exynos-linux-stable/drivers/s390/net
Julian Wiedmann 51533c4bf1 s390/qeth: no ETH header for outbound AF_IUCV
[ Upstream commit acd9776b5c45ef02d1a210969a6fcc058afb76e3 ]

With AF_IUCV traffic, the skb passed to hard_start_xmit() has a 14 byte
slot at skb->data, intended for an ETH header. qeth_l3_fill_af_iucv_hdr()
fills this ETH header... and then immediately moves it to the
skb's headroom, where it disappears and is never seen again.

But it's still possible for us to return NETDEV_TX_BUSY after the skb has
been modified. Since we didn't get a private copy of the skb, the next
time the skb is delivered to hard_start_xmit() it no longer has the
expected layout (we moved the ETH header to the headroom, so skb->data
now starts at the IUCV_TRANS header). So when qeth_l3_fill_af_iucv_hdr()
does another round of rebuilding, the resulting qeth header ends up
all wrong. On transmission, the buffer is then rejected by
the HiperSockets device with SBALF15 = x'04'.
When this error is passed back to af_iucv as TX_NOTIFY_UNREACHABLE, it
tears down the offending socket.

As the ETH header for AF_IUCV serves no purpose, just align the code to
what we do for IP traffic on L3 HiperSockets: keep the ETH header at
skb->data, and pass down data_offset = ETH_HLEN to qeth_fill_buffer().
When mapping the payload into the SBAL elements, the ETH header is then
stripped off. This avoids the skb manipulations in
qeth_l3_fill_af_iucv_hdr(), and any buffer re-entering hard_start_xmit()
after NETDEV_TX_BUSY is now processed properly.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-25 14:23:40 +01:00
..
ctcm_dbug.c
ctcm_dbug.h
ctcm_fsms.c
ctcm_fsms.h
ctcm_main.c
ctcm_main.h
ctcm_mpc.c
ctcm_mpc.h
ctcm_sysfs.c
fsm.c
fsm.h
Kconfig
lcs.c
lcs.h
Makefile
netiucv.c
qeth_core.h s390/qeth: size calculation outbound buffers 2017-12-25 14:23:40 +01:00
qeth_core_main.c s390/qeth: size calculation outbound buffers 2017-12-25 14:23:40 +01:00
qeth_core_mpc.c
qeth_core_mpc.h
qeth_core_sys.c s390/qeth: unbreak OSM and OSN support 2017-06-07 12:07:42 +02:00
qeth_l2.h s390/qeth: unbreak OSM and OSN support 2017-06-07 12:07:42 +02:00
qeth_l2_main.c s390/qeth: size calculation outbound buffers 2017-12-25 14:23:40 +01:00
qeth_l2_sys.c s390/qeth: unbreak OSM and OSN support 2017-06-07 12:07:42 +02:00
qeth_l3.h
qeth_l3_main.c s390/qeth: no ETH header for outbound AF_IUCV 2017-12-25 14:23:40 +01:00
qeth_l3_sys.c s390/qeth: fix retrieval of vipa and proxy-arp addresses 2017-11-15 15:53:16 +01:00
smsgiucv.c
smsgiucv.h
smsgiucv_app.c