sys/netpfil/pf/pf_ruleset.c

   1 /*-
   2  * Copyright (c) 2001 Daniel Hartmeier
   3  * Copyright (c) 2002,2003 Henning Brauer
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  *    - Redistributions of source code must retain the above copyright
  11  *      notice, this list of conditions and the following disclaimer.
  12  *    - Redistributions in binary form must reproduce the above
  13  *      copyright notice, this list of conditions and the following
  14  *      disclaimer in the documentation and/or other materials provided
  15  *      with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  20  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  21  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  27  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * Effort sponsored in part by the Defense Advanced Research Projects
  31  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  32  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
  33  *
  34  *      $OpenBSD: pf_ruleset.c,v 1.2 2008/12/18 15:31:37 dhill Exp $
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/socket.h>
  42 #ifdef _KERNEL
  43 # include <sys/systm.h>
  44 # include <sys/refcount.h>
  45 #endif /* _KERNEL */
  46 #include <sys/mbuf.h>
  47
  48 #include <netinet/in.h>
  49 #include <netinet/in_systm.h>
  50 #include <netinet/ip.h>
  51 #include <netinet/tcp.h>
  52
  53 #include <net/if.h>
  54 #include <net/pfvar.h>
  55
  56 #ifdef INET6
  57 #include <netinet/ip6.h>
  58 #endif /* INET6 */
  59
  60
  61 #ifdef _KERNEL
  62 #define DPFPRINTF(format, x...)                         \
  63         if (V_pf_status.debug >= PF_DEBUG_NOISY)        \
  64                 printf(format , ##x)
  65 #define rs_malloc(x)            malloc(x, M_TEMP, M_NOWAIT|M_ZERO)
  66 #define rs_free(x)              free(x, M_TEMP)
  67
  68 #else
  69 /* Userland equivalents so we can lend code to pfctl et al. */
  70
  71 #include <arpa/inet.h>
  72 #include <errno.h>
  73 #include <stdio.h>
  74 #include <stdlib.h>
  75 #include <string.h>
  76 #define rs_malloc(x)             calloc(1, x)
  77 #define rs_free(x)               free(x)
  78
  79 #ifdef PFDEBUG
  80 #include <sys/stdarg.h>
  81 #define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
  82 #else
  83 #define DPFPRINTF(format, x...) ((void)0)
  84 #endif /* PFDEBUG */
  85 #endif /* _KERNEL */
  86
  87 #ifdef _KERNEL
  88 VNET_DEFINE(struct pf_anchor_global,    pf_anchors);
  89 VNET_DEFINE(struct pf_anchor,           pf_main_anchor);
  90 #else /* ! _KERNEL */
  91 struct pf_anchor_global  pf_anchors;
  92 struct pf_anchor         pf_main_anchor;
  93 #undef V_pf_anchors
  94 #define V_pf_anchors             pf_anchors
  95 #undef pf_main_ruleset
  96 #define pf_main_ruleset          pf_main_anchor.ruleset
  97 #endif /* _KERNEL */
  98
  99 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 100
 101 static struct pf_anchor         *pf_find_anchor(const char *);
 102
 103 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 104 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 105
 106 static __inline int
 107 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 108 {
 109         int c = strcmp(a->path, b->path);
 110
 111         return (c ? (c < 0 ? -1 : 1) : 0);
 112 }
 113
 114 int
 115 pf_get_ruleset_number(u_int8_t action)
 116 {
 117         switch (action) {
 118         case PF_SCRUB:
 119         case PF_NOSCRUB:
 120                 return (PF_RULESET_SCRUB);
 121                 break;
 122         case PF_PASS:
 123         case PF_DROP:
 124                 return (PF_RULESET_FILTER);
 125                 break;
 126         case PF_NAT:
 127         case PF_NONAT:
 128                 return (PF_RULESET_NAT);
 129                 break;
 130         case PF_BINAT:
 131         case PF_NOBINAT:
 132                 return (PF_RULESET_BINAT);
 133                 break;
 134         case PF_RDR:
 135         case PF_NORDR:
 136                 return (PF_RULESET_RDR);
 137                 break;
 138         default:
 139                 return (PF_RULESET_MAX);
 140                 break;
 141         }
 142 }
 143
 144 void
 145 pf_init_ruleset(struct pf_ruleset *ruleset)
 146 {
 147         int     i;
 148
 149         memset(ruleset, 0, sizeof(struct pf_ruleset));
 150         for (i = 0; i < PF_RULESET_MAX; i++) {
 151                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 152                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 153                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 154                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 155         }
 156 }
 157
 158 static struct pf_anchor *
 159 pf_find_anchor(const char *path)
 160 {
 161         struct pf_anchor        *key, *found;
 162
 163         key = (struct pf_anchor *)rs_malloc(sizeof(*key));
 164         if (key == NULL)
 165                 return (NULL);
 166         strlcpy(key->path, path, sizeof(key->path));
 167         found = RB_FIND(pf_anchor_global, &V_pf_anchors, key);
 168         rs_free(key);
 169         return (found);
 170 }
 171
 172 struct pf_ruleset *
 173 pf_find_ruleset(const char *path)
 174 {
 175         struct pf_anchor        *anchor;
 176
 177         while (*path == '/')
 178                 path++;
 179         if (!*path)
 180                 return (&pf_main_ruleset);
 181         anchor = pf_find_anchor(path);
 182         if (anchor == NULL)
 183                 return (NULL);
 184         else
 185                 return (&anchor->ruleset);
 186 }
 187
 188 struct pf_ruleset *
 189 pf_find_or_create_ruleset(const char *path)
 190 {
 191         char                    *p, *q, *r;
 192         struct pf_ruleset       *ruleset;
 193         struct pf_anchor        *anchor = NULL, *dup, *parent = NULL;
 194
 195         if (path[0] == 0)
 196                 return (&pf_main_ruleset);
 197         while (*path == '/')
 198                 path++;
 199         ruleset = pf_find_ruleset(path);
 200         if (ruleset != NULL)
 201                 return (ruleset);
 202         p = (char *)rs_malloc(MAXPATHLEN);
 203         if (p == NULL)
 204                 return (NULL);
 205         strlcpy(p, path, MAXPATHLEN);
 206         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 207                 *q = 0;
 208                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 209                         parent = ruleset->anchor;
 210                         break;
 211                 }
 212         }
 213         if (q == NULL)
 214                 q = p;
 215         else
 216                 q++;
 217         strlcpy(p, path, MAXPATHLEN);
 218         if (!*q) {
 219                 rs_free(p);
 220                 return (NULL);
 221         }
 222         while ((r = strchr(q, '/')) != NULL || *q) {
 223                 if (r != NULL)
 224                         *r = 0;
 225                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 226                     (parent != NULL && strlen(parent->path) >=
 227                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 228                         rs_free(p);
 229                         return (NULL);
 230                 }
 231                 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
 232                 if (anchor == NULL) {
 233                         rs_free(p);
 234                         return (NULL);
 235                 }
 236                 RB_INIT(&anchor->children);
 237                 strlcpy(anchor->name, q, sizeof(anchor->name));
 238                 if (parent != NULL) {
 239                         strlcpy(anchor->path, parent->path,
 240                             sizeof(anchor->path));
 241                         strlcat(anchor->path, "/", sizeof(anchor->path));
 242                 }
 243                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 244                 if ((dup = RB_INSERT(pf_anchor_global, &V_pf_anchors, anchor)) !=
 245                     NULL) {
 246                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 247                             "'%s' '%s' collides with '%s' '%s'\n",
 248                             anchor->path, anchor->name, dup->path, dup->name);
 249                         rs_free(anchor);
 250                         rs_free(p);
 251                         return (NULL);
 252                 }
 253                 if (parent != NULL) {
 254                         anchor->parent = parent;
 255                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 256                             anchor)) != NULL) {
 257                                 printf("pf_find_or_create_ruleset: "
 258                                     "RB_INSERT2 '%s' '%s' collides with "
 259                                     "'%s' '%s'\n", anchor->path, anchor->name,
 260                                     dup->path, dup->name);
 261                                 RB_REMOVE(pf_anchor_global, &V_pf_anchors,
 262                                     anchor);
 263                                 rs_free(anchor);
 264                                 rs_free(p);
 265                                 return (NULL);
 266                         }
 267                 }
 268                 pf_init_ruleset(&anchor->ruleset);
 269                 anchor->ruleset.anchor = anchor;
 270                 parent = anchor;
 271                 if (r != NULL)
 272                         q = r + 1;
 273                 else
 274                         *q = 0;
 275         }
 276         rs_free(p);
 277         return (&anchor->ruleset);
 278 }
 279
 280 void
 281 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 282 {
 283         struct pf_anchor        *parent;
 284         int                      i;
 285
 286         while (ruleset != NULL) {
 287                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 288                     !RB_EMPTY(&ruleset->anchor->children) ||
 289                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 290                     ruleset->topen)
 291                         return;
 292                 for (i = 0; i < PF_RULESET_MAX; ++i)
 293                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 294                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 295                             ruleset->rules[i].inactive.open)
 296                                 return;
 297                 RB_REMOVE(pf_anchor_global, &V_pf_anchors, ruleset->anchor);
 298                 if ((parent = ruleset->anchor->parent) != NULL)
 299                         RB_REMOVE(pf_anchor_node, &parent->children,
 300                             ruleset->anchor);
 301                 rs_free(ruleset->anchor);
 302                 if (parent == NULL)
 303                         return;
 304                 ruleset = &parent->ruleset;
 305         }
 306 }
 307
 308 int
 309 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 310     const char *name)
 311 {
 312         char                    *p, *path;
 313         struct pf_ruleset       *ruleset;
 314
 315         r->anchor = NULL;
 316         r->anchor_relative = 0;
 317         r->anchor_wildcard = 0;
 318         if (!name[0])
 319                 return (0);
 320         path = (char *)rs_malloc(MAXPATHLEN);
 321         if (path == NULL)
 322                 return (1);
 323         if (name[0] == '/')
 324                 strlcpy(path, name + 1, MAXPATHLEN);
 325         else {
 326                 /* relative path */
 327                 r->anchor_relative = 1;
 328                 if (s->anchor == NULL || !s->anchor->path[0])
 329                         path[0] = 0;
 330                 else
 331                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 332                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 333                         if (!path[0]) {
 334                                 printf("pf_anchor_setup: .. beyond root\n");
 335                                 rs_free(path);
 336                                 return (1);
 337                         }
 338                         if ((p = strrchr(path, '/')) != NULL)
 339                                 *p = 0;
 340                         else
 341                                 path[0] = 0;
 342                         r->anchor_relative++;
 343                         name += 3;
 344                 }
 345                 if (path[0])
 346                         strlcat(path, "/", MAXPATHLEN);
 347                 strlcat(path, name, MAXPATHLEN);
 348         }
 349         if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
 350                 r->anchor_wildcard = 1;
 351                 *p = 0;
 352         }
 353         ruleset = pf_find_or_create_ruleset(path);
 354         rs_free(path);
 355         if (ruleset == NULL || ruleset->anchor == NULL) {
 356                 printf("pf_anchor_setup: ruleset\n");
 357                 return (1);
 358         }
 359         r->anchor = ruleset->anchor;
 360         r->anchor->refcnt++;
 361         return (0);
 362 }
 363
 364 int
 365 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 366     struct pfioc_rule *pr)
 367 {
 368         pr->anchor_call[0] = 0;
 369         if (r->anchor == NULL)
 370                 return (0);
 371         if (!r->anchor_relative) {
 372                 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
 373                 strlcat(pr->anchor_call, r->anchor->path,
 374                     sizeof(pr->anchor_call));
 375         } else {
 376                 char    *a, *p;
 377                 int      i;
 378
 379                 a = (char *)rs_malloc(MAXPATHLEN);
 380                 if (a == NULL)
 381                         return (1);
 382                 if (rs->anchor == NULL)
 383                         a[0] = 0;
 384                 else
 385                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 386                 for (i = 1; i < r->anchor_relative; ++i) {
 387                         if ((p = strrchr(a, '/')) == NULL)
 388                                 p = a;
 389                         *p = 0;
 390                         strlcat(pr->anchor_call, "../",
 391                             sizeof(pr->anchor_call));
 392                 }
 393                 if (strncmp(a, r->anchor->path, strlen(a))) {
 394                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 395                             r->anchor->path);
 396                         rs_free(a);
 397                         return (1);
 398                 }
 399                 if (strlen(r->anchor->path) > strlen(a))
 400                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 401                             strlen(a) + 1 : 0), sizeof(pr->anchor_call));
 402                 rs_free(a);
 403         }
 404         if (r->anchor_wildcard)
 405                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 406                     sizeof(pr->anchor_call));
 407         return (0);
 408 }
 409
 410 void
 411 pf_anchor_remove(struct pf_rule *r)
 412 {
 413         if (r->anchor == NULL)
 414                 return;
 415         if (r->anchor->refcnt <= 0) {
 416                 printf("pf_anchor_remove: broken refcount\n");
 417                 r->anchor = NULL;
 418                 return;
 419         }
 420         if (!--r->anchor->refcnt)
 421                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 422         r->anchor = NULL;
 423 }