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 #define _KERNEL_STRUCTURES
  38 #include <sys/param.h>
  39 #include <sys/socket.h>
  40 #ifdef _KERNEL
  41 # include <sys/systm.h>
  42 #endif /* _KERNEL */
  43 #include <sys/mbuf.h>
  44
  45 #include <netinet/in.h>
  46 #include <netinet/in_systm.h>
  47 #include <netinet/ip.h>
  48 #include <netinet/tcp.h>
  49
  50 #include <net/if.h>
  51 #include <net/pf/pfvar.h>
  52
  53 #ifdef INET6
  54 #include <netinet/ip6.h>
  55 #endif /* INET6 */
  56
  57
  58 #ifdef _KERNEL
  59 # define DPFPRINTF(format, x...)                \
  60         if (pf_status.debug >= PF_DEBUG_NOISY)  \
  61                 kprintf(format , ##x)
  62 #define rs_malloc(x)            kmalloc(x, M_PFRS, M_WAITOK)
  63 #define rs_free(x)              kfree(x, M_PFRS)
  64 #define printf  kprintf
  65
  66 static MALLOC_DEFINE(M_PFRS, "pfrulesetpl", "pf ruleset pool list");
  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)           malloc(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 struct pf_anchor_global  pf_anchors;
  88 struct pf_anchor         pf_main_anchor;
  89
  90 /*
  91 * XXX: hum?
  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
 101 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
 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 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         memset(key, 0, sizeof(*key));
 165         strlcpy(key->path, path, sizeof(key->path));
 166         found = RB_FIND(pf_anchor_global, &pf_anchors, key);
 167         rs_free(key);
 168         return (found);
 169 }
 170
 171 struct pf_ruleset *
 172 pf_find_ruleset(const char *path)
 173 {
 174         struct pf_anchor        *anchor;
 175
 176         while (*path == '/')
 177                 path++;
 178         if (!*path)
 179                 return (&pf_main_ruleset);
 180         anchor = pf_find_anchor(path);
 181         if (anchor == NULL)
 182                 return (NULL);
 183         else
 184                 return (&anchor->ruleset);
 185 }
 186
 187 struct pf_ruleset *
 188 pf_find_or_create_ruleset(const char *path)
 189 {
 190         char                    *p, *q, *r;
 191         struct pf_ruleset       *ruleset;
 192         struct pf_anchor        *anchor = NULL, *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 }