Commit 77adfd3a authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

net: dropreason: add SKB_DROP_REASON_FRAG_REASM_TIMEOUT 



Used to track skbs freed after a timeout happened
in a reassmbly unit.

Passing a @reason argument to inet_frag_rbtree_purge()
allows to use correct consumed status for frags
that have been successfully re-assembled.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4ecbb1c2

include/net/dropreason.h

+3 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ 
	FN(IP_INNOROUTES)		\

	FN(PKT_TOO_BIG)			\

	FN(DUP_FRAG)			\

	FN(FRAG_REASM_TIMEOUT)		\

	FNe(MAX)



/**
@@ -303,6 +304,8 @@ enum skb_drop_reason { 
	SKB_DROP_REASON_PKT_TOO_BIG,

	/** @SKB_DROP_REASON_DUP_FRAG: duplicate fragment */

	SKB_DROP_REASON_DUP_FRAG,

	/** @SKB_DROP_REASON_FRAG_REASM_TIMEOUT: fragment reassembly timeout */

	SKB_DROP_REASON_FRAG_REASM_TIMEOUT,

	/**

	 * @SKB_DROP_REASON_MAX: the maximum of drop reason, which shouldn't be

	 * used as a real 'reason'

include/net/inet_frag.h

+5 −1
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/in6.h>

#include <linux/rbtree_types.h>

#include <linux/refcount.h>

#include <net/dropreason.h>



/* Per netns frag queues directory */

struct fqdir {
@@ -34,12 +35,14 @@ struct fqdir { 
 * @INET_FRAG_LAST_IN: final fragment has arrived

 * @INET_FRAG_COMPLETE: frag queue has been processed and is due for destruction

 * @INET_FRAG_HASH_DEAD: inet_frag_kill() has not removed fq from rhashtable

 * @INET_FRAG_DROP: if skbs must be dropped (instead of being consumed)

 */

enum {

	INET_FRAG_FIRST_IN	= BIT(0),

	INET_FRAG_LAST_IN	= BIT(1),

	INET_FRAG_COMPLETE	= BIT(2),

	INET_FRAG_HASH_DEAD	= BIT(3),

	INET_FRAG_DROP		= BIT(4),

};



struct frag_v4_compare_key {
@@ -139,7 +142,8 @@ void inet_frag_destroy(struct inet_frag_queue *q); 
struct inet_frag_queue *inet_frag_find(struct fqdir *fqdir, void *key);



/* Free all skbs in the queue; return the sum of their truesizes. */

unsigned int inet_frag_rbtree_purge(struct rb_root *root);

unsigned int inet_frag_rbtree_purge(struct rb_root *root,

				    enum skb_drop_reason reason);



static inline void inet_frag_put(struct inet_frag_queue *q)

{

include/net/ipv6_frag.h

+2 −1
Original line number Diff line number Diff line
@@ -76,6 +76,7 @@ ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq) 
	if (fq->q.flags & INET_FRAG_COMPLETE)

		goto out;



	fq->q.flags |= INET_FRAG_DROP;

	inet_frag_kill(&fq->q);



	dev = dev_get_by_index_rcu(net, fq->iif);
@@ -101,7 +102,7 @@ ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq) 
	spin_unlock(&fq->q.lock);



	icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);

	kfree_skb(head);

	kfree_skb_reason(head, SKB_DROP_REASON_FRAG_REASM_TIMEOUT);

	goto out_rcu_unlock;



out:

net/ipv4/inet_fragment.c

+10 −4
Original line number Diff line number Diff line
@@ -133,6 +133,7 @@ static void inet_frags_free_cb(void *ptr, void *arg) 
	count = del_timer_sync(&fq->timer) ? 1 : 0;



	spin_lock_bh(&fq->lock);

	fq->flags |= INET_FRAG_DROP;

	if (!(fq->flags & INET_FRAG_COMPLETE)) {

		fq->flags |= INET_FRAG_COMPLETE;

		count++;
@@ -260,7 +261,8 @@ static void inet_frag_destroy_rcu(struct rcu_head *head) 
	kmem_cache_free(f->frags_cachep, q);

}



unsigned int inet_frag_rbtree_purge(struct rb_root *root)

unsigned int inet_frag_rbtree_purge(struct rb_root *root,

				    enum skb_drop_reason reason)

{

	struct rb_node *p = rb_first(root);

	unsigned int sum = 0;
@@ -274,7 +276,7 @@ unsigned int inet_frag_rbtree_purge(struct rb_root *root) 
			struct sk_buff *next = FRAG_CB(skb)->next_frag;



			sum += skb->truesize;

			kfree_skb(skb);

			kfree_skb_reason(skb, reason);

			skb = next;

		}

	}
@@ -284,17 +286,21 @@ EXPORT_SYMBOL(inet_frag_rbtree_purge); 


void inet_frag_destroy(struct inet_frag_queue *q)

{

	struct fqdir *fqdir;

	unsigned int sum, sum_truesize = 0;

	enum skb_drop_reason reason;

	struct inet_frags *f;

	struct fqdir *fqdir;



	WARN_ON(!(q->flags & INET_FRAG_COMPLETE));

	reason = (q->flags & INET_FRAG_DROP) ?

			SKB_DROP_REASON_FRAG_REASM_TIMEOUT :

			SKB_CONSUMED;

	WARN_ON(del_timer(&q->timer) != 0);



	/* Release all fragment data. */

	fqdir = q->fqdir;

	f = fqdir->f;

	sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments);

	sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments, reason);

	sum = sum_truesize + f->qsize;



	call_rcu(&q->rcu, inet_frag_destroy_rcu);

net/ipv4/ip_fragment.c

+4 −2
Original line number Diff line number Diff line
@@ -153,6 +153,7 @@ static void ip_expire(struct timer_list *t) 
	if (qp->q.flags & INET_FRAG_COMPLETE)

		goto out;



	qp->q.flags |= INET_FRAG_DROP;

	ipq_kill(qp);

	__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);

	__IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
@@ -194,7 +195,7 @@ static void ip_expire(struct timer_list *t) 
	spin_unlock(&qp->q.lock);

out_rcu_unlock:

	rcu_read_unlock();

	kfree_skb(head);

	kfree_skb_reason(head, SKB_DROP_REASON_FRAG_REASM_TIMEOUT);

	ipq_put(qp);

}
@@ -254,7 +255,8 @@ static int ip_frag_reinit(struct ipq *qp) 
		return -ETIMEDOUT;

	}



	sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments);

	sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments,

					      SKB_DROP_REASON_NOT_SPECIFIED);

	sub_frag_mem_limit(qp->q.fqdir, sum_truesize);



	qp->q.flags = 0;