/*
* Given an interface name (e.g., eth0), return the MAC address in human
* readable format (e.g., 00:11:52:12:D9:A0). Return NULL for no match.
*/
char *iface_mac2str(char *ifname) {
int buflen = 20;
char *buf = NULL;
struct nl_handle *handle = NULL;
struct nl_cache *cache = NULL;
struct rtnl_link *link = NULL;
struct nl_addr *addr = NULL;
if (ifname == NULL) {
return NULL;
}
if ((cache = _iface_get_link_cache(&handle)) == NULL) {
return NULL;
}
if ((link = rtnl_link_get_by_name(cache, ifname)) == NULL) {
goto mac2str_error2;
}
if ((addr = rtnl_link_get_addr(link)) == NULL) {
goto mac2str_error3;
}
if ((buf = calloc(sizeof(char *), buflen)) == NULL) {
goto mac2str_error4;
}
if ((buf = nl_addr2str(addr, buf, buflen)) != NULL) {
char *oldbuf = buf;
buf = g_ascii_strup(buf, -1);
free(oldbuf);
}
mac2str_error4:
nl_addr_destroy(addr);
mac2str_error3:
rtnl_link_put(link);
mac2str_error2:
nl_close(handle);
nl_handle_destroy(handle);
return buf;
}
/* Given an interface's MAC address, return the name (e.g., eth0) in human
* readable format. Return NULL for no match
*/
char *iface_mac2device(char *mac) {
struct nl_handle *handle = NULL;
struct nl_cache *cache = NULL;
struct rtnl_link *link = NULL;
struct nl_addr *mac_as_nl_addr = NULL;
char *retval = NULL;
int i, n;
if (mac == NULL) {
return NULL;
}
if ((mac_as_nl_addr = nl_addr_parse(mac, AF_LLC)) == NULL) {
return NULL;
}
if ((cache = _iface_get_link_cache(&handle)) == NULL) {
return NULL;
}
n = nl_cache_nitems(cache);
for (i = 0; i <= n; i++) {
struct nl_addr *addr;
if ((link = rtnl_link_get(cache, i)) == NULL) {
continue;
}
addr = rtnl_link_get_addr(link);
if (!nl_addr_cmp(mac_as_nl_addr, addr)) {
retval = strdup(rtnl_link_get_name(link));
rtnl_link_put(link);
break;
}
rtnl_link_put(link);
}
nl_close(handle);
nl_handle_destroy(handle);
return retval;
}
/*
* Set the MTU on the specified device.
*/
int iface_set_interface_mtu(char *ifname, int mtu) {
int ret = 0;
struct nl_handle *handle = NULL;
struct nl_cache *cache = NULL;
struct rtnl_link *link = NULL;
struct rtnl_link *request = NULL;
if (ifname == NULL) {
return -1;
}
if (mtu <= 0) {
return -2;
}
if ((cache = _iface_get_link_cache(&handle)) == NULL) {
return -3;
}
if ((link = rtnl_link_get_by_name(cache, ifname)) == NULL) {
ret = -4;
goto ifacemtu_error1;
}
request = rtnl_link_alloc();
rtnl_link_set_mtu(request, mtu);
if (rtnl_link_change(handle, link, request, 0)) {
ret = -5;
goto ifacemtu_error2;
}
ifacemtu_error2:
rtnl_link_put(link);
ifacemtu_error1:
nl_close(handle);
nl_handle_destroy(handle);
return ret;
}
