xref: /illumos-gate/usr/src/uts/common/xen/io/xnbo.c (revision 2850d85b7b93f31e578520dc3b3feb24db609c62)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Xen network backend - mac client edition.
31  *
32  * A driver that sits above an existing GLDv3/Nemo MAC driver and
33  * relays packets to/from that driver from/to a guest domain.
34  */
35 
36 #include "xnb.h"
37 
38 #include <sys/sunddi.h>
39 #include <sys/modctl.h>
40 #include <sys/strsubr.h>
41 #include <sys/mac.h>
42 #include <net/if.h>
43 #include <sys/dlpi.h>
44 #include <sys/pattr.h>
45 #include <xen/sys/xenbus_impl.h>
46 #include <xen/sys/xendev.h>
47 
48 typedef struct xnbo {
49 	mac_handle_t		o_mh;
50 	mac_rx_handle_t		o_mrh;
51 	const mac_txinfo_t	*o_mtx;
52 	mac_notify_handle_t	o_mnh;
53 	boolean_t		o_running;
54 	boolean_t		o_promiscuous;
55 	uint32_t		o_hcksum_capab;
56 } xnbo_t;
57 
58 static void xnbo_close_mac(xnbo_t *);
59 
60 /*
61  * Packets from the peer come here.  We pass them to the mac device.
62  */
63 static void
64 xnbo_to_mac(xnb_t *xnbp, mblk_t *mp)
65 {
66 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
67 
68 	ASSERT(mp != NULL);
69 
70 	if (!xnbop->o_running) {
71 		xnbp->xnb_stat_rx_too_early++;
72 		goto fail;
73 	}
74 
75 	mp = xnbop->o_mtx->mt_fn(xnbop->o_mtx->mt_arg, mp);
76 
77 	if (mp != NULL) {
78 		xnbp->xnb_stat_mac_full++;
79 		goto fail;
80 	}
81 
82 	return;
83 
84 fail:
85 	freemsgchain(mp);
86 }
87 
88 static mblk_t *
89 xnbo_cksum_from_peer(xnb_t *xnbp, mblk_t *mp, uint16_t flags)
90 {
91 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
92 
93 	ASSERT(mp->b_next == NULL);
94 
95 	if ((flags & NETTXF_csum_blank) != 0) {
96 		/*
97 		 * It would be nice to ASSERT that xnbp->xnb_cksum_offload
98 		 * is TRUE here, but some peers insist on assuming
99 		 * that it is available even when they have been told
100 		 * otherwise.
101 		 *
102 		 * The checksum in the packet is blank.  Determine
103 		 * whether we can do hardware offload and, if so,
104 		 * update the flags on the mblk according.  If not,
105 		 * calculate and insert the checksum using software.
106 		 */
107 		mp = xnb_process_cksum_flags(xnbp, mp,
108 		    xnbop->o_hcksum_capab);
109 	}
110 
111 	return (mp);
112 }
113 
114 static uint16_t
115 xnbo_cksum_to_peer(xnb_t *xnbp, mblk_t *mp)
116 {
117 	uint16_t r = 0;
118 
119 	/*
120 	 * We might also check for HCK_PARTIALCKSUM here and,
121 	 * providing that the partial checksum covers the TCP/UDP
122 	 * payload, return NETRXF_data_validated.
123 	 *
124 	 * It seems that it's probably not worthwhile, as even MAC
125 	 * devices which advertise HCKSUM_INET_PARTIAL in their
126 	 * capabilities tend to use HCK_FULLCKSUM on the receive side
127 	 * - they are actually saying that in the output path the
128 	 * caller must use HCK_PARTIALCKSUM.
129 	 */
130 
131 	if (xnbp->xnb_cksum_offload) {
132 		uint32_t pflags, csum;
133 
134 		/*
135 		 * XXPV dme: Pull in improved hcksum_retrieve() from
136 		 * Crossbow, which gives back the csum in the seventh
137 		 * argument for HCK_FULLCKSUM.
138 		 */
139 		hcksum_retrieve(mp, NULL, NULL, NULL, NULL,
140 		    NULL, NULL, &pflags);
141 		csum = DB_CKSUM16(mp);
142 
143 		/*
144 		 * If the MAC driver has asserted that the checksum is
145 		 * good, let the peer know.
146 		 */
147 		if (((pflags & HCK_FULLCKSUM) != 0) &&
148 		    (((pflags & HCK_FULLCKSUM_OK) != 0) ||
149 		    (csum == 0xffff)))
150 			r |= NETRXF_data_validated;
151 	}
152 
153 	return (r);
154 }
155 
156 /*
157  * Packets from the mac device come here.  We pass them to the peer.
158  */
159 /*ARGSUSED*/
160 static void
161 xnbo_from_mac(void *arg, mac_resource_handle_t mrh, mblk_t *mp)
162 {
163 	xnb_t *xnbp = arg;
164 
165 	mp = xnb_copy_to_peer(xnbp, mp);
166 
167 	if (mp != NULL)
168 		freemsgchain(mp);
169 }
170 
171 /*
172  * Packets from the mac device come here. We pass them to the peer if
173  * the destination mac address matches or it's a multicast/broadcast
174  * address.
175  */
176 /*ARGSUSED*/
177 static void
178 xnbo_from_mac_filter(void *arg, mac_resource_handle_t mrh, mblk_t *mp)
179 {
180 	xnb_t *xnbp = arg;
181 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
182 	mblk_t *next, *keep, *keep_head, *free, *free_head;
183 
184 	keep = keep_head = free = free_head = NULL;
185 
186 #define	ADD(list, bp)				\
187 	if (list != NULL)			\
188 		list->b_next = bp;		\
189 	else					\
190 		list##_head = bp;		\
191 	list = bp;
192 
193 	for (; mp != NULL; mp = next) {
194 		mac_header_info_t hdr_info;
195 
196 		next = mp->b_next;
197 		mp->b_next = NULL;
198 
199 		if (mac_header_info(xnbop->o_mh, mp, &hdr_info) != 0) {
200 			ADD(free, mp);
201 			continue;
202 		}
203 
204 		if ((hdr_info.mhi_dsttype == MAC_ADDRTYPE_BROADCAST) ||
205 		    (hdr_info.mhi_dsttype == MAC_ADDRTYPE_MULTICAST)) {
206 			ADD(keep, mp);
207 			continue;
208 		}
209 
210 		if (bcmp(hdr_info.mhi_daddr, xnbp->xnb_mac_addr,
211 		    sizeof (xnbp->xnb_mac_addr)) == 0) {
212 			ADD(keep, mp);
213 			continue;
214 		}
215 
216 		ADD(free, mp);
217 	}
218 #undef	ADD
219 
220 	if (keep_head != NULL)
221 		xnbo_from_mac(xnbp, mrh, keep_head);
222 
223 	if (free_head != NULL)
224 		freemsgchain(free_head);
225 }
226 
227 static void
228 xnbo_notify(void *arg, mac_notify_type_t type)
229 {
230 	xnb_t *xnbp = arg;
231 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
232 
233 	switch (type) {
234 	case MAC_NOTE_PROMISC:
235 		xnbop->o_mtx = mac_tx_get(xnbop->o_mh);
236 		break;
237 	}
238 }
239 
240 static boolean_t
241 xnbo_open_mac(xnb_t *xnbp, char *mac)
242 {
243 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
244 	int err, need_rx_filter, need_setphysaddr, need_promiscuous;
245 	const mac_info_t *mi;
246 	char *xsname;
247 	void (*rx_fn)(void *, mac_resource_handle_t, mblk_t *);
248 
249 	xsname = xvdi_get_xsname(xnbp->xnb_devinfo);
250 
251 	if ((err = mac_open(mac, &xnbop->o_mh)) != 0) {
252 		cmn_err(CE_WARN, "xnbo_open_mac: "
253 		    "cannot open mac device %s (%d)", mac, err);
254 		return (B_FALSE);
255 	}
256 	ASSERT(xnbop->o_mh != NULL);
257 
258 	mi = mac_info(xnbop->o_mh);
259 	ASSERT(mi != NULL);
260 
261 	if (mi->mi_media != DL_ETHER) {
262 		cmn_err(CE_WARN, "xnbo_open_mac: "
263 		    "mac device is not DL_ETHER (%d)", mi->mi_media);
264 		xnbo_close_mac(xnbop);
265 		return (B_FALSE);
266 	}
267 	if (mi->mi_media != mi->mi_nativemedia) {
268 		cmn_err(CE_WARN, "xnbo_open_mac: "
269 		    "mac device media and native media mismatch (%d != %d)",
270 		    mi->mi_media, mi->mi_nativemedia);
271 		xnbo_close_mac(xnbop);
272 		return (B_FALSE);
273 	}
274 	if (mi->mi_sdu_max > XNBMAXPKT) {
275 		cmn_err(CE_WARN, "xnbo_open_mac: "
276 		    "mac device SDU too big (%d)", mi->mi_sdu_max);
277 		xnbo_close_mac(xnbop);
278 		return (B_FALSE);
279 	}
280 
281 	xnbop->o_mnh = mac_notify_add(xnbop->o_mh, xnbo_notify, xnbp);
282 	ASSERT(xnbop->o_mnh != NULL);
283 
284 	/*
285 	 * Should the receive path filter packets from the downstream
286 	 * NIC before passing them to the peer? The default is "no".
287 	 */
288 	if (xenbus_scanf(XBT_NULL, xsname,
289 	    "SUNW-need-rx-filter", "%d", &need_rx_filter) != 0)
290 		need_rx_filter = 0;
291 	if (need_rx_filter > 0)
292 		rx_fn = xnbo_from_mac_filter;
293 	else
294 		rx_fn = xnbo_from_mac;
295 
296 	xnbop->o_mrh = mac_rx_add(xnbop->o_mh, rx_fn, xnbp);
297 	ASSERT(xnbop->o_mrh != NULL);
298 
299 	xnbop->o_mtx = mac_tx_get(xnbop->o_mh);
300 	ASSERT(xnbop->o_mtx != NULL);
301 
302 	if (!mac_capab_get(xnbop->o_mh, MAC_CAPAB_HCKSUM,
303 	    &xnbop->o_hcksum_capab))
304 		xnbop->o_hcksum_capab = 0;
305 
306 	/*
307 	 * Should we set the physical address of the underlying NIC
308 	 * to match that assigned to the peer? The default is "no".
309 	 */
310 	if (xenbus_scanf(XBT_NULL, xsname,
311 	    "SUNW-need-set-physaddr", "%d", &need_setphysaddr) != 0)
312 		need_setphysaddr = 0;
313 	if (need_setphysaddr > 0) {
314 		struct ether_addr ea;
315 
316 		err = mac_unicst_set(xnbop->o_mh, xnbp->xnb_mac_addr);
317 		/* Warn, but continue on. */
318 		if (err != 0) {
319 			bcopy(xnbp->xnb_mac_addr, ea.ether_addr_octet,
320 			    ETHERADDRL);
321 			cmn_err(CE_WARN, "xnbo_open_mac: "
322 			    "cannot set MAC address of %s to "
323 			    "%s: %d", mac, ether_sprintf(&ea),
324 			    err);
325 		}
326 	}
327 
328 	/*
329 	 * Should we set the underlying NIC into promiscuous mode? The
330 	 * default is "no".
331 	 */
332 	if (xenbus_scanf(XBT_NULL, xsname,
333 	    "SUNW-need-promiscuous", "%d", &need_promiscuous) != 0)
334 		need_promiscuous = 0;
335 	if (need_promiscuous > 0) {
336 		err = mac_promisc_set(xnbop->o_mh, B_TRUE, MAC_DEVPROMISC);
337 		if (err != 0) {
338 			cmn_err(CE_WARN, "xnbo_open_mac: "
339 			    "cannot enable promiscuous mode of %s: %d",
340 			    mac, err);
341 			xnbo_close_mac(xnbop);
342 			return (B_FALSE);
343 		}
344 		xnbop->o_promiscuous = B_TRUE;
345 	}
346 
347 	if ((err = mac_start(xnbop->o_mh)) != 0) {
348 		cmn_err(CE_WARN, "xnbo_open_mac: "
349 		    "cannot start mac device (%d)", err);
350 		xnbo_close_mac(xnbop);
351 		return (B_FALSE);
352 	}
353 	xnbop->o_running = B_TRUE;
354 
355 	return (B_TRUE);
356 }
357 
358 /*
359  * xnb calls back here when the user-level hotplug code reports that
360  * the hotplug has successfully completed. For this flavour that means
361  * that the underlying MAC device that we will use is ready to be
362  * opened.
363  */
364 static boolean_t
365 xnbo_hotplug(xnb_t *xnbp)
366 {
367 	char *xsname;
368 	char mac[LIFNAMSIZ];
369 
370 	xsname = xvdi_get_xsname(xnbp->xnb_devinfo);
371 	if (xenbus_scanf(XBT_NULL, xsname, "nic", "%s", mac) != 0) {
372 		cmn_err(CE_WARN, "xnbo_hotplug: "
373 		    "cannot read nic name from %s", xsname);
374 		return (B_FALSE);
375 	}
376 
377 	return (xnbo_open_mac(xnbp, mac));
378 }
379 
380 static void
381 xnbo_close_mac(xnbo_t *xnbop)
382 {
383 	if (xnbop->o_mh == NULL)
384 		return;
385 
386 	if (xnbop->o_running) {
387 		mac_stop(xnbop->o_mh);
388 		xnbop->o_running = B_FALSE;
389 	}
390 
391 	if (xnbop->o_promiscuous) {
392 		(void) mac_promisc_set(xnbop->o_mh, B_FALSE,
393 		    MAC_DEVPROMISC);
394 		xnbop->o_promiscuous = B_FALSE;
395 	}
396 
397 	xnbop->o_mtx = NULL;
398 
399 	if (xnbop->o_mrh != NULL) {
400 		mac_rx_remove(xnbop->o_mh, xnbop->o_mrh, B_TRUE);
401 		xnbop->o_mrh = NULL;
402 	}
403 
404 	if (xnbop->o_mnh != NULL) {
405 		mac_notify_remove(xnbop->o_mh, xnbop->o_mnh);
406 		xnbop->o_mnh = NULL;
407 	}
408 
409 	mac_close(xnbop->o_mh);
410 	xnbop->o_mh = NULL;
411 }
412 
413 /*
414  * xnb calls back here when we successfully synchronize with the
415  * driver in the guest domain. In this flavour there is nothing to do as
416  * we open the underlying MAC device on successful hotplug completion.
417  */
418 /*ARGSUSED*/
419 static void
420 xnbo_connected(xnb_t *xnbp)
421 {
422 }
423 
424 /*
425  * xnb calls back here when the driver in the guest domain has closed
426  * down the inter-domain connection. We close the underlying MAC device.
427  */
428 static void
429 xnbo_disconnected(xnb_t *xnbp)
430 {
431 	xnbo_close_mac(xnbp->xnb_flavour_data);
432 }
433 
434 static int
435 xnbo_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
436 {
437 	static xnb_flavour_t flavour = {
438 		xnbo_to_mac, xnbo_connected, xnbo_disconnected, xnbo_hotplug,
439 		xnbo_cksum_from_peer, xnbo_cksum_to_peer,
440 	};
441 	xnbo_t *xnbop;
442 
443 	switch (cmd) {
444 	case DDI_ATTACH:
445 		break;
446 	case DDI_RESUME:
447 		return (DDI_SUCCESS);
448 	default:
449 		return (DDI_FAILURE);
450 	}
451 
452 	xnbop = kmem_zalloc(sizeof (*xnbop), KM_SLEEP);
453 
454 	xnbop->o_mh = NULL;
455 	xnbop->o_mrh = NULL;
456 	xnbop->o_mtx = NULL;
457 	xnbop->o_running = B_FALSE;
458 	xnbop->o_hcksum_capab = 0;
459 
460 	if (xnb_attach(dip, &flavour, xnbop) != DDI_SUCCESS) {
461 		kmem_free(xnbop, sizeof (*xnbop));
462 		return (DDI_FAILURE);
463 	}
464 
465 	return (DDI_SUCCESS);
466 }
467 
468 static int
469 xnbo_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
470 {
471 	xnb_t *xnbp = ddi_get_driver_private(dip);
472 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
473 
474 	switch (cmd) {
475 	case DDI_DETACH:
476 		break;
477 	case DDI_SUSPEND:
478 		return (DDI_SUCCESS);
479 	default:
480 		return (DDI_FAILURE);
481 	}
482 
483 	mutex_enter(&xnbp->xnb_tx_lock);
484 	mutex_enter(&xnbp->xnb_rx_lock);
485 
486 	if (!xnbp->xnb_detachable || xnbp->xnb_connected ||
487 	    (xnbp->xnb_rx_buf_count > 0)) {
488 		mutex_exit(&xnbp->xnb_rx_lock);
489 		mutex_exit(&xnbp->xnb_tx_lock);
490 
491 		return (DDI_FAILURE);
492 	}
493 
494 	mutex_exit(&xnbp->xnb_rx_lock);
495 	mutex_exit(&xnbp->xnb_tx_lock);
496 
497 	xnbo_close_mac(xnbop);
498 	kmem_free(xnbop, sizeof (*xnbop));
499 
500 	xnb_detach(dip);
501 
502 	return (DDI_SUCCESS);
503 }
504 
505 static struct cb_ops cb_ops = {
506 	nulldev,		/* open */
507 	nulldev,		/* close */
508 	nodev,			/* strategy */
509 	nodev,			/* print */
510 	nodev,			/* dump */
511 	nodev,			/* read */
512 	nodev,			/* write */
513 	nodev,			/* ioctl */
514 	nodev,			/* devmap */
515 	nodev,			/* mmap */
516 	nodev,			/* segmap */
517 	nochpoll,		/* poll */
518 	ddi_prop_op,		/* cb_prop_op */
519 	0,			/* streamtab  */
520 	D_NEW | D_MP | D_64BIT	/* Driver compatibility flag */
521 };
522 
523 static struct dev_ops ops = {
524 	DEVO_REV,		/* devo_rev */
525 	0,			/* devo_refcnt  */
526 	nulldev,		/* devo_getinfo */
527 	nulldev,		/* devo_identify */
528 	nulldev,		/* devo_probe */
529 	xnbo_attach,		/* devo_attach */
530 	xnbo_detach,		/* devo_detach */
531 	nodev,			/* devo_reset */
532 	&cb_ops,		/* devo_cb_ops */
533 	(struct bus_ops *)0,	/* devo_bus_ops */
534 	NULL			/* devo_power */
535 };
536 
537 static struct modldrv modldrv = {
538 	&mod_driverops, "xnbo driver %I%", &ops,
539 };
540 
541 static struct modlinkage modlinkage = {
542 	MODREV_1, &modldrv, NULL
543 };
544 
545 int
546 _init(void)
547 {
548 	return (mod_install(&modlinkage));
549 }
550 
551 int
552 _info(struct modinfo *modinfop)
553 {
554 	return (mod_info(&modlinkage, modinfop));
555 }
556 
557 int
558 _fini(void)
559 {
560 	return (mod_remove(&modlinkage));
561 }
562