[Dnsmasq-discuss] timing of dhcp-script for tftp downloads
simon at thekelleys.org.uk
Sat Nov 16 15:01:15 GMT 2013
On 16/11/13 14:21, Maule Mark wrote:
> When is dhcp-script called after doing a tftp download? Is that script
> invoked immediately, or is it queued operation that has an indeterminate
> delay between tftp completion and script start?
It's queued at transfer completion. There are at least two sources of delay.
1) Only one instance of the script is running at any time, so a TFTP
completion event can be queued indefinitely waiting for a previous
invocation of the script to exit.
2) "transfer completion" is defined as receipt of the ACK for the last
block, but some clients never send this: as soon as they have all the
blocks they return, and never send the last ACK; also the last ACK may
be lost. In this case, the transfer complete at the server occurs after
multiple timeouts and retransmissions, at the point at which a failed
transfer would otherwise be signalled.
> Also, is there any way to know when a tftp download starts vs.ends?
No, I don't think so.
> Dnsmasq-discuss mailing list
> Dnsmasq-discuss at lists.thekelleys.org.uk
More information about the Dnsmasq-discuss