[Devel] [PATCH RHEL7 COMMIT] ms/ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel

[Vasily Averin]

The commit is pushed to "branch-rh7-3.10.0-1160.42.2.vz7.184.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-1160.42.2.vz7.184.2
------>
commit 2429adcaa3c4c3eedea87d57c69bdb7ff504056d
Author: Tom Herbert <tom at herbertland.com>
Date:   Tue Oct 26 14:26:23 2021 +0300

    ms/ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel
    
    We can't call skb_get_hash here since the packet is not complete to do
    flow_dissector. Create hash based on flowi6 instead.
    
    Signed-off-by: Tom Herbert <tom at herbertland.com>
    Signed-off-by: David S. Miller <davem at davemloft.net>
    (cherry picked from commit 67800f9b1f4eb5bbefc32e3f5044097354bc85b3)
    [VvS: minor context changes]
    Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
---
 include/net/ipv6.h    | 5 +++--
 net/ipv6/ip6_gre.c    | 3 ++-
 net/ipv6/ip6_output.c | 4 ++--
 net/ipv6/ip6_tunnel.c | 2 +-
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index a22cd2e..a210ef0 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -718,12 +718,13 @@ static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 
 #if IS_ENABLED(CONFIG_IPV6)
 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
-					__be32 flowlabel, bool autolabel)
+					__be32 flowlabel, bool autolabel,
+					struct flowi6 *fl6)
 {
 	if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
 		u32 hash;
 
-		hash = skb_get_hash(skb);
+		hash = skb_get_hash_flowi6(skb, fl6);
 
 		/* Since this is being sent on the wire obfuscate hash a bit
 		 * to minimize possbility that any useful information to an
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index cd29f46..146425e 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1045,7 +1045,8 @@ static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
 	ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
 	ip6_flow_hdr(ipv6h, 0,
 		     ip6_make_flowlabel(dev_net(dev), skb,
-					t->fl.u.ip6.flowlabel, false));
+					t->fl.u.ip6.flowlabel, false,
+					&t->fl.u.ip6));
 	ipv6h->hop_limit = t->parms.hop_limit;
 	ipv6h->nexthdr = NEXTHDR_GRE;
 	ipv6h->saddr = t->parms.laddr;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index f6e951e..367691c 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -225,7 +225,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 		hlimit = ip6_dst_hoplimit(dst);
 
 	ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
-						     np->autoflowlabel));
+						     np->autoflowlabel, fl6));
 
 	hdr->payload_len = htons(seg_len);
 	hdr->nexthdr = proto;
@@ -1656,7 +1656,7 @@ struct sk_buff * __ip6_make_skb(struct sock *sk,
 
 	ip6_flow_hdr(hdr, v6_cork->tclass,
 		     ip6_make_flowlabel(net, skb, fl6->flowlabel,
-					np->autoflowlabel));
+					np->autoflowlabel, fl6));
 	hdr->hop_limit = v6_cork->hop_limit;
 	hdr->nexthdr = proto;
 	hdr->saddr = fl6->saddr;
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index d1d2d88..f4ae66f4 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1194,7 +1194,7 @@ route_lookup:
 	skb_reset_network_header(skb);
 	ipv6h = ipv6_hdr(skb);
 	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
-		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
+		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false, fl6));
 	ipv6h->hop_limit = hop_limit;
 	ipv6h->nexthdr = proto;
 	ipv6h->saddr = fl6->saddr;