Function resolve [src]
Prototype
pub fn resolve(buf: []const u8, port: u16) IPv6ResolveError!Ip6Address Parameters
buf: []const u8port: u16 Possible Errors
Permission to create a socket of the specified type and/or pro‐tocol is denied.
The implementation does not support the specified address family.
The per-process limit on the number of open file descriptors has been reached.
Unknown protocol, or protocol family not available.
The protocol type or the specified protocol is not supported within this domain.
The socket type is not supported by the protocol.
The system-wide limit on the total number of open files has been reached.
Insufficient memory is available. The socket cannot be created until sufficient resources are freed.
The Operating System returned an undocumented error code.
This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.
When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.
Source
pub fn resolve(buf: []const u8, port: u16) IPv6ResolveError!Ip6Address {
// TODO: Unify the implementations of resolveIp6 and parseIp6.
var result = Ip6Address{
.sa = posix.sockaddr.in6{
.scope_id = 0,
.port = mem.nativeToBig(u16, port),
.flowinfo = 0,
.addr = undefined,
},
};
var ip_slice: *[16]u8 = result.sa.addr[0..];
var tail: [16]u8 = undefined;
var x: u16 = 0;
var saw_any_digits = false;
var index: u8 = 0;
var abbrv = false;
var scope_id = false;
var scope_id_value: [posix.IFNAMESIZE - 1]u8 = undefined;
var scope_id_index: usize = 0;
for (buf, 0..) |c, i| {
if (scope_id) {
// Handling of percent-encoding should be for an URI library.
if ((c >= '0' and c <= '9') or
(c >= 'A' and c <= 'Z') or
(c >= 'a' and c <= 'z') or
(c == '-') or (c == '.') or (c == '_') or (c == '~'))
{
if (scope_id_index >= scope_id_value.len) {
return error.Overflow;
}
scope_id_value[scope_id_index] = c;
scope_id_index += 1;
} else {
return error.InvalidCharacter;
}
} else if (c == ':') {
if (!saw_any_digits) {
if (abbrv) return error.InvalidCharacter; // ':::'
if (i != 0) abbrv = true;
@memset(ip_slice[index..], 0);
ip_slice = tail[0..];
index = 0;
continue;
}
if (index == 14) {
return error.InvalidEnd;
}
ip_slice[index] = @as(u8, @truncate(x >> 8));
index += 1;
ip_slice[index] = @as(u8, @truncate(x));
index += 1;
x = 0;
saw_any_digits = false;
} else if (c == '%') {
if (!saw_any_digits) {
return error.InvalidCharacter;
}
scope_id = true;
saw_any_digits = false;
} else if (c == '.') {
if (!abbrv or ip_slice[0] != 0xff or ip_slice[1] != 0xff) {
// must start with '::ffff:'
return error.InvalidIpv4Mapping;
}
const start_index = mem.lastIndexOfScalar(u8, buf[0..i], ':').? + 1;
const addr = (Ip4Address.parse(buf[start_index..], 0) catch {
return error.InvalidIpv4Mapping;
}).sa.addr;
ip_slice = result.sa.addr[0..];
ip_slice[10] = 0xff;
ip_slice[11] = 0xff;
const ptr = mem.sliceAsBytes(@as(*const [1]u32, &addr)[0..]);
ip_slice[12] = ptr[0];
ip_slice[13] = ptr[1];
ip_slice[14] = ptr[2];
ip_slice[15] = ptr[3];
return result;
} else {
const digit = try std.fmt.charToDigit(c, 16);
{
const ov = @mulWithOverflow(x, 16);
if (ov[1] != 0) return error.Overflow;
x = ov[0];
}
{
const ov = @addWithOverflow(x, digit);
if (ov[1] != 0) return error.Overflow;
x = ov[0];
}
saw_any_digits = true;
}
}
if (!saw_any_digits and !abbrv) {
return error.Incomplete;
}
if (scope_id and scope_id_index == 0) {
return error.Incomplete;
}
var resolved_scope_id: u32 = 0;
if (scope_id_index > 0) {
const scope_id_str = scope_id_value[0..scope_id_index];
resolved_scope_id = std.fmt.parseInt(u32, scope_id_str, 10) catch |err| blk: {
if (err != error.InvalidCharacter) return err;
break :blk try if_nametoindex(scope_id_str);
};
}
result.sa.scope_id = resolved_scope_id;
if (index == 14) {
ip_slice[14] = @as(u8, @truncate(x >> 8));
ip_slice[15] = @as(u8, @truncate(x));
return result;
} else {
ip_slice[index] = @as(u8, @truncate(x >> 8));
index += 1;
ip_slice[index] = @as(u8, @truncate(x));
index += 1;
@memcpy(result.sa.addr[16 - index ..][0..index], ip_slice[0..index]);
return result;
}
}