usr.sbin/jail/command.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   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/types.h>
  30 #include <sys/cpuset.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 static cpusetid_t
  86 root_cpuset_id(void)
  87 {
  88         static cpusetid_t setid = CPUSET_INVALID;
  89         static int error;
  90
  91         /* Only try to get the cpuset once. */
  92         if (error == 0 && setid == CPUSET_INVALID)
  93                 error = cpuset_getid(CPU_LEVEL_ROOT, CPU_WHICH_PID, -1, &setid);
  94         if (error != 0)
  95                 return (CPUSET_INVALID);
  96         return (setid);
  97 }
  98
  99 /*
 100  * Run the next command associated with a jail.
 101  */
 102 int
 103 next_command(struct cfjail *j)
 104 {
 105         enum intparam comparam;
 106         int create_failed, stopping;
 107
 108         if (paralimit == 0) {
 109                 if (j->flags & JF_FROM_RUNQ)
 110                         requeue_head(j, &runnable);
 111                 else
 112                         requeue(j, &runnable);
 113                 return 1;
 114         }
 115         j->flags &= ~JF_FROM_RUNQ;
 116         create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
 117         stopping = (j->flags & JF_STOP) != 0;
 118         comparam = *j->comparam;
 119         for (;;) {
 120                 if (j->comstring == NULL) {
 121                         j->comparam += create_failed ? -1 : 1;
 122                         switch ((comparam = *j->comparam)) {
 123                         case IP__NULL:
 124                                 return 0;
 125                         case IP_MOUNT_DEVFS:
 126                                 if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
 127                                         continue;
 128                                 j->comstring = &dummystring;
 129                                 break;
 130                         case IP_MOUNT_FDESCFS:
 131                                 if (!bool_param(j->intparams[IP_MOUNT_FDESCFS]))
 132                                         continue;
 133                                 j->comstring = &dummystring;
 134                                 break;
 135                         case IP_MOUNT_PROCFS:
 136                                 if (!bool_param(j->intparams[IP_MOUNT_PROCFS]))
 137                                         continue;
 138                                 j->comstring = &dummystring;
 139                                 break;
 140                         case IP__OP:
 141                         case IP_STOP_TIMEOUT:
 142                                 j->comstring = &dummystring;
 143                                 break;
 144                         default:
 145                                 if (j->intparams[comparam] == NULL)
 146                                         continue;
 147                                 j->comstring = create_failed || (stopping &&
 148                                     (j->intparams[comparam]->flags & PF_REV))
 149                                     ? TAILQ_LAST(&j->intparams[comparam]->val,
 150                                         cfstrings)
 151                                     : TAILQ_FIRST(&j->intparams[comparam]->val);
 152                         }
 153                 } else {
 154                         j->comstring = j->comstring == &dummystring ? NULL :
 155                             create_failed || (stopping &&
 156                             (j->intparams[comparam]->flags & PF_REV))
 157                             ? TAILQ_PREV(j->comstring, cfstrings, tq)
 158                             : TAILQ_NEXT(j->comstring, tq);
 159                 }
 160                 if (j->comstring == NULL || j->comstring->len == 0 ||
 161                     (create_failed && (comparam == IP_EXEC_PRESTART ||
 162                     comparam == IP_EXEC_CREATED || comparam == IP_EXEC_START ||
 163                     comparam == IP_COMMAND || comparam == IP_EXEC_POSTSTART ||
 164                     comparam == IP_EXEC_PREPARE)))
 165                         continue;
 166                 switch (run_command(j)) {
 167                 case -1:
 168                         failed(j);
 169                         /* FALLTHROUGH */
 170                 case 1:
 171                         return 1;
 172                 }
 173         }
 174 }
 175
 176 /*
 177  * Check command exit status
 178  */
 179 int
 180 finish_command(struct cfjail *j)
 181 {
 182         struct cfjail *rj;
 183         int error;
 184
 185         if (!(j->flags & JF_SLEEPQ))
 186                 return 0;
 187         j->flags &= ~JF_SLEEPQ;
 188         if (*j->comparam == IP_STOP_TIMEOUT) {
 189                 j->flags &= ~JF_TIMEOUT;
 190                 j->pstatus = 0;
 191                 return 0;
 192         }
 193         paralimit++;
 194         if (!TAILQ_EMPTY(&runnable)) {
 195                 rj = TAILQ_FIRST(&runnable);
 196                 rj->flags |= JF_FROM_RUNQ;
 197                 requeue(rj, &ready);
 198         }
 199         error = 0;
 200         if (j->flags & JF_TIMEOUT) {
 201                 j->flags &= ~JF_TIMEOUT;
 202                 if (*j->comparam != IP_STOP_TIMEOUT) {
 203                         jail_warnx(j, "%s: timed out", j->comline);
 204                         failed(j);
 205                         error = -1;
 206                 } else if (verbose > 0)
 207                         jail_note(j, "timed out\n");
 208         } else if (j->pstatus != 0) {
 209                 if (WIFSIGNALED(j->pstatus))
 210                         jail_warnx(j, "%s: exited on signal %d",
 211                             j->comline, WTERMSIG(j->pstatus));
 212                 else
 213                         jail_warnx(j, "%s: failed", j->comline);
 214                 j->pstatus = 0;
 215                 failed(j);
 216                 error = -1;
 217         }
 218         free(j->comline);
 219         j->comline = NULL;
 220         return error;
 221 }
 222
 223 /*
 224  * Check for finished processes or timeouts.
 225  */
 226 struct cfjail *
 227 next_proc(int nonblock)
 228 {
 229         struct kevent ke;
 230         struct timespec ts;
 231         struct timespec *tsp;
 232         struct cfjail *j;
 233
 234         if (!TAILQ_EMPTY(&sleeping)) {
 235         again:
 236                 tsp = NULL;
 237                 if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
 238                         clock_gettime(CLOCK_REALTIME, &ts);
 239                         ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
 240                         ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
 241                         if (ts.tv_nsec < 0) {
 242                                 ts.tv_sec--;
 243                                 ts.tv_nsec += 1000000000;
 244                         }
 245                         if (ts.tv_sec < 0 ||
 246                             (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
 247                                 j->flags |= JF_TIMEOUT;
 248                                 clear_procs(j);
 249                                 return j;
 250                         }
 251                         tsp = &ts;
 252                 }
 253                 if (nonblock) {
 254                         ts.tv_sec = 0;
 255                         ts.tv_nsec = 0;
 256                         tsp = &ts;
 257                 }
 258                 switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
 259                 case -1:
 260                         if (errno != EINTR)
 261                                 err(1, "kevent");
 262                         goto again;
 263                 case 0:
 264                         if (!nonblock) {
 265                                 j = TAILQ_FIRST(&sleeping);
 266                                 j->flags |= JF_TIMEOUT;
 267                                 clear_procs(j);
 268                                 return j;
 269                         }
 270                         break;
 271                 case 1:
 272                         (void)waitpid(ke.ident, NULL, WNOHANG);
 273                         if ((j = find_proc(ke.ident))) {
 274                                 j->pstatus = ke.data;
 275                                 return j;
 276                         }
 277                         goto again;
 278                 }
 279         }
 280         return NULL;
 281 }
 282
 283 /*
 284  * Run a single command for a jail, possibly inside the jail.
 285  */
 286 static int
 287 run_command(struct cfjail *j)
 288 {
 289         const struct passwd *pwd;
 290         const struct cfstring *comstring, *s;
 291         login_cap_t *lcap;
 292         const char **argv;
 293         char *acs, *cs, *comcs, *devpath;
 294         const char *jidstr, *conslog, *fmt, *path, *ruleset, *term, *username;
 295         enum intparam comparam;
 296         size_t comlen, ret;
 297         pid_t pid;
 298         cpusetid_t setid;
 299         int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
 300 #if defined(INET) || defined(INET6)
 301         char *addr, *extrap, *p, *val;
 302 #endif
 303
 304         static char *cleanenv;
 305
 306         /* Perform some operations that aren't actually commands */
 307         comparam = *j->comparam;
 308         down = j->flags & (JF_STOP | JF_FAILED);
 309         switch (comparam) {
 310         case IP_STOP_TIMEOUT:
 311                 return term_procs(j);
 312
 313         case IP__OP:
 314                 if (down) {
 315                         if (jail_remove(j->jid) < 0 && errno == EPERM) {
 316                                 jail_warnx(j, "jail_remove: %s",
 317                                            strerror(errno));
 318                                 return -1;
 319                         }
 320                         if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
 321                             ? note_remove : j->name != NULL)))
 322                             jail_note(j, "removed\n");
 323                         j->jid = -1;
 324                         if (j->flags & JF_STOP)
 325                                 dep_done(j, DF_LIGHT);
 326                         else
 327                                 j->flags &= ~JF_PERSIST;
 328                 } else {
 329                         if (create_jail(j) < 0)
 330                                 return -1;
 331                         if (iflag)
 332                                 printf("%d\n", j->jid);
 333                         if (verbose >= 0 && (j->name || verbose > 0))
 334                                 jail_note(j, "created\n");
 335                         dep_done(j, DF_LIGHT);
 336                 }
 337                 return 0;
 338
 339         default: ;
 340         }
 341         /*
 342          * Collect exec arguments.  Internal commands for network and
 343          * mounting build their own argument lists.
 344          */
 345         comstring = j->comstring;
 346         bg = 0;
 347         switch (comparam) {
 348 #ifdef INET
 349         case IP__IP4_IFADDR:
 350                 argc = 0;
 351                 val = alloca(strlen(comstring->s) + 1);
 352                 strcpy(val, comstring->s);
 353                 cs = val;
 354                 extrap = NULL;
 355                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 356                         if (extrap == NULL) {
 357                                 *p = '\0';
 358                                 extrap = p + 1;
 359                         }
 360                         cs = p + 1;
 361                         argc++;
 362                 }
 363
 364                 argv = alloca((8 + argc) * sizeof(char *));
 365                 argv[0] = _PATH_IFCONFIG;
 366                 if ((cs = strchr(val, '|'))) {
 367                         argv[1] = acs = alloca(cs - val + 1);
 368                         strlcpy(acs, val, cs - val + 1);
 369                         addr = cs + 1;
 370                 } else {
 371                         argv[1] = string_param(j->intparams[IP_INTERFACE]);
 372                         addr = val;
 373                 }
 374                 argv[2] = "inet";
 375                 if (!(cs = strchr(addr, '/'))) {
 376                         argv[3] = addr;
 377                         argv[4] = "netmask";
 378                         argv[5] = "255.255.255.255";
 379                         argc = 6;
 380                 } else if (strchr(cs + 1, '.')) {
 381                         argv[3] = acs = alloca(cs - addr + 1);
 382                         strlcpy(acs, addr, cs - addr + 1);
 383                         argv[4] = "netmask";
 384                         argv[5] = cs + 1;
 385                         argc = 6;
 386                 } else {
 387                         argv[3] = addr;
 388                         argc = 4;
 389                 }
 390
 391                 if (!down && extrap != NULL) {
 392                         for (cs = strtok(extrap, " "); cs;
 393                              cs = strtok(NULL, " ")) {
 394                                 size_t len = strlen(cs) + 1;
 395                                 argv[argc++] = acs = alloca(len);
 396                                 strlcpy(acs, cs, len);
 397                         }
 398                 }
 399
 400                 argv[argc] = down ? "-alias" : "alias";
 401                 argv[argc + 1] = NULL;
 402                 break;
 403 #endif
 404
 405 #ifdef INET6
 406         case IP__IP6_IFADDR:
 407                 argc = 0;
 408                 val = alloca(strlen(comstring->s) + 1);
 409                 strcpy(val, comstring->s);
 410                 cs = val;
 411                 extrap = NULL;
 412                 while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
 413                         if (extrap == NULL) {
 414                                 *p = '\0';
 415                                 extrap = p + 1;
 416                         }
 417                         cs = p + 1;
 418                         argc++;
 419                 }
 420
 421                 argv = alloca((8 + argc) * sizeof(char *));
 422                 argv[0] = _PATH_IFCONFIG;
 423                 if ((cs = strchr(val, '|'))) {
 424                         argv[1] = acs = alloca(cs - val + 1);
 425                         strlcpy(acs, val, cs - val + 1);
 426                         addr = cs + 1;
 427                 } else {
 428                         argv[1] = string_param(j->intparams[IP_INTERFACE]);
 429                         addr = val;
 430                 }
 431                 argv[2] = "inet6";
 432                 argv[3] = addr;
 433                 if (!(cs = strchr(addr, '/'))) {
 434                         argv[4] = "prefixlen";
 435                         argv[5] = "128";
 436                         argc = 6;
 437                 } else
 438                         argc = 4;
 439
 440                 if (!down && extrap != NULL) {
 441                         for (cs = strtok(extrap, " "); cs;
 442                              cs = strtok(NULL, " ")) {
 443                                 size_t len = strlen(cs) + 1;
 444                                 argv[argc++] = acs = alloca(len);
 445                                 strlcpy(acs, cs, len);
 446                         }
 447                 }
 448
 449                 argv[argc] = down ? "-alias" : "alias";
 450                 argv[argc + 1] = NULL;
 451                 break;
 452 #endif
 453
 454         case IP_VNET_INTERFACE:
 455                 argv = alloca(5 * sizeof(char *));
 456                 argv[0] = _PATH_IFCONFIG;
 457                 argv[1] = comstring->s;
 458                 argv[2] = down ? "-vnet" : "vnet";
 459                 jidstr = string_param(j->intparams[KP_JID]);
 460                 argv[3] = jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
 461                 argv[4] = NULL;
 462                 break;
 463
 464         case IP_MOUNT:
 465         case IP__MOUNT_FROM_FSTAB:
 466                 argv = alloca(8 * sizeof(char *));
 467                 comcs = alloca(comstring->len + 1);
 468                 strcpy(comcs, comstring->s);
 469                 argc = 0;
 470                 for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
 471                      cs = strtok(NULL, " \t\f\v\r\n")) {
 472                         if (argc <= 1 && strunvis(cs, cs) < 0) {
 473                                 jail_warnx(j, "%s: %s: fstab parse error",
 474                                     j->intparams[comparam]->name, comstring->s);
 475                                 return -1;
 476                         }
 477                         argv[argc++] = cs;
 478                 }
 479                 if (argc == 0)
 480                         return 0;
 481                 if (argc < 3) {
 482                         jail_warnx(j, "%s: %s: missing information",
 483                             j->intparams[comparam]->name, comstring->s);
 484                         return -1;
 485                 }
 486                 if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
 487                     down ? argv[2] : NULL) < 0)
 488                         return -1;
 489                 if (down) {
 490                         argv[4] = NULL;
 491                         argv[3] = argv[1];
 492                         argv[0] = "/sbin/umount";
 493                 } else {
 494                         if (argc == 4) {
 495                                 argv[7] = NULL;
 496                                 argv[6] = argv[1];
 497                                 argv[5] = argv[0];
 498                                 argv[4] = argv[3];
 499                                 argv[3] = "-o";
 500                         } else {
 501                                 argv[5] = NULL;
 502                                 argv[4] = argv[1];
 503                                 argv[3] = argv[0];
 504                         }
 505                         argv[0] = _PATH_MOUNT;
 506                 }
 507                 argv[1] = "-t";
 508                 break;
 509
 510         case IP_MOUNT_DEVFS:
 511                 argv = alloca(7 * sizeof(char *));
 512                 path = string_param(j->intparams[KP_PATH]);
 513                 if (path == NULL) {
 514                         jail_warnx(j, "mount.devfs: no jail root path defined");
 515                         return -1;
 516                 }
 517                 devpath = alloca(strlen(path) + 5);
 518                 sprintf(devpath, "%s/dev", path);
 519                 if (check_path(j, "mount.devfs", devpath, 0,
 520                     down ? "devfs" : NULL) < 0)
 521                         return -1;
 522                 if (down) {
 523                         argv[0] = "/sbin/umount";
 524                         argv[1] = devpath;
 525                         argv[2] = NULL;
 526                 } else {
 527                         argv[0] = _PATH_MOUNT;
 528                         argv[1] = "-t";
 529                         argv[2] = "devfs";
 530                         ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
 531                         if (!ruleset)
 532                             ruleset = "4";      /* devfsrules_jail */
 533                         argv[3] = acs = alloca(11 + strlen(ruleset));
 534                         sprintf(acs, "-oruleset=%s", ruleset);
 535                         argv[4] = ".";
 536                         argv[5] = devpath;
 537                         argv[6] = NULL;
 538                 }
 539                 break;
 540
 541         case IP_MOUNT_FDESCFS:
 542                 argv = alloca(7 * sizeof(char *));
 543                 path = string_param(j->intparams[KP_PATH]);
 544                 if (path == NULL) {
 545                         jail_warnx(j, "mount.fdescfs: no jail root path defined");
 546                         return -1;
 547                 }
 548                 devpath = alloca(strlen(path) + 8);
 549                 sprintf(devpath, "%s/dev/fd", path);
 550                 if (check_path(j, "mount.fdescfs", devpath, 0,
 551                     down ? "fdescfs" : NULL) < 0)
 552                         return -1;
 553                 if (down) {
 554                         argv[0] = "/sbin/umount";
 555                         argv[1] = devpath;
 556                         argv[2] = NULL;
 557                 } else {
 558                         argv[0] = _PATH_MOUNT;
 559                         argv[1] = "-t";
 560                         argv[2] = "fdescfs";
 561                         argv[3] = ".";
 562                         argv[4] = devpath;
 563                         argv[5] = NULL;
 564                 }
 565                 break;
 566
 567         case IP_MOUNT_PROCFS:
 568                 argv = alloca(7 * sizeof(char *));
 569                 path = string_param(j->intparams[KP_PATH]);
 570                 if (path == NULL) {
 571                         jail_warnx(j, "mount.procfs: no jail root path defined");
 572                         return -1;
 573                 }
 574                 devpath = alloca(strlen(path) + 6);
 575                 sprintf(devpath, "%s/proc", path);
 576                 if (check_path(j, "mount.procfs", devpath, 0,
 577                     down ? "procfs" : NULL) < 0)
 578                         return -1;
 579                 if (down) {
 580                         argv[0] = "/sbin/umount";
 581                         argv[1] = devpath;
 582                         argv[2] = NULL;
 583                 } else {
 584                         argv[0] = _PATH_MOUNT;
 585                         argv[1] = "-t";
 586                         argv[2] = "procfs";
 587                         argv[3] = ".";
 588                         argv[4] = devpath;
 589                         argv[5] = NULL;
 590                 }
 591                 break;
 592
 593         case IP_ZFS_DATASET:
 594                 argv = alloca(4 * sizeof(char *));
 595                 jidstr = string_param(j->intparams[KP_JID]) ?
 596                     string_param(j->intparams[KP_JID]) :
 597                     string_param(j->intparams[KP_NAME]);
 598                 fmt = "if [ $(/sbin/zfs get -H -o value jailed %s) = on ]; then /sbin/zfs jail %s %s || echo error, attaching %s to jail %s failed; else echo error, you need to set jailed=on for dataset %s; fi";
 599                 comlen = strlen(fmt)
 600                     + 2 * strlen(jidstr)
 601                     + 4 * comstring->len
 602                     - 6 * 2     /* 6 * "%s" */
 603                     + 1;
 604                 comcs = alloca(comlen);
 605                 ret = snprintf(comcs, comlen, fmt, comstring->s,
 606                     jidstr, comstring->s, comstring->s, jidstr,
 607                     comstring->s);
 608                 if (ret >= comlen) {
 609                         jail_warnx(j, "internal error in ZFS dataset handling");
 610                         exit(1);
 611                 }
 612                 argv[0] = _PATH_BSHELL;
 613                 argv[1] = "-c";
 614                 argv[2] = comcs;
 615                 argv[3] = NULL;
 616                 break;
 617
 618         case IP_COMMAND:
 619                 if (j->name != NULL)
 620                         goto default_command;
 621                 argc = 0;
 622                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 623                         argc++;
 624                 argv = alloca((argc + 1) * sizeof(char *));
 625                 argc = 0;
 626                 TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
 627                         argv[argc++] = s->s;
 628                 argv[argc] = NULL;
 629                 j->comstring = &dummystring;
 630                 break;
 631
 632         default:
 633         default_command:
 634                 if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
 635                     !(cs[0] == '&' && cs[1] == '\0')) {
 636                         argv = alloca(4 * sizeof(char *));
 637                         argv[0] = _PATH_BSHELL;
 638                         argv[1] = "-c";
 639                         argv[2] = comstring->s;
 640                         argv[3] = NULL;
 641                 } else {
 642                         if (cs) {
 643                                 *cs = 0;
 644                                 bg = 1;
 645                         }
 646                         comcs = alloca(comstring->len + 1);
 647                         strcpy(comcs, comstring->s);
 648                         argc = 0;
 649                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 650                              cs = strtok(NULL, " \t\f\v\r\n"))
 651                                 argc++;
 652                         argv = alloca((argc + 1) * sizeof(char *));
 653                         strcpy(comcs, comstring->s);
 654                         argc = 0;
 655                         for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
 656                              cs = strtok(NULL, " \t\f\v\r\n"))
 657                                 argv[argc++] = cs;
 658                         argv[argc] = NULL;
 659                 }
 660         }
 661         if (argv[0] == NULL)
 662                 return 0;
 663
 664         if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
 665             timeout != 0) {
 666                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 667                 j->timeout.tv_sec += timeout;
 668         } else
 669                 j->timeout.tv_sec = 0;
 670
 671         injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
 672             comparam == IP_EXEC_STOP;
 673         if (injail)
 674                 setid = root_cpuset_id();
 675         else
 676                 setid = CPUSET_INVALID;
 677         clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
 678         username = string_param(j->intparams[injail
 679             ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
 680         sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
 681
 682         consfd = 0;
 683         if (injail &&
 684             (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
 685                 if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
 686                         return -1;
 687                 consfd =
 688                     open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
 689                 if (consfd < 0) {
 690                         jail_warnx(j, "open %s: %s", conslog, strerror(errno));
 691                         return -1;
 692                 }
 693         }
 694
 695         comlen = 0;
 696         for (i = 0; argv[i]; i++)
 697                 comlen += strlen(argv[i]) + 1;
 698         j->comline = cs = emalloc(comlen);
 699         for (i = 0; argv[i]; i++) {
 700                 strcpy(cs, argv[i]);
 701                 if (argv[i + 1]) {
 702                         cs += strlen(argv[i]) + 1;
 703                         cs[-1] = ' ';
 704                 }
 705         }
 706         if (verbose > 0)
 707                 jail_note(j, "run command%s%s%s: %s\n",
 708                     injail ? " in jail" : "", username ? " as " : "",
 709                     username ? username : "", j->comline);
 710
 711         pid = fork();
 712         if (pid < 0)
 713                 err(1, "fork");
 714         if (pid > 0) {
 715                 if (bg || !add_proc(j, pid)) {
 716                         free(j->comline);
 717                         j->comline = NULL;
 718                         return 0;
 719                 } else {
 720                         paralimit--;
 721                         return 1;
 722                 }
 723         }
 724         if (bg)
 725                 setsid();
 726
 727         /* Set up the environment and run the command */
 728         pwd = NULL;
 729         lcap = NULL;
 730         if ((clean || username) && injail && sjuser &&
 731             get_user_info(j, username, &pwd, &lcap) < 0)
 732                 exit(1);
 733         if (injail) {
 734                 /* jail_attach won't chdir along with its chroot. */
 735                 path = string_param(j->intparams[KP_PATH]);
 736                 if (path && chdir(path) < 0) {
 737                         jail_warnx(j, "chdir %s: %s", path, strerror(errno));
 738                         exit(1);
 739                 }
 740                 if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
 741                     setfib(fib) < 0) {
 742                         jail_warnx(j, "setfib: %s", strerror(errno));
 743                         exit(1);
 744                 }
 745
 746                 /*
 747                  * We wouldn't have specialized our affinity, so just setid to
 748                  * root.  We do this prior to attaching to avoid the kernel
 749                  * having to create a transient cpuset that we'll promptly
 750                  * free up with a reset to the jail's cpuset.
 751                  *
 752                  * This is just a best-effort to use as wide of mask as
 753                  * possible.
 754                  */
 755                 if (setid != CPUSET_INVALID)
 756                         (void)cpuset_setid(CPU_WHICH_PID, -1, setid);
 757
 758                 if (jail_attach(j->jid) < 0) {
 759                         jail_warnx(j, "jail_attach: %s", strerror(errno));
 760                         exit(1);
 761                 }
 762         }
 763         if (clean || username) {
 764                 if (!(injail && sjuser) &&
 765                     get_user_info(j, username, &pwd, &lcap) < 0)
 766                         exit(1);
 767                 if (clean) {
 768                         term = getenv("TERM");
 769                         environ = &cleanenv;
 770                         setenv("PATH", "/bin:/usr/bin", 0);
 771                         if (term != NULL)
 772                                 setenv("TERM", term, 1);
 773                 }
 774                 if (setgid(pwd->pw_gid) < 0) {
 775                         jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
 776                             strerror(errno));
 777                         exit(1);
 778                 }
 779                 if (setusercontext(lcap, pwd, pwd->pw_uid, username
 780                     ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
 781                     : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
 782                         jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
 783                             strerror(errno));
 784                         exit(1);
 785                 }
 786                 login_close(lcap);
 787                 setenv("USER", pwd->pw_name, 1);
 788                 setenv("HOME", pwd->pw_dir, 1);
 789                 setenv("SHELL",
 790                     *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
 791                 if (clean && chdir(pwd->pw_dir) < 0) {
 792                         jail_warnx(j, "chdir %s: %s",
 793                             pwd->pw_dir, strerror(errno));
 794                         exit(1);
 795                 }
 796                 endpwent();
 797         }
 798
 799         if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
 800                 jail_warnx(j, "exec.consolelog: %s", strerror(errno));
 801                 exit(1);
 802         }
 803         closefrom(3);
 804         execvp(argv[0], __DECONST(char *const*, argv));
 805         jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
 806         exit(1);
 807 }
 808
 809 /*
 810  * Add a process to the hash, tied to a jail.
 811  */
 812 static int
 813 add_proc(struct cfjail *j, pid_t pid)
 814 {
 815         struct kevent ke;
 816         struct cfjail *tj;
 817         struct phash *ph;
 818
 819         if (!kq && (kq = kqueue()) < 0)
 820                 err(1, "kqueue");
 821         EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
 822         if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
 823                 if (errno == ESRCH)
 824                         return 0;
 825                 err(1, "kevent");
 826         }
 827         ph = emalloc(sizeof(struct phash));
 828         ph->j = j;
 829         ph->pid = pid;
 830         LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
 831         j->nprocs++;
 832         j->flags |= JF_SLEEPQ;
 833         if (j->timeout.tv_sec == 0)
 834                 requeue(j, &sleeping);
 835         else {
 836                 /* File the jail in the sleep queue according to its timeout. */
 837                 TAILQ_REMOVE(j->queue, j, tq);
 838                 TAILQ_FOREACH(tj, &sleeping, tq) {
 839                         if (!tj->timeout.tv_sec ||
 840                             j->timeout.tv_sec < tj->timeout.tv_sec ||
 841                             (j->timeout.tv_sec == tj->timeout.tv_sec &&
 842                             j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
 843                                 TAILQ_INSERT_BEFORE(tj, j, tq);
 844                                 break;
 845                         }
 846                 }
 847                 if (tj == NULL)
 848                         TAILQ_INSERT_TAIL(&sleeping, j, tq);
 849                 j->queue = &sleeping;
 850         }
 851         return 1;
 852 }
 853
 854 /*
 855  * Remove any processes from the hash that correspond to a jail.
 856  */
 857 static void
 858 clear_procs(struct cfjail *j)
 859 {
 860         struct kevent ke;
 861         struct phash *ph, *tph;
 862         int i;
 863
 864         j->nprocs = 0;
 865         for (i = 0; i < PHASH_SIZE; i++)
 866                 LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
 867                         if (ph->j == j) {
 868                                 EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
 869                                     NOTE_EXIT, 0, NULL);
 870                                 (void)kevent(kq, &ke, 1, NULL, 0, NULL);
 871                                 LIST_REMOVE(ph, le);
 872                                 free(ph);
 873                         }
 874 }
 875
 876 /*
 877  * Find the jail that corresponds to an exited process.
 878  */
 879 static struct cfjail *
 880 find_proc(pid_t pid)
 881 {
 882         struct cfjail *j;
 883         struct phash *ph;
 884
 885         LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
 886                 if (ph->pid == pid) {
 887                         j = ph->j;
 888                         LIST_REMOVE(ph, le);
 889                         free(ph);
 890                         return --j->nprocs ? NULL : j;
 891                 }
 892         return NULL;
 893 }
 894
 895 /*
 896  * Send SIGTERM to all processes in a jail and wait for them to die.
 897  */
 898 static int
 899 term_procs(struct cfjail *j)
 900 {
 901         struct kinfo_proc *ki;
 902         int i, noted, pcnt, timeout;
 903
 904         static kvm_t *kd;
 905
 906         if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
 907                 timeout = DEFAULT_STOP_TIMEOUT;
 908         else if (timeout == 0)
 909                 return 0;
 910
 911         if (kd == NULL) {
 912                 kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
 913                 if (kd == NULL)
 914                         return 0;
 915         }
 916
 917         ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
 918         if (ki == NULL)
 919                 return 0;
 920         noted = 0;
 921         for (i = 0; i < pcnt; i++)
 922                 if (ki[i].ki_jid == j->jid &&
 923                     kill(ki[i].ki_pid, SIGTERM) == 0) {
 924                         (void)add_proc(j, ki[i].ki_pid);
 925                         if (verbose > 0) {
 926                                 if (!noted) {
 927                                         noted = 1;
 928                                         jail_note(j, "sent SIGTERM to:");
 929                                 }
 930                                 printf(" %d", ki[i].ki_pid);
 931                         }
 932                 }
 933         if (noted)
 934                 printf("\n");
 935         if (j->nprocs > 0) {
 936                 clock_gettime(CLOCK_REALTIME, &j->timeout);
 937                 j->timeout.tv_sec += timeout;
 938                 return 1;
 939         }
 940         return 0;
 941 }
 942
 943 /*
 944  * Look up a user in the passwd and login.conf files.
 945  */
 946 static int
 947 get_user_info(struct cfjail *j, const char *username,
 948     const struct passwd **pwdp, login_cap_t **lcapp)
 949 {
 950         const struct passwd *pwd;
 951
 952         errno = 0;
 953         *pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
 954         if (pwd == NULL) {
 955                 if (errno)
 956                         jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
 957                             username ? username : "", strerror(errno));
 958                 else if (username)
 959                         jail_warnx(j, "%s: no such user", username);
 960                 else
 961                         jail_warnx(j, "unknown uid %d", getuid());
 962                 return -1;
 963         }
 964         *lcapp = login_getpwclass(pwd);
 965         if (*lcapp == NULL) {
 966                 jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
 967                     strerror(errno));
 968                 return -1;
 969         }
 970         /* Set the groups while the group file is still available */
 971         if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
 972                 jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
 973                     strerror(errno));
 974                 return -1;
 975         }
 976         return 0;
 977 }
 978
 979 /*
 980  * Make sure a mount or consolelog path is a valid absolute pathname
 981  * with no symlinks.
 982  */
 983 static int
 984 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
 985     const char *umount_type)
 986 {
 987         struct stat st, mpst;
 988         struct statfs stfs;
 989         char *tpath, *p;
 990         const char *jailpath;
 991         size_t jplen;
 992
 993         if (path[0] != '/') {
 994                 jail_warnx(j, "%s: %s: not an absolute pathname",
 995                     pname, path);
 996                 return -1;
 997         }
 998         /*
 999          * Only check for symlinks in components below the jail's path,
1000          * since that's where the security risk lies.
1001          */
1002         jailpath = string_param(j->intparams[KP_PATH]);
1003         if (jailpath == NULL)
1004                 jailpath = "";
1005         jplen = strlen(jailpath);
1006         if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
1007                 tpath = alloca(strlen(path) + 1);
1008                 strcpy(tpath, path);
1009                 for (p = tpath + jplen; p != NULL; ) {
1010                         p = strchr(p + 1, '/');
1011                         if (p)
1012                                 *p = '\0';
1013                         if (lstat(tpath, &st) < 0) {
1014                                 if (errno == ENOENT && isfile && !p)
1015                                         break;
1016                                 jail_warnx(j, "%s: %s: %s", pname, tpath,
1017                                     strerror(errno));
1018                                 return -1;
1019                         }
1020                         if (S_ISLNK(st.st_mode)) {
1021                                 jail_warnx(j, "%s: %s is a symbolic link",
1022                                     pname, tpath);
1023                                 return -1;
1024                         }
1025                         if (p)
1026                                 *p = '/';
1027                 }
1028         }
1029         if (umount_type != NULL) {
1030                 if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
1031                         jail_warnx(j, "%s: %s: %s", pname, path,
1032                             strerror(errno));
1033                         return -1;
1034                 }
1035                 if (stat(stfs.f_mntonname, &mpst) < 0) {
1036                         jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
1037                             strerror(errno));
1038                         return -1;
1039                 }
1040                 if (st.st_ino != mpst.st_ino) {
1041                         jail_warnx(j, "%s: %s: not a mount point",
1042                             pname, path);
1043                         return -1;
1044                 }
1045                 if (strcmp(stfs.f_fstypename, umount_type)) {
1046                         jail_warnx(j, "%s: %s: not a %s mount",
1047                             pname, path, umount_type);
1048                         return -1;
1049                 }
1050         }
1051         return 0;
1052 }