ndhc v2024-05-24

Stable snapshot of ndhc as of 2024-05-24.

Notable changes since the previous snapshot include:

• Fix renew requests for networks where the DHCP server is on a different subnet.
• Speed up fingerprinting when DHCP agent is on a different subnet.
• Don't try to fingerprint networks with no gateway or ARP-reachable DHCP agent.
• Build with LTO and -Os by default; yields smaller binary size.

ndhc v2024-02-09

Stable snapshot of ndhc as of 2024-02-09.

Notable changes since the previous snapshot include:

• RFC conformance fix: a DHCP server may originate UDP messages on any port.
• Small binary size reductions.
• Guard against clobbering valid leasefiles if no lease is retrieved.

ndhc v2022-12-01

Stable snapshot of ndhc as of 2022-12-01.

Notable changes since the previous snapshot include:

• Improve xid handling.
• scriptd notifies s6 on script completion.
• Randomness improvements.
• Minor bugfixes and robustness improvements.

ndhc v2022-03-08

Stable snapshot of ndhc as of 2022-03-08.

Notable changes since the previous snapshot include:

• Support for running a script/executable file when the lease state is updated.
• Reduced CPU usage by caching network carrier state and optimized internet checksum calculations.
• Support the startup notification protocol added in recent versions of s6. Readiness is signalled when a lease is acquired.
• Relicense as MIT rather than BSD-2.
• Minor bugfixes and robustness improvements.

For packagers or those that build from source, please note that you no longer need to build anything with Ragel as the Ragel-generated files are prebuilt in the repository. Additionally, GNU Make is now used as the sole buildsystem. It should be possible to simply build ndhc within the repository directory with make.

ndhc v2020-10-20

Stable snapshot of ndhc as of 2020-10-20.

Notable changes since the previous snapshot include:

• Correct a longstanding bug where certain fatal errors in privsep children may not cause the master process to abort in all cases (see 8d89ca9 for full details).
• Don't require ncmlib to be separately installed to the source directory.
• Remove legacy background feature.
• Remove legacy pidfile feature.
• Remove legacy quit feature.
• Update the plain Makefile so that it no longer tries to link against -rt.
• Use poll() instead of epoll().
• Use POSIX signal handling rather than signalfd().

For packagers or those that build from source, please note that you no longer need to fetch ncmlib. All the necessary files to build ndhc are now contained in this repo.

I have removed some features that are unnecessary or incompatible when ndhc is run under a process supervisor (such as runit or s6). Running without process supervision has been something I have not supported for years, as ndhc relies upon being restarted on hard failure for reliable operation.

ndhc v2020-10-19

Stable snapshot of ndhc as of 2020-10-19.

Notable changes since the previous snapshot include:

• Quickly switch to using broadcast (REBIND) if server seems to ignore unicast (RENEW).
• Detect when network fingerprinting via ARP fails and give up.
• Correct old regression that prevented SIGUSR signals from working.
• Minor RFC conformance changes not motivated by any known problems.

ndhc v2018-02-18

Stable snapshot of ndhc as of 2018-02-18.

Notable changes since the previous snapshot include:

• Remove seccomp support. Whitelisting syscalls is too brittle and too much work to maintain.
• Faster recovery from carrier loss events during initial network fingerprinting.
• Compile cleanly with stricter signed/unsigned conversion checks.

ndhc v2017-02-24

Stable snapshot of ndhc as of 2017-02-24.

Notable changes since the previous snapshot include:

• More correct carrier detection that should tolerate changes to carrier state during system suspend.
• Better tolerate disruptions to link state during initial ARP fingerprint and collision checking.

ndhc v2016-05-06

Stable snapshot of ndhc as of 2016-05-06.