#define _LINUX_SOURCE 1
#include <sys/syscall.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/swap.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <time.h>

	if (sock_v6 != -1) {
		close(sock_v6);
	}

	return(retval);
}

#ifndef DISABLE_UNIX_SOCKETS
struct tclsystem_socket_unix__chan_id {
	int fd;
	Tcl_Channel chan;
};

static int tclsystem_socket_unix__chan_close(ClientData id_p, Tcl_Interp *interp) {
	struct tclsystem_socket_unix__chan_id *id;
	int fd;

	id = id_p;

	fd = id->fd;

	close(fd);

	free(id);

	return(TCL_OK);
}

static int tclsystem_socket_unix__chan_read(ClientData id_p, char *buf, int bufsize, int *errorCodePtr) {
	struct tclsystem_socket_unix__chan_id *id;
	ssize_t read_ret;
	int fd;
	int retval;

	id = id_p;

	fd = id->fd;

	read_ret = read(fd, buf, bufsize);
	if (read_ret < 0) {
		*errorCodePtr = errno;

		return(-1);
	}

	retval = read_ret;

	return(retval);
}

static int tclsystem_socket_unix__chan_write(ClientData id_p, const char *buf, int toWrite, int *errorCodePtr) {
	struct tclsystem_socket_unix__chan_id *id;
	ssize_t write_ret;
	int fd;
	int bytesWritten;

	id = id_p;

	fd = id->fd;

	bytesWritten = 0;
	while (toWrite) {
		write_ret = write(fd, buf, toWrite);
		if (write_ret == 0) {
			break;
		}

		if (write_ret < 0) {
			*errorCodePtr = errno;

			return(-1);
		}

		toWrite -= write_ret;
		buf += write_ret;
		bytesWritten += write_ret;
	}

	if (bytesWritten == 0) {
		*errorCodePtr = EAGAIN;

		return(-1);
	}

	return(bytesWritten);
}

static void tclsystem_socket_unix__chan_eventhandler(ClientData id_p, int mask) {
	struct tclsystem_socket_unix__chan_id *id;
	Tcl_Channel chan;

	id = id_p;

	chan = id->chan;

	if (!chan) {
		return;
	}

	Tcl_NotifyChannel(chan, mask);
}

static void tclsystem_socket_unix__chan_watch(ClientData id_p, int mask) {
	struct tclsystem_socket_unix__chan_id *id;
	int fd;

	id = id_p;

	fd = id->fd;

	Tcl_CreateFileHandler(fd, mask, tclsystem_socket_unix__chan_eventhandler, id);

	return;
}

static int tclsystem_socket_unix__chan_gethandle(ClientData id_p, int direction, ClientData *handlePtr) {
	struct tclsystem_socket_unix__chan_id *id;
	int fd;
	ClientData fd_cd;

	id = id_p;

	fd = id->fd;

	memcpy(&fd_cd, &fd, sizeof(fd));

	*handlePtr = fd_cd;

	return(TCL_OK);
}

static Tcl_Channel tclsystem_socket_unix_sock2tclchan(int sock) {
	struct tclsystem_socket_unix__chan_id *id;
	static Tcl_ChannelType tcl_chan_type;
	static int tcl_chan_type_init = 0;
	Tcl_Channel tcl_chan;
	char chan_name[32];
	int sock_flags;

	if (!tcl_chan_type_init) {
		tcl_chan_type.typeName = "socket";
		tcl_chan_type.version = TCL_CHANNEL_VERSION_2;
		tcl_chan_type.closeProc = tclsystem_socket_unix__chan_close;
		tcl_chan_type.inputProc = tclsystem_socket_unix__chan_read;
		tcl_chan_type.outputProc = tclsystem_socket_unix__chan_write;
		tcl_chan_type.watchProc = tclsystem_socket_unix__chan_watch;
		tcl_chan_type.getHandleProc = tclsystem_socket_unix__chan_gethandle;
		tcl_chan_type.seekProc = NULL;
		tcl_chan_type.setOptionProc = NULL;
		tcl_chan_type.getOptionProc = NULL;
		tcl_chan_type.close2Proc = NULL;
		tcl_chan_type.blockModeProc = NULL;
		tcl_chan_type.flushProc = NULL;
		tcl_chan_type.handlerProc = NULL;
		tcl_chan_type.wideSeekProc = NULL;
		tcl_chan_type.threadActionProc = NULL;
		tcl_chan_type.truncateProc = NULL;

		tcl_chan_type_init = 1;
	}

	snprintf(chan_name, sizeof(chan_name), "sock%u", sock);

	id = malloc(sizeof(*id));
	if (id == NULL) {
		return(NULL);
	}

	id->fd = sock;
	id->chan = NULL;

	/* Configure socket as non-blocking */
	sock_flags = fcntl(sock, F_GETFL, 0);
	if (sock_flags == -1) {
		sock_flags = O_NONBLOCK;
	} else {
		sock_flags |= O_NONBLOCK;
	}
	fcntl(sock, F_SETFL, (long) sock_flags);

	/* Create the channel */
	tcl_chan = Tcl_CreateChannel(&tcl_chan_type, chan_name, id, TCL_READABLE | TCL_WRITABLE);

	/* Update the structure passed to each function to include the channel name */
	id->chan = tcl_chan;

	return(tcl_chan);
}

struct tclsystem_socket_unix__chan_accept_cd {
	int fd;
	Tcl_Interp *interp;
	Tcl_Obj *command;
};

static void tclsystem_socket_unix__chan_accept(ClientData cd_p, int mask) {
	struct tclsystem_socket_unix__chan_accept_cd *cd;
	Tcl_Interp *interp;
	Tcl_Channel chan;
	Tcl_Obj *command, *command_to_run_objs[5], *command_to_run;
	int setsockopt_ret;
	int pass_creds_true = 1;
	int fd;
	int sock;

	if ((mask & TCL_READABLE) != TCL_READABLE) {
		return;
	}
	
	cd = cd_p;

	fd = cd->fd;
	interp = cd->interp;
	command = cd->command;

	sock = accept(fd, NULL, NULL);
	if (sock < 0) {
		return;
	}

	chan = tclsystem_socket_unix_sock2tclchan(sock);
	if (chan == NULL) {
		close(sock);

		return;
	}

	setsockopt_ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &pass_creds_true, sizeof(pass_creds_true));
	if (setsockopt_ret != 0) {
		close(sock);

		return;
	}

	Tcl_RegisterChannel(interp, chan);

	command_to_run_objs[0] = command;
	command_to_run_objs[1] = Tcl_NewStringObj(Tcl_GetChannelName(chan), -1);
	command_to_run_objs[2] = Tcl_NewStringObj("...uid...", -1); /* XXX: TODO */
	command_to_run_objs[3] = Tcl_NewStringObj("...gid...", -1); /* XXX: TODO */
	command_to_run_objs[4] = Tcl_NewStringObj("...pid...", -1); /* XXX: TODO */
	command_to_run = Tcl_ConcatObj(sizeof(command_to_run_objs) / sizeof(command_to_run_objs[0]), command_to_run_objs);

	Tcl_EvalObjEx(interp, command_to_run, TCL_EVAL_GLOBAL);

	return;
}

static int tclsystem_socket_unix_server(ClientData cd, Tcl_Interp *interp, int sock, const char *path, Tcl_Obj *command) {
	struct tclsystem_socket_unix__chan_accept_cd *accept_cd;
	struct sockaddr_un dest;
	ssize_t pathlen;
	int bind_ret, listen_ret;

	pathlen = strlen(path) + 1;
	if (pathlen <= 0) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj("path too short", -1));

		return(TCL_ERROR);
	}

	if (pathlen > sizeof(dest.sun_path)) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj("path too long", -1));

		return(TCL_ERROR);
	}

	dest.sun_family = AF_UNIX;
	memcpy(dest.sun_path, path, pathlen);

	bind_ret = bind(sock, (struct sockaddr *) &dest, sizeof(dest));
	if (bind_ret != 0) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(strerror(errno), -1));

		return(TCL_ERROR);
	}

	listen_ret = listen(sock, 2);
	if (listen_ret != 0) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(strerror(errno), -1));

		return(TCL_ERROR);
	}

	accept_cd = malloc(sizeof(*accept_cd));
	if (accept_cd == NULL) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(strerror(errno), -1));

		return(TCL_ERROR);
	}

	accept_cd->fd = sock;
	accept_cd->interp = interp;
	accept_cd->command = command;

	Tcl_IncrRefCount(command);

	Tcl_CreateFileHandler(sock, TCL_READABLE, tclsystem_socket_unix__chan_accept, accept_cd);

	return(TCL_OK);
}

static int tclsystem_socket_unix_client(ClientData cd, Tcl_Interp *interp, int sock, const char *path) {
	Tcl_Channel chan;
	struct sockaddr_un dest;
	ssize_t pathlen;
	int connect_ret, setsockopt_ret;
	int pass_creds_true = 1;

	pathlen = strlen(path) + 1;
	if (pathlen <= 0) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj("path too short", -1));

		return(TCL_ERROR);
	}

	if (pathlen > sizeof(dest.sun_path)) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj("path too long", -1));

		return(TCL_ERROR);
	}

	dest.sun_family = AF_UNIX;
	memcpy(dest.sun_path, path, pathlen);

	connect_ret = connect(sock, (struct sockaddr *) &dest, sizeof(dest));
	if (connect_ret != 0) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(strerror(errno), -1));

		return(TCL_ERROR);
	}

	setsockopt_ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &pass_creds_true, sizeof(pass_creds_true));
	if (setsockopt_ret != 0) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(strerror(errno), -1));

		return(TCL_ERROR);
	}

	chan = tclsystem_socket_unix_sock2tclchan(sock);
	if (chan == NULL) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj("unable to create Tcl channel", -1));

		return(TCL_ERROR);
	}

	Tcl_RegisterChannel(interp, chan);

	Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(chan), -1));

	return(TCL_OK);
}

static int tclsystem_socket_unix(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
	Tcl_Obj *path_obj, *command_obj;
	char *path;
	int retval;
	int sock;

	if (objc < 2) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj("wrong # args: should be \"::system::syscall::socket_unix path\" or \"::system::syscall::socket_unix -server command path\"", -1));

		return(TCL_ERROR);
	}

	path_obj = objv[1];
	path = Tcl_GetString(path_obj);

	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock == -1) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(strerror(errno), -1));

		return(TCL_ERROR);
	}

	if (strcmp(path, "-server") == 0) {
		if (objc != 4) {
			Tcl_SetObjResult(interp, Tcl_NewStringObj("wrong # args: should be \"::system::syscall::socket_unix -server command path\"", -1));

			close(sock);

			return(TCL_ERROR);
		}

		command_obj = objv[2];
		path_obj = objv[3];

		path = Tcl_GetString(path_obj);

		retval = tclsystem_socket_unix_server(cd, interp, sock, path, command_obj);
	} else {
		if (objc != 2) {
			Tcl_SetObjResult(interp, Tcl_NewStringObj("wrong # args: should be \"::system::syscall::socket_unix path\"", -1));

			close(sock);

			return(TCL_ERROR);
		}

		retval = tclsystem_socket_unix_client(cd, interp, sock, path);
	}

	if (retval != TCL_OK) {
		close(sock);
	}

	return(retval);
}
#else
static int tclsystem_socket_unix(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj("not implemented", -1));
	return(TCL_ERROR)
}
#endif

static int tclsystem_tsmf_start_svc(ClientData cd, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
	struct timeval select_timeout;
	Tcl_WideInt umask_val, timeout_val, uid_val, gid_val;
	Tcl_Obj *filename_obj, *env_obj, *logfile_obj, **env_entry_objv, *cwd_obj, *umask_obj, *uid_obj, *gid_obj;
	Tcl_Obj *sri_obj, *timeout_obj;
	pid_t child, child_pgid = -1, waitpid_ret;

	/* Network related commands */
	Tcl_CreateObjCommand(interp, "::system::syscall::ifconfig", tclsystem_ifconfig, NULL, NULL);
	Tcl_CreateObjCommand(interp, "::system::syscall::route", tclsystem_route, NULL, NULL);
	Tcl_CreateObjCommand(interp, "::system::syscall::brctl", tclsystem_brctl, NULL, NULL);
	Tcl_CreateObjCommand(interp, "::system::syscall::vconfig", tclsystem_vconfig, NULL, NULL);

	/* Needed commands for basic services Tcl lacks */
	Tcl_CreateObjCommand(interp, "::system::syscall::socket_unix", tclsystem_socket_unix, NULL, NULL);

	/* Service (TSMF) related commands */
	Tcl_CreateObjCommand(interp, "::system::syscall::tsmf_start_svc", tclsystem_tsmf_start_svc, NULL, NULL);

	/* Internal functions */
	Tcl_CreateObjCommand(interp, "::system::internal::hash", tclsystem_internalproc_simplehash, NULL, NULL);

	/* Define constants */