This change adds TCP_NLA_EDT to SCM_TIMESTAMPING_OPT_STATS that reports the earliest departure time(EDT) of the timestamped skb. By tracking EDT values of the skb from different timestamps, we can observe when and how much the value changed. This allows to measure the precise delay injected on the sender host e.g. by a bpf-base throttler.
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| @@ -313,6 +313,7 @@ enum { · 312 unmodified lines | ||
| 313 | 313 | TCP_NLA_SRTT, /* smoothed RTT in usecs */ |
| 314 | 314 | TCP_NLA_TIMEOUT_REHASH, /* Timeout-triggered rehash attempts */ |
| 315 | 315 | TCP_NLA_BYTES_NOTSENT, /* Bytes in write queue not yet sent */ |
| 316 | + TCP_NLA_EDT, /* Earliest departure time (CLOCK_MONOTONIC) */ | |
| 316 | 317 | }; |
| 317 | 318 | |
| 318 | 319 | /* for TCP_MD5SIG socket option */ |