/*********************************************************/
/*  toksvc: a framework-native token broker service      */
/*  Copyright (C) 2020  Z. Gilboa                        */
/*  Released under GPLv2 and GPLv3; see COPYING.TOKSVC.  */
/*********************************************************/

#include <ntapi/ntapi.h>
#include <ntapi/nt_atomic.h>

#include <stdint.h>

#include <toksvc/toksvc.h>
#include "toksvc_init_impl.h"
#include "toksvc_nolibc_impl.h"

#define ARGV_DRIVER

#include "toksvc_version.h"
#include "toksvc_daemon_impl.h"
#include "toksvc_dprintf_impl.h"
#include "toksvc_driver_impl.h"
#include "argv/argv.h"

/* pty integration */
#include <psxtypes/section/freestd.h>

__attr_section_decl__(".freestd")
static const nt_tty_affiliation tty_affiliation
	__attr_section__(".freestd")
	= NT_TTY_AFFILIATION_DEFAULT;

/* ntapi accessor table */
const ntapi_vtbl * toks_ntapi;

/* daemon */
static struct toks_daemon_ctx toks_daemon_ctx;
static const  nt_guid toks_daemon_default_guid = TOKS_PORT_GUID_DAEMON;
static const  wchar16_t toks_service_name[6]   = TOKS_PORT_NAME_PREFIX;

/* package info */
static const struct toks_source_version toks_src_version = {
	TOKS_TAG_VER_MAJOR,
	TOKS_TAG_VER_MINOR,
	TOKS_TAG_VER_PATCH,
	TOKSVC_GIT_VERSION
};

struct toks_driver_ctx_alloc {
	struct argv_meta *		meta;
	struct toks_driver_ctx_impl	ctx;
	uint64_t			guard;
};

struct toks_split_vector {
	char **		targv;
	char **		eargv;
};

static uint32_t toks_argv_flags(uint32_t flags)
{
	uint32_t ret = ARGV_CLONE_VECTOR;

	if (flags & TOKS_DRIVER_VERBOSITY_NONE)
		ret |= ARGV_VERBOSITY_NONE;

	if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
		ret |= ARGV_VERBOSITY_ERRORS;

	if (flags & TOKS_DRIVER_VERBOSITY_STATUS)
		ret |= ARGV_VERBOSITY_STATUS;

	return ret;
}

static int toks_driver_usage(
	const char *			program,
	const char *			arg,
	const struct argv_option **	optv,
	struct argv_meta *		meta)
{
	char header[512];

	snprintf(header,sizeof(header),
		"Usage: %s [options] <file>...\n" "Options:\n",
		program);

	argv_usage(STDOUT_FILENO,header,optv,arg);
	argv_free(meta);

	return TOKS_USAGE;
}

static int32_t toks_query_performance_counters_failover(nt_filetime * ticks)
{
	(void)ticks;
	return 0;
}

static int32_t toks_daemon_library_once;

static int32_t toks_daemon_library_init(void)
{
	int32_t		status;
	int		argc;
	char **		argv;
	char **		envp;
	nt_rtdata *	rtdata;
	nt_timeout	timeout;

	switch (at_locked_cas_32(&toks_daemon_library_once,0,1)) {
		case 0:
			status = ntapi->tt_get_argv_envp_utf8(
				&argc,&argv,&envp,
				0,0,0);

			if (status) {
				at_store_32(&toks_daemon_library_once,3);
				return status;
			}

			if ((status = ntapi->tt_get_runtime_data(&rtdata,0))) {
				at_store_32(&toks_daemon_library_once,3);
				return status;
			}

			ntapi->tt_guid_copy(
				&rtdata->srv_guid,
				&toks_daemon_default_guid);

			at_locked_inc_32(&toks_daemon_library_once);
			return 0;

		case 1:
			timeout.quad = -10;

			for (; (at_locked_cas_32(&toks_daemon_library_once,0,1) == 1); )
				ntapi->zw_delay_execution(
					NT_SYNC_ALERTABLE,
					&timeout);

			return (toks_daemon_library_once == 2)
				? 0 : -1;

		case 2:
			return 0;

		case 3:
		default:
			return -1;
	}

	return NT_STATUS_INTERNAL_ERROR;
}

static struct toks_driver_ctx_impl * toks_driver_ctx_alloc(
	struct argv_meta *		meta,
	const struct toks_common_ctx *	cctx)
{
	struct toks_driver_ctx_alloc *	ictx;
	size_t				size;
	nt_runtime_data *		rtdata;

	switch (ntapi->tt_get_runtime_data(&rtdata,0)) {
		case NT_STATUS_SUCCESS:
			break;

		case NT_STATUS_MORE_PROCESSING_REQUIRED:
			toks_daemon_library_init();

			if (ntapi->tt_get_runtime_data(&rtdata,0))
				return 0;

		default:
			return 0;
	}

	size =  sizeof(struct toks_driver_ctx_alloc);

	if (!(ictx = calloc(1,size)))
		return 0;

	if (cctx)
		memcpy(&ictx->ctx.cctx,cctx,sizeof(*cctx));

	ictx->ctx.ticks.qpc         = toks_query_performance_counters_failover;
	ictx->ctx.ticks.pcfreq.quad = 0;

	ictx->meta = meta;
	ictx->ctx.rtdata = rtdata;
	return &ictx->ctx;
}

static int toks_get_driver_ctx_fail(struct argv_meta * meta)
{
	argv_free(meta);
	return -1;
}

#define TOKS_SARGV_ELEMENTS		1024

static int toks_split_argv(
	char **				argv,
	struct toks_split_vector *	sargv)
{
	ptrdiff_t	argc;
	char **		parg;

	/* argc */
	for (parg=argv; *parg; )
		parg++;

	if ((argc = parg - argv) >= TOKS_SARGV_ELEMENTS)
		return -1;

	/* clone argv into targv */
	ntapi->tt_aligned_block_memset(
		(uintptr_t *)sargv->targv,
		0,TOKS_SARGV_ELEMENTS*sizeof(char *));

	ntapi->tt_aligned_block_memcpy(
		(uintptr_t *)sargv->targv,
		(uintptr_t *)argv,
		argc*sizeof(char *));

	/* eargv */
	for (parg=sargv->targv; *parg; parg++) {
		if (!(strcmp(*parg,"-e")) || !(strcmp(*parg,"--exec"))) {
			sargv->eargv = &argv[parg-sargv->targv];
			sargv->eargv++;
			*parg = 0;
			return 0;
		}
	}

	return 0;
}

int toks_get_driver_ctx(
	char **				argv,
	char **				envp,
	uint32_t			flags,
	struct toks_driver_ctx **	pctx)
{
	int32_t				status;
	struct toks_driver_ctx_impl *	ctx;
	struct toks_common_ctx		cctx;
	struct toks_split_vector	sargv;
	const struct argv_option *	optv[TOKS_OPTV_ELEMENTS];
	struct argv_meta *		meta;
	struct argv_entry *		entry;
	struct argv_entry *		uuid;
	struct argv_entry *		pid;
	struct argv_entry *		msecs;
	struct toks_token_string	key;
	size_t				keylen;
	nt_guid				svcguid;
	const char *			program;
	const char *			refstr;
	const char *			ch;
	int				ntokens;
	int32_t				tokpid;
	int64_t				timeout;
	void *				hkernel32;
	char *				targv[TOKS_SARGV_ELEMENTS];

	(void)envp;

	if (toks_init())
		return -1;

	argv_optv_init(toks_default_options,optv);

	sargv.targv = targv;
	sargv.eargv = 0;

	if (toks_split_argv(argv,&sargv))
		return -1;

	if (!(meta = argv_get(
			sargv.targv,optv,
			toks_argv_flags(flags),
			STDERR_FILENO)))
		return -1;

	if (!(flags & TOKS_DRIVER_MODE_CLIENT))
		flags |= TOKS_DRIVER_MODE_SERVER;

	uuid    = 0;
	tokpid  = 0;
	keylen  = 0;
	ntokens = 0;
	timeout = (-1);
	program = argv_program_name(argv[0]);

	memset(&cctx,0,sizeof(cctx));
	cctx.drvflags = flags;
	cctx.eargv = sargv.eargv;

	if (!argv[1] && (flags & TOKS_DRIVER_VERBOSITY_USAGE))
		return toks_driver_usage(program,0,optv,meta);

	for (entry=meta->entries; entry->fopt || entry->arg; entry++) {
		if (entry->fopt) {
			switch (entry->tag) {
				case TAG_HELP:
					if (flags & TOKS_DRIVER_VERBOSITY_USAGE)
						return toks_driver_usage(program,entry->arg,optv,meta);

				case TAG_VERSION:
					cctx.drvflags |= TOKS_DRIVER_VERSION;
					break;

				case TAG_DAEMON:
					if (!strcmp("always",entry->arg))
						cctx.drvflags |= TOKS_DRIVER_DAEMON_ALWAYS;

					else if (!strcmp("never",entry->arg))
						cctx.drvflags |= TOKS_DRIVER_DAEMON_NEVER;

					break;

				case TAG_SYSROOT:
					cctx.sysroot = entry->arg;
					break;

				case TAG_UUID:
					uuid = entry;
					break;

				case TAG_REFSTR:
					refstr = entry->arg;
					break;

				case TAG_PID:
					pid = entry;

					for (tokpid=0, ch=entry->arg; *ch && (tokpid>=0); ch++)
						if ((*ch < '0') || (*ch >'9'))
							tokpid = -1;
						else
							tokpid = tokpid * 10 + (*ch - '0');
					break;

				case TAG_TIMEOUT:
					msecs = entry;

					for (timeout=0, ch=entry->arg; *ch && (timeout>=0); ch++)
						if ((*ch < '0') || (*ch >'9'))
							timeout = -2;
						else if ((ch - entry->arg) > 15)
							timeout = -2;
						else
							timeout = timeout * 10 + (*ch - '0');

					break;

				case TAG_TOKENS:
					for (ntokens=0, ch=entry->arg; *ch && (ntokens>=0); ch++)
						if ((*ch < '0') || (*ch >'9'))
							ntokens = -1;
						else if (ntokens >= 1000)
							ntokens = -1;
						else
							ntokens = ntokens * 10 + (*ch - '0');
					break;

				case TAG_CONNECT:
					cctx.drvflags &= ~(uint64_t)TOKS_DRIVER_MODE_SERVER;
					cctx.drvflags |= TOKS_DRIVER_MODE_CLIENT;
					break;

				case TAG_ABORT:
					cctx.drvflags &= ~(uint64_t)TOKS_DRIVER_MODE_SERVER;
					cctx.drvflags |= TOKS_DRIVER_MODE_CLIENT;
					cctx.drvflags |= TOKS_DRIVER_ACTION_ABORT;
					break;

				case TAG_ACQUIRE:
					cctx.drvflags &= ~(uint64_t)TOKS_DRIVER_MODE_SERVER;
					cctx.drvflags |= TOKS_DRIVER_MODE_CLIENT;
					cctx.drvflags |= TOKS_DRIVER_ACTION_ACQUIRE;
					break;

				case TAG_RELEASE:
					cctx.drvflags &= ~(uint64_t)TOKS_DRIVER_MODE_SERVER;
					cctx.drvflags |= TOKS_DRIVER_MODE_CLIENT;
					cctx.drvflags |= TOKS_DRIVER_ACTION_RELEASE;

					keylen = toks_strlen(entry->arg);

					ntapi->tt_generic_memset(
						&key,0,sizeof(key));

					if (keylen < sizeof(key.token))
						ntapi->tt_generic_memcpy(
							&key.token,entry->arg,
							keylen);
					break;
			}
		} else
			/* strict */
			return toks_driver_usage(program,0,optv,meta);
	}

	if ((cctx.drvflags & TOKS_DRIVER_MODE_CLIENT) && (tokpid < 0)) {
		if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
			toks_dprintf(STDERR_FILENO,
				"%s: error: %s is not a valid process id.",
				program,pid->arg);
		return toks_get_driver_ctx_fail(meta);
	}

	if ((cctx.drvflags & TOKS_DRIVER_MODE_CLIENT) && (timeout < (-1))) {
		if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
			toks_dprintf(STDERR_FILENO,
				"%s: error: %s is not a valid timeout in milliseconds.",
				program,msecs->arg);
		return toks_get_driver_ctx_fail(meta);
	}

	if ((cctx.drvflags & TOKS_DRIVER_MODE_SERVER) && (ntokens <= 0)) {
		if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
			toks_dprintf(STDERR_FILENO,
				"%s: error: number of tokens not set or is invalid.",
				program);
		return toks_get_driver_ctx_fail(meta);
	}

	if (uuid && ntapi->tt_string_to_guid_utf8(uuid->arg,&svcguid)) {
		if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
			toks_dprintf(STDERR_FILENO,
				"%s: error: '%s' is not a valid service guid (did you forget the braces?)",
				program,uuid->arg);
		return toks_get_driver_ctx_fail(meta);

	}

	if (cctx.sysroot && toks_open_dir(&cctx.hroot,0,cctx.sysroot,false)) {
		if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
			toks_dprintf(STDERR_FILENO,
				"%s: error: could not open sysroot directory '%s'",
				program,cctx.sysroot);
		return toks_get_driver_ctx_fail(meta);
	}

	if (!(ctx = toks_driver_ctx_alloc(meta,&cctx)))
		return toks_get_driver_ctx_fail(meta);

	if ((cctx.drvflags & TOKS_DRIVER_ACTION_RELEASE)) {
		if (toks_client_str_to_token(&ctx->ctx,&key)) {
			if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
				toks_dprintf(STDERR_FILENO,
					"%s: error: [%s] is not a valid token.",
					program,key.token);
			return toks_get_driver_ctx_fail(meta);
		}
	}

	ntapi->tt_guid_copy(
		&ctx->uuid,
		uuid ? &svcguid : &ctx->rtdata->srv_guid);

	if ((toks_ntapi->tt_create_private_event(
			&ctx->hevent,
			NT_NOTIFICATION_EVENT,
			NT_EVENT_NOT_SIGNALED)))
		return toks_get_driver_ctx_fail(meta);

	if ((ntapi->tt_open_dev_object_directory(
			&ctx->hsvcdir,
			NT_SEC_READ_CONTROL
				| NT_DIRECTORY_QUERY
				| NT_DIRECTORY_TRAVERSE
				| NT_DIRECTORY_CREATE_OBJECT
				| NT_DIRECTORY_CREATE_SUBDIRECTORY,
			toks_service_name,
			&toks_daemon_default_guid)))
		return toks_get_driver_ctx_fail(meta);

	if ((hkernel32 = pe_get_kernel32_module_handle()))
		if ((ctx->ticks.qpc = pe_get_procedure_address(
				hkernel32,"QueryPerformanceCounter")))
			ntapi->zw_query_performance_counter(
				&(nt_filetime){{0,0}},
				&ctx->ticks.pcfreq);

	ctx->tokpid             = tokpid;
	ctx->ntokens            = ntokens;
	ctx->timeout            = timeout;
	ctx->ctx.program	= program;
	ctx->ctx.cctx		= &ctx->cctx;
	ctx->cctx.uuid          = &ctx->uuid;

	toks_set_driver_refstr(&ctx->ctx,refstr);

	if (cctx.drvflags & TOKS_DRIVER_MODE_SERVER) {
		if (!(ctx->waiters = toks_calloc(
				TOKS_MAX_WAITERS,
				sizeof(struct toks_waiter))))
			return toks_get_driver_ctx_fail(meta);

		toks_daemon_ctx.driver_ctx   = &ctx->ctx;
		toks_daemon_ctx.waiter_base  = ctx->waiters;
		toks_daemon_ctx.waiter_first = ctx->waiters;
		toks_daemon_ctx.waiter_next  = ctx->waiters;
		toks_daemon_ctx.waiter_cap   = &ctx->waiters[TOKS_MAX_WAITERS];


		if (!(ctx->tokens = toks_calloc(ntokens,sizeof(*ctx->tokens))))
			return toks_get_driver_ctx_fail(meta);

		if (toks_daemon_init(&toks_daemon_ctx,&ctx->uuid))
			return toks_get_driver_ctx_fail(meta);
	}

	if (cctx.drvflags & TOKS_DRIVER_MODE_CLIENT) {
		if (cctx.drvflags & TOKS_DRIVER_DAEMON_ALWAYS) {
			toks_daemon_ctx.driver_ctx = &ctx->ctx;

			switch ((status = toks_daemon_init(&toks_daemon_ctx,0))) {
				case NT_STATUS_SUCCESS:
					break;

				default:
					if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
						toks_dprintf(STDERR_FILENO,
							"%s: error: failed to initialize signal handling "
							"(check the system's documentation) [0x%x].",
							program,status);

					return toks_get_driver_ctx_fail(meta);
			}
		}

		switch ((status = toks_client_connect(&ctx->ctx))) {
			case NT_STATUS_SUCCESS:
				break;

			case NT_STATUS_OBJECT_NAME_NOT_FOUND:
				if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
					toks_dprintf(STDERR_FILENO,
						"%s: error: could not connect "
						"(server not running) [0x%x].",
						program,status);

				return toks_get_driver_ctx_fail(meta);

			case NT_STATUS_CONNECTION_REFUSED:
			case NT_STATUS_PORT_CONNECTION_REFUSED:
				if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
					toks_dprintf(STDERR_FILENO,
						"%s: error: could not connect "
						"(connection refused) [0x%x].",
						program,status);

				return toks_get_driver_ctx_fail(meta);

			case NT_STATUS_ACCESS_DENIED:
				if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
					toks_dprintf(STDERR_FILENO,
						"%s: error: could not connect "
						"(access denied) [0x%x].",
						program,status);

				return toks_get_driver_ctx_fail(meta);

			default:
				if (flags & TOKS_DRIVER_VERBOSITY_ERRORS)
					toks_dprintf(STDERR_FILENO,
						"%s: error: could not connect "
						"(check the system's documentation) [0x%x].",
						program,status);

				return toks_get_driver_ctx_fail(meta);
		}
	}

	*pctx = &ctx->ctx;
	return TOKS_OK;
}

static void toks_free_driver_ctx_impl(struct toks_driver_ctx_alloc * ictx)
{
	if (ictx->ctx.hevent)
		ntapi->zw_close(ictx->ctx.hevent);

	if (ictx->ctx.hsvcdir)
		ntapi->zw_close(ictx->ctx.hsvcdir);

	if (ictx->ctx.hsvclink)
		ntapi->zw_close(ictx->ctx.hsvclink);

	if (ictx->ctx.hservice)
		ntapi->zw_close(ictx->ctx.hservice);

	if (ictx->ctx.tokens)
		toks_free(ictx->ctx.tokens);

	if (ictx->ctx.waiters)
		toks_free(ictx->ctx.waiters);

	argv_free(ictx->meta);
	free(ictx);
}

void toks_free_driver_ctx(struct toks_driver_ctx * ctx)
{
	struct toks_driver_ctx_alloc *	ictx;
	uintptr_t			addr;

	if (ctx) {
		addr = (uintptr_t)ctx - offsetof(struct toks_driver_ctx_impl,ctx);
		addr = addr - offsetof(struct toks_driver_ctx_alloc,ctx);
		ictx = (struct toks_driver_ctx_alloc *)addr;
		toks_free_driver_ctx_impl(ictx);
	}
}

void toks_driver_set_timeout(struct toks_driver_ctx * dctx, int64_t millisecs)
{
	toks_set_driver_timeout(dctx,millisecs);
}

void toks_driver_unset_timeout(struct toks_driver_ctx * dctx)
{
	toks_set_driver_timeout(dctx,(-1));
}

const struct toks_source_version * toks_source_version(void)
{
	return &toks_src_version;
}