xref: /dragonfly/libexec/bootpd/getether.c (revision 36a3d1d6) 
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 1.4 2008/06/05 18:01:49 swildner 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 /*
123  * ifname - interface name from ifconfig structure
124  * eap    - Ether address (output)
125  */
126 int
127 getether(char *ifname, char *eap)
128 {
129 	int fd, rc = -1;
130 	int n;
131 	struct ifreq ibuf[16];
132 	struct ifconf ifc;
133 	struct ifreq *ifrp, *ifend;
134 
135 	/* Fetch the interface configuration */
136 	fd = socket(AF_INET, SOCK_DGRAM, 0);
137 	if (fd < 0) {
138 		report(LOG_ERR, "getether: socket %s: %s", ifname, get_errmsg());
139 		return (fd);
140 	}
141 	ifc.ifc_len = sizeof(ibuf);
142 	ifc.ifc_buf = (caddr_t) ibuf;
143 	if (ioctl(fd, SIOCGIFCONF, (char *) &ifc) < 0 ||
144 		ifc.ifc_len < sizeof(struct ifreq)) {
145 		report(LOG_ERR, "getether: SIOCGIFCONF: %s", get_errmsg());
146 		goto out;
147 	}
148 	/* Search interface configuration list for link layer address. */
149 	ifrp = ibuf;
150 	ifend = (struct ifreq *) ((char *) ibuf + ifc.ifc_len);
151 	while (ifrp < ifend) {
152 		/* Look for interface */
153 		if (strcmp(ifname, ifrp->ifr_name) == 0 &&
154 			ifrp->ifr_addr.sa_family == AF_LINK &&
155 		((struct sockaddr_dl *) &ifrp->ifr_addr)->sdl_type == IFT_ETHER) {
156 			bcopy(LLADDR((struct sockaddr_dl *) &ifrp->ifr_addr), eap, EALEN);
157 			rc = 0;
158 			break;
159 		}
160 		/* Bump interface config pointer */
161 		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
162 		if (n < sizeof(*ifrp))
163 			n = sizeof(*ifrp);
164 		ifrp = (struct ifreq *) ((char *) ifrp + n);
165 	}
166 
167   out:
168 	close(fd);
169 	return (rc);
170 }
171 
172 #define	GETETHER
173 #endif /* __NetBSD__ */
174 
175 
176 #ifdef	SVR4
177 /*
178  * This is for "Streams TCP/IP" by Lachman Associates.
179  * They sure made this cumbersome!  -gwr
180  */
181 
182 #include <sys/sockio.h>
183 #include <sys/dlpi.h>
184 #include <stropts.h>
185 #include <string.h>
186 
187 int
188 getether(ifname, eap)
189 	char *ifname;				/* interface name from ifconfig structure */
190 	char *eap;					/* Ether address (output) */
191 {
192 	int rc = -1;
193 	char devname[32];
194 	char tmpbuf[sizeof(union DL_primitives) + 16];
195 	struct strbuf cbuf;
196 	int fd, flags;
197 	union DL_primitives *dlp;
198 	char *enaddr;
199 	int unit = -1;				/* which unit to attach */
200 
201 	snprintf(devname, sizeof(devname), "%s%s", _PATH_DEV, ifname);
202 	fd = open(devname, 2);
203 	if (fd < 0) {
204 		/* Try without the trailing digit. */
205 		char *p = devname + 5;
206 		while (isalpha(*p))
207 			p++;
208 		if (isdigit(*p)) {
209 			unit = *p - '0';
210 			*p = '\0';
211 		}
212 		fd = open(devname, 2);
213 		if (fd < 0) {
214 			report(LOG_ERR, "getether: open %s: %s",
215 				   devname, get_errmsg());
216 			return rc;
217 		}
218 	}
219 #ifdef	DL_ATTACH_REQ
220 	/*
221 	 * If this is a "Style 2" DLPI, then we must "attach" first
222 	 * to tell the driver which unit (board, port) we want.
223 	 * For now, decide this based on the device name.
224 	 * (Should do "info_req" and check dl_provider_style ...)
225 	 */
226 	if (unit >= 0) {
227 		memset(tmpbuf, 0, sizeof(tmpbuf));
228 		dlp = (union DL_primitives *) tmpbuf;
229 		dlp->dl_primitive = DL_ATTACH_REQ;
230 		dlp->attach_req.dl_ppa = unit;
231 		cbuf.buf = tmpbuf;
232 		cbuf.len = DL_ATTACH_REQ_SIZE;
233 		if (putmsg(fd, &cbuf, NULL, 0) < 0) {
234 			report(LOG_ERR, "getether: attach: putmsg: %s", get_errmsg());
235 			goto out;
236 		}
237 		/* Recv the ack. */
238 		cbuf.buf = tmpbuf;
239 		cbuf.maxlen = sizeof(tmpbuf);
240 		flags = 0;
241 		if (getmsg(fd, &cbuf, NULL, &flags) < 0) {
242 			report(LOG_ERR, "getether: attach: getmsg: %s", get_errmsg());
243 			goto out;
244 		}
245 		/*
246 		 * Check the type, etc.
247 		 */
248 		if (dlp->dl_primitive == DL_ERROR_ACK) {
249 			report(LOG_ERR, "getether: attach: dlpi_errno=%d, unix_errno=%d",
250 				   dlp->error_ack.dl_errno,
251 				   dlp->error_ack.dl_unix_errno);
252 			goto out;
253 		}
254 		if (dlp->dl_primitive != DL_OK_ACK) {
255 			report(LOG_ERR, "getether: attach: not OK or ERROR");
256 			goto out;
257 		}
258 	} /* unit >= 0 */
259 #endif	/* DL_ATTACH_REQ */
260 
261 	/*
262 	 * Get the Ethernet address the same way the ARP module
263 	 * does when it is pushed onto a new stream (bind).
264 	 * One should instead be able just do an dl_info_req
265 	 * but many drivers do not supply the hardware address
266 	 * in the response to dl_info_req (they MUST supply it
267 	 * for dl_bind_ack because the ARP module requires it).
268 	 */
269 	memset(tmpbuf, 0, sizeof(tmpbuf));
270 	dlp = (union DL_primitives *) tmpbuf;
271 	dlp->dl_primitive = DL_BIND_REQ;
272 	dlp->bind_req.dl_sap = 0x8FF;	/* XXX - Unused SAP */
273 	cbuf.buf = tmpbuf;
274 	cbuf.len = DL_BIND_REQ_SIZE;
275 	if (putmsg(fd, &cbuf, NULL, 0) < 0) {
276 		report(LOG_ERR, "getether: bind: putmsg: %s", get_errmsg());
277 		goto out;
278 	}
279 	/* Recv the ack. */
280 	cbuf.buf = tmpbuf;
281 	cbuf.maxlen = sizeof(tmpbuf);
282 	flags = 0;
283 	if (getmsg(fd, &cbuf, NULL, &flags) < 0) {
284 		report(LOG_ERR, "getether: bind: getmsg: %s", get_errmsg());
285 		goto out;
286 	}
287 	/*
288 	 * Check the type, etc.
289 	 */
290 	if (dlp->dl_primitive == DL_ERROR_ACK) {
291 		report(LOG_ERR, "getether: bind: dlpi_errno=%d, unix_errno=%d",
292 			   dlp->error_ack.dl_errno,
293 			   dlp->error_ack.dl_unix_errno);
294 		goto out;
295 	}
296 	if (dlp->dl_primitive != DL_BIND_ACK) {
297 		report(LOG_ERR, "getether: bind: not OK or ERROR");
298 		goto out;
299 	}
300 	if (dlp->bind_ack.dl_addr_offset == 0) {
301 		report(LOG_ERR, "getether: bind: ack has no address");
302 		goto out;
303 	}
304 	if (dlp->bind_ack.dl_addr_length < EALEN) {
305 		report(LOG_ERR, "getether: bind: ack address truncated");
306 		goto out;
307 	}
308 	/*
309 	 * Copy the Ethernet address out of the message.
310 	 */
311 	enaddr = tmpbuf + dlp->bind_ack.dl_addr_offset;
312 	memcpy(eap, enaddr, EALEN);
313 	rc = 0;
314 
315   out:
316 	close(fd);
317 	return rc;
318 }
319 
320 #define	GETETHER
321 #endif /* SVR4 */
322 
323 
324 #ifdef	__linux__
325 /*
326  * This is really easy on Linux!  This version (for linux)
327  * written by Nigel Metheringham <nigelm@ohm.york.ac.uk> and
328  * updated by Pauline Middelink <middelin@polyware.iaf.nl>
329  *
330  * The code is almost identical to the Ultrix code - however
331  * the names are different to confuse the innocent :-)
332  * Most of this code was stolen from the Ultrix bit above.
333  */
334 
335 #include <memory.h>
336 #include <sys/ioctl.h>
337 #include <net/if.h>	       	/* struct ifreq */
338 #include <sys/socketio.h>	/* Needed for IOCTL defs */
339 
340 int
341 getether(ifname, eap)
342 	char *ifname, *eap;
343 {
344 	int rc = -1;
345 	int fd;
346 	struct ifreq phys;
347 
348 	memset(&phys, 0, sizeof(phys));
349 	strcpy(phys.ifr_name, ifname);
350 	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
351 		report(LOG_ERR, "getether: socket(INET,DGRAM) failed");
352 		return -1;
353 	}
354 	if (ioctl(fd, SIOCGIFHWADDR, &phys) < 0) {
355 		report(LOG_ERR, "getether: ioctl SIOCGIFHWADDR failed");
356 	} else {
357 		memcpy(eap, &phys.ifr_hwaddr.sa_data, EALEN);
358 		rc = 0;
359 	}
360 	close(fd);
361 	return rc;
362 }
363 
364 #define	GETETHER
365 #endif	/* __linux__ */
366 
367 
368 /* If we don't know how on this system, just return an error. */
369 #ifndef	GETETHER
370 int
371 getether(ifname, eap)
372 	char *ifname, *eap;
373 {
374 	return -1;
375 }
376 
377 #endif /* !GETETHER */
378 
379 /*
380  * Local Variables:
381  * tab-width: 4
382  * c-indent-level: 4
383  * c-argdecl-indent: 4
384  * c-continued-statement-offset: 4
385  * c-continued-brace-offset: -4
386  * c-label-offset: -4
387  * c-brace-offset: 0
388  * End:
389  */
390