usr.sbin/jail/command.c

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