Hello,

I discovered a potential problem in getaddrinfo/__lookup_name.

When calling getaddrinfo with an IP string not matching the specified family,

name_from_numeric() in __lookup_name() will not recognize it and the

external dns resolver will be used.

So the following code:

const struct addrinfo hints = {

.ai_flags = AI_ADDRCONFIG,

.ai_family = AF_INET,

.ai_socktype = SOCK_STREAM,

};

getaddrinfo("::1", NULL, &hints, &result);

will actually succeed instead of returning EAI_NONAME,

and perform a "A ::1" query.

Some misbehaving dns servers will then answer with 0.0.0.1.

I don’t know if this behavior is desirable. If not, I’m still not sure

where this should be fixed. Maybe should we prevent sending

A and AAAA dns queries with IP as hostname in __res_mkquery() ?

—

Julien