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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> | |
cfc80d9a SS |
22 | #include <linux/netpoll.h> |
23 | #include <linux/rtnetlink.h> | |
24 | #include <linux/if_vlan.h> | |
25 | #include <linux/pci.h> | |
26 | #include <net/sch_generic.h> | |
27 | #include <uapi/linux/if_arp.h> | |
28 | #include <net/net_failover.h> | |
29 | ||
30 | static bool net_failover_xmit_ready(struct net_device *dev) | |
31 | { | |
32 | return netif_running(dev) && netif_carrier_ok(dev); | |
33 | } | |
34 | ||
35 | static int net_failover_open(struct net_device *dev) | |
36 | { | |
37 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
38 | struct net_device *primary_dev, *standby_dev; | |
39 | int err; | |
40 | ||
41 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
42 | if (primary_dev) { | |
00f54e68 | 43 | err = dev_open(primary_dev, NULL); |
cfc80d9a SS |
44 | if (err) |
45 | goto err_primary_open; | |
46 | } | |
47 | ||
48 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
49 | if (standby_dev) { | |
00f54e68 | 50 | err = dev_open(standby_dev, NULL); |
cfc80d9a SS |
51 | if (err) |
52 | goto err_standby_open; | |
53 | } | |
54 | ||
55 | if ((primary_dev && net_failover_xmit_ready(primary_dev)) || | |
56 | (standby_dev && net_failover_xmit_ready(standby_dev))) { | |
57 | netif_carrier_on(dev); | |
58 | netif_tx_wake_all_queues(dev); | |
59 | } | |
60 | ||
61 | return 0; | |
62 | ||
63 | err_standby_open: | |
64 | dev_close(primary_dev); | |
65 | err_primary_open: | |
66 | netif_tx_disable(dev); | |
67 | return err; | |
68 | } | |
69 | ||
70 | static int net_failover_close(struct net_device *dev) | |
71 | { | |
72 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
73 | struct net_device *slave_dev; | |
74 | ||
75 | netif_tx_disable(dev); | |
76 | ||
77 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
78 | if (slave_dev) | |
79 | dev_close(slave_dev); | |
80 | ||
81 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
82 | if (slave_dev) | |
83 | dev_close(slave_dev); | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
88 | static netdev_tx_t net_failover_drop_xmit(struct sk_buff *skb, | |
89 | struct net_device *dev) | |
90 | { | |
91 | atomic_long_inc(&dev->tx_dropped); | |
92 | dev_kfree_skb_any(skb); | |
93 | return NETDEV_TX_OK; | |
94 | } | |
95 | ||
96 | static netdev_tx_t net_failover_start_xmit(struct sk_buff *skb, | |
97 | struct net_device *dev) | |
98 | { | |
99 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
100 | struct net_device *xmit_dev; | |
101 | ||
102 | /* Try xmit via primary netdev followed by standby netdev */ | |
103 | xmit_dev = rcu_dereference_bh(nfo_info->primary_dev); | |
104 | if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) { | |
105 | xmit_dev = rcu_dereference_bh(nfo_info->standby_dev); | |
106 | if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) | |
107 | return net_failover_drop_xmit(skb, dev); | |
108 | } | |
109 | ||
110 | skb->dev = xmit_dev; | |
111 | skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping; | |
112 | ||
113 | return dev_queue_xmit(skb); | |
114 | } | |
115 | ||
116 | static u16 net_failover_select_queue(struct net_device *dev, | |
4f49dec9 | 117 | struct sk_buff *skb, |
a350ecce | 118 | struct net_device *sb_dev) |
cfc80d9a SS |
119 | { |
120 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
121 | struct net_device *primary_dev; | |
122 | u16 txq; | |
123 | ||
124 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
125 | if (primary_dev) { | |
126 | const struct net_device_ops *ops = primary_dev->netdev_ops; | |
127 | ||
128 | if (ops->ndo_select_queue) | |
a350ecce | 129 | txq = ops->ndo_select_queue(primary_dev, skb, sb_dev); |
cfc80d9a | 130 | else |
a350ecce | 131 | txq = netdev_pick_tx(primary_dev, skb, NULL); |
cfc80d9a SS |
132 | |
133 | qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; | |
134 | ||
135 | return txq; | |
136 | } | |
137 | ||
138 | txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0; | |
139 | ||
140 | /* Save the original txq to restore before passing to the driver */ | |
141 | qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; | |
142 | ||
143 | if (unlikely(txq >= dev->real_num_tx_queues)) { | |
144 | do { | |
145 | txq -= dev->real_num_tx_queues; | |
146 | } while (txq >= dev->real_num_tx_queues); | |
147 | } | |
148 | ||
149 | return txq; | |
150 | } | |
151 | ||
152 | /* fold stats, assuming all rtnl_link_stats64 fields are u64, but | |
153 | * that some drivers can provide 32bit values only. | |
154 | */ | |
155 | static void net_failover_fold_stats(struct rtnl_link_stats64 *_res, | |
156 | const struct rtnl_link_stats64 *_new, | |
157 | const struct rtnl_link_stats64 *_old) | |
158 | { | |
159 | const u64 *new = (const u64 *)_new; | |
160 | const u64 *old = (const u64 *)_old; | |
161 | u64 *res = (u64 *)_res; | |
162 | int i; | |
163 | ||
164 | for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { | |
165 | u64 nv = new[i]; | |
166 | u64 ov = old[i]; | |
167 | s64 delta = nv - ov; | |
168 | ||
169 | /* detects if this particular field is 32bit only */ | |
170 | if (((nv | ov) >> 32) == 0) | |
171 | delta = (s64)(s32)((u32)nv - (u32)ov); | |
172 | ||
173 | /* filter anomalies, some drivers reset their stats | |
174 | * at down/up events. | |
175 | */ | |
176 | if (delta > 0) | |
177 | res[i] += delta; | |
178 | } | |
179 | } | |
180 | ||
181 | static void net_failover_get_stats(struct net_device *dev, | |
182 | struct rtnl_link_stats64 *stats) | |
183 | { | |
184 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
185 | const struct rtnl_link_stats64 *new; | |
186 | struct rtnl_link_stats64 temp; | |
187 | struct net_device *slave_dev; | |
188 | ||
189 | spin_lock(&nfo_info->stats_lock); | |
190 | memcpy(stats, &nfo_info->failover_stats, sizeof(*stats)); | |
191 | ||
192 | rcu_read_lock(); | |
193 | ||
194 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
195 | if (slave_dev) { | |
196 | new = dev_get_stats(slave_dev, &temp); | |
197 | net_failover_fold_stats(stats, new, &nfo_info->primary_stats); | |
198 | memcpy(&nfo_info->primary_stats, new, sizeof(*new)); | |
199 | } | |
200 | ||
201 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
202 | if (slave_dev) { | |
203 | new = dev_get_stats(slave_dev, &temp); | |
204 | net_failover_fold_stats(stats, new, &nfo_info->standby_stats); | |
205 | memcpy(&nfo_info->standby_stats, new, sizeof(*new)); | |
206 | } | |
207 | ||
208 | rcu_read_unlock(); | |
209 | ||
210 | memcpy(&nfo_info->failover_stats, stats, sizeof(*stats)); | |
211 | spin_unlock(&nfo_info->stats_lock); | |
212 | } | |
213 | ||
214 | static int net_failover_change_mtu(struct net_device *dev, int new_mtu) | |
215 | { | |
216 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
217 | struct net_device *primary_dev, *standby_dev; | |
218 | int ret = 0; | |
219 | ||
3260155a | 220 | primary_dev = rtnl_dereference(nfo_info->primary_dev); |
cfc80d9a SS |
221 | if (primary_dev) { |
222 | ret = dev_set_mtu(primary_dev, new_mtu); | |
223 | if (ret) | |
224 | return ret; | |
225 | } | |
226 | ||
3260155a | 227 | standby_dev = rtnl_dereference(nfo_info->standby_dev); |
cfc80d9a SS |
228 | if (standby_dev) { |
229 | ret = dev_set_mtu(standby_dev, new_mtu); | |
230 | if (ret) { | |
231 | if (primary_dev) | |
232 | dev_set_mtu(primary_dev, dev->mtu); | |
233 | return ret; | |
234 | } | |
235 | } | |
236 | ||
237 | dev->mtu = new_mtu; | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | static void net_failover_set_rx_mode(struct net_device *dev) | |
243 | { | |
244 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
245 | struct net_device *slave_dev; | |
246 | ||
247 | rcu_read_lock(); | |
248 | ||
249 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
250 | if (slave_dev) { | |
251 | dev_uc_sync_multiple(slave_dev, dev); | |
252 | dev_mc_sync_multiple(slave_dev, dev); | |
253 | } | |
254 | ||
255 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
256 | if (slave_dev) { | |
257 | dev_uc_sync_multiple(slave_dev, dev); | |
258 | dev_mc_sync_multiple(slave_dev, dev); | |
259 | } | |
260 | ||
261 | rcu_read_unlock(); | |
262 | } | |
263 | ||
264 | static int net_failover_vlan_rx_add_vid(struct net_device *dev, __be16 proto, | |
265 | u16 vid) | |
266 | { | |
267 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
268 | struct net_device *primary_dev, *standby_dev; | |
269 | int ret = 0; | |
270 | ||
271 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
272 | if (primary_dev) { | |
273 | ret = vlan_vid_add(primary_dev, proto, vid); | |
274 | if (ret) | |
275 | return ret; | |
276 | } | |
277 | ||
278 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
279 | if (standby_dev) { | |
280 | ret = vlan_vid_add(standby_dev, proto, vid); | |
281 | if (ret) | |
282 | if (primary_dev) | |
283 | vlan_vid_del(primary_dev, proto, vid); | |
284 | } | |
285 | ||
286 | return ret; | |
287 | } | |
288 | ||
289 | static int net_failover_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, | |
290 | u16 vid) | |
291 | { | |
292 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
293 | struct net_device *slave_dev; | |
294 | ||
295 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
296 | if (slave_dev) | |
297 | vlan_vid_del(slave_dev, proto, vid); | |
298 | ||
299 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
300 | if (slave_dev) | |
301 | vlan_vid_del(slave_dev, proto, vid); | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | static const struct net_device_ops failover_dev_ops = { | |
307 | .ndo_open = net_failover_open, | |
308 | .ndo_stop = net_failover_close, | |
309 | .ndo_start_xmit = net_failover_start_xmit, | |
310 | .ndo_select_queue = net_failover_select_queue, | |
311 | .ndo_get_stats64 = net_failover_get_stats, | |
312 | .ndo_change_mtu = net_failover_change_mtu, | |
313 | .ndo_set_rx_mode = net_failover_set_rx_mode, | |
314 | .ndo_vlan_rx_add_vid = net_failover_vlan_rx_add_vid, | |
315 | .ndo_vlan_rx_kill_vid = net_failover_vlan_rx_kill_vid, | |
316 | .ndo_validate_addr = eth_validate_addr, | |
317 | .ndo_features_check = passthru_features_check, | |
318 | }; | |
319 | ||
320 | #define FAILOVER_NAME "net_failover" | |
321 | #define FAILOVER_VERSION "0.1" | |
322 | ||
323 | static void nfo_ethtool_get_drvinfo(struct net_device *dev, | |
324 | struct ethtool_drvinfo *drvinfo) | |
325 | { | |
326 | strlcpy(drvinfo->driver, FAILOVER_NAME, sizeof(drvinfo->driver)); | |
327 | strlcpy(drvinfo->version, FAILOVER_VERSION, sizeof(drvinfo->version)); | |
328 | } | |
329 | ||
330 | static int nfo_ethtool_get_link_ksettings(struct net_device *dev, | |
331 | struct ethtool_link_ksettings *cmd) | |
332 | { | |
333 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
334 | struct net_device *slave_dev; | |
335 | ||
336 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
337 | if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { | |
338 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
339 | if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { | |
340 | cmd->base.duplex = DUPLEX_UNKNOWN; | |
341 | cmd->base.port = PORT_OTHER; | |
342 | cmd->base.speed = SPEED_UNKNOWN; | |
343 | ||
344 | return 0; | |
345 | } | |
346 | } | |
347 | ||
348 | return __ethtool_get_link_ksettings(slave_dev, cmd); | |
349 | } | |
350 | ||
351 | static const struct ethtool_ops failover_ethtool_ops = { | |
352 | .get_drvinfo = nfo_ethtool_get_drvinfo, | |
353 | .get_link = ethtool_op_get_link, | |
354 | .get_link_ksettings = nfo_ethtool_get_link_ksettings, | |
355 | }; | |
356 | ||
357 | /* Called when slave dev is injecting data into network stack. | |
358 | * Change the associated network device from lower dev to failover dev. | |
359 | * note: already called with rcu_read_lock | |
360 | */ | |
361 | static rx_handler_result_t net_failover_handle_frame(struct sk_buff **pskb) | |
362 | { | |
363 | struct sk_buff *skb = *pskb; | |
364 | struct net_device *dev = rcu_dereference(skb->dev->rx_handler_data); | |
365 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
366 | struct net_device *primary_dev, *standby_dev; | |
367 | ||
368 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
369 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
370 | ||
371 | if (primary_dev && skb->dev == standby_dev) | |
372 | return RX_HANDLER_EXACT; | |
373 | ||
374 | skb->dev = dev; | |
375 | ||
376 | return RX_HANDLER_ANOTHER; | |
377 | } | |
378 | ||
379 | static void net_failover_compute_features(struct net_device *dev) | |
380 | { | |
a746407a DC |
381 | netdev_features_t vlan_features = FAILOVER_VLAN_FEATURES & |
382 | NETIF_F_ALL_FOR_ALL; | |
cfc80d9a SS |
383 | netdev_features_t enc_features = FAILOVER_ENC_FEATURES; |
384 | unsigned short max_hard_header_len = ETH_HLEN; | |
385 | unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE | | |
386 | IFF_XMIT_DST_RELEASE_PERM; | |
387 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
388 | struct net_device *primary_dev, *standby_dev; | |
389 | ||
390 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
391 | if (primary_dev) { | |
392 | vlan_features = | |
393 | netdev_increment_features(vlan_features, | |
394 | primary_dev->vlan_features, | |
395 | FAILOVER_VLAN_FEATURES); | |
396 | enc_features = | |
397 | netdev_increment_features(enc_features, | |
398 | primary_dev->hw_enc_features, | |
399 | FAILOVER_ENC_FEATURES); | |
400 | ||
401 | dst_release_flag &= primary_dev->priv_flags; | |
402 | if (primary_dev->hard_header_len > max_hard_header_len) | |
403 | max_hard_header_len = primary_dev->hard_header_len; | |
404 | } | |
405 | ||
406 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
407 | if (standby_dev) { | |
408 | vlan_features = | |
409 | netdev_increment_features(vlan_features, | |
410 | standby_dev->vlan_features, | |
411 | FAILOVER_VLAN_FEATURES); | |
412 | enc_features = | |
413 | netdev_increment_features(enc_features, | |
414 | standby_dev->hw_enc_features, | |
415 | FAILOVER_ENC_FEATURES); | |
416 | ||
417 | dst_release_flag &= standby_dev->priv_flags; | |
418 | if (standby_dev->hard_header_len > max_hard_header_len) | |
419 | max_hard_header_len = standby_dev->hard_header_len; | |
420 | } | |
421 | ||
422 | dev->vlan_features = vlan_features; | |
423 | dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL; | |
424 | dev->hard_header_len = max_hard_header_len; | |
425 | ||
426 | dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; | |
427 | if (dst_release_flag == (IFF_XMIT_DST_RELEASE | | |
428 | IFF_XMIT_DST_RELEASE_PERM)) | |
429 | dev->priv_flags |= IFF_XMIT_DST_RELEASE; | |
430 | ||
431 | netdev_change_features(dev); | |
432 | } | |
433 | ||
434 | static void net_failover_lower_state_changed(struct net_device *slave_dev, | |
435 | struct net_device *primary_dev, | |
436 | struct net_device *standby_dev) | |
437 | { | |
438 | struct netdev_lag_lower_state_info info; | |
439 | ||
440 | if (netif_carrier_ok(slave_dev)) | |
441 | info.link_up = true; | |
442 | else | |
443 | info.link_up = false; | |
444 | ||
445 | if (slave_dev == primary_dev) { | |
446 | if (netif_running(primary_dev)) | |
447 | info.tx_enabled = true; | |
448 | else | |
449 | info.tx_enabled = false; | |
450 | } else { | |
451 | if ((primary_dev && netif_running(primary_dev)) || | |
452 | (!netif_running(standby_dev))) | |
453 | info.tx_enabled = false; | |
454 | else | |
455 | info.tx_enabled = true; | |
456 | } | |
457 | ||
458 | netdev_lower_state_changed(slave_dev, &info); | |
459 | } | |
460 | ||
461 | static int net_failover_slave_pre_register(struct net_device *slave_dev, | |
462 | struct net_device *failover_dev) | |
463 | { | |
464 | struct net_device *standby_dev, *primary_dev; | |
465 | struct net_failover_info *nfo_info; | |
466 | bool slave_is_standby; | |
467 | ||
468 | nfo_info = netdev_priv(failover_dev); | |
469 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
470 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
471 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
472 | if (slave_is_standby ? standby_dev : primary_dev) { | |
473 | netdev_err(failover_dev, "%s attempting to register as slave dev when %s already present\n", | |
474 | slave_dev->name, | |
475 | slave_is_standby ? "standby" : "primary"); | |
476 | return -EINVAL; | |
477 | } | |
478 | ||
479 | /* We want to allow only a direct attached VF device as a primary | |
480 | * netdev. As there is no easy way to check for a VF device, restrict | |
481 | * this to a pci device. | |
482 | */ | |
483 | if (!slave_is_standby && (!slave_dev->dev.parent || | |
484 | !dev_is_pci(slave_dev->dev.parent))) | |
485 | return -EINVAL; | |
486 | ||
487 | if (failover_dev->features & NETIF_F_VLAN_CHALLENGED && | |
488 | vlan_uses_dev(failover_dev)) { | |
489 | netdev_err(failover_dev, "Device %s is VLAN challenged and failover device has VLAN set up\n", | |
490 | failover_dev->name); | |
491 | return -EINVAL; | |
492 | } | |
493 | ||
494 | return 0; | |
495 | } | |
496 | ||
497 | static int net_failover_slave_register(struct net_device *slave_dev, | |
498 | struct net_device *failover_dev) | |
499 | { | |
500 | struct net_device *standby_dev, *primary_dev; | |
501 | struct net_failover_info *nfo_info; | |
502 | bool slave_is_standby; | |
503 | u32 orig_mtu; | |
504 | int err; | |
505 | ||
506 | /* Align MTU of slave with failover dev */ | |
507 | orig_mtu = slave_dev->mtu; | |
508 | err = dev_set_mtu(slave_dev, failover_dev->mtu); | |
509 | if (err) { | |
510 | netdev_err(failover_dev, "unable to change mtu of %s to %u register failed\n", | |
511 | slave_dev->name, failover_dev->mtu); | |
512 | goto done; | |
513 | } | |
514 | ||
515 | dev_hold(slave_dev); | |
516 | ||
517 | if (netif_running(failover_dev)) { | |
00f54e68 | 518 | err = dev_open(slave_dev, NULL); |
cfc80d9a SS |
519 | if (err && (err != -EBUSY)) { |
520 | netdev_err(failover_dev, "Opening slave %s failed err:%d\n", | |
521 | slave_dev->name, err); | |
522 | goto err_dev_open; | |
523 | } | |
524 | } | |
525 | ||
526 | netif_addr_lock_bh(failover_dev); | |
527 | dev_uc_sync_multiple(slave_dev, failover_dev); | |
e5223438 | 528 | dev_mc_sync_multiple(slave_dev, failover_dev); |
cfc80d9a SS |
529 | netif_addr_unlock_bh(failover_dev); |
530 | ||
531 | err = vlan_vids_add_by_dev(slave_dev, failover_dev); | |
532 | if (err) { | |
533 | netdev_err(failover_dev, "Failed to add vlan ids to device %s err:%d\n", | |
534 | slave_dev->name, err); | |
535 | goto err_vlan_add; | |
536 | } | |
537 | ||
538 | nfo_info = netdev_priv(failover_dev); | |
539 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
540 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
541 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
542 | ||
543 | if (slave_is_standby) { | |
544 | rcu_assign_pointer(nfo_info->standby_dev, slave_dev); | |
545 | standby_dev = slave_dev; | |
546 | dev_get_stats(standby_dev, &nfo_info->standby_stats); | |
547 | } else { | |
548 | rcu_assign_pointer(nfo_info->primary_dev, slave_dev); | |
549 | primary_dev = slave_dev; | |
550 | dev_get_stats(primary_dev, &nfo_info->primary_stats); | |
551 | failover_dev->min_mtu = slave_dev->min_mtu; | |
552 | failover_dev->max_mtu = slave_dev->max_mtu; | |
553 | } | |
554 | ||
555 | net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); | |
556 | net_failover_compute_features(failover_dev); | |
557 | ||
558 | call_netdevice_notifiers(NETDEV_JOIN, slave_dev); | |
559 | ||
560 | netdev_info(failover_dev, "failover %s slave:%s registered\n", | |
561 | slave_is_standby ? "standby" : "primary", slave_dev->name); | |
562 | ||
563 | return 0; | |
564 | ||
565 | err_vlan_add: | |
566 | dev_uc_unsync(slave_dev, failover_dev); | |
567 | dev_mc_unsync(slave_dev, failover_dev); | |
568 | dev_close(slave_dev); | |
569 | err_dev_open: | |
570 | dev_put(slave_dev); | |
571 | dev_set_mtu(slave_dev, orig_mtu); | |
572 | done: | |
573 | return err; | |
574 | } | |
575 | ||
576 | static int net_failover_slave_pre_unregister(struct net_device *slave_dev, | |
577 | struct net_device *failover_dev) | |
578 | { | |
579 | struct net_device *standby_dev, *primary_dev; | |
580 | struct net_failover_info *nfo_info; | |
581 | ||
582 | nfo_info = netdev_priv(failover_dev); | |
583 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
584 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
585 | ||
586 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
587 | return -ENODEV; | |
588 | ||
589 | return 0; | |
590 | } | |
591 | ||
592 | static int net_failover_slave_unregister(struct net_device *slave_dev, | |
593 | struct net_device *failover_dev) | |
594 | { | |
595 | struct net_device *standby_dev, *primary_dev; | |
596 | struct net_failover_info *nfo_info; | |
597 | bool slave_is_standby; | |
598 | ||
599 | nfo_info = netdev_priv(failover_dev); | |
600 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
601 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
602 | ||
9e7e6cab Y |
603 | if (WARN_ON_ONCE(slave_dev != primary_dev && slave_dev != standby_dev)) |
604 | return -ENODEV; | |
605 | ||
cfc80d9a SS |
606 | vlan_vids_del_by_dev(slave_dev, failover_dev); |
607 | dev_uc_unsync(slave_dev, failover_dev); | |
608 | dev_mc_unsync(slave_dev, failover_dev); | |
609 | dev_close(slave_dev); | |
610 | ||
611 | nfo_info = netdev_priv(failover_dev); | |
612 | dev_get_stats(failover_dev, &nfo_info->failover_stats); | |
613 | ||
614 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
615 | if (slave_is_standby) { | |
616 | RCU_INIT_POINTER(nfo_info->standby_dev, NULL); | |
617 | } else { | |
618 | RCU_INIT_POINTER(nfo_info->primary_dev, NULL); | |
619 | if (standby_dev) { | |
620 | failover_dev->min_mtu = standby_dev->min_mtu; | |
621 | failover_dev->max_mtu = standby_dev->max_mtu; | |
622 | } | |
623 | } | |
624 | ||
625 | dev_put(slave_dev); | |
626 | ||
627 | net_failover_compute_features(failover_dev); | |
628 | ||
629 | netdev_info(failover_dev, "failover %s slave:%s unregistered\n", | |
630 | slave_is_standby ? "standby" : "primary", slave_dev->name); | |
631 | ||
632 | return 0; | |
633 | } | |
634 | ||
635 | static int net_failover_slave_link_change(struct net_device *slave_dev, | |
636 | struct net_device *failover_dev) | |
637 | { | |
638 | struct net_device *primary_dev, *standby_dev; | |
639 | struct net_failover_info *nfo_info; | |
640 | ||
641 | nfo_info = netdev_priv(failover_dev); | |
642 | ||
643 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
644 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
645 | ||
646 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
647 | return -ENODEV; | |
648 | ||
649 | if ((primary_dev && net_failover_xmit_ready(primary_dev)) || | |
650 | (standby_dev && net_failover_xmit_ready(standby_dev))) { | |
651 | netif_carrier_on(failover_dev); | |
652 | netif_tx_wake_all_queues(failover_dev); | |
653 | } else { | |
654 | dev_get_stats(failover_dev, &nfo_info->failover_stats); | |
655 | netif_carrier_off(failover_dev); | |
656 | netif_tx_stop_all_queues(failover_dev); | |
657 | } | |
658 | ||
659 | net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); | |
660 | ||
661 | return 0; | |
662 | } | |
663 | ||
664 | static int net_failover_slave_name_change(struct net_device *slave_dev, | |
665 | struct net_device *failover_dev) | |
666 | { | |
667 | struct net_device *primary_dev, *standby_dev; | |
668 | struct net_failover_info *nfo_info; | |
669 | ||
670 | nfo_info = netdev_priv(failover_dev); | |
671 | ||
672 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
673 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
674 | ||
675 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
676 | return -ENODEV; | |
677 | ||
678 | /* We need to bring up the slave after the rename by udev in case | |
679 | * open failed with EBUSY when it was registered. | |
680 | */ | |
00f54e68 | 681 | dev_open(slave_dev, NULL); |
cfc80d9a SS |
682 | |
683 | return 0; | |
684 | } | |
685 | ||
686 | static struct failover_ops net_failover_ops = { | |
687 | .slave_pre_register = net_failover_slave_pre_register, | |
688 | .slave_register = net_failover_slave_register, | |
689 | .slave_pre_unregister = net_failover_slave_pre_unregister, | |
690 | .slave_unregister = net_failover_slave_unregister, | |
691 | .slave_link_change = net_failover_slave_link_change, | |
692 | .slave_name_change = net_failover_slave_name_change, | |
693 | .slave_handle_frame = net_failover_handle_frame, | |
694 | }; | |
695 | ||
696 | /** | |
697 | * net_failover_create - Create and register a failover instance | |
698 | * | |
699 | * @dev: standby netdev | |
700 | * | |
701 | * Creates a failover netdev and registers a failover instance for a standby | |
702 | * netdev. Used by paravirtual drivers that use 3-netdev model. | |
703 | * The failover netdev acts as a master device and controls 2 slave devices - | |
704 | * the original standby netdev and a VF netdev with the same MAC gets | |
705 | * registered as primary netdev. | |
706 | * | |
707 | * Return: pointer to failover instance | |
708 | */ | |
709 | struct failover *net_failover_create(struct net_device *standby_dev) | |
710 | { | |
711 | struct device *dev = standby_dev->dev.parent; | |
712 | struct net_device *failover_dev; | |
713 | struct failover *failover; | |
714 | int err; | |
715 | ||
716 | /* Alloc at least 2 queues, for now we are going with 16 assuming | |
717 | * that VF devices being enslaved won't have too many queues. | |
718 | */ | |
719 | failover_dev = alloc_etherdev_mq(sizeof(struct net_failover_info), 16); | |
720 | if (!failover_dev) { | |
721 | dev_err(dev, "Unable to allocate failover_netdev!\n"); | |
722 | return ERR_PTR(-ENOMEM); | |
723 | } | |
724 | ||
725 | dev_net_set(failover_dev, dev_net(standby_dev)); | |
726 | SET_NETDEV_DEV(failover_dev, dev); | |
727 | ||
728 | failover_dev->netdev_ops = &failover_dev_ops; | |
729 | failover_dev->ethtool_ops = &failover_ethtool_ops; | |
730 | ||
731 | /* Initialize the device options */ | |
732 | failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; | |
733 | failover_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | | |
734 | IFF_TX_SKB_SHARING); | |
735 | ||
736 | /* don't acquire failover netdev's netif_tx_lock when transmitting */ | |
737 | failover_dev->features |= NETIF_F_LLTX; | |
738 | ||
739 | /* Don't allow failover devices to change network namespaces. */ | |
740 | failover_dev->features |= NETIF_F_NETNS_LOCAL; | |
741 | ||
742 | failover_dev->hw_features = FAILOVER_VLAN_FEATURES | | |
743 | NETIF_F_HW_VLAN_CTAG_TX | | |
744 | NETIF_F_HW_VLAN_CTAG_RX | | |
745 | NETIF_F_HW_VLAN_CTAG_FILTER; | |
746 | ||
747 | failover_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL; | |
748 | failover_dev->features |= failover_dev->hw_features; | |
749 | ||
750 | memcpy(failover_dev->dev_addr, standby_dev->dev_addr, | |
751 | failover_dev->addr_len); | |
752 | ||
753 | failover_dev->min_mtu = standby_dev->min_mtu; | |
754 | failover_dev->max_mtu = standby_dev->max_mtu; | |
755 | ||
756 | err = register_netdev(failover_dev); | |
757 | if (err) { | |
758 | dev_err(dev, "Unable to register failover_dev!\n"); | |
759 | goto err_register_netdev; | |
760 | } | |
761 | ||
762 | netif_carrier_off(failover_dev); | |
763 | ||
764 | failover = failover_register(failover_dev, &net_failover_ops); | |
09317da3 Y |
765 | if (IS_ERR(failover)) { |
766 | err = PTR_ERR(failover); | |
cfc80d9a | 767 | goto err_failover_register; |
09317da3 | 768 | } |
cfc80d9a SS |
769 | |
770 | return failover; | |
771 | ||
772 | err_failover_register: | |
773 | unregister_netdev(failover_dev); | |
774 | err_register_netdev: | |
775 | free_netdev(failover_dev); | |
776 | ||
777 | return ERR_PTR(err); | |
778 | } | |
779 | EXPORT_SYMBOL_GPL(net_failover_create); | |
780 | ||
781 | /** | |
782 | * net_failover_destroy - Destroy a failover instance | |
783 | * | |
784 | * @failover: pointer to failover instance | |
785 | * | |
786 | * Unregisters any slave netdevs associated with the failover instance by | |
787 | * calling failover_slave_unregister(). | |
788 | * unregisters the failover instance itself and finally frees the failover | |
789 | * netdev. Used by paravirtual drivers that use 3-netdev model. | |
790 | * | |
791 | */ | |
792 | void net_failover_destroy(struct failover *failover) | |
793 | { | |
794 | struct net_failover_info *nfo_info; | |
795 | struct net_device *failover_dev; | |
796 | struct net_device *slave_dev; | |
797 | ||
798 | if (!failover) | |
799 | return; | |
800 | ||
801 | failover_dev = rcu_dereference(failover->failover_dev); | |
802 | nfo_info = netdev_priv(failover_dev); | |
803 | ||
804 | netif_device_detach(failover_dev); | |
805 | ||
806 | rtnl_lock(); | |
807 | ||
808 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
809 | if (slave_dev) | |
810 | failover_slave_unregister(slave_dev); | |
811 | ||
812 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
813 | if (slave_dev) | |
814 | failover_slave_unregister(slave_dev); | |
815 | ||
816 | failover_unregister(failover); | |
817 | ||
818 | unregister_netdevice(failover_dev); | |
819 | ||
820 | rtnl_unlock(); | |
821 | ||
822 | free_netdev(failover_dev); | |
823 | } | |
824 | EXPORT_SYMBOL_GPL(net_failover_destroy); | |
825 | ||
826 | static __init int | |
827 | net_failover_init(void) | |
828 | { | |
829 | return 0; | |
830 | } | |
831 | module_init(net_failover_init); | |
832 | ||
833 | static __exit | |
834 | void net_failover_exit(void) | |
835 | { | |
836 | } | |
837 | module_exit(net_failover_exit); | |
838 | ||
839 | MODULE_DESCRIPTION("Failover driver for Paravirtual drivers"); | |
840 | MODULE_LICENSE("GPL v2"); |