Getaddrinfo sucks. everything else is much worse

Because that's what they are; that's the representation.

Look at the classic struct sockaddr_in structure it has a member sin_addr of type struct in_addr. What is that?

In my header files here I have it as:

  typedef uint32_t in_addr_t;
  struct in_addr
  {
    in_addr_t s_addr;
  };

The C structure has an integer, so the Lisp analog does also.

C socket code does things like

  addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);

INADDR_LOOPBACK is 127.0.0.1 encoded as an integer.

It's easy to to do bitwise arithmetic on it. E.g. to apply a netmask like 255.0.0.0, you literally just form the netmask as 0xFF000000, and use your & operator: addr & 0xFF00000000.

In the case of IPv6, there is a union: a view of the address as 16 bytes, 8 words, or 4 double words.

Since I have bignum integers, I just made it a simple integer, so it looks like the IPv4 case. You can do bitwise arithmetic on it in a straightforward.

We can get the addresses in text format like this:

  1> (getaddrinfo "news.ycombinator.com")
  (#S(sockaddr-in canonname nil addr 3520653007 port 0 prefix 32)
   #S(sockaddr-in canonname nil addr 3520653007 port 0 prefix 32)
   #S(sockaddr-in6 canonname nil addr 50544109533264435600708011529282256934 port 0
                   flow-info 0 scope-id 0 prefix 128)
   #S(sockaddr-in6 canonname nil addr 50544109533264435600708011529282256934 port 0
                   flow-info 0 scope-id 0 prefix 128))
  2> (first *1)
  #S(sockaddr-in canonname nil addr 3520653007 port 0 prefix 32)
  3> (third *1)
  #S(sockaddr-in6 canonname nil addr 50544109533264435600708011529282256934 port 0
                  flow-info 0 scope-id 0 prefix 128)
  4> (str-inaddr *2.addr)
  "209.216.230.207"
  5> (str-in6addr *3.addr)
  "2606:7100:1:67::26"

str-inaddr and str-in6addr* take an integer and return a string.

Their rough opposites return a structure, because the general text format can encode prefix and port number info.

  6> (inaddr-str *4)
  #S(sockaddr-in canonname nil addr 3520653007 port 0 prefix 32)
  7> (in6addr-str *5)
  #S(sockaddr-in6 canonname nil addr 50544109533264435600708011529282256934 port 0
                  flow-info 0 scope-id 0 prefix 128)

The structures also support a generic method str-addr:

  8> (mapcar .(str-addr) (getaddrinfo "news.ycombinator.com"))
  ("209.216.230.207" "209.216.230.207" "2606:7100:1:67::26" "2606:7100:1:67::26")

This will take into account prefix and port number if they are present and nonzero.

We could define a custom print method in the sockaddr base:

  9> (defmeth sockaddr print (self stream pretty-p)
       (put-string `#<@(typeof self) @{self.(str-addr)}>` stream))
  (meth sockaddr
    print)
  10> (getaddrinfo "news.ycombinator.com")
  (#<sockaddr-in 209.216.230.207> #<sockaddr-in 209.216.230.207>
   #<sockaddr-in6 2606:7100:1:67::26> #<sockaddr-in6 2606:7100:1:67::26>)