v2.0.5

Add support for kernels 5.9+
	Tested on 5.11.0-rc5

CAN frames with length > 8 from userspace are rejected rather
than truncated

CHANGELOG

@@ -0,0 +1,33 @@
+v2.0.5
+	Add support for kernels 5.9+
+		Tested on 5.11.0-rc5
+	CAN frames with length > 8 from userspace are rejected rather than truncated
+
+v2.0.4
+	Ensure carrier is up on new kernels which require it
+
+v2.0.3
+	Add support for kernels 5.1+
+		Tested on 5.3.0 (Ubuntu 19.10)
+
+v2.0.2
+	Add support for older kernels
+		Tested working properly back to 4.4
+	Disabled aliasing for kernels <4.15
+		Required, as these kernels do not have netdevice aliasing
+	Use the correct format specifier for (s)size_t
+		Resolves a compile-time warning on 32-bit
+	Check the return type of copy_from_user
+		Resolves a compile-time warning on ARM
+	Standardize kernel version checking
+	Requires icsscand >= v2.0.1
+		icsscand v2.0.0 will not work with older kernels, and would display an obscure error
+
+v2.0.1
+	Resolve runtime warning message on changing MTU
+	Reviewed our locking behavior, made tweaks where necessary
+
+v2.0.0
+	Full rewrite
+	Initial release with CAN-FD support
+	Requires icsscand >= v2.0.0

README.md

@@ -1,10 +1,10 @@
-Version 2.0.1
+Version 2.0.5
 
 This is the kernel object portion of the Intrepid Control Systems SocketCAN support. For SocketCAN to work with Intrepid devices you will need to have this kernel object loaded on your system. Once the module is built and loaded run [icsscand](https://github.com/intrepidcs/icsscand) to turn on SocketCAN support.
 
 First, install the necessary dependencies for building kernel modules.
 
-On Ubuntu, this is acomplished by running `sudo apt install linux-headers-generic build-essential gcc git`
+On Ubuntu, this is accomplished by running `sudo apt install linux-headers-generic build-essential gcc git`
 
 Clone this repository by running `git clone https://github.com/intrepidcs/intrepid-socketcan-kernel-module.git`
 

intrepid.c

@@ -57,7 +57,7 @@
 #define KO_DESC "Netdevice driver for Intrepid CAN/Ethernet devices"
 #define KO_MAJOR 2
 #define KO_MINOR 0
-#define KO_PATCH 1
+#define KO_PATCH 5
 #define KO_VERSION str(KO_MAJOR) "." str(KO_MINOR) "." str(KO_PATCH)
 #define KO_VERSION_INT (KO_MAJOR << 16) | (KO_MINOR << 8) | KO_PATCH
 
@@ -89,6 +89,15 @@ MODULE_VERSION(KO_VERSION);
  */
 #define MAX_MTU                         CANFD_MTU
 
+#define KERNEL_CHECKS_MTU_RANGE         (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
+#define KERNEL_FAULT_TAKES_VMA          (LINUX_VERSION_CODE <  KERNEL_VERSION(4,11,0))
+#define KERNEL_SUPPORTS_ALIASES         (LINUX_VERSION_CODE >= KERNEL_VERSION(4,15,0))
+#define KERNEL_DEFINES_VM_FAULT_T       (LINUX_VERSION_CODE >= KERNEL_VERSION(4,17,0))
+
+#if KERNEL_DEFINES_VM_FAULT_T == 0
+typedef int vm_fault_t;
+#endif
+
 struct intrepid_pending_tx_info {
 	int tx_box_index;
 	int count;
@@ -233,7 +242,7 @@ static netdev_tx_t intrepid_netdevice_xmit(struct sk_buff *skb, struct net_devic
 		/* This should never happen, the queue should be paused before this */
 		ssize_t offset = TX_BOX_SIZE;
 		offset -= (tx_box_bytes[current_tx_box] + sizeof(neomessage_can_t) + msg.length);
-		pr_err("intrepid: %ld length message caused NETDEV_TX_BUSY (%ld)\n", msg.length, offset);
+		pr_err("intrepid: %zu length message caused NETDEV_TX_BUSY (%zd)\n", msg.length, offset);
 		ret = NETDEV_TX_BUSY;
 		goto exit;
 	}
@@ -264,6 +273,7 @@ static int intrepid_netdevice_stop(struct net_device *dev)
 
 	spin_lock_bh(&ics->lock);
 	netif_stop_queue(dev);
+	netif_carrier_off(dev);
 	spin_unlock_bh(&ics->lock);
 
 	return 0;
@@ -272,6 +282,7 @@ static int intrepid_netdevice_stop(struct net_device *dev)
 static int intrepid_netdevice_open(struct net_device *dev)
 {
 	netif_start_queue(dev);
+	netif_carrier_on(dev);
 	return 0;
 }
 
@@ -317,7 +328,10 @@ static int intrepid_remove_can_if(int index)
 
 static int intrepid_add_can_if(struct intrepid_netdevice **result, const char *requestedName)
 {
+	// The `requestedName` parameter is always NULL if KERNEL_SUPPORTS_ALIASES is false
+#if KERNEL_SUPPORTS_ALIASES
 	size_t aliasLen = 0;
+#endif
 	int i;
 	int ret = -EPERM;
 	struct net_device *dev = NULL;
@@ -345,19 +359,23 @@ static int intrepid_add_can_if(struct intrepid_netdevice **result, const char *r
 
 	dev->base_addr          = i;
 	dev->flags             |= IFF_ECHO;
+#if KERNEL_CHECKS_MTU_RANGE
 	dev->min_mtu            = CAN_MTU;
-	dev->max_mtu            = CANFD_MTU;
+	dev->max_mtu            = MAX_MTU;
+#endif
 	dev->mtu                = CANFD_MTU; /* TODO: Check CAN-FD support from usermode daemon */
 	dev->netdev_ops         = &intrepid_netdevice_ops;
+#if KERNEL_SUPPORTS_ALIASES
 	if (requestedName && ((aliasLen = strlen(requestedName)) > 0) && aliasLen < IFALIASZ) {
 		dev->ifalias = kzalloc(sizeof(struct dev_ifalias) + aliasLen + 1, GFP_KERNEL);
 		if (dev->ifalias == NULL) {
-			pr_alert("intrepid: Could not allocate space for ifalias %lu\n", sizeof(struct dev_ifalias));
+			pr_alert("intrepid: Could not allocate space for ifalias %zu\n", sizeof(struct dev_ifalias));
 		} else {
 			strncpy(dev->ifalias->ifalias, requestedName, aliasLen + 1);
 			pr_info("intrepid: %s alias set to %s\n", dev->name, requestedName);
 		}
 	}
+#endif
 	ics                  = netdev_priv(dev);
 	ics->dev             = dev;
 	ics->is_stopped      = 0;
@@ -453,7 +471,10 @@ static int intrepid_fill_can_frame_from_neomessage(
 	if (msg->status.remoteFrame)
 		cf->can_id |= CAN_RTR_FLAG;
 
-	cf->can_dlc = get_can_dlc(msg->length);
+	if (unlikely(msg->length > 8))
+		return -1;
+
+	cf->can_dlc = msg->length;
 	memcpy(cf->data, data, cf->can_dlc);
 
 	stats->rx_bytes += cf->can_dlc;
@@ -582,14 +603,20 @@ static long intrepid_dev_ioctl(struct file *fp, unsigned int cmd, unsigned long
 	switch (cmd) {
 		case SIOCSADDIF: {
 			struct intrepid_netdevice *result = NULL;
+#if KERNEL_SUPPORTS_ALIASES
 			char requestedNameBuffer[IFALIASZ] = {0};
 			char* requestedName = NULL;
+			int bytesNotCopied = 0;
 			if ((void __user*)arg != NULL) {
-				copy_from_user(requestedNameBuffer, (void __user*)arg, IFALIASZ);
+				bytesNotCopied = copy_from_user(requestedNameBuffer, (void __user*)arg, IFALIASZ);
+				if(bytesNotCopied != 0)
+					pr_warn("intrepid: %d bytes not copied for alias", bytesNotCopied);
 				requestedName = requestedNameBuffer;
 			}
-
 			ret = intrepid_add_can_if(&result, requestedName);
+#else
+			ret = intrepid_add_can_if(&result, NULL);
+#endif
 			break;
 		}
 		case SIOCSREMOVEIF:
@@ -607,9 +634,11 @@ static long intrepid_dev_ioctl(struct file *fp, unsigned int cmd, unsigned long
 		case SIOCGCLIENTVEROK:
 			/* Here we can do checks to see if the usermode daemon is
 			 * a compatible version with us. We don't enforce anything
-			 * on the kernel side. For now, being version 2.X.X is good.
+			 * on the kernel side. icsscand v2.0.0 will not work with
+			 * older kernels, and would display an obscure error, thus
+			 * we want to ask the user to update to v2.0.1 or later
 			 */
-			if (VER_MAJ_FROM_INT(arg) == 2)
+			if (VER_MAJ_FROM_INT(arg) == 2 && (VER_MIN_FROM_INT(arg) > 0 || VER_PATCH_FROM_INT(arg) >= 1))
 				ret = 0; /* ok to start */
 			else
 				ret = 1;
@@ -632,8 +661,8 @@ static long intrepid_dev_ioctl(struct file *fp, unsigned int cmd, unsigned long
  *
  * Starting in kernel version 4.11, (struct vm_operations_struct *)->fault() no
  * longer takes the vma parameter (since it resides in vmf) */
-static int intrepid_vm_fault(
+static vm_fault_t intrepid_vm_fault(
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4,11,0)
+#if KERNEL_FAULT_TAKES_VMA
 	struct vm_area_struct *vma,
 #endif
 	struct vm_fault *vmf)
@@ -809,7 +838,7 @@ exit:
 	return ret;
 
 free_net_devices:
-	kzfree(net_devices);
+	kfree(net_devices);
 free_shared_mem:
 	vfree(shared_mem);
 	return ret;