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| author | Yan Zhai <yan@cloudflare.com> | 2023-12-04 11:33:28 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-12-05 20:49:40 -0800 |
| commit | 2f57dd94bdef083855366138646b26b05f410d99 (patch) | |
| tree | fe70ed53771fe6e27cc88289f414c6598a6e62cd /net/packet | |
| parent | 19b707c3f23a7923ab40732521123d9b59965cc4 (diff) | |
| download | linux-2f57dd94bdef083855366138646b26b05f410d99.tar.gz linux-2f57dd94bdef083855366138646b26b05f410d99.tar.bz2 linux-2f57dd94bdef083855366138646b26b05f410d99.zip | |
packet: add a generic drop reason for receive
Commit da37845fdce2 ("packet: uses kfree_skb() for errors.") switches
from consume_skb to kfree_skb to improve error handling. However, this
could bring a lot of noises when we monitor real packet drops in
kfree_skb[1], because in tpacket_rcv or packet_rcv only packet clones
can be freed, not actual packets.
Adding a generic drop reason to allow distinguish these "clone drops".
[1]: https://lore.kernel.org/netdev/CABWYdi00L+O30Q=Zah28QwZ_5RU-xcxLFUK2Zj08A8MrLk9jzg@mail.gmail.com/
Fixes: da37845fdce2 ("packet: uses kfree_skb() for errors.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/ZW4piNbx3IenYnuw@debian.debian
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index a84e00b5904b..f92edba4c40f 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2121,13 +2121,13 @@ static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { + enum skb_drop_reason drop_reason = SKB_CONSUMED; struct sock *sk; struct sockaddr_ll *sll; struct packet_sock *po; u8 *skb_head = skb->data; int skb_len = skb->len; unsigned int snaplen, res; - bool is_drop_n_account = false; if (skb->pkt_type == PACKET_LOOPBACK) goto drop; @@ -2217,9 +2217,9 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, return 0; drop_n_acct: - is_drop_n_account = true; atomic_inc(&po->tp_drops); atomic_inc(&sk->sk_drops); + drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; drop_n_restore: if (skb_head != skb->data && skb_shared(skb)) { @@ -2227,16 +2227,14 @@ drop_n_restore: skb->len = skb_len; } drop: - if (!is_drop_n_account) - consume_skb(skb); - else - kfree_skb(skb); + kfree_skb_reason(skb, drop_reason); return 0; } static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { + enum skb_drop_reason drop_reason = SKB_CONSUMED; struct sock *sk; struct packet_sock *po; struct sockaddr_ll *sll; @@ -2250,7 +2248,6 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct sk_buff *copy_skb = NULL; struct timespec64 ts; __u32 ts_status; - bool is_drop_n_account = false; unsigned int slot_id = 0; int vnet_hdr_sz = 0; @@ -2498,19 +2495,16 @@ drop_n_restore: skb->len = skb_len; } drop: - if (!is_drop_n_account) - consume_skb(skb); - else - kfree_skb(skb); + kfree_skb_reason(skb, drop_reason); return 0; drop_n_account: spin_unlock(&sk->sk_receive_queue.lock); atomic_inc(&po->tp_drops); - is_drop_n_account = true; + drop_reason = SKB_DROP_REASON_PACKET_SOCK_ERROR; sk->sk_data_ready(sk); - kfree_skb(copy_skb); + kfree_skb_reason(copy_skb, drop_reason); goto drop_n_restore; } |