/* * 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/etherdevice.h> #include <linux/rtnetlink.h> #include "br_private.h" #include "br_private_stp.h" /* Port id is composed of priority and port number. * NB: least significant 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)); } /* called under bridge lock */ void br_init_port(struct net_bridge_port *p) { p->port_id = br_make_port_id(p->priority, p->port_no); br_become_designated_port(p); p->state = BR_STATE_BLOCKING; p->topology_change_ack = 0; p->config_pending = 0; } /* called under bridge lock */ void br_stp_enable_bridge(struct net_bridge *br) { struct net_bridge_port *p; spin_lock_bh(&br->lock); mod_timer(&br->hello_timer, jiffies + br->hello_time); mod_timer(&br->gc_timer, jiffies + HZ/10); br_config_bpdu_generation(br); list_for_each_entry(p, &br->port_list, list) { if ((p->dev->flags & IFF_UP) && netif_carrier_ok(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->topology_change = 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); del_timer_sync(&br->gc_timer); } /* 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_log_state(p); } /* called under bridge lock */ void br_stp_disable_port(struct net_bridge_port *p) { struct net_bridge *br = p->br; int wasroot; br_log_state(p); wasroot = br_is_root_bridge(br); br_become_designated_port(p); p->state = BR_STATE_DISABLED; p->topology_change_ack = 0; p->config_pending = 0; 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); 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 void br_stp_start(struct net_bridge *br) { int r; char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL }; char *envp[] = { NULL }; r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC); if (r == 0) { 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 */ spin_lock_bh(&br->lock); br_port_state_selection(br); spin_unlock_bh(&br->lock); } } static void br_stp_stop(struct net_bridge *br) { int r; char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL }; char *envp[] = { NULL }; if (br->stp_enabled == BR_USER_STP) { r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC); br_info(br, "userspace STP stopped, return code %d\n", r); /* 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 compare_ether_addr() */ 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); 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 (!compare_ether_addr(p->designated_bridge.addr, oldaddr)) memcpy(p->designated_bridge.addr, addr, ETH_ALEN); if (!compare_ether_addr(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 compare_ether_addr() */ static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1]; /* called under bridge lock */ void 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->flags & BR_SET_MAC_ADDR) return; 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 (compare_ether_addr(br->bridge_id.addr, addr)) br_stp_change_bridge_id(br, addr); } /* called under bridge lock */ void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio) { struct net_bridge_port *p; int wasroot; 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); } /* called under bridge lock */ void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio) { port_id 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); } } /* called under bridge lock */ void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost) { p->path_cost = path_cost; br_configuration_update(p->br); br_port_state_selection(p->br); } 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]); }