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