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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.

 */

/**

 * @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 <typedefs.h>

#include <arch/types.h>

#include <adt/list.h>

#include <arch.h>

#include <macros.h>

#include <debug.h>

#include <func.h>

#include <symtab.h>

#include <macros.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 cmd_info_t *parse_cmdline(char *cmdline, size_t len);

static bool parse_argument(char *cmdline, size_t len, index_t *start, index_t *end);

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

/** Initialize kconsole data structures. */

void kconsole_init(void)

{

	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 0 on failure, 1 on success.

 */

int 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;

		hlp = list_get_instance(cur, cmd_info_t, link);

		if (hlp == cmd) {

			/* The command is already there. */

			spinlock_unlock(&cmd_lock);

			return 0;

		}

		/* Avoid deadlock. */

		if (hlp < cmd) {

			spinlock_lock(&hlp->lock);

			spinlock_lock(&cmd->lock);

		} else {

			spinlock_lock(&cmd->lock);

			spinlock_lock(&hlp->lock);

		}

		if ((strncmp(hlp->name, 

			     cmd->name, max(strlen(cmd->name),

					    strlen(hlp->name))) == 0)) {

			/* The command is already there. */

			spinlock_unlock(&hlp->lock);

			spinlock_unlock(&cmd->lock);

			spinlock_unlock(&cmd_lock);

			return 0;

		}

		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 1;

}

/** Print count times a character */

static void rdln_print_c(char ch, int count)

{

	int i;

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

		putchar(ch);

}

/** Insert character to string */

static void insert_char(char *str, char ch, int pos)

{

	int i;

	for (i=strlen(str);i > pos; i--)

		str[i] = str[i-1];

	str[pos] = ch;

}

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

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

{

	int namelen = strlen(name);

	const char *curname;

	spinlock_lock(&cmd_lock);

	if (!*startpos)

		*startpos = cmd_head.next;

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

		cmd_info_t *hlp;

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

		curname = hlp->name;

		if (strlen(curname) < namelen)

			continue;

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

			spinlock_unlock(&cmd_lock);	

			return curname+namelen;

		}

	}

	spinlock_unlock(&cmd_lock);	

	return NULL;

}

/** Command completion of the commands 

 *

 * @param name - string to match, changed to hint on exit

 * @return number of found matches

 */

static int cmdtab_compl(char *name)

{

	char output[MAX_SYMBOL_NAME+1];

	link_t *startpos = NULL;

	const char *foundtxt;

	int found = 0;

	int i;

	output[0] = '\0';

	while ((foundtxt = cmdtab_search_one(name, &startpos))) {

		startpos = startpos->next;

		if (!found)

			strncpy(output, foundtxt, strlen(foundtxt)+1);

		else {

			for (i=0; output[i] && foundtxt[i] && output[i]==foundtxt[i]; i++)

				;

			output[i] = '\0';

		}

		found++;

	}

	if (!found)

		return 0;

	if (found > 1 && !strlen(output)) {

		printf("\n");

		startpos = NULL;

		while ((foundtxt = cmdtab_search_one(name, &startpos))) {

			cmd_info_t *hlp;

			hlp = list_get_instance(startpos, cmd_info_t, link);

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

			startpos = startpos->next;

		}

	}

	strncpy(name, output, MAX_SYMBOL_NAME);

	return found;

}

static char * clever_readline(const char *prompt, chardev_t *input)

{

	static int histposition = 0;

	char tmp[MAX_CMDLINE+1];

	int curlen = 0, position = 0;

	char *current = history[histposition];

	int i;

	char mod; /* Command Modifier */

	char c;

	printf("%s> ", prompt);

	while (1) {

		c = _getc(input);

		if (c == '\n') {

			putchar(c);

			break;

		} if (c == '\b') { /* Backspace */

			if (position == 0)

				continue;

			for (i=position; i<curlen;i++)

				current[i-1] = current[i];

			curlen--;

			position--;

			putchar('\b');

			for (i=position;i<curlen;i++)

				putchar(current[i]);

			putchar(' ');

			rdln_print_c('\b',curlen-position+1);

			continue;

		}

		if (c == '\t') { /* Tabulator */

			int found;

			/* Move to the end of the word */

			for (;position<curlen && current[position]!=' ';position++)

				putchar(current[position]);

			/* Copy to tmp last word */

			for (i=position-1;i >= 0 && current[i]!=' ' ;i--)

				;

			/* If word begins with * or &, skip it */

			if (tmp[0] == '*' || tmp[0] == '&')

				for (i=1;tmp[i];i++)

					tmp[i-1] = tmp[i];

			i++; /* I is at the start of the word */

			strncpy(tmp, current+i, position-i+1);

			if (i==0) { /* Command completion */

				found = cmdtab_compl(tmp);

			} else { /* Symtab completion */

				found = symtab_compl(tmp);

			}

			if (found == 0) 

				continue;

			for (i=0;tmp[i] && curlen < MAX_CMDLINE;i++,curlen++)

				insert_char(current, tmp[i], i+position);

			if (strlen(tmp) || found==1) { /* If we have a hint */

				for (i=position;i<curlen;i++) 

					putchar(current[i]);

				position += strlen(tmp);

				/* Add space to end */

				if (found == 1 && position == curlen && \

				    curlen < MAX_CMDLINE) {

					current[position] = ' ';

					curlen++;

					position++;

					putchar(' ');

				}

			} else { /* No hint, table was printed */

				printf("%s> ", prompt);

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

					putchar(current[i]);

				position += strlen(tmp);

			}

			rdln_print_c('\b', curlen-position);

			continue;

		}

		if (c == 0x1b) { /* Special command */

			mod = _getc(input);

			c = _getc(input);

			if (mod != 0x5b && mod != 0x4f)

				continue;

			if (c == 0x33 && _getc(input) == 0x7e) {

				/* Delete */

				if (position == curlen)

					continue;

				for (i=position+1; i<curlen;i++) {

					putchar(current[i]);

					current[i-1] = current[i];

				}

				putchar(' ');

				rdln_print_c('\b',curlen-position);

				curlen--;

			}

			else if (c == 0x48) { /* Home */

				rdln_print_c('\b',position);

				position = 0;

			} 

			else if (c == 0x46) {  /* End */

				for (i=position;i<curlen;i++)

					putchar(current[i]);

				position = curlen;

			}

			else if (c == 0x44) { /* Left */

				if (position > 0) {

					putchar('\b');

					position--;

				}

				continue;

			}

			else if (c == 0x43) { /* Right */

				if (position < curlen) {

					putchar(current[position]);

					position++;

				}

				continue;

			}

			else if (c == 0x41 || c == 0x42) { 

                                /* Up,down */

				rdln_print_c('\b',position);

				rdln_print_c(' ',curlen);

				rdln_print_c('\b',curlen);

				if (c == 0x41) /* Up */

					histposition--;

				else

					histposition++;

				if (histposition < 0)

					histposition = KCONSOLE_HISTORY -1 ;

				else

					histposition =  histposition % KCONSOLE_HISTORY;

				current = history[histposition];

				printf("%s", current);

				curlen = strlen(current);

				position = curlen;

				continue;

			}

			continue;

		}

		if (curlen >= MAX_CMDLINE)

			continue;

		insert_char(current, c, position);

		curlen++;

		for (i=position;i<curlen;i++)

			putchar(current[i]);

		position++;

		rdln_print_c('\b',curlen-position);

	} 

	if (curlen) {

		histposition++;

		histposition = histposition % KCONSOLE_HISTORY;

	}

	current[curlen] = '\0';

	return current;

}

/** Kernel console managing thread.

 *

 * @param arg Not used.

 */

void kconsole(void *prompt)

{

	cmd_info_t *cmd_info;

	count_t len;

	char *cmdline;

	if (!stdin) {

		printf("%s: no stdin\n", __FUNCTION__);

		return;

	}

	while (true) {

		cmdline = clever_readline(prompt, stdin);

		len = strlen(cmdline);

		if (!len)

			continue;

		cmd_info = parse_cmdline(cmdline, len);

		if (!cmd_info)

			continue;

		if (strncmp(cmd_info->name,"exit", \

			    min(strlen(cmd_info->name),5)) == 0)

			break;

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

	}

}

static int parse_int_arg(char *text, size_t len, __native *result)

{

	char symname[MAX_SYMBOL_NAME];

	__address symaddr;

	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') {

		strncpy(symname, text, min(len+1, MAX_SYMBOL_NAME));

		symaddr = get_symbol_addr(symname);

		if (!symaddr) {

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

			return -1;

		}

		if (symaddr == (__address) -1) {

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

			symtab_print_search(symname);

			return -1;

		}

		if (isaddr)

			*result = (__native)symaddr;

		else if (isptr)

			*result = **((__native **)symaddr);

		else

			*result = *((__native *)symaddr);

	} else { /* It's a number - convert it */

		*result = atoi(text);

		if (isptr)

			*result = *((__native *)*result);

	}

	return 0;

}

/** Parse command line.

 *

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

 * @param len Command line length.

 *

 * @return Structure describing the command.

 */

cmd_info_t *parse_cmdline(char *cmdline, size_t len)

{

	index_t start = 0, end = 0;

	cmd_info_t *cmd = NULL;

	link_t *cur;

	int i;

	int error = 0;

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

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

		return NULL;

	}

	spinlock_lock(&cmd_lock);

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

		cmd_info_t *hlp;

		hlp = list_get_instance(cur, cmd_info_t, link);

		spinlock_lock(&hlp->lock);

		if (strncmp(hlp->name, &cmdline[start], max(strlen(hlp->name),

							    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.

	 */

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

		char *buf;

		start = end + 1;

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

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

			spinlock_unlock(&cmd->lock);

			return NULL;

		}

		error = 0;

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

		case ARG_TYPE_STRING:

		    	buf = cmd->argv[i].buffer;

		    	strncpy(buf, (const char *) &cmdline[start], min((end - start) + 2, cmd->argv[i].len));

			buf[min((end - start) + 1, cmd->argv[i].len - 1)] = '\0';

			break;

		case ARG_TYPE_INT: 

			if (parse_int_arg(cmdline+start, end-start+1, 

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

				error = 1;

			break;

		case ARG_TYPE_VAR:

			if (start != end && cmdline[start] == '"' && cmdline[end] == '"') {

				buf = cmd->argv[i].buffer;

				strncpy(buf, (const char *) &cmdline[start+1], 

					min((end-start), cmd->argv[i].len));

				buf[min((end - start), cmd->argv[i].len - 1)] = '\0';

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

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

			} else if (!parse_int_arg(cmdline+start, end-start+1, 

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

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

			else {

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

				error = 1;

			}

			break;

		case ARG_TYPE_INVALID:

		default:

			printf("invalid argument type\n");

			error = 1;

			break;

		}

	}

	if (error) {

		spinlock_unlock(&cmd->lock);

		return NULL;

	}

	start = end + 1;

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

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

		spinlock_unlock(&cmd->lock);

		return NULL;

	}

	spinlock_unlock(&cmd->lock);

	return cmd;

}

/** Parse argument.

 *

 * Find start and end positions of command line argument.

 *

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

 * @param len Number of characters in cmdline.

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

 *        of first unprocessed character of cmdline.

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

 * @param end Undefined on entry. On exit, 'end' points to the last character

 *        of the next argument.

 *

 * @return false on failure, true on success.

 */

bool parse_argument(char *cmdline, size_t len, index_t *start, index_t *end)

{

	int i;

	bool found_start = false;

	ASSERT(start != NULL);

	ASSERT(end != NULL);

	for (i = *start; i < len; i++) {

		if (!found_start) {

			if (is_white(cmdline[i]))

				(*start)++;

			else

				found_start = true;

		} else {

			if (is_white(cmdline[i]))

				break;

		}

	}

	*end = i - 1;

	return found_start;

}