/* * Bridge netlink control interface * * Authors: * Stephen Hemminger <shemminger@osdl.org> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/kernel.h> #include <net/rtnetlink.h> #include <net/net_namespace.h> #include <net/sock.h> #include "br_private.h" static inline size_t br_nlmsg_size(void) { return NLMSG_ALIGN(sizeof(struct ifinfomsg)) + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */ + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */ + nla_total_size(4) /* IFLA_MASTER */ + nla_total_size(4) /* IFLA_MTU */ + nla_total_size(4) /* IFLA_LINK */ + nla_total_size(1) /* IFLA_OPERSTATE */ + nla_total_size(1); /* IFLA_PROTINFO */ } /* * Create one netlink message for one interface * Contains port and master info as well as carrier and bridge state. */ static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port, u32 pid, u32 seq, int event, unsigned int flags) { const struct net_bridge *br = port->br; const struct net_device *dev = port->dev; struct ifinfomsg *hdr; struct nlmsghdr *nlh; u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN; pr_debug("br_fill_info event %d port %s master %s\n", event, dev->name, br->dev->name); nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags); if (nlh == NULL) return -EMSGSIZE; hdr = nlmsg_data(nlh); hdr->ifi_family = AF_BRIDGE; hdr->__ifi_pad = 0; hdr->ifi_type = dev->type; hdr->ifi_index = dev->ifindex; hdr->ifi_flags = dev_get_flags(dev); hdr->ifi_change = 0; NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name); NLA_PUT_U32(skb, IFLA_MASTER, br->dev->ifindex); NLA_PUT_U32(skb, IFLA_MTU, dev->mtu); NLA_PUT_U8(skb, IFLA_OPERSTATE, operstate); if (dev->addr_len) NLA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr); if (dev->ifindex != dev->iflink) NLA_PUT_U32(skb, IFLA_LINK, dev->iflink); if (event == RTM_NEWLINK) NLA_PUT_U8(skb, IFLA_PROTINFO, port->state); return nlmsg_end(skb, nlh); nla_put_failure: nlmsg_cancel(skb, nlh); return -EMSGSIZE; } /* * Notify listeners of a change in port information */ void br_ifinfo_notify(int event, struct net_bridge_port *port) { struct net *net = dev_net(port->dev); struct sk_buff *skb; int err = -ENOBUFS; pr_debug("bridge notify event=%d\n", event); skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC); if (skb == NULL) goto errout; err = br_fill_ifinfo(skb, port, 0, 0, event, 0); if (err < 0) { /* -EMSGSIZE implies BUG in br_nlmsg_size() */ WARN_ON(err == -EMSGSIZE); kfree_skb(skb); goto errout; } err = rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC); errout: if (err < 0) rtnl_set_sk_err(net, RTNLGRP_LINK, err); } /* * Dump information about all ports, in response to GETLINK */ static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); struct net_device *dev; int idx; idx = 0; for_each_netdev(net, dev) { /* not a bridge port */ if (dev->br_port == NULL || idx < cb->args[0]) goto skip; if (br_fill_ifinfo(skb, dev->br_port, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI) < 0) break; skip: ++idx; } cb->args[0] = idx; return skb->len; } /* * Change state of port (ie from forwarding to blocking etc) * Used by spanning tree in user space. */ static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) { struct net *net = sock_net(skb->sk); struct ifinfomsg *ifm; struct nlattr *protinfo; struct net_device *dev; struct net_bridge_port *p; u8 new_state; if (nlmsg_len(nlh) < sizeof(*ifm)) return -EINVAL; ifm = nlmsg_data(nlh); if (ifm->ifi_family != AF_BRIDGE) return -EPFNOSUPPORT; protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO); if (!protinfo || nla_len(protinfo) < sizeof(u8)) return -EINVAL; new_state = nla_get_u8(protinfo); if (new_state > BR_STATE_BLOCKING) return -EINVAL; dev = __dev_get_by_index(net, ifm->ifi_index); if (!dev) return -ENODEV; p = dev->br_port; if (!p) return -EINVAL; /* if kernel STP is running, don't allow changes */ if (p->br->stp_enabled == BR_KERNEL_STP) return -EBUSY; if (!netif_running(dev) || (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)) return -ENETDOWN; p->state = new_state; br_log_state(p); return 0; } int __init br_netlink_init(void) { if (__rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo)) return -ENOBUFS; /* Only the first call to __rtnl_register can fail */ __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL); return 0; } void __exit br_netlink_fini(void) { rtnl_unregister_all(PF_BRIDGE); }