xref: /src/contrib/libpcap/pcap-libdlpi.c (revision 16cef5f7a65588def71db4fdfa961f959847e3b6)
1 /*
2  * Copyright (c) 1993, 1994, 1995, 1996, 1997
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  *
21  * This code contributed by Sagun Shakya (sagun.shakya@sun.com)
22  */
23 /*
24  * Packet capture routines for DLPI using libdlpi under SunOS 5.11.
25  */
26 
27 #include <config.h>
28 
29 #include <sys/types.h>
30 #include <sys/time.h>
31 #include <sys/bufmod.h>
32 #include <sys/stream.h>
33 #include <libdlpi.h>
34 #include <errno.h>
35 #include <memory.h>
36 #include <stropts.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 #include "pcap-int.h"
42 #include "dlpisubs.h"
43 
44 /* Forwards. */
45 static int dlpromiscon(pcap_t *, bpf_u_int32);
46 static int pcap_read_libdlpi(pcap_t *, int, pcap_handler, u_char *);
47 static int pcap_inject_libdlpi(pcap_t *, const void *, int);
48 static void pcap_libdlpi_err(const char *, const char *, int, char *);
49 static void pcap_cleanup_libdlpi(pcap_t *);
50 
51 /*
52  * list_interfaces() will list all the network links that are
53  * available on a system.
54  */
55 static boolean_t list_interfaces(const char *, void *);
56 
57 typedef struct linknamelist {
58 	char	linkname[DLPI_LINKNAME_MAX];
59 	struct linknamelist *lnl_next;
60 } linknamelist_t;
61 
62 typedef struct linkwalk {
63 	linknamelist_t	*lw_list;
64 	int		lw_err;
65 } linkwalk_t;
66 
67 /*
68  * The caller of this function should free the memory allocated
69  * for each linknamelist_t "entry" allocated.
70  */
71 static boolean_t
list_interfaces(const char * linkname,void * arg)72 list_interfaces(const char *linkname, void *arg)
73 {
74 	linkwalk_t	*lwp = arg;
75 	linknamelist_t	*entry;
76 
77 	if ((entry = calloc(1, sizeof(linknamelist_t))) == NULL) {
78 		lwp->lw_err = ENOMEM;
79 		return (B_TRUE);
80 	}
81 	(void) pcapint_strlcpy(entry->linkname, linkname, DLPI_LINKNAME_MAX);
82 
83 	if (lwp->lw_list == NULL) {
84 		lwp->lw_list = entry;
85 	} else {
86 		entry->lnl_next = lwp->lw_list;
87 		lwp->lw_list = entry;
88 	}
89 
90 	return (B_FALSE);
91 }
92 
93 static int
pcap_activate_libdlpi(pcap_t * p)94 pcap_activate_libdlpi(pcap_t *p)
95 {
96 	struct pcap_dlpi *pd = p->priv;
97 	int status = 0;
98 	int retv;
99 	dlpi_handle_t dh;
100 	dlpi_info_t dlinfo;
101 
102 	/*
103 	 * Enable Solaris raw and passive DLPI extensions;
104 	 * dlpi_open() will not fail if the underlying link does not support
105 	 * passive mode. See dlpi(7P) for details.
106 	 */
107 	retv = dlpi_open(p->opt.device, &dh, DLPI_RAW|DLPI_PASSIVE);
108 	if (retv != DLPI_SUCCESS) {
109 		if (retv == DLPI_ELINKNAMEINVAL) {
110 			/*
111 			 * The interface name is not syntactiacally
112 			 * valid, and thus doesn't correspond to
113 			 * an interface.
114 			 *
115 			 * There's nothing more to say, so clear the
116 			 * error message.
117 			 */
118 			status = PCAP_ERROR_NO_SUCH_DEVICE;
119 			p->errbuf[0] = '\0';
120 		} else if (retv == DLPI_ENOLINK) {
121 			/*
122 			 * The interface name is syntactically valid,
123 			 * but we don't have a DLPI device that
124 			 * would be used for that interface.
125 			 */
126 			status = handle_nonexistent_dlpi_device(p->opt.device,
127 			    p->errbuf);
128 		} else if (retv == DL_SYSERR &&
129 		    (errno == EPERM || errno == EACCES)) {
130 			/*
131 			 * We got EPERM or EACCES trying to open the
132 			 * DLPI device, so we know it exists.
133 			 */
134 			status = PCAP_ERROR_PERM_DENIED;
135 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
136 			    "Attempt to open DLPI device failed with %s - root privilege may be required",
137 			    (errno == EPERM) ? "EPERM" : "EACCES");
138 		} else {
139 			/*
140 			 * pcap_libdlpi_err() calls dlpi_strerror(),
141 			 * which handles DL_SYSERR.
142 			 *
143 			 * XXX - does DLPI_ERAWNOTSUP mean that the
144 			 * interface exists and supports DLPI but,
145 			 * as it doesn't support raw mode, it
146 			 * doesn't support packet capture?
147 			 *
148 			 * XXX - what does DLPI_EBADLINK mean?
149 			 */
150 			status = PCAP_ERROR;
151 			pcap_libdlpi_err(p->opt.device, "dlpi_open", retv,
152 			    p->errbuf);
153 		}
154 		return (status);
155 	}
156 	pd->dlpi_hd = dh;
157 
158 	if (p->opt.rfmon) {
159 		/*
160 		 * This device exists, but we don't support monitor mode
161 		 * on any platforms that support DLPI.
162 		 */
163 		status = PCAP_ERROR_RFMON_NOTSUP;
164 		goto bad;
165 	}
166 
167 	/* Bind with DLPI_ANY_SAP. */
168 	if ((retv = dlpi_bind(pd->dlpi_hd, DLPI_ANY_SAP, 0)) != DLPI_SUCCESS) {
169 		status = PCAP_ERROR;
170 		pcap_libdlpi_err(p->opt.device, "dlpi_bind", retv, p->errbuf);
171 		goto bad;
172 	}
173 
174 	/*
175 	 * Turn a negative snapshot value (invalid), a snapshot value of
176 	 * 0 (unspecified), or a value bigger than the normal maximum
177 	 * value, into the maximum allowed value.
178 	 *
179 	 * If some application really *needs* a bigger snapshot
180 	 * length, we should just increase MAXIMUM_SNAPLEN.
181 	 */
182 	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
183 		p->snapshot = MAXIMUM_SNAPLEN;
184 
185 	/* Enable promiscuous mode. */
186 	if (p->opt.promisc) {
187 		retv = dlpromiscon(p, DL_PROMISC_PHYS);
188 		if (retv < 0) {
189 			/*
190 			 * "You don't have permission to capture on
191 			 * this device" and "you don't have permission
192 			 * to capture in promiscuous mode on this
193 			 * device" are different; let the user know,
194 			 * so if they can't get permission to
195 			 * capture in promiscuous mode, they can at
196 			 * least try to capture in non-promiscuous
197 			 * mode.
198 			 *
199 			 * XXX - you might have to capture in
200 			 * promiscuous mode to see outgoing packets.
201 			 */
202 			if (retv == PCAP_ERROR_PERM_DENIED)
203 				status = PCAP_ERROR_PROMISC_PERM_DENIED;
204 			else
205 				status = retv;
206 			goto bad;
207 		}
208 	} else {
209 		/* Try to enable multicast. */
210 		retv = dlpromiscon(p, DL_PROMISC_MULTI);
211 		if (retv < 0) {
212 			status = retv;
213 			goto bad;
214 		}
215 	}
216 
217 	/* Try to enable SAP promiscuity. */
218 	retv = dlpromiscon(p, DL_PROMISC_SAP);
219 	if (retv < 0) {
220 		/*
221 		 * Not fatal, since the DL_PROMISC_PHYS mode worked.
222 		 * Report it as a warning, however.
223 		 */
224 		if (p->opt.promisc)
225 			status = PCAP_WARNING;
226 		else {
227 			status = retv;
228 			goto bad;
229 		}
230 	}
231 
232 	/* Determine link type.  */
233 	if ((retv = dlpi_info(pd->dlpi_hd, &dlinfo, 0)) != DLPI_SUCCESS) {
234 		status = PCAP_ERROR;
235 		pcap_libdlpi_err(p->opt.device, "dlpi_info", retv, p->errbuf);
236 		goto bad;
237 	}
238 
239 	if (pcap_process_mactype(p, dlinfo.di_mactype) != 0) {
240 		status = PCAP_ERROR;
241 		goto bad;
242 	}
243 
244 	p->fd = dlpi_fd(pd->dlpi_hd);
245 
246 	/* Push and configure bufmod. */
247 	if (pcap_conf_bufmod(p, p->snapshot) != 0) {
248 		status = PCAP_ERROR;
249 		goto bad;
250 	}
251 
252 	/*
253 	 * Flush the read side.
254 	 */
255 	if (ioctl(p->fd, I_FLUSH, FLUSHR) != 0) {
256 		status = PCAP_ERROR;
257 		pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
258 		    errno, "FLUSHR");
259 		goto bad;
260 	}
261 
262 	/* Allocate data buffer. */
263 	if (pcap_alloc_databuf(p) != 0) {
264 		status = PCAP_ERROR;
265 		goto bad;
266 	}
267 
268 	/*
269 	 * "p->fd" is a FD for a STREAMS device, so "select()" and
270 	 * "poll()" should work on it.
271 	 */
272 	p->selectable_fd = p->fd;
273 
274 	p->read_op = pcap_read_libdlpi;
275 	p->inject_op = pcap_inject_libdlpi;
276 	p->setfilter_op = pcapint_install_bpf_program;	/* No kernel filtering */
277 	p->setdirection_op = NULL;	/* Not implemented */
278 	p->set_datalink_op = NULL;	/* Can't change data link type */
279 	p->getnonblock_op = pcapint_getnonblock_fd;
280 	p->setnonblock_op = pcapint_setnonblock_fd;
281 	p->stats_op = pcap_stats_dlpi;
282 	p->cleanup_op = pcap_cleanup_libdlpi;
283 
284 	return (status);
285 bad:
286 	pcap_cleanup_libdlpi(p);
287 	return (status);
288 }
289 
290 #define STRINGIFY(n)	#n
291 
292 static int
dlpromiscon(pcap_t * p,bpf_u_int32 level)293 dlpromiscon(pcap_t *p, bpf_u_int32 level)
294 {
295 	struct pcap_dlpi *pd = p->priv;
296 	int retv;
297 	int err;
298 
299 	retv = dlpi_promiscon(pd->dlpi_hd, level);
300 	if (retv != DLPI_SUCCESS) {
301 		if (retv == DL_SYSERR &&
302 		    (errno == EPERM || errno == EACCES)) {
303 			if (level == DL_PROMISC_PHYS) {
304 				err = PCAP_ERROR_PROMISC_PERM_DENIED;
305 				snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
306 				    "Attempt to set promiscuous mode failed with %s - root privilege may be required",
307 				    (errno == EPERM) ? "EPERM" : "EACCES");
308 			} else {
309 				err = PCAP_ERROR_PERM_DENIED;
310 				snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
311 				    "Attempt to set %s mode failed with %s - root privilege may be required",
312 				    (level == DL_PROMISC_MULTI) ? "multicast" : "SAP promiscuous",
313 				    (errno == EPERM) ? "EPERM" : "EACCES");
314 			}
315 		} else {
316 			err = PCAP_ERROR;
317 			pcap_libdlpi_err(p->opt.device,
318 			    "dlpi_promiscon" STRINGIFY(level),
319 			    retv, p->errbuf);
320 		}
321 		return (err);
322 	}
323 	return (0);
324 }
325 
326 /*
327  * Presumably everything returned by dlpi_walk() is a DLPI device,
328  * so there's no work to be done here to check whether name refers
329  * to a DLPI device.
330  */
331 static int
is_dlpi_interface(const char * name _U_)332 is_dlpi_interface(const char *name _U_)
333 {
334 	return (1);
335 }
336 
337 static int
get_if_flags(const char * name _U_,bpf_u_int32 * flags _U_,char * errbuf _U_)338 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
339 {
340 	/*
341 	 * Nothing we can do other than mark loopback devices as "the
342 	 * connected/disconnected status doesn't apply".
343 	 *
344 	 * XXX - on Solaris, can we do what the dladm command does,
345 	 * i.e. get a connected/disconnected indication from a kstat?
346 	 * (Note that you can also get the link speed, and possibly
347 	 * other information, from a kstat as well.)
348 	 */
349 	if (*flags & PCAP_IF_LOOPBACK) {
350 		/*
351 		 * Loopback devices aren't wireless, and "connected"/
352 		 * "disconnected" doesn't apply to them.
353 		 */
354 		*flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
355 		return (0);
356 	}
357 	return (0);
358 }
359 
360 /*
361  * In Solaris, the "standard" mechanism" i.e SIOCGLIFCONF will only find
362  * network links that are plumbed and are up. dlpi_walk(3DLPI) will find
363  * additional network links present in the system.
364  */
365 int
pcapint_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)366 pcapint_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
367 {
368 	int retv = 0;
369 
370 	linknamelist_t	*entry, *next;
371 	linkwalk_t	lw = {NULL, 0};
372 	int		save_errno;
373 
374 	/*
375 	 * Get the list of regular interfaces first.
376 	 */
377 	if (pcapint_findalldevs_interfaces(devlistp, errbuf,
378 	    is_dlpi_interface, get_if_flags) == -1)
379 		return (-1);	/* failure */
380 
381 	/* dlpi_walk() for loopback will be added here. */
382 
383 	/*
384 	 * Find all DLPI devices in the current zone.
385 	 *
386 	 * XXX - will pcapint_findalldevs_interfaces() find any devices
387 	 * outside the current zone?  If not, the only reason to call
388 	 * it would be to get the interface addresses.
389 	 */
390 	dlpi_walk(list_interfaces, &lw, 0);
391 
392 	if (lw.lw_err != 0) {
393 		pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
394 		    lw.lw_err, "dlpi_walk");
395 		retv = -1;
396 		goto done;
397 	}
398 
399 	/* Add linkname if it does not exist on the list. */
400 	for (entry = lw.lw_list; entry != NULL; entry = entry->lnl_next) {
401 		/*
402 		 * If it isn't already in the list of devices, try to
403 		 * add it.
404 		 */
405 		if (pcapint_find_or_add_dev(devlistp, entry->linkname, 0, get_if_flags,
406 		    NULL, errbuf) == NULL)
407 			retv = -1;
408 	}
409 done:
410 	save_errno = errno;
411 	for (entry = lw.lw_list; entry != NULL; entry = next) {
412 		next = entry->lnl_next;
413 		free(entry);
414 	}
415 	errno = save_errno;
416 
417 	return (retv);
418 }
419 
420 /*
421  * Read data received on DLPI handle. Returns -2 if told to terminate, else
422  * returns the number of packets read.
423  */
424 static int
pcap_read_libdlpi(pcap_t * p,int count,pcap_handler callback,u_char * user)425 pcap_read_libdlpi(pcap_t *p, int count, pcap_handler callback, u_char *user)
426 {
427 	struct pcap_dlpi *pd = p->priv;
428 	int len;
429 	u_char *bufp;
430 	size_t msglen;
431 	int retv;
432 
433 	len = p->cc;
434 	if (len != 0) {
435 		bufp = p->bp;
436 		goto process_pkts;
437 	}
438 	do {
439 		/* Has "pcap_breakloop()" been called? */
440 		if (p->break_loop) {
441 			/*
442 			 * Yes - clear the flag that indicates that it has,
443 			 * and return -2 to indicate that we were told to
444 			 * break out of the loop.
445 			 */
446 			p->break_loop = 0;
447 			return (-2);
448 		}
449 
450 		msglen = p->bufsize;
451 		bufp = (u_char *)p->buffer + p->offset;
452 
453 		retv = dlpi_recv(pd->dlpi_hd, NULL, NULL, bufp,
454 		    &msglen, -1, NULL);
455 		if (retv != DLPI_SUCCESS) {
456 			/*
457 			 * This is most likely a call to terminate out of the
458 			 * loop. So, do not return an error message, instead
459 			 * check if "pcap_breakloop()" has been called above.
460 			 */
461 			if (retv == DL_SYSERR && errno == EINTR) {
462 				len = 0;
463 				continue;
464 			}
465 			pcap_libdlpi_err(dlpi_linkname(pd->dlpi_hd),
466 			    "dlpi_recv", retv, p->errbuf);
467 			return (-1);
468 		}
469 		len = msglen;
470 	} while (len == 0);
471 
472 process_pkts:
473 	return (pcap_process_pkts(p, callback, user, count, bufp, len));
474 }
475 
476 static int
pcap_inject_libdlpi(pcap_t * p,const void * buf,int size)477 pcap_inject_libdlpi(pcap_t *p, const void *buf, int size)
478 {
479 	struct pcap_dlpi *pd = p->priv;
480 	int retv;
481 
482 	retv = dlpi_send(pd->dlpi_hd, NULL, 0, buf, size, NULL);
483 	if (retv != DLPI_SUCCESS) {
484 		pcap_libdlpi_err(dlpi_linkname(pd->dlpi_hd), "dlpi_send", retv,
485 		    p->errbuf);
486 		return (-1);
487 	}
488 	/*
489 	 * dlpi_send(3DLPI) does not provide a way to return the number of
490 	 * bytes sent on the wire. Based on the fact that DLPI_SUCCESS was
491 	 * returned we are assuming 'size' bytes were sent.
492 	 */
493 	return (size);
494 }
495 
496 /*
497  * Close dlpi handle.
498  */
499 static void
pcap_cleanup_libdlpi(pcap_t * p)500 pcap_cleanup_libdlpi(pcap_t *p)
501 {
502 	struct pcap_dlpi *pd = p->priv;
503 
504 	if (pd->dlpi_hd != NULL) {
505 		dlpi_close(pd->dlpi_hd);
506 		pd->dlpi_hd = NULL;
507 		p->fd = -1;
508 	}
509 	pcapint_cleanup_live_common(p);
510 }
511 
512 /*
513  * Write error message to buffer.
514  */
515 static void
pcap_libdlpi_err(const char * linkname,const char * func,int err,char * errbuf)516 pcap_libdlpi_err(const char *linkname, const char *func, int err, char *errbuf)
517 {
518 	snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s failed on %s: %s",
519 	    func, linkname, dlpi_strerror(err));
520 }
521 
522 pcap_t *
pcapint_create_interface(const char * device _U_,char * ebuf)523 pcapint_create_interface(const char *device _U_, char *ebuf)
524 {
525 	pcap_t *p;
526 
527 	p = PCAP_CREATE_COMMON(ebuf, struct pcap_dlpi);
528 	if (p == NULL)
529 		return (NULL);
530 
531 	p->activate_op = pcap_activate_libdlpi;
532 	return (p);
533 }
534 
535 /*
536  * Libpcap version string.
537  */
538 const char *
pcap_lib_version(void)539 pcap_lib_version(void)
540 {
541 	return (PCAP_VERSION_STRING);
542 }
543