[PATCH 4.4 59/74] ipv6: Fix getsockopt() for sockets with default IPV6_AUTOFLOWLABEL

From: Greg Kroah-Hartman
Date: Mon Jan 29 2018 - 15:46:02 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>


[ Upstream commit e9191ffb65d8e159680ce0ad2224e1acbde6985c ]

Commit 513674b5a2c9 ("net: reevalulate autoflowlabel setting after
sysctl setting") removed the initialisation of
ipv6_pinfo::autoflowlabel and added a second flag to indicate
whether this field or the net namespace default should be used.

The getsockopt() handling for this case was not updated, so it
currently returns 0 for all sockets for which IPV6_AUTOFLOWLABEL is
not explicitly enabled. Fix it to return the effective value, whether
that has been set at the socket or net namespace level.

Fixes: 513674b5a2c9 ("net: reevalulate autoflowlabel setting after sysctl ...")
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/ipv6.h | 1 +
net/ipv6/ip6_output.c | 2 +-
net/ipv6/ipv6_sockglue.c | 2 +-
3 files changed, 3 insertions(+), 2 deletions(-)

--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -281,6 +281,7 @@ int ipv6_flowlabel_opt_get(struct sock *
int flags);
int ip6_flowlabel_init(void);
void ip6_flowlabel_cleanup(void);
+bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np);

static inline void fl6_sock_release(struct ip6_flowlabel *fl)
{
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -148,7 +148,7 @@ int ip6_output(struct net *net, struct s
!(IP6CB(skb)->flags & IP6SKB_REROUTED));
}

-static bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
+bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
{
if (!np->autoflowlabel_set)
return ip6_default_np_autolabel(net);
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1313,7 +1313,7 @@ static int do_ipv6_getsockopt(struct soc
break;

case IPV6_AUTOFLOWLABEL:
- val = np->autoflowlabel;
+ val = ip6_autoflowlabel(sock_net(sk), np);
break;

default: