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_port_info_size(void)
  24 {
  25         return nla_total_size(1)        /* IFLA_BRPORT_STATE  */
  26                 + nla_total_size(2)     /* IFLA_BRPORT_PRIORITY */
  27                 + nla_total_size(4)     /* IFLA_BRPORT_COST */
  28                 + nla_total_size(1)     /* IFLA_BRPORT_MODE */
  29                 + nla_total_size(1)     /* IFLA_BRPORT_GUARD */
  30                 + nla_total_size(1)     /* IFLA_BRPORT_PROTECT */
  31                 + 0;
  32 }
  33
  34 static inline size_t br_nlmsg_size(void)
  35 {
  36         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  37                 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  38                 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  39                 + nla_total_size(4) /* IFLA_MASTER */
  40                 + nla_total_size(4) /* IFLA_MTU */
  41                 + nla_total_size(4) /* IFLA_LINK */
  42                 + nla_total_size(1) /* IFLA_OPERSTATE */
  43                 + nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
  44 }
  45
  46 static int br_port_fill_attrs(struct sk_buff *skb,
  47                               const struct net_bridge_port *p)
  48 {
  49         u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
  50
  51         if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
  52             nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
  53             nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
  54             nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
  55             nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
  56             nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)))
  57                 return -EMSGSIZE;
  58
  59         return 0;
  60 }
  61
  62 /*
  63  * Create one netlink message for one interface
  64  * Contains port and master info as well as carrier and bridge state.
  65  */
  66 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
  67                           u32 pid, u32 seq, int event, unsigned int flags)
  68 {
  69         const struct net_bridge *br = port->br;
  70         const struct net_device *dev = port->dev;
  71         struct ifinfomsg *hdr;
  72         struct nlmsghdr *nlh;
  73         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  74
  75         br_debug(br, "br_fill_info event %d port %s master %s\n",
  76                      event, dev->name, br->dev->name);
  77
  78         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  79         if (nlh == NULL)
  80                 return -EMSGSIZE;
  81
  82         hdr = nlmsg_data(nlh);
  83         hdr->ifi_family = AF_BRIDGE;
  84         hdr->__ifi_pad = 0;
  85         hdr->ifi_type = dev->type;
  86         hdr->ifi_index = dev->ifindex;
  87         hdr->ifi_flags = dev_get_flags(dev);
  88         hdr->ifi_change = 0;
  89
  90         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
  91             nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
  92             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
  93             nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
  94             (dev->addr_len &&
  95              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
  96             (dev->ifindex != dev->iflink &&
  97              nla_put_u32(skb, IFLA_LINK, dev->iflink)))
  98                 goto nla_put_failure;
  99
 100         if (event == RTM_NEWLINK) {
 101                 struct nlattr *nest
 102                         = nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
 103
 104                 if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
 105                         goto nla_put_failure;
 106                 nla_nest_end(skb, nest);
 107         }
 108
 109         return nlmsg_end(skb, nlh);
 110
 111 nla_put_failure:
 112         nlmsg_cancel(skb, nlh);
 113         return -EMSGSIZE;
 114 }
 115
 116 /*
 117  * Notify listeners of a change in port information
 118  */
 119 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 120 {
 121         struct net *net = dev_net(port->dev);
 122         struct sk_buff *skb;
 123         int err = -ENOBUFS;
 124
 125         br_debug(port->br, "port %u(%s) event %d\n",
 126                  (unsigned int)port->port_no, port->dev->name, event);
 127
 128         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
 129         if (skb == NULL)
 130                 goto errout;
 131
 132         err = br_fill_ifinfo(skb, port, 0, 0, event, 0);
 133         if (err < 0) {
 134                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 135                 WARN_ON(err == -EMSGSIZE);
 136                 kfree_skb(skb);
 137                 goto errout;
 138         }
 139         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 140         return;
 141 errout:
 142         if (err < 0)
 143                 rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 144 }
 145
 146 /*
 147  * Dump information about all ports, in response to GETLINK
 148  */
 149 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 150                struct net_device *dev)
 151 {
 152         int err = 0;
 153         struct net_bridge_port *port = br_port_get_rcu(dev);
 154
 155         /* not a bridge port */
 156         if (!port)
 157                 goto out;
 158
 159         err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI);
 160 out:
 161         return err;
 162 }
 163
 164 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
 165         [IFLA_BRPORT_STATE]     = { .type = NLA_U8 },
 166         [IFLA_BRPORT_COST]      = { .type = NLA_U32 },
 167         [IFLA_BRPORT_PRIORITY]  = { .type = NLA_U16 },
 168         [IFLA_BRPORT_MODE]      = { .type = NLA_U8 },
 169         [IFLA_BRPORT_GUARD]     = { .type = NLA_U8 },
 170         [IFLA_BRPORT_PROTECT]   = { .type = NLA_U8 },
 171 };
 172
 173 /* Change the state of the port and notify spanning tree */
 174 static int br_set_port_state(struct net_bridge_port *p, u8 state)
 175 {
 176         if (state > BR_STATE_BLOCKING)
 177                 return -EINVAL;
 178
 179         /* if kernel STP is running, don't allow changes */
 180         if (p->br->stp_enabled == BR_KERNEL_STP)
 181                 return -EBUSY;
 182
 183         if (!netif_running(p->dev) ||
 184             (!netif_carrier_ok(p->dev) && state != BR_STATE_DISABLED))
 185                 return -ENETDOWN;
 186
 187         p->state = state;
 188         br_log_state(p);
 189         br_port_state_selection(p->br);
 190         return 0;
 191 }
 192
 193 /* Set/clear or port flags based on attribute */
 194 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 195                            int attrtype, unsigned long mask)
 196 {
 197         if (tb[attrtype]) {
 198                 u8 flag = nla_get_u8(tb[attrtype]);
 199                 if (flag)
 200                         p->flags |= mask;
 201                 else
 202                         p->flags &= ~mask;
 203         }
 204 }
 205
 206 /* Process bridge protocol info on port */
 207 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 208 {
 209         int err;
 210
 211         br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 212         br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
 213
 214         if (tb[IFLA_BRPORT_COST]) {
 215                 err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 216                 if (err)
 217                         return err;
 218         }
 219
 220         if (tb[IFLA_BRPORT_PRIORITY]) {
 221                 err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
 222                 if (err)
 223                         return err;
 224         }
 225
 226         if (tb[IFLA_BRPORT_STATE]) {
 227                 err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
 228                 if (err)
 229                         return err;
 230         }
 231         return 0;
 232 }
 233
 234 /* Change state and parameters on port. */
 235 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 236 {
 237         struct ifinfomsg *ifm;
 238         struct nlattr *protinfo;
 239         struct net_bridge_port *p;
 240         struct nlattr *tb[IFLA_BRPORT_MAX];
 241         int err;
 242
 243         ifm = nlmsg_data(nlh);
 244
 245         protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
 246         if (!protinfo)
 247                 return 0;
 248
 249         p = br_port_get_rtnl(dev);
 250         if (!p)
 251                 return -EINVAL;
 252
 253         if (protinfo->nla_type & NLA_F_NESTED) {
 254                 err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
 255                                        protinfo, ifla_brport_policy);
 256                 if (err)
 257                         return err;
 258
 259                 spin_lock_bh(&p->br->lock);
 260                 err = br_setport(p, tb);
 261                 spin_unlock_bh(&p->br->lock);
 262         } else {
 263                 /* Binary compatability with old RSTP */
 264                 if (nla_len(protinfo) < sizeof(u8))
 265                         return -EINVAL;
 266
 267                 spin_lock_bh(&p->br->lock);
 268                 err = br_set_port_state(p, nla_get_u8(protinfo));
 269                 spin_unlock_bh(&p->br->lock);
 270         }
 271
 272         if (err == 0)
 273                 br_ifinfo_notify(RTM_NEWLINK, p);
 274
 275         return err;
 276 }
 277
 278 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 279 {
 280         if (tb[IFLA_ADDRESS]) {
 281                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 282                         return -EINVAL;
 283                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 284                         return -EADDRNOTAVAIL;
 285         }
 286
 287         return 0;
 288 }
 289
 290 struct rtnl_link_ops br_link_ops __read_mostly = {
 291         .kind           = "bridge",
 292         .priv_size      = sizeof(struct net_bridge),
 293         .setup          = br_dev_setup,
 294         .validate       = br_validate,
 295         .dellink        = br_dev_delete,
 296 };
 297
 298 int __init br_netlink_init(void)
 299 {
 300         return rtnl_link_register(&br_link_ops);
 301 }
 302
 303 void __exit br_netlink_fini(void)
 304 {
 305         rtnl_link_unregister(&br_link_ops);
 306         rtnl_unregister_all(PF_BRIDGE);
 307 }