Extended IP address parsing for net.rs

net.rs

/*
Module: net
*/

import core::{vec, uint, str};

/* Section: Types */

/*
Tag: ip_addr

An IP address
*/
tag ip_addr {
    /*
    Variant: ipv4

    An IPv4 address
    */
    ipv4(u8, u8, u8, u8);
    
    /*
    Variant: ipv6
    
    An IPv6 address
    */
    ipv6(u16, u16, u16, u16, u16, u16, u16, u16);
}

/* Section: Operations */

/*
Function: format_addr

Convert an <ip_addr> to a str
*/
fn format_addr(ip: ip_addr) -> str {
    alt ip {
      ipv4(a, b, c, d) {
        #fmt["%u.%u.%u.%u", a as uint, b as uint, c as uint, d as uint]
      }
      ipv6(a, b, c, d, e, f, g, h) {
        #fmt["%s:%s:%s:%s:%s:%s:%s:%s",
            core::uint::to_str(a as uint, 16u),
            core::uint::to_str(b as uint, 16u),
            core::uint::to_str(c as uint, 16u),
            core::uint::to_str(d as uint, 16u),
            core::uint::to_str(e as uint, 16u),
            core::uint::to_str(f as uint, 16u),
            core::uint::to_str(g as uint, 16u),
            core::uint::to_str(h as uint, 16u)
        ]
      }
      _ { fail "Unsupported address type"; }
    }
}

/*
Function: parse_addr

Convert a str to <ip_addr>

Converts a string of the format "x.x.x.x" or "x:x:x:x:x:x:x:x" into an ip_addr tag.

Failure:

String must be a valid IPv4 or IPv6 address
*/
fn parse_addr(ip: str) -> ip_addr {
    if str::is_empty(ip) { fail "Invalid IP address"; }
    if str::index(ip, ":"[0]) != -1 {
       let parts_str = str::split(ip, ":"[0]);
       let parts = vec::to_mut([0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u]);
       let i = 0u;
       let found_sub = false;
       let parts_str_len = vec::len(parts_str);
       if parts_str_len > 8u { fail "Too many colons in IP address"; }
       
       for part in parts_str {
           if str::char_len(part) > 4u { fail "Invalid IP address part"; }
           if str::is_empty(part) {
                   if !found_sub {
                       found_sub = true;
                       let j = 0u;
                       let amount = 8u - parts_str_len + 1u;
                       if i < parts_str_len - 1u && str::is_empty(parts_str[i + 1u]) { amount += 1u; }
                       while j < amount {
                           parts[i + j] = 0u;
                           j += 1u;
                       }
                       i = i + amount;
                   }
                   cont;
           }
           else { parts[i] = uint::parse_buf(str::bytes(part), 16u);}
           if parts[i] > 65535u { fail "Invalid IP address part"; }
           i += 1u;
       }
        
       ret ipv6(
           parts[0] as u16,
           parts[1] as u16,
           parts[2] as u16,
           parts[3] as u16,
           parts[4] as u16,
           parts[5] as u16,
           parts[6] as u16,
           parts[7] as u16
       );
    }
    
    let parts = vec::map(str::split(ip, "."[0]), {|s| uint::from_str(s) });
    if vec::len(parts) != 4u { fail "Too many dots in IP address"; }
    for i in parts { if i > 255u { fail "Invalid IP address part"; } }
    ipv4(parts[0] as u8, parts[1] as u8, parts[2] as u8, parts[3] as u8)
}