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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 <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)

{

    size_t 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)

{

    static 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;

    static 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 prompt Kernel console prompt (e.g kconsole/panic).

 */

void kconsole(void *prompt)

{

    cmd_info_t *cmd_info;

    count_t len;

    char *cmdline;

    if (!stdin) {

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

        return;

    }

    while (true) {

        cmdline = clever_readline((char *) 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, unative_t *result)

{

    static char symname[MAX_SYMBOL_NAME];

    uintptr_t 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 == (uintptr_t) -1) {

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

            symtab_print_search(symname);

            return -1;

        }

        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 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;

    count_t 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 = (char *) 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 = (char *) 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 = (unative_t) 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)

{

    index_t 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;

}

/** @}

 */