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