169 lines
3.7 KiB
C
Executable file
169 lines
3.7 KiB
C
Executable file
/*
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* net/core/dst_cache.c - dst entry cache
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*
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* Copyright (c) 2016 Paolo Abeni <pabeni@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/percpu.h>
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#include <net/dst_cache.h>
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#include <net/route.h>
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#if IS_ENABLED(CONFIG_IPV6)
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#include <net/ip6_fib.h>
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#endif
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#include <uapi/linux/in.h>
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struct dst_cache_pcpu {
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unsigned long refresh_ts;
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struct dst_entry *dst;
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u32 cookie;
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union {
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struct in_addr in_saddr;
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struct in6_addr in6_saddr;
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};
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};
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static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
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struct dst_entry *dst, u32 cookie)
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{
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dst_release(dst_cache->dst);
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if (dst)
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dst_hold(dst);
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dst_cache->cookie = cookie;
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dst_cache->dst = dst;
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}
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static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
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struct dst_cache_pcpu *idst)
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{
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struct dst_entry *dst;
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dst = idst->dst;
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if (!dst)
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goto fail;
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/* the cache already hold a dst reference; it can't go away */
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dst_hold(dst);
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if (unlikely(!time_after(idst->refresh_ts, dst_cache->reset_ts) ||
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(dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
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dst_cache_per_cpu_dst_set(idst, NULL, 0);
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dst_release(dst);
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goto fail;
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}
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return dst;
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fail:
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idst->refresh_ts = jiffies;
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return NULL;
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}
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struct dst_entry *dst_cache_get(struct dst_cache *dst_cache)
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{
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if (!dst_cache->cache)
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return NULL;
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return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
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}
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EXPORT_SYMBOL_GPL(dst_cache_get);
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struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr)
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{
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struct dst_cache_pcpu *idst;
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struct dst_entry *dst;
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if (!dst_cache->cache)
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return NULL;
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idst = this_cpu_ptr(dst_cache->cache);
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dst = dst_cache_per_cpu_get(dst_cache, idst);
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if (!dst)
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return NULL;
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*saddr = idst->in_saddr.s_addr;
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return container_of(dst, struct rtable, dst);
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}
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EXPORT_SYMBOL_GPL(dst_cache_get_ip4);
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void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
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__be32 saddr)
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{
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struct dst_cache_pcpu *idst;
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if (!dst_cache->cache)
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return;
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idst = this_cpu_ptr(dst_cache->cache);
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dst_cache_per_cpu_dst_set(idst, dst, 0);
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idst->in_saddr.s_addr = saddr;
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}
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EXPORT_SYMBOL_GPL(dst_cache_set_ip4);
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#if IS_ENABLED(CONFIG_IPV6)
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void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
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const struct in6_addr *saddr)
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{
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struct dst_cache_pcpu *idst;
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if (!dst_cache->cache)
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return;
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idst = this_cpu_ptr(dst_cache->cache);
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dst_cache_per_cpu_dst_set(this_cpu_ptr(dst_cache->cache), dst,
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rt6_get_cookie((struct rt6_info *)dst));
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idst->in6_saddr = *saddr;
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}
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EXPORT_SYMBOL_GPL(dst_cache_set_ip6);
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struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
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struct in6_addr *saddr)
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{
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struct dst_cache_pcpu *idst;
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struct dst_entry *dst;
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if (!dst_cache->cache)
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return NULL;
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idst = this_cpu_ptr(dst_cache->cache);
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dst = dst_cache_per_cpu_get(dst_cache, idst);
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if (!dst)
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return NULL;
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*saddr = idst->in6_saddr;
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return dst;
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}
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EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
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#endif
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int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
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{
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dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
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gfp | __GFP_ZERO);
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if (!dst_cache->cache)
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return -ENOMEM;
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dst_cache_reset(dst_cache);
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return 0;
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}
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EXPORT_SYMBOL_GPL(dst_cache_init);
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void dst_cache_destroy(struct dst_cache *dst_cache)
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{
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int i;
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if (!dst_cache->cache)
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return;
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for_each_possible_cpu(i)
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dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);
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free_percpu(dst_cache->cache);
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}
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EXPORT_SYMBOL_GPL(dst_cache_destroy);
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