[PATCH net-next 0/2] net: enable udp v6 sockets receiving v4 packets with UDP GRO

Currently, udp v6 socket can not process v4 packets with UDP GRO, as
udp_encap_needed_key is not increased when udp_tunnel_encap_enable()
is called for v6 socket. This patchset is to increase it and remove
the unnecessary code in bareudp.

Xin Long (2):
  udp: call udp_encap_enable for v6 sockets when enabling encap
  Revert "bareudp: Fixed bareudp receive handling"

 drivers/net/bareudp.c    | 6 ------
 include/net/udp_tunnel.h | 3 +--
 net/ipv6/udp.c           | 4 +++-
 3 files changed, 4 insertions(+), 9 deletions(-)

-- 
2.1.0

As udp_encap_enable() is already called in udp_tunnel_encap_enable()
since the last patch, and we don't need it any more. So remove it by
reverting commit 81f954a44567567c7d74a97b1db78fb43afc253d.
---
 drivers/net/bareudp.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index 85de5f9..aed5049 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c

@@ -240,12 +240,6 @@ static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
 	tunnel_cfg.encap_destroy = NULL;
 	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
 
-	/* As the setup_udp_tunnel_sock does not call udp_encap_enable if the
-	 * socket type is v6 an explicit call to udp_encap_enable is needed.
-	 */
-	if (sock->sk->sk_family == AF_INET6)
-		udp_encap_enable();
-
 	rcu_assign_pointer(bareudp->sock, sock);
 	return 0;
 }

-- 
2.1.0

When enabling encap for a ipv6 socket without udp_encap_needed_key
increased, UDP GRO won't work for v4 mapped v6 address packets as
sk will be NULL in udp4_gro_receive().

This patch is to enable it by increasing udp_encap_needed_key for
v6 sockets in udp_tunnel_encap_enable(), and correspondingly
decrease udp_encap_needed_key in udpv6_destroy_sock().

Reported-by: Chen Yi <redacted>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/net/udp_tunnel.h | 3 +--
 net/ipv6/udp.c           | 4 +++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 282d10e..afc7ce7 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h

@@ -181,9 +181,8 @@ static inline void udp_tunnel_encap_enable(struct socket *sock)
 #if IS_ENABLED(CONFIG_IPV6)
 	if (sock->sk->sk_family == PF_INET6)
 		ipv6_stub->udpv6_encap_enable();
-	else
 #endif
-		udp_encap_enable();
+	udp_encap_enable();
 }
 
 #define UDP_TUNNEL_NIC_MAX_TABLES	4

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index b9f3dfd..265b6a0 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c

@@ -1608,8 +1608,10 @@ void udpv6_destroy_sock(struct sock *sk)
 			if (encap_destroy)
 				encap_destroy(sk);
 		}
-		if (up->encap_enabled)
+		if (up->encap_enabled) {
 			static_branch_dec(&udpv6_encap_needed_key);
+			static_branch_dec(&udp_encap_needed_key);
+		}
 	}
 
 	inet6_destroy_sock(sk);

-- 
2.1.0

Hi Xin,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Xin-Long/net-enable-udp-v6-sockets-receiving-v4-packets-with-UDP-GRO/20210111-205115
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 73b7a6047971aa6ce4a70fc4901964d14f077171
config: m68k-defconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/62229592b4c3e929eeafea82e758dacb2953fbde
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Xin-Long/net-enable-udp-v6-sockets-receiving-v4-packets-with-UDP-GRO/20210111-205115
        git checkout 62229592b4c3e929eeafea82e758dacb2953fbde
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All errors (new ones prefixed by >>, old ones prefixed by <<):

quoted

ERROR: modpost: "udp_encap_needed_key" [net/ipv6/ipv6.ko] undefined!

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

On Tue, Jan 12, 2021 at 2:02 AM kernel test robot [off-list ref] wrote:

Hi Xin,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Xin-Long/net-enable-udp-v6-sockets-receiving-v4-packets-with-UDP-GRO/20210111-205115
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 73b7a6047971aa6ce4a70fc4901964d14f077171
config: m68k-defconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/62229592b4c3e929eeafea82e758dacb2953fbde
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Xin-Long/net-enable-udp-v6-sockets-receiving-v4-packets-with-UDP-GRO/20210111-205115
        git checkout 62229592b4c3e929eeafea82e758dacb2953fbde
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All errors (new ones prefixed by >>, old ones prefixed by <<):

quoted

quoted

ERROR: modpost: "udp_encap_needed_key" [net/ipv6/ipv6.ko] undefined!

I will add udp_encap_disable() and export, thanks.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org