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 #include "pfctl.h"
  68
  69 #ifdef PFDEBUG
  70 #include <sys/stdarg.h>
  71 #define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
  72 #else
  73 #define DPFPRINTF(format, x...) ((void)0)
  74 #endif /* PFDEBUG */
  75
  76 struct pfctl_anchor_global       pf_anchors;
  77 struct pfctl_anchor      pf_main_anchor;
  78 #undef V_pf_anchors
  79 #define V_pf_anchors             pf_anchors
  80 #undef pf_main_ruleset
  81 #define pf_main_ruleset          pf_main_anchor.ruleset
  82
  83 static __inline int             pf_anchor_compare(struct pfctl_anchor *,
  84                                     struct pfctl_anchor *);
  85 static struct pfctl_anchor      *pf_find_anchor(const char *);
  86
  87 RB_GENERATE(pfctl_anchor_global, pfctl_anchor, entry_global,
  88     pf_anchor_compare);
  89 RB_GENERATE(pfctl_anchor_node, pfctl_anchor, entry_node, pf_anchor_compare);
  90
  91 static __inline int
  92 pf_anchor_compare(struct pfctl_anchor *a, struct pfctl_anchor *b)
  93 {
  94         int c = strcmp(a->path, b->path);
  95
  96         return (c ? (c < 0 ? -1 : 1) : 0);
  97 }
  98
  99 int
 100 pf_get_ruleset_number(u_int8_t action)
 101 {
 102         switch (action) {
 103         case PF_SCRUB:
 104         case PF_NOSCRUB:
 105                 return (PF_RULESET_SCRUB);
 106                 break;
 107         case PF_PASS:
 108         case PF_DROP:
 109         case PF_MATCH:
 110                 return (PF_RULESET_FILTER);
 111                 break;
 112         case PF_NAT:
 113         case PF_NONAT:
 114                 return (PF_RULESET_NAT);
 115                 break;
 116         case PF_BINAT:
 117         case PF_NOBINAT:
 118                 return (PF_RULESET_BINAT);
 119                 break;
 120         case PF_RDR:
 121         case PF_NORDR:
 122                 return (PF_RULESET_RDR);
 123                 break;
 124         default:
 125                 return (PF_RULESET_MAX);
 126                 break;
 127         }
 128 }
 129
 130 void
 131 pf_init_ruleset(struct pfctl_ruleset *ruleset)
 132 {
 133         int     i;
 134
 135         memset(ruleset, 0, sizeof(struct pfctl_ruleset));
 136         for (i = 0; i < PF_RULESET_MAX; i++) {
 137                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 138                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 139                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 140                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 141         }
 142 }
 143
 144 static struct pfctl_anchor *
 145 pf_find_anchor(const char *path)
 146 {
 147         struct pfctl_anchor     *key, *found;
 148
 149         key = (struct pfctl_anchor *)rs_malloc(sizeof(*key));
 150         if (key == NULL)
 151                 return (NULL);
 152         strlcpy(key->path, path, sizeof(key->path));
 153         found = RB_FIND(pfctl_anchor_global, &V_pf_anchors, key);
 154         rs_free(key);
 155         return (found);
 156 }
 157
 158 struct pfctl_ruleset *
 159 pf_find_ruleset(const char *path)
 160 {
 161         struct pfctl_anchor     *anchor;
 162
 163         while (*path == '/')
 164                 path++;
 165         if (!*path)
 166                 return (&pf_main_ruleset);
 167         anchor = pf_find_anchor(path);
 168         if (anchor == NULL)
 169                 return (NULL);
 170         else
 171                 return (&anchor->ruleset);
 172 }
 173
 174 struct pfctl_ruleset *
 175 pf_find_or_create_ruleset(const char *path)
 176 {
 177         char                    *p, *q, *r;
 178         struct pfctl_ruleset    *ruleset;
 179         struct pfctl_anchor     *anchor = NULL, *dup, *parent = NULL;
 180
 181         if (path[0] == 0)
 182                 return (&pf_main_ruleset);
 183         while (*path == '/')
 184                 path++;
 185         ruleset = pf_find_ruleset(path);
 186         if (ruleset != NULL)
 187                 return (ruleset);
 188         p = (char *)rs_malloc(MAXPATHLEN);
 189         if (p == NULL)
 190                 return (NULL);
 191         strlcpy(p, path, MAXPATHLEN);
 192         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 193                 *q = 0;
 194                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 195                         parent = ruleset->anchor;
 196                         break;
 197                 }
 198         }
 199         if (q == NULL)
 200                 q = p;
 201         else
 202                 q++;
 203         strlcpy(p, path, MAXPATHLEN);
 204         if (!*q) {
 205                 rs_free(p);
 206                 return (NULL);
 207         }
 208         while ((r = strchr(q, '/')) != NULL || *q) {
 209                 if (r != NULL)
 210                         *r = 0;
 211                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 212                     (parent != NULL && strlen(parent->path) >=
 213                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 214                         rs_free(p);
 215                         return (NULL);
 216                 }
 217                 anchor = (struct pfctl_anchor *)rs_malloc(sizeof(*anchor));
 218                 if (anchor == NULL) {
 219                         rs_free(p);
 220                         return (NULL);
 221                 }
 222                 RB_INIT(&anchor->children);
 223                 strlcpy(anchor->name, q, sizeof(anchor->name));
 224                 if (parent != NULL) {
 225                         strlcpy(anchor->path, parent->path,
 226                             sizeof(anchor->path));
 227                         strlcat(anchor->path, "/", sizeof(anchor->path));
 228                 }
 229                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 230                 if ((dup = RB_INSERT(pfctl_anchor_global, &V_pf_anchors, anchor)) !=
 231                     NULL) {
 232                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 233                             "'%s' '%s' collides with '%s' '%s'\n",
 234                             anchor->path, anchor->name, dup->path, dup->name);
 235                         rs_free(anchor);
 236                         rs_free(p);
 237                         return (NULL);
 238                 }
 239                 if (parent != NULL) {
 240                         anchor->parent = parent;
 241                         if ((dup = RB_INSERT(pfctl_anchor_node, &parent->children,
 242                             anchor)) != NULL) {
 243                                 printf("pf_find_or_create_ruleset: "
 244                                     "RB_INSERT2 '%s' '%s' collides with "
 245                                     "'%s' '%s'\n", anchor->path, anchor->name,
 246                                     dup->path, dup->name);
 247                                 RB_REMOVE(pfctl_anchor_global, &V_pf_anchors,
 248                                     anchor);
 249                                 rs_free(anchor);
 250                                 rs_free(p);
 251                                 return (NULL);
 252                         }
 253                 }
 254                 pf_init_ruleset(&anchor->ruleset);
 255                 anchor->ruleset.anchor = anchor;
 256                 parent = anchor;
 257                 if (r != NULL)
 258                         q = r + 1;
 259                 else
 260                         *q = 0;
 261         }
 262         rs_free(p);
 263         return (&anchor->ruleset);
 264 }
 265
 266 void
 267 pf_remove_if_empty_ruleset(struct pfctl_ruleset *ruleset)
 268 {
 269         struct pfctl_anchor     *parent;
 270         int                      i;
 271
 272         while (ruleset != NULL) {
 273                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 274                     !RB_EMPTY(&ruleset->anchor->children) ||
 275                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 276                     ruleset->topen)
 277                         return;
 278                 for (i = 0; i < PF_RULESET_MAX; ++i)
 279                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 280                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 281                             ruleset->rules[i].inactive.open)
 282                                 return;
 283                 RB_REMOVE(pfctl_anchor_global, &V_pf_anchors, ruleset->anchor);
 284                 if ((parent = ruleset->anchor->parent) != NULL)
 285                         RB_REMOVE(pfctl_anchor_node, &parent->children,
 286                             ruleset->anchor);
 287                 rs_free(ruleset->anchor);
 288                 if (parent == NULL)
 289                         return;
 290                 ruleset = &parent->ruleset;
 291         }
 292 }
 293 int
 294 pfctl_anchor_setup(struct pfctl_rule *r, const struct pfctl_ruleset *s,
 295     const char *name)
 296 {
 297         char                    *p, *path;
 298         struct pfctl_ruleset    *ruleset;
 299
 300         r->anchor = NULL;
 301         r->anchor_relative = 0;
 302         r->anchor_wildcard = 0;
 303         if (!name[0])
 304                 return (0);
 305         path = (char *)rs_malloc(MAXPATHLEN);
 306         if (path == NULL)
 307                 return (1);
 308         if (name[0] == '/')
 309                 strlcpy(path, name + 1, MAXPATHLEN);
 310         else {
 311                 /* relative path */
 312                 r->anchor_relative = 1;
 313                 if (s->anchor == NULL || !s->anchor->path[0])
 314                         path[0] = 0;
 315                 else
 316                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 317                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 318                         if (!path[0]) {
 319                                 printf("pfctl_anchor_setup: .. beyond root\n");
 320                                 rs_free(path);
 321                                 return (1);
 322                         }
 323                         if ((p = strrchr(path, '/')) != NULL)
 324                                 *p = 0;
 325                         else
 326                                 path[0] = 0;
 327                         r->anchor_relative++;
 328                         name += 3;
 329                 }
 330                 if (path[0])
 331                         strlcat(path, "/", MAXPATHLEN);
 332                 strlcat(path, name, MAXPATHLEN);
 333         }
 334         if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
 335                 r->anchor_wildcard = 1;
 336                 *p = 0;
 337         }
 338         ruleset = pf_find_or_create_ruleset(path);
 339         rs_free(path);
 340         if (ruleset == NULL || ruleset->anchor == NULL) {
 341                 printf("pfctl_anchor_setup: ruleset\n");
 342                 return (1);
 343         }
 344         r->anchor = ruleset->anchor;
 345         r->anchor->refcnt++;
 346         return (0);
 347 }