[iphone] Add iPhone tethering driver

USB tethering via an iPhone is unreasonably complicated due to the
requirement to perform a pairing operation that involves establishing
a TLS session over a completely unrelated USB function that speaks a
protocol that is almost, but not quite, entirely unlike TCP.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 291 insertions, 0 deletions

diff --git a/src/drivers/net/iphone.h b/src/drivers/net/iphone.h
new file mode 100644
index 000000000..2db6da7bd
--- /dev/null
+++ b/src/drivers/net/iphone.h
@@ -0,0 +1,291 @@
+#ifndef _IPHONE_H
+#define _IPHONE_H
+
+/** @file
+ *
+ * iPhone USB Ethernet driver
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/usb.h>
+#include <ipxe/usbnet.h>
+#include <ipxe/process.h>
+#include <ipxe/timer.h>
+#include <ipxe/retry.h>
+#include <ipxe/tcp.h>
+#include <ipxe/x509.h>
+#include <ipxe/privkey.h>
+
+/******************************************************************************
+ *
+ * iPhone pairing certificates
+ *
+ ******************************************************************************
+ */
+
+/** An iPhone pairing certificate set */
+struct icert {
+	/** "Private" key */
+	struct private_key *key;
+	/** Root certificate */
+	struct x509_certificate *root;
+	/** Host certificate */
+	struct x509_certificate *host;
+	/** Device certificate */
+	struct x509_certificate *device;
+};
+
+/******************************************************************************
+ *
+ * iPhone USB multiplexer
+ *
+ ******************************************************************************
+ */
+
+/** An iPhone USB multiplexed packet header */
+struct imux_header {
+	/** Protocol */
+	uint32_t protocol;
+	/** Length (including this header) */
+	uint32_t len;
+	/** Reserved */
+	uint32_t reserved;
+	/** Output sequence number */
+	uint16_t out_seq;
+	/** Input sequence number */
+	uint16_t in_seq;
+} __attribute__ (( packed ));
+
+/** iPhone USB multiplexer protocols */
+enum imux_protocol {
+	/** Version number */
+	IMUX_VERSION = 0,
+	/** Log message */
+	IMUX_LOG = 1,
+	/** TCP packet */
+	IMUX_TCP = IP_TCP,
+};
+
+/** An iPhone USB multiplexed version message header */
+struct imux_header_version {
+	/** Multiplexed packet header */
+	struct imux_header hdr;
+	/** Reserved */
+	uint32_t reserved;
+} __attribute__ (( packed ));
+
+/** An iPhone USB multiplexed log message header */
+struct imux_header_log {
+	/** Multiplexed packet header */
+	struct imux_header hdr;
+	/** Log level */
+	uint8_t level;
+	/** Message */
+	char msg[0];
+} __attribute__ (( packed ));
+
+/** An iPhone USB multiplexed pseudo-TCP message header */
+struct imux_header_tcp {
+	/** Multiplexed packet header */
+	struct imux_header hdr;
+	/** Pseudo-TCP header */
+	struct tcp_header tcp;
+} __attribute__ (( packed ));
+
+/** Local port number
+ *
+ * This is a policy decision.
+ */
+#define IMUX_PORT_LOCAL 0x18ae
+
+/** Lockdown daemon port number */
+#define IMUX_PORT_LOCKDOWND 62078
+
+/** Advertised TCP window
+ *
+ * This is a policy decision.
+ */
+#define IMUX_WINDOW 0x0200
+
+/** An iPhone USB multiplexer */
+struct imux {
+	/** Reference counter */
+	struct refcnt refcnt;
+	/** USB device */
+	struct usb_device *usb;
+	/** USB bus */
+	struct usb_bus *bus;
+	/** USB network device */
+	struct usbnet_device usbnet;
+	/** List of USB multiplexers */
+	struct list_head list;
+
+	/** Polling process */
+	struct process process;
+	/** Pending action
+	 *
+	 * @v imux		USB multiplexer
+	 * @ret rc		Return status code
+	 */
+	int ( * action ) ( struct imux *imux );
+
+	/** Input sequence */
+	uint16_t in_seq;
+	/** Output sequence */
+	uint16_t out_seq;
+	/** Pseudo-TCP sequence number */
+	uint32_t tcp_seq;
+	/** Pseudo-TCP acknowledgement number */
+	uint32_t tcp_ack;
+	/** Pseudo-TCP local port number */
+	uint16_t port;
+
+	/** Pseudo-TCP lockdown socket interface */
+	struct interface tcp;
+	/** Pairing flags */
+	unsigned int flags;
+	/** Pairing status */
+	int rc;
+};
+
+/** Multiplexer bulk IN maximum fill level
+ *
+ * This is a policy decision.
+ */
+#define IMUX_IN_MAX_FILL 1
+
+/** Multiplexer bulk IN buffer size
+ *
+ * This is a policy decision.
+ */
+#define IMUX_IN_MTU 4096
+
+/******************************************************************************
+ *
+ * iPhone pairing client
+ *
+ ******************************************************************************
+ */
+
+/** An iPhone USB multiplexed pseudo-TCP XML message header */
+struct ipair_header {
+	/** Message length */
+	uint32_t len;
+	/** Message */
+	char msg[0];
+} __attribute__ (( packed ));
+
+/** An iPhone pairing client */
+struct ipair {
+	/** Reference counter */
+	struct refcnt refcnt;
+	/** Data transfer interface */
+	struct interface xfer;
+
+	/** Pairing timer */
+	struct retry_timer timer;
+	/** Transmit message
+	 *
+	 * @v ipair		Pairing client
+	 * @ret rc		Return status code
+	 */
+	int ( * tx ) ( struct ipair *ipair );
+	/** Receive message
+	 *
+	 * @v ipair		Pairing client
+	 * @v msg		XML message
+	 * @ret rc		Return status code
+	 */
+	int ( * rx ) ( struct ipair *ipair, char *msg );
+	/** State flags */
+	unsigned int flags;
+
+	/** Pairing certificates */
+	struct icert icert;
+};
+
+/** Pairing client state flags */
+enum ipair_flags {
+	/** Request a new pairing */
+	IPAIR_REQUEST = 0x0001,
+	/** Standalone length has been received */
+	IPAIR_RX_LEN = 0x0002,
+	/** TLS session has been started */
+	IPAIR_TLS = 0x0004,
+};
+
+/** Pairing retry delay
+ *
+ * This is a policy decision.
+ */
+#define IPAIR_RETRY_DELAY ( 1 * TICKS_PER_SEC )
+
+/******************************************************************************
+ *
+ * iPhone USB networking
+ *
+ ******************************************************************************
+ */
+
+/** Get MAC address */
+#define IPHONE_GET_MAC							\
+	( USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE |		\
+	  USB_REQUEST_TYPE ( 0x00 ) )
+
+/** Get link status */
+#define IPHONE_GET_LINK							\
+	( USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE |		\
+	  USB_REQUEST_TYPE ( 0x45 ) )
+
+/** An iPhone link status */
+enum iphone_link_status {
+	/** Personal Hotspot is disabled */
+	IPHONE_LINK_DISABLED = 0x03,
+	/** Link up */
+	IPHONE_LINK_UP = 0x04,
+	/** Link not yet determined */
+	IPHONE_LINK_UNKNOWN = -1U,
+};
+
+/** An iPhone network device */
+struct iphone {
+	/** USB device */
+	struct usb_device *usb;
+	/** USB bus */
+	struct usb_bus *bus;
+	/** Network device */
+	struct net_device *netdev;
+	/** USB network device */
+	struct usbnet_device usbnet;
+
+	/** List of iPhone network devices */
+	struct list_head list;
+	/** Link status check timer */
+	struct retry_timer timer;
+};
+
+/** Bulk IN padding */
+#define IPHONE_IN_PAD 2
+
+/** Bulk IN buffer size
+ *
+ * This is a policy decision.
+ */
+#define IPHONE_IN_MTU ( ETH_FRAME_LEN + IPHONE_IN_PAD )
+
+/** Bulk IN maximum fill level
+ *
+ * This is a policy decision.
+ */
+#define IPHONE_IN_MAX_FILL 8
+
+/** Link check interval
+ *
+ * This is a policy decision.
+ */
+#define IPHONE_LINK_CHECK_INTERVAL ( 5 * TICKS_PER_SEC )
+
+#endif /* _IPHONE_H */