WIP: hack away at std.Io return flight

lib/std/Io.zig

@@ -719,31 +719,38 @@ pub const Timestamp = struct {
         ///
         /// The epoch is implementation-defined. For example NTFS/Windows uses
         /// 1601-01-01.
-        realtime,
+        real,
         /// A nonsettable system-wide clock that represents time since some
         /// unspecified point in the past.
         ///
-        /// On Linux, corresponds to how long the system has been running since
+        /// Monotonic: Guarantees that the time returned by consecutive calls
-        /// it booted.
+        /// will not go backwards, but successive calls may return identical
-        ///
-        /// Not affected by discontinuous jumps in the system time (e.g., if
-        /// the system administrator manually changes the clock), but is
-        /// affected by frequency adjustments. **This clock does not count time
-        /// that the system is suspended.**
-        ///
-        /// Guarantees that the time returned by consecutive calls will not go
-        /// backwards, but successive calls may return identical
         /// (not-increased) time values.
         ///
-        /// May or may not include time the system is suspended, but
+        /// Not affected by discontinuous jumps in the system time (e.g., if
-        /// implementations should exclude that time if possible.
+        /// the system administrator manually changes the clock), but may be
-        monotonic,
+        /// affected by frequency adjustments.
-        /// Identical to `monotonic` except it also includes any time that the
+        ///
-        /// system is suspended, if possible. However, it may be implemented
+        /// This clock expresses intent to **exclude time that the system is
-        /// identically to `monotonic`.
+        /// suspended**. However, implementations may be unable to satisify
-        boottime,
+        /// this, and may include that time.
-        process_cputime_id,
+        ///
-        thread_cputime_id,
+        /// * On Linux, corresponds `CLOCK_MONOTONIC`.
+        /// * On macOS, corresponds to `CLOCK_UPTIME_RAW`.
+        awake,
+        /// Identical to `awake` except it expresses intent to include time
+        /// that the system is suspended, however, it may be implemented
+        /// identically to `awake`.
+        ///
+        /// * On Linux, corresponds `CLOCK_BOOTTIME`.
+        /// * On macOS, corresponds to `CLOCK_MONOTONIC_RAW`.
+        boot,
+        /// Tracks the amount of CPU in user or kernel mode used by the calling
+        /// process.
+        cpu_process,
+        /// Tracks the amount of CPU in user or kernel mode used by the calling
+        /// thread.
+        cpu_thread,
     };
 
     pub fn durationTo(from: Timestamp, to: Timestamp) Duration {
@@ -825,7 +832,7 @@ pub const Duration = struct {
     }
 
     pub fn sleep(duration: Duration, io: Io) SleepError!void {
-        return io.vtable.sleep(io.userdata, .{ .duration = .{ .duration = duration, .clock = .monotonic } });
+        return io.vtable.sleep(io.userdata, .{ .duration = .{ .duration = duration, .clock = .awake } });
     }
 };
 

lib/std/Io/File.zig

@@ -319,6 +319,11 @@ pub const Reader = struct {
         };
     }
 
+    /// Takes a legacy `std.fs.File` to help with upgrading.
+    pub fn initAdapted(file: std.fs.File, io: Io, buffer: []u8) Reader {
+        return .init(.{ .handle = file.handle }, io, buffer);
+    }
+
     pub fn initSize(file: File, io: Io, buffer: []u8, size: ?u64) Reader {
         return .{
             .io = io,

lib/std/Io/Threaded.zig

@@ -1032,7 +1032,7 @@ fn nowWindows(userdata: ?*anyopaque, clock: Io.Timestamp.Clock) Io.Timestamp.Err
             // and uses the NTFS/Windows epoch, which is 1601-01-01.
             return @as(i96, windows.ntdll.RtlGetSystemTimePrecise()) * 100;
         },
-        .monotonic, .boottime => {
+        .monotonic, .uptime => {
             // QPC on windows doesn't fail on >= XP/2000 and includes time suspended.
             return .{ .timestamp = windows.QueryPerformanceCounter() };
         },
@@ -1132,7 +1132,8 @@ fn sleepPosix(userdata: ?*anyopaque, timeout: Io.Timeout) Io.SleepError!void {
             .sec = std.math.maxInt(sec_type),
             .nsec = std.math.maxInt(nsec_type),
         };
-        if (d.clock != .monotonic) return error.UnsupportedClock;
+        // TODO check which clock nanosleep uses on this host
+        // and return error.UnsupportedClock if it does not match
         const ns = d.duration.nanoseconds;
         break :t .{
             .sec = @intCast(@divFloor(ns, std.time.ns_per_s)),
@@ -1331,11 +1332,15 @@ fn setSocketOption(pool: *Pool, fd: posix.fd_t, level: i32, opt_name: u32, optio
 fn ipConnectPosix(
     userdata: ?*anyopaque,
     address: *const Io.net.IpAddress,
-    options: Io.net.IpAddress.BindOptions,
+    options: Io.net.IpAddress.ConnectOptions,
 ) Io.net.IpAddress.ConnectError!Io.net.Stream {
+    if (options.timeout != .none) @panic("TODO");
     const pool: *Pool = @ptrCast(@alignCast(userdata));
     const family = posixAddressFamily(address);
-    const socket_fd = try openSocketPosix(pool, family, options);
+    const socket_fd = try openSocketPosix(pool, family, .{
+        .mode = options.mode,
+        .protocol = options.protocol,
+    });
     var storage: PosixAddress = undefined;
     var addr_len = addressToPosix(address, &storage);
     try posixConnect(pool, socket_fd, &storage.any, addr_len);
@@ -1490,11 +1495,11 @@ fn netSend(
     const pool: *Pool = @ptrCast(@alignCast(userdata));
 
     const posix_flags: u32 =
-        @as(u32, if (flags.confirm) posix.MSG.CONFIRM else 0) |
+        @as(u32, if (@hasDecl(posix.MSG, "CONFIRM") and flags.confirm) posix.MSG.CONFIRM else 0) |
         @as(u32, if (flags.dont_route) posix.MSG.DONTROUTE else 0) |
         @as(u32, if (flags.eor) posix.MSG.EOR else 0) |
         @as(u32, if (flags.oob) posix.MSG.OOB else 0) |
-        @as(u32, if (flags.fastopen) posix.MSG.FASTOPEN else 0) |
+        @as(u32, if (@hasDecl(posix.MSG, "FASTOPEN") and flags.fastopen) posix.MSG.FASTOPEN else 0) |
         posix.MSG.NOSIGNAL;
 
     var i: usize = 0;
@@ -2024,11 +2029,17 @@ fn recoverableOsBugDetected() void {
 
 fn clockToPosix(clock: Io.Timestamp.Clock) posix.clockid_t {
     return switch (clock) {
-        .realtime => posix.CLOCK.REALTIME,
+        .real => posix.CLOCK.REALTIME,
-        .monotonic => posix.CLOCK.MONOTONIC,
+        .awake => switch (builtin.os.tag) {
-        .boottime => posix.CLOCK.BOOTTIME,
+            .macos, .ios, .watchos, .tvos => posix.CLOCK.UPTIME_RAW,
-        .process_cputime_id => posix.CLOCK.PROCESS_CPUTIME_ID,
+            else => posix.CLOCK.MONOTONIC,
-        .thread_cputime_id => posix.CLOCK.THREAD_CPUTIME_ID,
+        },
+        .boot => switch (builtin.os.tag) {
+            .macos, .ios, .watchos, .tvos => posix.CLOCK.MONOTONIC_RAW,
+            else => posix.CLOCK.BOOTTIME,
+        },
+        .cpu_process => posix.CLOCK.PROCESS_CPUTIME_ID,
+        .cpu_thread => posix.CLOCK.THREAD_CPUTIME_ID,
     };
 }
 
@@ -2036,7 +2047,7 @@ fn clockToWasi(clock: Io.Timestamp.Clock) std.os.wasi.clockid_t {
     return switch (clock) {
         .realtime => .REALTIME,
         .monotonic => .MONOTONIC,
-        .boottime => .MONOTONIC,
+        .uptime => .MONOTONIC,
         .process_cputime_id => .PROCESS_CPUTIME_ID,
         .thread_cputime_id => .THREAD_CPUTIME_ID,
     };

lib/std/Io/net.zig

@@ -186,7 +186,7 @@ pub const IpAddress = union(enum) {
     /// Waits for a TCP connection. When using this API, `bind` does not need
     /// to be called. The returned `Server` has an open `stream`.
     pub fn listen(address: IpAddress, io: Io, options: ListenOptions) ListenError!Server {
-        return io.vtable.tcpListen(io.userdata, address, options);
+        return io.vtable.listen(io.userdata, address, options);
     }
 
     pub const BindError = error{
@@ -236,6 +236,8 @@ pub const IpAddress = union(enum) {
         AddressInUse,
         AddressUnavailable,
         AddressFamilyUnsupported,
+        /// Insufficient memory or other resource internal to the operating system.
+        SystemResources,
         ConnectionPending,
         ConnectionRefused,
         ConnectionResetByPeer,
@@ -246,12 +248,23 @@ pub const IpAddress = union(enum) {
         /// One of the `ConnectOptions` is not supported by the Io
         /// implementation.
         OptionUnsupported,
-    } || Io.UnexpectedError || Io.Cancelable;
+        /// Per-process limit on the number of open file descriptors has been reached.
+        ProcessFdQuotaExceeded,
+        /// System-wide limit on the total number of open files has been reached.
+        SystemFdQuotaExceeded,
+        ProtocolUnsupportedBySystem,
+        ProtocolUnsupportedByAddressFamily,
+        SocketModeUnsupported,
+    } || Io.Timeout.Error || Io.UnexpectedError || Io.Cancelable;
 
-    pub const ConnectOptions = BindOptions;
+    pub const ConnectOptions = struct {
+        mode: Socket.Mode,
+        protocol: ?Protocol = null,
+        timeout: Io.Timeout = .none,
+    };
 
     /// Initiates a connection-oriented network stream.
-    pub fn connect(address: IpAddress, io: Io, options: ConnectOptions) ConnectError!Stream {
+    pub fn connect(address: *const IpAddress, io: Io, options: ConnectOptions) ConnectError!Stream {
         return io.vtable.ipConnect(io.userdata, address, options);
     }
 };
@@ -997,7 +1010,7 @@ pub const Stream = struct {
     socket: Socket,
 
     pub fn close(s: *Stream, io: Io) void {
-        io.vtable.netClose(io.userdata, s.socket);
+        io.vtable.netClose(io.userdata, s.socket.handle);
         s.* = undefined;
     }
 
@@ -1040,10 +1053,13 @@ pub const Stream = struct {
             return n;
         }
 
-        fn readVec(io_r: *Reader, data: [][]u8) Io.Reader.Error!usize {
+        fn readVec(io_r: *Io.Reader, data: [][]u8) Io.Reader.Error!usize {
             const r: *Reader = @alignCast(@fieldParentPtr("interface", io_r));
             const io = r.io;
-            return io.vtable.netReadVec(io.vtable.userdata, r.stream, io_r, data);
+            return io.vtable.netRead(io.userdata, r.stream, data) catch |err| {
+                r.err = err;
+                return error.ReadFailed;
+            };
         }
     };
 
@@ -1078,7 +1094,10 @@ pub const Stream = struct {
             const w: *Writer = @alignCast(@fieldParentPtr("interface", io_w));
             const io = w.io;
             const buffered = io_w.buffered();
-            const n = try io.vtable.netWrite(io.vtable.userdata, w.stream, buffered, data, splat);
+            const n = io.vtable.netWrite(io.userdata, w.stream, buffered, data, splat) catch |err| {
+                w.err = err;
+                return error.WriteFailed;
+            };
             return io_w.consume(n);
         }
     };
@@ -1104,7 +1123,7 @@ pub const Server = struct {
 
     /// Blocks until a client connects to the server.
     pub fn accept(s: *Server, io: Io) AcceptError!Stream {
-        return io.vtable.accept(io, s);
+        return io.vtable.accept(io.userdata, s);
     }
 };
 

lib/std/Io/net/HostName.zig

@@ -19,12 +19,12 @@ bytes: []const u8,
 
 pub const max_len = 255;
 
-pub const InitError = error{
+pub const ValidateError = error{
     NameTooLong,
     InvalidHostName,
 };
 
-pub fn init(bytes: []const u8) InitError!HostName {
+pub fn validate(bytes: []const u8) ValidateError!void {
     if (bytes.len > max_len) return error.NameTooLong;
     if (!std.unicode.utf8ValidateSlice(bytes)) return error.InvalidHostName;
     for (bytes) |byte| {
@@ -33,10 +33,34 @@ pub fn init(bytes: []const u8) InitError!HostName {
         }
         return error.InvalidHostName;
     }
+}
+
+pub fn init(bytes: []const u8) ValidateError!HostName {
+    try validate(bytes);
     return .{ .bytes = bytes };
 }
 
-/// TODO add a retry field here
+pub fn sameParentDomain(parent_host: HostName, child_host: HostName) bool {
+    const parent_bytes = parent_host.bytes;
+    const child_bytes = child_host.bytes;
+    if (!std.ascii.endsWithIgnoreCase(child_bytes, parent_bytes)) return false;
+    if (child_bytes.len == parent_bytes.len) return true;
+    if (parent_bytes.len > child_bytes.len) return false;
+    return child_bytes[child_bytes.len - parent_bytes.len - 1] == '.';
+}
+
+test sameParentDomain {
+    try std.testing.expect(!sameParentDomain(try .init("foo.com"), try .init("bar.com")));
+    try std.testing.expect(sameParentDomain(try .init("foo.com"), try .init("foo.com")));
+    try std.testing.expect(sameParentDomain(try .init("foo.com"), try .init("bar.foo.com")));
+    try std.testing.expect(!sameParentDomain(try .init("bar.foo.com"), try .init("foo.com")));
+}
+
+/// Domain names are case-insensitive (RFC 5890, Section 2.3.2.4)
+pub fn eql(a: HostName, b: HostName) bool {
+    return std.ascii.eqlIgnoreCase(a.bytes, b.bytes);
+}
+
 pub const LookupOptions = struct {
     port: u16,
     /// Must have at least length 2.
@@ -266,15 +290,15 @@ fn lookupDns(io: Io, lookup_canon_name: []const u8, rc: *const ResolvConf, optio
     var answers_remaining = answers.len;
     for (answers) |*answer| answer.len = 0;
 
-    // boottime is chosen because time the computer is suspended should count
+    // boot clock is chosen because time the computer is suspended should count
     // against time spent waiting for external messages to arrive.
-    var now_ts = try Io.Timestamp.now(io, .boottime);
+    var now_ts = try Io.Timestamp.now(io, .boot);
     const final_ts = now_ts.addDuration(.fromSeconds(rc.timeout_seconds));
     const attempt_duration: Io.Duration = .{
         .nanoseconds = std.time.ns_per_s * @as(usize, rc.timeout_seconds) / rc.attempts,
     };
 
-    send: while (now_ts.compare(.lt, final_ts)) : (now_ts = try Io.Timestamp.now(io, .boottime)) {
+    send: while (now_ts.compare(.lt, final_ts)) : (now_ts = try Io.Timestamp.now(io, .boot)) {
         const max_messages = queries_buffer.len * ResolvConf.max_nameservers;
         {
             var message_buffer: [max_messages]Io.net.OutgoingMessage = undefined;
@@ -518,7 +542,7 @@ fn writeResolutionQuery(q: *[280]u8, op: u4, dname: []const u8, class: u8, ty: u
     return n;
 }
 
-pub const ExpandError = error{InvalidDnsPacket} || InitError;
+pub const ExpandError = error{InvalidDnsPacket} || ValidateError;
 
 /// Decompresses a DNS name.
 ///
@@ -618,22 +642,36 @@ pub const DnsResponse = struct {
     }
 };
 
-pub const ConnectTcpError = LookupError || IpAddress.ConnectTcpError;
+pub const ConnectError = LookupError || IpAddress.ConnectError;
 
-pub fn connectTcp(host_name: HostName, io: Io, port: u16) ConnectTcpError!Stream {
+pub fn connect(
+    host_name: HostName,
+    io: Io,
+    port: u16,
+    options: IpAddress.ConnectOptions,
+) ConnectError!Stream {
     var addresses_buffer: [32]IpAddress = undefined;
+    var canonical_name_buffer: [HostName.max_len]u8 = undefined;
 
-    const results = try lookup(host_name, .{
+    const results = try lookup(host_name, io, .{
         .port = port,
         .addresses_buffer = &addresses_buffer,
-        .canonical_name_buffer = &.{},
+        .canonical_name_buffer = &canonical_name_buffer,
     });
     const addresses = addresses_buffer[0..results.addresses_len];
 
     if (addresses.len == 0) return error.UnknownHostName;
 
-    for (addresses) |addr| {
+    // TODO instead of serially, use a Select API to send out
-        return addr.connectTcp(io) catch |err| switch (err) {
+    // the connections simultaneously and then keep the first
+    // successful one, canceling the rest.
+
+    // TODO On Linux this should additionally use an Io.Queue based
+    // DNS resolution API in order to send out a connection after
+    // each DNS response before waiting for the rest of them.
+
+    for (addresses) |*addr| {
+        return addr.connect(io, options) catch |err| switch (err) {
             error.ConnectionRefused => continue,
             else => |e| return e,
         };

lib/std/Io/net/test.zig

@@ -7,32 +7,30 @@ const testing = std.testing;
 test "parse and render IP addresses at comptime" {
     comptime {
         const ipv6addr = net.IpAddress.parse("::1", 0) catch unreachable;
-        try std.testing.expectFmt("[::1]:0", "{f}", .{ipv6addr});
+        try testing.expectFmt("[::1]:0", "{f}", .{ipv6addr});
 
         const ipv4addr = net.IpAddress.parse("127.0.0.1", 0) catch unreachable;
-        try std.testing.expectFmt("127.0.0.1:0", "{f}", .{ipv4addr});
+        try testing.expectFmt("127.0.0.1:0", "{f}", .{ipv4addr});
 
         try testing.expectError(error.ParseFailed, net.IpAddress.parse("::123.123.123.123", 0));
         try testing.expectError(error.ParseFailed, net.IpAddress.parse("127.01.0.1", 0));
-        try testing.expectError(error.ParseFailed, net.IpAddress.resolveIp("::123.123.123.123", 0));
-        try testing.expectError(error.ParseFailed, net.IpAddress.resolveIp("127.01.0.1", 0));
     }
 }
 
 test "format IPv6 address with no zero runs" {
-    const addr = try std.net.IpAddress.parseIp6("2001:db8:1:2:3:4:5:6", 0);
+    const addr = try net.IpAddress.parseIp6("2001:db8:1:2:3:4:5:6", 0);
-    try std.testing.expectFmt("[2001:db8:1:2:3:4:5:6]:0", "{f}", .{addr});
+    try testing.expectFmt("[2001:db8:1:2:3:4:5:6]:0", "{f}", .{addr});
 }
 
 test "parse IPv6 addresses and check compressed form" {
-    try std.testing.expectFmt("[2001:db8::1:0:0:2]:0", "{f}", .{
+    try testing.expectFmt("[2001:db8::1:0:0:2]:0", "{f}", .{
-        try std.net.IpAddress.parseIp6("2001:0db8:0000:0000:0001:0000:0000:0002", 0),
+        try net.IpAddress.parseIp6("2001:0db8:0000:0000:0001:0000:0000:0002", 0),
     });
-    try std.testing.expectFmt("[2001:db8::1:2]:0", "{f}", .{
+    try testing.expectFmt("[2001:db8::1:2]:0", "{f}", .{
-        try std.net.IpAddress.parseIp6("2001:0db8:0000:0000:0000:0000:0001:0002", 0),
+        try net.IpAddress.parseIp6("2001:0db8:0000:0000:0000:0000:0001:0002", 0),
     });
-    try std.testing.expectFmt("[2001:db8:1:0:1::2]:0", "{f}", .{
+    try testing.expectFmt("[2001:db8:1:0:1::2]:0", "{f}", .{
-        try std.net.IpAddress.parseIp6("2001:0db8:0001:0000:0001:0000:0000:0002", 0),
+        try net.IpAddress.parseIp6("2001:0db8:0001:0000:0001:0000:0000:0002", 0),
     });
 }
 
@@ -43,14 +41,14 @@ test "parse IPv6 address, check raw bytes" {
         0x00, 0x01, 0x00, 0x00, // :0001:0000
         0x00, 0x00, 0x00, 0x02, // :0000:0002
     };
-
+    const addr = try net.IpAddress.parseIp6("2001:db8:0000:0000:0001:0000:0000:0002", 0);
-    const addr = try std.net.IpAddress.parseIp6("2001:db8:0000:0000:0001:0000:0000:0002", 0);
+    try testing.expectEqualSlices(u8, &expected_raw, &addr.ip6.bytes);
-
-    const actual_raw = addr.in6.sa.addr[0..];
-    try std.testing.expectEqualSlices(u8, expected_raw[0..], actual_raw);
 }
 
 test "parse and render IPv6 addresses" {
+    // TODO make this test parsing and rendering only, then it doesn't need I/O
+    const io = testing.io;
+
     var buffer: [100]u8 = undefined;
     const ips = [_][]const u8{
         "FF01:0:0:0:0:0:0:FB",
@@ -79,12 +77,12 @@ test "parse and render IPv6 addresses" {
     for (ips, 0..) |ip, i| {
         const addr = net.IpAddress.parseIp6(ip, 0) catch unreachable;
         var newIp = std.fmt.bufPrint(buffer[0..], "{f}", .{addr}) catch unreachable;
-        try std.testing.expect(std.mem.eql(u8, printed[i], newIp[1 .. newIp.len - 3]));
+        try testing.expect(std.mem.eql(u8, printed[i], newIp[1 .. newIp.len - 3]));
 
         if (builtin.os.tag == .linux) {
-            const addr_via_resolve = net.IpAddress.resolveIp6(ip, 0) catch unreachable;
+            const addr_via_resolve = net.IpAddress.resolveIp6(io, ip, 0) catch unreachable;
             var newResolvedIp = std.fmt.bufPrint(buffer[0..], "{f}", .{addr_via_resolve}) catch unreachable;
-            try std.testing.expect(std.mem.eql(u8, printed[i], newResolvedIp[1 .. newResolvedIp.len - 3]));
+            try testing.expect(std.mem.eql(u8, printed[i], newResolvedIp[1 .. newResolvedIp.len - 3]));
         }
     }
 
@@ -97,21 +95,23 @@ test "parse and render IPv6 addresses" {
     try testing.expectError(error.Incomplete, net.IpAddress.parseIp6("1", 0));
     // TODO Make this test pass on other operating systems.
     if (builtin.os.tag == .linux or comptime builtin.os.tag.isDarwin() or builtin.os.tag == .windows) {
-        try testing.expectError(error.Incomplete, net.IpAddress.resolveIp6("ff01::fb%", 0));
+        try testing.expectError(error.Incomplete, net.IpAddress.resolveIp6(io, "ff01::fb%", 0));
         // Assumes IFNAMESIZE will always be a multiple of 2
-        try testing.expectError(error.Overflow, net.IpAddress.resolveIp6("ff01::fb%wlp3" ++ "s0" ** @divExact(std.posix.IFNAMESIZE - 4, 2), 0));
+        try testing.expectError(error.Overflow, net.IpAddress.resolveIp6(io, "ff01::fb%wlp3" ++ "s0" ** @divExact(std.posix.IFNAMESIZE - 4, 2), 0));
-        try testing.expectError(error.Overflow, net.IpAddress.resolveIp6("ff01::fb%12345678901234", 0));
+        try testing.expectError(error.Overflow, net.IpAddress.resolveIp6(io, "ff01::fb%12345678901234", 0));
     }
 }
 
 test "invalid but parseable IPv6 scope ids" {
+    const io = testing.io;
+
     if (builtin.os.tag != .linux and comptime !builtin.os.tag.isDarwin() and builtin.os.tag != .windows) {
         // Currently, resolveIp6 with alphanumerical scope IDs only works on Linux.
         // TODO Make this test pass on other operating systems.
         return error.SkipZigTest;
     }
 
-    try testing.expectError(error.InterfaceNotFound, net.IpAddress.resolveIp6("ff01::fb%123s45678901234", 0));
+    try testing.expectError(error.InterfaceNotFound, net.IpAddress.resolveIp6(io, "ff01::fb%123s45678901234", 0));
 }
 
 test "parse and render IPv4 addresses" {
@@ -125,7 +125,7 @@ test "parse and render IPv4 addresses" {
     }) |ip| {
         const addr = net.IpAddress.parseIp4(ip, 0) catch unreachable;
         var newIp = std.fmt.bufPrint(buffer[0..], "{f}", .{addr}) catch unreachable;
-        try std.testing.expect(std.mem.eql(u8, ip, newIp[0 .. newIp.len - 2]));
+        try testing.expect(std.mem.eql(u8, ip, newIp[0 .. newIp.len - 2]));
     }
 
     try testing.expectError(error.Overflow, net.IpAddress.parseIp4("256.0.0.1", 0));
@@ -136,50 +136,43 @@ test "parse and render IPv4 addresses" {
     try testing.expectError(error.NonCanonical, net.IpAddress.parseIp4("127.01.0.1", 0));
 }
 
-test "parse and render UNIX addresses" {
-    if (builtin.os.tag == .wasi) return error.SkipZigTest;
-    if (!net.has_unix_sockets) return error.SkipZigTest;
-
-    const addr = net.Address.initUnix("/tmp/testpath") catch unreachable;
-    try std.testing.expectFmt("/tmp/testpath", "{f}", .{addr});
-
-    const too_long = [_]u8{'a'} ** 200;
-    try testing.expectError(error.NameTooLong, net.Address.initUnix(too_long[0..]));
-}
-
 test "resolve DNS" {
     if (builtin.os.tag == .wasi) return error.SkipZigTest;
 
-    if (builtin.os.tag == .windows) {
+    const io = testing.io;
-        _ = try std.os.windows.WSAStartup(2, 2);
-    }
-    defer {
-        if (builtin.os.tag == .windows) {
-            std.os.windows.WSACleanup() catch unreachable;
-        }
-    }
 
     // Resolve localhost, this should not fail.
     {
         const localhost_v4 = try net.IpAddress.parse("127.0.0.1", 80);
         const localhost_v6 = try net.IpAddress.parse("::2", 80);
 
-        const result = try net.getAddressList(testing.allocator, "localhost", 80);
+        var addresses_buffer: [8]net.IpAddress = undefined;
-        defer result.deinit();
+        var canon_name_buffer: [net.HostName.max_len]u8 = undefined;
-        for (result.addrs) |addr| {
+        const result = try net.HostName.lookup(try .init("localhost"), io, .{
-            if (addr.eql(localhost_v4) or addr.eql(localhost_v6)) break;
+            .port = 80,
+            .addresses_buffer = &addresses_buffer,
+            .canonical_name_buffer = &canon_name_buffer,
+        });
+        for (addresses_buffer[0..result.addresses_len]) |addr| {
+            if (addr.eql(&localhost_v4) or addr.eql(&localhost_v6)) break;
         } else @panic("unexpected address for localhost");
     }
 
     {
         // The tests are required to work even when there is no Internet connection,
         // so some of these errors we must accept and skip the test.
-        const result = net.getAddressList(testing.allocator, "example.com", 80) catch |err| switch (err) {
+        var addresses_buffer: [8]net.IpAddress = undefined;
+        var canon_name_buffer: [net.HostName.max_len]u8 = undefined;
+        const result = net.HostName.lookup(try .init("example.com"), io, .{
+            .port = 80,
+            .addresses_buffer = &addresses_buffer,
+            .canonical_name_buffer = &canon_name_buffer,
+        }) catch |err| switch (err) {
             error.UnknownHostName => return error.SkipZigTest,
-            error.TemporaryNameServerFailure => return error.SkipZigTest,
+            error.NameServerFailure => return error.SkipZigTest,
             else => return err,
         };
-        result.deinit();
+        _ = result;
     }
 }
 
@@ -187,6 +180,8 @@ test "listen on a port, send bytes, receive bytes" {
     if (builtin.single_threaded) return error.SkipZigTest;
     if (builtin.os.tag == .wasi) return error.SkipZigTest;
 
+    const io = testing.io;
+
     if (builtin.os.tag == .windows) {
         _ = try std.os.windows.WSAStartup(2, 2);
     }
@@ -198,28 +193,28 @@ test "listen on a port, send bytes, receive bytes" {
 
     // Try only the IPv4 variant as some CI builders have no IPv6 localhost
     // configured.
-    const localhost = try net.IpAddress.parse("127.0.0.1", 0);
+    const localhost: net.IpAddress = .{ .ip4 = .loopback(0) };
 
-    var server = try localhost.listen(.{});
+    var server = try localhost.listen(io, .{});
-    defer server.deinit();
+    defer server.deinit(io);
 
     const S = struct {
         fn clientFn(server_address: net.IpAddress) !void {
-            const socket = try net.tcpConnectToAddress(server_address);
+            var stream = try server_address.connect(io, .{ .mode = .stream });
-            defer socket.close();
+            defer stream.close(io);
 
-            var stream_writer = socket.writer(&.{});
+            var stream_writer = stream.writer(io, &.{});
             try stream_writer.interface.writeAll("Hello world!");
         }
     };
 
-    const t = try std.Thread.spawn(.{}, S.clientFn, .{server.listen_address});
+    const t = try std.Thread.spawn(.{}, S.clientFn, .{server.socket.address});
     defer t.join();
 
-    var client = try server.accept();
+    var client = try server.accept(io);
-    defer client.stream.close();
+    defer client.stream.close(io);
     var buf: [16]u8 = undefined;
-    var stream_reader = client.stream.reader(&.{});
+    var stream_reader = client.stream.reader(io, &.{});
     const n = try stream_reader.interface().readSliceShort(&buf);
 
     try testing.expectEqual(@as(usize, 12), n);
@@ -232,13 +227,15 @@ test "listen on an in use port" {
         return error.SkipZigTest;
     }
 
-    const localhost = try net.IpAddress.parse("127.0.0.1", 0);
+    const io = testing.io;
 
-    var server1 = try localhost.listen(.{ .reuse_address = true });
+    const localhost: net.IpAddress = .{ .ip4 = .loopback(0) };
-    defer server1.deinit();
 
-    var server2 = try server1.listen_address.listen(.{ .reuse_address = true });
+    var server1 = try localhost.listen(io, .{ .reuse_address = true });
-    defer server2.deinit();
+    defer server1.deinit(io);
+
+    var server2 = try server1.socket.address.listen(io, .{ .reuse_address = true });
+    defer server2.deinit(io);
 }
 
 fn testClientToHost(allocator: mem.Allocator, name: []const u8, port: u16) anyerror!void {
@@ -268,9 +265,11 @@ fn testClient(addr: net.IpAddress) anyerror!void {
 fn testServer(server: *net.Server) anyerror!void {
     if (builtin.os.tag == .wasi) return error.SkipZigTest;
 
-    var client = try server.accept();
+    const io = testing.io;
 
-    const stream = client.stream.writer();
+    var client = try server.accept(io);
+
+    const stream = client.stream.writer(io);
     try stream.print("hello from server\n", .{});
 }
 
@@ -278,6 +277,8 @@ test "listen on a unix socket, send bytes, receive bytes" {
     if (builtin.single_threaded) return error.SkipZigTest;
     if (!net.has_unix_sockets) return error.SkipZigTest;
 
+    const io = testing.io;
+
     if (builtin.os.tag == .windows) {
         _ = try std.os.windows.WSAStartup(2, 2);
     }
@@ -293,15 +294,15 @@ test "listen on a unix socket, send bytes, receive bytes" {
     const socket_addr = try net.IpAddress.initUnix(socket_path);
     defer std.fs.cwd().deleteFile(socket_path) catch {};
 
-    var server = try socket_addr.listen(.{});
+    var server = try socket_addr.listen(io, .{});
-    defer server.deinit();
+    defer server.deinit(io);
 
     const S = struct {
         fn clientFn(path: []const u8) !void {
-            const socket = try net.connectUnixSocket(path);
+            var stream = try net.connectUnixSocket(path);
-            defer socket.close();
+            defer stream.close(io);
 
-            var stream_writer = socket.writer(&.{});
+            var stream_writer = stream.writer(io, &.{});
             try stream_writer.interface.writeAll("Hello world!");
         }
     };
@@ -309,10 +310,10 @@ test "listen on a unix socket, send bytes, receive bytes" {
     const t = try std.Thread.spawn(.{}, S.clientFn, .{socket_path});
     defer t.join();
 
-    var client = try server.accept();
+    var client = try server.accept(io);
-    defer client.stream.close();
+    defer client.stream.close(io);
     var buf: [16]u8 = undefined;
-    var stream_reader = client.stream.reader(&.{});
+    var stream_reader = client.stream.reader(io, &.{});
     const n = try stream_reader.interface().readSliceShort(&buf);
 
     try testing.expectEqual(@as(usize, 12), n);
@@ -324,14 +325,16 @@ test "listen on a unix socket with reuse_address option" {
     // Windows doesn't implement reuse port option.
     if (builtin.os.tag == .windows) return error.SkipZigTest;
 
+    const io = testing.io;
+
     const socket_path = try generateFileName("socket.unix");
     defer testing.allocator.free(socket_path);
 
     const socket_addr = try net.Address.initUnix(socket_path);
     defer std.fs.cwd().deleteFile(socket_path) catch {};
 
-    var server = try socket_addr.listen(.{ .reuse_address = true });
+    var server = try socket_addr.listen(io, .{ .reuse_address = true });
-    server.deinit();
+    server.deinit(io);
 }
 
 fn generateFileName(base_name: []const u8) ![]const u8 {
@@ -351,19 +354,21 @@ test "non-blocking tcp server" {
         return error.SkipZigTest;
     }
 
-    const localhost = try net.IpAddress.parse("127.0.0.1", 0);
+    const io = testing.io;
-    var server = localhost.listen(.{ .force_nonblocking = true });
-    defer server.deinit();
 
-    const accept_err = server.accept();
+    const localhost: net.IpAddress = .{ .ip4 = .loopback(0) };
+    var server = localhost.listen(io, .{ .force_nonblocking = true });
+    defer server.deinit(io);
+
+    const accept_err = server.accept(io);
     try testing.expectError(error.WouldBlock, accept_err);
 
-    const socket_file = try net.tcpConnectToAddress(server.listen_address);
+    const socket_file = try net.tcpConnectToAddress(server.socket.address);
     defer socket_file.close();
 
-    var client = try server.accept();
+    var client = try server.accept(io);
-    defer client.stream.close();
+    defer client.stream.close(io);
-    const stream = client.stream.writer();
+    const stream = client.stream.writer(io);
     try stream.print("hello from server\n", .{});
 
     var buf: [100]u8 = undefined;

lib/std/Uri.zig

@@ -1,45 +1,48 @@
-//! Uniform Resource Identifier (URI) parsing roughly adhering to <https://tools.ietf.org/html/rfc3986>.
+//! Uniform Resource Identifier (URI) parsing roughly adhering to
-//! Does not do perfect grammar and character class checking, but should be robust against URIs in the wild.
+//! <https://tools.ietf.org/html/rfc3986>. Does not do perfect grammar and
+//! character class checking, but should be robust against URIs in the wild.
 
 const std = @import("std.zig");
 const testing = std.testing;
 const Uri = @This();
 const Allocator = std.mem.Allocator;
 const Writer = std.Io.Writer;
+const HostName = std.Io.net.HostName;
 
 scheme: []const u8,
 user: ?Component = null,
 password: ?Component = null,
+/// If non-null, already validated.
 host: ?Component = null,
 port: ?u16 = null,
 path: Component = Component.empty,
 query: ?Component = null,
 fragment: ?Component = null,
 
-pub const host_name_max = 255;
+pub const GetHostError = error{UriMissingHost};
 
 /// Returned value may point into `buffer` or be the original string.
 ///
-/// Suggested buffer length: `host_name_max`.
-///
 /// See also:
 /// * `getHostAlloc`
-pub fn getHost(uri: Uri, buffer: []u8) error{ UriMissingHost, UriHostTooLong }![]const u8 {
+pub fn getHost(uri: Uri, buffer: *[HostName.max_len]u8) GetHostError!HostName {
     const component = uri.host orelse return error.UriMissingHost;
-    return component.toRaw(buffer) catch |err| switch (err) {
+    const bytes = component.toRaw(buffer) catch |err| switch (err) {
-        error.NoSpaceLeft => return error.UriHostTooLong,
+        error.NoSpaceLeft => unreachable, // `host` already validated.
     };
+    return .{ .bytes = bytes };
 }
 
+pub const GetHostAllocError = GetHostError || error{OutOfMemory};
+
 /// Returned value may point into `buffer` or be the original string.
 ///
 /// See also:
 /// * `getHost`
-pub fn getHostAlloc(uri: Uri, arena: Allocator) error{ UriMissingHost, UriHostTooLong, OutOfMemory }![]const u8 {
+pub fn getHostAlloc(uri: Uri, arena: Allocator) GetHostAllocError![]const u8 {
     const component = uri.host orelse return error.UriMissingHost;
-    const result = try component.toRawMaybeAlloc(arena);
+    const bytes = try component.toRawMaybeAlloc(arena);
-    if (result.len > host_name_max) return error.UriHostTooLong;
+    return .{ .bytes = bytes };
-    return result;
 }
 
 pub const Component = union(enum) {
@@ -397,7 +400,7 @@ pub fn resolveInPlace(base: Uri, new_len: usize, aux_buf: *[]u8) ResolveInPlaceE
         .scheme = new_parsed.scheme,
         .user = new_parsed.user,
         .password = new_parsed.password,
-        .host = new_parsed.host,
+        .host = try validateHost(new_parsed.host),
         .port = new_parsed.port,
         .path = remove_dot_segments(new_path),
         .query = new_parsed.query,
@@ -408,7 +411,7 @@ pub fn resolveInPlace(base: Uri, new_len: usize, aux_buf: *[]u8) ResolveInPlaceE
         .scheme = base.scheme,
         .user = new_parsed.user,
         .password = new_parsed.password,
-        .host = host,
+        .host = try validateHost(host),
         .port = new_parsed.port,
         .path = remove_dot_segments(new_path),
         .query = new_parsed.query,
@@ -430,7 +433,7 @@ pub fn resolveInPlace(base: Uri, new_len: usize, aux_buf: *[]u8) ResolveInPlaceE
         .scheme = base.scheme,
         .user = base.user,
         .password = base.password,
-        .host = base.host,
+        .host = try validateHost(base.host),
         .port = base.port,
         .path = path,
         .query = query,
@@ -438,6 +441,11 @@ pub fn resolveInPlace(base: Uri, new_len: usize, aux_buf: *[]u8) ResolveInPlaceE
     };
 }
 
+fn validateHost(bytes: []const u8) []const u8 {
+    try HostName.validate(bytes);
+    return bytes;
+}
+
 /// In-place implementation of RFC 3986, Section 5.2.4.
 fn remove_dot_segments(path: []u8) Component {
     var in_i: usize = 0;

lib/std/fs/test.zig

@@ -2281,7 +2281,7 @@ test "seekTo flushes buffered data" {
     }
 
     var read_buffer: [16]u8 = undefined;
-    var file_reader: std.Io.File.Reader = .init(file, io, &read_buffer);
+    var file_reader: std.Io.File.Reader = .initAdapted(file, io, &read_buffer);
 
     var buf: [4]u8 = undefined;
     try file_reader.interface.readSliceAll(&buf);

lib/std/http/Client.zig

@@ -15,6 +15,7 @@ const assert = std.debug.assert;
 const Io = std.Io;
 const Writer = std.Io.Writer;
 const Reader = std.Io.Reader;
+const HostName = std.Io.net.HostName;
 
 const Client = @This();
 
@@ -69,7 +70,7 @@ pub const ConnectionPool = struct {
 
     /// The criteria for a connection to be considered a match.
     pub const Criteria = struct {
-        host: []const u8,
+        host: HostName,
         port: u16,
         protocol: Protocol,
     };
@@ -89,7 +90,7 @@ pub const ConnectionPool = struct {
             if (connection.port != criteria.port) continue;
 
             // Domain names are case-insensitive (RFC 5890, Section 2.3.2.4)
-            if (!std.ascii.eqlIgnoreCase(connection.host(), criteria.host)) continue;
+            if (!connection.host().eql(criteria.host)) continue;
 
             pool.acquireUnsafe(connection);
             return connection;
@@ -118,19 +119,19 @@ pub const ConnectionPool = struct {
     /// If the connection is marked as closing, it will be closed instead.
     ///
     /// Threadsafe.
-    pub fn release(pool: *ConnectionPool, connection: *Connection) void {
+    pub fn release(pool: *ConnectionPool, connection: *Connection, io: Io) void {
         pool.mutex.lock();
         defer pool.mutex.unlock();
 
         pool.used.remove(&connection.pool_node);
 
-        if (connection.closing or pool.free_size == 0) return connection.destroy();
+        if (connection.closing or pool.free_size == 0) return connection.destroy(io);
 
         if (pool.free_len >= pool.free_size) {
             const popped: *Connection = @alignCast(@fieldParentPtr("pool_node", pool.free.popFirst().?));
             pool.free_len -= 1;
 
-            popped.destroy();
+            popped.destroy(io);
         }
 
         if (connection.proxied) {
@@ -178,21 +179,21 @@ pub const ConnectionPool = struct {
     /// All future operations on the connection pool will deadlock.
     ///
     /// Threadsafe.
-    pub fn deinit(pool: *ConnectionPool) void {
+    pub fn deinit(pool: *ConnectionPool, io: Io) void {
         pool.mutex.lock();
 
         var next = pool.free.first;
         while (next) |node| {
             const connection: *Connection = @alignCast(@fieldParentPtr("pool_node", node));
             next = node.next;
-            connection.destroy();
+            connection.destroy(io);
         }
 
         next = pool.used.first;
         while (next) |node| {
             const connection: *Connection = @alignCast(@fieldParentPtr("pool_node", node));
             next = node.next;
-            connection.destroy();
+            connection.destroy(io);
         }
 
         pool.* = undefined;
@@ -242,19 +243,19 @@ pub const Connection = struct {
 
         fn create(
             client: *Client,
-            remote_host: []const u8,
+            remote_host: HostName,
             port: u16,
             stream: Io.net.Stream,
         ) error{OutOfMemory}!*Plain {
             const gpa = client.allocator;
-            const alloc_len = allocLen(client, remote_host.len);
+            const alloc_len = allocLen(client, remote_host.bytes.len);
             const base = try gpa.alignedAlloc(u8, .of(Plain), alloc_len);
             errdefer gpa.free(base);
-            const host_buffer = base[@sizeOf(Plain)..][0..remote_host.len];
+            const host_buffer = base[@sizeOf(Plain)..][0..remote_host.bytes.len];
             const socket_read_buffer = host_buffer.ptr[host_buffer.len..][0..client.read_buffer_size];
             const socket_write_buffer = socket_read_buffer.ptr[socket_read_buffer.len..][0..client.write_buffer_size];
             assert(base.ptr + alloc_len == socket_write_buffer.ptr + socket_write_buffer.len);
-            @memcpy(host_buffer, remote_host);
+            @memcpy(host_buffer, remote_host.bytes);
             const plain: *Plain = @ptrCast(base);
             plain.* = .{
                 .connection = .{
@@ -263,7 +264,7 @@ pub const Connection = struct {
                     .stream_reader = stream.reader(socket_read_buffer),
                     .pool_node = .{},
                     .port = port,
-                    .host_len = @intCast(remote_host.len),
+                    .host_len = @intCast(remote_host.bytes.len),
                     .proxied = false,
                     .closing = false,
                     .protocol = .plain,
@@ -283,9 +284,9 @@ pub const Connection = struct {
             return @sizeOf(Plain) + host_len + client.read_buffer_size + client.write_buffer_size;
         }
 
-        fn host(plain: *Plain) []u8 {
+        fn host(plain: *Plain) HostName {
             const base: [*]u8 = @ptrCast(plain);
-            return base[@sizeOf(Plain)..][0..plain.connection.host_len];
+            return .{ .bytes = base[@sizeOf(Plain)..][0..plain.connection.host_len] };
         }
     };
 
@@ -295,15 +296,15 @@ pub const Connection = struct {
 
         fn create(
             client: *Client,
-            remote_host: []const u8,
+            remote_host: HostName,
             port: u16,
             stream: Io.net.Stream,
         ) error{ OutOfMemory, TlsInitializationFailed }!*Tls {
             const gpa = client.allocator;
-            const alloc_len = allocLen(client, remote_host.len);
+            const alloc_len = allocLen(client, remote_host.bytes.len);
             const base = try gpa.alignedAlloc(u8, .of(Tls), alloc_len);
             errdefer gpa.free(base);
-            const host_buffer = base[@sizeOf(Tls)..][0..remote_host.len];
+            const host_buffer = base[@sizeOf(Tls)..][0..remote_host.bytes.len];
             // The TLS client wants enough buffer for the max encrypted frame
             // size, and the HTTP body reader wants enough buffer for the
             // entire HTTP header. This means we need a combined upper bound.
@@ -313,7 +314,7 @@ pub const Connection = struct {
             const socket_write_buffer = tls_write_buffer.ptr[tls_write_buffer.len..][0..client.write_buffer_size];
             const socket_read_buffer = socket_write_buffer.ptr[socket_write_buffer.len..][0..client.tls_buffer_size];
             assert(base.ptr + alloc_len == socket_read_buffer.ptr + socket_read_buffer.len);
-            @memcpy(host_buffer, remote_host);
+            @memcpy(host_buffer, remote_host.bytes);
             const tls: *Tls = @ptrCast(base);
             tls.* = .{
                 .connection = .{
@@ -322,17 +323,17 @@ pub const Connection = struct {
                     .stream_reader = stream.reader(socket_read_buffer),
                     .pool_node = .{},
                     .port = port,
-                    .host_len = @intCast(remote_host.len),
+                    .host_len = @intCast(remote_host.bytes.len),
                     .proxied = false,
                     .closing = false,
                     .protocol = .tls,
                 },
                 // TODO data race here on ca_bundle if the user sets next_https_rescan_certs to true
                 .client = std.crypto.tls.Client.init(
-                    tls.connection.stream_reader.interface(),
+                    &tls.connection.stream_reader.interface,
                     &tls.connection.stream_writer.interface,
                     .{
-                        .host = .{ .explicit = remote_host },
+                        .host = .{ .explicit = remote_host.bytes },
                         .ca = .{ .bundle = client.ca_bundle },
                         .ssl_key_log = client.ssl_key_log,
                         .read_buffer = tls_read_buffer,
@@ -359,9 +360,9 @@ pub const Connection = struct {
                 client.write_buffer_size + client.tls_buffer_size;
         }
 
-        fn host(tls: *Tls) []u8 {
+        fn host(tls: *Tls) HostName {
             const base: [*]u8 = @ptrCast(tls);
-            return base[@sizeOf(Tls)..][0..tls.connection.host_len];
+            return .{ .bytes = base[@sizeOf(Tls)..][0..tls.connection.host_len] };
         }
     };
 
@@ -384,7 +385,7 @@ pub const Connection = struct {
         return c.stream_reader.stream;
     }
 
-    pub fn host(c: *Connection) []u8 {
+    pub fn host(c: *Connection) HostName {
         return switch (c.protocol) {
             .tls => {
                 if (disable_tls) unreachable;
@@ -400,8 +401,8 @@ pub const Connection = struct {
 
     /// If this is called without calling `flush` or `end`, data will be
     /// dropped unsent.
-    pub fn destroy(c: *Connection) void {
+    pub fn destroy(c: *Connection, io: Io) void {
-        c.getStream().close();
+        c.stream_reader.stream.close(io);
         switch (c.protocol) {
             .tls => {
                 if (disable_tls) unreachable;
@@ -437,7 +438,7 @@ pub const Connection = struct {
                 const tls: *Tls = @alignCast(@fieldParentPtr("connection", c));
                 return &tls.client.reader;
             },
-            .plain => c.stream_reader.interface(),
+            .plain => &c.stream_reader.interface,
         };
     }
 
@@ -866,6 +867,7 @@ pub const Request = struct {
 
     /// Returns the request's `Connection` back to the pool of the `Client`.
     pub fn deinit(r: *Request) void {
+        const io = r.client.io;
         if (r.connection) |connection| {
             connection.closing = connection.closing or switch (r.reader.state) {
                 .ready => false,
@@ -880,7 +882,7 @@ pub const Request = struct {
                 },
                 else => true,
             };
-            r.client.connection_pool.release(connection);
+            r.client.connection_pool.release(connection, io);
         }
         r.* = undefined;
     }
@@ -1182,6 +1184,7 @@ pub const Request = struct {
     ///
     /// `aux_buf` must outlive accesses to `Request.uri`.
     fn redirect(r: *Request, head: *const Response.Head, aux_buf: *[]u8) !void {
+        const io = r.client.io;
         const new_location = head.location orelse return error.HttpRedirectLocationMissing;
         if (new_location.len > aux_buf.*.len) return error.HttpRedirectLocationOversize;
         const location = aux_buf.*[0..new_location.len];
@@ -1204,13 +1207,13 @@ pub const Request = struct {
         const protocol = Protocol.fromUri(new_uri) orelse return error.UnsupportedUriScheme;
         const old_connection = r.connection.?;
         const old_host = old_connection.host();
-        var new_host_name_buffer: [Uri.host_name_max]u8 = undefined;
+        var new_host_name_buffer: [HostName.max_len]u8 = undefined;
         const new_host = try new_uri.getHost(&new_host_name_buffer);
         const keep_privileged_headers =
             std.ascii.eqlIgnoreCase(r.uri.scheme, new_uri.scheme) and
-            sameParentDomain(old_host, new_host);
+            old_host.sameParentDomain(new_host);
 
-        r.client.connection_pool.release(old_connection);
+        r.client.connection_pool.release(old_connection, io);
         r.connection = null;
 
         if (!keep_privileged_headers) {
@@ -1266,7 +1269,7 @@ pub const Request = struct {
 
 pub const Proxy = struct {
     protocol: Protocol,
-    host: []const u8,
+    host: HostName,
     authorization: ?[]const u8,
     port: u16,
     supports_connect: bool,
@@ -1277,9 +1280,10 @@ pub const Proxy = struct {
 /// All pending requests must be de-initialized and all active connections released
 /// before calling this function.
 pub fn deinit(client: *Client) void {
+    const io = client.io;
     assert(client.connection_pool.used.first == null); // There are still active requests.
 
-    client.connection_pool.deinit();
+    client.connection_pool.deinit(io);
     if (!disable_tls) client.ca_bundle.deinit(client.allocator);
 
     client.* = undefined;
@@ -1385,7 +1389,7 @@ pub const basic_authorization = struct {
     }
 };
 
-pub const ConnectTcpError = Allocator.Error || error{
+pub const ConnectTcpError = error{
     ConnectionRefused,
     NetworkUnreachable,
     ConnectionTimedOut,
@@ -1393,17 +1397,16 @@ pub const ConnectTcpError = Allocator.Error || error{
     TemporaryNameServerFailure,
     NameServerFailure,
     UnknownHostName,
-    HostLacksNetworkAddresses,
     UnexpectedConnectFailure,
     TlsInitializationFailed,
-};
+} || Allocator.Error || Io.Cancelable;
 
 /// Reuses a `Connection` if one matching `host` and `port` is already open.
 ///
 /// Threadsafe.
 pub fn connectTcp(
     client: *Client,
-    host: []const u8,
+    host: HostName,
     port: u16,
     protocol: Protocol,
 ) ConnectTcpError!*Connection {
@@ -1411,16 +1414,17 @@ pub fn connectTcp(
 }
 
 pub const ConnectTcpOptions = struct {
-    host: Io.net.HostName,
+    host: HostName,
     port: u16,
     protocol: Protocol,
 
-    proxied_host: ?[]const u8 = null,
+    proxied_host: ?HostName = null,
     proxied_port: ?u16 = null,
+    timeout: Io.Timeout = .none,
 };
 
 pub fn connectTcpOptions(client: *Client, options: ConnectTcpOptions) ConnectTcpError!*Connection {
-    const host = options.host_name;
+    const host = options.host;
     const port = options.port;
     const protocol = options.protocol;
 
@@ -1433,17 +1437,15 @@ pub fn connectTcpOptions(client: *Client, options: ConnectTcpOptions) ConnectTcp
         .protocol = protocol,
     })) |conn| return conn;
 
-    const stream = host.connectTcp(client.io, port) catch |err| switch (err) {
+    const stream = host.connect(client.io, port, .{ .mode = .stream }) catch |err| switch (err) {
         error.ConnectionRefused => return error.ConnectionRefused,
         error.NetworkUnreachable => return error.NetworkUnreachable,
         error.ConnectionTimedOut => return error.ConnectionTimedOut,
         error.ConnectionResetByPeer => return error.ConnectionResetByPeer,
-        error.TemporaryNameServerFailure => return error.TemporaryNameServerFailure,
         error.NameServerFailure => return error.NameServerFailure,
         error.UnknownHostName => return error.UnknownHostName,
-        error.HostLacksNetworkAddresses => return error.HostLacksNetworkAddresses,
         error.Canceled => return error.Canceled,
-        else => return error.UnexpectedConnectFailure,
+        //else => return error.UnexpectedConnectFailure,
     };
     errdefer stream.close();
 
@@ -1479,7 +1481,7 @@ pub fn connectUnix(client: *Client, path: []const u8) ConnectUnixError!*Connecti
     errdefer client.allocator.destroy(conn);
     conn.* = .{ .data = undefined };
 
-    const stream = try std.net.connectUnixSocket(path);
+    const stream = try Io.net.connectUnixSocket(path);
     errdefer stream.close();
 
     conn.data = .{
@@ -1504,9 +1506,10 @@ pub fn connectUnix(client: *Client, path: []const u8) ConnectUnixError!*Connecti
 pub fn connectProxied(
     client: *Client,
     proxy: *Proxy,
-    proxied_host: []const u8,
+    proxied_host: HostName,
     proxied_port: u16,
 ) !*Connection {
+    const io = client.io;
     if (!proxy.supports_connect) return error.TunnelNotSupported;
 
     if (client.connection_pool.findConnection(.{
@@ -1526,12 +1529,12 @@ pub fn connectProxied(
         });
         errdefer {
             connection.closing = true;
-            client.connection_pool.release(connection);
+            client.connection_pool.release(connection, io);
         }
 
         var req = client.request(.CONNECT, .{
             .scheme = "http",
-            .host = .{ .raw = proxied_host },
+            .host = .{ .raw = proxied_host.bytes },
             .port = proxied_port,
         }, .{
             .redirect_behavior = .unhandled,
@@ -1576,7 +1579,7 @@ pub const ConnectError = ConnectTcpError || RequestError;
 /// This function is threadsafe.
 pub fn connect(
     client: *Client,
-    host: []const u8,
+    host: HostName,
     port: u16,
     protocol: Protocol,
 ) ConnectError!*Connection {
@@ -1586,9 +1589,7 @@ pub fn connect(
     } orelse return client.connectTcp(host, port, protocol);
 
     // Prevent proxying through itself.
-    if (std.ascii.eqlIgnoreCase(proxy.host, host) and
+    if (proxy.host.eql(host) and proxy.port == port and proxy.protocol == protocol) {
-        proxy.port == port and proxy.protocol == protocol)
-    {
         return client.connectTcp(host, port, protocol);
     }
 
@@ -1608,7 +1609,6 @@ pub fn connect(
 pub const RequestError = ConnectTcpError || error{
     UnsupportedUriScheme,
     UriMissingHost,
-    UriHostTooLong,
     CertificateBundleLoadFailure,
 };
 
@@ -1697,7 +1697,7 @@ pub fn request(
     }
 
     const connection = options.connection orelse c: {
-        var host_name_buffer: [Uri.host_name_max]u8 = undefined;
+        var host_name_buffer: [HostName.max_len]u8 = undefined;
         const host_name = try uri.getHost(&host_name_buffer);
         break :c try client.connect(host_name, uriPort(uri, protocol), protocol);
     };
@@ -1835,20 +1835,6 @@ pub fn fetch(client: *Client, options: FetchOptions) FetchError!FetchResult {
     return .{ .status = response.head.status };
 }
 
-pub fn sameParentDomain(parent_host: []const u8, child_host: []const u8) bool {
-    if (!std.ascii.endsWithIgnoreCase(child_host, parent_host)) return false;
-    if (child_host.len == parent_host.len) return true;
-    if (parent_host.len > child_host.len) return false;
-    return child_host[child_host.len - parent_host.len - 1] == '.';
-}
-
-test sameParentDomain {
-    try testing.expect(!sameParentDomain("foo.com", "bar.com"));
-    try testing.expect(sameParentDomain("foo.com", "foo.com"));
-    try testing.expect(sameParentDomain("foo.com", "bar.foo.com"));
-    try testing.expect(!sameParentDomain("bar.foo.com", "foo.com"));
-}
-
 test {
     _ = Response;
 }

lib/std/http/test.zig

@@ -53,7 +53,7 @@ test "trailers" {
 
     const gpa = std.testing.allocator;
 
-    var client: http.Client = .{ .allocator = gpa };
+    var client: http.Client = .{ .allocator = gpa, .io = io };
     defer client.deinit();
 
     const location = try std.fmt.allocPrint(gpa, "http://127.0.0.1:{d}/trailer", .{
@@ -141,12 +141,13 @@ test "HTTP server handles a chunked transfer coding request" {
         "0\r\n" ++
         "\r\n";
 
-    const gpa = std.testing.allocator;
+    const host_name: net.HostName = try .init("127.0.0.1");
-    var stream = try net.tcpConnectToHost(gpa, "127.0.0.1", test_server.port());
+    var stream = try host_name.connect(io, test_server.port(), .{ .mode = .stream });
     defer stream.close(io);
-    var stream_writer = stream.writer(&.{});
+    var stream_writer = stream.writer(io, &.{});
     try stream_writer.interface.writeAll(request_bytes);
 
+    const gpa = std.testing.allocator;
     const expected_response =
         "HTTP/1.1 200 OK\r\n" ++
         "connection: close\r\n" ++
@@ -154,8 +155,8 @@ test "HTTP server handles a chunked transfer coding request" {
         "content-type: text/plain\r\n" ++
         "\r\n" ++
         "message from server!\n";
-    var stream_reader = stream.reader(&.{});
+    var stream_reader = stream.reader(io, &.{});
-    const response = try stream_reader.interface().allocRemaining(gpa, .limited(expected_response.len + 1));
+    const response = try stream_reader.interface.allocRemaining(gpa, .limited(expected_response.len + 1));
     defer gpa.free(response);
     try expectEqualStrings(expected_response, response);
 }
@@ -241,7 +242,7 @@ test "echo content server" {
     defer test_server.destroy();
 
     {
-        var client: http.Client = .{ .allocator = std.testing.allocator };
+        var client: http.Client = .{ .allocator = std.testing.allocator, .io = io };
         defer client.deinit();
 
         try echoTests(&client, test_server.port());
@@ -294,14 +295,15 @@ test "Server.Request.respondStreaming non-chunked, unknown content-length" {
     defer test_server.destroy();
 
     const request_bytes = "GET /foo HTTP/1.1\r\n\r\n";
-    const gpa = std.testing.allocator;
+    const host_name: net.HostName = try .init("127.0.0.1");
-    var stream = try net.tcpConnectToHost(gpa, "127.0.0.1", test_server.port());
+    var stream = try host_name.connect(io, test_server.port(), .{ .mode = .stream });
     defer stream.close(io);
-    var stream_writer = stream.writer(&.{});
+    var stream_writer = stream.writer(io, &.{});
     try stream_writer.interface.writeAll(request_bytes);
 
-    var stream_reader = stream.reader(&.{});
+    var stream_reader = stream.reader(io, &.{});
-    const response = try stream_reader.interface().allocRemaining(gpa, .unlimited);
+    const gpa = std.testing.allocator;
+    const response = try stream_reader.interface.allocRemaining(gpa, .unlimited);
     defer gpa.free(response);
 
     var expected_response = std.array_list.Managed(u8).init(gpa);
@@ -366,14 +368,15 @@ test "receiving arbitrary http headers from the client" {
         "CoNneCtIoN:close\r\n" ++
         "aoeu:  asdf \r\n" ++
         "\r\n";
-    const gpa = std.testing.allocator;
+    const host_name: net.HostName = try .init("127.0.0.1");
-    var stream = try net.tcpConnectToHost(gpa, "127.0.0.1", test_server.port());
+    var stream = try host_name.connect(io, test_server.port(), .{ .mode = .stream });
     defer stream.close(io);
-    var stream_writer = stream.writer(&.{});
+    var stream_writer = stream.writer(io, &.{});
     try stream_writer.interface.writeAll(request_bytes);
 
-    var stream_reader = stream.reader(&.{});
+    var stream_reader = stream.reader(io, &.{});
-    const response = try stream_reader.interface().allocRemaining(gpa, .unlimited);
+    const gpa = std.testing.allocator;
+    const response = try stream_reader.interface.allocRemaining(gpa, .unlimited);
     defer gpa.free(response);
 
     var expected_response = std.array_list.Managed(u8).init(gpa);
@@ -413,7 +416,7 @@ test "general client/server API coverage" {
                         else => |e| return e,
                     };
 
-                    try handleRequest(&request, net_server.listen_address.getPort());
+                    try handleRequest(&request, net_server.socket.address.getPort());
                 }
             }
         }
@@ -543,9 +546,9 @@ test "general client/server API coverage" {
 
         fn getUnusedTcpPort() !u16 {
             const addr = try net.IpAddress.parse("127.0.0.1", 0);
-            var s = try addr.listen(.{});
+            var s = try addr.listen(io, .{});
-            defer s.deinit();
+            defer s.deinit(io);
-            return s.listen_address.in.getPort();
+            return s.socket.address.getPort();
         }
     });
     defer test_server.destroy();
@@ -553,7 +556,7 @@ test "general client/server API coverage" {
     const log = std.log.scoped(.client);
 
     const gpa = std.testing.allocator;
-    var client: http.Client = .{ .allocator = gpa };
+    var client: http.Client = .{ .allocator = gpa, .io = io };
     defer client.deinit();
 
     const port = test_server.port();
@@ -918,7 +921,10 @@ test "Server streams both reading and writing" {
     });
     defer test_server.destroy();
 
-    var client: http.Client = .{ .allocator = std.testing.allocator };
+    var client: http.Client = .{
+        .allocator = std.testing.allocator,
+        .io = io,
+    };
     defer client.deinit();
 
     var redirect_buffer: [555]u8 = undefined;
@@ -1089,17 +1095,20 @@ fn echoTests(client: *http.Client, port: u16) !void {
 }
 
 const TestServer = struct {
+    io: Io,
     shutting_down: bool,
     server_thread: std.Thread,
     net_server: net.Server,
 
     fn destroy(self: *@This()) void {
+        const io = self.io;
         self.shutting_down = true;
-        const conn = net.tcpConnectToAddress(self.net_server.listen_address) catch @panic("shutdown failure");
+        var stream = self.net_server.socket.address.connect(io, .{ .mode = .stream }) catch
-        conn.close();
+            @panic("shutdown failure");
+        stream.close(io);
 
         self.server_thread.join();
-        self.net_server.deinit();
+        self.net_server.deinit(io);
         std.testing.allocator.destroy(self);
     }
 
@@ -1118,6 +1127,7 @@ fn createTestServer(io: Io, S: type) !*TestServer {
     const address = try net.IpAddress.parse("127.0.0.1", 0);
     const test_server = try std.testing.allocator.create(TestServer);
     test_server.* = .{
+        .io = io,
         .net_server = try address.listen(io, .{ .reuse_address = true }),
         .shutting_down = false,
         .server_thread = try std.Thread.spawn(.{}, S.run, .{test_server}),