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 if (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 (dev->addr_len && 68 nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) || 69 (dev->ifindex != dev->iflink && 70 nla_put_u32(skb, IFLA_LINK, dev->iflink)) || 71 (event == RTM_NEWLINK && 72 nla_put_u8(skb, IFLA_PROTINFO, port->state))) 73 goto nla_put_failure; 74 return nlmsg_end(skb, nlh); 75 76 nla_put_failure: 77 nlmsg_cancel(skb, nlh); 78 return -EMSGSIZE; 79 } 80 81 /* 82 * Notify listeners of a change in port information 83 */ 84 void br_ifinfo_notify(int event, struct net_bridge_port *port) 85 { 86 struct net *net = dev_net(port->dev); 87 struct sk_buff *skb; 88 int err = -ENOBUFS; 89 90 br_debug(port->br, "port %u(%s) event %d\n", 91 (unsigned int)port->port_no, port->dev->name, event); 92 93 skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC); 94 if (skb == NULL) 95 goto errout; 96 97 err = br_fill_ifinfo(skb, port, 0, 0, event, 0); 98 if (err < 0) { 99 /* -EMSGSIZE implies BUG in br_nlmsg_size() */ 100 WARN_ON(err == -EMSGSIZE); 101 kfree_skb(skb); 102 goto errout; 103 } 104 rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC); 105 return; 106 errout: 107 if (err < 0) 108 rtnl_set_sk_err(net, RTNLGRP_LINK, err); 109 } 110 111 /* 112 * Dump information about all ports, in response to GETLINK 113 */ 114 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) 115 { 116 struct net *net = sock_net(skb->sk); 117 struct net_device *dev; 118 int idx; 119 120 idx = 0; 121 rcu_read_lock(); 122 for_each_netdev_rcu(net, dev) { 123 struct net_bridge_port *port = br_port_get_rcu(dev); 124 125 /* not a bridge port */ 126 if (!port || idx < cb->args[0]) 127 goto skip; 128 129 if (br_fill_ifinfo(skb, port, 130 NETLINK_CB(cb->skb).portid, 131 cb->nlh->nlmsg_seq, RTM_NEWLINK, 132 NLM_F_MULTI) < 0) 133 break; 134 skip: 135 ++idx; 136 } 137 rcu_read_unlock(); 138 cb->args[0] = idx; 139 140 return skb->len; 141 } 142 143 /* 144 * Change state of port (ie from forwarding to blocking etc) 145 * Used by spanning tree in user space. 146 */ 147 static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 148 { 149 struct net *net = sock_net(skb->sk); 150 struct ifinfomsg *ifm; 151 struct nlattr *protinfo; 152 struct net_device *dev; 153 struct net_bridge_port *p; 154 u8 new_state; 155 156 if (nlmsg_len(nlh) < sizeof(*ifm)) 157 return -EINVAL; 158 159 ifm = nlmsg_data(nlh); 160 if (ifm->ifi_family != AF_BRIDGE) 161 return -EPFNOSUPPORT; 162 163 protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO); 164 if (!protinfo || nla_len(protinfo) < sizeof(u8)) 165 return -EINVAL; 166 167 new_state = nla_get_u8(protinfo); 168 if (new_state > BR_STATE_BLOCKING) 169 return -EINVAL; 170 171 dev = __dev_get_by_index(net, ifm->ifi_index); 172 if (!dev) 173 return -ENODEV; 174 175 p = br_port_get_rtnl(dev); 176 if (!p) 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(dev) || 184 (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)) 185 return -ENETDOWN; 186 187 p->state = new_state; 188 br_log_state(p); 189 190 spin_lock_bh(&p->br->lock); 191 br_port_state_selection(p->br); 192 spin_unlock_bh(&p->br->lock); 193 194 br_ifinfo_notify(RTM_NEWLINK, p); 195 196 return 0; 197 } 198 199 static int br_validate(struct nlattr *tb[], struct nlattr *data[]) 200 { 201 if (tb[IFLA_ADDRESS]) { 202 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 203 return -EINVAL; 204 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 205 return -EADDRNOTAVAIL; 206 } 207 208 return 0; 209 } 210 211 struct rtnl_link_ops br_link_ops __read_mostly = { 212 .kind = "bridge", 213 .priv_size = sizeof(struct net_bridge), 214 .setup = br_dev_setup, 215 .validate = br_validate, 216 .dellink = br_dev_delete, 217 }; 218 219 int __init br_netlink_init(void) 220 { 221 int err; 222 223 err = rtnl_link_register(&br_link_ops); 224 if (err < 0) 225 goto err1; 226 227 err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, 228 br_dump_ifinfo, NULL); 229 if (err) 230 goto err2; 231 err = __rtnl_register(PF_BRIDGE, RTM_SETLINK, 232 br_rtm_setlink, NULL, NULL); 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