| /* |
| * Spanning tree protocol; interface code |
| * Linux ethernet bridge |
| * |
| * Authors: |
| * Lennert Buytenhek <buytenh@gnu.org> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/kmod.h> |
| #include <linux/etherdevice.h> |
| #include <linux/rtnetlink.h> |
| #include <net/switchdev.h> |
| |
| #include "br_private.h" |
| #include "br_private_stp.h" |
| |
| |
| /* Port id is composed of priority and port number. |
| * NB: some bits of priority are dropped to |
| * make room for more ports. |
| */ |
| static inline port_id br_make_port_id(__u8 priority, __u16 port_no) |
| { |
| return ((u16)priority << BR_PORT_BITS) |
| | (port_no & ((1<<BR_PORT_BITS)-1)); |
| } |
| |
| #define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS) |
| |
| /* called under bridge lock */ |
| void br_init_port(struct net_bridge_port *p) |
| { |
| int err; |
| |
| p->port_id = br_make_port_id(p->priority, p->port_no); |
| br_become_designated_port(p); |
| br_set_state(p, BR_STATE_BLOCKING); |
| p->topology_change_ack = 0; |
| p->config_pending = 0; |
| |
| err = __set_ageing_time(p->dev, p->br->ageing_time); |
| if (err) |
| netdev_err(p->dev, "failed to offload ageing time\n"); |
| } |
| |
| /* NO locks held */ |
| void br_stp_enable_bridge(struct net_bridge *br) |
| { |
| struct net_bridge_port *p; |
| |
| spin_lock_bh(&br->lock); |
| if (br->stp_enabled == BR_KERNEL_STP) |
| mod_timer(&br->hello_timer, jiffies + br->hello_time); |
| mod_delayed_work(system_long_wq, &br->gc_work, HZ / 10); |
| |
| br_config_bpdu_generation(br); |
| |
| list_for_each_entry(p, &br->port_list, list) { |
| if (netif_running(p->dev) && netif_oper_up(p->dev)) |
| br_stp_enable_port(p); |
| |
| } |
| spin_unlock_bh(&br->lock); |
| } |
| |
| /* NO locks held */ |
| void br_stp_disable_bridge(struct net_bridge *br) |
| { |
| struct net_bridge_port *p; |
| |
| spin_lock_bh(&br->lock); |
| list_for_each_entry(p, &br->port_list, list) { |
| if (p->state != BR_STATE_DISABLED) |
| br_stp_disable_port(p); |
| |
| } |
| |
| __br_set_topology_change(br, 0); |
| br->topology_change_detected = 0; |
| spin_unlock_bh(&br->lock); |
| |
| del_timer_sync(&br->hello_timer); |
| del_timer_sync(&br->topology_change_timer); |
| del_timer_sync(&br->tcn_timer); |
| cancel_delayed_work_sync(&br->gc_work); |
| } |
| |
| /* called under bridge lock */ |
| void br_stp_enable_port(struct net_bridge_port *p) |
| { |
| br_init_port(p); |
| br_port_state_selection(p->br); |
| br_ifinfo_notify(RTM_NEWLINK, p); |
| } |
| |
| /* called under bridge lock */ |
| void br_stp_disable_port(struct net_bridge_port *p) |
| { |
| struct net_bridge *br = p->br; |
| int wasroot; |
| |
| wasroot = br_is_root_bridge(br); |
| br_become_designated_port(p); |
| br_set_state(p, BR_STATE_DISABLED); |
| p->topology_change_ack = 0; |
| p->config_pending = 0; |
| |
| br_ifinfo_notify(RTM_NEWLINK, p); |
| |
| del_timer(&p->message_age_timer); |
| del_timer(&p->forward_delay_timer); |
| del_timer(&p->hold_timer); |
| |
| br_fdb_delete_by_port(br, p, 0, 0); |
| br_multicast_disable_port(p); |
| |
| br_configuration_update(br); |
| |
| br_port_state_selection(br); |
| |
| if (br_is_root_bridge(br) && !wasroot) |
| br_become_root_bridge(br); |
| } |
| |
| static int br_stp_call_user(struct net_bridge *br, char *arg) |
| { |
| char *argv[] = { BR_STP_PROG, br->dev->name, arg, NULL }; |
| char *envp[] = { NULL }; |
| int rc; |
| |
| /* call userspace STP and report program errors */ |
| rc = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC); |
| if (rc > 0) { |
| if (rc & 0xff) |
| br_debug(br, BR_STP_PROG " received signal %d\n", |
| rc & 0x7f); |
| else |
| br_debug(br, BR_STP_PROG " exited with code %d\n", |
| (rc >> 8) & 0xff); |
| } |
| |
| return rc; |
| } |
| |
| static void br_stp_start(struct net_bridge *br) |
| { |
| int err = -ENOENT; |
| |
| if (net_eq(dev_net(br->dev), &init_net)) |
| err = br_stp_call_user(br, "start"); |
| |
| if (err && err != -ENOENT) |
| br_err(br, "failed to start userspace STP (%d)\n", err); |
| |
| spin_lock_bh(&br->lock); |
| |
| if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY) |
| __br_set_forward_delay(br, BR_MIN_FORWARD_DELAY); |
| else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY) |
| __br_set_forward_delay(br, BR_MAX_FORWARD_DELAY); |
| |
| if (!err) { |
| br->stp_enabled = BR_USER_STP; |
| br_debug(br, "userspace STP started\n"); |
| } else { |
| br->stp_enabled = BR_KERNEL_STP; |
| br_debug(br, "using kernel STP\n"); |
| |
| /* To start timers on any ports left in blocking */ |
| mod_timer(&br->hello_timer, jiffies + br->hello_time); |
| br_port_state_selection(br); |
| } |
| |
| spin_unlock_bh(&br->lock); |
| } |
| |
| static void br_stp_stop(struct net_bridge *br) |
| { |
| int err; |
| |
| if (br->stp_enabled == BR_USER_STP) { |
| err = br_stp_call_user(br, "stop"); |
| if (err) |
| br_err(br, "failed to stop userspace STP (%d)\n", err); |
| |
| /* To start timers on any ports left in blocking */ |
| spin_lock_bh(&br->lock); |
| br_port_state_selection(br); |
| spin_unlock_bh(&br->lock); |
| } |
| |
| br->stp_enabled = BR_NO_STP; |
| } |
| |
| void br_stp_set_enabled(struct net_bridge *br, unsigned long val) |
| { |
| ASSERT_RTNL(); |
| |
| if (val) { |
| if (br->stp_enabled == BR_NO_STP) |
| br_stp_start(br); |
| } else { |
| if (br->stp_enabled != BR_NO_STP) |
| br_stp_stop(br); |
| } |
| } |
| |
| /* called under bridge lock */ |
| void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr) |
| { |
| /* should be aligned on 2 bytes for ether_addr_equal() */ |
| unsigned short oldaddr_aligned[ETH_ALEN >> 1]; |
| unsigned char *oldaddr = (unsigned char *)oldaddr_aligned; |
| struct net_bridge_port *p; |
| int wasroot; |
| |
| wasroot = br_is_root_bridge(br); |
| |
| br_fdb_change_mac_address(br, addr); |
| |
| memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN); |
| memcpy(br->bridge_id.addr, addr, ETH_ALEN); |
| memcpy(br->dev->dev_addr, addr, ETH_ALEN); |
| |
| list_for_each_entry(p, &br->port_list, list) { |
| if (ether_addr_equal(p->designated_bridge.addr, oldaddr)) |
| memcpy(p->designated_bridge.addr, addr, ETH_ALEN); |
| |
| if (ether_addr_equal(p->designated_root.addr, oldaddr)) |
| memcpy(p->designated_root.addr, addr, ETH_ALEN); |
| } |
| |
| br_configuration_update(br); |
| br_port_state_selection(br); |
| if (br_is_root_bridge(br) && !wasroot) |
| br_become_root_bridge(br); |
| } |
| |
| /* should be aligned on 2 bytes for ether_addr_equal() */ |
| static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1]; |
| |
| /* called under bridge lock */ |
| bool br_stp_recalculate_bridge_id(struct net_bridge *br) |
| { |
| const unsigned char *br_mac_zero = |
| (const unsigned char *)br_mac_zero_aligned; |
| const unsigned char *addr = br_mac_zero; |
| struct net_bridge_port *p; |
| |
| /* user has chosen a value so keep it */ |
| if (br->dev->addr_assign_type == NET_ADDR_SET) |
| return false; |
| |
| list_for_each_entry(p, &br->port_list, list) { |
| if (addr == br_mac_zero || |
| memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0) |
| addr = p->dev->dev_addr; |
| |
| } |
| |
| if (ether_addr_equal(br->bridge_id.addr, addr)) |
| return false; /* no change */ |
| |
| br_stp_change_bridge_id(br, addr); |
| return true; |
| } |
| |
| /* Acquires and releases bridge lock */ |
| void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio) |
| { |
| struct net_bridge_port *p; |
| int wasroot; |
| |
| spin_lock_bh(&br->lock); |
| wasroot = br_is_root_bridge(br); |
| |
| list_for_each_entry(p, &br->port_list, list) { |
| if (p->state != BR_STATE_DISABLED && |
| br_is_designated_port(p)) { |
| p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF; |
| p->designated_bridge.prio[1] = newprio & 0xFF; |
| } |
| |
| } |
| |
| br->bridge_id.prio[0] = (newprio >> 8) & 0xFF; |
| br->bridge_id.prio[1] = newprio & 0xFF; |
| br_configuration_update(br); |
| br_port_state_selection(br); |
| if (br_is_root_bridge(br) && !wasroot) |
| br_become_root_bridge(br); |
| spin_unlock_bh(&br->lock); |
| } |
| |
| /* called under bridge lock */ |
| int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio) |
| { |
| port_id new_port_id; |
| |
| if (newprio > BR_MAX_PORT_PRIORITY) |
| return -ERANGE; |
| |
| new_port_id = br_make_port_id(newprio, p->port_no); |
| if (br_is_designated_port(p)) |
| p->designated_port = new_port_id; |
| |
| p->port_id = new_port_id; |
| p->priority = newprio; |
| if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) && |
| p->port_id < p->designated_port) { |
| br_become_designated_port(p); |
| br_port_state_selection(p->br); |
| } |
| |
| return 0; |
| } |
| |
| /* called under bridge lock */ |
| int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost) |
| { |
| if (path_cost < BR_MIN_PATH_COST || |
| path_cost > BR_MAX_PATH_COST) |
| return -ERANGE; |
| |
| p->flags |= BR_ADMIN_COST; |
| p->path_cost = path_cost; |
| br_configuration_update(p->br); |
| br_port_state_selection(p->br); |
| return 0; |
| } |
| |
| ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id) |
| { |
| return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n", |
| id->prio[0], id->prio[1], |
| id->addr[0], id->addr[1], id->addr[2], |
| id->addr[3], id->addr[4], id->addr[5]); |
| } |