From 153380ec4b9b6802bba61ebd34da432a54994e9d Mon Sep 17 00:00:00 2001 From: Mateusz Bajorski Date: Wed, 29 Jun 2016 09:22:10 +0200 Subject: [PATCH] fib_rules: Added NLM_F_EXCL support to fib_nl_newrule 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 Acked-by: David Ahern Signed-off-by: David S. Miller --- net/core/fib_rules.c | 49 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 98298b11f534..be4629c344a6 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -269,6 +269,49 @@ errout: return err; } +static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, + struct nlattr **tb, struct fib_rule *rule) +{ + struct fib_rule *r; + + list_for_each_entry(r, &ops->rules_list, list) { + if (r->action != rule->action) + continue; + + if (r->table != rule->table) + continue; + + if (r->pref != rule->pref) + continue; + + if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) + continue; + + if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) + continue; + + if (r->mark != rule->mark) + continue; + + if (r->mark_mask != rule->mark_mask) + continue; + + if (r->tun_id != rule->tun_id) + continue; + + if (r->fr_net != rule->fr_net) + continue; + + if (r->l3mdev != rule->l3mdev) + continue; + + if (!ops->compare(r, frh, tb)) + continue; + return 1; + } + return 0; +} + int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); @@ -386,6 +429,12 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh) if (rule->l3mdev && rule->table) goto errout_free; + if ((nlh->nlmsg_flags & NLM_F_EXCL) && + rule_exists(ops, frh, tb, rule)) { + err = -EEXIST; + goto errout_free; + } + err = ops->configure(rule, skb, frh, tb); if (err < 0) goto errout_free; -- 2.20.1