sys/kern/kern_jail.c

   1 /*
   2  * ----------------------------------------------------------------------------
   3  * "THE BEER-WARE LICENSE" (Revision 42):
   4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
   5  * can do whatever you want with this stuff. If we meet some day, and you think
   6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
   7  * ----------------------------------------------------------------------------
   8  *
   9  */
  10 /*-
  11  * Copyright (c) 2006 Victor Balada Diaz <victor@bsdes.net>
  12  * All rights reserved.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36
  37 /*
  38  * $FreeBSD: src/sys/kern/kern_jail.c,v 1.6.2.3 2001/08/17 01:00:26 rwatson Exp $
  39  * $DragonFly: src/sys/kern/kern_jail.c,v 1.19 2008/05/17 18:20:33 dillon Exp $
  40  */
  41
  42 #include "opt_inet6.h"
  43
  44 #include <sys/param.h>
  45 #include <sys/types.h>
  46 #include <sys/kernel.h>
  47 #include <sys/systm.h>
  48 #include <sys/errno.h>
  49 #include <sys/sysproto.h>
  50 #include <sys/malloc.h>
  51 #include <sys/nlookup.h>
  52 #include <sys/namecache.h>
  53 #include <sys/proc.h>
  54 #include <sys/priv.h>
  55 #include <sys/jail.h>
  56 #include <sys/socket.h>
  57 #include <sys/sysctl.h>
  58 #include <sys/kern_syscall.h>
  59 #include <net/if.h>
  60 #include <netinet/in.h>
  61 #include <netinet6/in6_var.h>
  62
  63 #include <sys/mplock2.h>
  64
  65 static struct prison    *prison_find(int);
  66 static void             prison_ipcache_init(struct prison *);
  67
  68 MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
  69
  70 SYSCTL_NODE(, OID_AUTO, jail, CTLFLAG_RW, 0,
  71     "Jail rules");
  72
  73 int     jail_set_hostname_allowed = 1;
  74 SYSCTL_INT(_jail, OID_AUTO, set_hostname_allowed, CTLFLAG_RW,
  75     &jail_set_hostname_allowed, 0,
  76     "Processes in jail can set their hostnames");
  77
  78 int     jail_socket_unixiproute_only = 1;
  79 SYSCTL_INT(_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW,
  80     &jail_socket_unixiproute_only, 0,
  81     "Processes in jail are limited to creating UNIX/IPv[46]/route sockets only");
  82
  83 int     jail_sysvipc_allowed = 0;
  84 SYSCTL_INT(_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW,
  85     &jail_sysvipc_allowed, 0,
  86     "Processes in jail can use System V IPC primitives");
  87
  88 int    jail_chflags_allowed = 0;
  89 SYSCTL_INT(_jail, OID_AUTO, chflags_allowed, CTLFLAG_RW,
  90     &jail_chflags_allowed, 0,
  91     "Process in jail can set chflags(1)");
  92
  93 int    jail_allow_raw_sockets = 0;
  94 SYSCTL_INT(_jail, OID_AUTO, allow_raw_sockets, CTLFLAG_RW,
  95     &jail_allow_raw_sockets, 0,
  96     "Process in jail can create raw sockets");
  97
  98 int     lastprid = 0;
  99 int     prisoncount = 0;
 100
 101 LIST_HEAD(prisonlist, prison);
 102 struct  prisonlist allprison = LIST_HEAD_INITIALIZER(&allprison);
 103
 104 static int
 105 kern_jail_attach(int jid)
 106 {
 107         struct proc *p = curthread->td_proc;
 108         struct prison *pr;
 109         int error;
 110
 111         pr = prison_find(jid);
 112         if (pr == NULL)
 113                 return(EINVAL);
 114
 115         error = kern_chroot(&pr->pr_root);
 116         if (error)
 117                 return(error);
 118
 119         prison_hold(pr);
 120         cratom(&p->p_ucred);
 121         p->p_ucred->cr_prison = pr;
 122         p->p_flag |= P_JAILED;
 123
 124         return(0);
 125 }
 126
 127 static int
 128 assign_prison_id(struct prison *pr)
 129 {
 130         int tryprid;
 131         struct prison *tpr;
 132
 133         tryprid = lastprid + 1;
 134         if (tryprid == JAIL_MAX)
 135                 tryprid = 1;
 136 next:
 137         LIST_FOREACH(tpr, &allprison, pr_list) {
 138                 if (tpr->pr_id != tryprid)
 139                         continue;
 140                 tryprid++;
 141                 if (tryprid == JAIL_MAX) {
 142                         return (ERANGE);
 143                 }
 144                 goto next;
 145         }
 146         pr->pr_id = lastprid = tryprid;
 147
 148         return (0);
 149 }
 150
 151 static int
 152 kern_jail(struct prison *pr, struct jail *j)
 153 {
 154         int error;
 155         struct nlookupdata nd;
 156
 157         error = nlookup_init(&nd, j->path, UIO_USERSPACE, NLC_FOLLOW);
 158         if (error) {
 159                 nlookup_done(&nd);
 160                 return (error);
 161         }
 162         error = nlookup(&nd);
 163         if (error) {
 164                 nlookup_done(&nd);
 165                 return (error);
 166         }
 167         cache_copy(&nd.nl_nch, &pr->pr_root);
 168
 169         varsymset_init(&pr->pr_varsymset, NULL);
 170         prison_ipcache_init(pr);
 171
 172         error = assign_prison_id(pr);
 173         if (error) {
 174                 varsymset_clean(&pr->pr_varsymset);
 175                 nlookup_done(&nd);
 176                 return (error);
 177         }
 178
 179         LIST_INSERT_HEAD(&allprison, pr, pr_list);
 180         ++prisoncount;
 181
 182         error = kern_jail_attach(pr->pr_id);
 183         if (error) {
 184                 LIST_REMOVE(pr, pr_list);
 185                 --prisoncount;
 186                 varsymset_clean(&pr->pr_varsymset);
 187         }
 188         nlookup_done(&nd);
 189         return (error);
 190 }
 191
 192 /*
 193  * jail()
 194  *
 195  * jail_args(syscallarg(struct jail *) jail)
 196  *
 197  * MPALMOSTSAFE
 198  */
 199 int
 200 sys_jail(struct jail_args *uap)
 201 {
 202         struct thread *td = curthread;
 203         struct prison *pr;
 204         struct jail_ip_storage *jip;
 205         struct jail j;
 206         int error;
 207         uint32_t jversion;
 208
 209         uap->sysmsg_result = -1;
 210
 211         error = priv_check(td, PRIV_JAIL_CREATE);
 212         if (error)
 213                 return (error);
 214
 215         error = copyin(uap->jail, &jversion, sizeof(jversion));
 216         if (error)
 217                 return (error);
 218
 219         pr = kmalloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
 220         SLIST_INIT(&pr->pr_ips);
 221         get_mplock();
 222
 223         switch (jversion) {
 224         case 0:
 225                 /* Single IPv4 jails. */
 226                 {
 227                 struct jail_v0 jv0;
 228                 struct sockaddr_in ip4addr;
 229
 230                 error = copyin(uap->jail, &jv0, sizeof(jv0));
 231                 if (error)
 232                         goto out;
 233
 234                 j.path = jv0.path;
 235                 j.hostname = jv0.hostname;
 236
 237                 jip = kmalloc(sizeof(*jip),  M_PRISON, M_WAITOK | M_ZERO);
 238                 ip4addr.sin_family = AF_INET;
 239                 ip4addr.sin_addr.s_addr = htonl(jv0.ip_number);
 240                 memcpy(&jip->ip, &ip4addr, sizeof(ip4addr));
 241                 SLIST_INSERT_HEAD(&pr->pr_ips, jip, entries);
 242                 break;
 243                 }
 244
 245         case 1:
 246                 /*
 247                  * DragonFly multi noIP/IPv4/IPv6 jails
 248                  *
 249                  * NOTE: This version is unsupported by FreeBSD
 250                  * (which uses version 2 instead).
 251                  */
 252
 253                 error = copyin(uap->jail, &j, sizeof(j));
 254                 if (error)
 255                         goto out;
 256
 257                 for (int i = 0; i < j.n_ips; i++) {
 258                         jip = kmalloc(sizeof(*jip), M_PRISON,
 259                                       M_WAITOK | M_ZERO);
 260                         SLIST_INSERT_HEAD(&pr->pr_ips, jip, entries);
 261                         error = copyin(&j.ips[i], &jip->ip,
 262                                         sizeof(struct sockaddr_storage));
 263                         if (error)
 264                                 goto out;
 265                 }
 266                 break;
 267         default:
 268                 error = EINVAL;
 269                 goto out;
 270         }
 271
 272         error = copyinstr(j.hostname, &pr->pr_host, sizeof(pr->pr_host), 0);
 273         if (error)
 274                 goto out;
 275
 276         error = kern_jail(pr, &j);
 277         if (error)
 278                 goto out;
 279
 280         uap->sysmsg_result = pr->pr_id;
 281         rel_mplock();
 282         return (0);
 283
 284 out:
 285         /* Delete all ips */
 286         while (!SLIST_EMPTY(&pr->pr_ips)) {
 287                 jip = SLIST_FIRST(&pr->pr_ips);
 288                 SLIST_REMOVE_HEAD(&pr->pr_ips, entries);
 289                 kfree(jip, M_PRISON);
 290         }
 291         rel_mplock();
 292         kfree(pr, M_PRISON);
 293         return (error);
 294 }
 295
 296 /*
 297  * int jail_attach(int jid);
 298  *
 299  * MPALMOSTSAFE
 300  */
 301 int
 302 sys_jail_attach(struct jail_attach_args *uap)
 303 {
 304         struct thread *td = curthread;
 305         int error;
 306
 307         error = priv_check(td, PRIV_JAIL_ATTACH);
 308         if (error)
 309                 return(error);
 310         get_mplock();
 311         error = kern_jail_attach(uap->jid);
 312         rel_mplock();
 313         return (error);
 314 }
 315
 316 static void
 317 prison_ipcache_init(struct prison *pr)
 318 {
 319         struct jail_ip_storage *jis;
 320         struct sockaddr_in *ip4;
 321         struct sockaddr_in6 *ip6;
 322
 323         SLIST_FOREACH(jis, &pr->pr_ips, entries) {
 324                 switch (jis->ip.ss_family) {
 325                 case AF_INET:
 326                         ip4 = (struct sockaddr_in *)&jis->ip;
 327                         if ((ntohl(ip4->sin_addr.s_addr) >> IN_CLASSA_NSHIFT) ==
 328                             IN_LOOPBACKNET) {
 329                                 /* loopback address */
 330                                 if (pr->local_ip4 == NULL)
 331                                         pr->local_ip4 = ip4;
 332                         } else {
 333                                 /* public address */
 334                                 if (pr->nonlocal_ip4 == NULL)
 335                                         pr->nonlocal_ip4 = ip4;
 336                         }
 337                         break;
 338
 339                 case AF_INET6:
 340                         ip6 = (struct sockaddr_in6 *)&jis->ip;
 341                         if (IN6_IS_ADDR_LOOPBACK(&ip6->sin6_addr)) {
 342                                 /* loopback address */
 343                                 if (pr->local_ip6 == NULL)
 344                                         pr->local_ip6 = ip6;
 345                         } else {
 346                                 /* public address */
 347                                 if (pr->nonlocal_ip6 == NULL)
 348                                         pr->nonlocal_ip6 = ip6;
 349                         }
 350                         break;
 351                 }
 352         }
 353 }
 354
 355 /*
 356  * Changes INADDR_LOOPBACK for a valid jail address.
 357  * ip is in network byte order.
 358  * Returns 1 if the ip is among jail valid ips.
 359  * Returns 0 if is not among jail valid ips or
 360  * if couldn't replace INADDR_LOOPBACK for a valid
 361  * IP.
 362  */
 363 int
 364 prison_replace_wildcards(struct thread *td, struct sockaddr *ip)
 365 {
 366         struct sockaddr_in *ip4 = (struct sockaddr_in *)ip;
 367         struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip;
 368         struct prison *pr;
 369
 370         if (td->td_proc == NULL)
 371                 return (1);
 372         if ((pr = td->td_ucred->cr_prison) == NULL)
 373                 return (1);
 374
 375         if ((ip->sa_family == AF_INET &&
 376             ip4->sin_addr.s_addr == htonl(INADDR_ANY)) ||
 377             (ip->sa_family == AF_INET6 &&
 378             IN6_IS_ADDR_UNSPECIFIED(&ip6->sin6_addr)))
 379                 return (1);
 380         if ((ip->sa_family == AF_INET &&
 381             ip4->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) ||
 382             (ip->sa_family == AF_INET6 &&
 383             IN6_IS_ADDR_LOOPBACK(&ip6->sin6_addr))) {
 384                 if (!prison_get_local(pr, ip->sa_family, ip) &&
 385                     !prison_get_nonlocal(pr, ip->sa_family, ip))
 386                         return(0);
 387                 else
 388                         return(1);
 389         }
 390         if (jailed_ip(pr, ip))
 391                 return(1);
 392         return(0);
 393 }
 394
 395 int
 396 prison_remote_ip(struct thread *td, struct sockaddr *ip)
 397 {
 398         struct sockaddr_in *ip4 = (struct sockaddr_in *)ip;
 399         struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip;
 400         struct prison *pr;
 401
 402         if (td == NULL || td->td_proc == NULL)
 403                 return(1);
 404         if ((pr = td->td_ucred->cr_prison) == NULL)
 405                 return(1);
 406         if ((ip->sa_family == AF_INET &&
 407             ip4->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) ||
 408             (ip->sa_family == AF_INET6 &&
 409             IN6_IS_ADDR_LOOPBACK(&ip6->sin6_addr))) {
 410                 if (!prison_get_local(pr, ip->sa_family, ip) &&
 411                     !prison_get_nonlocal(pr, ip->sa_family, ip))
 412                         return(0);
 413                 else
 414                         return(1);
 415         }
 416         return(1);
 417 }
 418
 419 /*
 420  * Prison get non loopback ip:
 421  * - af is the address family of the ip we want (AF_INET|AF_INET6).
 422  * - If ip != NULL, put the first IP address that is not a loopback address
 423  *   into *ip.
 424  *
 425  * ip is in network by order and we don't touch it unless we find a valid ip.
 426  * No matter if ip == NULL or not, we return either a valid struct sockaddr *,
 427  * or NULL.  This struct may not be modified.
 428  */
 429 struct sockaddr *
 430 prison_get_nonlocal(struct prison *pr, sa_family_t af, struct sockaddr *ip)
 431 {
 432         struct sockaddr_in *ip4 = (struct sockaddr_in *)ip;
 433         struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip;
 434
 435         /* Check if it is cached */
 436         switch(af) {
 437         case AF_INET:
 438                 if (ip4 != NULL && pr->nonlocal_ip4 != NULL)
 439                         ip4->sin_addr.s_addr = pr->nonlocal_ip4->sin_addr.s_addr;
 440                 return (struct sockaddr *)pr->nonlocal_ip4;
 441
 442         case AF_INET6:
 443                 if (ip6 != NULL && pr->nonlocal_ip6 != NULL)
 444                         ip6->sin6_addr = pr->nonlocal_ip6->sin6_addr;
 445                 return (struct sockaddr *)pr->nonlocal_ip6;
 446         }
 447
 448         /* NOTREACHED */
 449         return NULL;
 450 }
 451
 452 /*
 453  * Prison get loopback ip.
 454  * - af is the address family of the ip we want (AF_INET|AF_INET6).
 455  * - If ip != NULL, put the first IP address that is not a loopback address
 456  *   into *ip.
 457  *
 458  * ip is in network by order and we don't touch it unless we find a valid ip.
 459  * No matter if ip == NULL or not, we return either a valid struct sockaddr *,
 460  * or NULL.  This struct may not be modified.
 461  */
 462 struct sockaddr *
 463 prison_get_local(struct prison *pr, sa_family_t af, struct sockaddr *ip)
 464 {
 465         struct sockaddr_in *ip4 = (struct sockaddr_in *)ip;
 466         struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip;
 467
 468         /* Check if it is cached */
 469         switch(af) {
 470         case AF_INET:
 471                 if (ip4 != NULL && pr->local_ip4 != NULL)
 472                         ip4->sin_addr.s_addr = pr->local_ip4->sin_addr.s_addr;
 473                 return (struct sockaddr *)pr->local_ip4;
 474
 475         case AF_INET6:
 476                 if (ip6 != NULL && pr->local_ip6 != NULL)
 477                         ip6->sin6_addr = pr->local_ip6->sin6_addr;
 478                 return (struct sockaddr *)pr->local_ip6;
 479         }
 480
 481         /* NOTREACHED */
 482         return NULL;
 483 }
 484
 485 /* Check if the IP is among ours, if it is return 1, else 0 */
 486 int
 487 jailed_ip(struct prison *pr, struct sockaddr *ip)
 488 {
 489         struct jail_ip_storage *jis;
 490         struct sockaddr_in *jip4, *ip4;
 491         struct sockaddr_in6 *jip6, *ip6;
 492
 493         if (pr == NULL)
 494                 return(0);
 495         ip4 = (struct sockaddr_in *)ip;
 496         ip6 = (struct sockaddr_in6 *)ip;
 497         SLIST_FOREACH(jis, &pr->pr_ips, entries) {
 498                 switch (ip->sa_family) {
 499                 case AF_INET:
 500                         jip4 = (struct sockaddr_in *) &jis->ip;
 501                         if (jip4->sin_family == AF_INET &&
 502                             ip4->sin_addr.s_addr == jip4->sin_addr.s_addr)
 503                                 return(1);
 504                         break;
 505                 case AF_INET6:
 506                         jip6 = (struct sockaddr_in6 *) &jis->ip;
 507                         if (jip6->sin6_family == AF_INET6 &&
 508                             IN6_ARE_ADDR_EQUAL(&ip6->sin6_addr,
 509                                                &jip6->sin6_addr))
 510                                 return(1);
 511                         break;
 512                 }
 513         }
 514         /* Ip not in list */
 515         return(0);
 516 }
 517
 518 int
 519 prison_if(struct ucred *cred, struct sockaddr *sa)
 520 {
 521         struct prison *pr;
 522         struct sockaddr_in *sai = (struct sockaddr_in*) sa;
 523
 524         pr = cred->cr_prison;
 525
 526         if (((sai->sin_family != AF_INET) && (sai->sin_family != AF_INET6))
 527             && jail_socket_unixiproute_only)
 528                 return(1);
 529         else if ((sai->sin_family != AF_INET) && (sai->sin_family != AF_INET6))
 530                 return(0);
 531         else if (jailed_ip(pr, sa))
 532                 return(0);
 533         return(1);
 534 }
 535
 536 /*
 537  * Returns a prison instance, or NULL on failure.
 538  */
 539 static struct prison *
 540 prison_find(int prid)
 541 {
 542         struct prison *pr;
 543
 544         LIST_FOREACH(pr, &allprison, pr_list) {
 545                 if (pr->pr_id == prid)
 546                         break;
 547         }
 548         return(pr);
 549 }
 550
 551 static int
 552 sysctl_jail_list(SYSCTL_HANDLER_ARGS)
 553 {
 554         struct thread *td = curthread;
 555         struct jail_ip_storage *jip;
 556 #ifdef INET6
 557         struct sockaddr_in6 *jsin6;
 558 #endif
 559         struct sockaddr_in *jsin;
 560         struct lwp *lp;
 561         struct prison *pr;
 562         unsigned int jlssize, jlsused;
 563         int count, error;
 564         char *jls; /* Jail list */
 565         char *oip; /* Output ip */
 566         char *fullpath, *freepath;
 567
 568         jlsused = 0;
 569
 570         if (jailed(td->td_ucred))
 571                 return (0);
 572         lp = td->td_lwp;
 573 retry:
 574         count = prisoncount;
 575
 576         if (count == 0)
 577                 return(0);
 578
 579         jlssize = (count * 1024);
 580         jls = kmalloc(jlssize + 1, M_TEMP, M_WAITOK | M_ZERO);
 581         if (count < prisoncount) {
 582                 kfree(jls, M_TEMP);
 583                 goto retry;
 584         }
 585         count = prisoncount;
 586
 587         LIST_FOREACH(pr, &allprison, pr_list) {
 588                 error = cache_fullpath(lp->lwp_proc, &pr->pr_root,
 589                                         &fullpath, &freepath);
 590                 if (error)
 591                         continue;
 592                 if (jlsused && jlsused < jlssize)
 593                         jls[jlsused++] = '\n';
 594                 count = ksnprintf(jls + jlsused, (jlssize - jlsused),
 595                                  "%d %s %s",
 596                                  pr->pr_id, pr->pr_host, fullpath);
 597                 kfree(freepath, M_TEMP);
 598                 if (count < 0)
 599                         goto end;
 600                 jlsused += count;
 601
 602                 /* Copy the IPS */
 603                 SLIST_FOREACH(jip, &pr->pr_ips, entries) {
 604                         jsin = (struct sockaddr_in *)&jip->ip;
 605
 606                         switch(jsin->sin_family) {
 607                         case AF_INET:
 608                                 oip = inet_ntoa(jsin->sin_addr);
 609                                 break;
 610 #ifdef INET6
 611                         case AF_INET6:
 612                                 jsin6 = (struct sockaddr_in6 *)&jip->ip;
 613                                 oip = ip6_sprintf(&jsin6->sin6_addr);
 614                                 break;
 615 #endif
 616                         default:
 617                                 oip = "?family?";
 618                                 break;
 619                         }
 620
 621                         if ((jlssize - jlsused) < (strlen(oip) + 1)) {
 622                                 error = ERANGE;
 623                                 goto end;
 624                         }
 625                         count = ksnprintf(jls + jlsused, (jlssize - jlsused),
 626                                           " %s", oip);
 627                         if (count < 0)
 628                                 goto end;
 629                         jlsused += count;
 630                 }
 631         }
 632
 633         /*
 634          * The format is:
 635          * pr_id <SPC> hostname1 <SPC> PATH1 <SPC> IP1 <SPC> IP2\npr_id...
 636          */
 637         error = SYSCTL_OUT(req, jls, jlsused);
 638 end:
 639         kfree(jls, M_TEMP);
 640         return(error);
 641 }
 642
 643 SYSCTL_OID(_jail, OID_AUTO, list, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0,
 644            sysctl_jail_list, "A", "List of active jails");
 645
 646 /*
 647  * MPSAFE
 648  */
 649 void
 650 prison_hold(struct prison *pr)
 651 {
 652         atomic_add_int(&pr->pr_ref, 1);
 653 }
 654
 655 /*
 656  * MPALMOSTSAFE
 657  */
 658 void
 659 prison_free(struct prison *pr)
 660 {
 661         struct jail_ip_storage *jls;
 662
 663         KKASSERT(pr->pr_ref > 0);
 664         if (atomic_fetchadd_int(&pr->pr_ref, -1) != 1)
 665                 return;
 666
 667         /*
 668          * The MP lock is needed on the last ref to adjust
 669          * the list.
 670          */
 671         get_mplock();
 672         if (pr->pr_ref) {
 673                 rel_mplock();
 674                 return;
 675         }
 676         LIST_REMOVE(pr, pr_list);
 677         --prisoncount;
 678         rel_mplock();
 679
 680         /*
 681          * Clean up
 682          */
 683         while (!SLIST_EMPTY(&pr->pr_ips)) {
 684                 jls = SLIST_FIRST(&pr->pr_ips);
 685                 SLIST_REMOVE_HEAD(&pr->pr_ips, entries);
 686                 kfree(jls, M_PRISON);
 687         }
 688
 689         if (pr->pr_linux != NULL)
 690                 kfree(pr->pr_linux, M_PRISON);
 691         varsymset_clean(&pr->pr_varsymset);
 692         cache_drop(&pr->pr_root);
 693         kfree(pr, M_PRISON);
 694 }
 695
 696 /*
 697  * Check if permisson for a specific privilege is granted within jail.
 698  *
 699  * MPSAFE
 700  */
 701 int
 702 prison_priv_check(struct ucred *cred, int priv)
 703 {
 704         if (!jailed(cred))
 705                 return (0);
 706
 707         switch (priv) {
 708         case PRIV_CRED_SETUID:
 709         case PRIV_CRED_SETEUID:
 710         case PRIV_CRED_SETGID:
 711         case PRIV_CRED_SETEGID:
 712         case PRIV_CRED_SETGROUPS:
 713         case PRIV_CRED_SETREUID:
 714         case PRIV_CRED_SETREGID:
 715         case PRIV_CRED_SETRESUID:
 716         case PRIV_CRED_SETRESGID:
 717
 718         case PRIV_VFS_SYSFLAGS:
 719         case PRIV_VFS_CHOWN:
 720         case PRIV_VFS_CHMOD:
 721         case PRIV_VFS_CHROOT:
 722         case PRIV_VFS_LINK:
 723         case PRIV_VFS_CHFLAGS_DEV:
 724         case PRIV_VFS_REVOKE:
 725         case PRIV_VFS_MKNOD_BAD:
 726         case PRIV_VFS_MKNOD_WHT:
 727         case PRIV_VFS_MKNOD_DIR:
 728         case PRIV_VFS_SETATTR:
 729         case PRIV_VFS_SETGID:
 730
 731         case PRIV_PROC_SETRLIMIT:
 732         case PRIV_PROC_SETLOGIN:
 733
 734         case PRIV_SYSCTL_WRITEJAIL:
 735
 736         case PRIV_VARSYM_SYS:
 737
 738         case PRIV_SETHOSTNAME:
 739
 740         case PRIV_PROC_TRESPASS:
 741
 742                 return (0);
 743
 744         case PRIV_UFS_QUOTAON:
 745         case PRIV_UFS_QUOTAOFF:
 746         case PRIV_VFS_SETQUOTA:
 747         case PRIV_UFS_SETUSE:
 748         case PRIV_VFS_GETQUOTA:
 749                 return (0);
 750
 751
 752         case PRIV_DEBUG_UNPRIV:
 753                 return (0);
 754
 755
 756                 /*
 757                  * Allow jailed root to bind reserved ports.
 758                  */
 759         case PRIV_NETINET_RESERVEDPORT:
 760                 return (0);
 761
 762
 763                 /*
 764                  * Conditionally allow creating raw sockets in jail.
 765                  */
 766         case PRIV_NETINET_RAW:
 767                 if (jail_allow_raw_sockets)
 768                         return (0);
 769                 else
 770                         return (EPERM);
 771
 772         case PRIV_HAMMER_IOCTL:
 773                 return (0);
 774
 775         default:
 776
 777                 return (EPERM);
 778         }
 779 }