v4.19.13 snapshot.
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
new file mode 100644
index 0000000..760a9e5
--- /dev/null
+++ b/net/ipv4/inet_fragment.c
@@ -0,0 +1,226 @@
+/*
+ * inet fragments management
+ *
+ * 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.
+ *
+ * Authors: Pavel Emelyanov <xemul@openvz.org>
+ * Started as consolidation of ipv4/ip_fragment.c,
+ * ipv6/reassembly. and ipv6 nf conntrack reassembly
+ */
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/random.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/rhashtable.h>
+
+#include <net/sock.h>
+#include <net/inet_frag.h>
+#include <net/inet_ecn.h>
+
+/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
+ * Value : 0xff if frame should be dropped.
+ * 0 or INET_ECN_CE value, to be ORed in to final iph->tos field
+ */
+const u8 ip_frag_ecn_table[16] = {
+ /* at least one fragment had CE, and others ECT_0 or ECT_1 */
+ [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE,
+ [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
+ [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
+
+ /* invalid combinations : drop frame */
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
+ [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
+};
+EXPORT_SYMBOL(ip_frag_ecn_table);
+
+int inet_frags_init(struct inet_frags *f)
+{
+ f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0,
+ NULL);
+ if (!f->frags_cachep)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL(inet_frags_init);
+
+void inet_frags_fini(struct inet_frags *f)
+{
+ /* We must wait that all inet_frag_destroy_rcu() have completed. */
+ rcu_barrier();
+
+ kmem_cache_destroy(f->frags_cachep);
+ f->frags_cachep = NULL;
+}
+EXPORT_SYMBOL(inet_frags_fini);
+
+static void inet_frags_free_cb(void *ptr, void *arg)
+{
+ struct inet_frag_queue *fq = ptr;
+
+ /* If we can not cancel the timer, it means this frag_queue
+ * is already disappearing, we have nothing to do.
+ * Otherwise, we own a refcount until the end of this function.
+ */
+ if (!del_timer(&fq->timer))
+ return;
+
+ spin_lock_bh(&fq->lock);
+ if (!(fq->flags & INET_FRAG_COMPLETE)) {
+ fq->flags |= INET_FRAG_COMPLETE;
+ refcount_dec(&fq->refcnt);
+ }
+ spin_unlock_bh(&fq->lock);
+
+ inet_frag_put(fq);
+}
+
+void inet_frags_exit_net(struct netns_frags *nf)
+{
+ nf->high_thresh = 0; /* prevent creation of new frags */
+
+ rhashtable_free_and_destroy(&nf->rhashtable, inet_frags_free_cb, NULL);
+}
+EXPORT_SYMBOL(inet_frags_exit_net);
+
+void inet_frag_kill(struct inet_frag_queue *fq)
+{
+ if (del_timer(&fq->timer))
+ refcount_dec(&fq->refcnt);
+
+ if (!(fq->flags & INET_FRAG_COMPLETE)) {
+ struct netns_frags *nf = fq->net;
+
+ fq->flags |= INET_FRAG_COMPLETE;
+ rhashtable_remove_fast(&nf->rhashtable, &fq->node, nf->f->rhash_params);
+ refcount_dec(&fq->refcnt);
+ }
+}
+EXPORT_SYMBOL(inet_frag_kill);
+
+static void inet_frag_destroy_rcu(struct rcu_head *head)
+{
+ struct inet_frag_queue *q = container_of(head, struct inet_frag_queue,
+ rcu);
+ struct inet_frags *f = q->net->f;
+
+ if (f->destructor)
+ f->destructor(q);
+ kmem_cache_free(f->frags_cachep, q);
+}
+
+void inet_frag_destroy(struct inet_frag_queue *q)
+{
+ struct sk_buff *fp;
+ struct netns_frags *nf;
+ unsigned int sum, sum_truesize = 0;
+ struct inet_frags *f;
+
+ WARN_ON(!(q->flags & INET_FRAG_COMPLETE));
+ WARN_ON(del_timer(&q->timer) != 0);
+
+ /* Release all fragment data. */
+ fp = q->fragments;
+ nf = q->net;
+ f = nf->f;
+ if (fp) {
+ do {
+ struct sk_buff *xp = fp->next;
+
+ sum_truesize += fp->truesize;
+ kfree_skb(fp);
+ fp = xp;
+ } while (fp);
+ } else {
+ sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments);
+ }
+ sum = sum_truesize + f->qsize;
+
+ call_rcu(&q->rcu, inet_frag_destroy_rcu);
+
+ sub_frag_mem_limit(nf, sum);
+}
+EXPORT_SYMBOL(inet_frag_destroy);
+
+static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
+ struct inet_frags *f,
+ void *arg)
+{
+ struct inet_frag_queue *q;
+
+ q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC);
+ if (!q)
+ return NULL;
+
+ q->net = nf;
+ f->constructor(q, arg);
+ add_frag_mem_limit(nf, f->qsize);
+
+ timer_setup(&q->timer, f->frag_expire, 0);
+ spin_lock_init(&q->lock);
+ refcount_set(&q->refcnt, 3);
+
+ return q;
+}
+
+static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
+ void *arg,
+ struct inet_frag_queue **prev)
+{
+ struct inet_frags *f = nf->f;
+ struct inet_frag_queue *q;
+
+ q = inet_frag_alloc(nf, f, arg);
+ if (!q) {
+ *prev = ERR_PTR(-ENOMEM);
+ return NULL;
+ }
+ mod_timer(&q->timer, jiffies + nf->timeout);
+
+ *prev = rhashtable_lookup_get_insert_key(&nf->rhashtable, &q->key,
+ &q->node, f->rhash_params);
+ if (*prev) {
+ q->flags |= INET_FRAG_COMPLETE;
+ inet_frag_kill(q);
+ inet_frag_destroy(q);
+ return NULL;
+ }
+ return q;
+}
+
+/* TODO : call from rcu_read_lock() and no longer use refcount_inc_not_zero() */
+struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key)
+{
+ struct inet_frag_queue *fq = NULL, *prev;
+
+ if (!nf->high_thresh || frag_mem_limit(nf) > nf->high_thresh)
+ return NULL;
+
+ rcu_read_lock();
+
+ prev = rhashtable_lookup(&nf->rhashtable, key, nf->f->rhash_params);
+ if (!prev)
+ fq = inet_frag_create(nf, key, &prev);
+ if (prev && !IS_ERR(prev)) {
+ fq = prev;
+ if (!refcount_inc_not_zero(&fq->refcnt))
+ fq = NULL;
+ }
+ rcu_read_unlock();
+ return fq;
+}
+EXPORT_SYMBOL(inet_frag_find);