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         if (maclen != ETH_ALEN)
  24                 BUG();
  25
  26         rtnl_lock();
  27         dev = __dev_getfirstbyhwtype(&init_net, ARPHRD_ETHER);
  28         if (dev) {
  29                 memcpy(mac, dev->dev_addr, maclen);
  30                 ret = 0;
  31         }
  32         rtnl_unlock();
  33         return ret;
  34 }
  35
  36 /*
  37  * get a list of this system's interface IPv4 addresses, netmasks and MTUs
  38  * - maxbufs must be at least 1
  39  * - returns the number of interface records in the buffer
  40  */
  41 int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
  42                             bool wantloopback)
  43 {
  44         struct net_device *dev;
  45         struct in_device *idev;
  46         int n = 0;
  47
  48         ASSERT(maxbufs > 0);
  49
  50         rtnl_lock();
  51         for_each_netdev(&init_net, dev) {
  52                 if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
  53                         continue;
  54                 idev = __in_dev_get_rtnl(dev);
  55                 if (!idev)
  56                         continue;
  57                 for_primary_ifa(idev) {
  58                         bufs[n].address.s_addr = ifa->ifa_address;
  59                         bufs[n].netmask.s_addr = ifa->ifa_mask;
  60                         bufs[n].mtu = dev->mtu;
  61                         n++;
  62                         if (n >= maxbufs)
  63                                 goto out;
  64                 } endfor_ifa(idev);
  65         }
  66 out:
  67         rtnl_unlock();
  68         return n;
  69 }