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