1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21#include "common.h"
22
23struct backend_info {
24 struct xenbus_device *dev;
25 struct xenvif *vif;
26
27
28
29
30 enum xenbus_state state;
31
32 enum xenbus_state frontend_state;
33 struct xenbus_watch hotplug_status_watch;
34 u8 have_hotplug_status_watch:1;
35};
36
37static int connect_rings(struct backend_info *);
38static void connect(struct backend_info *);
39static void backend_create_xenvif(struct backend_info *be);
40static void unregister_hotplug_status_watch(struct backend_info *be);
41static void set_backend_state(struct backend_info *be,
42 enum xenbus_state state);
43
44static int netback_remove(struct xenbus_device *dev)
45{
46 struct backend_info *be = dev_get_drvdata(&dev->dev);
47
48 set_backend_state(be, XenbusStateClosed);
49
50 unregister_hotplug_status_watch(be);
51 if (be->vif) {
52 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
53 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
54 xenvif_free(be->vif);
55 be->vif = NULL;
56 }
57 kfree(be);
58 dev_set_drvdata(&dev->dev, NULL);
59 return 0;
60}
61
62
63
64
65
66
67static int netback_probe(struct xenbus_device *dev,
68 const struct xenbus_device_id *id)
69{
70 const char *message;
71 struct xenbus_transaction xbt;
72 int err;
73 int sg;
74 struct backend_info *be = kzalloc(sizeof(struct backend_info),
75 GFP_KERNEL);
76 if (!be) {
77 xenbus_dev_fatal(dev, -ENOMEM,
78 "allocating backend structure");
79 return -ENOMEM;
80 }
81
82 be->dev = dev;
83 dev_set_drvdata(&dev->dev, be);
84
85 sg = 1;
86
87 do {
88 err = xenbus_transaction_start(&xbt);
89 if (err) {
90 xenbus_dev_fatal(dev, err, "starting transaction");
91 goto fail;
92 }
93
94 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
95 if (err) {
96 message = "writing feature-sg";
97 goto abort_transaction;
98 }
99
100 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
101 "%d", sg);
102 if (err) {
103 message = "writing feature-gso-tcpv4";
104 goto abort_transaction;
105 }
106
107 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
108 "%d", sg);
109 if (err) {
110 message = "writing feature-gso-tcpv6";
111 goto abort_transaction;
112 }
113
114
115 err = xenbus_printf(xbt, dev->nodename,
116 "feature-ipv6-csum-offload",
117 "%d", 1);
118 if (err) {
119 message = "writing feature-ipv6-csum-offload";
120 goto abort_transaction;
121 }
122
123
124 err = xenbus_printf(xbt, dev->nodename,
125 "feature-rx-copy", "%d", 1);
126 if (err) {
127 message = "writing feature-rx-copy";
128 goto abort_transaction;
129 }
130
131
132
133
134
135 err = xenbus_printf(xbt, dev->nodename,
136 "feature-rx-flip", "%d", 0);
137 if (err) {
138 message = "writing feature-rx-flip";
139 goto abort_transaction;
140 }
141
142 err = xenbus_transaction_end(xbt, 0);
143 } while (err == -EAGAIN);
144
145 if (err) {
146 xenbus_dev_fatal(dev, err, "completing transaction");
147 goto fail;
148 }
149
150
151
152
153
154 err = xenbus_printf(XBT_NIL, dev->nodename,
155 "feature-split-event-channels",
156 "%u", separate_tx_rx_irq);
157 if (err)
158 pr_debug("Error writing feature-split-event-channels\n");
159
160 err = xenbus_switch_state(dev, XenbusStateInitWait);
161 if (err)
162 goto fail;
163
164 be->state = XenbusStateInitWait;
165
166
167 backend_create_xenvif(be);
168
169 return 0;
170
171abort_transaction:
172 xenbus_transaction_end(xbt, 1);
173 xenbus_dev_fatal(dev, err, "%s", message);
174fail:
175 pr_debug("failed\n");
176 netback_remove(dev);
177 return err;
178}
179
180
181
182
183
184
185
186static int netback_uevent(struct xenbus_device *xdev,
187 struct kobj_uevent_env *env)
188{
189 struct backend_info *be = dev_get_drvdata(&xdev->dev);
190 char *val;
191
192 val = xenbus_read(XBT_NIL, xdev->nodename, "script", NULL);
193 if (IS_ERR(val)) {
194 int err = PTR_ERR(val);
195 xenbus_dev_fatal(xdev, err, "reading script");
196 return err;
197 } else {
198 if (add_uevent_var(env, "script=%s", val)) {
199 kfree(val);
200 return -ENOMEM;
201 }
202 kfree(val);
203 }
204
205 if (!be || !be->vif)
206 return 0;
207
208 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
209}
210
211
212static void backend_create_xenvif(struct backend_info *be)
213{
214 int err;
215 long handle;
216 struct xenbus_device *dev = be->dev;
217
218 if (be->vif != NULL)
219 return;
220
221 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
222 if (err != 1) {
223 xenbus_dev_fatal(dev, err, "reading handle");
224 return;
225 }
226
227 be->vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
228 if (IS_ERR(be->vif)) {
229 err = PTR_ERR(be->vif);
230 be->vif = NULL;
231 xenbus_dev_fatal(dev, err, "creating interface");
232 return;
233 }
234
235 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
236}
237
238static void backend_disconnect(struct backend_info *be)
239{
240 if (be->vif)
241 xenvif_disconnect(be->vif);
242}
243
244static void backend_connect(struct backend_info *be)
245{
246 if (be->vif)
247 connect(be);
248}
249
250static inline void backend_switch_state(struct backend_info *be,
251 enum xenbus_state state)
252{
253 struct xenbus_device *dev = be->dev;
254
255 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
256 be->state = state;
257
258
259
260
261 if (!be->have_hotplug_status_watch)
262 xenbus_switch_state(dev, state);
263}
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285static void set_backend_state(struct backend_info *be,
286 enum xenbus_state state)
287{
288 while (be->state != state) {
289 switch (be->state) {
290 case XenbusStateClosed:
291 switch (state) {
292 case XenbusStateInitWait:
293 case XenbusStateConnected:
294 pr_info("%s: prepare for reconnect\n",
295 be->dev->nodename);
296 backend_switch_state(be, XenbusStateInitWait);
297 break;
298 case XenbusStateClosing:
299 backend_switch_state(be, XenbusStateClosing);
300 break;
301 default:
302 BUG();
303 }
304 break;
305 case XenbusStateInitWait:
306 switch (state) {
307 case XenbusStateConnected:
308 backend_connect(be);
309 backend_switch_state(be, XenbusStateConnected);
310 break;
311 case XenbusStateClosing:
312 case XenbusStateClosed:
313 backend_switch_state(be, XenbusStateClosing);
314 break;
315 default:
316 BUG();
317 }
318 break;
319 case XenbusStateConnected:
320 switch (state) {
321 case XenbusStateInitWait:
322 case XenbusStateClosing:
323 case XenbusStateClosed:
324 backend_disconnect(be);
325 backend_switch_state(be, XenbusStateClosing);
326 break;
327 default:
328 BUG();
329 }
330 break;
331 case XenbusStateClosing:
332 switch (state) {
333 case XenbusStateInitWait:
334 case XenbusStateConnected:
335 case XenbusStateClosed:
336 backend_switch_state(be, XenbusStateClosed);
337 break;
338 default:
339 BUG();
340 }
341 break;
342 default:
343 BUG();
344 }
345 }
346}
347
348
349
350
351static void frontend_changed(struct xenbus_device *dev,
352 enum xenbus_state frontend_state)
353{
354 struct backend_info *be = dev_get_drvdata(&dev->dev);
355
356 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
357
358 be->frontend_state = frontend_state;
359
360 switch (frontend_state) {
361 case XenbusStateInitialising:
362 set_backend_state(be, XenbusStateInitWait);
363 break;
364
365 case XenbusStateInitialised:
366 break;
367
368 case XenbusStateConnected:
369 set_backend_state(be, XenbusStateConnected);
370 break;
371
372 case XenbusStateClosing:
373 set_backend_state(be, XenbusStateClosing);
374 break;
375
376 case XenbusStateClosed:
377 set_backend_state(be, XenbusStateClosed);
378 if (xenbus_dev_is_online(dev))
379 break;
380
381 case XenbusStateUnknown:
382 set_backend_state(be, XenbusStateClosed);
383 device_unregister(&dev->dev);
384 break;
385
386 default:
387 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
388 frontend_state);
389 break;
390 }
391}
392
393
394static void xen_net_read_rate(struct xenbus_device *dev,
395 unsigned long *bytes, unsigned long *usec)
396{
397 char *s, *e;
398 unsigned long b, u;
399 char *ratestr;
400
401
402 *bytes = ~0UL;
403 *usec = 0;
404
405 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
406 if (IS_ERR(ratestr))
407 return;
408
409 s = ratestr;
410 b = simple_strtoul(s, &e, 10);
411 if ((s == e) || (*e != ','))
412 goto fail;
413
414 s = e + 1;
415 u = simple_strtoul(s, &e, 10);
416 if ((s == e) || (*e != '\0'))
417 goto fail;
418
419 *bytes = b;
420 *usec = u;
421
422 kfree(ratestr);
423 return;
424
425 fail:
426 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
427 kfree(ratestr);
428}
429
430static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
431{
432 char *s, *e, *macstr;
433 int i;
434
435 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
436 if (IS_ERR(macstr))
437 return PTR_ERR(macstr);
438
439 for (i = 0; i < ETH_ALEN; i++) {
440 mac[i] = simple_strtoul(s, &e, 16);
441 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
442 kfree(macstr);
443 return -ENOENT;
444 }
445 s = e+1;
446 }
447
448 kfree(macstr);
449 return 0;
450}
451
452static void unregister_hotplug_status_watch(struct backend_info *be)
453{
454 if (be->have_hotplug_status_watch) {
455 unregister_xenbus_watch(&be->hotplug_status_watch);
456 kfree(be->hotplug_status_watch.node);
457 }
458 be->have_hotplug_status_watch = 0;
459}
460
461static void hotplug_status_changed(struct xenbus_watch *watch,
462 const char **vec,
463 unsigned int vec_size)
464{
465 struct backend_info *be = container_of(watch,
466 struct backend_info,
467 hotplug_status_watch);
468 char *str;
469 unsigned int len;
470
471 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
472 if (IS_ERR(str))
473 return;
474 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
475
476 xenbus_switch_state(be->dev, be->state);
477
478
479 unregister_hotplug_status_watch(be);
480 }
481 kfree(str);
482}
483
484static void connect(struct backend_info *be)
485{
486 int err;
487 struct xenbus_device *dev = be->dev;
488
489 err = connect_rings(be);
490 if (err)
491 return;
492
493 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
494 if (err) {
495 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
496 return;
497 }
498
499 xen_net_read_rate(dev, &be->vif->credit_bytes,
500 &be->vif->credit_usec);
501 be->vif->remaining_credit = be->vif->credit_bytes;
502
503 unregister_hotplug_status_watch(be);
504 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
505 hotplug_status_changed,
506 "%s/%s", dev->nodename, "hotplug-status");
507 if (!err)
508 be->have_hotplug_status_watch = 1;
509
510 netif_wake_queue(be->vif->dev);
511}
512
513
514static int connect_rings(struct backend_info *be)
515{
516 struct xenvif *vif = be->vif;
517 struct xenbus_device *dev = be->dev;
518 unsigned long tx_ring_ref, rx_ring_ref;
519 unsigned int tx_evtchn, rx_evtchn, rx_copy;
520 int err;
521 int val;
522
523 err = xenbus_gather(XBT_NIL, dev->otherend,
524 "tx-ring-ref", "%lu", &tx_ring_ref,
525 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
526 if (err) {
527 xenbus_dev_fatal(dev, err,
528 "reading %s/ring-ref",
529 dev->otherend);
530 return err;
531 }
532
533
534 err = xenbus_gather(XBT_NIL, dev->otherend,
535 "event-channel-tx", "%u", &tx_evtchn,
536 "event-channel-rx", "%u", &rx_evtchn, NULL);
537 if (err < 0) {
538 err = xenbus_scanf(XBT_NIL, dev->otherend,
539 "event-channel", "%u", &tx_evtchn);
540 if (err < 0) {
541 xenbus_dev_fatal(dev, err,
542 "reading %s/event-channel(-tx/rx)",
543 dev->otherend);
544 return err;
545 }
546 rx_evtchn = tx_evtchn;
547 }
548
549 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
550 &rx_copy);
551 if (err == -ENOENT) {
552 err = 0;
553 rx_copy = 0;
554 }
555 if (err < 0) {
556 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
557 dev->otherend);
558 return err;
559 }
560 if (!rx_copy)
561 return -EOPNOTSUPP;
562
563 if (vif->dev->tx_queue_len != 0) {
564 if (xenbus_scanf(XBT_NIL, dev->otherend,
565 "feature-rx-notify", "%d", &val) < 0)
566 val = 0;
567 if (val)
568 vif->can_queue = 1;
569 else
570
571 vif->dev->tx_queue_len = 1;
572 }
573
574 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
575 "%d", &val) < 0)
576 val = 0;
577 vif->can_sg = !!val;
578
579 vif->gso_mask = 0;
580 vif->gso_prefix_mask = 0;
581
582 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
583 "%d", &val) < 0)
584 val = 0;
585 if (val)
586 vif->gso_mask |= GSO_BIT(TCPV4);
587
588 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
589 "%d", &val) < 0)
590 val = 0;
591 if (val)
592 vif->gso_prefix_mask |= GSO_BIT(TCPV4);
593
594 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
595 "%d", &val) < 0)
596 val = 0;
597 if (val)
598 vif->gso_mask |= GSO_BIT(TCPV6);
599
600 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
601 "%d", &val) < 0)
602 val = 0;
603 if (val)
604 vif->gso_prefix_mask |= GSO_BIT(TCPV6);
605
606 if (vif->gso_mask & vif->gso_prefix_mask) {
607 xenbus_dev_fatal(dev, err,
608 "%s: gso and gso prefix flags are not "
609 "mutually exclusive",
610 dev->otherend);
611 return -EOPNOTSUPP;
612 }
613
614 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
615 "%d", &val) < 0)
616 val = 0;
617 vif->ip_csum = !val;
618
619 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload",
620 "%d", &val) < 0)
621 val = 0;
622 vif->ipv6_csum = !!val;
623
624
625 err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref,
626 tx_evtchn, rx_evtchn);
627 if (err) {
628 xenbus_dev_fatal(dev, err,
629 "mapping shared-frames %lu/%lu port tx %u rx %u",
630 tx_ring_ref, rx_ring_ref,
631 tx_evtchn, rx_evtchn);
632 return err;
633 }
634 return 0;
635}
636
637
638
639
640
641static const struct xenbus_device_id netback_ids[] = {
642 { "vif" },
643 { "" }
644};
645
646
647static DEFINE_XENBUS_DRIVER(netback, ,
648 .probe = netback_probe,
649 .remove = netback_remove,
650 .uevent = netback_uevent,
651 .otherend_changed = frontend_changed,
652);
653
654int xenvif_xenbus_init(void)
655{
656 return xenbus_register_backend(&netback_driver);
657}
658
659void xenvif_xenbus_fini(void)
660{
661 return xenbus_unregister_driver(&netback_driver);
662}
663