net/bridge/br_netlink.c

   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/rtnetlink.h>
  15 #include "br_private.h"
  16
  17 /*
  18  * Create one netlink message for one interface
  19  * Contains port and master info as well as carrier and bridge state.
  20  */
  21 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
  22                           u32 pid, u32 seq, int event, unsigned int flags)
  23 {
  24         const struct net_bridge *br = port->br;
  25         const struct net_device *dev = port->dev;
  26         struct ifinfomsg *r;
  27         struct nlmsghdr *nlh;
  28         unsigned char *b = skb->tail;
  29         u32 mtu = dev->mtu;
  30         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  31         u8 portstate = port->state;
  32
  33         pr_debug("br_fill_info event %d port %s master %s\n",
  34                  event, dev->name, br->dev->name);
  35
  36         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
  37         r = NLMSG_DATA(nlh);
  38         r->ifi_family = AF_BRIDGE;
  39         r->__ifi_pad = 0;
  40         r->ifi_type = dev->type;
  41         r->ifi_index = dev->ifindex;
  42         r->ifi_flags = dev_get_flags(dev);
  43         r->ifi_change = 0;
  44
  45         RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name);
  46
  47         RTA_PUT(skb, IFLA_MASTER, sizeof(int), &br->dev->ifindex);
  48
  49         if (dev->addr_len)
  50                 RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
  51
  52         RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu);
  53         if (dev->ifindex != dev->iflink)
  54                 RTA_PUT(skb, IFLA_LINK, sizeof(int), &dev->iflink);
  55
  56
  57         RTA_PUT(skb, IFLA_OPERSTATE, sizeof(operstate), &operstate);
  58
  59         if (event == RTM_NEWLINK)
  60                 RTA_PUT(skb, IFLA_PROTINFO, sizeof(portstate), &portstate);
  61
  62         nlh->nlmsg_len = skb->tail - b;
  63
  64         return skb->len;
  65
  66 nlmsg_failure:
  67 rtattr_failure:
  68
  69         skb_trim(skb, b - skb->data);
  70         return -EINVAL;
  71 }
  72
  73 /*
  74  * Notify listeners of a change in port information
  75  */
  76 void br_ifinfo_notify(int event, struct net_bridge_port *port)
  77 {
  78         struct sk_buff *skb;
  79         int err = -ENOMEM;
  80
  81         pr_debug("bridge notify event=%d\n", event);
  82         skb = alloc_skb(NLMSG_SPACE(sizeof(struct ifinfomsg) + 128),
  83                         GFP_ATOMIC);
  84         if (!skb)
  85                 goto err_out;
  86
  87         err = br_fill_ifinfo(skb, port, current->pid, 0, event, 0);
  88         if (err)
  89                 goto err_kfree;
  90
  91         NETLINK_CB(skb).dst_group = RTNLGRP_LINK;
  92         netlink_broadcast(rtnl, skb, 0, RTNLGRP_LINK, GFP_ATOMIC);
  93         return;
  94
  95 err_kfree:
  96         kfree_skb(skb);
  97 err_out:
  98         netlink_set_err(rtnl, 0, RTNLGRP_LINK, err);
  99 }
 100
 101 /*
 102  * Dump information about all ports, in response to GETLINK
 103  */
 104 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 105 {
 106         struct net_device *dev;
 107         int idx;
 108         int s_idx = cb->args[0];
 109         int err = 0;
 110
 111         read_lock(&dev_base_lock);
 112         for (dev = dev_base, idx = 0; dev; dev = dev->next) {
 113                 struct net_bridge_port *p = dev->br_port;
 114
 115                 /* not a bridge port */
 116                 if (!p)
 117                         continue;
 118
 119                 if (idx < s_idx)
 120                         goto cont;
 121
 122                 err = br_fill_ifinfo(skb, p, NETLINK_CB(cb->skb).pid,
 123                                      cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI);
 124                 if (err <= 0)
 125                         break;
 126 cont:
 127                 ++idx;
 128         }
 129         read_unlock(&dev_base_lock);
 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 rtattr  **rta = arg;
 143         struct ifinfomsg *ifm = NLMSG_DATA(nlh);
 144         struct net_device *dev;
 145         struct net_bridge_port *p;
 146         u8 new_state;
 147
 148         if (ifm->ifi_family != AF_BRIDGE)
 149                 return -EPFNOSUPPORT;
 150
 151         /* Must pass valid state as PROTINFO */
 152         if (rta[IFLA_PROTINFO-1]) {
 153                 u8 *pstate = RTA_DATA(rta[IFLA_PROTINFO-1]);
 154                 new_state = *pstate;
 155         } else
 156                 return -EINVAL;
 157
 158         if (new_state > BR_STATE_BLOCKING)
 159                 return -EINVAL;
 160
 161         /* Find bridge port */
 162         dev = __dev_get_by_index(ifm->ifi_index);
 163         if (!dev)
 164                 return -ENODEV;
 165
 166         p = dev->br_port;
 167         if (!p)
 168                 return -EINVAL;
 169
 170         /* if kernel STP is running, don't allow changes */
 171         if (p->br->stp_enabled)
 172                 return -EBUSY;
 173
 174         if (!netif_running(dev))
 175                 return -ENETDOWN;
 176
 177         if (!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 static struct rtnetlink_link bridge_rtnetlink_table[RTM_NR_MSGTYPES] = {
 187         [RTM_GETLINK - RTM_BASE] = { .dumpit    = br_dump_ifinfo, },
 188         [RTM_SETLINK - RTM_BASE] = { .doit      = br_rtm_setlink, },
 189 };
 190
 191 void __init br_netlink_init(void)
 192 {
 193         rtnetlink_links[PF_BRIDGE] = bridge_rtnetlink_table;
 194 }
 195
 196 void __exit br_netlink_fini(void)
 197 {
 198         rtnetlink_links[PF_BRIDGE] = NULL;
 199 }
 200