[IPV6]: Support several new sockopt / ancillary data in Advanced API (RFC3542).

Support several new socket options / ancillary data:
  IPV6_RECVPKTINFO, IPV6_PKTINFO,
  IPV6_RECVHOPOPTS, IPV6_HOPOPTS,
  IPV6_RECVDSTOPTS, IPV6_DSTOPTS, IPV6_RTHDRDSTOPTS,
  IPV6_RECVRTHDR, IPV6_RTHDR,
  IPV6_RECVHOPOPTS, IPV6_HOPOPTS

Old semantics are preserved as IPV6_2292xxxx so that
we can maintain backward compatibility.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index b6c73da5ff35..2d5ce376c265 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -225,16 +225,20 @@ struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
                                          struct ip6_flowlabel * fl,
                                          struct ipv6_txoptions * fopt)
 {
-        struct ipv6_txoptions * fl_opt = fl->opt;
+        struct ipv6_txoptions * fl_opt = fl ? fl->opt : NULL;
 
-        if (fopt == NULL || fopt->opt_flen == 0)
-                return fl_opt;
+        if (fopt == NULL || fopt->opt_flen == 0) {
+                if (!fl_opt || !fl_opt->dst0opt || fl_opt->srcrt)
+                        return fl_opt;
+        }
 
         if (fl_opt != NULL) {
                 opt_space->hopopt = fl_opt->hopopt;
-                opt_space->dst0opt = fl_opt->dst0opt;
+                opt_space->dst0opt = fl_opt->srcrt ? fl_opt->dst0opt : NULL;
                 opt_space->srcrt = fl_opt->srcrt;
                 opt_space->opt_nflen = fl_opt->opt_nflen;
+                if (fl_opt->dst0opt && !fl_opt->srcrt)
+                        opt_space->opt_nflen -= ipv6_optlen(fl_opt->dst0opt);
         } else {
                 if (fopt->opt_nflen == 0)
                         return fopt;