sys/netinet/in_jail.c

   1 /*-
   2  * Copyright (c) 1999 Poul-Henning Kamp.
   3  * Copyright (c) 2008 Bjoern A. Zeeb.
   4  * Copyright (c) 2009 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 #include "opt_ddb.h"
  31 #include "opt_inet.h"
  32 #include "opt_inet6.h"
  33
  34 #include <sys/param.h>
  35 #include <sys/types.h>
  36 #include <sys/kernel.h>
  37 #include <sys/systm.h>
  38 #include <sys/errno.h>
  39 #include <sys/sysproto.h>
  40 #include <sys/malloc.h>
  41 #include <sys/osd.h>
  42 #include <sys/priv.h>
  43 #include <sys/proc.h>
  44 #include <sys/taskqueue.h>
  45 #include <sys/fcntl.h>
  46 #include <sys/jail.h>
  47 #include <sys/lock.h>
  48 #include <sys/mutex.h>
  49 #include <sys/racct.h>
  50 #include <sys/refcount.h>
  51 #include <sys/sx.h>
  52 #include <sys/namei.h>
  53 #include <sys/mount.h>
  54 #include <sys/queue.h>
  55 #include <sys/socket.h>
  56 #include <sys/syscallsubr.h>
  57 #include <sys/sysctl.h>
  58 #include <sys/vnode.h>
  59
  60 #include <net/if.h>
  61 #include <net/vnet.h>
  62
  63 #include <netinet/in.h>
  64
  65 static in_addr_t
  66 prison_primary_ip4(const struct prison *pr)
  67 {
  68
  69         return (((const struct in_addr *)prison_ip_get0(pr, PR_INET))->s_addr);
  70 }
  71
  72 int
  73 prison_qcmp_v4(const void *ip1, const void *ip2)
  74 {
  75         in_addr_t iaa, iab;
  76
  77         /*
  78          * We need to compare in HBO here to get the list sorted as expected
  79          * by the result of the code.  Sorting NBO addresses gives you
  80          * interesting results.  If you do not understand, do not try.
  81          */
  82         iaa = ntohl(((const struct in_addr *)ip1)->s_addr);
  83         iab = ntohl(((const struct in_addr *)ip2)->s_addr);
  84
  85         /*
  86          * Do not simply return the difference of the two numbers, the int is
  87          * not wide enough.
  88          */
  89         if (iaa > iab)
  90                 return (1);
  91         else if (iaa < iab)
  92                 return (-1);
  93         else
  94                 return (0);
  95 }
  96
  97 bool
  98 prison_valid_v4(const void *ip)
  99 {
 100         in_addr_t ia = ((const struct in_addr *)ip)->s_addr;
 101
 102         /*
 103          * We do not have to care about byte order for these
 104          * checks so we will do them in NBO.
 105          */
 106         return (ia != INADDR_ANY && ia != INADDR_BROADCAST);
 107 }
 108
 109 /*
 110  * Pass back primary IPv4 address of this jail.
 111  *
 112  * If not restricted return success but do not alter the address.  Caller has
 113  * to make sure to initialize it correctly (e.g. INADDR_ANY).
 114  *
 115  * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
 116  * Address returned in NBO.
 117  */
 118 int
 119 prison_get_ip4(struct ucred *cred, struct in_addr *ia)
 120 {
 121         struct prison *pr;
 122
 123         KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
 124         KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
 125
 126         pr = cred->cr_prison;
 127         if (!(pr->pr_flags & PR_IP4))
 128                 return (0);
 129         mtx_lock(&pr->pr_mtx);
 130         if (!(pr->pr_flags & PR_IP4)) {
 131                 mtx_unlock(&pr->pr_mtx);
 132                 return (0);
 133         }
 134         if (pr->pr_addrs[PR_INET] == NULL) {
 135                 mtx_unlock(&pr->pr_mtx);
 136                 return (EAFNOSUPPORT);
 137         }
 138
 139         ia->s_addr = prison_primary_ip4(pr);
 140         mtx_unlock(&pr->pr_mtx);
 141         return (0);
 142 }
 143
 144 /*
 145  * Return true if we should do proper source address selection or are not jailed.
 146  * We will return false if we should bypass source address selection in favour
 147  * of the primary jail IPv4 address. Only in this case *ia will be updated and
 148  * returned in NBO.
 149  * Return true, even in case this jail does not allow IPv4.
 150  */
 151 bool
 152 prison_saddrsel_ip4(struct ucred *cred, struct in_addr *ia)
 153 {
 154         struct prison *pr;
 155         struct in_addr lia;
 156
 157         KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
 158         KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
 159
 160         if (!jailed(cred))
 161                 return (true);
 162
 163         pr = cred->cr_prison;
 164         if (pr->pr_flags & PR_IP4_SADDRSEL)
 165                 return (true);
 166
 167         lia.s_addr = INADDR_ANY;
 168         if (prison_get_ip4(cred, &lia) != 0)
 169                 return (true);
 170         if (lia.s_addr == INADDR_ANY)
 171                 return (true);
 172
 173         ia->s_addr = lia.s_addr;
 174         return (false);
 175 }
 176
 177 /*
 178  * Return true if pr1 and pr2 have the same IPv4 address restrictions.
 179  */
 180 bool
 181 prison_equal_ip4(struct prison *pr1, struct prison *pr2)
 182 {
 183
 184         if (pr1 == pr2)
 185                 return (true);
 186
 187         /*
 188          * No need to lock since the PR_IP4_USER flag can't be altered for
 189          * existing prisons.
 190          */
 191         while (pr1 != &prison0 &&
 192 #ifdef VIMAGE
 193                !(pr1->pr_flags & PR_VNET) &&
 194 #endif
 195                !(pr1->pr_flags & PR_IP4_USER))
 196                 pr1 = pr1->pr_parent;
 197         while (pr2 != &prison0 &&
 198 #ifdef VIMAGE
 199                !(pr2->pr_flags & PR_VNET) &&
 200 #endif
 201                !(pr2->pr_flags & PR_IP4_USER))
 202                 pr2 = pr2->pr_parent;
 203         return (pr1 == pr2);
 204 }
 205
 206 /*
 207  * Make sure our (source) address is set to something meaningful to this
 208  * jail.
 209  *
 210  * Returns 0 if jail doesn't restrict IPv4 or if address belongs to jail,
 211  * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail
 212  * doesn't allow IPv4.  Address passed in in NBO and returned in NBO.
 213  */
 214 int
 215 prison_local_ip4(struct ucred *cred, struct in_addr *ia)
 216 {
 217         struct prison *pr;
 218         struct in_addr ia0;
 219         int error;
 220
 221         KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
 222         KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
 223
 224         pr = cred->cr_prison;
 225         if (!(pr->pr_flags & PR_IP4))
 226                 return (0);
 227         mtx_lock(&pr->pr_mtx);
 228         if (!(pr->pr_flags & PR_IP4)) {
 229                 mtx_unlock(&pr->pr_mtx);
 230                 return (0);
 231         }
 232         if (pr->pr_addrs[PR_INET] == NULL) {
 233                 mtx_unlock(&pr->pr_mtx);
 234                 return (EAFNOSUPPORT);
 235         }
 236
 237         ia0.s_addr = ntohl(ia->s_addr);
 238
 239         if (ia0.s_addr == INADDR_ANY) {
 240                 /*
 241                  * In case there is only 1 IPv4 address, bind directly.
 242                  */
 243                 if (prison_ip_cnt(pr, PR_INET) == 1)
 244                         ia->s_addr = prison_primary_ip4(pr);
 245                 mtx_unlock(&pr->pr_mtx);
 246                 return (0);
 247         }
 248
 249         error = prison_check_ip4_locked(pr, ia);
 250         if (error == EADDRNOTAVAIL && ia0.s_addr == INADDR_LOOPBACK) {
 251                 ia->s_addr = prison_primary_ip4(pr);
 252                 error = 0;
 253         }
 254
 255         mtx_unlock(&pr->pr_mtx);
 256         return (error);
 257 }
 258
 259 /*
 260  * Rewrite destination address in case we will connect to loopback address.
 261  *
 262  * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
 263  * Address passed in in NBO and returned in NBO.
 264  */
 265 int
 266 prison_remote_ip4(struct ucred *cred, struct in_addr *ia)
 267 {
 268         struct prison *pr;
 269
 270         KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
 271         KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
 272
 273         pr = cred->cr_prison;
 274         if (!(pr->pr_flags & PR_IP4))
 275                 return (0);
 276         mtx_lock(&pr->pr_mtx);
 277         if (!(pr->pr_flags & PR_IP4)) {
 278                 mtx_unlock(&pr->pr_mtx);
 279                 return (0);
 280         }
 281         if (pr->pr_addrs[PR_INET] == NULL) {
 282                 mtx_unlock(&pr->pr_mtx);
 283                 return (EAFNOSUPPORT);
 284         }
 285
 286         if (ntohl(ia->s_addr) == INADDR_LOOPBACK &&
 287             prison_check_ip4_locked(pr, ia) == EADDRNOTAVAIL) {
 288                 ia->s_addr = prison_primary_ip4(pr);
 289                 mtx_unlock(&pr->pr_mtx);
 290                 return (0);
 291         }
 292
 293         /*
 294          * Return success because nothing had to be changed.
 295          */
 296         mtx_unlock(&pr->pr_mtx);
 297         return (0);
 298 }
 299
 300 /*
 301  * Check if given address belongs to the jail referenced by cred/prison.
 302  *
 303  * Returns 0 if address belongs to jail,
 304  * EADDRNOTAVAIL if the address doesn't belong to the jail.
 305  */
 306 int
 307 prison_check_ip4_locked(const struct prison *pr, const struct in_addr *ia)
 308 {
 309
 310         if (!(pr->pr_flags & PR_IP4))
 311                 return (0);
 312
 313         return (prison_ip_check(pr, PR_INET, ia));
 314 }
 315
 316 int
 317 prison_check_ip4(const struct ucred *cred, const struct in_addr *ia)
 318 {
 319         struct prison *pr;
 320         int error;
 321
 322         KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
 323         KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
 324
 325         pr = cred->cr_prison;
 326         if (!(pr->pr_flags & PR_IP4))
 327                 return (0);
 328         mtx_lock(&pr->pr_mtx);
 329         if (!(pr->pr_flags & PR_IP4)) {
 330                 mtx_unlock(&pr->pr_mtx);
 331                 return (0);
 332         }
 333         if (pr->pr_addrs[PR_INET] == NULL) {
 334                 mtx_unlock(&pr->pr_mtx);
 335                 return (EAFNOSUPPORT);
 336         }
 337
 338         error = prison_check_ip4_locked(pr, ia);
 339         mtx_unlock(&pr->pr_mtx);
 340         return (error);
 341 }