Re: [PATCH net-next v2 1/1] net: Allow a rule to track originating protocol

On 2/22/18 1:23 AM, Ido Schimmel wrote:

quoted

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 98e1066c3d55..c1d4ab5b2d9f 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c

@@ -51,6 +51,7 @@ int fib_default_rule_add(struct fib_rules_ops *ops,
 	r->pref = pref;
 	r->table = table;
 	r->flags = flags;
+	r->proto = RTPROT_KERNEL;
 	r->fr_net = ops->fro_net;
 	r->uid_range = fib_kuid_range_unset;
 

@@ -465,6 +466,7 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 	}
 	refcount_set(&rule->refcnt, 1);
 	rule->fr_net = net;
+	rule->proto = frh->proto;
 
 	rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
 	                              : fib_default_rule_pref(ops);

@@ -664,6 +666,9 @@ int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 	}
 
 	list_for_each_entry(rule, &ops->rules_list, list) {
+		if (frh->proto && (frh->proto != rule->proto))
+			continue;

This breaks my scripts:
# ip -4 rule show
0:      from all lookup local
32766:  from all lookup main
32767:  from all lookup default

# ip -4 rule del pref 0
RTNETLINK answers: No such file or directory

Using iproute 4.15 in Fedora 27:
# ip -V
ip utility, iproute2-ss180129

Problem is iproute sets protocol to RTPROT_BOOT while rules are
installed with RTPROT_KERNEL.

Maybe add FRA_PROTOCOL?

Thanks!

ugh. Another iproute2 bug that the kernel has to deal with. iproute2 has
been using rtm for the ancillary header for rules when it should have
been fib_rule_hdr. That bug allowed someone to set the protocol field to
RTPROT_BOOT which was complete nonsense for rules until Donald's recent
patch.

That means all FIB rules need to default to RTPROT_BOOT. I hate to
inherit that for the l3mdev rule, but looking at the iproute2 code I
don't see any options.

Donald: send a patch that changes the protocol for kernel installed
rules to RTPROT_BOOT.