uipc_accf.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2000 Paycounter, Inc.
    5  * Copyright (c) 2005 Robert N. M. Watson
    6  * Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org>
    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  * 1. Redistributions of source code must retain the above copyright
   13  *    notice, this list of conditions and the following disclaimer.
   14  * 2. Redistributions in binary form must reproduce the above copyright
   15  *    notice, this list of conditions and the following disclaimer in the
   16  *    documentation and/or other materials provided with the distribution.
   17  *
   18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   28  * SUCH DAMAGE.
   29  */
   30 
   31 #include <sys/cdefs.h>
   32 __FBSDID("$FreeBSD$");
   33 
   34 #define ACCEPT_FILTER_MOD
   35 
   36 #include "opt_param.h"
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/domain.h>
   40 #include <sys/kernel.h>
   41 #include <sys/lock.h>
   42 #include <sys/malloc.h>
   43 #include <sys/mbuf.h>
   44 #include <sys/module.h>
   45 #include <sys/mutex.h>
   46 #include <sys/protosw.h>
   47 #include <sys/sysctl.h>
   48 #include <sys/socket.h>
   49 #include <sys/socketvar.h>
   50 #include <sys/queue.h>
   51 
   52 static struct mtx accept_filter_mtx;
   53 MTX_SYSINIT(accept_filter, &accept_filter_mtx, "accept_filter_mtx",
   54         MTX_DEF);
   55 #define ACCEPT_FILTER_LOCK()    mtx_lock(&accept_filter_mtx)
   56 #define ACCEPT_FILTER_UNLOCK()  mtx_unlock(&accept_filter_mtx)
   57 
   58 static SLIST_HEAD(, accept_filter) accept_filtlsthd =
   59         SLIST_HEAD_INITIALIZER(accept_filtlsthd);
   60 
   61 MALLOC_DEFINE(M_ACCF, "accf", "accept filter data");
   62 
   63 static int unloadable = 0;
   64 
   65 SYSCTL_NODE(_net, OID_AUTO, accf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
   66     "Accept filters");
   67 SYSCTL_INT(_net_accf, OID_AUTO, unloadable, CTLFLAG_RW, &unloadable, 0,
   68         "Allow unload of accept filters (not recommended)");
   69 
   70 /*
   71  * Must be passed a malloc'd structure so we don't explode if the kld is
   72  * unloaded, we leak the struct on deallocation to deal with this, but if a
   73  * filter is loaded with the same name as a leaked one we re-use the entry.
   74  */
   75 int
   76 accept_filt_add(struct accept_filter *filt)
   77 {
   78         struct accept_filter *p;
   79 
   80         ACCEPT_FILTER_LOCK();
   81         SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
   82                 if (strcmp(p->accf_name, filt->accf_name) == 0)  {
   83                         if (p->accf_callback != NULL) {
   84                                 ACCEPT_FILTER_UNLOCK();
   85                                 return (EEXIST);
   86                         } else {
   87                                 p->accf_callback = filt->accf_callback;
   88                                 ACCEPT_FILTER_UNLOCK();
   89                                 free(filt, M_ACCF);
   90                                 return (0);
   91                         }
   92                 }
   93                                 
   94         if (p == NULL)
   95                 SLIST_INSERT_HEAD(&accept_filtlsthd, filt, accf_next);
   96         ACCEPT_FILTER_UNLOCK();
   97         return (0);
   98 }
   99 
  100 int
  101 accept_filt_del(char *name)
  102 {
  103         struct accept_filter *p;
  104 
  105         p = accept_filt_get(name);
  106         if (p == NULL)
  107                 return (ENOENT);
  108 
  109         p->accf_callback = NULL;
  110         return (0);
  111 }
  112 
  113 struct accept_filter *
  114 accept_filt_get(char *name)
  115 {
  116         struct accept_filter *p;
  117 
  118         ACCEPT_FILTER_LOCK();
  119         SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
  120                 if (strcmp(p->accf_name, name) == 0)
  121                         break;
  122         ACCEPT_FILTER_UNLOCK();
  123 
  124         return (p);
  125 }
  126 
  127 int
  128 accept_filt_generic_mod_event(module_t mod, int event, void *data)
  129 {
  130         struct accept_filter *p;
  131         struct accept_filter *accfp = (struct accept_filter *) data;
  132         int error;
  133 
  134         switch (event) {
  135         case MOD_LOAD:
  136                 p = malloc(sizeof(*p), M_ACCF, M_WAITOK);
  137                 bcopy(accfp, p, sizeof(*p));
  138                 error = accept_filt_add(p);
  139                 break;
  140 
  141         case MOD_UNLOAD:
  142                 /*
  143                  * Do not support unloading yet. we don't keep track of
  144                  * refcounts and unloading an accept filter callback and then
  145                  * having it called is a bad thing.  A simple fix would be to
  146                  * track the refcount in the struct accept_filter.
  147                  */
  148                 if (unloadable != 0) {
  149                         error = accept_filt_del(accfp->accf_name);
  150                 } else
  151                         error = EOPNOTSUPP;
  152                 break;
  153 
  154         case MOD_SHUTDOWN:
  155                 error = 0;
  156                 break;
  157 
  158         default:
  159                 error = EOPNOTSUPP;
  160                 break;
  161         }
  162 
  163         return (error);
  164 }
  165 
  166 int
  167 accept_filt_getopt(struct socket *so, struct sockopt *sopt)
  168 {
  169         struct accept_filter_arg *afap;
  170         int error;
  171 
  172         error = 0;
  173         afap = malloc(sizeof(*afap), M_TEMP, M_WAITOK | M_ZERO);
  174         SOCK_LOCK(so);
  175         if (!SOLISTENING(so)) {
  176                 error = EINVAL;
  177                 goto out;
  178         }
  179         if (so->sol_accept_filter == NULL) {
  180                 error = EINVAL;
  181                 goto out;
  182         }
  183         strcpy(afap->af_name, so->sol_accept_filter->accf_name);
  184         if (so->sol_accept_filter_str != NULL)
  185                 strcpy(afap->af_arg, so->sol_accept_filter_str);
  186 out:
  187         SOCK_UNLOCK(so);
  188         if (error == 0)
  189                 error = sooptcopyout(sopt, afap, sizeof(*afap));
  190         free(afap, M_TEMP);
  191         return (error);
  192 }
  193 
  194 int
  195 accept_filt_setopt(struct socket *so, struct sockopt *sopt)
  196 {
  197         struct accept_filter_arg *afap;
  198         struct accept_filter *afp;
  199         char *accept_filter_str = NULL;
  200         void *accept_filter_arg = NULL;
  201         int error;
  202 
  203         /*
  204          * Handle the simple delete case first.
  205          */
  206         if (sopt == NULL || sopt->sopt_val == NULL) {
  207                 struct socket *sp, *sp1;
  208                 int wakeup;
  209 
  210                 SOCK_LOCK(so);
  211                 if (!SOLISTENING(so)) {
  212                         SOCK_UNLOCK(so);
  213                         return (EINVAL);
  214                 }
  215                 if (so->sol_accept_filter == NULL) {
  216                         SOCK_UNLOCK(so);
  217                         return (0);
  218                 }
  219                 if (so->sol_accept_filter->accf_destroy != NULL)
  220                         so->sol_accept_filter->accf_destroy(so);
  221                 if (so->sol_accept_filter_str != NULL)
  222                         free(so->sol_accept_filter_str, M_ACCF);
  223                 so->sol_accept_filter = NULL;
  224                 so->sol_accept_filter_arg = NULL;
  225                 so->sol_accept_filter_str = NULL;
  226                 so->so_options &= ~SO_ACCEPTFILTER;
  227 
  228                 /*
  229                  * Move from incomplete queue to complete only those
  230                  * connections, that are blocked by us.
  231                  */
  232                 wakeup = 0;
  233                 TAILQ_FOREACH_SAFE(sp, &so->sol_incomp, so_list, sp1) {
  234                         SOCK_LOCK(sp);
  235                         if (sp->so_options & SO_ACCEPTFILTER) {
  236                                 TAILQ_REMOVE(&so->sol_incomp, sp, so_list);
  237                                 TAILQ_INSERT_TAIL(&so->sol_comp, sp, so_list);
  238                                 sp->so_qstate = SQ_COMP;
  239                                 sp->so_options &= ~SO_ACCEPTFILTER;
  240                                 so->sol_incqlen--;
  241                                 so->sol_qlen++;
  242                                 wakeup = 1;
  243                         }
  244                         SOCK_UNLOCK(sp);
  245                 }
  246                 if (wakeup)
  247                         solisten_wakeup(so);  /* unlocks */
  248                 else
  249                         SOLISTEN_UNLOCK(so);
  250                 return (0);
  251         }
  252 
  253         /*
  254          * Pre-allocate any memory we may need later to avoid blocking at
  255          * untimely moments.  This does not optimize for invalid arguments.
  256          */
  257         afap = malloc(sizeof(*afap), M_TEMP, M_WAITOK);
  258         error = sooptcopyin(sopt, afap, sizeof *afap, sizeof *afap);
  259         afap->af_name[sizeof(afap->af_name)-1] = '\0';
  260         afap->af_arg[sizeof(afap->af_arg)-1] = '\0';
  261         if (error) {
  262                 free(afap, M_TEMP);
  263                 return (error);
  264         }
  265         afp = accept_filt_get(afap->af_name);
  266         if (afp == NULL) {
  267                 free(afap, M_TEMP);
  268                 return (ENOENT);
  269         }
  270         if (afp->accf_create != NULL && afap->af_name[0] != '\0') {
  271                 size_t len = strlen(afap->af_name) + 1;
  272                 accept_filter_str = malloc(len, M_ACCF, M_WAITOK);
  273                 strcpy(accept_filter_str, afap->af_name);
  274         }
  275 
  276         /*
  277          * Require a listen socket; don't try to replace an existing filter
  278          * without first removing it.
  279          */
  280         SOCK_LOCK(so);
  281         if (!SOLISTENING(so) || so->sol_accept_filter != NULL) {
  282                 error = EINVAL;
  283                 goto out;
  284         }
  285 
  286         /*
  287          * Invoke the accf_create() method of the filter if required.  The
  288          * socket mutex is held over this call, so create methods for filters
  289          * can't block.
  290          */
  291         if (afp->accf_create != NULL) {
  292                 accept_filter_arg = afp->accf_create(so, afap->af_arg);
  293                 if (accept_filter_arg == NULL) {
  294                         error = EINVAL;
  295                         goto out;
  296                 }
  297         }
  298         so->sol_accept_filter = afp;
  299         so->sol_accept_filter_arg = accept_filter_arg;
  300         so->sol_accept_filter_str = accept_filter_str;
  301         accept_filter_str = NULL;
  302         so->so_options |= SO_ACCEPTFILTER;
  303 out:
  304         SOCK_UNLOCK(so);
  305         if (accept_filter_str != NULL)
  306                 free(accept_filter_str, M_ACCF);
  307         free(afap, M_TEMP);
  308         return (error);
  309 }
Cache object: 7eecf448a7d1067fa76f321aa5a94e5a
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/uipc_accf.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_accf.c
