fs/afs/netdevices.c

   1 /* AFS network device helpers
   2  *
   3  * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
   4  */
   5
   6 #include <linux/string.h>
   7 #include <linux/rtnetlink.h>
   8 #include <linux/inetdevice.h>
   9 #include <linux/netdevice.h>
  10 #include <linux/if_arp.h>
  11 #include <net/net_namespace.h>
  12 #include "internal.h"
  13
  14 /*
  15  * get a MAC address from a random ethernet interface that has a real one
  16  * - the buffer will normally be 6 bytes in size
  17  */
  18 int afs_get_MAC_address(u8 *mac, size_t maclen)
  19 {
  20         struct net_device *dev;
  21         int ret = -ENODEV;
  22
  23         BUG_ON(maclen != ETH_ALEN);
  24
  25         rtnl_lock();
  26         dev = __dev_getfirstbyhwtype(&init_net, ARPHRD_ETHER);
  27         if (dev) {
  28                 memcpy(mac, dev->dev_addr, maclen);
  29                 ret = 0;
  30         }
  31         rtnl_unlock();
  32         return ret;
  33 }
  34
  35 /*
  36  * get a list of this system's interface IPv4 addresses, netmasks and MTUs
  37  * - maxbufs must be at least 1
  38  * - returns the number of interface records in the buffer
  39  */
  40 int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
  41                             bool wantloopback)
  42 {
  43         struct net_device *dev;
  44         struct in_device *idev;
  45         int n = 0;
  46
  47         ASSERT(maxbufs > 0);
  48
  49         rtnl_lock();
  50         for_each_netdev(&init_net, dev) {
  51                 if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
  52                         continue;
  53                 idev = __in_dev_get_rtnl(dev);
  54                 if (!idev)
  55                         continue;
  56                 for_primary_ifa(idev) {
  57                         bufs[n].address.s_addr = ifa->ifa_address;
  58                         bufs[n].netmask.s_addr = ifa->ifa_mask;
  59                         bufs[n].mtu = dev->mtu;
  60                         n++;
  61                         if (n >= maxbufs)
  62                                 goto out;
  63                 } endfor_ifa(idev);
  64         }
  65 out:
  66         rtnl_unlock();
  67         return n;
  68 }