diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h index 8759cfb8aa2e..01b5069a73a5 100644 --- a/include/uapi/linux/if_link.h +++ b/include/uapi/linux/if_link.h @@ -334,6 +334,7 @@ enum { IFLA_BRPORT_GROUP_FWD_MASK, IFLA_BRPORT_NEIGH_SUPPRESS, IFLA_BRPORT_ISOLATED, + IFLA_BRPORT_BACKUP_PORT, __IFLA_BRPORT_MAX }; #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1) diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index 9019f326fe81..5372e2042adf 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -142,7 +142,20 @@ static int deliver_clone(const struct net_bridge_port *prev, void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, bool local_rcv, bool local_orig) { - if (to && should_deliver(to, skb)) { + if (unlikely(!to)) + goto out; + + /* redirect to backup link if the destination port is down */ + if (rcu_access_pointer(to->backup_port) && !netif_carrier_ok(to->dev)) { + struct net_bridge_port *backup_port; + + backup_port = rcu_dereference(to->backup_port); + if (unlikely(!backup_port)) + goto out; + to = backup_port; + } + + if (should_deliver(to, skb)) { if (local_rcv) deliver_clone(to, skb, local_orig); else @@ -150,6 +163,7 @@ void br_forward(const struct net_bridge_port *to, return; } +out: if (!local_rcv) kfree_skb(skb); } diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index e7c8d55212aa..0363f1bdc401 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -170,6 +170,58 @@ void br_manage_promisc(struct net_bridge *br) } } +int nbp_backup_change(struct net_bridge_port *p, + struct net_device *backup_dev) +{ + struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port); + struct net_bridge_port *backup_p = NULL; + + ASSERT_RTNL(); + + if (backup_dev) { + if (!br_port_exists(backup_dev)) + return -ENOENT; + + backup_p = br_port_get_rtnl(backup_dev); + if (backup_p->br != p->br) + return -EINVAL; + } + + if (p == backup_p) + return -EINVAL; + + if (old_backup == backup_p) + return 0; + + /* if the backup link is already set, clear it */ + if (old_backup) + old_backup->backup_redirected_cnt--; + + if (backup_p) + backup_p->backup_redirected_cnt++; + rcu_assign_pointer(p->backup_port, backup_p); + + return 0; +} + +static void nbp_backup_clear(struct net_bridge_port *p) +{ + nbp_backup_change(p, NULL); + if (p->backup_redirected_cnt) { + struct net_bridge_port *cur_p; + + list_for_each_entry(cur_p, &p->br->port_list, list) { + struct net_bridge_port *backup_p; + + backup_p = rtnl_dereference(cur_p->backup_port); + if (backup_p == p) + nbp_backup_change(cur_p, NULL); + } + } + + WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt); +} + static void nbp_update_port_count(struct net_bridge *br) { struct net_bridge_port *p; @@ -295,6 +347,7 @@ static void del_nbp(struct net_bridge_port *p) nbp_vlan_flush(p); br_fdb_delete_by_port(br, p, 0, 1); switchdev_deferred_process(); + nbp_backup_clear(p); nbp_update_port_count(br); diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index 9f5eb05b0373..ec2b58a09f76 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -169,13 +169,15 @@ static inline size_t br_nlmsg_size(struct net_device *dev, u32 filter_mask) + nla_total_size(1) /* IFLA_OPERSTATE */ + nla_total_size(br_port_info_size()) /* IFLA_PROTINFO */ + nla_total_size(br_get_link_af_size_filtered(dev, - filter_mask)); /* IFLA_AF_SPEC */ + filter_mask)) /* IFLA_AF_SPEC */ + + nla_total_size(4); /* IFLA_BRPORT_BACKUP_PORT */ } static int br_port_fill_attrs(struct sk_buff *skb, const struct net_bridge_port *p) { u8 mode = !!(p->flags & BR_HAIRPIN_MODE); + struct net_bridge_port *backup_p; u64 timerval; if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) || @@ -237,6 +239,14 @@ static int br_port_fill_attrs(struct sk_buff *skb, return -EMSGSIZE; #endif + /* we might be called only with br->lock */ + rcu_read_lock(); + backup_p = rcu_dereference(p->backup_port); + if (backup_p) + nla_put_u32(skb, IFLA_BRPORT_BACKUP_PORT, + backup_p->dev->ifindex); + rcu_read_unlock(); + return 0; } @@ -663,6 +673,7 @@ static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = { [IFLA_BRPORT_GROUP_FWD_MASK] = { .type = NLA_U16 }, [IFLA_BRPORT_NEIGH_SUPPRESS] = { .type = NLA_U8 }, [IFLA_BRPORT_ISOLATED] = { .type = NLA_U8 }, + [IFLA_BRPORT_BACKUP_PORT] = { .type = NLA_U32 }, }; /* Change the state of the port and notify spanning tree */ @@ -817,6 +828,23 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[]) if (err) return err; + if (tb[IFLA_BRPORT_BACKUP_PORT]) { + struct net_device *backup_dev = NULL; + u32 backup_ifindex; + + backup_ifindex = nla_get_u32(tb[IFLA_BRPORT_BACKUP_PORT]); + if (backup_ifindex) { + backup_dev = __dev_get_by_index(dev_net(p->dev), + backup_ifindex); + if (!backup_dev) + return -ENOENT; + } + + err = nbp_backup_change(p, backup_dev); + if (err) + return err; + } + br_port_flags_change(p, old_flags ^ p->flags); return 0; } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index cf0005d2a4d0..11ed2029985f 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -237,6 +237,7 @@ struct net_bridge_port { #ifdef CONFIG_BRIDGE_VLAN_FILTERING struct net_bridge_vlan_group __rcu *vlgrp; #endif + struct net_bridge_port __rcu *backup_port; /* STP */ u8 priority; @@ -281,6 +282,7 @@ struct net_bridge_port { int offload_fwd_mark; #endif u16 group_fwd_mask; + u16 backup_redirected_cnt; }; #define kobj_to_brport(obj) container_of(obj, struct net_bridge_port, kobj) @@ -597,6 +599,7 @@ netdev_features_t br_features_recompute(struct net_bridge *br, netdev_features_t features); void br_port_flags_change(struct net_bridge_port *port, unsigned long mask); void br_manage_promisc(struct net_bridge *br); +int nbp_backup_change(struct net_bridge_port *p, struct net_device *backup_dev); /* br_input.c */ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb); diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c index 4ac940067754..7c87a2fe5248 100644 --- a/net/bridge/br_sysfs_if.c +++ b/net/bridge/br_sysfs_if.c @@ -191,6 +191,38 @@ static int store_group_fwd_mask(struct net_bridge_port *p, static BRPORT_ATTR(group_fwd_mask, 0644, show_group_fwd_mask, store_group_fwd_mask); +static ssize_t show_backup_port(struct net_bridge_port *p, char *buf) +{ + struct net_bridge_port *backup_p; + int ret = 0; + + rcu_read_lock(); + backup_p = rcu_dereference(p->backup_port); + if (backup_p) + ret = sprintf(buf, "%s\n", backup_p->dev->name); + rcu_read_unlock(); + + return ret; +} + +static int store_backup_port(struct net_bridge_port *p, char *buf) +{ + struct net_device *backup_dev = NULL; + char *nl = strchr(buf, '\n'); + + if (nl) + *nl = '\0'; + + if (strlen(buf) > 0) { + backup_dev = __dev_get_by_name(dev_net(p->dev), buf); + if (!backup_dev) + return -ENOENT; + } + + return nbp_backup_change(p, backup_dev); +} +static BRPORT_ATTR_RAW(backup_port, 0644, show_backup_port, store_backup_port); + BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE); BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD); BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK); @@ -254,6 +286,7 @@ static const struct brport_attribute *brport_attrs[] = { &brport_attr_group_fwd_mask, &brport_attr_neigh_suppress, &brport_attr_isolated, + &brport_attr_backup_port, NULL };