xref: /openbmc/u-boot/common/cli.c (revision 89d48594)
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 /*
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_SYS_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_SYS_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 
72 int run_command_list(const char *cmd, int len, int flag)
73 {
74 	int need_buff = 1;
75 	char *buff = (char *)cmd;	/* cast away const */
76 	int rcode = 0;
77 
78 	if (len == -1) {
79 		len = strlen(cmd);
80 #ifdef CONFIG_SYS_HUSH_PARSER
81 		/* hush will never change our string */
82 		need_buff = 0;
83 #else
84 		/* the built-in parser will change our string if it sees \n */
85 		need_buff = strchr(cmd, '\n') != NULL;
86 #endif
87 	}
88 	if (need_buff) {
89 		buff = malloc(len + 1);
90 		if (!buff)
91 			return 1;
92 		memcpy(buff, cmd, len);
93 		buff[len] = '\0';
94 	}
95 #ifdef CONFIG_SYS_HUSH_PARSER
96 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
97 #else
98 	/*
99 	 * This function will overwrite any \n it sees with a \0, which
100 	 * is why it can't work with a const char *. Here we are making
101 	 * using of internal knowledge of this function, to avoid always
102 	 * doing a malloc() which is actually required only in a case that
103 	 * is pretty rare.
104 	 */
105 	rcode = cli_simple_run_command_list(buff, flag);
106 #endif
107 	if (need_buff)
108 		free(buff);
109 
110 	return rcode;
111 }
112 
113 /****************************************************************************/
114 
115 #if defined(CONFIG_CMD_RUN)
116 int do_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
117 {
118 	int i;
119 
120 	if (argc < 2)
121 		return CMD_RET_USAGE;
122 
123 	for (i = 1; i < argc; ++i) {
124 		char *arg;
125 
126 		arg = getenv(argv[i]);
127 		if (arg == NULL) {
128 			printf("## Error: \"%s\" not defined\n", argv[i]);
129 			return 1;
130 		}
131 
132 		if (run_command(arg, flag | CMD_FLAG_ENV) != 0)
133 			return 1;
134 	}
135 	return 0;
136 }
137 #endif
138 
139 #if CONFIG_IS_ENABLED(OF_CONTROL)
140 bool cli_process_fdt(const char **cmdp)
141 {
142 	/* Allow the fdt to override the boot command */
143 	char *env = fdtdec_get_config_string(gd->fdt_blob, "bootcmd");
144 	if (env)
145 		*cmdp = env;
146 	/*
147 	 * If the bootsecure option was chosen, use secure_boot_cmd().
148 	 * Always use 'env' in this case, since bootsecure requres that the
149 	 * bootcmd was specified in the FDT too.
150 	 */
151 	return fdtdec_get_config_int(gd->fdt_blob, "bootsecure", 0) != 0;
152 }
153 
154 /*
155  * Runs the given boot command securely.  Specifically:
156  * - Doesn't run the command with the shell (run_command or parse_string_outer),
157  *   since that's a lot of code surface that an attacker might exploit.
158  *   Because of this, we don't do any argument parsing--the secure boot command
159  *   has to be a full-fledged u-boot command.
160  * - Doesn't check for keypresses before booting, since that could be a
161  *   security hole; also disables Ctrl-C.
162  * - Doesn't allow the command to return.
163  *
164  * Upon any failures, this function will drop into an infinite loop after
165  * printing the error message to console.
166  */
167 void cli_secure_boot_cmd(const char *cmd)
168 {
169 	cmd_tbl_t *cmdtp;
170 	int rc;
171 
172 	if (!cmd) {
173 		printf("## Error: Secure boot command not specified\n");
174 		goto err;
175 	}
176 
177 	/* Disable Ctrl-C just in case some command is used that checks it. */
178 	disable_ctrlc(1);
179 
180 	/* Find the command directly. */
181 	cmdtp = find_cmd(cmd);
182 	if (!cmdtp) {
183 		printf("## Error: \"%s\" not defined\n", cmd);
184 		goto err;
185 	}
186 
187 	/* Run the command, forcing no flags and faking argc and argv. */
188 	rc = (cmdtp->cmd)(cmdtp, 0, 1, (char **)&cmd);
189 
190 	/* Shouldn't ever return from boot command. */
191 	printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);
192 
193 err:
194 	/*
195 	 * Not a whole lot to do here.  Rebooting won't help much, since we'll
196 	 * just end up right back here.  Just loop.
197 	 */
198 	hang();
199 }
200 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
201 
202 void cli_loop(void)
203 {
204 #ifdef CONFIG_SYS_HUSH_PARSER
205 	parse_file_outer();
206 	/* This point is never reached */
207 	for (;;);
208 #else
209 	cli_simple_loop();
210 #endif /*CONFIG_SYS_HUSH_PARSER*/
211 }
212 
213 void cli_init(void)
214 {
215 #ifdef CONFIG_SYS_HUSH_PARSER
216 	u_boot_hush_start();
217 #endif
218 
219 #if defined(CONFIG_HUSH_INIT_VAR)
220 	hush_init_var();
221 #endif
222 }
223