[PATCH net-next v2 2/4] net: sched: em_ipt: set the family based on the packet if it's unspecified

[Nikolay Aleksandrov]

Set the family based on the packet if it's unspecified otherwise
protocol-neutral matches will have wrong information (e.g. NFPROTO_UNSPEC).
In preparation for using NFPROTO_UNSPEC xt matches.

v2: set the nfproto only when unspecified

Suggested-by: Eyal Birger <eyal.bir...@gmail.com>
Signed-off-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com>
---
 net/sched/em_ipt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/sched/em_ipt.c b/net/sched/em_ipt.c
index 64dbafe4e94c..fd7f5b288c31 100644
--- a/net/sched/em_ipt.c
+++ b/net/sched/em_ipt.c
@@ -182,6 +182,7 @@ static int em_ipt_match(struct sk_buff *skb, struct 
tcf_ematch *em,
        const struct em_ipt_match *im = (const void *)em->data;
        struct xt_action_param acpar = {};
        struct net_device *indev = NULL;
+       u8 nfproto = im->match->family;
        struct nf_hook_state state;
        int ret;
 
@@ -189,10 +190,14 @@ static int em_ipt_match(struct sk_buff *skb, struct 
tcf_ematch *em,
        case htons(ETH_P_IP):
                if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
                        return 0;
+               if (nfproto == NFPROTO_UNSPEC)
+                       nfproto = NFPROTO_IPV4;
                break;
        case htons(ETH_P_IPV6):
                if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
                        return 0;
+               if (nfproto == NFPROTO_UNSPEC)
+                       nfproto = NFPROTO_IPV6;
                break;
        default:
                return 0;
@@ -203,7 +208,7 @@ static int em_ipt_match(struct sk_buff *skb, struct 
tcf_ematch *em,
        if (skb->skb_iif)
                indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
 
-       nf_hook_state_init(&state, im->hook, im->match->family,
+       nf_hook_state_init(&state, im->hook, nfproto,
                           indev ?: skb->dev, skb->dev, NULL, em->net, NULL);
 
        acpar.match = im->match;
-- 
2.20.1