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1 #include <stdlib.h>
2 #include <stddef.h>
3 #include <string.h>
4 
5 #include "private.h"
6 #include "debug.h"
7 #include "handle.h"
8 
9 #include <sepol/policydb/policydb.h>
10 #include <sepol/policydb/hashtab.h>
11 #include <sepol/policydb/expand.h>
12 #include "user_internal.h"
13 #include "mls.h"
14 
user_to_record(sepol_handle_t * handle,const policydb_t * policydb,int user_idx,sepol_user_t ** record)15 static int user_to_record(sepol_handle_t * handle,
16 			  const policydb_t * policydb,
17 			  int user_idx, sepol_user_t ** record)
18 {
19 
20 	const char *name = policydb->p_user_val_to_name[user_idx];
21 	user_datum_t *usrdatum = policydb->user_val_to_struct[user_idx];
22 	ebitmap_t *roles = &(usrdatum->roles.roles);
23 	ebitmap_node_t *rnode;
24 	unsigned bit;
25 
26 	sepol_user_t *tmp_record = NULL;
27 
28 	if (sepol_user_create(handle, &tmp_record) < 0)
29 		goto err;
30 
31 	if (sepol_user_set_name(handle, tmp_record, name) < 0)
32 		goto err;
33 
34 	/* Extract roles */
35 	ebitmap_for_each_bit(roles, rnode, bit) {
36 		if (ebitmap_node_get_bit(rnode, bit)) {
37 			char *role = policydb->p_role_val_to_name[bit];
38 			if (sepol_user_add_role(handle, tmp_record, role) < 0)
39 				goto err;
40 		}
41 	}
42 
43 	/* Extract MLS info */
44 	if (policydb->mls) {
45 		context_struct_t context;
46 		char *str;
47 
48 		context_init(&context);
49 		if (mls_level_cpy(&context.range.level[0],
50 				  &usrdatum->exp_dfltlevel) < 0) {
51 			ERR(handle, "could not copy MLS level");
52 			context_destroy(&context);
53 			goto err;
54 		}
55 		if (mls_level_cpy(&context.range.level[1],
56 				  &usrdatum->exp_dfltlevel) < 0) {
57 			ERR(handle, "could not copy MLS level");
58 			context_destroy(&context);
59 			goto err;
60 		}
61 		if (mls_to_string(handle, policydb, &context, &str) < 0) {
62 			context_destroy(&context);
63 			goto err;
64 		}
65 		context_destroy(&context);
66 
67 		if (sepol_user_set_mlslevel(handle, tmp_record, str) < 0) {
68 			free(str);
69 			goto err;
70 		}
71 		free(str);
72 
73 		context_init(&context);
74 		if (mls_range_cpy(&context.range, &usrdatum->exp_range) < 0) {
75 			ERR(handle, "could not copy MLS range");
76 			context_destroy(&context);
77 			goto err;
78 		}
79 		if (mls_to_string(handle, policydb, &context, &str) < 0) {
80 			context_destroy(&context);
81 			goto err;
82 		}
83 		context_destroy(&context);
84 
85 		if (sepol_user_set_mlsrange(handle, tmp_record, str) < 0) {
86 			free(str);
87 			goto err;
88 		}
89 		free(str);
90 	}
91 
92 	*record = tmp_record;
93 	return STATUS_SUCCESS;
94 
95       err:
96 	/* FIXME: handle error */
97 	sepol_user_free(tmp_record);
98 	return STATUS_ERR;
99 }
100 
sepol_user_modify(sepol_handle_t * handle,sepol_policydb_t * p,const sepol_user_key_t * key,const sepol_user_t * user)101 int sepol_user_modify(sepol_handle_t * handle,
102 		      sepol_policydb_t * p,
103 		      const sepol_user_key_t * key, const sepol_user_t * user)
104 {
105 
106 	policydb_t *policydb = &p->p;
107 
108 	/* For user data */
109 	const char *cname, *cmls_level, *cmls_range;
110 	char *name = NULL;
111 
112 	const char **roles = NULL;
113 	unsigned int num_roles = 0;
114 
115 	/* Low-level representation */
116 	user_datum_t *usrdatum = NULL;
117 	role_datum_t *roldatum;
118 	unsigned int i;
119 
120 	context_struct_t context;
121 	unsigned bit;
122 	int new = 0;
123 
124 	ebitmap_node_t *rnode;
125 
126 	/* First, extract all the data */
127 	sepol_user_key_unpack(key, &cname);
128 
129 	cmls_level = sepol_user_get_mlslevel(user);
130 	cmls_range = sepol_user_get_mlsrange(user);
131 
132 	/* Make sure that worked properly */
133 	if (sepol_user_get_roles(handle, user, &roles, &num_roles) < 0)
134 		goto err;
135 
136 	/* Now, see if a user exists */
137 	usrdatum = hashtab_search(policydb->p_users.table,
138 				  (const hashtab_key_t)cname);
139 
140 	/* If it does, we will modify it */
141 	if (usrdatum) {
142 
143 		int value_cp = usrdatum->s.value;
144 		user_datum_destroy(usrdatum);
145 		user_datum_init(usrdatum);
146 		usrdatum->s.value = value_cp;
147 
148 		/* Otherwise, create a new one */
149 	} else {
150 		usrdatum = (user_datum_t *) malloc(sizeof(user_datum_t));
151 		if (!usrdatum)
152 			goto omem;
153 		user_datum_init(usrdatum);
154 		new = 1;
155 	}
156 
157 	/* For every role */
158 	for (i = 0; i < num_roles; i++) {
159 
160 		/* Search for the role */
161 		roldatum = hashtab_search(policydb->p_roles.table,
162 					  (const hashtab_key_t)roles[i]);
163 		if (!roldatum) {
164 			ERR(handle, "undefined role %s for user %s",
165 			    roles[i], cname);
166 			goto err;
167 		}
168 
169 		/* Set the role and every role it dominates */
170 		ebitmap_for_each_bit(&roldatum->dominates, rnode, bit) {
171 			if (ebitmap_node_get_bit(rnode, bit)) {
172 				if (ebitmap_set_bit
173 				    (&(usrdatum->roles.roles), bit, 1))
174 					goto omem;
175 			}
176 		}
177 	}
178 
179 	/* For MLS systems */
180 	if (policydb->mls) {
181 
182 		/* MLS level */
183 		if (cmls_level == NULL) {
184 			ERR(handle, "MLS is enabled, but no MLS "
185 			    "default level was defined for user %s", cname);
186 			goto err;
187 		}
188 
189 		context_init(&context);
190 		if (mls_from_string(handle, policydb, cmls_level, &context) < 0) {
191 			context_destroy(&context);
192 			goto err;
193 		}
194 		if (mls_level_cpy(&usrdatum->exp_dfltlevel,
195 				  &context.range.level[0]) < 0) {
196 			ERR(handle, "could not copy MLS level %s", cmls_level);
197 			context_destroy(&context);
198 			goto err;
199 		}
200 		context_destroy(&context);
201 
202 		/* MLS range */
203 		if (cmls_range == NULL) {
204 			ERR(handle, "MLS is enabled, but no MLS"
205 			    "range was defined for user %s", cname);
206 			goto err;
207 		}
208 
209 		context_init(&context);
210 		if (mls_from_string(handle, policydb, cmls_range, &context) < 0) {
211 			context_destroy(&context);
212 			goto err;
213 		}
214 		if (mls_range_cpy(&usrdatum->exp_range, &context.range) < 0) {
215 			ERR(handle, "could not copy MLS range %s", cmls_range);
216 			context_destroy(&context);
217 			goto err;
218 		}
219 		context_destroy(&context);
220 	} else if (cmls_level != NULL || cmls_range != NULL) {
221 		ERR(handle, "MLS is disabled, but MLS level/range "
222 		    "was found for user %s", cname);
223 		goto err;
224 	}
225 
226 	/* If there are no errors, and this is a new user, add the user to policy */
227 	if (new) {
228 		void *tmp_ptr;
229 
230 		/* Ensure reverse lookup array has enough space */
231 		tmp_ptr = realloc(policydb->user_val_to_struct,
232 				  (policydb->p_users.nprim +
233 				   1) * sizeof(user_datum_t *));
234 		if (!tmp_ptr)
235 			goto omem;
236 		policydb->user_val_to_struct = tmp_ptr;
237 
238 		tmp_ptr = realloc(policydb->sym_val_to_name[SYM_USERS],
239 				  (policydb->p_users.nprim +
240 				   1) * sizeof(char *));
241 		if (!tmp_ptr)
242 			goto omem;
243 		policydb->sym_val_to_name[SYM_USERS] = tmp_ptr;
244 
245 		/* Need to copy the user name */
246 		name = strdup(cname);
247 		if (!name)
248 			goto omem;
249 
250 		/* Store user */
251 		usrdatum->s.value = ++policydb->p_users.nprim;
252 		if (hashtab_insert(policydb->p_users.table, name,
253 				   (hashtab_datum_t) usrdatum) < 0)
254 			goto omem;
255 
256 		/* Set up reverse entry */
257 		policydb->p_user_val_to_name[usrdatum->s.value - 1] = name;
258 		policydb->user_val_to_struct[usrdatum->s.value - 1] = usrdatum;
259 		name = NULL;
260 
261 		/* Expand roles */
262 		if (role_set_expand(&usrdatum->roles, &usrdatum->cache,
263 				    policydb, NULL, NULL)) {
264 			ERR(handle, "unable to expand role set");
265 			goto err;
266 		}
267 	}
268 
269 	free(roles);
270 	return STATUS_SUCCESS;
271 
272       omem:
273 	ERR(handle, "out of memory");
274 
275       err:
276 	ERR(handle, "could not load %s into policy", name);
277 
278 	free(name);
279 	free(roles);
280 	if (new && usrdatum) {
281 		role_set_destroy(&usrdatum->roles);
282 		free(usrdatum);
283 	}
284 	return STATUS_ERR;
285 }
286 
sepol_user_exists(sepol_handle_t * handle,const sepol_policydb_t * p,const sepol_user_key_t * key,int * response)287 int sepol_user_exists(sepol_handle_t * handle __attribute__ ((unused)),
288 		      const sepol_policydb_t * p,
289 		      const sepol_user_key_t * key, int *response)
290 {
291 
292 	const policydb_t *policydb = &p->p;
293 
294 	const char *cname;
295 	sepol_user_key_unpack(key, &cname);
296 
297 	*response = (hashtab_search(policydb->p_users.table,
298 				    (const hashtab_key_t)cname) != NULL);
299 
300 	handle = NULL;
301 	return STATUS_SUCCESS;
302 }
303 
sepol_user_count(sepol_handle_t * handle,const sepol_policydb_t * p,unsigned int * response)304 int sepol_user_count(sepol_handle_t * handle __attribute__ ((unused)),
305 		     const sepol_policydb_t * p, unsigned int *response)
306 {
307 
308 	const policydb_t *policydb = &p->p;
309 	*response = policydb->p_users.nprim;
310 
311 	handle = NULL;
312 	return STATUS_SUCCESS;
313 }
314 
sepol_user_query(sepol_handle_t * handle,const sepol_policydb_t * p,const sepol_user_key_t * key,sepol_user_t ** response)315 int sepol_user_query(sepol_handle_t * handle,
316 		     const sepol_policydb_t * p,
317 		     const sepol_user_key_t * key, sepol_user_t ** response)
318 {
319 
320 	const policydb_t *policydb = &p->p;
321 	user_datum_t *usrdatum = NULL;
322 
323 	const char *cname;
324 	sepol_user_key_unpack(key, &cname);
325 
326 	usrdatum = hashtab_search(policydb->p_users.table,
327 				  (const hashtab_key_t)cname);
328 
329 	if (!usrdatum) {
330 		*response = NULL;
331 		return STATUS_SUCCESS;
332 	}
333 
334 	if (user_to_record(handle, policydb, usrdatum->s.value - 1, response) <
335 	    0)
336 		goto err;
337 
338 	return STATUS_SUCCESS;
339 
340       err:
341 	ERR(handle, "could not query user %s", cname);
342 	return STATUS_ERR;
343 }
344 
sepol_user_iterate(sepol_handle_t * handle,const sepol_policydb_t * p,int (* fn)(const sepol_user_t * user,void * fn_arg),void * arg)345 int sepol_user_iterate(sepol_handle_t * handle,
346 		       const sepol_policydb_t * p,
347 		       int (*fn) (const sepol_user_t * user,
348 				  void *fn_arg), void *arg)
349 {
350 
351 	const policydb_t *policydb = &p->p;
352 	unsigned int nusers = policydb->p_users.nprim;
353 	sepol_user_t *user = NULL;
354 	unsigned int i;
355 
356 	/* For each user */
357 	for (i = 0; i < nusers; i++) {
358 
359 		int status;
360 
361 		if (user_to_record(handle, policydb, i, &user) < 0)
362 			goto err;
363 
364 		/* Invoke handler */
365 		status = fn(user, arg);
366 		if (status < 0)
367 			goto err;
368 
369 		sepol_user_free(user);
370 		user = NULL;
371 
372 		/* Handler requested exit */
373 		if (status > 0)
374 			break;
375 	}
376 
377 	return STATUS_SUCCESS;
378 
379       err:
380 	ERR(handle, "could not iterate over users");
381 	sepol_user_free(user);
382 	return STATUS_ERR;
383 }
384