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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);

}

/** @}

 */