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