sys/dist/pf/net/pf_ruleset.c

   1 /*      $NetBSD$ */
   2 /*      $OpenBSD: pf_ruleset.c,v 1.1 2006/10/27 13:56:51 mcbride Exp $ */
   3
   4 /*
   5  * Copyright (c) 2001 Daniel Hartmeier
   6  * Copyright (c) 2002,2003 Henning Brauer
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  *    - Redistributions of source code must retain the above copyright
  14  *      notice, this list of conditions and the following disclaimer.
  15  *    - Redistributions in binary form must reproduce the above
  16  *      copyright notice, this list of conditions and the following
  17  *      disclaimer in the documentation and/or other materials provided
  18  *      with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  28  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  30  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * Effort sponsored in part by the Defense Advanced Research Projects
  34  * Agency (DARPA) and Air Force Research Laboratory, Air Force
  35  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
  36  *
  37  */
  38
  39 #include <sys/cdefs.h>
  40 __KERNEL_RCSID(0, "$NetBSD$");
  41
  42 #include <sys/param.h>
  43 #include <sys/socket.h>
  44 #ifdef _KERNEL
  45 # include <sys/systm.h>
  46 #endif /* _KERNEL */
  47 #include <sys/mbuf.h>
  48
  49 #include <netinet/in.h>
  50 #include <netinet/in_systm.h>
  51 #include <netinet/ip.h>
  52 #include <netinet/tcp.h>
  53
  54 #include <net/if.h>
  55 #include <net/pfvar.h>
  56
  57 #ifdef INET6
  58 #include <netinet/ip6.h>
  59 #endif /* INET6 */
  60
  61
  62 #ifdef _KERNEL
  63 # define DPFPRINTF(format, x...)                \
  64         if (pf_status.debug >= PF_DEBUG_NOISY)  \
  65                 printf(format , ##x)
  66 #define rs_malloc(x)            malloc(x, M_TEMP, M_WAITOK)
  67 #define rs_free(x)              free(x, M_TEMP)
  68
  69 #else
  70 /* Userland equivalents so we can lend code to pfctl et al. */
  71
  72 # include <arpa/inet.h>
  73 # include <errno.h>
  74 # include <stdio.h>
  75 # include <stdlib.h>
  76 # include <string.h>
  77 # define rs_malloc(x)            malloc(x)
  78 # define rs_free(x)              free(x)
  79
  80 # ifdef PFDEBUG
  81 #  include <sys/stdarg.h>
  82 #  define DPFPRINTF(format, x...)       fprintf(stderr, format , ##x)
  83 # else
  84 #  define DPFPRINTF(format, x...)       ((void)0)
  85 # endif /* PFDEBUG */
  86 #endif /* _KERNEL */
  87
  88
  89 struct pf_anchor_global  pf_anchors;
  90 struct pf_anchor         pf_main_anchor;
  91
  92 int                      pf_get_ruleset_number(u_int8_t);
  93 void                     pf_init_ruleset(struct pf_ruleset *);
  94 int                      pf_anchor_setup(struct pf_rule *,
  95                             const struct pf_ruleset *, const char *);
  96 int                      pf_anchor_copyout(const struct pf_ruleset *,
  97                             const struct pf_rule *, struct pfioc_rule *);
  98 void                     pf_anchor_remove(struct pf_rule *);
  99
 100 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 101
 102 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 103 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 104
 105 static __inline int
 106 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 107 {
 108         int c = strcmp(a->path, b->path);
 109
 110         return (c ? (c < 0 ? -1 : 1) : 0);
 111 }
 112
 113 int
 114 pf_get_ruleset_number(u_int8_t action)
 115 {
 116         switch (action) {
 117         case PF_SCRUB:
 118         case PF_NOSCRUB:
 119                 return (PF_RULESET_SCRUB);
 120                 break;
 121         case PF_PASS:
 122         case PF_DROP:
 123                 return (PF_RULESET_FILTER);
 124                 break;
 125         case PF_NAT:
 126         case PF_NONAT:
 127                 return (PF_RULESET_NAT);
 128                 break;
 129         case PF_BINAT:
 130         case PF_NOBINAT:
 131                 return (PF_RULESET_BINAT);
 132                 break;
 133         case PF_RDR:
 134         case PF_NORDR:
 135                 return (PF_RULESET_RDR);
 136                 break;
 137         default:
 138                 return (PF_RULESET_MAX);
 139                 break;
 140         }
 141 }
 142
 143 void
 144 pf_init_ruleset(struct pf_ruleset *ruleset)
 145 {
 146         int     i;
 147
 148         memset(ruleset, 0, sizeof(struct pf_ruleset));
 149         for (i = 0; i < PF_RULESET_MAX; i++) {
 150                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 151                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 152                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 153                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 154         }
 155 }
 156
 157 struct pf_anchor *
 158 pf_find_anchor(const char *path)
 159 {
 160         struct pf_anchor        *key, *found;
 161
 162         key = (struct pf_anchor *)rs_malloc(sizeof(*key));
 163         memset(key, 0, sizeof(*key));
 164         strlcpy(key->path, path, sizeof(key->path));
 165         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 166         rs_free(key);
 167         return (found);
 168 }
 169
 170 struct pf_ruleset *
 171 pf_find_ruleset(const char *path)
 172 {
 173         struct pf_anchor        *anchor;
 174
 175         while (*path == '/')
 176                 path++;
 177         if (!*path)
 178                 return (&pf_main_ruleset);
 179         anchor = pf_find_anchor(path);
 180         if (anchor == NULL)
 181                 return (NULL);
 182         else
 183                 return (&anchor->ruleset);
 184 }
 185
 186 struct pf_ruleset *
 187 pf_find_or_create_ruleset(const char *path)
 188 {
 189         char                    *p, *q, *r;
 190         struct pf_ruleset       *ruleset;
 191         struct pf_anchor        *anchor = NULL /* XXX gcc */;
 192         struct pf_anchor        *dup, *parent = NULL;
 193
 194         if (path[0] == 0)
 195                 return (&pf_main_ruleset);
 196         while (*path == '/')
 197                 path++;
 198         ruleset = pf_find_ruleset(path);
 199         if (ruleset != NULL)
 200                 return (ruleset);
 201         p = (char *)rs_malloc(MAXPATHLEN);
 202         bzero(p, MAXPATHLEN);
 203         strlcpy(p, path, MAXPATHLEN);
 204         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 205                 *q = 0;
 206                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 207                         parent = ruleset->anchor;
 208                         break;
 209                 }
 210         }
 211         if (q == NULL)
 212                 q = p;
 213         else
 214                 q++;
 215         strlcpy(p, path, MAXPATHLEN);
 216         if (!*q) {
 217                 rs_free(p);
 218                 return (NULL);
 219         }
 220         while ((r = strchr(q, '/')) != NULL || *q) {
 221                 if (r != NULL)
 222                         *r = 0;
 223                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 224                     (parent != NULL && strlen(parent->path) >=
 225                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 226                         rs_free(p);
 227                         return (NULL);
 228                 }
 229                 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
 230                 if (anchor == NULL) {
 231                         rs_free(p);
 232                         return (NULL);
 233                 }
 234                 memset(anchor, 0, sizeof(*anchor));
 235                 RB_INIT(&anchor->children);
 236                 strlcpy(anchor->name, q, sizeof(anchor->name));
 237                 if (parent != NULL) {
 238                         strlcpy(anchor->path, parent->path,
 239                             sizeof(anchor->path));
 240                         strlcat(anchor->path, "/", sizeof(anchor->path));
 241                 }
 242                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 243                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 244                     NULL) {
 245                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 246                             "'%s' '%s' collides with '%s' '%s'\n",
 247                             anchor->path, anchor->name, dup->path, dup->name);
 248                         rs_free(anchor);
 249                         rs_free(p);
 250                         return (NULL);
 251                 }
 252                 if (parent != NULL) {
 253                         anchor->parent = parent;
 254                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 255                             anchor)) != NULL) {
 256                                 printf("pf_find_or_create_ruleset: "
 257                                     "RB_INSERT2 '%s' '%s' collides with "
 258                                     "'%s' '%s'\n", anchor->path, anchor->name,
 259                                     dup->path, dup->name);
 260                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 261                                     anchor);
 262                                 rs_free(anchor);
 263                                 rs_free(p);
 264                                 return (NULL);
 265                         }
 266                 }
 267                 pf_init_ruleset(&anchor->ruleset);
 268                 anchor->ruleset.anchor = anchor;
 269                 parent = anchor;
 270                 if (r != NULL)
 271                         q = r + 1;
 272                 else
 273                         *q = 0;
 274         }
 275         rs_free(p);
 276         return (&anchor->ruleset);
 277 }
 278
 279 void
 280 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 281 {
 282         struct pf_anchor        *parent;
 283         int                      i;
 284
 285         while (ruleset != NULL) {
 286                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 287                     !RB_EMPTY(&ruleset->anchor->children) ||
 288                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 289                     ruleset->topen)
 290                         return;
 291                 for (i = 0; i < PF_RULESET_MAX; ++i)
 292                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 293                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 294                             ruleset->rules[i].inactive.open)
 295                                 return;
 296                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 297                 if ((parent = ruleset->anchor->parent) != NULL)
 298                         RB_REMOVE(pf_anchor_node, &parent->children,
 299                             ruleset->anchor);
 300                 rs_free(ruleset->anchor);
 301                 if (parent == NULL)
 302                         return;
 303                 ruleset = &parent->ruleset;
 304         }
 305 }
 306
 307 int
 308 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 309     const char *name)
 310 {
 311         char                    *p, *path;
 312         struct pf_ruleset       *ruleset;
 313
 314         r->anchor = NULL;
 315         r->anchor_relative = 0;
 316         r->anchor_wildcard = 0;
 317         if (!name[0])
 318                 return (0);
 319         path = (char *)rs_malloc(MAXPATHLEN);
 320         bzero(path, MAXPATHLEN);
 321         if (name[0] == '/')
 322                 strlcpy(path, name + 1, MAXPATHLEN);
 323         else {
 324                 /* relative path */
 325                 r->anchor_relative = 1;
 326                 if (s->anchor == NULL || !s->anchor->path[0])
 327                         path[0] = 0;
 328                 else
 329                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 330                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 331                         if (!path[0]) {
 332                                 printf("pf_anchor_setup: .. beyond root\n");
 333                                 rs_free(path);
 334                                 return (1);
 335                         }
 336                         if ((p = strrchr(path, '/')) != NULL)
 337                                 *p = 0;
 338                         else
 339                                 path[0] = 0;
 340                         r->anchor_relative++;
 341                         name += 3;
 342                 }
 343                 if (path[0])
 344                         strlcat(path, "/", MAXPATHLEN);
 345                 strlcat(path, name, MAXPATHLEN);
 346         }
 347         if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
 348                 r->anchor_wildcard = 1;
 349                 *p = 0;
 350         }
 351         ruleset = pf_find_or_create_ruleset(path);
 352         rs_free(path);
 353         if (ruleset == NULL || ruleset->anchor == NULL) {
 354                 printf("pf_anchor_setup: ruleset\n");
 355                 return (1);
 356         }
 357         r->anchor = ruleset->anchor;
 358         r->anchor->refcnt++;
 359         return (0);
 360 }
 361
 362 int
 363 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 364     struct pfioc_rule *pr)
 365 {
 366         pr->anchor_call[0] = 0;
 367         if (r->anchor == NULL)
 368                 return (0);
 369         if (!r->anchor_relative) {
 370                 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
 371                 strlcat(pr->anchor_call, r->anchor->path,
 372                     sizeof(pr->anchor_call));
 373         } else {
 374                 char    *a, *p;
 375                 int      i;
 376
 377                 a = (char *)rs_malloc(MAXPATHLEN);
 378                 bzero(a, MAXPATHLEN);
 379                 if (rs->anchor == NULL)
 380                         a[0] = 0;
 381                 else
 382                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 383                 for (i = 1; i < r->anchor_relative; ++i) {
 384                         if ((p = strrchr(a, '/')) == NULL)
 385                                 p = a;
 386                         *p = 0;
 387                         strlcat(pr->anchor_call, "../",
 388                             sizeof(pr->anchor_call));
 389                 }
 390                 if (strncmp(a, r->anchor->path, strlen(a))) {
 391                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 392                             r->anchor->path);
 393                         rs_free(a);
 394                         return (1);
 395                 }
 396                 if (strlen(r->anchor->path) > strlen(a))
 397                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 398                             strlen(a) + 1 : 0), sizeof(pr->anchor_call));
 399                 rs_free(a);
 400         }
 401         if (r->anchor_wildcard)
 402                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 403                     sizeof(pr->anchor_call));
 404         return (0);
 405 }
 406
 407 void
 408 pf_anchor_remove(struct pf_rule *r)
 409 {
 410         if (r->anchor == NULL)
 411                 return;
 412         if (r->anchor->refcnt <= 0) {
 413                 printf("pf_anchor_remove: broken refcount\n");
 414                 r->anchor = NULL;
 415                 return;
 416         }
 417         if (!--r->anchor->refcnt)
 418                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 419         r->anchor = NULL;
 420 }