When adding rule with NLM_F_EXCL flag then check if the same rule exist.
If yes then exit with -EEXIST.
This is already implemented in iproute2:
if (cmd == RTM_NEWRULE) {
req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
req.r.rtm_type = RTN_UNICAST;
}
Tested ipv4 and ipv6 with net-next linux on qemu x86
expected behavior after patch:
localhost ~ # ip rule
0: from all lookup local
32766: from all lookup main
32767: from all lookup default
localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005
localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005
RTNETLINK answers: File exists
localhost ~ # ip rule
0: from all lookup local
1005: from 10.46.177.97 lookup 104
32766: from all lookup main
32767: from all lookup default
There was already topic regarding this but I don't see any changes
merged and problem still occurs.
https://lkml.kernel.org/r/1135778809.5944.7.camel+%28%29+localhost+%21+localdomain
Signed-off-by: Mateusz Bajorski <mateusz.bajor...@nokia.com>
---
net/core/fib_rules.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 840aceb..b9816a3 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -291,6 +291,47 @@ static int fib_nl_newrule(struct sk_buff *skb, struct
nlmsghdr* nlh)
if (err < 0)
goto errout;
+ if (nlh->nlmsg_flags & NLM_F_EXCL) {
+ list_for_each_entry(rule, &ops->rules_list, list) {
+ if (frh->action && (frh->action != rule->action))
+ continue;
+
+ if (frh_get_table(frh, tb) &&
+ frh_get_table(frh, tb) != rule->table)
+ continue;
+
+ if (tb[FRA_PRIORITY] &&
+ rule->pref != nla_get_u32(tb[FRA_PRIORITY]))
+ continue;
+
+ if (tb[FRA_IIFNAME] &&
+ nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
+ continue;
+
+ if (tb[FRA_OIFNAME] &&
+ nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
+ continue;
+
+ if (tb[FRA_FWMARK] &&
+ rule->mark != nla_get_u32(tb[FRA_FWMARK]))
+ continue;
+
+ if (tb[FRA_FWMASK] &&
+ rule->mark_mask != nla_get_u32(tb[FRA_FWMASK]))
+ continue;
+
+ if (tb[FRA_TUN_ID] &&
+ rule->tun_id != nla_get_be64(tb[FRA_TUN_ID]))
+ continue;
+
+ if (!ops->compare(rule, frh, tb))
+ continue;
+
+ err = -EEXIST;
+ goto errout;
+ }
+ }
+
rule = kzalloc(ops->rule_size, GFP_KERNEL);
if (rule == NULL) {
err = -ENOMEM;
--
2.6.4
