usr.sbin/jail/command.c

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