minimal packet handling

README.md

@@ -23,8 +23,24 @@ puis mettre a jour le initramfs :
 
 ```
 sudo update-initramfs -u
+
 ```
 
+En l'etat (5/2/26) le driver s'installe, s'attache au device ch349 puis creer une interface reseau sur la machine. on peut alors recuperer le nom de l'interface grace a :
+
+```
+ip a
+```
+
+puis attribuer une IP a l'interface grace aux commandes suivantes :
+
+```
+sudo ip addr add 192.168.1.100/24 dev <nom_interface>
+sudo ip link set <nom_interface> up
+```
+
+ce qui nous permet ensuite, depuis une autre machine d'envoyer des pings a l'ip (192.168.1.100) qui sont ensuite parses en hexadecimal et affiches sur l'interface usb (visibles en executant dmesg | grep ch349)
+
 ## Todo
 
 - Enregistrer une interface réseau
@@ -47,4 +63,3 @@ sudo update-initramfs -u
 ## Utile
 
 <https://cdn.promelec.ru/upload/items/2025/09/18/CH397_.pdf>
-

src/ch349_driver.c

@@ -5,6 +5,7 @@
  *
  */
 
+#include <linux/etherdevice.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -23,6 +24,8 @@ struct ch349_device {
 	__u8 bulk_out_endpointAddr;
 	size_t bulk_in_size;
 	unsigned char *bulk_in_buffer;
+	struct urb *rx_urb;
+	struct net_device *netdev;
 };
 
 static const struct usb_device_id ch349_table[] = {
@@ -32,27 +35,246 @@ static const struct usb_device_id ch349_table[] = {
 };
 MODULE_DEVICE_TABLE(usb, ch349_table);
 
+// Fonction pour récupérer la MAC
+static int ch349_get_mac_address(struct ch349_device *dev, u8 *mac)
+{
+	char buf[13];
+	int ret, i;
+
+	ret = usb_string(dev->udev, 3, buf, sizeof(buf));
+	if (ret != 12) {
+		dev_err(&dev->interface->dev,
+			"Cannot read MAC (got %d bytes)\n", ret);
+		// MAC par défaut si échec
+		eth_random_addr(mac);
+		return 0;
+	}
+
+	// Convertir "DC3262229393" -> DC:32:62:22:93:93
+	for (i = 0; i < 6; i++) {
+		char hex[3] = { buf[i * 2], buf[i * 2 + 1], 0 };
+		if (kstrtou8(hex, 16, &mac[i])) {
+			dev_err(&dev->interface->dev, "Invalid MAC format\n");
+			eth_random_addr(mac);
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+static void ch349_hexdump(const struct device *dev, const char *prefix,
+			  const void *data, size_t len)
+{
+	const unsigned char *buf = data;
+	char line[80];
+	size_t i, j;
+
+	for (i = 0; i < len; i += 16) {
+		char *p = line;
+		p += sprintf(p, "%s %04zx: ", prefix, i);
+
+		// Hexa
+		for (j = 0; j < 16; j++) {
+			if (i + j < len)
+				p += sprintf(p, "%02x ", buf[i + j]);
+			else
+				p += sprintf(p, "   ");
+		}
+
+		p += sprintf(p, " ");
+
+		// ASCII
+		for (j = 0; j < 16 && i + j < len; j++) {
+			unsigned char c = buf[i + j];
+			p += sprintf(p, "%c", (c >= 32 && c < 127) ? c : '.');
+		}
+
+		dev_info(dev, "%s\n", line);
+	}
+}
+
+static void ch349_read_callback(struct urb *urb)
+{
+	struct ch349_device *dev = urb->context;
+	struct net_device *netdev = dev->netdev;
+	struct sk_buff *skb;
+	struct ethhdr *eth;
+	int status = urb->status;
+
+	switch (status) {
+	case 0: // Success!
+		if (urb->actual_length > 0) {
+			dev_info(&dev->interface->dev,
+				 "ch349: Received %d bytes\n",
+				 urb->actual_length);
+			ch349_hexdump(&dev->interface->dev, "RX",
+				      urb->transfer_buffer, urb->actual_length);
+
+			// Créer un sk_buff et passer au network stack
+			skb = netdev_alloc_skb(netdev, urb->actual_length + 2);
+			if (skb) {
+				skb_reserve(skb,
+					    2); // Alignement IP
+				skb_put_data(skb, urb->transfer_buffer,
+					     urb->actual_length);
+				skb->protocol = eth_type_trans(skb, netdev);
+
+				// Passer au kernel network stack
+				netif_rx(skb);
+
+				netdev->stats.rx_packets++;
+				netdev->stats.rx_bytes += urb->actual_length;
+
+				printk(KERN_INFO
+				       "ch349: Packet passed to network stack\n");
+			} else {
+				netdev->stats.rx_dropped++;
+				printk(KERN_ERR "ch349: Cannot allocate skb\n");
+			}
+		}
+		break;
+
+	case -ENOENT:
+	case -ECONNRESET:
+	case -ESHUTDOWN:
+		return;
+
+	default:
+		dev_err(&dev->interface->dev, "RX URB error: %d\n", status);
+		netdev->stats.rx_errors++;
+		break;
+	}
+
+	// Resoumettre l'URB
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+	if (status) {
+		dev_err(&dev->interface->dev, "Failed to resubmit URB: %d\n",
+			status);
+		netdev->stats.rx_errors++;
+	}
+}
+
+// Fonction pour démarrer la lecture
+static int ch349_start_rx(struct ch349_device *dev)
+{
+	struct urb *urb;
+	int retval;
+
+	// Allouer un URB
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!urb) {
+		dev_err(&dev->interface->dev, "Cannot allocate URB\n");
+		return -ENOMEM;
+	}
+
+	// En CDC-ECM, les packets peuvent être jusqu'à ~1600 bytes
+
+	// Préparer l'URB
+	usb_fill_bulk_urb(urb, dev->udev,
+			  usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
+			  dev->bulk_in_buffer, dev->bulk_in_size,
+			  ch349_read_callback, dev);
+
+	// Sauvegarder l'URB dans la structure
+	dev->rx_urb = urb;
+
+	// Soumettre l'URB
+	retval = usb_submit_urb(urb, GFP_KERNEL);
+	if (retval) {
+		dev_err(&dev->interface->dev, "Failed to submit URB: %d\n",
+			retval);
+		usb_free_urb(urb);
+		dev->rx_urb = NULL;
+		return retval;
+	}
+
+	dev_info(&dev->interface->dev, "RX started, waiting for packets...\n");
+	return 0;
+}
+
+// Fonction pour arrêter la lecture
+static void ch349_stop_rx(struct ch349_device *dev)
+{
+	if (dev->rx_urb) {
+		usb_kill_urb(dev->rx_urb);
+		usb_free_urb(dev->rx_urb);
+		dev->rx_urb = NULL;
+	}
+}
+
+static int ch349_net_open(struct net_device *netdev)
+{
+	struct ch349_device *dev = netdev_priv(netdev);
+	int retval;
+
+	printk(KERN_INFO "ch349: Interface UP\n");
+
+	retval = ch349_start_rx(dev);
+	if (retval)
+		return retval;
+
+	netif_start_queue(netdev);
+	return 0;
+}
+
+static int ch349_net_stop(struct net_device *netdev)
+{
+	struct ch349_device *dev = netdev_priv(netdev);
+
+	printk(KERN_INFO "ch349: Interface DOWN\n");
+
+	netif_stop_queue(netdev);
+	ch349_stop_rx(dev);
+
+	return 0;
+}
+
+static netdev_tx_t ch349_start_xmit(struct sk_buff *skb,
+				    struct net_device *netdev)
+{
+	// Pour l'instant, on drop juste les packets TX
+	//printk(KERN_INFO "ch349: TX packet dropped (not implemented yet)\n");
+	dev_kfree_skb(skb);
+	netdev->stats.tx_dropped++;
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops ch349_netdev_ops = {
+	.ndo_open = ch349_net_open,
+	.ndo_stop = ch349_net_stop,
+	.ndo_start_xmit = ch349_start_xmit,
+	.ndo_validate_addr = eth_validate_addr,
+	.ndo_set_mac_address = eth_mac_addr,
+};
+
 static int ch349_probe(struct usb_interface *interface,
 		       const struct usb_device_id *id)
 {
 	struct ch349_device *dev;
+	struct net_device *netdev;
 	struct usb_endpoint_descriptor *endpoint;
-	//size_t buffer_size;
+	u8 mac[ETH_ALEN];
 	int i;
 	int retval = -ENOMEM;
 
 	dev_info(&interface->dev, "Probing CH349 device\n");
 
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev) {
-		dev_err(&interface->dev, "Out of memory\n");
-		goto error;
+	// Allouer net_device + notre structure
+	netdev = alloc_etherdev(sizeof(struct ch349_device));
+	if (!netdev) {
+		dev_err(&interface->dev, "Cannot allocate netdev\n");
+		return -ENOMEM;
 	}
 
+	dev = netdev_priv(netdev);
+	dev->netdev = netdev;
+
 	mutex_init(&dev->io_mutex);
 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
 	dev->interface = interface;
 
+	// Sélectionne l'altsetting 1
 	retval = usb_set_interface(
 		dev->udev, interface->cur_altsetting->desc.bInterfaceNumber, 1);
 	if (retval) {
@@ -63,15 +285,6 @@ static int ch349_probe(struct usb_interface *interface,
 
 	dev_info(&interface->dev, "Interface obtained\n");
 
-	if (dev->udev->actconfig->desc.bConfigurationValue != 2) {
-		retval = usb_set_configuration(dev->udev, 2);
-		if (retval) {
-			dev_err(&interface->dev,
-				"Cannot set configuration 2\n");
-			goto error;
-		}
-	}
-
 	for (i = 0; i < interface->cur_altsetting->desc.bNumEndpoints; i++) {
 		endpoint = &interface->cur_altsetting->endpoint[i].desc;
 
@@ -81,7 +294,7 @@ static int ch349_probe(struct usb_interface *interface,
 		if (!dev->bulk_in_endpointAddr &&
 		    usb_endpoint_is_bulk_in(endpoint)) {
 			dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
-			dev->bulk_in_size = usb_endpoint_maxp(endpoint);
+			dev->bulk_in_size = 2048; // Buffer ethernet
 			dev->bulk_in_buffer =
 				kmalloc(dev->bulk_in_size, GFP_KERNEL);
 			if (!dev->bulk_in_buffer) {
@@ -109,29 +322,61 @@ static int ch349_probe(struct usb_interface *interface,
 		goto error;
 	}
 
+	// Récupère la MAC
+	ch349_get_mac_address(dev, mac);
+	eth_hw_addr_set(netdev, mac);
+
+	// Configure net_device
+	netdev->netdev_ops = &ch349_netdev_ops;
+	netdev->watchdog_timeo = 5 * HZ;
+
 	usb_set_intfdata(interface, dev);
 
-	dev_info(&interface->dev, "CH349 device now attached\n");
+	// Enregistre l'interface réseau
+	retval = register_netdev(netdev);
+	if (retval) {
+		dev_err(&interface->dev, "Cannot register netdev: %d\n",
+			retval);
+		goto error;
+	}
+
+	dev_info(&interface->dev, "CH349 attached as %s (MAC: %pM)\n",
+		 netdev->name, mac);
+
+	//retval = ch349_start_rx(dev);
+	//if (retval)
+	//	goto error;
 
 	return 0;
 
 error:
-	if (dev)
+	if (dev) {
 		kfree(dev->bulk_in_buffer);
-	kfree(dev);
+		usb_put_dev(dev->udev);
+	}
+	if (netdev)
+		free_netdev(netdev);
 	return retval;
 }
 
 static void ch349_disconnect(struct usb_interface *interface)
 {
 	struct ch349_device *dev;
+	struct net_device *netdev;
 
 	dev = usb_get_intfdata(interface);
+	if (!dev)
+		return;
+
+	netdev = dev->netdev;
 	usb_set_intfdata(interface, NULL);
 
+	unregister_netdev(netdev);
+	ch349_stop_rx(dev);
+
 	kfree(dev->bulk_in_buffer);
 	usb_put_dev(dev->udev);
-	kfree(dev);
+	free_netdev(netdev);
 
 	dev_info(&interface->dev, "CH349 device now disconnected\n");
 }