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Maniphest T1439

DHCPv6 static-mappings not working due to excess quotes around dhcp6.client-id
Closed, ResolvedPublicBUG
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Description

vyos generates host-identifier option with excess quotes, causing the static host declarations to not work, clients get addresses from the dynamic pool instead. isc-dhcpd shows no error.

Vyos-generated non-working /etc/dhcp/dhcpd6.conf snippet (values are examples - tx is time, mx is MAC in type 1 DUID):

host FOO-6pool_foohost {
    host-identifier option dhcp6.client-id "00:01:00:01:t1:t2:t3:t4:m1:m2:m3:m4:m5:m6";
    fixed-address6 2001:db8::123;
}

Tested working:

host FOO-6pool_foohost {
    host-identifier option dhcp6.client-id 00:01:00:01:t1:t2:t3:t4:m1:m2:m3:m4:m5:m6;
    fixed-address6 2001:db8::123;
}

Details

Version
1.2.0-rolling+201905261657
Is it a breaking change?
Unspecified (possibly destroys the router)

Related Objects

Event Timeline

jjakob created this task.Jun 16 2019, 12:56 PM
pasik subscribed.Jun 16 2019, 1:18 PM
jjakob claimed this task.Jun 16 2019, 2:23 PM
jjakob added a comment.Jun 16 2019, 2:48 PM

ISC-dhcp can parse this option either as a quoted string or colon-separated hex list. common/tables.c

On input, the option can be specified either as a quoted string or as a colon-separated hex list.

In my (limited) experience, the hex list is much more commonly used as most DUIDs contain unprintable data. It's also easier to look up on the client as most distros use hex-list notation as default (Windows uses a hyphen-separated hex list, which is easy to convert to colon-separated)
Nonetheless, there are two options:

  1. we require the use of colon-separated hex lists (easier to implement and add a validator)
  2. we support both hex lists and strings and add a vaildator to validate both.

Option 1 is preferred IMO as it lessens the confusion and possible mistakes by users as they can't mistakenly enter a hex-list as a quoted string and not knowing why it doesn't work.

In addition to removing the quotes from the output I'd clarify the configuration help messages and add a validator.

jjakob changed the task status from Open to In progress.Jun 16 2019, 5:29 PM

https://github.com/vyos/vyos-1x/pull/71

jjakob triaged this task as High priority.Jun 16 2019, 5:34 PM

Change priority to high as the bug makes DHCPv6 static mappings inoperable.

jjakob added a comment.Jun 16 2019, 7:22 PM

Closed PR and reopened in https://github.com/vyos/vyos-1x/pull/72 due to creating a new branch

c-po mentioned this in rVYOSONEXb04a9791226f: T1439: remove quotes around dhcp6.client-id.Jun 16 2019, 8:55 PM
c-po mentioned this in rVYOSONEX6a6634b02d73: T1439: move DUID validator to regex.
c-po mentioned this in rVYOSONEX87df87e3983e: T1439: add dhcpv6-client-id validator.
c-po mentioned this in rVYOSONEX03c09b1b0d7d: T1439: remove beginning and end anchors, they are implied with re.fullmatch.
jjakob added a comment.Jun 23 2019, 11:52 PM

Tested working on 1.2.0-rolling+201906210337

jjakob added a subscriber: c-po.Jun 23 2019, 11:55 PM
jjakob closed this task as Unknown Status.Jun 24 2019, 6:23 PM
jjakob added a project: VyOS 1.3 Equuleus.
jjakob moved this task from Need Triage to Finished on the VyOS 1.3 Equuleus board.
jjakob added a comment.Jun 26 2019, 12:31 PM

Since this changed dhcp6.client-id to only accept colon-separated hex lists, configs that still have the strings will fail to apply, leading to nonworking configs.
Should we bump the dhcp-server vyatta-config-version and write a migration script?
Shouldn't there be a separate dhcpv6-server/relay vyatta-config-version? Perhaps the migration script could add those.

jjakob moved this task from Finished to Need Triage on the VyOS 1.3 Equuleus board.Jun 26 2019, 12:32 PM
jjakob added a comment.Jun 28 2019, 5:51 PM

Putting the migration script on hold until I can get sample configs for "service dhcp6-server static-mapping identifier ..." and related host entries in /etc/dhcp/dhcpdv6.conf from an old vyos version with the old vyatta-cfg-dhcp-server scripts.
In particular if it was possible to set quoted strings as identifier which would be set unchanged in dhcpd6.conf, this would necessitate detecting whether the identifier was a quoted string or not, and converting the string to hex. If it wasn't possible to set quoted strings the migration script is not necessary.

jjakob mentioned this in T1527: Typo in dhcpv6-server description.Jul 16 2019, 11:50 PM
syncer reassigned this task from jjakob to c-po.Aug 30 2019, 11:43 PM
syncer removed a project: VyOS 1.2 Crux.
syncer added a project: VyOS 1.2 Crux (VyOS 1.2.4).
syncer subscribed.

Please backport this

c-po mentioned this in rVYOSONEX7072bb8eb694: T1439: remove quotes around dhcp6.client-id.Sep 4 2019, 7:27 PM
c-po mentioned this in rVYOSONEX40cf05fdf294: T1439: add dhcpv6-client-id validator.
c-po mentioned this in rVYOSONEX294b14c3c8b9: T1439: move DUID validator to regex.
c-po mentioned this in rVYOSONEXc1d834cf38d6: T1439: remove beginning and end anchors, they are implied with re.fullmatch.
c-po changed the task status from Unknown Status to Resolved.Sep 4 2019, 7:27 PM
c-po moved this task from Need Triage to Finished on the VyOS 1.3 Equuleus board.
c-po moved this task from VyOS 1.2.4 to VyOS 1.2.3 on the VyOS 1.2 Crux board.
c-po edited projects, added VyOS 1.2 Crux (VyOS 1.2.3); removed VyOS 1.2 Crux (VyOS 1.2.4).
c-po moved this task from Needs Triage to Finished on the VyOS 1.2 Crux (VyOS 1.2.3) board.
c-po set Is it a breaking change? to Unspecified (possibly destroys the router).
dmbaturin removed a project: VyOS 1.3 Equuleus.Sep 10 2021, 2:22 PM