add support for hyphen separated wildcard domains

[marriva]

Hello!

Please add support for wildcards separated by a hyphen as in dnsmasq.
For example, *-dev.example.org and *-prod.example.org

I need to use different upstreams for something-dev.example.org and something-prod.example.org

[codecov-commenter]

Codecov Report

Merging #246 (30823c5) into master (771d486) will increase coverage by 0.01%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master     #246      +/-   ##
==========================================
+ Coverage   70.21%   70.23%   +0.01%     
==========================================
  Files          39       39              
  Lines        2377     2392      +15     
==========================================
+ Hits         1669     1680      +11     
- Misses        509      512       +3     
- Partials      199      200       +1     

Impacted Files	Coverage Δ
proxy/upstreams.go	87.50% <75.00%> (-3.23%)	⬇️
fastip/fastest.go	78.43% <0.00%> (-1.97%)	⬇️
proxy/server_udp.go	58.57% <0.00%> (+2.85%)	⬆️

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[ameshkov]

Hi, thank you for the contribution!

Could you please also add unit-tests for that?

Sample configurations for the test:

conf := []string{
		"0.0.0.1",
		"[/a.x/]0.0.0.2",
		"[/*-b.a.x/]0.0.0.3",
		"[/b.a.x/]0.0.0.4",
		"[/*-c.b.a.x/]0.0.0.5",
		"[/c.b.a.x/]#",
	}

conf := []string{
		"0.0.0.1",
		"[/a.x/]0.0.0.2",
		"[/*.a.x/]0.0.0.3",
		"[/*-b.a.x/]0.0.0.4",
		"[/b.a.x/]0.0.0.5",
	}

"[/*-a.b.c/]0.0.0.1", 
"[/*-.b.c/]0.0.0.2", 
"[/*.b-x.c/]0.0.0.3"

[EugeneOne1]

@marriva, hello. The Dnsmasq's documentation states:

Matching of domains is normally done on complete labels, so /google.com/ matches google.com and www.google.com but NOT supergoogle.com. This can be overridden with a * at the start of a pattern only: /*google.com/ will match google.com and www.google.com AND supergoogle.com. The non-wildcard form has priority, so if /google.com/ and /*google.com/ are both specified then google.com and www.google.com will match /google.com/ and /google.com/ will only match supergoogle.com.
For historical reasons, the pattern /.google.com/ is equivalent to /google.com/ if you wish to match any subdomain of google.com but NOT google.com itself, use /.google.com/

AFAIK, it doesn't apply any special handling for domains (and patterns) with hyphens. As per the man page, Dnsmasq supports the following wildcard pattern types:

• domain.tld – matching both domain.tld and *.domain.tld (supported by dnsproxy);
• *.domain.tld – matching only subdomains of domain.tld (supported by dnsproxy);
• *domain.tld – matching domain.tld itself and any name having suffix of domain.tld.

Thus the PR seems a bit incomplete in terms of adding support for the last pattern type since it only handles the *-domain.tld case. If we'll accept this, it may be complicated to implement the rest of the logic afterwards so I believe it should be done at once.

@ameshkov, what do you think?

[Nuttapon-Makchoos]

@marriva

[Nuttapon-Makchoos]

@marriva

[Nuttapon-Makchoos]

#284