[net-next PATCH 6/6] tc ife action fix late binding

[Jamal Hadi Salim]

From: Jamal Hadi Salim <j...@mojatatu.com>

The process below was broken and is fixed with this patch.

//add an ife action and give it an instance id of 1
sudo tc actions add action ife encode \
type 0xDEAD allow mark dst 02:15:15:15:15:15 index 1

//create a filter which binds to skbedit action id 1
sudo tc filter add dev $DEV parent ffff: protocol ip prio 1 u32\
match ip dst 17.0.0.1/32 flowid 1:11 action ife index 1

Message before fix was:
RTNETLINK answers: Invalid argument
We have an error talking to the kernel

Signed-off-by: Jamal Hadi Salim <j...@mojatatu.com>
---
 net/sched/act_ife.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
index 556f44c..17520ed 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -423,7 +423,7 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
        u16 ife_type = 0;
        u8 *daddr = NULL;
        u8 *saddr = NULL;
-       int ret = 0;
+       int ret = 0, aexists = 0;
        int err;
 
        err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy);
@@ -435,25 +435,29 @@ static int tcf_ife_init(struct net *net, struct nlattr 
*nla,
 
        parm = nla_data(tb[TCA_IFE_PARMS]);
 
+       aexists = tcf_hash_check(tn, parm->index, a, bind);
+       if (aexists && bind)
+               return 0;
+
        if (parm->flags & IFE_ENCODE) {
                /* Until we get issued the ethertype, we cant have
                 * a default..
                **/
                if (!tb[TCA_IFE_TYPE]) {
+                       if (aexists)
+                               tcf_hash_release(a, bind);
                        pr_info("You MUST pass etherype for encoding\n");
                        return -EINVAL;
                }
        }
 
-       if (!tcf_hash_check(tn, parm->index, a, bind)) {
+       if (!aexists) {
                ret = tcf_hash_create(tn, parm->index, est, a, sizeof(*ife),
                                      bind, false);
                if (ret)
                        return ret;
                ret = ACT_P_CREATED;
        } else {
-               if (bind)       /* dont override defaults */
-                       return 0;
                tcf_hash_release(a, bind);
                if (!ovr)
                        return -EEXIST;
@@ -495,6 +499,8 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
                                       NULL);
                if (err) {
 metadata_parse_err:
+                       if (aexists)
+                               tcf_hash_release(a, bind);
                        if (ret == ACT_P_CREATED)
                                _tcf_ife_cleanup(a, bind);
 
@@ -689,7 +695,7 @@ static int tcf_ife_encode(struct sk_buff *skb, const struct 
tc_action *a,
        /*
           OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
           where ORIGDATA = original ethernet header ...
-        */
+       */
        u16 metalen = ife_get_sz(skb, ife);
        int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
        unsigned int skboff = skb->dev->hard_header_len;
-- 
1.9.1