCH] bridge: Fix problems around fdb entries pointing to the bridge device Adding fdb entries pointing to the bridge device uses fdb_insert(), which lacks various checks and does not respect added_by_user flag. As a result, some inconsistent behavior can happen: * Adding temporary entries succeeds but results in permanent entries. * Same goes for "dynamic" and "use". * Changing mac address of the bridge device causes deletion of user-added entries. * Replacing existing entries looks successful from userspace but actually not, regardless of NLM_F_EXCL flag. Use the same logic as other entries and fix them. Fixes: 3741873b4f73 ("bridge: allow adding of fdb entries pointing to the bridge device") Signed-off-by: Toshiaki Makita Acked-by: Roopa Prabhu Signed-off-by: David S. Miller --- net/bridge/br_fdb.c | 52 +++++++++++++++++++++++---------------------- 1 file changed, 27 insertions(+), 25 deletions(-) diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index c18080ad4085..cd620fab41b0 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -267,7 +267,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) /* If old entry was unassociated with any port, then delete it. */ f = __br_fdb_get(br, br->dev->dev_addr, 0); - if (f && f->is_local && !f->dst) + if (f && f->is_local && !f->dst && !f->added_by_user) fdb_delete_local(br, NULL, f); fdb_insert(br, NULL, newaddr, 0); @@ -282,7 +282,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) if (!br_vlan_should_use(v)) continue; f = __br_fdb_get(br, br->dev->dev_addr, v->vid); - if (f && f->is_local && !f->dst) + if (f && f->is_local && !f->dst && !f->added_by_user) fdb_delete_local(br, NULL, f); fdb_insert(br, NULL, newaddr, v->vid); } @@ -764,20 +764,25 @@ out: } /* Update (create or replace) forwarding database entry */ -static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr, - __u16 state, __u16 flags, __u16 vid) +static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source, + const __u8 *addr, __u16 state, __u16 flags, __u16 vid) { - struct net_bridge *br = source->br; struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *fdb; bool modified = false; /* If the port cannot learn allow only local and static entries */ - if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) && + if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) && !(source->state == BR_STATE_LEARNING || source->state == BR_STATE_FORWARDING)) return -EPERM; + if (!source && !(state & NUD_PERMANENT)) { + pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n", + br->dev->name); + return -EINVAL; + } + fdb = fdb_find(head, addr, vid); if (fdb == NULL) { if (!(flags & NLM_F_CREATE)) @@ -832,22 +837,28 @@ static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr, return 0; } -static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p, - const unsigned char *addr, u16 nlh_flags, u16 vid) +static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br, + struct net_bridge_port *p, const unsigned char *addr, + u16 nlh_flags, u16 vid) { int err = 0; if (ndm->ndm_flags & NTF_USE) { + if (!p) { + pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n", + br->dev->name); + return -EINVAL; + } local_bh_disable(); rcu_read_lock(); - br_fdb_update(p->br, p, addr, vid, true); + br_fdb_update(br, p, addr, vid, true); rcu_read_unlock(); local_bh_enable(); } else { - spin_lock_bh(&p->br->hash_lock); - err = fdb_add_entry(p, addr, ndm->ndm_state, + spin_lock_bh(&br->hash_lock); + err = fdb_add_entry(br, p, addr, ndm->ndm_state, nlh_flags, vid); - spin_unlock_bh(&p->br->hash_lock); + spin_unlock_bh(&br->hash_lock); } return err; @@ -884,6 +895,7 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], dev->name); return -EINVAL; } + br = p->br; vg = nbp_vlan_group(p); } @@ -895,15 +907,9 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], } /* VID was specified, so use it. */ - if (dev->priv_flags & IFF_EBRIDGE) - err = br_fdb_insert(br, NULL, addr, vid); - else - err = __br_fdb_add(ndm, p, addr, nlh_flags, vid); + err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid); } else { - if (dev->priv_flags & IFF_EBRIDGE) - err = br_fdb_insert(br, NULL, addr, 0); - else - err = __br_fdb_add(ndm, p, addr, nlh_flags, 0); + err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0); if (err || !vg || !vg->num_vlans) goto out; @@ -914,11 +920,7 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], list_for_each_entry(v, &vg->vlan_list, vlist) { if (!br_vlan_should_use(v)) continue; - if (dev->priv_flags & IFF_EBRIDGE) - err = br_fdb_insert(br, NULL, addr, v->vid); - else - err = __br_fdb_add(ndm, p, addr, nlh_flags, - v->vid); + err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid); if (err) goto out; } -- 2.30.2