Always chose best (= maximum match) subnet for clients

[DL6ER]

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This allows to configure specific settings for a whole range of devices but still exclude others. Complain softly (no error) if multiple configured subnets match with the same number of relevant bits.

We log in case there are multiple groups defined matching equally which one FTL chose. It will deterministic chose the most matching last added one.

resulting in the following log line (only the last line is logged in non-DEBUG mode, I kept all for illustrative proposes here):

[2020-05-11 20:26:55.425 18858] SQL: Comparing 127.0.0.1 vs. 127.0.0.0/8 (subnet 255.0.0.0) - !! MATCH !!                                            
[2020-05-11 20:26:55.425 18858] SQL: Comparing 127.0.0.1 vs. 127.0.0.0/8 (subnet 255.0.0.0) - !! MATCH !!
[2020-05-11 20:26:55.425 18858] SQL: Comparing 127.0.0.1 vs. 127.0.0.1/8 (subnet 255.0.0.0) - !! MATCH !!
[2020-05-11 20:26:55.425 18858] SQL: Comparing 127.0.0.1 vs. 127.0.0.1/8 (subnet 255.0.0.0) - !! MATCH !!                                                                    
[2020-05-11 20:26:55.425 18858] SQL: Comparing 127.0.0.1 vs. 127.0.0.1/8 (subnet 255.0.0.0) - !! MATCH !!                                            
[2020-05-11 20:26:55.425 18858] SUBNET WARNING: Client 127.0.0.1 is managed by 2 groups (IDs 1,37), all describing /8 subnets. FTL chose the most recent entry 127.0.0.1/8 (ID 37) for this client.

This will also show up on the dashboard when the new Pi-hole diagnostics system has been merged:

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/subnetting-is-not-working-with-most-relevant-entry/31482/12

[dschaper]

Okay, match first, match last, match least, match greatest, what ever works for you and we use that as a project standard.

👍

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/question-regarding-multiple-group-assignments-for-same-clients/34184/3

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/please-explain-group-management/34387/8

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/pi-hole-5-1-released/35577/1