cregit-Linux how code gets into the kernel

Release 4.8 net/bridge/br_fdb.c

Directory: net/bridge
/*
 *      Forwarding database
 *      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/init.h>
#include <linux/rculist.h>
#include <linux/spinlock.h>
#include <linux/times.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/atomic.h>
#include <asm/unaligned.h>
#include <linux/if_vlan.h>
#include <net/switchdev.h>
#include "br_private.h"


static struct kmem_cache *br_fdb_cache __read_mostly;
static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
					     const unsigned char *addr,
					     __u16 vid);
static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		      const unsigned char *addr, u16 vid);
static void fdb_notify(struct net_bridge *br,
		       const struct net_bridge_fdb_entry *, int);


static u32 fdb_salt __read_mostly;


int __init br_fdb_init(void) { br_fdb_cache = kmem_cache_create("bridge_fdb_cache", sizeof(struct net_bridge_fdb_entry), 0, SLAB_HWCACHE_ALIGN, NULL); if (!br_fdb_cache) return -ENOMEM; get_random_bytes(&fdb_salt, sizeof(fdb_salt)); return 0; }

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akinobu mitaakinobu mita1326.00%133.33%
Total50100.00%3100.00%


void br_fdb_fini(void) { kmem_cache_destroy(br_fdb_cache); }

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stephen hemmingerstephen hemminger12100.00%1100.00%
Total12100.00%1100.00%

/* if topology_changing then use forward_delay (default 15 sec) * otherwise keep longer (default 5 minutes) */
static inline unsigned long hold_time(const struct net_bridge *br) { return br->topology_change ? br->forward_delay : br->ageing_time; }

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Total27100.00%3100.00%


static inline int has_expired(const struct net_bridge *br, const struct net_bridge_fdb_entry *fdb) { return !fdb->is_static && time_before_eq(fdb->updated + hold_time(br), jiffies); }

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pre-gitpre-git3076.92%125.00%
stephen hemmingerstephen hemminger923.08%375.00%
Total39100.00%4100.00%


static inline int br_mac_hash(const unsigned char *mac, __u16 vid) { /* use 1 byte of OUI and 3 bytes of NIC */ u32 key = get_unaligned((u32 *)(mac + 2)); return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1); }

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stephen hemmingerstephen hemminger2346.94%360.00%
pre-gitpre-git1938.78%120.00%
vlad yasevichvlad yasevich714.29%120.00%
Total49100.00%5100.00%


static void fdb_rcu_free(struct rcu_head *head) { struct net_bridge_fdb_entry *ent = container_of(head, struct net_bridge_fdb_entry, rcu); kmem_cache_free(br_fdb_cache, ent); }

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michal miroslawmichal miroslaw33100.00%1100.00%
Total33100.00%1100.00%

/* When a static FDB entry is added, the mac address from the entry is * added to the bridge private HW address list and all required ports * are then updated with the new information. * Called under RTNL. */
static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr) { int err; struct net_bridge_port *p; ASSERT_RTNL(); list_for_each_entry(p, &br->port_list, list) { if (!br_promisc_port(p)) { err = dev_uc_add(p->dev, addr); if (err) goto undo; } } return; undo: list_for_each_entry_continue_reverse(p, &br->port_list, list) { if (!br_promisc_port(p)) dev_uc_del(p->dev, addr); } }

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li rongqingli rongqing44.17%133.33%
jiri pirkojiri pirko11.04%133.33%
Total96100.00%3100.00%

/* When a static FDB entry is deleted, the HW address from that entry is * also removed from the bridge private HW address list and updates all * the ports with needed information. * Called under RTNL. */
static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr) { struct net_bridge_port *p; ASSERT_RTNL(); list_for_each_entry(p, &br->port_list, list) { if (!br_promisc_port(p)) dev_uc_del(p->dev, addr); } }

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vlad yasevichvlad yasevich5198.08%150.00%
jiri pirkojiri pirko11.92%150.00%
Total52100.00%2100.00%


static void fdb_del_external_learn(struct net_bridge_fdb_entry *f) { struct switchdev_obj_port_fdb fdb = { .obj = { .orig_dev = f->dst->dev, .id = SWITCHDEV_OBJ_ID_PORT_FDB, .flags = SWITCHDEV_F_DEFER, }, .vid = f->vlan_id, }; ether_addr_copy(fdb.addr, f->addr.addr); switchdev_port_obj_del(f->dst->dev, &fdb.obj); }

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scott feldmanscott feldman3344.00%112.50%
jiri pirkojiri pirko3141.33%562.50%
ido schimmelido schimmel912.00%112.50%
vivien didelotvivien didelot22.67%112.50%
Total75100.00%8100.00%


static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f) { if (f->is_static) fdb_del_hw_addr(br, f->addr.addr); if (f->added_by_external_learn) fdb_del_external_learn(f); hlist_del_rcu(&f->hlist); fdb_notify(br, f, RTM_DELNEIGH); call_rcu(&f->rcu, fdb_rcu_free); }

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stephen hemmingerstephen hemminger3752.11%342.86%
vlad yasevichvlad yasevich1622.54%114.29%
scott feldmanscott feldman1115.49%114.29%
michal miroslawmichal miroslaw68.45%114.29%
jiri pirkojiri pirko11.41%114.29%
Total71100.00%7100.00%

/* Delete a local entry if no other port had the same address. */
static void fdb_delete_local(struct net_bridge *br, const struct net_bridge_port *p, struct net_bridge_fdb_entry *f) { const unsigned char *addr = f->addr.addr; struct net_bridge_vlan_group *vg; const struct net_bridge_vlan *v; struct net_bridge_port *op; u16 vid = f->vlan_id; /* Maybe another port has same hw addr? */ list_for_each_entry(op, &br->port_list, list) { vg = nbp_vlan_group(op); if (op != p && ether_addr_equal(op->dev->dev_addr, addr) && (!vid || br_vlan_find(vg, vid))) { f->dst = op; f->added_by_user = 0; return; } } vg = br_vlan_group(br); v = br_vlan_find(vg, vid); /* Maybe bridge device has same hw addr? */ if (p && ether_addr_equal(br->dev->dev_addr, addr) && (!vid || (v && br_vlan_should_use(v)))) { f->dst = NULL; f->added_by_user = 0; return; } fdb_delete(br, f); }

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toshiaki makitatoshiaki makita14074.87%266.67%
nikolay aleksandrovnikolay aleksandrov4725.13%133.33%
Total187100.00%3100.00%


void br_fdb_find_delete_local(struct net_bridge *br, const struct net_bridge_port *p, const unsigned char *addr, u16 vid) { struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *f; spin_lock_bh(&br->hash_lock); f = fdb_find(head, addr, vid); if (f && f->is_local && !f->added_by_user && f->dst == p) fdb_delete_local(br, p, f); spin_unlock_bh(&br->hash_lock); }

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toshiaki makitatoshiaki makita103100.00%1100.00%
Total103100.00%1100.00%


void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr) { struct net_bridge_vlan_group *vg; struct net_bridge *br = p->br; struct net_bridge_vlan *v; int i; spin_lock_bh(&br->hash_lock); vg = nbp_vlan_group(p); /* Search all chains since old address/hash is unknown */ for (i = 0; i < BR_HASH_SIZE; i++) { struct hlist_node *h; hlist_for_each(h, &br->hash[i]) { struct net_bridge_fdb_entry *f; f = hlist_entry(h, struct net_bridge_fdb_entry, hlist); if (f->dst == p && f->is_local && !f->added_by_user) { /* delete old one */ fdb_delete_local(br, p, f); /* if this port has no vlan information * configured, we can safely be done at * this point. */ if (!vg || !vg->num_vlans) goto insert; } } } insert: /* insert new address, may fail if invalid address or dup. */ fdb_insert(br, p, newaddr, 0); if (!vg || !vg->num_vlans) goto done; /* Now add entries for every VLAN configured on the port. * This function runs under RTNL so the bitmap will not change * from under us. */ list_for_each_entry(v, &vg->vlan_list, vlist) fdb_insert(br, p, newaddr, v->vid); done: spin_unlock_bh(&br->hash_lock); }

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pre-gitpre-git7135.32%18.33%
stephen hemmingerstephen hemminger4823.88%650.00%
toshiaki makitatoshiaki makita3818.91%325.00%
nikolay aleksandrovnikolay aleksandrov3416.92%18.33%
vlad yasevichvlad yasevich104.98%18.33%
Total201100.00%12100.00%


void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) { struct net_bridge_vlan_group *vg; struct net_bridge_fdb_entry *f; struct net_bridge_vlan *v; spin_lock_bh(&br->hash_lock); /* 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 && !f->added_by_user) fdb_delete_local(br, NULL, f); fdb_insert(br, NULL, newaddr, 0); vg = br_vlan_group(br); if (!vg || !vg->num_vlans) goto out; /* Now remove and add entries for every VLAN configured on the * bridge. This function runs under RTNL so the bitmap will not * change from under us. */ list_for_each_entry(v, &vg->vlan_list, vlist) { 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 && !f->added_by_user) fdb_delete_local(br, NULL, f); fdb_insert(br, NULL, newaddr, v->vid); } out: spin_unlock_bh(&br->hash_lock); }

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vlad yasevichvlad yasevich6733.67%225.00%
stephen hemmingerstephen hemminger6231.16%112.50%
toshiaki makitatoshiaki makita4623.12%450.00%
nikolay aleksandrovnikolay aleksandrov2412.06%112.50%
Total199100.00%8100.00%


void br_fdb_cleanup(unsigned long _data) { struct net_bridge *br = (struct net_bridge *)_data; unsigned long delay = hold_time(br); unsigned long next_timer = jiffies + br->ageing_time; int i; spin_lock(&br->hash_lock); for (i = 0; i < BR_HASH_SIZE; i++) { struct net_bridge_fdb_entry *f; struct hlist_node *n; hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) { unsigned long this_timer; if (f->is_static) continue; if (f->added_by_external_learn) continue; this_timer = f->updated + delay; if (time_before_eq(this_timer, jiffies)) fdb_delete(br, f); else if (time_before(this_timer, next_timer)) next_timer = this_timer; } } spin_unlock(&br->hash_lock); mod_timer(&br->gc_timer, round_jiffies_up(next_timer)); }

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stephen hemmingerstephen hemminger7042.42%650.00%
pre-gitpre-git4426.67%18.33%
baruch evenbaruch even3621.82%18.33%
siva mannemsiva mannem74.24%18.33%
fabio checconifabio checconi42.42%18.33%
eric dumazeteric dumazet21.21%18.33%
andrew mortonandrew morton21.21%18.33%
Total165100.00%12100.00%

/* Completely flush all dynamic entries in forwarding database.*/
void br_fdb_flush(struct net_bridge *br) { int i; spin_lock_bh(&br->hash_lock); for (i = 0; i < BR_HASH_SIZE; i++) { struct net_bridge_fdb_entry *f; struct hlist_node *n; hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) { if (!f->is_static) fdb_delete(br, f); } } spin_unlock_bh(&br->hash_lock); }

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stephen hemmingerstephen hemminger80100.00%2100.00%
Total80100.00%2100.00%

/* Flush all entries referring to a specific port. * if do_all is set also flush static entries * if vid is set delete all entries that match the vlan_id */
void br_fdb_delete_by_port(struct net_bridge *br, const struct net_bridge_port *p, u16 vid, int do_all) { int i; spin_lock_bh(&br->hash_lock); for (i = 0; i < BR_HASH_SIZE; i++) { struct hlist_node *h, *g; hlist_for_each_safe(h, g, &br->hash[i]) { struct net_bridge_fdb_entry *f = hlist_entry(h, struct net_bridge_fdb_entry, hlist); if (f->dst != p) continue; if (!do_all) if (f->is_static || (vid && f->vlan_id != vid)) continue; if (f->is_local) fdb_delete_local(br, p, f); else fdb_delete(br, f); } } spin_unlock_bh(&br->hash_lock); }

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pre-gitpre-git6746.85%112.50%
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nikolay aleksandrovnikolay aleksandrov1711.89%112.50%
toshiaki makitatoshiaki makita32.10%112.50%
Total143100.00%8100.00%

/* No locking or refcounting, assumes caller has rcu_read_lock */
struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br, const unsigned char *addr, __u16 vid) { struct net_bridge_fdb_entry *fdb; hlist_for_each_entry_rcu(fdb, &br->hash[br_mac_hash(addr, vid)], hlist) { if (ether_addr_equal(fdb->addr.addr, addr) && fdb->vlan_id == vid) { if (unlikely(has_expired(br, fdb))) break; return fdb; } } return NULL; }

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pre-gitpre-git3951.32%120.00%
stephen hemmingerstephen hemminger2634.21%240.00%
vlad yasevichvlad yasevich1013.16%120.00%
joe perchesjoe perches11.32%120.00%
Total76100.00%5100.00%

#if IS_ENABLED(CONFIG_ATM_LANE) /* Interface used by ATM LANE hook to test * if an addr is on some other bridge port */
int br_fdb_test_addr(struct net_device *dev, unsigned char *addr) { struct net_bridge_fdb_entry *fdb; struct net_bridge_port *port; int ret; rcu_read_lock(); port = br_port_get_rcu(dev); if (!port) ret = 0; else { fdb = __br_fdb_get(port->br, addr, 0); ret = fdb && fdb->dst && fdb->dst->dev != dev && fdb->dst->state == BR_STATE_FORWARDING; } rcu_read_unlock(); return ret; }

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stephen hemmingerstephen hemminger5053.76%337.50%
michal miroslawmichal miroslaw2627.96%112.50%
pre-gitpre-git1111.83%112.50%
vlad yasevichvlad yasevich22.15%112.50%
patrick mchardypatrick mchardy22.15%112.50%
jiri pirkojiri pirko22.15%112.50%
Total93100.00%8100.00%

#endif /* CONFIG_ATM_LANE */ /* * Fill buffer with forwarding table records in * the API format. */
int br_fdb_fillbuf(struct net_bridge *br, void *buf, unsigned long maxnum, unsigned long skip) { struct __fdb_entry *fe = buf; int i, num = 0; struct net_bridge_fdb_entry *f; memset(buf, 0, maxnum*sizeof(struct __fdb_entry)); rcu_read_lock(); for (i = 0; i < BR_HASH_SIZE; i++) { hlist_for_each_entry_rcu(f, &br->hash[i], hlist) { if (num >= maxnum) goto out; if (has_expired(br, f)) continue; /* ignore pseudo entry for local MAC address */ if (!f->dst) continue; if (skip) { --skip; continue; } /* convert from internal format to API */ memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN); /* due to ABI compat need to split into hi/lo */ fe->port_no = f->dst->port_no; fe->port_hi = f->dst->port_no >> 8; fe->is_local = f->is_local; if (!f->is_static) fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated); ++fe; ++num; } } out: rcu_read_unlock(); return num; }

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stephen hemmingerstephen hemminger11958.62%770.00%
pre-gitpre-git8340.89%220.00%
eric dumazeteric dumazet10.49%110.00%
Total203100.00%10100.00%


static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head, const unsigned char *addr, __u16 vid) { struct net_bridge_fdb_entry *fdb; hlist_for_each_entry(fdb, head, hlist) { if (ether_addr_equal(fdb->addr.addr, addr) && fdb->vlan_id == vid) return fdb; } return NULL; }

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stephen hemmingerstephen hemminger3658.06%457.14%
pre-gitpre-git1625.81%114.29%
vlad yasevichvlad yasevich914.52%114.29%
joe perchesjoe perches11.61%114.29%
Total62100.00%7100.00%


static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head, const unsigned char *addr, __u16 vid) { struct net_bridge_fdb_entry *fdb; hlist_for_each_entry_rcu(fdb, head, hlist) { if (ether_addr_equal(fdb->addr.addr, addr) && fdb->vlan_id == vid) return fdb; } return NULL; }

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stephen hemmingerstephen hemminger4064.52%562.50%
pre-gitpre-git1219.35%112.50%
vlad yasevichvlad yasevich914.52%112.50%
joe perchesjoe perches11.61%112.50%
Total62100.00%8100.00%


static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head, struct net_bridge_port *source, const unsigned char *addr, __u16 vid, unsigned char is_local, unsigned char is_static) { struct net_bridge_fdb_entry *fdb; fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC); if (fdb) { memcpy(fdb->addr.addr, addr, ETH_ALEN); fdb->dst = source; fdb->vlan_id = vid; fdb->is_local = is_local; fdb->is_static = is_static; fdb->added_by_user = 0; fdb->added_by_external_learn = 0; fdb->updated = fdb->used = jiffies; hlist_add_head_rcu(&fdb->hlist, head); } return fdb; }

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pre-gitpre-git4636.22%110.00%
stephen hemmingerstephen hemminger4031.50%440.00%
roopa prabhuroopa prabhu107.87%110.00%
pavel emelianovpavel emelianov107.87%110.00%
vlad yasevichvlad yasevich97.09%110.00%
toshiaki makitatoshiaki makita64.72%110.00%
scott feldmanscott feldman64.72%110.00%
Total127100.00%10100.00%


static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, const unsigned char *addr, u16 vid) { struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *fdb; if (!is_valid_ether_addr(addr)) return -EINVAL; fdb = fdb_find(head, addr, vid); if (fdb) { /* it is okay to have multiple ports with same * address, just use the first one. */ if (fdb->is_local) return 0; br_warn(br, "adding interface %s with same address " "as a received packet\n", source ? source->dev->name : br->dev->name); fdb_delete(br, fdb); } fdb = fdb_create(head, source, addr, vid, 1, 1); if (!fdb) return -ENOMEM; fdb_add_hw_addr(br, addr); fdb_notify(br, fdb, RTM_NEWNEIGH); return 0; }

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stephen hemmingerstephen hemminger13281.99%646.15%
vlad yasevichvlad yasevich159.32%323.08%
hong zhi guohong zhi guo84.97%17.69%
roopa prabhuroopa prabhu42.48%17.69%
hideaki yoshifujihideaki yoshifuji10.62%17.69%
jiri pirkojiri pirko10.62%17.69%
Total161100.00%13100.00%

/* Add entry for local address of interface */
int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source, const unsigned char *addr, u16 vid) { int ret; spin_lock_bh(&br->hash_lock); ret = fdb_insert(br, source, addr, vid); spin_unlock_bh(&br->hash_lock); return ret; }

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stephen hemmingerstephen hemminger4677.97%360.00%
pre-gitpre-git813.56%120.00%
vlad yasevichvlad yasevich58.47%120.00%
Total59100.00%5100.00%


void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, const unsigned char *addr, u16 vid, bool added_by_user) { struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *fdb; bool fdb_modified = false; /* some users want to always flood. */ if (hold_time(br) == 0) return; /* ignore packets unless we are using this port */ if (!(source->state == BR_STATE_LEARNING || source->state == BR_STATE_FORWARDING)) return; fdb = fdb_find_rcu(head, addr, vid); if (likely(fdb)) { /* attempt to update an entry for a local interface */ if (unlikely(fdb->is_local)) { if (net_ratelimit()) br_warn(br, "received packet on %s with " "own address as source address\n", source->dev->name); } else { /* fastpath: update of existing entry */ if (unlikely(source != fdb->dst)) { fdb->dst = source; fdb_modified = true; } fdb->updated = jiffies; if (unlikely(added_by_user)) fdb->added_by_user = 1; if (unlikely(fdb_modified)) fdb_notify(br, fdb, RTM_NEWNEIGH); } } else { spin_lock(&br->hash_lock); if (likely(!fdb_find(head, addr, vid))) { fdb = fdb_create(head, source, addr, vid, 0, 0); if (fdb) { if (unlikely(added_by_user)) fdb->added_by_user = 1; fdb_notify(br, fdb, RTM_NEWNEIGH); } } /* else we lose race and someone else inserts * it first, don't bother updating */ spin_unlock(&br->hash_lock); } }

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stephen hemmingerstephen hemminger19569.64%1066.67%
jon maxwelljon maxwell3813.57%16.67%
toshiaki makitatoshiaki makita3111.07%16.67%
vlad yasevichvlad yasevich113.93%16.67%
roopa prabhuroopa prabhu41.43%16.67%
jiri pirkojiri pirko10.36%16.67%
Total280100.00%15100.00%


static int fdb_to_nud(const struct net_bridge *br, const struct net_bridge_fdb_entry *fdb)