xref: /titanic_41/usr/src/uts/common/xen/io/xnbo.c (revision 0f1702c5201310f0529cd5abb77652e5e9b241b6)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Xen network backend - mac client edition.
29  *
30  * A driver that sits above an existing GLDv3/Nemo MAC driver and
31  * relays packets to/from that driver from/to a guest domain.
32  */
33 
34 #include "xnb.h"
35 
36 #include <sys/sunddi.h>
37 #include <sys/ddi.h>
38 #include <sys/modctl.h>
39 #include <sys/strsubr.h>
40 #include <sys/mac_client.h>
41 #include <sys/mac_provider.h>
42 #include <sys/mac_client_priv.h>
43 #include <sys/mac.h>
44 #include <net/if.h>
45 #include <sys/dlpi.h>
46 #include <sys/pattr.h>
47 #include <xen/sys/xenbus_impl.h>
48 #include <xen/sys/xendev.h>
49 
50 typedef struct xnbo {
51 	mac_handle_t		o_mh;
52 	mac_client_handle_t	o_mch;
53 	mac_unicast_handle_t	o_mah;
54 	mac_promisc_handle_t	o_mphp;
55 	boolean_t		o_running;
56 	boolean_t		o_promiscuous;
57 	uint32_t		o_hcksum_capab;
58 } xnbo_t;
59 
60 static void xnbo_close_mac(xnbo_t *);
61 
62 /*
63  * Packets from the peer come here.  We pass them to the mac device.
64  */
65 static void
66 xnbo_to_mac(xnb_t *xnbp, mblk_t *mp)
67 {
68 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
69 
70 	ASSERT(mp != NULL);
71 
72 	if (!xnbop->o_running) {
73 		xnbp->xnb_stat_tx_too_early++;
74 		goto fail;
75 	}
76 
77 	if (mac_tx(xnbop->o_mch, mp, 0,
78 	    MAC_DROP_ON_NO_DESC, NULL) != NULL) {
79 		xnbp->xnb_stat_mac_full++;
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     boolean_t loopback)
163 {
164 	xnb_t *xnbp = arg;
165 
166 	mp = xnb_copy_to_peer(xnbp, mp);
167 
168 	if (mp != NULL)
169 		freemsgchain(mp);
170 }
171 
172 /*
173  * Packets from the mac device come here. We pass them to the peer if
174  * the destination mac address matches or it's a multicast/broadcast
175  * address.
176  */
177 /*ARGSUSED*/
178 static void
179 xnbo_from_mac_filter(void *arg, mac_resource_handle_t mrh, mblk_t *mp,
180     boolean_t loopback)
181 {
182 	xnb_t *xnbp = arg;
183 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
184 	mblk_t *next, *keep, *keep_head, *free, *free_head;
185 
186 	keep = keep_head = free = free_head = NULL;
187 
188 #define	ADD(list, bp)				\
189 	if (list != NULL)			\
190 		list->b_next = bp;		\
191 	else					\
192 		list##_head = bp;		\
193 	list = bp;
194 
195 	for (; mp != NULL; mp = next) {
196 		mac_header_info_t hdr_info;
197 
198 		next = mp->b_next;
199 		mp->b_next = NULL;
200 
201 		if (mac_header_info(xnbop->o_mh, mp, &hdr_info) != 0) {
202 			ADD(free, mp);
203 			continue;
204 		}
205 
206 		if ((hdr_info.mhi_dsttype == MAC_ADDRTYPE_BROADCAST) ||
207 		    (hdr_info.mhi_dsttype == MAC_ADDRTYPE_MULTICAST)) {
208 			ADD(keep, mp);
209 			continue;
210 		}
211 
212 		if (bcmp(hdr_info.mhi_daddr, xnbp->xnb_mac_addr,
213 		    sizeof (xnbp->xnb_mac_addr)) == 0) {
214 			ADD(keep, mp);
215 			continue;
216 		}
217 
218 		ADD(free, mp);
219 	}
220 #undef	ADD
221 
222 	if (keep_head != NULL)
223 		xnbo_from_mac(xnbp, mrh, keep_head, B_FALSE);
224 
225 	if (free_head != NULL)
226 		freemsgchain(free_head);
227 }
228 
229 static boolean_t
230 xnbo_open_mac(xnb_t *xnbp, char *mac)
231 {
232 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
233 	int err, need_rx_filter, need_setphysaddr, need_promiscuous;
234 	const mac_info_t *mi;
235 	char *xsname;
236 	void (*rx_fn)(void *, mac_resource_handle_t, mblk_t *, boolean_t);
237 	struct ether_addr ea;
238 	uint_t max_sdu;
239 	mac_diag_t diag;
240 
241 	xsname = xvdi_get_xsname(xnbp->xnb_devinfo);
242 
243 	if ((err = mac_open_by_linkname(mac, &xnbop->o_mh)) != 0) {
244 		cmn_err(CE_WARN, "xnbo_open_mac: "
245 		    "cannot open mac for link %s (%d)", mac, err);
246 		return (B_FALSE);
247 	}
248 	ASSERT(xnbop->o_mh != NULL);
249 
250 	mi = mac_info(xnbop->o_mh);
251 	ASSERT(mi != NULL);
252 
253 	if (mi->mi_media != DL_ETHER) {
254 		cmn_err(CE_WARN, "xnbo_open_mac: "
255 		    "device is not DL_ETHER (%d)", mi->mi_media);
256 		xnbo_close_mac(xnbop);
257 		return (B_FALSE);
258 	}
259 	if (mi->mi_media != mi->mi_nativemedia) {
260 		cmn_err(CE_WARN, "xnbo_open_mac: "
261 		    "device media and native media mismatch (%d != %d)",
262 		    mi->mi_media, mi->mi_nativemedia);
263 		xnbo_close_mac(xnbop);
264 		return (B_FALSE);
265 	}
266 
267 	mac_sdu_get(xnbop->o_mh, NULL, &max_sdu);
268 	if (max_sdu > XNBMAXPKT) {
269 		cmn_err(CE_WARN, "xnbo_open_mac: mac device SDU too big (%d)",
270 		    max_sdu);
271 		xnbo_close_mac(xnbop);
272 		return (B_FALSE);
273 	}
274 
275 	if (mac_client_open(xnbop->o_mh, &xnbop->o_mch, NULL,
276 	    MAC_OPEN_FLAGS_USE_DATALINK_NAME) != 0) {
277 		cmn_err(CE_WARN, "xnbo_open_mac: "
278 		    "error (%d) opening mac client", err);
279 		xnbo_close_mac(xnbop);
280 		return (B_FALSE);
281 	}
282 
283 	err = mac_unicast_primary_add(xnbop->o_mch, &xnbop->o_mah, &diag);
284 	if (err != 0) {
285 		cmn_err(CE_WARN, "xnbo_open_mac: "
286 		    "failed to get the primary MAC address of "
287 		    "%s: %d", mac, err);
288 		xnbo_close_mac(xnbop);
289 		return (B_FALSE);
290 	}
291 
292 	/*
293 	 * Should the receive path filter packets from the downstream
294 	 * NIC before passing them to the peer? The default is "no".
295 	 */
296 	if (xenbus_scanf(XBT_NULL, xsname,
297 	    "SUNW-need-rx-filter", "%d", &need_rx_filter) != 0)
298 		need_rx_filter = 0;
299 	if (need_rx_filter > 0)
300 		rx_fn = xnbo_from_mac_filter;
301 	else
302 		rx_fn = xnbo_from_mac;
303 
304 	/*
305 	 * Should we set the underlying NIC into promiscuous mode? The
306 	 * default is "no".
307 	 */
308 	if (xenbus_scanf(XBT_NULL, xsname,
309 	    "SUNW-need-promiscuous", "%d", &need_promiscuous) != 0)
310 		need_promiscuous = 0;
311 	if (need_promiscuous == 0) {
312 		mac_rx_set(xnbop->o_mch, rx_fn, xnbp);
313 	} else {
314 		err = mac_promisc_add(xnbop->o_mch, MAC_CLIENT_PROMISC_ALL,
315 		    rx_fn, xnbp, &xnbop->o_mphp, MAC_PROMISC_FLAGS_NO_TX_LOOP);
316 		if (err != 0) {
317 			cmn_err(CE_WARN, "xnbo_open_mac: "
318 			    "cannot enable promiscuous mode of %s: %d",
319 			    mac, err);
320 			xnbo_close_mac(xnbop);
321 			return (B_FALSE);
322 		}
323 		xnbop->o_promiscuous = B_TRUE;
324 	}
325 
326 	if (!mac_capab_get(xnbop->o_mh, MAC_CAPAB_HCKSUM,
327 	    &xnbop->o_hcksum_capab))
328 		xnbop->o_hcksum_capab = 0;
329 
330 	/*
331 	 * Should we set the physical address of the underlying NIC
332 	 * to match that assigned to the peer? The default is "no".
333 	 */
334 	if (xenbus_scanf(XBT_NULL, xsname,
335 	    "SUNW-need-set-physaddr", "%d", &need_setphysaddr) != 0)
336 		need_setphysaddr = 0;
337 	if (need_setphysaddr > 0) {
338 		err = mac_unicast_primary_set(xnbop->o_mh, xnbp->xnb_mac_addr);
339 		/* Warn, but continue on. */
340 		if (err != 0) {
341 			bcopy(xnbp->xnb_mac_addr, ea.ether_addr_octet,
342 			    ETHERADDRL);
343 			cmn_err(CE_WARN, "xnbo_open_mac: "
344 			    "cannot set MAC address of %s to "
345 			    "%s: %d", mac, ether_sprintf(&ea), err);
346 		}
347 	}
348 
349 	xnbop->o_running = B_TRUE;
350 
351 	return (B_TRUE);
352 }
353 
354 /*
355  * xnb calls back here when the user-level hotplug code reports that
356  * the hotplug has successfully completed. For this flavour that means
357  * that the underlying MAC device that we will use is ready to be
358  * opened.
359  */
360 static boolean_t
361 xnbo_hotplug(xnb_t *xnbp)
362 {
363 	char *xsname;
364 	char mac[LIFNAMSIZ];
365 
366 	xsname = xvdi_get_xsname(xnbp->xnb_devinfo);
367 	if (xenbus_scanf(XBT_NULL, xsname, "nic", "%s", mac) != 0) {
368 		cmn_err(CE_WARN, "xnbo_hotplug: "
369 		    "cannot read nic name from %s", xsname);
370 		return (B_FALSE);
371 	}
372 
373 	return (xnbo_open_mac(xnbp, mac));
374 }
375 
376 static void
377 xnbo_close_mac(xnbo_t *xnbop)
378 {
379 	if (xnbop->o_mh == NULL)
380 		return;
381 
382 	if (xnbop->o_running) {
383 		xnbop->o_running = B_FALSE;
384 	}
385 
386 	if (xnbop->o_promiscuous) {
387 		(void) mac_promisc_remove(xnbop->o_mphp);
388 		xnbop->o_promiscuous = B_FALSE;
389 	} else {
390 		mac_rx_clear(xnbop->o_mch);
391 	}
392 
393 	if (xnbop->o_mah != NULL) {
394 		(void) mac_unicast_remove(xnbop->o_mch, xnbop->o_mah);
395 		xnbop->o_mah = NULL;
396 	}
397 
398 	if (xnbop->o_mch != NULL) {
399 		mac_client_close(xnbop->o_mch, 0);
400 		xnbop->o_mch = NULL;
401 	}
402 
403 	mac_close(xnbop->o_mh);
404 	xnbop->o_mh = NULL;
405 }
406 
407 /*
408  * xnb calls back here when we successfully synchronize with the
409  * driver in the guest domain. In this flavour there is nothing to do as
410  * we open the underlying MAC device on successful hotplug completion.
411  */
412 /*ARGSUSED*/
413 static void
414 xnbo_connected(xnb_t *xnbp)
415 {
416 }
417 
418 /*
419  * xnb calls back here when the driver in the guest domain has closed
420  * down the inter-domain connection. We close the underlying MAC device.
421  */
422 static void
423 xnbo_disconnected(xnb_t *xnbp)
424 {
425 	xnbo_close_mac(xnbp->xnb_flavour_data);
426 }
427 
428 static int
429 xnbo_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
430 {
431 	static xnb_flavour_t flavour = {
432 		xnbo_to_mac, xnbo_connected, xnbo_disconnected, xnbo_hotplug,
433 		xnbo_cksum_from_peer, xnbo_cksum_to_peer,
434 	};
435 	xnbo_t *xnbop;
436 
437 	switch (cmd) {
438 	case DDI_ATTACH:
439 		break;
440 	case DDI_RESUME:
441 		return (DDI_SUCCESS);
442 	default:
443 		return (DDI_FAILURE);
444 	}
445 
446 	xnbop = kmem_zalloc(sizeof (*xnbop), KM_SLEEP);
447 
448 	xnbop->o_mh = NULL;
449 	xnbop->o_mch = NULL;
450 	xnbop->o_mah = NULL;
451 	xnbop->o_mphp = NULL;
452 	xnbop->o_running = B_FALSE;
453 	xnbop->o_hcksum_capab = 0;
454 
455 	if (xnb_attach(dip, &flavour, xnbop) != DDI_SUCCESS) {
456 		kmem_free(xnbop, sizeof (*xnbop));
457 		return (DDI_FAILURE);
458 	}
459 
460 	return (DDI_SUCCESS);
461 }
462 
463 static int
464 xnbo_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
465 {
466 	xnb_t *xnbp = ddi_get_driver_private(dip);
467 	xnbo_t *xnbop = xnbp->xnb_flavour_data;
468 
469 	switch (cmd) {
470 	case DDI_DETACH:
471 		break;
472 	case DDI_SUSPEND:
473 		return (DDI_SUCCESS);
474 	default:
475 		return (DDI_FAILURE);
476 	}
477 
478 	mutex_enter(&xnbp->xnb_tx_lock);
479 	mutex_enter(&xnbp->xnb_rx_lock);
480 
481 	if (!xnbp->xnb_detachable || xnbp->xnb_connected ||
482 	    (xnbp->xnb_tx_buf_count > 0)) {
483 		mutex_exit(&xnbp->xnb_rx_lock);
484 		mutex_exit(&xnbp->xnb_tx_lock);
485 
486 		return (DDI_FAILURE);
487 	}
488 
489 	mutex_exit(&xnbp->xnb_rx_lock);
490 	mutex_exit(&xnbp->xnb_tx_lock);
491 
492 	xnbo_close_mac(xnbop);
493 	kmem_free(xnbop, sizeof (*xnbop));
494 
495 	xnb_detach(dip);
496 
497 	return (DDI_SUCCESS);
498 }
499 
500 static struct cb_ops cb_ops = {
501 	nulldev,		/* open */
502 	nulldev,		/* close */
503 	nodev,			/* strategy */
504 	nodev,			/* print */
505 	nodev,			/* dump */
506 	nodev,			/* read */
507 	nodev,			/* write */
508 	nodev,			/* ioctl */
509 	nodev,			/* devmap */
510 	nodev,			/* mmap */
511 	nodev,			/* segmap */
512 	nochpoll,		/* poll */
513 	ddi_prop_op,		/* cb_prop_op */
514 	0,			/* streamtab  */
515 	D_NEW | D_MP | D_64BIT	/* Driver compatibility flag */
516 };
517 
518 static struct dev_ops ops = {
519 	DEVO_REV,		/* devo_rev */
520 	0,			/* devo_refcnt  */
521 	nulldev,		/* devo_getinfo */
522 	nulldev,		/* devo_identify */
523 	nulldev,		/* devo_probe */
524 	xnbo_attach,		/* devo_attach */
525 	xnbo_detach,		/* devo_detach */
526 	nodev,			/* devo_reset */
527 	&cb_ops,		/* devo_cb_ops */
528 	(struct bus_ops *)0,	/* devo_bus_ops */
529 	NULL,			/* devo_power */
530 	ddi_quiesce_not_needed,		/* devo_quiesce */
531 };
532 
533 static struct modldrv modldrv = {
534 	&mod_driverops, "xnbo driver", &ops,
535 };
536 
537 static struct modlinkage modlinkage = {
538 	MODREV_1, &modldrv, NULL
539 };
540 
541 int
542 _init(void)
543 {
544 	return (mod_install(&modlinkage));
545 }
546 
547 int
548 _info(struct modinfo *modinfop)
549 {
550 	return (mod_info(&modlinkage, modinfop));
551 }
552 
553 int
554 _fini(void)
555 {
556 	return (mod_remove(&modlinkage));
557 }
558