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  */
ovs_vport_init(void)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  */
ovs_vport_exit(void)50 void ovs_vport_exit(void)
51 {
52 	kfree(dev_table);
53 }
54 
hash_bucket(const struct net * net,const char * name)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 
__ovs_vport_ops_register(struct vport_ops * ops)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 
ovs_vport_ops_unregister(struct vport_ops * ops)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  */
ovs_vport_locate(const struct net * net,const char * name)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  */
ovs_vport_alloc(int priv_size,const struct vport_ops * ops,const struct vport_parms * parms)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 
128 	alloc_size = sizeof(struct vport);
129 	if (priv_size) {
130 		alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
131 		alloc_size += priv_size;
132 	}
133 
134 	vport = kzalloc(alloc_size, GFP_KERNEL);
135 	if (!vport)
136 		return ERR_PTR(-ENOMEM);
137 
138 	vport->dp = parms->dp;
139 	vport->port_no = parms->port_no;
140 	vport->ops = ops;
141 	INIT_HLIST_NODE(&vport->dp_hash_node);
142 
143 	if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) {
144 		kfree(vport);
145 		return ERR_PTR(-EINVAL);
146 	}
147 
148 	return vport;
149 }
150 EXPORT_SYMBOL_GPL(ovs_vport_alloc);
151 
152 /**
153  *	ovs_vport_free - uninitialize and free vport
154  *
155  * @vport: vport to free
156  *
157  * Frees a vport allocated with vport_alloc() when it is no longer needed.
158  *
159  * The caller must ensure that an RCU grace period has passed since the last
160  * time @vport was in a datapath.
161  */
ovs_vport_free(struct vport * vport)162 void ovs_vport_free(struct vport *vport)
163 {
164 	/* vport is freed from RCU callback or error path, Therefore
165 	 * it is safe to use raw dereference.
166 	 */
167 	kfree(rcu_dereference_raw(vport->upcall_portids));
168 	kfree(vport);
169 }
170 EXPORT_SYMBOL_GPL(ovs_vport_free);
171 
ovs_vport_lookup(const struct vport_parms * parms)172 static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms)
173 {
174 	struct vport_ops *ops;
175 
176 	list_for_each_entry(ops, &vport_ops_list, list)
177 		if (ops->type == parms->type)
178 			return ops;
179 
180 	return NULL;
181 }
182 
183 /**
184  *	ovs_vport_add - add vport device (for kernel callers)
185  *
186  * @parms: Information about new vport.
187  *
188  * Creates a new vport with the specified configuration (which is dependent on
189  * device type).  ovs_mutex must be held.
190  */
ovs_vport_add(const struct vport_parms * parms)191 struct vport *ovs_vport_add(const struct vport_parms *parms)
192 {
193 	struct vport_ops *ops;
194 	struct vport *vport;
195 
196 	ops = ovs_vport_lookup(parms);
197 	if (ops) {
198 		struct hlist_head *bucket;
199 
200 		if (!try_module_get(ops->owner))
201 			return ERR_PTR(-EAFNOSUPPORT);
202 
203 		vport = ops->create(parms);
204 		if (IS_ERR(vport)) {
205 			module_put(ops->owner);
206 			return vport;
207 		}
208 
209 		bucket = hash_bucket(ovs_dp_get_net(vport->dp),
210 				     ovs_vport_name(vport));
211 		hlist_add_head_rcu(&vport->hash_node, bucket);
212 		return vport;
213 	}
214 
215 	/* Unlock to attempt module load and return -EAGAIN if load
216 	 * was successful as we need to restart the port addition
217 	 * workflow.
218 	 */
219 	ovs_unlock();
220 	request_module("vport-type-%d", parms->type);
221 	ovs_lock();
222 
223 	if (!ovs_vport_lookup(parms))
224 		return ERR_PTR(-EAFNOSUPPORT);
225 	else
226 		return ERR_PTR(-EAGAIN);
227 }
228 
229 /**
230  *	ovs_vport_set_options - modify existing vport device (for kernel callers)
231  *
232  * @vport: vport to modify.
233  * @options: New configuration.
234  *
235  * Modifies an existing device with the specified configuration (which is
236  * dependent on device type).  ovs_mutex must be held.
237  */
ovs_vport_set_options(struct vport * vport,struct nlattr * options)238 int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
239 {
240 	if (!vport->ops->set_options)
241 		return -EOPNOTSUPP;
242 	return vport->ops->set_options(vport, options);
243 }
244 
245 /**
246  *	ovs_vport_del - delete existing vport device
247  *
248  * @vport: vport to delete.
249  *
250  * Detaches @vport from its datapath and destroys it.  ovs_mutex must
251  * be held.
252  */
ovs_vport_del(struct vport * vport)253 void ovs_vport_del(struct vport *vport)
254 {
255 	hlist_del_rcu(&vport->hash_node);
256 	module_put(vport->ops->owner);
257 	vport->ops->destroy(vport);
258 }
259 
260 /**
261  *	ovs_vport_get_stats - retrieve device stats
262  *
263  * @vport: vport from which to retrieve the stats
264  * @stats: location to store stats
265  *
266  * Retrieves transmit, receive, and error stats for the given device.
267  *
268  * Must be called with ovs_mutex or rcu_read_lock.
269  */
ovs_vport_get_stats(struct vport * vport,struct ovs_vport_stats * stats)270 void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
271 {
272 	const struct rtnl_link_stats64 *dev_stats;
273 	struct rtnl_link_stats64 temp;
274 
275 	dev_stats = dev_get_stats(vport->dev, &temp);
276 	stats->rx_errors  = dev_stats->rx_errors;
277 	stats->tx_errors  = dev_stats->tx_errors;
278 	stats->tx_dropped = dev_stats->tx_dropped;
279 	stats->rx_dropped = dev_stats->rx_dropped;
280 
281 	stats->rx_bytes	  = dev_stats->rx_bytes;
282 	stats->rx_packets = dev_stats->rx_packets;
283 	stats->tx_bytes	  = dev_stats->tx_bytes;
284 	stats->tx_packets = dev_stats->tx_packets;
285 }
286 
287 /**
288  *	ovs_vport_get_options - retrieve device options
289  *
290  * @vport: vport from which to retrieve the options.
291  * @skb: sk_buff where options should be appended.
292  *
293  * Retrieves the configuration of the given device, appending an
294  * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
295  * vport-specific attributes to @skb.
296  *
297  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
298  * negative error code if a real error occurred.  If an error occurs, @skb is
299  * left unmodified.
300  *
301  * Must be called with ovs_mutex or rcu_read_lock.
302  */
ovs_vport_get_options(const struct vport * vport,struct sk_buff * skb)303 int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
304 {
305 	struct nlattr *nla;
306 	int err;
307 
308 	if (!vport->ops->get_options)
309 		return 0;
310 
311 	nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_OPTIONS);
312 	if (!nla)
313 		return -EMSGSIZE;
314 
315 	err = vport->ops->get_options(vport, skb);
316 	if (err) {
317 		nla_nest_cancel(skb, nla);
318 		return err;
319 	}
320 
321 	nla_nest_end(skb, nla);
322 	return 0;
323 }
324 
325 /**
326  *	ovs_vport_set_upcall_portids - set upcall portids of @vport.
327  *
328  * @vport: vport to modify.
329  * @ids: new configuration, an array of port ids.
330  *
331  * Sets the vport's upcall_portids to @ids.
332  *
333  * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed
334  * as an array of U32.
335  *
336  * Must be called with ovs_mutex.
337  */
ovs_vport_set_upcall_portids(struct vport * vport,const struct nlattr * ids)338 int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids)
339 {
340 	struct vport_portids *old, *vport_portids;
341 
342 	if (!nla_len(ids) || nla_len(ids) % sizeof(u32))
343 		return -EINVAL;
344 
345 	old = ovsl_dereference(vport->upcall_portids);
346 
347 	vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids),
348 				GFP_KERNEL);
349 	if (!vport_portids)
350 		return -ENOMEM;
351 
352 	vport_portids->n_ids = nla_len(ids) / sizeof(u32);
353 	vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids);
354 	nla_memcpy(vport_portids->ids, ids, nla_len(ids));
355 
356 	rcu_assign_pointer(vport->upcall_portids, vport_portids);
357 
358 	if (old)
359 		kfree_rcu(old, rcu);
360 	return 0;
361 }
362 
363 /**
364  *	ovs_vport_get_upcall_portids - get the upcall_portids of @vport.
365  *
366  * @vport: vport from which to retrieve the portids.
367  * @skb: sk_buff where portids should be appended.
368  *
369  * Retrieves the configuration of the given vport, appending the
370  * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall
371  * portids to @skb.
372  *
373  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room.
374  * If an error occurs, @skb is left unmodified.  Must be called with
375  * ovs_mutex or rcu_read_lock.
376  */
ovs_vport_get_upcall_portids(const struct vport * vport,struct sk_buff * skb)377 int ovs_vport_get_upcall_portids(const struct vport *vport,
378 				 struct sk_buff *skb)
379 {
380 	struct vport_portids *ids;
381 
382 	ids = rcu_dereference_ovsl(vport->upcall_portids);
383 
384 	if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS)
385 		return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID,
386 			       ids->n_ids * sizeof(u32), (void *)ids->ids);
387 	else
388 		return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]);
389 }
390 
391 /**
392  *	ovs_vport_find_upcall_portid - find the upcall portid to send upcall.
393  *
394  * @vport: vport from which the missed packet is received.
395  * @skb: skb that the missed packet was received.
396  *
397  * Uses the skb_get_hash() to select the upcall portid to send the
398  * upcall.
399  *
400  * Returns the portid of the target socket.  Must be called with rcu_read_lock.
401  */
ovs_vport_find_upcall_portid(const struct vport * vport,struct sk_buff * skb)402 u32 ovs_vport_find_upcall_portid(const struct vport *vport,
403 				 struct sk_buff *skb)
404 {
405 	struct vport_portids *ids;
406 	u32 ids_index;
407 	u32 hash;
408 
409 	ids = rcu_dereference(vport->upcall_portids);
410 
411 	/* If there is only one portid, select it in the fast-path. */
412 	if (ids->n_ids == 1)
413 		return ids->ids[0];
414 
415 	hash = skb_get_hash(skb);
416 	ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids);
417 	return ids->ids[ids_index];
418 }
419 
420 /**
421  *	ovs_vport_receive - pass up received packet to the datapath for processing
422  *
423  * @vport: vport that received the packet
424  * @skb: skb that was received
425  * @tun_info: tunnel (if any) that carried packet
426  *
427  * Must be called with rcu_read_lock.  The packet cannot be shared and
428  * skb->data should point to the Ethernet header.
429  */
ovs_vport_receive(struct vport * vport,struct sk_buff * skb,const struct ip_tunnel_info * tun_info)430 int ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
431 		      const struct ip_tunnel_info *tun_info)
432 {
433 	struct sw_flow_key key;
434 	int error;
435 
436 	OVS_CB(skb)->input_vport = vport;
437 	OVS_CB(skb)->mru = 0;
438 	OVS_CB(skb)->cutlen = 0;
439 	if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) {
440 		u32 mark;
441 
442 		mark = skb->mark;
443 		skb_scrub_packet(skb, true);
444 		skb->mark = mark;
445 		tun_info = NULL;
446 	}
447 
448 	/* Extract flow from 'skb' into 'key'. */
449 	error = ovs_flow_key_extract(tun_info, skb, &key);
450 	if (unlikely(error)) {
451 		kfree_skb(skb);
452 		return error;
453 	}
454 	ovs_dp_process_packet(skb, &key);
455 	return 0;
456 }
457 
packet_length(const struct sk_buff * skb,struct net_device * dev)458 static int packet_length(const struct sk_buff *skb,
459 			 struct net_device *dev)
460 {
461 	int length = skb->len - dev->hard_header_len;
462 
463 	if (!skb_vlan_tag_present(skb) &&
464 	    eth_type_vlan(skb->protocol))
465 		length -= VLAN_HLEN;
466 
467 	/* Don't subtract for multiple VLAN tags. Most (all?) drivers allow
468 	 * (ETH_LEN + VLAN_HLEN) in addition to the mtu value, but almost none
469 	 * account for 802.1ad. e.g. is_skb_forwardable().
470 	 */
471 
472 	return length > 0 ? length : 0;
473 }
474 
ovs_vport_send(struct vport * vport,struct sk_buff * skb,u8 mac_proto)475 void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
476 {
477 	int mtu = vport->dev->mtu;
478 
479 	switch (vport->dev->type) {
480 	case ARPHRD_NONE:
481 		if (mac_proto == MAC_PROTO_ETHERNET) {
482 			skb_reset_network_header(skb);
483 			skb_reset_mac_len(skb);
484 			skb->protocol = htons(ETH_P_TEB);
485 		} else if (mac_proto != MAC_PROTO_NONE) {
486 			WARN_ON_ONCE(1);
487 			goto drop;
488 		}
489 		break;
490 	case ARPHRD_ETHER:
491 		if (mac_proto != MAC_PROTO_ETHERNET)
492 			goto drop;
493 		break;
494 	default:
495 		goto drop;
496 	}
497 
498 	if (unlikely(packet_length(skb, vport->dev) > mtu &&
499 		     !skb_is_gso(skb))) {
500 		vport->dev->stats.tx_errors++;
501 		if (vport->dev->flags & IFF_UP)
502 			net_warn_ratelimited("%s: dropped over-mtu packet: "
503 					     "%d > %d\n", vport->dev->name,
504 					     packet_length(skb, vport->dev),
505 					     mtu);
506 		goto drop;
507 	}
508 
509 	skb->dev = vport->dev;
510 	skb_clear_tstamp(skb);
511 	vport->ops->send(skb);
512 	return;
513 
514 drop:
515 	kfree_skb(skb);
516 }
517