usbip_common.c

Realize the usbip function, which could be simulate usb port through net

		msg.msg_namelen = 0;
		msg.msg_control = NULL;
		msg.msg_controllen = 0;
		msg.msg_namelen    = 0;
		msg.msg_flags      = msg_flags | MSG_NOSIGNAL;

		if (send)
			result = kernel_sendmsg(sock, &msg, &iov, 1, size);
		else
			result = kernel_recvmsg(sock, &msg, &iov, 1, size, MSG_WAITALL);

		if (result <= 0) {
			udbg("usbip_xmit: %s sock %p buf %p size %u ret %d total %d\n",
					send ? "send" : "receive", sock, buf, size, result, total);
			goto err;
		}

		size -= result;
		buf += result;
		total += result;

	} while (size > 0);


	if (dbg_flag_xmit) {
		if (!send) {
			if (!in_interrupt())
				printk(KERN_DEBUG "%-10s:", current->comm);
			else
				printk(KERN_DEBUG "interupt  :");

			printk("usbip_xmit: receiving....\n");
			usbip_dump_buffer(bp, osize);
			printk("usbip_xmit: received, osize %d ret %d size %d total %d\n",
					osize, result, size, total);
		}

		if (send) {
			printk("usbip_xmit: send, total %d\n", total);
		}
	}

	return total;

err:
	return result;
}
EXPORT_SYMBOL(usbip_xmit);


/* now a usrland utility should set options. */
#if 0
int setquickack(struct socket *socket)
{
	mm_segment_t oldfs;
	int val = 1;
	int ret;

	oldfs = get_fs();
	set_fs(get_ds());
	ret = socket->ops->setsockopt(socket, SOL_TCP, TCP_QUICKACK,
			(char __user *) &val, sizeof(ret));
	set_fs(oldfs);

	return ret;
}

int setnodelay(struct socket *socket)
{
	mm_segment_t oldfs;
	int val = 1;
	int ret;

	oldfs = get_fs();
	set_fs(get_ds());
	ret = socket->ops->setsockopt(socket, SOL_TCP, TCP_NODELAY,
			(char __user *) &val, sizeof(ret));
	set_fs(oldfs);

	return ret;
}

int setkeepalive(struct socket *socket)
{
	mm_segment_t oldfs;
	int val = 1;
	int ret;

	oldfs = get_fs();
	set_fs(get_ds());
	ret = socket->ops->setsockopt(socket, SOL_SOCKET, SO_KEEPALIVE,
			(char __user *) &val, sizeof(ret));
	set_fs(oldfs);

	return ret;
}

void setreuse(struct socket *socket)
{
	socket->sk->sk_reuse = 1;
}
#endif

struct socket *sockfd_to_socket(unsigned int sockfd)
{
	struct socket *socket;
	struct file *file;
	struct inode *inode;

	file = fget(sockfd);
	if (!file) {
		uerr("invalid sockfd\n");
		return NULL;
	}

	inode = file->f_dentry->d_inode;

	if (!inode || !S_ISSOCK(inode->i_mode))
		return NULL;

	socket = SOCKET_I(inode);

	return socket;
}
EXPORT_SYMBOL(sockfd_to_socket);



/*-------------------------------------------------------------------------*/
/* pdu routines */

/* there may be more cases to tweak the flags. */
static unsigned int tweak_transfer_flags(unsigned int flags)
{

	if (flags & URB_NO_TRANSFER_DMA_MAP)
		/*
		 * vhci_hcd does not provide DMA-mapped I/O. The upper
		 * driver does not need to set this flag. The remote
		 * usbip.ko does not still perform DMA-mapped I/O for
		 * DMA-caplable host controllers. So, clear this flag.
		 */
		flags &= ~URB_NO_TRANSFER_DMA_MAP;

	if (flags & URB_NO_SETUP_DMA_MAP)
		flags &= ~URB_NO_SETUP_DMA_MAP;

	return flags;
}

static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb, int pack)
{
	struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;

	/*
	 * Some members are not still implemented in usbip. I hope this issue
	 * will be discussed when usbip is ported to other operating systems.
	 */
	if (pack) {
		/* vhci_tx.c */
		spdu->transfer_flags		= tweak_transfer_flags(urb->transfer_flags);

		spdu->transfer_buffer_length	= urb->transfer_buffer_length;
		spdu->start_frame		= urb->start_frame;
		spdu->number_of_packets		= urb->number_of_packets;
		spdu->interval			= urb->interval;
	} else  {
		/* stub_rx.c */
		urb->transfer_flags         = spdu->transfer_flags;

		urb->transfer_buffer_length = spdu->transfer_buffer_length;
		urb->start_frame            = spdu->start_frame;
		urb->number_of_packets      = spdu->number_of_packets;
		urb->interval               = spdu->interval;
	}
}

static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb, int pack)
{
	struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;

	if (pack) {
		/* stub_tx.c */

		rpdu->status		= urb->status;
		rpdu->actual_length	= urb->actual_length;
		rpdu->start_frame	= urb->start_frame;
		rpdu->error_count	= urb->error_count;
	} else {
		/* vhci_rx.c */

		urb->status		= rpdu->status;
		urb->actual_length	= rpdu->actual_length;
		urb->start_frame	= rpdu->start_frame;
		urb->error_count	= rpdu->error_count;
	}
}


void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd, int pack)
{
	switch(cmd) {
		case USBIP_CMD_SUBMIT:
			usbip_pack_cmd_submit(pdu, urb, pack);
			break;
		case USBIP_RET_SUBMIT:
			usbip_pack_ret_submit(pdu, urb, pack);
			break;
		default:
			err("unknown command");
			/* NOTREACHED */
			//BUG();
	}
}
EXPORT_SYMBOL(usbip_pack_pdu);


static void correct_endian_basic(struct usbip_header_basic *base, int send)
{
	if (send) {
		base->command	= cpu_to_be32(base->command);
		base->busnum	= cpu_to_be32(base->busnum);
		base->devnum	= cpu_to_be32(base->devnum);
		base->seqnum	= cpu_to_be32(base->seqnum);
		base->pipe	= cpu_to_be32(base->pipe);
	} else {
		base->command	= be32_to_cpu(base->command);
		base->busnum	= be32_to_cpu(base->busnum);
		base->devnum	= be32_to_cpu(base->devnum);
		base->seqnum	= be32_to_cpu(base->seqnum);
		base->pipe	= be32_to_cpu(base->pipe);
	}
}

static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu, int send)
{
	if (send) {
		pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);

		cpu_to_be32s(&pdu->transfer_buffer_length);
		cpu_to_be32s(&pdu->start_frame);
		cpu_to_be32s(&pdu->number_of_packets);
		cpu_to_be32s(&pdu->interval);
	} else {
		pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);

		be32_to_cpus(&pdu->transfer_buffer_length);
		be32_to_cpus(&pdu->start_frame);
		be32_to_cpus(&pdu->number_of_packets);
		be32_to_cpus(&pdu->interval);
	}
}

static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu, int send)
{
	if (send) {
		cpu_to_be32s(&pdu->status);
		cpu_to_be32s(&pdu->actual_length);
		cpu_to_be32s(&pdu->start_frame);
		cpu_to_be32s(&pdu->error_count);
	} else {
		be32_to_cpus(&pdu->status);
		be32_to_cpus(&pdu->actual_length);
		be32_to_cpus(&pdu->start_frame);
		be32_to_cpus(&pdu->error_count);
	}
}

static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu, int send)
{
	if (send)
		pdu->seqnum = cpu_to_be32(pdu->seqnum);
	else
		pdu->seqnum = be32_to_cpu(pdu->seqnum);
}

static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu, int send)
{
	if (send)
		cpu_to_be32s(&pdu->status);
	else
		be32_to_cpus(&pdu->status);
}

void usbip_header_correct_endian(struct usbip_header *pdu, int send)
{
	__u32 cmd = 0;

	if (send)
		cmd = pdu->base.command;

	correct_endian_basic(&pdu->base, send);

	if (!send)
		cmd = pdu->base.command;

	switch (cmd) {
		case USBIP_CMD_SUBMIT:
			correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
			break;
		case USBIP_RET_SUBMIT:
			correct_endian_ret_submit(&pdu->u.ret_submit, send);
			break;

		case USBIP_CMD_UNLINK:
			correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
			break;
		case USBIP_RET_UNLINK:
			correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
			break;

		default:
			/* NOTREACHED */
			err("unknown command in pdu header: %d", cmd);
			//BUG();
	}
}
EXPORT_SYMBOL(usbip_header_correct_endian);

static void usbip_iso_pakcet_correct_endian(struct usbip_iso_packet_descriptor *iso, int send)
{
	/* does not need all members. but copy all simply. */
	if (send) {
		iso->offset	= cpu_to_be32(iso->offset);
		iso->length	= cpu_to_be32(iso->length);
		iso->status	= cpu_to_be32(iso->status);
		iso->actual_length = cpu_to_be32(iso->actual_length);
	} else {
		iso->offset	= be32_to_cpu(iso->offset);
		iso->length	= be32_to_cpu(iso->length);
		iso->status	= be32_to_cpu(iso->status);
		iso->actual_length = be32_to_cpu(iso->actual_length);
	}
}

static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
		struct usb_iso_packet_descriptor *uiso, int pack)
{
	if (pack) {
		iso->offset		= uiso->offset;
		iso->length		= uiso->length;
		iso->status		= uiso->status;
		iso->actual_length	= uiso->actual_length;
	} else {
		uiso->offset		= iso->offset;
		uiso->length		= iso->length;
		uiso->status		= iso->status;
		uiso->actual_length	= iso->actual_length;
	}
}


/* must free buffer */
void *usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
{
	void *buff;
	struct usbip_iso_packet_descriptor *iso;
	int np = urb->number_of_packets;
	ssize_t size = np * sizeof(*iso);
	int i;

	buff = kzalloc(size, GFP_KERNEL);
	if (!buff)
		return NULL;

	for (i = 0; i < np; i++) {
		iso = buff + (i * sizeof(*iso));

		usbip_pack_iso(iso, &urb->iso_frame_desc[i], 1);
		usbip_iso_pakcet_correct_endian(iso, 1);
	}

	*bufflen = size;

	return buff;
}
EXPORT_SYMBOL(usbip_alloc_iso_desc_pdu);

/* some members of urb must be substituted before. */
int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
{
	void *buff;
	struct usbip_iso_packet_descriptor *iso;
	int np = urb->number_of_packets;
	int size = np * sizeof(*iso);
	int i;
	int ret;

	if (!usb_pipeisoc(urb->pipe))
		return 0;

	buff = kzalloc(size, GFP_KERNEL);
	if (!buff)
		return -ENOMEM;

	ret = usbip_xmit(0, ud->tcp_socket, buff, size, 0);
	if (ret != size) {
		uerr("recv iso_frame_descriptor, %d\n", ret);
		kfree(buff);

		if (ud->side == USBIP_STUB)
			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		else
			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);

		return -EPIPE;
	}

	for (i = 0; i < np; i++) {
		iso = buff + (i * sizeof(*iso));

		usbip_iso_pakcet_correct_endian(iso, 0);
		usbip_pack_iso(iso, &urb->iso_frame_desc[i], 0);
	}


	kfree(buff);

	return ret;
}
EXPORT_SYMBOL(usbip_recv_iso);


/* some members of urb must be substituted before. */
int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
{
	int ret;
	int size;

	if (ud->side == USBIP_STUB) {
		/* stub_rx.c */
		/* the direction of urb must be OUT. */
		if (usb_pipein(urb->pipe))
			return 0;

		size = urb->transfer_buffer_length;
	} else {
		/* vhci_rx.c */
		/* the direction of urb must be IN. */
		if (usb_pipeout(urb->pipe))
			return 0;

		size = urb->actual_length;
	}

	/* no need to recv xbuff */
	if (!(size > 0))
		return 0;

	ret = usbip_xmit(0, ud->tcp_socket, (char *) urb->transfer_buffer, size, 0);
	if (ret != size) {
		uerr("recv xbuf, %d\n", ret);
		if (ud->side == USBIP_STUB) {
			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		} else {
			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
			return -EPIPE;
		}
	}

	return ret;
}
EXPORT_SYMBOL(usbip_recv_xbuff);


/*-------------------------------------------------------------------------*/

static int __init usbip_common_init(void)
{
	info(DRIVER_DESC "" DRIVER_VERSION);

	return 0;
}

static void __exit usbip_common_exit(void)
{
	return;
}




module_init(usbip_common_init);
module_exit(usbip_common_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");