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 <net/rtnetlink.h> 16 #include <net/net_namespace.h> 17 #include <net/sock.h> 18 #include "br_private.h" 19 20 static inline size_t br_nlmsg_size(void) 21 { 22 return NLMSG_ALIGN(sizeof(struct ifinfomsg)) 23 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */ 24 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */ 25 + nla_total_size(4) /* IFLA_MASTER */ 26 + nla_total_size(4) /* IFLA_MTU */ 27 + nla_total_size(4) /* IFLA_LINK */ 28 + nla_total_size(1) /* IFLA_OPERSTATE */ 29 + nla_total_size(1); /* IFLA_PROTINFO */ 30 } 31 32 /* 33 * Create one netlink message for one interface 34 * Contains port and master info as well as carrier and bridge state. 35 */ 36 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port, 37 u32 pid, u32 seq, int event, unsigned int flags) 38 { 39 const struct net_bridge *br = port->br; 40 const struct net_device *dev = port->dev; 41 struct ifinfomsg *hdr; 42 struct nlmsghdr *nlh; 43 u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN; 44 45 br_debug(br, "br_fill_info event %d port %s master %s\n", 46 event, dev->name, br->dev->name); 47 48 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags); 49 if (nlh == NULL) 50 return -EMSGSIZE; 51 52 hdr = nlmsg_data(nlh); 53 hdr->ifi_family = AF_BRIDGE; 54 hdr->__ifi_pad = 0; 55 hdr->ifi_type = dev->type; 56 hdr->ifi_index = dev->ifindex; 57 hdr->ifi_flags = dev_get_flags(dev); 58 hdr->ifi_change = 0; 59 60 NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name); 61 NLA_PUT_U32(skb, IFLA_MASTER, br->dev->ifindex); 62 NLA_PUT_U32(skb, IFLA_MTU, dev->mtu); 63 NLA_PUT_U8(skb, IFLA_OPERSTATE, operstate); 64 65 if (dev->addr_len) 66 NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr); 67 68 if (dev->ifindex != dev->iflink) 69 NLA_PUT_U32(skb, IFLA_LINK, dev->iflink); 70 71 if (event == RTM_NEWLINK) 72 NLA_PUT_U8(skb, IFLA_PROTINFO, port->state); 73 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)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 for_each_netdev(net, dev) { 122 /* not a bridge port */ 123 if (!br_port_exists(dev) || idx < cb->args[0]) 124 goto skip; 125 126 if (br_fill_ifinfo(skb, br_port_get(dev), 127 NETLINK_CB(cb->skb).pid, 128 cb->nlh->nlmsg_seq, RTM_NEWLINK, 129 NLM_F_MULTI) < 0) 130 break; 131 skip: 132 ++idx; 133 } 134 135 cb->args[0] = idx; 136 137 return skb->len; 138 } 139 140 /* 141 * Change state of port (ie from forwarding to blocking etc) 142 * Used by spanning tree in user space. 143 */ 144 static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 145 { 146 struct net *net = sock_net(skb->sk); 147 struct ifinfomsg *ifm; 148 struct nlattr *protinfo; 149 struct net_device *dev; 150 struct net_bridge_port *p; 151 u8 new_state; 152 153 if (nlmsg_len(nlh) < sizeof(*ifm)) 154 return -EINVAL; 155 156 ifm = nlmsg_data(nlh); 157 if (ifm->ifi_family != AF_BRIDGE) 158 return -EPFNOSUPPORT; 159 160 protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO); 161 if (!protinfo || nla_len(protinfo) < sizeof(u8)) 162 return -EINVAL; 163 164 new_state = nla_get_u8(protinfo); 165 if (new_state > BR_STATE_BLOCKING) 166 return -EINVAL; 167 168 dev = __dev_get_by_index(net, ifm->ifi_index); 169 if (!dev) 170 return -ENODEV; 171 172 if (!br_port_exists(dev)) 173 return -EINVAL; 174 p = br_port_get(dev); 175 176 /* if kernel STP is running, don't allow changes */ 177 if (p->br->stp_enabled == BR_KERNEL_STP) 178 return -EBUSY; 179 180 if (!netif_running(dev) || 181 (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)) 182 return -ENETDOWN; 183 184 p->state = new_state; 185 br_log_state(p); 186 return 0; 187 } 188 189 190 int __init br_netlink_init(void) 191 { 192 if (__rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo)) 193 return -ENOBUFS; 194 195 /* Only the first call to __rtnl_register can fail */ 196 __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL); 197 198 return 0; 199 } 200 201 void __exit br_netlink_fini(void) 202 { 203 rtnl_unregister_all(PF_BRIDGE); 204 } 205 206