[kamailio/kamailio] permissions: Perform LPM to find the longest matching subnet (PR #4297)
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#### Description <!-- Describe your changes in detail -->
This PR allows the functions `allow_address_group` and `allow_source_address_group` to search for Longest Prefix Match (LPM) when searching for an IP is in a subnet instead of the first found.
Since this is a stricter check, i don't think we require an extra param for it, but feel free to suggest otherwise if there are any use-cases that required the first matched. You can view, comment on, or merge this pull request online at:
https://github.com/kamailio/kamailio/pull/4297
-- Commit Summary --
* permissions: Perform LPM to find the longest matching subnet
-- File Changes --
M src/modules/permissions/hash.c (23)
-- Patch Links --
https://github.com/kamailio/kamailio/pull/4297.patch https://github.com/kamailio/kamailio/pull/4297.diff
miconda left a comment (kamailio/kamailio#4297)
It is a stricter check, but still changing the existing behaviour, so I am not sure what would be the best. Personally I don't think that I am affected, I don't remember having need to have records of overlapping subnets, but maybe there are others that are affected, so they have to comment.
My concern comes from another perspective, whether now the behaviour is consistent with the matching a subnet record with `allow_[source_]address()`. If one has overlapping subnets in the same group, will the same record as `allow_[source_]address_group()` be matched? Even I don't have it so far, one reason I could think of right now to have overlapping subnets is to return different values from the tag column.
So whatever mode it ends up with, new parameter or not, matching should be coherent across the module functions.
@xkaraman pushed 1 commit.
94d077e84da94b3293f77d7475401282f33f464a permissions: Perform LPM to find the longest matching subnet
xkaraman left a comment (kamailio/kamailio#4297)
@miconda Thanks for the review!
Indeed, the `allow_source_address` could return a different tag value with this approach! So with the new commit a similar LPM is performed to verify whether is in that group for overlapping domains!
We confirmed that now, both functions return the same tag!
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Daniel-Constantin Mierla -
Xenofon Karamanos