cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

br_stp_timer.c (4327B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *	Spanning tree protocol; timer-related code
      4 *	Linux ethernet bridge
      5 *
      6 *	Authors:
      7 *	Lennert Buytenhek		<buytenh@gnu.org>
      8 */
      9
     10#include <linux/kernel.h>
     11#include <linux/times.h>
     12
     13#include "br_private.h"
     14#include "br_private_stp.h"
     15
     16/* called under bridge lock */
     17static int br_is_designated_for_some_port(const struct net_bridge *br)
     18{
     19	struct net_bridge_port *p;
     20
     21	list_for_each_entry(p, &br->port_list, list) {
     22		if (p->state != BR_STATE_DISABLED &&
     23		    !memcmp(&p->designated_bridge, &br->bridge_id, 8))
     24			return 1;
     25	}
     26
     27	return 0;
     28}
     29
     30static void br_hello_timer_expired(struct timer_list *t)
     31{
     32	struct net_bridge *br = from_timer(br, t, hello_timer);
     33
     34	br_debug(br, "hello timer expired\n");
     35	spin_lock(&br->lock);
     36	if (br->dev->flags & IFF_UP) {
     37		br_config_bpdu_generation(br);
     38
     39		if (br->stp_enabled == BR_KERNEL_STP)
     40			mod_timer(&br->hello_timer,
     41				  round_jiffies(jiffies + br->hello_time));
     42	}
     43	spin_unlock(&br->lock);
     44}
     45
     46static void br_message_age_timer_expired(struct timer_list *t)
     47{
     48	struct net_bridge_port *p = from_timer(p, t, message_age_timer);
     49	struct net_bridge *br = p->br;
     50	const bridge_id *id = &p->designated_bridge;
     51	int was_root;
     52
     53	if (p->state == BR_STATE_DISABLED)
     54		return;
     55
     56	br_info(br, "port %u(%s) neighbor %.2x%.2x.%pM lost\n",
     57		(unsigned int) p->port_no, p->dev->name,
     58		id->prio[0], id->prio[1], &id->addr);
     59
     60	/*
     61	 * According to the spec, the message age timer cannot be
     62	 * running when we are the root bridge. So..  this was_root
     63	 * check is redundant. I'm leaving it in for now, though.
     64	 */
     65	spin_lock(&br->lock);
     66	if (p->state == BR_STATE_DISABLED)
     67		goto unlock;
     68	was_root = br_is_root_bridge(br);
     69
     70	br_become_designated_port(p);
     71	br_configuration_update(br);
     72	br_port_state_selection(br);
     73	if (br_is_root_bridge(br) && !was_root)
     74		br_become_root_bridge(br);
     75 unlock:
     76	spin_unlock(&br->lock);
     77}
     78
     79static void br_forward_delay_timer_expired(struct timer_list *t)
     80{
     81	struct net_bridge_port *p = from_timer(p, t, forward_delay_timer);
     82	struct net_bridge *br = p->br;
     83
     84	br_debug(br, "port %u(%s) forward delay timer\n",
     85		 (unsigned int) p->port_no, p->dev->name);
     86	spin_lock(&br->lock);
     87	if (p->state == BR_STATE_LISTENING) {
     88		br_set_state(p, BR_STATE_LEARNING);
     89		mod_timer(&p->forward_delay_timer,
     90			  jiffies + br->forward_delay);
     91	} else if (p->state == BR_STATE_LEARNING) {
     92		br_set_state(p, BR_STATE_FORWARDING);
     93		if (br_is_designated_for_some_port(br))
     94			br_topology_change_detection(br);
     95		netif_carrier_on(br->dev);
     96	}
     97	rcu_read_lock();
     98	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
     99	rcu_read_unlock();
    100	spin_unlock(&br->lock);
    101}
    102
    103static void br_tcn_timer_expired(struct timer_list *t)
    104{
    105	struct net_bridge *br = from_timer(br, t, tcn_timer);
    106
    107	br_debug(br, "tcn timer expired\n");
    108	spin_lock(&br->lock);
    109	if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) {
    110		br_transmit_tcn(br);
    111
    112		mod_timer(&br->tcn_timer, jiffies + br->bridge_hello_time);
    113	}
    114	spin_unlock(&br->lock);
    115}
    116
    117static void br_topology_change_timer_expired(struct timer_list *t)
    118{
    119	struct net_bridge *br = from_timer(br, t, topology_change_timer);
    120
    121	br_debug(br, "topo change timer expired\n");
    122	spin_lock(&br->lock);
    123	br->topology_change_detected = 0;
    124	__br_set_topology_change(br, 0);
    125	spin_unlock(&br->lock);
    126}
    127
    128static void br_hold_timer_expired(struct timer_list *t)
    129{
    130	struct net_bridge_port *p = from_timer(p, t, hold_timer);
    131
    132	br_debug(p->br, "port %u(%s) hold timer expired\n",
    133		 (unsigned int) p->port_no, p->dev->name);
    134
    135	spin_lock(&p->br->lock);
    136	if (p->config_pending)
    137		br_transmit_config(p);
    138	spin_unlock(&p->br->lock);
    139}
    140
    141void br_stp_timer_init(struct net_bridge *br)
    142{
    143	timer_setup(&br->hello_timer, br_hello_timer_expired, 0);
    144	timer_setup(&br->tcn_timer, br_tcn_timer_expired, 0);
    145	timer_setup(&br->topology_change_timer,
    146		    br_topology_change_timer_expired, 0);
    147}
    148
    149void br_stp_port_timer_init(struct net_bridge_port *p)
    150{
    151	timer_setup(&p->message_age_timer, br_message_age_timer_expired, 0);
    152	timer_setup(&p->forward_delay_timer, br_forward_delay_timer_expired, 0);
    153	timer_setup(&p->hold_timer, br_hold_timer_expired, 0);
    154}
    155
    156/* Report ticks left (in USER_HZ) used for API */
    157unsigned long br_timer_value(const struct timer_list *timer)
    158{
    159	return timer_pending(timer)
    160		? jiffies_delta_to_clock_t(timer->expires - jiffies) : 0;
    161}