u-boot/common/cli.c
Francis Laniel 3ea3c57ef5 cli: add modern hush as parser for run_command*()
Enables using, in code, modern hush as parser for run_command function family.
It also enables the command run to be used by CLI user of modern hush.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>
2023-12-28 12:02:56 -05:00

339 lines
8.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* Add to readline cmdline-editing by
* (C) Copyright 2005
* JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
*/
#define pr_fmt(fmt) "cli: %s: " fmt, __func__
#include <common.h>
#include <bootstage.h>
#include <cli.h>
#include <cli_hush.h>
#include <command.h>
#include <console.h>
#include <env.h>
#include <fdtdec.h>
#include <hang.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <dm/ofnode.h>
#include <linux/errno.h>
#ifdef CONFIG_CMDLINE
static inline bool use_hush_old(void)
{
return IS_ENABLED(CONFIG_HUSH_SELECTABLE) ?
gd->flags & GD_FLG_HUSH_OLD_PARSER :
IS_ENABLED(CONFIG_HUSH_OLD_PARSER);
}
/*
* Run a command using the selected parser.
*
* @param cmd Command to run
* @param flag Execution flags (CMD_FLAG_...)
* Return: 0 on success, or != 0 on error.
*/
int run_command(const char *cmd, int flag)
{
#if !IS_ENABLED(CONFIG_HUSH_PARSER)
/*
* cli_run_command can return 0 or 1 for success, so clean up
* its result.
*/
if (cli_simple_run_command(cmd, flag) == -1)
return 1;
return 0;
#else
if (use_hush_old()) {
int hush_flags = FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP;
if (flag & CMD_FLAG_ENV)
hush_flags |= FLAG_CONT_ON_NEWLINE;
return parse_string_outer(cmd, hush_flags);
}
/*
* Possible values for flags are the following:
* FLAG_EXIT_FROM_LOOP: This flags ensures we exit from loop in
* parse_and_run_stream() after first iteration while normal
* behavior, * i.e. when called from cli_loop(), is to loop
* infinitely.
* FLAG_PARSE_SEMICOLON: modern Hush parses ';' and does not stop
* first time it sees one. So, I think we do not need this flag.
* FLAG_REPARSING: For the moment, I do not understand the goal
* of this flag.
* FLAG_CONT_ON_NEWLINE: This flag seems to be used to continue
* parsing even when reading '\n' when coming from
* run_command(). In this case, modern Hush reads until it finds
* '\0'. So, I think we do not need this flag.
*/
return parse_string_outer_modern(cmd, FLAG_EXIT_FROM_LOOP);
#endif
}
/*
* Run a command using the selected parser, and check if it is repeatable.
*
* @param cmd Command to run
* @param flag Execution flags (CMD_FLAG_...)
* Return: 0 (not repeatable) or 1 (repeatable) on success, -1 on error.
*/
int run_command_repeatable(const char *cmd, int flag)
{
#ifndef CONFIG_HUSH_PARSER
return cli_simple_run_command(cmd, flag);
#else
int ret;
if (use_hush_old()) {
ret = parse_string_outer(cmd,
FLAG_PARSE_SEMICOLON
| FLAG_EXIT_FROM_LOOP);
} else {
ret = parse_string_outer_modern(cmd,
FLAG_PARSE_SEMICOLON
| FLAG_EXIT_FROM_LOOP);
}
/*
* parse_string_outer() returns 1 for failure, so clean up
* its result.
*/
if (ret)
return -1;
return 0;
#endif
}
#else
__weak int board_run_command(const char *cmdline)
{
printf("## Commands are disabled. Please enable CONFIG_CMDLINE.\n");
return 1;
}
#endif /* CONFIG_CMDLINE */
int run_command_list(const char *cmd, int len, int flag)
{
int need_buff = 1;
char *buff = (char *)cmd; /* cast away const */
int rcode = 0;
if (len == -1) {
len = strlen(cmd);
#ifdef CONFIG_HUSH_PARSER
/* hush will never change our string */
need_buff = 0;
#else
/* the built-in parser will change our string if it sees \n */
need_buff = strchr(cmd, '\n') != NULL;
#endif
}
if (need_buff) {
buff = malloc(len + 1);
if (!buff)
return 1;
memcpy(buff, cmd, len);
buff[len] = '\0';
}
#ifdef CONFIG_HUSH_PARSER
if (use_hush_old()) {
rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
} else {
rcode = parse_string_outer_modern(buff, FLAG_PARSE_SEMICOLON);
}
#else
/*
* This function will overwrite any \n it sees with a \0, which
* is why it can't work with a const char *. Here we are making
* using of internal knowledge of this function, to avoid always
* doing a malloc() which is actually required only in a case that
* is pretty rare.
*/
#ifdef CONFIG_CMDLINE
rcode = cli_simple_run_command_list(buff, flag);
#else
rcode = board_run_command(buff);
#endif
#endif
if (need_buff)
free(buff);
return rcode;
}
int run_commandf(const char *fmt, ...)
{
va_list args;
int nbytes;
va_start(args, fmt);
/*
* Limit the console_buffer space being used to CONFIG_SYS_CBSIZE,
* because its last byte is used to fit the replacement of \0 by \n\0
* in underlying hush parser
*/
nbytes = vsnprintf(console_buffer, CONFIG_SYS_CBSIZE, fmt, args);
va_end(args);
if (nbytes < 0) {
pr_debug("I/O internal error occurred.\n");
return -EIO;
} else if (nbytes >= CONFIG_SYS_CBSIZE) {
pr_debug("'fmt' size:%d exceeds the limit(%d)\n",
nbytes, CONFIG_SYS_CBSIZE);
return -ENOSPC;
}
return run_command(console_buffer, 0);
}
/****************************************************************************/
#if defined(CONFIG_CMD_RUN)
int do_run(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
int i, ret;
if (argc < 2)
return CMD_RET_USAGE;
for (i = 1; i < argc; ++i) {
char *arg;
arg = env_get(argv[i]);
if (arg == NULL) {
printf("## Error: \"%s\" not defined\n", argv[i]);
return 1;
}
ret = run_command(arg, flag | CMD_FLAG_ENV);
if (ret)
return ret;
}
return 0;
}
#endif
#if CONFIG_IS_ENABLED(OF_CONTROL)
bool cli_process_fdt(const char **cmdp)
{
/* Allow the fdt to override the boot command */
const char *env = ofnode_conf_read_str("bootcmd");
if (env)
*cmdp = env;
/*
* If the bootsecure option was chosen, use secure_boot_cmd().
* Always use 'env' in this case, since bootsecure requres that the
* bootcmd was specified in the FDT too.
*/
return ofnode_conf_read_int("bootsecure", 0);
}
/*
* Runs the given boot command securely. Specifically:
* - Doesn't run the command with the shell (run_command or parse_string_outer),
* since that's a lot of code surface that an attacker might exploit.
* Because of this, we don't do any argument parsing--the secure boot command
* has to be a full-fledged u-boot command.
* - Doesn't check for keypresses before booting, since that could be a
* security hole; also disables Ctrl-C.
* - Doesn't allow the command to return.
*
* Upon any failures, this function will drop into an infinite loop after
* printing the error message to console.
*/
void cli_secure_boot_cmd(const char *cmd)
{
#ifdef CONFIG_CMDLINE
struct cmd_tbl *cmdtp;
#endif
int rc;
if (!cmd) {
printf("## Error: Secure boot command not specified\n");
goto err;
}
/* Disable Ctrl-C just in case some command is used that checks it. */
disable_ctrlc(1);
/* Find the command directly. */
#ifdef CONFIG_CMDLINE
cmdtp = find_cmd(cmd);
if (!cmdtp) {
printf("## Error: \"%s\" not defined\n", cmd);
goto err;
}
/* Run the command, forcing no flags and faking argc and argv. */
rc = (cmdtp->cmd)(cmdtp, 0, 1, (char **)&cmd);
#else
rc = board_run_command(cmd);
#endif
/* Shouldn't ever return from boot command. */
printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);
err:
/*
* Not a whole lot to do here. Rebooting won't help much, since we'll
* just end up right back here. Just loop.
*/
hang();
}
#endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
void cli_loop(void)
{
bootstage_mark(BOOTSTAGE_ID_ENTER_CLI_LOOP);
#if CONFIG_IS_ENABLED(HUSH_PARSER)
if (gd->flags & GD_FLG_HUSH_MODERN_PARSER)
parse_and_run_file();
else if (gd->flags & GD_FLG_HUSH_OLD_PARSER)
parse_file_outer();
printf("Problem\n");
/* This point is never reached */
for (;;);
#elif defined(CONFIG_CMDLINE)
cli_simple_loop();
#else
printf("## U-Boot command line is disabled. Please enable CONFIG_CMDLINE\n");
#endif /*CONFIG_HUSH_PARSER*/
}
void cli_init(void)
{
#ifdef CONFIG_HUSH_PARSER
/* This if block is used to initialize hush parser gd flag. */
if (!(gd->flags & GD_FLG_HUSH_OLD_PARSER)
&& !(gd->flags & GD_FLG_HUSH_MODERN_PARSER)) {
if (CONFIG_IS_ENABLED(HUSH_OLD_PARSER))
gd->flags |= GD_FLG_HUSH_OLD_PARSER;
else if (CONFIG_IS_ENABLED(HUSH_MODERN_PARSER))
gd->flags |= GD_FLG_HUSH_MODERN_PARSER;
}
if (gd->flags & GD_FLG_HUSH_OLD_PARSER) {
u_boot_hush_start();
} else if (gd->flags & GD_FLG_HUSH_MODERN_PARSER) {
u_boot_hush_start_modern();
} else {
printf("No valid hush parser to use, cli will not initialized!\n");
return;
}
#endif
#if defined(CONFIG_HUSH_INIT_VAR)
hush_init_var();
#endif
}