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 } 266