xref: /openbmc/u-boot/common/cli.c (revision 39cb4f3c)
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 #include <common.h>
12 #include <cli.h>
13 #include <cli_hush.h>
14 #include <console.h>
15 #include <fdtdec.h>
16 #include <malloc.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 #ifdef CONFIG_CMDLINE
21 /*
22  * Run a command using the selected parser.
23  *
24  * @param cmd	Command to run
25  * @param flag	Execution flags (CMD_FLAG_...)
26  * @return 0 on success, or != 0 on error.
27  */
28 int run_command(const char *cmd, int flag)
29 {
30 #ifndef CONFIG_HUSH_PARSER
31 	/*
32 	 * cli_run_command can return 0 or 1 for success, so clean up
33 	 * its result.
34 	 */
35 	if (cli_simple_run_command(cmd, flag) == -1)
36 		return 1;
37 
38 	return 0;
39 #else
40 	int hush_flags = FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP;
41 
42 	if (flag & CMD_FLAG_ENV)
43 		hush_flags |= FLAG_CONT_ON_NEWLINE;
44 	return parse_string_outer(cmd, hush_flags);
45 #endif
46 }
47 
48 /*
49  * Run a command using the selected parser, and check if it is repeatable.
50  *
51  * @param cmd	Command to run
52  * @param flag	Execution flags (CMD_FLAG_...)
53  * @return 0 (not repeatable) or 1 (repeatable) on success, -1 on error.
54  */
55 int run_command_repeatable(const char *cmd, int flag)
56 {
57 #ifndef CONFIG_HUSH_PARSER
58 	return cli_simple_run_command(cmd, flag);
59 #else
60 	/*
61 	 * parse_string_outer() returns 1 for failure, so clean up
62 	 * its result.
63 	 */
64 	if (parse_string_outer(cmd,
65 			       FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP))
66 		return -1;
67 
68 	return 0;
69 #endif
70 }
71 #endif /* CONFIG_CMDLINE */
72 
73 int run_command_list(const char *cmd, int len, int flag)
74 {
75 	int need_buff = 1;
76 	char *buff = (char *)cmd;	/* cast away const */
77 	int rcode = 0;
78 
79 	if (len == -1) {
80 		len = strlen(cmd);
81 #ifdef CONFIG_HUSH_PARSER
82 		/* hush will never change our string */
83 		need_buff = 0;
84 #else
85 		/* the built-in parser will change our string if it sees \n */
86 		need_buff = strchr(cmd, '\n') != NULL;
87 #endif
88 	}
89 	if (need_buff) {
90 		buff = malloc(len + 1);
91 		if (!buff)
92 			return 1;
93 		memcpy(buff, cmd, len);
94 		buff[len] = '\0';
95 	}
96 #ifdef CONFIG_HUSH_PARSER
97 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
98 #else
99 	/*
100 	 * This function will overwrite any \n it sees with a \0, which
101 	 * is why it can't work with a const char *. Here we are making
102 	 * using of internal knowledge of this function, to avoid always
103 	 * doing a malloc() which is actually required only in a case that
104 	 * is pretty rare.
105 	 */
106 #ifdef CONFIG_CMDLINE
107 	rcode = cli_simple_run_command_list(buff, flag);
108 #else
109 	rcode = board_run_command(buff);
110 #endif
111 #endif
112 	if (need_buff)
113 		free(buff);
114 
115 	return rcode;
116 }
117 
118 /****************************************************************************/
119 
120 #if defined(CONFIG_CMD_RUN)
121 int do_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
122 {
123 	int i;
124 
125 	if (argc < 2)
126 		return CMD_RET_USAGE;
127 
128 	for (i = 1; i < argc; ++i) {
129 		char *arg;
130 
131 		arg = env_get(argv[i]);
132 		if (arg == NULL) {
133 			printf("## Error: \"%s\" not defined\n", argv[i]);
134 			return 1;
135 		}
136 
137 		if (run_command(arg, flag | CMD_FLAG_ENV) != 0)
138 			return 1;
139 	}
140 	return 0;
141 }
142 #endif
143 
144 #if CONFIG_IS_ENABLED(OF_CONTROL)
145 bool cli_process_fdt(const char **cmdp)
146 {
147 	/* Allow the fdt to override the boot command */
148 	char *env = fdtdec_get_config_string(gd->fdt_blob, "bootcmd");
149 	if (env)
150 		*cmdp = env;
151 	/*
152 	 * If the bootsecure option was chosen, use secure_boot_cmd().
153 	 * Always use 'env' in this case, since bootsecure requres that the
154 	 * bootcmd was specified in the FDT too.
155 	 */
156 	return fdtdec_get_config_int(gd->fdt_blob, "bootsecure", 0) != 0;
157 }
158 
159 /*
160  * Runs the given boot command securely.  Specifically:
161  * - Doesn't run the command with the shell (run_command or parse_string_outer),
162  *   since that's a lot of code surface that an attacker might exploit.
163  *   Because of this, we don't do any argument parsing--the secure boot command
164  *   has to be a full-fledged u-boot command.
165  * - Doesn't check for keypresses before booting, since that could be a
166  *   security hole; also disables Ctrl-C.
167  * - Doesn't allow the command to return.
168  *
169  * Upon any failures, this function will drop into an infinite loop after
170  * printing the error message to console.
171  */
172 void cli_secure_boot_cmd(const char *cmd)
173 {
174 #ifdef CONFIG_CMDLINE
175 	cmd_tbl_t *cmdtp;
176 #endif
177 	int rc;
178 
179 	if (!cmd) {
180 		printf("## Error: Secure boot command not specified\n");
181 		goto err;
182 	}
183 
184 	/* Disable Ctrl-C just in case some command is used that checks it. */
185 	disable_ctrlc(1);
186 
187 	/* Find the command directly. */
188 #ifdef CONFIG_CMDLINE
189 	cmdtp = find_cmd(cmd);
190 	if (!cmdtp) {
191 		printf("## Error: \"%s\" not defined\n", cmd);
192 		goto err;
193 	}
194 
195 	/* Run the command, forcing no flags and faking argc and argv. */
196 	rc = (cmdtp->cmd)(cmdtp, 0, 1, (char **)&cmd);
197 
198 #else
199 	rc = board_run_command(cmd);
200 #endif
201 
202 	/* Shouldn't ever return from boot command. */
203 	printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);
204 
205 err:
206 	/*
207 	 * Not a whole lot to do here.  Rebooting won't help much, since we'll
208 	 * just end up right back here.  Just loop.
209 	 */
210 	hang();
211 }
212 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
213 
214 void cli_loop(void)
215 {
216 #ifdef CONFIG_HUSH_PARSER
217 	parse_file_outer();
218 	/* This point is never reached */
219 	for (;;);
220 #elif defined(CONFIG_CMDLINE)
221 	cli_simple_loop();
222 #else
223 	printf("## U-Boot command line is disabled. Please enable CONFIG_CMDLINE\n");
224 #endif /*CONFIG_HUSH_PARSER*/
225 }
226 
227 void cli_init(void)
228 {
229 #ifdef CONFIG_HUSH_PARSER
230 	u_boot_hush_start();
231 #endif
232 
233 #if defined(CONFIG_HUSH_INIT_VAR)
234 	hush_init_var();
235 #endif
236 }
237