usr.sbin/jail/command.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2011 James Gritton
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/types.h>
  33 #include <sys/cpuset.h>
  34 #include <sys/event.h>
  35 #include <sys/mount.h>
  36 #include <sys/stat.h>
  37 #include <sys/sysctl.h>
  38 #include <sys/user.h>
  39 #include <sys/wait.h>
  40
  41 #include <err.h>
  42 #include <errno.h>
  43 #include <fcntl.h>
  44 #include <kvm.h>
  45 #include <login_cap.h>
  46 #include <paths.h>
  47 #include <pwd.h>
  48 #include <signal.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53 #include <vis.h>
  54
  55 #include "jailp.h"
  56
  57 #define DEFAULT_STOP_TIMEOUT    10
  58 #define PHASH_SIZE              256
  59
  60 LIST_HEAD(phhead, phash);
  61
  62 struct phash {
  63         LIST_ENTRY(phash)       le;
  64         struct cfjail           *j;
  65         pid_t                   pid;
  66 };
  67
  68 int paralimit = -1;
  69
  70 extern char **environ;
  71
  72 static int run_command(struct cfjail *j);
  73 static int add_proc(struct cfjail *j, pid_t pid);
  74 static void clear_procs(struct cfjail *j);
  75 static struct cfjail *find_proc(pid_t pid);
  76 static int term_procs(struct cfjail *j);
  77 static int get_user_info(struct cfjail *j, const char *username,
  78     const struct passwd **pwdp, login_cap_t **lcapp);
  79 static int check_path(struct cfjail *j, const char *pname, const char *path,
  80     int isfile, const char *umount_type);
  81
  82 static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
  83 static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
  84 static struct cfstring dummystring = { .len = 1 };
  85 static struct phhead phash[PHASH_SIZE];
  86 static int kq;
  87
  88 static cpusetid_t
  89 root_cpuset_id(void)
  90 {
  91         static cpusetid_t setid = CPUSET_INVALID;
  92         static int error;
  93
  94         /* Only try to get the cpuset once. */
  95         if (error == 0 && setid == CPUSET_INVALID)
  96                 error = cpuset_getid(CPU_LEVEL_ROOT, CPU_WHICH_PID, -1, &setid);
  97         if (error != 0)
  98                 return (CPUSET_INVALID);
  99         return (setid);
 100 }
 101
 102 /*
 103  * Run the next command associated with a jail.
 104  */
 105 int
 106 next_command(struct cfjail *j)
 107 {
 108         enum intparam comparam;
 109         int create_failed, stopping;
 110
 111         if (paralimit == 0) {
 112                 if (j->flags & JF_FROM_RUNQ)
 113                         requeue_head(j, &runnable);
 114                 else
 115                         requeue(j, &runnable);
 116                 return 1;
 117         }
 118         j->flags &= ~JF_FROM_RUNQ;
 119         create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
 120         stopping = (j->flags & JF_STOP) != 0;
 121         comparam = *j->comparam;
 122         for (;;) {
 123                 if (j->comstring == NULL) {
 124                         j->comparam += create_failed ? -1 : 1;
 125                         switch ((comparam = *j->comparam)) {
 126                         case IP__NULL:
 127                                 return 0;
 128                         case IP_MOUNT_DEVFS:
 129                                 if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
 130                                         continue;
 131                                 j->comstring = &dummystring;
 132                                 break;
 133                         case IP_MOUNT_FDESCFS:
 134                                 if (!bool_param(j->intparams[IP_MOUNT_FDESCFS]))
 135                                         continue;
 136                                 j->comstring = &dummystring;
 137                                 break;
 138                         case IP_MOUNT_PROCFS:
 139                                 if (!bool_param(j->intparams[IP_MOUNT_PROCFS]))
 140                                         continue;
 141                                 j->comstring = &dummystring;
 142                                 break;
 143                         case IP__OP:
 144                         case IP_STOP_TIMEOUT:
 145                                 j->comstring = &dummystring;
 146                                 break;
 147                         default:
 148                                 if (j->intparams[comparam] == NULL)
 149                                         continue;
 150                                 j->comstring = create_failed || (stopping &&
 151                                     (j->intparams[comparam]->flags & PF_REV))
 152                                     ? TAILQ_LAST(&j->intparams[comparam]->val,
 153                                         cfstrings)
 154                                     : TAILQ_FIRST(&j->intparams[comparam]->val);
 155                         }
 156                 } else {
 157                         j->comstring = j->comstring == &dummystring ? NULL :
 158                             create_failed || (stopping &&
 159                             (j->intparams[comparam]->flags & PF_REV))
 160                             ? TAILQ_PREV(j->comstring, cfstrings, tq)
 161                             : TAILQ_NEXT(j->comstring, tq);
 162                 }
 163                 if (j->comstring == NULL || j->comstring->len == 0 ||
 164                     (create_failed && (comparam == IP_EXEC_PRESTART ||
 165                     comparam == IP_EXEC_CREATED || comparam == IP_EXEC_START ||
 166                     comparam == IP_COMMAND || comparam == IP_EXEC_POSTSTART ||
 167                     comparam == IP_EXEC_PREPARE)))
 168                         continue;
 169                 switch (run_command(j)) {
 170                 case -1:
 171                         failed(j);
 172                         /* FALLTHROUGH */
 173                 case 1:
 174                         return 1;
 175                 }
 176         }
 177 }
 178
 179 /*
 180  * Check command exit status
 181  */
 182 int
 183 finish_command(struct cfjail *j)
 184 {
 185         struct cfjail *rj;
 186         int error;
 187
 188         if (!(j->flags & JF_SLEEPQ))
 189                 return 0;
 190         j->flags &= ~JF_SLEEPQ;
 191         if (*j->comparam == IP_STOP_TIMEOUT) {
 192                 j->flags &= ~JF_TIMEOUT;
 193                 j->pstatus = 0;
 194                 return 0;
 195         }
 196         paralimit++;
 197         if (!TAILQ_EMPTY(&runnable)) {
 198                 rj = TAILQ_FIRST(&runnable);
 199                 rj->flags |= JF_FROM_RUNQ;
 200                 requeue(rj, &ready);
 201         }
 202         error = 0;
 203         if (j->flags & JF_TIMEOUT) {
 204                 j->flags &= ~JF_TIMEOUT;
 205                 if (*j->comparam != IP_STOP_TIMEOUT) {
 206                         jail_warnx(j, "%s: timed out", j->comline);
 207                         failed(j);
 208                         error = -1;
 209                 } else if (verbose > 0)
 210                         jail_note(j, "timed out\n");
 211         } else if (j->pstatus != 0) {
 212                 if (WIFSIGNALED(j->pstatus))
 213                         jail_warnx(j, "%s: exited on signal %d",
 214                             j->comline, WTERMSIG(j->pstatus));
 215                 else
 216                         jail_warnx(j, "%s: failed", j->comline);
 217                 j->pstatus = 0;
 218                 failed(j);
 219                 error = -1;
 220         }
 221         free(j->comline);
 222         j->comline = NULL;
 223         return error;
 224 }
 225
 226 /*
 227  * Check for finished processes or timeouts.
 228  */
 229 struct cfjail *
 230 next_proc(int nonblock)
 231 {
 232         struct kevent ke;
 233         struct timespec ts;
 234         struct timespec *tsp;
 235         struct cfjail *j;
 236
 237         if (!TAILQ_EMPTY(&sleeping)) {
 238         again:
 239                 tsp = NULL;
 240                 if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
 241                         clock_gettime(CLOCK_REALTIME, &ts);
 242                         ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
 243                         ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
 244                         if (ts.tv_nsec < 0) {
 245                                 ts.tv_sec--;
 246                                 ts.tv_nsec += 1000000000;
 247                         }
 248                         if (ts.tv_sec < 0 ||
 249                             (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
 250                                 j->flags |= JF_TIMEOUT;
 251                                 clear_procs(j);
 252                                 return j;
 253                         }
 254                         tsp = &ts;
 255                 }
 256                 if (nonblock) {
 257                         ts.tv_sec = 0;
 258                         ts.tv_nsec = 0;
 259                         tsp = &ts;
 260                 }
 261                 switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
 262                 case -1:
 263                         if (errno != EINTR)
 264                                 err(1, "kevent");
 265                         goto again;
 266                 case 0:
 267                         if (!nonblock) {
 268                                 j = TAILQ_FIRST(&sleeping);
 269                                 j->flags |= JF_TIMEOUT;
 270                                 clear_procs(j);
 271                                 return j;
 272                         }
 273                         break;
 274                 case 1:
 275                         (void)waitpid(ke.ident, NULL, WNOHANG);
 276                         if ((j = find_proc(ke.ident))) {
 277                                 j->pstatus = ke.data;
 278                                 return j;
 279                         }
 280                         goto again;
 281                 }
 282         }
 283         return NULL;
 284 }
 285
 286 /*
 287  * Run a single command for a jail, possibly inside the jail.
 288  */
 289 static int
 290 run_command(struct cfjail *j)
 291 {
 292         const struct passwd *pwd;
 293         const struct cfstring *comstring, *s;
 294         login_cap_t *lcap;
 295         const char **argv;
 296         char *acs, *cs, *comcs, *devpath;
 297         const char *jidstr, *conslog, *path, *ruleset, *term, *username;
 298         enum intparam comparam;
 299         size_t comlen;
 300         pid_t pid;
 301         cpusetid_t setid;
 302         int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
 303 #if defined(INET) || defined(INET6)
 304         char *addr, *extrap, *p, *val;
 305 #endif
 306
 307         static char *cleanenv;
 308
 309         /* Perform some operations that aren't actually commands */
 310         comparam = *j->comparam;
 311         down = j->flags & (JF_STOP | JF_FAILED);
 312         switch (comparam) {
 313         case IP_STOP_TIMEOUT:
 314                 return term_procs(j);
 315
 316         case IP__OP:
 317                 if (down) {
 318                         if (jail_remove(j->jid) < 0 && errno == EPERM) {
 319                                 jail_warnx(j, "jail_remove: %s",
 320                                            strerror(errno));
 321                                 return -1;
 322                         }
 323                         if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
 324                             ? note_remove : j->name != NULL)))
 325                             jail_note(j, "removed\n");
 326                         j->jid = -1;
 327                         if (j->flags & JF_STOP)
 328                                 dep_done(j, DF_LIGHT);
 329                         else
 330                                 j->flags &= ~JF_PERSIST;
 331                 } else {
 332                         if (create_jail(j) < 0)
 333                                 return -1;
 334                         if (iflag)
 335                                 printf("%d\n", j->jid);
 336                         if (verbose >= 0 && (j->name || verbose > 0))
 337                                 jail_note(j, "created\n");
 338                         dep_done(j, DF_LIGHT);
 339                 }
 340                 return 0;
 341
 342         default: ;
 343         }
 344         /*
 345          * Collect exec arguments.  Internal commands for network and
 346          * mounting build their own argument lists.
 347          */
 348         comstring = j->comstring;
 349         bg = 0;
 350         switch (comparam) {
 351 #ifdef INET
 352         case IP__IP4_IFADDR:
 353                 argc = 0;
 354                 val = alloca(strlen(comstring->s) + 1);
 355                 strcpy(val, comstring->s);
 356                 cs = val;
 357                 extrap = NULL;
 358                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 359                         if (extrap == NULL) {
 360                                 *p = '\0';
 361                                 extrap = p + 1;
 362                         }
 363                         cs = p + 1;
 364                         argc++;
 365                 }
 366
 367                 argv = alloca((8 + argc) * sizeof(char *));
 368                 argv[0] = _PATH_IFCONFIG;
 369                 if ((cs = strchr(val, '|'))) {
 370                         argv[1] = acs = alloca(cs - val + 1);
 371                         strlcpy(acs, val, cs - val + 1);
 372                         addr = cs + 1;
 373                 } else {
 374                         argv[1] = string_param(j->intparams[IP_INTERFACE]);
 375                         addr = val;
 376                 }
 377                 argv[2] = "inet";
 378                 if (!(cs = strchr(addr, '/'))) {
 379                         argv[3] = addr;
 380                         argv[4] = "netmask";
 381                         argv[5] = "255.255.255.255";
 382                         argc = 6;
 383                 } else if (strchr(cs + 1, '.')) {
 384                         argv[3] = acs = alloca(cs - addr + 1);
 385                         strlcpy(acs, addr, cs - addr + 1);
 386                         argv[4] = "netmask";
 387                         argv[5] = cs + 1;
 388                         argc = 6;
 389                 } else {
 390                         argv[3] = addr;
 391                         argc = 4;
 392                 }
 393
 394                 if (!down && extrap != NULL) {
 395                         for (cs = strtok(extrap, " "); cs;
 396                              cs = strtok(NULL, " ")) {
 397                                 size_t len = strlen(cs) + 1;
 398                                 argv[argc++] = acs = alloca(len);
 399                                 strlcpy(acs, cs, len);
 400                         }
 401                 }
 402
 403                 argv[argc] = down ? "-alias" : "alias";
 404                 argv[argc + 1] = NULL;
 405                 break;
 406 #endif
 407
 408 #ifdef INET6
 409         case IP__IP6_IFADDR:
 410                 argc = 0;
 411                 val = alloca(strlen(comstring->s) + 1);
 412                 strcpy(val, comstring->s);
 413                 cs = val;
 414                 extrap = NULL;
 415                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 416                         if (extrap == NULL) {
 417                                 *p = '\0';
 418                                 extrap = p + 1;
 419                         }
 420                         cs = p + 1;
 421                         argc++;
 422                 }
 423
 424                 argv = alloca((8 + argc) * sizeof(char *));
 425                 argv[0] = _PATH_IFCONFIG;
 426                 if ((cs = strchr(val, '|'))) {
 427                         argv[1] = acs = alloca(cs - val + 1);
 428                         strlcpy(acs, val, cs - val + 1);
 429                         addr = cs + 1;
 430                 } else {
 431                         argv[1] = string_param(j->intparams[IP_INTERFACE]);
 432                         addr = val;
 433                 }
 434                 argv[2] = "inet6";
 435                 argv[3] = addr;
 436                 if (!(cs = strchr(addr, '/'))) {
 437                         argv[4] = "prefixlen";
 438                         argv[5] = "128";
 439                         argc = 6;
 440                 } else
 441                         argc = 4;
 442
 443                 if (!down) {
 444                         for (cs = strtok(extrap, " "); cs;
 445                              cs = strtok(NULL, " ")) {
 446                                 size_t len = strlen(cs) + 1;
 447                                 argv[argc++] = acs = alloca(len);
 448                                 strlcpy(acs, cs, len);
 449                         }
 450                 }
 451
 452                 argv[argc] = down ? "-alias" : "alias";
 453                 argv[argc + 1] = NULL;
 454                 break;
 455 #endif
 456
 457         case IP_VNET_INTERFACE:
 458                 argv = alloca(5 * sizeof(char *));
 459                 argv[0] = _PATH_IFCONFIG;
 460                 argv[1] = comstring->s;
 461                 argv[2] = down ? "-vnet" : "vnet";
 462                 jidstr = string_param(j->intparams[KP_JID]);
 463                 argv[3] = jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
 464                 argv[4] = NULL;
 465                 break;
 466
 467         case IP_MOUNT:
 468         case IP__MOUNT_FROM_FSTAB:
 469                 argv = alloca(8 * sizeof(char *));
 470                 comcs = alloca(comstring->len + 1);
 471                 strcpy(comcs, comstring->s);
 472                 argc = 0;
 473                 for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
 474                      cs = strtok(NULL, " \t\f\v\r\n")) {
 475                         if (argc <= 1 && strunvis(cs, cs) < 0) {
 476                                 jail_warnx(j, "%s: %s: fstab parse error",
 477                                     j->intparams[comparam]->name, comstring->s);
 478                                 return -1;
 479                         }
 480                         argv[argc++] = cs;
 481                 }
 482                 if (argc == 0)
 483                         return 0;
 484                 if (argc < 3) {
 485                         jail_warnx(j, "%s: %s: missing information",
 486                             j->intparams[comparam]->name, comstring->s);
 487                         return -1;
 488                 }
 489                 if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
 490                     down ? argv[2] : NULL) < 0)
 491                         return -1;
 492                 if (down) {
 493                         argv[4] = NULL;
 494                         argv[3] = argv[1];
 495                         argv[0] = "/sbin/umount";
 496                 } else {
 497                         if (argc == 4) {
 498                                 argv[7] = NULL;
 499                                 argv[6] = argv[1];
 500                                 argv[5] = argv[0];
 501                                 argv[4] = argv[3];
 502                                 argv[3] = "-o";
 503                         } else {
 504                                 argv[5] = NULL;
 505                                 argv[4] = argv[1];
 506                                 argv[3] = argv[0];
 507                         }
 508                         argv[0] = _PATH_MOUNT;
 509                 }
 510                 argv[1] = "-t";
 511                 break;
 512
 513         case IP_MOUNT_DEVFS:
 514                 argv = alloca(7 * sizeof(char *));
 515                 path = string_param(j->intparams[KP_PATH]);
 516                 if (path == NULL) {
 517                         jail_warnx(j, "mount.devfs: no jail root path defined");
 518                         return -1;
 519                 }
 520                 devpath = alloca(strlen(path) + 5);
 521                 sprintf(devpath, "%s/dev", path);
 522                 if (check_path(j, "mount.devfs", devpath, 0,
 523                     down ? "devfs" : NULL) < 0)
 524                         return -1;
 525                 if (down) {
 526                         argv[0] = "/sbin/umount";
 527                         argv[1] = devpath;
 528                         argv[2] = NULL;
 529                 } else {
 530                         argv[0] = _PATH_MOUNT;
 531                         argv[1] = "-t";
 532                         argv[2] = "devfs";
 533                         ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
 534                         if (!ruleset)
 535                             ruleset = "4";      /* devfsrules_jail */
 536                         argv[3] = acs = alloca(11 + strlen(ruleset));
 537                         sprintf(acs, "-oruleset=%s", ruleset);
 538                         argv[4] = ".";
 539                         argv[5] = devpath;
 540                         argv[6] = NULL;
 541                 }
 542                 break;
 543
 544         case IP_MOUNT_FDESCFS:
 545                 argv = alloca(7 * sizeof(char *));
 546                 path = string_param(j->intparams[KP_PATH]);
 547                 if (path == NULL) {
 548                         jail_warnx(j, "mount.fdescfs: no jail root path defined");
 549                         return -1;
 550                 }
 551                 devpath = alloca(strlen(path) + 8);
 552                 sprintf(devpath, "%s/dev/fd", path);
 553                 if (check_path(j, "mount.fdescfs", devpath, 0,
 554                     down ? "fdescfs" : NULL) < 0)
 555                         return -1;
 556                 if (down) {
 557                         argv[0] = "/sbin/umount";
 558                         argv[1] = devpath;
 559                         argv[2] = NULL;
 560                 } else {
 561                         argv[0] = _PATH_MOUNT;
 562                         argv[1] = "-t";
 563                         argv[2] = "fdescfs";
 564                         argv[3] = ".";
 565                         argv[4] = devpath;
 566                         argv[5] = NULL;
 567                 }
 568                 break;
 569
 570         case IP_MOUNT_PROCFS:
 571                 argv = alloca(7 * sizeof(char *));
 572                 path = string_param(j->intparams[KP_PATH]);
 573                 if (path == NULL) {
 574                         jail_warnx(j, "mount.procfs: no jail root path defined");
 575                         return -1;
 576                 }
 577                 devpath = alloca(strlen(path) + 6);
 578                 sprintf(devpath, "%s/proc", path);
 579                 if (check_path(j, "mount.procfs", devpath, 0,
 580                     down ? "procfs" : NULL) < 0)
 581                         return -1;
 582                 if (down) {
 583                         argv[0] = "/sbin/umount";
 584                         argv[1] = devpath;
 585                         argv[2] = NULL;
 586                 } else {
 587                         argv[0] = _PATH_MOUNT;
 588                         argv[1] = "-t";
 589                         argv[2] = "procfs";
 590                         argv[3] = ".";
 591                         argv[4] = devpath;
 592                         argv[5] = NULL;
 593                 }
 594                 break;
 595
 596         case IP_COMMAND:
 597                 if (j->name != NULL)
 598                         goto default_command;
 599                 argc = 0;
 600                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 601                         argc++;
 602                 argv = alloca((argc + 1) * sizeof(char *));
 603                 argc = 0;
 604                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 605                         argv[argc++] = s->s;
 606                 argv[argc] = NULL;
 607                 j->comstring = &dummystring;
 608                 break;
 609
 610         default:
 611         default_command:
 612                 if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
 613                     !(cs[0] == '&' && cs[1] == '\0')) {
 614                         argv = alloca(4 * sizeof(char *));
 615                         argv[0] = _PATH_BSHELL;
 616                         argv[1] = "-c";
 617                         argv[2] = comstring->s;
 618                         argv[3] = NULL;
 619                 } else {
 620                         if (cs) {
 621                                 *cs = 0;
 622                                 bg = 1;
 623                         }
 624                         comcs = alloca(comstring->len + 1);
 625                         strcpy(comcs, comstring->s);
 626                         argc = 0;
 627                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 628                              cs = strtok(NULL, " \t\f\v\r\n"))
 629                                 argc++;
 630                         argv = alloca((argc + 1) * sizeof(char *));
 631                         strcpy(comcs, comstring->s);
 632                         argc = 0;
 633                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 634                              cs = strtok(NULL, " \t\f\v\r\n"))
 635                                 argv[argc++] = cs;
 636                         argv[argc] = NULL;
 637                 }
 638         }
 639         if (argv[0] == NULL)
 640                 return 0;
 641
 642         if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
 643             timeout != 0) {
 644                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 645                 j->timeout.tv_sec += timeout;
 646         } else
 647                 j->timeout.tv_sec = 0;
 648
 649         injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
 650             comparam == IP_EXEC_STOP;
 651         if (injail)
 652                 setid = root_cpuset_id();
 653         else
 654                 setid = CPUSET_INVALID;
 655         clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
 656         username = string_param(j->intparams[injail
 657             ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
 658         sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
 659
 660         consfd = 0;
 661         if (injail &&
 662             (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
 663                 if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
 664                         return -1;
 665                 consfd =
 666                     open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
 667                 if (consfd < 0) {
 668                         jail_warnx(j, "open %s: %s", conslog, strerror(errno));
 669                         return -1;
 670                 }
 671         }
 672
 673         comlen = 0;
 674         for (i = 0; argv[i]; i++)
 675                 comlen += strlen(argv[i]) + 1;
 676         j->comline = cs = emalloc(comlen);
 677         for (i = 0; argv[i]; i++) {
 678                 strcpy(cs, argv[i]);
 679                 if (argv[i + 1]) {
 680                         cs += strlen(argv[i]) + 1;
 681                         cs[-1] = ' ';
 682                 }
 683         }
 684         if (verbose > 0)
 685                 jail_note(j, "run command%s%s%s: %s\n",
 686                     injail ? " in jail" : "", username ? " as " : "",
 687                     username ? username : "", j->comline);
 688
 689         pid = fork();
 690         if (pid < 0)
 691                 err(1, "fork");
 692         if (pid > 0) {
 693                 if (bg || !add_proc(j, pid)) {
 694                         free(j->comline);
 695                         j->comline = NULL;
 696                         return 0;
 697                 } else {
 698                         paralimit--;
 699                         return 1;
 700                 }
 701         }
 702         if (bg)
 703                 setsid();
 704
 705         /* Set up the environment and run the command */
 706         pwd = NULL;
 707         lcap = NULL;
 708         if ((clean || username) && injail && sjuser &&
 709             get_user_info(j, username, &pwd, &lcap) < 0)
 710                 exit(1);
 711         if (injail) {
 712                 /* jail_attach won't chdir along with its chroot. */
 713                 path = string_param(j->intparams[KP_PATH]);
 714                 if (path && chdir(path) < 0) {
 715                         jail_warnx(j, "chdir %s: %s", path, strerror(errno));
 716                         exit(1);
 717                 }
 718                 if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
 719                     setfib(fib) < 0) {
 720                         jail_warnx(j, "setfib: %s", strerror(errno));
 721                         exit(1);
 722                 }
 723
 724                 /*
 725                  * We wouldn't have specialized our affinity, so just setid to
 726                  * root.  We do this prior to attaching to avoid the kernel
 727                  * having to create a transient cpuset that we'll promptly
 728                  * free up with a reset to the jail's cpuset.
 729                  *
 730                  * This is just a best-effort to use as wide of mask as
 731                  * possible.
 732                  */
 733                 if (setid != CPUSET_INVALID)
 734                         (void)cpuset_setid(CPU_WHICH_PID, -1, setid);
 735
 736                 if (jail_attach(j->jid) < 0) {
 737                         jail_warnx(j, "jail_attach: %s", strerror(errno));
 738                         exit(1);
 739                 }
 740         }
 741         if (clean || username) {
 742                 if (!(injail && sjuser) &&
 743                     get_user_info(j, username, &pwd, &lcap) < 0)
 744                         exit(1);
 745                 if (clean) {
 746                         term = getenv("TERM");
 747                         environ = &cleanenv;
 748                         setenv("PATH", "/bin:/usr/bin", 0);
 749                         if (term != NULL)
 750                                 setenv("TERM", term, 1);
 751                 }
 752                 if (setgid(pwd->pw_gid) < 0) {
 753                         jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
 754                             strerror(errno));
 755                         exit(1);
 756                 }
 757                 if (setusercontext(lcap, pwd, pwd->pw_uid, username
 758                     ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
 759                     : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
 760                         jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
 761                             strerror(errno));
 762                         exit(1);
 763                 }
 764                 login_close(lcap);
 765                 setenv("USER", pwd->pw_name, 1);
 766                 setenv("HOME", pwd->pw_dir, 1);
 767                 setenv("SHELL",
 768                     *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
 769                 if (clean && chdir(pwd->pw_dir) < 0) {
 770                         jail_warnx(j, "chdir %s: %s",
 771                             pwd->pw_dir, strerror(errno));
 772                         exit(1);
 773                 }
 774                 endpwent();
 775         }
 776
 777         if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
 778                 jail_warnx(j, "exec.consolelog: %s", strerror(errno));
 779                 exit(1);
 780         }
 781         closefrom(3);
 782         execvp(argv[0], __DECONST(char *const*, argv));
 783         jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
 784         exit(1);
 785 }
 786
 787 /*
 788  * Add a process to the hash, tied to a jail.
 789  */
 790 static int
 791 add_proc(struct cfjail *j, pid_t pid)
 792 {
 793         struct kevent ke;
 794         struct cfjail *tj;
 795         struct phash *ph;
 796
 797         if (!kq && (kq = kqueue()) < 0)
 798                 err(1, "kqueue");
 799         EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
 800         if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
 801                 if (errno == ESRCH)
 802                         return 0;
 803                 err(1, "kevent");
 804         }
 805         ph = emalloc(sizeof(struct phash));
 806         ph->j = j;
 807         ph->pid = pid;
 808         LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
 809         j->nprocs++;
 810         j->flags |= JF_SLEEPQ;
 811         if (j->timeout.tv_sec == 0)
 812                 requeue(j, &sleeping);
 813         else {
 814                 /* File the jail in the sleep queue according to its timeout. */
 815                 TAILQ_REMOVE(j->queue, j, tq);
 816                 TAILQ_FOREACH(tj, &sleeping, tq) {
 817                         if (!tj->timeout.tv_sec ||
 818                             j->timeout.tv_sec < tj->timeout.tv_sec ||
 819                             (j->timeout.tv_sec == tj->timeout.tv_sec &&
 820                             j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
 821                                 TAILQ_INSERT_BEFORE(tj, j, tq);
 822                                 break;
 823                         }
 824                 }
 825                 if (tj == NULL)
 826                         TAILQ_INSERT_TAIL(&sleeping, j, tq);
 827                 j->queue = &sleeping;
 828         }
 829         return 1;
 830 }
 831
 832 /*
 833  * Remove any processes from the hash that correspond to a jail.
 834  */
 835 static void
 836 clear_procs(struct cfjail *j)
 837 {
 838         struct kevent ke;
 839         struct phash *ph, *tph;
 840         int i;
 841
 842         j->nprocs = 0;
 843         for (i = 0; i < PHASH_SIZE; i++)
 844                 LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
 845                         if (ph->j == j) {
 846                                 EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
 847                                     NOTE_EXIT, 0, NULL);
 848                                 (void)kevent(kq, &ke, 1, NULL, 0, NULL);
 849                                 LIST_REMOVE(ph, le);
 850                                 free(ph);
 851                         }
 852 }
 853
 854 /*
 855  * Find the jail that corresponds to an exited process.
 856  */
 857 static struct cfjail *
 858 find_proc(pid_t pid)
 859 {
 860         struct cfjail *j;
 861         struct phash *ph;
 862
 863         LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
 864                 if (ph->pid == pid) {
 865                         j = ph->j;
 866                         LIST_REMOVE(ph, le);
 867                         free(ph);
 868                         return --j->nprocs ? NULL : j;
 869                 }
 870         return NULL;
 871 }
 872
 873 /*
 874  * Send SIGTERM to all processes in a jail and wait for them to die.
 875  */
 876 static int
 877 term_procs(struct cfjail *j)
 878 {
 879         struct kinfo_proc *ki;
 880         int i, noted, pcnt, timeout;
 881
 882         static kvm_t *kd;
 883
 884         if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
 885                 timeout = DEFAULT_STOP_TIMEOUT;
 886         else if (timeout == 0)
 887                 return 0;
 888
 889         if (kd == NULL) {
 890                 kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
 891                 if (kd == NULL)
 892                         return 0;
 893         }
 894
 895         ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
 896         if (ki == NULL)
 897                 return 0;
 898         noted = 0;
 899         for (i = 0; i < pcnt; i++)
 900                 if (ki[i].ki_jid == j->jid &&
 901                     kill(ki[i].ki_pid, SIGTERM) == 0) {
 902                         (void)add_proc(j, ki[i].ki_pid);
 903                         if (verbose > 0) {
 904                                 if (!noted) {
 905                                         noted = 1;
 906                                         jail_note(j, "sent SIGTERM to:");
 907                                 }
 908                                 printf(" %d", ki[i].ki_pid);
 909                         }
 910                 }
 911         if (noted)
 912                 printf("\n");
 913         if (j->nprocs > 0) {
 914                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 915                 j->timeout.tv_sec += timeout;
 916                 return 1;
 917         }
 918         return 0;
 919 }
 920
 921 /*
 922  * Look up a user in the passwd and login.conf files.
 923  */
 924 static int
 925 get_user_info(struct cfjail *j, const char *username,
 926     const struct passwd **pwdp, login_cap_t **lcapp)
 927 {
 928         const struct passwd *pwd;
 929
 930         errno = 0;
 931         *pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
 932         if (pwd == NULL) {
 933                 if (errno)
 934                         jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
 935                             username ? username : "", strerror(errno));
 936                 else if (username)
 937                         jail_warnx(j, "%s: no such user", username);
 938                 else
 939                         jail_warnx(j, "unknown uid %d", getuid());
 940                 return -1;
 941         }
 942         *lcapp = login_getpwclass(pwd);
 943         if (*lcapp == NULL) {
 944                 jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
 945                     strerror(errno));
 946                 return -1;
 947         }
 948         /* Set the groups while the group file is still available */
 949         if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
 950                 jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
 951                     strerror(errno));
 952                 return -1;
 953         }
 954         return 0;
 955 }
 956
 957 /*
 958  * Make sure a mount or consolelog path is a valid absolute pathname
 959  * with no symlinks.
 960  */
 961 static int
 962 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
 963     const char *umount_type)
 964 {
 965         struct stat st, mpst;
 966         struct statfs stfs;
 967         char *tpath, *p;
 968         const char *jailpath;
 969         size_t jplen;
 970
 971         if (path[0] != '/') {
 972                 jail_warnx(j, "%s: %s: not an absolute pathname",
 973                     pname, path);
 974                 return -1;
 975         }
 976         /*
 977          * Only check for symlinks in components below the jail's path,
 978          * since that's where the security risk lies.
 979          */
 980         jailpath = string_param(j->intparams[KP_PATH]);
 981         if (jailpath == NULL)
 982                 jailpath = "";
 983         jplen = strlen(jailpath);
 984         if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
 985                 tpath = alloca(strlen(path) + 1);
 986                 strcpy(tpath, path);
 987                 for (p = tpath + jplen; p != NULL; ) {
 988                         p = strchr(p + 1, '/');
 989                         if (p)
 990                                 *p = '\0';
 991                         if (lstat(tpath, &st) < 0) {
 992                                 if (errno == ENOENT && isfile && !p)
 993                                         break;
 994                                 jail_warnx(j, "%s: %s: %s", pname, tpath,
 995                                     strerror(errno));
 996                                 return -1;
 997                         }
 998                         if (S_ISLNK(st.st_mode)) {
 999                                 jail_warnx(j, "%s: %s is a symbolic link",
1000                                     pname, tpath);
1001                                 return -1;
1002                         }
1003                         if (p)
1004                                 *p = '/';
1005                 }
1006         }
1007         if (umount_type != NULL) {
1008                 if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
1009                         jail_warnx(j, "%s: %s: %s", pname, path,
1010                             strerror(errno));
1011                         return -1;
1012                 }
1013                 if (stat(stfs.f_mntonname, &mpst) < 0) {
1014                         jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
1015                             strerror(errno));
1016                         return -1;
1017                 }
1018                 if (st.st_ino != mpst.st_ino) {
1019                         jail_warnx(j, "%s: %s: not a mount point",
1020                             pname, path);
1021                         return -1;
1022                 }
1023                 if (strcmp(stfs.f_fstypename, umount_type)) {
1024                         jail_warnx(j, "%s: %s: not a %s mount",
1025                             pname, path, umount_type);
1026                         return -1;
1027                 }
1028         }
1029         return 0;
1030 }