From 4ecbb1c27c363686d11a241cd682a454a8454c2b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 29 Oct 2022 15:45:18 +0000 Subject: 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 Signed-off-by: Jakub Kicinski --- include/net/dropreason.h | 3 +++ net/ipv4/ip_fragment.c | 13 +++++++++---- net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +- net/ipv6/reassembly.c | 13 +++++++++---- 4 files changed, 22 insertions(+), 9 deletions(-) diff --git a/include/net/dropreason.h b/include/net/dropreason.h index 0bd18c14dae0..602d555a5f83 100644 --- a/include/net/dropreason.h +++ b/include/net/dropreason.h @@ -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' diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index fb153569889e..676bd8d25955 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -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; } diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 38db0064d661..d13240f13607 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -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; diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index ff866f2a879e..5bc8a28e67f9 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -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; } -- cgit v1.2.3