Ansify some function definitions that were previously overlooked.
[dragonfly.git] / libexec / rbootd / bpf.c
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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
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45 *
46 * @(#)bpf.c 8.1 (Berkeley) 6/4/93
47 * $FreeBSD: src/libexec/rbootd/bpf.c,v 1.10 1999/08/28 00:09:44 peter Exp $
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48 */
49
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50#include <sys/param.h>
51#include <sys/ioctl.h>
52#include <sys/socket.h>
53#include <sys/time.h>
54
55#include <net/if.h>
56#include <net/bpf.h>
57
58#include <ctype.h>
59#include <errno.h>
60#include <fcntl.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>
64#include <syslog.h>
65#include <unistd.h>
66#include "defs.h"
67#include "pathnames.h"
68
69static int BpfFd = -1;
70static unsigned BpfLen = 0;
71static u_int8_t *BpfPkt = NULL;
72
73/*
74** BpfOpen -- Open and initialize a BPF device.
75**
76** Parameters:
77** None.
78**
79** Returns:
80** File descriptor of opened BPF device (for select() etc).
81**
82** Side Effects:
83** If an error is encountered, the program terminates here.
84*/
85int
89a89091 86BpfOpen(void)
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87{
88 struct ifreq ifr;
89 char bpfdev[32];
90 int n = 0;
91
92 /*
93 * Open the first available BPF device.
94 */
95 do {
96 (void) sprintf(bpfdev, _PATH_BPF, n++);
97 BpfFd = open(bpfdev, O_RDWR);
98 } while (BpfFd < 0 && (errno == EBUSY || errno == EPERM));
99
100 if (BpfFd < 0) {
101 syslog(LOG_ERR, "bpf: no available devices: %m");
102 Exit(0);
103 }
104
105 /*
106 * Set interface name for bpf device, get data link layer
107 * type and make sure it's type Ethernet.
108 */
109 (void) strncpy(ifr.ifr_name, IntfName, sizeof(ifr.ifr_name));
110 if (ioctl(BpfFd, BIOCSETIF, (caddr_t)&ifr) < 0) {
111 syslog(LOG_ERR, "bpf: ioctl(BIOCSETIF,%s): %m", IntfName);
112 Exit(0);
113 }
114
115 /*
116 * Make sure we are dealing with an Ethernet device.
117 */
118 if (ioctl(BpfFd, BIOCGDLT, (caddr_t)&n) < 0) {
119 syslog(LOG_ERR, "bpf: ioctl(BIOCGDLT): %m");
120 Exit(0);
121 }
122 if (n != DLT_EN10MB) {
123 syslog(LOG_ERR,"bpf: %s: data-link type %d unsupported",
124 IntfName, n);
125 Exit(0);
126 }
127
128 /*
129 * On read(), return packets immediately (do not buffer them).
130 */
131 n = 1;
132 if (ioctl(BpfFd, BIOCIMMEDIATE, (caddr_t)&n) < 0) {
133 syslog(LOG_ERR, "bpf: ioctl(BIOCIMMEDIATE): %m");
134 Exit(0);
135 }
136
137 /*
138 * Try to enable the chip/driver's multicast address filter to
139 * grab our RMP address. If this fails, try promiscuous mode.
140 * If this fails, there's no way we are going to get any RMP
141 * packets so just exit here.
142 */
143#ifdef MSG_EOR
144 ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
145#endif
146 ifr.ifr_addr.sa_family = AF_UNSPEC;
147 memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
148 if (ioctl(BpfFd, BIOCPROMISC, (caddr_t)0) < 0) {
149 syslog(LOG_ERR, "bpf: can't set promiscuous mode: %m");
150 Exit(0);
151 }
152
153 /*
154 * Ask BPF how much buffer space it requires and allocate one.
155 */
156 if (ioctl(BpfFd, BIOCGBLEN, (caddr_t)&BpfLen) < 0) {
157 syslog(LOG_ERR, "bpf: ioctl(BIOCGBLEN): %m");
158 Exit(0);
159 }
160 if (BpfPkt == NULL)
161 BpfPkt = (u_int8_t *)malloc(BpfLen);
162
163 if (BpfPkt == NULL) {
164 syslog(LOG_ERR, "bpf: out of memory (%u bytes for bpfpkt)",
165 BpfLen);
166 Exit(0);
167 }
168
169 /*
170 * Write a little program to snarf RMP Boot packets and stuff
171 * it down BPF's throat (i.e. set up the packet filter).
172 */
173 {
174#define RMP ((struct rmp_packet *)0)
175 static struct bpf_insn bpf_insn[] = {
176 { BPF_LD|BPF_B|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dsap },
177 { BPF_JMP|BPF_JEQ|BPF_K, 0, 5, IEEE_DSAP_HP },
178 { BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.cntrl },
179 { BPF_JMP|BPF_JEQ|BPF_K, 0, 3, IEEE_CNTL_HP },
180 { BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dxsap },
181 { BPF_JMP|BPF_JEQ|BPF_K, 0, 1, HPEXT_DXSAP },
182 { BPF_RET|BPF_K, 0, 0, RMP_MAX_PACKET },
183 { BPF_RET|BPF_K, 0, 0, 0x0 }
184 };
185#undef RMP
186 static struct bpf_program bpf_pgm = {
187 sizeof(bpf_insn)/sizeof(bpf_insn[0]), bpf_insn
188 };
189
190 if (ioctl(BpfFd, BIOCSETF, (caddr_t)&bpf_pgm) < 0) {
191 syslog(LOG_ERR, "bpf: ioctl(BIOCSETF): %m");
192 Exit(0);
193 }
194 }
195
196 return(BpfFd);
197}
198
199/*
200** BPF GetIntfName -- Return the name of a network interface attached to
201** the system, or 0 if none can be found. The interface
202** must be configured up; the lowest unit number is
203** preferred; loopback is ignored.
204**
205** Parameters:
206** errmsg - if no network interface found, *errmsg explains why.
207**
208** Returns:
209** A (static) pointer to interface name, or NULL on error.
210**
211** Side Effects:
212** None.
213*/
214char *
89a89091 215BpfGetIntfName(char **errmsg)
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216{
217 struct ifreq ibuf[8], *ifrp, *ifend, *mp;
218 struct ifconf ifc;
219 int fd;
220 int minunit, n;
221 char *cp;
222 static char device[sizeof(ifrp->ifr_name)];
223 static char errbuf[128] = "No Error!";
224
225 if (errmsg != NULL)
226 *errmsg = errbuf;
227
228 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
229 (void) strcpy(errbuf, "bpf: socket: %m");
230 return(NULL);
231 }
232 ifc.ifc_len = sizeof ibuf;
233 ifc.ifc_buf = (caddr_t)ibuf;
234
235#ifdef OSIOCGIFCONF
236 if (ioctl(fd, OSIOCGIFCONF, (char *)&ifc) < 0 ||
237 ifc.ifc_len < sizeof(struct ifreq)) {
238 (void) strcpy(errbuf, "bpf: ioctl(OSIOCGIFCONF): %m");
239 return(NULL);
240 }
241#else
242 if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
243 ifc.ifc_len < sizeof(struct ifreq)) {
244 (void) strcpy(errbuf, "bpf: ioctl(SIOCGIFCONF): %m");
245 return(NULL);
246 }
247#endif
248 ifrp = ibuf;
249 ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
250
678e8cc6 251 mp = NULL;
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252 minunit = 666;
253 for (; ifrp < ifend; ++ifrp) {
254 if (ioctl(fd, SIOCGIFFLAGS, (char *)ifrp) < 0) {
255 (void) strcpy(errbuf, "bpf: ioctl(SIOCGIFFLAGS): %m");
256 return(NULL);
257 }
258
259 /*
260 * If interface is down or this is the loopback interface,
261 * ignore it.
262 */
263 if ((ifrp->ifr_flags & IFF_UP) == 0 ||
264#ifdef IFF_LOOPBACK
265 (ifrp->ifr_flags & IFF_LOOPBACK))
266#else
267 (strcmp(ifrp->ifr_name, "lo0") == 0))
268#endif
269 continue;
270
271 for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp)
272 ;
273 n = atoi(cp);
274 if (n < minunit) {
275 minunit = n;
276 mp = ifrp;
277 }
278 }
279
280 (void) close(fd);
678e8cc6 281 if (mp == NULL) {
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282 (void) strcpy(errbuf, "bpf: no interfaces found");
283 return(NULL);
284 }
285
286 (void) strcpy(device, mp->ifr_name);
287 return(device);
288}
289
290/*
291** BpfRead -- Read packets from a BPF device and fill in `rconn'.
292**
293** Parameters:
294** rconn - filled in with next packet.
295** doread - is True if we can issue a read() syscall.
296**
297** Returns:
298** True if `rconn' contains a new packet, False otherwise.
299**
300** Side Effects:
301** None.
302*/
303int
89a89091 304BpfRead(RMPCONN *rconn, int doread)
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305{
306 int datlen, caplen, hdrlen;
307 static u_int8_t *bp = NULL, *ep = NULL;
308 int cc;
309
310 /*
311 * The read() may block, or it may return one or more packets.
312 * We let the caller decide whether or not we can issue a read().
313 */
314 if (doread) {
315 if ((cc = read(BpfFd, (char *)BpfPkt, (int)BpfLen)) < 0) {
316 syslog(LOG_ERR, "bpf: read: %m");
317 return(0);
318 } else {
319 bp = BpfPkt;
320 ep = BpfPkt + cc;
321 }
322 }
323
324#define bhp ((struct bpf_hdr *)bp)
325 /*
326 * If there is a new packet in the buffer, stuff it into `rconn'
327 * and return a success indication.
328 */
329 if (bp < ep) {
330 datlen = bhp->bh_datalen;
331 caplen = bhp->bh_caplen;
332 hdrlen = bhp->bh_hdrlen;
333
334 if (caplen != datlen)
335 syslog(LOG_ERR,
336 "bpf: short packet dropped (%d of %d bytes)",
337 caplen, datlen);
338 else if (caplen > sizeof(struct rmp_packet))
339 syslog(LOG_ERR, "bpf: large packet dropped (%d bytes)",
340 caplen);
341 else {
342 rconn->rmplen = caplen;
343 memmove((char *)&rconn->tstamp, (char *)&bhp->bh_tstamp,
344 sizeof(struct timeval));
345 memmove((char *)&rconn->rmp, (char *)bp + hdrlen, caplen);
346 }
347 bp += BPF_WORDALIGN(caplen + hdrlen);
348 return(1);
349 }
350#undef bhp
351
352 return(0);
353}
354
355/*
356** BpfWrite -- Write packet to BPF device.
357**
358** Parameters:
359** rconn - packet to send.
360**
361** Returns:
362** True if write succeeded, False otherwise.
363**
364** Side Effects:
365** None.
366*/
367int
89a89091 368BpfWrite(RMPCONN *rconn)
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369{
370 if (write(BpfFd, (char *)&rconn->rmp, rconn->rmplen) < 0) {
371 syslog(LOG_ERR, "write: %s: %m", EnetStr(rconn));
372 return(0);
373 }
374
375 return(1);
376}
377
378/*
379** BpfClose -- Close a BPF device.
380**
381** Parameters:
382** None.
383**
384** Returns:
385** Nothing.
386**
387** Side Effects:
388** None.
389*/
390void
89a89091 391BpfClose(void)
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392{
393 struct ifreq ifr;
394
395 if (BpfPkt != NULL) {
396 free((char *)BpfPkt);
397 BpfPkt = NULL;
398 }
399
400 if (BpfFd == -1)
401 return;
402
403#ifdef MSG_EOR
404 ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
405#endif
406 ifr.ifr_addr.sa_family = AF_UNSPEC;
407 memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
408 if (ioctl(BpfFd, SIOCDELMULTI, (caddr_t)&ifr) < 0)
409 (void) ioctl(BpfFd, BIOCPROMISC, (caddr_t)0);
410
411 (void) close(BpfFd);
412 BpfFd = -1;
413}