Loading...
1/*
2 * Copyright (c) 2007-2011 Nicira Networks.
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/dcache.h>
20#include <linux/etherdevice.h>
21#include <linux/if.h>
22#include <linux/if_vlan.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
31#include "vport.h"
32#include "vport-internal_dev.h"
33
34/* List of statically compiled vport implementations. Don't forget to also
35 * add yours to the list at the bottom of vport.h. */
36static const struct vport_ops *vport_ops_list[] = {
37 &ovs_netdev_vport_ops,
38 &ovs_internal_vport_ops,
39};
40
41/* Protected by RCU read lock for reading, RTNL lock for writing. */
42static struct hlist_head *dev_table;
43#define VPORT_HASH_BUCKETS 1024
44
45/**
46 * ovs_vport_init - initialize vport subsystem
47 *
48 * Called at module load time to initialize the vport subsystem.
49 */
50int ovs_vport_init(void)
51{
52 dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
53 GFP_KERNEL);
54 if (!dev_table)
55 return -ENOMEM;
56
57 return 0;
58}
59
60/**
61 * ovs_vport_exit - shutdown vport subsystem
62 *
63 * Called at module exit time to shutdown the vport subsystem.
64 */
65void ovs_vport_exit(void)
66{
67 kfree(dev_table);
68}
69
70static struct hlist_head *hash_bucket(const char *name)
71{
72 unsigned int hash = full_name_hash(name, strlen(name));
73 return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
74}
75
76/**
77 * ovs_vport_locate - find a port that has already been created
78 *
79 * @name: name of port to find
80 *
81 * Must be called with RTNL or RCU read lock.
82 */
83struct vport *ovs_vport_locate(const char *name)
84{
85 struct hlist_head *bucket = hash_bucket(name);
86 struct vport *vport;
87 struct hlist_node *node;
88
89 hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
90 if (!strcmp(name, vport->ops->get_name(vport)))
91 return vport;
92
93 return NULL;
94}
95
96/**
97 * ovs_vport_alloc - allocate and initialize new vport
98 *
99 * @priv_size: Size of private data area to allocate.
100 * @ops: vport device ops
101 *
102 * Allocate and initialize a new vport defined by @ops. The vport will contain
103 * a private data area of size @priv_size that can be accessed using
104 * vport_priv(). vports that are no longer needed should be released with
105 * vport_free().
106 */
107struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
108 const struct vport_parms *parms)
109{
110 struct vport *vport;
111 size_t alloc_size;
112
113 alloc_size = sizeof(struct vport);
114 if (priv_size) {
115 alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
116 alloc_size += priv_size;
117 }
118
119 vport = kzalloc(alloc_size, GFP_KERNEL);
120 if (!vport)
121 return ERR_PTR(-ENOMEM);
122
123 vport->dp = parms->dp;
124 vport->port_no = parms->port_no;
125 vport->upcall_pid = parms->upcall_pid;
126 vport->ops = ops;
127
128 vport->percpu_stats = alloc_percpu(struct vport_percpu_stats);
129 if (!vport->percpu_stats) {
130 kfree(vport);
131 return ERR_PTR(-ENOMEM);
132 }
133
134 spin_lock_init(&vport->stats_lock);
135
136 return vport;
137}
138
139/**
140 * ovs_vport_free - uninitialize and free vport
141 *
142 * @vport: vport to free
143 *
144 * Frees a vport allocated with vport_alloc() when it is no longer needed.
145 *
146 * The caller must ensure that an RCU grace period has passed since the last
147 * time @vport was in a datapath.
148 */
149void ovs_vport_free(struct vport *vport)
150{
151 free_percpu(vport->percpu_stats);
152 kfree(vport);
153}
154
155/**
156 * ovs_vport_add - add vport device (for kernel callers)
157 *
158 * @parms: Information about new vport.
159 *
160 * Creates a new vport with the specified configuration (which is dependent on
161 * device type). RTNL lock must be held.
162 */
163struct vport *ovs_vport_add(const struct vport_parms *parms)
164{
165 struct vport *vport;
166 int err = 0;
167 int i;
168
169 ASSERT_RTNL();
170
171 for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
172 if (vport_ops_list[i]->type == parms->type) {
173 vport = vport_ops_list[i]->create(parms);
174 if (IS_ERR(vport)) {
175 err = PTR_ERR(vport);
176 goto out;
177 }
178
179 hlist_add_head_rcu(&vport->hash_node,
180 hash_bucket(vport->ops->get_name(vport)));
181 return vport;
182 }
183 }
184
185 err = -EAFNOSUPPORT;
186
187out:
188 return ERR_PTR(err);
189}
190
191/**
192 * ovs_vport_set_options - modify existing vport device (for kernel callers)
193 *
194 * @vport: vport to modify.
195 * @port: New configuration.
196 *
197 * Modifies an existing device with the specified configuration (which is
198 * dependent on device type). RTNL lock must be held.
199 */
200int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
201{
202 ASSERT_RTNL();
203
204 if (!vport->ops->set_options)
205 return -EOPNOTSUPP;
206 return vport->ops->set_options(vport, options);
207}
208
209/**
210 * ovs_vport_del - delete existing vport device
211 *
212 * @vport: vport to delete.
213 *
214 * Detaches @vport from its datapath and destroys it. It is possible to fail
215 * for reasons such as lack of memory. RTNL lock must be held.
216 */
217void ovs_vport_del(struct vport *vport)
218{
219 ASSERT_RTNL();
220
221 hlist_del_rcu(&vport->hash_node);
222
223 vport->ops->destroy(vport);
224}
225
226/**
227 * ovs_vport_get_stats - retrieve device stats
228 *
229 * @vport: vport from which to retrieve the stats
230 * @stats: location to store stats
231 *
232 * Retrieves transmit, receive, and error stats for the given device.
233 *
234 * Must be called with RTNL lock or rcu_read_lock.
235 */
236void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
237{
238 int i;
239
240 memset(stats, 0, sizeof(*stats));
241
242 /* We potentially have 2 sources of stats that need to be combined:
243 * those we have collected (split into err_stats and percpu_stats) from
244 * set_stats() and device error stats from netdev->get_stats() (for
245 * errors that happen downstream and therefore aren't reported through
246 * our vport_record_error() function).
247 * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
248 * netdev-stats can be directly read over netlink-ioctl.
249 */
250
251 spin_lock_bh(&vport->stats_lock);
252
253 stats->rx_errors = vport->err_stats.rx_errors;
254 stats->tx_errors = vport->err_stats.tx_errors;
255 stats->tx_dropped = vport->err_stats.tx_dropped;
256 stats->rx_dropped = vport->err_stats.rx_dropped;
257
258 spin_unlock_bh(&vport->stats_lock);
259
260 for_each_possible_cpu(i) {
261 const struct vport_percpu_stats *percpu_stats;
262 struct vport_percpu_stats local_stats;
263 unsigned int start;
264
265 percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
266
267 do {
268 start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
269 local_stats = *percpu_stats;
270 } while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));
271
272 stats->rx_bytes += local_stats.rx_bytes;
273 stats->rx_packets += local_stats.rx_packets;
274 stats->tx_bytes += local_stats.tx_bytes;
275 stats->tx_packets += local_stats.tx_packets;
276 }
277}
278
279/**
280 * ovs_vport_get_options - retrieve device options
281 *
282 * @vport: vport from which to retrieve the options.
283 * @skb: sk_buff where options should be appended.
284 *
285 * Retrieves the configuration of the given device, appending an
286 * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
287 * vport-specific attributes to @skb.
288 *
289 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
290 * negative error code if a real error occurred. If an error occurs, @skb is
291 * left unmodified.
292 *
293 * Must be called with RTNL lock or rcu_read_lock.
294 */
295int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
296{
297 struct nlattr *nla;
298
299 nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
300 if (!nla)
301 return -EMSGSIZE;
302
303 if (vport->ops->get_options) {
304 int err = vport->ops->get_options(vport, skb);
305 if (err) {
306 nla_nest_cancel(skb, nla);
307 return err;
308 }
309 }
310
311 nla_nest_end(skb, nla);
312 return 0;
313}
314
315/**
316 * ovs_vport_receive - pass up received packet to the datapath for processing
317 *
318 * @vport: vport that received the packet
319 * @skb: skb that was received
320 *
321 * Must be called with rcu_read_lock. The packet cannot be shared and
322 * skb->data should point to the Ethernet header. The caller must have already
323 * called compute_ip_summed() to initialize the checksumming fields.
324 */
325void ovs_vport_receive(struct vport *vport, struct sk_buff *skb)
326{
327 struct vport_percpu_stats *stats;
328
329 stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
330
331 u64_stats_update_begin(&stats->sync);
332 stats->rx_packets++;
333 stats->rx_bytes += skb->len;
334 u64_stats_update_end(&stats->sync);
335
336 ovs_dp_process_received_packet(vport, skb);
337}
338
339/**
340 * ovs_vport_send - send a packet on a device
341 *
342 * @vport: vport on which to send the packet
343 * @skb: skb to send
344 *
345 * Sends the given packet and returns the length of data sent. Either RTNL
346 * lock or rcu_read_lock must be held.
347 */
348int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
349{
350 int sent = vport->ops->send(vport, skb);
351
352 if (likely(sent)) {
353 struct vport_percpu_stats *stats;
354
355 stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
356
357 u64_stats_update_begin(&stats->sync);
358 stats->tx_packets++;
359 stats->tx_bytes += sent;
360 u64_stats_update_end(&stats->sync);
361 }
362 return sent;
363}
364
365/**
366 * ovs_vport_record_error - indicate device error to generic stats layer
367 *
368 * @vport: vport that encountered the error
369 * @err_type: one of enum vport_err_type types to indicate the error type
370 *
371 * If using the vport generic stats layer indicate that an error of the given
372 * type has occured.
373 */
374void ovs_vport_record_error(struct vport *vport, enum vport_err_type err_type)
375{
376 spin_lock(&vport->stats_lock);
377
378 switch (err_type) {
379 case VPORT_E_RX_DROPPED:
380 vport->err_stats.rx_dropped++;
381 break;
382
383 case VPORT_E_RX_ERROR:
384 vport->err_stats.rx_errors++;
385 break;
386
387 case VPORT_E_TX_DROPPED:
388 vport->err_stats.tx_dropped++;
389 break;
390
391 case VPORT_E_TX_ERROR:
392 vport->err_stats.tx_errors++;
393 break;
394 };
395
396 spin_unlock(&vport->stats_lock);
397}