Add library in src/ to exchange file descriptor.
This commit is contained in:
parent
b43fd57704
commit
78670e5b71
217
zig-impl/src/exchange-fd.zig
Normal file
217
zig-impl/src/exchange-fd.zig
Normal file
@ -0,0 +1,217 @@
|
||||
const std = @import("std");
|
||||
const testing = std.testing;
|
||||
const os = std.os;
|
||||
const print = std.debug.print;
|
||||
|
||||
const builtin = @import("builtin");
|
||||
const windows = std.os.windows;
|
||||
const errno = std.os.errno;
|
||||
const system = std.os.system;
|
||||
const unexpectedErrno = std.os.unexpectedErrno;
|
||||
const SendMsgError = std.os.SendMsgError;
|
||||
|
||||
const SCM_RIGHTS: c_int = 1;
|
||||
|
||||
/// This definition enables the use of Zig types with a cmsghdr structure.
|
||||
/// The oddity of this layout is that the data must be aligned to @sizeOf(usize)
|
||||
/// rather than its natural alignment.
|
||||
pub fn Cmsghdr(comptime T: type) type {
|
||||
const Header = extern struct {
|
||||
len: usize,
|
||||
level: c_int,
|
||||
@"type": c_int,
|
||||
};
|
||||
|
||||
const data_align = @sizeOf(usize);
|
||||
const data_offset = std.mem.alignForward(@sizeOf(Header), data_align);
|
||||
|
||||
return extern struct {
|
||||
const Self = @This();
|
||||
|
||||
bytes: [data_offset + @sizeOf(T)]u8 align(@alignOf(Header)),
|
||||
|
||||
pub fn init(args: struct {
|
||||
level: c_int,
|
||||
@"type": c_int,
|
||||
data: T,
|
||||
}) Self {
|
||||
var self: Self = undefined;
|
||||
self.headerPtr().* = .{
|
||||
.len = data_offset + @sizeOf(T),
|
||||
.level = args.level,
|
||||
.@"type" = args.@"type",
|
||||
};
|
||||
self.dataPtr().* = args.data;
|
||||
return self;
|
||||
}
|
||||
|
||||
// TODO: include this version if we submit a PR to add this to std
|
||||
pub fn initNoData(args: struct {
|
||||
level: c_int,
|
||||
@"type": c_int,
|
||||
}) Self {
|
||||
var self: Self = undefined;
|
||||
self.headerPtr().* = .{
|
||||
.len = data_offset + @sizeOf(T),
|
||||
.level = args.level,
|
||||
.@"type" = args.@"type",
|
||||
};
|
||||
return self;
|
||||
}
|
||||
|
||||
pub fn headerPtr(self: *Self) *Header {
|
||||
return @ptrCast(*Header, self);
|
||||
}
|
||||
pub fn dataPtr(self: *Self) *align(data_align) T {
|
||||
return @ptrCast(*T, self.bytes[data_offset..]);
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
test {
|
||||
std.testing.refAllDecls(Cmsghdr([3]std.os.fd_t));
|
||||
}
|
||||
|
||||
pub fn send_fd(sockfd: os.socket_t, msg: []const u8, fd: os.fd_t) void {
|
||||
var iov = [_]os.iovec_const{
|
||||
.{
|
||||
.iov_base = msg.ptr,
|
||||
.iov_len = msg.len,
|
||||
},
|
||||
};
|
||||
|
||||
var cmsg = Cmsghdr(os.fd_t).init(.{
|
||||
.level = os.SOL.SOCKET,
|
||||
.@"type" = SCM_RIGHTS,
|
||||
.data = fd,
|
||||
});
|
||||
|
||||
const len = os.sendmsg(sockfd, .{
|
||||
.name = undefined,
|
||||
.namelen = 0,
|
||||
.iov = &iov,
|
||||
.iovlen = iov.len,
|
||||
.control = &cmsg,
|
||||
.controllen = @sizeOf(@TypeOf(cmsg)),
|
||||
.flags = 0,
|
||||
}, 0) catch |err| {
|
||||
print("error sendmsg failed with {s}", .{@errorName(err)});
|
||||
return;
|
||||
};
|
||||
|
||||
if (len != msg.len) {
|
||||
// we don't have much choice but to exit here
|
||||
// log.err(@src(), "expected sendmsg to return {} but got {}", .{msg.len, len});
|
||||
print("expected sendmsg to return {} but got {}", .{msg.len, len});
|
||||
os.exit(0xff);
|
||||
}
|
||||
}
|
||||
|
||||
// WARNING: errors aren't RECEPTION errors.
|
||||
pub fn recvmsg(
|
||||
/// The file descriptor of the sending socket.
|
||||
sockfd: os.socket_t,
|
||||
/// Message header and iovecs
|
||||
msg: std.os.msghdr,
|
||||
flags: u32,
|
||||
) SendMsgError!usize {
|
||||
while (true) {
|
||||
var m = msg;
|
||||
const rc = system.recvmsg(sockfd, @ptrCast(*std.x.os.Socket.Message, &m), @intCast(c_int, flags));
|
||||
if (builtin.os.tag == .windows) {
|
||||
if (rc == windows.ws2_32.SOCKET_ERROR) {
|
||||
switch (windows.ws2_32.WSAGetLastError()) {
|
||||
.WSAEACCES => return error.AccessDenied,
|
||||
.WSAEADDRNOTAVAIL => return error.AddressNotAvailable,
|
||||
.WSAECONNRESET => return error.ConnectionResetByPeer,
|
||||
.WSAEMSGSIZE => return error.MessageTooBig,
|
||||
.WSAENOBUFS => return error.SystemResources,
|
||||
.WSAENOTSOCK => return error.FileDescriptorNotASocket,
|
||||
.WSAEAFNOSUPPORT => return error.AddressFamilyNotSupported,
|
||||
.WSAEDESTADDRREQ => unreachable, // A destination address is required.
|
||||
.WSAEFAULT => unreachable, // The lpBuffers, lpTo, lpOverlapped, lpNumberOfBytesSent, or lpCompletionRoutine parameters are not part of the user address space, or the lpTo parameter is too small.
|
||||
.WSAEHOSTUNREACH => return error.NetworkUnreachable,
|
||||
// TODO: WSAEINPROGRESS, WSAEINTR
|
||||
.WSAEINVAL => unreachable,
|
||||
.WSAENETDOWN => return error.NetworkSubsystemFailed,
|
||||
.WSAENETRESET => return error.ConnectionResetByPeer,
|
||||
.WSAENETUNREACH => return error.NetworkUnreachable,
|
||||
.WSAENOTCONN => return error.SocketNotConnected,
|
||||
.WSAESHUTDOWN => unreachable, // The socket has been shut down; it is not possible to WSASendTo on a socket after shutdown has been invoked with how set to SD_SEND or SD_BOTH.
|
||||
.WSAEWOULDBLOCK => return error.WouldBlock,
|
||||
.WSANOTINITIALISED => unreachable, // A successful WSAStartup call must occur before using this function.
|
||||
else => |err| return windows.unexpectedWSAError(err),
|
||||
}
|
||||
} else {
|
||||
return @intCast(usize, rc);
|
||||
}
|
||||
} else {
|
||||
switch (errno(rc)) {
|
||||
.SUCCESS => return @intCast(usize, rc),
|
||||
|
||||
.ACCES => return error.AccessDenied,
|
||||
.AGAIN => return error.WouldBlock,
|
||||
.ALREADY => return error.FastOpenAlreadyInProgress,
|
||||
.BADF => unreachable, // always a race condition
|
||||
.CONNRESET => return error.ConnectionResetByPeer,
|
||||
.DESTADDRREQ => unreachable, // The socket is not connection-mode, and no peer address is set.
|
||||
.FAULT => unreachable, // An invalid user space address was specified for an argument.
|
||||
.INTR => continue,
|
||||
.INVAL => unreachable, // Invalid argument passed.
|
||||
.ISCONN => unreachable, // connection-mode socket was connected already but a recipient was specified
|
||||
.MSGSIZE => return error.MessageTooBig,
|
||||
.NOBUFS => return error.SystemResources,
|
||||
.NOMEM => return error.SystemResources,
|
||||
.NOTSOCK => unreachable, // The file descriptor sockfd does not refer to a socket.
|
||||
.OPNOTSUPP => unreachable, // Some bit in the flags argument is inappropriate for the socket type.
|
||||
.PIPE => return error.BrokenPipe,
|
||||
.AFNOSUPPORT => return error.AddressFamilyNotSupported,
|
||||
.LOOP => return error.SymLinkLoop,
|
||||
.NAMETOOLONG => return error.NameTooLong,
|
||||
.NOENT => return error.FileNotFound,
|
||||
.NOTDIR => return error.NotDir,
|
||||
.HOSTUNREACH => return error.NetworkUnreachable,
|
||||
.NETUNREACH => return error.NetworkUnreachable,
|
||||
.NOTCONN => return error.SocketNotConnected,
|
||||
.NETDOWN => return error.NetworkSubsystemFailed,
|
||||
else => |err| return unexpectedErrno(err),
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub fn receive_fd(sockfd: os.socket_t) !os.fd_t {
|
||||
var buffer: [100]u8 = undefined;
|
||||
|
||||
var iov = [1]os.iovec{
|
||||
.{
|
||||
.iov_base = buffer[0..],
|
||||
.iov_len = buffer.len,
|
||||
},
|
||||
};
|
||||
|
||||
var cmsg = Cmsghdr(os.fd_t).init(.{
|
||||
.level = os.SOL.SOCKET,
|
||||
.@"type" = SCM_RIGHTS,
|
||||
.data = undefined,
|
||||
});
|
||||
|
||||
var msg: std.os.msghdr = .{
|
||||
.name = undefined,
|
||||
.namelen = 0,
|
||||
.iov = &iov,
|
||||
.iovlen = iov.len,
|
||||
.control = &cmsg,
|
||||
.controllen = @sizeOf(@TypeOf(cmsg)),
|
||||
.flags = 0,
|
||||
};
|
||||
|
||||
const len = recvmsg(sockfd, msg, 0) catch |err| {
|
||||
print("error sendmsg failed with {s}", .{@errorName(err)});
|
||||
return 0;
|
||||
};
|
||||
|
||||
print("received {} bytes, fd is {}\n", .{len, @as(i32, cmsg.dataPtr().*)});
|
||||
print("iov base {s}\n", .{iov[0].iov_base[0..iov[0].iov_len - 1]});
|
||||
return @as(i32, cmsg.dataPtr().*);
|
||||
}
|
||||
Reference in New Issue
Block a user