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/*

 * Copyright (c) 2005 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup genericconsole

 * @{

 */

/**

 * @file  kconsole.c

 * @brief Kernel console.

 *

 * This file contains kernel thread managing the kernel console.

 *

 */

#include <console/kconsole.h>

#include <console/console.h>

#include <console/chardev.h>

#include <console/cmd.h>

#include <print.h>

#include <panic.h>

#include <arch/types.h>

#include <adt/list.h>

#include <arch.h>

#include <macros.h>

#include <debug.h>

#include <func.h>

#include <string.h>

#include <macros.h>

#include <sysinfo/sysinfo.h>

#include <ddi/device.h>

#include <symtab.h>

#include <errno.h>

#include <putchar.h>

#include <string.h>

/** Simple kernel console.

 *

 * The console is realized by kernel thread kconsole.

 * It doesn't understand any useful command on its own,

 * but makes it possible for other kernel subsystems to

 * register their own commands.

 */

/** Locking.

 *

 * There is a list of cmd_info_t structures. This list

 * is protected by cmd_lock spinlock. Note that specially

 * the link elements of cmd_info_t are protected by

 * this lock.

 *

 * Each cmd_info_t also has its own lock, which protects

 * all elements thereof except the link element.

 *

 * cmd_lock must be acquired before any cmd_info lock.

 * When locking two cmd info structures, structure with

 * lower address must be locked first.

 */

SPINLOCK_INITIALIZE(cmd_lock);  /**< Lock protecting command list. */

LIST_INITIALIZE(cmd_head);      /**< Command list. */

static wchar_t history[KCONSOLE_HISTORY][MAX_CMDLINE] = {};

static size_t history_pos = 0;

/** Initialize kconsole data structures

 *

 * This is the most basic initialization, almost no

 * other kernel subsystem is ready yet.

 *

 */

void kconsole_init(void)

{

	unsigned int i;

	cmd_init();

	for (i = 0; i < KCONSOLE_HISTORY; i++)

		history[i][0] = 0;

}

/** Register kconsole command.

 *

 * @param cmd Structure describing the command.

 *

 * @return False on failure, true on success.

 *

 */

bool cmd_register(cmd_info_t *cmd)

{

	link_t *cur;

	spinlock_lock(&cmd_lock);

	/*

	 * Make sure the command is not already listed.

	 */

	for (cur = cmd_head.next; cur != &cmd_head; cur = cur->next) {

		cmd_info_t *hlp = list_get_instance(cur, cmd_info_t, link);

		if (hlp == cmd) {

			/* The command is already there. */

			spinlock_unlock(&cmd_lock);

			return false;

		}

		/* Avoid deadlock. */

		if (hlp < cmd) {

			spinlock_lock(&hlp->lock);

			spinlock_lock(&cmd->lock);

		} else {

			spinlock_lock(&cmd->lock);

			spinlock_lock(&hlp->lock);

		}

		if (str_cmp(hlp->name, cmd->name) == 0) {

			/* The command is already there. */

			spinlock_unlock(&hlp->lock);

			spinlock_unlock(&cmd->lock);

			spinlock_unlock(&cmd_lock);

			return false;

		}

		spinlock_unlock(&hlp->lock);

		spinlock_unlock(&cmd->lock);

	}

	/*

	 * Now the command can be added.

	 */

	list_append(&cmd->link, &cmd_head);

	spinlock_unlock(&cmd_lock);

	return true;

}

/** Print count times a character */

static void print_cc(wchar_t ch, size_t count)

{

	size_t i;

	for (i = 0; i < count; i++)

		putchar(ch);

}

/** Try to find a command beginning with prefix */

static const char *cmdtab_search_one(const char *name, link_t **startpos)

{

	size_t namelen = str_length(name);

	spinlock_lock(&cmd_lock);

	if (*startpos == NULL)

		*startpos = cmd_head.next;

	for (; *startpos != &cmd_head; *startpos = (*startpos)->next) {

		cmd_info_t *hlp = list_get_instance(*startpos, cmd_info_t, link);

		const char *curname = hlp->name;

		if (str_length(curname) < namelen)

			continue;

		if (str_lcmp(curname, name, namelen) == 0) {

			spinlock_unlock(&cmd_lock);

			return (curname + str_lsize(curname, namelen));

		}

	}

	spinlock_unlock(&cmd_lock);

	return NULL;

}

/** Command completion of the commands

 *

 * @param name String to match, changed to hint on exit

 * @param size Input buffer size

 *

 * @return Number of found matches

 *

 */

static int cmdtab_compl(char *input, size_t size)

{

	const char *name = input;

	size_t found = 0;

	link_t *pos = NULL;

	const char *hint;

	char output[MAX_CMDLINE];

	output[0] = 0;

	while ((hint = cmdtab_search_one(name, &pos))) {

		if ((found == 0) || (str_length(output) > str_length(hint)))

			str_cpy(output, MAX_CMDLINE, hint);

		pos = pos->next;

		found++;

	}

	if ((found > 1) && (str_length(output) != 0)) {

		printf("\n");

		pos = NULL;

		while ((hint = cmdtab_search_one(name, &pos))) {

			cmd_info_t *hlp = list_get_instance(pos, cmd_info_t, link);

			printf("%s (%s)\n", hlp->name, hlp->description);

			pos = pos->next;

		}

	}

	if (found > 0)

		str_cpy(input, size, output);

	return found;

}

static wchar_t *clever_readline(const char *prompt, indev_t *indev)

{

	printf("%s> ", prompt);

	size_t position = 0;

	wchar_t *current = history[history_pos];

	current[0] = 0;

	while (true) {

		wchar_t ch = indev_pop_character(indev);

		if (ch == '\n') {

			/* Enter */

			putchar(ch);

			break;

		}

		if (ch == '\b') {

			/* Backspace */

			if (position == 0)

				continue;

			if (wstr_remove(current, position - 1)) {

				position--;

				putchar('\b');

				printf("%ls ", current + position);

				print_cc('\b', wstr_length(current) - position + 1);

				continue;

			}

		}

		if (ch == '\t') {

			/* Tab completion */

			/* Move to the end of the word */

			for (; (current[position] != 0) && (!isspace(current[position]));

			    position++)

				putchar(current[position]);

			if (position == 0)

				continue;

			/* Find the beginning of the word

			   and copy it to tmp */

			size_t beg;

			for (beg = position - 1; (beg > 0) && (!isspace(current[beg]));

			    beg--);

			if (isspace(current[beg]))

				beg++;

			char tmp[STR_BOUNDS(MAX_CMDLINE)];

			wstr_nstr(tmp, current + beg, position - beg + 1);

			int found;

			if (beg == 0) {

				/* Command completion */

				found = cmdtab_compl(tmp, STR_BOUNDS(MAX_CMDLINE));

			} else {

				/* Symbol completion */

				found = symtab_compl(tmp, STR_BOUNDS(MAX_CMDLINE));

			}

			if (found == 0)

				continue;

			if (found > 1) {

				/* No unique hint, list was printed */

				printf("%s> ", prompt);

				printf("%ls", current);

				print_cc('\b', wstr_length(current) - position);

				continue;

			}

			/* We have a hint */

			size_t off = 0;

			size_t i = 0;

			while ((ch = str_decode(tmp, &off, STR_NO_LIMIT)) != 0) {

				if (!wstr_linsert(current, ch, position + i, MAX_CMDLINE))

					break;

				i++;

			}

			printf("%ls", current + position);

			position += str_length(tmp);

			print_cc('\b', wstr_length(current) - position);

			if (position == wstr_length(current)) {

				/* Insert a space after the last completed argument */

				if (wstr_linsert(current, ' ', position, MAX_CMDLINE)) {

					printf("%ls", current + position);

					position++;

				}

			}

			continue;

		}

		if (ch == U_LEFT_ARROW) {

			/* Left */

			if (position > 0) {

				putchar('\b');

				position--;

			}

			continue;

		}

		if (ch == U_RIGHT_ARROW) {

			/* Right */

			if (position < wstr_length(current)) {

				putchar(current[position]);

				position++;

			}

			continue;

		}

		if ((ch == U_UP_ARROW) || (ch == U_DOWN_ARROW)) {

			/* Up, down */

			print_cc('\b', position);

			print_cc(' ', wstr_length(current));

			print_cc('\b', wstr_length(current));

			if (ch == U_UP_ARROW) {

				/* Up */

				if (history_pos == 0)

					history_pos = KCONSOLE_HISTORY - 1;

				else

					history_pos--;

			} else {

				/* Down */

				history_pos++;

				history_pos = history_pos % KCONSOLE_HISTORY;

			}

			current = history[history_pos];

			printf("%ls", current);

			position = wstr_length(current);

			continue;

		}

		if (ch == U_HOME_ARROW) {

			/* Home */

			print_cc('\b', position);

			position = 0;

			continue;

		}

		if (ch == U_END_ARROW) {

			/* End */

			printf("%ls", current + position);

			position = wstr_length(current);

			continue;

		}

		if (ch == U_DELETE) {

			/* Delete */

			if (position == wstr_length(current))

				continue;

			if (wstr_remove(current, position)) {

				printf("%ls ", current + position);

				print_cc('\b', wstr_length(current) - position + 1);

			}

			continue;

		}

		if (wstr_linsert(current, ch, position, MAX_CMDLINE)) {

			printf("%ls", current + position);

			position++;

			print_cc('\b', wstr_length(current) - position);

		}

	}

	if (wstr_length(current) > 0) {

		history_pos++;

		history_pos = history_pos % KCONSOLE_HISTORY;

	}

	return current;

}

bool kconsole_check_poll(void)

{

	return check_poll(stdin);

}

static bool parse_int_arg(const char *text, size_t len, unative_t *result)

{

	bool isaddr = false;

	bool isptr = false;

	/* If we get a name, try to find it in symbol table */

	if (text[0] == '&') {

		isaddr = true;

		text++;

		len--;

	} else if (text[0] == '*') {

		isptr = true;

		text++;

		len--;

	}

	if ((text[0] < '0') || (text[0] > '9')) {

		char symname[MAX_SYMBOL_NAME];

		str_ncpy(symname, MAX_SYMBOL_NAME, text, len + 1);

		uintptr_t symaddr;

		int rc = symtab_addr_lookup(symname, &symaddr);

		switch (rc) {

		case ENOENT:

			printf("Symbol %s not found.\n", symname);

			return false;

		case EOVERFLOW:

			printf("Duplicate symbol %s.\n", symname);

			symtab_print_search(symname);

			return false;

		case ENOTSUP:

			printf("No symbol information available.\n");

			return false;

		}

		if (isaddr)

			*result = (unative_t) symaddr;

		else if (isptr)

			*result = **((unative_t **) symaddr);

		else

			*result = *((unative_t *) symaddr);

	} else {

		/* It's a number - convert it */

		*result = atoi(text);

		if (isptr)

			*result = *((unative_t *) *result);

	}

	return true;

}

/** Parse argument.

 *

 * Find start and end positions of command line argument.

 *

 * @param cmdline Command line as read from the input device.

 * @param size    Size (in bytes) of the string.

 * @param start   On entry, 'start' contains pointer to the offset

 *                of the first unprocessed character of cmdline.

 *                On successful exit, it marks beginning of the next argument.

 * @param end     Undefined on entry. On exit, 'end' is the offset of the first

 *                character behind the next argument.

 *

 * @return False on failure, true on success.

 *

 */

static bool parse_argument(const char *cmdline, size_t size, size_t *start, size_t *end)

{

	ASSERT(start != NULL);

	ASSERT(end != NULL);

	bool found_start = false;

	size_t offset = *start;

	size_t prev = *start;

	wchar_t ch;

	while ((ch = str_decode(cmdline, &offset, size)) != 0) {

		if (!found_start) {

			if (!isspace(ch)) {

				*start = prev;

				found_start = true;

			}

		} else {

			if (isspace(ch))

				break;

		}

		prev = offset;

	}

	*end = prev;

	return found_start;

}

/** Parse command line.

 *

 * @param cmdline Command line as read from input device. 

 * @param size    Size (in bytes) of the string.

 *

 * @return Structure describing the command.

 *

 */

static cmd_info_t *parse_cmdline(const char *cmdline, size_t size)

{

	size_t start = 0;

	size_t end = 0;

	if (!parse_argument(cmdline, size, &start, &end)) {

		/* Command line did not contain alphanumeric word. */

		return NULL;

	}

	spinlock_lock(&cmd_lock);

	cmd_info_t *cmd = NULL;

	link_t *cur;

	for (cur = cmd_head.next; cur != &cmd_head; cur = cur->next) {

		cmd_info_t *hlp = list_get_instance(cur, cmd_info_t, link);

		spinlock_lock(&hlp->lock);

		if (str_lcmp(hlp->name, cmdline + start,

		    max(str_length(hlp->name),

		    str_nlength(cmdline + start, (size_t) (end - start) - 1))) == 0) {

			cmd = hlp;

			break;

		}

		spinlock_unlock(&hlp->lock);

	}

	spinlock_unlock(&cmd_lock);

	if (!cmd) {

		/* Unknown command. */

		printf("Unknown command.\n");

		return NULL;

	}

	/* cmd == hlp is locked */

	/*

	 * The command line must be further analyzed and

	 * the parameters therefrom must be matched and

	 * converted to those specified in the cmd info

	 * structure.

	 */

	bool error = false;

	size_t i;

	for (i = 0; i < cmd->argc; i++) {

		start = end;

		if (!parse_argument(cmdline, size, &start, &end)) {

			printf("Too few arguments.\n");

			spinlock_unlock(&cmd->lock);

			return NULL;

		}

		char *buf;

		switch (cmd->argv[i].type) {

		case ARG_TYPE_STRING:

			buf = (char *) cmd->argv[i].buffer;

			str_ncpy(buf, cmd->argv[i].len, cmdline + start,

			    end - start);

			break;

		case ARG_TYPE_INT:

			if (!parse_int_arg(cmdline + start, end - start,

			    &cmd->argv[i].intval))

				error = true;

			break;

		case ARG_TYPE_VAR:

			if ((start < end - 1) && (cmdline[start] == '"')) {

				if (cmdline[end - 1] == '"') {

					buf = (char *) cmd->argv[i].buffer;

					str_ncpy(buf, cmd->argv[i].len,

					    cmdline + start + 1,

					    (end - start) - 1);

					cmd->argv[i].intval = (unative_t) buf;

					cmd->argv[i].vartype = ARG_TYPE_STRING;

				} else {

					printf("Wrong synxtax.\n");

					error = true;

				}

			} else if (parse_int_arg(cmdline + start,

			    end - start, &cmd->argv[i].intval)) {

				cmd->argv[i].vartype = ARG_TYPE_INT;

			} else {

				printf("Unrecognized variable argument.\n");

				error = true;

			}

			break;

		case ARG_TYPE_INVALID:

		default:

			printf("Invalid argument type\n");

			error = true;

			break;

		}

	}

	if (error) {

		spinlock_unlock(&cmd->lock);

		return NULL;

	}

	start = end;

	if (parse_argument(cmdline, size, &start, &end)) {

		printf("Too many arguments.\n");

		spinlock_unlock(&cmd->lock);

		return NULL;

	}

	spinlock_unlock(&cmd->lock);

	return cmd;

}

/** Kernel console prompt.

 *

 * @param prompt Kernel console prompt (e.g kconsole/panic).

 * @param msg    Message to display in the beginning.

 * @param kcon   Wait for keypress to show the prompt

 *               and never exit.

 *

 */

void kconsole(char *prompt, char *msg, bool kcon)

{

	if (!stdin) {

		LOG("No stdin for kernel console");

		return;

	}

	if (msg)

		printf("%s", msg);

	if (kcon)

		indev_pop_character(stdin);

	else

		printf("Type \"exit\" to leave the console.\n");

	while (true) {

		wchar_t *tmp = clever_readline((char *) prompt, stdin);

		size_t len = wstr_length(tmp);

		if (!len)

			continue;

		char cmdline[STR_BOUNDS(MAX_CMDLINE)];

		wstr_nstr(cmdline, tmp, STR_BOUNDS(MAX_CMDLINE));

		if ((!kcon) && (len == 4) && (str_lcmp(cmdline, "exit", 4) == 0))

			break;

		cmd_info_t *cmd_info = parse_cmdline(cmdline, STR_BOUNDS(MAX_CMDLINE));

		if (!cmd_info)

			continue;

		(void) cmd_info->func(cmd_info->argv);

	}

}

/** Kernel console managing thread.

 *

 */

void kconsole_thread(void *data)

{

	kconsole("kconsole", "Kernel console ready (press any key to activate)\n", true);

}

/** @}

 */