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