1139804Simp/*- 265534Salfred * Copyright (c) 2000 Paycounter, Inc. 3143427Srwatson * Copyright (c) 2005 Robert N. M. Watson 465534Salfred * Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org> 561837Salfred * All rights reserved. 661837Salfred * 761837Salfred * Redistribution and use in source and binary forms, with or without 861837Salfred * modification, are permitted provided that the following conditions 961837Salfred * are met: 1061837Salfred * 1. Redistributions of source code must retain the above copyright 1161837Salfred * notice, this list of conditions and the following disclaimer. 1261837Salfred * 2. Redistributions in binary form must reproduce the above copyright 1361837Salfred * notice, this list of conditions and the following disclaimer in the 1461837Salfred * documentation and/or other materials provided with the distribution. 1561837Salfred * 1661837Salfred * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1761837Salfred * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1861837Salfred * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1961837Salfred * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 2061837Salfred * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2161837Salfred * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2261837Salfred * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2361837Salfred * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2461837Salfred * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2561837Salfred * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2661837Salfred * SUCH DAMAGE. 2761837Salfred */ 2861837Salfred 29116182Sobrien#include <sys/cdefs.h> 30116182Sobrien__FBSDID("$FreeBSD: releng/10.3/sys/kern/uipc_accf.c 201145 2009-12-28 22:56:30Z antoine $"); 31116182Sobrien 3261837Salfred#define ACCEPT_FILTER_MOD 3361837Salfred 3477598Sjesper#include "opt_param.h" 3561837Salfred#include <sys/param.h> 3661837Salfred#include <sys/systm.h> 3761837Salfred#include <sys/domain.h> 3861837Salfred#include <sys/kernel.h> 39129920Srwatson#include <sys/lock.h> 4061837Salfred#include <sys/malloc.h> 4161837Salfred#include <sys/mbuf.h> 42129876Sphk#include <sys/module.h> 43129920Srwatson#include <sys/mutex.h> 4461837Salfred#include <sys/protosw.h> 4565534Salfred#include <sys/sysctl.h> 4661837Salfred#include <sys/socket.h> 4761837Salfred#include <sys/socketvar.h> 4861837Salfred#include <sys/queue.h> 4961837Salfred 50129920Srwatsonstatic struct mtx accept_filter_mtx; 51129920SrwatsonMTX_SYSINIT(accept_filter, &accept_filter_mtx, "accept_filter_mtx", 52129920Srwatson MTX_DEF); 53129920Srwatson#define ACCEPT_FILTER_LOCK() mtx_lock(&accept_filter_mtx) 54129920Srwatson#define ACCEPT_FILTER_UNLOCK() mtx_unlock(&accept_filter_mtx) 55129920Srwatson 5661837Salfredstatic SLIST_HEAD(, accept_filter) accept_filtlsthd = 57201145Santoine SLIST_HEAD_INITIALIZER(accept_filtlsthd); 5861837Salfred 5961837SalfredMALLOC_DEFINE(M_ACCF, "accf", "accept filter data"); 6061837Salfred 6165534Salfredstatic int unloadable = 0; 6265534Salfred 6365534SalfredSYSCTL_DECL(_net_inet); /* XXX: some header should do this for me */ 6465534SalfredSYSCTL_NODE(_net_inet, OID_AUTO, accf, CTLFLAG_RW, 0, "Accept filters"); 6565534SalfredSYSCTL_INT(_net_inet_accf, OID_AUTO, unloadable, CTLFLAG_RW, &unloadable, 0, 6665534Salfred "Allow unload of accept filters (not recommended)"); 6765534Salfred 6861837Salfred/* 69142056Srwatson * Must be passed a malloc'd structure so we don't explode if the kld is 70142056Srwatson * unloaded, we leak the struct on deallocation to deal with this, but if a 71142056Srwatson * filter is loaded with the same name as a leaked one we re-use the entry. 7261837Salfred */ 7361837Salfredint 7461837Salfredaccept_filt_add(struct accept_filter *filt) 7561837Salfred{ 7661837Salfred struct accept_filter *p; 7761837Salfred 78129920Srwatson ACCEPT_FILTER_LOCK(); 7961837Salfred SLIST_FOREACH(p, &accept_filtlsthd, accf_next) 8061837Salfred if (strcmp(p->accf_name, filt->accf_name) == 0) { 8161837Salfred if (p->accf_callback != NULL) { 82129920Srwatson ACCEPT_FILTER_UNLOCK(); 8361837Salfred return (EEXIST); 8461837Salfred } else { 8561837Salfred p->accf_callback = filt->accf_callback; 86129920Srwatson ACCEPT_FILTER_UNLOCK(); 87184205Sdes free(filt, M_ACCF); 8861837Salfred return (0); 8961837Salfred } 9061837Salfred } 9161837Salfred 9261837Salfred if (p == NULL) 9361837Salfred SLIST_INSERT_HEAD(&accept_filtlsthd, filt, accf_next); 94129920Srwatson ACCEPT_FILTER_UNLOCK(); 9561837Salfred return (0); 9661837Salfred} 9761837Salfred 9861837Salfredint 9961837Salfredaccept_filt_del(char *name) 10061837Salfred{ 10161837Salfred struct accept_filter *p; 10261837Salfred 10361837Salfred p = accept_filt_get(name); 10461837Salfred if (p == NULL) 10561837Salfred return (ENOENT); 10661837Salfred 10761837Salfred p->accf_callback = NULL; 10861837Salfred return (0); 10961837Salfred} 11061837Salfred 11161837Salfredstruct accept_filter * 11261837Salfredaccept_filt_get(char *name) 11361837Salfred{ 11461837Salfred struct accept_filter *p; 11561837Salfred 116129920Srwatson ACCEPT_FILTER_LOCK(); 11761837Salfred SLIST_FOREACH(p, &accept_filtlsthd, accf_next) 11861837Salfred if (strcmp(p->accf_name, name) == 0) 119129920Srwatson break; 120129920Srwatson ACCEPT_FILTER_UNLOCK(); 12161837Salfred 122129920Srwatson return (p); 12361837Salfred} 12461837Salfred 12561837Salfredint 12661837Salfredaccept_filt_generic_mod_event(module_t mod, int event, void *data) 12761837Salfred{ 12861837Salfred struct accept_filter *p; 12961837Salfred struct accept_filter *accfp = (struct accept_filter *) data; 130142060Srwatson int error; 13161837Salfred 13261837Salfred switch (event) { 13361837Salfred case MOD_LOAD: 134184205Sdes p = malloc(sizeof(*p), M_ACCF, 135142056Srwatson M_WAITOK); 13661837Salfred bcopy(accfp, p, sizeof(*p)); 13761837Salfred error = accept_filt_add(p); 13861837Salfred break; 13961837Salfred 14061837Salfred case MOD_UNLOAD: 14163645Salfred /* 142142056Srwatson * Do not support unloading yet. we don't keep track of 143142056Srwatson * refcounts and unloading an accept filter callback and then 144142056Srwatson * having it called is a bad thing. A simple fix would be to 145142056Srwatson * track the refcount in the struct accept_filter. 14663645Salfred */ 14765534Salfred if (unloadable != 0) { 14865534Salfred error = accept_filt_del(accfp->accf_name); 14965534Salfred } else 15065534Salfred error = EOPNOTSUPP; 15161837Salfred break; 15261837Salfred 15361837Salfred case MOD_SHUTDOWN: 15461837Salfred error = 0; 15561837Salfred break; 15661837Salfred 15761837Salfred default: 15861837Salfred error = EOPNOTSUPP; 15961837Salfred break; 16061837Salfred } 16161837Salfred 16261837Salfred return (error); 16361837Salfred} 164142058Srwatson 165142058Srwatsonint 166143463Srwatsondo_getopt_accept_filter(struct socket *so, struct sockopt *sopt) 167143463Srwatson{ 168143463Srwatson struct accept_filter_arg *afap; 169143463Srwatson int error; 170143463Srwatson 171143463Srwatson error = 0; 172184205Sdes afap = malloc(sizeof(*afap), M_TEMP, 173143463Srwatson M_WAITOK | M_ZERO); 174143463Srwatson SOCK_LOCK(so); 175143463Srwatson if ((so->so_options & SO_ACCEPTCONN) == 0) { 176143463Srwatson error = EINVAL; 177143463Srwatson goto out; 178143463Srwatson } 179147300Smaxim if ((so->so_options & SO_ACCEPTFILTER) == 0) { 180147300Smaxim error = EINVAL; 181143463Srwatson goto out; 182147300Smaxim } 183143463Srwatson strcpy(afap->af_name, so->so_accf->so_accept_filter->accf_name); 184143463Srwatson if (so->so_accf->so_accept_filter_str != NULL) 185143463Srwatson strcpy(afap->af_arg, so->so_accf->so_accept_filter_str); 186143463Srwatsonout: 187143463Srwatson SOCK_UNLOCK(so); 188143463Srwatson if (error == 0) 189143463Srwatson error = sooptcopyout(sopt, afap, sizeof(*afap)); 190184205Sdes free(afap, M_TEMP); 191143463Srwatson return (error); 192143463Srwatson} 193143463Srwatson 194143463Srwatsonint 195142060Srwatsondo_setopt_accept_filter(struct socket *so, struct sockopt *sopt) 196142058Srwatson{ 197142060Srwatson struct accept_filter_arg *afap; 198142060Srwatson struct accept_filter *afp; 199142060Srwatson struct so_accf *newaf; 200142060Srwatson int error = 0; 201142058Srwatson 202142058Srwatson /* 203143427Srwatson * Handle the simple delete case first. 204142058Srwatson */ 205147300Smaxim if (sopt == NULL || sopt->sopt_val == NULL) { 206143427Srwatson SOCK_LOCK(so); 207143427Srwatson if ((so->so_options & SO_ACCEPTCONN) == 0) { 208143427Srwatson SOCK_UNLOCK(so); 209143427Srwatson return (EINVAL); 210143427Srwatson } 211142058Srwatson if (so->so_accf != NULL) { 212142058Srwatson struct so_accf *af = so->so_accf; 213142058Srwatson if (af->so_accept_filter != NULL && 214142058Srwatson af->so_accept_filter->accf_destroy != NULL) { 215142058Srwatson af->so_accept_filter->accf_destroy(so); 216142058Srwatson } 217143427Srwatson if (af->so_accept_filter_str != NULL) 218184205Sdes free(af->so_accept_filter_str, M_ACCF); 219184205Sdes free(af, M_ACCF); 220142058Srwatson so->so_accf = NULL; 221142058Srwatson } 222142058Srwatson so->so_options &= ~SO_ACCEPTFILTER; 223142058Srwatson SOCK_UNLOCK(so); 224142058Srwatson return (0); 225142058Srwatson } 226143427Srwatson 227143427Srwatson /* 228143461Srwatson * Pre-allocate any memory we may need later to avoid blocking at 229143461Srwatson * untimely moments. This does not optimize for invalid arguments. 230143427Srwatson */ 231184205Sdes afap = malloc(sizeof(*afap), M_TEMP, 232142058Srwatson M_WAITOK); 233142058Srwatson error = sooptcopyin(sopt, afap, sizeof *afap, sizeof *afap); 234142058Srwatson afap->af_name[sizeof(afap->af_name)-1] = '\0'; 235142058Srwatson afap->af_arg[sizeof(afap->af_arg)-1] = '\0'; 236142058Srwatson if (error) { 237184205Sdes free(afap, M_TEMP); 238142058Srwatson return (error); 239142058Srwatson } 240142058Srwatson afp = accept_filt_get(afap->af_name); 241142058Srwatson if (afp == NULL) { 242184205Sdes free(afap, M_TEMP); 243142058Srwatson return (ENOENT); 244142058Srwatson } 245142058Srwatson /* 246143461Srwatson * Allocate the new accept filter instance storage. We may 247143461Srwatson * have to free it again later if we fail to attach it. If 248143461Srwatson * attached properly, 'newaf' is NULLed to avoid a free() 249143461Srwatson * while in use. 250142058Srwatson */ 251184205Sdes newaf = malloc(sizeof(*newaf), M_ACCF, M_WAITOK | 252142058Srwatson M_ZERO); 253142058Srwatson if (afp->accf_create != NULL && afap->af_name[0] != '\0') { 254142058Srwatson int len = strlen(afap->af_name) + 1; 255184205Sdes newaf->so_accept_filter_str = malloc(len, M_ACCF, 256142058Srwatson M_WAITOK); 257142058Srwatson strcpy(newaf->so_accept_filter_str, afap->af_name); 258142058Srwatson } 259142058Srwatson 260143461Srwatson /* 261143461Srwatson * Require a listen socket; don't try to replace an existing filter 262143461Srwatson * without first removing it. 263143461Srwatson */ 264142058Srwatson SOCK_LOCK(so); 265143461Srwatson if (((so->so_options & SO_ACCEPTCONN) == 0) || 266143461Srwatson (so->so_accf != NULL)) { 267142058Srwatson error = EINVAL; 268142058Srwatson goto out; 269142058Srwatson } 270143461Srwatson 271142058Srwatson /* 272143461Srwatson * Invoke the accf_create() method of the filter if required. The 273143461Srwatson * socket mutex is held over this call, so create methods for filters 274143461Srwatson * can't block. 275142058Srwatson */ 276142058Srwatson if (afp->accf_create != NULL) { 277142058Srwatson newaf->so_accept_filter_arg = 278142058Srwatson afp->accf_create(so, afap->af_arg); 279142058Srwatson if (newaf->so_accept_filter_arg == NULL) { 280142058Srwatson error = EINVAL; 281142058Srwatson goto out; 282142058Srwatson } 283142058Srwatson } 284142058Srwatson newaf->so_accept_filter = afp; 285142058Srwatson so->so_accf = newaf; 286142058Srwatson so->so_options |= SO_ACCEPTFILTER; 287142058Srwatson newaf = NULL; 288142058Srwatsonout: 289142058Srwatson SOCK_UNLOCK(so); 290142058Srwatson if (newaf != NULL) { 291142058Srwatson if (newaf->so_accept_filter_str != NULL) 292184205Sdes free(newaf->so_accept_filter_str, M_ACCF); 293184205Sdes free(newaf, M_ACCF); 294142058Srwatson } 295142058Srwatson if (afap != NULL) 296184205Sdes free(afap, M_TEMP); 297142058Srwatson return (error); 298142058Srwatson} 299