/********************************************************/

/*  ntapi: Native API core library                      */

/*  Copyright (C) 2013--2021  SysDeer Technologies, LLC */

/*  Released under GPLv2 and GPLv3; see COPYING.NTAPI.  */

/********************************************************/

#include <psxtypes/psxtypes.h>

#include <pemagine/pemagine.h>

#include <ntapi/ntapi.h>

#include "ntapi_impl.h"

/**

 *  rules for parsing the process's command line arguments

 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

 *

 *  delimiters:

 *  -----------

 *  + white space    (ascii 0x20)

 *  + horizontal tab (ascii 0x09)

 *

 *  quoted strings, and special characters

 *  --------------------------------------

 *  + delimiter characters within a quoted string ("string with white space",

 *    or string" with white "space), stand for their literal respective

 *    characters.

 *

 *  + a backslash followed by a double quote (\") stands for a literal

 *    double quote.

 *

 *  + unless followed by a double quote, a backslash is just a (literal)

 *    backslash.

 *

 *  + when followed by a double quotation mark, an even sequence of 2 or

 *    more backslashes (2n) should be interpreted as a sequence of n literal

 *    backslashes.  The double quotation mark then designates the start

 *    or end of a double quoted string.

 *

 *  + when followed by a double quotation mark, an odd sequence of 2 or

 *    more backslashes (2n+1) should be interpreted as a sequence of n

 *    literal backslashes, followed by a single literal double quote.

 *

 *  + if found within a double quoted string, a sequence of two double

 *    quotation marks should be interpreted as a single literal double

 *    quote.

 *

 *  +  balanced nesting of syntactic double quotes is permitted.

 *

**/

/* free-standing process runtime data */

static nt_runtime_data	__rtdata;

int32_t __stdcall __ntapi_tt_parse_cmd_line_args_utf16(

	__in	wchar16_t *	cmd_line,

	__out	int *		arg_count,

	__in	wchar16_t *	args_buffer,

	__in	size_t		args_buffer_len,

	__out	size_t *	args_bytes_written __optional,

	__in	wchar16_t **	argv_buffer,

	__in	size_t		argv_buffer_len,

	__in	uint32_t	arg_flags)

{

	/**

	  * parse the command line arguments pointed to by cmd_line,

	  * copy the parsed arguments to args_buffer,

	  * and return 0 upon success.

	  *

	  * cmd_line must be a valid pointer to a command line string,

	  * and args_buffer, argv_buffer, and arg_count should

	  * all be aligned; furthermore, args_buffer_len and

	  * and argv_buffer_len must be exact multiples of sizeof(size_t).

	  *

	  * In case of an error, report failure using the appropriate

	  * native status code.

	**/

	/**

	 *  UTF-16: no need to fully determine the code point of the

	 *  current character; all we need to do is validate the

	 *  character or surrogate pair, and set the value of

	 *  wch_next accordingly.

	**/

	#define HORIZONTAL_TAB	0x09

	#define WHITE_SPACE	0x20

	#define DOUBLE_QUOTE	0x22

	#define SINGLE_QUOTE	0x27

	#define BACKSLASH	0x5C

	#define IS_DELIMITER(x)	((x == HORIZONTAL_TAB) || (x == WHITE_SPACE))

	#define TEST_ARGS_BUFFER(nbytes) \

				if ((uintptr_t)arg + nbytes \

						> (uintptr_t)args_buffer + args_buffer_len) { \

					return NT_STATUS_BUFFER_TOO_SMALL; \

				}

	#define ADD_N_BACKSLASHES \

				TEST_ARGS_BUFFER(backslash_count * sizeof(wchar16_t)); \

				for (islash = 0; \

						islash < backslash_count; \

						islash++) { \

					*arg = BACKSLASH; \

					arg++; \

				} \

				backslash_count = 0;

	#define ADD_SINGLE_WCHAR16_t(x) \

				TEST_ARGS_BUFFER(sizeof(wchar16_t)); \

				*arg = x; \

				arg++;

	wchar16_t *	arg;		/* null-terminated, copied to buffer */

	wchar16_t **	parg;		/* next pointer in the argv array */

	wchar16_t *	wch;		/* character being processed */

	wchar16_t *	wch_next;

	unsigned int	backslash_count;

	unsigned int	islash;

	unsigned char	quoted_state;

	/* unused param */

	(void)arg_flags;

	/* check parameters for validity and alignment */

	if ((!(uintptr_t)cmd_line) || (*cmd_line == 0))

		/* we require at least one argument */

		return NT_STATUS_INVALID_PARAMETER_1;

	else if (__NT_IS_MISALIGNED_BUFFER(args_buffer))

		return NT_STATUS_INVALID_PARAMETER_3;

	else if (__NT_IS_MISALIGNED_LENGTH(args_buffer_len))

		return NT_STATUS_INVALID_PARAMETER_4;

	else if (__NT_IS_MISALIGNED_BUFFER(argv_buffer))

		return NT_STATUS_INVALID_PARAMETER_6;

	else if (__NT_IS_MISALIGNED_LENGTH(argv_buffer_len))

		return NT_STATUS_INVALID_PARAMETER_7;

	else if (__NT_IS_MISALIGNED_INT_BUFFER(arg_count))

		return NT_STATUS_INVALID_PARAMETER_2;

	/* zero-out the aligned buffers */

	__ntapi->tt_aligned_block_memset(args_buffer,0,args_buffer_len);

	__ntapi->tt_aligned_block_memset(argv_buffer,0,argv_buffer_len);

	/* initialize */

	wch		= cmd_line;

	arg		= args_buffer;

	parg		= argv_buffer;

	*parg		= arg;

	*arg_count	= 0;

	quoted_state	= 0;

	backslash_count	= 0;

	/* arg points to the first character of a command line argument */

	/* parg points to the next pointer in argv_buffer */

	while (*wch) {

		if (!(quoted_state) && (IS_DELIMITER(*wch))) {

			/* pending backslashes? */

			if (backslash_count)

				ADD_N_BACKSLASHES;

			/* reached a delimiter outside of a quoted string */

			/* argument: alignment and null-termination */

			arg = (wchar16_t *)((((uintptr_t)arg + sizeof(size_t))

					| (sizeof(size_t) - 1))

					^ (sizeof(size_t) - 1));

			/* skip this and remaining delimiters */

			wch_next = wch + 1;

			while ((*wch_next) && (IS_DELIMITER(*wch_next)))

				wch_next++;

			/* keep going? */

			if (*wch_next == 0) {

				/* no more characters to process */

				/* nothing to do */

			} else if ((uintptr_t)parg >= \

					(uintptr_t)argv_buffer \

					+ argv_buffer_len) {

				/* argv_buffer is too small */

				return NT_STATUS_BUFFER_TOO_SMALL;

			} else if ((uintptr_t)arg >= \

					(uintptr_t)args_buffer \

					+ args_buffer_len) {

				/* args_buffer is too small */

				return NT_STATUS_BUFFER_TOO_SMALL;

			} else {

				/* advance parg, set last member  */

				parg++;

				*parg = arg;

			}

		} else {

			/* the current character is not a delimiter... */

			/* determine wch_next */

			if ((*wch < 0xD800) || (*wch >= 0xE000)) {

				/* in the BMP, single 16-bit representation */

				wch_next = wch + 1;

			} else if ((*wch >= 0xD800) && (*wch < 0xDC00)) {

				/* validate surrogate pair */

				wch_next = wch + 1;

				if ((*wch_next >= 0xDC00) && (*wch_next < 0xE000))

					/* this is a valid surrogate pair */

					wch_next++;

				else

					return NT_STATUS_ILLEGAL_CHARACTER;

			} else

				return NT_STATUS_ILLEGAL_CHARACTER;

			/* we now know the position of this and the next character */

			/* continue with special cases */

			if (quoted_state && (*wch == DOUBLE_QUOTE) \

					&& (*wch_next == DOUBLE_QUOTE)) {

				/**

				 *  two consecutive double quotation marks

				 *  within a quoted string:

				 *  add a single quotation mark to the argument

				**/

				ADD_SINGLE_WCHAR16_t(DOUBLE_QUOTE);

				wch_next++;

			} else if (((backslash_count % 2) == 0) \

					&& (*wch == BACKSLASH) \

					&& (*wch_next == DOUBLE_QUOTE)) {

				/* 2n+1 backslashes followed by a double quote */

				backslash_count /= 2;

				/* add n backslashes */

				ADD_N_BACKSLASHES;

				/* add a literal double quotation mark */

				ADD_SINGLE_WCHAR16_t(DOUBLE_QUOTE);

				/* get ready for next character */

				wch_next++;

			} else if (backslash_count && (*wch == DOUBLE_QUOTE)) {

				/* 2n backslashes followed by a double quote */

				backslash_count /= 2;

				/* add n backslashes */

				ADD_N_BACKSLASHES;

				/* turn quoted_state on/off */

				quoted_state = !quoted_state;

			} else if ((*wch == BACKSLASH) \

						&& (*wch_next == BACKSLASH)) {

				/* this is a sequence of two backslashes */

				backslash_count += 2;

				wch_next++;

			} else {

				/* copy pending backslashes as needed */

				if (backslash_count)

					ADD_N_BACKSLASHES;

				if (*wch == DOUBLE_QUOTE) {

					/* turn quoted_state on/off */

					quoted_state = !quoted_state;

				} else {

					/* copy either two or four bytes */

					ADD_SINGLE_WCHAR16_t(*wch);

					wch++;

					/* surrogate pair? */

					if (wch < wch_next) {

						ADD_SINGLE_WCHAR16_t(*wch);

					}

				}

			}

		}

		/* proceed to the next character (or null termination) */

		wch = wch_next;

	}

	/* pending backslashes? */

	if (backslash_count)

		ADD_N_BACKSLASHES;

	/* null termination */

	ADD_SINGLE_WCHAR16_t(0);

	/* how many arguments did you say? */

	*arg_count = (int)(((uintptr_t)parg - (uintptr_t)argv_buffer)

				/ sizeof(size_t) + 1);

	/* output bytes written */

	if (args_bytes_written)

		*args_bytes_written = (uintptr_t)arg - (uintptr_t)args_buffer;

	return NT_STATUS_SUCCESS;

}

int32_t __stdcall __ntapi_tt_get_argv_envp_utf16(

	__out	int *		argc,

	__out	wchar16_t ***	wargv,

	__out	wchar16_t ***	wenvp,

	__in	uint32_t	flags,

	__in	void *		ext_params	__optional,

	__out	void *		reserved	__optional)

{

	nt_runtime_data *		rtdata;

	nt_argv_envp_block_info		main_params_internal;

	nt_argv_envp_block_info *	main_params;

	nt_get_argv_envp_ext_params *	__ext_params;

	ntapi_internals *		__internals;

	unsigned	idx;

	int32_t		status;

	uintptr_t	addr;

	intptr_t	offset;

	wchar16_t *	wch_s;

	wchar16_t *	wch_dst;

	wchar16_t **	wch_p;

	char **		ch_p;

	uintptr_t *	psrc;

	uintptr_t *	pdst;

	uintptr_t *	paligned;

	wchar16_t *	pboundary;

	/* unused param */

	(void)reserved;

	/* init */

	__internals = __ntapi_internals();

	/* use internal buffer? */

	if (flags & NT_GET_ARGV_ENVP_USE_CALLER_BUFFER) {

		__ext_params = (nt_get_argv_envp_ext_params *)ext_params;

		main_params  = &(__ext_params->argv_envp_block_info);

	} else {

		/* pointers to internal/local structures */

		main_params = &main_params_internal;

		/* init */

		__ntapi->tt_aligned_block_memset(

			main_params,0,

			sizeof(*main_params));

		/* use internal buffer */

		main_params->cmd_line		 = __ntapi_tt_get_cmd_line_utf16();

		main_params->wargv_buffer	 = __internals->ntapi_img_sec_bss->argv_envp_array;

		main_params->wargv_buffer_len	 = __NT_BSS_ARGV_BUFFER_SIZE;

		main_params->argv_envp_ptr_total	 = (int)(main_params->wargv_buffer_len

							/ sizeof(uintptr_t));

		main_params->wargs_buffer	 = (wchar16_t *)&(__internals->ntapi_img_sec_bss->args_envs_buffer);

		main_params->wargs_buffer_len	 = __NT_BSS_ARGS_BUFFER_SIZE;

	}

	/* (__ntapi_parse_cmd_line_args_utf16 will zero-out both buffers) */

	status = __ntapi_tt_parse_cmd_line_args_utf16(

		main_params->cmd_line,

		&main_params->argc,

		main_params->wargs_buffer,

		main_params->wargs_buffer_len,

		&main_params->wargs_bytes_written,

		main_params->wargv_buffer,

		main_params->wargv_buffer_len,

		0);

	if (status) return status;

	/* argv[] needs a terminating null pointer */

	if ((unsigned)main_params->argc == main_params->argv_envp_ptr_total)

		return NT_STATUS_BUFFER_TOO_SMALL;

	/* set idx to the envp[0] array index */

	idx = main_params->argc + 1;

	/* set wenvp[] to its starting address */

	main_params->wenvp_buffer = &main_params->wargv_buffer[idx];

	/* update wargv_buffer_len and envp_buffer_len */

	main_params->wenvp_buffer_len = main_params->wargv_buffer_len

					- (idx * sizeof(uintptr_t));

	main_params->wargv_buffer_len = idx * sizeof(uintptr_t);

	/* align wenvs at pointer-size boundary */

	main_params->wargs_bytes_written += sizeof(uintptr_t) - 1;

	main_params->wargs_bytes_written /= sizeof(uintptr_t);

	main_params->wargs_bytes_written *= sizeof(uintptr_t);

	/* book-keeping */

	main_params->wenvs_buffer  = main_params->wargs_buffer

					+ main_params->wargs_bytes_written;

	main_params->wenvs_buffer_len = main_params->wargs_buffer_len 

					- main_params->wargs_bytes_written;

	main_params->wargs_buffer_len = main_params->wargs_bytes_written;

	/* peb environment block (read-only) */

	wch_s = __ntapi_tt_get_peb_env_block_utf16();

	if ((!wch_s) || (!*wch_s))

		return NT_STATUS_DLL_INIT_FAILED;

	/* populate the envp[] array */

	while ((*wch_s) && (idx < main_params->argv_envp_ptr_total)) {

		main_params->envc++;

		wch_p = &(main_params->wargv_buffer[idx]);

		*wch_p = wch_s;

		/* skip the rest of the environment variable */

		while (*++wch_s);

		/* advance to the next variable (or final null termination) */

		wch_s++;

		idx++;

	}

	/* envp[] needs a terminating null pointer */

	if ((*wch_s) && (idx = main_params->argv_envp_ptr_total))

		return NT_STATUS_BUFFER_TOO_SMALL;

	/* copy environment? */

	if (flags & NT_GET_ARGV_ENVP_COPY_ENVIRONMENT) {

		/* wch_s now points at the final null termination */

		main_params->wenvs_bytes_used =

				((uintptr_t)wch_s

				- (uintptr_t)(*main_params->wenvp_buffer));

		/* do we have enough room? */

		if (main_params->wenvs_buffer_len < main_params->wenvs_bytes_used)

			return NT_STATUS_BUFFER_TOO_SMALL;

		/* upper boundary */

		pboundary = ++wch_s;

		/* you'd expect the peb environment block to be aligned, 

		   but one can never know... */

		wch_s 	= *main_params->wenvp_buffer;

		wch_dst = main_params->wenvs_buffer;

		while ((uintptr_t)wch_s % sizeof(uintptr_t)) {

			*wch_dst = *wch_s;

			wch_s++;

			wch_dst++;

		}

		/* copy the aligned portion of the environment block */

		addr = (uintptr_t)(pboundary);

		addr /= sizeof(uintptr_t);

		addr *= sizeof(uintptr_t);

		paligned = (uintptr_t *)addr;

		psrc = (uintptr_t *)wch_s;

		pdst = (uintptr_t *)wch_dst;

		while (psrc < paligned) {

			*pdst = *psrc;

			psrc++;

			pdst++;

		}

		/* copy any remaining bytes */

		wch_s	= (wchar16_t *)paligned;

		wch_dst	= (wchar16_t *)pdst;

		while (wch_s < pboundary) {

			*wch_dst = *wch_s;

			wch_s++;

			wch_dst++;

		}

		/* finally, we update the envp[] pointers */

		offset = (intptr_t)main_params->wenvs_buffer

			- (intptr_t)*main_params->wenvp_buffer;

		wch_p = main_params->wenvp_buffer;

		while (*wch_p) {

			addr = ((uintptr_t)*wch_p) + offset;

			*wch_p = (wchar16_t *)addr;

			wch_p++;

		}

	}

	/* (command line arguments always get validated) */

	/* validate the environment block? */

	if (flags & NT_GET_ARGV_ENVP_VALIDATE_UTF16) {

		wch_p = main_params->wenvp_buffer;

		while (*wch_p) {

			status = __ntapi->uc_validate_unicode_stream_utf16(

				*wch_p,

				0,0,0,0,0);

			if (status != NT_STATUS_SUCCESS)

				return status;

			else

				wch_p++;

		}

	}

	/* once */

	if (!__internals->rtdata) {

		__ntapi->tt_get_runtime_data(

			&__internals->rtdata,

			main_params->wargv_buffer);

		if (!__internals->rtdata) {

			__internals->rtdata = &__rtdata;

			if ((status =__ntapi->tt_init_runtime_data(&__rtdata)))

				return status;

		} else if ((status =__ntapi->tt_update_runtime_data(__internals->rtdata)))

			return status;

		rtdata = __internals->rtdata;

		rtdata->peb_envc  = main_params->envc;

		rtdata->peb_argc	  = main_params->argc;

		rtdata->peb_wargv = main_params->wargv_buffer;

		rtdata->peb_wenvp = main_params->wenvp_buffer;

		/* integral wargv, wenvp, argv, envp */

		if (rtdata->wargv) {

			rtdata->wargv += (uintptr_t)rtdata / sizeof(wchar16_t *);

			for (wch_p=rtdata->wargv; *wch_p; wch_p++)

				*wch_p += (uintptr_t)rtdata / sizeof(wchar16_t);

		};

		if (rtdata->wenvp) {

			rtdata->wenvp += (uintptr_t)rtdata / sizeof(wchar16_t *);

			for (wch_p=rtdata->wenvp; *wch_p; wch_p++)

				*wch_p += (uintptr_t)rtdata / sizeof(wchar16_t);

		}

		if (rtdata->argv) {

			rtdata->argv += (uintptr_t)rtdata / sizeof(char *);

			for (ch_p=rtdata->argv; *ch_p; ch_p++)

				*ch_p += (uintptr_t)rtdata;

			rtdata->argc = (int32_t)(ch_p - rtdata->argv);

		};

		if (rtdata->envp) {

			rtdata->envp += (uintptr_t)rtdata / sizeof(char *);

			for (ch_p=rtdata->envp; *ch_p; ch_p++)

				*ch_p += (uintptr_t)rtdata;

			rtdata->envc = (int32_t)(ch_p - rtdata->envp);

		};

	}

	/* we're good */

	*argc = main_params->argc;

	*wargv = main_params->wargv_buffer;

	*wenvp = main_params->wenvp_buffer;

	return NT_STATUS_SUCCESS;

}

int32_t __stdcall 	__ntapi_tt_get_argv_envp_utf8(

	__out	int *		argc,

	__out	char ***	argv,

	__out	char ***	envp,

	__in	uint32_t	flags,

	__in	void *		ext_params	__optional,

	__out	void *		reserved	__optional)

{

	int32_t			status;

	ntapi_internals *	__internals;

	wchar16_t **	wargv;

	wchar16_t **	wenvp;

	uint32_t	pcount;

	nt_get_argv_envp_ext_params	__ext_params_internal;

	nt_get_argv_envp_ext_params *	__ext_params;

	nt_argv_envp_block_info *	main_params;

	/* use internal buffer? */

	if (flags & NT_GET_ARGV_ENVP_USE_CALLER_BUFFER) {

		__ext_params = (nt_get_argv_envp_ext_params *)ext_params;

		main_params  = &__ext_params->argv_envp_block_info;

	} else {

		/* pointers to internal/local structures */

		__ext_params = &__ext_params_internal;

		main_params  = &__ext_params->argv_envp_block_info;

		/* init */

		__ntapi->tt_aligned_block_memset(

			main_params,0,

			sizeof(*main_params));

		__internals = __ntapi_internals();

		/* use internal buffer */

		main_params->cmd_line		 = __ntapi_tt_get_cmd_line_utf16();

		main_params->wargv_buffer	 = __internals->ntapi_img_sec_bss->argv_envp_array;

		main_params->wargv_buffer_len	 = __NT_BSS_ARGV_BUFFER_SIZE;

		main_params->argv_envp_ptr_total	 = (int)(main_params->wargv_buffer_len

							/ sizeof(uintptr_t));

		main_params->wargs_buffer	 = (wchar16_t *)&(__internals->ntapi_img_sec_bss->args_envs_buffer);

		main_params->wargs_buffer_len	 = __NT_BSS_ARGS_BUFFER_SIZE;

	}

	/* start with obtaining the utf-16 environment */

	status = __ntapi->tt_get_argv_envp_utf16(

		argc,

		&wargv,

		&wenvp,

		flags | NT_GET_ARGV_ENVP_USE_CALLER_BUFFER,

		__ext_params,

		reserved);

	if (status) return status;

	/* enough pointers left? */

	pcount = main_params->argc + 1 + main_params->envc + 1;

	if (pcount > (main_params->argv_envp_ptr_total / 2))

		return NT_STATUS_BUFFER_TOO_SMALL;

	else if ((main_params->wenvs_buffer_len - main_params->wenvs_bytes_used)

			< sizeof(uintptr_t))

		return NT_STATUS_BUFFER_TOO_SMALL;

	/* first args byte should be aligned at pointer-size boundary */

	main_params->wenvs_bytes_used += sizeof(uintptr_t) - 1;

	main_params->wenvs_bytes_used /= sizeof(uintptr_t);

	main_params->wenvs_bytes_used *= sizeof(uintptr_t);

	/* book-keeping */

	/* block reminder: wargs -- wenvs -- args -- envs */

	main_params->argv = (char **)main_params->wenvp_buffer;

	main_params->argv += main_params->envc + 1;

	main_params->args_buffer = (char *)main_params->wenvs_buffer;

	main_params->args_buffer += main_params->wenvs_bytes_used;

	main_params->args_buffer_len = main_params->wenvs_buffer_len

					- main_params->wenvs_bytes_used;

	main_params->wenvs_buffer_len = main_params->wenvs_bytes_used;

	/* create a utf-8 argv[] array */

	status = __ntapi_tt_array_convert_utf16_to_utf8(

		main_params->wargv_buffer,

		main_params->argv,

		0,

		main_params->args_buffer,

		main_params->args_buffer_len,

		&main_params->args_bytes_written);

	if (status) return status;

	/* first envs byte should be aligned to pointer-size boundary */

	main_params->args_bytes_written += sizeof(uintptr_t) - 1;

	main_params->args_bytes_written /= sizeof(uintptr_t);

	main_params->args_bytes_written *= sizeof(uintptr_t);

	/* book-keeping */

	main_params->envp = main_params->argv + main_params->argc + 1;

	main_params->envs_buffer  = main_params->args_buffer

					+ main_params->args_bytes_written;

	main_params->envs_buffer_len = main_params->args_buffer_len 

					- main_params->args_bytes_written;

	main_params->args_buffer_len = main_params->args_bytes_written;

	/* subsequent streams (if any) should be aligned to pointer-size boundary */

	main_params->envs_bytes_used += sizeof(uintptr_t) - 1;

	main_params->envs_bytes_used /= sizeof(uintptr_t);

	main_params->envs_bytes_used *= sizeof(uintptr_t);

	/* create a utf-8 envp[] array */

	status = __ntapi_tt_array_convert_utf16_to_utf8(

		main_params->wenvp_buffer,

		main_params->envp,

		0,

		main_params->envs_buffer,

		main_params->envs_buffer_len,

		&main_params->envs_bytes_used);

	if (status) return status;

	/* we're good */

	*argc = main_params->argc;

	*argv = main_params->argv;

	*envp = main_params->envp;

	return NT_STATUS_SUCCESS;

}

wchar16_t * __stdcall __ntapi_tt_get_cmd_line_utf16(void)

{

	nt_peb * peb;

	return (peb = (nt_peb *)pe_get_peb_address())

		? peb->process_params->command_line.buffer

		: 0;

}

wchar16_t * __stdcall __ntapi_tt_get_peb_env_block_utf16(void)

{

	nt_peb * peb;

	return (peb = (nt_peb *)pe_get_peb_address())

		? peb->process_params->environment

		: 0;

}