1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 20 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 21 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 22 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/jail.h> 33 #include <sys/mount.h> 34 #include <sys/wait.h> 35 #include <err.h> 36 #include <jail.h> 37 #include <stdbool.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <unistd.h> 41 42 #include <be.h> 43 #include "bectl.h" 44 45 #define MNTTYPE_ZFS 222 46 47 static void jailparam_add(const char *name, const char *val); 48 static int jailparam_del(const char *name); 49 static bool jailparam_addarg(char *arg); 50 static int jailparam_delarg(char *arg); 51 52 static int bectl_search_jail_paths(const char *mnt); 53 static int bectl_locate_jail(const char *ident); 54 static int bectl_jail_cleanup(char *mountpoint, int jid); 55 56 static char mnt_loc[BE_MAXPATHLEN]; 57 static nvlist_t *jailparams; 58 59 static const char *disabled_params[] = { 60 "command", "exec.start", "nopersist", "persist", NULL 61 }; 62 63 64 static void 65 jailparam_add(const char *name, const char *val) 66 { 67 68 nvlist_add_string(jailparams, name, val); 69 } 70 71 static int 72 jailparam_del(const char *name) 73 { 74 75 nvlist_remove_all(jailparams, name); 76 return (0); 77 } 78 79 static bool 80 jailparam_addarg(char *arg) 81 { 82 char *name, *val; 83 size_t i, len; 84 85 if (arg == NULL) 86 return (false); 87 name = arg; 88 if ((val = strchr(arg, '=')) == NULL) { 89 fprintf(stderr, "bectl jail: malformed jail option '%s'\n", 90 arg); 91 return (false); 92 } 93 94 *val++ = '\0'; 95 if (strcmp(name, "path") == 0) { 96 if (strlen(val) >= BE_MAXPATHLEN) { 97 fprintf(stderr, 98 "bectl jail: skipping too long path assignment '%s' (max length = %d)\n", 99 val, BE_MAXPATHLEN); 100 return (false); 101 } 102 strlcpy(mnt_loc, val, sizeof(mnt_loc)); 103 } 104 105 for (i = 0; disabled_params[i] != NULL; i++) { 106 len = strlen(disabled_params[i]); 107 if (strncmp(disabled_params[i], name, len) == 0) { 108 fprintf(stderr, "invalid jail parameter: %s\n", name); 109 return (false); 110 } 111 } 112 113 jailparam_add(name, val); 114 return (true); 115 } 116 117 static int 118 jailparam_delarg(char *arg) 119 { 120 char *name, *val; 121 122 if (arg == NULL) 123 return (EINVAL); 124 name = arg; 125 if ((val = strchr(name, '=')) != NULL) 126 *val++ = '\0'; 127 128 if (strcmp(name, "path") == 0) 129 *mnt_loc = '\0'; 130 return (jailparam_del(name)); 131 } 132 133 static int 134 build_jailcmd(char ***argvp, bool interactive, int argc, char *argv[]) 135 { 136 char *cmd, **jargv, *name, *val; 137 nvpair_t *nvp; 138 size_t i, iarg, nargv; 139 140 cmd = NULL; 141 nvp = NULL; 142 iarg = i = 0; 143 if (nvlist_size(jailparams, &nargv, NV_ENCODE_NATIVE) != 0) 144 return (1); 145 146 /* 147 * Number of args + "/usr/sbin/jail", "-c", and ending NULL. 148 * If interactive also include command. 149 */ 150 nargv += 3; 151 if (interactive) { 152 if (argc == 0) 153 nargv++; 154 else 155 nargv += argc; 156 } 157 158 jargv = *argvp = calloc(nargv, sizeof(*jargv)); 159 if (jargv == NULL) 160 err(2, "calloc"); 161 162 jargv[iarg++] = strdup("/usr/sbin/jail"); 163 jargv[iarg++] = strdup("-c"); 164 while ((nvp = nvlist_next_nvpair(jailparams, nvp)) != NULL) { 165 name = nvpair_name(nvp); 166 if (nvpair_value_string(nvp, &val) != 0) 167 continue; 168 169 if (asprintf(&jargv[iarg++], "%s=%s", name, val) < 0) 170 goto error; 171 } 172 if (interactive) { 173 if (argc < 1) 174 cmd = strdup("/bin/sh"); 175 else { 176 cmd = argv[0]; 177 argc--; 178 argv++; 179 } 180 181 if (asprintf(&jargv[iarg++], "command=%s", cmd) < 0) { 182 goto error; 183 } 184 if (argc < 1) { 185 free(cmd); 186 cmd = NULL; 187 } 188 189 for (; argc > 0; argc--) { 190 if (asprintf(&jargv[iarg++], "%s", argv[0]) < 0) 191 goto error; 192 argv++; 193 } 194 } 195 196 return (0); 197 198 error: 199 if (interactive && argc < 1) 200 free(cmd); 201 for (; i < iarg - 1; i++) { 202 free(jargv[i]); 203 } 204 free(jargv); 205 return (1); 206 } 207 208 /* Remove jail and cleanup any non zfs mounts. */ 209 static int 210 bectl_jail_cleanup(char *mountpoint, int jid) 211 { 212 struct statfs *mntbuf; 213 size_t i, searchlen, mntsize; 214 215 if (jid >= 0 && jail_remove(jid) != 0) { 216 fprintf(stderr, "unable to remove jail"); 217 return (1); 218 } 219 220 searchlen = strnlen(mountpoint, MAXPATHLEN); 221 mntsize = getmntinfo(&mntbuf, MNT_NOWAIT); 222 for (i = 0; i < mntsize; i++) { 223 if (strncmp(mountpoint, mntbuf[i].f_mntonname, searchlen) == 0 && 224 mntbuf[i].f_type != MNTTYPE_ZFS) { 225 226 if (unmount(mntbuf[i].f_mntonname, 0) != 0) { 227 fprintf(stderr, "bectl jail: unable to unmount filesystem %s", 228 mntbuf[i].f_mntonname); 229 return (1); 230 } 231 } 232 } 233 234 return (0); 235 } 236 237 int 238 bectl_cmd_jail(int argc, char *argv[]) 239 { 240 char *bootenv, **jargv, *mountpoint; 241 int i, jid, mntflags, opt, ret; 242 bool default_hostname, interactive, unjail; 243 pid_t pid; 244 245 246 /* XXX TODO: Allow shallow */ 247 mntflags = BE_MNT_DEEP; 248 default_hostname = interactive = unjail = true; 249 250 if ((nvlist_alloc(&jailparams, NV_UNIQUE_NAME, 0)) != 0) { 251 fprintf(stderr, "nvlist_alloc() failed\n"); 252 return (1); 253 } 254 255 jailparam_add("persist", "true"); 256 jailparam_add("allow.mount", "true"); 257 jailparam_add("allow.mount.devfs", "true"); 258 jailparam_add("enforce_statfs", "1"); 259 260 while ((opt = getopt(argc, argv, "bo:Uu:")) != -1) { 261 switch (opt) { 262 case 'b': 263 interactive = false; 264 break; 265 case 'o': 266 if (jailparam_addarg(optarg)) { 267 /* 268 * optarg has been modified to null terminate 269 * at the assignment operator. 270 */ 271 if (strcmp(optarg, "host.hostname") == 0) 272 default_hostname = false; 273 } else { 274 return (1); 275 } 276 break; 277 case 'U': 278 unjail = false; 279 break; 280 case 'u': 281 if ((ret = jailparam_delarg(optarg)) == 0) { 282 if (strcmp(optarg, "host.hostname") == 0) 283 default_hostname = true; 284 } else if (ret != ENOENT) { 285 fprintf(stderr, 286 "bectl jail: error unsetting \"%s\"\n", 287 optarg); 288 return (ret); 289 } 290 break; 291 default: 292 fprintf(stderr, "bectl jail: unknown option '-%c'\n", 293 optopt); 294 return (usage(false)); 295 } 296 } 297 298 argc -= optind; 299 argv += optind; 300 301 if (argc < 1) { 302 fprintf(stderr, "bectl jail: missing boot environment name\n"); 303 return (usage(false)); 304 } 305 306 bootenv = argv[0]; 307 argc--; 308 argv++; 309 310 /* 311 * XXX TODO: if its already mounted, perhaps there should be a flag to 312 * indicate its okay to proceed?? 313 */ 314 if (*mnt_loc == '\0') 315 mountpoint = NULL; 316 else 317 mountpoint = mnt_loc; 318 if (be_mount(be, bootenv, mountpoint, mntflags, mnt_loc) != BE_ERR_SUCCESS) { 319 fprintf(stderr, "could not mount bootenv\n"); 320 return (1); 321 } 322 323 if (default_hostname) 324 jailparam_add("host.hostname", bootenv); 325 326 /* 327 * This is our indicator that path was not set by the user, so we'll use 328 * the path that libbe generated for us. 329 */ 330 if (mountpoint == NULL) { 331 jailparam_add("path", mnt_loc); 332 mountpoint = mnt_loc; 333 } 334 335 if ((build_jailcmd(&jargv, interactive, argc, argv)) != 0) { 336 fprintf(stderr, "unable to build argument list for jail command\n"); 337 return (1); 338 } 339 340 pid = fork(); 341 342 switch (pid) { 343 case -1: 344 perror("fork"); 345 return (1); 346 case 0: 347 execv("/usr/sbin/jail", jargv); 348 fprintf(stderr, "bectl jail: failed to execute\n"); 349 return (1); 350 default: 351 waitpid(pid, NULL, 0); 352 } 353 354 for (i = 0; jargv[i] != NULL; i++) { 355 free(jargv[i]); 356 } 357 free(jargv); 358 359 if (!interactive) 360 return (0); 361 362 if (unjail) { 363 /* 364 * We're not checking the jail id result here because in the 365 * case of invalid param, or last command in jail was an error 366 * the jail will not exist upon exit. bectl_jail_cleanup will 367 * only jail_remove if the jid is >= 0. 368 */ 369 jid = bectl_locate_jail(bootenv); 370 bectl_jail_cleanup(mountpoint, jid); 371 be_unmount(be, bootenv, 0); 372 } 373 374 return (0); 375 } 376 377 static int 378 bectl_search_jail_paths(const char *mnt) 379 { 380 int jid; 381 char lastjid[16]; 382 char jailpath[MAXPATHLEN]; 383 384 /* jail_getv expects name/value strings */ 385 snprintf(lastjid, sizeof(lastjid), "%d", 0); 386 387 while ((jid = jail_getv(0, "lastjid", lastjid, "path", &jailpath, 388 NULL)) != -1) { 389 390 /* the jail we've been looking for */ 391 if (strcmp(jailpath, mnt) == 0) 392 return (jid); 393 394 /* update lastjid and keep on looking */ 395 snprintf(lastjid, sizeof(lastjid), "%d", jid); 396 } 397 398 return (-1); 399 } 400 401 /* 402 * Locate a jail based on an arbitrary identifier. This may be either a name, 403 * a jid, or a BE name. Returns the jid or -1 on failure. 404 */ 405 static int 406 bectl_locate_jail(const char *ident) 407 { 408 nvlist_t *belist, *props; 409 char *mnt; 410 int jid; 411 412 /* Try the easy-match first */ 413 jid = jail_getid(ident); 414 /* 415 * jail_getid(0) will always return 0, because this prison does exist. 416 * bectl(8) knows that this is not what it wants, so we should fall 417 * back to mount point search. 418 */ 419 if (jid > 0) 420 return (jid); 421 422 /* Attempt to try it as a BE name, first */ 423 if (be_prop_list_alloc(&belist) != 0) 424 return (-1); 425 426 if (be_get_bootenv_props(be, belist) != 0) 427 return (-1); 428 429 if (nvlist_lookup_nvlist(belist, ident, &props) == 0) { 430 431 /* path where a boot environment is mounted */ 432 if (nvlist_lookup_string(props, "mounted", &mnt) == 0) { 433 434 /* looking for a jail that matches our bootenv path */ 435 jid = bectl_search_jail_paths(mnt); 436 be_prop_list_free(belist); 437 return (jid); 438 } 439 440 be_prop_list_free(belist); 441 } 442 443 return (-1); 444 } 445 446 int 447 bectl_cmd_unjail(int argc, char *argv[]) 448 { 449 char path[MAXPATHLEN]; 450 char *cmd, *name, *target; 451 int jid; 452 453 /* Store alias used */ 454 cmd = argv[0]; 455 456 if (argc != 2) { 457 fprintf(stderr, "bectl %s: wrong number of arguments\n", cmd); 458 return (usage(false)); 459 } 460 461 target = argv[1]; 462 463 /* Locate the jail */ 464 if ((jid = bectl_locate_jail(target)) == -1) { 465 fprintf(stderr, "bectl %s: failed to locate BE by '%s'\n", cmd, 466 target); 467 return (1); 468 } 469 470 bzero(&path, MAXPATHLEN); 471 name = jail_getname(jid); 472 if (jail_getv(0, "name", name, "path", path, NULL) != jid) { 473 free(name); 474 fprintf(stderr, 475 "bectl %s: failed to get path for jail requested by '%s'\n", 476 cmd, target); 477 return (1); 478 } 479 480 free(name); 481 482 if (be_mounted_at(be, path, NULL) != 0) { 483 fprintf(stderr, "bectl %s: jail requested by '%s' not a BE\n", 484 cmd, target); 485 return (1); 486 } 487 488 bectl_jail_cleanup(path, jid); 489 be_unmount(be, target, 0); 490 491 return (0); 492 } 493