xref: /freebsd/usr.sbin/binmiscctl/binmiscctl.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71) 
1 /*-
2  * Copyright (c) 2013 Stacey D. Son
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/types.h>
32 #include <sys/imgact_binmisc.h>
33 #include <sys/linker.h>
34 #include <sys/module.h>
35 #include <sys/sysctl.h>
36 
37 #include <ctype.h>
38 #include <errno.h>
39 #include <getopt.h>
40 #include <stdio.h>
41 #include <stdarg.h>
42 #include <stdint.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 enum cmd {
47 	CMD_ADD = 0,
48 	CMD_REMOVE,
49 	CMD_DISABLE,
50 	CMD_ENABLE,
51 	CMD_LOOKUP,
52 	CMD_LIST,
53 };
54 
55 extern char *__progname;
56 
57 typedef int (*cmd_func_t)(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
58 
59 int add_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
60 int name_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
61 int noname_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
62 
63 static const struct {
64 	const int token;
65 	const char *name;
66 	cmd_func_t func;
67 	const char *desc;
68 	const char *args;
69 } cmds[] = {
70 	{
71 		CMD_ADD,
72 		"add",
73 		add_cmd,
74 		"Add a new binary image activator (requires 'root' privilege)",
75 		"<name> --interpreter <path_and_arguments> \\\n"
76 		"\t\t--magic <magic_bytes> [--mask <mask_bytes>] \\\n"
77 		"\t\t--size <magic_size> [--offset <magic_offset>] \\\n"
78 		"\t\t[--set-enabled]"
79 	},
80 	{
81 		CMD_REMOVE,
82 		"remove",
83 		name_cmd,
84 		"Remove a binary image activator (requires 'root' privilege)",
85 		"<name>"
86 	},
87 	{
88 		CMD_DISABLE,
89 		"disable",
90 		name_cmd,
91 		"Disable a binary image activator (requires 'root' privilege)",
92 		"<name>"
93 	},
94 	{
95 		CMD_ENABLE,
96 		"enable",
97 		name_cmd,
98 		"Enable a binary image activator (requires 'root' privilege)",
99 		"<name>"
100 	},
101 	{
102 		CMD_LOOKUP,
103 		"lookup",
104 		name_cmd,
105 		"Lookup a binary image activator",
106 		"<name>"
107 	},
108 	{
109 		CMD_LIST,
110 		"list",
111 		noname_cmd,
112 		"List all the binary image activators",
113 		""
114 	},
115 };
116 
117 static const struct option
118 add_opts[] = {
119 	{ "set-enabled",	no_argument,		NULL,	'e' },
120 	{ "interpreter",	required_argument,	NULL,	'i' },
121 	{ "mask",		required_argument,	NULL,	'M' },
122 	{ "magic",		required_argument,	NULL,	'm' },
123 	{ "offset",		required_argument,	NULL,	'o' },
124 	{ "size",		required_argument,	NULL,	's' },
125 	{ NULL,			0,			NULL,	0   }
126 };
127 
128 static char const *cmd_sysctl_name[] = {
129 	IBE_SYSCTL_NAME_ADD,
130 	IBE_SYSCTL_NAME_REMOVE,
131 	IBE_SYSCTL_NAME_DISABLE,
132 	IBE_SYSCTL_NAME_ENABLE,
133 	IBE_SYSCTL_NAME_LOOKUP,
134 	IBE_SYSCTL_NAME_LIST
135 };
136 
137 static void __dead2
138 usage(const char *format, ...)
139 {
140 	va_list args;
141 	size_t i;
142 	int error = 0;
143 
144 	va_start(args, format);
145 	if (format) {
146 		vfprintf(stderr, format, args);
147 		error = -1;
148 	}
149 	va_end(args);
150 	fprintf(stderr, "\n");
151 	fprintf(stderr, "usage: %s command [args...]\n\n", __progname);
152 
153 	for(i = 0; i < nitems(cmds); i++) {
154 		fprintf(stderr, "%s:\n", cmds[i].desc);
155 		fprintf(stderr, "\t%s %s %s\n\n", __progname, cmds[i].name,
156 		    cmds[i].args);
157 	}
158 
159 	exit (error);
160 }
161 
162 static void __dead2
163 fatal(const char *format, ...)
164 {
165 	va_list args;
166 
167 	va_start(args, format);
168 	if (format)
169 		vfprintf(stderr, format, args);
170 	fprintf(stderr, "\n");
171 
172 	exit(-1);
173 }
174 
175 static void
176 getoptstr(char *str, size_t size, const char *argname)
177 {
178 	if (strlen(optarg) > size)
179 		usage("'%s' too large", argname);
180 	strlcpy(str, optarg, size);
181 }
182 
183 static void
184 printxbe(ximgact_binmisc_entry_t *xbe)
185 {
186 	uint32_t i, flags = xbe->xbe_flags;
187 
188 	if (xbe->xbe_version != IBE_VERSION) {
189 		fprintf(stderr, "Error: XBE version mismatch\n");
190 		return;
191 	}
192 
193 	printf("name: %s\n", xbe->xbe_name);
194 	printf("interpreter: %s\n", xbe->xbe_interpreter);
195 	printf("flags: %s%s\n", (flags & IBF_ENABLED) ? "ENABLED " : "",
196 	    (flags & IBF_USE_MASK) ? "USE_MASK " : "");
197 	printf("magic size: %u\n", xbe->xbe_msize);
198 	printf("magic offset: %u\n", xbe->xbe_moffset);
199 
200 	printf("magic: ");
201 	for(i = 0; i < xbe->xbe_msize;  i++) {
202 		if (i && !(i % 12))
203 			printf("\n       ");
204 		else
205 			if (i && !(i % 4))
206 				printf(" ");
207 		printf("0x%02x ", xbe->xbe_magic[i]);
208 	}
209 	printf("\n");
210 
211 	if (flags & IBF_USE_MASK) {
212 		printf("mask:  ");
213 		for(i = 0; i < xbe->xbe_msize;  i++) {
214 			if (i && !(i % 12))
215 				printf("\n       ");
216 			else
217 				if (i && !(i % 4))
218 					printf(" ");
219 			printf("0x%02x ", xbe->xbe_mask[i]);
220 		}
221 		printf("\n");
222 	}
223 
224 	printf("\n");
225 }
226 
227 static int
228 demux_cmd(__unused int argc, char *const argv[])
229 {
230 	size_t i;
231 
232 	optind = 1;
233 	optreset = 1;
234 
235 	for(i = 0; i < nitems(cmds); i++) {
236 		if (!strcasecmp(cmds[i].name, argv[0])) {
237 			return (i);
238 		}
239 	}
240 
241 	/* Unknown command */
242 	return (-1);
243 }
244 
245 static int
246 strlit2bin_cpy(uint8_t *d, char *s, size_t size)
247 {
248 	int c;
249 	size_t cnt = 0;
250 
251 	while((c = *s++) != '\0') {
252 		if (c == '\\') {
253 			/* Do '\' escapes. */
254 			switch (*s) {
255 			case '\\':
256 				*d++ = '\\';
257 				break;
258 
259 			case 'x':
260 				s++;
261 				c = toupper(*s++);
262 				*d = (c - (isdigit(c) ? '0' : ('A' - 10))) << 4;
263 				c = toupper(*s++);
264 				*d++ |= c - (isdigit(c) ? '0' : ('A' - 10));
265 				break;
266 
267 			default:
268 				return (-1);
269 			}
270 		} else
271 			*d++ = c;
272 
273 		if (++cnt > size)
274 			return (-1);
275 	}
276 
277 	return (cnt);
278 }
279 
280 int
281 add_cmd(__unused int argc, char *argv[], ximgact_binmisc_entry_t *xbe)
282 {
283 	int ch;
284 	char *magic = NULL, *mask = NULL;
285 	int sz;
286 
287 	if (strlen(argv[0]) > IBE_NAME_MAX)
288 		usage("'%s' string length longer than IBE_NAME_MAX (%d)",
289 		    IBE_NAME_MAX);
290 	strlcpy(&xbe->xbe_name[0], argv[0], IBE_NAME_MAX);
291 
292 	while ((ch = getopt_long(argc, argv, "ei:m:M:o:s:", add_opts, NULL))
293 	    != -1) {
294 
295 		switch(ch) {
296 		case 'i':
297 			getoptstr(xbe->xbe_interpreter, IBE_INTERP_LEN_MAX,
298 			    "interpreter");
299 			break;
300 
301 		case 'm':
302 			free(magic);
303 			magic = strdup(optarg);
304 			break;
305 
306 		case 'M':
307 			free(mask);
308 			mask = strdup(optarg);
309 			xbe->xbe_flags |= IBF_USE_MASK;
310 			break;
311 
312 		case 'e':
313 			xbe->xbe_flags |= IBF_ENABLED;
314 			break;
315 
316 		case 'o':
317 			xbe->xbe_moffset = atol(optarg);
318 			break;
319 
320 		case 's':
321 			xbe->xbe_msize = atol(optarg);
322 			if (xbe->xbe_msize == 0 ||
323 			    xbe->xbe_msize > IBE_MAGIC_MAX)
324 				usage("Error: Not valid '--size' value. "
325 				    "(Must be > 0 and < %u.)\n",
326 				    xbe->xbe_msize);
327 			break;
328 
329 		default:
330 			usage("Unknown argument: '%c'", ch);
331 		}
332 	}
333 
334 	if (xbe->xbe_msize == 0) {
335 		if (NULL != magic)
336 			free(magic);
337 		if (NULL != mask)
338 			free(mask);
339 		usage("Error: Missing '--size' argument");
340 	}
341 
342 	if (NULL != magic) {
343 		if (xbe->xbe_msize == 0) {
344 			if (magic)
345 				free(magic);
346 			if (mask)
347 				free(mask);
348 			usage("Error: Missing magic size argument");
349 		}
350 		sz = strlit2bin_cpy(xbe->xbe_magic, magic, IBE_MAGIC_MAX);
351 		free(magic);
352 		if (sz == -1 || (uint32_t)sz != xbe->xbe_msize) {
353 			if (mask)
354 				free(mask);
355 			usage("Error: invalid magic argument");
356 		}
357 		if (mask) {
358 			sz = strlit2bin_cpy(xbe->xbe_mask, mask, IBE_MAGIC_MAX);
359 			free(mask);
360 			if (sz == -1 || (uint32_t)sz != xbe->xbe_msize)
361 				usage("Error: invalid mask argument");
362 		}
363 	} else {
364 		if (mask)
365 			free(mask);
366 		usage("Error: Missing magic argument");
367 	}
368 
369 	if (!strnlen(xbe->xbe_interpreter, IBE_INTERP_LEN_MAX)) {
370 		usage("Error: Missing 'interpreter' argument");
371 	}
372 
373 	return (0);
374 }
375 
376 int
377 name_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe)
378 {
379 	if (argc == 0)
380 		usage("Required argument missing\n");
381 	if (strlen(argv[0]) > IBE_NAME_MAX)
382 		usage("'%s' string length longer than IBE_NAME_MAX (%d)",
383 		    IBE_NAME_MAX);
384 	strlcpy(&xbe->xbe_name[0], argv[0], IBE_NAME_MAX);
385 
386 	return (0);
387 }
388 
389 int
390 noname_cmd(__unused int argc, __unused char *argv[],
391     __unused ximgact_binmisc_entry_t *xbe)
392 {
393 
394 	return (0);
395 }
396 
397 int
398 main(int argc, char **argv)
399 {
400 	int error = 0, cmd = -1;
401 	ximgact_binmisc_entry_t xbe_in, *xbe_inp = NULL;
402 	ximgact_binmisc_entry_t xbe_out, *xbe_outp = NULL;
403 	size_t xbe_in_sz = 0;
404 	size_t xbe_out_sz = 0, *xbe_out_szp = NULL;
405 	uint32_t i;
406 
407 	if (modfind(KMOD_NAME) == -1) {
408 		if (kldload(KMOD_NAME) == -1)
409 			fatal("Can't load %s kernel module: %s",
410 			    KMOD_NAME, strerror(errno));
411 	}
412 
413 	bzero(&xbe_in, sizeof(xbe_in));
414 	bzero(&xbe_out, sizeof(xbe_out));
415 	xbe_in.xbe_version = IBE_VERSION;
416 
417 	if (argc < 2)
418 		usage("Error: requires at least one argument");
419 
420 	argc--, argv++;
421 	cmd = demux_cmd(argc, argv);
422 	if (cmd < 0)
423 		usage("Error: Unknown command \"%s\"", argv[0]);
424 	argc--, argv++;
425 
426 	error = (*cmds[cmd].func)(argc, argv, &xbe_in);
427 	if (error)
428 		usage("Can't parse command-line for '%s' command",
429 		    cmds[cmd].name);
430 
431 	if (cmd != CMD_LIST) {
432 		xbe_inp = &xbe_in;
433 		xbe_in_sz = sizeof(xbe_in);
434 	} else
435 		xbe_out_szp = &xbe_out_sz;
436 	if (cmd == CMD_LOOKUP) {
437 		xbe_out_sz = sizeof(xbe_out);
438 		xbe_outp = &xbe_out;
439 		xbe_out_szp = &xbe_out_sz;
440 	}
441 
442 	error = sysctlbyname(cmd_sysctl_name[cmd], xbe_outp, xbe_out_szp,
443 	    xbe_inp, xbe_in_sz);
444 
445 	if (error)
446 		switch(errno) {
447 		case EINVAL:
448 			usage("Invalid interpreter name or --interpreter, "
449 			    "--magic, --mask, or --size argument value");
450 			break;
451 
452 		case EEXIST:
453 			usage("'%s' is not unique in activator list",
454 			    xbe_in.xbe_name);
455 			break;
456 
457 		case ENOENT:
458 			usage("'%s' is not found in activator list",
459 			    xbe_in.xbe_name);
460 			break;
461 
462 		case ENOSPC:
463 			fatal("Fatal: no more room in the activator list "
464 			    "(limited to %d enties)", IBE_MAX_ENTRIES);
465 			break;
466 
467 		case EPERM:
468 			usage("Insufficient privileges for '%s' command",
469 			    cmds[cmd].name);
470 			break;
471 
472 		default:
473 			fatal("Fatal: sysctlbyname() returned: %s",
474 			    strerror(errno));
475 			break;
476 		}
477 
478 
479 	if (cmd == CMD_LOOKUP)
480 		printxbe(xbe_outp);
481 
482 	if (cmd == CMD_LIST && xbe_out_sz > 0) {
483 		xbe_outp = malloc(xbe_out_sz);
484 		if (!xbe_outp)
485 			fatal("Fatal: out of memory");
486 		while(1) {
487 			size_t osize = xbe_out_sz;
488 			error = sysctlbyname(cmd_sysctl_name[cmd], xbe_outp,
489 			    &xbe_out_sz, NULL, 0);
490 
491 			if (error == -1 && errno == ENOMEM &&
492 			    xbe_out_sz == osize) {
493 				/*
494 				 * Buffer too small. Increase it by one
495 				 * entry.
496 				 */
497 				xbe_out_sz += sizeof(xbe_out);
498 				xbe_outp = realloc(xbe_outp, xbe_out_sz);
499 				if (!xbe_outp)
500 					fatal("Fatal: out of memory");
501 			} else
502 				break;
503 		}
504 		if (error) {
505 			free(xbe_outp);
506 			fatal("Fatal: %s", strerror(errno));
507 		}
508 		for(i = 0; i < howmany(xbe_out_sz, sizeof(xbe_out)); i++)
509 			printxbe(&xbe_outp[i]);
510 	}
511 
512 	return (error);
513 }
514