xref: /openbmc/u-boot/common/cli.c (revision c3d89140)
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 <fdtdec.h>
16 #include <malloc.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 /*
21  * Run a command using the selected parser.
22  *
23  * @param cmd	Command to run
24  * @param flag	Execution flags (CMD_FLAG_...)
25  * @return 0 on success, or != 0 on error.
26  */
27 int run_command(const char *cmd, int flag)
28 {
29 #ifndef CONFIG_SYS_HUSH_PARSER
30 	/*
31 	 * cli_run_command can return 0 or 1 for success, so clean up
32 	 * its result.
33 	 */
34 	if (cli_simple_run_command(cmd, flag) == -1)
35 		return 1;
36 
37 	return 0;
38 #else
39 	int hush_flags = FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP;
40 
41 	if (flag & CMD_FLAG_ENV)
42 		hush_flags |= FLAG_CONT_ON_NEWLINE;
43 	return parse_string_outer(cmd, hush_flags);
44 #endif
45 }
46 
47 /*
48  * Run a command using the selected parser, and check if it is repeatable.
49  *
50  * @param cmd	Command to run
51  * @param flag	Execution flags (CMD_FLAG_...)
52  * @return 0 (not repeatable) or 1 (repeatable) on success, -1 on error.
53  */
54 int run_command_repeatable(const char *cmd, int flag)
55 {
56 #ifndef CONFIG_SYS_HUSH_PARSER
57 	return cli_simple_run_command(cmd, flag);
58 #else
59 	/*
60 	 * parse_string_outer() returns 1 for failure, so clean up
61 	 * its result.
62 	 */
63 	if (parse_string_outer(cmd,
64 			       FLAG_PARSE_SEMICOLON | FLAG_EXIT_FROM_LOOP))
65 		return -1;
66 
67 	return 0;
68 #endif
69 }
70 
71 int run_command_list(const char *cmd, int len, int flag)
72 {
73 	int need_buff = 1;
74 	char *buff = (char *)cmd;	/* cast away const */
75 	int rcode = 0;
76 
77 	if (len == -1) {
78 		len = strlen(cmd);
79 #ifdef CONFIG_SYS_HUSH_PARSER
80 		/* hush will never change our string */
81 		need_buff = 0;
82 #else
83 		/* the built-in parser will change our string if it sees \n */
84 		need_buff = strchr(cmd, '\n') != NULL;
85 #endif
86 	}
87 	if (need_buff) {
88 		buff = malloc(len + 1);
89 		if (!buff)
90 			return 1;
91 		memcpy(buff, cmd, len);
92 		buff[len] = '\0';
93 	}
94 #ifdef CONFIG_SYS_HUSH_PARSER
95 	rcode = parse_string_outer(buff, FLAG_PARSE_SEMICOLON);
96 #else
97 	/*
98 	 * This function will overwrite any \n it sees with a \0, which
99 	 * is why it can't work with a const char *. Here we are making
100 	 * using of internal knowledge of this function, to avoid always
101 	 * doing a malloc() which is actually required only in a case that
102 	 * is pretty rare.
103 	 */
104 	rcode = cli_simple_run_command_list(buff, flag);
105 	if (need_buff)
106 		free(buff);
107 #endif
108 
109 	return rcode;
110 }
111 
112 /****************************************************************************/
113 
114 #if defined(CONFIG_CMD_RUN)
115 int do_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
116 {
117 	int i;
118 
119 	if (argc < 2)
120 		return CMD_RET_USAGE;
121 
122 	for (i = 1; i < argc; ++i) {
123 		char *arg;
124 
125 		arg = getenv(argv[i]);
126 		if (arg == NULL) {
127 			printf("## Error: \"%s\" not defined\n", argv[i]);
128 			return 1;
129 		}
130 
131 		if (run_command(arg, flag | CMD_FLAG_ENV) != 0)
132 			return 1;
133 	}
134 	return 0;
135 }
136 #endif
137 
138 #if CONFIG_IS_ENABLED(OF_CONTROL)
139 bool cli_process_fdt(const char **cmdp)
140 {
141 	/* Allow the fdt to override the boot command */
142 	char *env = fdtdec_get_config_string(gd->fdt_blob, "bootcmd");
143 	if (env)
144 		*cmdp = env;
145 	/*
146 	 * If the bootsecure option was chosen, use secure_boot_cmd().
147 	 * Always use 'env' in this case, since bootsecure requres that the
148 	 * bootcmd was specified in the FDT too.
149 	 */
150 	return fdtdec_get_config_int(gd->fdt_blob, "bootsecure", 0) != 0;
151 }
152 
153 /*
154  * Runs the given boot command securely.  Specifically:
155  * - Doesn't run the command with the shell (run_command or parse_string_outer),
156  *   since that's a lot of code surface that an attacker might exploit.
157  *   Because of this, we don't do any argument parsing--the secure boot command
158  *   has to be a full-fledged u-boot command.
159  * - Doesn't check for keypresses before booting, since that could be a
160  *   security hole; also disables Ctrl-C.
161  * - Doesn't allow the command to return.
162  *
163  * Upon any failures, this function will drop into an infinite loop after
164  * printing the error message to console.
165  */
166 void cli_secure_boot_cmd(const char *cmd)
167 {
168 	cmd_tbl_t *cmdtp;
169 	int rc;
170 
171 	if (!cmd) {
172 		printf("## Error: Secure boot command not specified\n");
173 		goto err;
174 	}
175 
176 	/* Disable Ctrl-C just in case some command is used that checks it. */
177 	disable_ctrlc(1);
178 
179 	/* Find the command directly. */
180 	cmdtp = find_cmd(cmd);
181 	if (!cmdtp) {
182 		printf("## Error: \"%s\" not defined\n", cmd);
183 		goto err;
184 	}
185 
186 	/* Run the command, forcing no flags and faking argc and argv. */
187 	rc = (cmdtp->cmd)(cmdtp, 0, 1, (char **)&cmd);
188 
189 	/* Shouldn't ever return from boot command. */
190 	printf("## Error: \"%s\" returned (code %d)\n", cmd, rc);
191 
192 err:
193 	/*
194 	 * Not a whole lot to do here.  Rebooting won't help much, since we'll
195 	 * just end up right back here.  Just loop.
196 	 */
197 	hang();
198 }
199 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
200 
201 void cli_loop(void)
202 {
203 #ifdef CONFIG_SYS_HUSH_PARSER
204 	parse_file_outer();
205 	/* This point is never reached */
206 	for (;;);
207 #else
208 	cli_simple_loop();
209 #endif /*CONFIG_SYS_HUSH_PARSER*/
210 }
211 
212 void cli_init(void)
213 {
214 #ifdef CONFIG_SYS_HUSH_PARSER
215 	u_boot_hush_start();
216 #endif
217 
218 #if defined(CONFIG_HUSH_INIT_VAR)
219 	hush_init_var();
220 #endif
221 }
222