ipv4: Handle RTA_GATEWAY set to 0

Govindarajulu reported a regression with Network Manager which sends an
RTA_GATEWAY attribute with the address set to 0. Fixup the handling of
RTA_GATEWAY to only set fc_gw_family if the gateway address is actually
set.

Fixes: f35b794b3b405 ("ipv4: Prepare fib_config for IPv6 gateway")
Reported-by: Govindarajulu Varadarajan <govind.varadar@gmail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 310060e..d4b63f9 100644 (file)
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -755,8 +755,9 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
                        break;
                case RTA_GATEWAY:
                        has_gw = true;
-                       cfg->fc_gw_family = AF_INET;
                        cfg->fc_gw4 = nla_get_be32(attr);
+                       if (cfg->fc_gw4)
+                               cfg->fc_gw_family = AF_INET;
                        break;
                case RTA_VIA:
                        has_via = true;

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 0172738..779d2be 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -616,8 +616,9 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
                                return -EINVAL;
                        }
                        if (nla) {
-                               fib_cfg.fc_gw_family = AF_INET;
                                fib_cfg.fc_gw4 = nla_get_in_addr(nla);
+                               if (fib_cfg.fc_gw4)
+                                       fib_cfg.fc_gw_family = AF_INET;
                        } else if (nlav) {
                                ret = fib_gw_from_via(&fib_cfg, nlav, extack);
                                if (ret)