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 sk_buff *skb; 86 int err = -ENOBUFS; 87 88 pr_debug("bridge notify event=%d\n", event); 89 skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC); 90 if (skb == NULL) 91 goto errout; 92 93 err = br_fill_ifinfo(skb, port, 0, 0, event, 0); 94 if (err < 0) { 95 /* -EMSGSIZE implies BUG in br_nlmsg_size() */ 96 WARN_ON(err == -EMSGSIZE); 97 kfree_skb(skb); 98 goto errout; 99 } 100 err = rtnl_notify(skb, &init_net,0, RTNLGRP_LINK, NULL, GFP_ATOMIC); 101 errout: 102 if (err < 0) 103 rtnl_set_sk_err(&init_net, RTNLGRP_LINK, err); 104 } 105 106 /* 107 * Dump information about all ports, in response to GETLINK 108 */ 109 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) 110 { 111 struct net *net = sock_net(skb->sk); 112 struct net_device *dev; 113 int idx; 114 115 if (net != &init_net) 116 return 0; 117 118 idx = 0; 119 for_each_netdev(&init_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 (net != &init_net) 151 return -EINVAL; 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(&init_net, ifm->ifi_index); 169 if (!dev) 170 return -ENODEV; 171 172 p = dev->br_port; 173 if (!p) 174 return -EINVAL; 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