sys/net/pfil.c

   1 /*      $NetBSD: pfil.c,v 1.20 2001/11/12 23:49:46 lukem Exp $  */
   2
   3 /*-
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  *
   6  * Copyright (c) 2019 Gleb Smirnoff <glebius@FreeBSD.org>
   7  * Copyright (c) 1996 Matthew R. Green
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  24  * IN NO EVENT SHALL THE AUTHOR 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 CAUSED
  28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/conf.h>
  36 #include <sys/kernel.h>
  37 #include <sys/epoch.h>
  38 #include <sys/errno.h>
  39 #include <sys/lock.h>
  40 #include <sys/malloc.h>
  41 #include <sys/socket.h>
  42 #include <sys/socketvar.h>
  43 #include <sys/systm.h>
  44 #include <sys/lock.h>
  45 #include <sys/mutex.h>
  46 #include <sys/proc.h>
  47 #include <sys/queue.h>
  48 #include <sys/ucred.h>
  49 #include <sys/jail.h>
  50
  51 #include <net/if.h>
  52 #include <net/if_var.h>
  53 #include <net/pfil.h>
  54
  55 static MALLOC_DEFINE(M_PFIL, "pfil", "pfil(9) packet filter hooks");
  56
  57 static int pfil_ioctl(struct cdev *, u_long, caddr_t, int, struct thread *);
  58 static struct cdevsw pfil_cdevsw = {
  59         .d_ioctl =      pfil_ioctl,
  60         .d_name =       PFILDEV,
  61         .d_version =    D_VERSION,
  62 };
  63 static struct cdev *pfil_dev;
  64
  65 static struct mtx pfil_lock;
  66 MTX_SYSINIT(pfil_mtxinit, &pfil_lock, "pfil(9) lock", MTX_DEF);
  67 #define PFIL_LOCK()     mtx_lock(&pfil_lock)
  68 #define PFIL_UNLOCK()   mtx_unlock(&pfil_lock)
  69 #define PFIL_LOCK_ASSERT()      mtx_assert(&pfil_lock, MA_OWNED)
  70
  71 struct pfil_hook {
  72         pfil_mbuf_chk_t  hook_mbuf_chk;
  73         pfil_mem_chk_t   hook_mem_chk;
  74         void            *hook_ruleset;
  75         int              hook_flags;
  76         int              hook_links;
  77         enum pfil_types  hook_type;
  78         const char      *hook_modname;
  79         const char      *hook_rulname;
  80         LIST_ENTRY(pfil_hook) hook_list;
  81 };
  82
  83 struct pfil_link {
  84         CK_STAILQ_ENTRY(pfil_link) link_chain;
  85         pfil_mbuf_chk_t          link_mbuf_chk;
  86         pfil_mem_chk_t           link_mem_chk;
  87         void                    *link_ruleset;
  88         int                      link_flags;
  89         struct pfil_hook        *link_hook;
  90         struct epoch_context     link_epoch_ctx;
  91 };
  92
  93 typedef CK_STAILQ_HEAD(pfil_chain, pfil_link)   pfil_chain_t;
  94 struct pfil_head {
  95         int              head_nhooksin;
  96         int              head_nhooksout;
  97         pfil_chain_t     head_in;
  98         pfil_chain_t     head_out;
  99         int              head_flags;
 100         enum pfil_types  head_type;
 101         LIST_ENTRY(pfil_head) head_list;
 102         const char      *head_name;
 103 };
 104
 105 LIST_HEAD(pfilheadhead, pfil_head);
 106 VNET_DEFINE_STATIC(struct pfilheadhead, pfil_head_list) =
 107     LIST_HEAD_INITIALIZER(pfil_head_list);
 108 #define V_pfil_head_list        VNET(pfil_head_list)
 109
 110 LIST_HEAD(pfilhookhead, pfil_hook);
 111 VNET_DEFINE_STATIC(struct pfilhookhead, pfil_hook_list) =
 112     LIST_HEAD_INITIALIZER(pfil_hook_list);
 113 #define V_pfil_hook_list        VNET(pfil_hook_list)
 114
 115 static struct pfil_link *pfil_link_remove(pfil_chain_t *, pfil_hook_t );
 116 static void pfil_link_free(epoch_context_t);
 117
 118 /*
 119  * To couple a filtering point that provides memory pointer with a filter that
 120  * works on mbufs only.
 121  */
 122 static __noinline int
 123 pfil_fake_mbuf(pfil_mbuf_chk_t func, void *mem, u_int len, struct ifnet *ifp,
 124     int flags, void *ruleset, struct mbuf **mp)
 125 {
 126         struct mbuf m;
 127         pfil_return_t rv;
 128
 129         (void)m_init(&m, M_NOWAIT, MT_DATA, M_NOFREE | M_PKTHDR);
 130         m_extadd(&m, mem, len, NULL, NULL, NULL, 0, EXT_RXRING);
 131         m.m_len = m.m_pkthdr.len = len;
 132         *mp = &m;
 133
 134         rv = func(mp, ifp, flags, ruleset, NULL);
 135         if (rv == PFIL_PASS && *mp != &m) {
 136                 /*
 137                  * Firewalls that need pfil_fake_mbuf() most likely don't
 138                  * know they need return PFIL_REALLOCED.
 139                  */
 140                 rv = PFIL_REALLOCED;
 141         }
 142
 143         return (rv);
 144 }
 145
 146 static __always_inline int
 147 pfil_mem_common(pfil_chain_t *pch, void *mem, u_int len, int flags,
 148     struct ifnet *ifp, struct mbuf **m)
 149 {
 150         struct pfil_link *link;
 151         pfil_return_t rv;
 152         bool realloc = false;
 153
 154         NET_EPOCH_ASSERT();
 155         KASSERT(flags == PFIL_IN || flags == PFIL_OUT,
 156             ("%s: unsupported flags %d", __func__, flags));
 157
 158         rv = PFIL_PASS;
 159         CK_STAILQ_FOREACH(link, pch, link_chain) {
 160                 if (__predict_true(link->link_mem_chk != NULL && !realloc))
 161                         rv = link->link_mem_chk(mem, len, flags, ifp,
 162                             link->link_ruleset, m);
 163                 else if (!realloc)
 164                         rv = pfil_fake_mbuf(link->link_mbuf_chk, mem, len, ifp,
 165                             flags, link->link_ruleset, m);
 166                 else
 167                         rv = link->link_mbuf_chk(m, ifp, flags,
 168                             link->link_ruleset, NULL);
 169
 170                 if (rv == PFIL_DROPPED || rv == PFIL_CONSUMED)
 171                         break;
 172                 else if (rv == PFIL_REALLOCED)
 173                         realloc = true;
 174         }
 175         if (realloc && rv == PFIL_PASS)
 176                 rv = PFIL_REALLOCED;
 177         return (rv);
 178 }
 179
 180 int
 181 pfil_mem_in(struct pfil_head *head, void *mem, u_int len, struct ifnet *ifp,
 182     struct mbuf **m)
 183 {
 184
 185         return (pfil_mem_common(&head->head_in, mem, len, PFIL_IN, ifp, m));
 186 }
 187
 188 int
 189 pfil_mem_out(struct pfil_head *head, void *mem, u_int len, struct ifnet *ifp,
 190     struct mbuf **m)
 191 {
 192
 193         return (pfil_mem_common(&head->head_out, mem, len, PFIL_OUT, ifp, m));
 194 }
 195
 196 static __always_inline int
 197 pfil_mbuf_common(pfil_chain_t *pch, struct mbuf **m, struct ifnet *ifp,
 198     int flags, struct inpcb *inp)
 199 {
 200         struct pfil_link *link;
 201         pfil_return_t rv;
 202
 203         NET_EPOCH_ASSERT();
 204         KASSERT((flags & ~(PFIL_IN|PFIL_OUT|PFIL_FWD)) == 0,
 205             ("%s: unsupported flags %#x", __func__, flags));
 206         KASSERT((flags & ~PFIL_FWD) == PFIL_IN ||
 207             (flags & ~PFIL_FWD) == PFIL_OUT,
 208             ("%s: conflicting directions %#x", __func__, flags));
 209
 210         rv = PFIL_PASS;
 211         CK_STAILQ_FOREACH(link, pch, link_chain) {
 212                 rv = link->link_mbuf_chk(m, ifp, flags, link->link_ruleset,
 213                     inp);
 214                 if (rv == PFIL_DROPPED || rv == PFIL_CONSUMED)
 215                         break;
 216         }
 217         return (rv);
 218 }
 219
 220 int
 221 pfil_mbuf_in(struct pfil_head *head, struct mbuf **m, struct ifnet *ifp,
 222    struct inpcb *inp)
 223 {
 224
 225         return (pfil_mbuf_common(&head->head_in, m, ifp, PFIL_IN, inp));
 226 }
 227
 228 int
 229 pfil_mbuf_out(struct pfil_head *head, struct mbuf **m, struct ifnet *ifp,
 230     struct inpcb *inp)
 231 {
 232
 233         return (pfil_mbuf_common(&head->head_out, m, ifp, PFIL_OUT, inp));
 234 }
 235
 236 int
 237 pfil_mbuf_fwd(struct pfil_head *head, struct mbuf **m, struct ifnet *ifp,
 238     struct inpcb *inp)
 239 {
 240
 241         return (pfil_mbuf_common(&head->head_out, m, ifp, PFIL_OUT | PFIL_FWD, inp));
 242 }
 243
 244 /*
 245  * pfil_head_register() registers a pfil_head with the packet filter hook
 246  * mechanism.
 247  */
 248 pfil_head_t
 249 pfil_head_register(struct pfil_head_args *pa)
 250 {
 251         struct pfil_head *head, *list;
 252
 253         MPASS(pa->pa_version == PFIL_VERSION);
 254
 255         head = malloc(sizeof(struct pfil_head), M_PFIL, M_WAITOK);
 256
 257         head->head_nhooksin = head->head_nhooksout = 0;
 258         head->head_flags = pa->pa_flags;
 259         head->head_type = pa->pa_type;
 260         head->head_name = pa->pa_headname;
 261         CK_STAILQ_INIT(&head->head_in);
 262         CK_STAILQ_INIT(&head->head_out);
 263
 264         PFIL_LOCK();
 265         LIST_FOREACH(list, &V_pfil_head_list, head_list)
 266                 if (strcmp(pa->pa_headname, list->head_name) == 0) {
 267                         printf("pfil: duplicate head \"%s\"\n",
 268                             pa->pa_headname);
 269                 }
 270         LIST_INSERT_HEAD(&V_pfil_head_list, head, head_list);
 271         PFIL_UNLOCK();
 272
 273         return (head);
 274 }
 275
 276 /*
 277  * pfil_head_unregister() removes a pfil_head from the packet filter hook
 278  * mechanism.  The producer of the hook promises that all outstanding
 279  * invocations of the hook have completed before it unregisters the hook.
 280  */
 281 void
 282 pfil_head_unregister(pfil_head_t ph)
 283 {
 284         struct pfil_link *link, *next;
 285
 286         PFIL_LOCK();
 287         LIST_REMOVE(ph, head_list);
 288
 289         CK_STAILQ_FOREACH_SAFE(link, &ph->head_in, link_chain, next) {
 290                 link->link_hook->hook_links--;
 291                 free(link, M_PFIL);
 292         }
 293         CK_STAILQ_FOREACH_SAFE(link, &ph->head_out, link_chain, next) {
 294                 link->link_hook->hook_links--;
 295                 free(link, M_PFIL);
 296         }
 297         PFIL_UNLOCK();
 298 }
 299
 300 pfil_hook_t
 301 pfil_add_hook(struct pfil_hook_args *pa)
 302 {
 303         struct pfil_hook *hook, *list;
 304
 305         MPASS(pa->pa_version == PFIL_VERSION);
 306
 307         hook = malloc(sizeof(struct pfil_hook), M_PFIL, M_WAITOK | M_ZERO);
 308         hook->hook_mbuf_chk = pa->pa_mbuf_chk;
 309         hook->hook_mem_chk = pa->pa_mem_chk;
 310         hook->hook_ruleset = pa->pa_ruleset;
 311         hook->hook_flags = pa->pa_flags;
 312         hook->hook_type = pa->pa_type;
 313         hook->hook_modname = pa->pa_modname;
 314         hook->hook_rulname = pa->pa_rulname;
 315
 316         PFIL_LOCK();
 317         LIST_FOREACH(list, &V_pfil_hook_list, hook_list)
 318                 if (strcmp(pa->pa_modname, list->hook_modname) == 0 &&
 319                     strcmp(pa->pa_rulname, list->hook_rulname) == 0) {
 320                         printf("pfil: duplicate hook \"%s:%s\"\n",
 321                             pa->pa_modname, pa->pa_rulname);
 322                 }
 323         LIST_INSERT_HEAD(&V_pfil_hook_list, hook, hook_list);
 324         PFIL_UNLOCK();
 325
 326         return (hook);
 327 }
 328
 329 static int
 330 pfil_unlink(struct pfil_link_args *pa, pfil_head_t head, pfil_hook_t hook)
 331 {
 332         struct pfil_link *in, *out;
 333
 334         PFIL_LOCK_ASSERT();
 335
 336         if (pa->pa_flags & PFIL_IN) {
 337                 in = pfil_link_remove(&head->head_in, hook);
 338                 if (in != NULL) {
 339                         head->head_nhooksin--;
 340                         hook->hook_links--;
 341                 }
 342         } else
 343                 in = NULL;
 344         if (pa->pa_flags & PFIL_OUT) {
 345                 out = pfil_link_remove(&head->head_out, hook);
 346                 if (out != NULL) {
 347                         head->head_nhooksout--;
 348                         hook->hook_links--;
 349                 }
 350         } else
 351                 out = NULL;
 352         PFIL_UNLOCK();
 353
 354         if (in != NULL)
 355                 NET_EPOCH_CALL(pfil_link_free, &in->link_epoch_ctx);
 356         if (out != NULL)
 357                 NET_EPOCH_CALL(pfil_link_free, &out->link_epoch_ctx);
 358
 359         if (in == NULL && out == NULL)
 360                 return (ENOENT);
 361         else
 362                 return (0);
 363 }
 364
 365 int
 366 pfil_link(struct pfil_link_args *pa)
 367 {
 368         struct pfil_link *in, *out, *link;
 369         struct pfil_head *head;
 370         struct pfil_hook *hook;
 371         int error;
 372
 373         MPASS(pa->pa_version == PFIL_VERSION);
 374
 375         if ((pa->pa_flags & (PFIL_IN | PFIL_UNLINK)) == PFIL_IN)
 376                 in = malloc(sizeof(*in), M_PFIL, M_WAITOK | M_ZERO);
 377         else
 378                 in = NULL;
 379         if ((pa->pa_flags & (PFIL_OUT | PFIL_UNLINK)) == PFIL_OUT)
 380                 out = malloc(sizeof(*out), M_PFIL, M_WAITOK | M_ZERO);
 381         else
 382                 out = NULL;
 383
 384         PFIL_LOCK();
 385         if (pa->pa_flags & PFIL_HEADPTR)
 386                 head = pa->pa_head;
 387         else
 388                 LIST_FOREACH(head, &V_pfil_head_list, head_list)
 389                         if (strcmp(pa->pa_headname, head->head_name) == 0)
 390                                 break;
 391         if (pa->pa_flags & PFIL_HOOKPTR)
 392                 hook = pa->pa_hook;
 393         else
 394                 LIST_FOREACH(hook, &V_pfil_hook_list, hook_list)
 395                         if (strcmp(pa->pa_modname, hook->hook_modname) == 0 &&
 396                             strcmp(pa->pa_rulname, hook->hook_rulname) == 0)
 397                                 break;
 398         if (head == NULL || hook == NULL) {
 399                 error = ENOENT;
 400                 goto fail;
 401         }
 402
 403         if (pa->pa_flags & PFIL_UNLINK)
 404                 return (pfil_unlink(pa, head, hook));
 405
 406         if (head->head_type != hook->hook_type ||
 407             ((hook->hook_flags & pa->pa_flags) & ~head->head_flags)) {
 408                 error = EINVAL;
 409                 goto fail;
 410         }
 411
 412         if (pa->pa_flags & PFIL_IN)
 413                 CK_STAILQ_FOREACH(link, &head->head_in, link_chain)
 414                         if (link->link_hook == hook) {
 415                                 error = EEXIST;
 416                                 goto fail;
 417                         }
 418         if (pa->pa_flags & PFIL_OUT)
 419                 CK_STAILQ_FOREACH(link, &head->head_out, link_chain)
 420                         if (link->link_hook == hook) {
 421                                 error = EEXIST;
 422                                 goto fail;
 423                         }
 424
 425         if (pa->pa_flags & PFIL_IN) {
 426                 in->link_hook = hook;
 427                 in->link_mbuf_chk = hook->hook_mbuf_chk;
 428                 in->link_mem_chk = hook->hook_mem_chk;
 429                 in->link_flags = hook->hook_flags;
 430                 in->link_ruleset = hook->hook_ruleset;
 431                 if (pa->pa_flags & PFIL_APPEND)
 432                         CK_STAILQ_INSERT_TAIL(&head->head_in, in, link_chain);
 433                 else
 434                         CK_STAILQ_INSERT_HEAD(&head->head_in, in, link_chain);
 435                 hook->hook_links++;
 436                 head->head_nhooksin++;
 437         }
 438         if (pa->pa_flags & PFIL_OUT) {
 439                 out->link_hook = hook;
 440                 out->link_mbuf_chk = hook->hook_mbuf_chk;
 441                 out->link_mem_chk = hook->hook_mem_chk;
 442                 out->link_flags = hook->hook_flags;
 443                 out->link_ruleset = hook->hook_ruleset;
 444                 if (pa->pa_flags & PFIL_APPEND)
 445                         CK_STAILQ_INSERT_HEAD(&head->head_out, out, link_chain);
 446                 else
 447                         CK_STAILQ_INSERT_TAIL(&head->head_out, out, link_chain);
 448                 hook->hook_links++;
 449                 head->head_nhooksout++;
 450         }
 451         PFIL_UNLOCK();
 452
 453         return (0);
 454
 455 fail:
 456         PFIL_UNLOCK();
 457         free(in, M_PFIL);
 458         free(out, M_PFIL);
 459         return (error);
 460 }
 461
 462 static void
 463 pfil_link_free(epoch_context_t ctx)
 464 {
 465         struct pfil_link *link;
 466
 467         link = __containerof(ctx, struct pfil_link, link_epoch_ctx);
 468         free(link, M_PFIL);
 469 }
 470
 471 /*
 472  * pfil_remove_hook removes a filter from all filtering points.
 473  */
 474 void
 475 pfil_remove_hook(pfil_hook_t hook)
 476 {
 477         struct pfil_head *head;
 478         struct pfil_link *in, *out;
 479
 480         PFIL_LOCK();
 481         LIST_FOREACH(head, &V_pfil_head_list, head_list) {
 482 retry:
 483                 in = pfil_link_remove(&head->head_in, hook);
 484                 if (in != NULL) {
 485                         head->head_nhooksin--;
 486                         hook->hook_links--;
 487                         NET_EPOCH_CALL(pfil_link_free, &in->link_epoch_ctx);
 488                 }
 489                 out = pfil_link_remove(&head->head_out, hook);
 490                 if (out != NULL) {
 491                         head->head_nhooksout--;
 492                         hook->hook_links--;
 493                         NET_EPOCH_CALL(pfil_link_free, &out->link_epoch_ctx);
 494                 }
 495                 if (in != NULL || out != NULL)
 496                         /* What if some stupid admin put same filter twice? */
 497                         goto retry;
 498         }
 499         LIST_REMOVE(hook, hook_list);
 500         PFIL_UNLOCK();
 501         MPASS(hook->hook_links == 0);
 502         free(hook, M_PFIL);
 503 }
 504
 505 /*
 506  * Internal: Remove a pfil hook from a hook chain.
 507  */
 508 static struct pfil_link *
 509 pfil_link_remove(pfil_chain_t *chain, pfil_hook_t hook)
 510 {
 511         struct pfil_link *link;
 512
 513         PFIL_LOCK_ASSERT();
 514
 515         CK_STAILQ_FOREACH(link, chain, link_chain)
 516                 if (link->link_hook == hook) {
 517                         CK_STAILQ_REMOVE(chain, link, pfil_link, link_chain);
 518                         return (link);
 519                 }
 520
 521         return (NULL);
 522 }
 523
 524 static void
 525 pfil_init(const void *unused __unused)
 526 {
 527         struct make_dev_args args;
 528         int error __diagused;
 529
 530         make_dev_args_init(&args);
 531         args.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
 532         args.mda_devsw = &pfil_cdevsw;
 533         args.mda_uid = UID_ROOT;
 534         args.mda_gid = GID_WHEEL;
 535         args.mda_mode = 0600;
 536         error = make_dev_s(&args, &pfil_dev, PFILDEV);
 537         KASSERT(error == 0, ("%s: failed to create dev: %d", __func__, error));
 538 }
 539 /*
 540  * Make sure the pfil bits are first before any possible subsystem which
 541  * might piggyback on the SI_SUB_PROTO_PFIL.
 542  */
 543 SYSINIT(pfil_init, SI_SUB_PROTO_PFIL, SI_ORDER_FIRST, pfil_init, NULL);
 544
 545 /*
 546  * User control interface.
 547  */
 548 static int pfilioc_listheads(struct pfilioc_list *);
 549 static int pfilioc_listhooks(struct pfilioc_list *);
 550 static int pfilioc_link(struct pfilioc_link *);
 551
 552 static int
 553 pfil_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
 554     struct thread *td)
 555 {
 556         int error;
 557
 558         CURVNET_SET(TD_TO_VNET(td));
 559         error = 0;
 560         switch (cmd) {
 561         case PFILIOC_LISTHEADS:
 562                 error = pfilioc_listheads((struct pfilioc_list *)addr);
 563                 break;
 564         case PFILIOC_LISTHOOKS:
 565                 error = pfilioc_listhooks((struct pfilioc_list *)addr);
 566                 break;
 567         case PFILIOC_LINK:
 568                 error = pfilioc_link((struct pfilioc_link *)addr);
 569                 break;
 570         default:
 571                 error = EINVAL;
 572                 break;
 573         }
 574         CURVNET_RESTORE();
 575         return (error);
 576 }
 577
 578 static int
 579 pfilioc_listheads(struct pfilioc_list *req)
 580 {
 581         struct pfil_head *head;
 582         struct pfil_link *link;
 583         struct pfilioc_head *iohead;
 584         struct pfilioc_hook *iohook;
 585         u_int nheads, nhooks, hd, hk;
 586         int error;
 587
 588         PFIL_LOCK();
 589 restart:
 590         nheads = nhooks = 0;
 591         LIST_FOREACH(head, &V_pfil_head_list, head_list) {
 592                 nheads++;
 593                 nhooks += head->head_nhooksin + head->head_nhooksout;
 594         }
 595         PFIL_UNLOCK();
 596
 597         if (req->pio_nheads < nheads || req->pio_nhooks < nhooks) {
 598                 req->pio_nheads = nheads;
 599                 req->pio_nhooks = nhooks;
 600                 return (0);
 601         }
 602
 603         iohead = malloc(sizeof(*iohead) * nheads, M_TEMP, M_WAITOK);
 604         iohook = malloc(sizeof(*iohook) * nhooks, M_TEMP, M_WAITOK);
 605
 606         hd = hk = 0;
 607         PFIL_LOCK();
 608         LIST_FOREACH(head, &V_pfil_head_list, head_list) {
 609                 if (hd + 1 > nheads ||
 610                     hk + head->head_nhooksin + head->head_nhooksout > nhooks) {
 611                         /* Configuration changed during malloc(). */
 612                         free(iohead, M_TEMP);
 613                         free(iohook, M_TEMP);
 614                         goto restart;
 615                 }
 616                 strlcpy(iohead[hd].pio_name, head->head_name,
 617                         sizeof(iohead[0].pio_name));
 618                 iohead[hd].pio_nhooksin = head->head_nhooksin;
 619                 iohead[hd].pio_nhooksout = head->head_nhooksout;
 620                 iohead[hd].pio_type = head->head_type;
 621                 CK_STAILQ_FOREACH(link, &head->head_in, link_chain) {
 622                         strlcpy(iohook[hk].pio_module,
 623                             link->link_hook->hook_modname,
 624                             sizeof(iohook[0].pio_module));
 625                         strlcpy(iohook[hk].pio_ruleset,
 626                             link->link_hook->hook_rulname,
 627                             sizeof(iohook[0].pio_ruleset));
 628                         hk++;
 629                 }
 630                 CK_STAILQ_FOREACH(link, &head->head_out, link_chain) {
 631                         strlcpy(iohook[hk].pio_module,
 632                             link->link_hook->hook_modname,
 633                             sizeof(iohook[0].pio_module));
 634                         strlcpy(iohook[hk].pio_ruleset,
 635                             link->link_hook->hook_rulname,
 636                             sizeof(iohook[0].pio_ruleset));
 637                         hk++;
 638                 }
 639                 hd++;
 640         }
 641         PFIL_UNLOCK();
 642
 643         error = copyout(iohead, req->pio_heads,
 644             sizeof(*iohead) * min(hd, req->pio_nheads));
 645         if (error == 0)
 646                 error = copyout(iohook, req->pio_hooks,
 647                     sizeof(*iohook) * min(req->pio_nhooks, hk));
 648
 649         req->pio_nheads = hd;
 650         req->pio_nhooks = hk;
 651
 652         free(iohead, M_TEMP);
 653         free(iohook, M_TEMP);
 654
 655         return (error);
 656 }
 657
 658 static int
 659 pfilioc_listhooks(struct pfilioc_list *req)
 660 {
 661         struct pfil_hook *hook;
 662         struct pfilioc_hook *iohook;
 663         u_int nhooks, hk;
 664         int error;
 665
 666         PFIL_LOCK();
 667 restart:
 668         nhooks = 0;
 669         LIST_FOREACH(hook, &V_pfil_hook_list, hook_list)
 670                 nhooks++;
 671         PFIL_UNLOCK();
 672
 673         if (req->pio_nhooks < nhooks) {
 674                 req->pio_nhooks = nhooks;
 675                 return (0);
 676         }
 677
 678         iohook = malloc(sizeof(*iohook) * nhooks, M_TEMP, M_WAITOK);
 679
 680         hk = 0;
 681         PFIL_LOCK();
 682         LIST_FOREACH(hook, &V_pfil_hook_list, hook_list) {
 683                 if (hk + 1 > nhooks) {
 684                         /* Configuration changed during malloc(). */
 685                         free(iohook, M_TEMP);
 686                         goto restart;
 687                 }
 688                 strlcpy(iohook[hk].pio_module, hook->hook_modname,
 689                     sizeof(iohook[0].pio_module));
 690                 strlcpy(iohook[hk].pio_ruleset, hook->hook_rulname,
 691                     sizeof(iohook[0].pio_ruleset));
 692                 iohook[hk].pio_type = hook->hook_type;
 693                 iohook[hk].pio_flags = hook->hook_flags;
 694                 hk++;
 695         }
 696         PFIL_UNLOCK();
 697
 698         error = copyout(iohook, req->pio_hooks,
 699             sizeof(*iohook) * min(req->pio_nhooks, hk));
 700         req->pio_nhooks = hk;
 701         free(iohook, M_TEMP);
 702
 703         return (error);
 704 }
 705
 706 static int
 707 pfilioc_link(struct pfilioc_link *req)
 708 {
 709         struct pfil_link_args args;
 710
 711         if (req->pio_flags & ~(PFIL_IN | PFIL_OUT | PFIL_UNLINK | PFIL_APPEND))
 712                 return (EINVAL);
 713
 714         args.pa_version = PFIL_VERSION;
 715         args.pa_flags = req->pio_flags;
 716         args.pa_headname = req->pio_name;
 717         args.pa_modname = req->pio_module;
 718         args.pa_rulname = req->pio_ruleset;
 719
 720         return (pfil_link(&args));
 721 }