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8f2c3a70 SH |
1 | /* |
2 | * lxc: linux Container library | |
3 | * | |
4 | * (C) Copyright Canonical, Inc. 2012 | |
5 | * | |
6 | * Authors: | |
7 | * Serge Hallyn <serge.hallyn@canonical.com> | |
8 | * | |
9 | * This library is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU Lesser General Public | |
11 | * License as published by the Free Software Foundation; either | |
12 | * version 2.1 of the License, or (at your option) any later version. | |
13 | * | |
14 | * This library is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * Lesser General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU Lesser General Public | |
20 | * License along with this library; if not, write to the Free Software | |
250b1eec | 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
8f2c3a70 SH |
22 | */ |
23 | ||
24 | #define _GNU_SOURCE | |
567b2049 | 25 | #include <errno.h> |
8f2c3a70 SH |
26 | #include <stdio.h> |
27 | #include <stdlib.h> | |
28 | #include <seccomp.h> | |
6166fa6d | 29 | #include <sys/mount.h> |
567b2049 | 30 | #include <sys/utsname.h> |
f2363e38 | 31 | |
769872f9 | 32 | #include "config.h" |
8f2c3a70 | 33 | #include "log.h" |
567b2049 | 34 | #include "lxcseccomp.h" |
8f2c3a70 SH |
35 | |
36 | lxc_log_define(lxc_seccomp, lxc); | |
37 | ||
50798138 SH |
38 | static int parse_config_v1(FILE *f, struct lxc_conf *conf) |
39 | { | |
40 | char line[1024]; | |
41 | int ret; | |
42 | ||
43 | while (fgets(line, 1024, f)) { | |
44 | int nr; | |
45 | ret = sscanf(line, "%d", &nr); | |
46 | if (ret != 1) | |
47 | return -1; | |
48 | ret = seccomp_rule_add( | |
49 | #if HAVE_SCMP_FILTER_CTX | |
f06c6207 | 50 | conf->seccomp_ctx, |
50798138 | 51 | #endif |
f06c6207 | 52 | SCMP_ACT_ALLOW, nr, 0); |
50798138 | 53 | if (ret < 0) { |
3ee26d19 | 54 | ERROR("Failed loading allow rule for %d", nr); |
50798138 SH |
55 | return ret; |
56 | } | |
57 | } | |
58 | return 0; | |
59 | } | |
60 | ||
2b0ae718 | 61 | #if HAVE_DECL_SECCOMP_SYSCALL_RESOLVE_NAME_ARCH |
50798138 SH |
62 | static void remove_trailing_newlines(char *l) |
63 | { | |
64 | char *p = l; | |
65 | ||
66 | while (*p) | |
67 | p++; | |
68 | while (--p >= l && *p == '\n') | |
69 | *p = '\0'; | |
70 | } | |
71 | ||
72 | static uint32_t get_v2_default_action(char *line) | |
73 | { | |
74 | uint32_t ret_action = -1; | |
75 | ||
f06c6207 CB |
76 | while (*line == ' ') |
77 | line++; | |
1a0e70ac | 78 | /* After 'whitelist' or 'blacklist' comes default behavior. */ |
50798138 SH |
79 | if (strncmp(line, "kill", 4) == 0) |
80 | ret_action = SCMP_ACT_KILL; | |
81 | else if (strncmp(line, "errno", 5) == 0) { | |
82 | int e; | |
f06c6207 | 83 | if (sscanf(line + 5, "%d", &e) != 1) { |
3ee26d19 | 84 | ERROR("Bad errno value in %s", line); |
50798138 SH |
85 | return -2; |
86 | } | |
87 | ret_action = SCMP_ACT_ERRNO(e); | |
88 | } else if (strncmp(line, "allow", 5) == 0) | |
89 | ret_action = SCMP_ACT_ALLOW; | |
90 | else if (strncmp(line, "trap", 4) == 0) | |
91 | ret_action = SCMP_ACT_TRAP; | |
92 | return ret_action; | |
93 | } | |
94 | ||
4836330b | 95 | static const char *get_action_name(uint32_t action) |
96 | { | |
1a0e70ac | 97 | /* The upper 16 bits indicate the type of the seccomp action. */ |
4836330b | 98 | switch(action & 0xffff0000){ |
99 | case SCMP_ACT_KILL: | |
100 | return "kill"; | |
101 | case SCMP_ACT_ALLOW: | |
102 | return "allow"; | |
103 | case SCMP_ACT_TRAP: | |
104 | return "trap"; | |
105 | case SCMP_ACT_ERRNO(0): | |
106 | return "errno"; | |
107 | default: | |
108 | return "invalid action"; | |
109 | } | |
110 | } | |
111 | ||
3ee26d19 | 112 | static uint32_t get_v2_action(char *line, uint32_t def_action) |
50798138 SH |
113 | { |
114 | char *p = strchr(line, ' '); | |
115 | uint32_t ret; | |
116 | ||
117 | if (!p) | |
118 | return def_action; | |
50798138 SH |
119 | p++; |
120 | while (*p == ' ') | |
121 | p++; | |
122 | if (!*p || *p == '#') | |
123 | return def_action; | |
124 | ret = get_v2_default_action(p); | |
125 | switch(ret) { | |
126 | case -2: return -1; | |
127 | case -1: return def_action; | |
128 | default: return ret; | |
129 | } | |
130 | } | |
3ee26d19 L |
131 | |
132 | struct v2_rule_args { | |
133 | uint32_t index; | |
134 | uint64_t value; | |
135 | uint64_t mask; | |
136 | enum scmp_compare op; | |
137 | }; | |
138 | ||
139 | struct seccomp_v2_rule { | |
140 | uint32_t action; | |
141 | uint32_t args_num; | |
142 | struct v2_rule_args args_value[6]; | |
143 | }; | |
144 | ||
145 | static enum scmp_compare parse_v2_rule_op(char *s) | |
146 | { | |
3ee26d19 | 147 | if (strcmp(s, "SCMP_CMP_NE") == 0 || strcmp(s, "!=") == 0) |
29cb2617 | 148 | return SCMP_CMP_NE; |
3ee26d19 | 149 | else if (strcmp(s, "SCMP_CMP_LT") == 0 || strcmp(s, "<") == 0) |
29cb2617 | 150 | return SCMP_CMP_LT; |
3ee26d19 | 151 | else if (strcmp(s, "SCMP_CMP_LE") == 0 || strcmp(s, "<=") == 0) |
29cb2617 | 152 | return SCMP_CMP_LE; |
3ee26d19 | 153 | else if (strcmp(s, "SCMP_CMP_EQ") == 0 || strcmp(s, "==") == 0) |
29cb2617 | 154 | return SCMP_CMP_EQ; |
3ee26d19 | 155 | else if (strcmp(s, "SCMP_CMP_GE") == 0 || strcmp(s, ">=") == 0) |
29cb2617 | 156 | return SCMP_CMP_GE; |
3ee26d19 | 157 | else if (strcmp(s, "SCMP_CMP_GT") == 0 || strcmp(s, ">") == 0) |
29cb2617 | 158 | return SCMP_CMP_GT; |
3ee26d19 | 159 | else if (strcmp(s, "SCMP_CMP_MASKED_EQ") == 0 || strcmp(s, "&=") == 0) |
29cb2617 | 160 | return SCMP_CMP_MASKED_EQ; |
3ee26d19 | 161 | |
29cb2617 | 162 | return _SCMP_CMP_MAX; |
3ee26d19 L |
163 | } |
164 | ||
165 | /* This function is used to parse the args string into the structure. | |
166 | * args string format:[index,value,op,valueTwo] or [index,value,op] | |
167 | * For one arguments, [index,value,valueTwo,op] | |
168 | * index: the index for syscall arguments (type uint) | |
169 | * value: the value for syscall arguments (type uint64) | |
170 | * op: the operator for syscall arguments(string), | |
171 | a valid list of constants as of libseccomp v2.3.2 is | |
172 | SCMP_CMP_NE,SCMP_CMP_LE,SCMP_CMP_LE, SCMP_CMP_EQ, SCMP_CMP_GE, | |
173 | SCMP_CMP_GT, SCMP_CMP_MASKED_EQ, or !=,<=,==,>=,>,&= | |
174 | * valueTwo: the value for syscall arguments only used for mask eq (type uint64, optional) | |
175 | * Returns 0 on success, < 0 otherwise. | |
176 | */ | |
177 | static int get_seccomp_arg_value(char *key, struct v2_rule_args *rule_args) | |
178 | { | |
179 | int ret = 0; | |
180 | uint64_t value = 0; | |
181 | uint64_t mask = 0; | |
182 | enum scmp_compare op = 0; | |
183 | uint32_t index = 0; | |
184 | char s[30] = {0}; | |
185 | char *tmp = NULL; | |
186 | ||
187 | memset(s, 0, sizeof(s)); | |
188 | tmp = strchr(key, '['); | |
189 | if (!tmp) { | |
190 | ERROR("Failed to interpret args"); | |
191 | return -1; | |
192 | } | |
193 | ret = sscanf(tmp, "[%i,%lli,%30[^0-9^,],%lli", &index, (long long unsigned int *)&value, s, (long long unsigned int *)&mask); | |
194 | if ((ret != 3 && ret != 4) || index >= 6) { | |
195 | ERROR("Failed to interpret args value"); | |
196 | return -1; | |
197 | } | |
198 | ||
199 | op = parse_v2_rule_op(s); | |
200 | if (op == _SCMP_CMP_MAX) { | |
201 | ERROR("Failed to interpret args operator value"); | |
202 | return -1; | |
203 | } | |
204 | ||
205 | rule_args->index = index; | |
206 | rule_args->value = value; | |
207 | rule_args->mask = mask; | |
208 | rule_args->op = op; | |
209 | return 0; | |
210 | } | |
211 | ||
212 | /* This function is used to parse the seccomp rule entry. | |
213 | * @line : seccomp rule entry string. | |
214 | * @def_action : default action used in the case if the 'line' contain non valid action. | |
215 | * @rules : output struct. | |
216 | * Returns 0 on success, < 0 otherwise. | |
217 | */ | |
218 | static int parse_v2_rules(char *line, uint32_t def_action, struct seccomp_v2_rule *rules) | |
219 | { | |
220 | int ret = 0 ; | |
221 | int i = 0; | |
222 | char *tmp = NULL; | |
223 | char *key = NULL; | |
224 | char *saveptr = NULL; | |
225 | ||
226 | tmp = strdup(line); | |
227 | if (!tmp) | |
228 | return -1; | |
229 | ||
230 | /* read optional action which follows the syscall */ | |
231 | rules->action = get_v2_action(tmp, def_action); | |
232 | if (rules->action == -1) { | |
233 | ERROR("Failed to interpret action"); | |
234 | ret = -1; | |
235 | goto out; | |
236 | } | |
237 | ||
238 | rules->args_num = 0; | |
239 | if (!strchr(tmp, '[')) { | |
240 | ret = 0; | |
241 | goto out; | |
242 | } | |
243 | ||
244 | for ((key = strtok_r(tmp, "]", &saveptr)), i = 0; key && i < 6; (key = strtok_r(NULL, "]", &saveptr)), i++) { | |
245 | ret = get_seccomp_arg_value(key, &rules->args_value[i]); | |
246 | if (ret < 0) { | |
247 | ret = -1; | |
248 | goto out; | |
249 | } | |
250 | rules->args_num++; | |
251 | } | |
252 | ||
253 | ret = 0; | |
254 | out: | |
255 | free(tmp); | |
256 | return ret; | |
257 | } | |
258 | ||
2b0ae718 | 259 | #endif |
50798138 | 260 | |
d58c6ad0 SH |
261 | #if HAVE_DECL_SECCOMP_SYSCALL_RESOLVE_NAME_ARCH |
262 | enum lxc_hostarch_t { | |
263 | lxc_seccomp_arch_all = 0, | |
264 | lxc_seccomp_arch_native, | |
265 | lxc_seccomp_arch_i386, | |
11de80d6 | 266 | lxc_seccomp_arch_x32, |
d58c6ad0 SH |
267 | lxc_seccomp_arch_amd64, |
268 | lxc_seccomp_arch_arm, | |
9d291dd2 | 269 | lxc_seccomp_arch_arm64, |
b4067426 BP |
270 | lxc_seccomp_arch_ppc64, |
271 | lxc_seccomp_arch_ppc64le, | |
272 | lxc_seccomp_arch_ppc, | |
2ccd9eda JC |
273 | lxc_seccomp_arch_mips, |
274 | lxc_seccomp_arch_mips64, | |
275 | lxc_seccomp_arch_mips64n32, | |
276 | lxc_seccomp_arch_mipsel, | |
277 | lxc_seccomp_arch_mipsel64, | |
278 | lxc_seccomp_arch_mipsel64n32, | |
be038e49 | 279 | lxc_seccomp_arch_s390x, |
d58c6ad0 SH |
280 | lxc_seccomp_arch_unknown = 999, |
281 | }; | |
282 | ||
2ccd9eda JC |
283 | #ifdef __MIPSEL__ |
284 | # define MIPS_ARCH_O32 lxc_seccomp_arch_mipsel | |
285 | # define MIPS_ARCH_N64 lxc_seccomp_arch_mipsel64 | |
286 | #else | |
287 | # define MIPS_ARCH_O32 lxc_seccomp_arch_mips | |
288 | # define MIPS_ARCH_N64 lxc_seccomp_arch_mips64 | |
289 | #endif | |
290 | ||
d58c6ad0 SH |
291 | int get_hostarch(void) |
292 | { | |
293 | struct utsname uts; | |
294 | if (uname(&uts) < 0) { | |
3ee26d19 | 295 | SYSERROR("Failed to read host arch"); |
d58c6ad0 SH |
296 | return -1; |
297 | } | |
298 | if (strcmp(uts.machine, "i686") == 0) | |
299 | return lxc_seccomp_arch_i386; | |
1a0e70ac | 300 | /* no x32 kernels */ |
d58c6ad0 SH |
301 | else if (strcmp(uts.machine, "x86_64") == 0) |
302 | return lxc_seccomp_arch_amd64; | |
303 | else if (strncmp(uts.machine, "armv7", 5) == 0) | |
304 | return lxc_seccomp_arch_arm; | |
9d291dd2 BP |
305 | else if (strncmp(uts.machine, "aarch64", 7) == 0) |
306 | return lxc_seccomp_arch_arm64; | |
b4067426 BP |
307 | else if (strncmp(uts.machine, "ppc64le", 7) == 0) |
308 | return lxc_seccomp_arch_ppc64le; | |
309 | else if (strncmp(uts.machine, "ppc64", 5) == 0) | |
310 | return lxc_seccomp_arch_ppc64; | |
311 | else if (strncmp(uts.machine, "ppc", 3) == 0) | |
312 | return lxc_seccomp_arch_ppc; | |
2ccd9eda JC |
313 | else if (strncmp(uts.machine, "mips64", 6) == 0) |
314 | return MIPS_ARCH_N64; | |
315 | else if (strncmp(uts.machine, "mips", 4) == 0) | |
316 | return MIPS_ARCH_O32; | |
be038e49 CB |
317 | else if (strncmp(uts.machine, "s390x", 5) == 0) |
318 | return lxc_seccomp_arch_s390x; | |
d58c6ad0 SH |
319 | return lxc_seccomp_arch_unknown; |
320 | } | |
321 | ||
322 | scmp_filter_ctx get_new_ctx(enum lxc_hostarch_t n_arch, uint32_t default_policy_action) | |
323 | { | |
324 | scmp_filter_ctx ctx; | |
325 | int ret; | |
326 | uint32_t arch; | |
327 | ||
328 | switch(n_arch) { | |
329 | case lxc_seccomp_arch_i386: arch = SCMP_ARCH_X86; break; | |
11de80d6 | 330 | case lxc_seccomp_arch_x32: arch = SCMP_ARCH_X32; break; |
d58c6ad0 SH |
331 | case lxc_seccomp_arch_amd64: arch = SCMP_ARCH_X86_64; break; |
332 | case lxc_seccomp_arch_arm: arch = SCMP_ARCH_ARM; break; | |
9d291dd2 BP |
333 | #ifdef SCMP_ARCH_AARCH64 |
334 | case lxc_seccomp_arch_arm64: arch = SCMP_ARCH_AARCH64; break; | |
335 | #endif | |
b4067426 BP |
336 | #ifdef SCMP_ARCH_PPC64LE |
337 | case lxc_seccomp_arch_ppc64le: arch = SCMP_ARCH_PPC64LE; break; | |
338 | #endif | |
339 | #ifdef SCMP_ARCH_PPC64 | |
340 | case lxc_seccomp_arch_ppc64: arch = SCMP_ARCH_PPC64; break; | |
341 | #endif | |
342 | #ifdef SCMP_ARCH_PPC | |
343 | case lxc_seccomp_arch_ppc: arch = SCMP_ARCH_PPC; break; | |
2ccd9eda JC |
344 | #endif |
345 | #ifdef SCMP_ARCH_MIPS | |
346 | case lxc_seccomp_arch_mips: arch = SCMP_ARCH_MIPS; break; | |
347 | case lxc_seccomp_arch_mips64: arch = SCMP_ARCH_MIPS64; break; | |
348 | case lxc_seccomp_arch_mips64n32: arch = SCMP_ARCH_MIPS64N32; break; | |
349 | case lxc_seccomp_arch_mipsel: arch = SCMP_ARCH_MIPSEL; break; | |
350 | case lxc_seccomp_arch_mipsel64: arch = SCMP_ARCH_MIPSEL64; break; | |
351 | case lxc_seccomp_arch_mipsel64n32: arch = SCMP_ARCH_MIPSEL64N32; break; | |
be038e49 CB |
352 | #endif |
353 | #ifdef SCMP_ARCH_S390X | |
354 | case lxc_seccomp_arch_s390x: arch = SCMP_ARCH_S390X; break; | |
b4067426 | 355 | #endif |
d58c6ad0 SH |
356 | default: return NULL; |
357 | } | |
358 | ||
359 | if ((ctx = seccomp_init(default_policy_action)) == NULL) { | |
3ee26d19 | 360 | ERROR("Error initializing seccomp context"); |
d58c6ad0 SH |
361 | return NULL; |
362 | } | |
363 | if (seccomp_attr_set(ctx, SCMP_FLTATR_CTL_NNP, 0)) { | |
3ee26d19 | 364 | ERROR("Failed to turn off no-new-privs"); |
d58c6ad0 SH |
365 | seccomp_release(ctx); |
366 | return NULL; | |
367 | } | |
127c5293 SH |
368 | #ifdef SCMP_FLTATR_ATL_TSKIP |
369 | if (seccomp_attr_set(ctx, SCMP_FLTATR_ATL_TSKIP, 1)) { | |
370 | WARN("Failed to turn on seccomp nop-skip, continuing"); | |
371 | } | |
372 | #endif | |
b5ed021b | 373 | |
adfee3a8 CB |
374 | ret = seccomp_arch_exist(ctx, arch); |
375 | if (ret < 0) { | |
376 | if (ret != -EEXIST) { | |
377 | ERROR("%s - Failed to determine whether arch %d is " | |
378 | "already present in the main seccomp context", | |
379 | strerror(-ret), (int)n_arch); | |
380 | seccomp_release(ctx); | |
381 | return NULL; | |
382 | } | |
383 | ||
b5ed021b CB |
384 | ret = seccomp_arch_add(ctx, arch); |
385 | if (ret != 0) { | |
adfee3a8 CB |
386 | ERROR("%s - Failed to add arch %d to main seccomp context", |
387 | strerror(-ret), (int)n_arch); | |
b5ed021b CB |
388 | seccomp_release(ctx); |
389 | return NULL; | |
390 | } | |
adfee3a8 | 391 | TRACE("Added arch %d to main seccomp context", (int)n_arch); |
b5ed021b | 392 | |
adfee3a8 CB |
393 | ret = seccomp_arch_remove(ctx, SCMP_ARCH_NATIVE); |
394 | if (ret != 0) { | |
395 | ERROR("Failed to remove native arch from main seccomp context"); | |
b5ed021b CB |
396 | seccomp_release(ctx); |
397 | return NULL; | |
398 | } | |
adfee3a8 CB |
399 | TRACE("Removed native arch from main seccomp context"); |
400 | } else { | |
401 | TRACE("Arch %d already present in main seccomp context", (int)n_arch); | |
d58c6ad0 SH |
402 | } |
403 | ||
404 | return ctx; | |
405 | } | |
406 | ||
407 | bool do_resolve_add_rule(uint32_t arch, char *line, scmp_filter_ctx ctx, | |
3ee26d19 | 408 | struct seccomp_v2_rule *rule) |
d58c6ad0 | 409 | { |
3ee26d19 L |
410 | int nr, ret, i; |
411 | struct scmp_arg_cmp arg_cmp[6]; | |
412 | ||
413 | memset(arg_cmp, 0 ,sizeof(arg_cmp)); | |
d58c6ad0 | 414 | |
f06c6207 CB |
415 | ret = seccomp_arch_exist(ctx, arch); |
416 | if (arch && ret != 0) { | |
417 | ERROR("BUG: Seccomp: rule and context arch do not match (arch " | |
3ee26d19 | 418 | "%d): %s", |
f06c6207 | 419 | arch, strerror(-ret)); |
d58c6ad0 SH |
420 | return false; |
421 | } | |
6166fa6d | 422 | |
3ee26d19 L |
423 | /*get the syscall name*/ |
424 | char *p = strchr(line, ' '); | |
425 | if (p) | |
426 | *p = '\0'; | |
427 | ||
6166fa6d | 428 | if (strncmp(line, "reject_force_umount", 19) == 0) { |
3ee26d19 | 429 | INFO("Setting Seccomp rule to reject force umounts"); |
6166fa6d SH |
430 | ret = seccomp_rule_add_exact(ctx, SCMP_ACT_ERRNO(EACCES), SCMP_SYS(umount2), |
431 | 1, SCMP_A1(SCMP_CMP_MASKED_EQ , MNT_FORCE , MNT_FORCE )); | |
432 | if (ret < 0) { | |
f06c6207 | 433 | ERROR("Failed (%d) loading rule to reject force " |
3ee26d19 | 434 | "umount: %s", |
f06c6207 | 435 | ret, strerror(-ret)); |
6166fa6d SH |
436 | return false; |
437 | } | |
438 | return true; | |
439 | } | |
440 | ||
cd75548b | 441 | nr = seccomp_syscall_resolve_name(line); |
d58c6ad0 | 442 | if (nr == __NR_SCMP_ERROR) { |
3ee26d19 L |
443 | WARN("Seccomp: failed to resolve syscall: %s", line); |
444 | WARN("This syscall will NOT be blacklisted"); | |
d58c6ad0 SH |
445 | return true; |
446 | } | |
447 | if (nr < 0) { | |
3ee26d19 L |
448 | WARN("Seccomp: got negative for syscall: %d: %s", nr, line); |
449 | WARN("This syscall will NOT be blacklisted"); | |
d58c6ad0 SH |
450 | return true; |
451 | } | |
3ee26d19 L |
452 | |
453 | for (i = 0; i < rule->args_num; i++) { | |
454 | INFO("arg_cmp[%d]:SCMP_CMP(%u, %llu, %llu, %llu)", i, | |
455 | rule->args_value[i].index, | |
456 | (long long unsigned int)rule->args_value[i].op, | |
457 | (long long unsigned int)rule->args_value[i].mask, | |
458 | (long long unsigned int)rule->args_value[i].value); | |
459 | ||
460 | if (SCMP_CMP_MASKED_EQ == rule->args_value[i].op) | |
461 | arg_cmp[i] = SCMP_CMP(rule->args_value[i].index, rule->args_value[i].op, rule->args_value[i].mask, rule->args_value[i].value); | |
462 | else | |
463 | arg_cmp[i] = SCMP_CMP(rule->args_value[i].index, rule->args_value[i].op, rule->args_value[i].value); | |
464 | } | |
465 | ||
466 | ret = seccomp_rule_add_exact_array(ctx, rule->action, nr, rule->args_num, arg_cmp); | |
d58c6ad0 | 467 | if (ret < 0) { |
3ee26d19 L |
468 | ERROR("Failed (%d) loading rule for %s (nr %d action %d(%s)): %s", |
469 | ret, line, nr, rule->action, get_action_name(rule->action), strerror(-ret)); | |
d58c6ad0 SH |
470 | return false; |
471 | } | |
472 | return true; | |
473 | } | |
474 | ||
50798138 SH |
475 | /* |
476 | * v2 consists of | |
477 | * [x86] | |
478 | * open | |
479 | * read | |
480 | * write | |
481 | * close | |
482 | * # a comment | |
483 | * [x86_64] | |
484 | * open | |
485 | * read | |
486 | * write | |
487 | * close | |
488 | */ | |
489 | static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf) | |
490 | { | |
50798138 SH |
491 | char *p; |
492 | int ret; | |
f06c6207 | 493 | scmp_filter_ctx compat_ctx[2] = {NULL, NULL}; |
50798138 | 494 | bool blacklist = false; |
3ee26d19 | 495 | uint32_t default_policy_action = -1, default_rule_action = -1; |
d58c6ad0 SH |
496 | enum lxc_hostarch_t native_arch = get_hostarch(), |
497 | cur_rule_arch = native_arch; | |
f06c6207 | 498 | uint32_t compat_arch[2] = {SCMP_ARCH_NATIVE, SCMP_ARCH_NATIVE}; |
3ee26d19 | 499 | struct seccomp_v2_rule rule; |
50798138 SH |
500 | |
501 | if (strncmp(line, "blacklist", 9) == 0) | |
502 | blacklist = true; | |
503 | else if (strncmp(line, "whitelist", 9) != 0) { | |
3ee26d19 | 504 | ERROR("Bad seccomp policy style: %s", line); |
50798138 SH |
505 | return -1; |
506 | } | |
507 | ||
508 | if ((p = strchr(line, ' '))) { | |
f06c6207 | 509 | default_policy_action = get_v2_default_action(p + 1); |
50798138 SH |
510 | if (default_policy_action == -2) |
511 | return -1; | |
512 | } | |
513 | ||
514 | /* for blacklist, allow any syscall which has no rule */ | |
515 | if (blacklist) { | |
516 | if (default_policy_action == -1) | |
517 | default_policy_action = SCMP_ACT_ALLOW; | |
518 | if (default_rule_action == -1) | |
519 | default_rule_action = SCMP_ACT_KILL; | |
520 | } else { | |
521 | if (default_policy_action == -1) | |
522 | default_policy_action = SCMP_ACT_KILL; | |
523 | if (default_rule_action == -1) | |
524 | default_rule_action = SCMP_ACT_ALLOW; | |
525 | } | |
526 | ||
d58c6ad0 SH |
527 | if (native_arch == lxc_seccomp_arch_amd64) { |
528 | cur_rule_arch = lxc_seccomp_arch_all; | |
2ccd9eda JC |
529 | compat_arch[0] = SCMP_ARCH_X86; |
530 | compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_i386, | |
ab5e52f6 | 531 | default_policy_action); |
11de80d6 AB |
532 | compat_arch[1] = SCMP_ARCH_X32; |
533 | compat_ctx[1] = get_new_ctx(lxc_seccomp_arch_x32, | |
534 | default_policy_action); | |
535 | if (!compat_ctx[0] || !compat_ctx[1]) | |
ab5e52f6 | 536 | goto bad; |
ca399594 | 537 | #ifdef SCMP_ARCH_PPC |
7635139a SH |
538 | } else if (native_arch == lxc_seccomp_arch_ppc64) { |
539 | cur_rule_arch = lxc_seccomp_arch_all; | |
2ccd9eda JC |
540 | compat_arch[0] = SCMP_ARCH_PPC; |
541 | compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_ppc, | |
7635139a | 542 | default_policy_action); |
2ccd9eda | 543 | if (!compat_ctx[0]) |
7635139a | 544 | goto bad; |
ca399594 CB |
545 | #endif |
546 | #ifdef SCMP_ARCH_ARM | |
7635139a SH |
547 | } else if (native_arch == lxc_seccomp_arch_arm64) { |
548 | cur_rule_arch = lxc_seccomp_arch_all; | |
2ccd9eda JC |
549 | compat_arch[0] = SCMP_ARCH_ARM; |
550 | compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_arm, | |
7635139a | 551 | default_policy_action); |
2ccd9eda JC |
552 | if (!compat_ctx[0]) |
553 | goto bad; | |
554 | #endif | |
555 | #ifdef SCMP_ARCH_MIPS | |
556 | } else if (native_arch == lxc_seccomp_arch_mips64) { | |
557 | cur_rule_arch = lxc_seccomp_arch_all; | |
558 | compat_arch[0] = SCMP_ARCH_MIPS; | |
559 | compat_arch[1] = SCMP_ARCH_MIPS64N32; | |
560 | compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_mips, | |
561 | default_policy_action); | |
562 | compat_ctx[1] = get_new_ctx(lxc_seccomp_arch_mips64n32, | |
563 | default_policy_action); | |
564 | if (!compat_ctx[0] || !compat_ctx[1]) | |
565 | goto bad; | |
566 | } else if (native_arch == lxc_seccomp_arch_mipsel64) { | |
567 | cur_rule_arch = lxc_seccomp_arch_all; | |
568 | compat_arch[0] = SCMP_ARCH_MIPSEL; | |
569 | compat_arch[1] = SCMP_ARCH_MIPSEL64N32; | |
570 | compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_mipsel, | |
571 | default_policy_action); | |
572 | compat_ctx[1] = get_new_ctx(lxc_seccomp_arch_mipsel64n32, | |
573 | default_policy_action); | |
574 | if (!compat_ctx[0] || !compat_ctx[1]) | |
7635139a | 575 | goto bad; |
be038e49 | 576 | #endif |
d58c6ad0 SH |
577 | } |
578 | ||
50798138 SH |
579 | if (default_policy_action != SCMP_ACT_KILL) { |
580 | ret = seccomp_reset(conf->seccomp_ctx, default_policy_action); | |
581 | if (ret != 0) { | |
3ee26d19 | 582 | ERROR("Error re-initializing Seccomp"); |
50798138 SH |
583 | return -1; |
584 | } | |
585 | if (seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_CTL_NNP, 0)) { | |
3ee26d19 | 586 | ERROR("Failed to turn off no-new-privs"); |
50798138 SH |
587 | return -1; |
588 | } | |
127c5293 SH |
589 | #ifdef SCMP_FLTATR_ATL_TSKIP |
590 | if (seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_ATL_TSKIP, 1)) { | |
591 | WARN("Failed to turn on seccomp nop-skip, continuing"); | |
592 | } | |
593 | #endif | |
50798138 SH |
594 | } |
595 | ||
596 | while (fgets(line, 1024, f)) { | |
50798138 SH |
597 | |
598 | if (line[0] == '#') | |
599 | continue; | |
600 | if (strlen(line) == 0) | |
601 | continue; | |
602 | remove_trailing_newlines(line); | |
3ee26d19 | 603 | INFO("processing: .%s", line); |
50798138 | 604 | if (line[0] == '[') { |
1a0e70ac | 605 | /* Read the architecture for next set of rules. */ |
50798138 | 606 | if (strcmp(line, "[x86]") == 0 || |
f06c6207 | 607 | strcmp(line, "[X86]") == 0) { |
d58c6ad0 | 608 | if (native_arch != lxc_seccomp_arch_i386 && |
7635139a | 609 | native_arch != lxc_seccomp_arch_amd64) { |
d58c6ad0 SH |
610 | cur_rule_arch = lxc_seccomp_arch_unknown; |
611 | continue; | |
612 | } | |
613 | cur_rule_arch = lxc_seccomp_arch_i386; | |
11de80d6 AB |
614 | } else if (strcmp(line, "[x32]") == 0 || |
615 | strcmp(line, "[X32]") == 0) { | |
616 | if (native_arch != lxc_seccomp_arch_amd64) { | |
617 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
618 | continue; | |
619 | } | |
620 | cur_rule_arch = lxc_seccomp_arch_x32; | |
d58c6ad0 | 621 | } else if (strcmp(line, "[X86_64]") == 0 || |
f06c6207 | 622 | strcmp(line, "[x86_64]") == 0) { |
d58c6ad0 SH |
623 | if (native_arch != lxc_seccomp_arch_amd64) { |
624 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
625 | continue; | |
626 | } | |
627 | cur_rule_arch = lxc_seccomp_arch_amd64; | |
d58c6ad0 | 628 | } else if (strcmp(line, "[all]") == 0 || |
f06c6207 | 629 | strcmp(line, "[ALL]") == 0) { |
d58c6ad0 | 630 | cur_rule_arch = lxc_seccomp_arch_all; |
d58c6ad0 | 631 | } |
2b0ae718 | 632 | #ifdef SCMP_ARCH_ARM |
50798138 | 633 | else if (strcmp(line, "[arm]") == 0 || |
f06c6207 | 634 | strcmp(line, "[ARM]") == 0) { |
7635139a SH |
635 | if (native_arch != lxc_seccomp_arch_arm && |
636 | native_arch != lxc_seccomp_arch_arm64) { | |
d58c6ad0 SH |
637 | cur_rule_arch = lxc_seccomp_arch_unknown; |
638 | continue; | |
639 | } | |
640 | cur_rule_arch = lxc_seccomp_arch_arm; | |
d58c6ad0 | 641 | } |
b4067426 | 642 | #endif |
9d291dd2 BP |
643 | #ifdef SCMP_ARCH_AARCH64 |
644 | else if (strcmp(line, "[arm64]") == 0 || | |
f06c6207 | 645 | strcmp(line, "[ARM64]") == 0) { |
9d291dd2 BP |
646 | if (native_arch != lxc_seccomp_arch_arm64) { |
647 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
648 | continue; | |
649 | } | |
650 | cur_rule_arch = lxc_seccomp_arch_arm64; | |
651 | } | |
652 | #endif | |
b4067426 BP |
653 | #ifdef SCMP_ARCH_PPC64LE |
654 | else if (strcmp(line, "[ppc64le]") == 0 || | |
f06c6207 | 655 | strcmp(line, "[PPC64LE]") == 0) { |
b4067426 BP |
656 | if (native_arch != lxc_seccomp_arch_ppc64le) { |
657 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
658 | continue; | |
659 | } | |
660 | cur_rule_arch = lxc_seccomp_arch_ppc64le; | |
661 | } | |
662 | #endif | |
663 | #ifdef SCMP_ARCH_PPC64 | |
664 | else if (strcmp(line, "[ppc64]") == 0 || | |
f06c6207 | 665 | strcmp(line, "[PPC64]") == 0) { |
b4067426 BP |
666 | if (native_arch != lxc_seccomp_arch_ppc64) { |
667 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
668 | continue; | |
669 | } | |
670 | cur_rule_arch = lxc_seccomp_arch_ppc64; | |
671 | } | |
672 | #endif | |
673 | #ifdef SCMP_ARCH_PPC | |
674 | else if (strcmp(line, "[ppc]") == 0 || | |
f06c6207 | 675 | strcmp(line, "[PPC]") == 0) { |
7635139a SH |
676 | if (native_arch != lxc_seccomp_arch_ppc && |
677 | native_arch != lxc_seccomp_arch_ppc64) { | |
b4067426 BP |
678 | cur_rule_arch = lxc_seccomp_arch_unknown; |
679 | continue; | |
680 | } | |
681 | cur_rule_arch = lxc_seccomp_arch_ppc; | |
682 | } | |
2ccd9eda JC |
683 | #endif |
684 | #ifdef SCMP_ARCH_MIPS | |
685 | else if (strcmp(line, "[mips64]") == 0 || | |
f06c6207 | 686 | strcmp(line, "[MIPS64]") == 0) { |
2ccd9eda JC |
687 | if (native_arch != lxc_seccomp_arch_mips64) { |
688 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
689 | continue; | |
690 | } | |
691 | cur_rule_arch = lxc_seccomp_arch_mips64; | |
692 | } else if (strcmp(line, "[mips64n32]") == 0 || | |
f06c6207 | 693 | strcmp(line, "[MIPS64N32]") == 0) { |
2ccd9eda JC |
694 | if (native_arch != lxc_seccomp_arch_mips64) { |
695 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
696 | continue; | |
697 | } | |
698 | cur_rule_arch = lxc_seccomp_arch_mips64n32; | |
699 | } else if (strcmp(line, "[mips]") == 0 || | |
f06c6207 | 700 | strcmp(line, "[MIPS]") == 0) { |
2ccd9eda JC |
701 | if (native_arch != lxc_seccomp_arch_mips && |
702 | native_arch != lxc_seccomp_arch_mips64) { | |
703 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
704 | continue; | |
705 | } | |
706 | cur_rule_arch = lxc_seccomp_arch_mips; | |
707 | } else if (strcmp(line, "[mipsel64]") == 0 || | |
f06c6207 | 708 | strcmp(line, "[MIPSEL64]") == 0) { |
2ccd9eda JC |
709 | if (native_arch != lxc_seccomp_arch_mipsel64) { |
710 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
711 | continue; | |
712 | } | |
713 | cur_rule_arch = lxc_seccomp_arch_mipsel64; | |
714 | } else if (strcmp(line, "[mipsel64n32]") == 0 || | |
f06c6207 | 715 | strcmp(line, "[MIPSEL64N32]") == 0) { |
2ccd9eda JC |
716 | if (native_arch != lxc_seccomp_arch_mipsel64) { |
717 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
718 | continue; | |
719 | } | |
720 | cur_rule_arch = lxc_seccomp_arch_mipsel64n32; | |
721 | } else if (strcmp(line, "[mipsel]") == 0 || | |
f06c6207 | 722 | strcmp(line, "[MIPSEL]") == 0) { |
2ccd9eda JC |
723 | if (native_arch != lxc_seccomp_arch_mipsel && |
724 | native_arch != lxc_seccomp_arch_mipsel64) { | |
725 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
726 | continue; | |
727 | } | |
728 | cur_rule_arch = lxc_seccomp_arch_mipsel; | |
729 | } | |
be038e49 CB |
730 | #endif |
731 | #ifdef SCMP_ARCH_S390X | |
732 | else if (strcmp(line, "[s390x]") == 0 || | |
f06c6207 | 733 | strcmp(line, "[S390X]") == 0) { |
be038e49 CB |
734 | if (native_arch != lxc_seccomp_arch_s390x) { |
735 | cur_rule_arch = lxc_seccomp_arch_unknown; | |
736 | continue; | |
737 | } | |
738 | cur_rule_arch = lxc_seccomp_arch_s390x; | |
739 | } | |
2b0ae718 | 740 | #endif |
50798138 SH |
741 | else |
742 | goto bad_arch; | |
d58c6ad0 | 743 | |
50798138 SH |
744 | continue; |
745 | } | |
746 | ||
d58c6ad0 SH |
747 | /* irrelevant arch - i.e. arm on i386 */ |
748 | if (cur_rule_arch == lxc_seccomp_arch_unknown) | |
749 | continue; | |
750 | ||
3ee26d19 | 751 | memset(&rule, 0, sizeof(rule)); |
d58c6ad0 | 752 | /* read optional action which follows the syscall */ |
3ee26d19 L |
753 | ret = parse_v2_rules(line, default_rule_action, &rule); |
754 | if (ret != 0) { | |
755 | ERROR("Failed to interpret seccomp rule"); | |
50798138 SH |
756 | goto bad_rule; |
757 | } | |
d58c6ad0 | 758 | |
d6417887 WB |
759 | if (cur_rule_arch == native_arch || |
760 | cur_rule_arch == lxc_seccomp_arch_native || | |
2ccd9eda | 761 | compat_arch[0] == SCMP_ARCH_NATIVE) { |
3ee26d19 | 762 | if (!do_resolve_add_rule(SCMP_ARCH_NATIVE, line, conf->seccomp_ctx, &rule)) |
d58c6ad0 | 763 | goto bad_rule; |
94d56054 CB |
764 | INFO("Added native rule for arch %d for %s action %d(%s)", |
765 | SCMP_ARCH_NATIVE, line, rule.action, | |
3ee26d19 | 766 | get_action_name(rule.action)); |
94d56054 CB |
767 | } else if (cur_rule_arch != lxc_seccomp_arch_all) { |
768 | int arch_index = 0; | |
769 | ||
770 | if ((cur_rule_arch == lxc_seccomp_arch_mips64n32) || | |
771 | (cur_rule_arch == lxc_seccomp_arch_mipsel64n32)) | |
772 | arch_index = 1; | |
773 | ||
3ee26d19 | 774 | if (!do_resolve_add_rule(compat_arch[arch_index], line, compat_ctx[arch_index], &rule)) |
d6417887 | 775 | goto bad_rule; |
94d56054 CB |
776 | INFO("Added compat-only rule for arch %d for %s action %d(%s)", |
777 | compat_arch[arch_index], line, rule.action, | |
3ee26d19 | 778 | get_action_name(rule.action)); |
94d56054 | 779 | } else { |
3ee26d19 | 780 | if (!do_resolve_add_rule(SCMP_ARCH_NATIVE, line, conf->seccomp_ctx, &rule)) |
d6417887 | 781 | goto bad_rule; |
94d56054 CB |
782 | INFO("Added native rule for arch %d for %s action %d(%s)", |
783 | SCMP_ARCH_NATIVE, line, rule.action, | |
3ee26d19 | 784 | get_action_name(rule.action)); |
94d56054 CB |
785 | |
786 | if (compat_arch[0] != SCMP_ARCH_NATIVE) { | |
787 | if (!do_resolve_add_rule(compat_arch[0], line, compat_ctx[0], &rule)) | |
788 | goto bad_rule; | |
789 | INFO("Added compat rule for arch %d for %s " | |
790 | "action %d(%s)", compat_arch[0], line, | |
791 | rule.action, get_action_name(rule.action)); | |
792 | } | |
793 | ||
794 | if (compat_arch[1] != SCMP_ARCH_NATIVE) { | |
795 | if (!do_resolve_add_rule(compat_arch[1], line, compat_ctx[1], &rule)) | |
796 | goto bad_rule; | |
797 | INFO("Added compat rule for arch %d for %s " | |
798 | "action %d(%s)", compat_arch[1], line, | |
799 | rule.action, get_action_name(rule.action)); | |
800 | } | |
50798138 SH |
801 | } |
802 | } | |
d58c6ad0 | 803 | |
d648e178 | 804 | INFO("Merging compat seccomp contexts into main context"); |
2ccd9eda | 805 | if (compat_ctx[0]) { |
d648e178 CB |
806 | if ((compat_arch[0] != native_arch) && |
807 | (compat_arch[0] != seccomp_arch_native())) { | |
b5ed021b CB |
808 | ret = seccomp_merge(conf->seccomp_ctx, compat_ctx[0]); |
809 | if (ret < 0) { | |
d648e178 CB |
810 | ERROR("Failed to merge first compat seccomp " |
811 | "context into main context"); | |
b5ed021b CB |
812 | goto bad; |
813 | } | |
814 | TRACE("Merged first compat seccomp context into main context"); | |
d648e178 CB |
815 | } else { |
816 | seccomp_release(compat_ctx[0]); | |
817 | compat_ctx[0] = NULL; | |
b5ed021b | 818 | } |
d648e178 | 819 | } |
b5ed021b | 820 | |
d648e178 CB |
821 | if (compat_ctx[1]) { |
822 | if ((compat_arch[1] != native_arch) && | |
823 | (compat_arch[1] != seccomp_arch_native())) { | |
b5ed021b CB |
824 | ret = seccomp_merge(conf->seccomp_ctx, compat_ctx[1]); |
825 | if (ret < 0) { | |
d648e178 CB |
826 | ERROR("Failed to merge first compat seccomp " |
827 | "context into main context"); | |
b5ed021b CB |
828 | goto bad; |
829 | } | |
830 | TRACE("Merged second compat seccomp context into main context"); | |
d648e178 CB |
831 | } else { |
832 | seccomp_release(compat_ctx[1]); | |
833 | compat_ctx[1] = NULL; | |
50798138 SH |
834 | } |
835 | } | |
6166fa6d | 836 | |
50798138 SH |
837 | return 0; |
838 | ||
839 | bad_arch: | |
f06c6207 | 840 | ERROR("Unsupported arch: %s.", line); |
50798138 | 841 | bad_rule: |
d58c6ad0 | 842 | bad: |
2ccd9eda JC |
843 | if (compat_ctx[0]) |
844 | seccomp_release(compat_ctx[0]); | |
845 | if (compat_ctx[1]) | |
846 | seccomp_release(compat_ctx[1]); | |
50798138 | 847 | return -1; |
d58c6ad0 SH |
848 | } |
849 | #else /* HAVE_DECL_SECCOMP_SYSCALL_RESOLVE_NAME_ARCH */ | |
850 | static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf) | |
851 | { | |
50798138 | 852 | return -1; |
50798138 | 853 | } |
d58c6ad0 | 854 | #endif /* HAVE_DECL_SECCOMP_SYSCALL_RESOLVE_NAME_ARCH */ |
50798138 | 855 | |
8f2c3a70 SH |
856 | /* |
857 | * The first line of the config file has a policy language version | |
858 | * the second line has some directives | |
859 | * then comes policy subject to the directives | |
998cd2f4 | 860 | * right now version must be '1' or '2' |
861 | * the directives must include 'whitelist'(version == 1 or 2) or 'blacklist' | |
862 | * (version == 2) and can include 'debug' (though debug is not yet supported). | |
8f2c3a70 SH |
863 | */ |
864 | static int parse_config(FILE *f, struct lxc_conf *conf) | |
865 | { | |
866 | char line[1024]; | |
867 | int ret, version; | |
868 | ||
869 | ret = fscanf(f, "%d\n", &version); | |
50798138 | 870 | if (ret != 1 || (version != 1 && version != 2)) { |
3ee26d19 | 871 | ERROR("Invalid version"); |
8f2c3a70 SH |
872 | return -1; |
873 | } | |
874 | if (!fgets(line, 1024, f)) { | |
3ee26d19 | 875 | ERROR("Invalid config file"); |
8f2c3a70 SH |
876 | return -1; |
877 | } | |
50798138 | 878 | if (version == 1 && !strstr(line, "whitelist")) { |
3ee26d19 | 879 | ERROR("Only whitelist policy is supported"); |
8f2c3a70 SH |
880 | return -1; |
881 | } | |
50798138 | 882 | |
8f2c3a70 | 883 | if (strstr(line, "debug")) { |
3ee26d19 | 884 | ERROR("Debug not yet implemented"); |
8f2c3a70 SH |
885 | return -1; |
886 | } | |
50798138 SH |
887 | |
888 | if (version == 1) | |
889 | return parse_config_v1(f, conf); | |
890 | return parse_config_v2(f, line, conf); | |
8f2c3a70 SH |
891 | } |
892 | ||
cd75548b SH |
893 | /* |
894 | * use_seccomp: return true if we should try and apply a seccomp policy | |
895 | * if defined for the container. | |
896 | * This will return false if | |
897 | * 1. seccomp is not enabled in the kernel | |
898 | * 2. a seccomp policy is already enabled for this task | |
899 | */ | |
900 | static bool use_seccomp(void) | |
d58c6ad0 SH |
901 | { |
902 | FILE *f = fopen("/proc/self/status", "r"); | |
903 | char line[1024]; | |
cd75548b SH |
904 | bool already_enabled = false; |
905 | bool found = false; | |
d58c6ad0 SH |
906 | int ret, v; |
907 | ||
908 | if (!f) | |
cd75548b | 909 | return true; |
d58c6ad0 SH |
910 | |
911 | while (fgets(line, 1024, f)) { | |
912 | if (strncmp(line, "Seccomp:", 8) == 0) { | |
cd75548b | 913 | found = true; |
f06c6207 | 914 | ret = sscanf(line + 8, "%d", &v); |
cd75548b SH |
915 | if (ret == 1 && v != 0) |
916 | already_enabled = true; | |
917 | break; | |
d58c6ad0 SH |
918 | } |
919 | } | |
920 | ||
d58c6ad0 | 921 | fclose(f); |
f06c6207 | 922 | if (!found) { /* no Seccomp line, no seccomp in kernel */ |
3ee26d19 | 923 | INFO("Seccomp is not enabled in the kernel"); |
cd75548b SH |
924 | return false; |
925 | } | |
f06c6207 | 926 | if (already_enabled) { /* already seccomp-confined */ |
3ee26d19 | 927 | INFO("Already seccomp-confined, not loading new policy"); |
cd75548b SH |
928 | return false; |
929 | } | |
930 | return true; | |
d58c6ad0 SH |
931 | } |
932 | ||
8f2c3a70 SH |
933 | int lxc_read_seccomp_config(struct lxc_conf *conf) |
934 | { | |
935 | FILE *f; | |
936 | int ret; | |
727c3073 | 937 | int check_seccomp_attr_set; |
8f2c3a70 | 938 | |
769872f9 SH |
939 | if (!conf->seccomp) |
940 | return 0; | |
941 | ||
cd75548b | 942 | if (!use_seccomp()) |
d58c6ad0 | 943 | return 0; |
769872f9 SH |
944 | #if HAVE_SCMP_FILTER_CTX |
945 | /* XXX for debug, pass in SCMP_ACT_TRAP */ | |
50798138 | 946 | conf->seccomp_ctx = seccomp_init(SCMP_ACT_KILL); |
769872f9 SH |
947 | ret = !conf->seccomp_ctx; |
948 | #else | |
50798138 | 949 | ret = seccomp_init(SCMP_ACT_KILL) < 0; |
769872f9 SH |
950 | #endif |
951 | if (ret) { | |
3ee26d19 | 952 | ERROR("Failed initializing seccomp"); |
8f2c3a70 SH |
953 | return -1; |
954 | } | |
8f2c3a70 | 955 | |
127c5293 | 956 | /* turn off no-new-privs. We don't want it in lxc, and it breaks |
f06c6207 | 957 | * with apparmor */ |
769872f9 | 958 | #if HAVE_SCMP_FILTER_CTX |
f06c6207 | 959 | check_seccomp_attr_set = seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_CTL_NNP, 0); |
727c3073 | 960 | #else |
f06c6207 | 961 | check_seccomp_attr_set = seccomp_attr_set(SCMP_FLTATR_CTL_NNP, 0); |
769872f9 | 962 | #endif |
727c3073 | 963 | if (check_seccomp_attr_set) { |
3ee26d19 | 964 | ERROR("Failed to turn off no-new-privs"); |
8f2c3a70 SH |
965 | return -1; |
966 | } | |
127c5293 SH |
967 | #ifdef SCMP_FLTATR_ATL_TSKIP |
968 | if (seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_ATL_TSKIP, 1)) { | |
969 | WARN("Failed to turn on seccomp nop-skip, continuing"); | |
970 | } | |
971 | #endif | |
8f2c3a70 SH |
972 | |
973 | f = fopen(conf->seccomp, "r"); | |
974 | if (!f) { | |
3ee26d19 | 975 | SYSERROR("Failed to open seccomp policy file %s", conf->seccomp); |
8f2c3a70 SH |
976 | return -1; |
977 | } | |
978 | ret = parse_config(f, conf); | |
979 | fclose(f); | |
980 | return ret; | |
981 | } | |
982 | ||
983 | int lxc_seccomp_load(struct lxc_conf *conf) | |
984 | { | |
985 | int ret; | |
986 | if (!conf->seccomp) | |
987 | return 0; | |
cd75548b | 988 | if (!use_seccomp()) |
d58c6ad0 | 989 | return 0; |
769872f9 SH |
990 | ret = seccomp_load( |
991 | #if HAVE_SCMP_FILTER_CTX | |
f06c6207 | 992 | conf->seccomp_ctx |
769872f9 | 993 | #endif |
f06c6207 | 994 | ); |
8f2c3a70 | 995 | if (ret < 0) { |
3ee26d19 | 996 | ERROR("Error loading the seccomp policy: %s", strerror(-ret)); |
8f2c3a70 SH |
997 | return -1; |
998 | } | |
5107af32 | 999 | |
1000 | /* After load seccomp filter into the kernel successfully, export the current seccomp | |
1001 | * filter to log file */ | |
1002 | #if HAVE_SCMP_FILTER_CTX | |
4b73005c | 1003 | if ((lxc_log_get_level() <= LXC_LOG_LEVEL_TRACE || conf->loglevel <= LXC_LOG_LEVEL_TRACE) && |
5107af32 | 1004 | lxc_log_fd >= 0) { |
1005 | ret = seccomp_export_pfc(conf->seccomp_ctx, lxc_log_fd); | |
1006 | /* Just give an warning when export error */ | |
1007 | if (ret < 0) | |
3ee26d19 | 1008 | WARN("Failed to export seccomp filter to log file: %s", strerror(-ret)); |
5107af32 | 1009 | } |
1010 | #endif | |
8f2c3a70 SH |
1011 | return 0; |
1012 | } | |
769872f9 | 1013 | |
f06c6207 CB |
1014 | void lxc_seccomp_free(struct lxc_conf *conf) |
1015 | { | |
f10fad2f ME |
1016 | free(conf->seccomp); |
1017 | conf->seccomp = NULL; | |
769872f9 SH |
1018 | #if HAVE_SCMP_FILTER_CTX |
1019 | if (conf->seccomp_ctx) { | |
1020 | seccomp_release(conf->seccomp_ctx); | |
1021 | conf->seccomp_ctx = NULL; | |
1022 | } | |
1023 | #endif | |
1024 | } |