diff options
| author | Dongli Zhang <dongli.zhang@oracle.com> | 2022-03-04 17:55:07 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-03-06 14:04:01 +0300 |
| commit | 4b4f052e2d89c2eb7e13ee28ba9e85f8097aef3d (patch) | |
| tree | 55ae97b17bc598e205cf4908021040685f8a4a7b /include | |
| parent | 45a15d89fbcd280571eba8e5ca309e14ba6afa8f (diff) | |
| download | linux-4b4f052e2d89c2eb7e13ee28ba9e85f8097aef3d.tar.xz | |
net: tun: track dropped skb via kfree_skb_reason()
The TUN can be used as vhost-net backend. E.g, the tun_net_xmit() is the
interface to forward the skb from TUN to vhost-net/virtio-net.
However, there are many "goto drop" in the TUN driver. Therefore, the
kfree_skb_reason() is involved at each "goto drop" to help userspace
ftrace/ebpf to track the reason for the loss of packets.
The below reasons are introduced:
- SKB_DROP_REASON_DEV_READY
- SKB_DROP_REASON_NOMEM
- SKB_DROP_REASON_HDR_TRUNC
- SKB_DROP_REASON_TAP_FILTER
- SKB_DROP_REASON_TAP_TXFILTER
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/skbuff.h | 18 | ||||
| -rw-r--r-- | include/trace/events/skb.h | 5 |
2 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 67cfff4065b6..34f572271c0c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -424,7 +424,25 @@ enum skb_drop_reason { SKB_DROP_REASON_DEV_HDR, /* device driver specific * header/metadata is invalid */ + /* the device is not ready to xmit/recv due to any of its data + * structure that is not up/ready/initialized, e.g., the IFF_UP is + * not set, or driver specific tun->tfiles[txq] is not initialized + */ + SKB_DROP_REASON_DEV_READY, SKB_DROP_REASON_FULL_RING, /* ring buffer is full */ + SKB_DROP_REASON_NOMEM, /* error due to OOM */ + SKB_DROP_REASON_HDR_TRUNC, /* failed to trunc/extract the header + * from networking data, e.g., failed + * to pull the protocol header from + * frags via pskb_may_pull() + */ + SKB_DROP_REASON_TAP_FILTER, /* dropped by (ebpf) filter directly + * attached to tun/tap, e.g., via + * TUNSETFILTEREBPF + */ + SKB_DROP_REASON_TAP_TXFILTER, /* dropped by tx filter implemented + * at tun/tap, e.g., check_filter() + */ SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 240e7e7591fc..e1670e1e4934 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -55,7 +55,12 @@ EM(SKB_DROP_REASON_SKB_GSO_SEG, SKB_GSO_SEG) \ EM(SKB_DROP_REASON_SKB_UCOPY_FAULT, SKB_UCOPY_FAULT) \ EM(SKB_DROP_REASON_DEV_HDR, DEV_HDR) \ + EM(SKB_DROP_REASON_DEV_READY, DEV_READY) \ EM(SKB_DROP_REASON_FULL_RING, FULL_RING) \ + EM(SKB_DROP_REASON_NOMEM, NOMEM) \ + EM(SKB_DROP_REASON_HDR_TRUNC, HDR_TRUNC) \ + EM(SKB_DROP_REASON_TAP_FILTER, TAP_FILTER) \ + EM(SKB_DROP_REASON_TAP_TXFILTER, TAP_TXFILTER) \ EMe(SKB_DROP_REASON_MAX, MAX) #undef EM |