1 /* 2 * Copyright (c) 1988, 1992 The University of Utah and the Center 3 * for Software Science (CSS). 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Center for Software Science of the University of Utah Computer 9 * Science Department. CSS requests users of this software to return 10 * to css-dist@cs.utah.edu any improvements that they make and grant 11 * CSS redistribution rights. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * from: @(#)bpf.c 8.1 (Berkeley) 6/4/93 42 * 43 * From: Utah Hdr: bpf.c 3.1 92/07/06 44 * Author: Jeff Forys, University of Utah CSS 45 */ 46 47 #ifndef lint 48 #if 0 49 static const char sccsid[] = "@(#)bpf.c 8.1 (Berkeley) 6/4/93"; 50 #endif 51 static const char rcsid[] = 52 "$FreeBSD$"; 53 #endif /* not lint */ 54 55 #include <sys/param.h> 56 #include <sys/ioctl.h> 57 #include <sys/socket.h> 58 #include <sys/time.h> 59 60 #include <net/if.h> 61 #include <net/bpf.h> 62 63 #include <ctype.h> 64 #include <errno.h> 65 #include <fcntl.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <syslog.h> 70 #include <unistd.h> 71 #include "defs.h" 72 #include "pathnames.h" 73 74 static int BpfFd = -1; 75 static unsigned BpfLen = 0; 76 static u_int8_t *BpfPkt = NULL; 77 78 /* 79 ** BpfOpen -- Open and initialize a BPF device. 80 ** 81 ** Parameters: 82 ** None. 83 ** 84 ** Returns: 85 ** File descriptor of opened BPF device (for select() etc). 86 ** 87 ** Side Effects: 88 ** If an error is encountered, the program terminates here. 89 */ 90 int 91 BpfOpen(void) 92 { 93 struct ifreq ifr; 94 char bpfdev[32]; 95 int n = 0; 96 97 /* 98 * Open the first available BPF device. 99 */ 100 do { 101 (void) sprintf(bpfdev, _PATH_BPF, n++); 102 BpfFd = open(bpfdev, O_RDWR); 103 } while (BpfFd < 0 && (errno == EBUSY || errno == EPERM)); 104 105 if (BpfFd < 0) { 106 syslog(LOG_ERR, "bpf: no available devices: %m"); 107 Exit(0); 108 } 109 110 /* 111 * Set interface name for bpf device, get data link layer 112 * type and make sure it's type Ethernet. 113 */ 114 (void) strncpy(ifr.ifr_name, IntfName, sizeof(ifr.ifr_name)); 115 if (ioctl(BpfFd, BIOCSETIF, (caddr_t)&ifr) < 0) { 116 syslog(LOG_ERR, "bpf: ioctl(BIOCSETIF,%s): %m", IntfName); 117 Exit(0); 118 } 119 120 /* 121 * Make sure we are dealing with an Ethernet device. 122 */ 123 if (ioctl(BpfFd, BIOCGDLT, (caddr_t)&n) < 0) { 124 syslog(LOG_ERR, "bpf: ioctl(BIOCGDLT): %m"); 125 Exit(0); 126 } 127 if (n != DLT_EN10MB) { 128 syslog(LOG_ERR,"bpf: %s: data-link type %d unsupported", 129 IntfName, n); 130 Exit(0); 131 } 132 133 /* 134 * On read(), return packets immediately (do not buffer them). 135 */ 136 n = 1; 137 if (ioctl(BpfFd, BIOCIMMEDIATE, (caddr_t)&n) < 0) { 138 syslog(LOG_ERR, "bpf: ioctl(BIOCIMMEDIATE): %m"); 139 Exit(0); 140 } 141 142 /* 143 * Try to enable the chip/driver's multicast address filter to 144 * grab our RMP address. If this fails, try promiscuous mode. 145 * If this fails, there's no way we are going to get any RMP 146 * packets so just exit here. 147 */ 148 #ifdef MSG_EOR 149 ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2; 150 #endif 151 ifr.ifr_addr.sa_family = AF_UNSPEC; 152 memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN); 153 if (ioctl(BpfFd, BIOCPROMISC, (caddr_t)0) < 0) { 154 syslog(LOG_ERR, "bpf: can't set promiscuous mode: %m"); 155 Exit(0); 156 } 157 158 /* 159 * Ask BPF how much buffer space it requires and allocate one. 160 */ 161 if (ioctl(BpfFd, BIOCGBLEN, (caddr_t)&BpfLen) < 0) { 162 syslog(LOG_ERR, "bpf: ioctl(BIOCGBLEN): %m"); 163 Exit(0); 164 } 165 if (BpfPkt == NULL) 166 BpfPkt = (u_int8_t *)malloc(BpfLen); 167 168 if (BpfPkt == NULL) { 169 syslog(LOG_ERR, "bpf: out of memory (%u bytes for bpfpkt)", 170 BpfLen); 171 Exit(0); 172 } 173 174 /* 175 * Write a little program to snarf RMP Boot packets and stuff 176 * it down BPF's throat (i.e. set up the packet filter). 177 */ 178 { 179 #define RMP ((struct rmp_packet *)0) 180 static struct bpf_insn bpf_insn[] = { 181 { BPF_LD|BPF_B|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dsap }, 182 { BPF_JMP|BPF_JEQ|BPF_K, 0, 5, IEEE_DSAP_HP }, 183 { BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.cntrl }, 184 { BPF_JMP|BPF_JEQ|BPF_K, 0, 3, IEEE_CNTL_HP }, 185 { BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dxsap }, 186 { BPF_JMP|BPF_JEQ|BPF_K, 0, 1, HPEXT_DXSAP }, 187 { BPF_RET|BPF_K, 0, 0, RMP_MAX_PACKET }, 188 { BPF_RET|BPF_K, 0, 0, 0x0 } 189 }; 190 #undef RMP 191 static struct bpf_program bpf_pgm = { 192 sizeof(bpf_insn)/sizeof(bpf_insn[0]), bpf_insn 193 }; 194 195 if (ioctl(BpfFd, BIOCSETF, (caddr_t)&bpf_pgm) < 0) { 196 syslog(LOG_ERR, "bpf: ioctl(BIOCSETF): %m"); 197 Exit(0); 198 } 199 } 200 201 return(BpfFd); 202 } 203 204 /* 205 ** BPF GetIntfName -- Return the name of a network interface attached to 206 ** the system, or 0 if none can be found. The interface 207 ** must be configured up; the lowest unit number is 208 ** preferred; loopback is ignored. 209 ** 210 ** Parameters: 211 ** errmsg - if no network interface found, *errmsg explains why. 212 ** 213 ** Returns: 214 ** A (static) pointer to interface name, or NULL on error. 215 ** 216 ** Side Effects: 217 ** None. 218 */ 219 char * 220 BpfGetIntfName(char **errmsg) 221 { 222 struct ifreq ibuf[8], *ifrp, *ifend, *mp; 223 struct ifconf ifc; 224 int fd; 225 int minunit, n; 226 char *cp; 227 static char device[sizeof(ifrp->ifr_name)]; 228 static char errbuf[128] = "No Error!"; 229 230 if (errmsg != NULL) 231 *errmsg = errbuf; 232 233 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 234 (void) strcpy(errbuf, "bpf: socket: %m"); 235 return(NULL); 236 } 237 ifc.ifc_len = sizeof ibuf; 238 ifc.ifc_buf = (caddr_t)ibuf; 239 240 #ifdef OSIOCGIFCONF 241 if (ioctl(fd, OSIOCGIFCONF, (char *)&ifc) < 0 || 242 ifc.ifc_len < sizeof(struct ifreq)) { 243 (void) strcpy(errbuf, "bpf: ioctl(OSIOCGIFCONF): %m"); 244 return(NULL); 245 } 246 #else 247 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 || 248 ifc.ifc_len < sizeof(struct ifreq)) { 249 (void) strcpy(errbuf, "bpf: ioctl(SIOCGIFCONF): %m"); 250 return(NULL); 251 } 252 #endif 253 ifrp = ibuf; 254 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len); 255 256 mp = 0; 257 minunit = 666; 258 for (; ifrp < ifend; ++ifrp) { 259 if (ioctl(fd, SIOCGIFFLAGS, (char *)ifrp) < 0) { 260 (void) strcpy(errbuf, "bpf: ioctl(SIOCGIFFLAGS): %m"); 261 return(NULL); 262 } 263 264 /* 265 * If interface is down or this is the loopback interface, 266 * ignore it. 267 */ 268 if ((ifrp->ifr_flags & IFF_UP) == 0 || 269 #ifdef IFF_LOOPBACK 270 (ifrp->ifr_flags & IFF_LOOPBACK)) 271 #else 272 (strcmp(ifrp->ifr_name, "lo0") == 0)) 273 #endif 274 continue; 275 276 for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp) 277 ; 278 n = atoi(cp); 279 if (n < minunit) { 280 minunit = n; 281 mp = ifrp; 282 } 283 } 284 285 (void) close(fd); 286 if (mp == 0) { 287 (void) strcpy(errbuf, "bpf: no interfaces found"); 288 return(NULL); 289 } 290 291 (void) strcpy(device, mp->ifr_name); 292 return(device); 293 } 294 295 /* 296 ** BpfRead -- Read packets from a BPF device and fill in `rconn'. 297 ** 298 ** Parameters: 299 ** rconn - filled in with next packet. 300 ** doread - is True if we can issue a read() syscall. 301 ** 302 ** Returns: 303 ** True if `rconn' contains a new packet, False otherwise. 304 ** 305 ** Side Effects: 306 ** None. 307 */ 308 int 309 BpfRead(RMPCONN *rconn, int doread) 310 { 311 int datlen, caplen, hdrlen; 312 static u_int8_t *bp = NULL, *ep = NULL; 313 int cc; 314 315 /* 316 * The read() may block, or it may return one or more packets. 317 * We let the caller decide whether or not we can issue a read(). 318 */ 319 if (doread) { 320 if ((cc = read(BpfFd, (char *)BpfPkt, (int)BpfLen)) < 0) { 321 syslog(LOG_ERR, "bpf: read: %m"); 322 return(0); 323 } else { 324 bp = BpfPkt; 325 ep = BpfPkt + cc; 326 } 327 } 328 329 #define bhp ((struct bpf_hdr *)bp) 330 /* 331 * If there is a new packet in the buffer, stuff it into `rconn' 332 * and return a success indication. 333 */ 334 if (bp < ep) { 335 datlen = bhp->bh_datalen; 336 caplen = bhp->bh_caplen; 337 hdrlen = bhp->bh_hdrlen; 338 339 if (caplen != datlen) 340 syslog(LOG_ERR, 341 "bpf: short packet dropped (%d of %d bytes)", 342 caplen, datlen); 343 else if (caplen > sizeof(struct rmp_packet)) 344 syslog(LOG_ERR, "bpf: large packet dropped (%d bytes)", 345 caplen); 346 else { 347 rconn->rmplen = caplen; 348 memmove((char *)&rconn->tstamp, (char *)&bhp->bh_tstamp, 349 sizeof(struct timeval)); 350 memmove((char *)&rconn->rmp, (char *)bp + hdrlen, caplen); 351 } 352 bp += BPF_WORDALIGN(caplen + hdrlen); 353 return(1); 354 } 355 #undef bhp 356 357 return(0); 358 } 359 360 /* 361 ** BpfWrite -- Write packet to BPF device. 362 ** 363 ** Parameters: 364 ** rconn - packet to send. 365 ** 366 ** Returns: 367 ** True if write succeeded, False otherwise. 368 ** 369 ** Side Effects: 370 ** None. 371 */ 372 int 373 BpfWrite(RMPCONN *rconn) 374 { 375 if (write(BpfFd, (char *)&rconn->rmp, rconn->rmplen) < 0) { 376 syslog(LOG_ERR, "write: %s: %m", EnetStr(rconn)); 377 return(0); 378 } 379 380 return(1); 381 } 382 383 /* 384 ** BpfClose -- Close a BPF device. 385 ** 386 ** Parameters: 387 ** None. 388 ** 389 ** Returns: 390 ** Nothing. 391 ** 392 ** Side Effects: 393 ** None. 394 */ 395 void 396 BpfClose(void) 397 { 398 struct ifreq ifr; 399 400 if (BpfPkt != NULL) { 401 free((char *)BpfPkt); 402 BpfPkt = NULL; 403 } 404 405 if (BpfFd == -1) 406 return; 407 408 #ifdef MSG_EOR 409 ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2; 410 #endif 411 ifr.ifr_addr.sa_family = AF_UNSPEC; 412 memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN); 413 if (ioctl(BpfFd, SIOCDELMULTI, (caddr_t)&ifr) < 0) 414 (void) ioctl(BpfFd, BIOCPROMISC, (caddr_t)0); 415 416 (void) close(BpfFd); 417 BpfFd = -1; 418 } 419