1/*
2 * Copyright (c) 2007-2014 Nicira, Inc.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16 * 02110-1301, USA
17 */
18
19#include <linux/etherdevice.h>
20#include <linux/if.h>
21#include <linux/if_vlan.h>
22#include <linux/jhash.h>
23#include <linux/kernel.h>
24#include <linux/list.h>
25#include <linux/mutex.h>
26#include <linux/percpu.h>
27#include <linux/rcupdate.h>
28#include <linux/rtnetlink.h>
29#include <linux/compat.h>
30#include <net/net_namespace.h>
31#include <linux/module.h>
32
33#include "datapath.h"
34#include "vport.h"
35#include "vport-internal_dev.h"
36
37static LIST_HEAD(vport_ops_list);
38
39/* Protected by RCU read lock for reading, ovs_mutex for writing. */
40static struct hlist_head *dev_table;
41#define VPORT_HASH_BUCKETS 1024
42
43/**
44 *	ovs_vport_init - initialize vport subsystem
45 *
46 * Called at module load time to initialize the vport subsystem.
47 */
48int ovs_vport_init(void)
49{
50	dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
51			    GFP_KERNEL);
52	if (!dev_table)
53		return -ENOMEM;
54
55	return 0;
56}
57
58/**
59 *	ovs_vport_exit - shutdown vport subsystem
60 *
61 * Called at module exit time to shutdown the vport subsystem.
62 */
63void ovs_vport_exit(void)
64{
65	kfree(dev_table);
66}
67
68static struct hlist_head *hash_bucket(const struct net *net, const char *name)
69{
70	unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
71	return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
72}
73
74int __ovs_vport_ops_register(struct vport_ops *ops)
75{
76	int err = -EEXIST;
77	struct vport_ops *o;
78
79	ovs_lock();
80	list_for_each_entry(o, &vport_ops_list, list)
81		if (ops->type == o->type)
82			goto errout;
83
84	list_add_tail(&ops->list, &vport_ops_list);
85	err = 0;
86errout:
87	ovs_unlock();
88	return err;
89}
90EXPORT_SYMBOL_GPL(__ovs_vport_ops_register);
91
92void ovs_vport_ops_unregister(struct vport_ops *ops)
93{
94	ovs_lock();
95	list_del(&ops->list);
96	ovs_unlock();
97}
98EXPORT_SYMBOL_GPL(ovs_vport_ops_unregister);
99
100/**
101 *	ovs_vport_locate - find a port that has already been created
102 *
103 * @name: name of port to find
104 *
105 * Must be called with ovs or RCU read lock.
106 */
107struct vport *ovs_vport_locate(const struct net *net, const char *name)
108{
109	struct hlist_head *bucket = hash_bucket(net, name);
110	struct vport *vport;
111
112	hlist_for_each_entry_rcu(vport, bucket, hash_node)
113		if (!strcmp(name, ovs_vport_name(vport)) &&
114		    net_eq(ovs_dp_get_net(vport->dp), net))
115			return vport;
116
117	return NULL;
118}
119
120/**
121 *	ovs_vport_alloc - allocate and initialize new vport
122 *
123 * @priv_size: Size of private data area to allocate.
124 * @ops: vport device ops
125 *
126 * Allocate and initialize a new vport defined by @ops.  The vport will contain
127 * a private data area of size @priv_size that can be accessed using
128 * vport_priv().  vports that are no longer needed should be released with
129 * vport_free().
130 */
131struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
132			  const struct vport_parms *parms)
133{
134	struct vport *vport;
135	size_t alloc_size;
136
137	alloc_size = sizeof(struct vport);
138	if (priv_size) {
139		alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
140		alloc_size += priv_size;
141	}
142
143	vport = kzalloc(alloc_size, GFP_KERNEL);
144	if (!vport)
145		return ERR_PTR(-ENOMEM);
146
147	vport->dp = parms->dp;
148	vport->port_no = parms->port_no;
149	vport->ops = ops;
150	INIT_HLIST_NODE(&vport->dp_hash_node);
151
152	if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) {
153		kfree(vport);
154		return ERR_PTR(-EINVAL);
155	}
156
157	return vport;
158}
159EXPORT_SYMBOL_GPL(ovs_vport_alloc);
160
161/**
162 *	ovs_vport_free - uninitialize and free vport
163 *
164 * @vport: vport to free
165 *
166 * Frees a vport allocated with vport_alloc() when it is no longer needed.
167 *
168 * The caller must ensure that an RCU grace period has passed since the last
169 * time @vport was in a datapath.
170 */
171void ovs_vport_free(struct vport *vport)
172{
173	/* vport is freed from RCU callback or error path, Therefore
174	 * it is safe to use raw dereference.
175	 */
176	kfree(rcu_dereference_raw(vport->upcall_portids));
177	kfree(vport);
178}
179EXPORT_SYMBOL_GPL(ovs_vport_free);
180
181static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms)
182{
183	struct vport_ops *ops;
184
185	list_for_each_entry(ops, &vport_ops_list, list)
186		if (ops->type == parms->type)
187			return ops;
188
189	return NULL;
190}
191
192/**
193 *	ovs_vport_add - add vport device (for kernel callers)
194 *
195 * @parms: Information about new vport.
196 *
197 * Creates a new vport with the specified configuration (which is dependent on
198 * device type).  ovs_mutex must be held.
199 */
200struct vport *ovs_vport_add(const struct vport_parms *parms)
201{
202	struct vport_ops *ops;
203	struct vport *vport;
204
205	ops = ovs_vport_lookup(parms);
206	if (ops) {
207		struct hlist_head *bucket;
208
209		if (!try_module_get(ops->owner))
210			return ERR_PTR(-EAFNOSUPPORT);
211
212		vport = ops->create(parms);
213		if (IS_ERR(vport)) {
214			module_put(ops->owner);
215			return vport;
216		}
217
218		bucket = hash_bucket(ovs_dp_get_net(vport->dp),
219				     ovs_vport_name(vport));
220		hlist_add_head_rcu(&vport->hash_node, bucket);
221		return vport;
222	}
223
224	/* Unlock to attempt module load and return -EAGAIN if load
225	 * was successful as we need to restart the port addition
226	 * workflow.
227	 */
228	ovs_unlock();
229	request_module("vport-type-%d", parms->type);
230	ovs_lock();
231
232	if (!ovs_vport_lookup(parms))
233		return ERR_PTR(-EAFNOSUPPORT);
234	else
235		return ERR_PTR(-EAGAIN);
236}
237
238/**
239 *	ovs_vport_set_options - modify existing vport device (for kernel callers)
240 *
241 * @vport: vport to modify.
242 * @options: New configuration.
243 *
244 * Modifies an existing device with the specified configuration (which is
245 * dependent on device type).  ovs_mutex must be held.
246 */
247int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
248{
249	if (!vport->ops->set_options)
250		return -EOPNOTSUPP;
251	return vport->ops->set_options(vport, options);
252}
253
254/**
255 *	ovs_vport_del - delete existing vport device
256 *
257 * @vport: vport to delete.
258 *
259 * Detaches @vport from its datapath and destroys it.  ovs_mutex must
260 * be held.
261 */
262void ovs_vport_del(struct vport *vport)
263{
264	ASSERT_OVSL();
265
266	hlist_del_rcu(&vport->hash_node);
267	module_put(vport->ops->owner);
268	vport->ops->destroy(vport);
269}
270
271/**
272 *	ovs_vport_get_stats - retrieve device stats
273 *
274 * @vport: vport from which to retrieve the stats
275 * @stats: location to store stats
276 *
277 * Retrieves transmit, receive, and error stats for the given device.
278 *
279 * Must be called with ovs_mutex or rcu_read_lock.
280 */
281void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
282{
283	const struct rtnl_link_stats64 *dev_stats;
284	struct rtnl_link_stats64 temp;
285
286	dev_stats = dev_get_stats(vport->dev, &temp);
287	stats->rx_errors  = dev_stats->rx_errors;
288	stats->tx_errors  = dev_stats->tx_errors;
289	stats->tx_dropped = dev_stats->tx_dropped;
290	stats->rx_dropped = dev_stats->rx_dropped;
291
292	stats->rx_bytes	  = dev_stats->rx_bytes;
293	stats->rx_packets = dev_stats->rx_packets;
294	stats->tx_bytes	  = dev_stats->tx_bytes;
295	stats->tx_packets = dev_stats->tx_packets;
296}
297
298/**
299 *	ovs_vport_get_options - retrieve device options
300 *
301 * @vport: vport from which to retrieve the options.
302 * @skb: sk_buff where options should be appended.
303 *
304 * Retrieves the configuration of the given device, appending an
305 * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
306 * vport-specific attributes to @skb.
307 *
308 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
309 * negative error code if a real error occurred.  If an error occurs, @skb is
310 * left unmodified.
311 *
312 * Must be called with ovs_mutex or rcu_read_lock.
313 */
314int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
315{
316	struct nlattr *nla;
317	int err;
318
319	if (!vport->ops->get_options)
320		return 0;
321
322	nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
323	if (!nla)
324		return -EMSGSIZE;
325
326	err = vport->ops->get_options(vport, skb);
327	if (err) {
328		nla_nest_cancel(skb, nla);
329		return err;
330	}
331
332	nla_nest_end(skb, nla);
333	return 0;
334}
335
336/**
337 *	ovs_vport_set_upcall_portids - set upcall portids of @vport.
338 *
339 * @vport: vport to modify.
340 * @ids: new configuration, an array of port ids.
341 *
342 * Sets the vport's upcall_portids to @ids.
343 *
344 * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed
345 * as an array of U32.
346 *
347 * Must be called with ovs_mutex.
348 */
349int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids)
350{
351	struct vport_portids *old, *vport_portids;
352
353	if (!nla_len(ids) || nla_len(ids) % sizeof(u32))
354		return -EINVAL;
355
356	old = ovsl_dereference(vport->upcall_portids);
357
358	vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids),
359				GFP_KERNEL);
360	if (!vport_portids)
361		return -ENOMEM;
362
363	vport_portids->n_ids = nla_len(ids) / sizeof(u32);
364	vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids);
365	nla_memcpy(vport_portids->ids, ids, nla_len(ids));
366
367	rcu_assign_pointer(vport->upcall_portids, vport_portids);
368
369	if (old)
370		kfree_rcu(old, rcu);
371	return 0;
372}
373
374/**
375 *	ovs_vport_get_upcall_portids - get the upcall_portids of @vport.
376 *
377 * @vport: vport from which to retrieve the portids.
378 * @skb: sk_buff where portids should be appended.
379 *
380 * Retrieves the configuration of the given vport, appending the
381 * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall
382 * portids to @skb.
383 *
384 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room.
385 * If an error occurs, @skb is left unmodified.  Must be called with
386 * ovs_mutex or rcu_read_lock.
387 */
388int ovs_vport_get_upcall_portids(const struct vport *vport,
389				 struct sk_buff *skb)
390{
391	struct vport_portids *ids;
392
393	ids = rcu_dereference_ovsl(vport->upcall_portids);
394
395	if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS)
396		return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID,
397			       ids->n_ids * sizeof(u32), (void *)ids->ids);
398	else
399		return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]);
400}
401
402/**
403 *	ovs_vport_find_upcall_portid - find the upcall portid to send upcall.
404 *
405 * @vport: vport from which the missed packet is received.
406 * @skb: skb that the missed packet was received.
407 *
408 * Uses the skb_get_hash() to select the upcall portid to send the
409 * upcall.
410 *
411 * Returns the portid of the target socket.  Must be called with rcu_read_lock.
412 */
413u32 ovs_vport_find_upcall_portid(const struct vport *vport, struct sk_buff *skb)
414{
415	struct vport_portids *ids;
416	u32 ids_index;
417	u32 hash;
418
419	ids = rcu_dereference(vport->upcall_portids);
420
421	if (ids->n_ids == 1 && ids->ids[0] == 0)
422		return 0;
423
424	hash = skb_get_hash(skb);
425	ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids);
426	return ids->ids[ids_index];
427}
428
429/**
430 *	ovs_vport_receive - pass up received packet to the datapath for processing
431 *
432 * @vport: vport that received the packet
433 * @skb: skb that was received
434 * @tun_key: tunnel (if any) that carried packet
435 *
436 * Must be called with rcu_read_lock.  The packet cannot be shared and
437 * skb->data should point to the Ethernet header.
438 */
439int ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
440		      const struct ip_tunnel_info *tun_info)
441{
442	struct sw_flow_key key;
443	int error;
444
445	OVS_CB(skb)->input_vport = vport;
446	OVS_CB(skb)->mru = 0;
447	if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) {
448		u32 mark;
449
450		mark = skb->mark;
451		skb_scrub_packet(skb, true);
452		skb->mark = mark;
453		tun_info = NULL;
454	}
455
456	/* Extract flow from 'skb' into 'key'. */
457	error = ovs_flow_key_extract(tun_info, skb, &key);
458	if (unlikely(error)) {
459		kfree_skb(skb);
460		return error;
461	}
462	ovs_dp_process_packet(skb, &key);
463	return 0;
464}
465EXPORT_SYMBOL_GPL(ovs_vport_receive);
466
467static void free_vport_rcu(struct rcu_head *rcu)
468{
469	struct vport *vport = container_of(rcu, struct vport, rcu);
470
471	ovs_vport_free(vport);
472}
473
474void ovs_vport_deferred_free(struct vport *vport)
475{
476	if (!vport)
477		return;
478
479	call_rcu(&vport->rcu, free_vport_rcu);
480}
481EXPORT_SYMBOL_GPL(ovs_vport_deferred_free);
482
483static unsigned int packet_length(const struct sk_buff *skb)
484{
485	unsigned int length = skb->len - ETH_HLEN;
486
487	if (skb->protocol == htons(ETH_P_8021Q))
488		length -= VLAN_HLEN;
489
490	return length;
491}
492
493void ovs_vport_send(struct vport *vport, struct sk_buff *skb)
494{
495	int mtu = vport->dev->mtu;
496
497	if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
498		net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
499				     vport->dev->name,
500				     packet_length(skb), mtu);
501		vport->dev->stats.tx_errors++;
502		goto drop;
503	}
504
505	skb->dev = vport->dev;
506	vport->ops->send(skb);
507	return;
508
509drop:
510	kfree_skb(skb);
511}
512