1 /* $NetBSD: pf.c,v 1.3 1997/03/25 03:07:27 thorpej 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 #ifndef LINT 37 static char rcsid[] = "$NetBSD: pf.c,v 1.3 1997/03/25 03:07:27 thorpej Exp $"; 38 #endif 39 40 #include <stdio.h> 41 #include <unistd.h> 42 #include <sys/types.h> 43 #include <sys/time.h> 44 #include <sys/ioctl.h> 45 #include <sys/file.h> 46 #include <sys/socket.h> 47 #include <sys/uio.h> 48 #include <net/if.h> 49 50 #include <net/bpf.h> 51 #include <sys/errno.h> 52 53 #include <netinet/in.h> 54 #include <netinet/if_inarp.h> 55 56 #include <netdb.h> 57 #include <ctype.h> 58 #include <strings.h> 59 60 #include <syslog.h> 61 #include <varargs.h> 62 63 #include "common/mopdef.h" 64 65 /* 66 * Variables 67 */ 68 69 extern int errno; 70 extern int promisc; 71 72 /* 73 * Return information to device.c how to open device. 74 * In this case the driver can handle both Ethernet type II and 75 * IEEE 802.3 frames (SNAP) in a single pfOpen. 76 */ 77 78 int 79 pfTrans(interface) 80 char *interface; 81 { 82 return TRANS_ETHER+TRANS_8023+TRANS_AND; 83 } 84 85 /* 86 * Open and initialize packet filter. 87 */ 88 89 int 90 pfInit(interface, mode, protocol, typ) 91 char *interface; 92 u_short protocol; 93 int typ, mode; 94 { 95 int fd; 96 int n = 0; 97 char device[sizeof "/dev/bpf000"]; 98 struct ifreq ifr; 99 u_int dlt; 100 int immediate; 101 102 static struct bpf_insn insns[] = { 103 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12), 104 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0), 105 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20), 106 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3), 107 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14), 108 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1), 109 BPF_STMT(BPF_RET | BPF_K, 1520), 110 BPF_STMT(BPF_RET | BPF_K, 0), 111 }; 112 static struct bpf_program filter = { 113 sizeof insns / sizeof(insns[0]), 114 insns 115 }; 116 117 /* Go through all the minors and find one that isn't in use. */ 118 do { 119 (void) sprintf(device, "/dev/bpf%d", n++); 120 fd = open(device, mode); 121 } while (fd < 0 && errno == EBUSY); 122 123 if (fd < 0) { 124 syslog(LOG_ERR,"pfInit: open bpf %m"); 125 return(-1); 126 } 127 128 /* Set immediate mode so packets are processed as they arrive. */ 129 immediate = 1; 130 if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) { 131 syslog(LOG_ERR,"pfInit: BIOCIMMEDIATE: %m"); 132 return(-1); 133 } 134 (void) strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name); 135 if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) { 136 syslog(LOG_ERR,"pfInit: BIOCSETIF: %m"); 137 return(-1); 138 } 139 /* Check that the data link layer is an Ethernet; this code won't work 140 * with anything else. */ 141 if (ioctl(fd, BIOCGDLT, (caddr_t) & dlt) < 0) { 142 syslog(LOG_ERR,"pfInit: BIOCGDLT: %m"); 143 return(-1); 144 } 145 if (dlt != DLT_EN10MB) { 146 syslog(LOG_ERR,"pfInit: %s is not ethernet", device); 147 return(-1); 148 } 149 if (promisc) { 150 /* Set promiscuous mode. */ 151 if (ioctl(fd, BIOCPROMISC, (caddr_t)0) < 0) { 152 syslog(LOG_ERR,"pfInit: BIOCPROMISC: %m"); 153 return(-1); 154 } 155 } 156 /* Set filter program. */ 157 insns[1].k = protocol; 158 insns[3].k = protocol; 159 160 if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) { 161 syslog(LOG_ERR,"pfInit: BIOCSETF: %m"); 162 return(-1); 163 } 164 return(fd); 165 } 166 167 /* 168 * Add a Multicast address to the interface 169 */ 170 171 int 172 pfAddMulti(s, interface, addr) 173 int s; 174 char *interface, *addr; 175 { 176 struct ifreq ifr; 177 int fd; 178 179 strcpy(ifr.ifr_name, interface); 180 181 ifr.ifr_addr.sa_family = AF_UNSPEC; 182 bcopy(addr, ifr.ifr_addr.sa_data, 6); 183 184 /* 185 * open a socket, temporarily, to use for SIOC* ioctls 186 * 187 */ 188 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 189 syslog(LOG_ERR, "pfAddMulti: socket: %m"); 190 return(-1); 191 } 192 if (ioctl(fd, SIOCADDMULTI, (caddr_t)&ifr) < 0) { 193 syslog(LOG_ERR, "pfAddMulti: SIOCADDMULTI: %m"); 194 close(fd); 195 return(-1); 196 } 197 close(fd); 198 199 return(0); 200 } 201 202 /* 203 * Delete a Multicast address from the interface 204 */ 205 206 int 207 pfDelMulti(s, interface, addr) 208 int s; 209 char *interface, *addr; 210 { 211 struct ifreq ifr; 212 int fd; 213 214 strcpy(ifr.ifr_name, interface); 215 216 ifr.ifr_addr.sa_family = AF_UNSPEC; 217 bcopy(addr, ifr.ifr_addr.sa_data, 6); 218 219 /* 220 * open a socket, temporarily, to use for SIOC* ioctls 221 * 222 */ 223 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 224 syslog(LOG_ERR, "pfDelMulti: socket: %m"); 225 return(-1); 226 } 227 if (ioctl(fd, SIOCDELMULTI, (caddr_t)&ifr) < 0) { 228 syslog(LOG_ERR, "pfAddMulti: SIOCDELMULTI: %m"); 229 close(fd); 230 return(-1); 231 } 232 close(fd); 233 234 return(0); 235 } 236 237 /* 238 * read a packet 239 */ 240 241 int 242 pfRead(fd, buf, len) 243 int fd, len; 244 u_char *buf; 245 { 246 return(read(fd, buf, len)); 247 } 248 249 /* 250 * write a packet 251 */ 252 253 int 254 pfWrite(fd, buf, len, trans) 255 int fd, len, trans; 256 u_char *buf; 257 { 258 259 struct iovec iov[2]; 260 261 switch (trans) { 262 case TRANS_8023: 263 iov[0].iov_base = (caddr_t)buf; 264 iov[0].iov_len = 22; 265 iov[1].iov_base = (caddr_t)buf+22; 266 iov[1].iov_len = len-22; 267 break; 268 default: 269 iov[0].iov_base = (caddr_t)buf; 270 iov[0].iov_len = 14; 271 iov[1].iov_base = (caddr_t)buf+14; 272 iov[1].iov_len = len-14; 273 break; 274 } 275 276 if (writev(fd, iov, 2) == len) 277 return(len); 278 279 return(-1); 280 } 281 282