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