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 __FBSDID("$FreeBSD$"); 31 32 #include "opt_ddb.h" 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 36 #include <sys/param.h> 37 #include <sys/types.h> 38 #include <sys/kernel.h> 39 #include <sys/systm.h> 40 #include <sys/errno.h> 41 #include <sys/sysproto.h> 42 #include <sys/malloc.h> 43 #include <sys/osd.h> 44 #include <sys/priv.h> 45 #include <sys/proc.h> 46 #include <sys/taskqueue.h> 47 #include <sys/fcntl.h> 48 #include <sys/jail.h> 49 #include <sys/lock.h> 50 #include <sys/mutex.h> 51 #include <sys/racct.h> 52 #include <sys/refcount.h> 53 #include <sys/sx.h> 54 #include <sys/sysent.h> 55 #include <sys/namei.h> 56 #include <sys/mount.h> 57 #include <sys/queue.h> 58 #include <sys/socket.h> 59 #include <sys/syscallsubr.h> 60 #include <sys/sysctl.h> 61 #include <sys/vnode.h> 62 63 #include <net/if.h> 64 #include <net/vnet.h> 65 66 #include <netinet/in.h> 67 68 int 69 prison_qcmp_v4(const void *ip1, const void *ip2) 70 { 71 in_addr_t iaa, iab; 72 73 /* 74 * We need to compare in HBO here to get the list sorted as expected 75 * by the result of the code. Sorting NBO addresses gives you 76 * interesting results. If you do not understand, do not try. 77 */ 78 iaa = ntohl(((const struct in_addr *)ip1)->s_addr); 79 iab = ntohl(((const struct in_addr *)ip2)->s_addr); 80 81 /* 82 * Do not simply return the difference of the two numbers, the int is 83 * not wide enough. 84 */ 85 if (iaa > iab) 86 return (1); 87 else if (iaa < iab) 88 return (-1); 89 else 90 return (0); 91 } 92 93 /* 94 * Restrict a prison's IP address list with its parent's, possibly replacing 95 * it. Return true if the replacement buffer was used (or would have been). 96 */ 97 int 98 prison_restrict_ip4(struct prison *pr, struct in_addr *newip4) 99 { 100 int ii, ij, used; 101 struct prison *ppr; 102 103 ppr = pr->pr_parent; 104 if (!(pr->pr_flags & PR_IP4_USER)) { 105 /* This has no user settings, so just copy the parent's list. */ 106 if (pr->pr_ip4s < ppr->pr_ip4s) { 107 /* 108 * There's no room for the parent's list. Use the 109 * new list buffer, which is assumed to be big enough 110 * (if it was passed). If there's no buffer, try to 111 * allocate one. 112 */ 113 used = 1; 114 if (newip4 == NULL) { 115 newip4 = malloc(ppr->pr_ip4s * sizeof(*newip4), 116 M_PRISON, M_NOWAIT); 117 if (newip4 != NULL) 118 used = 0; 119 } 120 if (newip4 != NULL) { 121 bcopy(ppr->pr_ip4, newip4, 122 ppr->pr_ip4s * sizeof(*newip4)); 123 free(pr->pr_ip4, M_PRISON); 124 pr->pr_ip4 = newip4; 125 pr->pr_ip4s = ppr->pr_ip4s; 126 } 127 return (used); 128 } 129 pr->pr_ip4s = ppr->pr_ip4s; 130 if (pr->pr_ip4s > 0) 131 bcopy(ppr->pr_ip4, pr->pr_ip4, 132 pr->pr_ip4s * sizeof(*newip4)); 133 else if (pr->pr_ip4 != NULL) { 134 free(pr->pr_ip4, M_PRISON); 135 pr->pr_ip4 = NULL; 136 } 137 } else if (pr->pr_ip4s > 0) { 138 /* Remove addresses that aren't in the parent. */ 139 for (ij = 0; ij < ppr->pr_ip4s; ij++) 140 if (pr->pr_ip4[0].s_addr == ppr->pr_ip4[ij].s_addr) 141 break; 142 if (ij < ppr->pr_ip4s) 143 ii = 1; 144 else { 145 bcopy(pr->pr_ip4 + 1, pr->pr_ip4, 146 --pr->pr_ip4s * sizeof(*pr->pr_ip4)); 147 ii = 0; 148 } 149 for (ij = 1; ii < pr->pr_ip4s; ) { 150 if (pr->pr_ip4[ii].s_addr == ppr->pr_ip4[0].s_addr) { 151 ii++; 152 continue; 153 } 154 switch (ij >= ppr->pr_ip4s ? -1 : 155 prison_qcmp_v4(&pr->pr_ip4[ii], &ppr->pr_ip4[ij])) { 156 case -1: 157 bcopy(pr->pr_ip4 + ii + 1, pr->pr_ip4 + ii, 158 (--pr->pr_ip4s - ii) * sizeof(*pr->pr_ip4)); 159 break; 160 case 0: 161 ii++; 162 ij++; 163 break; 164 case 1: 165 ij++; 166 break; 167 } 168 } 169 if (pr->pr_ip4s == 0) { 170 free(pr->pr_ip4, M_PRISON); 171 pr->pr_ip4 = NULL; 172 } 173 } 174 return (0); 175 } 176 177 /* 178 * Pass back primary IPv4 address of this jail. 179 * 180 * If not restricted return success but do not alter the address. Caller has 181 * to make sure to initialize it correctly (e.g. INADDR_ANY). 182 * 183 * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4. 184 * Address returned in NBO. 185 */ 186 int 187 prison_get_ip4(struct ucred *cred, struct in_addr *ia) 188 { 189 struct prison *pr; 190 191 KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); 192 KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); 193 194 pr = cred->cr_prison; 195 if (!(pr->pr_flags & PR_IP4)) 196 return (0); 197 mtx_lock(&pr->pr_mtx); 198 if (!(pr->pr_flags & PR_IP4)) { 199 mtx_unlock(&pr->pr_mtx); 200 return (0); 201 } 202 if (pr->pr_ip4 == NULL) { 203 mtx_unlock(&pr->pr_mtx); 204 return (EAFNOSUPPORT); 205 } 206 207 ia->s_addr = pr->pr_ip4[0].s_addr; 208 mtx_unlock(&pr->pr_mtx); 209 return (0); 210 } 211 212 /* 213 * Return 1 if we should do proper source address selection or are not jailed. 214 * We will return 0 if we should bypass source address selection in favour 215 * of the primary jail IPv4 address. Only in this case *ia will be updated and 216 * returned in NBO. 217 * Return EAFNOSUPPORT, in case this jail does not allow IPv4. 218 */ 219 int 220 prison_saddrsel_ip4(struct ucred *cred, struct in_addr *ia) 221 { 222 struct prison *pr; 223 struct in_addr lia; 224 int error; 225 226 KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); 227 KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); 228 229 if (!jailed(cred)) 230 return (1); 231 232 pr = cred->cr_prison; 233 if (pr->pr_flags & PR_IP4_SADDRSEL) 234 return (1); 235 236 lia.s_addr = INADDR_ANY; 237 error = prison_get_ip4(cred, &lia); 238 if (error) 239 return (error); 240 if (lia.s_addr == INADDR_ANY) 241 return (1); 242 243 ia->s_addr = lia.s_addr; 244 return (0); 245 } 246 247 /* 248 * Return true if pr1 and pr2 have the same IPv4 address restrictions. 249 */ 250 int 251 prison_equal_ip4(struct prison *pr1, struct prison *pr2) 252 { 253 254 if (pr1 == pr2) 255 return (1); 256 257 /* 258 * No need to lock since the PR_IP4_USER flag can't be altered for 259 * existing prisons. 260 */ 261 while (pr1 != &prison0 && 262 #ifdef VIMAGE 263 !(pr1->pr_flags & PR_VNET) && 264 #endif 265 !(pr1->pr_flags & PR_IP4_USER)) 266 pr1 = pr1->pr_parent; 267 while (pr2 != &prison0 && 268 #ifdef VIMAGE 269 !(pr2->pr_flags & PR_VNET) && 270 #endif 271 !(pr2->pr_flags & PR_IP4_USER)) 272 pr2 = pr2->pr_parent; 273 return (pr1 == pr2); 274 } 275 276 /* 277 * Make sure our (source) address is set to something meaningful to this 278 * jail. 279 * 280 * Returns 0 if jail doesn't restrict IPv4 or if address belongs to jail, 281 * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail 282 * doesn't allow IPv4. Address passed in in NBO and returned in NBO. 283 */ 284 int 285 prison_local_ip4(struct ucred *cred, struct in_addr *ia) 286 { 287 struct prison *pr; 288 struct in_addr ia0; 289 int error; 290 291 KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); 292 KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); 293 294 pr = cred->cr_prison; 295 if (!(pr->pr_flags & PR_IP4)) 296 return (0); 297 mtx_lock(&pr->pr_mtx); 298 if (!(pr->pr_flags & PR_IP4)) { 299 mtx_unlock(&pr->pr_mtx); 300 return (0); 301 } 302 if (pr->pr_ip4 == NULL) { 303 mtx_unlock(&pr->pr_mtx); 304 return (EAFNOSUPPORT); 305 } 306 307 ia0.s_addr = ntohl(ia->s_addr); 308 309 if (ia0.s_addr == INADDR_ANY) { 310 /* 311 * In case there is only 1 IPv4 address, bind directly. 312 */ 313 if (pr->pr_ip4s == 1) 314 ia->s_addr = pr->pr_ip4[0].s_addr; 315 mtx_unlock(&pr->pr_mtx); 316 return (0); 317 } 318 319 error = prison_check_ip4_locked(pr, ia); 320 if (error == EADDRNOTAVAIL && ia0.s_addr == INADDR_LOOPBACK) { 321 ia->s_addr = pr->pr_ip4[0].s_addr; 322 error = 0; 323 } 324 325 mtx_unlock(&pr->pr_mtx); 326 return (error); 327 } 328 329 /* 330 * Rewrite destination address in case we will connect to loopback address. 331 * 332 * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4. 333 * Address passed in in NBO and returned in NBO. 334 */ 335 int 336 prison_remote_ip4(struct ucred *cred, struct in_addr *ia) 337 { 338 struct prison *pr; 339 340 KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); 341 KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); 342 343 pr = cred->cr_prison; 344 if (!(pr->pr_flags & PR_IP4)) 345 return (0); 346 mtx_lock(&pr->pr_mtx); 347 if (!(pr->pr_flags & PR_IP4)) { 348 mtx_unlock(&pr->pr_mtx); 349 return (0); 350 } 351 if (pr->pr_ip4 == NULL) { 352 mtx_unlock(&pr->pr_mtx); 353 return (EAFNOSUPPORT); 354 } 355 356 if (ntohl(ia->s_addr) == INADDR_LOOPBACK && 357 prison_check_ip4_locked(pr, ia) == EADDRNOTAVAIL) { 358 ia->s_addr = pr->pr_ip4[0].s_addr; 359 mtx_unlock(&pr->pr_mtx); 360 return (0); 361 } 362 363 /* 364 * Return success because nothing had to be changed. 365 */ 366 mtx_unlock(&pr->pr_mtx); 367 return (0); 368 } 369 370 /* 371 * Check if given address belongs to the jail referenced by cred/prison. 372 * 373 * Returns 0 if address belongs to jail, 374 * EADDRNOTAVAIL if the address doesn't belong to the jail. 375 */ 376 int 377 prison_check_ip4_locked(const struct prison *pr, const struct in_addr *ia) 378 { 379 int i, a, z, d; 380 381 /* 382 * Check the primary IP. 383 */ 384 if (pr->pr_ip4[0].s_addr == ia->s_addr) 385 return (0); 386 387 /* 388 * All the other IPs are sorted so we can do a binary search. 389 */ 390 a = 0; 391 z = pr->pr_ip4s - 2; 392 while (a <= z) { 393 i = (a + z) / 2; 394 d = prison_qcmp_v4(&pr->pr_ip4[i+1], ia); 395 if (d > 0) 396 z = i - 1; 397 else if (d < 0) 398 a = i + 1; 399 else 400 return (0); 401 } 402 403 return (EADDRNOTAVAIL); 404 } 405 406 int 407 prison_check_ip4(const struct ucred *cred, const struct in_addr *ia) 408 { 409 struct prison *pr; 410 int error; 411 412 KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); 413 KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); 414 415 pr = cred->cr_prison; 416 if (!(pr->pr_flags & PR_IP4)) 417 return (0); 418 mtx_lock(&pr->pr_mtx); 419 if (!(pr->pr_flags & PR_IP4)) { 420 mtx_unlock(&pr->pr_mtx); 421 return (0); 422 } 423 if (pr->pr_ip4 == NULL) { 424 mtx_unlock(&pr->pr_mtx); 425 return (EAFNOSUPPORT); 426 } 427 428 error = prison_check_ip4_locked(pr, ia); 429 mtx_unlock(&pr->pr_mtx); 430 return (error); 431 } 432