usr.sbin/jail/command.c

   1 /*-
   2  * Copyright (c) 2011 James Gritton
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/types.h>
  31 #include <sys/event.h>
  32 #include <sys/mount.h>
  33 #include <sys/stat.h>
  34 #include <sys/sysctl.h>
  35 #include <sys/user.h>
  36 #include <sys/wait.h>
  37
  38 #include <err.h>
  39 #include <errno.h>
  40 #include <fcntl.h>
  41 #include <kvm.h>
  42 #include <login_cap.h>
  43 #include <paths.h>
  44 #include <pwd.h>
  45 #include <signal.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <vis.h>
  51
  52 #include "jailp.h"
  53
  54 #define DEFAULT_STOP_TIMEOUT    10
  55 #define PHASH_SIZE              256
  56
  57 LIST_HEAD(phhead, phash);
  58
  59 struct phash {
  60         LIST_ENTRY(phash)       le;
  61         struct cfjail           *j;
  62         pid_t                   pid;
  63 };
  64
  65 int paralimit = -1;
  66
  67 extern char **environ;
  68
  69 static int run_command(struct cfjail *j);
  70 static int add_proc(struct cfjail *j, pid_t pid);
  71 static void clear_procs(struct cfjail *j);
  72 static struct cfjail *find_proc(pid_t pid);
  73 static int term_procs(struct cfjail *j);
  74 static int get_user_info(struct cfjail *j, const char *username,
  75     const struct passwd **pwdp, login_cap_t **lcapp);
  76 static int check_path(struct cfjail *j, const char *pname, const char *path,
  77     int isfile, const char *umount_type);
  78
  79 static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
  80 static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
  81 static struct cfstring dummystring = { .len = 1 };
  82 static struct phhead phash[PHASH_SIZE];
  83 static int kq;
  84
  85 /*
  86  * Run the next command associated with a jail.
  87  */
  88 int
  89 next_command(struct cfjail *j)
  90 {
  91         enum intparam comparam;
  92         int create_failed, stopping;
  93
  94         if (paralimit == 0) {
  95                 if (j->flags & JF_FROM_RUNQ)
  96                         requeue_head(j, &runnable);
  97                 else
  98                         requeue(j, &runnable);
  99                 return 1;
 100         }
 101         j->flags &= ~JF_FROM_RUNQ;
 102         create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
 103         stopping = (j->flags & JF_STOP) != 0;
 104         comparam = *j->comparam;
 105         for (;;) {
 106                 if (j->comstring == NULL) {
 107                         j->comparam += create_failed ? -1 : 1;
 108                         switch ((comparam = *j->comparam)) {
 109                         case IP__NULL:
 110                                 return 0;
 111                         case IP_MOUNT_DEVFS:
 112                                 if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
 113                                         continue;
 114                                 j->comstring = &dummystring;
 115                                 break;
 116                         case IP_MOUNT_FDESCFS:
 117                                 if (!bool_param(j->intparams[IP_MOUNT_FDESCFS]))
 118                                         continue;
 119                                 j->comstring = &dummystring;
 120                                 break;
 121                         case IP_MOUNT_PROCFS:
 122                                 if (!bool_param(j->intparams[IP_MOUNT_PROCFS]))
 123                                         continue;
 124                                 j->comstring = &dummystring;
 125                                 break;
 126                         case IP__OP:
 127                         case IP_STOP_TIMEOUT:
 128                                 j->comstring = &dummystring;
 129                                 break;
 130                         default:
 131                                 if (j->intparams[comparam] == NULL)
 132                                         continue;
 133                                 j->comstring = create_failed || (stopping &&
 134                                     (j->intparams[comparam]->flags & PF_REV))
 135                                     ? TAILQ_LAST(&j->intparams[comparam]->val,
 136                                         cfstrings)
 137                                     : TAILQ_FIRST(&j->intparams[comparam]->val);
 138                         }
 139                 } else {
 140                         j->comstring = j->comstring == &dummystring ? NULL :
 141                             create_failed || (stopping &&
 142                             (j->intparams[comparam]->flags & PF_REV))
 143                             ? TAILQ_PREV(j->comstring, cfstrings, tq)
 144                             : TAILQ_NEXT(j->comstring, tq);
 145                 }
 146                 if (j->comstring == NULL || j->comstring->len == 0 ||
 147                     (create_failed && (comparam == IP_EXEC_PRESTART ||
 148                     comparam == IP_EXEC_START || comparam == IP_COMMAND ||
 149                     comparam == IP_EXEC_POSTSTART)))
 150                         continue;
 151                 switch (run_command(j)) {
 152                 case -1:
 153                         failed(j);
 154                         /* FALLTHROUGH */
 155                 case 1:
 156                         return 1;
 157                 }
 158         }
 159 }
 160
 161 /*
 162  * Check command exit status
 163  */
 164 int
 165 finish_command(struct cfjail *j)
 166 {
 167         struct cfjail *rj;
 168         int error;
 169
 170         if (!(j->flags & JF_SLEEPQ))
 171                 return 0;
 172         j->flags &= ~JF_SLEEPQ;
 173         if (*j->comparam == IP_STOP_TIMEOUT) {
 174                 j->flags &= ~JF_TIMEOUT;
 175                 j->pstatus = 0;
 176                 return 0;
 177         }
 178         paralimit++;
 179         if (!TAILQ_EMPTY(&runnable)) {
 180                 rj = TAILQ_FIRST(&runnable);
 181                 rj->flags |= JF_FROM_RUNQ;
 182                 requeue(rj, &ready);
 183         }
 184         error = 0;
 185         if (j->flags & JF_TIMEOUT) {
 186                 j->flags &= ~JF_TIMEOUT;
 187                 if (*j->comparam != IP_STOP_TIMEOUT) {
 188                         jail_warnx(j, "%s: timed out", j->comline);
 189                         failed(j);
 190                         error = -1;
 191                 } else if (verbose > 0)
 192                         jail_note(j, "timed out\n");
 193         } else if (j->pstatus != 0) {
 194                 if (WIFSIGNALED(j->pstatus))
 195                         jail_warnx(j, "%s: exited on signal %d",
 196                             j->comline, WTERMSIG(j->pstatus));
 197                 else
 198                         jail_warnx(j, "%s: failed", j->comline);
 199                 j->pstatus = 0;
 200                 failed(j);
 201                 error = -1;
 202         }
 203         free(j->comline);
 204         j->comline = NULL;
 205         return error;
 206 }
 207
 208 /*
 209  * Check for finished processes or timeouts.
 210  */
 211 struct cfjail *
 212 next_proc(int nonblock)
 213 {
 214         struct kevent ke;
 215         struct timespec ts;
 216         struct timespec *tsp;
 217         struct cfjail *j;
 218
 219         if (!TAILQ_EMPTY(&sleeping)) {
 220         again:
 221                 tsp = NULL;
 222                 if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
 223                         clock_gettime(CLOCK_REALTIME, &ts);
 224                         ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
 225                         ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
 226                         if (ts.tv_nsec < 0) {
 227                                 ts.tv_sec--;
 228                                 ts.tv_nsec += 1000000000;
 229                         }
 230                         if (ts.tv_sec < 0 ||
 231                             (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
 232                                 j->flags |= JF_TIMEOUT;
 233                                 clear_procs(j);
 234                                 return j;
 235                         }
 236                         tsp = &ts;
 237                 }
 238                 if (nonblock) {
 239                         ts.tv_sec = 0;
 240                         ts.tv_nsec = 0;
 241                         tsp = &ts;
 242                 }
 243                 switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
 244                 case -1:
 245                         if (errno != EINTR)
 246                                 err(1, "kevent");
 247                         goto again;
 248                 case 0:
 249                         if (!nonblock) {
 250                                 j = TAILQ_FIRST(&sleeping);
 251                                 j->flags |= JF_TIMEOUT;
 252                                 clear_procs(j);
 253                                 return j;
 254                         }
 255                         break;
 256                 case 1:
 257                         (void)waitpid(ke.ident, NULL, WNOHANG);
 258                         if ((j = find_proc(ke.ident))) {
 259                                 j->pstatus = ke.data;
 260                                 return j;
 261                         }
 262                         goto again;
 263                 }
 264         }
 265         return NULL;
 266 }
 267
 268 /*
 269  * Run a single command for a jail, possibly inside the jail.
 270  */
 271 static int
 272 run_command(struct cfjail *j)
 273 {
 274         const struct passwd *pwd;
 275         const struct cfstring *comstring, *s;
 276         login_cap_t *lcap;
 277         char **argv;
 278         char *cs, *comcs, *devpath;
 279         const char *jidstr, *conslog, *path, *ruleset, *term, *username;
 280         enum intparam comparam;
 281         size_t comlen;
 282         pid_t pid;
 283         int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
 284 #if defined(INET) || defined(INET6)
 285         char *addr, *extrap, *p, *val;
 286 #endif
 287
 288         static char *cleanenv;
 289
 290         /* Perform some operations that aren't actually commands */
 291         comparam = *j->comparam;
 292         down = j->flags & (JF_STOP | JF_FAILED);
 293         switch (comparam) {
 294         case IP_STOP_TIMEOUT:
 295                 return term_procs(j);
 296
 297         case IP__OP:
 298                 if (down) {
 299                         if (jail_remove(j->jid) < 0 && errno == EPERM) {
 300                                 jail_warnx(j, "jail_remove: %s",
 301                                            strerror(errno));
 302                                 return -1;
 303                         }
 304                         if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
 305                             ? note_remove : j->name != NULL)))
 306                             jail_note(j, "removed\n");
 307                         j->jid = -1;
 308                         if (j->flags & JF_STOP)
 309                                 dep_done(j, DF_LIGHT);
 310                         else
 311                                 j->flags &= ~JF_PERSIST;
 312                 } else {
 313                         if (create_jail(j) < 0)
 314                                 return -1;
 315                         if (iflag)
 316                                 printf("%d\n", j->jid);
 317                         if (verbose >= 0 && (j->name || verbose > 0))
 318                                 jail_note(j, "created\n");
 319                         dep_done(j, DF_LIGHT);
 320                 }
 321                 return 0;
 322
 323         default: ;
 324         }
 325         /*
 326          * Collect exec arguments.  Internal commands for network and
 327          * mounting build their own argument lists.
 328          */
 329         comstring = j->comstring;
 330         bg = 0;
 331         switch (comparam) {
 332 #ifdef INET
 333         case IP__IP4_IFADDR:
 334                 argc = 0;
 335                 val = alloca(strlen(comstring->s) + 1);
 336                 strcpy(val, comstring->s);
 337                 cs = val;
 338                 extrap = NULL;
 339                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 340                         if (extrap == NULL) {
 341                                 *p = '\0';
 342                                 extrap = p + 1;
 343                         }
 344                         cs = p + 1;
 345                         argc++;
 346                 }
 347
 348                 argv = alloca((8 + argc) * sizeof(char *));
 349                 *(const char **)&argv[0] = _PATH_IFCONFIG;
 350                 if ((cs = strchr(val, '|'))) {
 351                         argv[1] = alloca(cs - val + 1);
 352                         strlcpy(argv[1], val, cs - val + 1);
 353                         addr = cs + 1;
 354                 } else {
 355                         *(const char **)&argv[1] =
 356                             string_param(j->intparams[IP_INTERFACE]);
 357                         addr = val;
 358                 }
 359                 *(const char **)&argv[2] = "inet";
 360                 if (!(cs = strchr(addr, '/'))) {
 361                         argv[3] = addr;
 362                         *(const char **)&argv[4] = "netmask";
 363                         *(const char **)&argv[5] = "255.255.255.255";
 364                         argc = 6;
 365                 } else if (strchr(cs + 1, '.')) {
 366                         argv[3] = alloca(cs - addr + 1);
 367                         strlcpy(argv[3], addr, cs - addr + 1);
 368                         *(const char **)&argv[4] = "netmask";
 369                         *(const char **)&argv[5] = cs + 1;
 370                         argc = 6;
 371                 } else {
 372                         argv[3] = addr;
 373                         argc = 4;
 374                 }
 375
 376                 if (!down) {
 377                         for (cs = strtok(extrap, " "); cs; cs = strtok(NULL, " ")) {
 378                                 size_t len = strlen(cs) + 1;
 379                                 argv[argc] = alloca(len);
 380                                 strlcpy(argv[argc++], cs, len);
 381                         }
 382                 }
 383
 384                 *(const char **)&argv[argc] = down ? "-alias" : "alias";
 385                 argv[argc + 1] = NULL;
 386                 break;
 387 #endif
 388
 389 #ifdef INET6
 390         case IP__IP6_IFADDR:
 391                 argc = 0;
 392                 val = alloca(strlen(comstring->s) + 1);
 393                 strcpy(val, comstring->s);
 394                 cs = val;
 395                 extrap = NULL;
 396                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 397                         if (extrap == NULL) {
 398                                 *p = '\0';
 399                                 extrap = p + 1;
 400                         }
 401                         cs = p + 1;
 402                         argc++;
 403                 }
 404
 405                 argv = alloca((8 + argc) * sizeof(char *));
 406                 *(const char **)&argv[0] = _PATH_IFCONFIG;
 407                 if ((cs = strchr(val, '|'))) {
 408                         argv[1] = alloca(cs - val + 1);
 409                         strlcpy(argv[1], val, cs - val + 1);
 410                         addr = cs + 1;
 411                 } else {
 412                         *(const char **)&argv[1] =
 413                             string_param(j->intparams[IP_INTERFACE]);
 414                         addr = val;
 415                 }
 416                 *(const char **)&argv[2] = "inet6";
 417                 argv[3] = addr;
 418                 if (!(cs = strchr(addr, '/'))) {
 419                         *(const char **)&argv[4] = "prefixlen";
 420                         *(const char **)&argv[5] = "128";
 421                         argc = 6;
 422                 } else
 423                         argc = 4;
 424
 425                 if (!down) {
 426                         for (cs = strtok(extrap, " "); cs; cs = strtok(NULL, " ")) {
 427                                 size_t len = strlen(cs) + 1;
 428                                 argv[argc] = alloca(len);
 429                                 strlcpy(argv[argc++], cs, len);
 430                         }
 431                 }
 432
 433                 *(const char **)&argv[argc] = down ? "-alias" : "alias";
 434                 argv[argc + 1] = NULL;
 435                 break;
 436 #endif
 437
 438         case IP_VNET_INTERFACE:
 439                 argv = alloca(5 * sizeof(char *));
 440                 *(const char **)&argv[0] = _PATH_IFCONFIG;
 441                 argv[1] = comstring->s;
 442                 *(const char **)&argv[2] = down ? "-vnet" : "vnet";
 443                 jidstr = string_param(j->intparams[KP_JID]);
 444                 *(const char **)&argv[3] =
 445                         jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
 446                 argv[4] = NULL;
 447                 break;
 448
 449         case IP_MOUNT:
 450         case IP__MOUNT_FROM_FSTAB:
 451                 argv = alloca(8 * sizeof(char *));
 452                 comcs = alloca(comstring->len + 1);
 453                 strcpy(comcs, comstring->s);
 454                 argc = 0;
 455                 for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
 456                      cs = strtok(NULL, " \t\f\v\r\n")) {
 457                         if (argc <= 1 && strunvis(cs, cs) < 0) {
 458                                 jail_warnx(j, "%s: %s: fstab parse error",
 459                                     j->intparams[comparam]->name, comstring->s);
 460                                 return -1;
 461                         }
 462                         argv[argc++] = cs;
 463                 }
 464                 if (argc == 0)
 465                         return 0;
 466                 if (argc < 3) {
 467                         jail_warnx(j, "%s: %s: missing information",
 468                             j->intparams[comparam]->name, comstring->s);
 469                         return -1;
 470                 }
 471                 if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
 472                     down ? argv[2] : NULL) < 0)
 473                         return -1;
 474                 if (down) {
 475                         argv[4] = NULL;
 476                         argv[3] = argv[1];
 477                         *(const char **)&argv[0] = "/sbin/umount";
 478                 } else {
 479                         if (argc == 4) {
 480                                 argv[7] = NULL;
 481                                 argv[6] = argv[1];
 482                                 argv[5] = argv[0];
 483                                 argv[4] = argv[3];
 484                                 *(const char **)&argv[3] = "-o";
 485                         } else {
 486                                 argv[5] = NULL;
 487                                 argv[4] = argv[1];
 488                                 argv[3] = argv[0];
 489                         }
 490                         *(const char **)&argv[0] = _PATH_MOUNT;
 491                 }
 492                 *(const char **)&argv[1] = "-t";
 493                 break;
 494
 495         case IP_MOUNT_DEVFS:
 496                 argv = alloca(7 * sizeof(char *));
 497                 path = string_param(j->intparams[KP_PATH]);
 498                 if (path == NULL) {
 499                         jail_warnx(j, "mount.devfs: no path");
 500                         return -1;
 501                 }
 502                 devpath = alloca(strlen(path) + 5);
 503                 sprintf(devpath, "%s/dev", path);
 504                 if (check_path(j, "mount.devfs", devpath, 0,
 505                     down ? "devfs" : NULL) < 0)
 506                         return -1;
 507                 if (down) {
 508                         *(const char **)&argv[0] = "/sbin/umount";
 509                         argv[1] = devpath;
 510                         argv[2] = NULL;
 511                 } else {
 512                         *(const char **)&argv[0] = _PATH_MOUNT;
 513                         *(const char **)&argv[1] = "-t";
 514                         *(const char **)&argv[2] = "devfs";
 515                         ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
 516                         if (!ruleset)
 517                             ruleset = "4";      /* devfsrules_jail */
 518                         argv[3] = alloca(11 + strlen(ruleset));
 519                         sprintf(argv[3], "-oruleset=%s", ruleset);
 520                         *(const char **)&argv[4] = ".";
 521                         argv[5] = devpath;
 522                         argv[6] = NULL;
 523                 }
 524                 break;
 525
 526         case IP_MOUNT_FDESCFS:
 527                 argv = alloca(7 * sizeof(char *));
 528                 path = string_param(j->intparams[KP_PATH]);
 529                 if (path == NULL) {
 530                         jail_warnx(j, "mount.fdescfs: no path");
 531                         return -1;
 532                 }
 533                 devpath = alloca(strlen(path) + 8);
 534                 sprintf(devpath, "%s/dev/fd", path);
 535                 if (check_path(j, "mount.fdescfs", devpath, 0,
 536                     down ? "fdescfs" : NULL) < 0)
 537                         return -1;
 538                 if (down) {
 539                         *(const char **)&argv[0] = "/sbin/umount";
 540                         argv[1] = devpath;
 541                         argv[2] = NULL;
 542                 } else {
 543                         *(const char **)&argv[0] = _PATH_MOUNT;
 544                         *(const char **)&argv[1] = "-t";
 545                         *(const char **)&argv[2] = "fdescfs";
 546                         *(const char **)&argv[3] = ".";
 547                         argv[4] = devpath;
 548                         argv[5] = NULL;
 549                 }
 550                 break;
 551
 552         case IP_MOUNT_PROCFS:
 553                 argv = alloca(7 * sizeof(char *));
 554                 path = string_param(j->intparams[KP_PATH]);
 555                 if (path == NULL) {
 556                         jail_warnx(j, "mount.procfs: no path");
 557                         return -1;
 558                 }
 559                 devpath = alloca(strlen(path) + 6);
 560                 sprintf(devpath, "%s/proc", path);
 561                 if (check_path(j, "mount.procfs", devpath, 0,
 562                     down ? "procfs" : NULL) < 0)
 563                         return -1;
 564                 if (down) {
 565                         *(const char **)&argv[0] = "/sbin/umount";
 566                         argv[1] = devpath;
 567                         argv[2] = NULL;
 568                 } else {
 569                         *(const char **)&argv[0] = _PATH_MOUNT;
 570                         *(const char **)&argv[1] = "-t";
 571                         *(const char **)&argv[2] = "procfs";
 572                         *(const char **)&argv[3] = ".";
 573                         argv[4] = devpath;
 574                         argv[5] = NULL;
 575                 }
 576                 break;
 577
 578         case IP_COMMAND:
 579                 if (j->name != NULL)
 580                         goto default_command;
 581                 argc = 0;
 582                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 583                         argc++;
 584                 argv = alloca((argc + 1) * sizeof(char *));
 585                 argc = 0;
 586                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 587                         argv[argc++] = s->s;
 588                 argv[argc] = NULL;
 589                 j->comstring = &dummystring;
 590                 break;
 591
 592         default:
 593         default_command:
 594                 if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
 595                     !(cs[0] == '&' && cs[1] == '\0')) {
 596                         argv = alloca(4 * sizeof(char *));
 597                         *(const char **)&argv[0] = _PATH_BSHELL;
 598                         *(const char **)&argv[1] = "-c";
 599                         argv[2] = comstring->s;
 600                         argv[3] = NULL;
 601                 } else {
 602                         if (cs) {
 603                                 *cs = 0;
 604                                 bg = 1;
 605                         }
 606                         comcs = alloca(comstring->len + 1);
 607                         strcpy(comcs, comstring->s);
 608                         argc = 0;
 609                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 610                              cs = strtok(NULL, " \t\f\v\r\n"))
 611                                 argc++;
 612                         argv = alloca((argc + 1) * sizeof(char *));
 613                         strcpy(comcs, comstring->s);
 614                         argc = 0;
 615                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 616                              cs = strtok(NULL, " \t\f\v\r\n"))
 617                                 argv[argc++] = cs;
 618                         argv[argc] = NULL;
 619                 }
 620         }
 621         if (argv[0] == NULL)
 622                 return 0;
 623
 624         if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
 625             timeout != 0) {
 626                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 627                 j->timeout.tv_sec += timeout;
 628         } else
 629                 j->timeout.tv_sec = 0;
 630
 631         injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
 632             comparam == IP_EXEC_STOP;
 633         clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
 634         username = string_param(j->intparams[injail
 635             ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
 636         sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
 637
 638         consfd = 0;
 639         if (injail &&
 640             (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
 641                 if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
 642                         return -1;
 643                 consfd =
 644                     open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
 645                 if (consfd < 0) {
 646                         jail_warnx(j, "open %s: %s", conslog, strerror(errno));
 647                         return -1;
 648                 }
 649         }
 650
 651         comlen = 0;
 652         for (i = 0; argv[i]; i++)
 653                 comlen += strlen(argv[i]) + 1;
 654         j->comline = cs = emalloc(comlen);
 655         for (i = 0; argv[i]; i++) {
 656                 strcpy(cs, argv[i]);
 657                 if (argv[i + 1]) {
 658                         cs += strlen(argv[i]) + 1;
 659                         cs[-1] = ' ';
 660                 }
 661         }
 662         if (verbose > 0)
 663                 jail_note(j, "run command%s%s%s: %s\n",
 664                     injail ? " in jail" : "", username ? " as " : "",
 665                     username ? username : "", j->comline);
 666
 667         pid = fork();
 668         if (pid < 0)
 669                 err(1, "fork");
 670         if (pid > 0) {
 671                 if (bg || !add_proc(j, pid)) {
 672                         free(j->comline);
 673                         j->comline = NULL;
 674                         return 0;
 675                 } else {
 676                         paralimit--;
 677                         return 1;
 678                 }
 679         }
 680         if (bg)
 681                 setsid();
 682
 683         /* Set up the environment and run the command */
 684         pwd = NULL;
 685         lcap = NULL;
 686         if ((clean || username) && injail && sjuser &&
 687             get_user_info(j, username, &pwd, &lcap) < 0)
 688                 exit(1);
 689         if (injail) {
 690                 /* jail_attach won't chdir along with its chroot. */
 691                 path = string_param(j->intparams[KP_PATH]);
 692                 if (path && chdir(path) < 0) {
 693                         jail_warnx(j, "chdir %s: %s", path, strerror(errno));
 694                         exit(1);
 695                 }
 696                 if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
 697                     setfib(fib) < 0) {
 698                         jail_warnx(j, "setfib: %s", strerror(errno));
 699                         exit(1);
 700                 }
 701                 if (jail_attach(j->jid) < 0) {
 702                         jail_warnx(j, "jail_attach: %s", strerror(errno));
 703                         exit(1);
 704                 }
 705         }
 706         if (clean || username) {
 707                 if (!(injail && sjuser) &&
 708                     get_user_info(j, username, &pwd, &lcap) < 0)
 709                         exit(1);
 710                 if (clean) {
 711                         term = getenv("TERM");
 712                         environ = &cleanenv;
 713                         setenv("PATH", "/bin:/usr/bin", 0);
 714                         if (term != NULL)
 715                                 setenv("TERM", term, 1);
 716                 }
 717                 if (setgid(pwd->pw_gid) < 0) {
 718                         jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
 719                             strerror(errno));
 720                         exit(1);
 721                 }
 722                 if (setusercontext(lcap, pwd, pwd->pw_uid, username
 723                     ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
 724                     : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
 725                         jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
 726                             strerror(errno));
 727                         exit(1);
 728                 }
 729                 login_close(lcap);
 730                 setenv("USER", pwd->pw_name, 1);
 731                 setenv("HOME", pwd->pw_dir, 1);
 732                 setenv("SHELL",
 733                     *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
 734                 if (clean && chdir(pwd->pw_dir) < 0) {
 735                         jail_warnx(j, "chdir %s: %s",
 736                             pwd->pw_dir, strerror(errno));
 737                         exit(1);
 738                 }
 739                 endpwent();
 740         }
 741
 742         if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
 743                 jail_warnx(j, "exec.consolelog: %s", strerror(errno));
 744                 exit(1);
 745         }
 746         closefrom(3);
 747         execvp(argv[0], argv);
 748         jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
 749         exit(1);
 750 }
 751
 752 /*
 753  * Add a process to the hash, tied to a jail.
 754  */
 755 static int
 756 add_proc(struct cfjail *j, pid_t pid)
 757 {
 758         struct kevent ke;
 759         struct cfjail *tj;
 760         struct phash *ph;
 761
 762         if (!kq && (kq = kqueue()) < 0)
 763                 err(1, "kqueue");
 764         EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
 765         if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
 766                 if (errno == ESRCH)
 767                         return 0;
 768                 err(1, "kevent");
 769         }
 770         ph = emalloc(sizeof(struct phash));
 771         ph->j = j;
 772         ph->pid = pid;
 773         LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
 774         j->nprocs++;
 775         j->flags |= JF_SLEEPQ;
 776         if (j->timeout.tv_sec == 0)
 777                 requeue(j, &sleeping);
 778         else {
 779                 /* File the jail in the sleep queue according to its timeout. */
 780                 TAILQ_REMOVE(j->queue, j, tq);
 781                 TAILQ_FOREACH(tj, &sleeping, tq) {
 782                         if (!tj->timeout.tv_sec ||
 783                             j->timeout.tv_sec < tj->timeout.tv_sec ||
 784                             (j->timeout.tv_sec == tj->timeout.tv_sec &&
 785                             j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
 786                                 TAILQ_INSERT_BEFORE(tj, j, tq);
 787                                 break;
 788                         }
 789                 }
 790                 if (tj == NULL)
 791                         TAILQ_INSERT_TAIL(&sleeping, j, tq);
 792                 j->queue = &sleeping;
 793         }
 794         return 1;
 795 }
 796
 797 /*
 798  * Remove any processes from the hash that correspond to a jail.
 799  */
 800 static void
 801 clear_procs(struct cfjail *j)
 802 {
 803         struct kevent ke;
 804         struct phash *ph, *tph;
 805         int i;
 806
 807         j->nprocs = 0;
 808         for (i = 0; i < PHASH_SIZE; i++)
 809                 LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
 810                         if (ph->j == j) {
 811                                 EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
 812                                     NOTE_EXIT, 0, NULL);
 813                                 (void)kevent(kq, &ke, 1, NULL, 0, NULL);
 814                                 LIST_REMOVE(ph, le);
 815                                 free(ph);
 816                         }
 817 }
 818
 819 /*
 820  * Find the jail that corresponds to an exited process.
 821  */
 822 static struct cfjail *
 823 find_proc(pid_t pid)
 824 {
 825         struct cfjail *j;
 826         struct phash *ph;
 827
 828         LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
 829                 if (ph->pid == pid) {
 830                         j = ph->j;
 831                         LIST_REMOVE(ph, le);
 832                         free(ph);
 833                         return --j->nprocs ? NULL : j;
 834                 }
 835         return NULL;
 836 }
 837
 838 /*
 839  * Send SIGTERM to all processes in a jail and wait for them to die.
 840  */
 841 static int
 842 term_procs(struct cfjail *j)
 843 {
 844         struct kinfo_proc *ki;
 845         int i, noted, pcnt, timeout;
 846
 847         static kvm_t *kd;
 848
 849         if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
 850                 timeout = DEFAULT_STOP_TIMEOUT;
 851         else if (timeout == 0)
 852                 return 0;
 853
 854         if (kd == NULL) {
 855                 kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
 856                 if (kd == NULL)
 857                         return 0;
 858         }
 859
 860         ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
 861         if (ki == NULL)
 862                 return 0;
 863         noted = 0;
 864         for (i = 0; i < pcnt; i++)
 865                 if (ki[i].ki_jid == j->jid &&
 866                     kill(ki[i].ki_pid, SIGTERM) == 0) {
 867                         (void)add_proc(j, ki[i].ki_pid);
 868                         if (verbose > 0) {
 869                                 if (!noted) {
 870                                         noted = 1;
 871                                         jail_note(j, "sent SIGTERM to:");
 872                                 }
 873                                 printf(" %d", ki[i].ki_pid);
 874                         }
 875                 }
 876         if (noted)
 877                 printf("\n");
 878         if (j->nprocs > 0) {
 879                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 880                 j->timeout.tv_sec += timeout;
 881                 return 1;
 882         }
 883         return 0;
 884 }
 885
 886 /*
 887  * Look up a user in the passwd and login.conf files.
 888  */
 889 static int
 890 get_user_info(struct cfjail *j, const char *username,
 891     const struct passwd **pwdp, login_cap_t **lcapp)
 892 {
 893         const struct passwd *pwd;
 894
 895         errno = 0;
 896         *pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
 897         if (pwd == NULL) {
 898                 if (errno)
 899                         jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
 900                             username ? username : "", strerror(errno));
 901                 else if (username)
 902                         jail_warnx(j, "%s: no such user", username);
 903                 else
 904                         jail_warnx(j, "unknown uid %d", getuid());
 905                 return -1;
 906         }
 907         *lcapp = login_getpwclass(pwd);
 908         if (*lcapp == NULL) {
 909                 jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
 910                     strerror(errno));
 911                 return -1;
 912         }
 913         /* Set the groups while the group file is still available */
 914         if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
 915                 jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
 916                     strerror(errno));
 917                 return -1;
 918         }
 919         return 0;
 920 }
 921
 922 /*
 923  * Make sure a mount or consolelog path is a valid absolute pathname
 924  * with no symlinks.
 925  */
 926 static int
 927 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
 928     const char *umount_type)
 929 {
 930         struct stat st, mpst;
 931         struct statfs stfs;
 932         char *tpath, *p;
 933         const char *jailpath;
 934         size_t jplen;
 935
 936         if (path[0] != '/') {
 937                 jail_warnx(j, "%s: %s: not an absolute pathname",
 938                     pname, path);
 939                 return -1;
 940         }
 941         /*
 942          * Only check for symlinks in components below the jail's path,
 943          * since that's where the security risk lies.
 944          */
 945         jailpath = string_param(j->intparams[KP_PATH]);
 946         if (jailpath == NULL)
 947                 jailpath = "";
 948         jplen = strlen(jailpath);
 949         if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
 950                 tpath = alloca(strlen(path) + 1);
 951                 strcpy(tpath, path);
 952                 for (p = tpath + jplen; p != NULL; ) {
 953                         p = strchr(p + 1, '/');
 954                         if (p)
 955                                 *p = '\0';
 956                         if (lstat(tpath, &st) < 0) {
 957                                 if (errno == ENOENT && isfile && !p)
 958                                         break;
 959                                 jail_warnx(j, "%s: %s: %s", pname, tpath,
 960                                     strerror(errno));
 961                                 return -1;
 962                         }
 963                         if (S_ISLNK(st.st_mode)) {
 964                                 jail_warnx(j, "%s: %s is a symbolic link",
 965                                     pname, tpath);
 966                                 return -1;
 967                         }
 968                         if (p)
 969                                 *p = '/';
 970                 }
 971         }
 972         if (umount_type != NULL) {
 973                 if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
 974                         jail_warnx(j, "%s: %s: %s", pname, path,
 975                             strerror(errno));
 976                         return -1;
 977                 }
 978                 if (stat(stfs.f_mntonname, &mpst) < 0) {
 979                         jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
 980                             strerror(errno));
 981                         return -1;
 982                 }
 983                 if (st.st_ino != mpst.st_ino) {
 984                         jail_warnx(j, "%s: %s: not a mount point",
 985                             pname, path);
 986                         return -1;
 987                 }
 988                 if (strcmp(stfs.f_fstypename, umount_type)) {
 989                         jail_warnx(j, "%s: %s: not a %s mount",
 990                             pname, path, umount_type);
 991                         return -1;
 992                 }
 993         }
 994         return 0;
 995 }