usr.sbin/jail/command.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 2011 James Gritton
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 #include <sys/types.h>
  31 #include <sys/cpuset.h>
  32 #include <sys/event.h>
  33 #include <sys/mount.h>
  34 #include <sys/stat.h>
  35 #include <sys/sysctl.h>
  36 #include <sys/user.h>
  37 #include <sys/wait.h>
  38
  39 #include <err.h>
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <kvm.h>
  43 #include <login_cap.h>
  44 #include <paths.h>
  45 #include <pwd.h>
  46 #include <signal.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51 #include <vis.h>
  52
  53 #include "jailp.h"
  54
  55 #define DEFAULT_STOP_TIMEOUT    10
  56 #define PHASH_SIZE              256
  57
  58 LIST_HEAD(phhead, phash);
  59
  60 struct phash {
  61         LIST_ENTRY(phash)       le;
  62         struct cfjail           *j;
  63         pid_t                   pid;
  64 };
  65
  66 int paralimit = -1;
  67
  68 extern char **environ;
  69
  70 static int run_command(struct cfjail *j);
  71 static int add_proc(struct cfjail *j, pid_t pid);
  72 static void clear_procs(struct cfjail *j);
  73 static struct cfjail *find_proc(pid_t pid);
  74 static int term_procs(struct cfjail *j);
  75 static int get_user_info(struct cfjail *j, const char *username,
  76     const struct passwd **pwdp, login_cap_t **lcapp);
  77 static int check_path(struct cfjail *j, const char *pname, const char *path,
  78     int isfile, const char *umount_type);
  79
  80 static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
  81 static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
  82 static struct cfstring dummystring = { .len = 1 };
  83 static struct phhead phash[PHASH_SIZE];
  84 static int kq;
  85
  86 static cpusetid_t
  87 root_cpuset_id(void)
  88 {
  89         static cpusetid_t setid = CPUSET_INVALID;
  90         static int error;
  91
  92         /* Only try to get the cpuset once. */
  93         if (error == 0 && setid == CPUSET_INVALID)
  94                 error = cpuset_getid(CPU_LEVEL_ROOT, CPU_WHICH_PID, -1, &setid);
  95         if (error != 0)
  96                 return (CPUSET_INVALID);
  97         return (setid);
  98 }
  99
 100 /*
 101  * Run the next command associated with a jail.
 102  */
 103 int
 104 next_command(struct cfjail *j)
 105 {
 106         enum intparam comparam;
 107         int create_failed, stopping;
 108
 109         if (paralimit == 0) {
 110                 if (j->flags & JF_FROM_RUNQ)
 111                         requeue_head(j, &runnable);
 112                 else
 113                         requeue(j, &runnable);
 114                 return 1;
 115         }
 116         j->flags &= ~JF_FROM_RUNQ;
 117         create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
 118         stopping = (j->flags & JF_STOP) != 0;
 119         comparam = *j->comparam;
 120         for (;;) {
 121                 if (j->comstring == NULL) {
 122                         j->comparam += create_failed ? -1 : 1;
 123                         switch ((comparam = *j->comparam)) {
 124                         case IP__NULL:
 125                                 return 0;
 126                         case IP_MOUNT_DEVFS:
 127                                 if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
 128                                         continue;
 129                                 j->comstring = &dummystring;
 130                                 break;
 131                         case IP_MOUNT_FDESCFS:
 132                                 if (!bool_param(j->intparams[IP_MOUNT_FDESCFS]))
 133                                         continue;
 134                                 j->comstring = &dummystring;
 135                                 break;
 136                         case IP_MOUNT_PROCFS:
 137                                 if (!bool_param(j->intparams[IP_MOUNT_PROCFS]))
 138                                         continue;
 139                                 j->comstring = &dummystring;
 140                                 break;
 141                         case IP__OP:
 142                         case IP_STOP_TIMEOUT:
 143                                 j->comstring = &dummystring;
 144                                 break;
 145                         default:
 146                                 if (j->intparams[comparam] == NULL)
 147                                         continue;
 148                                 j->comstring = create_failed || (stopping &&
 149                                     (j->intparams[comparam]->flags & PF_REV))
 150                                     ? TAILQ_LAST(&j->intparams[comparam]->val,
 151                                         cfstrings)
 152                                     : TAILQ_FIRST(&j->intparams[comparam]->val);
 153                         }
 154                 } else {
 155                         j->comstring = j->comstring == &dummystring ? NULL :
 156                             create_failed || (stopping &&
 157                             (j->intparams[comparam]->flags & PF_REV))
 158                             ? TAILQ_PREV(j->comstring, cfstrings, tq)
 159                             : TAILQ_NEXT(j->comstring, tq);
 160                 }
 161                 if (j->comstring == NULL || j->comstring->len == 0 ||
 162                     (create_failed && (comparam == IP_EXEC_PRESTART ||
 163                     comparam == IP_EXEC_CREATED || comparam == IP_EXEC_START ||
 164                     comparam == IP_COMMAND || comparam == IP_EXEC_POSTSTART ||
 165                     comparam == IP_EXEC_PREPARE)))
 166                         continue;
 167                 switch (run_command(j)) {
 168                 case -1:
 169                         failed(j);
 170                         /* FALLTHROUGH */
 171                 case 1:
 172                         return 1;
 173                 }
 174         }
 175 }
 176
 177 /*
 178  * Check command exit status
 179  */
 180 int
 181 finish_command(struct cfjail *j)
 182 {
 183         struct cfjail *rj;
 184         int error;
 185
 186         if (!(j->flags & JF_SLEEPQ))
 187                 return 0;
 188         j->flags &= ~JF_SLEEPQ;
 189         if (*j->comparam == IP_STOP_TIMEOUT) {
 190                 j->flags &= ~JF_TIMEOUT;
 191                 j->pstatus = 0;
 192                 return 0;
 193         }
 194         paralimit++;
 195         if (!TAILQ_EMPTY(&runnable)) {
 196                 rj = TAILQ_FIRST(&runnable);
 197                 rj->flags |= JF_FROM_RUNQ;
 198                 requeue(rj, &ready);
 199         }
 200         error = 0;
 201         if (j->flags & JF_TIMEOUT) {
 202                 j->flags &= ~JF_TIMEOUT;
 203                 if (*j->comparam != IP_STOP_TIMEOUT) {
 204                         jail_warnx(j, "%s: timed out", j->comline);
 205                         failed(j);
 206                         error = -1;
 207                 } else if (verbose > 0)
 208                         jail_note(j, "timed out\n");
 209         } else if (j->pstatus != 0) {
 210                 if (WIFSIGNALED(j->pstatus))
 211                         jail_warnx(j, "%s: exited on signal %d",
 212                             j->comline, WTERMSIG(j->pstatus));
 213                 else
 214                         jail_warnx(j, "%s: failed", j->comline);
 215                 j->pstatus = 0;
 216                 failed(j);
 217                 error = -1;
 218         }
 219         free(j->comline);
 220         j->comline = NULL;
 221         return error;
 222 }
 223
 224 /*
 225  * Check for finished processes or timeouts.
 226  */
 227 struct cfjail *
 228 next_proc(int nonblock)
 229 {
 230         struct kevent ke;
 231         struct timespec ts;
 232         struct timespec *tsp;
 233         struct cfjail *j;
 234
 235         if (!TAILQ_EMPTY(&sleeping)) {
 236         again:
 237                 tsp = NULL;
 238                 if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
 239                         clock_gettime(CLOCK_REALTIME, &ts);
 240                         ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
 241                         ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
 242                         if (ts.tv_nsec < 0) {
 243                                 ts.tv_sec--;
 244                                 ts.tv_nsec += 1000000000;
 245                         }
 246                         if (ts.tv_sec < 0 ||
 247                             (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
 248                                 j->flags |= JF_TIMEOUT;
 249                                 clear_procs(j);
 250                                 return j;
 251                         }
 252                         tsp = &ts;
 253                 }
 254                 if (nonblock) {
 255                         ts.tv_sec = 0;
 256                         ts.tv_nsec = 0;
 257                         tsp = &ts;
 258                 }
 259                 switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
 260                 case -1:
 261                         if (errno != EINTR)
 262                                 err(1, "kevent");
 263                         goto again;
 264                 case 0:
 265                         if (!nonblock) {
 266                                 j = TAILQ_FIRST(&sleeping);
 267                                 j->flags |= JF_TIMEOUT;
 268                                 clear_procs(j);
 269                                 return j;
 270                         }
 271                         break;
 272                 case 1:
 273                         (void)waitpid(ke.ident, NULL, WNOHANG);
 274                         if ((j = find_proc(ke.ident))) {
 275                                 j->pstatus = ke.data;
 276                                 return j;
 277                         }
 278                         goto again;
 279                 }
 280         }
 281         return NULL;
 282 }
 283
 284 /*
 285  * Run a single command for a jail, possibly inside the jail.
 286  */
 287 static int
 288 run_command(struct cfjail *j)
 289 {
 290         const struct passwd *pwd;
 291         const struct cfstring *comstring, *s;
 292         login_cap_t *lcap;
 293         const char **argv;
 294         char *acs, *cs, *comcs, *devpath;
 295         const char *jidstr, *conslog, *path, *ruleset, *term, *username;
 296         enum intparam comparam;
 297         size_t comlen;
 298         pid_t pid;
 299         cpusetid_t setid;
 300         int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
 301 #if defined(INET) || defined(INET6)
 302         char *addr, *extrap, *p, *val;
 303 #endif
 304
 305         static char *cleanenv;
 306
 307         /* Perform some operations that aren't actually commands */
 308         comparam = *j->comparam;
 309         down = j->flags & (JF_STOP | JF_FAILED);
 310         switch (comparam) {
 311         case IP_STOP_TIMEOUT:
 312                 return term_procs(j);
 313
 314         case IP__OP:
 315                 if (down) {
 316                         if (jail_remove(j->jid) < 0 && errno == EPERM) {
 317                                 jail_warnx(j, "jail_remove: %s",
 318                                            strerror(errno));
 319                                 return -1;
 320                         }
 321                         if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
 322                             ? note_remove : j->name != NULL)))
 323                             jail_note(j, "removed\n");
 324                         j->jid = -1;
 325                         if (j->flags & JF_STOP)
 326                                 dep_done(j, DF_LIGHT);
 327                         else
 328                                 j->flags &= ~JF_PERSIST;
 329                 } else {
 330                         if (create_jail(j) < 0)
 331                                 return -1;
 332                         if (iflag)
 333                                 printf("%d\n", j->jid);
 334                         if (verbose >= 0 && (j->name || verbose > 0))
 335                                 jail_note(j, "created\n");
 336                         dep_done(j, DF_LIGHT);
 337                 }
 338                 return 0;
 339
 340         default: ;
 341         }
 342         /*
 343          * Collect exec arguments.  Internal commands for network and
 344          * mounting build their own argument lists.
 345          */
 346         comstring = j->comstring;
 347         bg = 0;
 348         switch (comparam) {
 349 #ifdef INET
 350         case IP__IP4_IFADDR:
 351                 argc = 0;
 352                 val = alloca(strlen(comstring->s) + 1);
 353                 strcpy(val, comstring->s);
 354                 cs = val;
 355                 extrap = NULL;
 356                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 357                         if (extrap == NULL) {
 358                                 *p = '\0';
 359                                 extrap = p + 1;
 360                         }
 361                         cs = p + 1;
 362                         argc++;
 363                 }
 364
 365                 argv = alloca((8 + argc) * sizeof(char *));
 366                 argv[0] = _PATH_IFCONFIG;
 367                 if ((cs = strchr(val, '|'))) {
 368                         argv[1] = acs = alloca(cs - val + 1);
 369                         strlcpy(acs, val, cs - val + 1);
 370                         addr = cs + 1;
 371                 } else {
 372                         argv[1] = string_param(j->intparams[IP_INTERFACE]);
 373                         addr = val;
 374                 }
 375                 argv[2] = "inet";
 376                 if (!(cs = strchr(addr, '/'))) {
 377                         argv[3] = addr;
 378                         argv[4] = "netmask";
 379                         argv[5] = "255.255.255.255";
 380                         argc = 6;
 381                 } else if (strchr(cs + 1, '.')) {
 382                         argv[3] = acs = alloca(cs - addr + 1);
 383                         strlcpy(acs, addr, cs - addr + 1);
 384                         argv[4] = "netmask";
 385                         argv[5] = cs + 1;
 386                         argc = 6;
 387                 } else {
 388                         argv[3] = addr;
 389                         argc = 4;
 390                 }
 391
 392                 if (!down && extrap != NULL) {
 393                         for (cs = strtok(extrap, " "); cs;
 394                              cs = strtok(NULL, " ")) {
 395                                 size_t len = strlen(cs) + 1;
 396                                 argv[argc++] = acs = alloca(len);
 397                                 strlcpy(acs, cs, len);
 398                         }
 399                 }
 400
 401                 argv[argc] = down ? "-alias" : "alias";
 402                 argv[argc + 1] = NULL;
 403                 break;
 404 #endif
 405
 406 #ifdef INET6
 407         case IP__IP6_IFADDR:
 408                 argc = 0;
 409                 val = alloca(strlen(comstring->s) + 1);
 410                 strcpy(val, comstring->s);
 411                 cs = val;
 412                 extrap = NULL;
 413                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 414                         if (extrap == NULL) {
 415                                 *p = '\0';
 416                                 extrap = p + 1;
 417                         }
 418                         cs = p + 1;
 419                         argc++;
 420                 }
 421
 422                 argv = alloca((8 + argc) * sizeof(char *));
 423                 argv[0] = _PATH_IFCONFIG;
 424                 if ((cs = strchr(val, '|'))) {
 425                         argv[1] = acs = alloca(cs - val + 1);
 426                         strlcpy(acs, val, cs - val + 1);
 427                         addr = cs + 1;
 428                 } else {
 429                         argv[1] = string_param(j->intparams[IP_INTERFACE]);
 430                         addr = val;
 431                 }
 432                 argv[2] = "inet6";
 433                 argv[3] = addr;
 434                 if (!(cs = strchr(addr, '/'))) {
 435                         argv[4] = "prefixlen";
 436                         argv[5] = "128";
 437                         argc = 6;
 438                 } else
 439                         argc = 4;
 440
 441                 if (!down && extrap != NULL) {
 442                         for (cs = strtok(extrap, " "); cs;
 443                              cs = strtok(NULL, " ")) {
 444                                 size_t len = strlen(cs) + 1;
 445                                 argv[argc++] = acs = alloca(len);
 446                                 strlcpy(acs, cs, len);
 447                         }
 448                 }
 449
 450                 argv[argc] = down ? "-alias" : "alias";
 451                 argv[argc + 1] = NULL;
 452                 break;
 453 #endif
 454
 455         case IP_VNET_INTERFACE:
 456                 argv = alloca(5 * sizeof(char *));
 457                 argv[0] = _PATH_IFCONFIG;
 458                 argv[1] = comstring->s;
 459                 argv[2] = down ? "-vnet" : "vnet";
 460                 jidstr = string_param(j->intparams[KP_JID]);
 461                 argv[3] = jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
 462                 argv[4] = NULL;
 463                 break;
 464
 465         case IP_MOUNT:
 466         case IP__MOUNT_FROM_FSTAB:
 467                 argv = alloca(8 * sizeof(char *));
 468                 comcs = alloca(comstring->len + 1);
 469                 strcpy(comcs, comstring->s);
 470                 argc = 0;
 471                 for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
 472                      cs = strtok(NULL, " \t\f\v\r\n")) {
 473                         if (argc <= 1 && strunvis(cs, cs) < 0) {
 474                                 jail_warnx(j, "%s: %s: fstab parse error",
 475                                     j->intparams[comparam]->name, comstring->s);
 476                                 return -1;
 477                         }
 478                         argv[argc++] = cs;
 479                 }
 480                 if (argc == 0)
 481                         return 0;
 482                 if (argc < 3) {
 483                         jail_warnx(j, "%s: %s: missing information",
 484                             j->intparams[comparam]->name, comstring->s);
 485                         return -1;
 486                 }
 487                 if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
 488                     down ? argv[2] : NULL) < 0)
 489                         return -1;
 490                 if (down) {
 491                         argv[4] = NULL;
 492                         argv[3] = argv[1];
 493                         argv[0] = "/sbin/umount";
 494                 } else {
 495                         if (argc == 4) {
 496                                 argv[7] = NULL;
 497                                 argv[6] = argv[1];
 498                                 argv[5] = argv[0];
 499                                 argv[4] = argv[3];
 500                                 argv[3] = "-o";
 501                         } else {
 502                                 argv[5] = NULL;
 503                                 argv[4] = argv[1];
 504                                 argv[3] = argv[0];
 505                         }
 506                         argv[0] = _PATH_MOUNT;
 507                 }
 508                 argv[1] = "-t";
 509                 break;
 510
 511         case IP_MOUNT_DEVFS:
 512                 argv = alloca(7 * sizeof(char *));
 513                 path = string_param(j->intparams[KP_PATH]);
 514                 if (path == NULL) {
 515                         jail_warnx(j, "mount.devfs: no jail root path defined");
 516                         return -1;
 517                 }
 518                 devpath = alloca(strlen(path) + 5);
 519                 sprintf(devpath, "%s/dev", path);
 520                 if (check_path(j, "mount.devfs", devpath, 0,
 521                     down ? "devfs" : NULL) < 0)
 522                         return -1;
 523                 if (down) {
 524                         argv[0] = "/sbin/umount";
 525                         argv[1] = devpath;
 526                         argv[2] = NULL;
 527                 } else {
 528                         argv[0] = _PATH_MOUNT;
 529                         argv[1] = "-t";
 530                         argv[2] = "devfs";
 531                         ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
 532                         if (!ruleset)
 533                             ruleset = "4";      /* devfsrules_jail */
 534                         argv[3] = acs = alloca(11 + strlen(ruleset));
 535                         sprintf(acs, "-oruleset=%s", ruleset);
 536                         argv[4] = ".";
 537                         argv[5] = devpath;
 538                         argv[6] = NULL;
 539                 }
 540                 break;
 541
 542         case IP_MOUNT_FDESCFS:
 543                 argv = alloca(7 * sizeof(char *));
 544                 path = string_param(j->intparams[KP_PATH]);
 545                 if (path == NULL) {
 546                         jail_warnx(j, "mount.fdescfs: no jail root path defined");
 547                         return -1;
 548                 }
 549                 devpath = alloca(strlen(path) + 8);
 550                 sprintf(devpath, "%s/dev/fd", path);
 551                 if (check_path(j, "mount.fdescfs", devpath, 0,
 552                     down ? "fdescfs" : NULL) < 0)
 553                         return -1;
 554                 if (down) {
 555                         argv[0] = "/sbin/umount";
 556                         argv[1] = devpath;
 557                         argv[2] = NULL;
 558                 } else {
 559                         argv[0] = _PATH_MOUNT;
 560                         argv[1] = "-t";
 561                         argv[2] = "fdescfs";
 562                         argv[3] = ".";
 563                         argv[4] = devpath;
 564                         argv[5] = NULL;
 565                 }
 566                 break;
 567
 568         case IP_MOUNT_PROCFS:
 569                 argv = alloca(7 * sizeof(char *));
 570                 path = string_param(j->intparams[KP_PATH]);
 571                 if (path == NULL) {
 572                         jail_warnx(j, "mount.procfs: no jail root path defined");
 573                         return -1;
 574                 }
 575                 devpath = alloca(strlen(path) + 6);
 576                 sprintf(devpath, "%s/proc", path);
 577                 if (check_path(j, "mount.procfs", devpath, 0,
 578                     down ? "procfs" : NULL) < 0)
 579                         return -1;
 580                 if (down) {
 581                         argv[0] = "/sbin/umount";
 582                         argv[1] = devpath;
 583                         argv[2] = NULL;
 584                 } else {
 585                         argv[0] = _PATH_MOUNT;
 586                         argv[1] = "-t";
 587                         argv[2] = "procfs";
 588                         argv[3] = ".";
 589                         argv[4] = devpath;
 590                         argv[5] = NULL;
 591                 }
 592                 break;
 593
 594         case IP_COMMAND:
 595                 if (j->name != NULL)
 596                         goto default_command;
 597                 argc = 0;
 598                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 599                         argc++;
 600                 argv = alloca((argc + 1) * sizeof(char *));
 601                 argc = 0;
 602                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 603                         argv[argc++] = s->s;
 604                 argv[argc] = NULL;
 605                 j->comstring = &dummystring;
 606                 break;
 607
 608         default:
 609         default_command:
 610                 if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
 611                     !(cs[0] == '&' && cs[1] == '\0')) {
 612                         argv = alloca(4 * sizeof(char *));
 613                         argv[0] = _PATH_BSHELL;
 614                         argv[1] = "-c";
 615                         argv[2] = comstring->s;
 616                         argv[3] = NULL;
 617                 } else {
 618                         if (cs) {
 619                                 *cs = 0;
 620                                 bg = 1;
 621                         }
 622                         comcs = alloca(comstring->len + 1);
 623                         strcpy(comcs, comstring->s);
 624                         argc = 0;
 625                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 626                              cs = strtok(NULL, " \t\f\v\r\n"))
 627                                 argc++;
 628                         argv = alloca((argc + 1) * sizeof(char *));
 629                         strcpy(comcs, comstring->s);
 630                         argc = 0;
 631                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 632                              cs = strtok(NULL, " \t\f\v\r\n"))
 633                                 argv[argc++] = cs;
 634                         argv[argc] = NULL;
 635                 }
 636         }
 637         if (argv[0] == NULL)
 638                 return 0;
 639
 640         if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
 641             timeout != 0) {
 642                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 643                 j->timeout.tv_sec += timeout;
 644         } else
 645                 j->timeout.tv_sec = 0;
 646
 647         injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
 648             comparam == IP_EXEC_STOP;
 649         if (injail)
 650                 setid = root_cpuset_id();
 651         else
 652                 setid = CPUSET_INVALID;
 653         clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
 654         username = string_param(j->intparams[injail
 655             ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
 656         sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
 657
 658         consfd = 0;
 659         if (injail &&
 660             (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
 661                 if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
 662                         return -1;
 663                 consfd =
 664                     open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
 665                 if (consfd < 0) {
 666                         jail_warnx(j, "open %s: %s", conslog, strerror(errno));
 667                         return -1;
 668                 }
 669         }
 670
 671         comlen = 0;
 672         for (i = 0; argv[i]; i++)
 673                 comlen += strlen(argv[i]) + 1;
 674         j->comline = cs = emalloc(comlen);
 675         for (i = 0; argv[i]; i++) {
 676                 strcpy(cs, argv[i]);
 677                 if (argv[i + 1]) {
 678                         cs += strlen(argv[i]) + 1;
 679                         cs[-1] = ' ';
 680                 }
 681         }
 682         if (verbose > 0)
 683                 jail_note(j, "run command%s%s%s: %s\n",
 684                     injail ? " in jail" : "", username ? " as " : "",
 685                     username ? username : "", j->comline);
 686
 687         pid = fork();
 688         if (pid < 0)
 689                 err(1, "fork");
 690         if (pid > 0) {
 691                 if (bg || !add_proc(j, pid)) {
 692                         free(j->comline);
 693                         j->comline = NULL;
 694                         return 0;
 695                 } else {
 696                         paralimit--;
 697                         return 1;
 698                 }
 699         }
 700         if (bg)
 701                 setsid();
 702
 703         /* Set up the environment and run the command */
 704         pwd = NULL;
 705         lcap = NULL;
 706         if ((clean || username) && injail && sjuser &&
 707             get_user_info(j, username, &pwd, &lcap) < 0)
 708                 exit(1);
 709         if (injail) {
 710                 /* jail_attach won't chdir along with its chroot. */
 711                 path = string_param(j->intparams[KP_PATH]);
 712                 if (path && chdir(path) < 0) {
 713                         jail_warnx(j, "chdir %s: %s", path, strerror(errno));
 714                         exit(1);
 715                 }
 716                 if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
 717                     setfib(fib) < 0) {
 718                         jail_warnx(j, "setfib: %s", strerror(errno));
 719                         exit(1);
 720                 }
 721
 722                 /*
 723                  * We wouldn't have specialized our affinity, so just setid to
 724                  * root.  We do this prior to attaching to avoid the kernel
 725                  * having to create a transient cpuset that we'll promptly
 726                  * free up with a reset to the jail's cpuset.
 727                  *
 728                  * This is just a best-effort to use as wide of mask as
 729                  * possible.
 730                  */
 731                 if (setid != CPUSET_INVALID)
 732                         (void)cpuset_setid(CPU_WHICH_PID, -1, setid);
 733
 734                 if (jail_attach(j->jid) < 0) {
 735                         jail_warnx(j, "jail_attach: %s", strerror(errno));
 736                         exit(1);
 737                 }
 738         }
 739         if (clean || username) {
 740                 if (!(injail && sjuser) &&
 741                     get_user_info(j, username, &pwd, &lcap) < 0)
 742                         exit(1);
 743                 if (clean) {
 744                         term = getenv("TERM");
 745                         environ = &cleanenv;
 746                         setenv("PATH", "/bin:/usr/bin", 0);
 747                         if (term != NULL)
 748                                 setenv("TERM", term, 1);
 749                 }
 750                 if (setgid(pwd->pw_gid) < 0) {
 751                         jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
 752                             strerror(errno));
 753                         exit(1);
 754                 }
 755                 if (setusercontext(lcap, pwd, pwd->pw_uid, username
 756                     ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
 757                     : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
 758                         jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
 759                             strerror(errno));
 760                         exit(1);
 761                 }
 762                 login_close(lcap);
 763                 setenv("USER", pwd->pw_name, 1);
 764                 setenv("HOME", pwd->pw_dir, 1);
 765                 setenv("SHELL",
 766                     *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
 767                 if (clean && chdir(pwd->pw_dir) < 0) {
 768                         jail_warnx(j, "chdir %s: %s",
 769                             pwd->pw_dir, strerror(errno));
 770                         exit(1);
 771                 }
 772                 endpwent();
 773         }
 774
 775         if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
 776                 jail_warnx(j, "exec.consolelog: %s", strerror(errno));
 777                 exit(1);
 778         }
 779         closefrom(3);
 780         execvp(argv[0], __DECONST(char *const*, argv));
 781         jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
 782         exit(1);
 783 }
 784
 785 /*
 786  * Add a process to the hash, tied to a jail.
 787  */
 788 static int
 789 add_proc(struct cfjail *j, pid_t pid)
 790 {
 791         struct kevent ke;
 792         struct cfjail *tj;
 793         struct phash *ph;
 794
 795         if (!kq && (kq = kqueue()) < 0)
 796                 err(1, "kqueue");
 797         EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
 798         if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
 799                 if (errno == ESRCH)
 800                         return 0;
 801                 err(1, "kevent");
 802         }
 803         ph = emalloc(sizeof(struct phash));
 804         ph->j = j;
 805         ph->pid = pid;
 806         LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
 807         j->nprocs++;
 808         j->flags |= JF_SLEEPQ;
 809         if (j->timeout.tv_sec == 0)
 810                 requeue(j, &sleeping);
 811         else {
 812                 /* File the jail in the sleep queue according to its timeout. */
 813                 TAILQ_REMOVE(j->queue, j, tq);
 814                 TAILQ_FOREACH(tj, &sleeping, tq) {
 815                         if (!tj->timeout.tv_sec ||
 816                             j->timeout.tv_sec < tj->timeout.tv_sec ||
 817                             (j->timeout.tv_sec == tj->timeout.tv_sec &&
 818                             j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
 819                                 TAILQ_INSERT_BEFORE(tj, j, tq);
 820                                 break;
 821                         }
 822                 }
 823                 if (tj == NULL)
 824                         TAILQ_INSERT_TAIL(&sleeping, j, tq);
 825                 j->queue = &sleeping;
 826         }
 827         return 1;
 828 }
 829
 830 /*
 831  * Remove any processes from the hash that correspond to a jail.
 832  */
 833 static void
 834 clear_procs(struct cfjail *j)
 835 {
 836         struct kevent ke;
 837         struct phash *ph, *tph;
 838         int i;
 839
 840         j->nprocs = 0;
 841         for (i = 0; i < PHASH_SIZE; i++)
 842                 LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
 843                         if (ph->j == j) {
 844                                 EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
 845                                     NOTE_EXIT, 0, NULL);
 846                                 (void)kevent(kq, &ke, 1, NULL, 0, NULL);
 847                                 LIST_REMOVE(ph, le);
 848                                 free(ph);
 849                         }
 850 }
 851
 852 /*
 853  * Find the jail that corresponds to an exited process.
 854  */
 855 static struct cfjail *
 856 find_proc(pid_t pid)
 857 {
 858         struct cfjail *j;
 859         struct phash *ph;
 860
 861         LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
 862                 if (ph->pid == pid) {
 863                         j = ph->j;
 864                         LIST_REMOVE(ph, le);
 865                         free(ph);
 866                         return --j->nprocs ? NULL : j;
 867                 }
 868         return NULL;
 869 }
 870
 871 /*
 872  * Send SIGTERM to all processes in a jail and wait for them to die.
 873  */
 874 static int
 875 term_procs(struct cfjail *j)
 876 {
 877         struct kinfo_proc *ki;
 878         int i, noted, pcnt, timeout;
 879
 880         static kvm_t *kd;
 881
 882         if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
 883                 timeout = DEFAULT_STOP_TIMEOUT;
 884         else if (timeout == 0)
 885                 return 0;
 886
 887         if (kd == NULL) {
 888                 kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
 889                 if (kd == NULL)
 890                         return 0;
 891         }
 892
 893         ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
 894         if (ki == NULL)
 895                 return 0;
 896         noted = 0;
 897         for (i = 0; i < pcnt; i++)
 898                 if (ki[i].ki_jid == j->jid &&
 899                     kill(ki[i].ki_pid, SIGTERM) == 0) {
 900                         (void)add_proc(j, ki[i].ki_pid);
 901                         if (verbose > 0) {
 902                                 if (!noted) {
 903                                         noted = 1;
 904                                         jail_note(j, "sent SIGTERM to:");
 905                                 }
 906                                 printf(" %d", ki[i].ki_pid);
 907                         }
 908                 }
 909         if (noted)
 910                 printf("\n");
 911         if (j->nprocs > 0) {
 912                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 913                 j->timeout.tv_sec += timeout;
 914                 return 1;
 915         }
 916         return 0;
 917 }
 918
 919 /*
 920  * Look up a user in the passwd and login.conf files.
 921  */
 922 static int
 923 get_user_info(struct cfjail *j, const char *username,
 924     const struct passwd **pwdp, login_cap_t **lcapp)
 925 {
 926         const struct passwd *pwd;
 927
 928         errno = 0;
 929         *pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
 930         if (pwd == NULL) {
 931                 if (errno)
 932                         jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
 933                             username ? username : "", strerror(errno));
 934                 else if (username)
 935                         jail_warnx(j, "%s: no such user", username);
 936                 else
 937                         jail_warnx(j, "unknown uid %d", getuid());
 938                 return -1;
 939         }
 940         *lcapp = login_getpwclass(pwd);
 941         if (*lcapp == NULL) {
 942                 jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
 943                     strerror(errno));
 944                 return -1;
 945         }
 946         /* Set the groups while the group file is still available */
 947         if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
 948                 jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
 949                     strerror(errno));
 950                 return -1;
 951         }
 952         return 0;
 953 }
 954
 955 /*
 956  * Make sure a mount or consolelog path is a valid absolute pathname
 957  * with no symlinks.
 958  */
 959 static int
 960 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
 961     const char *umount_type)
 962 {
 963         struct stat st, mpst;
 964         struct statfs stfs;
 965         char *tpath, *p;
 966         const char *jailpath;
 967         size_t jplen;
 968
 969         if (path[0] != '/') {
 970                 jail_warnx(j, "%s: %s: not an absolute pathname",
 971                     pname, path);
 972                 return -1;
 973         }
 974         /*
 975          * Only check for symlinks in components below the jail's path,
 976          * since that's where the security risk lies.
 977          */
 978         jailpath = string_param(j->intparams[KP_PATH]);
 979         if (jailpath == NULL)
 980                 jailpath = "";
 981         jplen = strlen(jailpath);
 982         if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
 983                 tpath = alloca(strlen(path) + 1);
 984                 strcpy(tpath, path);
 985                 for (p = tpath + jplen; p != NULL; ) {
 986                         p = strchr(p + 1, '/');
 987                         if (p)
 988                                 *p = '\0';
 989                         if (lstat(tpath, &st) < 0) {
 990                                 if (errno == ENOENT && isfile && !p)
 991                                         break;
 992                                 jail_warnx(j, "%s: %s: %s", pname, tpath,
 993                                     strerror(errno));
 994                                 return -1;
 995                         }
 996                         if (S_ISLNK(st.st_mode)) {
 997                                 jail_warnx(j, "%s: %s is a symbolic link",
 998                                     pname, tpath);
 999                                 return -1;
1000                         }
1001                         if (p)
1002                                 *p = '/';
1003                 }
1004         }
1005         if (umount_type != NULL) {
1006                 if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
1007                         jail_warnx(j, "%s: %s: %s", pname, path,
1008                             strerror(errno));
1009                         return -1;
1010                 }
1011                 if (stat(stfs.f_mntonname, &mpst) < 0) {
1012                         jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
1013                             strerror(errno));
1014                         return -1;
1015                 }
1016                 if (st.st_ino != mpst.st_ino) {
1017                         jail_warnx(j, "%s: %s: not a mount point",
1018                             pname, path);
1019                         return -1;
1020                 }
1021                 if (strcmp(stfs.f_fstypename, umount_type)) {
1022                         jail_warnx(j, "%s: %s: not a %s mount",
1023                             pname, path, umount_type);
1024                         return -1;
1025                 }
1026         }
1027         return 0;
1028 }