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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: | |
e8224bfe VA |
64 | if (primary_dev) |
65 | dev_close(primary_dev); | |
cfc80d9a SS |
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 | { | |
625788b5 | 92 | dev_core_stats_tx_dropped_inc(dev); |
cfc80d9a SS |
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, | |
4f49dec9 | 118 | struct sk_buff *skb, |
a350ecce | 119 | struct net_device *sb_dev) |
cfc80d9a SS |
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) | |
a350ecce | 130 | txq = ops->ndo_select_queue(primary_dev, skb, sb_dev); |
cfc80d9a | 131 | else |
a350ecce | 132 | txq = netdev_pick_tx(primary_dev, skb, NULL); |
e3cbdcb0 FM |
133 | } else { |
134 | txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0; | |
cfc80d9a SS |
135 | } |
136 | ||
cfc80d9a SS |
137 | /* Save the original txq to restore before passing to the driver */ |
138 | qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping; | |
139 | ||
140 | if (unlikely(txq >= dev->real_num_tx_queues)) { | |
141 | do { | |
142 | txq -= dev->real_num_tx_queues; | |
143 | } while (txq >= dev->real_num_tx_queues); | |
144 | } | |
145 | ||
146 | return txq; | |
147 | } | |
148 | ||
149 | /* fold stats, assuming all rtnl_link_stats64 fields are u64, but | |
150 | * that some drivers can provide 32bit values only. | |
151 | */ | |
152 | static void net_failover_fold_stats(struct rtnl_link_stats64 *_res, | |
153 | const struct rtnl_link_stats64 *_new, | |
154 | const struct rtnl_link_stats64 *_old) | |
155 | { | |
156 | const u64 *new = (const u64 *)_new; | |
157 | const u64 *old = (const u64 *)_old; | |
158 | u64 *res = (u64 *)_res; | |
159 | int i; | |
160 | ||
161 | for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { | |
162 | u64 nv = new[i]; | |
163 | u64 ov = old[i]; | |
164 | s64 delta = nv - ov; | |
165 | ||
166 | /* detects if this particular field is 32bit only */ | |
167 | if (((nv | ov) >> 32) == 0) | |
168 | delta = (s64)(s32)((u32)nv - (u32)ov); | |
169 | ||
170 | /* filter anomalies, some drivers reset their stats | |
171 | * at down/up events. | |
172 | */ | |
173 | if (delta > 0) | |
174 | res[i] += delta; | |
175 | } | |
176 | } | |
177 | ||
178 | static void net_failover_get_stats(struct net_device *dev, | |
179 | struct rtnl_link_stats64 *stats) | |
180 | { | |
181 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
182 | const struct rtnl_link_stats64 *new; | |
183 | struct rtnl_link_stats64 temp; | |
184 | struct net_device *slave_dev; | |
185 | ||
186 | spin_lock(&nfo_info->stats_lock); | |
187 | memcpy(stats, &nfo_info->failover_stats, sizeof(*stats)); | |
188 | ||
189 | rcu_read_lock(); | |
190 | ||
191 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
192 | if (slave_dev) { | |
193 | new = dev_get_stats(slave_dev, &temp); | |
194 | net_failover_fold_stats(stats, new, &nfo_info->primary_stats); | |
195 | memcpy(&nfo_info->primary_stats, new, sizeof(*new)); | |
196 | } | |
197 | ||
198 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
199 | if (slave_dev) { | |
200 | new = dev_get_stats(slave_dev, &temp); | |
201 | net_failover_fold_stats(stats, new, &nfo_info->standby_stats); | |
202 | memcpy(&nfo_info->standby_stats, new, sizeof(*new)); | |
203 | } | |
204 | ||
205 | rcu_read_unlock(); | |
206 | ||
207 | memcpy(&nfo_info->failover_stats, stats, sizeof(*stats)); | |
208 | spin_unlock(&nfo_info->stats_lock); | |
209 | } | |
210 | ||
211 | static int net_failover_change_mtu(struct net_device *dev, int new_mtu) | |
212 | { | |
213 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
214 | struct net_device *primary_dev, *standby_dev; | |
215 | int ret = 0; | |
216 | ||
3260155a | 217 | primary_dev = rtnl_dereference(nfo_info->primary_dev); |
cfc80d9a SS |
218 | if (primary_dev) { |
219 | ret = dev_set_mtu(primary_dev, new_mtu); | |
220 | if (ret) | |
221 | return ret; | |
222 | } | |
223 | ||
3260155a | 224 | standby_dev = rtnl_dereference(nfo_info->standby_dev); |
cfc80d9a SS |
225 | if (standby_dev) { |
226 | ret = dev_set_mtu(standby_dev, new_mtu); | |
227 | if (ret) { | |
228 | if (primary_dev) | |
229 | dev_set_mtu(primary_dev, dev->mtu); | |
230 | return ret; | |
231 | } | |
232 | } | |
233 | ||
234 | dev->mtu = new_mtu; | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static void net_failover_set_rx_mode(struct net_device *dev) | |
240 | { | |
241 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
242 | struct net_device *slave_dev; | |
243 | ||
244 | rcu_read_lock(); | |
245 | ||
246 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
247 | if (slave_dev) { | |
248 | dev_uc_sync_multiple(slave_dev, dev); | |
249 | dev_mc_sync_multiple(slave_dev, dev); | |
250 | } | |
251 | ||
252 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
253 | if (slave_dev) { | |
254 | dev_uc_sync_multiple(slave_dev, dev); | |
255 | dev_mc_sync_multiple(slave_dev, dev); | |
256 | } | |
257 | ||
258 | rcu_read_unlock(); | |
259 | } | |
260 | ||
261 | static int net_failover_vlan_rx_add_vid(struct net_device *dev, __be16 proto, | |
262 | u16 vid) | |
263 | { | |
264 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
265 | struct net_device *primary_dev, *standby_dev; | |
266 | int ret = 0; | |
267 | ||
268 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
269 | if (primary_dev) { | |
270 | ret = vlan_vid_add(primary_dev, proto, vid); | |
271 | if (ret) | |
272 | return ret; | |
273 | } | |
274 | ||
275 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
276 | if (standby_dev) { | |
277 | ret = vlan_vid_add(standby_dev, proto, vid); | |
278 | if (ret) | |
279 | if (primary_dev) | |
280 | vlan_vid_del(primary_dev, proto, vid); | |
281 | } | |
282 | ||
283 | return ret; | |
284 | } | |
285 | ||
286 | static int net_failover_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, | |
287 | u16 vid) | |
288 | { | |
289 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
290 | struct net_device *slave_dev; | |
291 | ||
292 | slave_dev = rcu_dereference(nfo_info->primary_dev); | |
293 | if (slave_dev) | |
294 | vlan_vid_del(slave_dev, proto, vid); | |
295 | ||
296 | slave_dev = rcu_dereference(nfo_info->standby_dev); | |
297 | if (slave_dev) | |
298 | vlan_vid_del(slave_dev, proto, vid); | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | static const struct net_device_ops failover_dev_ops = { | |
304 | .ndo_open = net_failover_open, | |
305 | .ndo_stop = net_failover_close, | |
306 | .ndo_start_xmit = net_failover_start_xmit, | |
307 | .ndo_select_queue = net_failover_select_queue, | |
308 | .ndo_get_stats64 = net_failover_get_stats, | |
309 | .ndo_change_mtu = net_failover_change_mtu, | |
310 | .ndo_set_rx_mode = net_failover_set_rx_mode, | |
311 | .ndo_vlan_rx_add_vid = net_failover_vlan_rx_add_vid, | |
312 | .ndo_vlan_rx_kill_vid = net_failover_vlan_rx_kill_vid, | |
313 | .ndo_validate_addr = eth_validate_addr, | |
314 | .ndo_features_check = passthru_features_check, | |
315 | }; | |
316 | ||
317 | #define FAILOVER_NAME "net_failover" | |
318 | #define FAILOVER_VERSION "0.1" | |
319 | ||
320 | static void nfo_ethtool_get_drvinfo(struct net_device *dev, | |
321 | struct ethtool_drvinfo *drvinfo) | |
322 | { | |
fb3ceec1 WS |
323 | strscpy(drvinfo->driver, FAILOVER_NAME, sizeof(drvinfo->driver)); |
324 | strscpy(drvinfo->version, FAILOVER_VERSION, sizeof(drvinfo->version)); | |
cfc80d9a SS |
325 | } |
326 | ||
327 | static int nfo_ethtool_get_link_ksettings(struct net_device *dev, | |
328 | struct ethtool_link_ksettings *cmd) | |
329 | { | |
330 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
331 | struct net_device *slave_dev; | |
332 | ||
333 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
334 | if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { | |
335 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
336 | if (!slave_dev || !net_failover_xmit_ready(slave_dev)) { | |
337 | cmd->base.duplex = DUPLEX_UNKNOWN; | |
338 | cmd->base.port = PORT_OTHER; | |
339 | cmd->base.speed = SPEED_UNKNOWN; | |
340 | ||
341 | return 0; | |
342 | } | |
343 | } | |
344 | ||
345 | return __ethtool_get_link_ksettings(slave_dev, cmd); | |
346 | } | |
347 | ||
348 | static const struct ethtool_ops failover_ethtool_ops = { | |
349 | .get_drvinfo = nfo_ethtool_get_drvinfo, | |
350 | .get_link = ethtool_op_get_link, | |
351 | .get_link_ksettings = nfo_ethtool_get_link_ksettings, | |
352 | }; | |
353 | ||
354 | /* Called when slave dev is injecting data into network stack. | |
355 | * Change the associated network device from lower dev to failover dev. | |
356 | * note: already called with rcu_read_lock | |
357 | */ | |
358 | static rx_handler_result_t net_failover_handle_frame(struct sk_buff **pskb) | |
359 | { | |
360 | struct sk_buff *skb = *pskb; | |
361 | struct net_device *dev = rcu_dereference(skb->dev->rx_handler_data); | |
362 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
363 | struct net_device *primary_dev, *standby_dev; | |
364 | ||
365 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
366 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
367 | ||
368 | if (primary_dev && skb->dev == standby_dev) | |
369 | return RX_HANDLER_EXACT; | |
370 | ||
371 | skb->dev = dev; | |
372 | ||
373 | return RX_HANDLER_ANOTHER; | |
374 | } | |
375 | ||
376 | static void net_failover_compute_features(struct net_device *dev) | |
377 | { | |
a746407a DC |
378 | netdev_features_t vlan_features = FAILOVER_VLAN_FEATURES & |
379 | NETIF_F_ALL_FOR_ALL; | |
cfc80d9a SS |
380 | netdev_features_t enc_features = FAILOVER_ENC_FEATURES; |
381 | unsigned short max_hard_header_len = ETH_HLEN; | |
382 | unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE | | |
383 | IFF_XMIT_DST_RELEASE_PERM; | |
384 | struct net_failover_info *nfo_info = netdev_priv(dev); | |
385 | struct net_device *primary_dev, *standby_dev; | |
386 | ||
387 | primary_dev = rcu_dereference(nfo_info->primary_dev); | |
388 | if (primary_dev) { | |
389 | vlan_features = | |
390 | netdev_increment_features(vlan_features, | |
391 | primary_dev->vlan_features, | |
392 | FAILOVER_VLAN_FEATURES); | |
393 | enc_features = | |
394 | netdev_increment_features(enc_features, | |
395 | primary_dev->hw_enc_features, | |
396 | FAILOVER_ENC_FEATURES); | |
397 | ||
398 | dst_release_flag &= primary_dev->priv_flags; | |
399 | if (primary_dev->hard_header_len > max_hard_header_len) | |
400 | max_hard_header_len = primary_dev->hard_header_len; | |
401 | } | |
402 | ||
403 | standby_dev = rcu_dereference(nfo_info->standby_dev); | |
404 | if (standby_dev) { | |
405 | vlan_features = | |
406 | netdev_increment_features(vlan_features, | |
407 | standby_dev->vlan_features, | |
408 | FAILOVER_VLAN_FEATURES); | |
409 | enc_features = | |
410 | netdev_increment_features(enc_features, | |
411 | standby_dev->hw_enc_features, | |
412 | FAILOVER_ENC_FEATURES); | |
413 | ||
414 | dst_release_flag &= standby_dev->priv_flags; | |
415 | if (standby_dev->hard_header_len > max_hard_header_len) | |
416 | max_hard_header_len = standby_dev->hard_header_len; | |
417 | } | |
418 | ||
419 | dev->vlan_features = vlan_features; | |
420 | dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL; | |
421 | dev->hard_header_len = max_hard_header_len; | |
422 | ||
423 | dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; | |
424 | if (dst_release_flag == (IFF_XMIT_DST_RELEASE | | |
425 | IFF_XMIT_DST_RELEASE_PERM)) | |
426 | dev->priv_flags |= IFF_XMIT_DST_RELEASE; | |
427 | ||
428 | netdev_change_features(dev); | |
429 | } | |
430 | ||
431 | static void net_failover_lower_state_changed(struct net_device *slave_dev, | |
432 | struct net_device *primary_dev, | |
433 | struct net_device *standby_dev) | |
434 | { | |
435 | struct netdev_lag_lower_state_info info; | |
436 | ||
437 | if (netif_carrier_ok(slave_dev)) | |
438 | info.link_up = true; | |
439 | else | |
440 | info.link_up = false; | |
441 | ||
442 | if (slave_dev == primary_dev) { | |
443 | if (netif_running(primary_dev)) | |
444 | info.tx_enabled = true; | |
445 | else | |
446 | info.tx_enabled = false; | |
447 | } else { | |
448 | if ((primary_dev && netif_running(primary_dev)) || | |
449 | (!netif_running(standby_dev))) | |
450 | info.tx_enabled = false; | |
451 | else | |
452 | info.tx_enabled = true; | |
453 | } | |
454 | ||
455 | netdev_lower_state_changed(slave_dev, &info); | |
456 | } | |
457 | ||
458 | static int net_failover_slave_pre_register(struct net_device *slave_dev, | |
459 | struct net_device *failover_dev) | |
460 | { | |
461 | struct net_device *standby_dev, *primary_dev; | |
462 | struct net_failover_info *nfo_info; | |
463 | bool slave_is_standby; | |
464 | ||
465 | nfo_info = netdev_priv(failover_dev); | |
466 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
467 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
468 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
469 | if (slave_is_standby ? standby_dev : primary_dev) { | |
470 | netdev_err(failover_dev, "%s attempting to register as slave dev when %s already present\n", | |
471 | slave_dev->name, | |
472 | slave_is_standby ? "standby" : "primary"); | |
473 | return -EINVAL; | |
474 | } | |
475 | ||
476 | /* We want to allow only a direct attached VF device as a primary | |
477 | * netdev. As there is no easy way to check for a VF device, restrict | |
478 | * this to a pci device. | |
479 | */ | |
480 | if (!slave_is_standby && (!slave_dev->dev.parent || | |
481 | !dev_is_pci(slave_dev->dev.parent))) | |
482 | return -EINVAL; | |
483 | ||
484 | if (failover_dev->features & NETIF_F_VLAN_CHALLENGED && | |
485 | vlan_uses_dev(failover_dev)) { | |
486 | netdev_err(failover_dev, "Device %s is VLAN challenged and failover device has VLAN set up\n", | |
487 | failover_dev->name); | |
488 | return -EINVAL; | |
489 | } | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
494 | static int net_failover_slave_register(struct net_device *slave_dev, | |
495 | struct net_device *failover_dev) | |
496 | { | |
497 | struct net_device *standby_dev, *primary_dev; | |
498 | struct net_failover_info *nfo_info; | |
499 | bool slave_is_standby; | |
500 | u32 orig_mtu; | |
501 | int err; | |
502 | ||
503 | /* Align MTU of slave with failover dev */ | |
504 | orig_mtu = slave_dev->mtu; | |
505 | err = dev_set_mtu(slave_dev, failover_dev->mtu); | |
506 | if (err) { | |
507 | netdev_err(failover_dev, "unable to change mtu of %s to %u register failed\n", | |
508 | slave_dev->name, failover_dev->mtu); | |
509 | goto done; | |
510 | } | |
511 | ||
512 | dev_hold(slave_dev); | |
513 | ||
514 | if (netif_running(failover_dev)) { | |
00f54e68 | 515 | err = dev_open(slave_dev, NULL); |
cfc80d9a SS |
516 | if (err && (err != -EBUSY)) { |
517 | netdev_err(failover_dev, "Opening slave %s failed err:%d\n", | |
518 | slave_dev->name, err); | |
519 | goto err_dev_open; | |
520 | } | |
521 | } | |
522 | ||
523 | netif_addr_lock_bh(failover_dev); | |
524 | dev_uc_sync_multiple(slave_dev, failover_dev); | |
e5223438 | 525 | dev_mc_sync_multiple(slave_dev, failover_dev); |
cfc80d9a SS |
526 | netif_addr_unlock_bh(failover_dev); |
527 | ||
528 | err = vlan_vids_add_by_dev(slave_dev, failover_dev); | |
529 | if (err) { | |
530 | netdev_err(failover_dev, "Failed to add vlan ids to device %s err:%d\n", | |
531 | slave_dev->name, err); | |
532 | goto err_vlan_add; | |
533 | } | |
534 | ||
535 | nfo_info = netdev_priv(failover_dev); | |
536 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
537 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
538 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
539 | ||
540 | if (slave_is_standby) { | |
541 | rcu_assign_pointer(nfo_info->standby_dev, slave_dev); | |
542 | standby_dev = slave_dev; | |
543 | dev_get_stats(standby_dev, &nfo_info->standby_stats); | |
544 | } else { | |
545 | rcu_assign_pointer(nfo_info->primary_dev, slave_dev); | |
546 | primary_dev = slave_dev; | |
547 | dev_get_stats(primary_dev, &nfo_info->primary_stats); | |
548 | failover_dev->min_mtu = slave_dev->min_mtu; | |
549 | failover_dev->max_mtu = slave_dev->max_mtu; | |
550 | } | |
551 | ||
552 | net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); | |
553 | net_failover_compute_features(failover_dev); | |
554 | ||
555 | call_netdevice_notifiers(NETDEV_JOIN, slave_dev); | |
556 | ||
557 | netdev_info(failover_dev, "failover %s slave:%s registered\n", | |
558 | slave_is_standby ? "standby" : "primary", slave_dev->name); | |
559 | ||
560 | return 0; | |
561 | ||
562 | err_vlan_add: | |
563 | dev_uc_unsync(slave_dev, failover_dev); | |
564 | dev_mc_unsync(slave_dev, failover_dev); | |
565 | dev_close(slave_dev); | |
566 | err_dev_open: | |
567 | dev_put(slave_dev); | |
568 | dev_set_mtu(slave_dev, orig_mtu); | |
569 | done: | |
570 | return err; | |
571 | } | |
572 | ||
573 | static int net_failover_slave_pre_unregister(struct net_device *slave_dev, | |
574 | struct net_device *failover_dev) | |
575 | { | |
576 | struct net_device *standby_dev, *primary_dev; | |
577 | struct net_failover_info *nfo_info; | |
578 | ||
579 | nfo_info = netdev_priv(failover_dev); | |
580 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
581 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
582 | ||
583 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
584 | return -ENODEV; | |
585 | ||
586 | return 0; | |
587 | } | |
588 | ||
589 | static int net_failover_slave_unregister(struct net_device *slave_dev, | |
590 | struct net_device *failover_dev) | |
591 | { | |
592 | struct net_device *standby_dev, *primary_dev; | |
593 | struct net_failover_info *nfo_info; | |
594 | bool slave_is_standby; | |
595 | ||
596 | nfo_info = netdev_priv(failover_dev); | |
597 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
598 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
599 | ||
9e7e6cab Y |
600 | if (WARN_ON_ONCE(slave_dev != primary_dev && slave_dev != standby_dev)) |
601 | return -ENODEV; | |
602 | ||
cfc80d9a SS |
603 | vlan_vids_del_by_dev(slave_dev, failover_dev); |
604 | dev_uc_unsync(slave_dev, failover_dev); | |
605 | dev_mc_unsync(slave_dev, failover_dev); | |
606 | dev_close(slave_dev); | |
607 | ||
608 | nfo_info = netdev_priv(failover_dev); | |
609 | dev_get_stats(failover_dev, &nfo_info->failover_stats); | |
610 | ||
611 | slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent; | |
612 | if (slave_is_standby) { | |
613 | RCU_INIT_POINTER(nfo_info->standby_dev, NULL); | |
614 | } else { | |
615 | RCU_INIT_POINTER(nfo_info->primary_dev, NULL); | |
616 | if (standby_dev) { | |
617 | failover_dev->min_mtu = standby_dev->min_mtu; | |
618 | failover_dev->max_mtu = standby_dev->max_mtu; | |
619 | } | |
620 | } | |
621 | ||
622 | dev_put(slave_dev); | |
623 | ||
624 | net_failover_compute_features(failover_dev); | |
625 | ||
626 | netdev_info(failover_dev, "failover %s slave:%s unregistered\n", | |
627 | slave_is_standby ? "standby" : "primary", slave_dev->name); | |
628 | ||
629 | return 0; | |
630 | } | |
631 | ||
632 | static int net_failover_slave_link_change(struct net_device *slave_dev, | |
633 | struct net_device *failover_dev) | |
634 | { | |
635 | struct net_device *primary_dev, *standby_dev; | |
636 | struct net_failover_info *nfo_info; | |
637 | ||
638 | nfo_info = netdev_priv(failover_dev); | |
639 | ||
640 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
641 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
642 | ||
643 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
644 | return -ENODEV; | |
645 | ||
646 | if ((primary_dev && net_failover_xmit_ready(primary_dev)) || | |
647 | (standby_dev && net_failover_xmit_ready(standby_dev))) { | |
648 | netif_carrier_on(failover_dev); | |
649 | netif_tx_wake_all_queues(failover_dev); | |
650 | } else { | |
651 | dev_get_stats(failover_dev, &nfo_info->failover_stats); | |
652 | netif_carrier_off(failover_dev); | |
653 | netif_tx_stop_all_queues(failover_dev); | |
654 | } | |
655 | ||
656 | net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev); | |
657 | ||
658 | return 0; | |
659 | } | |
660 | ||
661 | static int net_failover_slave_name_change(struct net_device *slave_dev, | |
662 | struct net_device *failover_dev) | |
663 | { | |
664 | struct net_device *primary_dev, *standby_dev; | |
665 | struct net_failover_info *nfo_info; | |
666 | ||
667 | nfo_info = netdev_priv(failover_dev); | |
668 | ||
669 | primary_dev = rtnl_dereference(nfo_info->primary_dev); | |
670 | standby_dev = rtnl_dereference(nfo_info->standby_dev); | |
671 | ||
672 | if (slave_dev != primary_dev && slave_dev != standby_dev) | |
673 | return -ENODEV; | |
674 | ||
675 | /* We need to bring up the slave after the rename by udev in case | |
676 | * open failed with EBUSY when it was registered. | |
677 | */ | |
00f54e68 | 678 | dev_open(slave_dev, NULL); |
cfc80d9a SS |
679 | |
680 | return 0; | |
681 | } | |
682 | ||
683 | static struct failover_ops net_failover_ops = { | |
684 | .slave_pre_register = net_failover_slave_pre_register, | |
685 | .slave_register = net_failover_slave_register, | |
686 | .slave_pre_unregister = net_failover_slave_pre_unregister, | |
687 | .slave_unregister = net_failover_slave_unregister, | |
688 | .slave_link_change = net_failover_slave_link_change, | |
689 | .slave_name_change = net_failover_slave_name_change, | |
690 | .slave_handle_frame = net_failover_handle_frame, | |
691 | }; | |
692 | ||
693 | /** | |
694 | * net_failover_create - Create and register a failover instance | |
695 | * | |
c1c0f6ea | 696 | * @standby_dev: standby netdev |
cfc80d9a SS |
697 | * |
698 | * Creates a failover netdev and registers a failover instance for a standby | |
699 | * netdev. Used by paravirtual drivers that use 3-netdev model. | |
700 | * The failover netdev acts as a master device and controls 2 slave devices - | |
701 | * the original standby netdev and a VF netdev with the same MAC gets | |
702 | * registered as primary netdev. | |
703 | * | |
704 | * Return: pointer to failover instance | |
705 | */ | |
706 | struct failover *net_failover_create(struct net_device *standby_dev) | |
707 | { | |
708 | struct device *dev = standby_dev->dev.parent; | |
709 | struct net_device *failover_dev; | |
710 | struct failover *failover; | |
711 | int err; | |
712 | ||
713 | /* Alloc at least 2 queues, for now we are going with 16 assuming | |
714 | * that VF devices being enslaved won't have too many queues. | |
715 | */ | |
716 | failover_dev = alloc_etherdev_mq(sizeof(struct net_failover_info), 16); | |
717 | if (!failover_dev) { | |
718 | dev_err(dev, "Unable to allocate failover_netdev!\n"); | |
719 | return ERR_PTR(-ENOMEM); | |
720 | } | |
721 | ||
722 | dev_net_set(failover_dev, dev_net(standby_dev)); | |
723 | SET_NETDEV_DEV(failover_dev, dev); | |
724 | ||
725 | failover_dev->netdev_ops = &failover_dev_ops; | |
726 | failover_dev->ethtool_ops = &failover_ethtool_ops; | |
727 | ||
728 | /* Initialize the device options */ | |
729 | failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; | |
730 | failover_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | | |
731 | IFF_TX_SKB_SHARING); | |
732 | ||
733 | /* don't acquire failover netdev's netif_tx_lock when transmitting */ | |
734 | failover_dev->features |= NETIF_F_LLTX; | |
735 | ||
736 | /* Don't allow failover devices to change network namespaces. */ | |
737 | failover_dev->features |= NETIF_F_NETNS_LOCAL; | |
738 | ||
739 | failover_dev->hw_features = FAILOVER_VLAN_FEATURES | | |
740 | NETIF_F_HW_VLAN_CTAG_TX | | |
741 | NETIF_F_HW_VLAN_CTAG_RX | | |
742 | NETIF_F_HW_VLAN_CTAG_FILTER; | |
743 | ||
744 | failover_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL; | |
745 | failover_dev->features |= failover_dev->hw_features; | |
746 | ||
ea52a0b5 | 747 | dev_addr_set(failover_dev, standby_dev->dev_addr); |
cfc80d9a SS |
748 | |
749 | failover_dev->min_mtu = standby_dev->min_mtu; | |
750 | failover_dev->max_mtu = standby_dev->max_mtu; | |
751 | ||
752 | err = register_netdev(failover_dev); | |
753 | if (err) { | |
754 | dev_err(dev, "Unable to register failover_dev!\n"); | |
755 | goto err_register_netdev; | |
756 | } | |
757 | ||
758 | netif_carrier_off(failover_dev); | |
759 | ||
760 | failover = failover_register(failover_dev, &net_failover_ops); | |
09317da3 Y |
761 | if (IS_ERR(failover)) { |
762 | err = PTR_ERR(failover); | |
cfc80d9a | 763 | goto err_failover_register; |
09317da3 | 764 | } |
cfc80d9a SS |
765 | |
766 | return failover; | |
767 | ||
768 | err_failover_register: | |
769 | unregister_netdev(failover_dev); | |
770 | err_register_netdev: | |
771 | free_netdev(failover_dev); | |
772 | ||
773 | return ERR_PTR(err); | |
774 | } | |
775 | EXPORT_SYMBOL_GPL(net_failover_create); | |
776 | ||
777 | /** | |
778 | * net_failover_destroy - Destroy a failover instance | |
779 | * | |
780 | * @failover: pointer to failover instance | |
781 | * | |
782 | * Unregisters any slave netdevs associated with the failover instance by | |
783 | * calling failover_slave_unregister(). | |
784 | * unregisters the failover instance itself and finally frees the failover | |
785 | * netdev. Used by paravirtual drivers that use 3-netdev model. | |
786 | * | |
787 | */ | |
788 | void net_failover_destroy(struct failover *failover) | |
789 | { | |
790 | struct net_failover_info *nfo_info; | |
791 | struct net_device *failover_dev; | |
792 | struct net_device *slave_dev; | |
793 | ||
794 | if (!failover) | |
795 | return; | |
796 | ||
797 | failover_dev = rcu_dereference(failover->failover_dev); | |
798 | nfo_info = netdev_priv(failover_dev); | |
799 | ||
800 | netif_device_detach(failover_dev); | |
801 | ||
802 | rtnl_lock(); | |
803 | ||
804 | slave_dev = rtnl_dereference(nfo_info->primary_dev); | |
805 | if (slave_dev) | |
806 | failover_slave_unregister(slave_dev); | |
807 | ||
808 | slave_dev = rtnl_dereference(nfo_info->standby_dev); | |
809 | if (slave_dev) | |
810 | failover_slave_unregister(slave_dev); | |
811 | ||
812 | failover_unregister(failover); | |
813 | ||
814 | unregister_netdevice(failover_dev); | |
815 | ||
816 | rtnl_unlock(); | |
817 | ||
818 | free_netdev(failover_dev); | |
819 | } | |
820 | EXPORT_SYMBOL_GPL(net_failover_destroy); | |
821 | ||
822 | static __init int | |
823 | net_failover_init(void) | |
824 | { | |
825 | return 0; | |
826 | } | |
827 | module_init(net_failover_init); | |
828 | ||
829 | static __exit | |
830 | void net_failover_exit(void) | |
831 | { | |
832 | } | |
833 | module_exit(net_failover_exit); | |
834 | ||
835 | MODULE_DESCRIPTION("Failover driver for Paravirtual drivers"); | |
836 | MODULE_LICENSE("GPL v2"); |