netdevices.c

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/* AFS network device helpers
 *
 * Copyright (c) 2007 Patrick McHardy <[email protected]>
 */

#include <linux/string.h>
#include <linux/rtnetlink.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <net/net_namespace.h>
#include "internal.h"

/*
 * get a MAC address from a random ethernet interface that has a real one
 * - the buffer will normally be 6 bytes in size
 */
int afs_get_MAC_address(u8 *mac, size_t maclen)
{
    struct net_device *dev;
    int ret = -ENODEV;

    BUG_ON(maclen != ETH_ALEN);

    rtnl_lock();
    dev = __dev_getfirstbyhwtype(&init_net, ARPHRD_ETHER);
    if (dev) {
        memcpy(mac, dev->dev_addr, maclen);
        ret = 0;
    }
    rtnl_unlock();
    return ret;
}

/*
 * get a list of this system's interface IPv4 addresses, netmasks and MTUs
 * - maxbufs must be at least 1
 * - returns the number of interface records in the buffer
 */
int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
                bool wantloopback)
{
    struct net_device *dev;
    struct in_device *idev;
    int n = 0;

    ASSERT(maxbufs > 0);

    rtnl_lock();
    for_each_netdev(&init_net, dev) {
        if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
            continue;
        idev = __in_dev_get_rtnl(dev);
        if (!idev)
            continue;
        for_primary_ifa(idev) {
            bufs[n].address.s_addr = ifa->ifa_address;
            bufs[n].netmask.s_addr = ifa->ifa_mask;
            bufs[n].mtu = dev->mtu;
            n++;
            if (n >= maxbufs)
                goto out;
        } endfor_ifa(idev);
    }
out:
    rtnl_unlock();
    return n;
}