datapath/vport-patch.c

   1 /*
   2  * Copyright (c) 2007-2012 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/kernel.h>
  20 #include <linux/jhash.h>
  21 #include <linux/list.h>
  22 #include <linux/rtnetlink.h>
  23 #include <net/net_namespace.h>
  24
  25 #include "compat.h"
  26 #include "datapath.h"
  27 #include "vport.h"
  28 #include "vport-generic.h"
  29
  30 struct patch_config {
  31         struct rcu_head rcu;
  32
  33         char peer_name[IFNAMSIZ];
  34         unsigned char eth_addr[ETH_ALEN];
  35 };
  36
  37 struct patch_vport {
  38         struct rcu_head rcu;
  39
  40         char name[IFNAMSIZ];
  41
  42         /* Protected by RTNL lock. */
  43         struct hlist_node hash_node;
  44
  45         struct vport __rcu *peer;
  46         struct patch_config __rcu *patchconf;
  47 };
  48
  49 /* Protected by RTNL lock. */
  50 static struct hlist_head *peer_table;
  51 #define PEER_HASH_BUCKETS 256
  52
  53 static void update_peers(struct net *, const char *name, struct vport *);
  54
  55 static struct patch_vport *patch_vport_priv(const struct vport *vport)
  56 {
  57         return vport_priv(vport);
  58 }
  59
  60 /* RCU callback. */
  61 static void free_config(struct rcu_head *rcu)
  62 {
  63         struct patch_config *c = container_of(rcu, struct patch_config, rcu);
  64         kfree(c);
  65 }
  66
  67 static void assign_config_rcu(struct vport *vport,
  68                               struct patch_config *new_config)
  69 {
  70         struct patch_vport *patch_vport = patch_vport_priv(vport);
  71         struct patch_config *old_config;
  72
  73         old_config = rtnl_dereference(patch_vport->patchconf);
  74         rcu_assign_pointer(patch_vport->patchconf, new_config);
  75         call_rcu(&old_config->rcu, free_config);
  76 }
  77
  78 static struct hlist_head *hash_bucket(struct net *net, const char *name)
  79 {
  80         unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
  81         return &peer_table[hash & (PEER_HASH_BUCKETS - 1)];
  82 }
  83
  84 static int patch_init(void)
  85 {
  86         peer_table = kzalloc(PEER_HASH_BUCKETS * sizeof(struct hlist_head),
  87                             GFP_KERNEL);
  88         if (!peer_table)
  89                 return -ENOMEM;
  90
  91         return 0;
  92 }
  93
  94 static void patch_exit(void)
  95 {
  96         kfree(peer_table);
  97 }
  98
  99 static const struct nla_policy patch_policy[OVS_PATCH_ATTR_MAX + 1] = {
 100 #ifdef HAVE_NLA_NUL_STRING
 101         [OVS_PATCH_ATTR_PEER] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
 102 #endif
 103 };
 104
 105 static int patch_set_config(struct vport *vport, const struct nlattr *options,
 106                             struct patch_config *patchconf)
 107 {
 108         struct patch_vport *patch_vport = patch_vport_priv(vport);
 109         struct nlattr *a[OVS_PATCH_ATTR_MAX + 1];
 110         const char *peer_name;
 111         int err;
 112
 113         if (!options)
 114                 return -EINVAL;
 115
 116         err = nla_parse_nested(a, OVS_PATCH_ATTR_MAX, options, patch_policy);
 117         if (err)
 118                 return err;
 119
 120         if (!a[OVS_PATCH_ATTR_PEER] ||
 121             CHECK_NUL_STRING(a[OVS_PATCH_ATTR_PEER], IFNAMSIZ - 1))
 122                 return -EINVAL;
 123
 124         peer_name = nla_data(a[OVS_PATCH_ATTR_PEER]);
 125         if (!strcmp(patch_vport->name, peer_name))
 126                 return -EINVAL;
 127
 128         strcpy(patchconf->peer_name, peer_name);
 129
 130         return 0;
 131 }
 132
 133 static struct vport *patch_create(const struct vport_parms *parms)
 134 {
 135         struct vport *vport;
 136         struct patch_vport *patch_vport;
 137         const char *peer_name;
 138         struct patch_config *patchconf;
 139         struct net *net = ovs_dp_get_net(parms->dp);
 140         int err;
 141
 142         vport = ovs_vport_alloc(sizeof(struct patch_vport),
 143                                 &ovs_patch_vport_ops, parms);
 144         if (IS_ERR(vport)) {
 145                 err = PTR_ERR(vport);
 146                 goto error;
 147         }
 148
 149         patch_vport = patch_vport_priv(vport);
 150
 151         strcpy(patch_vport->name, parms->name);
 152
 153         patchconf = kmalloc(sizeof(struct patch_config), GFP_KERNEL);
 154         if (!patchconf) {
 155                 err = -ENOMEM;
 156                 goto error_free_vport;
 157         }
 158
 159         err = patch_set_config(vport, parms->options, patchconf);
 160         if (err)
 161                 goto error_free_patchconf;
 162
 163         random_ether_addr(patchconf->eth_addr);
 164
 165         rcu_assign_pointer(patch_vport->patchconf, patchconf);
 166
 167         peer_name = patchconf->peer_name;
 168         hlist_add_head(&patch_vport->hash_node, hash_bucket(net, peer_name));
 169         rcu_assign_pointer(patch_vport->peer, ovs_vport_locate(net, peer_name));
 170         update_peers(net, patch_vport->name, vport);
 171
 172         return vport;
 173
 174 error_free_patchconf:
 175         kfree(patchconf);
 176 error_free_vport:
 177         ovs_vport_free(vport);
 178 error:
 179         return ERR_PTR(err);
 180 }
 181
 182 static void free_port_rcu(struct rcu_head *rcu)
 183 {
 184         struct patch_vport *patch_vport = container_of(rcu,
 185                                           struct patch_vport, rcu);
 186
 187         kfree((struct patch_config __force *)patch_vport->patchconf);
 188         ovs_vport_free(vport_from_priv(patch_vport));
 189 }
 190
 191 static void patch_destroy(struct vport *vport)
 192 {
 193         struct patch_vport *patch_vport = patch_vport_priv(vport);
 194
 195         update_peers(ovs_dp_get_net(vport->dp), patch_vport->name, NULL);
 196         hlist_del(&patch_vport->hash_node);
 197         call_rcu(&patch_vport->rcu, free_port_rcu);
 198 }
 199
 200 static int patch_set_options(struct vport *vport, struct nlattr *options)
 201 {
 202         struct patch_vport *patch_vport = patch_vport_priv(vport);
 203         struct patch_config *patchconf;
 204         int err;
 205
 206         patchconf = kmemdup(rtnl_dereference(patch_vport->patchconf),
 207                           sizeof(struct patch_config), GFP_KERNEL);
 208         if (!patchconf) {
 209                 err = -ENOMEM;
 210                 goto error;
 211         }
 212
 213         err = patch_set_config(vport, options, patchconf);
 214         if (err)
 215                 goto error_free;
 216
 217         assign_config_rcu(vport, patchconf);
 218
 219         hlist_del(&patch_vport->hash_node);
 220
 221         rcu_assign_pointer(patch_vport->peer,
 222                 ovs_vport_locate(ovs_dp_get_net(vport->dp), patchconf->peer_name));
 223
 224         hlist_add_head(&patch_vport->hash_node,
 225                        hash_bucket(ovs_dp_get_net(vport->dp), patchconf->peer_name));
 226
 227         return 0;
 228 error_free:
 229         kfree(patchconf);
 230 error:
 231         return err;
 232 }
 233
 234 static void update_peers(struct net *net, const char *name, struct vport *vport)
 235 {
 236         struct hlist_head *bucket = hash_bucket(net, name);
 237         struct patch_vport *peer_vport;
 238         struct hlist_node *node;
 239
 240         hlist_for_each_entry(peer_vport, node, bucket, hash_node) {
 241                 struct vport *curr_vport = vport_from_priv(peer_vport);
 242                 const char *peer_name;
 243
 244                 peer_name = rtnl_dereference(peer_vport->patchconf)->peer_name;
 245                 if (!strcmp(peer_name, name) && net_eq(ovs_dp_get_net(curr_vport->dp), net))
 246                         rcu_assign_pointer(peer_vport->peer, vport);
 247         }
 248 }
 249
 250 static int patch_set_addr(struct vport *vport, const unsigned char *addr)
 251 {
 252         struct patch_vport *patch_vport = patch_vport_priv(vport);
 253         struct patch_config *patchconf;
 254
 255         patchconf = kmemdup(rtnl_dereference(patch_vport->patchconf),
 256                           sizeof(struct patch_config), GFP_KERNEL);
 257         if (!patchconf)
 258                 return -ENOMEM;
 259
 260         memcpy(patchconf->eth_addr, addr, ETH_ALEN);
 261         assign_config_rcu(vport, patchconf);
 262
 263         return 0;
 264 }
 265
 266
 267 static const char *patch_get_name(const struct vport *vport)
 268 {
 269         const struct patch_vport *patch_vport = patch_vport_priv(vport);
 270         return patch_vport->name;
 271 }
 272
 273 static const unsigned char *patch_get_addr(const struct vport *vport)
 274 {
 275         const struct patch_vport *patch_vport = patch_vport_priv(vport);
 276         return rcu_dereference_rtnl(patch_vport->patchconf)->eth_addr;
 277 }
 278
 279 static int patch_get_options(const struct vport *vport, struct sk_buff *skb)
 280 {
 281         struct patch_vport *patch_vport = patch_vport_priv(vport);
 282         struct patch_config *patchconf = rcu_dereference_rtnl(patch_vport->patchconf);
 283
 284         return nla_put_string(skb, OVS_PATCH_ATTR_PEER, patchconf->peer_name);
 285 }
 286
 287 static int patch_send(struct vport *vport, struct sk_buff *skb)
 288 {
 289         struct patch_vport *patch_vport = patch_vport_priv(vport);
 290         struct vport *peer = rcu_dereference(patch_vport->peer);
 291         int skb_len = skb->len;
 292
 293         if (!peer) {
 294                 kfree_skb(skb);
 295                 ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 296
 297                 return 0;
 298         }
 299
 300         ovs_vport_receive(peer, skb);
 301         return skb_len;
 302 }
 303
 304 const struct vport_ops ovs_patch_vport_ops = {
 305         .type           = OVS_VPORT_TYPE_PATCH,
 306         .init           = patch_init,
 307         .exit           = patch_exit,
 308         .create         = patch_create,
 309         .destroy        = patch_destroy,
 310         .set_addr       = patch_set_addr,
 311         .get_name       = patch_get_name,
 312         .get_addr       = patch_get_addr,
 313         .get_options    = patch_get_options,
 314         .set_options    = patch_set_options,
 315         .get_dev_flags  = ovs_vport_gen_get_dev_flags,
 316         .is_running     = ovs_vport_gen_is_running,
 317         .get_operstate  = ovs_vport_gen_get_operstate,
 318         .send           = patch_send,
 319 };