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                 + nla_total_size(1)     /* IFLA_BRPORT_FAST_LEAVE */
  33                 + nla_total_size(1)     /* IFLA_BRPORT_LEARNING */
  34                 + nla_total_size(1)     /* IFLA_BRPORT_UNICAST_FLOOD */
  35                 + 0;
  36 }
  37
  38 static inline size_t br_nlmsg_size(void)
  39 {
  40         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  41                 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  42                 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  43                 + nla_total_size(4) /* IFLA_MASTER */
  44                 + nla_total_size(4) /* IFLA_MTU */
  45                 + nla_total_size(4) /* IFLA_LINK */
  46                 + nla_total_size(1) /* IFLA_OPERSTATE */
  47                 + nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
  48 }
  49
  50 static int br_port_fill_attrs(struct sk_buff *skb,
  51                               const struct net_bridge_port *p)
  52 {
  53         u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
  54
  55         if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
  56             nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
  57             nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
  58             nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
  59             nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
  60             nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
  61             nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)) ||
  62             nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(p->flags & BR_LEARNING)) ||
  63             nla_put_u8(skb, IFLA_BRPORT_UNICAST_FLOOD, !!(p->flags & BR_FLOOD)))
  64                 return -EMSGSIZE;
  65
  66         return 0;
  67 }
  68
  69 /*
  70  * Create one netlink message for one interface
  71  * Contains port and master info as well as carrier and bridge state.
  72  */
  73 static int br_fill_ifinfo(struct sk_buff *skb,
  74                           const struct net_bridge_port *port,
  75                           u32 pid, u32 seq, int event, unsigned int flags,
  76                           u32 filter_mask, const struct net_device *dev)
  77 {
  78         const struct net_bridge *br;
  79         struct ifinfomsg *hdr;
  80         struct nlmsghdr *nlh;
  81         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  82
  83         if (port)
  84                 br = port->br;
  85         else
  86                 br = netdev_priv(dev);
  87
  88         br_debug(br, "br_fill_info event %d port %s master %s\n",
  89                      event, dev->name, br->dev->name);
  90
  91         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  92         if (nlh == NULL)
  93                 return -EMSGSIZE;
  94
  95         hdr = nlmsg_data(nlh);
  96         hdr->ifi_family = AF_BRIDGE;
  97         hdr->__ifi_pad = 0;
  98         hdr->ifi_type = dev->type;
  99         hdr->ifi_index = dev->ifindex;
 100         hdr->ifi_flags = dev_get_flags(dev);
 101         hdr->ifi_change = 0;
 102
 103         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
 104             nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
 105             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
 106             nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
 107             (dev->addr_len &&
 108              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
 109             (dev->ifindex != dev->iflink &&
 110              nla_put_u32(skb, IFLA_LINK, dev->iflink)))
 111                 goto nla_put_failure;
 112
 113         if (event == RTM_NEWLINK && port) {
 114                 struct nlattr *nest
 115                         = nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
 116
 117                 if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
 118                         goto nla_put_failure;
 119                 nla_nest_end(skb, nest);
 120         }
 121
 122         /* Check if  the VID information is requested */
 123         if (filter_mask & RTEXT_FILTER_BRVLAN) {
 124                 struct nlattr *af;
 125                 const struct net_port_vlans *pv;
 126                 struct bridge_vlan_info vinfo;
 127                 u16 vid;
 128                 u16 pvid;
 129
 130                 if (port)
 131                         pv = nbp_get_vlan_info(port);
 132                 else
 133                         pv = br_get_vlan_info(br);
 134
 135                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID))
 136                         goto done;
 137
 138                 af = nla_nest_start(skb, IFLA_AF_SPEC);
 139                 if (!af)
 140                         goto nla_put_failure;
 141
 142                 pvid = br_get_pvid(pv);
 143                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 144                         vinfo.vid = vid;
 145                         vinfo.flags = 0;
 146                         if (vid == pvid)
 147                                 vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
 148
 149                         if (test_bit(vid, pv->untagged_bitmap))
 150                                 vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 151
 152                         if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
 153                                     sizeof(vinfo), &vinfo))
 154                                 goto nla_put_failure;
 155                 }
 156
 157                 nla_nest_end(skb, af);
 158         }
 159
 160 done:
 161         return nlmsg_end(skb, nlh);
 162
 163 nla_put_failure:
 164         nlmsg_cancel(skb, nlh);
 165         return -EMSGSIZE;
 166 }
 167
 168 /*
 169  * Notify listeners of a change in port information
 170  */
 171 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 172 {
 173         struct net *net;
 174         struct sk_buff *skb;
 175         int err = -ENOBUFS;
 176
 177         if (!port)
 178                 return;
 179
 180         net = dev_net(port->dev);
 181         br_debug(port->br, "port %u(%s) event %d\n",
 182                  (unsigned int)port->port_no, port->dev->name, event);
 183
 184         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
 185         if (skb == NULL)
 186                 goto errout;
 187
 188         err = br_fill_ifinfo(skb, port, 0, 0, event, 0, 0, port->dev);
 189         if (err < 0) {
 190                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 191                 WARN_ON(err == -EMSGSIZE);
 192                 kfree_skb(skb);
 193                 goto errout;
 194         }
 195         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 196         return;
 197 errout:
 198         rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 199 }
 200
 201
 202 /*
 203  * Dump information about all ports, in response to GETLINK
 204  */
 205 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 206                struct net_device *dev, u32 filter_mask)
 207 {
 208         int err = 0;
 209         struct net_bridge_port *port = br_port_get_rtnl(dev);
 210
 211         /* not a bridge port and  */
 212         if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
 213                 goto out;
 214
 215         err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
 216                              filter_mask, dev);
 217 out:
 218         return err;
 219 }
 220
 221 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
 222         [IFLA_BRIDGE_FLAGS]     = { .type = NLA_U16 },
 223         [IFLA_BRIDGE_MODE]      = { .type = NLA_U16 },
 224         [IFLA_BRIDGE_VLAN_INFO] = { .type = NLA_BINARY,
 225                                     .len = sizeof(struct bridge_vlan_info), },
 226 };
 227
 228 static int br_afspec(struct net_bridge *br,
 229                      struct net_bridge_port *p,
 230                      struct nlattr *af_spec,
 231                      int cmd)
 232 {
 233         struct nlattr *tb[IFLA_BRIDGE_MAX+1];
 234         int err = 0;
 235
 236         err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
 237         if (err)
 238                 return err;
 239
 240         if (tb[IFLA_BRIDGE_VLAN_INFO]) {
 241                 struct bridge_vlan_info *vinfo;
 242
 243                 vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
 244
 245                 if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
 246                         return -EINVAL;
 247
 248                 switch (cmd) {
 249                 case RTM_SETLINK:
 250                         if (p) {
 251                                 err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
 252                                 if (err)
 253                                         break;
 254
 255                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 256                                         err = br_vlan_add(p->br, vinfo->vid,
 257                                                           vinfo->flags);
 258                         } else
 259                                 err = br_vlan_add(br, vinfo->vid, vinfo->flags);
 260
 261                         if (err)
 262                                 break;
 263
 264                         break;
 265
 266                 case RTM_DELLINK:
 267                         if (p) {
 268                                 nbp_vlan_delete(p, vinfo->vid);
 269                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 270                                         br_vlan_delete(p->br, vinfo->vid);
 271                         } else
 272                                 br_vlan_delete(br, vinfo->vid);
 273                         break;
 274                 }
 275         }
 276
 277         return err;
 278 }
 279
 280 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
 281         [IFLA_BRPORT_STATE]     = { .type = NLA_U8 },
 282         [IFLA_BRPORT_COST]      = { .type = NLA_U32 },
 283         [IFLA_BRPORT_PRIORITY]  = { .type = NLA_U16 },
 284         [IFLA_BRPORT_MODE]      = { .type = NLA_U8 },
 285         [IFLA_BRPORT_GUARD]     = { .type = NLA_U8 },
 286         [IFLA_BRPORT_PROTECT]   = { .type = NLA_U8 },
 287         [IFLA_BRPORT_LEARNING]  = { .type = NLA_U8 },
 288         [IFLA_BRPORT_UNICAST_FLOOD] = { .type = NLA_U8 },
 289 };
 290
 291 /* Change the state of the port and notify spanning tree */
 292 static int br_set_port_state(struct net_bridge_port *p, u8 state)
 293 {
 294         if (state > BR_STATE_BLOCKING)
 295                 return -EINVAL;
 296
 297         /* if kernel STP is running, don't allow changes */
 298         if (p->br->stp_enabled == BR_KERNEL_STP)
 299                 return -EBUSY;
 300
 301         /* if device is not up, change is not allowed
 302          * if link is not present, only allowable state is disabled
 303          */
 304         if (!netif_running(p->dev) ||
 305             (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
 306                 return -ENETDOWN;
 307
 308         p->state = state;
 309         br_log_state(p);
 310         br_port_state_selection(p->br);
 311         return 0;
 312 }
 313
 314 /* Set/clear or port flags based on attribute */
 315 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 316                            int attrtype, unsigned long mask)
 317 {
 318         if (tb[attrtype]) {
 319                 u8 flag = nla_get_u8(tb[attrtype]);
 320                 if (flag)
 321                         p->flags |= mask;
 322                 else
 323                         p->flags &= ~mask;
 324         }
 325 }
 326
 327 /* Process bridge protocol info on port */
 328 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 329 {
 330         int err;
 331
 332         br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 333         br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
 334         br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
 335         br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
 336         br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
 337         br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
 338
 339         if (tb[IFLA_BRPORT_COST]) {
 340                 err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 341                 if (err)
 342                         return err;
 343         }
 344
 345         if (tb[IFLA_BRPORT_PRIORITY]) {
 346                 err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
 347                 if (err)
 348                         return err;
 349         }
 350
 351         if (tb[IFLA_BRPORT_STATE]) {
 352                 err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
 353                 if (err)
 354                         return err;
 355         }
 356         return 0;
 357 }
 358
 359 /* Change state and parameters on port. */
 360 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 361 {
 362         struct nlattr *protinfo;
 363         struct nlattr *afspec;
 364         struct net_bridge_port *p;
 365         struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 366         int err = 0;
 367
 368         protinfo = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_PROTINFO);
 369         afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
 370         if (!protinfo && !afspec)
 371                 return 0;
 372
 373         p = br_port_get_rtnl(dev);
 374         /* We want to accept dev as bridge itself if the AF_SPEC
 375          * is set to see if someone is setting vlan info on the bridge
 376          */
 377         if (!p && !afspec)
 378                 return -EINVAL;
 379
 380         if (p && protinfo) {
 381                 if (protinfo->nla_type & NLA_F_NESTED) {
 382                         err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
 383                                                protinfo, ifla_brport_policy);
 384                         if (err)
 385                                 return err;
 386
 387                         spin_lock_bh(&p->br->lock);
 388                         err = br_setport(p, tb);
 389                         spin_unlock_bh(&p->br->lock);
 390                 } else {
 391                         /* Binary compatibility with old RSTP */
 392                         if (nla_len(protinfo) < sizeof(u8))
 393                                 return -EINVAL;
 394
 395                         spin_lock_bh(&p->br->lock);
 396                         err = br_set_port_state(p, nla_get_u8(protinfo));
 397                         spin_unlock_bh(&p->br->lock);
 398                 }
 399                 if (err)
 400                         goto out;
 401         }
 402
 403         if (afspec) {
 404                 err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 405                                 afspec, RTM_SETLINK);
 406         }
 407
 408         if (err == 0)
 409                 br_ifinfo_notify(RTM_NEWLINK, p);
 410
 411 out:
 412         return err;
 413 }
 414
 415 /* Delete port information */
 416 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
 417 {
 418         struct nlattr *afspec;
 419         struct net_bridge_port *p;
 420         int err;
 421
 422         afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), 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_rtnl(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         rtnl_af_register(&br_af_ops);
 485
 486         err = rtnl_link_register(&br_link_ops);
 487         if (err)
 488                 goto out_af;
 489
 490         return 0;
 491
 492 out_af:
 493         rtnl_af_unregister(&br_af_ops);
 494         br_mdb_uninit();
 495         return err;
 496 }
 497
 498 void __exit br_netlink_fini(void)
 499 {
 500         br_mdb_uninit();
 501         rtnl_af_unregister(&br_af_ops);
 502         rtnl_link_unregister(&br_link_ops);
 503 }