jimzah/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2024-12-03 18:38:45 +00:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity
d10e407977
zig/lib/std/net.zig
Andrew Kelley 53d011fa1a (breaking) std.time fixups and API changes 
Remove the constants that assume a base unit in favor of explicit
x_per_y constants.

nanosecond calendar timestamps now use i128 for the type. This affects
fs.File.Stat, std.time.nanoTimestamp, and fs.File.updateTimes.

calendar timestamps are now signed, because the value can be less than
the epoch (the user can set their computer time to whatever they wish).

implement std.os.clock_gettime for Windows when clock id is
CLOCK_CALENDAR.
2020-05-24 21:40:08 -04:00

1398 lines
47 KiB
Zig
Raw Blame History

const std = @import("std.zig");
const builtin = @import("builtin");
const assert = std.debug.assert;
const net = @This();
const mem = std.mem;
const os = std.os;
const fs = std.fs;
test "" {
_ = @import("net/test.zig");
}
const has_unix_sockets = @hasDecl(os, "sockaddr_un");
pub const Address = extern union {
any: os.sockaddr,
in: os.sockaddr_in,
in6: os.sockaddr_in6,
un: if (has_unix_sockets) os.sockaddr_un else void,
// TODO this crashed the compiler. https://github.com/ziglang/zig/issues/3512
//pub const localhost = initIp4(parseIp4("127.0.0.1") catch unreachable, 0);
pub fn parseIp(name: []const u8, port: u16) !Address {
if (parseIp4(name, port)) |ip4| return ip4 else |err| switch (err) {
error.Overflow,
error.InvalidEnd,
error.InvalidCharacter,
error.Incomplete,
=> {},
}
if (parseIp6(name, port)) |ip6| return ip6 else |err| switch (err) {
error.Overflow,
error.InvalidEnd,
error.InvalidCharacter,
error.Incomplete,
error.InvalidIpv4Mapping,
=> {},
}
return error.InvalidIPAddressFormat;
}
pub fn parseExpectingFamily(name: []const u8, family: os.sa_family_t, port: u16) !Address {
switch (family) {
os.AF_INET => return parseIp4(name, port),
os.AF_INET6 => return parseIp6(name, port),
os.AF_UNSPEC => return parseIp(name, port),
else => unreachable,
}
}
pub fn parseIp6(buf: []const u8, port: u16) !Address {
var result = Address{
.in6 = os.sockaddr_in6{
.scope_id = 0,
.port = mem.nativeToBig(u16, port),
.flowinfo = 0,
.addr = undefined,
},
};
var ip_slice = result.in6.addr[0..];
var tail: [16]u8 = undefined;
var x: u16 = 0;
var saw_any_digits = false;
var index: u8 = 0;
var scope_id = false;
var abbrv = false;
for (buf) |c, i| {
if (scope_id) {
if (c >= '0' and c <= '9') {
const digit = c - '0';
if (@mulWithOverflow(u32, result.in6.scope_id, 10, &result.in6.scope_id)) {
return error.Overflow;
}
if (@addWithOverflow(u32, result.in6.scope_id, digit, &result.in6.scope_id)) {
return error.Overflow;
}
} else {
return error.InvalidCharacter;
}
} else if (c == ':') {
if (!saw_any_digits) {
if (abbrv) return error.InvalidCharacter; // ':::'
if (i != 0) abbrv = true;
mem.set(u8, ip_slice[index..], 0);
ip_slice = tail[0..];
index = 0;
continue;
}
if (index == 14) {
return error.InvalidEnd;
}
ip_slice[index] = @truncate(u8, x >> 8);
index += 1;
ip_slice[index] = @truncate(u8, 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 = (parseIp4(buf[start_index..], 0) catch {
return error.InvalidIpv4Mapping;
}).in.addr;
ip_slice = result.in6.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);
if (@mulWithOverflow(u16, x, 16, &x)) {
return error.Overflow;
}
if (@addWithOverflow(u16, x, digit, &x)) {
return error.Overflow;
}
saw_any_digits = true;
}
}
if (!saw_any_digits and !abbrv) {
return error.Incomplete;
}
if (index == 14) {
ip_slice[14] = @truncate(u8, x >> 8);
ip_slice[15] = @truncate(u8, x);
return result;
} else {
ip_slice[index] = @truncate(u8, x >> 8);
index += 1;
ip_slice[index] = @truncate(u8, x);
index += 1;
mem.copy(u8, result.in6.addr[16 - index ..], ip_slice[0..index]);
return result;
}
}
pub fn parseIp4(buf: []const u8, port: u16) !Address {
var result = Address{
.in = os.sockaddr_in{
.port = mem.nativeToBig(u16, port),
.addr = undefined,
},
};
const out_ptr = mem.sliceAsBytes(@as(*[1]u32, &result.in.addr)[0..]);
var x: u8 = 0;
var index: u8 = 0;
var saw_any_digits = false;
for (buf) |c| {
if (c == '.') {
if (!saw_any_digits) {
return error.InvalidCharacter;
}
if (index == 3) {
return error.InvalidEnd;
}
out_ptr[index] = x;
index += 1;
x = 0;
saw_any_digits = false;
} else if (c >= '0' and c <= '9') {
saw_any_digits = true;
x = try std.math.mul(u8, x, 10);
x = try std.math.add(u8, x, c - '0');
} else {
return error.InvalidCharacter;
}
}
if (index == 3 and saw_any_digits) {
out_ptr[index] = x;
return result;
}
return error.Incomplete;
}
pub fn initIp4(addr: [4]u8, port: u16) Address {
return Address{
.in = os.sockaddr_in{
.port = mem.nativeToBig(u16, port),
.addr = @ptrCast(*align(1) const u32, &addr).*,
},
};
}
pub fn initIp6(addr: [16]u8, port: u16, flowinfo: u32, scope_id: u32) Address {
return Address{
.in6 = os.sockaddr_in6{
.addr = addr,
.port = mem.nativeToBig(u16, port),
.flowinfo = flowinfo,
.scope_id = scope_id,
},
};
}
pub fn initUnix(path: []const u8) !Address {
var sock_addr = os.sockaddr_un{
.family = os.AF_UNIX,
.path = undefined,
};
// this enables us to have the proper length of the socket in getOsSockLen
mem.set(u8, &sock_addr.path, 0);
if (path.len > sock_addr.path.len) return error.NameTooLong;
mem.copy(u8, &sock_addr.path, path);
return Address{ .un = sock_addr };
}
/// Returns the port in native endian.
/// Asserts that the address is ip4 or ip6.
pub fn getPort(self: Address) u16 {
const big_endian_port = switch (self.any.family) {
os.AF_INET => self.in.port,
os.AF_INET6 => self.in6.port,
else => unreachable,
};
return mem.bigToNative(u16, big_endian_port);
}
/// `port` is native-endian.
/// Asserts that the address is ip4 or ip6.
pub fn setPort(self: *Address, port: u16) void {
const ptr = switch (self.any.family) {
os.AF_INET => &self.in.port,
os.AF_INET6 => &self.in6.port,
else => unreachable,
};
ptr.* = mem.nativeToBig(u16, port);
}
/// Asserts that `addr` is an IP address.
/// This function will read past the end of the pointer, with a size depending
/// on the address family.
pub fn initPosix(addr: *align(4) const os.sockaddr) Address {
switch (addr.family) {
os.AF_INET => return Address{ .in = @ptrCast(*const os.sockaddr_in, addr).* },
os.AF_INET6 => return Address{ .in6 = @ptrCast(*const os.sockaddr_in6, addr).* },
else => unreachable,
}
}
pub fn format(
self: Address,
comptime fmt: []const u8,
options: std.fmt.FormatOptions,
out_stream: var,
) !void {
switch (self.any.family) {
os.AF_INET => {
const port = mem.bigToNative(u16, self.in.port);
const bytes = @ptrCast(*const [4]u8, &self.in.addr);
try std.fmt.format(out_stream, "{}.{}.{}.{}:{}", .{
bytes[0],
bytes[1],
bytes[2],
bytes[3],
port,
});
},
os.AF_INET6 => {
const port = mem.bigToNative(u16, self.in6.port);
if (mem.eql(u8, self.in6.addr[0..12], &[_]u8{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff })) {
try std.fmt.format(out_stream, "[::ffff:{}.{}.{}.{}]:{}", .{
self.in6.addr[12],
self.in6.addr[13],
self.in6.addr[14],
self.in6.addr[15],
port,
});
return;
}
const big_endian_parts = @ptrCast(*align(1) const [8]u16, &self.in6.addr);
const native_endian_parts = switch (builtin.endian) {
.Big => big_endian_parts.*,
.Little => blk: {
var buf: [8]u16 = undefined;
for (big_endian_parts) |part, i| {
buf[i] = mem.bigToNative(u16, part);
}
break :blk buf;
},
};
try out_stream.writeAll("[");
var i: usize = 0;
var abbrv = false;
while (i < native_endian_parts.len) : (i += 1) {
if (native_endian_parts[i] == 0) {
if (!abbrv) {
try out_stream.writeAll(if (i == 0) "::" else ":");
abbrv = true;
}
continue;
}
try std.fmt.format(out_stream, "{x}", .{native_endian_parts[i]});
if (i != native_endian_parts.len - 1) {
try out_stream.writeAll(":");
}
}
try std.fmt.format(out_stream, "]:{}", .{port});
},
os.AF_UNIX => {
if (!has_unix_sockets) {
unreachable;
}
try std.fmt.format(out_stream, "{}", .{&self.un.path});
},
else => unreachable,
}
}
pub fn eql(a: Address, b: Address) bool {
const a_bytes = @ptrCast([*]const u8, &a.any)[0..a.getOsSockLen()];
const b_bytes = @ptrCast([*]const u8, &b.any)[0..b.getOsSockLen()];
return mem.eql(u8, a_bytes, b_bytes);
}
pub fn getOsSockLen(self: Address) os.socklen_t {
switch (self.any.family) {
os.AF_INET => return @sizeOf(os.sockaddr_in),
os.AF_INET6 => return @sizeOf(os.sockaddr_in6),
os.AF_UNIX => {
if (!has_unix_sockets) {
unreachable;
}
const path_len = std.mem.len(@ptrCast([*:0]const u8, &self.un.path));
return @intCast(os.socklen_t, @sizeOf(os.sockaddr_un) - self.un.path.len + path_len);
},
else => unreachable,
}
}
};
pub fn connectUnixSocket(path: []const u8) !fs.File {
const opt_non_block = if (std.io.is_async) os.SOCK_NONBLOCK else 0;
const sockfd = try os.socket(
os.AF_UNIX,
os.SOCK_STREAM | os.SOCK_CLOEXEC | opt_non_block,
0,
);
errdefer os.close(sockfd);
var addr = try std.net.Address.initUnix(path);
try os.connect(
sockfd,
&addr.any,
addr.getOsSockLen(),
);
return fs.File{
.handle = sockfd,
};
}
pub const AddressList = struct {
arena: std.heap.ArenaAllocator,
addrs: []Address,
canon_name: ?[]u8,
pub fn deinit(self: *AddressList) void {
// Here we copy the arena allocator into stack memory, because
// otherwise it would destroy itself while it was still working.
var arena = self.arena;
arena.deinit();
// self is destroyed
}
};
/// All memory allocated with `allocator` will be freed before this function returns.
pub fn tcpConnectToHost(allocator: *mem.Allocator, name: []const u8, port: u16) !fs.File {
const list = try getAddressList(allocator, name, port);
defer list.deinit();
if (list.addrs.len == 0) return error.UnknownHostName;
return tcpConnectToAddress(list.addrs[0]);
}
pub fn tcpConnectToAddress(address: Address) !fs.File {
const nonblock = if (std.io.is_async) os.SOCK_NONBLOCK else 0;
const sock_flags = os.SOCK_STREAM | os.SOCK_CLOEXEC | nonblock;
const sockfd = try os.socket(address.any.family, sock_flags, os.IPPROTO_TCP);
errdefer os.close(sockfd);
try os.connect(sockfd, &address.any, address.getOsSockLen());
return fs.File{ .handle = sockfd };
}
/// Call `AddressList.deinit` on the result.
pub fn getAddressList(allocator: *mem.Allocator, name: []const u8, port: u16) !*AddressList {
const result = blk: {
var arena = std.heap.ArenaAllocator.init(allocator);
errdefer arena.deinit();
const result = try arena.allocator.create(AddressList);
result.* = AddressList{
.arena = arena,
.addrs = undefined,
.canon_name = null,
};
break :blk result;
};
const arena = &result.arena.allocator;
errdefer result.arena.deinit();
if (builtin.link_libc) {
const c = std.c;
const name_c = try std.cstr.addNullByte(allocator, name);
defer allocator.free(name_c);
const port_c = try std.fmt.allocPrint(allocator, "{}\x00", .{port});
defer allocator.free(port_c);
const hints = os.addrinfo{
.flags = c.AI_NUMERICSERV,
.family = os.AF_UNSPEC,
.socktype = os.SOCK_STREAM,
.protocol = os.IPPROTO_TCP,
.canonname = null,
.addr = null,
.addrlen = 0,
.next = null,
};
var res: *os.addrinfo = undefined;
switch (os.system.getaddrinfo(name_c.ptr, @ptrCast([*:0]const u8, port_c.ptr), &hints, &res)) {
@intToEnum(os.system.EAI, 0) => {},
.ADDRFAMILY => return error.HostLacksNetworkAddresses,
.AGAIN => return error.TemporaryNameServerFailure,
.BADFLAGS => unreachable, // Invalid hints
.FAIL => return error.NameServerFailure,
.FAMILY => return error.AddressFamilyNotSupported,
.MEMORY => return error.OutOfMemory,
.NODATA => return error.HostLacksNetworkAddresses,
.NONAME => return error.UnknownHostName,
.SERVICE => return error.ServiceUnavailable,
.SOCKTYPE => unreachable, // Invalid socket type requested in hints
.SYSTEM => switch (os.errno(-1)) {
else => |e| return os.unexpectedErrno(e),
},
else => unreachable,
}
defer os.system.freeaddrinfo(res);
const addr_count = blk: {
var count: usize = 0;
var it: ?*os.addrinfo = res;
while (it) |info| : (it = info.next) {
if (info.addr != null) {
count += 1;
}
}
break :blk count;
};
result.addrs = try arena.alloc(Address, addr_count);
var it: ?*os.addrinfo = res;
var i: usize = 0;
while (it) |info| : (it = info.next) {
const addr = info.addr orelse continue;
result.addrs[i] = Address.initPosix(@alignCast(4, addr));
if (info.canonname) |n| {
if (result.canon_name == null) {
result.canon_name = try mem.dupe(arena, u8, mem.spanZ(n));
}
}
i += 1;
}
return result;
}
if (builtin.os.tag == .linux) {
const flags = std.c.AI_NUMERICSERV;
const family = os.AF_UNSPEC;
var lookup_addrs = std.ArrayList(LookupAddr).init(allocator);
defer lookup_addrs.deinit();
var canon = std.ArrayListSentineled(u8, 0).initNull(arena);
defer canon.deinit();
try linuxLookupName(&lookup_addrs, &canon, name, family, flags, port);
result.addrs = try arena.alloc(Address, lookup_addrs.items.len);
if (!canon.isNull()) {
result.canon_name = canon.toOwnedSlice();
}
for (lookup_addrs.span()) |lookup_addr, i| {
result.addrs[i] = lookup_addr.addr;
assert(result.addrs[i].getPort() == port);
}
return result;
}
@compileError("std.net.getAddresses unimplemented for this OS");
}
const LookupAddr = struct {
addr: Address,
sortkey: i32 = 0,
};
const DAS_USABLE = 0x40000000;
const DAS_MATCHINGSCOPE = 0x20000000;
const DAS_MATCHINGLABEL = 0x10000000;
const DAS_PREC_SHIFT = 20;
const DAS_SCOPE_SHIFT = 16;
const DAS_PREFIX_SHIFT = 8;
const DAS_ORDER_SHIFT = 0;
fn linuxLookupName(
addrs: *std.ArrayList(LookupAddr),
canon: *std.ArrayListSentineled(u8, 0),
opt_name: ?[]const u8,
family: os.sa_family_t,
flags: u32,
port: u16,
) !void {
if (opt_name) |name| {
// reject empty name and check len so it fits into temp bufs
try canon.replaceContents(name);
if (Address.parseExpectingFamily(name, family, port)) |addr| {
try addrs.append(LookupAddr{ .addr = addr });
} else |name_err| if ((flags & std.c.AI_NUMERICHOST) != 0) {
return name_err;
} else {
try linuxLookupNameFromHosts(addrs, canon, name, family, port);
if (addrs.items.len == 0) {
try linuxLookupNameFromDnsSearch(addrs, canon, name, family, port);
}
}
} else {
try canon.resize(0);
try linuxLookupNameFromNull(addrs, family, flags, port);
}
if (addrs.items.len == 0) return error.UnknownHostName;
// No further processing is needed if there are fewer than 2
// results or if there are only IPv4 results.
if (addrs.items.len == 1 or family == os.AF_INET) return;
const all_ip4 = for (addrs.span()) |addr| {
if (addr.addr.any.family != os.AF_INET) break false;
} else true;
if (all_ip4) return;
// The following implements a subset of RFC 3484/6724 destination
// address selection by generating a single 31-bit sort key for
// each address. Rules 3, 4, and 7 are omitted for having
// excessive runtime and code size cost and dubious benefit.
// So far the label/precedence table cannot be customized.
// This implementation is ported from musl libc.
// A more idiomatic "ziggy" implementation would be welcome.
for (addrs.span()) |*addr, i| {
var key: i32 = 0;
var sa6: os.sockaddr_in6 = undefined;
@memset(@ptrCast([*]u8, &sa6), 0, @sizeOf(os.sockaddr_in6));
var da6 = os.sockaddr_in6{
.family = os.AF_INET6,
.scope_id = addr.addr.in6.scope_id,
.port = 65535,
.flowinfo = 0,
.addr = [1]u8{0} ** 16,
};
var sa4: os.sockaddr_in = undefined;
@memset(@ptrCast([*]u8, &sa4), 0, @sizeOf(os.sockaddr_in));
var da4 = os.sockaddr_in{
.family = os.AF_INET,
.port = 65535,
.addr = 0,
.zero = [1]u8{0} ** 8,
};
var sa: *align(4) os.sockaddr = undefined;
var da: *align(4) os.sockaddr = undefined;
var salen: os.socklen_t = undefined;
var dalen: os.socklen_t = undefined;
if (addr.addr.any.family == os.AF_INET6) {
mem.copy(u8, &da6.addr, &addr.addr.in6.addr);
da = @ptrCast(*os.sockaddr, &da6);
dalen = @sizeOf(os.sockaddr_in6);
sa = @ptrCast(*os.sockaddr, &sa6);
salen = @sizeOf(os.sockaddr_in6);
} else {
mem.copy(u8, &sa6.addr, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff");
mem.copy(u8, &da6.addr, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff");
mem.writeIntNative(u32, da6.addr[12..], addr.addr.in.addr);
da4.addr = addr.addr.in.addr;
da = @ptrCast(*os.sockaddr, &da4);
dalen = @sizeOf(os.sockaddr_in);
sa = @ptrCast(*os.sockaddr, &sa4);
salen = @sizeOf(os.sockaddr_in);
}
const dpolicy = policyOf(da6.addr);
const dscope: i32 = scopeOf(da6.addr);
const dlabel = dpolicy.label;
const dprec: i32 = dpolicy.prec;
const MAXADDRS = 3;
var prefixlen: i32 = 0;
const sock_flags = os.SOCK_DGRAM | os.SOCK_CLOEXEC;
if (os.socket(addr.addr.any.family, sock_flags, os.IPPROTO_UDP)) |fd| syscalls: {
defer os.close(fd);
os.connect(fd, da, dalen) catch break :syscalls;
key |= DAS_USABLE;
os.getsockname(fd, sa, &salen) catch break :syscalls;
if (addr.addr.any.family == os.AF_INET) {
// TODO sa6.addr[12..16] should return *[4]u8, making this cast unnecessary.
mem.writeIntNative(u32, @ptrCast(*[4]u8, &sa6.addr[12]), sa4.addr);
}
if (dscope == @as(i32, scopeOf(sa6.addr))) key |= DAS_MATCHINGSCOPE;
if (dlabel == labelOf(sa6.addr)) key |= DAS_MATCHINGLABEL;
prefixlen = prefixMatch(sa6.addr, da6.addr);
} else |_| {}
key |= dprec << DAS_PREC_SHIFT;
key |= (15 - dscope) << DAS_SCOPE_SHIFT;
key |= prefixlen << DAS_PREFIX_SHIFT;
key |= (MAXADDRS - @intCast(i32, i)) << DAS_ORDER_SHIFT;
addr.sortkey = key;
}
std.sort.sort(LookupAddr, addrs.span(), addrCmpLessThan);
}
const Policy = struct {
addr: [16]u8,
len: u8,
mask: u8,
prec: u8,
label: u8,
};
const defined_policies = [_]Policy{
Policy{
.addr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01".*,
.len = 15,
.mask = 0xff,
.prec = 50,
.label = 0,
},
Policy{
.addr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x00".*,
.len = 11,
.mask = 0xff,
.prec = 35,
.label = 4,
},
Policy{
.addr = "\x20\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00".*,
.len = 1,
.mask = 0xff,
.prec = 30,
.label = 2,
},
Policy{
.addr = "\x20\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00".*,
.len = 3,
.mask = 0xff,
.prec = 5,
.label = 5,
},
Policy{
.addr = "\xfc\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00".*,
.len = 0,
.mask = 0xfe,
.prec = 3,
.label = 13,
},
// These are deprecated and/or returned to the address
// pool, so despite the RFC, treating them as special
// is probably wrong.
// { "", 11, 0xff, 1, 3 },
// { "\xfe\xc0", 1, 0xc0, 1, 11 },
// { "\x3f\xfe", 1, 0xff, 1, 12 },
// Last rule must match all addresses to stop loop.
Policy{
.addr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00".*,
.len = 0,
.mask = 0,
.prec = 40,
.label = 1,
},
};
fn policyOf(a: [16]u8) *const Policy {
for (defined_policies) |*policy| {
if (!mem.eql(u8, a[0..policy.len], policy.addr[0..policy.len])) continue;
if ((a[policy.len] & policy.mask) != policy.addr[policy.len]) continue;
return policy;
}
unreachable;
}
fn scopeOf(a: [16]u8) u8 {
if (IN6_IS_ADDR_MULTICAST(a)) return a[1] & 15;
if (IN6_IS_ADDR_LINKLOCAL(a)) return 2;
if (IN6_IS_ADDR_LOOPBACK(a)) return 2;
if (IN6_IS_ADDR_SITELOCAL(a)) return 5;
return 14;
}
fn prefixMatch(s: [16]u8, d: [16]u8) u8 {
// TODO: This FIXME inherited from porting from musl libc.
// I don't want this to go into zig std lib 1.0.0.
// FIXME: The common prefix length should be limited to no greater
// than the nominal length of the prefix portion of the source
// address. However the definition of the source prefix length is
// not clear and thus this limiting is not yet implemented.
var i: u8 = 0;
while (i < 128 and ((s[i / 8] ^ d[i / 8]) & (@as(u8, 128) >> @intCast(u3, i % 8))) == 0) : (i += 1) {}
return i;
}
fn labelOf(a: [16]u8) u8 {
return policyOf(a).label;
}
fn IN6_IS_ADDR_MULTICAST(a: [16]u8) bool {
return a[0] == 0xff;
}
fn IN6_IS_ADDR_LINKLOCAL(a: [16]u8) bool {
return a[0] == 0xfe and (a[1] & 0xc0) == 0x80;
}
fn IN6_IS_ADDR_LOOPBACK(a: [16]u8) bool {
return a[0] == 0 and a[1] == 0 and
a[2] == 0 and
a[12] == 0 and a[13] == 0 and
a[14] == 0 and a[15] == 1;
}
fn IN6_IS_ADDR_SITELOCAL(a: [16]u8) bool {
return a[0] == 0xfe and (a[1] & 0xc0) == 0xc0;
}
// Parameters `b` and `a` swapped to make this descending.
fn addrCmpLessThan(b: LookupAddr, a: LookupAddr) bool {
return a.sortkey < b.sortkey;
}
fn linuxLookupNameFromNull(
addrs: *std.ArrayList(LookupAddr),
family: os.sa_family_t,
flags: u32,
port: u16,
) !void {
if ((flags & std.c.AI_PASSIVE) != 0) {
if (family != os.AF_INET6) {
(try addrs.addOne()).* = LookupAddr{
.addr = Address.initIp4([1]u8{0} ** 4, port),
};
}
if (family != os.AF_INET) {
(try addrs.addOne()).* = LookupAddr{
.addr = Address.initIp6([1]u8{0} ** 16, port, 0, 0),
};
}
} else {
if (family != os.AF_INET6) {
(try addrs.addOne()).* = LookupAddr{
.addr = Address.initIp4([4]u8{ 127, 0, 0, 1 }, port),
};
}
if (family != os.AF_INET) {
(try addrs.addOne()).* = LookupAddr{
.addr = Address.initIp6(([1]u8{0} ** 15) ++ [1]u8{1}, port, 0, 0),
};
}
}
}
fn linuxLookupNameFromHosts(
addrs: *std.ArrayList(LookupAddr),
canon: *std.ArrayListSentineled(u8, 0),
name: []const u8,
family: os.sa_family_t,
port: u16,
) !void {
const file = fs.openFileAbsoluteZ("/etc/hosts", .{}) catch |err| switch (err) {
error.FileNotFound,
error.NotDir,
error.AccessDenied,
=> return,
else => |e| return e,
};
defer file.close();
const stream = std.io.bufferedInStream(file.inStream()).inStream();
var line_buf: [512]u8 = undefined;
while (stream.readUntilDelimiterOrEof(&line_buf, '\n') catch |err| switch (err) {
error.StreamTooLong => blk: {
// Skip to the delimiter in the stream, to fix parsing
try stream.skipUntilDelimiterOrEof('\n');
// Use the truncated line. A truncated comment or hostname will be handled correctly.
break :blk &line_buf;
},
else => |e| return e,
}) |line| {
const no_comment_line = mem.split(line, "#").next().?;
var line_it = mem.tokenize(no_comment_line, " \t");
const ip_text = line_it.next() orelse continue;
var first_name_text: ?[]const u8 = null;
while (line_it.next()) |name_text| {
if (first_name_text == null) first_name_text = name_text;
if (mem.eql(u8, name_text, name)) {
break;
}
} else continue;
const addr = Address.parseExpectingFamily(ip_text, family, port) catch |err| switch (err) {
error.Overflow,
error.InvalidEnd,
error.InvalidCharacter,
error.Incomplete,
error.InvalidIPAddressFormat,
error.InvalidIpv4Mapping,
=> continue,
};
try addrs.append(LookupAddr{ .addr = addr });
// first name is canonical name
const name_text = first_name_text.?;
if (isValidHostName(name_text)) {
try canon.replaceContents(name_text);
}
}
}
pub fn isValidHostName(hostname: []const u8) bool {
if (hostname.len >= 254) return false;
if (!std.unicode.utf8ValidateSlice(hostname)) return false;
for (hostname) |byte| {
if (byte >= 0x80 or byte == '.' or byte == '-' or std.ascii.isAlNum(byte)) {
continue;
}
return false;
}
return true;
}
fn linuxLookupNameFromDnsSearch(
addrs: *std.ArrayList(LookupAddr),
canon: *std.ArrayListSentineled(u8, 0),
name: []const u8,
family: os.sa_family_t,
port: u16,
) !void {
var rc: ResolvConf = undefined;
try getResolvConf(addrs.allocator, &rc);
defer rc.deinit();
// Count dots, suppress search when >=ndots or name ends in
// a dot, which is an explicit request for global scope.
var dots: usize = 0;
for (name) |byte| {
if (byte == '.') dots += 1;
}
const search = if (rc.search.isNull() or dots >= rc.ndots or mem.endsWith(u8, name, "."))
&[_]u8{}
else
rc.search.span();
var canon_name = name;
// Strip final dot for canon, fail if multiple trailing dots.
if (mem.endsWith(u8, canon_name, ".")) canon_name.len -= 1;
if (mem.endsWith(u8, canon_name, ".")) return error.UnknownHostName;
// Name with search domain appended is setup in canon[]. This both
// provides the desired default canonical name (if the requested
// name is not a CNAME record) and serves as a buffer for passing
// the full requested name to name_from_dns.
try canon.resize(canon_name.len);
mem.copy(u8, canon.span(), canon_name);
try canon.append('.');
var tok_it = mem.tokenize(search, " \t");
while (tok_it.next()) |tok| {
canon.shrink(canon_name.len + 1);
try canon.appendSlice(tok);
try linuxLookupNameFromDns(addrs, canon, canon.span(), family, rc, port);
if (addrs.items.len != 0) return;
}
canon.shrink(canon_name.len);
return linuxLookupNameFromDns(addrs, canon, name, family, rc, port);
}
const dpc_ctx = struct {
addrs: *std.ArrayList(LookupAddr),
canon: *std.ArrayListSentineled(u8, 0),
port: u16,
};
fn linuxLookupNameFromDns(
addrs: *std.ArrayList(LookupAddr),
canon: *std.ArrayListSentineled(u8, 0),
name: []const u8,
family: os.sa_family_t,
rc: ResolvConf,
port: u16,
) !void {
var ctx = dpc_ctx{
.addrs = addrs,
.canon = canon,
.port = port,
};
const AfRr = struct {
af: os.sa_family_t,
rr: u8,
};
const afrrs = [_]AfRr{
AfRr{ .af = os.AF_INET6, .rr = os.RR_A },
AfRr{ .af = os.AF_INET, .rr = os.RR_AAAA },
};
var qbuf: [2][280]u8 = undefined;
var abuf: [2][512]u8 = undefined;
var qp: [2][]const u8 = undefined;
const apbuf = [2][]u8{ &abuf[0], &abuf[1] };
var nq: usize = 0;
for (afrrs) |afrr| {
if (family != afrr.af) {
const len = os.res_mkquery(0, name, 1, afrr.rr, &[_]u8{}, null, &qbuf[nq]);
qp[nq] = qbuf[nq][0..len];
nq += 1;
}
}
var ap = [2][]u8{ apbuf[0], apbuf[1] };
ap[0].len = 0;
ap[1].len = 0;
try resMSendRc(qp[0..nq], ap[0..nq], apbuf[0..nq], rc);
var i: usize = 0;
while (i < nq) : (i += 1) {
dnsParse(ap[i], ctx, dnsParseCallback) catch {};
}
if (addrs.items.len != 0) return;
if (ap[0].len < 4 or (ap[0][3] & 15) == 2) return error.TemporaryNameServerFailure;
if ((ap[0][3] & 15) == 0) return error.UnknownHostName;
if ((ap[0][3] & 15) == 3) return;
return error.NameServerFailure;
}
const ResolvConf = struct {
attempts: u32,
ndots: u32,
timeout: u32,
search: std.ArrayListSentineled(u8, 0),
ns: std.ArrayList(LookupAddr),
fn deinit(rc: *ResolvConf) void {
rc.ns.deinit();
rc.search.deinit();
rc.* = undefined;
}
};
/// Ignores lines longer than 512 bytes.
/// TODO: https://github.com/ziglang/zig/issues/2765 and https://github.com/ziglang/zig/issues/2761
fn getResolvConf(allocator: *mem.Allocator, rc: *ResolvConf) !void {
rc.* = ResolvConf{
.ns = std.ArrayList(LookupAddr).init(allocator),
.search = std.ArrayListSentineled(u8, 0).initNull(allocator),
.ndots = 1,
.timeout = 5,
.attempts = 2,
};
errdefer rc.deinit();
const file = fs.openFileAbsoluteZ("/etc/resolv.conf", .{}) catch |err| switch (err) {
error.FileNotFound,
error.NotDir,
error.AccessDenied,
=> return linuxLookupNameFromNumericUnspec(&rc.ns, "127.0.0.1", 53),
else => |e| return e,
};
defer file.close();
const stream = std.io.bufferedInStream(file.inStream()).inStream();
var line_buf: [512]u8 = undefined;
while (stream.readUntilDelimiterOrEof(&line_buf, '\n') catch |err| switch (err) {
error.StreamTooLong => blk: {
// Skip to the delimiter in the stream, to fix parsing
try stream.skipUntilDelimiterOrEof('\n');
// Give an empty line to the while loop, which will be skipped.
break :blk line_buf[0..0];
},
else => |e| return e,
}) |line| {
const no_comment_line = mem.split(line, "#").next().?;
var line_it = mem.tokenize(no_comment_line, " \t");
const token = line_it.next() orelse continue;
if (mem.eql(u8, token, "options")) {
while (line_it.next()) |sub_tok| {
var colon_it = mem.split(sub_tok, ":");
const name = colon_it.next().?;
const value_txt = colon_it.next() orelse continue;
const value = std.fmt.parseInt(u8, value_txt, 10) catch |err| switch (err) {
error.Overflow => 255,
error.InvalidCharacter => continue,
};
if (mem.eql(u8, name, "ndots")) {
rc.ndots = std.math.min(value, 15);
} else if (mem.eql(u8, name, "attempts")) {
rc.attempts = std.math.min(value, 10);
} else if (mem.eql(u8, name, "timeout")) {
rc.timeout = std.math.min(value, 60);
}
}
} else if (mem.eql(u8, token, "nameserver")) {
const ip_txt = line_it.next() orelse continue;
try linuxLookupNameFromNumericUnspec(&rc.ns, ip_txt, 53);
} else if (mem.eql(u8, token, "domain") or mem.eql(u8, token, "search")) {
try rc.search.replaceContents(line_it.rest());
}
}
if (rc.ns.items.len == 0) {
return linuxLookupNameFromNumericUnspec(&rc.ns, "127.0.0.1", 53);
}
}
fn linuxLookupNameFromNumericUnspec(
addrs: *std.ArrayList(LookupAddr),
name: []const u8,
port: u16,
) !void {
const addr = try Address.parseIp(name, port);
(try addrs.addOne()).* = LookupAddr{ .addr = addr };
}
fn resMSendRc(
queries: []const []const u8,
answers: [][]u8,
answer_bufs: []const []u8,
rc: ResolvConf,
) !void {
const timeout = 1000 * rc.timeout;
const attempts = rc.attempts;
var sl: os.socklen_t = @sizeOf(os.sockaddr_in);
var family: os.sa_family_t = os.AF_INET;
var ns_list = std.ArrayList(Address).init(rc.ns.allocator);
defer ns_list.deinit();
try ns_list.resize(rc.ns.items.len);
const ns = ns_list.span();
for (rc.ns.span()) |iplit, i| {
ns[i] = iplit.addr;
assert(ns[i].getPort() == 53);
if (iplit.addr.any.family != os.AF_INET) {
sl = @sizeOf(os.sockaddr_in6);
family = os.AF_INET6;
}
}
// Get local address and open/bind a socket
var sa: Address = undefined;
@memset(@ptrCast([*]u8, &sa), 0, @sizeOf(Address));
sa.any.family = family;
const flags = os.SOCK_DGRAM | os.SOCK_CLOEXEC | os.SOCK_NONBLOCK;
const fd = os.socket(family, flags, 0) catch |err| switch (err) {
error.AddressFamilyNotSupported => blk: {
// Handle case where system lacks IPv6 support
if (family == os.AF_INET6) {
family = os.AF_INET;
break :blk try os.socket(os.AF_INET, flags, 0);
}
return err;
},
else => |e| return e,
};
defer os.close(fd);
try os.bind(fd, &sa.any, sl);
// Past this point, there are no errors. Each individual query will
// yield either no reply (indicated by zero length) or an answer
// packet which is up to the caller to interpret.
// Convert any IPv4 addresses in a mixed environment to v4-mapped
// TODO
//if (family == AF_INET6) {
// setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &(int){0}, sizeof 0);
// for (i=0; i<nns; i++) {
// if (ns[i].sin.sin_family != AF_INET) continue;
// memcpy(ns[i].sin6.sin6_addr.s6_addr+12,
// &ns[i].sin.sin_addr, 4);
// memcpy(ns[i].sin6.sin6_addr.s6_addr,
// "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
// ns[i].sin6.sin6_family = AF_INET6;
// ns[i].sin6.sin6_flowinfo = 0;
// ns[i].sin6.sin6_scope_id = 0;
// }
//}
var pfd = [1]os.pollfd{os.pollfd{
.fd = fd,
.events = os.POLLIN,
.revents = undefined,
}};
const retry_interval = timeout / attempts;
var next: u32 = 0;
var t2: u64 = @bitCast(u64, std.time.milliTimestamp());
var t0 = t2;
var t1 = t2 - retry_interval;
var servfail_retry: usize = undefined;
outer: while (t2 - t0 < timeout) : (t2 = @bitCast(u64, std.time.milliTimestamp())) {
if (t2 - t1 >= retry_interval) {
// Query all configured nameservers in parallel
var i: usize = 0;
while (i < queries.len) : (i += 1) {
if (answers[i].len == 0) {
var j: usize = 0;
while (j < ns.len) : (j += 1) {
_ = os.sendto(fd, queries[i], os.MSG_NOSIGNAL, &ns[j].any, sl) catch undefined;
}
}
}
t1 = t2;
servfail_retry = 2 * queries.len;
}
// Wait for a response, or until time to retry
const clamped_timeout = std.math.min(@as(u31, std.math.maxInt(u31)), t1 + retry_interval - t2);
const nevents = os.poll(&pfd, clamped_timeout) catch 0;
if (nevents == 0) continue;
while (true) {
var sl_copy = sl;
const rlen = os.recvfrom(fd, answer_bufs[next], 0, &sa.any, &sl_copy) catch break;
// Ignore non-identifiable packets
if (rlen < 4) continue;
// Ignore replies from addresses we didn't send to
var j: usize = 0;
while (j < ns.len and !ns[j].eql(sa)) : (j += 1) {}
if (j == ns.len) continue;
// Find which query this answer goes with, if any
var i: usize = next;
while (i < queries.len and (answer_bufs[next][0] != queries[i][0] or
answer_bufs[next][1] != queries[i][1])) : (i += 1)
{}
if (i == queries.len) continue;
if (answers[i].len != 0) continue;
// Only accept positive or negative responses;
// retry immediately on server failure, and ignore
// all other codes such as refusal.
switch (answer_bufs[next][3] & 15) {
0, 3 => {},
2 => if (servfail_retry != 0) {
servfail_retry -= 1;
_ = os.sendto(fd, queries[i], os.MSG_NOSIGNAL, &ns[j].any, sl) catch undefined;
},
else => continue,
}
// Store answer in the right slot, or update next
// available temp slot if it's already in place.
answers[i].len = rlen;
if (i == next) {
while (next < queries.len and answers[next].len != 0) : (next += 1) {}
} else {
mem.copy(u8, answer_bufs[i], answer_bufs[next][0..rlen]);
}
if (next == queries.len) break :outer;
}
}
}
fn dnsParse(
r: []const u8,
ctx: var,
comptime callback: var,
) !void {
// This implementation is ported from musl libc.
// A more idiomatic "ziggy" implementation would be welcome.
if (r.len < 12) return error.InvalidDnsPacket;
if ((r[3] & 15) != 0) return;
var p = r.ptr + 12;
var qdcount = r[4] * @as(usize, 256) + r[5];
var ancount = r[6] * @as(usize, 256) + r[7];
if (qdcount + ancount > 64) return error.InvalidDnsPacket;
while (qdcount != 0) {
qdcount -= 1;
while (@ptrToInt(p) - @ptrToInt(r.ptr) < r.len and p[0] -% 1 < 127) p += 1;
if (p[0] > 193 or (p[0] == 193 and p[1] > 254) or @ptrToInt(p) > @ptrToInt(r.ptr) + r.len - 6)
return error.InvalidDnsPacket;
p += @as(usize, 5) + @boolToInt(p[0] != 0);
}
while (ancount != 0) {
ancount -= 1;
while (@ptrToInt(p) - @ptrToInt(r.ptr) < r.len and p[0] -% 1 < 127) p += 1;
if (p[0] > 193 or (p[0] == 193 and p[1] > 254) or @ptrToInt(p) > @ptrToInt(r.ptr) + r.len - 6)
return error.InvalidDnsPacket;
p += @as(usize, 1) + @boolToInt(p[0] != 0);
const len = p[8] * @as(usize, 256) + p[9];
if (@ptrToInt(p) + len > @ptrToInt(r.ptr) + r.len) return error.InvalidDnsPacket;
try callback(ctx, p[1], p[10 .. 10 + len], r);
p += 10 + len;
}
}
fn dnsParseCallback(ctx: dpc_ctx, rr: u8, data: []const u8, packet: []const u8) !void {
switch (rr) {
os.RR_A => {
if (data.len != 4) return error.InvalidDnsARecord;
const new_addr = try ctx.addrs.addOne();
new_addr.* = LookupAddr{
// TODO slice [0..4] to make this *[4]u8 without @ptrCast
.addr = Address.initIp4(@ptrCast(*const [4]u8, data.ptr).*, ctx.port),
};
},
os.RR_AAAA => {
if (data.len != 16) return error.InvalidDnsAAAARecord;
const new_addr = try ctx.addrs.addOne();
new_addr.* = LookupAddr{
// TODO slice [0..16] to make this *[16]u8 without @ptrCast
.addr = Address.initIp6(@ptrCast(*const [16]u8, data.ptr).*, ctx.port, 0, 0),
};
},
os.RR_CNAME => {
var tmp: [256]u8 = undefined;
// Returns len of compressed name. strlen to get canon name.
_ = try os.dn_expand(packet, data, &tmp);
const canon_name = mem.spanZ(@ptrCast([*:0]const u8, &tmp));
if (isValidHostName(canon_name)) {
try ctx.canon.replaceContents(canon_name);
}
},
else => return,
}
}
pub const StreamServer = struct {
/// Copied from `Options` on `init`.
kernel_backlog: u32,
reuse_address: bool,
/// `undefined` until `listen` returns successfully.
listen_address: Address,
sockfd: ?os.fd_t,
pub const Options = struct {
/// How many connections the kernel will accept on the application's behalf.
/// If more than this many connections pool in the kernel, clients will start
/// seeing "Connection refused".
kernel_backlog: u32 = 128,
/// Enable SO_REUSEADDR on the socket.
reuse_address: bool = false,
};
/// After this call succeeds, resources have been acquired and must
/// be released with `deinit`.
pub fn init(options: Options) StreamServer {
return StreamServer{
.sockfd = null,
.kernel_backlog = options.kernel_backlog,
.reuse_address = options.reuse_address,
.listen_address = undefined,
};
}
/// Release all resources. The `StreamServer` memory becomes `undefined`.
pub fn deinit(self: *StreamServer) void {
self.close();
self.* = undefined;
}
pub fn listen(self: *StreamServer, address: Address) !void {
const nonblock = if (std.io.is_async) os.SOCK_NONBLOCK else 0;
const sock_flags = os.SOCK_STREAM | os.SOCK_CLOEXEC | nonblock;
const proto = if (address.any.family == os.AF_UNIX) @as(u32, 0) else os.IPPROTO_TCP;
const sockfd = try os.socket(address.any.family, sock_flags, proto);
self.sockfd = sockfd;
errdefer {
os.close(sockfd);
self.sockfd = null;
}
if (self.reuse_address) {
try os.setsockopt(
self.sockfd.?,
os.SOL_SOCKET,
os.SO_REUSEADDR,
&mem.toBytes(@as(c_int, 1)),
);
}
var socklen = address.getOsSockLen();
try os.bind(sockfd, &address.any, socklen);
try os.listen(sockfd, self.kernel_backlog);
try os.getsockname(sockfd, &self.listen_address.any, &socklen);
}
/// Stop listening. It is still necessary to call `deinit` after stopping listening.
/// Calling `deinit` will automatically call `close`. It is safe to call `close` when
/// not listening.
pub fn close(self: *StreamServer) void {
if (self.sockfd) |fd| {
os.close(fd);
self.sockfd = null;
self.listen_address = undefined;
}
}
pub const AcceptError = error{
ConnectionAborted,
/// The per-process limit on the number of open file descriptors has been reached.
ProcessFdQuotaExceeded,
/// The system-wide limit on the total number of open files has been reached.
SystemFdQuotaExceeded,
/// Not enough free memory. This often means that the memory allocation is limited
/// by the socket buffer limits, not by the system memory.
SystemResources,
ProtocolFailure,
/// Firewall rules forbid connection.
BlockedByFirewall,
/// Permission to create a socket of the specified type and/or
/// protocol is denied.
PermissionDenied,
} || os.UnexpectedError;
pub const Connection = struct {
file: fs.File,
address: Address,
};
/// If this function succeeds, the returned `Connection` is a caller-managed resource.
pub fn accept(self: *StreamServer) AcceptError!Connection {
const nonblock = if (std.io.is_async) os.SOCK_NONBLOCK else 0;
const accept_flags = nonblock | os.SOCK_CLOEXEC;
var accepted_addr: Address = undefined;
var adr_len: os.socklen_t = @sizeOf(Address);
if (os.accept(self.sockfd.?, &accepted_addr.any, &adr_len, accept_flags)) |fd| {
return Connection{
.file = fs.File{ .handle = fd },
.address = accepted_addr,
};
} else |err| switch (err) {
// We only give SOCK_NONBLOCK when I/O mode is async, in which case this error
// is handled by os.accept4.
error.WouldBlock => unreachable,
else => |e| return e,
}
}
};
Reference in New Issue View Git Blame Copy Permalink