1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2000
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  *
6  * Add to readline cmdline-editing by
7  * (C) Copyright 2005
8  * JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
9  */
10 
11 #define pr_fmt(fmt) "cli: %s: " fmt, __func__
12 
13 #include <common.h>
14 #include <bootstage.h>
15 #include <cli.h>
16 #include <cli_hush.h>
17 #include <command.h>
18 #include <console.h>
19 #include <env.h>
20 #include <fdtdec.h>
21 #include <hang.h>
22 #include <malloc.h>
23 #include <asm/global_data.h>
24 #include <dm/ofnode.h>
25 #include <linux/errno.h>
26 
27 #ifdef CONFIG_CMDLINE
28 /*
29  * Run a command using the selected parser.
30  *
31  * @param cmd	Command to run
32  * @param flag	Execution flags (CMD_FLAG_...)
33  * Return: 0 on success, or != 0 on error.
34  */
run_command(const char * cmd,int flag)35 int run_command(const char *cmd, int flag)
36 {
37 #if !IS_ENABLED(CONFIG_HUSH_PARSER)
38 	/*
39 	 * cli_run_command can return 0 or 1 for success, so clean up
40 	 * its result.
41 	 */
42 	if (cli_simple_run_command(cmd, flag) == -1)
43 		return 1;
44 
45 	return 0;
46 #else
47 	int hush_flags = FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP;
48 
49 	if (flag & CMD_FLAG_ENV)
50 		hush_flags |= FLAG_CONT_ON_NEWLINE;
51 	return parse_string_outer(cmd, hush_flags);
52 #endif
53 }
54 
55 /*
56  * Run a command using the selected parser, and check if it is repeatable.
57  *
58  * @param cmd	Command to run
59  * @param flag	Execution flags (CMD_FLAG_...)
60  * Return: 0 (not repeatable) or 1 (repeatable) on success, -1 on error.
61  */
run_command_repeatable(const char * cmd,int flag)62 int run_command_repeatable(const char *cmd, int flag)
63 {
64 #ifndef CONFIG_HUSH_PARSER
65 	return cli_simple_run_command(cmd, flag);
66 #else
67 	/*
68 	 * parse_string_outer() returns 1 for failure, so clean up
69 	 * its result.
70 	 */
71 	if (parse_string_outer(cmd,
72 			       FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP))
73 		return -1;
74 
75 	return 0;
76 #endif
77 }
78 #else
board_run_command(const char * cmdline)79 __weak int board_run_command(const char *cmdline)
80 {
81 	printf("## Commands are disabled. Please enable CONFIG_CMDLINE.\n");
82 
83 	return 1;
84 }
85 #endif /* CONFIG_CMDLINE */
86 
run_command_list(const char * cmd,int len,int flag)87 int run_command_list(const char *cmd, int len, int flag)
88 {
89 	int need_buff = 1;
90 	char *buff = (char *)cmd;	/* cast away const */
91 	int rcode = 0;
92 
93 	if (len == -1) {
94 		len = strlen(cmd);
95 #ifdef CONFIG_HUSH_PARSER
96 		/* hush will never change our string */
97 		need_buff = 0;
98 #else
99 		/* the built-in parser will change our string if it sees \n */
100 		need_buff = strchr(cmd, '\n') != NULL;
101 #endif
102 	}
103 	if (need_buff) {
104 		buff = malloc(len + 1);
105 		if (!buff)
106 			return 1;
107 		memcpy(buff, cmd, len);
108 		buff[len] = '\0';
109 	}
110 #ifdef CONFIG_HUSH_PARSER
111 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
112 #else
113 	/*
114 	 * This function will overwrite any \n it sees with a \0, which
115 	 * is why it can't work with a const char *. Here we are making
116 	 * using of internal knowledge of this function, to avoid always
117 	 * doing a malloc() which is actually required only in a case that
118 	 * is pretty rare.
119 	 */
120 #ifdef CONFIG_CMDLINE
121 	rcode = cli_simple_run_command_list(buff, flag);
122 #else
123 	rcode = board_run_command(buff);
124 #endif
125 #endif
126 	if (need_buff)
127 		free(buff);
128 
129 	return rcode;
130 }
131 
run_commandf(const char * fmt,...)132 int run_commandf(const char *fmt, ...)
133 {
134 	va_list args;
135 	int nbytes;
136 
137 	va_start(args, fmt);
138 	/*
139 	 * Limit the console_buffer space being used to CONFIG_SYS_CBSIZE,
140 	 * because its last byte is used to fit the replacement of \0 by \n\0
141 	 * in underlying hush parser
142 	 */
143 	nbytes = vsnprintf(console_buffer, CONFIG_SYS_CBSIZE, fmt, args);
144 	va_end(args);
145 
146 	if (nbytes < 0) {
147 		pr_debug("I/O internal error occurred.\n");
148 		return -EIO;
149 	} else if (nbytes >= CONFIG_SYS_CBSIZE) {
150 		pr_debug("'fmt' size:%d exceeds the limit(%d)\n",
151 			 nbytes, CONFIG_SYS_CBSIZE);
152 		return -ENOSPC;
153 	}
154 	return run_command(console_buffer, 0);
155 }
156 
157 /****************************************************************************/
158 
159 #if defined(CONFIG_CMD_RUN)
do_run(struct cmd_tbl * cmdtp,int flag,int argc,char * const argv[])160 int do_run(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
161 {
162 	int i, ret;
163 
164 	if (argc < 2)
165 		return CMD_RET_USAGE;
166 
167 	for (i = 1; i < argc; ++i) {
168 		char *arg;
169 
170 		arg = env_get(argv[i]);
171 		if (arg == NULL) {
172 			printf("## Error: \"%s\" not defined\n", argv[i]);
173 			return 1;
174 		}
175 
176 		ret = run_command(arg, flag | CMD_FLAG_ENV);
177 		if (ret)
178 			return ret;
179 	}
180 	return 0;
181 }
182 #endif
183 
184 #if CONFIG_IS_ENABLED(OF_CONTROL)
cli_process_fdt(const char ** cmdp)185 bool cli_process_fdt(const char **cmdp)
186 {
187 	/* Allow the fdt to override the boot command */
188 	const char *env = ofnode_conf_read_str("bootcmd");
189 	if (env)
190 		*cmdp = env;
191 	/*
192 	 * If the bootsecure option was chosen, use secure_boot_cmd().
193 	 * Always use 'env' in this case, since bootsecure requres that the
194 	 * bootcmd was specified in the FDT too.
195 	 */
196 	return ofnode_conf_read_int("bootsecure", 0);
197 }
198 
199 /*
200  * Runs the given boot command securely.  Specifically:
201  * - Doesn't run the command with the shell (run_command or parse_string_outer),
202  *   since that's a lot of code surface that an attacker might exploit.
203  *   Because of this, we don't do any argument parsing--the secure boot command
204  *   has to be a full-fledged u-boot command.
205  * - Doesn't check for keypresses before booting, since that could be a
206  *   security hole; also disables Ctrl-C.
207  * - Doesn't allow the command to return.
208  *
209  * Upon any failures, this function will drop into an infinite loop after
210  * printing the error message to console.
211  */
cli_secure_boot_cmd(const char * cmd)212 void cli_secure_boot_cmd(const char *cmd)
213 {
214 #ifdef CONFIG_CMDLINE
215 	struct cmd_tbl *cmdtp;
216 #endif
217 	int rc;
218 
219 	if (!cmd) {
220 		printf("## Error: Secure boot command not specified\n");
221 		goto err;
222 	}
223 
224 	/* Disable Ctrl-C just in case some command is used that checks it. */
225 	disable_ctrlc(1);
226 
227 	/* Find the command directly. */
228 #ifdef CONFIG_CMDLINE
229 	cmdtp = find_cmd(cmd);
230 	if (!cmdtp) {
231 		printf("## Error: \"%s\" not defined\n", cmd);
232 		goto err;
233 	}
234 
235 	/* Run the command, forcing no flags and faking argc and argv. */
236 	rc = (cmdtp->cmd)(cmdtp, 0, 1, (char **)&cmd);
237 
238 #else
239 	rc = board_run_command(cmd);
240 #endif
241 
242 	/* Shouldn't ever return from boot command. */
243 	printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);
244 
245 err:
246 	/*
247 	 * Not a whole lot to do here.  Rebooting won't help much, since we'll
248 	 * just end up right back here.  Just loop.
249 	 */
250 	hang();
251 }
252 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
253 
cli_loop(void)254 void cli_loop(void)
255 {
256 	bootstage_mark(BOOTSTAGE_ID_ENTER_CLI_LOOP);
257 #ifdef CONFIG_HUSH_PARSER
258 	parse_file_outer();
259 	/* This point is never reached */
260 	for (;;);
261 #elif defined(CONFIG_CMDLINE)
262 	cli_simple_loop();
263 #else
264 	printf("## U-Boot command line is disabled. Please enable CONFIG_CMDLINE\n");
265 #endif /*CONFIG_HUSH_PARSER*/
266 }
267 
cli_init(void)268 void cli_init(void)
269 {
270 #ifdef CONFIG_HUSH_PARSER
271 	u_boot_hush_start();
272 #endif
273 
274 #if defined(CONFIG_HUSH_INIT_VAR)
275 	hush_init_var();
276 #endif
277 }
278