On 11/6/25 12:56 PM, Paolo Abeni wrote:

On 10/30/25 3:34 PM, chia-yu.chang@nokia-bell-labs.com wrote:

quoted

From: Chia-Yu Chang <redacted>

Before this patch, num_retrans = 0 for the first SYN/ACK and the first
retransmitted SYN/ACK; however, an upcoming change will need to
differentiate between those two conditions. 

AFAICS, send_synack is invoked with a NULL dst only on retransmissions.
Perhaps you could use that info instead? moving forward and backward a
counter is not so nice.

... except you need to propagate the information to nested call.
Possibly adding a TCP_SYNACK_RETRANS synack_type would fit?

/P