source: mainline/kernel/generic/src/console/kconsole.c@ 3ff2b54

/*
 * 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 (isspace(cmdline[i]))
                                (*start)++;
                        else
                                found_start = true;
                } else {
                        if (isspace(cmdline[i]))
                                break;
                }
        }
        *end = i - 1;

        return found_start;
}

/** @}
 */