net: dropreason: add SKB_DROP_REASON_DUP_FRAG

This is used to track when a duplicate segment received by various
reassembly units is dropped.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2022-10-29 15:45:18 +00:00 committed by Jakub Kicinski
parent 511a3eda2f
commit 4ecbb1c27c
4 changed files with 22 additions and 9 deletions

View File

@ -68,6 +68,7 @@
FN(IP_INADDRERRORS) \
FN(IP_INNOROUTES) \
FN(PKT_TOO_BIG) \
FN(DUP_FRAG) \
FNe(MAX)
/**
@ -300,6 +301,8 @@ enum skb_drop_reason {
* MTU)
*/
SKB_DROP_REASON_PKT_TOO_BIG,
/** @SKB_DROP_REASON_DUP_FRAG: duplicate fragment */
SKB_DROP_REASON_DUP_FRAG,
/**
* @SKB_DROP_REASON_MAX: the maximum of drop reason, which shouldn't be
* used as a real 'reason'

View File

@ -278,10 +278,14 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
struct net_device *dev;
unsigned int fragsize;
int err = -ENOENT;
SKB_DR(reason);
u8 ecn;
if (qp->q.flags & INET_FRAG_COMPLETE)
/* If reassembly is already done, @skb must be a duplicate frag. */
if (qp->q.flags & INET_FRAG_COMPLETE) {
SKB_DR_SET(reason, DUP_FRAG);
goto err;
}
if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
unlikely(ip_frag_too_far(qp)) &&
@ -382,8 +386,9 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
insert_error:
if (err == IPFRAG_DUP) {
kfree_skb(skb);
return -EINVAL;
SKB_DR_SET(reason, DUP_FRAG);
err = -EINVAL;
goto err;
}
err = -EINVAL;
__IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
@ -391,7 +396,7 @@ discard_qp:
inet_frag_kill(&qp->q);
__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
err:
kfree_skb(skb);
kfree_skb_reason(skb, reason);
return err;
}

View File

@ -253,7 +253,7 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
if (err) {
if (err == IPFRAG_DUP) {
/* No error for duplicates, pretend they got queued. */
kfree_skb(skb);
kfree_skb_reason(skb, SKB_DROP_REASON_DUP_FRAG);
return -EINPROGRESS;
}
goto insert_error;

View File

@ -112,10 +112,14 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
struct sk_buff *prev_tail;
struct net_device *dev;
int err = -ENOENT;
SKB_DR(reason);
u8 ecn;
if (fq->q.flags & INET_FRAG_COMPLETE)
/* If reassembly is already done, @skb must be a duplicate frag. */
if (fq->q.flags & INET_FRAG_COMPLETE) {
SKB_DR_SET(reason, DUP_FRAG);
goto err;
}
err = -EINVAL;
offset = ntohs(fhdr->frag_off) & ~0x7;
@ -226,8 +230,9 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
insert_error:
if (err == IPFRAG_DUP) {
kfree_skb(skb);
return -EINVAL;
SKB_DR_SET(reason, DUP_FRAG);
err = -EINVAL;
goto err;
}
err = -EINVAL;
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
@ -237,7 +242,7 @@ discard_fq:
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_REASMFAILS);
err:
kfree_skb(skb);
kfree_skb_reason(skb, reason);
return err;
}