mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 22:16:39 +07:00
7088ad74e6
All fragmentation hash secrets now get initialized by their corresponding hash function with net_get_random_once. Thus we can eliminate the initial seeding. Also provide a comment that hash secret seeding happens at the first call to the corresponding hashing function. Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
361 lines
8.6 KiB
C
361 lines
8.6 KiB
C
/*
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* inet fragments management
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Pavel Emelyanov <xemul@openvz.org>
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* Started as consolidation of ipv4/ip_fragment.c,
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* ipv6/reassembly. and ipv6 nf conntrack reassembly
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*/
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/timer.h>
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#include <linux/mm.h>
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#include <linux/random.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/slab.h>
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#include <net/sock.h>
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#include <net/inet_frag.h>
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#include <net/inet_ecn.h>
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/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
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* Value : 0xff if frame should be dropped.
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* 0 or INET_ECN_CE value, to be ORed in to final iph->tos field
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*/
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const u8 ip_frag_ecn_table[16] = {
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/* at least one fragment had CE, and others ECT_0 or ECT_1 */
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[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE,
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[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
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[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
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/* invalid combinations : drop frame */
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
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[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
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};
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EXPORT_SYMBOL(ip_frag_ecn_table);
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static void inet_frag_secret_rebuild(unsigned long dummy)
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{
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struct inet_frags *f = (struct inet_frags *)dummy;
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unsigned long now = jiffies;
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int i;
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/* Per bucket lock NOT needed here, due to write lock protection */
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write_lock(&f->lock);
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get_random_bytes(&f->rnd, sizeof(u32));
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for (i = 0; i < INETFRAGS_HASHSZ; i++) {
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struct inet_frag_bucket *hb;
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struct inet_frag_queue *q;
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struct hlist_node *n;
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hb = &f->hash[i];
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hlist_for_each_entry_safe(q, n, &hb->chain, list) {
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unsigned int hval = f->hashfn(q);
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if (hval != i) {
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struct inet_frag_bucket *hb_dest;
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hlist_del(&q->list);
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/* Relink to new hash chain. */
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hb_dest = &f->hash[hval];
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hlist_add_head(&q->list, &hb_dest->chain);
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}
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}
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}
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write_unlock(&f->lock);
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mod_timer(&f->secret_timer, now + f->secret_interval);
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}
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void inet_frags_init(struct inet_frags *f)
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{
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int i;
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for (i = 0; i < INETFRAGS_HASHSZ; i++) {
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struct inet_frag_bucket *hb = &f->hash[i];
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spin_lock_init(&hb->chain_lock);
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INIT_HLIST_HEAD(&hb->chain);
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}
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rwlock_init(&f->lock);
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setup_timer(&f->secret_timer, inet_frag_secret_rebuild,
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(unsigned long)f);
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f->secret_timer.expires = jiffies + f->secret_interval;
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add_timer(&f->secret_timer);
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}
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EXPORT_SYMBOL(inet_frags_init);
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void inet_frags_init_net(struct netns_frags *nf)
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{
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nf->nqueues = 0;
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init_frag_mem_limit(nf);
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INIT_LIST_HEAD(&nf->lru_list);
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spin_lock_init(&nf->lru_lock);
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}
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EXPORT_SYMBOL(inet_frags_init_net);
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void inet_frags_fini(struct inet_frags *f)
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{
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del_timer(&f->secret_timer);
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}
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EXPORT_SYMBOL(inet_frags_fini);
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void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f)
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{
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nf->low_thresh = 0;
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local_bh_disable();
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inet_frag_evictor(nf, f, true);
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local_bh_enable();
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percpu_counter_destroy(&nf->mem);
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}
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EXPORT_SYMBOL(inet_frags_exit_net);
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static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
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{
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struct inet_frag_bucket *hb;
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unsigned int hash;
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read_lock(&f->lock);
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hash = f->hashfn(fq);
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hb = &f->hash[hash];
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spin_lock(&hb->chain_lock);
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hlist_del(&fq->list);
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spin_unlock(&hb->chain_lock);
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read_unlock(&f->lock);
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inet_frag_lru_del(fq);
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}
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void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f)
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{
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if (del_timer(&fq->timer))
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atomic_dec(&fq->refcnt);
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if (!(fq->last_in & INET_FRAG_COMPLETE)) {
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fq_unlink(fq, f);
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atomic_dec(&fq->refcnt);
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fq->last_in |= INET_FRAG_COMPLETE;
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}
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}
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EXPORT_SYMBOL(inet_frag_kill);
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static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f,
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struct sk_buff *skb)
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{
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if (f->skb_free)
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f->skb_free(skb);
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kfree_skb(skb);
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}
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void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
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int *work)
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{
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struct sk_buff *fp;
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struct netns_frags *nf;
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unsigned int sum, sum_truesize = 0;
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WARN_ON(!(q->last_in & INET_FRAG_COMPLETE));
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WARN_ON(del_timer(&q->timer) != 0);
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/* Release all fragment data. */
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fp = q->fragments;
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nf = q->net;
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while (fp) {
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struct sk_buff *xp = fp->next;
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sum_truesize += fp->truesize;
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frag_kfree_skb(nf, f, fp);
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fp = xp;
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}
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sum = sum_truesize + f->qsize;
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if (work)
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*work -= sum;
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sub_frag_mem_limit(q, sum);
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if (f->destructor)
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f->destructor(q);
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kfree(q);
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}
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EXPORT_SYMBOL(inet_frag_destroy);
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int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force)
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{
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struct inet_frag_queue *q;
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int work, evicted = 0;
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if (!force) {
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if (frag_mem_limit(nf) <= nf->high_thresh)
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return 0;
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}
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work = frag_mem_limit(nf) - nf->low_thresh;
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while (work > 0) {
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spin_lock(&nf->lru_lock);
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if (list_empty(&nf->lru_list)) {
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spin_unlock(&nf->lru_lock);
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break;
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}
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q = list_first_entry(&nf->lru_list,
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struct inet_frag_queue, lru_list);
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atomic_inc(&q->refcnt);
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/* Remove q from list to avoid several CPUs grabbing it */
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list_del_init(&q->lru_list);
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spin_unlock(&nf->lru_lock);
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spin_lock(&q->lock);
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if (!(q->last_in & INET_FRAG_COMPLETE))
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inet_frag_kill(q, f);
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spin_unlock(&q->lock);
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if (atomic_dec_and_test(&q->refcnt))
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inet_frag_destroy(q, f, &work);
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evicted++;
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}
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return evicted;
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}
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EXPORT_SYMBOL(inet_frag_evictor);
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static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
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struct inet_frag_queue *qp_in, struct inet_frags *f,
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void *arg)
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{
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struct inet_frag_bucket *hb;
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struct inet_frag_queue *qp;
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unsigned int hash;
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read_lock(&f->lock); /* Protects against hash rebuild */
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/*
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* While we stayed w/o the lock other CPU could update
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* the rnd seed, so we need to re-calculate the hash
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* chain. Fortunatelly the qp_in can be used to get one.
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*/
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hash = f->hashfn(qp_in);
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hb = &f->hash[hash];
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spin_lock(&hb->chain_lock);
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#ifdef CONFIG_SMP
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/* With SMP race we have to recheck hash table, because
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* such entry could be created on other cpu, while we
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* released the hash bucket lock.
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*/
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hlist_for_each_entry(qp, &hb->chain, list) {
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if (qp->net == nf && f->match(qp, arg)) {
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atomic_inc(&qp->refcnt);
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spin_unlock(&hb->chain_lock);
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read_unlock(&f->lock);
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qp_in->last_in |= INET_FRAG_COMPLETE;
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inet_frag_put(qp_in, f);
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return qp;
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}
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}
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#endif
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qp = qp_in;
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if (!mod_timer(&qp->timer, jiffies + nf->timeout))
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atomic_inc(&qp->refcnt);
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atomic_inc(&qp->refcnt);
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hlist_add_head(&qp->list, &hb->chain);
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spin_unlock(&hb->chain_lock);
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read_unlock(&f->lock);
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inet_frag_lru_add(nf, qp);
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return qp;
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}
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static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
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struct inet_frags *f, void *arg)
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{
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struct inet_frag_queue *q;
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q = kzalloc(f->qsize, GFP_ATOMIC);
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if (q == NULL)
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return NULL;
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q->net = nf;
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f->constructor(q, arg);
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add_frag_mem_limit(q, f->qsize);
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setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
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spin_lock_init(&q->lock);
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atomic_set(&q->refcnt, 1);
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INIT_LIST_HEAD(&q->lru_list);
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return q;
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}
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static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
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struct inet_frags *f, void *arg)
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{
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struct inet_frag_queue *q;
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q = inet_frag_alloc(nf, f, arg);
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if (q == NULL)
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return NULL;
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return inet_frag_intern(nf, q, f, arg);
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}
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struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
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struct inet_frags *f, void *key, unsigned int hash)
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__releases(&f->lock)
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{
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struct inet_frag_bucket *hb;
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struct inet_frag_queue *q;
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int depth = 0;
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hb = &f->hash[hash];
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spin_lock(&hb->chain_lock);
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hlist_for_each_entry(q, &hb->chain, list) {
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if (q->net == nf && f->match(q, key)) {
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atomic_inc(&q->refcnt);
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spin_unlock(&hb->chain_lock);
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read_unlock(&f->lock);
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return q;
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}
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depth++;
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}
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spin_unlock(&hb->chain_lock);
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read_unlock(&f->lock);
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if (depth <= INETFRAGS_MAXDEPTH)
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return inet_frag_create(nf, f, key);
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else
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return ERR_PTR(-ENOBUFS);
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}
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EXPORT_SYMBOL(inet_frag_find);
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void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
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const char *prefix)
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{
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static const char msg[] = "inet_frag_find: Fragment hash bucket"
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" list length grew over limit " __stringify(INETFRAGS_MAXDEPTH)
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". Dropping fragment.\n";
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if (PTR_ERR(q) == -ENOBUFS)
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LIMIT_NETDEBUG(KERN_WARNING "%s%s", prefix, msg);
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}
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EXPORT_SYMBOL(inet_frag_maybe_warn_overflow);
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