Merge tag 'linux-can-fixes-for-5.5-20200102' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2020-01-02

this is a pull request of 9 patches for net/master.

The first 5 patches target all the tcan4x5x driver. The first 3 patches
of them are by Dan Murphy and Sean Nyekjaer and improve the device
initialization (power on, reset and get device out of standby before
register access). The next patch is by Dan Murphy and disables the INH
pin device-state if the GPIO is unavailable. The last patch for the
tcan4x5x driver is by Gustavo A. R. Silva and fixes an inconsistent
PTR_ERR check in the tcan4x5x_parse_config() function.

The next patch is by Oliver Hartkopp and targets the generic CAN device
infrastructure. It ensures that an initialized headroom in outgoing CAN
sk_buffs (e.g. if injected by AF_PACKET).

The last 2 patches are by Johan Hovold and fix the kvaser_usb and gs_usb
drivers by always using the current alternate setting not blindly the
first one.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 34 insertions, 0 deletions

diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 9b3c720a31b1..5e3d45525bd3 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -18,6 +18,7 @@
 #include <linux/can/error.h>
 #include <linux/can/led.h>
 #include <linux/can/netlink.h>
+#include <linux/can/skb.h>
 #include <linux/netdevice.h>
 
 /*
@@ -91,6 +92,36 @@ struct can_priv {
 #define get_can_dlc(i)		(min_t(__u8, (i), CAN_MAX_DLC))
 #define get_canfd_dlc(i)	(min_t(__u8, (i), CANFD_MAX_DLC))
 
+/* Check for outgoing skbs that have not been created by the CAN subsystem */
+static inline bool can_skb_headroom_valid(struct net_device *dev,
+					  struct sk_buff *skb)
+{
+	/* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
+	if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
+		return false;
+
+	/* af_packet does not apply CAN skb specific settings */
+	if (skb->ip_summed == CHECKSUM_NONE) {
+		/* init headroom */
+		can_skb_prv(skb)->ifindex = dev->ifindex;
+		can_skb_prv(skb)->skbcnt = 0;
+
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+		/* preform proper loopback on capable devices */
+		if (dev->flags & IFF_ECHO)
+			skb->pkt_type = PACKET_LOOPBACK;
+		else
+			skb->pkt_type = PACKET_HOST;
+
+		skb_reset_mac_header(skb);
+		skb_reset_network_header(skb);
+		skb_reset_transport_header(skb);
+	}
+
+	return true;
+}
+
 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
 static inline bool can_dropped_invalid_skb(struct net_device *dev,
 					  struct sk_buff *skb)
@@ -108,6 +139,9 @@ static inline bool can_dropped_invalid_skb(struct net_device *dev,
 	} else
 		goto inval_skb;
 
+	if (!can_skb_headroom_valid(dev, skb))
+		goto inval_skb;
+
 	return false;
 
 inval_skb: