ftp: use global sequence counter to prevent stale response loops#2760
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ftp: use global sequence counter to prevent stale response loops#2760
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PX4's FTP server caches its last reply and uses seq+1 matching to detect retransmissions. When the client's seq counter reset to 0 for each new work item, PX4 would match against its cached reply and resend the old response instead of processing the new request. This caused sequential operations to time out. Move last_sent_seq_number from per-work-item to class-level so seq numbers increase monotonically. Also increment seq on retries so the client can escape stale cached replies from previous sessions.
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PX4's FTP server caches its last reply and uses seq+1 matching to detect retransmissions. When the client's seq counter reset to 0 for each new work item, PX4 would match against its cached reply and resend the old response instead of processing the new request. This caused sequential operations to time out.
Move last_sent_seq_number from per-work-item to class-level so seq numbers increase monotonically. Also increment seq on retries so the client can escape stale cached replies from previous sessions.