Merge tag 'linux-can-next-for-5.20-20220625' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2022-06-25

this is a pull request of 22 patches for net-next/master.

The first 2 patches target the xilinx driver. Srinivas Neeli's patch
adds Transmitter Delay Compensation (TDC) support, a patch by me fixes
a typo.

The next patch is by me and fixes a typo in the m_can driver.

Another patch by me allows the configuration of fixed bit rates
without need for do_set_bittiming callback.

The following 7 patches are by Vincent Mailhol and refactor the
can-dev module and Kbuild, de-inline the can_dropped_invalid_skb()
function, which has grown over the time, and drop outgoing skbs if the
controller is in listen only mode.

Max Staudt's patch fixes a reference in the networking/can.rst
documentation.

Vincent Mailhol provides 2 patches with cleanups for the etas_es58x
driver.

Conor Dooley adds bindings for the mpfs-can to the PolarFire SoC dtsi.

Another patch by me allows the configuration of fixed data bit rates
without need for do_set_data_bittiming callback.

The last 5 patches are by Frank Jungclaus. They prepare the esd_usb
driver to add support for the the CAN-USB/3 device in a later series.
====================

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

1 files changed, 72 insertions, 0 deletions

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 61660248c69e..8bb62dd864c8 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -5,6 +5,14 @@
  */
 
 #include <linux/can/dev.h>
+#include <linux/can/netlink.h>
+#include <linux/module.h>
+
+#define MOD_DESC "CAN device driver interface"
+
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 
 /* Local echo of CAN messages
  *
@@ -252,3 +260,67 @@ struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
 	return skb;
 }
 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
+
+/* Check for outgoing skbs that have not been created by the CAN subsystem */
+static 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;
+
+		/* perform 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. */
+bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
+{
+	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (skb->protocol == htons(ETH_P_CAN)) {
+		if (unlikely(skb->len != CAN_MTU ||
+			     cfd->len > CAN_MAX_DLEN))
+			goto inval_skb;
+	} else if (skb->protocol == htons(ETH_P_CANFD)) {
+		if (unlikely(skb->len != CANFD_MTU ||
+			     cfd->len > CANFD_MAX_DLEN))
+			goto inval_skb;
+	} else {
+		goto inval_skb;
+	}
+
+	if (!can_skb_headroom_valid(dev, skb)) {
+		goto inval_skb;
+	} else if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) {
+		netdev_info_once(dev,
+				 "interface in listen only mode, dropping skb\n");
+		goto inval_skb;
+	}
+
+	return false;
+
+inval_skb:
+	kfree_skb(skb);
+	dev->stats.tx_dropped++;
+	return true;
+}
+EXPORT_SYMBOL_GPL(can_dropped_invalid_skb);