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