Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 760a9e5..10d3173 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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
@@ -25,6 +21,62 @@
#include <net/sock.h>
#include <net/inet_frag.h>
#include <net/inet_ecn.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+
+/* Use skb->cb to track consecutive/adjacent fragments coming at
+ * the end of the queue. Nodes in the rb-tree queue will
+ * contain "runs" of one or more adjacent fragments.
+ *
+ * Invariants:
+ * - next_frag is NULL at the tail of a "run";
+ * - the head of a "run" has the sum of all fragment lengths in frag_run_len.
+ */
+struct ipfrag_skb_cb {
+ union {
+ struct inet_skb_parm h4;
+ struct inet6_skb_parm h6;
+ };
+ struct sk_buff *next_frag;
+ int frag_run_len;
+};
+
+#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
+
+static void fragcb_clear(struct sk_buff *skb)
+{
+ RB_CLEAR_NODE(&skb->rbnode);
+ FRAG_CB(skb)->next_frag = NULL;
+ FRAG_CB(skb)->frag_run_len = skb->len;
+}
+
+/* Append skb to the last "run". */
+static void fragrun_append_to_last(struct inet_frag_queue *q,
+ struct sk_buff *skb)
+{
+ fragcb_clear(skb);
+
+ FRAG_CB(q->last_run_head)->frag_run_len += skb->len;
+ FRAG_CB(q->fragments_tail)->next_frag = skb;
+ q->fragments_tail = skb;
+}
+
+/* Create a new "run" with the skb. */
+static void fragrun_create(struct inet_frag_queue *q, struct sk_buff *skb)
+{
+ BUILD_BUG_ON(sizeof(struct ipfrag_skb_cb) > sizeof(skb->cb));
+ fragcb_clear(skb);
+
+ if (q->last_run_head)
+ rb_link_node(&skb->rbnode, &q->last_run_head->rbnode,
+ &q->last_run_head->rbnode.rb_right);
+ else
+ rb_link_node(&skb->rbnode, NULL, &q->rb_fragments.rb_node);
+ rb_insert_color(&skb->rbnode, &q->rb_fragments);
+
+ q->fragments_tail = skb;
+ q->last_run_head = skb;
+}
/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
* Value : 0xff if frame should be dropped.
@@ -54,48 +106,90 @@
if (!f->frags_cachep)
return -ENOMEM;
+ refcount_set(&f->refcnt, 1);
+ init_completion(&f->completion);
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();
+ if (refcount_dec_and_test(&f->refcnt))
+ complete(&f->completion);
+
+ wait_for_completion(&f->completion);
kmem_cache_destroy(f->frags_cachep);
f->frags_cachep = NULL;
}
EXPORT_SYMBOL(inet_frags_fini);
+/* called from rhashtable_free_and_destroy() at netns_frags dismantle */
static void inet_frags_free_cb(void *ptr, void *arg)
{
struct inet_frag_queue *fq = ptr;
+ int count;
- /* 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;
+ count = del_timer_sync(&fq->timer) ? 1 : 0;
spin_lock_bh(&fq->lock);
if (!(fq->flags & INET_FRAG_COMPLETE)) {
fq->flags |= INET_FRAG_COMPLETE;
- refcount_dec(&fq->refcnt);
+ count++;
+ } else if (fq->flags & INET_FRAG_HASH_DEAD) {
+ count++;
}
spin_unlock_bh(&fq->lock);
- inet_frag_put(fq);
+ if (refcount_sub_and_test(count, &fq->refcnt))
+ inet_frag_destroy(fq);
}
-void inet_frags_exit_net(struct netns_frags *nf)
+static void fqdir_work_fn(struct work_struct *work)
{
- nf->high_thresh = 0; /* prevent creation of new frags */
+ struct fqdir *fqdir = container_of(work, struct fqdir, destroy_work);
+ struct inet_frags *f = fqdir->f;
- rhashtable_free_and_destroy(&nf->rhashtable, inet_frags_free_cb, NULL);
+ rhashtable_free_and_destroy(&fqdir->rhashtable, inet_frags_free_cb, NULL);
+
+ /* We need to make sure all ongoing call_rcu(..., inet_frag_destroy_rcu)
+ * have completed, since they need to dereference fqdir.
+ * Would it not be nice to have kfree_rcu_barrier() ? :)
+ */
+ rcu_barrier();
+
+ if (refcount_dec_and_test(&f->refcnt))
+ complete(&f->completion);
+
+ kfree(fqdir);
}
-EXPORT_SYMBOL(inet_frags_exit_net);
+
+int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f, struct net *net)
+{
+ struct fqdir *fqdir = kzalloc(sizeof(*fqdir), GFP_KERNEL);
+ int res;
+
+ if (!fqdir)
+ return -ENOMEM;
+ fqdir->f = f;
+ fqdir->net = net;
+ res = rhashtable_init(&fqdir->rhashtable, &fqdir->f->rhash_params);
+ if (res < 0) {
+ kfree(fqdir);
+ return res;
+ }
+ refcount_inc(&f->refcnt);
+ *fqdirp = fqdir;
+ return 0;
+}
+EXPORT_SYMBOL(fqdir_init);
+
+void fqdir_exit(struct fqdir *fqdir)
+{
+ INIT_WORK(&fqdir->destroy_work, fqdir_work_fn);
+ queue_work(system_wq, &fqdir->destroy_work);
+}
+EXPORT_SYMBOL(fqdir_exit);
void inet_frag_kill(struct inet_frag_queue *fq)
{
@@ -103,11 +197,23 @@
refcount_dec(&fq->refcnt);
if (!(fq->flags & INET_FRAG_COMPLETE)) {
- struct netns_frags *nf = fq->net;
+ struct fqdir *fqdir = fq->fqdir;
fq->flags |= INET_FRAG_COMPLETE;
- rhashtable_remove_fast(&nf->rhashtable, &fq->node, nf->f->rhash_params);
- refcount_dec(&fq->refcnt);
+ rcu_read_lock();
+ /* The RCU read lock provides a memory barrier
+ * guaranteeing that if fqdir->dead is false then
+ * the hash table destruction will not start until
+ * after we unlock. Paired with inet_frags_exit_net().
+ */
+ if (!fqdir->dead) {
+ rhashtable_remove_fast(&fqdir->rhashtable, &fq->node,
+ fqdir->f->rhash_params);
+ refcount_dec(&fq->refcnt);
+ } else {
+ fq->flags |= INET_FRAG_HASH_DEAD;
+ }
+ rcu_read_unlock();
}
}
EXPORT_SYMBOL(inet_frag_kill);
@@ -116,17 +222,38 @@
{
struct inet_frag_queue *q = container_of(head, struct inet_frag_queue,
rcu);
- struct inet_frags *f = q->net->f;
+ struct inet_frags *f = q->fqdir->f;
if (f->destructor)
f->destructor(q);
kmem_cache_free(f->frags_cachep, q);
}
+unsigned int inet_frag_rbtree_purge(struct rb_root *root)
+{
+ struct rb_node *p = rb_first(root);
+ unsigned int sum = 0;
+
+ while (p) {
+ struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
+
+ p = rb_next(p);
+ rb_erase(&skb->rbnode, root);
+ while (skb) {
+ struct sk_buff *next = FRAG_CB(skb)->next_frag;
+
+ sum += skb->truesize;
+ kfree_skb(skb);
+ skb = next;
+ }
+ }
+ return sum;
+}
+EXPORT_SYMBOL(inet_frag_rbtree_purge);
+
void inet_frag_destroy(struct inet_frag_queue *q)
{
- struct sk_buff *fp;
- struct netns_frags *nf;
+ struct fqdir *fqdir;
unsigned int sum, sum_truesize = 0;
struct inet_frags *f;
@@ -134,29 +261,18 @@
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);
- }
+ fqdir = q->fqdir;
+ f = fqdir->f;
+ 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);
+ sub_frag_mem_limit(fqdir, sum);
}
EXPORT_SYMBOL(inet_frag_destroy);
-static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
+static struct inet_frag_queue *inet_frag_alloc(struct fqdir *fqdir,
struct inet_frags *f,
void *arg)
{
@@ -166,9 +282,9 @@
if (!q)
return NULL;
- q->net = nf;
+ q->fqdir = fqdir;
f->constructor(q, arg);
- add_frag_mem_limit(nf, f->qsize);
+ add_frag_mem_limit(fqdir, f->qsize);
timer_setup(&q->timer, f->frag_expire, 0);
spin_lock_init(&q->lock);
@@ -177,21 +293,21 @@
return q;
}
-static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
+static struct inet_frag_queue *inet_frag_create(struct fqdir *fqdir,
void *arg,
struct inet_frag_queue **prev)
{
- struct inet_frags *f = nf->f;
+ struct inet_frags *f = fqdir->f;
struct inet_frag_queue *q;
- q = inet_frag_alloc(nf, f, arg);
+ q = inet_frag_alloc(fqdir, f, arg);
if (!q) {
*prev = ERR_PTR(-ENOMEM);
return NULL;
}
- mod_timer(&q->timer, jiffies + nf->timeout);
+ mod_timer(&q->timer, jiffies + fqdir->timeout);
- *prev = rhashtable_lookup_get_insert_key(&nf->rhashtable, &q->key,
+ *prev = rhashtable_lookup_get_insert_key(&fqdir->rhashtable, &q->key,
&q->node, f->rhash_params);
if (*prev) {
q->flags |= INET_FRAG_COMPLETE;
@@ -203,19 +319,19 @@
}
/* 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 *inet_frag_find(struct fqdir *fqdir, void *key)
{
struct inet_frag_queue *fq = NULL, *prev;
- if (!nf->high_thresh || frag_mem_limit(nf) > nf->high_thresh)
+ if (!fqdir->high_thresh || frag_mem_limit(fqdir) > fqdir->high_thresh)
return NULL;
rcu_read_lock();
- prev = rhashtable_lookup(&nf->rhashtable, key, nf->f->rhash_params);
+ prev = rhashtable_lookup(&fqdir->rhashtable, key, fqdir->f->rhash_params);
if (!prev)
- fq = inet_frag_create(nf, key, &prev);
- if (prev && !IS_ERR(prev)) {
+ fq = inet_frag_create(fqdir, key, &prev);
+ if (!IS_ERR_OR_NULL(prev)) {
fq = prev;
if (!refcount_inc_not_zero(&fq->refcnt))
fq = NULL;
@@ -224,3 +340,229 @@
return fq;
}
EXPORT_SYMBOL(inet_frag_find);
+
+int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
+ int offset, int end)
+{
+ struct sk_buff *last = q->fragments_tail;
+
+ /* RFC5722, Section 4, amended by Errata ID : 3089
+ * When reassembling an IPv6 datagram, if
+ * one or more its constituent fragments is determined to be an
+ * overlapping fragment, the entire datagram (and any constituent
+ * fragments) MUST be silently discarded.
+ *
+ * Duplicates, however, should be ignored (i.e. skb dropped, but the
+ * queue/fragments kept for later reassembly).
+ */
+ if (!last)
+ fragrun_create(q, skb); /* First fragment. */
+ else if (last->ip_defrag_offset + last->len < end) {
+ /* This is the common case: skb goes to the end. */
+ /* Detect and discard overlaps. */
+ if (offset < last->ip_defrag_offset + last->len)
+ return IPFRAG_OVERLAP;
+ if (offset == last->ip_defrag_offset + last->len)
+ fragrun_append_to_last(q, skb);
+ else
+ fragrun_create(q, skb);
+ } else {
+ /* Binary search. Note that skb can become the first fragment,
+ * but not the last (covered above).
+ */
+ struct rb_node **rbn, *parent;
+
+ rbn = &q->rb_fragments.rb_node;
+ do {
+ struct sk_buff *curr;
+ int curr_run_end;
+
+ parent = *rbn;
+ curr = rb_to_skb(parent);
+ curr_run_end = curr->ip_defrag_offset +
+ FRAG_CB(curr)->frag_run_len;
+ if (end <= curr->ip_defrag_offset)
+ rbn = &parent->rb_left;
+ else if (offset >= curr_run_end)
+ rbn = &parent->rb_right;
+ else if (offset >= curr->ip_defrag_offset &&
+ end <= curr_run_end)
+ return IPFRAG_DUP;
+ else
+ return IPFRAG_OVERLAP;
+ } while (*rbn);
+ /* Here we have parent properly set, and rbn pointing to
+ * one of its NULL left/right children. Insert skb.
+ */
+ fragcb_clear(skb);
+ rb_link_node(&skb->rbnode, parent, rbn);
+ rb_insert_color(&skb->rbnode, &q->rb_fragments);
+ }
+
+ skb->ip_defrag_offset = offset;
+
+ return IPFRAG_OK;
+}
+EXPORT_SYMBOL(inet_frag_queue_insert);
+
+void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
+ struct sk_buff *parent)
+{
+ struct sk_buff *fp, *head = skb_rb_first(&q->rb_fragments);
+ struct sk_buff **nextp;
+ int delta;
+
+ if (head != skb) {
+ fp = skb_clone(skb, GFP_ATOMIC);
+ if (!fp)
+ return NULL;
+ FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag;
+ if (RB_EMPTY_NODE(&skb->rbnode))
+ FRAG_CB(parent)->next_frag = fp;
+ else
+ rb_replace_node(&skb->rbnode, &fp->rbnode,
+ &q->rb_fragments);
+ if (q->fragments_tail == skb)
+ q->fragments_tail = fp;
+ skb_morph(skb, head);
+ FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag;
+ rb_replace_node(&head->rbnode, &skb->rbnode,
+ &q->rb_fragments);
+ consume_skb(head);
+ head = skb;
+ }
+ WARN_ON(head->ip_defrag_offset != 0);
+
+ delta = -head->truesize;
+
+ /* Head of list must not be cloned. */
+ if (skb_unclone(head, GFP_ATOMIC))
+ return NULL;
+
+ delta += head->truesize;
+ if (delta)
+ add_frag_mem_limit(q->fqdir, delta);
+
+ /* If the first fragment is fragmented itself, we split
+ * it to two chunks: the first with data and paged part
+ * and the second, holding only fragments.
+ */
+ if (skb_has_frag_list(head)) {
+ struct sk_buff *clone;
+ int i, plen = 0;
+
+ clone = alloc_skb(0, GFP_ATOMIC);
+ if (!clone)
+ return NULL;
+ skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+ skb_frag_list_init(head);
+ for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+ plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
+ clone->data_len = head->data_len - plen;
+ clone->len = clone->data_len;
+ head->truesize += clone->truesize;
+ clone->csum = 0;
+ clone->ip_summed = head->ip_summed;
+ add_frag_mem_limit(q->fqdir, clone->truesize);
+ skb_shinfo(head)->frag_list = clone;
+ nextp = &clone->next;
+ } else {
+ nextp = &skb_shinfo(head)->frag_list;
+ }
+
+ return nextp;
+}
+EXPORT_SYMBOL(inet_frag_reasm_prepare);
+
+void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
+ void *reasm_data, bool try_coalesce)
+{
+ struct sk_buff **nextp = (struct sk_buff **)reasm_data;
+ struct rb_node *rbn;
+ struct sk_buff *fp;
+ int sum_truesize;
+
+ skb_push(head, head->data - skb_network_header(head));
+
+ /* Traverse the tree in order, to build frag_list. */
+ fp = FRAG_CB(head)->next_frag;
+ rbn = rb_next(&head->rbnode);
+ rb_erase(&head->rbnode, &q->rb_fragments);
+
+ sum_truesize = head->truesize;
+ while (rbn || fp) {
+ /* fp points to the next sk_buff in the current run;
+ * rbn points to the next run.
+ */
+ /* Go through the current run. */
+ while (fp) {
+ struct sk_buff *next_frag = FRAG_CB(fp)->next_frag;
+ bool stolen;
+ int delta;
+
+ sum_truesize += fp->truesize;
+ if (head->ip_summed != fp->ip_summed)
+ head->ip_summed = CHECKSUM_NONE;
+ else if (head->ip_summed == CHECKSUM_COMPLETE)
+ head->csum = csum_add(head->csum, fp->csum);
+
+ if (try_coalesce && skb_try_coalesce(head, fp, &stolen,
+ &delta)) {
+ kfree_skb_partial(fp, stolen);
+ } else {
+ fp->prev = NULL;
+ memset(&fp->rbnode, 0, sizeof(fp->rbnode));
+ fp->sk = NULL;
+
+ head->data_len += fp->len;
+ head->len += fp->len;
+ head->truesize += fp->truesize;
+
+ *nextp = fp;
+ nextp = &fp->next;
+ }
+
+ fp = next_frag;
+ }
+ /* Move to the next run. */
+ if (rbn) {
+ struct rb_node *rbnext = rb_next(rbn);
+
+ fp = rb_to_skb(rbn);
+ rb_erase(rbn, &q->rb_fragments);
+ rbn = rbnext;
+ }
+ }
+ sub_frag_mem_limit(q->fqdir, sum_truesize);
+
+ *nextp = NULL;
+ skb_mark_not_on_list(head);
+ head->prev = NULL;
+ head->tstamp = q->stamp;
+}
+EXPORT_SYMBOL(inet_frag_reasm_finish);
+
+struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q)
+{
+ struct sk_buff *head, *skb;
+
+ head = skb_rb_first(&q->rb_fragments);
+ if (!head)
+ return NULL;
+ skb = FRAG_CB(head)->next_frag;
+ if (skb)
+ rb_replace_node(&head->rbnode, &skb->rbnode,
+ &q->rb_fragments);
+ else
+ rb_erase(&head->rbnode, &q->rb_fragments);
+ memset(&head->rbnode, 0, sizeof(head->rbnode));
+ barrier();
+
+ if (head == q->fragments_tail)
+ q->fragments_tail = NULL;
+
+ sub_frag_mem_limit(q->fqdir, head->truesize);
+
+ return head;
+}
+EXPORT_SYMBOL(inet_frag_pull_head);