sys/net/pf/pf_ruleset.c

   1 /*      $OpenBSD: pf_ruleset.c,v 1.1 2006/10/27 13:56:51 mcbride 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 #include <sys/param.h>
  39 #include <sys/socket.h>
  40 #ifdef _KERNEL
  41 # include <sys/systm.h>
  42 # include <sys/malloc.h>
  43 #endif /* _KERNEL */
  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/pf/pfvar.h>
  53
  54
  55 #ifdef _KERNEL
  56 # define DPFPRINTF(format, x...)                \
  57         if (pf_status.debug >= PF_DEBUG_NOISY)  \
  58                 kprintf(format , ##x)
  59 #define rs_malloc(x)            kmalloc(x, M_PFRS, M_WAITOK)
  60 #define rs_free(x)              kfree(x, M_PFRS)
  61 #define printf  kprintf
  62
  63 static MALLOC_DEFINE(M_PFRS, "pfrulesetpl", "pf ruleset pool list");
  64
  65 #else
  66 /* Userland equivalents so we can lend code to pfctl et al. */
  67
  68 # include <arpa/inet.h>
  69 # include <errno.h>
  70 # include <stdio.h>
  71 # include <stdlib.h>
  72 # include <string.h>
  73 # define rs_malloc(x)           malloc(x)
  74 # define rs_free(x)             free(x)
  75
  76 # ifdef PFDEBUG
  77 #  include <sys/stdarg.h>
  78 #  define DPFPRINTF(format, x...)       fprintf(stderr, format , ##x)
  79 # else
  80 #  define DPFPRINTF(format, x...)       ((void)0)
  81 # endif /* PFDEBUG */
  82 #endif /* _KERNEL */
  83
  84 struct pf_anchor_global  pf_anchors;
  85 struct pf_anchor         pf_main_anchor;
  86
  87 /*
  88 * XXX: hum?
  89 int                      pf_get_ruleset_number(u_int8_t);
  90 void                     pf_init_ruleset(struct pf_ruleset *);
  91 int                      pf_anchor_setup(struct pf_rule *,
  92                             const struct pf_ruleset *, const char *);
  93 int                      pf_anchor_copyout(const struct pf_ruleset *,
  94                             const struct pf_rule *, struct pfioc_rule *);
  95 void                     pf_anchor_remove(struct pf_rule *);
  96 */
  97
  98 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
  99
 100 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
 101 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
 102
 103 static __inline int
 104 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
 105 {
 106         int c = strcmp(a->path, b->path);
 107
 108         return (c ? (c < 0 ? -1 : 1) : 0);
 109 }
 110
 111 int
 112 pf_get_ruleset_number(u_int8_t action)
 113 {
 114         switch (action) {
 115         case PF_SCRUB:
 116         case PF_NOSCRUB:
 117                 return (PF_RULESET_SCRUB);
 118                 break;
 119         case PF_PASS:
 120         case PF_DROP:
 121                 return (PF_RULESET_FILTER);
 122                 break;
 123         case PF_NAT:
 124         case PF_NONAT:
 125                 return (PF_RULESET_NAT);
 126                 break;
 127         case PF_BINAT:
 128         case PF_NOBINAT:
 129                 return (PF_RULESET_BINAT);
 130                 break;
 131         case PF_RDR:
 132         case PF_NORDR:
 133                 return (PF_RULESET_RDR);
 134                 break;
 135         default:
 136                 return (PF_RULESET_MAX);
 137                 break;
 138         }
 139 }
 140
 141 void
 142 pf_init_ruleset(struct pf_ruleset *ruleset)
 143 {
 144         int     i;
 145
 146         memset(ruleset, 0, sizeof(struct pf_ruleset));
 147         for (i = 0; i < PF_RULESET_MAX; i++) {
 148                 TAILQ_INIT(&ruleset->rules[i].queues[0]);
 149                 TAILQ_INIT(&ruleset->rules[i].queues[1]);
 150                 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
 151                 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
 152         }
 153 }
 154
 155 struct pf_anchor *
 156 pf_find_anchor(const char *path)
 157 {
 158         struct pf_anchor        *key, *found;
 159
 160         key = (struct pf_anchor *)rs_malloc(sizeof(*key));
 161         memset(key, 0, sizeof(*key));
 162         strlcpy(key->path, path, sizeof(key->path));
 163         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 164         rs_free(key);
 165         return (found);
 166 }
 167
 168 struct pf_ruleset *
 169 pf_find_ruleset(const char *path)
 170 {
 171         struct pf_anchor        *anchor;
 172
 173         while (*path == '/')
 174                 path++;
 175         if (!*path)
 176                 return (&pf_main_ruleset);
 177         anchor = pf_find_anchor(path);
 178         if (anchor == NULL)
 179                 return (NULL);
 180         else
 181                 return (&anchor->ruleset);
 182 }
 183
 184 struct pf_ruleset *
 185 pf_find_or_create_ruleset(const char *path)
 186 {
 187         char                    *p, *q, *r;
 188         struct pf_ruleset       *ruleset;
 189         struct pf_anchor        *anchor = NULL, *dup, *parent = NULL;
 190
 191         if (path[0] == 0)
 192                 return (&pf_main_ruleset);
 193         while (*path == '/')
 194                 path++;
 195         ruleset = pf_find_ruleset(path);
 196         if (ruleset != NULL)
 197                 return (ruleset);
 198         p = (char *)rs_malloc(MAXPATHLEN);
 199         bzero(p, MAXPATHLEN);
 200         strlcpy(p, path, MAXPATHLEN);
 201         while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
 202                 *q = 0;
 203                 if ((ruleset = pf_find_ruleset(p)) != NULL) {
 204                         parent = ruleset->anchor;
 205                         break;
 206                 }
 207         }
 208         if (q == NULL)
 209                 q = p;
 210         else
 211                 q++;
 212         strlcpy(p, path, MAXPATHLEN);
 213         if (!*q) {
 214                 rs_free(p);
 215                 return (NULL);
 216         }
 217         while ((r = strchr(q, '/')) != NULL || *q) {
 218                 if (r != NULL)
 219                         *r = 0;
 220                 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
 221                     (parent != NULL && strlen(parent->path) >=
 222                     MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
 223                         rs_free(p);
 224                         return (NULL);
 225                 }
 226                 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
 227                 if (anchor == NULL) {
 228                         rs_free(p);
 229                         return (NULL);
 230                 }
 231                 memset(anchor, 0, sizeof(*anchor));
 232                 RB_INIT(&anchor->children);
 233                 strlcpy(anchor->name, q, sizeof(anchor->name));
 234                 if (parent != NULL) {
 235                         strlcpy(anchor->path, parent->path,
 236                             sizeof(anchor->path));
 237                         strlcat(anchor->path, "/", sizeof(anchor->path));
 238                 }
 239                 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
 240                 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
 241                     NULL) {
 242                         printf("pf_find_or_create_ruleset: RB_INSERT1 "
 243                             "'%s' '%s' collides with '%s' '%s'\n",
 244                             anchor->path, anchor->name, dup->path, dup->name);
 245                         rs_free(anchor);
 246                         rs_free(p);
 247                         return (NULL);
 248                 }
 249                 if (parent != NULL) {
 250                         anchor->parent = parent;
 251                         if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
 252                             anchor)) != NULL) {
 253                                 printf("pf_find_or_create_ruleset: "
 254                                     "RB_INSERT2 '%s' '%s' collides with "
 255                                     "'%s' '%s'\n", anchor->path, anchor->name,
 256                                     dup->path, dup->name);
 257                                 RB_REMOVE(pf_anchor_global, &pf_anchors,
 258                                     anchor);
 259                                 rs_free(anchor);
 260                                 rs_free(p);
 261                                 return (NULL);
 262                         }
 263                 }
 264                 pf_init_ruleset(&anchor->ruleset);
 265                 anchor->ruleset.anchor = anchor;
 266                 parent = anchor;
 267                 if (r != NULL)
 268                         q = r + 1;
 269                 else
 270                         *q = 0;
 271         }
 272         rs_free(p);
 273         return (&anchor->ruleset);
 274 }
 275
 276 void
 277 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
 278 {
 279         struct pf_anchor        *parent;
 280         int                      i;
 281
 282         while (ruleset != NULL) {
 283                 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
 284                     !RB_EMPTY(&ruleset->anchor->children) ||
 285                     ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
 286                     ruleset->topen)
 287                         return;
 288                 for (i = 0; i < PF_RULESET_MAX; ++i)
 289                         if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
 290                             !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
 291                             ruleset->rules[i].inactive.open)
 292                                 return;
 293                 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
 294                 if ((parent = ruleset->anchor->parent) != NULL)
 295                         RB_REMOVE(pf_anchor_node, &parent->children,
 296                             ruleset->anchor);
 297                 rs_free(ruleset->anchor);
 298                 if (parent == NULL)
 299                         return;
 300                 ruleset = &parent->ruleset;
 301         }
 302 }
 303
 304 int
 305 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
 306     const char *name)
 307 {
 308         char                    *p, *path;
 309         struct pf_ruleset       *ruleset;
 310
 311         r->anchor = NULL;
 312         r->anchor_relative = 0;
 313         r->anchor_wildcard = 0;
 314         if (!name[0])
 315                 return (0);
 316         path = (char *)rs_malloc(MAXPATHLEN);
 317         bzero(path, MAXPATHLEN);
 318         if (name[0] == '/')
 319                 strlcpy(path, name + 1, MAXPATHLEN);
 320         else {
 321                 /* relative path */
 322                 r->anchor_relative = 1;
 323                 if (s->anchor == NULL || !s->anchor->path[0])
 324                         path[0] = 0;
 325                 else
 326                         strlcpy(path, s->anchor->path, MAXPATHLEN);
 327                 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
 328                         if (!path[0]) {
 329                                 printf("pf_anchor_setup: .. beyond root\n");
 330                                 rs_free(path);
 331                                 return (1);
 332                         }
 333                         if ((p = strrchr(path, '/')) != NULL)
 334                                 *p = 0;
 335                         else
 336                                 path[0] = 0;
 337                         r->anchor_relative++;
 338                         name += 3;
 339                 }
 340                 if (path[0])
 341                         strlcat(path, "/", MAXPATHLEN);
 342                 strlcat(path, name, MAXPATHLEN);
 343         }
 344         if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
 345                 r->anchor_wildcard = 1;
 346                 *p = 0;
 347         }
 348         ruleset = pf_find_or_create_ruleset(path);
 349         rs_free(path);
 350         if (ruleset == NULL || ruleset->anchor == NULL) {
 351                 printf("pf_anchor_setup: ruleset\n");
 352                 return (1);
 353         }
 354         r->anchor = ruleset->anchor;
 355         r->anchor->refcnt++;
 356         return (0);
 357 }
 358
 359 int
 360 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
 361     struct pfioc_rule *pr)
 362 {
 363         pr->anchor_call[0] = 0;
 364         if (r->anchor == NULL)
 365                 return (0);
 366         if (!r->anchor_relative) {
 367                 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
 368                 strlcat(pr->anchor_call, r->anchor->path,
 369                     sizeof(pr->anchor_call));
 370         } else {
 371                 char    *a, *p;
 372                 int      i;
 373
 374                 a = (char *)rs_malloc(MAXPATHLEN);
 375                 bzero(a, MAXPATHLEN);
 376                 if (rs->anchor == NULL)
 377                         a[0] = 0;
 378                 else
 379                         strlcpy(a, rs->anchor->path, MAXPATHLEN);
 380                 for (i = 1; i < r->anchor_relative; ++i) {
 381                         if ((p = strrchr(a, '/')) == NULL)
 382                                 p = a;
 383                         *p = 0;
 384                         strlcat(pr->anchor_call, "../",
 385                             sizeof(pr->anchor_call));
 386                 }
 387                 if (strncmp(a, r->anchor->path, strlen(a))) {
 388                         printf("pf_anchor_copyout: '%s' '%s'\n", a,
 389                             r->anchor->path);
 390                         rs_free(a);
 391                         return (1);
 392                 }
 393                 if (strlen(r->anchor->path) > strlen(a))
 394                         strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
 395                             strlen(a) + 1 : 0), sizeof(pr->anchor_call));
 396                 rs_free(a);
 397         }
 398         if (r->anchor_wildcard)
 399                 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
 400                     sizeof(pr->anchor_call));
 401         return (0);
 402 }
 403
 404 void
 405 pf_anchor_remove(struct pf_rule *r)
 406 {
 407         if (r->anchor == NULL)
 408                 return;
 409         if (r->anchor->refcnt <= 0) {
 410                 printf("pf_anchor_remove: broken refcount\n");
 411                 r->anchor = NULL;
 412                 return;
 413         }
 414         if (!--r->anchor->refcnt)
 415                 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
 416         r->anchor = NULL;
 417 }