sys/contrib/pf/net/pf_ruleset.c

   1 /*      $OpenBSD: pf_ruleset.c,v 1.2 2008/12/18 15:31:37 dhill Exp $ */
   2
   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  */
  37
  38 #ifdef __FreeBSD__
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD$");
  41 #endif
  42
  43 #include <sys/param.h>
  44 #include <sys/socket.h>
  45 #ifdef _KERNEL
  46 # include <sys/systm.h>
  47 #endif /* _KERNEL */
  48 #include <sys/mbuf.h>
  49
  50 #include <netinet/in.h>
  51 #include <netinet/in_systm.h>
  52 #include <netinet/ip.h>
  53 #include <netinet/tcp.h>
  54
  55 #include <net/if.h>
  56 #include <net/pfvar.h>
  57
  58 #ifdef INET6
  59 #include <netinet/ip6.h>
  60 #endif /* INET6 */
  61
  62
  63 #ifdef _KERNEL
  64 #ifdef __FreeBSD__
  65 #define DPFPRINTF(format, x...)                         \
  66         if (V_pf_status.debug >= PF_DEBUG_NOISY)        \
  67                 printf(format , ##x)
  68 #else
  69 #define DPFPRINTF(format, x...)                         \
  70         if (pf_status.debug >= PF_DEBUG_NOISY)          \
  71                 printf(format , ##x)
  72 #endif
  73 #ifdef __FreeBSD__
  74 #define rs_malloc(x)            malloc(x, M_TEMP, M_NOWAIT|M_ZERO)
  75 #else
  76 #define rs_malloc(x)            malloc(x, M_TEMP, M_WAITOK|M_CANFAIL|M_ZERO)
  77 #endif
  78 #define rs_free(x)              free(x, M_TEMP)
  79
  80 #else
  81 /* Userland equivalents so we can lend code to pfctl et al. */
  82
  83 #include <arpa/inet.h>
  84 #include <errno.h>
  85 #include <stdio.h>
  86 #include <stdlib.h>
  87 #include <string.h>
  88 #define rs_malloc(x)             calloc(1, x)
  89 #define rs_free(x)               free(x)
  90
  91 #ifdef PFDEBUG
  92 #include <sys/stdarg.h>
  93 #define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
  94 #else
  95 #define DPFPRINTF(format, x...) ((void)0)
  96 #endif /* PFDEBUG */
  97 #endif /* _KERNEL */
  98
  99 #if defined(__FreeBSD__) && !defined(_KERNEL)
 100 #undef V_pf_anchors
 101 #define V_pf_anchors             pf_anchors
 102
 103 #undef pf_main_ruleset
 104 #define pf_main_ruleset          pf_main_anchor.ruleset
 105 #endif
 106
 107 #if defined(__FreeBSD__) && defined(_KERNEL)
 108 VNET_DEFINE(struct pf_anchor_global,    pf_anchors);
 109 VNET_DEFINE(struct pf_anchor,           pf_main_anchor);
 110 #else
 111 struct pf_anchor_global  pf_anchors;
 112 struct pf_anchor         pf_main_anchor;
 113 #endif
 114
 115 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 116
 117 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 118 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 119
 120 static __inline int
 121 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 122 {
 123         int c = strcmp(a->path, b->path);
 124
 125         return (c ? (c < 0 ? -1 : 1) : 0);
 126 }
 127
 128 int
 129 pf_get_ruleset_number(u_int8_t action)
 130 {
 131         switch (action) {
 132         case PF_SCRUB:
 133         case PF_NOSCRUB:
 134                 return (PF_RULESET_SCRUB);
 135                 break;
 136         case PF_PASS:
 137         case PF_DROP:
 138                 return (PF_RULESET_FILTER);
 139                 break;
 140         case PF_NAT:
 141         case PF_NONAT:
 142                 return (PF_RULESET_NAT);
 143                 break;
 144         case PF_BINAT:
 145         case PF_NOBINAT:
 146                 return (PF_RULESET_BINAT);
 147                 break;
 148         case PF_RDR:
 149         case PF_NORDR:
 150                 return (PF_RULESET_RDR);
 151                 break;
 152         default:
 153                 return (PF_RULESET_MAX);
 154                 break;
 155         }
 156 }
 157
 158 void
 159 pf_init_ruleset(struct pf_ruleset *ruleset)
 160 {
 161         int     i;
 162
 163         memset(ruleset, 0, sizeof(struct pf_ruleset));
 164         for (i = 0; i < PF_RULESET_MAX; i++) {
 165                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 166                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 167                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 168                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 169         }
 170 }
 171
 172 struct pf_anchor *
 173 pf_find_anchor(const char *path)
 174 {
 175         struct pf_anchor        *key, *found;
 176
 177         key = (struct pf_anchor *)rs_malloc(sizeof(*key));
 178         if (key == NULL)
 179                 return (NULL);
 180         strlcpy(key->path, path, sizeof(key->path));
 181 #ifdef __FreeBSD__
 182         found = RB_FIND(pf_anchor_global, &V_pf_anchors, key);
 183 #else
 184         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 185 #endif
 186         rs_free(key);
 187         return (found);
 188 }
 189
 190 struct pf_ruleset *
 191 pf_find_ruleset(const char *path)
 192 {
 193         struct pf_anchor        *anchor;
 194
 195         while (*path == '/')
 196                 path++;
 197         if (!*path)
 198                 return (&pf_main_ruleset);
 199         anchor = pf_find_anchor(path);
 200         if (anchor == NULL)
 201                 return (NULL);
 202         else
 203                 return (&anchor->ruleset);
 204 }
 205
 206 struct pf_ruleset *
 207 pf_find_or_create_ruleset(const char *path)
 208 {
 209         char                    *p, *q, *r;
 210         struct pf_ruleset       *ruleset;
 211 #ifdef __FreeBSD__
 212         struct pf_anchor        *anchor = NULL, *dup, *parent = NULL;
 213 #else
 214         struct pf_anchor        *anchor, *dup, *parent = NULL;
 215 #endif
 216
 217         if (path[0] == 0)
 218                 return (&pf_main_ruleset);
 219         while (*path == '/')
 220                 path++;
 221         ruleset = pf_find_ruleset(path);
 222         if (ruleset != NULL)
 223                 return (ruleset);
 224         p = (char *)rs_malloc(MAXPATHLEN);
 225         if (p == NULL)
 226                 return (NULL);
 227         strlcpy(p, path, MAXPATHLEN);
 228         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 229                 *q = 0;
 230                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 231                         parent = ruleset->anchor;
 232                         break;
 233                 }
 234         }
 235         if (q == NULL)
 236                 q = p;
 237         else
 238                 q++;
 239         strlcpy(p, path, MAXPATHLEN);
 240         if (!*q) {
 241                 rs_free(p);
 242                 return (NULL);
 243         }
 244         while ((r = strchr(q, '/')) != NULL || *q) {
 245                 if (r != NULL)
 246                         *r = 0;
 247                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 248                     (parent != NULL && strlen(parent->path) >=
 249                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 250                         rs_free(p);
 251                         return (NULL);
 252                 }
 253                 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
 254                 if (anchor == NULL) {
 255                         rs_free(p);
 256                         return (NULL);
 257                 }
 258                 RB_INIT(&anchor->children);
 259                 strlcpy(anchor->name, q, sizeof(anchor->name));
 260                 if (parent != NULL) {
 261                         strlcpy(anchor->path, parent->path,
 262                             sizeof(anchor->path));
 263                         strlcat(anchor->path, "/", sizeof(anchor->path));
 264                 }
 265                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 266 #ifdef __FreeBSD__
 267                 if ((dup = RB_INSERT(pf_anchor_global, &V_pf_anchors, anchor)) !=
 268 #else
 269                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 270 #endif
 271                     NULL) {
 272                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 273                             "'%s' '%s' collides with '%s' '%s'\n",
 274                             anchor->path, anchor->name, dup->path, dup->name);
 275                         rs_free(anchor);
 276                         rs_free(p);
 277                         return (NULL);
 278                 }
 279                 if (parent != NULL) {
 280                         anchor->parent = parent;
 281                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 282                             anchor)) != NULL) {
 283                                 printf("pf_find_or_create_ruleset: "
 284                                     "RB_INSERT2 '%s' '%s' collides with "
 285                                     "'%s' '%s'\n", anchor->path, anchor->name,
 286                                     dup->path, dup->name);
 287 #ifdef __FreeBSD__
 288                                 RB_REMOVE(pf_anchor_global, &V_pf_anchors,
 289 #else
 290                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 291 #endif
 292                                     anchor);
 293                                 rs_free(anchor);
 294                                 rs_free(p);
 295                                 return (NULL);
 296                         }
 297                 }
 298                 pf_init_ruleset(&anchor->ruleset);
 299                 anchor->ruleset.anchor = anchor;
 300                 parent = anchor;
 301                 if (r != NULL)
 302                         q = r + 1;
 303                 else
 304                         *q = 0;
 305         }
 306         rs_free(p);
 307         return (&anchor->ruleset);
 308 }
 309
 310 void
 311 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 312 {
 313         struct pf_anchor        *parent;
 314         int                      i;
 315
 316         while (ruleset != NULL) {
 317                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 318                     !RB_EMPTY(&ruleset->anchor->children) ||
 319                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 320                     ruleset->topen)
 321                         return;
 322                 for (i = 0; i < PF_RULESET_MAX; ++i)
 323                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 324                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 325                             ruleset->rules[i].inactive.open)
 326                                 return;
 327 #ifdef __FreeBSD__
 328                 RB_REMOVE(pf_anchor_global, &V_pf_anchors, ruleset->anchor);
 329 #else
 330                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 331 #endif
 332                 if ((parent = ruleset->anchor->parent) != NULL)
 333                         RB_REMOVE(pf_anchor_node, &parent->children,
 334                             ruleset->anchor);
 335                 rs_free(ruleset->anchor);
 336                 if (parent == NULL)
 337                         return;
 338                 ruleset = &parent->ruleset;
 339         }
 340 }
 341
 342 int
 343 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 344     const char *name)
 345 {
 346         char                    *p, *path;
 347         struct pf_ruleset       *ruleset;
 348
 349         r->anchor = NULL;
 350         r->anchor_relative = 0;
 351         r->anchor_wildcard = 0;
 352         if (!name[0])
 353                 return (0);
 354         path = (char *)rs_malloc(MAXPATHLEN);
 355         if (path == NULL)
 356                 return (1);
 357         if (name[0] == '/')
 358                 strlcpy(path, name + 1, MAXPATHLEN);
 359         else {
 360                 /* relative path */
 361                 r->anchor_relative = 1;
 362                 if (s->anchor == NULL || !s->anchor->path[0])
 363                         path[0] = 0;
 364                 else
 365                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 366                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 367                         if (!path[0]) {
 368                                 printf("pf_anchor_setup: .. beyond root\n");
 369                                 rs_free(path);
 370                                 return (1);
 371                         }
 372                         if ((p = strrchr(path, '/')) != NULL)
 373                                 *p = 0;
 374                         else
 375                                 path[0] = 0;
 376                         r->anchor_relative++;
 377                         name += 3;
 378                 }
 379                 if (path[0])
 380                         strlcat(path, "/", MAXPATHLEN);
 381                 strlcat(path, name, MAXPATHLEN);
 382         }
 383         if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
 384                 r->anchor_wildcard = 1;
 385                 *p = 0;
 386         }
 387         ruleset = pf_find_or_create_ruleset(path);
 388         rs_free(path);
 389         if (ruleset == NULL || ruleset->anchor == NULL) {
 390                 printf("pf_anchor_setup: ruleset\n");
 391                 return (1);
 392         }
 393         r->anchor = ruleset->anchor;
 394         r->anchor->refcnt++;
 395         return (0);
 396 }
 397
 398 int
 399 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 400     struct pfioc_rule *pr)
 401 {
 402         pr->anchor_call[0] = 0;
 403         if (r->anchor == NULL)
 404                 return (0);
 405         if (!r->anchor_relative) {
 406                 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
 407                 strlcat(pr->anchor_call, r->anchor->path,
 408                     sizeof(pr->anchor_call));
 409         } else {
 410                 char    *a, *p;
 411                 int      i;
 412
 413                 a = (char *)rs_malloc(MAXPATHLEN);
 414                 if (a == NULL)
 415                         return (1);
 416                 if (rs->anchor == NULL)
 417                         a[0] = 0;
 418                 else
 419                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 420                 for (i = 1; i < r->anchor_relative; ++i) {
 421                         if ((p = strrchr(a, '/')) == NULL)
 422                                 p = a;
 423                         *p = 0;
 424                         strlcat(pr->anchor_call, "../",
 425                             sizeof(pr->anchor_call));
 426                 }
 427                 if (strncmp(a, r->anchor->path, strlen(a))) {
 428                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 429                             r->anchor->path);
 430                         rs_free(a);
 431                         return (1);
 432                 }
 433                 if (strlen(r->anchor->path) > strlen(a))
 434                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 435                             strlen(a) + 1 : 0), sizeof(pr->anchor_call));
 436                 rs_free(a);
 437         }
 438         if (r->anchor_wildcard)
 439                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 440                     sizeof(pr->anchor_call));
 441         return (0);
 442 }
 443
 444 void
 445 pf_anchor_remove(struct pf_rule *r)
 446 {
 447         if (r->anchor == NULL)
 448                 return;
 449         if (r->anchor->refcnt <= 0) {
 450                 printf("pf_anchor_remove: broken refcount\n");
 451                 r->anchor = NULL;
 452                 return;
 453         }
 454         if (!--r->anchor->refcnt)
 455                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 456         r->anchor = NULL;
 457 }