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1 /*
2  * Authors: Joshua Brindle <jbrindle@tresys.com>
3  *	    Karl MacMillan <kmacmillan@tresys.com>
4  *          Jason Tang     <jtang@tresys.com>
5  *
6  *
7  * Copyright (C) 2004-5 Tresys Technology, LLC
8  *	This program is free software; you can redistribute it and/or modify
9  *  	it under the terms of the GNU General Public License as published by
10  *	the Free Software Foundation, version 2.
11  */
12 
13 #include <getopt.h>
14 #include <unistd.h>
15 #include <stdlib.h>
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <fcntl.h>
19 #include <stdio.h>
20 #include <errno.h>
21 #include <sys/mman.h>
22 #include <libgen.h>
23 
24 #include <sepol/module_to_cil.h>
25 #include <sepol/policydb/policydb.h>
26 #include <sepol/policydb/services.h>
27 #include <sepol/policydb/conditional.h>
28 #include <sepol/policydb/hierarchy.h>
29 #include <sepol/policydb/expand.h>
30 #include <sepol/policydb/link.h>
31 #include <sepol/policydb/sidtab.h>
32 
33 #include "queue.h"
34 #include "checkpolicy.h"
35 #include "parse_util.h"
36 
37 static sidtab_t sidtab;
38 
39 extern int mlspol;
40 extern int werror;
41 
42 static int handle_unknown = SEPOL_DENY_UNKNOWN;
43 static const char *txtfile = "policy.conf";
44 static const char *binfile = "policy";
45 
46 unsigned int policy_type = POLICY_BASE;
47 unsigned int policyvers = MOD_POLICYDB_VERSION_MAX;
48 
read_binary_policy(policydb_t * p,const char * file,const char * progname)49 static int read_binary_policy(policydb_t * p, const char *file, const char *progname)
50 {
51 	int fd;
52 	struct stat sb;
53 	void *map;
54 	struct policy_file f, *fp;
55 
56 	fd = open(file, O_RDONLY);
57 	if (fd < 0) {
58 		fprintf(stderr, "Can't open '%s':  %s\n",
59 			file, strerror(errno));
60 		return -1;
61 	}
62 	if (fstat(fd, &sb) < 0) {
63 		fprintf(stderr, "Can't stat '%s':  %s\n",
64 			file, strerror(errno));
65 		close(fd);
66 		return -1;
67 	}
68 	map =
69 	    mmap(NULL, sb.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
70 	close(fd);
71 	if (map == MAP_FAILED) {
72 		fprintf(stderr, "Can't map '%s':  %s\n", file, strerror(errno));
73 		return -1;
74 	}
75 	policy_file_init(&f);
76 	f.type = PF_USE_MEMORY;
77 	f.data = map;
78 	f.len = sb.st_size;
79 	fp = &f;
80 
81 	if (policydb_init(p)) {
82 		fprintf(stderr, "%s:  policydb_init:  Out of memory!\n",
83 			progname);
84 		return -1;
85 	}
86 	if (policydb_read(p, fp, 1)) {
87 		fprintf(stderr,
88 			"%s:  error(s) encountered while parsing configuration\n",
89 			progname);
90 		return -1;
91 	}
92 
93 	/* Check Policy Consistency */
94 	if (p->mls) {
95 		if (!mlspol) {
96 			fprintf(stderr, "%s:  MLS policy, but non-MLS"
97 				" is specified\n", progname);
98 			return -1;
99 		}
100 	} else {
101 		if (mlspol) {
102 			fprintf(stderr, "%s:  non-MLS policy, but MLS"
103 				" is specified\n", progname);
104 			return -1;
105 		}
106 	}
107 	return 0;
108 }
109 
write_binary_policy(policydb_t * p,FILE * outfp)110 static int write_binary_policy(policydb_t * p, FILE *outfp)
111 {
112 	struct policy_file pf;
113 
114 	p->policy_type = policy_type;
115 	p->policyvers = policyvers;
116 	p->handle_unknown = handle_unknown;
117 
118 	policy_file_init(&pf);
119 	pf.type = PF_USE_STDIO;
120 	pf.fp = outfp;
121 	return policydb_write(p, &pf);
122 }
123 
usage(const char * progname)124 static __attribute__((__noreturn__)) void usage(const char *progname)
125 {
126 	printf("usage:  %s [-h] [-V] [-b] [-C] [-E] [-U handle_unknown] [-m] [-M] [-o FILE] [-c VERSION] [INPUT]\n", progname);
127 	printf("Build base and policy modules.\n");
128 	printf("Options:\n");
129 	printf("  INPUT      build module from INPUT (else read from \"%s\")\n",
130 	       txtfile);
131 	printf("  -V         show policy versions created by this program\n");
132 	printf("  -b         treat input as a binary policy file\n");
133 	printf("  -C         output CIL policy instead of binary policy\n");
134 	printf("  -E         treat warnings as errors\n");
135 	printf("  -h         print usage\n");
136 	printf("  -U OPTION  How to handle unknown classes and permissions\n");
137 	printf("               deny: Deny unknown kernel checks\n");
138 	printf("               reject: Reject loading of policy with unknowns\n");
139 	printf("               allow: Allow unknown kernel checks\n");
140 	printf("  -m         build a policy module instead of a base module\n");
141 	printf("  -M         enable MLS policy\n");
142 	printf("  -o FILE    write module to FILE (else just check syntax)\n");
143 	printf("  -c VERSION build a policy module targeting a modular policy version (%d-%d)\n",
144 	       MOD_POLICYDB_VERSION_MIN, MOD_POLICYDB_VERSION_MAX);
145 	exit(1);
146 }
147 
main(int argc,char ** argv)148 int main(int argc, char **argv)
149 {
150 	const char *file = txtfile, *outfile = NULL;
151 	unsigned int binary = 0, cil = 0;
152 	int ch;
153 	int show_version = 0;
154 	policydb_t modpolicydb;
155 	const struct option long_options[] = {
156 		{"help", no_argument, NULL, 'h'},
157 		{"output", required_argument, NULL, 'o'},
158 		{"binary", no_argument, NULL, 'b'},
159 		{"version", no_argument, NULL, 'V'},
160 		{"handle-unknown", required_argument, NULL, 'U'},
161 		{"mls", no_argument, NULL, 'M'},
162 		{"cil", no_argument, NULL, 'C'},
163 		{"werror", no_argument, NULL, 'E'},
164 		{NULL, 0, NULL, 0}
165 	};
166 
167 	while ((ch = getopt_long(argc, argv, "ho:bVEU:mMCc:", long_options, NULL)) != -1) {
168 		switch (ch) {
169 		case 'h':
170 			usage(argv[0]);
171 			break;
172 		case 'o':
173 			outfile = optarg;
174 			break;
175 		case 'b':
176 			binary = 1;
177 			file = binfile;
178 			break;
179 		case 'V':
180 			show_version = 1;
181 			break;
182 		case 'E':
183 			werror = 1;
184 			break;
185 		case 'U':
186 			if (!strcasecmp(optarg, "deny")) {
187 				handle_unknown = DENY_UNKNOWN;
188 				break;
189 			}
190 			if (!strcasecmp(optarg, "reject")) {
191 				handle_unknown = REJECT_UNKNOWN;
192 				break;
193 			}
194 			if (!strcasecmp(optarg, "allow")) {
195 				handle_unknown = ALLOW_UNKNOWN;
196 				break;
197 			}
198 			usage(argv[0]);
199 		case 'm':
200 			policy_type = POLICY_MOD;
201 			break;
202 		case 'M':
203 			mlspol = 1;
204 			break;
205 		case 'C':
206 			cil = 1;
207 			break;
208 		case 'c': {
209 			long int n;
210 			errno = 0;
211 			n = strtol(optarg, NULL, 10);
212 			if (errno) {
213 				fprintf(stderr,
214 					"Invalid policyvers specified: %s\n",
215 					optarg);
216 				usage(argv[0]);
217 			}
218 
219 			if (n < MOD_POLICYDB_VERSION_MIN
220 			    || n > MOD_POLICYDB_VERSION_MAX) {
221 				fprintf(stderr,
222 					"policyvers value %ld not in range %d-%d\n",
223 					n, MOD_POLICYDB_VERSION_MIN,
224 					MOD_POLICYDB_VERSION_MAX);
225 				usage(argv[0]);
226 			}
227 
228 			policyvers = n;
229 			break;
230 		}
231 		default:
232 			usage(argv[0]);
233 		}
234 	}
235 
236 	if (show_version) {
237 		printf("Module versions %d-%d\n",
238 		       MOD_POLICYDB_VERSION_MIN, MOD_POLICYDB_VERSION_MAX);
239 		exit(0);
240 	}
241 
242 	if (handle_unknown && (policy_type != POLICY_BASE)) {
243 		fprintf(stderr, "%s:  Handling of unknown classes and permissions is only valid in the base module.\n", argv[0]);
244 		exit(1);
245 	}
246 
247 	if (binary && (policy_type != POLICY_BASE)) {
248 		fprintf(stderr, "%s:  -b and -m are incompatible with each other.\n", argv[0]);
249 		exit(1);
250 	}
251 
252 	if (optind != argc) {
253 		file = argv[optind++];
254 		if (optind != argc)
255 			usage(argv[0]);
256 	}
257 
258 	/* Set policydb and sidtab used by libsepol service functions
259 	   to my structures, so that I can directly populate and
260 	   manipulate them. */
261 	sepol_set_policydb(&modpolicydb);
262 	sepol_set_sidtab(&sidtab);
263 
264 	if (binary) {
265 		if (read_binary_policy(&modpolicydb, file, argv[0]) == -1) {
266 			exit(1);
267 		}
268 	} else {
269 		if (policydb_init(&modpolicydb)) {
270 			fprintf(stderr, "%s: out of memory!\n", argv[0]);
271 			exit(1);
272 		}
273 
274 		modpolicydb.policy_type = policy_type;
275 		modpolicydb.mls = mlspol;
276 		modpolicydb.handle_unknown = handle_unknown;
277 
278 		if (read_source_policy(&modpolicydb, file, argv[0]) == -1) {
279 			exit(1);
280 		}
281 
282 		if (hierarchy_check_constraints(NULL, &modpolicydb)) {
283 			exit(1);
284 		}
285 	}
286 
287 	if (policy_type != POLICY_BASE && outfile) {
288 		char *out_name;
289 		char *separator;
290 		char *mod_name = modpolicydb.name;
291 		char *out_path = strdup(outfile);
292 		if (out_path == NULL) {
293 			fprintf(stderr, "%s:  out of memory\n", argv[0]);
294 			exit(1);
295 		}
296 		out_name = basename(out_path);
297 		separator = strrchr(out_name, '.');
298 		if (separator) {
299 			*separator = '\0';
300 		}
301 		if (strcmp(mod_name, out_name) != 0) {
302 			fprintf(stderr,	"%s:  Module name %s is different than the output base filename %s\n", argv[0], mod_name, out_name);
303 			exit(1);
304 		}
305 		free(out_path);
306 	}
307 
308 	if (modpolicydb.policy_type == POLICY_BASE && !cil) {
309 		/* Verify that we can successfully expand the base module. */
310 		policydb_t kernpolicydb;
311 
312 		if (policydb_init(&kernpolicydb)) {
313 			fprintf(stderr, "%s:  policydb_init failed\n", argv[0]);
314 			exit(1);
315 		}
316 		if (link_modules(NULL, &modpolicydb, NULL, 0, 0)) {
317 			fprintf(stderr, "%s:  link modules failed\n", argv[0]);
318 			exit(1);
319 		}
320 		if (expand_module(NULL, &modpolicydb, &kernpolicydb, 0, 1)) {
321 			fprintf(stderr, "%s:  expand module failed\n", argv[0]);
322 			exit(1);
323 		}
324 		policydb_destroy(&kernpolicydb);
325 	}
326 
327 	if (policydb_load_isids(&modpolicydb, &sidtab))
328 		exit(1);
329 
330 	sepol_sidtab_destroy(&sidtab);
331 
332 	if (outfile) {
333 		FILE *outfp = fopen(outfile, "w");
334 
335 		if (!outfp) {
336 			fprintf(stderr, "%s:  error opening %s:  %s\n", argv[0], outfile, strerror(errno));
337 			exit(1);
338 		}
339 
340 		if (!cil) {
341 			if (write_binary_policy(&modpolicydb, outfp) != 0) {
342 				fprintf(stderr, "%s:  error writing %s\n", argv[0], outfile);
343 				exit(1);
344 			}
345 		} else {
346 			if (sepol_module_policydb_to_cil(outfp, &modpolicydb, 0) != 0) {
347 				fprintf(stderr, "%s:  error writing %s\n", argv[0], outfile);
348 				exit(1);
349 			}
350 		}
351 
352 		if (fclose(outfp)) {
353 			fprintf(stderr, "%s:  error closing %s:  %s\n", argv[0], outfile, strerror(errno));
354 			exit(1);
355 		}
356 	} else if (cil) {
357 		fprintf(stderr, "%s:  No file to write CIL was specified\n", argv[0]);
358 		exit(1);
359 	}
360 
361 	policydb_destroy(&modpolicydb);
362 
363 	return 0;
364 }
365 
366 /* FLASK */
367