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 <net/rtnetlink.h> 15 #include <net/net_namespace.h> 16 #include <net/sock.h> 17 #include "br_private.h" 18 19 static inline size_t br_nlmsg_size(void) 20 { 21 return NLMSG_ALIGN(sizeof(struct ifinfomsg)) 22 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */ 23 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */ 24 + nla_total_size(4) /* IFLA_MASTER */ 25 + nla_total_size(4) /* IFLA_MTU */ 26 + nla_total_size(4) /* IFLA_LINK */ 27 + nla_total_size(1) /* IFLA_OPERSTATE */ 28 + nla_total_size(1); /* IFLA_PROTINFO */ 29 } 30 31 /* 32 * Create one netlink message for one interface 33 * Contains port and master info as well as carrier and bridge state. 34 */ 35 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port, 36 u32 pid, u32 seq, int event, unsigned int flags) 37 { 38 const struct net_bridge *br = port->br; 39 const struct net_device *dev = port->dev; 40 struct ifinfomsg *hdr; 41 struct nlmsghdr *nlh; 42 u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN; 43 44 pr_debug("br_fill_info event %d port %s master %s\n", 45 event, dev->name, br->dev->name); 46 47 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags); 48 if (nlh == NULL) 49 return -EMSGSIZE; 50 51 hdr = nlmsg_data(nlh); 52 hdr->ifi_family = AF_BRIDGE; 53 hdr->__ifi_pad = 0; 54 hdr->ifi_type = dev->type; 55 hdr->ifi_index = dev->ifindex; 56 hdr->ifi_flags = dev_get_flags(dev); 57 hdr->ifi_change = 0; 58 59 NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name); 60 NLA_PUT_U32(skb, IFLA_MASTER, br->dev->ifindex); 61 NLA_PUT_U32(skb, IFLA_MTU, dev->mtu); 62 NLA_PUT_U8(skb, IFLA_OPERSTATE, operstate); 63 64 if (dev->addr_len) 65 NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr); 66 67 if (dev->ifindex != dev->iflink) 68 NLA_PUT_U32(skb, IFLA_LINK, dev->iflink); 69 70 if (event == RTM_NEWLINK) 71 NLA_PUT_U8(skb, IFLA_PROTINFO, port->state); 72 73 return nlmsg_end(skb, nlh); 74 75 nla_put_failure: 76 nlmsg_cancel(skb, nlh); 77 return -EMSGSIZE; 78 } 79 80 /* 81 * Notify listeners of a change in port information 82 */ 83 void br_ifinfo_notify(int event, struct net_bridge_port *port) 84 { 85 struct net *net = dev_net(port->dev); 86 struct sk_buff *skb; 87 int err = -ENOBUFS; 88 89 pr_debug("bridge notify event=%d\n", event); 90 skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC); 91 if (skb == NULL) 92 goto errout; 93 94 err = br_fill_ifinfo(skb, port, 0, 0, event, 0); 95 if (err < 0) { 96 /* -EMSGSIZE implies BUG in br_nlmsg_size() */ 97 WARN_ON(err == -EMSGSIZE); 98 kfree_skb(skb); 99 goto errout; 100 } 101 rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC); 102 return; 103 errout: 104 if (err < 0) 105 rtnl_set_sk_err(net, RTNLGRP_LINK, err); 106 } 107 108 /* 109 * Dump information about all ports, in response to GETLINK 110 */ 111 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) 112 { 113 struct net *net = sock_net(skb->sk); 114 struct net_device *dev; 115 int idx; 116 117 idx = 0; 118 for_each_netdev(net, dev) { 119 /* not a bridge port */ 120 if (dev->br_port == NULL || idx < cb->args[0]) 121 goto skip; 122 123 if (br_fill_ifinfo(skb, dev->br_port, NETLINK_CB(cb->skb).pid, 124 cb->nlh->nlmsg_seq, RTM_NEWLINK, 125 NLM_F_MULTI) < 0) 126 break; 127 skip: 128 ++idx; 129 } 130 131 cb->args[0] = idx; 132 133 return skb->len; 134 } 135 136 /* 137 * Change state of port (ie from forwarding to blocking etc) 138 * Used by spanning tree in user space. 139 */ 140 static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 141 { 142 struct net *net = sock_net(skb->sk); 143 struct ifinfomsg *ifm; 144 struct nlattr *protinfo; 145 struct net_device *dev; 146 struct net_bridge_port *p; 147 u8 new_state; 148 149 if (nlmsg_len(nlh) < sizeof(*ifm)) 150 return -EINVAL; 151 152 ifm = nlmsg_data(nlh); 153 if (ifm->ifi_family != AF_BRIDGE) 154 return -EPFNOSUPPORT; 155 156 protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO); 157 if (!protinfo || nla_len(protinfo) < sizeof(u8)) 158 return -EINVAL; 159 160 new_state = nla_get_u8(protinfo); 161 if (new_state > BR_STATE_BLOCKING) 162 return -EINVAL; 163 164 dev = __dev_get_by_index(net, ifm->ifi_index); 165 if (!dev) 166 return -ENODEV; 167 168 p = dev->br_port; 169 if (!p) 170 return -EINVAL; 171 172 /* if kernel STP is running, don't allow changes */ 173 if (p->br->stp_enabled == BR_KERNEL_STP) 174 return -EBUSY; 175 176 if (!netif_running(dev) || 177 (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)) 178 return -ENETDOWN; 179 180 p->state = new_state; 181 br_log_state(p); 182 return 0; 183 } 184 185 186 int __init br_netlink_init(void) 187 { 188 if (__rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo)) 189 return -ENOBUFS; 190 191 /* Only the first call to __rtnl_register can fail */ 192 __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL); 193 194 return 0; 195 } 196 197 void __exit br_netlink_fini(void) 198 { 199 rtnl_unregister_all(PF_BRIDGE); 200 } 201 202