pfil.c revision 1.1
1 /* $NetBSD: pfil.c,v 1.1 1996/09/14 14:40:20 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Matthew R. Green 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Matthew R. Green. 18 * 4. 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/errno.h> 36 #include <sys/malloc.h> 37 #include <sys/socket.h> 38 #include <sys/socketvar.h> 39 #include <sys/systm.h> 40 #include <sys/proc.h> 41 #include <sys/queue.h> 42 43 #include <net/if.h> 44 #include <net/pfil.h> 45 46 typedef LIST_HEAD(, packet_filter_hook) pfil_list_t; 47 pfil_list_t pfil_in_list; 48 pfil_list_t pfil_out_list; 49 pfil_list_t pfil_bad_list; 50 static int done_pfil_init; 51 52 void pfil_init __P((void)); 53 void pfil_list_add(pfil_list_t *, 54 int (*) __P((void *, int, struct ifnet *, int, struct mbuf **)), int); 55 void pfil_list_remove(struct packet_filter_hook *, 56 int (*) __P((void *, int, struct ifnet *, int, struct mbuf **))); 57 58 void 59 pfil_init() 60 { 61 LIST_INIT(&pfil_in_list); 62 LIST_INIT(&pfil_out_list); 63 LIST_INIT(&pfil_bad_list); 64 done_pfil_init = 1; 65 } 66 67 /* 68 * pfil_add_hook() adds a function to the packet filter hook. the 69 * flags are: 70 * PFIL_IN call me on incoming packets 71 * PFIL_OUT call me on outgoing packets 72 * PFIL_BAD call me when rejecting a packet (that was 73 * not already reject by in/out filters). 74 * PFIL_ALL call me on all of the above 75 * PFIL_WAITOK OK to call malloc with M_WAITOK. 76 */ 77 void 78 pfil_add_hook(func, flags) 79 int (*func) __P((void *, int, struct ifnet *, int, 80 struct mbuf **)); 81 int flags; 82 { 83 84 if (done_pfil_init == 0) 85 pfil_init(); 86 87 if (flags & PFIL_IN) 88 pfil_list_add(&pfil_in_list, func, flags); 89 if (flags & PFIL_OUT) 90 pfil_list_add(&pfil_out_list, func, flags); 91 if (flags & PFIL_BAD) 92 pfil_list_add(&pfil_bad_list, func, flags); 93 } 94 95 void 96 pfil_list_add(list, func, flags) 97 pfil_list_t *list; 98 int (*func) __P((void *, int, struct ifnet *, int, 99 struct mbuf **)); 100 int flags; 101 { 102 struct packet_filter_hook *pfh; 103 104 pfh = (struct packet_filter_hook *)malloc(sizeof(*pfh), M_IFADDR, 105 flags & PFIL_WAITOK ? M_WAITOK : M_NOWAIT); 106 if (pfh == NULL) 107 panic("no memory for packet filter hook"); 108 109 pfh->pfil_func = func; 110 LIST_INSERT_HEAD(list, pfh, pfil_link); 111 } 112 113 /* 114 * pfil_remove_hook removes a specific function from the packet filter 115 * hook list. 116 */ 117 void 118 pfil_remove_hook(func, flags) 119 int (*func) __P((void *, int, struct ifnet *, int, 120 struct mbuf **)); 121 int flags; 122 { 123 124 if (done_pfil_init == 0) 125 pfil_init(); 126 127 if (flags & PFIL_IN) 128 pfil_list_remove(pfil_in_list.lh_first, func); 129 if (flags & PFIL_OUT) 130 pfil_list_remove(pfil_out_list.lh_first, func); 131 if (flags & PFIL_BAD) 132 pfil_list_remove(pfil_bad_list.lh_first, func); 133 } 134 135 /* 136 * pfil_list_remove is an internal function that takes a function off the 137 * specified list. 138 */ 139 void 140 pfil_list_remove(list, func) 141 struct packet_filter_hook *list; 142 int (*func) __P((void *, int, struct ifnet *, int, 143 struct mbuf **)); 144 { 145 struct packet_filter_hook *pfh; 146 147 for (pfh = list; pfh; pfh = pfh->pfil_link.le_next) 148 if (pfh->pfil_func == func) { 149 LIST_REMOVE(pfh, pfil_link); 150 free(pfh, M_IFADDR); 151 return; 152 } 153 printf("pfil_list_remove: no function on list\n"); 154 #ifdef DIAGNOSTIC 155 panic("pfil_list_remove"); 156 #endif 157 } 158 159 struct packet_filter_hook * 160 pfil_hook_get(flag) 161 int flag; 162 { 163 if (done_pfil_init) 164 switch (flag) { 165 case PFIL_IN: 166 return (pfil_in_list.lh_first); 167 case PFIL_OUT: 168 return (pfil_out_list.lh_first); 169 case PFIL_BAD: 170 return (pfil_bad_list.lh_first); 171 } 172 return NULL; 173 } 174
Indexes created Wed Sep 24 15:09:51 GMT 2025