dhcpcd: Add support for arp persist defence #273
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rsmarples
reviewed
Dec 21, 2023
src/arp.c
Outdated
| logwarnx("%s: %d second defence failed for %s", | ||
| ifp->name, DEFEND_INTERVAL, inet_ntoa(astate->addr)); | ||
| eloop_timespec_diff(&now, &astate->defend, NULL) < | ||
| DEFEND_INTERVAL) { |
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Newline before the opening curly brace please
src/arp.c
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| DEFEND_INTERVAL) { | ||
| if ((ifp->options->options & | ||
| DHCPCD_ARP_PERSISTDEFENCE) == | ||
| DHCPCD_ARP_PERSISTDEFENCE) { |
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No need for == here - (a & b) will produce a truthy value.
Also, new line before the opening curly brace.
src/arp.c
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| if ((ifp->options->options & | ||
| DHCPCD_ARP_PERSISTDEFENCE) == | ||
| DHCPCD_ARP_PERSISTDEFENCE) { | ||
| logerrx("%s: %d second defence ignored as " \ |
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Scrap this diagnostic.
Just keep the existing diagnostic and early return if DHCPCD_ARP_PERSISTDEFENCE.
We can tell if it's set or not as the address will be kept or dropped.
rsmarples
reviewed
Dec 21, 2023
src/dhcpcd.conf.5.in
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| @@ -510,6 +510,8 @@ adding a new IPv4 address. | |||
| .It Ic noarp | |||
| Don't send any ARP requests. | |||
| This also disables IPv4LL. | |||
| .It Ic arp_persistdefence | |||
| Keep the IP address even if defense fails upon IP Address conflict. | |||
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British spelling of defence please :)
rsmarples
requested changes
Dec 21, 2023
|
Oh yeah, add |
RFC 5227 recommends 3 ways to deal with address conflict detection. a) Stop everything. b) Defend and then stop on fail - this is what dhcpcd currently does. c) Notify and carry on. The current change implements the option c. A new option arp_persistdefence has been added and when this is enabled, the a defence is attempted upon a conflict and when that fails, an error is logged on every other conflict within the DEFEND_INTERVAL and the current IP address is retained. Fixes #272
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Thanks for the patch! |
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RFC 5227 recommends 3 ways to deal with address conflict detection.
a) Stop everything.
b) Defend and then stop on fail - this is what dhcpcd currently does.
c) Notify and carry on.
The current change implements the option c. A new option arp_persistdefence has been added and when this is enabled, the a defence is attempted upon a conflict and when that fails, an error is logged on every other conflict within the DEFEND_INTERVAL and the current IP address is retained.