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 <net/netlink.h>
  16 #include "br_private.h"
  17
  18 /*
  19  * Create one netlink message for one interface
  20  * Contains port and master info as well as carrier and bridge state.
  21  */
  22 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
  23                           u32 pid, u32 seq, int event, unsigned int flags)
  24 {
  25         const struct net_bridge *br = port->br;
  26         const struct net_device *dev = port->dev;
  27         struct ifinfomsg *r;
  28         struct nlmsghdr *nlh;
  29         unsigned char *b = skb->tail;
  30         u32 mtu = dev->mtu;
  31         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  32         u8 portstate = port->state;
  33
  34         pr_debug("br_fill_info event %d port %s master %s\n",
  35                  event, dev->name, br->dev->name);
  36
  37         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
  38         r = NLMSG_DATA(nlh);
  39         r->ifi_family = AF_BRIDGE;
  40         r->__ifi_pad = 0;
  41         r->ifi_type = dev->type;
  42         r->ifi_index = dev->ifindex;
  43         r->ifi_flags = dev_get_flags(dev);
  44         r->ifi_change = 0;
  45
  46         RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name);
  47
  48         RTA_PUT(skb, IFLA_MASTER, sizeof(int), &br->dev->ifindex);
  49
  50         if (dev->addr_len)
  51                 RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
  52
  53         RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu);
  54         if (dev->ifindex != dev->iflink)
  55                 RTA_PUT(skb, IFLA_LINK, sizeof(int), &dev->iflink);
  56
  57
  58         RTA_PUT(skb, IFLA_OPERSTATE, sizeof(operstate), &operstate);
  59
  60         if (event == RTM_NEWLINK)
  61                 RTA_PUT(skb, IFLA_PROTINFO, sizeof(portstate), &portstate);
  62
  63         nlh->nlmsg_len = skb->tail - b;
  64
  65         return skb->len;
  66
  67 nlmsg_failure:
  68 rtattr_failure:
  69
  70         skb_trim(skb, b - skb->data);
  71         return -EINVAL;
  72 }
  73
  74 /*
  75  * Notify listeners of a change in port information
  76  */
  77 void br_ifinfo_notify(int event, struct net_bridge_port *port)
  78 {
  79         struct sk_buff *skb;
  80         int payload = sizeof(struct ifinfomsg) + 128;
  81         int err = -ENOBUFS;
  82
  83         pr_debug("bridge notify event=%d\n", event);
  84         skb = nlmsg_new(nlmsg_total_size(payload), GFP_ATOMIC);
  85         if (skb == NULL)
  86                 goto errout;
  87
  88         err = br_fill_ifinfo(skb, port, 0, 0, event, 0);
  89         if (err < 0) {
  90                 kfree_skb(skb);
  91                 goto errout;
  92         }
  93
  94         err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
  95 errout:
  96         if (err < 0)
  97                 rtnl_set_sk_err(RTNLGRP_LINK, err);
  98 }
  99
 100 /*
 101  * Dump information about all ports, in response to GETLINK
 102  */
 103 static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 104 {
 105         struct net_device *dev;
 106         int idx;
 107         int s_idx = cb->args[0];
 108         int err = 0;
 109
 110         read_lock(&dev_base_lock);
 111         for (dev = dev_base, idx = 0; dev; dev = dev->next) {
 112                 struct net_bridge_port *p = dev->br_port;
 113
 114                 /* not a bridge port */
 115                 if (!p)
 116                         continue;
 117
 118                 if (idx < s_idx)
 119                         goto cont;
 120
 121                 err = br_fill_ifinfo(skb, p, NETLINK_CB(cb->skb).pid,
 122                                      cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI);
 123                 if (err <= 0)
 124                         break;
 125 cont:
 126                 ++idx;
 127         }
 128         read_unlock(&dev_base_lock);
 129
 130         cb->args[0] = idx;
 131
 132         return skb->len;
 133 }
 134
 135 /*
 136  * Change state of port (ie from forwarding to blocking etc)
 137  * Used by spanning tree in user space.
 138  */
 139 static int br_rtm_setlink(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 140 {
 141         struct rtattr  **rta = arg;
 142         struct ifinfomsg *ifm = NLMSG_DATA(nlh);
 143         struct net_device *dev;
 144         struct net_bridge_port *p;
 145         u8 new_state;
 146
 147         if (ifm->ifi_family != AF_BRIDGE)
 148                 return -EPFNOSUPPORT;
 149
 150         /* Must pass valid state as PROTINFO */
 151         if (rta[IFLA_PROTINFO-1]) {
 152                 u8 *pstate = RTA_DATA(rta[IFLA_PROTINFO-1]);
 153                 new_state = *pstate;
 154         } else
 155                 return -EINVAL;
 156
 157         if (new_state > BR_STATE_BLOCKING)
 158                 return -EINVAL;
 159
 160         /* Find bridge port */
 161         dev = __dev_get_by_index(ifm->ifi_index);
 162         if (!dev)
 163                 return -ENODEV;
 164
 165         p = dev->br_port;
 166         if (!p)
 167                 return -EINVAL;
 168
 169         /* if kernel STP is running, don't allow changes */
 170         if (p->br->stp_enabled)
 171                 return -EBUSY;
 172
 173         if (!netif_running(dev))
 174                 return -ENETDOWN;
 175
 176         if (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED)
 177                 return -ENETDOWN;
 178
 179         p->state = new_state;
 180         br_log_state(p);
 181         return 0;
 182 }
 183
 184
 185 static struct rtnetlink_link bridge_rtnetlink_table[RTM_NR_MSGTYPES] = {
 186         [RTM_GETLINK - RTM_BASE] = { .dumpit    = br_dump_ifinfo, },
 187         [RTM_SETLINK - RTM_BASE] = { .doit      = br_rtm_setlink, },
 188 };
 189
 190 void __init br_netlink_init(void)
 191 {
 192         rtnetlink_links[PF_BRIDGE] = bridge_rtnetlink_table;
 193 }
 194
 195 void __exit br_netlink_fini(void)
 196 {
 197         rtnetlink_links[PF_BRIDGE] = NULL;
 198 }
 199