qemu/util/readline.c
Alex Chen 593621f36b readline: Fix possible array index out of bounds in readline_hist_add()
When the 'cmdline' is the last entry in 'rs->history' array, there is
no need to put this entry to the end of the array, partly because it is
the last entry, and partly because the next operition will lead to array
index out of bounds.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Message-id: 20201203135043.117072-1-alex.chen@huawei.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-01-04 11:13:39 +00:00

550 lines
15 KiB
C

/*
* QEMU readline utility
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu/readline.h"
#include "qemu/ctype.h"
#include "qemu/cutils.h"
#define IS_NORM 0
#define IS_ESC 1
#define IS_CSI 2
#define IS_SS3 3
void readline_show_prompt(ReadLineState *rs)
{
rs->printf_func(rs->opaque, "%s", rs->prompt);
rs->flush_func(rs->opaque);
rs->last_cmd_buf_index = 0;
rs->last_cmd_buf_size = 0;
rs->esc_state = IS_NORM;
}
/* update the displayed command line */
static void readline_update(ReadLineState *rs)
{
int i, delta, len;
if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
for (i = 0; i < rs->last_cmd_buf_index; i++) {
rs->printf_func(rs->opaque, "\033[D");
}
rs->cmd_buf[rs->cmd_buf_size] = '\0';
if (rs->read_password) {
len = strlen(rs->cmd_buf);
for (i = 0; i < len; i++) {
rs->printf_func(rs->opaque, "*");
}
} else {
rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
}
rs->printf_func(rs->opaque, "\033[K");
memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
rs->last_cmd_buf_size = rs->cmd_buf_size;
rs->last_cmd_buf_index = rs->cmd_buf_size;
}
if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
if (delta > 0) {
for (i = 0; i < delta; i++) {
rs->printf_func(rs->opaque, "\033[C");
}
} else {
delta = -delta;
for (i = 0; i < delta; i++) {
rs->printf_func(rs->opaque, "\033[D");
}
}
rs->last_cmd_buf_index = rs->cmd_buf_index;
}
rs->flush_func(rs->opaque);
}
static void readline_insert_char(ReadLineState *rs, int ch)
{
if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
rs->cmd_buf + rs->cmd_buf_index,
rs->cmd_buf_size - rs->cmd_buf_index);
rs->cmd_buf[rs->cmd_buf_index] = ch;
rs->cmd_buf_size++;
rs->cmd_buf_index++;
}
}
static void readline_backward_char(ReadLineState *rs)
{
if (rs->cmd_buf_index > 0) {
rs->cmd_buf_index--;
}
}
static void readline_forward_char(ReadLineState *rs)
{
if (rs->cmd_buf_index < rs->cmd_buf_size) {
rs->cmd_buf_index++;
}
}
static void readline_delete_char(ReadLineState *rs)
{
if (rs->cmd_buf_index < rs->cmd_buf_size) {
memmove(rs->cmd_buf + rs->cmd_buf_index,
rs->cmd_buf + rs->cmd_buf_index + 1,
rs->cmd_buf_size - rs->cmd_buf_index - 1);
rs->cmd_buf_size--;
}
}
static void readline_backspace(ReadLineState *rs)
{
if (rs->cmd_buf_index > 0) {
readline_backward_char(rs);
readline_delete_char(rs);
}
}
static void readline_backword(ReadLineState *rs)
{
int start;
if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
return;
}
start = rs->cmd_buf_index - 1;
/* find first word (backwards) */
while (start > 0) {
if (!qemu_isspace(rs->cmd_buf[start])) {
break;
}
--start;
}
/* find first space (backwards) */
while (start > 0) {
if (qemu_isspace(rs->cmd_buf[start])) {
++start;
break;
}
--start;
}
/* remove word */
if (start < rs->cmd_buf_index) {
memmove(rs->cmd_buf + start,
rs->cmd_buf + rs->cmd_buf_index,
rs->cmd_buf_size - rs->cmd_buf_index);
rs->cmd_buf_size -= rs->cmd_buf_index - start;
rs->cmd_buf_index = start;
}
}
static void readline_bol(ReadLineState *rs)
{
rs->cmd_buf_index = 0;
}
static void readline_eol(ReadLineState *rs)
{
rs->cmd_buf_index = rs->cmd_buf_size;
}
static void readline_up_char(ReadLineState *rs)
{
int idx;
if (rs->hist_entry == 0) {
return;
}
if (rs->hist_entry == -1) {
/* Find latest entry */
for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
if (rs->history[idx] == NULL) {
break;
}
}
rs->hist_entry = idx;
}
rs->hist_entry--;
if (rs->hist_entry >= 0) {
pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
rs->history[rs->hist_entry]);
rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
}
}
static void readline_down_char(ReadLineState *rs)
{
if (rs->hist_entry == -1) {
return;
}
if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
rs->history[++rs->hist_entry] != NULL) {
pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
rs->history[rs->hist_entry]);
} else {
rs->cmd_buf[0] = 0;
rs->hist_entry = -1;
}
rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
}
static void readline_hist_add(ReadLineState *rs, const char *cmdline)
{
char *hist_entry, *new_entry;
int idx;
if (cmdline[0] == '\0') {
return;
}
new_entry = NULL;
if (rs->hist_entry != -1) {
/* We were editing an existing history entry: replace it */
hist_entry = rs->history[rs->hist_entry];
idx = rs->hist_entry;
if (strcmp(hist_entry, cmdline) == 0) {
goto same_entry;
}
}
/* Search cmdline in history buffers */
for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
hist_entry = rs->history[idx];
if (hist_entry == NULL) {
break;
}
if (strcmp(hist_entry, cmdline) == 0) {
same_entry:
if (idx == READLINE_MAX_CMDS - 1) {
return;
}
new_entry = hist_entry;
/* Put this entry at the end of history */
memmove(&rs->history[idx], &rs->history[idx + 1],
(READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
rs->history[READLINE_MAX_CMDS - 1] = NULL;
for (; idx < READLINE_MAX_CMDS; idx++) {
if (rs->history[idx] == NULL) {
break;
}
}
break;
}
}
if (idx == READLINE_MAX_CMDS) {
/* Need to get one free slot */
g_free(rs->history[0]);
memmove(rs->history, &rs->history[1],
(READLINE_MAX_CMDS - 1) * sizeof(char *));
rs->history[READLINE_MAX_CMDS - 1] = NULL;
idx = READLINE_MAX_CMDS - 1;
}
if (new_entry == NULL) {
new_entry = g_strdup(cmdline);
}
rs->history[idx] = new_entry;
rs->hist_entry = -1;
}
/* completion support */
void readline_add_completion(ReadLineState *rs, const char *str)
{
if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
int i;
for (i = 0; i < rs->nb_completions; i++) {
if (!strcmp(rs->completions[i], str)) {
return;
}
}
rs->completions[rs->nb_completions++] = g_strdup(str);
}
}
void readline_set_completion_index(ReadLineState *rs, int index)
{
rs->completion_index = index;
}
static int completion_comp(const void *a, const void *b)
{
return strcmp(*(const char **) a, *(const char **) b);
}
static void readline_completion(ReadLineState *rs)
{
int len, i, j, max_width, nb_cols, max_prefix;
char *cmdline;
rs->nb_completions = 0;
cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
rs->completion_finder(rs->opaque, cmdline);
g_free(cmdline);
/* no completion found */
if (rs->nb_completions <= 0) {
return;
}
if (rs->nb_completions == 1) {
len = strlen(rs->completions[0]);
for (i = rs->completion_index; i < len; i++) {
readline_insert_char(rs, rs->completions[0][i]);
}
/* extra space for next argument. XXX: make it more generic */
if (len > 0 && rs->completions[0][len - 1] != '/') {
readline_insert_char(rs, ' ');
}
} else {
qsort(rs->completions, rs->nb_completions, sizeof(char *),
completion_comp);
rs->printf_func(rs->opaque, "\n");
max_width = 0;
max_prefix = 0;
for (i = 0; i < rs->nb_completions; i++) {
len = strlen(rs->completions[i]);
if (i == 0) {
max_prefix = len;
} else {
if (len < max_prefix) {
max_prefix = len;
}
for (j = 0; j < max_prefix; j++) {
if (rs->completions[i][j] != rs->completions[0][j]) {
max_prefix = j;
}
}
}
if (len > max_width) {
max_width = len;
}
}
if (max_prefix > 0)
for (i = rs->completion_index; i < max_prefix; i++) {
readline_insert_char(rs, rs->completions[0][i]);
}
max_width += 2;
if (max_width < 10) {
max_width = 10;
} else if (max_width > 80) {
max_width = 80;
}
nb_cols = 80 / max_width;
j = 0;
for (i = 0; i < rs->nb_completions; i++) {
rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
if (++j == nb_cols || i == (rs->nb_completions - 1)) {
rs->printf_func(rs->opaque, "\n");
j = 0;
}
}
readline_show_prompt(rs);
}
for (i = 0; i < rs->nb_completions; i++) {
g_free(rs->completions[i]);
}
}
static void readline_clear_screen(ReadLineState *rs)
{
rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
readline_show_prompt(rs);
}
/* return true if command handled */
void readline_handle_byte(ReadLineState *rs, int ch)
{
switch (rs->esc_state) {
case IS_NORM:
switch (ch) {
case 1:
readline_bol(rs);
break;
case 4:
readline_delete_char(rs);
break;
case 5:
readline_eol(rs);
break;
case 9:
readline_completion(rs);
break;
case 12:
readline_clear_screen(rs);
break;
case 10:
case 13:
rs->cmd_buf[rs->cmd_buf_size] = '\0';
if (!rs->read_password) {
readline_hist_add(rs, rs->cmd_buf);
}
rs->printf_func(rs->opaque, "\n");
rs->cmd_buf_index = 0;
rs->cmd_buf_size = 0;
rs->last_cmd_buf_index = 0;
rs->last_cmd_buf_size = 0;
rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
break;
case 23:
/* ^W */
readline_backword(rs);
break;
case 27:
rs->esc_state = IS_ESC;
break;
case 127:
case 8:
readline_backspace(rs);
break;
case 155:
rs->esc_state = IS_CSI;
break;
default:
if (ch >= 32) {
readline_insert_char(rs, ch);
}
break;
}
break;
case IS_ESC:
if (ch == '[') {
rs->esc_state = IS_CSI;
rs->esc_param = 0;
} else if (ch == 'O') {
rs->esc_state = IS_SS3;
rs->esc_param = 0;
} else {
rs->esc_state = IS_NORM;
}
break;
case IS_CSI:
switch (ch) {
case 'A':
case 'F':
readline_up_char(rs);
break;
case 'B':
case 'E':
readline_down_char(rs);
break;
case 'D':
readline_backward_char(rs);
break;
case 'C':
readline_forward_char(rs);
break;
case '0' ... '9':
rs->esc_param = rs->esc_param * 10 + (ch - '0');
goto the_end;
case '~':
switch (rs->esc_param) {
case 1:
readline_bol(rs);
break;
case 3:
readline_delete_char(rs);
break;
case 4:
readline_eol(rs);
break;
}
break;
default:
break;
}
rs->esc_state = IS_NORM;
the_end:
break;
case IS_SS3:
switch (ch) {
case 'F':
readline_eol(rs);
break;
case 'H':
readline_bol(rs);
break;
}
rs->esc_state = IS_NORM;
break;
}
readline_update(rs);
}
void readline_start(ReadLineState *rs, const char *prompt, int read_password,
ReadLineFunc *readline_func, void *opaque)
{
pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
rs->readline_func = readline_func;
rs->readline_opaque = opaque;
rs->read_password = read_password;
readline_restart(rs);
}
void readline_restart(ReadLineState *rs)
{
rs->cmd_buf_index = 0;
rs->cmd_buf_size = 0;
}
const char *readline_get_history(ReadLineState *rs, unsigned int index)
{
if (index >= READLINE_MAX_CMDS) {
return NULL;
}
return rs->history[index];
}
void readline_free(ReadLineState *rs)
{
int i;
if (!rs) {
return;
}
for (i = 0; i < READLINE_MAX_CMDS; i++) {
g_free(rs->history[i]);
}
g_free(rs);
}
ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
ReadLineFlushFunc *flush_func,
void *opaque,
ReadLineCompletionFunc *completion_finder)
{
ReadLineState *rs = g_new0(ReadLineState, 1);
rs->hist_entry = -1;
rs->opaque = opaque;
rs->printf_func = printf_func;
rs->flush_func = flush_func;
rs->completion_finder = completion_finder;
return rs;
}