1 /* 2 * Copyright (c) 2000 Paycounter, Inc. 3 * Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: src/sys/kern/uipc_accf.c,v 1.2.2.2 2000/09/20 21:19:21 ps Exp $ 28 * $DragonFly: src/sys/kern/uipc_accf.c,v 1.2 2003/06/17 04:28:41 dillon Exp $ 29 */ 30 31 #define ACCEPT_FILTER_MOD 32 33 #include "opt_param.h" 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/domain.h> 37 #include <sys/kernel.h> 38 #include <sys/proc.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/protosw.h> 42 #include <sys/sysctl.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/queue.h> 46 47 static SLIST_HEAD(, accept_filter) accept_filtlsthd = 48 SLIST_HEAD_INITIALIZER(&accept_filtlsthd); 49 50 MALLOC_DEFINE(M_ACCF, "accf", "accept filter data"); 51 52 static int unloadable = 0; 53 54 SYSCTL_DECL(_net_inet); /* XXX: some header should do this for me */ 55 SYSCTL_NODE(_net_inet, OID_AUTO, accf, CTLFLAG_RW, 0, "Accept filters"); 56 SYSCTL_INT(_net_inet_accf, OID_AUTO, unloadable, CTLFLAG_RW, &unloadable, 0, 57 "Allow unload of accept filters (not recommended)"); 58 59 /* 60 * must be passed a malloc'd structure so we don't explode if the kld 61 * is unloaded, we leak the struct on deallocation to deal with this, 62 * but if a filter is loaded with the same name as a leaked one we re-use 63 * the entry. 64 */ 65 int 66 accept_filt_add(struct accept_filter *filt) 67 { 68 struct accept_filter *p; 69 70 SLIST_FOREACH(p, &accept_filtlsthd, accf_next) 71 if (strcmp(p->accf_name, filt->accf_name) == 0) { 72 if (p->accf_callback != NULL) { 73 return (EEXIST); 74 } else { 75 p->accf_callback = filt->accf_callback; 76 FREE(filt, M_ACCF); 77 return (0); 78 } 79 } 80 81 if (p == NULL) 82 SLIST_INSERT_HEAD(&accept_filtlsthd, filt, accf_next); 83 return (0); 84 } 85 86 int 87 accept_filt_del(char *name) 88 { 89 struct accept_filter *p; 90 91 p = accept_filt_get(name); 92 if (p == NULL) 93 return (ENOENT); 94 95 p->accf_callback = NULL; 96 return (0); 97 } 98 99 struct accept_filter * 100 accept_filt_get(char *name) 101 { 102 struct accept_filter *p; 103 104 SLIST_FOREACH(p, &accept_filtlsthd, accf_next) 105 if (strcmp(p->accf_name, name) == 0) 106 return (p); 107 108 return (NULL); 109 } 110 111 int 112 accept_filt_generic_mod_event(module_t mod, int event, void *data) 113 { 114 struct accept_filter *p; 115 struct accept_filter *accfp = (struct accept_filter *) data; 116 int s, error; 117 118 switch (event) { 119 case MOD_LOAD: 120 MALLOC(p, struct accept_filter *, sizeof(*p), M_ACCF, M_WAITOK); 121 bcopy(accfp, p, sizeof(*p)); 122 s = splnet(); 123 error = accept_filt_add(p); 124 splx(s); 125 break; 126 127 case MOD_UNLOAD: 128 /* 129 * Do not support unloading yet. we don't keep track of refcounts 130 * and unloading an accept filter callback and then having it called 131 * is a bad thing. A simple fix would be to track the refcount 132 * in the struct accept_filter. 133 */ 134 if (unloadable != 0) { 135 s = splnet(); 136 error = accept_filt_del(accfp->accf_name); 137 splx(s); 138 } else 139 error = EOPNOTSUPP; 140 break; 141 142 case MOD_SHUTDOWN: 143 error = 0; 144 break; 145 146 default: 147 error = EOPNOTSUPP; 148 break; 149 } 150 151 return (error); 152 } 153