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