xref: /dragonfly/libexec/bootpd/getether.c (revision 2cd2d2b5) 
1 /*
2  * getether.c : get the ethernet address of an interface
3  *
4  * All of this code is quite system-specific.  As you may well
5  * guess, it took a good bit of detective work to figure out!
6  *
7  * If you figure out how to do this on another system,
8  * please let me know.  <gwr@mc.com>
9  *
10  * $FreeBSD: src/libexec/bootpd/getether.c,v 1.9.2.3 2003/02/15 05:36:01 kris Exp $
11  * $DragonFly: src/libexec/bootpd/getether.c,v 1.3 2004/02/13 03:49:47 dillon Exp $
12  */
13 
14 #include <sys/types.h>
15 #include <sys/socket.h>
16 
17 #ifndef	NO_UNISTD
18 #include <unistd.h>
19 #endif
20 
21 #include <ctype.h>
22 #include <paths.h>
23 #include <string.h>
24 #include <syslog.h>
25 
26 #include "getether.h"
27 #include "report.h"
28 #define EALEN 6
29 
30 #if defined(ultrix) || (defined(__osf__) && defined(__alpha))
31 /*
32  * This is really easy on Ultrix!  Thanks to
33  * Harald Lundberg <hl@tekla.fi> for this code.
34  *
35  * The code here is not specific to the Alpha, but that was the
36  * only symbol we could find to identify DEC's version of OSF.
37  * (Perhaps we should just define DEC in the Makefile... -gwr)
38  */
39 
40 #include <sys/ioctl.h>
41 #include <net/if.h>				/* struct ifdevea */
42 
43 getether(ifname, eap)
44 	char *ifname, *eap;
45 {
46 	int rc = -1;
47 	int fd;
48 	struct ifdevea phys;
49 	bzero(&phys, sizeof(phys));
50 	strcpy(phys.ifr_name, ifname);
51 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
52 		report(LOG_ERR, "getether: socket(INET,DGRAM) failed");
53 		return -1;
54 	}
55 	if (ioctl(fd, SIOCRPHYSADDR, &phys) < 0) {
56 		report(LOG_ERR, "getether: ioctl SIOCRPHYSADDR failed");
57 	} else {
58 		bcopy(&phys.current_pa[0], eap, EALEN);
59 		rc = 0;
60 	}
61 	close(fd);
62 	return rc;
63 }
64 
65 #define	GETETHER
66 #endif /* ultrix|osf1 */
67 
68 
69 #ifdef	SUNOS
70 
71 #include <sys/sockio.h>
72 #include <sys/time.h>			/* needed by net_if.h */
73 #include <net/nit_if.h>			/* for NIOCBIND */
74 #include <net/if.h>				/* for struct ifreq */
75 
76 getether(ifname, eap)
77 	char *ifname;				/* interface name from ifconfig structure */
78 	char *eap;					/* Ether address (output) */
79 {
80 	int rc = -1;
81 
82 	struct ifreq ifrnit;
83 	int nit;
84 
85 	bzero((char *) &ifrnit, sizeof(ifrnit));
86 	strncpy(&ifrnit.ifr_name[0], ifname, IFNAMSIZ);
87 
88 	nit = open("/dev/nit", 0);
89 	if (nit < 0) {
90 		report(LOG_ERR, "getether: open /dev/nit: %s",
91 			   get_errmsg());
92 		return rc;
93 	}
94 	do {
95 		if (ioctl(nit, NIOCBIND, &ifrnit) < 0) {
96 			report(LOG_ERR, "getether: NIOCBIND on nit");
97 			break;
98 		}
99 		if (ioctl(nit, SIOCGIFADDR, &ifrnit) < 0) {
100 			report(LOG_ERR, "getether: SIOCGIFADDR on nit");
101 			break;
102 		}
103 		bcopy(&ifrnit.ifr_addr.sa_data[0], eap, EALEN);
104 		rc = 0;
105 	} while (0);
106 	close(nit);
107 	return rc;
108 }
109 
110 #define	GETETHER
111 #endif /* SUNOS */
112 
113 
114 #if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__DragonFly__)
115 /* Thanks to John Brezak <brezak@ch.hp.com> for this code. */
116 #include <sys/ioctl.h>
117 #include <sys/time.h>
118 #include <net/if.h>
119 #include <net/if_dl.h>
120 #include <net/if_types.h>
121 
122 int
123 getether(ifname, eap)
124 	char *ifname;				/* interface name from ifconfig structure */
125 	char *eap;					/* Ether address (output) */
126 {
127 	int fd, rc = -1;
128 	register int n;
129 	struct ifreq ibuf[16];
130 	struct ifconf ifc;
131 	register struct ifreq *ifrp, *ifend;
132 
133 	/* Fetch the interface configuration */
134 	fd = socket(AF_INET, SOCK_DGRAM, 0);
135 	if (fd < 0) {
136 		report(LOG_ERR, "getether: socket %s: %s", ifname, get_errmsg());
137 		return (fd);
138 	}
139 	ifc.ifc_len = sizeof(ibuf);
140 	ifc.ifc_buf = (caddr_t) ibuf;
141 	if (ioctl(fd, SIOCGIFCONF, (char *) &ifc) < 0 ||
142 		ifc.ifc_len < sizeof(struct ifreq)) {
143 		report(LOG_ERR, "getether: SIOCGIFCONF: %s", get_errmsg());
144 		goto out;
145 	}
146 	/* Search interface configuration list for link layer address. */
147 	ifrp = ibuf;
148 	ifend = (struct ifreq *) ((char *) ibuf + ifc.ifc_len);
149 	while (ifrp < ifend) {
150 		/* Look for interface */
151 		if (strcmp(ifname, ifrp->ifr_name) == 0 &&
152 			ifrp->ifr_addr.sa_family == AF_LINK &&
153 		((struct sockaddr_dl *) &ifrp->ifr_addr)->sdl_type == IFT_ETHER) {
154 			bcopy(LLADDR((struct sockaddr_dl *) &ifrp->ifr_addr), eap, EALEN);
155 			rc = 0;
156 			break;
157 		}
158 		/* Bump interface config pointer */
159 		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
160 		if (n < sizeof(*ifrp))
161 			n = sizeof(*ifrp);
162 		ifrp = (struct ifreq *) ((char *) ifrp + n);
163 	}
164 
165   out:
166 	close(fd);
167 	return (rc);
168 }
169 
170 #define	GETETHER
171 #endif /* __NetBSD__ */
172 
173 
174 #ifdef	SVR4
175 /*
176  * This is for "Streams TCP/IP" by Lachman Associates.
177  * They sure made this cumbersome!  -gwr
178  */
179 
180 #include <sys/sockio.h>
181 #include <sys/dlpi.h>
182 #include <stropts.h>
183 #include <string.h>
184 #ifndef NULL
185 #define NULL 0
186 #endif
187 
188 int
189 getether(ifname, eap)
190 	char *ifname;				/* interface name from ifconfig structure */
191 	char *eap;					/* Ether address (output) */
192 {
193 	int rc = -1;
194 	char devname[32];
195 	char tmpbuf[sizeof(union DL_primitives) + 16];
196 	struct strbuf cbuf;
197 	int fd, flags;
198 	union DL_primitives *dlp;
199 	char *enaddr;
200 	int unit = -1;				/* which unit to attach */
201 
202 	snprintf(devname, sizeof(devname), "%s%s", _PATH_DEV, ifname);
203 	fd = open(devname, 2);
204 	if (fd < 0) {
205 		/* Try without the trailing digit. */
206 		char *p = devname + 5;
207 		while (isalpha(*p))
208 			p++;
209 		if (isdigit(*p)) {
210 			unit = *p - '0';
211 			*p = '\0';
212 		}
213 		fd = open(devname, 2);
214 		if (fd < 0) {
215 			report(LOG_ERR, "getether: open %s: %s",
216 				   devname, get_errmsg());
217 			return rc;
218 		}
219 	}
220 #ifdef	DL_ATTACH_REQ
221 	/*
222 	 * If this is a "Style 2" DLPI, then we must "attach" first
223 	 * to tell the driver which unit (board, port) we want.
224 	 * For now, decide this based on the device name.
225 	 * (Should do "info_req" and check dl_provider_style ...)
226 	 */
227 	if (unit >= 0) {
228 		memset(tmpbuf, 0, sizeof(tmpbuf));
229 		dlp = (union DL_primitives *) tmpbuf;
230 		dlp->dl_primitive = DL_ATTACH_REQ;
231 		dlp->attach_req.dl_ppa = unit;
232 		cbuf.buf = tmpbuf;
233 		cbuf.len = DL_ATTACH_REQ_SIZE;
234 		if (putmsg(fd, &cbuf, NULL, 0) < 0) {
235 			report(LOG_ERR, "getether: attach: putmsg: %s", get_errmsg());
236 			goto out;
237 		}
238 		/* Recv the ack. */
239 		cbuf.buf = tmpbuf;
240 		cbuf.maxlen = sizeof(tmpbuf);
241 		flags = 0;
242 		if (getmsg(fd, &cbuf, NULL, &flags) < 0) {
243 			report(LOG_ERR, "getether: attach: getmsg: %s", get_errmsg());
244 			goto out;
245 		}
246 		/*
247 		 * Check the type, etc.
248 		 */
249 		if (dlp->dl_primitive == DL_ERROR_ACK) {
250 			report(LOG_ERR, "getether: attach: dlpi_errno=%d, unix_errno=%d",
251 				   dlp->error_ack.dl_errno,
252 				   dlp->error_ack.dl_unix_errno);
253 			goto out;
254 		}
255 		if (dlp->dl_primitive != DL_OK_ACK) {
256 			report(LOG_ERR, "getether: attach: not OK or ERROR");
257 			goto out;
258 		}
259 	} /* unit >= 0 */
260 #endif	/* DL_ATTACH_REQ */
261 
262 	/*
263 	 * Get the Ethernet address the same way the ARP module
264 	 * does when it is pushed onto a new stream (bind).
265 	 * One should instead be able just do an dl_info_req
266 	 * but many drivers do not supply the hardware address
267 	 * in the response to dl_info_req (they MUST supply it
268 	 * for dl_bind_ack because the ARP module requires it).
269 	 */
270 	memset(tmpbuf, 0, sizeof(tmpbuf));
271 	dlp = (union DL_primitives *) tmpbuf;
272 	dlp->dl_primitive = DL_BIND_REQ;
273 	dlp->bind_req.dl_sap = 0x8FF;	/* XXX - Unused SAP */
274 	cbuf.buf = tmpbuf;
275 	cbuf.len = DL_BIND_REQ_SIZE;
276 	if (putmsg(fd, &cbuf, NULL, 0) < 0) {
277 		report(LOG_ERR, "getether: bind: putmsg: %s", get_errmsg());
278 		goto out;
279 	}
280 	/* Recv the ack. */
281 	cbuf.buf = tmpbuf;
282 	cbuf.maxlen = sizeof(tmpbuf);
283 	flags = 0;
284 	if (getmsg(fd, &cbuf, NULL, &flags) < 0) {
285 		report(LOG_ERR, "getether: bind: getmsg: %s", get_errmsg());
286 		goto out;
287 	}
288 	/*
289 	 * Check the type, etc.
290 	 */
291 	if (dlp->dl_primitive == DL_ERROR_ACK) {
292 		report(LOG_ERR, "getether: bind: dlpi_errno=%d, unix_errno=%d",
293 			   dlp->error_ack.dl_errno,
294 			   dlp->error_ack.dl_unix_errno);
295 		goto out;
296 	}
297 	if (dlp->dl_primitive != DL_BIND_ACK) {
298 		report(LOG_ERR, "getether: bind: not OK or ERROR");
299 		goto out;
300 	}
301 	if (dlp->bind_ack.dl_addr_offset == 0) {
302 		report(LOG_ERR, "getether: bind: ack has no address");
303 		goto out;
304 	}
305 	if (dlp->bind_ack.dl_addr_length < EALEN) {
306 		report(LOG_ERR, "getether: bind: ack address truncated");
307 		goto out;
308 	}
309 	/*
310 	 * Copy the Ethernet address out of the message.
311 	 */
312 	enaddr = tmpbuf + dlp->bind_ack.dl_addr_offset;
313 	memcpy(eap, enaddr, EALEN);
314 	rc = 0;
315 
316   out:
317 	close(fd);
318 	return rc;
319 }
320 
321 #define	GETETHER
322 #endif /* SVR4 */
323 
324 
325 #ifdef	__linux__
326 /*
327  * This is really easy on Linux!  This version (for linux)
328  * written by Nigel Metheringham <nigelm@ohm.york.ac.uk> and
329  * updated by Pauline Middelink <middelin@polyware.iaf.nl>
330  *
331  * The code is almost identical to the Ultrix code - however
332  * the names are different to confuse the innocent :-)
333  * Most of this code was stolen from the Ultrix bit above.
334  */
335 
336 #include <memory.h>
337 #include <sys/ioctl.h>
338 #include <net/if.h>	       	/* struct ifreq */
339 #include <sys/socketio.h>	/* Needed for IOCTL defs */
340 
341 int
342 getether(ifname, eap)
343 	char *ifname, *eap;
344 {
345 	int rc = -1;
346 	int fd;
347 	struct ifreq phys;
348 
349 	memset(&phys, 0, sizeof(phys));
350 	strcpy(phys.ifr_name, ifname);
351 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
352 		report(LOG_ERR, "getether: socket(INET,DGRAM) failed");
353 		return -1;
354 	}
355 	if (ioctl(fd, SIOCGIFHWADDR, &phys) < 0) {
356 		report(LOG_ERR, "getether: ioctl SIOCGIFHWADDR failed");
357 	} else {
358 		memcpy(eap, &phys.ifr_hwaddr.sa_data, EALEN);
359 		rc = 0;
360 	}
361 	close(fd);
362 	return rc;
363 }
364 
365 #define	GETETHER
366 #endif	/* __linux__ */
367 
368 
369 /* If we don't know how on this system, just return an error. */
370 #ifndef	GETETHER
371 int
372 getether(ifname, eap)
373 	char *ifname, *eap;
374 {
375 	return -1;
376 }
377 
378 #endif /* !GETETHER */
379 
380 /*
381  * Local Variables:
382  * tab-width: 4
383  * c-indent-level: 4
384  * c-argdecl-indent: 4
385  * c-continued-statement-offset: 4
386  * c-continued-brace-offset: -4
387  * c-label-offset: -4
388  * c-brace-offset: 0
389  * End:
390  */
391