sbin/pfctl/pf_ruleset.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 2001 Daniel Hartmeier
   5  * Copyright (c) 2002,2003 Henning Brauer
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  *    - Redistributions of source code must retain the above copyright
  13  *      notice, this list of conditions and the following disclaimer.
  14  *    - Redistributions in binary form must reproduce the above
  15  *      copyright notice, this list of conditions and the following
  16  *      disclaimer in the documentation and/or other materials provided
  17  *      with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  22  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  23  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  25  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  27  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  29  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * Effort sponsored in part by the Defense Advanced Research Projects
  33  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  34  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
  35  *
  36  *      $OpenBSD: pf_ruleset.c,v 1.2 2008/12/18 15:31:37 dhill Exp $
  37  */
  38
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD$");
  41
  42 #include <sys/param.h>
  43 #include <sys/socket.h>
  44 #include <sys/mbuf.h>
  45
  46 #include <netinet/in.h>
  47 #include <netinet/in_systm.h>
  48 #include <netinet/ip.h>
  49 #include <netinet/tcp.h>
  50
  51 #include <net/if.h>
  52 #include <net/vnet.h>
  53 #include <net/pfvar.h>
  54
  55 #ifdef INET6
  56 #include <netinet/ip6.h>
  57 #endif /* INET6 */
  58
  59 #include <arpa/inet.h>
  60 #include <errno.h>
  61 #include <stdio.h>
  62 #include <stdlib.h>
  63 #include <string.h>
  64 #define rs_malloc(x)             calloc(1, x)
  65 #define rs_free(x)               free(x)
  66
  67 #ifdef PFDEBUG
  68 #include <sys/stdarg.h>
  69 #define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
  70 #else
  71 #define DPFPRINTF(format, x...) ((void)0)
  72 #endif /* PFDEBUG */
  73
  74 struct pf_anchor_global  pf_anchors;
  75 struct pf_anchor         pf_main_anchor;
  76 #undef V_pf_anchors
  77 #define V_pf_anchors             pf_anchors
  78 #undef pf_main_ruleset
  79 #define pf_main_ruleset          pf_main_anchor.ruleset
  80
  81 static __inline int             pf_anchor_compare(struct pf_anchor *,
  82                                     struct pf_anchor *);
  83 static struct pf_anchor         *pf_find_anchor(const char *);
  84
  85 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
  86 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
  87
  88 static __inline int
  89 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
  90 {
  91         int c = strcmp(a->path, b->path);
  92
  93         return (c ? (c < 0 ? -1 : 1) : 0);
  94 }
  95
  96 int
  97 pf_get_ruleset_number(u_int8_t action)
  98 {
  99         switch (action) {
 100         case PF_SCRUB:
 101         case PF_NOSCRUB:
 102                 return (PF_RULESET_SCRUB);
 103                 break;
 104         case PF_PASS:
 105         case PF_DROP:
 106                 return (PF_RULESET_FILTER);
 107                 break;
 108         case PF_NAT:
 109         case PF_NONAT:
 110                 return (PF_RULESET_NAT);
 111                 break;
 112         case PF_BINAT:
 113         case PF_NOBINAT:
 114                 return (PF_RULESET_BINAT);
 115                 break;
 116         case PF_RDR:
 117         case PF_NORDR:
 118                 return (PF_RULESET_RDR);
 119                 break;
 120         default:
 121                 return (PF_RULESET_MAX);
 122                 break;
 123         }
 124 }
 125
 126 void
 127 pf_init_ruleset(struct pf_ruleset *ruleset)
 128 {
 129         int     i;
 130
 131         memset(ruleset, 0, sizeof(struct pf_ruleset));
 132         for (i = 0; i < PF_RULESET_MAX; i++) {
 133                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 134                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 135                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 136                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 137         }
 138 }
 139
 140 static struct pf_anchor *
 141 pf_find_anchor(const char *path)
 142 {
 143         struct pf_anchor        *key, *found;
 144
 145         key = (struct pf_anchor *)rs_malloc(sizeof(*key));
 146         if (key == NULL)
 147                 return (NULL);
 148         strlcpy(key->path, path, sizeof(key->path));
 149         found = RB_FIND(pf_anchor_global, &V_pf_anchors, key);
 150         rs_free(key);
 151         return (found);
 152 }
 153
 154 struct pf_ruleset *
 155 pf_find_ruleset(const char *path)
 156 {
 157         struct pf_anchor        *anchor;
 158
 159         while (*path == '/')
 160                 path++;
 161         if (!*path)
 162                 return (&pf_main_ruleset);
 163         anchor = pf_find_anchor(path);
 164         if (anchor == NULL)
 165                 return (NULL);
 166         else
 167                 return (&anchor->ruleset);
 168 }
 169
 170 struct pf_ruleset *
 171 pf_find_or_create_ruleset(const char *path)
 172 {
 173         char                    *p, *q, *r;
 174         struct pf_ruleset       *ruleset;
 175         struct pf_anchor        *anchor = NULL, *dup, *parent = NULL;
 176
 177         if (path[0] == 0)
 178                 return (&pf_main_ruleset);
 179         while (*path == '/')
 180                 path++;
 181         ruleset = pf_find_ruleset(path);
 182         if (ruleset != NULL)
 183                 return (ruleset);
 184         p = (char *)rs_malloc(MAXPATHLEN);
 185         if (p == NULL)
 186                 return (NULL);
 187         strlcpy(p, path, MAXPATHLEN);
 188         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 189                 *q = 0;
 190                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 191                         parent = ruleset->anchor;
 192                         break;
 193                 }
 194         }
 195         if (q == NULL)
 196                 q = p;
 197         else
 198                 q++;
 199         strlcpy(p, path, MAXPATHLEN);
 200         if (!*q) {
 201                 rs_free(p);
 202                 return (NULL);
 203         }
 204         while ((r = strchr(q, '/')) != NULL || *q) {
 205                 if (r != NULL)
 206                         *r = 0;
 207                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 208                     (parent != NULL && strlen(parent->path) >=
 209                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 210                         rs_free(p);
 211                         return (NULL);
 212                 }
 213                 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
 214                 if (anchor == NULL) {
 215                         rs_free(p);
 216                         return (NULL);
 217                 }
 218                 RB_INIT(&anchor->children);
 219                 strlcpy(anchor->name, q, sizeof(anchor->name));
 220                 if (parent != NULL) {
 221                         strlcpy(anchor->path, parent->path,
 222                             sizeof(anchor->path));
 223                         strlcat(anchor->path, "/", sizeof(anchor->path));
 224                 }
 225                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 226                 if ((dup = RB_INSERT(pf_anchor_global, &V_pf_anchors, anchor)) !=
 227                     NULL) {
 228                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 229                             "'%s' '%s' collides with '%s' '%s'\n",
 230                             anchor->path, anchor->name, dup->path, dup->name);
 231                         rs_free(anchor);
 232                         rs_free(p);
 233                         return (NULL);
 234                 }
 235                 if (parent != NULL) {
 236                         anchor->parent = parent;
 237                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 238                             anchor)) != NULL) {
 239                                 printf("pf_find_or_create_ruleset: "
 240                                     "RB_INSERT2 '%s' '%s' collides with "
 241                                     "'%s' '%s'\n", anchor->path, anchor->name,
 242                                     dup->path, dup->name);
 243                                 RB_REMOVE(pf_anchor_global, &V_pf_anchors,
 244                                     anchor);
 245                                 rs_free(anchor);
 246                                 rs_free(p);
 247                                 return (NULL);
 248                         }
 249                 }
 250                 pf_init_ruleset(&anchor->ruleset);
 251                 anchor->ruleset.anchor = anchor;
 252                 parent = anchor;
 253                 if (r != NULL)
 254                         q = r + 1;
 255                 else
 256                         *q = 0;
 257         }
 258         rs_free(p);
 259         return (&anchor->ruleset);
 260 }
 261
 262 void
 263 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 264 {
 265         struct pf_anchor        *parent;
 266         int                      i;
 267
 268         while (ruleset != NULL) {
 269                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 270                     !RB_EMPTY(&ruleset->anchor->children) ||
 271                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 272                     ruleset->topen)
 273                         return;
 274                 for (i = 0; i < PF_RULESET_MAX; ++i)
 275                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 276                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 277                             ruleset->rules[i].inactive.open)
 278                                 return;
 279                 RB_REMOVE(pf_anchor_global, &V_pf_anchors, ruleset->anchor);
 280                 if ((parent = ruleset->anchor->parent) != NULL)
 281                         RB_REMOVE(pf_anchor_node, &parent->children,
 282                             ruleset->anchor);
 283                 rs_free(ruleset->anchor);
 284                 if (parent == NULL)
 285                         return;
 286                 ruleset = &parent->ruleset;
 287         }
 288 }
 289 int
 290 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 291     const char *name)
 292 {
 293         char                    *p, *path;
 294         struct pf_ruleset       *ruleset;
 295
 296         r->anchor = NULL;
 297         r->anchor_relative = 0;
 298         r->anchor_wildcard = 0;
 299         if (!name[0])
 300                 return (0);
 301         path = (char *)rs_malloc(MAXPATHLEN);
 302         if (path == NULL)
 303                 return (1);
 304         if (name[0] == '/')
 305                 strlcpy(path, name + 1, MAXPATHLEN);
 306         else {
 307                 /* relative path */
 308                 r->anchor_relative = 1;
 309                 if (s->anchor == NULL || !s->anchor->path[0])
 310                         path[0] = 0;
 311                 else
 312                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 313                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 314                         if (!path[0]) {
 315                                 printf("pf_anchor_setup: .. beyond root\n");
 316                                 rs_free(path);
 317                                 return (1);
 318                         }
 319                         if ((p = strrchr(path, '/')) != NULL)
 320                                 *p = 0;
 321                         else
 322                                 path[0] = 0;
 323                         r->anchor_relative++;
 324                         name += 3;
 325                 }
 326                 if (path[0])
 327                         strlcat(path, "/", MAXPATHLEN);
 328                 strlcat(path, name, MAXPATHLEN);
 329         }
 330         if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
 331                 r->anchor_wildcard = 1;
 332                 *p = 0;
 333         }
 334         ruleset = pf_find_or_create_ruleset(path);
 335         rs_free(path);
 336         if (ruleset == NULL || ruleset->anchor == NULL) {
 337                 printf("pf_anchor_setup: ruleset\n");
 338                 return (1);
 339         }
 340         r->anchor = ruleset->anchor;
 341         r->anchor->refcnt++;
 342         return (0);
 343 }