datapath: Use compat directory only for backported code.
[openvswitch] / datapath / vport-patch.c
1 /*
2  * Copyright (c) 2010, 2011 Nicira Networks.
3  * Distributed under the terms of the GNU GPL version 2.
4  *
5  * Significant portions of this file may be copied from parts of the Linux
6  * kernel, by Linus Torvalds and others.
7  */
8
9 #include <linux/dcache.h>
10 #include <linux/kernel.h>
11 #include <linux/list.h>
12 #include <linux/rtnetlink.h>
13
14 #include "compat.h"
15 #include "datapath.h"
16 #include "vport.h"
17 #include "vport-generic.h"
18
19 struct patch_config {
20         struct rcu_head rcu;
21
22         char peer_name[IFNAMSIZ];
23         unsigned char eth_addr[ETH_ALEN];
24 };
25
26 struct patch_vport {
27         struct rcu_head rcu;
28
29         char name[IFNAMSIZ];
30
31         /* Protected by RTNL lock. */
32         struct hlist_node hash_node;
33
34         struct vport __rcu *peer;
35         struct patch_config __rcu *patchconf;
36 };
37
38 /* Protected by RTNL lock. */
39 static struct hlist_head *peer_table;
40 #define PEER_HASH_BUCKETS 256
41
42 static void update_peers(const char *name, struct vport *);
43
44 static inline struct patch_vport *patch_vport_priv(const struct vport *vport)
45 {
46         return vport_priv(vport);
47 }
48
49 /* RCU callback. */
50 static void free_config(struct rcu_head *rcu)
51 {
52         struct patch_config *c = container_of(rcu, struct patch_config, rcu);
53         kfree(c);
54 }
55
56 static void assign_config_rcu(struct vport *vport,
57                               struct patch_config *new_config)
58 {
59         struct patch_vport *patch_vport = patch_vport_priv(vport);
60         struct patch_config *old_config;
61
62         old_config = rtnl_dereference(patch_vport->patchconf);
63         rcu_assign_pointer(patch_vport->patchconf, new_config);
64         call_rcu(&old_config->rcu, free_config);
65 }
66
67 static struct hlist_head *hash_bucket(const char *name)
68 {
69         unsigned int hash = full_name_hash(name, strlen(name));
70         return &peer_table[hash & (PEER_HASH_BUCKETS - 1)];
71 }
72
73 static int patch_init(void)
74 {
75         peer_table = kzalloc(PEER_HASH_BUCKETS * sizeof(struct hlist_head),
76                             GFP_KERNEL);
77         if (!peer_table)
78                 return -ENOMEM;
79
80         return 0;
81 }
82
83 static void patch_exit(void)
84 {
85         kfree(peer_table);
86 }
87
88 static const struct nla_policy patch_policy[ODP_PATCH_ATTR_MAX + 1] = {
89 #ifdef HAVE_NLA_NUL_STRING
90         [ODP_PATCH_ATTR_PEER] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
91 #endif
92 };
93
94 static int patch_set_config(struct vport *vport, const struct nlattr *options,
95                             struct patch_config *patchconf)
96 {
97         struct patch_vport *patch_vport = patch_vport_priv(vport);
98         struct nlattr *a[ODP_PATCH_ATTR_MAX + 1];
99         const char *peer_name;
100         int err;
101
102         if (!options)
103                 return -EINVAL;
104
105         err = nla_parse_nested(a, ODP_PATCH_ATTR_MAX, options, patch_policy);
106         if (err)
107                 return err;
108
109         if (!a[ODP_PATCH_ATTR_PEER] ||
110             CHECK_NUL_STRING(a[ODP_PATCH_ATTR_PEER], IFNAMSIZ - 1))
111                 return -EINVAL;
112
113         peer_name = nla_data(a[ODP_PATCH_ATTR_PEER]);
114         if (!strcmp(patch_vport->name, peer_name))
115                 return -EINVAL;
116
117         strcpy(patchconf->peer_name, peer_name);
118
119         return 0;
120 }
121
122 static struct vport *patch_create(const struct vport_parms *parms)
123 {
124         struct vport *vport;
125         struct patch_vport *patch_vport;
126         const char *peer_name;
127         struct patch_config *patchconf;
128         int err;
129
130         vport = vport_alloc(sizeof(struct patch_vport), &patch_vport_ops, parms);
131         if (IS_ERR(vport)) {
132                 err = PTR_ERR(vport);
133                 goto error;
134         }
135
136         patch_vport = patch_vport_priv(vport);
137
138         strcpy(patch_vport->name, parms->name);
139
140         patchconf = kmalloc(sizeof(struct patch_config), GFP_KERNEL);
141         if (!patchconf) {
142                 err = -ENOMEM;
143                 goto error_free_vport;
144         }
145
146         err = patch_set_config(vport, parms->options, patchconf);
147         if (err)
148                 goto error_free_patchconf;
149
150         vport_gen_rand_ether_addr(patchconf->eth_addr);
151
152         rcu_assign_pointer(patch_vport->patchconf, patchconf);
153
154         peer_name = patchconf->peer_name;
155         hlist_add_head(&patch_vport->hash_node, hash_bucket(peer_name));
156         rcu_assign_pointer(patch_vport->peer, vport_locate(peer_name));
157         update_peers(patch_vport->name, vport);
158
159         return vport;
160
161 error_free_patchconf:
162         kfree(patchconf);
163 error_free_vport:
164         vport_free(vport);
165 error:
166         return ERR_PTR(err);
167 }
168
169 static void free_port_rcu(struct rcu_head *rcu)
170 {
171         struct patch_vport *patch_vport = container_of(rcu,
172                                           struct patch_vport, rcu);
173
174         kfree((struct patch_config __force *)patch_vport->patchconf);
175         vport_free(vport_from_priv(patch_vport));
176 }
177
178 static int patch_destroy(struct vport *vport)
179 {
180         struct patch_vport *patch_vport = patch_vport_priv(vport);
181
182         update_peers(patch_vport->name, NULL);
183         hlist_del(&patch_vport->hash_node);
184         call_rcu(&patch_vport->rcu, free_port_rcu);
185
186         return 0;
187 }
188
189 static int patch_set_options(struct vport *vport, struct nlattr *options)
190 {
191         struct patch_vport *patch_vport = patch_vport_priv(vport);
192         struct patch_config *patchconf;
193         int err;
194
195         patchconf = kmemdup(rtnl_dereference(patch_vport->patchconf),
196                           sizeof(struct patch_config), GFP_KERNEL);
197         if (!patchconf) {
198                 err = -ENOMEM;
199                 goto error;
200         }
201
202         err = patch_set_config(vport, options, patchconf);
203         if (err)
204                 goto error_free;
205
206         assign_config_rcu(vport, patchconf);
207
208         hlist_del(&patch_vport->hash_node);
209
210         rcu_assign_pointer(patch_vport->peer, vport_locate(patchconf->peer_name));
211         hlist_add_head(&patch_vport->hash_node, hash_bucket(patchconf->peer_name));
212
213         return 0;
214
215 error_free:
216         kfree(patchconf);
217 error:
218         return err;
219 }
220
221 static void update_peers(const char *name, struct vport *vport)
222 {
223         struct hlist_head *bucket = hash_bucket(name);
224         struct patch_vport *peer_vport;
225         struct hlist_node *node;
226
227         hlist_for_each_entry(peer_vport, node, bucket, hash_node) {
228                 const char *peer_name;
229
230                 peer_name = rtnl_dereference(peer_vport->patchconf)->peer_name;
231                 if (!strcmp(peer_name, name))
232                         rcu_assign_pointer(peer_vport->peer, vport);
233         }
234 }
235
236 static int patch_set_addr(struct vport *vport, const unsigned char *addr)
237 {
238         struct patch_vport *patch_vport = patch_vport_priv(vport);
239         struct patch_config *patchconf;
240
241         patchconf = kmemdup(rtnl_dereference(patch_vport->patchconf),
242                           sizeof(struct patch_config), GFP_KERNEL);
243         if (!patchconf)
244                 return -ENOMEM;
245
246         memcpy(patchconf->eth_addr, addr, ETH_ALEN);
247         assign_config_rcu(vport, patchconf);
248
249         return 0;
250 }
251
252
253 static const char *patch_get_name(const struct vport *vport)
254 {
255         const struct patch_vport *patch_vport = patch_vport_priv(vport);
256         return patch_vport->name;
257 }
258
259 static const unsigned char *patch_get_addr(const struct vport *vport)
260 {
261         const struct patch_vport *patch_vport = patch_vport_priv(vport);
262         return rcu_dereference_rtnl(patch_vport->patchconf)->eth_addr;
263 }
264
265 static int patch_get_options(const struct vport *vport, struct sk_buff *skb)
266 {
267         struct patch_vport *patch_vport = patch_vport_priv(vport);
268         struct patch_config *patchconf = rcu_dereference_rtnl(patch_vport->patchconf);
269
270         return nla_put_string(skb, ODP_PATCH_ATTR_PEER, patchconf->peer_name);
271 }
272
273 static int patch_send(struct vport *vport, struct sk_buff *skb)
274 {
275         struct patch_vport *patch_vport = patch_vport_priv(vport);
276         struct vport *peer = rcu_dereference(patch_vport->peer);
277         int skb_len = skb->len;
278
279         if (!peer) {
280                 kfree_skb(skb);
281                 vport_record_error(vport, VPORT_E_TX_DROPPED);
282
283                 return 0;
284         }
285
286         vport_receive(peer, skb);
287         return skb_len;
288 }
289
290 const struct vport_ops patch_vport_ops = {
291         .type           = ODP_VPORT_TYPE_PATCH,
292         .flags          = VPORT_F_GEN_STATS,
293         .init           = patch_init,
294         .exit           = patch_exit,
295         .create         = patch_create,
296         .destroy        = patch_destroy,
297         .set_addr       = patch_set_addr,
298         .get_name       = patch_get_name,
299         .get_addr       = patch_get_addr,
300         .get_options    = patch_get_options,
301         .set_options    = patch_set_options,
302         .get_dev_flags  = vport_gen_get_dev_flags,
303         .is_running     = vport_gen_is_running,
304         .get_operstate  = vport_gen_get_operstate,
305         .send           = patch_send,
306 };