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 pr_debug("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 pr_debug("bridge notify event=%d\n", event); 91 skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC); 92 if (skb == NULL) 93 goto errout; 94 95 err = br_fill_ifinfo(skb, port, 0, 0, event, 0); 96 if (err < 0) { 97 /* -EMSGSIZE implies BUG in br_nlmsg_size() */ 98 WARN_ON(err == -EMSGSIZE); 99 kfree_skb(skb); 100 goto errout; 101 } 102 rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC); 103 return; 104 errout: 105 if (err < 0) 106 rtnl_set_sk_err(net, RTNLGRP_LINK, err); 107 } 108 109 /* 110 * Dump information about all ports, in response to GETLINK 111 */ 112 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) 113 { 114 struct net *net = sock_net(skb->sk); 115 struct net_device *dev; 116 int idx; 117 118 idx = 0; 119 for_each_netdev(net, dev) { 120 /* not a bridge port */ 121 if (dev->br_port == NULL || idx < cb->args[0]) 122 goto skip; 123 124 if (br_fill_ifinfo(skb, dev->br_port, NETLINK_CB(cb->skb).pid, 125 cb->nlh->nlmsg_seq, RTM_NEWLINK, 126 NLM_F_MULTI) < 0) 127 break; 128 skip: 129 ++idx; 130 } 131 132 cb->args[0] = idx; 133 134 return skb->len; 135 } 136 137 /* 138 * Change state of port (ie from forwarding to blocking etc) 139 * Used by spanning tree in user space. 140 */ 141 static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 142 { 143 struct net *net = sock_net(skb->sk); 144 struct ifinfomsg *ifm; 145 struct nlattr *protinfo; 146 struct net_device *dev; 147 struct net_bridge_port *p; 148 u8 new_state; 149 150 if (nlmsg_len(nlh) < sizeof(*ifm)) 151 return -EINVAL; 152 153 ifm = nlmsg_data(nlh); 154 if (ifm->ifi_family != AF_BRIDGE) 155 return -EPFNOSUPPORT; 156 157 protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO); 158 if (!protinfo || nla_len(protinfo) < sizeof(u8)) 159 return -EINVAL; 160 161 new_state = nla_get_u8(protinfo); 162 if (new_state > BR_STATE_BLOCKING) 163 return -EINVAL; 164 165 dev = __dev_get_by_index(net, ifm->ifi_index); 166 if (!dev) 167 return -ENODEV; 168 169 p = dev->br_port; 170 if (!p) 171 return -EINVAL; 172 173 /* if kernel STP is running, don't allow changes */ 174 if (p->br->stp_enabled == BR_KERNEL_STP) 175 return -EBUSY; 176 177 if (!netif_running(dev) || 178 (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)) 179 return -ENETDOWN; 180 181 p->state = new_state; 182 br_log_state(p); 183 return 0; 184 } 185 186 187 int __init br_netlink_init(void) 188 { 189 if (__rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo)) 190 return -ENOBUFS; 191 192 /* Only the first call to __rtnl_register can fail */ 193 __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL); 194 195 return 0; 196 } 197 198 void __exit br_netlink_fini(void) 199 { 200 rtnl_unregister_all(PF_BRIDGE); 201 } 202 203