net: network device name ifalias support
This patch add support for keeping an additional character alias
associated with an network interface. This is useful for maintaining
the SNMP ifAlias value which is a user defined value. Routers use this
to hold information like which circuit or line it is connected to. It
is just an arbitrary text label on the network device.
There are two exposed interfaces with this patch, the value can be
read/written either via netlink or sysfs.
This could be maintained just by the snmp daemon, but it is more
generally useful for other management tools, and the kernel is good
place to act as an agreed upon interface to store it.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 71edb8b..8862498 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -586,6 +586,7 @@
{
return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+ nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
+ + nla_total_size(IFALIASZ) /* IFLA_IFALIAS */
+ nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
+ nla_total_size(sizeof(struct rtnl_link_ifmap))
+ nla_total_size(sizeof(struct rtnl_link_stats))
@@ -640,6 +641,9 @@
if (txq->qdisc_sleeping)
NLA_PUT_STRING(skb, IFLA_QDISC, txq->qdisc_sleeping->ops->id);
+ if (dev->ifalias)
+ NLA_PUT_STRING(skb, IFLA_IFALIAS, dev->ifalias);
+
if (1) {
struct rtnl_link_ifmap map = {
.mem_start = dev->mem_start,
@@ -713,6 +717,7 @@
[IFLA_LINKMODE] = { .type = NLA_U8 },
[IFLA_LINKINFO] = { .type = NLA_NESTED },
[IFLA_NET_NS_PID] = { .type = NLA_U32 },
+ [IFLA_IFALIAS] = { .type = NLA_STRING, .len = IFALIASZ-1 },
};
static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
@@ -853,6 +858,14 @@
modified = 1;
}
+ if (tb[IFLA_IFALIAS]) {
+ err = dev_set_alias(dev, nla_data(tb[IFLA_IFALIAS]),
+ nla_len(tb[IFLA_IFALIAS]));
+ if (err < 0)
+ goto errout;
+ modified = 1;
+ }
+
if (tb[IFLA_BROADCAST]) {
nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
send_addr_notify = 1;