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/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         case PF_PASS:
 156         case PF_DROP:
 157                 return (PF_RULESET_FILTER);
 158         case PF_NAT:
 159         case PF_NONAT:
 160                 return (PF_RULESET_NAT);
 161         case PF_BINAT:
 162         case PF_NOBINAT:
 163                 return (PF_RULESET_BINAT);
 164         case PF_RDR:
 165         case PF_NORDR:
 166         case PF_NAT64:
 167         case PF_NONAT64:
 168                 return (PF_RULESET_RDR);
 169 #if DUMMYNET
 170         case PF_DUMMYNET:
 171         case PF_NODUMMYNET:
 172                 return (PF_RULESET_DUMMYNET);
 173 #endif /* DUMMYNET */
 174         default:
 175                 return (PF_RULESET_MAX);
 176         }
 177 }
 178
 179 void
 180 pf_init_ruleset(struct pf_ruleset *ruleset)
 181 {
 182         int     i;
 183
 184         memset(ruleset, 0, sizeof (struct pf_ruleset));
 185         for (i = 0; i < PF_RULESET_MAX; i++) {
 186                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 187                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 188                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 189                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 190         }
 191 }
 192
 193 struct pf_anchor *
 194 pf_find_anchor(const char *path)
 195 {
 196         struct pf_anchor        *key, *found;
 197
 198         key = (struct pf_anchor *)rs_malloc(sizeof (*key));
 199         memset(key, 0, sizeof (*key));
 200         strlcpy(key->path, path, sizeof (key->path));
 201         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 202         rs_free(key);
 203         return (found);
 204 }
 205
 206 struct pf_ruleset *
 207 pf_find_ruleset(const char *path)
 208 {
 209         struct pf_anchor        *anchor;
 210
 211         while (*path == '/')
 212                 path++;
 213         if (!*path)
 214                 return (&pf_main_ruleset);
 215         anchor = pf_find_anchor(path);
 216         if (anchor == NULL)
 217                 return (NULL);
 218         else
 219                 return (&anchor->ruleset);
 220 }
 221
 222 struct pf_ruleset *
 223 pf_find_ruleset_with_owner(const char *path, const char *owner, int is_anchor,
 224     int *error)
 225 {
 226         struct pf_anchor        *anchor;
 227
 228         while (*path == '/')
 229                 path++;
 230         if (!*path)
 231                 return (&pf_main_ruleset);
 232         anchor = pf_find_anchor(path);
 233         if (anchor == NULL) {
 234                 *error = EINVAL;
 235                 return (NULL);
 236         } else {
 237                 if ((owner && (!strcmp(owner, anchor->owner)))
 238                     || (is_anchor && !strcmp(anchor->owner, "")))
 239                         return (&anchor->ruleset);
 240                 *error = EPERM;
 241                 return NULL;
 242         }
 243 }
 244
 245 struct pf_ruleset *
 246 pf_find_or_create_ruleset(const char *path)
 247 {
 248         char                    *p, *q, *r;
 249         struct pf_ruleset       *ruleset;
 250         struct pf_anchor        *anchor = 0, *dup, *parent = NULL;
 251
 252         if (path[0] == 0)
 253                 return (&pf_main_ruleset);
 254         while (*path == '/')
 255                 path++;
 256         ruleset = pf_find_ruleset(path);
 257         if (ruleset != NULL)
 258                 return (ruleset);
 259         p = (char *)rs_malloc(MAXPATHLEN);
 260         bzero(p, MAXPATHLEN);
 261         strlcpy(p, path, MAXPATHLEN);
 262         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 263                 *q = 0;
 264                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 265                         parent = ruleset->anchor;
 266                         break;
 267                 }
 268         }
 269         if (q == NULL)
 270                 q = p;
 271         else
 272                 q++;
 273         strlcpy(p, path, MAXPATHLEN);
 274         if (!*q) {
 275                 rs_free(p);
 276                 return (NULL);
 277         }
 278         while ((r = strchr(q, '/')) != NULL || *q) {
 279                 if (r != NULL)
 280                         *r = 0;
 281                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 282                     (parent != NULL && strlen(parent->path) >=
 283                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 284                         rs_free(p);
 285                         return (NULL);
 286                 }
 287                 anchor = (struct pf_anchor *)rs_malloc(sizeof (*anchor));
 288                 if (anchor == NULL) {
 289                         rs_free(p);
 290                         return (NULL);
 291                 }
 292                 memset(anchor, 0, sizeof (*anchor));
 293                 RB_INIT(&anchor->children);
 294                 strlcpy(anchor->name, q, sizeof (anchor->name));
 295                 if (parent != NULL) {
 296                         strlcpy(anchor->path, parent->path,
 297                             sizeof (anchor->path));
 298                         strlcat(anchor->path, "/", sizeof (anchor->path));
 299                 }
 300                 strlcat(anchor->path, anchor->name, sizeof (anchor->path));
 301                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 302                     NULL) {
 303                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 304                             "'%s' '%s' collides with '%s' '%s'\n",
 305                             anchor->path, anchor->name, dup->path, dup->name);
 306                         rs_free(anchor);
 307                         rs_free(p);
 308                         return (NULL);
 309                 }
 310                 if (parent != NULL) {
 311                         anchor->parent = parent;
 312                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 313                             anchor)) != NULL) {
 314                                 printf("pf_find_or_create_ruleset: "
 315                                     "RB_INSERT2 '%s' '%s' collides with "
 316                                     "'%s' '%s'\n", anchor->path, anchor->name,
 317                                     dup->path, dup->name);
 318                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 319                                     anchor);
 320                                 rs_free(anchor);
 321                                 rs_free(p);
 322                                 return (NULL);
 323                         }
 324                 }
 325                 pf_init_ruleset(&anchor->ruleset);
 326                 anchor->ruleset.anchor = anchor;
 327                 parent = anchor;
 328                 if (r != NULL)
 329                         q = r + 1;
 330                 else
 331                         *q = 0;
 332         }
 333         rs_free(p);
 334         return (anchor ? &anchor->ruleset : 0);
 335 }
 336
 337 void
 338 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 339 {
 340         struct pf_anchor        *parent;
 341         int                      i;
 342
 343         while (ruleset != NULL) {
 344                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 345                     !RB_EMPTY(&ruleset->anchor->children) ||
 346                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 347                     ruleset->topen)
 348                         return;
 349                 for (i = 0; i < PF_RULESET_MAX; ++i)
 350                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 351                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 352                             ruleset->rules[i].inactive.open)
 353                                 return;
 354                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 355                 if ((parent = ruleset->anchor->parent) != NULL)
 356                         RB_REMOVE(pf_anchor_node, &parent->children,
 357                             ruleset->anchor);
 358                 rs_free(ruleset->anchor);
 359                 if (parent == NULL)
 360                         return;
 361                 ruleset = &parent->ruleset;
 362         }
 363 }
 364
 365 int
 366 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 367     const char *name)
 368 {
 369         char                    *p, *path;
 370         struct pf_ruleset       *ruleset;
 371
 372         r->anchor = NULL;
 373         r->anchor_relative = 0;
 374         r->anchor_wildcard = 0;
 375         if (!name[0])
 376                 return (0);
 377         path = (char *)rs_malloc(MAXPATHLEN);
 378         bzero(path, MAXPATHLEN);
 379         if (name[0] == '/')
 380                 strlcpy(path, name + 1, MAXPATHLEN);
 381         else {
 382                 /* relative path */
 383                 r->anchor_relative = 1;
 384                 if (s->anchor == NULL || !s->anchor->path[0])
 385                         path[0] = 0;
 386                 else
 387                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 388                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 389                         if (!path[0]) {
 390                                 printf("pf_anchor_setup: .. beyond root\n");
 391                                 rs_free(path);
 392                                 return (1);
 393                         }
 394                         if ((p = strrchr(path, '/')) != NULL)
 395                                 *p = 0;
 396                         else
 397                                 path[0] = 0;
 398                         r->anchor_relative++;
 399                         name += 3;
 400                 }
 401                 if (path[0])
 402                         strlcat(path, "/", MAXPATHLEN);
 403                 strlcat(path, name, MAXPATHLEN);
 404         }
 405         if ((p = strrchr(path, '/')) != NULL && strcmp(p, "/*") == 0) {
 406                 r->anchor_wildcard = 1;
 407                 *p = 0;
 408         }
 409         ruleset = pf_find_or_create_ruleset(path);
 410         rs_free(path);
 411         if (ruleset == NULL || ruleset->anchor == NULL) {
 412                 printf("pf_anchor_setup: ruleset\n");
 413                 return (1);
 414         }
 415         r->anchor = ruleset->anchor;
 416         r->anchor->refcnt++;
 417         return (0);
 418 }
 419
 420 int
 421 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 422     struct pfioc_rule *pr)
 423 {
 424         pr->anchor_call[0] = 0;
 425         if (r->anchor == NULL)
 426                 return (0);
 427         if (!r->anchor_relative) {
 428                 strlcpy(pr->anchor_call, "/", sizeof (pr->anchor_call));
 429                 strlcat(pr->anchor_call, r->anchor->path,
 430                     sizeof (pr->anchor_call));
 431         } else {
 432                 char    *a, *p;
 433                 int      i;
 434
 435                 a = (char *)rs_malloc(MAXPATHLEN);
 436                 bzero(a, MAXPATHLEN);
 437                 if (rs->anchor == NULL)
 438                         a[0] = 0;
 439                 else
 440                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 441                 for (i = 1; i < r->anchor_relative; ++i) {
 442                         if ((p = strrchr(a, '/')) == NULL)
 443                                 p = a;
 444                         *p = 0;
 445                         strlcat(pr->anchor_call, "../",
 446                             sizeof (pr->anchor_call));
 447                 }
 448                 if (strncmp(a, r->anchor->path, strlen(a))) {
 449                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 450                             r->anchor->path);
 451                         rs_free(a);
 452                         return (1);
 453                 }
 454                 if (strlen(r->anchor->path) > strlen(a))
 455                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 456                             strlen(a) + 1 : 0), sizeof (pr->anchor_call));
 457                 rs_free(a);
 458         }
 459         if (r->anchor_wildcard)
 460                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 461                     sizeof (pr->anchor_call));
 462         return (0);
 463 }
 464
 465 void
 466 pf_anchor_remove(struct pf_rule *r)
 467 {
 468         if (r->anchor == NULL)
 469                 return;
 470         if (r->anchor->refcnt <= 0) {
 471                 printf("pf_anchor_remove: broken refcount\n");
 472                 r->anchor = NULL;
 473                 return;
 474         }
 475         if (!--r->anchor->refcnt)
 476                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 477         r->anchor = NULL;
 478 }