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 */
afs_get_MAC_address(u8 * mac,size_t maclen)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 */
afs_get_ipv4_interfaces(struct afs_interface * bufs,size_t maxbufs,bool wantloopback)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 }
69