bsd/net/pf_ruleset.c

   1 /*
   2  * Copyright (c) 2007-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*      $apfw: pf_ruleset.c,v 1.2 2007/08/10 03:00:16 jhw Exp $ */
  30 /*      $OpenBSD: pf_ruleset.c,v 1.1 2006/10/27 13:56:51 mcbride Exp $ */
  31
  32 /*
  33  * Copyright (c) 2001 Daniel Hartmeier
  34  * Copyright (c) 2002,2003 Henning Brauer
  35  * NAT64 - Copyright (c) 2010 Viagenie Inc. (http://www.viagenie.ca)
  36  * All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  *
  42  *    - Redistributions of source code must retain the above copyright
  43  *      notice, this list of conditions and the following disclaimer.
  44  *    - Redistributions in binary form must reproduce the above
  45  *      copyright notice, this list of conditions and the following
  46  *      disclaimer in the documentation and/or other materials provided
  47  *      with the distribution.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  50  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  51  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  52  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  53  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  54  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  55  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  56  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  57  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  59  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  60  * POSSIBILITY OF SUCH DAMAGE.
  61  *
  62  * Effort sponsored in part by the Defense Advanced Research Projects
  63  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  64  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
  65  *
  66  */
  67
  68 #include <sys/param.h>
  69 #include <sys/socket.h>
  70 #ifdef KERNEL
  71 #include <sys/systm.h>
  72 #include <sys/malloc.h>
  73 #include <libkern/libkern.h>
  74 #endif /* KERNEL */
  75 #include <sys/mbuf.h>
  76
  77 #include <netinet/ip_dummynet.h>
  78 #include <netinet/in.h>
  79 #include <netinet/in_systm.h>
  80 #include <netinet/ip.h>
  81 #include <netinet/tcp.h>
  82
  83 #include <net/if.h>
  84 #include <net/pfvar.h>
  85
  86 #if INET6
  87 #include <netinet/ip6.h>
  88 #endif /* INET6 */
  89
  90
  91 #ifdef KERNEL
  92 #define DPFPRINTF(format, x ...)         \
  93         if (pf_status.debug >= PF_DEBUG_NOISY)  \
  94                 printf(format, ##x)
  95 #define rs_malloc(x)            _MALLOC(x, M_TEMP, M_WAITOK)
  96 #define rs_free(x)              _FREE(x, M_TEMP)
  97 #define strrchr                 _strrchr
  98
  99 static char *
 100 _strrchr(const char *c, int ch)
 101 {
 102         char *p = (char *)(size_t)c, *save;
 103
 104         for (save = NULL;; ++p) {
 105                 if (*p == ch) {
 106                         save = (char *)p;
 107                 }
 108                 if (*p == '\0') {
 109                         return save;
 110                 }
 111         }
 112         /* NOTREACHED */
 113 }
 114
 115 #else
 116 /* Userland equivalents so we can lend code to pfctl et al. */
 117
 118 #include <arpa/inet.h>
 119 #include <errno.h>
 120 #include <stdio.h>
 121 #include <stdlib.h>
 122 #include <string.h>
 123 #define rs_malloc(x)             malloc(x)
 124 #define rs_free(x)               free(x)
 125
 126 #ifdef PFDEBUG
 127 #include <sys/stdarg.h>
 128 #define DPFPRINTF(format, x...) fprintf(stderr, format, ##x)
 129 #else
 130 #define DPFPRINTF(format, x...) ((void)0)
 131 #endif /* PFDEBUG */
 132 #endif /* KERNEL */
 133
 134
 135 struct pf_anchor_global  pf_anchors;
 136 struct pf_anchor         pf_main_anchor;
 137
 138 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 139
 140 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 141 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 142
 143 static __inline int
 144 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 145 {
 146         int c = strcmp(a->path, b->path);
 147
 148         return c ? (c < 0 ? -1 : 1) : 0;
 149 }
 150
 151 int
 152 pf_get_ruleset_number(u_int8_t action)
 153 {
 154         switch (action) {
 155         case PF_SCRUB:
 156         case PF_NOSCRUB:
 157                 return PF_RULESET_SCRUB;
 158         case PF_PASS:
 159         case PF_DROP:
 160                 return PF_RULESET_FILTER;
 161         case PF_NAT:
 162         case PF_NONAT:
 163                 return PF_RULESET_NAT;
 164         case PF_BINAT:
 165         case PF_NOBINAT:
 166                 return PF_RULESET_BINAT;
 167         case PF_RDR:
 168         case PF_NORDR:
 169         case PF_NAT64:
 170         case PF_NONAT64:
 171                 return PF_RULESET_RDR;
 172 #if DUMMYNET
 173         case PF_DUMMYNET:
 174         case PF_NODUMMYNET:
 175                 return PF_RULESET_DUMMYNET;
 176 #endif /* DUMMYNET */
 177         default:
 178                 return PF_RULESET_MAX;
 179         }
 180 }
 181
 182 void
 183 pf_init_ruleset(struct pf_ruleset *ruleset)
 184 {
 185         int     i;
 186
 187         memset(ruleset, 0, sizeof(struct pf_ruleset));
 188         for (i = 0; i < PF_RULESET_MAX; i++) {
 189                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 190                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 191                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 192                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 193         }
 194 }
 195
 196 struct pf_anchor *
 197 pf_find_anchor(const char *path)
 198 {
 199         struct pf_anchor        *key, *found;
 200
 201         key = (struct pf_anchor *)rs_malloc(sizeof(*key));
 202         memset(key, 0, sizeof(*key));
 203         strlcpy(key->path, path, sizeof(key->path));
 204         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 205         rs_free(key);
 206         return found;
 207 }
 208
 209 struct pf_ruleset *
 210 pf_find_ruleset(const char *path)
 211 {
 212         struct pf_anchor        *anchor;
 213
 214         while (*path == '/') {
 215                 path++;
 216         }
 217         if (!*path) {
 218                 return &pf_main_ruleset;
 219         }
 220         anchor = pf_find_anchor(path);
 221         if (anchor == NULL) {
 222                 return NULL;
 223         } else {
 224                 return &anchor->ruleset;
 225         }
 226 }
 227
 228 struct pf_ruleset *
 229 pf_find_ruleset_with_owner(const char *path, const char *owner, int is_anchor,
 230     int *error)
 231 {
 232         struct pf_anchor        *anchor;
 233
 234         while (*path == '/') {
 235                 path++;
 236         }
 237         if (!*path) {
 238                 return &pf_main_ruleset;
 239         }
 240         anchor = pf_find_anchor(path);
 241         if (anchor == NULL) {
 242                 *error = EINVAL;
 243                 return NULL;
 244         } else {
 245                 if ((owner && (!strcmp(owner, anchor->owner)))
 246                     || (is_anchor && !strcmp(anchor->owner, ""))) {
 247                         return &anchor->ruleset;
 248                 }
 249                 *error = EPERM;
 250                 return NULL;
 251         }
 252 }
 253
 254 struct pf_ruleset *
 255 pf_find_or_create_ruleset(const char *path)
 256 {
 257         char                    *p, *q = NULL, *r;
 258         struct pf_ruleset       *ruleset;
 259         struct pf_anchor        *anchor = 0, *dup, *parent = NULL;
 260
 261         if (path[0] == 0) {
 262                 return &pf_main_ruleset;
 263         }
 264         while (*path == '/') {
 265                 path++;
 266         }
 267         ruleset = pf_find_ruleset(path);
 268         if (ruleset != NULL) {
 269                 return ruleset;
 270         }
 271         p = (char *)rs_malloc(MAXPATHLEN);
 272         bzero(p, MAXPATHLEN);
 273         strlcpy(p, path, MAXPATHLEN);
 274         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 275                 *q = 0;
 276                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 277                         parent = ruleset->anchor;
 278                         break;
 279                 }
 280         }
 281         if (q == NULL) {
 282                 q = p;
 283         } else {
 284                 q++;
 285         }
 286         strlcpy(p, path, MAXPATHLEN);
 287         if (!*q) {
 288                 rs_free(p);
 289                 return NULL;
 290         }
 291         while ((r = strchr(q, '/')) != NULL || *q) {
 292                 if (r != NULL) {
 293                         *r = 0;
 294                 }
 295                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 296                     (parent != NULL && strlen(parent->path) >=
 297                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 298                         rs_free(p);
 299                         return NULL;
 300                 }
 301                 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
 302                 if (anchor == NULL) {
 303                         rs_free(p);
 304                         return NULL;
 305                 }
 306                 memset(anchor, 0, sizeof(*anchor));
 307                 RB_INIT(&anchor->children);
 308                 strlcpy(anchor->name, q, sizeof(anchor->name));
 309                 if (parent != NULL) {
 310                         strlcpy(anchor->path, parent->path,
 311                             sizeof(anchor->path));
 312                         strlcat(anchor->path, "/", sizeof(anchor->path));
 313                 }
 314                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 315                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 316                     NULL) {
 317                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 318                             "'%s' '%s' collides with '%s' '%s'\n",
 319                             anchor->path, anchor->name, dup->path, dup->name);
 320                         rs_free(anchor);
 321                         rs_free(p);
 322                         return NULL;
 323                 }
 324                 if (parent != NULL) {
 325                         anchor->parent = parent;
 326                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 327                             anchor)) != NULL) {
 328                                 printf("pf_find_or_create_ruleset: "
 329                                     "RB_INSERT2 '%s' '%s' collides with "
 330                                     "'%s' '%s'\n", anchor->path, anchor->name,
 331                                     dup->path, dup->name);
 332                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 333                                     anchor);
 334                                 rs_free(anchor);
 335                                 rs_free(p);
 336                                 return NULL;
 337                         }
 338                 }
 339                 pf_init_ruleset(&anchor->ruleset);
 340                 anchor->ruleset.anchor = anchor;
 341                 parent = anchor;
 342                 if (r != NULL) {
 343                         q = r + 1;
 344                 } else {
 345                         *q = 0;
 346                 }
 347 #if DUMMYNET
 348                 if (strncmp("com.apple.nlc", anchor->name,
 349                     sizeof("com.apple.nlc")) == 0) {
 350                         is_nlc_enabled_glb = TRUE;
 351                 }
 352 #endif
 353         }
 354         rs_free(p);
 355         return anchor ? &anchor->ruleset : 0;
 356 }
 357
 358 void
 359 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 360 {
 361         struct pf_anchor        *parent;
 362         int                      i;
 363
 364         while (ruleset != NULL) {
 365                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 366                     !RB_EMPTY(&ruleset->anchor->children) ||
 367                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 368                     ruleset->topen) {
 369                         return;
 370                 }
 371                 for (i = 0; i < PF_RULESET_MAX; ++i) {
 372                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 373                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 374                             ruleset->rules[i].inactive.open) {
 375                                 return;
 376                         }
 377                 }
 378                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 379 #if DUMMYNET
 380                 if (strncmp("com.apple.nlc", ruleset->anchor->name,
 381                     sizeof("com.apple.nlc")) == 0) {
 382                         struct dummynet_event dn_event;
 383                         bzero(&dn_event, sizeof(dn_event));
 384                         dn_event.dn_event_code = DUMMYNET_NLC_DISABLED;
 385                         dummynet_event_enqueue_nwk_wq_entry(&dn_event);
 386                         is_nlc_enabled_glb = FALSE;
 387                 }
 388 #endif
 389                 if ((parent = ruleset->anchor->parent) != NULL) {
 390                         RB_REMOVE(pf_anchor_node, &parent->children,
 391                             ruleset->anchor);
 392                 }
 393                 rs_free(ruleset->anchor);
 394                 if (parent == NULL) {
 395                         return;
 396                 }
 397                 ruleset = &parent->ruleset;
 398         }
 399 }
 400
 401 int
 402 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 403     const char *name)
 404 {
 405         char                    *p, *path;
 406         struct pf_ruleset       *ruleset;
 407
 408         r->anchor = NULL;
 409         r->anchor_relative = 0;
 410         r->anchor_wildcard = 0;
 411         if (!name[0]) {
 412                 return 0;
 413         }
 414         path = (char *)rs_malloc(MAXPATHLEN);
 415         bzero(path, MAXPATHLEN);
 416         if (name[0] == '/') {
 417                 strlcpy(path, name + 1, MAXPATHLEN);
 418         } else {
 419                 /* relative path */
 420                 r->anchor_relative = 1;
 421                 if (s->anchor == NULL || !s->anchor->path[0]) {
 422                         path[0] = 0;
 423                 } else {
 424                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 425                 }
 426                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 427                         if (!path[0]) {
 428                                 printf("pf_anchor_setup: .. beyond root\n");
 429                                 rs_free(path);
 430                                 return 1;
 431                         }
 432                         if ((p = strrchr(path, '/')) != NULL) {
 433                                 *p = 0;
 434                         } else {
 435                                 path[0] = 0;
 436                         }
 437                         r->anchor_relative++;
 438                         name += 3;
 439                 }
 440                 if (path[0]) {
 441                         strlcat(path, "/", MAXPATHLEN);
 442                 }
 443                 strlcat(path, name, MAXPATHLEN);
 444         }
 445         if ((p = strrchr(path, '/')) != NULL && strcmp(p, "/*") == 0) {
 446                 r->anchor_wildcard = 1;
 447                 *p = 0;
 448         }
 449         ruleset = pf_find_or_create_ruleset(path);
 450         rs_free(path);
 451         if (ruleset == NULL || ruleset->anchor == NULL) {
 452                 printf("pf_anchor_setup: ruleset\n");
 453                 return 1;
 454         }
 455         r->anchor = ruleset->anchor;
 456         r->anchor->refcnt++;
 457         return 0;
 458 }
 459
 460 int
 461 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 462     struct pfioc_rule *pr)
 463 {
 464         pr->anchor_call[0] = 0;
 465         if (r->anchor == NULL) {
 466                 return 0;
 467         }
 468         if (!r->anchor_relative) {
 469                 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
 470                 strlcat(pr->anchor_call, r->anchor->path,
 471                     sizeof(pr->anchor_call));
 472         } else {
 473                 char    *a, *p;
 474                 int      i;
 475
 476                 a = (char *)rs_malloc(MAXPATHLEN);
 477                 bzero(a, MAXPATHLEN);
 478                 if (rs->anchor == NULL) {
 479                         a[0] = 0;
 480                 } else {
 481                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 482                 }
 483                 for (i = 1; i < r->anchor_relative; ++i) {
 484                         if ((p = strrchr(a, '/')) == NULL) {
 485                                 p = a;
 486                         }
 487                         *p = 0;
 488                         strlcat(pr->anchor_call, "../",
 489                             sizeof(pr->anchor_call));
 490                 }
 491                 if (strncmp(a, r->anchor->path, strlen(a))) {
 492                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 493                             r->anchor->path);
 494                         rs_free(a);
 495                         return 1;
 496                 }
 497                 if (strlen(r->anchor->path) > strlen(a)) {
 498                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 499                             strlen(a) + 1 : 0), sizeof(pr->anchor_call));
 500                 }
 501                 rs_free(a);
 502         }
 503         if (r->anchor_wildcard) {
 504                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 505                     sizeof(pr->anchor_call));
 506         }
 507         return 0;
 508 }
 509
 510 void
 511 pf_anchor_remove(struct pf_rule *r)
 512 {
 513         if (r->anchor == NULL) {
 514                 return;
 515         }
 516         if (r->anchor->refcnt <= 0) {
 517                 printf("pf_anchor_remove: broken refcount\n");
 518                 r->anchor = NULL;
 519                 return;
 520         }
 521         if (!--r->anchor->refcnt) {
 522                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 523         }
 524         r->anchor = NULL;
 525 }