frr fix use of deprecated c-ares api

The c-ares api has deprecated ares_process() and ares_gethostbyname() and it causes a build failure on Fedora 40.

This PR replaces the deprecated functions with their replacements.

Apr 25 '24 08:04 acooks-at-bda

Somewhat similar theme as #14869

I'm not sure how to make this backwards compatible with older versions of c-ares, but FRR master doesn't currently build on Fedora 40 with the deprecated functions.

Apr 25 '24 10:04 acooks-at-bda

You need to put a bit in the configure.ac file that detects c-ares versioning, see usage of AC_CHECK_LIB examples in the file. If you are not sure how to do that respond here and we can work with you.

Apr 25 '24 11:04 donaldsharp

You need to put a bit in the configure.ac file that detects c-ares versioning, see usage of AC_CHECK_LIB examples in the file. If you are not sure how to do that respond here and we can work with you.

Thanks. I saw how to add a version dependency in configure.ac. Perhaps I misunderstood your suggestion, but in this case I think both old and new versions of c-ares would need to be supported. Luckily c-ares provides a ARES_VERSION macro in ares_version.h, which is already included.

Apr 26 '24 00:04 acooks-at-bda

ci:rerun

Apr 27 '24 00:04 acooks-at-bda

@Mergifyio backport stable/10.0