xref: /openbmc/u-boot/common/cli.c (revision 6ae3900a)
1 /*
2  * (C) Copyright 2000
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * Add to readline cmdline-editing by
6  * (C) Copyright 2005
7  * JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
8  *
9  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 #include <common.h>
13 #include <cli.h>
14 #include <cli_hush.h>
15 #include <console.h>
16 #include <fdtdec.h>
17 #include <malloc.h>
18 
19 DECLARE_GLOBAL_DATA_PTR;
20 
21 #ifdef CONFIG_CMDLINE
22 /*
23  * Run a command using the selected parser.
24  *
25  * @param cmd	Command to run
26  * @param flag	Execution flags (CMD_FLAG_...)
27  * @return 0 on success, or != 0 on error.
28  */
29 int run_command(const char *cmd, int flag)
30 {
31 #ifndef CONFIG_HUSH_PARSER
32 	/*
33 	 * cli_run_command can return 0 or 1 for success, so clean up
34 	 * its result.
35 	 */
36 	if (cli_simple_run_command(cmd, flag) == -1)
37 		return 1;
38 
39 	return 0;
40 #else
41 	int hush_flags = FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP;
42 
43 	if (flag & CMD_FLAG_ENV)
44 		hush_flags |= FLAG_CONT_ON_NEWLINE;
45 	return parse_string_outer(cmd, hush_flags);
46 #endif
47 }
48 
49 /*
50  * Run a command using the selected parser, and check if it is repeatable.
51  *
52  * @param cmd	Command to run
53  * @param flag	Execution flags (CMD_FLAG_...)
54  * @return 0 (not repeatable) or 1 (repeatable) on success, -1 on error.
55  */
56 int run_command_repeatable(const char *cmd, int flag)
57 {
58 #ifndef CONFIG_HUSH_PARSER
59 	return cli_simple_run_command(cmd, flag);
60 #else
61 	/*
62 	 * parse_string_outer() returns 1 for failure, so clean up
63 	 * its result.
64 	 */
65 	if (parse_string_outer(cmd,
66 			       FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP))
67 		return -1;
68 
69 	return 0;
70 #endif
71 }
72 #endif /* CONFIG_CMDLINE */
73 
74 int run_command_list(const char *cmd, int len, int flag)
75 {
76 	int need_buff = 1;
77 	char *buff = (char *)cmd;	/* cast away const */
78 	int rcode = 0;
79 
80 	if (len == -1) {
81 		len = strlen(cmd);
82 #ifdef CONFIG_HUSH_PARSER
83 		/* hush will never change our string */
84 		need_buff = 0;
85 #else
86 		/* the built-in parser will change our string if it sees \n */
87 		need_buff = strchr(cmd, '\n') != NULL;
88 #endif
89 	}
90 	if (need_buff) {
91 		buff = malloc(len + 1);
92 		if (!buff)
93 			return 1;
94 		memcpy(buff, cmd, len);
95 		buff[len] = '\0';
96 	}
97 #ifdef CONFIG_HUSH_PARSER
98 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
99 #else
100 	/*
101 	 * This function will overwrite any \n it sees with a \0, which
102 	 * is why it can't work with a const char *. Here we are making
103 	 * using of internal knowledge of this function, to avoid always
104 	 * doing a malloc() which is actually required only in a case that
105 	 * is pretty rare.
106 	 */
107 #ifdef CONFIG_CMDLINE
108 	rcode = cli_simple_run_command_list(buff, flag);
109 #else
110 	rcode = board_run_command(buff);
111 #endif
112 #endif
113 	if (need_buff)
114 		free(buff);
115 
116 	return rcode;
117 }
118 
119 /****************************************************************************/
120 
121 #if defined(CONFIG_CMD_RUN)
122 int do_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
123 {
124 	int i;
125 
126 	if (argc < 2)
127 		return CMD_RET_USAGE;
128 
129 	for (i = 1; i < argc; ++i) {
130 		char *arg;
131 
132 		arg = env_get(argv[i]);
133 		if (arg == NULL) {
134 			printf("## Error: \"%s\" not defined\n", argv[i]);
135 			return 1;
136 		}
137 
138 		if (run_command(arg, flag | CMD_FLAG_ENV) != 0)
139 			return 1;
140 	}
141 	return 0;
142 }
143 #endif
144 
145 #if CONFIG_IS_ENABLED(OF_CONTROL)
146 bool cli_process_fdt(const char **cmdp)
147 {
148 	/* Allow the fdt to override the boot command */
149 	char *env = fdtdec_get_config_string(gd->fdt_blob, "bootcmd");
150 	if (env)
151 		*cmdp = env;
152 	/*
153 	 * If the bootsecure option was chosen, use secure_boot_cmd().
154 	 * Always use 'env' in this case, since bootsecure requres that the
155 	 * bootcmd was specified in the FDT too.
156 	 */
157 	return fdtdec_get_config_int(gd->fdt_blob, "bootsecure", 0) != 0;
158 }
159 
160 /*
161  * Runs the given boot command securely.  Specifically:
162  * - Doesn't run the command with the shell (run_command or parse_string_outer),
163  *   since that's a lot of code surface that an attacker might exploit.
164  *   Because of this, we don't do any argument parsing--the secure boot command
165  *   has to be a full-fledged u-boot command.
166  * - Doesn't check for keypresses before booting, since that could be a
167  *   security hole; also disables Ctrl-C.
168  * - Doesn't allow the command to return.
169  *
170  * Upon any failures, this function will drop into an infinite loop after
171  * printing the error message to console.
172  */
173 void cli_secure_boot_cmd(const char *cmd)
174 {
175 #ifdef CONFIG_CMDLINE
176 	cmd_tbl_t *cmdtp;
177 #endif
178 	int rc;
179 
180 	if (!cmd) {
181 		printf("## Error: Secure boot command not specified\n");
182 		goto err;
183 	}
184 
185 	/* Disable Ctrl-C just in case some command is used that checks it. */
186 	disable_ctrlc(1);
187 
188 	/* Find the command directly. */
189 #ifdef CONFIG_CMDLINE
190 	cmdtp = find_cmd(cmd);
191 	if (!cmdtp) {
192 		printf("## Error: \"%s\" not defined\n", cmd);
193 		goto err;
194 	}
195 
196 	/* Run the command, forcing no flags and faking argc and argv. */
197 	rc = (cmdtp->cmd)(cmdtp, 0, 1, (char **)&cmd);
198 
199 #else
200 	rc = board_run_command(cmd);
201 #endif
202 
203 	/* Shouldn't ever return from boot command. */
204 	printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);
205 
206 err:
207 	/*
208 	 * Not a whole lot to do here.  Rebooting won't help much, since we'll
209 	 * just end up right back here.  Just loop.
210 	 */
211 	hang();
212 }
213 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
214 
215 void cli_loop(void)
216 {
217 #ifdef CONFIG_HUSH_PARSER
218 	parse_file_outer();
219 	/* This point is never reached */
220 	for (;;);
221 #elif defined(CONFIG_CMDLINE)
222 	cli_simple_loop();
223 #else
224 	printf("## U-Boot command line is disabled. Please enable CONFIG_CMDLINE\n");
225 #endif /*CONFIG_HUSH_PARSER*/
226 }
227 
228 void cli_init(void)
229 {
230 #ifdef CONFIG_HUSH_PARSER
231 	u_boot_hush_start();
232 #endif
233 
234 #if defined(CONFIG_HUSH_INIT_VAR)
235 	hush_init_var();
236 #endif
237 }
238