2 * SPDX-License-Identifier: BSD-3-Clause
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.
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.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
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.
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
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33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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39 * from: @(#)bpf.c 8.1 (Berkeley) 6/4/93
41 * From: Utah Hdr: bpf.c 3.1 92/07/06
42 * Author: Jeff Forys, University of Utah CSS
47 static const char sccsid[] = "@(#)bpf.c 8.1 (Berkeley) 6/4/93";
49 static const char rcsid[] =
53 #include <sys/param.h>
54 #include <sys/ioctl.h>
55 #include <sys/socket.h>
70 #include "pathnames.h"
72 static int BpfFd = -1;
73 static unsigned BpfLen = 0;
74 static u_int8_t *BpfPkt = NULL;
77 ** BpfOpen -- Open and initialize a BPF device.
83 ** File descriptor of opened BPF device (for select() etc).
86 ** If an error is encountered, the program terminates here.
96 * Open the first available BPF device.
99 (void) sprintf(bpfdev, _PATH_BPF, n++);
100 BpfFd = open(bpfdev, O_RDWR);
101 } while (BpfFd < 0 && (errno == EBUSY || errno == EPERM));
104 syslog(LOG_ERR, "bpf: no available devices: %m");
109 * Set interface name for bpf device, get data link layer
110 * type and make sure it's type Ethernet.
112 (void) strncpy(ifr.ifr_name, IntfName, sizeof(ifr.ifr_name));
113 if (ioctl(BpfFd, BIOCSETIF, (caddr_t)&ifr) < 0) {
114 syslog(LOG_ERR, "bpf: ioctl(BIOCSETIF,%s): %m", IntfName);
119 * Make sure we are dealing with an Ethernet device.
121 if (ioctl(BpfFd, BIOCGDLT, (caddr_t)&n) < 0) {
122 syslog(LOG_ERR, "bpf: ioctl(BIOCGDLT): %m");
125 if (n != DLT_EN10MB) {
126 syslog(LOG_ERR,"bpf: %s: data-link type %d unsupported",
132 * On read(), return packets immediately (do not buffer them).
135 if (ioctl(BpfFd, BIOCIMMEDIATE, (caddr_t)&n) < 0) {
136 syslog(LOG_ERR, "bpf: ioctl(BIOCIMMEDIATE): %m");
141 * Try to enable the chip/driver's multicast address filter to
142 * grab our RMP address. If this fails, try promiscuous mode.
143 * If this fails, there's no way we are going to get any RMP
144 * packets so just exit here.
147 ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
149 ifr.ifr_addr.sa_family = AF_UNSPEC;
150 memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
151 if (ioctl(BpfFd, BIOCPROMISC, (caddr_t)0) < 0) {
152 syslog(LOG_ERR, "bpf: can't set promiscuous mode: %m");
157 * Ask BPF how much buffer space it requires and allocate one.
159 if (ioctl(BpfFd, BIOCGBLEN, (caddr_t)&BpfLen) < 0) {
160 syslog(LOG_ERR, "bpf: ioctl(BIOCGBLEN): %m");
164 BpfPkt = (u_int8_t *)malloc(BpfLen);
166 if (BpfPkt == NULL) {
167 syslog(LOG_ERR, "bpf: out of memory (%u bytes for bpfpkt)",
173 * Write a little program to snarf RMP Boot packets and stuff
174 * it down BPF's throat (i.e. set up the packet filter).
177 #define RMP ((struct rmp_packet *)0)
178 static struct bpf_insn bpf_insn[] = {
179 { BPF_LD|BPF_B|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dsap },
180 { BPF_JMP|BPF_JEQ|BPF_K, 0, 5, IEEE_DSAP_HP },
181 { BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.cntrl },
182 { BPF_JMP|BPF_JEQ|BPF_K, 0, 3, IEEE_CNTL_HP },
183 { BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dxsap },
184 { BPF_JMP|BPF_JEQ|BPF_K, 0, 1, HPEXT_DXSAP },
185 { BPF_RET|BPF_K, 0, 0, RMP_MAX_PACKET },
186 { BPF_RET|BPF_K, 0, 0, 0x0 }
189 static struct bpf_program bpf_pgm = {
190 sizeof(bpf_insn)/sizeof(bpf_insn[0]), bpf_insn
193 if (ioctl(BpfFd, BIOCSETF, (caddr_t)&bpf_pgm) < 0) {
194 syslog(LOG_ERR, "bpf: ioctl(BIOCSETF): %m");
203 ** BPF GetIntfName -- Return the name of a network interface attached to
204 ** the system, or 0 if none can be found. The interface
205 ** must be configured up; the lowest unit number is
206 ** preferred; loopback is ignored.
209 ** errmsg - if no network interface found, *errmsg explains why.
212 ** A (static) pointer to interface name, or NULL on error.
218 BpfGetIntfName(char **errmsg)
220 struct ifreq ibuf[8], *ifrp, *ifend, *mp;
225 static char device[sizeof(ifrp->ifr_name)];
226 static char errbuf[128] = "No Error!";
231 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
232 (void) strcpy(errbuf, "bpf: socket: %m");
235 ifc.ifc_len = sizeof ibuf;
236 ifc.ifc_buf = (caddr_t)ibuf;
238 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
239 ifc.ifc_len < sizeof(struct ifreq)) {
240 (void) strcpy(errbuf, "bpf: ioctl(SIOCGIFCONF): %m");
244 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
248 for (; ifrp < ifend; ++ifrp) {
249 if (ioctl(fd, SIOCGIFFLAGS, (char *)ifrp) < 0) {
250 (void) strcpy(errbuf, "bpf: ioctl(SIOCGIFFLAGS): %m");
255 * If interface is down or this is the loopback interface,
258 if ((ifrp->ifr_flags & IFF_UP) == 0 ||
260 (ifrp->ifr_flags & IFF_LOOPBACK))
262 (strcmp(ifrp->ifr_name, "lo0") == 0))
266 for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp)
277 (void) strcpy(errbuf, "bpf: no interfaces found");
281 (void) strcpy(device, mp->ifr_name);
286 ** BpfRead -- Read packets from a BPF device and fill in `rconn'.
289 ** rconn - filled in with next packet.
290 ** doread - is True if we can issue a read() syscall.
293 ** True if `rconn' contains a new packet, False otherwise.
299 BpfRead(RMPCONN *rconn, int doread)
301 int datlen, caplen, hdrlen;
302 static u_int8_t *bp = NULL, *ep = NULL;
306 * The read() may block, or it may return one or more packets.
307 * We let the caller decide whether or not we can issue a read().
310 if ((cc = read(BpfFd, (char *)BpfPkt, (int)BpfLen)) < 0) {
311 syslog(LOG_ERR, "bpf: read: %m");
319 #define bhp ((struct bpf_hdr *)bp)
321 * If there is a new packet in the buffer, stuff it into `rconn'
322 * and return a success indication.
325 datlen = bhp->bh_datalen;
326 caplen = bhp->bh_caplen;
327 hdrlen = bhp->bh_hdrlen;
329 if (caplen != datlen)
331 "bpf: short packet dropped (%d of %d bytes)",
333 else if (caplen > sizeof(struct rmp_packet))
334 syslog(LOG_ERR, "bpf: large packet dropped (%d bytes)",
337 rconn->rmplen = caplen;
338 memmove((char *)&rconn->tstamp, (char *)&bhp->bh_tstamp,
339 sizeof(struct timeval));
340 memmove((char *)&rconn->rmp, (char *)bp + hdrlen, caplen);
342 bp += BPF_WORDALIGN(caplen + hdrlen);
351 ** BpfWrite -- Write packet to BPF device.
354 ** rconn - packet to send.
357 ** True if write succeeded, False otherwise.
363 BpfWrite(RMPCONN *rconn)
365 if (write(BpfFd, (char *)&rconn->rmp, rconn->rmplen) < 0) {
366 syslog(LOG_ERR, "write: %s: %m", EnetStr(rconn));
374 ** BpfClose -- Close a BPF device.
390 if (BpfPkt != NULL) {
391 free((char *)BpfPkt);
399 ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
401 ifr.ifr_addr.sa_family = AF_UNSPEC;
402 memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
403 if (ioctl(BpfFd, SIOCDELMULTI, (caddr_t)&ifr) < 0)
404 (void) ioctl(BpfFd, BIOCPROMISC, (caddr_t)0);