net: relax PKTINFO non local ipv6 udp xmit check

Allow transparent sockets to be less restrictive about
the source ip of ipv6 udp packets being sent.

Google-Bug-Id: 5018138
Signed-off-by: Maciej Żenczykowski <maze@google.com>
CC: "Erik Kline" <ek@google.com>
CC: "Lorenzo Colitti" <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 12 insertions, 11 deletions

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 9ef1831746ef..b46e9f88ce37 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -599,7 +599,7 @@ int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
         return 0;
 }
 
-int datagram_send_ctl(struct net *net,
+int datagram_send_ctl(struct net *net, struct sock *sk,
                       struct msghdr *msg, struct flowi6 *fl6,
                       struct ipv6_txoptions *opt,
                       int *hlimit, int *tclass, int *dontfrag)
@@ -658,7 +658,8 @@ int datagram_send_ctl(struct net *net,
 
                         if (addr_type != IPV6_ADDR_ANY) {
                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
-                                if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
+                                if (!inet_sk(sk)->transparent &&
+                                    !ipv6_chk_addr(net, &src_info->ipi6_addr,
                                                    strict ? dev : NULL, 0))
                                         err = -EINVAL;
                                 else
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index f3caf1b8d572..543039450193 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -322,8 +322,8 @@ static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned lo
 }
 
 static struct ip6_flowlabel *
-fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
-          int optlen, int *err_p)
+fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
+          char __user *optval, int optlen, int *err_p)
 {
         struct ip6_flowlabel *fl = NULL;
         int olen;
@@ -360,7 +360,7 @@ fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
                 msg.msg_control = (void*)(fl->opt+1);
                 memset(&flowi6, 0, sizeof(flowi6));
 
-                err = datagram_send_ctl(net, &msg, &flowi6, fl->opt, &junk,
+                err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
                                         &junk, &junk);
                 if (err)
                         goto done;
@@ -528,7 +528,7 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
                         return -EINVAL;
 
-                fl = fl_create(net, &freq, optval, optlen, &err);
+                fl = fl_create(net, sk, &freq, optval, optlen, &err);
                 if (fl == NULL)
                         return err;
                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 147ede38ab48..2fbda5fc4cc4 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -475,7 +475,7 @@ sticky_done:
                 msg.msg_controllen = optlen;
                 msg.msg_control = (void*)(opt+1);
 
-                retv = datagram_send_ctl(net, &msg, &fl6, opt, &junk, &junk,
+                retv = datagram_send_ctl(net, sk, &msg, &fl6, opt, &junk, &junk,
                                          &junk);
                 if (retv)
                         goto done;
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 6a79f3081bdb..343852e5c703 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -817,8 +817,8 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
                 memset(opt, 0, sizeof(struct ipv6_txoptions));
                 opt->tot_len = sizeof(struct ipv6_txoptions);
 
-                err = datagram_send_ctl(sock_net(sk), msg, &fl6, opt, &hlimit,
-                                        &tclass, &dontfrag);
+                err = datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
+                                        &hlimit, &tclass, &dontfrag);
                 if (err < 0) {
                         fl6_sock_release(flowlabel);
                         return err;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 29213b51c499..bb95e8e1c6f9 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1090,8 +1090,8 @@ do_udp_sendmsg:
                 memset(opt, 0, sizeof(struct ipv6_txoptions));
                 opt->tot_len = sizeof(*opt);
 
-                err = datagram_send_ctl(sock_net(sk), msg, &fl6, opt, &hlimit,
-                                        &tclass, &dontfrag);
+                err = datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
+                                        &hlimit, &tclass, &dontfrag);
                 if (err < 0) {
                         fl6_sock_release(flowlabel);
                         return err;