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