82 lines
2.1 KiB
Zig
82 lines
2.1 KiB
Zig
const std = @import("std");
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const ArgError = error{
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NotEnoughArgs,
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BadDomain,
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InvalidAddressVer,
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InterfaceRequired,
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InvalidInterface,
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EnvVarNotSet,
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};
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pub const IP_VER_ENUM = enum(u3) {
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IPv4 = 4,
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IPv6 = 6,
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};
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pub const IP = ?std.net.Address;
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pub const IPInfo = struct {
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version: IP_VER_ENUM,
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interface: ?[:0]const u8,
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};
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pub const Domain = struct {
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name: [:0]const u8,
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labels: [5][]const u8,
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};
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pub fn getenv(key: [*:0]const u8) ![*:0]const u8 {
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return (std.c.getenv(key) orelse ArgError.EnvVarNotSet);
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}
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pub fn check_perms() !void {
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var f = try std.fs.openFileAbsoluteZ(try getenv("OLD_HOSTS_PATH"), .{ .mode = .write_only });
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f.close();
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}
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pub fn get_input() !struct {
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Domain,
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IPInfo,
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} {
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var args = std.process.args();
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_ = args.next(); // consume calling binary arg
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const domain_str = args.next() orelse return ArgError.NotEnoughArgs;
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const domain = try check_domain(domain_str);
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const ip_ver_str = args.next() orelse return ArgError.NotEnoughArgs;
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const ip_ver = std.meta.intToEnum(IP_VER_ENUM, std.fmt.parseInt(u3, ip_ver_str, 10) catch return ArgError.InvalidAddressVer) catch return ArgError.InvalidAddressVer;
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var iface: ?[:0]const u8 = null;
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if (ip_ver == IP_VER_ENUM.IPv6) {
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iface = args.next() orelse return ArgError.InterfaceRequired;
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if (std.c.if_nametoindex(iface.?) == 0) {
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return ArgError.InvalidInterface;
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}
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}
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return .{ domain, IPInfo{ .version = ip_ver, .interface = iface } };
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}
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fn check_domain(domain_str: [:0]const u8) !Domain {
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var domain = Domain{
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.name = domain_str,
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.labels = [_][]const u8{&[_]u8{}} ** 5,
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};
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var labels = std.mem.splitScalar(u8, domain_str, '.');
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var last: []const u8 = "";
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var i: usize = 0;
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while (labels.next()) |segment| {
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if (i >= 5) {
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return ArgError.BadDomain;
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}
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last = segment;
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domain.labels[i] = segment;
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i += 1;
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}
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if (domain.labels.len <= 1 or !std.mem.eql(u8, last, "local")) {
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return ArgError.BadDomain;
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}
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return domain;
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}
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