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
  20 #include "br_private.h"
  21 #include "br_private_stp.h"
  22
  23 static inline size_t br_nlmsg_size(void)
  24 {
  25         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  26                + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  27                + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  28                + nla_total_size(4) /* IFLA_MASTER */
  29                + nla_total_size(4) /* IFLA_MTU */
  30                + nla_total_size(4) /* IFLA_LINK */
  31                + nla_total_size(1) /* IFLA_OPERSTATE */
  32                + nla_total_size(1); /* IFLA_PROTINFO */
  33 }
  34
  35 /*
  36  * Create one netlink message for one interface
  37  * Contains port and master info as well as carrier and bridge state.
  38  */
  39 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
  40                           u32 pid, u32 seq, int event, unsigned int flags)
  41 {
  42         const struct net_bridge *br = port->br;
  43         const struct net_device *dev = port->dev;
  44         struct ifinfomsg *hdr;
  45         struct nlmsghdr *nlh;
  46         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  47
  48         br_debug(br, "br_fill_info event %d port %s master %s\n",
  49                      event, dev->name, br->dev->name);
  50
  51         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  52         if (nlh == NULL)
  53                 return -EMSGSIZE;
  54
  55         hdr = nlmsg_data(nlh);
  56         hdr->ifi_family = AF_BRIDGE;
  57         hdr->__ifi_pad = 0;
  58         hdr->ifi_type = dev->type;
  59         hdr->ifi_index = dev->ifindex;
  60         hdr->ifi_flags = dev_get_flags(dev);
  61         hdr->ifi_change = 0;
  62
  63         NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
  64         NLA_PUT_U32(skb, IFLA_MASTER, br->dev->ifindex);
  65         NLA_PUT_U32(skb, IFLA_MTU, dev->mtu);
  66         NLA_PUT_U8(skb, IFLA_OPERSTATE, operstate);
  67
  68         if (dev->addr_len)
  69                 NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
  70
  71         if (dev->ifindex != dev->iflink)
  72                 NLA_PUT_U32(skb, IFLA_LINK, dev->iflink);
  73
  74         if (event == RTM_NEWLINK)
  75                 NLA_PUT_U8(skb, IFLA_PROTINFO, port->state);
  76
  77         return nlmsg_end(skb, nlh);
  78
  79 nla_put_failure:
  80         nlmsg_cancel(skb, nlh);
  81         return -EMSGSIZE;
  82 }
  83
  84 /*
  85  * Notify listeners of a change in port information
  86  */
  87 void br_ifinfo_notify(int event, struct net_bridge_port *port)
  88 {
  89         struct net *net = dev_net(port->dev);
  90         struct sk_buff *skb;
  91         int err = -ENOBUFS;
  92
  93         br_debug(port->br, "port %u(%s) event %d\n",
  94                  (unsigned)port->port_no, port->dev->name, event);
  95
  96         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
  97         if (skb == NULL)
  98                 goto errout;
  99
 100         err = br_fill_ifinfo(skb, port, 0, 0, event, 0);
 101         if (err < 0) {
 102                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 103                 WARN_ON(err == -EMSGSIZE);
 104                 kfree_skb(skb);
 105                 goto errout;
 106         }
 107         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 108         return;
 109 errout:
 110         if (err < 0)
 111                 rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 112 }
 113
 114 /*
 115  * Dump information about all ports, in response to GETLINK
 116  */
 117 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 118 {
 119         struct net *net = sock_net(skb->sk);
 120         struct net_device *dev;
 121         int idx;
 122
 123         idx = 0;
 124         rcu_read_lock();
 125         for_each_netdev_rcu(net, dev) {
 126                 struct net_bridge_port *port = br_port_get_rcu(dev);
 127
 128                 /* not a bridge port */
 129                 if (!port || idx < cb->args[0])
 130                         goto skip;
 131
 132                 if (br_fill_ifinfo(skb, port,
 133                                    NETLINK_CB(cb->skb).pid,
 134                                    cb->nlh->nlmsg_seq, RTM_NEWLINK,
 135                                    NLM_F_MULTI) < 0)
 136                         break;
 137 skip:
 138                 ++idx;
 139         }
 140         rcu_read_unlock();
 141         cb->args[0] = idx;
 142
 143         return skb->len;
 144 }
 145
 146 /*
 147  * Change state of port (ie from forwarding to blocking etc)
 148  * Used by spanning tree in user space.
 149  */
 150 static int br_rtm_setlink(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 151 {
 152         struct net *net = sock_net(skb->sk);
 153         struct ifinfomsg *ifm;
 154         struct nlattr *protinfo;
 155         struct net_device *dev;
 156         struct net_bridge_port *p;
 157         u8 new_state;
 158
 159         if (nlmsg_len(nlh) < sizeof(*ifm))
 160                 return -EINVAL;
 161
 162         ifm = nlmsg_data(nlh);
 163         if (ifm->ifi_family != AF_BRIDGE)
 164                 return -EPFNOSUPPORT;
 165
 166         protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
 167         if (!protinfo || nla_len(protinfo) < sizeof(u8))
 168                 return -EINVAL;
 169
 170         new_state = nla_get_u8(protinfo);
 171         if (new_state > BR_STATE_BLOCKING)
 172                 return -EINVAL;
 173
 174         dev = __dev_get_by_index(net, ifm->ifi_index);
 175         if (!dev)
 176                 return -ENODEV;
 177
 178         p = br_port_get_rtnl(dev);
 179         if (!p)
 180                 return -EINVAL;
 181
 182         /* if kernel STP is running, don't allow changes */
 183         if (p->br->stp_enabled == BR_KERNEL_STP)
 184                 return -EBUSY;
 185
 186         if (!netif_running(dev) ||
 187             (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED))
 188                 return -ENETDOWN;
 189
 190         p->state = new_state;
 191         br_log_state(p);
 192
 193         spin_lock_bh(&p->br->lock);
 194         br_port_state_selection(p->br);
 195         spin_unlock_bh(&p->br->lock);
 196
 197         br_ifinfo_notify(RTM_NEWLINK, p);
 198
 199         return 0;
 200 }
 201
 202 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 203 {
 204         if (tb[IFLA_ADDRESS]) {
 205                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 206                         return -EINVAL;
 207                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 208                         return -EADDRNOTAVAIL;
 209         }
 210
 211         return 0;
 212 }
 213
 214 static struct rtnl_link_ops br_link_ops __read_mostly = {
 215         .kind           = "bridge",
 216         .priv_size      = sizeof(struct net_bridge),
 217         .setup          = br_dev_setup,
 218         .validate       = br_validate,
 219         .dellink        = br_dev_delete,
 220 };
 221
 222 int __init br_netlink_init(void)
 223 {
 224         int err;
 225
 226         err = rtnl_link_register(&br_link_ops);
 227         if (err < 0)
 228                 goto err1;
 229
 230         err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL,
 231                               br_dump_ifinfo, NULL);
 232         if (err)
 233                 goto err2;
 234         err = __rtnl_register(PF_BRIDGE, RTM_SETLINK,
 235                               br_rtm_setlink, NULL, NULL);
 236         if (err)
 237                 goto err3;
 238         err = __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH,
 239                               br_fdb_add, NULL, NULL);
 240         if (err)
 241                 goto err3;
 242         err = __rtnl_register(PF_BRIDGE, RTM_DELNEIGH,
 243                               br_fdb_delete, NULL, NULL);
 244         if (err)
 245                 goto err3;
 246         err = __rtnl_register(PF_BRIDGE, RTM_GETNEIGH,
 247                               NULL, br_fdb_dump, NULL);
 248         if (err)
 249                 goto err3;
 250
 251         return 0;
 252
 253 err3:
 254         rtnl_unregister_all(PF_BRIDGE);
 255 err2:
 256         rtnl_link_unregister(&br_link_ops);
 257 err1:
 258         return err;
 259 }
 260
 261 void __exit br_netlink_fini(void)
 262 {
 263         rtnl_link_unregister(&br_link_ops);
 264         rtnl_unregister_all(PF_BRIDGE);
 265 }