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 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 */
afs_get_ipv4_interfaces(struct afs_interface * bufs,size_t maxbufs,bool wantloopback)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 }
70