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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/flask.h>
29 #include <sepol/policydb/hierarchy.h>
30 #include <sepol/policydb/expand.h>
31 #include <sepol/policydb/link.h>
32 #include <sepol/policydb/sidtab.h>
33 
34 #include "queue.h"
35 #include "checkpolicy.h"
36 #include "parse_util.h"
37 
38 extern char *optarg;
39 extern int optind;
40 
41 static sidtab_t sidtab;
42 
43 extern int mlspol;
44 
45 static int handle_unknown = SEPOL_DENY_UNKNOWN;
46 static const char *txtfile = "policy.conf";
47 static const char *binfile = "policy";
48 
49 unsigned int policy_type = POLICY_BASE;
50 unsigned int policyvers = MOD_POLICYDB_VERSION_MAX;
51 
read_binary_policy(policydb_t * p,const char * file,const char * progname)52 static int read_binary_policy(policydb_t * p, const char *file, const char *progname)
53 {
54 	int fd;
55 	struct stat sb;
56 	void *map;
57 	struct policy_file f, *fp;
58 
59 	fd = open(file, O_RDONLY);
60 	if (fd < 0) {
61 		fprintf(stderr, "Can't open '%s':  %s\n",
62 			file, strerror(errno));
63 		return -1;
64 	}
65 	if (fstat(fd, &sb) < 0) {
66 		fprintf(stderr, "Can't stat '%s':  %s\n",
67 			file, strerror(errno));
68 		close(fd);
69 		return -1;
70 	}
71 	map =
72 	    mmap(NULL, sb.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
73 	close(fd);
74 	if (map == MAP_FAILED) {
75 		fprintf(stderr, "Can't map '%s':  %s\n", file, strerror(errno));
76 		return -1;
77 	}
78 	policy_file_init(&f);
79 	f.type = PF_USE_MEMORY;
80 	f.data = map;
81 	f.len = sb.st_size;
82 	fp = &f;
83 
84 	if (policydb_init(p)) {
85 		fprintf(stderr, "%s:  policydb_init:  Out of memory!\n",
86 			progname);
87 		return -1;
88 	}
89 	if (policydb_read(p, fp, 1)) {
90 		fprintf(stderr,
91 			"%s:  error(s) encountered while parsing configuration\n",
92 			progname);
93 		return -1;
94 	}
95 
96 	/* Check Policy Consistency */
97 	if (p->mls) {
98 		if (!mlspol) {
99 			fprintf(stderr, "%s:  MLS policy, but non-MLS"
100 				" is specified\n", progname);
101 			return -1;
102 		}
103 	} else {
104 		if (mlspol) {
105 			fprintf(stderr, "%s:  non-MLS policy, but MLS"
106 				" is specified\n", progname);
107 			return -1;
108 		}
109 	}
110 	return 0;
111 }
112 
write_binary_policy(policydb_t * p,FILE * outfp)113 static int write_binary_policy(policydb_t * p, FILE *outfp)
114 {
115 	struct policy_file pf;
116 
117 	p->policy_type = policy_type;
118 	p->policyvers = policyvers;
119 	p->handle_unknown = handle_unknown;
120 
121 	policy_file_init(&pf);
122 	pf.type = PF_USE_STDIO;
123 	pf.fp = outfp;
124 	return policydb_write(p, &pf);
125 }
126 
usage(const char * progname)127 static __attribute__((__noreturn__)) void usage(const char *progname)
128 {
129 	printf("usage:  %s [-h] [-V] [-b] [-C] [-U handle_unknown] [-m] [-M] [-o FILE] [INPUT]\n", progname);
130 	printf("Build base and policy modules.\n");
131 	printf("Options:\n");
132 	printf("  INPUT      build module from INPUT (else read from \"%s\")\n",
133 	       txtfile);
134 	printf("  -V         show policy versions created by this program\n");
135 	printf("  -b         treat input as a binary policy file\n");
136 	printf("  -C         output CIL policy instead of binary policy\n");
137 	printf("  -h         print usage\n");
138 	printf("  -U OPTION  How to handle unknown classes and permissions\n");
139 	printf("               deny: Deny unknown kernel checks\n");
140 	printf("               reject: Reject loading of policy with unknowns\n");
141 	printf("               allow: Allow unknown kernel checks\n");
142 	printf("  -m         build a policy module instead of a base module\n");
143 	printf("  -M         enable MLS policy\n");
144 	printf("  -o FILE    write module to FILE (else just check syntax)\n");
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 	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 		{NULL, 0, NULL, 0}
164 	};
165 
166 	while ((ch = getopt_long(argc, argv, "ho:bVU:mMC", long_options, NULL)) != -1) {
167 		switch (ch) {
168 		case 'h':
169 			usage(argv[0]);
170 			break;
171 		case 'o':
172 			outfile = optarg;
173 			break;
174 		case 'b':
175 			binary = 1;
176 			file = binfile;
177 			break;
178 		case 'V':
179 			show_version = 1;
180 			break;
181 		case 'U':
182 			if (!strcasecmp(optarg, "deny")) {
183 				handle_unknown = DENY_UNKNOWN;
184 				break;
185 			}
186 			if (!strcasecmp(optarg, "reject")) {
187 				handle_unknown = REJECT_UNKNOWN;
188 				break;
189 			}
190 			if (!strcasecmp(optarg, "allow")) {
191 				handle_unknown = ALLOW_UNKNOWN;
192 				break;
193 			}
194 			usage(argv[0]);
195 		case 'm':
196 			policy_type = POLICY_MOD;
197 			policyvers = MOD_POLICYDB_VERSION_MAX;
198 			break;
199 		case 'M':
200 			mlspol = 1;
201 			break;
202 		case 'C':
203 			cil = 1;
204 			break;
205 		default:
206 			usage(argv[0]);
207 		}
208 	}
209 
210 	if (show_version) {
211 		printf("Module versions %d-%d\n",
212 		       MOD_POLICYDB_VERSION_MIN, MOD_POLICYDB_VERSION_MAX);
213 		exit(0);
214 	}
215 
216 	if (handle_unknown && (policy_type != POLICY_BASE)) {
217 		fprintf(stderr, "%s:  Handling of unknown classes and permissions is only valid in the base module.\n", argv[0]);
218 		exit(1);
219 	}
220 
221 	if (binary && (policy_type != POLICY_BASE)) {
222 		fprintf(stderr, "%s:  -b and -m are incompatible with each other.\n", argv[0]);
223 		exit(1);
224 	}
225 
226 	if (optind != argc) {
227 		file = argv[optind++];
228 		if (optind != argc)
229 			usage(argv[0]);
230 	}
231 	printf("%s:  loading policy configuration from %s\n", argv[0], file);
232 
233 	/* Set policydb and sidtab used by libsepol service functions
234 	   to my structures, so that I can directly populate and
235 	   manipulate them. */
236 	sepol_set_policydb(&modpolicydb);
237 	sepol_set_sidtab(&sidtab);
238 
239 	if (binary) {
240 		if (read_binary_policy(&modpolicydb, file, argv[0]) == -1) {
241 			exit(1);
242 		}
243 	} else {
244 		if (policydb_init(&modpolicydb)) {
245 			fprintf(stderr, "%s: out of memory!\n", argv[0]);
246 			return -1;
247 		}
248 
249 		modpolicydb.policy_type = policy_type;
250 		modpolicydb.mls = mlspol;
251 		modpolicydb.handle_unknown = handle_unknown;
252 
253 		if (read_source_policy(&modpolicydb, file, argv[0]) == -1) {
254 			exit(1);
255 		}
256 
257 		if (hierarchy_check_constraints(NULL, &modpolicydb)) {
258 			return -1;
259 		}
260 	}
261 
262 	if (policy_type != POLICY_BASE && outfile) {
263 		char *mod_name = modpolicydb.name;
264 		char *out_path = strdup(outfile);
265 		if (out_path == NULL) {
266 			fprintf(stderr, "%s:  out of memory\n", argv[0]);
267 			exit(1);
268 		}
269 		char *out_name = basename(out_path);
270 		char *separator = strrchr(out_name, '.');
271 		if (separator) {
272 			*separator = '\0';
273 		}
274 		if (strcmp(mod_name, out_name) != 0) {
275 			fprintf(stderr,	"%s:  Module name %s is different than the output base filename %s\n", argv[0], mod_name, out_name);
276 			exit(1);
277 		}
278 		free(out_path);
279 	}
280 
281 	if (modpolicydb.policy_type == POLICY_BASE && !cil) {
282 		/* Verify that we can successfully expand the base module. */
283 		policydb_t kernpolicydb;
284 
285 		if (policydb_init(&kernpolicydb)) {
286 			fprintf(stderr, "%s:  policydb_init failed\n", argv[0]);
287 			exit(1);
288 		}
289 		if (link_modules(NULL, &modpolicydb, NULL, 0, 0)) {
290 			fprintf(stderr, "%s:  link modules failed\n", argv[0]);
291 			exit(1);
292 		}
293 		if (expand_module(NULL, &modpolicydb, &kernpolicydb, 0, 1)) {
294 			fprintf(stderr, "%s:  expand module failed\n", argv[0]);
295 			exit(1);
296 		}
297 		policydb_destroy(&kernpolicydb);
298 	}
299 
300 	if (policydb_load_isids(&modpolicydb, &sidtab))
301 		exit(1);
302 
303 	sepol_sidtab_destroy(&sidtab);
304 
305 	printf("%s:  policy configuration loaded\n", argv[0]);
306 
307 	if (outfile) {
308 		FILE *outfp = fopen(outfile, "w");
309 
310 		if (!outfp) {
311 			perror(outfile);
312 			exit(1);
313 		}
314 
315 		if (!cil) {
316 			printf("%s:  writing binary representation (version %d) to %s\n",
317 				   argv[0], policyvers, outfile);
318 
319 			if (write_binary_policy(&modpolicydb, outfp) != 0) {
320 				fprintf(stderr, "%s:  error writing %s\n", argv[0], outfile);
321 				exit(1);
322 			}
323 		} else {
324 			printf("%s:  writing CIL to %s\n",argv[0], outfile);
325 
326 			if (sepol_module_policydb_to_cil(outfp, &modpolicydb, 0) != 0) {
327 				fprintf(stderr, "%s:  error writing %s\n", argv[0], outfile);
328 				exit(1);
329 			}
330 		}
331 
332 		fclose(outfp);
333 	} else if (cil) {
334 		fprintf(stderr, "%s:  No file to write CIL was specified\n", argv[0]);
335 		exit(1);
336 	}
337 
338 	policydb_destroy(&modpolicydb);
339 
340 	return 0;
341 }
342 
343 /* FLASK */
344