In this series, we add skb drop reasons support to VXLAN, and following
new skb drop reasons are introduced:

  SKB_DROP_REASON_VXLAN_INVALID_HDR
  SKB_DROP_REASON_VXLAN_VNI_NOT_FOUND
  SKB_DROP_REASON_VXLAN_INVALID_SMAC
  SKB_DROP_REASON_VXLAN_ENTRY_EXISTS
  SKB_DROP_REASON_VXLAN_NO_REMOTE
  SKB_DROP_REASON_IP_TUNNEL_ECN
  SKB_DROP_REASON_TUNNEL_TXINFO
  SKB_DROP_REASON_LOCAL_MAC

We add some helper functions in this series, who will capture the drop
reasons from pskb_may_pull_reason and return them:

  pskb_network_may_pull_reason()
  pskb_inet_may_pull_reason()
  skb_vlan_inet_prepare_reason()

And we also make the following functions return skb drop reasons:

  vxlan_remcsum()
  vxlan_snoop()
  vxlan_set_mac()

Changes since v2:
- move all the drop reasons of VXLAN to the "core", instead of introducing
  the VXLAN drop reason subsystem
- add the 6th patch, which capture the drop reasons from vxlan_snoop()
- move the commits for vxlan_remcsum() and vxlan_set_mac() after
  vxlan_rcv() to update the call of them accordingly
- fix some format problems

Changes since v1:
- document all the drop reasons that we introduce
- rename the drop reasons to make them more descriptive, as Ido advised
- remove the 2nd patch, which introduce the SKB_DR_RESET
- add the 4th patch, which adds skb_vlan_inet_prepare_reason() helper
- introduce the 6th patch, which make vxlan_set_mac return drop reasons
- introduce the 10th patch, which uses VXLAN_DROP_NO_REMOTE as the drop
  reasons, as Ido advised

Menglong Dong (12):
  net: skb: add pskb_network_may_pull_reason() helper
  net: tunnel: add pskb_inet_may_pull_reason() helper
  net: tunnel: add skb_vlan_inet_prepare_reason() helper
  net: vxlan: add skb drop reasons to vxlan_rcv()
  net: vxlan: make vxlan_remcsum() return drop reasons
  net: vxlan: make vxlan_snoop() return drop reasons
  net: vxlan: make vxlan_set_mac() return drop reasons
  net: vxlan: use kfree_skb_reason() in vxlan_xmit()
  net: vxlan: add drop reasons support to vxlan_xmit_one()
  net: vxlan: use kfree_skb_reason() in vxlan_mdb_xmit()
  net: vxlan: use kfree_skb_reason() in vxlan_encap_bypass()
  net: vxlan: use kfree_skb_reason() in encap_bypass_if_local()

 drivers/net/vxlan/vxlan_core.c | 111 +++++++++++++++++++++------------
 drivers/net/vxlan/vxlan_mdb.c  |   2 +-
 include/linux/skbuff.h         |   8 ++-
 include/net/dropreason-core.h  |  37 +++++++++++
 include/net/ip_tunnels.h       |  32 +++++++---
 5 files changed, 140 insertions(+), 50 deletions(-)

-- 
2.39.2