bsd/net/pf_ruleset.c

   1 /*
   2  * Copyright (c) 2007-2015 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/in.h>
  78 #include <netinet/in_systm.h>
  79 #include <netinet/ip.h>
  80 #include <netinet/tcp.h>
  81
  82 #include <net/if.h>
  83 #include <net/pfvar.h>
  84
  85 #if INET6
  86 #include <netinet/ip6.h>
  87 #endif /* INET6 */
  88
  89
  90 #ifdef KERNEL
  91 #define DPFPRINTF(format, x...)         \
  92         if (pf_status.debug >= PF_DEBUG_NOISY)  \
  93                 printf(format, ##x)
  94 #define rs_malloc(x)            _MALLOC(x, M_TEMP, M_WAITOK)
  95 #define rs_free(x)              _FREE(x, M_TEMP)
  96 #define strrchr                 _strrchr
  97
  98 static char *
  99 _strrchr(const char *c, int ch)
 100 {
 101         char *p = (char *)(size_t)c, *save;
 102
 103         for (save = NULL; ; ++p) {
 104                 if (*p == ch)
 105                         save = (char *)p;
 106                 if (*p == '\0')
 107                         return (save);
 108         }
 109         /* NOTREACHED */
 110 }
 111
 112 #else
 113 /* Userland equivalents so we can lend code to pfctl et al. */
 114
 115 #include <arpa/inet.h>
 116 #include <errno.h>
 117 #include <stdio.h>
 118 #include <stdlib.h>
 119 #include <string.h>
 120 #define rs_malloc(x)             malloc(x)
 121 #define rs_free(x)               free(x)
 122
 123 #ifdef PFDEBUG
 124 #include <sys/stdarg.h>
 125 #define DPFPRINTF(format, x...) fprintf(stderr, format, ##x)
 126 #else
 127 #define DPFPRINTF(format, x...) ((void)0)
 128 #endif /* PFDEBUG */
 129 #endif /* KERNEL */
 130
 131
 132 struct pf_anchor_global  pf_anchors;
 133 struct pf_anchor         pf_main_anchor;
 134
 135 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 136
 137 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 138 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 139
 140 static __inline int
 141 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 142 {
 143         int c = strcmp(a->path, b->path);
 144
 145         return (c ? (c < 0 ? -1 : 1) : 0);
 146 }
 147
 148 int
 149 pf_get_ruleset_number(u_int8_t action)
 150 {
 151         switch (action) {
 152         case PF_SCRUB:
 153         case PF_NOSCRUB:
 154                 return (PF_RULESET_SCRUB);
 155                 break;
 156         case PF_PASS:
 157         case PF_DROP:
 158                 return (PF_RULESET_FILTER);
 159                 break;
 160         case PF_NAT:
 161         case PF_NONAT:
 162                 return (PF_RULESET_NAT);
 163                 break;
 164         case PF_BINAT:
 165         case PF_NOBINAT:
 166                 return (PF_RULESET_BINAT);
 167                 break;
 168         case PF_RDR:
 169         case PF_NORDR:
 170         case PF_NAT64:
 171         case PF_NONAT64:
 172                 return (PF_RULESET_RDR);
 173                 break;
 174 #if DUMMYNET
 175         case PF_DUMMYNET:
 176         case PF_NODUMMYNET:
 177                 return (PF_RULESET_DUMMYNET);
 178 #endif /* DUMMYNET */
 179         default:
 180                 return (PF_RULESET_MAX);
 181                 break;
 182         }
 183 }
 184
 185 void
 186 pf_init_ruleset(struct pf_ruleset *ruleset)
 187 {
 188         int     i;
 189
 190         memset(ruleset, 0, sizeof (struct pf_ruleset));
 191         for (i = 0; i < PF_RULESET_MAX; i++) {
 192                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 193                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 194                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 195                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 196         }
 197 }
 198
 199 struct pf_anchor *
 200 pf_find_anchor(const char *path)
 201 {
 202         struct pf_anchor        *key, *found;
 203
 204         key = (struct pf_anchor *)rs_malloc(sizeof (*key));
 205         memset(key, 0, sizeof (*key));
 206         strlcpy(key->path, path, sizeof (key->path));
 207         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 208         rs_free(key);
 209         return (found);
 210 }
 211
 212 struct pf_ruleset *
 213 pf_find_ruleset(const char *path)
 214 {
 215         struct pf_anchor        *anchor;
 216
 217         while (*path == '/')
 218                 path++;
 219         if (!*path)
 220                 return (&pf_main_ruleset);
 221         anchor = pf_find_anchor(path);
 222         if (anchor == NULL)
 223                 return (NULL);
 224         else
 225                 return (&anchor->ruleset);
 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         if (!*path)
 237                 return (&pf_main_ruleset);
 238         anchor = pf_find_anchor(path);
 239         if (anchor == NULL) {
 240                 *error = EINVAL;
 241                 return (NULL);
 242         } else {
 243                 if ((owner && (!strcmp(owner, anchor->owner)))
 244                     || (is_anchor && !strcmp(anchor->owner, "")))
 245                         return (&anchor->ruleset);
 246                 *error = EPERM;
 247                 return NULL;
 248         }
 249 }
 250
 251 struct pf_ruleset *
 252 pf_find_or_create_ruleset(const char *path)
 253 {
 254         char                    *p, *q, *r;
 255         struct pf_ruleset       *ruleset;
 256         struct pf_anchor        *anchor = 0, *dup, *parent = NULL;
 257
 258         if (path[0] == 0)
 259                 return (&pf_main_ruleset);
 260         while (*path == '/')
 261                 path++;
 262         ruleset = pf_find_ruleset(path);
 263         if (ruleset != NULL)
 264                 return (ruleset);
 265         p = (char *)rs_malloc(MAXPATHLEN);
 266         bzero(p, MAXPATHLEN);
 267         strlcpy(p, path, MAXPATHLEN);
 268         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 269                 *q = 0;
 270                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 271                         parent = ruleset->anchor;
 272                         break;
 273                 }
 274         }
 275         if (q == NULL)
 276                 q = p;
 277         else
 278                 q++;
 279         strlcpy(p, path, MAXPATHLEN);
 280         if (!*q) {
 281                 rs_free(p);
 282                 return (NULL);
 283         }
 284         while ((r = strchr(q, '/')) != NULL || *q) {
 285                 if (r != NULL)
 286                         *r = 0;
 287                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 288                     (parent != NULL && strlen(parent->path) >=
 289                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 290                         rs_free(p);
 291                         return (NULL);
 292                 }
 293                 anchor = (struct pf_anchor *)rs_malloc(sizeof (*anchor));
 294                 if (anchor == NULL) {
 295                         rs_free(p);
 296                         return (NULL);
 297                 }
 298                 memset(anchor, 0, sizeof (*anchor));
 299                 RB_INIT(&anchor->children);
 300                 strlcpy(anchor->name, q, sizeof (anchor->name));
 301                 if (parent != NULL) {
 302                         strlcpy(anchor->path, parent->path,
 303                             sizeof (anchor->path));
 304                         strlcat(anchor->path, "/", sizeof (anchor->path));
 305                 }
 306                 strlcat(anchor->path, anchor->name, sizeof (anchor->path));
 307                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 308                     NULL) {
 309                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 310                             "'%s' '%s' collides with '%s' '%s'\n",
 311                             anchor->path, anchor->name, dup->path, dup->name);
 312                         rs_free(anchor);
 313                         rs_free(p);
 314                         return (NULL);
 315                 }
 316                 if (parent != NULL) {
 317                         anchor->parent = parent;
 318                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 319                             anchor)) != NULL) {
 320                                 printf("pf_find_or_create_ruleset: "
 321                                     "RB_INSERT2 '%s' '%s' collides with "
 322                                     "'%s' '%s'\n", anchor->path, anchor->name,
 323                                     dup->path, dup->name);
 324                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 325                                     anchor);
 326                                 rs_free(anchor);
 327                                 rs_free(p);
 328                                 return (NULL);
 329                         }
 330                 }
 331                 pf_init_ruleset(&anchor->ruleset);
 332                 anchor->ruleset.anchor = anchor;
 333                 parent = anchor;
 334                 if (r != NULL)
 335                         q = r + 1;
 336                 else
 337                         *q = 0;
 338         }
 339         rs_free(p);
 340         return (anchor ? &anchor->ruleset : 0);
 341 }
 342
 343 void
 344 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 345 {
 346         struct pf_anchor        *parent;
 347         int                      i;
 348
 349         while (ruleset != NULL) {
 350                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 351                     !RB_EMPTY(&ruleset->anchor->children) ||
 352                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 353                     ruleset->topen)
 354                         return;
 355                 for (i = 0; i < PF_RULESET_MAX; ++i)
 356                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 357                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 358                             ruleset->rules[i].inactive.open)
 359                                 return;
 360                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 361                 if ((parent = ruleset->anchor->parent) != NULL)
 362                         RB_REMOVE(pf_anchor_node, &parent->children,
 363                             ruleset->anchor);
 364                 rs_free(ruleset->anchor);
 365                 if (parent == NULL)
 366                         return;
 367                 ruleset = &parent->ruleset;
 368         }
 369 }
 370
 371 int
 372 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 373     const char *name)
 374 {
 375         char                    *p, *path;
 376         struct pf_ruleset       *ruleset;
 377
 378         r->anchor = NULL;
 379         r->anchor_relative = 0;
 380         r->anchor_wildcard = 0;
 381         if (!name[0])
 382                 return (0);
 383         path = (char *)rs_malloc(MAXPATHLEN);
 384         bzero(path, MAXPATHLEN);
 385         if (name[0] == '/')
 386                 strlcpy(path, name + 1, MAXPATHLEN);
 387         else {
 388                 /* relative path */
 389                 r->anchor_relative = 1;
 390                 if (s->anchor == NULL || !s->anchor->path[0])
 391                         path[0] = 0;
 392                 else
 393                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 394                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 395                         if (!path[0]) {
 396                                 printf("pf_anchor_setup: .. beyond root\n");
 397                                 rs_free(path);
 398                                 return (1);
 399                         }
 400                         if ((p = strrchr(path, '/')) != NULL)
 401                                 *p = 0;
 402                         else
 403                                 path[0] = 0;
 404                         r->anchor_relative++;
 405                         name += 3;
 406                 }
 407                 if (path[0])
 408                         strlcat(path, "/", MAXPATHLEN);
 409                 strlcat(path, name, MAXPATHLEN);
 410         }
 411         if ((p = strrchr(path, '/')) != NULL && strcmp(p, "/*") == 0) {
 412                 r->anchor_wildcard = 1;
 413                 *p = 0;
 414         }
 415         ruleset = pf_find_or_create_ruleset(path);
 416         rs_free(path);
 417         if (ruleset == NULL || ruleset->anchor == NULL) {
 418                 printf("pf_anchor_setup: ruleset\n");
 419                 return (1);
 420         }
 421         r->anchor = ruleset->anchor;
 422         r->anchor->refcnt++;
 423         return (0);
 424 }
 425
 426 int
 427 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 428     struct pfioc_rule *pr)
 429 {
 430         pr->anchor_call[0] = 0;
 431         if (r->anchor == NULL)
 432                 return (0);
 433         if (!r->anchor_relative) {
 434                 strlcpy(pr->anchor_call, "/", sizeof (pr->anchor_call));
 435                 strlcat(pr->anchor_call, r->anchor->path,
 436                     sizeof (pr->anchor_call));
 437         } else {
 438                 char    *a, *p;
 439                 int      i;
 440
 441                 a = (char *)rs_malloc(MAXPATHLEN);
 442                 bzero(a, MAXPATHLEN);
 443                 if (rs->anchor == NULL)
 444                         a[0] = 0;
 445                 else
 446                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 447                 for (i = 1; i < r->anchor_relative; ++i) {
 448                         if ((p = strrchr(a, '/')) == NULL)
 449                                 p = a;
 450                         *p = 0;
 451                         strlcat(pr->anchor_call, "../",
 452                             sizeof (pr->anchor_call));
 453                 }
 454                 if (strncmp(a, r->anchor->path, strlen(a))) {
 455                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 456                             r->anchor->path);
 457                         rs_free(a);
 458                         return (1);
 459                 }
 460                 if (strlen(r->anchor->path) > strlen(a))
 461                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 462                             strlen(a) + 1 : 0), sizeof (pr->anchor_call));
 463                 rs_free(a);
 464         }
 465         if (r->anchor_wildcard)
 466                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 467                     sizeof (pr->anchor_call));
 468         return (0);
 469 }
 470
 471 void
 472 pf_anchor_remove(struct pf_rule *r)
 473 {
 474         if (r->anchor == NULL)
 475                 return;
 476         if (r->anchor->refcnt <= 0) {
 477                 printf("pf_anchor_remove: broken refcount\n");
 478                 r->anchor = NULL;
 479                 return;
 480         }
 481         if (!--r->anchor->refcnt)
 482                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 483         r->anchor = NULL;
 484 }