ipv4: add support for linkdown sysctl to netconf

This kernel patch exports the value of the new
ignore_routes_with_linkdown via netconf.

v2: changes to notify userspace via netlink when sysctl values change
and proposed for 'net' since this could be considered a bugfix

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/netconf.h b/include/uapi/linux/netconf.h
index 669a1f0..23cbd34 100644 (file)
--- a/include/uapi/linux/netconf.h
+++ b/include/uapi/linux/netconf.h
@@ -15,6 +15,7 @@ enum {
        NETCONFA_RP_FILTER,
        NETCONFA_MC_FORWARDING,
        NETCONFA_PROXY_NEIGH,
+       NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
        __NETCONFA_MAX
 };
 #define NETCONFA_MAX   (__NETCONFA_MAX - 1)

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7498716..e813196 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1740,6 +1740,8 @@ static int inet_netconf_msgsize_devconf(int type)
                size += nla_total_size(4);
        if (type == -1 || type == NETCONFA_PROXY_NEIGH)
                size += nla_total_size(4);
+       if (type == -1 || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN)
+               size += nla_total_size(4);
 
        return size;
 }
@@ -1780,6 +1782,10 @@ static int inet_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
            nla_put_s32(skb, NETCONFA_PROXY_NEIGH,
                        IPV4_DEVCONF(*devconf, PROXY_ARP)) < 0)
                goto nla_put_failure;
+       if ((type == -1 || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) &&
+           nla_put_s32(skb, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
+                       IPV4_DEVCONF(*devconf, IGNORE_ROUTES_WITH_LINKDOWN)) < 0)
+               goto nla_put_failure;
 
        nlmsg_end(skb, nlh);
        return 0;
@@ -1819,6 +1825,7 @@ static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = {
        [NETCONFA_FORWARDING]   = { .len = sizeof(int) },
        [NETCONFA_RP_FILTER]    = { .len = sizeof(int) },
        [NETCONFA_PROXY_NEIGH]  = { .len = sizeof(int) },
+       [NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN]  = { .len = sizeof(int) },
 };
 
 static int inet_netconf_get_devconf(struct sk_buff *in_skb,
@@ -2048,6 +2055,12 @@ static int devinet_conf_proc(struct ctl_table *ctl, int write,
                        inet_netconf_notify_devconf(net, NETCONFA_PROXY_NEIGH,
                                                    ifindex, cnf);
                }
+               if (i == IPV4_DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN - 1 &&
+                   new_value != old_value) {
+                       ifindex = devinet_conf_ifindex(net, cnf);
+                       inet_netconf_notify_devconf(net, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
+                                                   ifindex, cnf);
+               }
        }
 
        return ret;