usr.sbin/jail/command.c

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