diff options
Diffstat (limited to 'net/core/neighbour.c')
-rw-r--r-- | net/core/neighbour.c | 159 |
1 files changed, 82 insertions, 77 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 8b6140e67e7f..e571007d083c 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -224,10 +224,13 @@ bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl) static int neigh_forced_gc(struct neigh_table *tbl) { - int max_clean = atomic_read(&tbl->gc_entries) - tbl->gc_thresh2; + int max_clean = atomic_read(&tbl->gc_entries) - + READ_ONCE(tbl->gc_thresh2); + u64 tmax = ktime_get_ns() + NSEC_PER_MSEC; unsigned long tref = jiffies - 5 * HZ; struct neighbour *n, *tmp; int shrunk = 0; + int loop = 0; NEIGH_CACHE_STAT_INC(tbl, forced_gc_runs); @@ -242,7 +245,7 @@ static int neigh_forced_gc(struct neigh_table *tbl) (n->nud_state == NUD_NOARP) || (tbl->is_multicast && tbl->is_multicast(n->primary_key)) || - time_after(tref, n->updated)) + !time_in_range(n->updated, tref, jiffies)) remove = true; write_unlock(&n->lock); @@ -250,11 +253,16 @@ static int neigh_forced_gc(struct neigh_table *tbl) shrunk++; if (shrunk >= max_clean) break; + if (++loop == 16) { + if (ktime_get_ns() > tmax) + goto unlock; + loop = 0; + } } } - tbl->last_flush = jiffies; - + WRITE_ONCE(tbl->last_flush, jiffies); +unlock: write_unlock_bh(&tbl->lock); return shrunk; @@ -262,7 +270,17 @@ static int neigh_forced_gc(struct neigh_table *tbl) static void neigh_add_timer(struct neighbour *n, unsigned long when) { + /* Use safe distance from the jiffies - LONG_MAX point while timer + * is running in DELAY/PROBE state but still show to user space + * large times in the past. + */ + unsigned long mint = jiffies - (LONG_MAX - 86400 * HZ); + neigh_hold(n); + if (!time_in_range(n->confirmed, mint, jiffies)) + n->confirmed = mint; + if (time_before(n->used, n->confirmed)) + n->used = n->confirmed; if (unlikely(mod_timer(&n->timer, when))) { printk("NEIGH: BUG, double timer add, state is %x\n", n->nud_state); @@ -280,11 +298,26 @@ static int neigh_del_timer(struct neighbour *n) return 0; } -static void pneigh_queue_purge(struct sk_buff_head *list) +static void pneigh_queue_purge(struct sk_buff_head *list, struct net *net) { + struct sk_buff_head tmp; + unsigned long flags; struct sk_buff *skb; - while ((skb = skb_dequeue(list)) != NULL) { + skb_queue_head_init(&tmp); + spin_lock_irqsave(&list->lock, flags); + skb = skb_peek(list); + while (skb != NULL) { + struct sk_buff *skb_next = skb_peek_next(skb, list); + if (net == NULL || net_eq(dev_net(skb->dev), net)) { + __skb_unlink(skb, list); + __skb_queue_tail(&tmp, skb); + } + skb = skb_next; + } + spin_unlock_irqrestore(&list->lock, flags); + + while ((skb = __skb_dequeue(&tmp))) { dev_put(skb->dev); kfree_skb(skb); } @@ -358,9 +391,9 @@ static int __neigh_ifdown(struct neigh_table *tbl, struct net_device *dev, write_lock_bh(&tbl->lock); neigh_flush_dev(tbl, dev, skip_perm); pneigh_ifdown_and_unlock(tbl, dev); - - del_timer_sync(&tbl->proxy_timer); - pneigh_queue_purge(&tbl->proxy_queue); + pneigh_queue_purge(&tbl->proxy_queue, dev ? dev_net(dev) : NULL); + if (skb_queue_empty_lockless(&tbl->proxy_queue)) + del_timer_sync(&tbl->proxy_timer); return 0; } @@ -384,17 +417,17 @@ static struct neighbour *neigh_alloc(struct neigh_table *tbl, { struct neighbour *n = NULL; unsigned long now = jiffies; - int entries; + int entries, gc_thresh3; if (exempt_from_gc) goto do_alloc; entries = atomic_inc_return(&tbl->gc_entries) - 1; - if (entries >= tbl->gc_thresh3 || - (entries >= tbl->gc_thresh2 && - time_after(now, tbl->last_flush + 5 * HZ))) { - if (!neigh_forced_gc(tbl) && - entries >= tbl->gc_thresh3) { + gc_thresh3 = READ_ONCE(tbl->gc_thresh3); + if (entries >= gc_thresh3 || + (entries >= READ_ONCE(tbl->gc_thresh2) && + time_after(now, READ_ONCE(tbl->last_flush) + 5 * HZ))) { + if (!neigh_forced_gc(tbl) && entries >= gc_thresh3) { net_info_ratelimited("%s: neighbor table overflow!\n", tbl->id); NEIGH_CACHE_STAT_INC(tbl, table_fulls); @@ -546,37 +579,6 @@ struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, } EXPORT_SYMBOL(neigh_lookup); -struct neighbour *neigh_lookup_nodev(struct neigh_table *tbl, struct net *net, - const void *pkey) -{ - struct neighbour *n; - unsigned int key_len = tbl->key_len; - u32 hash_val; - struct neigh_hash_table *nht; - - NEIGH_CACHE_STAT_INC(tbl, lookups); - - rcu_read_lock_bh(); - nht = rcu_dereference_bh(tbl->nht); - hash_val = tbl->hash(pkey, NULL, nht->hash_rnd) >> (32 - nht->hash_shift); - - for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); - n != NULL; - n = rcu_dereference_bh(n->next)) { - if (!memcmp(n->primary_key, pkey, key_len) && - net_eq(dev_net(n->dev), net)) { - if (!refcount_inc_not_zero(&n->refcnt)) - n = NULL; - NEIGH_CACHE_STAT_INC(tbl, hits); - break; - } - } - - rcu_read_unlock_bh(); - return n; -} -EXPORT_SYMBOL(neigh_lookup_nodev); - static struct neighbour * ___neigh_create(struct neigh_table *tbl, const void *pkey, struct net_device *dev, u8 flags, @@ -908,13 +910,14 @@ static void neigh_periodic_work(struct work_struct *work) if (time_after(jiffies, tbl->last_rand + 300 * HZ)) { struct neigh_parms *p; - tbl->last_rand = jiffies; + + WRITE_ONCE(tbl->last_rand, jiffies); list_for_each_entry(p, &tbl->parms_list, list) p->reachable_time = neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME)); } - if (atomic_read(&tbl->entries) < tbl->gc_thresh1) + if (atomic_read(&tbl->entries) < READ_ONCE(tbl->gc_thresh1)) goto out; for (i = 0 ; i < (1 << nht->hash_shift); i++) { @@ -933,13 +936,17 @@ static void neigh_periodic_work(struct work_struct *work) goto next_elt; } - if (time_before(n->used, n->confirmed)) + if (time_before(n->used, n->confirmed) && + time_is_before_eq_jiffies(n->confirmed)) n->used = n->confirmed; if (refcount_read(&n->refcnt) == 1 && (state == NUD_FAILED || - time_after(jiffies, n->used + NEIGH_VAR(n->parms, GC_STALETIME)))) { - *np = n->next; + !time_in_range_open(jiffies, n->used, + n->used + NEIGH_VAR(n->parms, GC_STALETIME)))) { + rcu_assign_pointer(*np, + rcu_dereference_protected(n->next, + lockdep_is_held(&tbl->lock))); neigh_mark_dead(n); write_unlock(&n->lock); neigh_cleanup_and_release(n); @@ -1741,7 +1748,7 @@ int neigh_table_clear(int index, struct neigh_table *tbl) /* It is not clean... Fix it to unload IPv6 module safely */ cancel_delayed_work_sync(&tbl->gc_work); del_timer_sync(&tbl->proxy_timer); - pneigh_queue_purge(&tbl->proxy_queue); + pneigh_queue_purge(&tbl->proxy_queue, NULL); neigh_ifdown(tbl, NULL); if (atomic_read(&tbl->entries)) pr_crit("neighbour leakage\n"); @@ -1773,9 +1780,6 @@ static struct neigh_table *neigh_find_table(int family) case AF_INET6: tbl = neigh_tables[NEIGH_ND_TABLE]; break; - case AF_DECnet: - tbl = neigh_tables[NEIGH_DN_TABLE]; - break; } return tbl; @@ -2055,15 +2059,16 @@ static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl, ndtmsg->ndtm_pad2 = 0; if (nla_put_string(skb, NDTA_NAME, tbl->id) || - nla_put_msecs(skb, NDTA_GC_INTERVAL, tbl->gc_interval, NDTA_PAD) || - nla_put_u32(skb, NDTA_THRESH1, tbl->gc_thresh1) || - nla_put_u32(skb, NDTA_THRESH2, tbl->gc_thresh2) || - nla_put_u32(skb, NDTA_THRESH3, tbl->gc_thresh3)) + nla_put_msecs(skb, NDTA_GC_INTERVAL, READ_ONCE(tbl->gc_interval), + NDTA_PAD) || + nla_put_u32(skb, NDTA_THRESH1, READ_ONCE(tbl->gc_thresh1)) || + nla_put_u32(skb, NDTA_THRESH2, READ_ONCE(tbl->gc_thresh2)) || + nla_put_u32(skb, NDTA_THRESH3, READ_ONCE(tbl->gc_thresh3))) goto nla_put_failure; { unsigned long now = jiffies; - long flush_delta = now - tbl->last_flush; - long rand_delta = now - tbl->last_rand; + long flush_delta = now - READ_ONCE(tbl->last_flush); + long rand_delta = now - READ_ONCE(tbl->last_rand); struct neigh_hash_table *nht; struct ndt_config ndc = { .ndtc_key_len = tbl->key_len, @@ -2071,7 +2076,7 @@ static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl, .ndtc_entries = atomic_read(&tbl->entries), .ndtc_last_flush = jiffies_to_msecs(flush_delta), .ndtc_last_rand = jiffies_to_msecs(rand_delta), - .ndtc_proxy_qlen = tbl->proxy_queue.qlen, + .ndtc_proxy_qlen = READ_ONCE(tbl->proxy_queue.qlen), }; rcu_read_lock_bh(); @@ -2094,17 +2099,17 @@ static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl, struct neigh_statistics *st; st = per_cpu_ptr(tbl->stats, cpu); - ndst.ndts_allocs += st->allocs; - ndst.ndts_destroys += st->destroys; - ndst.ndts_hash_grows += st->hash_grows; - ndst.ndts_res_failed += st->res_failed; - ndst.ndts_lookups += st->lookups; - ndst.ndts_hits += st->hits; - ndst.ndts_rcv_probes_mcast += st->rcv_probes_mcast; - ndst.ndts_rcv_probes_ucast += st->rcv_probes_ucast; - ndst.ndts_periodic_gc_runs += st->periodic_gc_runs; - ndst.ndts_forced_gc_runs += st->forced_gc_runs; - ndst.ndts_table_fulls += st->table_fulls; + ndst.ndts_allocs += READ_ONCE(st->allocs); + ndst.ndts_destroys += READ_ONCE(st->destroys); + ndst.ndts_hash_grows += READ_ONCE(st->hash_grows); + ndst.ndts_res_failed += READ_ONCE(st->res_failed); + ndst.ndts_lookups += READ_ONCE(st->lookups); + ndst.ndts_hits += READ_ONCE(st->hits); + ndst.ndts_rcv_probes_mcast += READ_ONCE(st->rcv_probes_mcast); + ndst.ndts_rcv_probes_ucast += READ_ONCE(st->rcv_probes_ucast); + ndst.ndts_periodic_gc_runs += READ_ONCE(st->periodic_gc_runs); + ndst.ndts_forced_gc_runs += READ_ONCE(st->forced_gc_runs); + ndst.ndts_table_fulls += READ_ONCE(st->table_fulls); } if (nla_put_64bit(skb, NDTA_STATS, sizeof(ndst), &ndst, @@ -2328,16 +2333,16 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh, goto errout_tbl_lock; if (tb[NDTA_THRESH1]) - tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]); + WRITE_ONCE(tbl->gc_thresh1, nla_get_u32(tb[NDTA_THRESH1])); if (tb[NDTA_THRESH2]) - tbl->gc_thresh2 = nla_get_u32(tb[NDTA_THRESH2]); + WRITE_ONCE(tbl->gc_thresh2, nla_get_u32(tb[NDTA_THRESH2])); if (tb[NDTA_THRESH3]) - tbl->gc_thresh3 = nla_get_u32(tb[NDTA_THRESH3]); + WRITE_ONCE(tbl->gc_thresh3, nla_get_u32(tb[NDTA_THRESH3])); if (tb[NDTA_GC_INTERVAL]) - tbl->gc_interval = nla_get_msecs(tb[NDTA_GC_INTERVAL]); + WRITE_ONCE(tbl->gc_interval, nla_get_msecs(tb[NDTA_GC_INTERVAL])); err = 0; |