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authorGravatar Dongli Zhang <dongli.zhang@oracle.com> 2022-03-04 06:55:07 -0800
committerGravatar David S. Miller <davem@davemloft.net> 2022-03-06 11:04:01 +0000
commit4b4f052e2d89c2eb7e13ee28ba9e85f8097aef3d (patch)
tree55ae97b17bc598e205cf4908021040685f8a4a7b /include/linux/skbuff.h
parentnet: tun: split run_ebpf_filter() and pskb_trim() into different "if statement" (diff)
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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/linux/skbuff.h')
-rw-r--r--include/linux/skbuff.h18
1 files changed, 18 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,
};