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cfc80d9a SS |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (c) 2018, Intel Corporation. */ | |
3 | ||
4 | /* This provides a net_failover interface for paravirtual drivers to | |
5 | * provide an alternate datapath by exporting APIs to create and | |
6 | * destroy a upper 'net_failover' netdev. The upper dev manages the | |
7 | * original paravirtual interface as a 'standby' netdev and uses the | |
8 | * generic failover infrastructure to register and manage a direct | |
9 | * attached VF as a 'primary' netdev. This enables live migration of | |
10 | * a VM with direct attached VF by failing over to the paravirtual | |
11 | * datapath when the VF is unplugged. | |
12 | * | |
13 | * Some of the netdev management routines are based on bond/team driver as | |
14 | * this driver provides active-backup functionality similar to those drivers. | |
15 | */ | |
16 | ||
17 | #include <linux/netdevice.h> | |
18 | #include <linux/etherdevice.h> | |
19 | #include <linux/ethtool.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/netdevice.h> | |
23 | #include <linux/netpoll.h> | |
24 | #include <linux/rtnetlink.h> | |
25 | #include <linux/if_vlan.h> | |
26 | #include <linux/pci.h> | |
27 | #include <net/sch_generic.h> | |
28 | #include <uapi/linux/if_arp.h> | |
29 | #include <net/net_failover.h> | |
30 | ||
31 | static bool net_failover_xmit_ready(struct net_device *dev) | |
32 | { | |
33 | return netif_running(dev) && netif_carrier_ok(dev); | |
34 | } | |
35 | ||
36 | static int net_failover_open(struct net_device *dev) | |
37 | { | |
38 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
39 | struct net_device *primary_dev, *standby_dev; | |
40 | int err; | |
41 | ||
42 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
43 | if (primary_dev) { | |
44 | err = dev_open(primary_dev); | |
45 | if (err) | |
46 | goto err_primary_open; | |
47 | } | |
48 | ||
49 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
50 | if (standby_dev) { | |
51 | err = dev_open(standby_dev); | |
52 | if (err) | |
53 | goto err_standby_open; | |
54 | } | |
55 | ||
56 | if ((primary_dev && net_failover_xmit_ready(primary_dev)) || | |
57 | (standby_dev && net_failover_xmit_ready(standby_dev))) { | |
58 | netif_carrier_on(dev); | |
59 | netif_tx_wake_all_queues(dev); | |
60 | } | |
61 | ||
62 | return 0; | |
63 | ||
64 | err_standby_open: | |
65 | dev_close(primary_dev); | |
66 | err_primary_open: | |
67 | netif_tx_disable(dev); | |
68 | return err; | |
69 | } | |
70 | ||
71 | static int net_failover_close(struct net_device *dev) | |
72 | { | |
73 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
74 | struct net_device *slave_dev; | |
75 | ||
76 | netif_tx_disable(dev); | |
77 | ||
78 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
79 | if (slave_dev) | |
80 | dev_close(slave_dev); | |
81 | ||
82 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
83 | if (slave_dev) | |
84 | dev_close(slave_dev); | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | static netdev_tx_t net_failover_drop_xmit(struct sk_buff *skb, | |
90 | struct net_device *dev) | |
91 | { | |
92 | atomic_long_inc(&dev->tx_dropped); | |
93 | dev_kfree_skb_any(skb); | |
94 | return NETDEV_TX_OK; | |
95 | } | |
96 | ||
97 | static netdev_tx_t net_failover_start_xmit(struct sk_buff *skb, | |
98 | struct net_device *dev) | |
99 | { | |
100 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
101 | struct net_device *xmit_dev; | |
102 | ||
103 | /* Try xmit via primary netdev followed by standby netdev */ | |
104 | xmit_dev = rcu_dereference_bh(nfo_info->primary_dev); | |
105 | if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) { | |
106 | xmit_dev = rcu_dereference_bh(nfo_info->standby_dev); | |
107 | if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) | |
108 | return net_failover_drop_xmit(skb, dev); | |
109 | } | |
110 | ||
111 | skb->dev = xmit_dev; | |
112 | skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping; | |
113 | ||
114 | return dev_queue_xmit(skb); | |
115 | } | |
116 | ||
117 | static u16 net_failover_select_queue(struct net_device *dev, | |
118 | struct sk_buff *skb, void *accel_priv, | |
119 | select_queue_fallback_t fallback) | |
120 | { | |
121 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
122 | struct net_device *primary_dev; | |
123 | u16 txq; | |
124 | ||
125 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
126 | if (primary_dev) { | |
127 | const struct net_device_ops *ops = primary_dev->netdev_ops; | |
128 | ||
129 | if (ops->ndo_select_queue) | |
130 | txq = ops->ndo_select_queue(primary_dev, skb, | |
131 | accel_priv, fallback); | |
132 | else | |
133 | txq = fallback(primary_dev, skb); | |
134 | ||
135 | qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; | |
136 | ||
137 | return txq; | |
138 | } | |
139 | ||
140 | txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0; | |
141 | ||
142 | /* Save the original txq to restore before passing to the driver */ | |
143 | qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; | |
144 | ||
145 | if (unlikely(txq >= dev->real_num_tx_queues)) { | |
146 | do { | |
147 | txq -= dev->real_num_tx_queues; | |
148 | } while (txq >= dev->real_num_tx_queues); | |
149 | } | |
150 | ||
151 | return txq; | |
152 | } | |
153 | ||
154 | /* fold stats, assuming all rtnl_link_stats64 fields are u64, but | |
155 | * that some drivers can provide 32bit values only. | |
156 | */ | |
157 | static void net_failover_fold_stats(struct rtnl_link_stats64 *_res, | |
158 | const struct rtnl_link_stats64 *_new, | |
159 | const struct rtnl_link_stats64 *_old) | |
160 | { | |
161 | const u64 *new = (const u64 *)_new; | |
162 | const u64 *old = (const u64 *)_old; | |
163 | u64 *res = (u64 *)_res; | |
164 | int i; | |
165 | ||
166 | for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { | |
167 | u64 nv = new[i]; | |
168 | u64 ov = old[i]; | |
169 | s64 delta = nv - ov; | |
170 | ||
171 | /* detects if this particular field is 32bit only */ | |
172 | if (((nv | ov) >> 32) == 0) | |
173 | delta = (s64)(s32)((u32)nv - (u32)ov); | |
174 | ||
175 | /* filter anomalies, some drivers reset their stats | |
176 | * at down/up events. | |
177 | */ | |
178 | if (delta > 0) | |
179 | res[i] += delta; | |
180 | } | |
181 | } | |
182 | ||
183 | static void net_failover_get_stats(struct net_device *dev, | |
184 | struct rtnl_link_stats64 *stats) | |
185 | { | |
186 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
187 | const struct rtnl_link_stats64 *new; | |
188 | struct rtnl_link_stats64 temp; | |
189 | struct net_device *slave_dev; | |
190 | ||
191 | spin_lock(&nfo_info->stats_lock); | |
192 | memcpy(stats, &nfo_info->failover_stats, sizeof(*stats)); | |
193 | ||
194 | rcu_read_lock(); | |
195 | ||
196 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
197 | if (slave_dev) { | |
198 | new = dev_get_stats(slave_dev, &temp); | |
199 | net_failover_fold_stats(stats, new, &nfo_info->primary_stats); | |
200 | memcpy(&nfo_info->primary_stats, new, sizeof(*new)); | |
201 | } | |
202 | ||
203 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
204 | if (slave_dev) { | |
205 | new = dev_get_stats(slave_dev, &temp); | |
206 | net_failover_fold_stats(stats, new, &nfo_info->standby_stats); | |
207 | memcpy(&nfo_info->standby_stats, new, sizeof(*new)); | |
208 | } | |
209 | ||
210 | rcu_read_unlock(); | |
211 | ||
212 | memcpy(&nfo_info->failover_stats, stats, sizeof(*stats)); | |
213 | spin_unlock(&nfo_info->stats_lock); | |
214 | } | |
215 | ||
216 | static int net_failover_change_mtu(struct net_device *dev, int new_mtu) | |
217 | { | |
218 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
219 | struct net_device *primary_dev, *standby_dev; | |
220 | int ret = 0; | |
221 | ||
222 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
223 | if (primary_dev) { | |
224 | ret = dev_set_mtu(primary_dev, new_mtu); | |
225 | if (ret) | |
226 | return ret; | |
227 | } | |
228 | ||
229 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
230 | if (standby_dev) { | |
231 | ret = dev_set_mtu(standby_dev, new_mtu); | |
232 | if (ret) { | |
233 | if (primary_dev) | |
234 | dev_set_mtu(primary_dev, dev->mtu); | |
235 | return ret; | |
236 | } | |
237 | } | |
238 | ||
239 | dev->mtu = new_mtu; | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static void net_failover_set_rx_mode(struct net_device *dev) | |
245 | { | |
246 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
247 | struct net_device *slave_dev; | |
248 | ||
249 | rcu_read_lock(); | |
250 | ||
251 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
252 | if (slave_dev) { | |
253 | dev_uc_sync_multiple(slave_dev, dev); | |
254 | dev_mc_sync_multiple(slave_dev, dev); | |
255 | } | |
256 | ||
257 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
258 | if (slave_dev) { | |
259 | dev_uc_sync_multiple(slave_dev, dev); | |
260 | dev_mc_sync_multiple(slave_dev, dev); | |
261 | } | |
262 | ||
263 | rcu_read_unlock(); | |
264 | } | |
265 | ||
266 | static int net_failover_vlan_rx_add_vid(struct net_device *dev, __be16 proto, | |
267 | u16 vid) | |
268 | { | |
269 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
270 | struct net_device *primary_dev, *standby_dev; | |
271 | int ret = 0; | |
272 | ||
273 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
274 | if (primary_dev) { | |
275 | ret = vlan_vid_add(primary_dev, proto, vid); | |
276 | if (ret) | |
277 | return ret; | |
278 | } | |
279 | ||
280 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
281 | if (standby_dev) { | |
282 | ret = vlan_vid_add(standby_dev, proto, vid); | |
283 | if (ret) | |
284 | if (primary_dev) | |
285 | vlan_vid_del(primary_dev, proto, vid); | |
286 | } | |
287 | ||
288 | return ret; | |
289 | } | |
290 | ||
291 | static int net_failover_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, | |
292 | u16 vid) | |
293 | { | |
294 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
295 | struct net_device *slave_dev; | |
296 | ||
297 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
298 | if (slave_dev) | |
299 | vlan_vid_del(slave_dev, proto, vid); | |
300 | ||
301 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
302 | if (slave_dev) | |
303 | vlan_vid_del(slave_dev, proto, vid); | |
304 | ||
305 | return 0; | |
306 | } | |
307 | ||
308 | static const struct net_device_ops failover_dev_ops = { | |
309 | .ndo_open = net_failover_open, | |
310 | .ndo_stop = net_failover_close, | |
311 | .ndo_start_xmit = net_failover_start_xmit, | |
312 | .ndo_select_queue = net_failover_select_queue, | |
313 | .ndo_get_stats64 = net_failover_get_stats, | |
314 | .ndo_change_mtu = net_failover_change_mtu, | |
315 | .ndo_set_rx_mode = net_failover_set_rx_mode, | |
316 | .ndo_vlan_rx_add_vid = net_failover_vlan_rx_add_vid, | |
317 | .ndo_vlan_rx_kill_vid = net_failover_vlan_rx_kill_vid, | |
318 | .ndo_validate_addr = eth_validate_addr, | |
319 | .ndo_features_check = passthru_features_check, | |
320 | }; | |
321 | ||
322 | #define FAILOVER_NAME "net_failover" | |
323 | #define FAILOVER_VERSION "0.1" | |
324 | ||
325 | static void nfo_ethtool_get_drvinfo(struct net_device *dev, | |
326 | struct ethtool_drvinfo *drvinfo) | |
327 | { | |
328 | strlcpy(drvinfo->driver, FAILOVER_NAME, sizeof(drvinfo->driver)); | |
329 | strlcpy(drvinfo->version, FAILOVER_VERSION, sizeof(drvinfo->version)); | |
330 | } | |
331 | ||
332 | static int nfo_ethtool_get_link_ksettings(struct net_device *dev, | |
333 | struct ethtool_link_ksettings *cmd) | |
334 | { | |
335 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
336 | struct net_device *slave_dev; | |
337 | ||
338 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
339 | if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { | |
340 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
341 | if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { | |
342 | cmd->base.duplex = DUPLEX_UNKNOWN; | |
343 | cmd->base.port = PORT_OTHER; | |
344 | cmd->base.speed = SPEED_UNKNOWN; | |
345 | ||
346 | return 0; | |
347 | } | |
348 | } | |
349 | ||
350 | return __ethtool_get_link_ksettings(slave_dev, cmd); | |
351 | } | |
352 | ||
353 | static const struct ethtool_ops failover_ethtool_ops = { | |
354 | .get_drvinfo = nfo_ethtool_get_drvinfo, | |
355 | .get_link = ethtool_op_get_link, | |
356 | .get_link_ksettings = nfo_ethtool_get_link_ksettings, | |
357 | }; | |
358 | ||
359 | /* Called when slave dev is injecting data into network stack. | |
360 | * Change the associated network device from lower dev to failover dev. | |
361 | * note: already called with rcu_read_lock | |
362 | */ | |
363 | static rx_handler_result_t net_failover_handle_frame(struct sk_buff **pskb) | |
364 | { | |
365 | struct sk_buff *skb = *pskb; | |
366 | struct net_device *dev = rcu_dereference(skb->dev->rx_handler_data); | |
367 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
368 | struct net_device *primary_dev, *standby_dev; | |
369 | ||
370 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
371 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
372 | ||
373 | if (primary_dev && skb->dev == standby_dev) | |
374 | return RX_HANDLER_EXACT; | |
375 | ||
376 | skb->dev = dev; | |
377 | ||
378 | return RX_HANDLER_ANOTHER; | |
379 | } | |
380 | ||
381 | static void net_failover_compute_features(struct net_device *dev) | |
382 | { | |
a746407a DC |
383 | netdev_features_t vlan_features = FAILOVER_VLAN_FEATURES & |
384 | NETIF_F_ALL_FOR_ALL; | |
cfc80d9a SS |
385 | netdev_features_t enc_features = FAILOVER_ENC_FEATURES; |
386 | unsigned short max_hard_header_len = ETH_HLEN; | |
387 | unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE | | |
388 | IFF_XMIT_DST_RELEASE_PERM; | |
389 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
390 | struct net_device *primary_dev, *standby_dev; | |
391 | ||
392 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
393 | if (primary_dev) { | |
394 | vlan_features = | |
395 | netdev_increment_features(vlan_features, | |
396 | primary_dev->vlan_features, | |
397 | FAILOVER_VLAN_FEATURES); | |
398 | enc_features = | |
399 | netdev_increment_features(enc_features, | |
400 | primary_dev->hw_enc_features, | |
401 | FAILOVER_ENC_FEATURES); | |
402 | ||
403 | dst_release_flag &= primary_dev->priv_flags; | |
404 | if (primary_dev->hard_header_len > max_hard_header_len) | |
405 | max_hard_header_len = primary_dev->hard_header_len; | |
406 | } | |
407 | ||
408 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
409 | if (standby_dev) { | |
410 | vlan_features = | |
411 | netdev_increment_features(vlan_features, | |
412 | standby_dev->vlan_features, | |
413 | FAILOVER_VLAN_FEATURES); | |
414 | enc_features = | |
415 | netdev_increment_features(enc_features, | |
416 | standby_dev->hw_enc_features, | |
417 | FAILOVER_ENC_FEATURES); | |
418 | ||
419 | dst_release_flag &= standby_dev->priv_flags; | |
420 | if (standby_dev->hard_header_len > max_hard_header_len) | |
421 | max_hard_header_len = standby_dev->hard_header_len; | |
422 | } | |
423 | ||
424 | dev->vlan_features = vlan_features; | |
425 | dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL; | |
426 | dev->hard_header_len = max_hard_header_len; | |
427 | ||
428 | dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; | |
429 | if (dst_release_flag == (IFF_XMIT_DST_RELEASE | | |
430 | IFF_XMIT_DST_RELEASE_PERM)) | |
431 | dev->priv_flags |= IFF_XMIT_DST_RELEASE; | |
432 | ||
433 | netdev_change_features(dev); | |
434 | } | |
435 | ||
436 | static void net_failover_lower_state_changed(struct net_device *slave_dev, | |
437 | struct net_device *primary_dev, | |
438 | struct net_device *standby_dev) | |
439 | { | |
440 | struct netdev_lag_lower_state_info info; | |
441 | ||
442 | if (netif_carrier_ok(slave_dev)) | |
443 | info.link_up = true; | |
444 | else | |
445 | info.link_up = false; | |
446 | ||
447 | if (slave_dev == primary_dev) { | |
448 | if (netif_running(primary_dev)) | |
449 | info.tx_enabled = true; | |
450 | else | |
451 | info.tx_enabled = false; | |
452 | } else { | |
453 | if ((primary_dev && netif_running(primary_dev)) || | |
454 | (!netif_running(standby_dev))) | |
455 | info.tx_enabled = false; | |
456 | else | |
457 | info.tx_enabled = true; | |
458 | } | |
459 | ||
460 | netdev_lower_state_changed(slave_dev, &info); | |
461 | } | |
462 | ||
463 | static int net_failover_slave_pre_register(struct net_device *slave_dev, | |
464 | struct net_device *failover_dev) | |
465 | { | |
466 | struct net_device *standby_dev, *primary_dev; | |
467 | struct net_failover_info *nfo_info; | |
468 | bool slave_is_standby; | |
469 | ||
470 | nfo_info = netdev_priv(failover_dev); | |
471 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
472 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
473 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
474 | if (slave_is_standby ? standby_dev : primary_dev) { | |
475 | netdev_err(failover_dev, "%s attempting to register as slave dev when %s already present\n", | |
476 | slave_dev->name, | |
477 | slave_is_standby ? "standby" : "primary"); | |
478 | return -EINVAL; | |
479 | } | |
480 | ||
481 | /* We want to allow only a direct attached VF device as a primary | |
482 | * netdev. As there is no easy way to check for a VF device, restrict | |
483 | * this to a pci device. | |
484 | */ | |
485 | if (!slave_is_standby && (!slave_dev->dev.parent || | |
486 | !dev_is_pci(slave_dev->dev.parent))) | |
487 | return -EINVAL; | |
488 | ||
489 | if (failover_dev->features & NETIF_F_VLAN_CHALLENGED && | |
490 | vlan_uses_dev(failover_dev)) { | |
491 | netdev_err(failover_dev, "Device %s is VLAN challenged and failover device has VLAN set up\n", | |
492 | failover_dev->name); | |
493 | return -EINVAL; | |
494 | } | |
495 | ||
496 | return 0; | |
497 | } | |
498 | ||
499 | static int net_failover_slave_register(struct net_device *slave_dev, | |
500 | struct net_device *failover_dev) | |
501 | { | |
502 | struct net_device *standby_dev, *primary_dev; | |
503 | struct net_failover_info *nfo_info; | |
504 | bool slave_is_standby; | |
505 | u32 orig_mtu; | |
506 | int err; | |
507 | ||
508 | /* Align MTU of slave with failover dev */ | |
509 | orig_mtu = slave_dev->mtu; | |
510 | err = dev_set_mtu(slave_dev, failover_dev->mtu); | |
511 | if (err) { | |
512 | netdev_err(failover_dev, "unable to change mtu of %s to %u register failed\n", | |
513 | slave_dev->name, failover_dev->mtu); | |
514 | goto done; | |
515 | } | |
516 | ||
517 | dev_hold(slave_dev); | |
518 | ||
519 | if (netif_running(failover_dev)) { | |
520 | err = dev_open(slave_dev); | |
521 | if (err && (err != -EBUSY)) { | |
522 | netdev_err(failover_dev, "Opening slave %s failed err:%d\n", | |
523 | slave_dev->name, err); | |
524 | goto err_dev_open; | |
525 | } | |
526 | } | |
527 | ||
528 | netif_addr_lock_bh(failover_dev); | |
529 | dev_uc_sync_multiple(slave_dev, failover_dev); | |
e5223438 | 530 | dev_mc_sync_multiple(slave_dev, failover_dev); |
cfc80d9a SS |
531 | netif_addr_unlock_bh(failover_dev); |
532 | ||
533 | err = vlan_vids_add_by_dev(slave_dev, failover_dev); | |
534 | if (err) { | |
535 | netdev_err(failover_dev, "Failed to add vlan ids to device %s err:%d\n", | |
536 | slave_dev->name, err); | |
537 | goto err_vlan_add; | |
538 | } | |
539 | ||
540 | nfo_info = netdev_priv(failover_dev); | |
541 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
542 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
543 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
544 | ||
545 | if (slave_is_standby) { | |
546 | rcu_assign_pointer(nfo_info->standby_dev, slave_dev); | |
547 | standby_dev = slave_dev; | |
548 | dev_get_stats(standby_dev, &nfo_info->standby_stats); | |
549 | } else { | |
550 | rcu_assign_pointer(nfo_info->primary_dev, slave_dev); | |
551 | primary_dev = slave_dev; | |
552 | dev_get_stats(primary_dev, &nfo_info->primary_stats); | |
553 | failover_dev->min_mtu = slave_dev->min_mtu; | |
554 | failover_dev->max_mtu = slave_dev->max_mtu; | |
555 | } | |
556 | ||
557 | net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); | |
558 | net_failover_compute_features(failover_dev); | |
559 | ||
560 | call_netdevice_notifiers(NETDEV_JOIN, slave_dev); | |
561 | ||
562 | netdev_info(failover_dev, "failover %s slave:%s registered\n", | |
563 | slave_is_standby ? "standby" : "primary", slave_dev->name); | |
564 | ||
565 | return 0; | |
566 | ||
567 | err_vlan_add: | |
568 | dev_uc_unsync(slave_dev, failover_dev); | |
569 | dev_mc_unsync(slave_dev, failover_dev); | |
570 | dev_close(slave_dev); | |
571 | err_dev_open: | |
572 | dev_put(slave_dev); | |
573 | dev_set_mtu(slave_dev, orig_mtu); | |
574 | done: | |
575 | return err; | |
576 | } | |
577 | ||
578 | static int net_failover_slave_pre_unregister(struct net_device *slave_dev, | |
579 | struct net_device *failover_dev) | |
580 | { | |
581 | struct net_device *standby_dev, *primary_dev; | |
582 | struct net_failover_info *nfo_info; | |
583 | ||
584 | nfo_info = netdev_priv(failover_dev); | |
585 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
586 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
587 | ||
588 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
589 | return -ENODEV; | |
590 | ||
591 | return 0; | |
592 | } | |
593 | ||
594 | static int net_failover_slave_unregister(struct net_device *slave_dev, | |
595 | struct net_device *failover_dev) | |
596 | { | |
597 | struct net_device *standby_dev, *primary_dev; | |
598 | struct net_failover_info *nfo_info; | |
599 | bool slave_is_standby; | |
600 | ||
601 | nfo_info = netdev_priv(failover_dev); | |
602 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
603 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
604 | ||
605 | vlan_vids_del_by_dev(slave_dev, failover_dev); | |
606 | dev_uc_unsync(slave_dev, failover_dev); | |
607 | dev_mc_unsync(slave_dev, failover_dev); | |
608 | dev_close(slave_dev); | |
609 | ||
610 | nfo_info = netdev_priv(failover_dev); | |
611 | dev_get_stats(failover_dev, &nfo_info->failover_stats); | |
612 | ||
613 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
614 | if (slave_is_standby) { | |
615 | RCU_INIT_POINTER(nfo_info->standby_dev, NULL); | |
616 | } else { | |
617 | RCU_INIT_POINTER(nfo_info->primary_dev, NULL); | |
618 | if (standby_dev) { | |
619 | failover_dev->min_mtu = standby_dev->min_mtu; | |
620 | failover_dev->max_mtu = standby_dev->max_mtu; | |
621 | } | |
622 | } | |
623 | ||
624 | dev_put(slave_dev); | |
625 | ||
626 | net_failover_compute_features(failover_dev); | |
627 | ||
628 | netdev_info(failover_dev, "failover %s slave:%s unregistered\n", | |
629 | slave_is_standby ? "standby" : "primary", slave_dev->name); | |
630 | ||
631 | return 0; | |
632 | } | |
633 | ||
634 | static int net_failover_slave_link_change(struct net_device *slave_dev, | |
635 | struct net_device *failover_dev) | |
636 | { | |
637 | struct net_device *primary_dev, *standby_dev; | |
638 | struct net_failover_info *nfo_info; | |
639 | ||
640 | nfo_info = netdev_priv(failover_dev); | |
641 | ||
642 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
643 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
644 | ||
645 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
646 | return -ENODEV; | |
647 | ||
648 | if ((primary_dev && net_failover_xmit_ready(primary_dev)) || | |
649 | (standby_dev && net_failover_xmit_ready(standby_dev))) { | |
650 | netif_carrier_on(failover_dev); | |
651 | netif_tx_wake_all_queues(failover_dev); | |
652 | } else { | |
653 | dev_get_stats(failover_dev, &nfo_info->failover_stats); | |
654 | netif_carrier_off(failover_dev); | |
655 | netif_tx_stop_all_queues(failover_dev); | |
656 | } | |
657 | ||
658 | net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); | |
659 | ||
660 | return 0; | |
661 | } | |
662 | ||
663 | static int net_failover_slave_name_change(struct net_device *slave_dev, | |
664 | struct net_device *failover_dev) | |
665 | { | |
666 | struct net_device *primary_dev, *standby_dev; | |
667 | struct net_failover_info *nfo_info; | |
668 | ||
669 | nfo_info = netdev_priv(failover_dev); | |
670 | ||
671 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
672 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
673 | ||
674 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
675 | return -ENODEV; | |
676 | ||
677 | /* We need to bring up the slave after the rename by udev in case | |
678 | * open failed with EBUSY when it was registered. | |
679 | */ | |
680 | dev_open(slave_dev); | |
681 | ||
682 | return 0; | |
683 | } | |
684 | ||
685 | static struct failover_ops net_failover_ops = { | |
686 | .slave_pre_register = net_failover_slave_pre_register, | |
687 | .slave_register = net_failover_slave_register, | |
688 | .slave_pre_unregister = net_failover_slave_pre_unregister, | |
689 | .slave_unregister = net_failover_slave_unregister, | |
690 | .slave_link_change = net_failover_slave_link_change, | |
691 | .slave_name_change = net_failover_slave_name_change, | |
692 | .slave_handle_frame = net_failover_handle_frame, | |
693 | }; | |
694 | ||
695 | /** | |
696 | * net_failover_create - Create and register a failover instance | |
697 | * | |
698 | * @dev: standby netdev | |
699 | * | |
700 | * Creates a failover netdev and registers a failover instance for a standby | |
701 | * netdev. Used by paravirtual drivers that use 3-netdev model. | |
702 | * The failover netdev acts as a master device and controls 2 slave devices - | |
703 | * the original standby netdev and a VF netdev with the same MAC gets | |
704 | * registered as primary netdev. | |
705 | * | |
706 | * Return: pointer to failover instance | |
707 | */ | |
708 | struct failover *net_failover_create(struct net_device *standby_dev) | |
709 | { | |
710 | struct device *dev = standby_dev->dev.parent; | |
711 | struct net_device *failover_dev; | |
712 | struct failover *failover; | |
713 | int err; | |
714 | ||
715 | /* Alloc at least 2 queues, for now we are going with 16 assuming | |
716 | * that VF devices being enslaved won't have too many queues. | |
717 | */ | |
718 | failover_dev = alloc_etherdev_mq(sizeof(struct net_failover_info), 16); | |
719 | if (!failover_dev) { | |
720 | dev_err(dev, "Unable to allocate failover_netdev!\n"); | |
721 | return ERR_PTR(-ENOMEM); | |
722 | } | |
723 | ||
724 | dev_net_set(failover_dev, dev_net(standby_dev)); | |
725 | SET_NETDEV_DEV(failover_dev, dev); | |
726 | ||
727 | failover_dev->netdev_ops = &failover_dev_ops; | |
728 | failover_dev->ethtool_ops = &failover_ethtool_ops; | |
729 | ||
730 | /* Initialize the device options */ | |
731 | failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; | |
732 | failover_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | | |
733 | IFF_TX_SKB_SHARING); | |
734 | ||
735 | /* don't acquire failover netdev's netif_tx_lock when transmitting */ | |
736 | failover_dev->features |= NETIF_F_LLTX; | |
737 | ||
738 | /* Don't allow failover devices to change network namespaces. */ | |
739 | failover_dev->features |= NETIF_F_NETNS_LOCAL; | |
740 | ||
741 | failover_dev->hw_features = FAILOVER_VLAN_FEATURES | | |
742 | NETIF_F_HW_VLAN_CTAG_TX | | |
743 | NETIF_F_HW_VLAN_CTAG_RX | | |
744 | NETIF_F_HW_VLAN_CTAG_FILTER; | |
745 | ||
746 | failover_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL; | |
747 | failover_dev->features |= failover_dev->hw_features; | |
748 | ||
749 | memcpy(failover_dev->dev_addr, standby_dev->dev_addr, | |
750 | failover_dev->addr_len); | |
751 | ||
752 | failover_dev->min_mtu = standby_dev->min_mtu; | |
753 | failover_dev->max_mtu = standby_dev->max_mtu; | |
754 | ||
755 | err = register_netdev(failover_dev); | |
756 | if (err) { | |
757 | dev_err(dev, "Unable to register failover_dev!\n"); | |
758 | goto err_register_netdev; | |
759 | } | |
760 | ||
761 | netif_carrier_off(failover_dev); | |
762 | ||
763 | failover = failover_register(failover_dev, &net_failover_ops); | |
764 | if (IS_ERR(failover)) | |
765 | goto err_failover_register; | |
766 | ||
767 | return failover; | |
768 | ||
769 | err_failover_register: | |
770 | unregister_netdev(failover_dev); | |
771 | err_register_netdev: | |
772 | free_netdev(failover_dev); | |
773 | ||
774 | return ERR_PTR(err); | |
775 | } | |
776 | EXPORT_SYMBOL_GPL(net_failover_create); | |
777 | ||
778 | /** | |
779 | * net_failover_destroy - Destroy a failover instance | |
780 | * | |
781 | * @failover: pointer to failover instance | |
782 | * | |
783 | * Unregisters any slave netdevs associated with the failover instance by | |
784 | * calling failover_slave_unregister(). | |
785 | * unregisters the failover instance itself and finally frees the failover | |
786 | * netdev. Used by paravirtual drivers that use 3-netdev model. | |
787 | * | |
788 | */ | |
789 | void net_failover_destroy(struct failover *failover) | |
790 | { | |
791 | struct net_failover_info *nfo_info; | |
792 | struct net_device *failover_dev; | |
793 | struct net_device *slave_dev; | |
794 | ||
795 | if (!failover) | |
796 | return; | |
797 | ||
798 | failover_dev = rcu_dereference(failover->failover_dev); | |
799 | nfo_info = netdev_priv(failover_dev); | |
800 | ||
801 | netif_device_detach(failover_dev); | |
802 | ||
803 | rtnl_lock(); | |
804 | ||
805 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
806 | if (slave_dev) | |
807 | failover_slave_unregister(slave_dev); | |
808 | ||
809 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
810 | if (slave_dev) | |
811 | failover_slave_unregister(slave_dev); | |
812 | ||
813 | failover_unregister(failover); | |
814 | ||
815 | unregister_netdevice(failover_dev); | |
816 | ||
817 | rtnl_unlock(); | |
818 | ||
819 | free_netdev(failover_dev); | |
820 | } | |
821 | EXPORT_SYMBOL_GPL(net_failover_destroy); | |
822 | ||
823 | static __init int | |
824 | net_failover_init(void) | |
825 | { | |
826 | return 0; | |
827 | } | |
828 | module_init(net_failover_init); | |
829 | ||
830 | static __exit | |
831 | void net_failover_exit(void) | |
832 | { | |
833 | } | |
834 | module_exit(net_failover_exit); | |
835 | ||
836 | MODULE_DESCRIPTION("Failover driver for Paravirtual drivers"); | |
837 | MODULE_LICENSE("GPL v2"); |