When host ping its peer, ICMP echo request packet triggers IPsec policy, then host negotiates SA secret with its peer. After IKE installed SA for OUT direction, but before SA for IN direction installed, host get ICMP echo reply from its peer. At the time being, the SA state for IN direction could be XFRM_STATE_ACQ, then the received packet will be dropped after adding LINUX_MIB_XFRMINSTATEINVALID statistic. Adding a LINUX_MIB_XFRMACQUIREERROR statistic counter for such scenario when SA in larval state is much clearer for user than LINUX_MIB_XFRMINSTATEINVALID which indicates the SA is totally bad.
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| @@ -287,6 +287,7 @@ enum · 286 unmodified lines | ||
| 287 | 287 | LINUX_MIB_XFRMOUTPOLERROR, /* XfrmOutPolError */ |
| 288 | 288 | LINUX_MIB_XFRMFWDHDRERROR, /* XfrmFwdHdrError*/ |
| 289 | 289 | LINUX_MIB_XFRMOUTSTATEINVALID, /* XfrmOutStateInvalid */ |
| 290 | + LINUX_MIB_XFRMACQUIREERROR, /* XfrmAcquireError */ | |
| 290 | 291 | __LINUX_MIB_XFRMMAX |
| 291 | 292 | }; |
| 292 | 293 | |