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 for_each_netdev(net, dev) { 124 struct net_bridge_port *port = br_port_get_rtnl(dev); 125 126 /* not a bridge port */ 127 if (!port || idx < cb->args[0]) 128 goto skip; 129 130 if (br_fill_ifinfo(skb, port, 131 NETLINK_CB(cb->skb).pid, 132 cb->nlh->nlmsg_seq, RTM_NEWLINK, 133 NLM_F_MULTI) < 0) 134 break; 135 skip: 136 ++idx; 137 } 138 139 cb->args[0] = idx; 140 141 return skb->len; 142 } 143 144 /* 145 * Change state of port (ie from forwarding to blocking etc) 146 * Used by spanning tree in user space. 147 */ 148 static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 149 { 150 struct net *net = sock_net(skb->sk); 151 struct ifinfomsg *ifm; 152 struct nlattr *protinfo; 153 struct net_device *dev; 154 struct net_bridge_port *p; 155 u8 new_state; 156 157 if (nlmsg_len(nlh) < sizeof(*ifm)) 158 return -EINVAL; 159 160 ifm = nlmsg_data(nlh); 161 if (ifm->ifi_family != AF_BRIDGE) 162 return -EPFNOSUPPORT; 163 164 protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO); 165 if (!protinfo || nla_len(protinfo) < sizeof(u8)) 166 return -EINVAL; 167 168 new_state = nla_get_u8(protinfo); 169 if (new_state > BR_STATE_BLOCKING) 170 return -EINVAL; 171 172 dev = __dev_get_by_index(net, ifm->ifi_index); 173 if (!dev) 174 return -ENODEV; 175 176 p = br_port_get_rtnl(dev); 177 if (!p) 178 return -EINVAL; 179 180 /* if kernel STP is running, don't allow changes */ 181 if (p->br->stp_enabled == BR_KERNEL_STP) 182 return -EBUSY; 183 184 if (!netif_running(dev) || 185 (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)) 186 return -ENETDOWN; 187 188 p->state = new_state; 189 br_log_state(p); 190 return 0; 191 } 192 193 static int br_validate(struct nlattr *tb[], struct nlattr *data[]) 194 { 195 if (tb[IFLA_ADDRESS]) { 196 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 197 return -EINVAL; 198 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 199 return -EADDRNOTAVAIL; 200 } 201 202 return 0; 203 } 204 205 static struct rtnl_link_ops br_link_ops __read_mostly = { 206 .kind = "bridge", 207 .priv_size = sizeof(struct net_bridge), 208 .setup = br_dev_setup, 209 .validate = br_validate, 210 }; 211 212 int __init br_netlink_init(void) 213 { 214 int err; 215 216 err = rtnl_link_register(&br_link_ops); 217 if (err < 0) 218 goto err1; 219 220 err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo); 221 if (err) 222 goto err2; 223 err = __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL); 224 if (err) 225 goto err3; 226 err = __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, br_fdb_add, NULL); 227 if (err) 228 goto err3; 229 err = __rtnl_register(PF_BRIDGE, RTM_DELNEIGH, br_fdb_delete, NULL); 230 if (err) 231 goto err3; 232 err = __rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, br_fdb_dump); 233 if (err) 234 goto err3; 235 236 return 0; 237 238 err3: 239 rtnl_unregister_all(PF_BRIDGE); 240 err2: 241 rtnl_link_unregister(&br_link_ops); 242 err1: 243 return err; 244 } 245 246 void __exit br_netlink_fini(void) 247 { 248 rtnl_link_unregister(&br_link_ops); 249 rtnl_unregister_all(PF_BRIDGE); 250 } 251