pf.c revision 1.7
1 /* $NetBSD: pf.c,v 1.7 2002/08/22 07:18:42 itojun Exp $ */ 2 3 /* 4 * Copyright (c) 1993-95 Mats O Jansson. All rights reserved. 5 * Copyright (c) 1990 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * This code is partly derived from rarpd. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by Mats O Jansson. 21 * 4. The name of the author may not be used to endorse or promote products 22 * derived from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __RCSID("$NetBSD: pf.c,v 1.7 2002/08/22 07:18:42 itojun Exp $"); 39 #endif 40 41 #include "os.h" 42 43 #include <sys/uio.h> 44 #include <net/bpf.h> 45 46 #include "mopdef.h" 47 #include "pf.h" 48 49 /* 50 * Variables 51 */ 52 53 extern int promisc; 54 55 /* 56 * Return information to device.c how to open device. 57 * In this case the driver can handle both Ethernet type II and 58 * IEEE 802.3 frames (SNAP) in a single pfOpen. 59 */ 60 61 int 62 pfTrans(interface) 63 char *interface; 64 { 65 return TRANS_ETHER+TRANS_8023+TRANS_AND; 66 } 67 68 /* 69 * Open and initialize packet filter. 70 */ 71 72 int 73 pfInit(interface, mode, protocol, typ) 74 char *interface; 75 u_short protocol; 76 int typ, mode; 77 { 78 int fd; 79 int n = 0; 80 char device[sizeof "/dev/bpf000"]; 81 struct ifreq ifr; 82 u_int dlt; 83 int immediate; 84 85 static struct bpf_insn insns[] = { 86 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12), 87 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0), 88 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20), 89 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3), 90 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14), 91 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1), 92 BPF_STMT(BPF_RET | BPF_K, 1520), 93 BPF_STMT(BPF_RET | BPF_K, 0), 94 }; 95 static struct bpf_program filter = { 96 sizeof insns / sizeof(insns[0]), 97 insns 98 }; 99 100 /* Go through all the minors and find one that isn't in use. */ 101 do { 102 (void) snprintf(device, sizeof(device), "/dev/bpf%d", n++); 103 fd = open(device, mode); 104 } while (fd < 0 && errno == EBUSY); 105 106 if (fd < 0) { 107 syslog(LOG_ERR,"pfInit: open %s: %m", device); 108 return(-1); 109 } 110 111 /* Set immediate mode so packets are processed as they arrive. */ 112 immediate = 1; 113 if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) { 114 syslog(LOG_ERR,"pfInit: BIOCIMMEDIATE: %m"); 115 return(-1); 116 } 117 (void) strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name); 118 if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) { 119 syslog(LOG_ERR,"pfInit: BIOCSETIF: %m"); 120 return(-1); 121 } 122 /* Check that the data link layer is an Ethernet; this code won't work 123 * with anything else. */ 124 if (ioctl(fd, BIOCGDLT, (caddr_t) & dlt) < 0) { 125 syslog(LOG_ERR,"pfInit: BIOCGDLT: %m"); 126 return(-1); 127 } 128 if (dlt != DLT_EN10MB) { 129 syslog(LOG_ERR,"pfInit: %s is not ethernet", device); 130 return(-1); 131 } 132 if (promisc) { 133 /* Set promiscuous mode. */ 134 if (ioctl(fd, BIOCPROMISC, (caddr_t)0) < 0) { 135 syslog(LOG_ERR,"pfInit: BIOCPROMISC: %m"); 136 return(-1); 137 } 138 } 139 /* Set filter program. */ 140 insns[1].k = protocol; 141 insns[3].k = protocol; 142 143 if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) { 144 syslog(LOG_ERR,"pfInit: BIOCSETF: %m"); 145 return(-1); 146 } 147 return(fd); 148 } 149 150 /* 151 * Add a Multicast address to the interface 152 */ 153 154 int 155 pfAddMulti(s, interface, addr) 156 int s; 157 char *interface, *addr; 158 { 159 struct ifreq ifr; 160 int fd; 161 162 strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name)); 163 164 ifr.ifr_addr.sa_family = AF_UNSPEC; 165 memmove(ifr.ifr_addr.sa_data, addr, 6); 166 167 /* 168 * open a socket, temporarily, to use for SIOC* ioctls 169 * 170 */ 171 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 172 syslog(LOG_ERR, "pfAddMulti: socket: %m"); 173 return(-1); 174 } 175 if (ioctl(fd, SIOCADDMULTI, (caddr_t)&ifr) < 0) { 176 syslog(LOG_ERR, "pfAddMulti: SIOCADDMULTI: %m"); 177 close(fd); 178 return(-1); 179 } 180 close(fd); 181 182 return(0); 183 } 184 185 /* 186 * Delete a Multicast address from the interface 187 */ 188 189 int 190 pfDelMulti(s, interface, addr) 191 int s; 192 char *interface, *addr; 193 { 194 struct ifreq ifr; 195 int fd; 196 197 strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name)); 198 199 ifr.ifr_addr.sa_family = AF_UNSPEC; 200 memmove(ifr.ifr_addr.sa_data, addr, 6); 201 202 /* 203 * open a socket, temporarily, to use for SIOC* ioctls 204 * 205 */ 206 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 207 syslog(LOG_ERR, "pfDelMulti: socket: %m"); 208 return(-1); 209 } 210 if (ioctl(fd, SIOCDELMULTI, (caddr_t)&ifr) < 0) { 211 syslog(LOG_ERR, "pfAddMulti: SIOCDELMULTI: %m"); 212 close(fd); 213 return(-1); 214 } 215 close(fd); 216 217 return(0); 218 } 219 220 /* 221 * read a packet 222 */ 223 224 int 225 pfRead(fd, buf, len) 226 int fd, len; 227 u_char *buf; 228 { 229 return(read(fd, buf, len)); 230 } 231 232 /* 233 * write a packet 234 */ 235 236 int 237 pfWrite(fd, buf, len, trans) 238 int fd, len, trans; 239 u_char *buf; 240 { 241 242 struct iovec iov[2]; 243 244 switch (trans) { 245 case TRANS_8023: 246 iov[0].iov_base = (caddr_t)buf; 247 iov[0].iov_len = 22; 248 iov[1].iov_base = (caddr_t)buf+22; 249 iov[1].iov_len = len-22; 250 break; 251 default: 252 iov[0].iov_base = (caddr_t)buf; 253 iov[0].iov_len = 14; 254 iov[1].iov_base = (caddr_t)buf+14; 255 iov[1].iov_len = len-14; 256 break; 257 } 258 259 if (writev(fd, iov, 2) == len) 260 return(len); 261 262 return(-1); 263 } 264 265
Indexes created Wed Sep 24 05:09:52 GMT 2025