pf.c revision 1.2
1 /* 2 * Copyright (c) 1993-95 Mats O Jansson. All rights reserved. 3 * Copyright (c) 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is partly derived from rarpd. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Mats O Jansson. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #ifndef LINT 35 static char rcsid[] = "$Id: pf.c,v 1.2 1997/03/17 10:39:53 veego Exp $"; 36 #endif 37 38 #include <stdio.h> 39 #include <unistd.h> 40 #include <sys/types.h> 41 #include <sys/time.h> 42 #include <sys/ioctl.h> 43 #include <sys/file.h> 44 #include <sys/socket.h> 45 #include <sys/uio.h> 46 #include <net/if.h> 47 48 #include <net/bpf.h> 49 #include <sys/errno.h> 50 51 #include <netinet/in.h> 52 #include <netinet/if_inarp.h> 53 54 #include <netdb.h> 55 #include <ctype.h> 56 #include <strings.h> 57 58 #include <syslog.h> 59 #include <varargs.h> 60 61 #include "common/mopdef.h" 62 63 /* 64 * Variables 65 */ 66 67 extern int errno; 68 extern int promisc; 69 70 /* 71 * Return information to device.c how to open device. 72 * In this case the driver can handle both Ethernet type II and 73 * IEEE 802.3 frames (SNAP) in a single pfOpen. 74 */ 75 76 int 77 pfTrans(interface) 78 char *interface; 79 { 80 return TRANS_ETHER+TRANS_8023+TRANS_AND; 81 } 82 83 /* 84 * Open and initialize packet filter. 85 */ 86 87 int 88 pfInit(interface, mode, protocol, typ) 89 char *interface; 90 u_short protocol; 91 int typ, mode; 92 { 93 int fd; 94 int n = 0; 95 char device[sizeof "/dev/bpf000"]; 96 struct ifreq ifr; 97 u_int dlt; 98 int immediate; 99 100 static struct bpf_insn insns[] = { 101 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12), 102 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0), 103 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20), 104 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3), 105 BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14), 106 BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1), 107 BPF_STMT(BPF_RET | BPF_K, 1520), 108 BPF_STMT(BPF_RET | BPF_K, 0), 109 }; 110 static struct bpf_program filter = { 111 sizeof insns / sizeof(insns[0]), 112 insns 113 }; 114 115 /* Go through all the minors and find one that isn't in use. */ 116 do { 117 (void) sprintf(device, "/dev/bpf%d", n++); 118 fd = open(device, mode); 119 } while (fd < 0 && errno == EBUSY); 120 121 if (fd < 0) { 122 syslog(LOG_ERR,"pfInit: open bpf %m"); 123 return(-1); 124 } 125 126 /* Set immediate mode so packets are processed as they arrive. */ 127 immediate = 1; 128 if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) { 129 syslog(LOG_ERR,"pfInit: BIOCIMMEDIATE: %m"); 130 return(-1); 131 } 132 (void) strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name); 133 if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) { 134 syslog(LOG_ERR,"pfInit: BIOCSETIF: %m"); 135 return(-1); 136 } 137 /* Check that the data link layer is an Ethernet; this code won't work 138 * with anything else. */ 139 if (ioctl(fd, BIOCGDLT, (caddr_t) & dlt) < 0) { 140 syslog(LOG_ERR,"pfInit: BIOCGDLT: %m"); 141 return(-1); 142 } 143 if (dlt != DLT_EN10MB) { 144 syslog(LOG_ERR,"pfInit: %s is not ethernet", device); 145 return(-1); 146 } 147 if (promisc) { 148 /* Set promiscuous mode. */ 149 if (ioctl(fd, BIOCPROMISC, (caddr_t)0) < 0) { 150 syslog(LOG_ERR,"pfInit: BIOCPROMISC: %m"); 151 return(-1); 152 } 153 } 154 /* Set filter program. */ 155 insns[1].k = protocol; 156 insns[3].k = protocol; 157 158 if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) { 159 syslog(LOG_ERR,"pfInit: BIOCSETF: %m"); 160 return(-1); 161 } 162 return(fd); 163 } 164 165 /* 166 * Add a Multicast address to the interface 167 */ 168 169 int 170 pfAddMulti(s, interface, addr) 171 int s; 172 char *interface, *addr; 173 { 174 struct ifreq ifr; 175 int fd; 176 177 strcpy(ifr.ifr_name, interface); 178 179 ifr.ifr_addr.sa_family = AF_UNSPEC; 180 bcopy(addr, ifr.ifr_addr.sa_data, 6); 181 182 /* 183 * open a socket, temporarily, to use for SIOC* ioctls 184 * 185 */ 186 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 187 syslog(LOG_ERR, "pfAddMulti: socket: %m"); 188 return(-1); 189 } 190 if (ioctl(fd, SIOCADDMULTI, (caddr_t)&ifr) < 0) { 191 syslog(LOG_ERR, "pfAddMulti: SIOCADDMULTI: %m"); 192 close(fd); 193 return(-1); 194 } 195 close(fd); 196 197 return(0); 198 } 199 200 /* 201 * Delete a Multicast address from the interface 202 */ 203 204 int 205 pfDelMulti(s, interface, addr) 206 int s; 207 char *interface, *addr; 208 { 209 struct ifreq ifr; 210 int fd; 211 212 strcpy(ifr.ifr_name, interface); 213 214 ifr.ifr_addr.sa_family = AF_UNSPEC; 215 bcopy(addr, ifr.ifr_addr.sa_data, 6); 216 217 /* 218 * open a socket, temporarily, to use for SIOC* ioctls 219 * 220 */ 221 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 222 syslog(LOG_ERR, "pfDelMulti: socket: %m"); 223 return(-1); 224 } 225 if (ioctl(fd, SIOCDELMULTI, (caddr_t)&ifr) < 0) { 226 syslog(LOG_ERR, "pfAddMulti: SIOCDELMULTI: %m"); 227 close(fd); 228 return(-1); 229 } 230 close(fd); 231 232 return(0); 233 } 234 235 /* 236 * read a packet 237 */ 238 239 int 240 pfRead(fd, buf, len) 241 int fd, len; 242 u_char *buf; 243 { 244 return(read(fd, buf, len)); 245 } 246 247 /* 248 * write a packet 249 */ 250 251 int 252 pfWrite(fd, buf, len, trans) 253 int fd, len, trans; 254 u_char *buf; 255 { 256 257 struct iovec iov[2]; 258 259 switch (trans) { 260 case TRANS_8023: 261 iov[0].iov_base = (caddr_t)buf; 262 iov[0].iov_len = 22; 263 iov[1].iov_base = (caddr_t)buf+22; 264 iov[1].iov_len = len-22; 265 break; 266 default: 267 iov[0].iov_base = (caddr_t)buf; 268 iov[0].iov_len = 14; 269 iov[1].iov_base = (caddr_t)buf+14; 270 iov[1].iov_len = len-14; 271 break; 272 } 273 274 if (writev(fd, iov, 2) == len) 275 return(len); 276 277 return(-1); 278 } 279 280
Indexes created Tue Sep 23 14:10:03 GMT 2025