ipv6: add a flag to get the flow label used remotly

This information is already available via IPV6_FLOWINFO
of IPV6_2292PKTOPTIONS, and them a filtering to get the flow label
information. But it is probably logical and easier for users to add this
here, and to control both sent/received flow label values with the
IPV6_FLOWLABEL_MGR option.

Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 2 deletions

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 55823f187446..01bf2524c72a 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -481,11 +481,17 @@ static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
         spin_unlock_bh(&ip6_sk_fl_lock);
 }
 
-int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq)
+int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
+                           int flags)
 {
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct ipv6_fl_socklist *sfl;
 
+        if (flags & IPV6_FL_F_REMOTE) {
+                freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
+                return 0;
+        }
+
         if (np->repflow) {
                 freq->flr_label = np->flow_label;
                 return 0;
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 2855b00ed49d..7024a874e901 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1221,6 +1221,7 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
         case IPV6_FLOWLABEL_MGR:
         {
                 struct in6_flowlabel_req freq;
+                int flags;
 
                 if (len < sizeof(freq))
                         return -EINVAL;
@@ -1232,9 +1233,11 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
                         return -EINVAL;
 
                 len = sizeof(freq);
+                flags = freq.flr_flags;
+
                 memset(&freq, 0, sizeof(freq));
 
-                val = ipv6_flowlabel_opt_get(sk, &freq);
+                val = ipv6_flowlabel_opt_get(sk, &freq, flags);
                 if (val < 0)
                         return val;