1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2007-2014 Nicira, Inc.
4 */
5
6 #include <linux/etherdevice.h>
7 #include <linux/if.h>
8 #include <linux/if_vlan.h>
9 #include <linux/jhash.h>
10 #include <linux/kernel.h>
11 #include <linux/list.h>
12 #include <linux/mutex.h>
13 #include <linux/percpu.h>
14 #include <linux/rcupdate.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/compat.h>
17 #include <net/net_namespace.h>
18 #include <linux/module.h>
19
20 #include "datapath.h"
21 #include "vport.h"
22 #include "vport-internal_dev.h"
23
24 static LIST_HEAD(vport_ops_list);
25
26 /* Protected by RCU read lock for reading, ovs_mutex for writing. */
27 static struct hlist_head *dev_table;
28 #define VPORT_HASH_BUCKETS 1024
29
30 /**
31 * ovs_vport_init - initialize vport subsystem
32 *
33 * Called at module load time to initialize the vport subsystem.
34 */
35 int ovs_vport_init(void)
36 {
37 dev_table = kcalloc(VPORT_HASH_BUCKETS, sizeof(struct hlist_head),
38 GFP_KERNEL);
39 if (!dev_table)
40 return -ENOMEM;
41
42 return 0;
43 }
44
45 /**
46 * ovs_vport_exit - shutdown vport subsystem
47 *
48 * Called at module exit time to shutdown the vport subsystem.
49 */
50 void ovs_vport_exit(void)
51 {
52 kfree(dev_table);
53 }
54
55 static struct hlist_head *hash_bucket(const struct net *net, const char *name)
56 {
57 unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
58 return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
59 }
60
61 int __ovs_vport_ops_register(struct vport_ops *ops)
62 {
63 int err = -EEXIST;
64 struct vport_ops *o;
65
66 ovs_lock();
67 list_for_each_entry(o, &vport_ops_list, list)
68 if (ops->type == o->type)
69 goto errout;
70
71 list_add_tail(&ops->list, &vport_ops_list);
72 err = 0;
73 errout:
74 ovs_unlock();
75 return err;
76 }
77 EXPORT_SYMBOL_GPL(__ovs_vport_ops_register);
78
79 void ovs_vport_ops_unregister(struct vport_ops *ops)
80 {
81 ovs_lock();
82 list_del(&ops->list);
83 ovs_unlock();
84 }
85 EXPORT_SYMBOL_GPL(ovs_vport_ops_unregister);
86
87 /**
88 * ovs_vport_locate - find a port that has already been created
89 *
90 * @net: network namespace
91 * @name: name of port to find
92 *
93 * Must be called with ovs or RCU read lock.
94 */
95 struct vport *ovs_vport_locate(const struct net *net, const char *name)
96 {
97 struct hlist_head *bucket = hash_bucket(net, name);
98 struct vport *vport;
99
100 hlist_for_each_entry_rcu(vport, bucket, hash_node,
101 lockdep_ovsl_is_held())
102 if (!strcmp(name, ovs_vport_name(vport)) &&
103 net_eq(ovs_dp_get_net(vport->dp), net))
104 return vport;
105
106 return NULL;
107 }
108
109 /**
110 * ovs_vport_alloc - allocate and initialize new vport
111 *
112 * @priv_size: Size of private data area to allocate.
113 * @ops: vport device ops
114 * @parms: information about new vport.
115 *
116 * Allocate and initialize a new vport defined by @ops. The vport will contain
117 * a private data area of size @priv_size that can be accessed using
118 * vport_priv(). Some parameters of the vport will be initialized from @parms.
119 * @vports that are no longer needed should be released with
120 * vport_free().
121 */
122 struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
123 const struct vport_parms *parms)
124 {
125 struct vport *vport;
126 size_t alloc_size;
127 int err;
128
129 alloc_size = sizeof(struct vport);
130 if (priv_size) {
131 alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
132 alloc_size += priv_size;
133 }
134
135 vport = kzalloc(alloc_size, GFP_KERNEL);
136 if (!vport)
137 return ERR_PTR(-ENOMEM);
138
139 vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
140 if (!vport->upcall_stats) {
141 err = -ENOMEM;
142 goto err_kfree_vport;
143 }
144
145 vport->dp = parms->dp;
146 vport->port_no = parms->port_no;
147 vport->ops = ops;
148 INIT_HLIST_NODE(&vport->dp_hash_node);
149
150 if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) {
151 err = -EINVAL;
152 goto err_free_percpu;
153 }
154
155 return vport;
156
157 err_free_percpu:
158 free_percpu(vport->upcall_stats);
159 err_kfree_vport:
160 kfree(vport);
161 return ERR_PTR(err);
162 }
163 EXPORT_SYMBOL_GPL(ovs_vport_alloc);
164
165 /**
166 * ovs_vport_free - uninitialize and free vport
167 *
168 * @vport: vport to free
169 *
170 * Frees a vport allocated with vport_alloc() when it is no longer needed.
171 *
172 * The caller must ensure that an RCU grace period has passed since the last
173 * time @vport was in a datapath.
174 */
175 void ovs_vport_free(struct vport *vport)
176 {
177 /* vport is freed from RCU callback or error path, Therefore
178 * it is safe to use raw dereference.
179 */
180 kfree(rcu_dereference_raw(vport->upcall_portids));
181 free_percpu(vport->upcall_stats);
182 kfree(vport);
183 }
184 EXPORT_SYMBOL_GPL(ovs_vport_free);
185
186 static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms)
187 {
188 struct vport_ops *ops;
189
190 list_for_each_entry(ops, &vport_ops_list, list)
191 if (ops->type == parms->type)
192 return ops;
193
194 return NULL;
195 }
196
197 /**
198 * ovs_vport_add - add vport device (for kernel callers)
199 *
200 * @parms: Information about new vport.
201 *
202 * Creates a new vport with the specified configuration (which is dependent on
203 * device type). ovs_mutex must be held.
204 */
205 struct vport *ovs_vport_add(const struct vport_parms *parms)
206 {
207 struct vport_ops *ops;
208 struct vport *vport;
209
210 ops = ovs_vport_lookup(parms);
211 if (ops) {
212 struct hlist_head *bucket;
213
214 if (!try_module_get(ops->owner))
215 return ERR_PTR(-EAFNOSUPPORT);
216
217 vport = ops->create(parms);
218 if (IS_ERR(vport)) {
219 module_put(ops->owner);
220 return vport;
221 }
222
223 bucket = hash_bucket(ovs_dp_get_net(vport->dp),
224 ovs_vport_name(vport));
225 hlist_add_head_rcu(&vport->hash_node, bucket);
226 return vport;
227 }
228
229 /* Unlock to attempt module load and return -EAGAIN if load
230 * was successful as we need to restart the port addition
231 * workflow.
232 */
233 ovs_unlock();
234 request_module("vport-type-%d", parms->type);
235 ovs_lock();
236
237 if (!ovs_vport_lookup(parms))
238 return ERR_PTR(-EAFNOSUPPORT);
239 else
240 return ERR_PTR(-EAGAIN);
241 }
242
243 /**
244 * ovs_vport_set_options - modify existing vport device (for kernel callers)
245 *
246 * @vport: vport to modify.
247 * @options: New configuration.
248 *
249 * Modifies an existing device with the specified configuration (which is
250 * dependent on device type). ovs_mutex must be held.
251 */
252 int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
253 {
254 if (!vport->ops->set_options)
255 return -EOPNOTSUPP;
256 return vport->ops->set_options(vport, options);
257 }
258
259 /**
260 * ovs_vport_del - delete existing vport device
261 *
262 * @vport: vport to delete.
263 *
264 * Detaches @vport from its datapath and destroys it. ovs_mutex must
265 * be held.
266 */
267 void ovs_vport_del(struct vport *vport)
268 {
269 hlist_del_rcu(&vport->hash_node);
270 module_put(vport->ops->owner);
271 vport->ops->destroy(vport);
272 }
273
274 /**
275 * ovs_vport_get_stats - retrieve device stats
276 *
277 * @vport: vport from which to retrieve the stats
278 * @stats: location to store stats
279 *
280 * Retrieves transmit, receive, and error stats for the given device.
281 *
282 * Must be called with ovs_mutex or rcu_read_lock.
283 */
284 void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
285 {
286 const struct rtnl_link_stats64 *dev_stats;
287 struct rtnl_link_stats64 temp;
288
289 dev_stats = dev_get_stats(vport->dev, &temp);
290 stats->rx_errors = dev_stats->rx_errors;
291 stats->tx_errors = dev_stats->tx_errors;
292 stats->tx_dropped = dev_stats->tx_dropped;
293 stats->rx_dropped = dev_stats->rx_dropped;
294
295 stats->rx_bytes = dev_stats->rx_bytes;
296 stats->rx_packets = dev_stats->rx_packets;
297 stats->tx_bytes = dev_stats->tx_bytes;
298 stats->tx_packets = dev_stats->tx_packets;
299 }
300
301 /**
302 * ovs_vport_get_upcall_stats - retrieve upcall stats
303 *
304 * @vport: vport from which to retrieve the stats.
305 * @skb: sk_buff where upcall stats should be appended.
306 *
307 * Retrieves upcall stats for the given device.
308 *
309 * Must be called with ovs_mutex or rcu_read_lock.
310 */
311 int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb)
312 {
313 struct nlattr *nla;
314 int i;
315
316 __u64 tx_success = 0;
317 __u64 tx_fail = 0;
318
319 for_each_possible_cpu(i) {
320 const struct vport_upcall_stats_percpu *stats;
321 unsigned int start;
322
323 stats = per_cpu_ptr(vport->upcall_stats, i);
324 do {
325 start = u64_stats_fetch_begin(&stats->syncp);
326 tx_success += u64_stats_read(&stats->n_success);
327 tx_fail += u64_stats_read(&stats->n_fail);
328 } while (u64_stats_fetch_retry(&stats->syncp, start));
329 }
330
331 nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS);
332 if (!nla)
333 return -EMSGSIZE;
334
335 if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_ATTR_SUCCESS, tx_success,
336 OVS_VPORT_ATTR_PAD)) {
337 nla_nest_cancel(skb, nla);
338 return -EMSGSIZE;
339 }
340
341 if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_ATTR_FAIL, tx_fail,
342 OVS_VPORT_ATTR_PAD)) {
343 nla_nest_cancel(skb, nla);
344 return -EMSGSIZE;
345 }
346 nla_nest_end(skb, nla);
347
348 return 0;
349 }
350
351 /**
352 * ovs_vport_get_options - retrieve device options
353 *
354 * @vport: vport from which to retrieve the options.
355 * @skb: sk_buff where options should be appended.
356 *
357 * Retrieves the configuration of the given device, appending an
358 * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
359 * vport-specific attributes to @skb.
360 *
361 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
362 * negative error code if a real error occurred. If an error occurs, @skb is
363 * left unmodified.
364 *
365 * Must be called with ovs_mutex or rcu_read_lock.
366 */
367 int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
368 {
369 struct nlattr *nla;
370 int err;
371
372 if (!vport->ops->get_options)
373 return 0;
374
375 nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_OPTIONS);
376 if (!nla)
377 return -EMSGSIZE;
378
379 err = vport->ops->get_options(vport, skb);
380 if (err) {
381 nla_nest_cancel(skb, nla);
382 return err;
383 }
384
385 nla_nest_end(skb, nla);
386 return 0;
387 }
388
389 /**
390 * ovs_vport_set_upcall_portids - set upcall portids of @vport.
391 *
392 * @vport: vport to modify.
393 * @ids: new configuration, an array of port ids.
394 *
395 * Sets the vport's upcall_portids to @ids.
396 *
397 * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed
398 * as an array of U32.
399 *
400 * Must be called with ovs_mutex.
401 */
402 int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids)
403 {
404 struct vport_portids *old, *vport_portids;
405
406 if (!nla_len(ids) || nla_len(ids) % sizeof(u32))
407 return -EINVAL;
408
409 old = ovsl_dereference(vport->upcall_portids);
410
411 vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids),
412 GFP_KERNEL);
413 if (!vport_portids)
414 return -ENOMEM;
415
416 vport_portids->n_ids = nla_len(ids) / sizeof(u32);
417 vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids);
418 nla_memcpy(vport_portids->ids, ids, nla_len(ids));
419
420 rcu_assign_pointer(vport->upcall_portids, vport_portids);
421
422 if (old)
423 kfree_rcu(old, rcu);
424 return 0;
425 }
426
427 /**
428 * ovs_vport_get_upcall_portids - get the upcall_portids of @vport.
429 *
430 * @vport: vport from which to retrieve the portids.
431 * @skb: sk_buff where portids should be appended.
432 *
433 * Retrieves the configuration of the given vport, appending the
434 * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall
435 * portids to @skb.
436 *
437 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room.
438 * If an error occurs, @skb is left unmodified. Must be called with
439 * ovs_mutex or rcu_read_lock.
440 */
441 int ovs_vport_get_upcall_portids(const struct vport *vport,
442 struct sk_buff *skb)
443 {
444 struct vport_portids *ids;
445
446 ids = rcu_dereference_ovsl(vport->upcall_portids);
447
448 if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS)
449 return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID,
450 ids->n_ids * sizeof(u32), (void *)ids->ids);
451 else
452 return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]);
453 }
454
455 /**
456 * ovs_vport_find_upcall_portid - find the upcall portid to send upcall.
457 *
458 * @vport: vport from which the missed packet is received.
459 * @skb: skb that the missed packet was received.
460 *
461 * Uses the skb_get_hash() to select the upcall portid to send the
462 * upcall.
463 *
464 * Returns the portid of the target socket. Must be called with rcu_read_lock.
465 */
466 u32 ovs_vport_find_upcall_portid(const struct vport *vport,
467 struct sk_buff *skb)
468 {
469 struct vport_portids *ids;
470 u32 ids_index;
471 u32 hash;
472
473 ids = rcu_dereference(vport->upcall_portids);
474
475 /* If there is only one portid, select it in the fast-path. */
476 if (ids->n_ids == 1)
477 return ids->ids[0];
478
479 hash = skb_get_hash(skb);
480 ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids);
481 return ids->ids[ids_index];
482 }
483
484 /**
485 * ovs_vport_receive - pass up received packet to the datapath for processing
486 *
487 * @vport: vport that received the packet
488 * @skb: skb that was received
489 * @tun_info: tunnel (if any) that carried packet
490 *
491 * Must be called with rcu_read_lock. The packet cannot be shared and
492 * skb->data should point to the Ethernet header.
493 */
494 int ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
495 const struct ip_tunnel_info *tun_info)
496 {
497 struct sw_flow_key key;
498 int error;
499
500 OVS_CB(skb)->input_vport = vport;
501 OVS_CB(skb)->mru = 0;
502 OVS_CB(skb)->cutlen = 0;
503 OVS_CB(skb)->probability = 0;
504 if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) {
505 u32 mark;
506
507 mark = skb->mark;
508 skb_scrub_packet(skb, true);
509 skb->mark = mark;
510 tun_info = NULL;
511 }
512
513 /* Extract flow from 'skb' into 'key'. */
514 error = ovs_flow_key_extract(tun_info, skb, &key);
515 if (unlikely(error)) {
516 kfree_skb(skb);
517 return error;
518 }
519 ovs_dp_process_packet(skb, &key);
520 return 0;
521 }
522
523 static int packet_length(const struct sk_buff *skb,
524 struct net_device *dev)
525 {
526 int length = skb->len - dev->hard_header_len;
527
528 if (!skb_vlan_tag_present(skb) &&
529 eth_type_vlan(skb->protocol))
530 length -= VLAN_HLEN;
531
532 /* Don't subtract for multiple VLAN tags. Most (all?) drivers allow
533 * (ETH_LEN + VLAN_HLEN) in addition to the mtu value, but almost none
534 * account for 802.1ad. e.g. is_skb_forwardable().
535 */
536
537 return length > 0 ? length : 0;
538 }
539
540 void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
541 {
542 int mtu = vport->dev->mtu;
543
544 switch (vport->dev->type) {
545 case ARPHRD_NONE:
546 if (mac_proto == MAC_PROTO_ETHERNET) {
547 skb_reset_network_header(skb);
548 skb_reset_mac_len(skb);
549 skb->protocol = htons(ETH_P_TEB);
550 } else if (mac_proto != MAC_PROTO_NONE) {
551 WARN_ON_ONCE(1);
552 goto drop;
553 }
554 break;
555 case ARPHRD_ETHER:
556 if (mac_proto != MAC_PROTO_ETHERNET)
557 goto drop;
558 break;
559 default:
560 goto drop;
561 }
562
563 if (unlikely(packet_length(skb, vport->dev) > mtu &&
564 !skb_is_gso(skb))) {
565 vport->dev->stats.tx_errors++;
566 if (vport->dev->flags & IFF_UP)
567 net_warn_ratelimited("%s: dropped over-mtu packet: "
568 "%d > %d\n", vport->dev->name,
569 packet_length(skb, vport->dev),
570 mtu);
571 goto drop;
572 }
573
574 skb->dev = vport->dev;
575 skb_clear_tstamp(skb);
576 vport->ops->send(skb);
577 return;
578
579 drop:
580 kfree_skb(skb);
581 }
582
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