1 /* $OpenBSD: pf_ruleset.c,v 1.15 2017/05/30 20:00:48 deraadt 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/mbuf.h> 43 #endif /* _KERNEL */ 44 #include <sys/syslog.h> 45 46 #include <netinet/in.h> 47 #include <netinet/ip.h> 48 #include <netinet/tcp.h> 49 50 #include <net/if.h> 51 #include <net/pfvar.h> 52 53 #ifdef INET6 54 #include <netinet/ip6.h> 55 #endif /* INET6 */ 56 57 58 #ifdef _KERNEL 59 #define rs_malloc(x) malloc(x, M_TEMP, M_WAITOK|M_CANFAIL|M_ZERO) 60 #define rs_free(x, siz) free(x, M_TEMP, siz) 61 62 #else /* !_KERNEL */ 63 /* Userland equivalents so we can lend code to pfctl et al. */ 64 65 #include <arpa/inet.h> 66 #include <errno.h> 67 #include <stdio.h> 68 #include <stdlib.h> 69 #include <string.h> 70 #define rs_malloc(x) calloc(1, x) 71 #define rs_free(x, siz) freezero(x, siz) 72 73 #ifdef PFDEBUG 74 #include <sys/stdarg.h> /* for DPFPRINTF() */ 75 #endif /* PFDEBUG */ 76 #endif /* _KERNEL */ 77 78 79 struct pf_anchor_global pf_anchors; 80 struct pf_anchor pf_main_anchor; 81 82 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *); 83 84 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare); 85 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare); 86 87 static __inline int 88 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b) 89 { 90 int c = strcmp(a->path, b->path); 91 92 return (c ? (c < 0 ? -1 : 1) : 0); 93 } 94 95 void 96 pf_init_ruleset(struct pf_ruleset *ruleset) 97 { 98 memset(ruleset, 0, sizeof(struct pf_ruleset)); 99 TAILQ_INIT(&ruleset->rules.queues[0]); 100 TAILQ_INIT(&ruleset->rules.queues[1]); 101 ruleset->rules.active.ptr = &ruleset->rules.queues[0]; 102 ruleset->rules.inactive.ptr = &ruleset->rules.queues[1]; 103 } 104 105 struct pf_anchor * 106 pf_find_anchor(const char *path) 107 { 108 struct pf_anchor *key, *found; 109 110 key = rs_malloc(sizeof(*key)); 111 if (key == NULL) 112 return (NULL); 113 strlcpy(key->path, path, sizeof(key->path)); 114 found = RB_FIND(pf_anchor_global, &pf_anchors, key); 115 rs_free(key, sizeof (*key)); 116 return (found); 117 } 118 119 struct pf_ruleset * 120 pf_find_ruleset(const char *path) 121 { 122 struct pf_anchor *anchor; 123 124 while (*path == '/') 125 path++; 126 if (!*path) 127 return (&pf_main_ruleset); 128 anchor = pf_find_anchor(path); 129 if (anchor == NULL) 130 return (NULL); 131 else 132 return (&anchor->ruleset); 133 } 134 135 struct pf_ruleset * 136 pf_find_or_create_ruleset(const char *path) 137 { 138 char *p, *q, *r; 139 struct pf_ruleset *ruleset; 140 struct pf_anchor *anchor, *dup, *parent = NULL; 141 142 if (path[0] == 0) 143 return (&pf_main_ruleset); 144 while (*path == '/') 145 path++; 146 ruleset = pf_find_ruleset(path); 147 if (ruleset != NULL) 148 return (ruleset); 149 p = rs_malloc(MAXPATHLEN); 150 if (p == NULL) 151 return (NULL); 152 strlcpy(p, path, MAXPATHLEN); 153 while (parent == NULL && (q = strrchr(p, '/')) != NULL) { 154 *q = 0; 155 if ((ruleset = pf_find_ruleset(p)) != NULL) { 156 parent = ruleset->anchor; 157 break; 158 } 159 } 160 if (q == NULL) 161 q = p; 162 else 163 q++; 164 strlcpy(p, path, MAXPATHLEN); 165 if (!*q) { 166 rs_free(p, MAXPATHLEN); 167 return (NULL); 168 } 169 while ((r = strchr(q, '/')) != NULL || *q) { 170 if (r != NULL) 171 *r = 0; 172 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE || 173 (parent != NULL && strlen(parent->path) >= 174 MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) { 175 rs_free(p, MAXPATHLEN); 176 return (NULL); 177 } 178 anchor = rs_malloc(sizeof(*anchor)); 179 if (anchor == NULL) { 180 rs_free(p, MAXPATHLEN); 181 return (NULL); 182 } 183 RB_INIT(&anchor->children); 184 strlcpy(anchor->name, q, sizeof(anchor->name)); 185 if (parent != NULL) { 186 strlcpy(anchor->path, parent->path, 187 sizeof(anchor->path)); 188 strlcat(anchor->path, "/", sizeof(anchor->path)); 189 } 190 strlcat(anchor->path, anchor->name, sizeof(anchor->path)); 191 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) != 192 NULL) { 193 DPFPRINTF(LOG_NOTICE, 194 "pf_find_or_create_ruleset: RB_INSERT1 " 195 "'%s' '%s' collides with '%s' '%s'", 196 anchor->path, anchor->name, dup->path, dup->name); 197 rs_free(anchor, sizeof(*anchor)); 198 rs_free(p, MAXPATHLEN); 199 return (NULL); 200 } 201 if (parent != NULL) { 202 anchor->parent = parent; 203 if ((dup = RB_INSERT(pf_anchor_node, &parent->children, 204 anchor)) != NULL) { 205 DPFPRINTF(LOG_NOTICE, 206 "pf_find_or_create_ruleset: " 207 "RB_INSERT2 '%s' '%s' collides with " 208 "'%s' '%s'", anchor->path, anchor->name, 209 dup->path, dup->name); 210 RB_REMOVE(pf_anchor_global, &pf_anchors, 211 anchor); 212 rs_free(anchor, sizeof(*anchor)); 213 rs_free(p, MAXPATHLEN); 214 return (NULL); 215 } 216 } 217 pf_init_ruleset(&anchor->ruleset); 218 anchor->ruleset.anchor = anchor; 219 parent = anchor; 220 if (r != NULL) 221 q = r + 1; 222 else 223 *q = 0; 224 } 225 rs_free(p, MAXPATHLEN); 226 return (&anchor->ruleset); 227 } 228 229 void 230 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset) 231 { 232 struct pf_anchor *parent; 233 234 while (ruleset != NULL) { 235 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL || 236 !RB_EMPTY(&ruleset->anchor->children) || 237 ruleset->anchor->refcnt > 0 || ruleset->tables > 0 || 238 ruleset->topen) 239 return; 240 if (!TAILQ_EMPTY(ruleset->rules.active.ptr) || 241 !TAILQ_EMPTY(ruleset->rules.inactive.ptr) || 242 ruleset->rules.inactive.open) 243 return; 244 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor); 245 if ((parent = ruleset->anchor->parent) != NULL) 246 RB_REMOVE(pf_anchor_node, &parent->children, 247 ruleset->anchor); 248 rs_free(ruleset->anchor, sizeof(*(ruleset->anchor))); 249 if (parent == NULL) 250 return; 251 ruleset = &parent->ruleset; 252 } 253 } 254 255 int 256 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s, 257 const char *name) 258 { 259 char *p, *path; 260 struct pf_ruleset *ruleset; 261 262 r->anchor = NULL; 263 r->anchor_relative = 0; 264 r->anchor_wildcard = 0; 265 if (!name[0]) 266 return (0); 267 path = rs_malloc(MAXPATHLEN); 268 if (path == NULL) 269 return (1); 270 if (name[0] == '/') 271 strlcpy(path, name + 1, MAXPATHLEN); 272 else { 273 /* relative path */ 274 r->anchor_relative = 1; 275 if (s->anchor == NULL || !s->anchor->path[0]) 276 path[0] = 0; 277 else 278 strlcpy(path, s->anchor->path, MAXPATHLEN); 279 while (name[0] == '.' && name[1] == '.' && name[2] == '/') { 280 if (!path[0]) { 281 DPFPRINTF(LOG_NOTICE, 282 "pf_anchor_setup: .. beyond root"); 283 rs_free(path, MAXPATHLEN); 284 return (1); 285 } 286 if ((p = strrchr(path, '/')) != NULL) 287 *p = 0; 288 else 289 path[0] = 0; 290 r->anchor_relative++; 291 name += 3; 292 } 293 if (path[0]) 294 strlcat(path, "/", MAXPATHLEN); 295 strlcat(path, name, MAXPATHLEN); 296 } 297 if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) { 298 r->anchor_wildcard = 1; 299 *p = 0; 300 } 301 ruleset = pf_find_or_create_ruleset(path); 302 rs_free(path, MAXPATHLEN); 303 if (ruleset == NULL || ruleset->anchor == NULL) { 304 DPFPRINTF(LOG_NOTICE, 305 "pf_anchor_setup: ruleset"); 306 return (1); 307 } 308 r->anchor = ruleset->anchor; 309 r->anchor->refcnt++; 310 return (0); 311 } 312 313 int 314 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r, 315 struct pfioc_rule *pr) 316 { 317 pr->anchor_call[0] = 0; 318 if (r->anchor == NULL) 319 return (0); 320 if (!r->anchor_relative) { 321 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call)); 322 strlcat(pr->anchor_call, r->anchor->path, 323 sizeof(pr->anchor_call)); 324 } else { 325 char *a, *p; 326 int i; 327 328 a = rs_malloc(MAXPATHLEN); 329 if (a == NULL) 330 return (1); 331 if (rs->anchor == NULL) 332 a[0] = 0; 333 else 334 strlcpy(a, rs->anchor->path, MAXPATHLEN); 335 for (i = 1; i < r->anchor_relative; ++i) { 336 if ((p = strrchr(a, '/')) == NULL) 337 p = a; 338 *p = 0; 339 strlcat(pr->anchor_call, "../", 340 sizeof(pr->anchor_call)); 341 } 342 if (strncmp(a, r->anchor->path, strlen(a))) { 343 DPFPRINTF(LOG_NOTICE, 344 "pf_anchor_copyout: '%s' '%s'", a, 345 r->anchor->path); 346 rs_free(a, MAXPATHLEN); 347 return (1); 348 } 349 if (strlen(r->anchor->path) > strlen(a)) 350 strlcat(pr->anchor_call, r->anchor->path + (a[0] ? 351 strlen(a) + 1 : 0), sizeof(pr->anchor_call)); 352 rs_free(a, MAXPATHLEN); 353 } 354 if (r->anchor_wildcard) 355 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*", 356 sizeof(pr->anchor_call)); 357 return (0); 358 } 359 360 void 361 pf_anchor_remove(struct pf_rule *r) 362 { 363 if (r->anchor == NULL) 364 return; 365 if (r->anchor->refcnt <= 0) { 366 DPFPRINTF(LOG_NOTICE, 367 "pf_anchor_remove: broken refcount"); 368 r->anchor = NULL; 369 return; 370 } 371 if (!--r->anchor->refcnt) 372 pf_remove_if_empty_ruleset(&r->anchor->ruleset); 373 r->anchor = NULL; 374 } 375