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