xref: /freebsd/usr.sbin/binmiscctl/binmiscctl.c (revision 1d386b48) 
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 #include <sys/types.h>
30 #include <sys/imgact_binmisc.h>
31 #include <sys/linker.h>
32 #include <sys/module.h>
33 #include <sys/sysctl.h>
34 
35 #include <ctype.h>
36 #include <errno.h>
37 #include <getopt.h>
38 #include <stdio.h>
39 #include <stdarg.h>
40 #include <stdint.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 enum cmd {
45 	CMD_ADD = 0,
46 	CMD_REMOVE,
47 	CMD_DISABLE,
48 	CMD_ENABLE,
49 	CMD_LOOKUP,
50 	CMD_LIST,
51 };
52 
53 extern char *__progname;
54 
55 typedef int (*cmd_func_t)(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
56 
57 int add_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
58 int name_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
59 int noname_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe);
60 
61 static const struct {
62 	const int token;
63 	const char *name;
64 	cmd_func_t func;
65 	const char *desc;
66 	const char *args;
67 } cmds[] = {
68 	{
69 		CMD_ADD,
70 		"add",
71 		add_cmd,
72 		"Add a new binary image activator (requires 'root' privilege)",
73 		"<name> --interpreter <path_and_arguments> \\\n"
74 		"\t\t--magic <magic_bytes> [--mask <mask_bytes>] \\\n"
75 		"\t\t--size <magic_size> [--offset <magic_offset>] \\\n"
76 		"\t\t[--set-enabled] \\\n"
77 		"\t\t[--pre-open]"
78 	},
79 	{
80 		CMD_REMOVE,
81 		"remove",
82 		name_cmd,
83 		"Remove a binary image activator (requires 'root' privilege)",
84 		"<name>"
85 	},
86 	{
87 		CMD_DISABLE,
88 		"disable",
89 		name_cmd,
90 		"Disable a binary image activator (requires 'root' privilege)",
91 		"<name>"
92 	},
93 	{
94 		CMD_ENABLE,
95 		"enable",
96 		name_cmd,
97 		"Enable a binary image activator (requires 'root' privilege)",
98 		"<name>"
99 	},
100 	{
101 		CMD_LOOKUP,
102 		"lookup",
103 		name_cmd,
104 		"Lookup a binary image activator",
105 		"<name>"
106 	},
107 	{
108 		CMD_LIST,
109 		"list",
110 		noname_cmd,
111 		"List all the binary image activators",
112 		""
113 	},
114 };
115 
116 static const struct option
117 add_opts[] = {
118 	{ "set-enabled",	no_argument,		NULL,	'e' },
119 	{ "interpreter",	required_argument,	NULL,	'i' },
120 	{ "mask",		required_argument,	NULL,	'M' },
121 	{ "magic",		required_argument,	NULL,	'm' },
122 	{ "offset",		required_argument,	NULL,	'o' },
123 	{ "size",		required_argument,	NULL,	's' },
124 	{ "pre-open",		no_argument,		NULL,	'p' },
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%s\n", (flags & IBF_ENABLED) ? "ENABLED " : "",
196 	    (flags & IBF_USE_MASK) ? "USE_MASK " : "",
197 	    (flags & IBF_PRE_OPEN) ? "PRE_OPEN " : "");
198 	printf("magic size: %u\n", xbe->xbe_msize);
199 	printf("magic offset: %u\n", xbe->xbe_moffset);
200 
201 	printf("magic: ");
202 	for(i = 0; i < xbe->xbe_msize;  i++) {
203 		if (i && !(i % 12))
204 			printf("\n       ");
205 		else
206 			if (i && !(i % 4))
207 				printf(" ");
208 		printf("0x%02x ", xbe->xbe_magic[i]);
209 	}
210 	printf("\n");
211 
212 	if (flags & IBF_USE_MASK) {
213 		printf("mask:  ");
214 		for(i = 0; i < xbe->xbe_msize;  i++) {
215 			if (i && !(i % 12))
216 				printf("\n       ");
217 			else
218 				if (i && !(i % 4))
219 					printf(" ");
220 			printf("0x%02x ", xbe->xbe_mask[i]);
221 		}
222 		printf("\n");
223 	}
224 
225 	printf("\n");
226 }
227 
228 static int
229 demux_cmd(__unused int argc, char *const argv[])
230 {
231 	size_t i;
232 
233 	optind = 1;
234 	optreset = 1;
235 
236 	for(i = 0; i < nitems(cmds); i++) {
237 		if (!strcasecmp(cmds[i].name, argv[0])) {
238 			return (i);
239 		}
240 	}
241 
242 	/* Unknown command */
243 	return (-1);
244 }
245 
246 static int
247 strlit2bin_cpy(uint8_t *d, char *s, size_t size)
248 {
249 	int c;
250 	size_t cnt = 0;
251 
252 	while((c = *s++) != '\0') {
253 		if (c == '\\') {
254 			/* Do '\' escapes. */
255 			switch (*s) {
256 			case '\\':
257 				*d++ = '\\';
258 				break;
259 
260 			case 'x':
261 				s++;
262 				c = toupper(*s++);
263 				*d = (c - (isdigit(c) ? '0' : ('A' - 10))) << 4;
264 				c = toupper(*s++);
265 				*d++ |= c - (isdigit(c) ? '0' : ('A' - 10));
266 				break;
267 
268 			default:
269 				return (-1);
270 			}
271 		} else
272 			*d++ = c;
273 
274 		if (++cnt > size)
275 			return (-1);
276 	}
277 
278 	return (cnt);
279 }
280 
281 int
282 add_cmd(__unused int argc, char *argv[], ximgact_binmisc_entry_t *xbe)
283 {
284 	int ch;
285 	char *magic = NULL, *mask = NULL;
286 	int sz;
287 
288 	if (argc == 0)
289 		usage("Required argument missing\n");
290 	if (strlen(argv[0]) > IBE_NAME_MAX)
291 		usage("'%s' string length longer than IBE_NAME_MAX (%d)",
292 		    IBE_NAME_MAX);
293 	strlcpy(&xbe->xbe_name[0], argv[0], IBE_NAME_MAX);
294 
295 	while ((ch = getopt_long(argc, argv, "epi:m:M:o:s:", add_opts, NULL))
296 	    != -1) {
297 
298 		switch(ch) {
299 		case 'i':
300 			getoptstr(xbe->xbe_interpreter, IBE_INTERP_LEN_MAX,
301 			    "interpreter");
302 			break;
303 
304 		case 'm':
305 			free(magic);
306 			magic = strdup(optarg);
307 			break;
308 
309 		case 'M':
310 			free(mask);
311 			mask = strdup(optarg);
312 			xbe->xbe_flags |= IBF_USE_MASK;
313 			break;
314 
315 		case 'e':
316 			xbe->xbe_flags |= IBF_ENABLED;
317 			break;
318 
319 		case 'o':
320 			xbe->xbe_moffset = atol(optarg);
321 			break;
322 
323 		case 's':
324 			xbe->xbe_msize = atol(optarg);
325 			if (xbe->xbe_msize == 0 ||
326 			    xbe->xbe_msize > IBE_MAGIC_MAX)
327 				usage("Error: Not valid '--size' value. "
328 				    "(Must be > 0 and < %u.)\n",
329 				    xbe->xbe_msize);
330 			break;
331 
332 		case 'p':
333 			xbe->xbe_flags |= IBF_PRE_OPEN;
334 			break;
335 
336 		default:
337 			usage("Unknown argument: '%c'", ch);
338 		}
339 	}
340 
341 	if (xbe->xbe_msize == 0) {
342 		if (NULL != magic)
343 			free(magic);
344 		if (NULL != mask)
345 			free(mask);
346 		usage("Error: Missing '--size' argument");
347 	}
348 
349 	if (NULL != magic) {
350 		if (xbe->xbe_msize == 0) {
351 			if (magic)
352 				free(magic);
353 			if (mask)
354 				free(mask);
355 			usage("Error: Missing magic size argument");
356 		}
357 		sz = strlit2bin_cpy(xbe->xbe_magic, magic, IBE_MAGIC_MAX);
358 		free(magic);
359 		if (sz == -1 || (uint32_t)sz != xbe->xbe_msize) {
360 			if (mask)
361 				free(mask);
362 			usage("Error: invalid magic argument");
363 		}
364 		if (mask) {
365 			sz = strlit2bin_cpy(xbe->xbe_mask, mask, IBE_MAGIC_MAX);
366 			free(mask);
367 			if (sz == -1 || (uint32_t)sz != xbe->xbe_msize)
368 				usage("Error: invalid mask argument");
369 		}
370 	} else {
371 		if (mask)
372 			free(mask);
373 		usage("Error: Missing magic argument");
374 	}
375 
376 	if (!strnlen(xbe->xbe_interpreter, IBE_INTERP_LEN_MAX)) {
377 		usage("Error: Missing 'interpreter' argument");
378 	}
379 
380 	return (0);
381 }
382 
383 int
384 name_cmd(int argc, char *argv[], ximgact_binmisc_entry_t *xbe)
385 {
386 	if (argc == 0)
387 		usage("Required argument missing\n");
388 	if (strlen(argv[0]) > IBE_NAME_MAX)
389 		usage("'%s' string length longer than IBE_NAME_MAX (%d)",
390 		    IBE_NAME_MAX);
391 	strlcpy(&xbe->xbe_name[0], argv[0], IBE_NAME_MAX);
392 
393 	return (0);
394 }
395 
396 int
397 noname_cmd(__unused int argc, __unused char *argv[],
398     __unused ximgact_binmisc_entry_t *xbe)
399 {
400 
401 	return (0);
402 }
403 
404 int
405 main(int argc, char **argv)
406 {
407 	int error = 0, cmd = -1;
408 	ximgact_binmisc_entry_t xbe_in, *xbe_inp = NULL;
409 	ximgact_binmisc_entry_t xbe_out, *xbe_outp = NULL;
410 	size_t xbe_in_sz = 0;
411 	size_t xbe_out_sz = 0, *xbe_out_szp = NULL;
412 	uint32_t i;
413 
414 	if (modfind(KMOD_NAME) == -1) {
415 		if (kldload(KMOD_NAME) == -1)
416 			fatal("Can't load %s kernel module: %s",
417 			    KMOD_NAME, strerror(errno));
418 	}
419 
420 	bzero(&xbe_in, sizeof(xbe_in));
421 	bzero(&xbe_out, sizeof(xbe_out));
422 	xbe_in.xbe_version = IBE_VERSION;
423 
424 	if (argc < 2)
425 		usage("Error: requires at least one argument");
426 
427 	argc--, argv++;
428 	cmd = demux_cmd(argc, argv);
429 	if (cmd < 0)
430 		usage("Error: Unknown command \"%s\"", argv[0]);
431 	argc--, argv++;
432 
433 	error = (*cmds[cmd].func)(argc, argv, &xbe_in);
434 	if (error)
435 		usage("Can't parse command-line for '%s' command",
436 		    cmds[cmd].name);
437 
438 	if (cmd != CMD_LIST) {
439 		xbe_inp = &xbe_in;
440 		xbe_in_sz = sizeof(xbe_in);
441 	} else
442 		xbe_out_szp = &xbe_out_sz;
443 	if (cmd == CMD_LOOKUP) {
444 		xbe_out_sz = sizeof(xbe_out);
445 		xbe_outp = &xbe_out;
446 		xbe_out_szp = &xbe_out_sz;
447 	}
448 
449 	error = sysctlbyname(cmd_sysctl_name[cmd], xbe_outp, xbe_out_szp,
450 	    xbe_inp, xbe_in_sz);
451 
452 	if (error)
453 		switch(errno) {
454 		case EINVAL:
455 			usage("Invalid interpreter name or --interpreter, "
456 			    "--magic, --mask, or --size argument value");
457 			break;
458 
459 		case EEXIST:
460 			usage("'%s' is not unique in activator list",
461 			    xbe_in.xbe_name);
462 			break;
463 
464 		case ENOENT:
465 			usage("'%s' is not found in activator list",
466 			    xbe_in.xbe_name);
467 			break;
468 
469 		case ENOSPC:
470 			fatal("Fatal: no more room in the activator list "
471 			    "(limited to %d enties)", IBE_MAX_ENTRIES);
472 			break;
473 
474 		case EPERM:
475 			usage("Insufficient privileges for '%s' command",
476 			    cmds[cmd].name);
477 			break;
478 
479 		default:
480 			fatal("Fatal: sysctlbyname() returned: %s",
481 			    strerror(errno));
482 			break;
483 		}
484 
485 
486 	if (cmd == CMD_LOOKUP)
487 		printxbe(xbe_outp);
488 
489 	if (cmd == CMD_LIST && xbe_out_sz > 0) {
490 		xbe_outp = malloc(xbe_out_sz);
491 		if (!xbe_outp)
492 			fatal("Fatal: out of memory");
493 		while(1) {
494 			size_t osize = xbe_out_sz;
495 			error = sysctlbyname(cmd_sysctl_name[cmd], xbe_outp,
496 			    &xbe_out_sz, NULL, 0);
497 
498 			if (error == -1 && errno == ENOMEM &&
499 			    xbe_out_sz == osize) {
500 				/*
501 				 * Buffer too small. Increase it by one
502 				 * entry.
503 				 */
504 				xbe_out_sz += sizeof(xbe_out);
505 				xbe_outp = realloc(xbe_outp, xbe_out_sz);
506 				if (!xbe_outp)
507 					fatal("Fatal: out of memory");
508 			} else
509 				break;
510 		}
511 		if (error) {
512 			free(xbe_outp);
513 			fatal("Fatal: %s", strerror(errno));
514 		}
515 		for(i = 0; i < howmany(xbe_out_sz, sizeof(xbe_out)); i++)
516 			printxbe(&xbe_outp[i]);
517 	}
518 
519 	return (error);
520 }
521