net/bridge/br_netlink.c

   1 /*
   2  *      Bridge netlink control interface
   3  *
   4  *      Authors:
   5  *      Stephen Hemminger               <shemminger@osdl.org>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/etherdevice.h>
  16 #include <net/rtnetlink.h>
  17 #include <net/net_namespace.h>
  18 #include <net/sock.h>
  19 #include <uapi/linux/if_bridge.h>
  20
  21 #include "br_private.h"
  22 #include "br_private_stp.h"
  23
  24 static inline size_t br_port_info_size(void)
  25 {
  26         return nla_total_size(1)        /* IFLA_BRPORT_STATE  */
  27                 + nla_total_size(2)     /* IFLA_BRPORT_PRIORITY */
  28                 + nla_total_size(4)     /* IFLA_BRPORT_COST */
  29                 + nla_total_size(1)     /* IFLA_BRPORT_MODE */
  30                 + nla_total_size(1)     /* IFLA_BRPORT_GUARD */
  31                 + nla_total_size(1)     /* IFLA_BRPORT_PROTECT */
  32                 + 0;
  33 }
  34
  35 static inline size_t br_nlmsg_size(void)
  36 {
  37         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  38                 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  39                 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  40                 + nla_total_size(4) /* IFLA_MASTER */
  41                 + nla_total_size(4) /* IFLA_MTU */
  42                 + nla_total_size(4) /* IFLA_LINK */
  43                 + nla_total_size(1) /* IFLA_OPERSTATE */
  44                 + nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
  45 }
  46
  47 static int br_port_fill_attrs(struct sk_buff *skb,
  48                               const struct net_bridge_port *p)
  49 {
  50         u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
  51
  52         if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
  53             nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
  54             nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
  55             nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
  56             nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
  57             nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
  58             nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)))
  59                 return -EMSGSIZE;
  60
  61         return 0;
  62 }
  63
  64 /*
  65  * Create one netlink message for one interface
  66  * Contains port and master info as well as carrier and bridge state.
  67  */
  68 static int br_fill_ifinfo(struct sk_buff *skb,
  69                           const struct net_bridge_port *port,
  70                           u32 pid, u32 seq, int event, unsigned int flags,
  71                           u32 filter_mask, const struct net_device *dev)
  72 {
  73         const struct net_bridge *br;
  74         struct ifinfomsg *hdr;
  75         struct nlmsghdr *nlh;
  76         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  77
  78         if (port)
  79                 br = port->br;
  80         else
  81                 br = netdev_priv(dev);
  82
  83         br_debug(br, "br_fill_info event %d port %s master %s\n",
  84                      event, dev->name, br->dev->name);
  85
  86         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  87         if (nlh == NULL)
  88                 return -EMSGSIZE;
  89
  90         hdr = nlmsg_data(nlh);
  91         hdr->ifi_family = AF_BRIDGE;
  92         hdr->__ifi_pad = 0;
  93         hdr->ifi_type = dev->type;
  94         hdr->ifi_index = dev->ifindex;
  95         hdr->ifi_flags = dev_get_flags(dev);
  96         hdr->ifi_change = 0;
  97
  98         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
  99             nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
 100             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
 101             nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
 102             (dev->addr_len &&
 103              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
 104             (dev->ifindex != dev->iflink &&
 105              nla_put_u32(skb, IFLA_LINK, dev->iflink)))
 106                 goto nla_put_failure;
 107
 108         if (event == RTM_NEWLINK && port) {
 109                 struct nlattr *nest
 110                         = nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
 111
 112                 if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
 113                         goto nla_put_failure;
 114                 nla_nest_end(skb, nest);
 115         }
 116
 117         /* Check if  the VID information is requested */
 118         if (filter_mask & RTEXT_FILTER_BRVLAN) {
 119                 struct nlattr *af;
 120                 const struct net_port_vlans *pv;
 121                 struct bridge_vlan_info vinfo;
 122                 u16 vid;
 123                 u16 pvid;
 124
 125                 if (port)
 126                         pv = nbp_get_vlan_info(port);
 127                 else
 128                         pv = br_get_vlan_info(br);
 129
 130                 if (!pv || bitmap_empty(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN))
 131                         goto done;
 132
 133                 af = nla_nest_start(skb, IFLA_AF_SPEC);
 134                 if (!af)
 135                         goto nla_put_failure;
 136
 137                 pvid = br_get_pvid(pv);
 138                 for (vid = find_first_bit(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN);
 139                      vid < BR_VLAN_BITMAP_LEN;
 140                      vid = find_next_bit(pv->vlan_bitmap,
 141                                          BR_VLAN_BITMAP_LEN, vid+1)) {
 142                         vinfo.vid = vid;
 143                         vinfo.flags = 0;
 144                         if (vid == pvid)
 145                                 vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
 146
 147                         if (test_bit(vid, pv->untagged_bitmap))
 148                                 vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 149
 150                         if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
 151                                     sizeof(vinfo), &vinfo))
 152                                 goto nla_put_failure;
 153                 }
 154
 155                 nla_nest_end(skb, af);
 156         }
 157
 158 done:
 159         return nlmsg_end(skb, nlh);
 160
 161 nla_put_failure:
 162         nlmsg_cancel(skb, nlh);
 163         return -EMSGSIZE;
 164 }
 165
 166 /*
 167  * Notify listeners of a change in port information
 168  */
 169 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 170 {
 171         struct net *net;
 172         struct sk_buff *skb;
 173         int err = -ENOBUFS;
 174
 175         if (!port)
 176                 return;
 177
 178         net = dev_net(port->dev);
 179         br_debug(port->br, "port %u(%s) event %d\n",
 180                  (unsigned int)port->port_no, port->dev->name, event);
 181
 182         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
 183         if (skb == NULL)
 184                 goto errout;
 185
 186         err = br_fill_ifinfo(skb, port, 0, 0, event, 0, 0, port->dev);
 187         if (err < 0) {
 188                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 189                 WARN_ON(err == -EMSGSIZE);
 190                 kfree_skb(skb);
 191                 goto errout;
 192         }
 193         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 194         return;
 195 errout:
 196         if (err < 0)
 197                 rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 198 }
 199
 200
 201 /*
 202  * Dump information about all ports, in response to GETLINK
 203  */
 204 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 205                struct net_device *dev, u32 filter_mask)
 206 {
 207         int err = 0;
 208         struct net_bridge_port *port = br_port_get_rcu(dev);
 209
 210         /* not a bridge port and  */
 211         if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
 212                 goto out;
 213
 214         err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
 215                              filter_mask, dev);
 216 out:
 217         return err;
 218 }
 219
 220 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
 221         [IFLA_BRIDGE_FLAGS]     = { .type = NLA_U16 },
 222         [IFLA_BRIDGE_MODE]      = { .type = NLA_U16 },
 223         [IFLA_BRIDGE_VLAN_INFO] = { .type = NLA_BINARY,
 224                                     .len = sizeof(struct bridge_vlan_info), },
 225 };
 226
 227 static int br_afspec(struct net_bridge *br,
 228                      struct net_bridge_port *p,
 229                      struct nlattr *af_spec,
 230                      int cmd)
 231 {
 232         struct nlattr *tb[IFLA_BRIDGE_MAX+1];
 233         int err = 0;
 234
 235         err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
 236         if (err)
 237                 return err;
 238
 239         if (tb[IFLA_BRIDGE_VLAN_INFO]) {
 240                 struct bridge_vlan_info *vinfo;
 241
 242                 vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
 243
 244                 if (vinfo->vid >= VLAN_N_VID)
 245                         return -EINVAL;
 246
 247                 switch (cmd) {
 248                 case RTM_SETLINK:
 249                         if (p) {
 250                                 err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
 251                                 if (err)
 252                                         break;
 253
 254                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 255                                         err = br_vlan_add(p->br, vinfo->vid,
 256                                                           vinfo->flags);
 257                         } else
 258                                 err = br_vlan_add(br, vinfo->vid, vinfo->flags);
 259
 260                         if (err)
 261                                 break;
 262
 263                         break;
 264
 265                 case RTM_DELLINK:
 266                         if (p) {
 267                                 nbp_vlan_delete(p, vinfo->vid);
 268                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 269                                         br_vlan_delete(p->br, vinfo->vid);
 270                         } else
 271                                 br_vlan_delete(br, vinfo->vid);
 272                         break;
 273                 }
 274         }
 275
 276         return err;
 277 }
 278
 279 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
 280         [IFLA_BRPORT_STATE]     = { .type = NLA_U8 },
 281         [IFLA_BRPORT_COST]      = { .type = NLA_U32 },
 282         [IFLA_BRPORT_PRIORITY]  = { .type = NLA_U16 },
 283         [IFLA_BRPORT_MODE]      = { .type = NLA_U8 },
 284         [IFLA_BRPORT_GUARD]     = { .type = NLA_U8 },
 285         [IFLA_BRPORT_PROTECT]   = { .type = NLA_U8 },
 286 };
 287
 288 /* Change the state of the port and notify spanning tree */
 289 static int br_set_port_state(struct net_bridge_port *p, u8 state)
 290 {
 291         if (state > BR_STATE_BLOCKING)
 292                 return -EINVAL;
 293
 294         /* if kernel STP is running, don't allow changes */
 295         if (p->br->stp_enabled == BR_KERNEL_STP)
 296                 return -EBUSY;
 297
 298         /* if device is not up, change is not allowed
 299          * if link is not present, only allowable state is disabled
 300          */
 301         if (!netif_running(p->dev) ||
 302             (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
 303                 return -ENETDOWN;
 304
 305         p->state = state;
 306         br_log_state(p);
 307         br_port_state_selection(p->br);
 308         return 0;
 309 }
 310
 311 /* Set/clear or port flags based on attribute */
 312 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 313                            int attrtype, unsigned long mask)
 314 {
 315         if (tb[attrtype]) {
 316                 u8 flag = nla_get_u8(tb[attrtype]);
 317                 if (flag)
 318                         p->flags |= mask;
 319                 else
 320                         p->flags &= ~mask;
 321         }
 322 }
 323
 324 /* Process bridge protocol info on port */
 325 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 326 {
 327         int err;
 328
 329         br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 330         br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
 331         br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
 332
 333         if (tb[IFLA_BRPORT_COST]) {
 334                 err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 335                 if (err)
 336                         return err;
 337         }
 338
 339         if (tb[IFLA_BRPORT_PRIORITY]) {
 340                 err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
 341                 if (err)
 342                         return err;
 343         }
 344
 345         if (tb[IFLA_BRPORT_STATE]) {
 346                 err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
 347                 if (err)
 348                         return err;
 349         }
 350         return 0;
 351 }
 352
 353 /* Change state and parameters on port. */
 354 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 355 {
 356         struct ifinfomsg *ifm;
 357         struct nlattr *protinfo;
 358         struct nlattr *afspec;
 359         struct net_bridge_port *p;
 360         struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 361         int err;
 362
 363         ifm = nlmsg_data(nlh);
 364
 365         protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
 366         afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
 367         if (!protinfo && !afspec)
 368                 return 0;
 369
 370         p = br_port_get_rtnl(dev);
 371         /* We want to accept dev as bridge itself if the AF_SPEC
 372          * is set to see if someone is setting vlan info on the brigde
 373          */
 374         if (!p && ((dev->priv_flags & IFF_EBRIDGE) && !afspec))
 375                 return -EINVAL;
 376
 377         if (p && protinfo) {
 378                 if (protinfo->nla_type & NLA_F_NESTED) {
 379                         err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
 380                                                protinfo, ifla_brport_policy);
 381                         if (err)
 382                                 return err;
 383
 384                         spin_lock_bh(&p->br->lock);
 385                         err = br_setport(p, tb);
 386                         spin_unlock_bh(&p->br->lock);
 387                 } else {
 388                         /* Binary compatability with old RSTP */
 389                         if (nla_len(protinfo) < sizeof(u8))
 390                                 return -EINVAL;
 391
 392                         spin_lock_bh(&p->br->lock);
 393                         err = br_set_port_state(p, nla_get_u8(protinfo));
 394                         spin_unlock_bh(&p->br->lock);
 395                 }
 396                 if (err)
 397                         goto out;
 398         }
 399
 400         if (afspec) {
 401                 err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 402                                 afspec, RTM_SETLINK);
 403         }
 404
 405         if (err == 0)
 406                 br_ifinfo_notify(RTM_NEWLINK, p);
 407
 408 out:
 409         return err;
 410 }
 411
 412 /* Delete port information */
 413 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
 414 {
 415         struct ifinfomsg *ifm;
 416         struct nlattr *afspec;
 417         struct net_bridge_port *p;
 418         int err;
 419
 420         ifm = nlmsg_data(nlh);
 421
 422         afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
 423         if (!afspec)
 424                 return 0;
 425
 426         p = br_port_get_rtnl(dev);
 427         /* We want to accept dev as bridge itself as well */
 428         if (!p && !(dev->priv_flags & IFF_EBRIDGE))
 429                 return -EINVAL;
 430
 431         err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 432                         afspec, RTM_DELLINK);
 433
 434         return err;
 435 }
 436 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 437 {
 438         if (tb[IFLA_ADDRESS]) {
 439                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 440                         return -EINVAL;
 441                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 442                         return -EADDRNOTAVAIL;
 443         }
 444
 445         return 0;
 446 }
 447
 448 static size_t br_get_link_af_size(const struct net_device *dev)
 449 {
 450         struct net_port_vlans *pv;
 451
 452         if (br_port_exists(dev))
 453                 pv = nbp_get_vlan_info(br_port_get_rcu(dev));
 454         else if (dev->priv_flags & IFF_EBRIDGE)
 455                 pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
 456         else
 457                 return 0;
 458
 459         if (!pv)
 460                 return 0;
 461
 462         /* Each VLAN is returned in bridge_vlan_info along with flags */
 463         return pv->num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
 464 }
 465
 466 static struct rtnl_af_ops br_af_ops = {
 467         .family                 = AF_BRIDGE,
 468         .get_link_af_size       = br_get_link_af_size,
 469 };
 470
 471 struct rtnl_link_ops br_link_ops __read_mostly = {
 472         .kind           = "bridge",
 473         .priv_size      = sizeof(struct net_bridge),
 474         .setup          = br_dev_setup,
 475         .validate       = br_validate,
 476         .dellink        = br_dev_delete,
 477 };
 478
 479 int __init br_netlink_init(void)
 480 {
 481         int err;
 482
 483         br_mdb_init();
 484         err = rtnl_af_register(&br_af_ops);
 485         if (err)
 486                 goto out;
 487
 488         err = rtnl_link_register(&br_link_ops);
 489         if (err)
 490                 goto out_af;
 491
 492         return 0;
 493
 494 out_af:
 495         rtnl_af_unregister(&br_af_ops);
 496 out:
 497         br_mdb_uninit();
 498         return err;
 499 }
 500
 501 void __exit br_netlink_fini(void)
 502 {
 503         br_mdb_uninit();
 504         rtnl_af_unregister(&br_af_ops);
 505         rtnl_link_unregister(&br_link_ops);
 506 }