bsd/net/pf_ruleset.c

   1 /*
   2  * Copyright (c) 2007-2011 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  * All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  *
  41  *    - Redistributions of source code must retain the above copyright
  42  *      notice, this list of conditions and the following disclaimer.
  43  *    - Redistributions in binary form must reproduce the above
  44  *      copyright notice, this list of conditions and the following
  45  *      disclaimer in the documentation and/or other materials provided
  46  *      with the distribution.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  49  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  50  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  51  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  52  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  54  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  55  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  56  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  58  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  59  * POSSIBILITY OF SUCH DAMAGE.
  60  *
  61  * Effort sponsored in part by the Defense Advanced Research Projects
  62  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  63  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
  64  *
  65  */
  66
  67 #include <sys/param.h>
  68 #include <sys/socket.h>
  69 #ifdef KERNEL
  70 #include <sys/systm.h>
  71 #include <sys/malloc.h>
  72 #include <libkern/libkern.h>
  73 #endif /* KERNEL */
  74 #include <sys/mbuf.h>
  75
  76 #include <netinet/in.h>
  77 #include <netinet/in_systm.h>
  78 #include <netinet/ip.h>
  79 #include <netinet/tcp.h>
  80
  81 #include <net/if.h>
  82 #include <net/pfvar.h>
  83
  84 #if INET6
  85 #include <netinet/ip6.h>
  86 #endif /* INET6 */
  87
  88
  89 #ifdef KERNEL
  90 #define DPFPRINTF(format, x...)         \
  91         if (pf_status.debug >= PF_DEBUG_NOISY)  \
  92                 printf(format, ##x)
  93 #define rs_malloc(x)            _MALLOC(x, M_TEMP, M_WAITOK)
  94 #define rs_free(x)              _FREE(x, M_TEMP)
  95 #define strrchr                 _strrchr
  96
  97 static char *
  98 _strrchr(const char *c, int ch)
  99 {
 100         char *p = (char *)(size_t)c, *save;
 101
 102         for (save = NULL; ; ++p) {
 103                 if (*p == ch)
 104                         save = (char *)p;
 105                 if (*p == '\0')
 106                         return (save);
 107         }
 108         /* NOTREACHED */
 109 }
 110
 111 #else
 112 /* Userland equivalents so we can lend code to pfctl et al. */
 113
 114 #include <arpa/inet.h>
 115 #include <errno.h>
 116 #include <stdio.h>
 117 #include <stdlib.h>
 118 #include <string.h>
 119 #define rs_malloc(x)             malloc(x)
 120 #define rs_free(x)               free(x)
 121
 122 #ifdef PFDEBUG
 123 #include <sys/stdarg.h>
 124 #define DPFPRINTF(format, x...) fprintf(stderr, format, ##x)
 125 #else
 126 #define DPFPRINTF(format, x...) ((void)0)
 127 #endif /* PFDEBUG */
 128 #endif /* KERNEL */
 129
 130
 131 struct pf_anchor_global  pf_anchors;
 132 struct pf_anchor         pf_main_anchor;
 133
 134 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 135
 136 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 137 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 138
 139 static __inline int
 140 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 141 {
 142         int c = strcmp(a->path, b->path);
 143
 144         return (c ? (c < 0 ? -1 : 1) : 0);
 145 }
 146
 147 int
 148 pf_get_ruleset_number(u_int8_t action)
 149 {
 150         switch (action) {
 151         case PF_SCRUB:
 152         case PF_NOSCRUB:
 153                 return (PF_RULESET_SCRUB);
 154                 break;
 155         case PF_PASS:
 156         case PF_DROP:
 157                 return (PF_RULESET_FILTER);
 158                 break;
 159         case PF_NAT:
 160         case PF_NONAT:
 161                 return (PF_RULESET_NAT);
 162                 break;
 163         case PF_BINAT:
 164         case PF_NOBINAT:
 165                 return (PF_RULESET_BINAT);
 166                 break;
 167         case PF_RDR:
 168         case PF_NORDR:
 169                 return (PF_RULESET_RDR);
 170                 break;
 171 #if DUMMYNET
 172         case PF_DUMMYNET:
 173         case PF_NODUMMYNET:
 174                 return (PF_RULESET_DUMMYNET);
 175 #endif /* DUMMYNET */
 176         default:
 177                 return (PF_RULESET_MAX);
 178                 break;
 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         if (!*path)
 217                 return (&pf_main_ruleset);
 218         anchor = pf_find_anchor(path);
 219         if (anchor == NULL)
 220                 return (NULL);
 221         else
 222                 return (&anchor->ruleset);
 223 }
 224
 225 struct pf_ruleset *
 226 pf_find_ruleset_with_owner(const char *path, const char *owner, int is_anchor,
 227     int *error)
 228 {
 229         struct pf_anchor        *anchor;
 230
 231         while (*path == '/')
 232                 path++;
 233         if (!*path)
 234                 return (&pf_main_ruleset);
 235         anchor = pf_find_anchor(path);
 236         if (anchor == NULL) {
 237                 *error = EINVAL;
 238                 return (NULL);
 239         } else {
 240                 if ((owner && anchor->owner && (!strcmp(owner, anchor->owner)))
 241                     || (is_anchor && !strcmp(anchor->owner, "")))
 242                         return (&anchor->ruleset);
 243                 *error = EPERM;
 244                 return NULL;
 245         }
 246 }
 247
 248 struct pf_ruleset *
 249 pf_find_or_create_ruleset(const char *path)
 250 {
 251         char                    *p, *q, *r;
 252         struct pf_ruleset       *ruleset;
 253         struct pf_anchor        *anchor = 0, *dup, *parent = NULL;
 254
 255         if (path[0] == 0)
 256                 return (&pf_main_ruleset);
 257         while (*path == '/')
 258                 path++;
 259         ruleset = pf_find_ruleset(path);
 260         if (ruleset != NULL)
 261                 return (ruleset);
 262         p = (char *)rs_malloc(MAXPATHLEN);
 263         bzero(p, MAXPATHLEN);
 264         strlcpy(p, path, MAXPATHLEN);
 265         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 266                 *q = 0;
 267                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 268                         parent = ruleset->anchor;
 269                         break;
 270                 }
 271         }
 272         if (q == NULL)
 273                 q = p;
 274         else
 275                 q++;
 276         strlcpy(p, path, MAXPATHLEN);
 277         if (!*q) {
 278                 rs_free(p);
 279                 return (NULL);
 280         }
 281         while ((r = strchr(q, '/')) != NULL || *q) {
 282                 if (r != NULL)
 283                         *r = 0;
 284                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 285                     (parent != NULL && strlen(parent->path) >=
 286                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 287                         rs_free(p);
 288                         return (NULL);
 289                 }
 290                 anchor = (struct pf_anchor *)rs_malloc(sizeof (*anchor));
 291                 if (anchor == NULL) {
 292                         rs_free(p);
 293                         return (NULL);
 294                 }
 295                 memset(anchor, 0, sizeof (*anchor));
 296                 RB_INIT(&anchor->children);
 297                 strlcpy(anchor->name, q, sizeof (anchor->name));
 298                 if (parent != NULL) {
 299                         strlcpy(anchor->path, parent->path,
 300                             sizeof (anchor->path));
 301                         strlcat(anchor->path, "/", sizeof (anchor->path));
 302                 }
 303                 strlcat(anchor->path, anchor->name, sizeof (anchor->path));
 304                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 305                     NULL) {
 306                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 307                             "'%s' '%s' collides with '%s' '%s'\n",
 308                             anchor->path, anchor->name, dup->path, dup->name);
 309                         rs_free(anchor);
 310                         rs_free(p);
 311                         return (NULL);
 312                 }
 313                 if (parent != NULL) {
 314                         anchor->parent = parent;
 315                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 316                             anchor)) != NULL) {
 317                                 printf("pf_find_or_create_ruleset: "
 318                                     "RB_INSERT2 '%s' '%s' collides with "
 319                                     "'%s' '%s'\n", anchor->path, anchor->name,
 320                                     dup->path, dup->name);
 321                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 322                                     anchor);
 323                                 rs_free(anchor);
 324                                 rs_free(p);
 325                                 return (NULL);
 326                         }
 327                 }
 328                 pf_init_ruleset(&anchor->ruleset);
 329                 anchor->ruleset.anchor = anchor;
 330                 parent = anchor;
 331                 if (r != NULL)
 332                         q = r + 1;
 333                 else
 334                         *q = 0;
 335         }
 336         rs_free(p);
 337         return (anchor ? &anchor->ruleset : 0);
 338 }
 339
 340 void
 341 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 342 {
 343         struct pf_anchor        *parent;
 344         int                      i;
 345
 346         while (ruleset != NULL) {
 347                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 348                     !RB_EMPTY(&ruleset->anchor->children) ||
 349                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 350                     ruleset->topen)
 351                         return;
 352                 for (i = 0; i < PF_RULESET_MAX; ++i)
 353                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 354                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 355                             ruleset->rules[i].inactive.open)
 356                                 return;
 357                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 358                 if ((parent = ruleset->anchor->parent) != NULL)
 359                         RB_REMOVE(pf_anchor_node, &parent->children,
 360                             ruleset->anchor);
 361                 rs_free(ruleset->anchor);
 362                 if (parent == NULL)
 363                         return;
 364                 ruleset = &parent->ruleset;
 365         }
 366 }
 367
 368 int
 369 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 370     const char *name)
 371 {
 372         char                    *p, *path;
 373         struct pf_ruleset       *ruleset;
 374
 375         r->anchor = NULL;
 376         r->anchor_relative = 0;
 377         r->anchor_wildcard = 0;
 378         if (!name[0])
 379                 return (0);
 380         path = (char *)rs_malloc(MAXPATHLEN);
 381         bzero(path, MAXPATHLEN);
 382         if (name[0] == '/')
 383                 strlcpy(path, name + 1, MAXPATHLEN);
 384         else {
 385                 /* relative path */
 386                 r->anchor_relative = 1;
 387                 if (s->anchor == NULL || !s->anchor->path[0])
 388                         path[0] = 0;
 389                 else
 390                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 391                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 392                         if (!path[0]) {
 393                                 printf("pf_anchor_setup: .. beyond root\n");
 394                                 rs_free(path);
 395                                 return (1);
 396                         }
 397                         if ((p = strrchr(path, '/')) != NULL)
 398                                 *p = 0;
 399                         else
 400                                 path[0] = 0;
 401                         r->anchor_relative++;
 402                         name += 3;
 403                 }
 404                 if (path[0])
 405                         strlcat(path, "/", MAXPATHLEN);
 406                 strlcat(path, name, MAXPATHLEN);
 407         }
 408         if ((p = strrchr(path, '/')) != NULL && strcmp(p, "/*") == 0) {
 409                 r->anchor_wildcard = 1;
 410                 *p = 0;
 411         }
 412         ruleset = pf_find_or_create_ruleset(path);
 413         rs_free(path);
 414         if (ruleset == NULL || ruleset->anchor == NULL) {
 415                 printf("pf_anchor_setup: ruleset\n");
 416                 return (1);
 417         }
 418         r->anchor = ruleset->anchor;
 419         r->anchor->refcnt++;
 420         return (0);
 421 }
 422
 423 int
 424 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 425     struct pfioc_rule *pr)
 426 {
 427         pr->anchor_call[0] = 0;
 428         if (r->anchor == NULL)
 429                 return (0);
 430         if (!r->anchor_relative) {
 431                 strlcpy(pr->anchor_call, "/", sizeof (pr->anchor_call));
 432                 strlcat(pr->anchor_call, r->anchor->path,
 433                     sizeof (pr->anchor_call));
 434         } else {
 435                 char    *a, *p;
 436                 int      i;
 437
 438                 a = (char *)rs_malloc(MAXPATHLEN);
 439                 bzero(a, MAXPATHLEN);
 440                 if (rs->anchor == NULL)
 441                         a[0] = 0;
 442                 else
 443                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 444                 for (i = 1; i < r->anchor_relative; ++i) {
 445                         if ((p = strrchr(a, '/')) == NULL)
 446                                 p = a;
 447                         *p = 0;
 448                         strlcat(pr->anchor_call, "../",
 449                             sizeof (pr->anchor_call));
 450                 }
 451                 if (strncmp(a, r->anchor->path, strlen(a))) {
 452                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 453                             r->anchor->path);
 454                         rs_free(a);
 455                         return (1);
 456                 }
 457                 if (strlen(r->anchor->path) > strlen(a))
 458                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 459                             strlen(a) + 1 : 0), sizeof (pr->anchor_call));
 460                 rs_free(a);
 461         }
 462         if (r->anchor_wildcard)
 463                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 464                     sizeof (pr->anchor_call));
 465         return (0);
 466 }
 467
 468 void
 469 pf_anchor_remove(struct pf_rule *r)
 470 {
 471         if (r->anchor == NULL)
 472                 return;
 473         if (r->anchor->refcnt <= 0) {
 474                 printf("pf_anchor_remove: broken refcount\n");
 475                 r->anchor = NULL;
 476                 return;
 477         }
 478         if (!--r->anchor->refcnt)
 479                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 480         r->anchor = NULL;
 481 }