net/ipv4: Initialize proto and ports in flow struct

Updating the FIB tracepoint for the recent change to allow rules using
the protocol and ports exposed a few places where the entries in the flow
struct are not initialized.

For __fib_validate_source add the call to fib4_rules_early_flow_dissect
since it is invoked for the input path. For netfilter, add the memset on
the flow struct to avoid future problems like this. In ip_route_input_slow
need to set the fields if the skb dissection does not happen.

Fixes: bfff4862653b ("net: fib_rules: support for match on ip_proto, sport and dport")
Signed-off-by: David Ahern <[e-mail]>
Acked-by: Roopa Prabhu <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/ipv4/fib_frontend.c

···
 				 u8 tos, int oif, struct net_device *dev,
 				 int rpf, struct in_device *idev, u32 *itag)
 {
+	struct net *net = dev_net(dev);
+	struct flow_keys flkeys;
 	int ret, no_addr;
 	struct fib_result res;
 	struct flowi4 fl4;
-	struct net *net = dev_net(dev);
 	bool dev_match;
 
 	fl4.flowi4_oif = 0;
···
 	no_addr = idev->ifa_list == NULL;
 
 	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
+	if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
+		fl4.flowi4_proto = 0;
+		fl4.fl4_sport = 0;
+		fl4.fl4_dport = 0;
+	}
 
 	trace_fib_validate_source(dev, &fl4);
 

net/ipv4/netfilter/ipt_rpfilter.c

···
 			return true ^ invert;
 	}
 
+	memset(&flow, 0, sizeof(flow));
 	flow.flowi4_iif = LOOPBACK_IFINDEX;
 	flow.daddr = iph->saddr;
 	flow.saddr = rpfilter_get_saddr(iph->daddr);
-	flow.flowi4_oif = 0;
 	flow.flowi4_mark = info->flags & XT_RPFILTER_VALID_MARK ? skb->mark : 0;
 	flow.flowi4_tos = RT_TOS(iph->tos);
 	flow.flowi4_scope = RT_SCOPE_UNIVERSE;

net/ipv4/route.c

···
 	fl4.saddr = saddr;
 	fl4.flowi4_uid = sock_net_uid(net, NULL);
 
-	if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys))
+	if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
 		flkeys = &_flkeys;
+	} else {
+		fl4.flowi4_proto = 0;
+		fl4.fl4_sport = 0;
+		fl4.fl4_dport = 0;
+	}
 
 	err = fib_lookup(net, &fl4, res, 0);
 	if (err != 0) {