[PATCH v2 net 0/4] s390/qeth: fixes 2019-06-04

[PATCH v2 net 0/4] s390/qeth: fixes 2019-06-04

[Julian Wiedmann]

Hi Dave,

same patch series as yesterday, except that patch 2 has been adjusted
as per your review to use dst_check(). Please have another look.


From the v1 cover letter:

Please apply the following set of qeth fixes to -net.

- The first two patches fix issues in the L3 driver's cast type
  selection for transmitted skbs.
- Alexandra adds a sanity check when retrieving VLAN information from
  neighbour address events.
- The last patch adds some missing error handling for qeth's new
  multiqueue code.

Thanks,
Julian


Alexandra Winter (1):
  s390/qeth: fix VLAN attribute in bridge_hostnotify udev event

Julian Wiedmann (3):
  s390/qeth: handle limited IPv4 broadcast in L3 TX path
  s390/qeth: check dst entry before use
  s390/qeth: handle error when updating TX queue count

 drivers/s390/net/qeth_core_main.c | 22 ++++++++++++++++------
 drivers/s390/net/qeth_l2_main.c   |  2 +-
 drivers/s390/net/qeth_l3_main.c   | 20 +++++++++++++++++---
 3 files changed, 34 insertions(+), 10 deletions(-)

-- 
2.17.1

[PATCH v2 net 1/4] s390/qeth: handle limited IPv4 broadcast in L3 TX path

[Julian Wiedmann]

When selecting the cast type of a neighbourless IPv4 skb (eg. on a raw
socket), qeth_l3 falls back to the packet's destination IP address.
For this case we should classify traffic sent to 255.255.255.255 as
broadcast.
This fixes DHCP requests, which were misclassified as unicast
(and for IQD interfaces thus ended up on the wrong HW queue).

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
 drivers/s390/net/qeth_l3_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 0271833da6a2..2df67abdfde7 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1911,6 +1911,8 @@ static int qeth_l3_get_cast_type(struct sk_buff *skb)
 	/* no neighbour (eg AF_PACKET), fall back to target's IP address ... */
 	switch (qeth_get_ip_version(skb)) {
 	case 4:
+		if (ipv4_is_lbcast(ip_hdr(skb)->daddr))
+			return RTN_BROADCAST;
 		return ipv4_is_multicast(ip_hdr(skb)->daddr) ?
 				RTN_MULTICAST : RTN_UNICAST;
 	case 6:
-- 
2.17.1

[PATCH v2 net 2/4] s390/qeth: check dst entry before use

[Julian Wiedmann]

While qeth_l3 uses netif_keep_dst() to hold onto the dst, a skb's dst
may still have been obsoleted (via dst_dev_put()) by the time that we
end up using it. The dst then points to the loopback interface, which
means the neighbour lookup in qeth_l3_get_cast_type() determines a bogus
cast type of RTN_BROADCAST.
For IQD interfaces this causes us to place such skbs on the wrong
HW queue, resulting in TX errors.

Fix-up the various call sites to first validate the dst entry with
dst_check(), and fall back accordingly.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
v1 -> v2: prefer dst_check() over dst->obsolete (davem)

 drivers/s390/net/qeth_l3_main.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 2df67abdfde7..2eae5cd745c9 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1888,13 +1888,19 @@ static int qeth_l3_do_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 
 static int qeth_l3_get_cast_type(struct sk_buff *skb)
 {
+	int ipv = qeth_get_ip_version(skb);
 	struct neighbour *n = NULL;
 	struct dst_entry *dst;
 
 	rcu_read_lock();
 	dst = skb_dst(skb);
-	if (dst)
-		n = dst_neigh_lookup_skb(dst, skb);
+	if (dst) {
+		u32 cookie = (ipv == 6) ? rt6_get_cookie(skb_rt6_info(skb)) : 0;
+
+		if (dst_check(dst, cookie))
+			n = dst_neigh_lookup_skb(dst, skb);
+	}
+
 	if (n) {
 		int cast_type = n->type;
 
@@ -1909,7 +1915,7 @@ static int qeth_l3_get_cast_type(struct sk_buff *skb)
 	rcu_read_unlock();
 
 	/* no neighbour (eg AF_PACKET), fall back to target's IP address ... */
-	switch (qeth_get_ip_version(skb)) {
+	switch (ipv) {
 	case 4:
 		if (ipv4_is_lbcast(ip_hdr(skb)->daddr))
 			return RTN_BROADCAST;
@@ -1990,6 +1996,9 @@ static void qeth_l3_fill_header(struct qeth_qdio_out_q *queue,
 	if (ipv == 4) {
 		struct rtable *rt = skb_rtable(skb);
 
+		if (rt && !dst_check(skb_dst(skb), 0))
+			rt = NULL;
+
 		*((__be32 *) &hdr->hdr.l3.next_hop.ipv4.addr) = (rt) ?
 				rt_nexthop(rt, ip_hdr(skb)->daddr) :
 				ip_hdr(skb)->daddr;
@@ -1997,6 +2006,9 @@ static void qeth_l3_fill_header(struct qeth_qdio_out_q *queue,
 		/* IPv6 */
 		const struct rt6_info *rt = skb_rt6_info(skb);
 
+		if (rt && !dst_check(skb_dst(skb), rt6_get_cookie(rt)))
+			rt = NULL;
+
 		if (rt && !ipv6_addr_any(&rt->rt6i_gateway))
 			l3_hdr->next_hop.ipv6_addr = rt->rt6i_gateway;
 		else
-- 
2.17.1

[PATCH v2 net 3/4] s390/qeth: fix VLAN attribute in bridge_hostnotify udev event

[Julian Wiedmann]

From: Alexandra Winter <wintera@linux.ibm.com>

Enabling sysfs attribute bridge_hostnotify triggers a series of udev events
for the MAC addresses of all currently connected peers. In case no VLAN is
set for a peer, the device reports the corresponding MAC addresses with
VLAN ID 4096. This currently results in attribute VLAN=4096 for all
non-VLAN interfaces in the initial series of events after host-notify is
enabled.

Instead, no VLAN attribute should be reported in the udev event for
non-VLAN interfaces.

Only the initial events face this issue. For dynamic changes that are
reported later, the device uses a validity flag.

This also changes the code so that it now sets the VLAN attribute for
MAC addresses with VID 0. On Linux, no qeth interface will ever be
registered with VID 0: Linux kernel registers VID 0 on all network
interfaces initially, but qeth will drop .ndo_vlan_rx_add_vid for VID 0.
Peers with other OSs could register MACs with VID 0.

Fixes: 9f48b9db9a22 ("qeth: bridgeport support - address notifications")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
 drivers/s390/net/qeth_l2_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 218801232ca2..ff8a6cd790b1 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -1680,7 +1680,7 @@ static void qeth_bridgeport_an_set_cb(void *priv,
 
 	l2entry = (struct qdio_brinfo_entry_l2 *)entry;
 	code = IPA_ADDR_CHANGE_CODE_MACADDR;
-	if (l2entry->addr_lnid.lnid)
+	if (l2entry->addr_lnid.lnid < VLAN_N_VID)
 		code |= IPA_ADDR_CHANGE_CODE_VLANID;
 	qeth_bridge_emit_host_event(card, anev_reg_unreg, code,
 		(struct net_if_token *)&l2entry->nit,
-- 
2.17.1

[PATCH v2 net 4/4] s390/qeth: handle error when updating TX queue count

[Julian Wiedmann]

netif_set_real_num_tx_queues() can return an error, deal with it.

Fixes: 73dc2daf110f ("s390/qeth: add TX multiqueue support for OSA devices")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 009f2c0ec504..b1823d75dd35 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1274,16 +1274,20 @@ static int qeth_setup_channel(struct qeth_channel *channel, bool alloc_buffers)
 	return 0;
 }
 
-static void qeth_osa_set_output_queues(struct qeth_card *card, bool single)
+static int qeth_osa_set_output_queues(struct qeth_card *card, bool single)
 {
 	unsigned int count = single ? 1 : card->dev->num_tx_queues;
+	int rc;
 
 	rtnl_lock();
-	netif_set_real_num_tx_queues(card->dev, count);
+	rc = netif_set_real_num_tx_queues(card->dev, count);
 	rtnl_unlock();
 
+	if (rc)
+		return rc;
+
 	if (card->qdio.no_out_queues == count)
-		return;
+		return 0;
 
 	if (atomic_read(&card->qdio.state) != QETH_QDIO_UNINITIALIZED)
 		qeth_free_qdio_queues(card);
@@ -1293,12 +1297,14 @@ static void qeth_osa_set_output_queues(struct qeth_card *card, bool single)
 
 	card->qdio.default_out_queue = single ? 0 : QETH_DEFAULT_QUEUE;
 	card->qdio.no_out_queues = count;
+	return 0;
 }
 
 static int qeth_update_from_chp_desc(struct qeth_card *card)
 {
 	struct ccw_device *ccwdev;
 	struct channel_path_desc_fmt0 *chp_dsc;
+	int rc = 0;
 
 	QETH_DBF_TEXT(SETUP, 2, "chp_desc");
 
@@ -1311,12 +1317,12 @@ static int qeth_update_from_chp_desc(struct qeth_card *card)
 
 	if (IS_OSD(card) || IS_OSX(card))
 		/* CHPP field bit 6 == 1 -> single queue */
-		qeth_osa_set_output_queues(card, chp_dsc->chpp & 0x02);
+		rc = qeth_osa_set_output_queues(card, chp_dsc->chpp & 0x02);
 
 	kfree(chp_dsc);
 	QETH_DBF_TEXT_(SETUP, 2, "nr:%x", card->qdio.no_out_queues);
 	QETH_DBF_TEXT_(SETUP, 2, "lvl:%02x", card->info.func_level);
-	return 0;
+	return rc;
 }
 
 static void qeth_init_qdio_info(struct qeth_card *card)
@@ -5597,8 +5603,12 @@ static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
 		dev->hw_features |= NETIF_F_SG;
 		dev->vlan_features |= NETIF_F_SG;
 		if (IS_IQD(card)) {
-			netif_set_real_num_tx_queues(dev, QETH_IQD_MIN_TXQ);
 			dev->features |= NETIF_F_SG;
+			if (netif_set_real_num_tx_queues(dev,
+							 QETH_IQD_MIN_TXQ)) {
+				free_netdev(dev);
+				return NULL;
+			}
 		}
 	}
 
-- 
2.17.1

Re: [PATCH v2 net 0/4] s390/qeth: fixes 2019-06-04

[David Miller]

From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Tue,  4 Jun 2019 10:15:05 +0200

> same patch series as yesterday, except that patch 2 has been adjusted
> as per your review to use dst_check(). Please have another look.

The correct usage is:

	dst = dst_check();