text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (C) 2017 - 2019 Cambridge Greys Limited
   * Copyright (C) 2011 - 2014 Cisco Systems Inc
   * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
   * James Leu (jleu@mindspring.net).
   * Copyright (C) 2001 by various other people who didn't put their name here.
   */
  
  #include <linux/memblock.h>
  #include <linux/etherdevice.h>
  #include <linux/ethtool.h>
  #include <linux/inetdevice.h>
  #include <linux/init.h>
  #include <linux/list.h>
  #include <linux/netdevice.h>
  #include <linux/platform_device.h>
  #include <linux/rtnetlink.h>
  #include <linux/skbuff.h>
  #include <linux/slab.h>
  #include <linux/interrupt.h>
  #include <linux/firmware.h>
  #include <linux/fs.h>
  #include <uapi/linux/filter.h>
  #include <init.h>
  #include <irq_kern.h>
  #include <irq_user.h>
  #include <net_kern.h>
  #include <os.h>
  #include "mconsole_kern.h"
  #include "vector_user.h"
  #include "vector_kern.h"
  
  /*
   * Adapted from network devices with the following major changes:
   * All transports are static - simplifies the code significantly
   * Multiple FDs/IRQs per device
   * Vector IO optionally used for read/write, falling back to legacy
   * based on configuration and/or availability
   * Configuration is no longer positional - L2TPv3 and GRE require up to
   * 10 parameters, passing this as positional is not fit for purpose.
   * Only socket transports are supported
   */
  
  
  #define DRIVER_NAME "uml-vector"
  struct vector_cmd_line_arg {
  	struct list_head list;
  	int unit;
  	char *arguments;
  };
  
  struct vector_device {
  	struct list_head list;
  	struct net_device *dev;
  	struct platform_device pdev;
  	int unit;
  	int opened;
  };
  
  static LIST_HEAD(vec_cmd_line);
  
  static DEFINE_SPINLOCK(vector_devices_lock);
  static LIST_HEAD(vector_devices);
  
  static int driver_registered;
  
  static void vector_eth_configure(int n, struct arglist *def);
  
  /* Argument accessors to set variables (and/or set default values)
   * mtu, buffer sizing, default headroom, etc
   */
  
  #define DEFAULT_HEADROOM 2
  #define SAFETY_MARGIN 32
  #define DEFAULT_VECTOR_SIZE 64
  #define TX_SMALL_PACKET 128
  #define MAX_IOV_SIZE (MAX_SKB_FRAGS + 1)
  #define MAX_ITERATIONS 64
  
  static const struct {
  	const char string[ETH_GSTRING_LEN];
  } ethtool_stats_keys[] = {
  	{ "rx_queue_max" },
  	{ "rx_queue_running_average" },
  	{ "tx_queue_max" },
  	{ "tx_queue_running_average" },
  	{ "rx_encaps_errors" },
  	{ "tx_timeout_count" },
  	{ "tx_restart_queue" },
  	{ "tx_kicks" },
  	{ "tx_flow_control_xon" },
  	{ "tx_flow_control_xoff" },
  	{ "rx_csum_offload_good" },
  	{ "rx_csum_offload_errors"},
  	{ "sg_ok"},
  	{ "sg_linearized"},
  };
  
  #define VECTOR_NUM_STATS	ARRAY_SIZE(ethtool_stats_keys)
  
  static void vector_reset_stats(struct vector_private *vp)
  {
  	vp->estats.rx_queue_max = 0;
  	vp->estats.rx_queue_running_average = 0;
  	vp->estats.tx_queue_max = 0;
  	vp->estats.tx_queue_running_average = 0;
  	vp->estats.rx_encaps_errors = 0;
  	vp->estats.tx_timeout_count = 0;
  	vp->estats.tx_restart_queue = 0;
  	vp->estats.tx_kicks = 0;
  	vp->estats.tx_flow_control_xon = 0;
  	vp->estats.tx_flow_control_xoff = 0;
  	vp->estats.sg_ok = 0;
  	vp->estats.sg_linearized = 0;
  }
  
  static int get_mtu(struct arglist *def)
  {
  	char *mtu = uml_vector_fetch_arg(def, "mtu");
  	long result;
  
  	if (mtu != NULL) {
  		if (kstrtoul(mtu, 10, &result) == 0)
  			if ((result < (1 << 16) - 1) && (result >= 576))
  				return result;
  	}
  	return ETH_MAX_PACKET;
  }
  
  static char *get_bpf_file(struct arglist *def)
  {
  	return uml_vector_fetch_arg(def, "bpffile");
  }
  
  static bool get_bpf_flash(struct arglist *def)
  {
  	char *allow = uml_vector_fetch_arg(def, "bpfflash");
  	long result;
  
  	if (allow != NULL) {
  		if (kstrtoul(allow, 10, &result) == 0)
  			return (allow > 0);
  	}
  	return false;
  }
  
  static int get_depth(struct arglist *def)
  {
  	char *mtu = uml_vector_fetch_arg(def, "depth");
  	long result;
  
  	if (mtu != NULL) {
  		if (kstrtoul(mtu, 10, &result) == 0)
  			return result;
  	}
  	return DEFAULT_VECTOR_SIZE;
  }
  
  static int get_headroom(struct arglist *def)
  {
  	char *mtu = uml_vector_fetch_arg(def, "headroom");
  	long result;
  
  	if (mtu != NULL) {
  		if (kstrtoul(mtu, 10, &result) == 0)
  			return result;
  	}
  	return DEFAULT_HEADROOM;
  }
  
  static int get_req_size(struct arglist *def)
  {
  	char *gro = uml_vector_fetch_arg(def, "gro");
  	long result;
  
  	if (gro != NULL) {
  		if (kstrtoul(gro, 10, &result) == 0) {
  			if (result > 0)
  				return 65536;
  		}
  	}
  	return get_mtu(def) + ETH_HEADER_OTHER +
  		get_headroom(def) + SAFETY_MARGIN;
  }
  
  
  static int get_transport_options(struct arglist *def)
  {
  	char *transport = uml_vector_fetch_arg(def, "transport");
  	char *vector = uml_vector_fetch_arg(def, "vec");
  
  	int vec_rx = VECTOR_RX;
  	int vec_tx = VECTOR_TX;
  	long parsed;
  	int result = 0;
  
  	if (transport == NULL)
  		return -EINVAL;
  
  	if (vector != NULL) {
  		if (kstrtoul(vector, 10, &parsed) == 0) {
  			if (parsed == 0) {
  				vec_rx = 0;
  				vec_tx = 0;
  			}
  		}
  	}
  
  	if (get_bpf_flash(def))
  		result = VECTOR_BPF_FLASH;
  
  	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
  		return result;
  	if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
  		return (result | vec_rx | VECTOR_BPF);
  	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
  		return (result | vec_rx | vec_tx | VECTOR_QDISC_BYPASS);
  	return (result | vec_rx | vec_tx);
  }
  
  
  /* A mini-buffer for packet drop read
   * All of our supported transports are datagram oriented and we always
   * read using recvmsg or recvmmsg. If we pass a buffer which is smaller
   * than the packet size it still counts as full packet read and will
   * clean the incoming stream to keep sigio/epoll happy
   */
  
  #define DROP_BUFFER_SIZE 32
  
  static char *drop_buffer;
  
  /* Array backed queues optimized for bulk enqueue/dequeue and
   * 1:N (small values of N) or 1:1 enqueuer/dequeuer ratios.
   * For more details and full design rationale see
   * http://foswiki.cambridgegreys.com/Main/EatYourTailAndEnjoyIt
   */
  
  
  /*
   * Advance the mmsg queue head by n = advance. Resets the queue to
   * maximum enqueue/dequeue-at-once capacity if possible. Called by
   * dequeuers. Caller must hold the head_lock!
   */
  
  static int vector_advancehead(struct vector_queue *qi, int advance)
  {
  	int queue_depth;
  
  	qi->head =
  		(qi->head + advance)
  			% qi->max_depth;
  
  
  	spin_lock(&qi->tail_lock);
  	qi->queue_depth -= advance;
  
  	/* we are at 0, use this to
  	 * reset head and tail so we can use max size vectors
  	 */
  
  	if (qi->queue_depth == 0) {
  		qi->head = 0;
  		qi->tail = 0;
  	}
  	queue_depth = qi->queue_depth;
  	spin_unlock(&qi->tail_lock);
  	return queue_depth;
  }
  
  /*	Advance the queue tail by n = advance.
   *	This is called by enqueuers which should hold the
   *	head lock already
   */
  
  static int vector_advancetail(struct vector_queue *qi, int advance)
  {
  	int queue_depth;
  
  	qi->tail =
  		(qi->tail + advance)
  			% qi->max_depth;
  	spin_lock(&qi->head_lock);
  	qi->queue_depth += advance;
  	queue_depth = qi->queue_depth;
  	spin_unlock(&qi->head_lock);
  	return queue_depth;
  }
  
  static int prep_msg(struct vector_private *vp,
  	struct sk_buff *skb,
  	struct iovec *iov)
  {
  	int iov_index = 0;
  	int nr_frags, frag;
  	skb_frag_t *skb_frag;
  
  	nr_frags = skb_shinfo(skb)->nr_frags;
  	if (nr_frags > MAX_IOV_SIZE) {
  		if (skb_linearize(skb) != 0)
  			goto drop;
  	}
  	if (vp->header_size > 0) {
  		iov[iov_index].iov_len = vp->header_size;
  		vp->form_header(iov[iov_index].iov_base, skb, vp);
  		iov_index++;
  	}
  	iov[iov_index].iov_base = skb->data;
  	if (nr_frags > 0) {
  		iov[iov_index].iov_len = skb->len - skb->data_len;
  		vp->estats.sg_ok++;
  	} else
  		iov[iov_index].iov_len = skb->len;
  	iov_index++;
  	for (frag = 0; frag < nr_frags; frag++) {
  		skb_frag = &skb_shinfo(skb)->frags[frag];
  		iov[iov_index].iov_base = skb_frag_address_safe(skb_frag);
  		iov[iov_index].iov_len = skb_frag_size(skb_frag);
  		iov_index++;
  	}
  	return iov_index;
  drop:
  	return -1;
  }
  /*
   * Generic vector enqueue with support for forming headers using transport
   * specific callback. Allows GRE, L2TPv3, RAW and other transports
   * to use a common enqueue procedure in vector mode
   */
  
  static int vector_enqueue(struct vector_queue *qi, struct sk_buff *skb)
  {
  	struct vector_private *vp = netdev_priv(qi->dev);
  	int queue_depth;
  	int packet_len;
  	struct mmsghdr *mmsg_vector = qi->mmsg_vector;
  	int iov_count;
  
  	spin_lock(&qi->tail_lock);
  	spin_lock(&qi->head_lock);
  	queue_depth = qi->queue_depth;
  	spin_unlock(&qi->head_lock);
  
  	if (skb)
  		packet_len = skb->len;
  
  	if (queue_depth < qi->max_depth) {
  
  		*(qi->skbuff_vector + qi->tail) = skb;
  		mmsg_vector += qi->tail;
  		iov_count = prep_msg(
  			vp,
  			skb,
  			mmsg_vector->msg_hdr.msg_iov
  		);
  		if (iov_count < 1)
  			goto drop;
  		mmsg_vector->msg_hdr.msg_iovlen = iov_count;
  		mmsg_vector->msg_hdr.msg_name = vp->fds->remote_addr;
  		mmsg_vector->msg_hdr.msg_namelen = vp->fds->remote_addr_size;
  		queue_depth = vector_advancetail(qi, 1);
  	} else
  		goto drop;
  	spin_unlock(&qi->tail_lock);
  	return queue_depth;
  drop:
  	qi->dev->stats.tx_dropped++;
  	if (skb != NULL) {
  		packet_len = skb->len;
  		dev_consume_skb_any(skb);
  		netdev_completed_queue(qi->dev, 1, packet_len);
  	}
  	spin_unlock(&qi->tail_lock);
  	return queue_depth;
  }
  
  static int consume_vector_skbs(struct vector_queue *qi, int count)
  {
  	struct sk_buff *skb;
  	int skb_index;
  	int bytes_compl = 0;
  
  	for (skb_index = qi->head; skb_index < qi->head + count; skb_index++) {
  		skb = *(qi->skbuff_vector + skb_index);
  		/* mark as empty to ensure correct destruction if
  		 * needed
  		 */
  		bytes_compl += skb->len;
  		*(qi->skbuff_vector + skb_index) = NULL;
  		dev_consume_skb_any(skb);
  	}
  	qi->dev->stats.tx_bytes += bytes_compl;
  	qi->dev->stats.tx_packets += count;
  	netdev_completed_queue(qi->dev, count, bytes_compl);
  	return vector_advancehead(qi, count);
  }
  
  /*
   * Generic vector deque via sendmmsg with support for forming headers
   * using transport specific callback. Allows GRE, L2TPv3, RAW and
   * other transports to use a common dequeue procedure in vector mode
   */
  
  
  static int vector_send(struct vector_queue *qi)
  {
  	struct vector_private *vp = netdev_priv(qi->dev);
  	struct mmsghdr *send_from;
  	int result = 0, send_len, queue_depth = qi->max_depth;
  
  	if (spin_trylock(&qi->head_lock)) {
  		if (spin_trylock(&qi->tail_lock)) {
  			/* update queue_depth to current value */
  			queue_depth = qi->queue_depth;
  			spin_unlock(&qi->tail_lock);
  			while (queue_depth > 0) {
  				/* Calculate the start of the vector */
  				send_len = queue_depth;
  				send_from = qi->mmsg_vector;
  				send_from += qi->head;
  				/* Adjust vector size if wraparound */
  				if (send_len + qi->head > qi->max_depth)
  					send_len = qi->max_depth - qi->head;
  				/* Try to TX as many packets as possible */
  				if (send_len > 0) {
  					result = uml_vector_sendmmsg(
  						 vp->fds->tx_fd,
  						 send_from,
  						 send_len,
  						 0
  					);
  					vp->in_write_poll =
  						(result != send_len);
  				}
  				/* For some of the sendmmsg error scenarios
  				 * we may end being unsure in the TX success
  				 * for all packets. It is safer to declare
  				 * them all TX-ed and blame the network.
  				 */
  				if (result < 0) {
  					if (net_ratelimit())
  						netdev_err(vp->dev, "sendmmsg err=%i\n",
  							result);
  					vp->in_error = true;
  					result = send_len;
  				}
  				if (result > 0) {
  					queue_depth =
  						consume_vector_skbs(qi, result);
  					/* This is equivalent to an TX IRQ.
  					 * Restart the upper layers to feed us
  					 * more packets.
  					 */
  					if (result > vp->estats.tx_queue_max)
  						vp->estats.tx_queue_max = result;
  					vp->estats.tx_queue_running_average =
  						(vp->estats.tx_queue_running_average + result) >> 1;
  				}
  				netif_trans_update(qi->dev);
  				netif_wake_queue(qi->dev);
  				/* if TX is busy, break out of the send loop,
  				 *  poll write IRQ will reschedule xmit for us
  				 */
  				if (result != send_len) {
  					vp->estats.tx_restart_queue++;
  					break;
  				}
  			}
  		}
  		spin_unlock(&qi->head_lock);
  	} else {
  		tasklet_schedule(&vp->tx_poll);
  	}
  	return queue_depth;
  }
  
  /* Queue destructor. Deliberately stateless so we can use
   * it in queue cleanup if initialization fails.
   */
  
  static void destroy_queue(struct vector_queue *qi)
  {
  	int i;
  	struct iovec *iov;
  	struct vector_private *vp = netdev_priv(qi->dev);
  	struct mmsghdr *mmsg_vector;
  
  	if (qi == NULL)
  		return;
  	/* deallocate any skbuffs - we rely on any unused to be
  	 * set to NULL.
  	 */
  	if (qi->skbuff_vector != NULL) {
  		for (i = 0; i < qi->max_depth; i++) {
  			if (*(qi->skbuff_vector + i) != NULL)
  				dev_kfree_skb_any(*(qi->skbuff_vector + i));
  		}
  		kfree(qi->skbuff_vector);
  	}
  	/* deallocate matching IOV structures including header buffs */
  	if (qi->mmsg_vector != NULL) {
  		mmsg_vector = qi->mmsg_vector;
  		for (i = 0; i < qi->max_depth; i++) {
  			iov = mmsg_vector->msg_hdr.msg_iov;
  			if (iov != NULL) {
  				if ((vp->header_size > 0) &&
  					(iov->iov_base != NULL))
  					kfree(iov->iov_base);
  				kfree(iov);
  			}
  			mmsg_vector++;
  		}
  		kfree(qi->mmsg_vector);
  	}
  	kfree(qi);
  }
  
  /*
   * Queue constructor. Create a queue with a given side.
   */
  static struct vector_queue *create_queue(
  	struct vector_private *vp,
  	int max_size,
  	int header_size,
  	int num_extra_frags)
  {
  	struct vector_queue *result;
  	int i;
  	struct iovec *iov;
  	struct mmsghdr *mmsg_vector;
  
  	result = kmalloc(sizeof(struct vector_queue), GFP_KERNEL);
  	if (result == NULL)
  		return NULL;
  	result->max_depth = max_size;
  	result->dev = vp->dev;
  	result->mmsg_vector = kmalloc(
  		(sizeof(struct mmsghdr) * max_size), GFP_KERNEL);
  	if (result->mmsg_vector == NULL)
  		goto out_mmsg_fail;
  	result->skbuff_vector = kmalloc(
  		(sizeof(void *) * max_size), GFP_KERNEL);
  	if (result->skbuff_vector == NULL)
  		goto out_skb_fail;
  
  	/* further failures can be handled safely by destroy_queue*/
  
  	mmsg_vector = result->mmsg_vector;
  	for (i = 0; i < max_size; i++) {
  		/* Clear all pointers - we use non-NULL as marking on
  		 * what to free on destruction
  		 */
  		*(result->skbuff_vector + i) = NULL;
  		mmsg_vector->msg_hdr.msg_iov = NULL;
  		mmsg_vector++;
  	}
  	mmsg_vector = result->mmsg_vector;
  	result->max_iov_frags = num_extra_frags;
  	for (i = 0; i < max_size; i++) {
  		if (vp->header_size > 0)
  			iov = kmalloc_array(3 + num_extra_frags,
  					    sizeof(struct iovec),
  					    GFP_KERNEL
  			);
  		else
  			iov = kmalloc_array(2 + num_extra_frags,
  					    sizeof(struct iovec),
  					    GFP_KERNEL
  			);
  		if (iov == NULL)
  			goto out_fail;
  		mmsg_vector->msg_hdr.msg_iov = iov;
  		mmsg_vector->msg_hdr.msg_iovlen = 1;
  		mmsg_vector->msg_hdr.msg_control = NULL;
  		mmsg_vector->msg_hdr.msg_controllen = 0;
  		mmsg_vector->msg_hdr.msg_flags = MSG_DONTWAIT;
  		mmsg_vector->msg_hdr.msg_name = NULL;
  		mmsg_vector->msg_hdr.msg_namelen = 0;
  		if (vp->header_size > 0) {
  			iov->iov_base = kmalloc(header_size, GFP_KERNEL);
  			if (iov->iov_base == NULL)
  				goto out_fail;
  			iov->iov_len = header_size;
  			mmsg_vector->msg_hdr.msg_iovlen = 2;
  			iov++;
  		}
  		iov->iov_base = NULL;
  		iov->iov_len = 0;
  		mmsg_vector++;
  	}
  	spin_lock_init(&result->head_lock);
  	spin_lock_init(&result->tail_lock);
  	result->queue_depth = 0;
  	result->head = 0;
  	result->tail = 0;
  	return result;
  out_skb_fail:
  	kfree(result->mmsg_vector);
  out_mmsg_fail:
  	kfree(result);
  	return NULL;
  out_fail:
  	destroy_queue(result);
  	return NULL;
  }
  
  /*
   * We do not use the RX queue as a proper wraparound queue for now
   * This is not necessary because the consumption via netif_rx()
   * happens in-line. While we can try using the return code of
   * netif_rx() for flow control there are no drivers doing this today.
   * For this RX specific use we ignore the tail/head locks and
   * just read into a prepared queue filled with skbuffs.
   */
  
  static struct sk_buff *prep_skb(
  	struct vector_private *vp,
  	struct user_msghdr *msg)
  {
  	int linear = vp->max_packet + vp->headroom + SAFETY_MARGIN;
  	struct sk_buff *result;
  	int iov_index = 0, len;
  	struct iovec *iov = msg->msg_iov;
  	int err, nr_frags, frag;
  	skb_frag_t *skb_frag;
  
  	if (vp->req_size <= linear)
  		len = linear;
  	else
  		len = vp->req_size;
  	result = alloc_skb_with_frags(
  		linear,
  		len - vp->max_packet,
  		3,
  		&err,
  		GFP_ATOMIC
  	);
  	if (vp->header_size > 0)
  		iov_index++;
  	if (result == NULL) {
  		iov[iov_index].iov_base = NULL;
  		iov[iov_index].iov_len = 0;
  		goto done;
  	}
  	skb_reserve(result, vp->headroom);
  	result->dev = vp->dev;
  	skb_put(result, vp->max_packet);
  	result->data_len = len - vp->max_packet;
  	result->len += len - vp->max_packet;
  	skb_reset_mac_header(result);
  	result->ip_summed = CHECKSUM_NONE;
  	iov[iov_index].iov_base = result->data;
  	iov[iov_index].iov_len = vp->max_packet;
  	iov_index++;
  
  	nr_frags = skb_shinfo(result)->nr_frags;
  	for (frag = 0; frag < nr_frags; frag++) {
  		skb_frag = &skb_shinfo(result)->frags[frag];
  		iov[iov_index].iov_base = skb_frag_address_safe(skb_frag);
  		if (iov[iov_index].iov_base != NULL)
  			iov[iov_index].iov_len = skb_frag_size(skb_frag);
  		else
  			iov[iov_index].iov_len = 0;
  		iov_index++;
  	}
  done:
  	msg->msg_iovlen = iov_index;
  	return result;
  }
  
  
  /* Prepare queue for recvmmsg one-shot rx - fill with fresh sk_buffs*/
  
  static void prep_queue_for_rx(struct vector_queue *qi)
  {
  	struct vector_private *vp = netdev_priv(qi->dev);
  	struct mmsghdr *mmsg_vector = qi->mmsg_vector;
  	void **skbuff_vector = qi->skbuff_vector;
  	int i;
  
  	if (qi->queue_depth == 0)
  		return;
  	for (i = 0; i < qi->queue_depth; i++) {
  		/* it is OK if allocation fails - recvmmsg with NULL data in
  		 * iov argument still performs an RX, just drops the packet
  		 * This allows us stop faffing around with a "drop buffer"
  		 */
  
  		*skbuff_vector = prep_skb(vp, &mmsg_vector->msg_hdr);
  		skbuff_vector++;
  		mmsg_vector++;
  	}
  	qi->queue_depth = 0;
  }
  
  static struct vector_device *find_device(int n)
  {
  	struct vector_device *device;
  	struct list_head *ele;
  
  	spin_lock(&vector_devices_lock);
  	list_for_each(ele, &vector_devices) {
  		device = list_entry(ele, struct vector_device, list);
  		if (device->unit == n)
  			goto out;
  	}
  	device = NULL;
   out:
  	spin_unlock(&vector_devices_lock);
  	return device;
  }
  
  static int vector_parse(char *str, int *index_out, char **str_out,
  			char **error_out)
  {
  	int n, len, err;
  	char *start = str;
  
  	len = strlen(str);
  
  	while ((*str != ':') && (strlen(str) > 1))
  		str++;
  	if (*str != ':') {
  		*error_out = "Expected ':' after device number";
  		return -EINVAL;
  	}
  	*str = '\0';
  
  	err = kstrtouint(start, 0, &n);
  	if (err < 0) {
  		*error_out = "Bad device number";
  		return err;
  	}
  
  	str++;
  	if (find_device(n)) {
  		*error_out = "Device already configured";
  		return -EINVAL;
  	}
  
  	*index_out = n;
  	*str_out = str;
  	return 0;
  }
  
  static int vector_config(char *str, char **error_out)
  {
  	int err, n;
  	char *params;
  	struct arglist *parsed;
  
  	err = vector_parse(str, &n, &params, error_out);
  	if (err != 0)
  		return err;
  
  	/* This string is broken up and the pieces used by the underlying
  	 * driver. We should copy it to make sure things do not go wrong
  	 * later.
  	 */
  
  	params = kstrdup(params, GFP_KERNEL);
  	if (params == NULL) {
  		*error_out = "vector_config failed to strdup string";
  		return -ENOMEM;
  	}
  
  	parsed = uml_parse_vector_ifspec(params);
  
  	if (parsed == NULL) {
  		*error_out = "vector_config failed to parse parameters";
  		return -EINVAL;
  	}
  
  	vector_eth_configure(n, parsed);
  	return 0;
  }
  
  static int vector_id(char **str, int *start_out, int *end_out)
  {
  	char *end;
  	int n;
  
  	n = simple_strtoul(*str, &end, 0);
  	if ((*end != '\0') || (end == *str))
  		return -1;
  
  	*start_out = n;
  	*end_out = n;
  	*str = end;
  	return n;
  }
  
  static int vector_remove(int n, char **error_out)
  {
  	struct vector_device *vec_d;
  	struct net_device *dev;
  	struct vector_private *vp;
  
  	vec_d = find_device(n);
  	if (vec_d == NULL)
  		return -ENODEV;
  	dev = vec_d->dev;
  	vp = netdev_priv(dev);
  	if (vp->fds != NULL)
  		return -EBUSY;
  	unregister_netdev(dev);
  	platform_device_unregister(&vec_d->pdev);
  	return 0;
  }
  
  /*
   * There is no shared per-transport initialization code, so
   * we will just initialize each interface one by one and
   * add them to a list
   */
  
  static struct platform_driver uml_net_driver = {
  	.driver = {
  		.name = DRIVER_NAME,
  	},
  };
  
  
  static void vector_device_release(struct device *dev)
  {
  	struct vector_device *device = dev_get_drvdata(dev);
  	struct net_device *netdev = device->dev;
  
  	list_del(&device->list);
  	kfree(device);
  	free_netdev(netdev);
  }
  
  /* Bog standard recv using recvmsg - not used normally unless the user
   * explicitly specifies not to use recvmmsg vector RX.
   */
  
  static int vector_legacy_rx(struct vector_private *vp)
  {
  	int pkt_len;
  	struct user_msghdr hdr;
  	struct iovec iov[2 + MAX_IOV_SIZE]; /* header + data use case only */
  	int iovpos = 0;
  	struct sk_buff *skb;
  	int header_check;
  
  	hdr.msg_name = NULL;
  	hdr.msg_namelen = 0;
  	hdr.msg_iov = (struct iovec *) &iov;
  	hdr.msg_control = NULL;
  	hdr.msg_controllen = 0;
  	hdr.msg_flags = 0;
  
  	if (vp->header_size > 0) {
  		iov[0].iov_base = vp->header_rxbuffer;
  		iov[0].iov_len = vp->header_size;
  	}
  
  	skb = prep_skb(vp, &hdr);
  
  	if (skb == NULL) {
  		/* Read a packet into drop_buffer and don't do
  		 * anything with it.
  		 */
  		iov[iovpos].iov_base = drop_buffer;
  		iov[iovpos].iov_len = DROP_BUFFER_SIZE;
  		hdr.msg_iovlen = 1;
  		vp->dev->stats.rx_dropped++;
  	}
  
  	pkt_len = uml_vector_recvmsg(vp->fds->rx_fd, &hdr, 0);
  	if (pkt_len < 0) {
  		vp->in_error = true;
  		return pkt_len;
  	}
  
  	if (skb != NULL) {
  		if (pkt_len > vp->header_size) {
  			if (vp->header_size > 0) {
  				header_check = vp->verify_header(
  					vp->header_rxbuffer, skb, vp);
  				if (header_check < 0) {
  					dev_kfree_skb_irq(skb);
  					vp->dev->stats.rx_dropped++;
  					vp->estats.rx_encaps_errors++;
  					return 0;
  				}
  				if (header_check > 0) {
  					vp->estats.rx_csum_offload_good++;
  					skb->ip_summed = CHECKSUM_UNNECESSARY;
  				}
  			}
  			pskb_trim(skb, pkt_len - vp->rx_header_size);
  			skb->protocol = eth_type_trans(skb, skb->dev);
  			vp->dev->stats.rx_bytes += skb->len;
  			vp->dev->stats.rx_packets++;
  			netif_rx(skb);
  		} else {
  			dev_kfree_skb_irq(skb);
  		}
  	}
  	return pkt_len;
  }
  
  /*
   * Packet at a time TX which falls back to vector TX if the
   * underlying transport is busy.
   */
  
  
  
  static int writev_tx(struct vector_private *vp, struct sk_buff *skb)
  {
  	struct iovec iov[3 + MAX_IOV_SIZE];
  	int iov_count, pkt_len = 0;
  
  	iov[0].iov_base = vp->header_txbuffer;
  	iov_count = prep_msg(vp, skb, (struct iovec *) &iov);
  
  	if (iov_count < 1)
  		goto drop;
  
  	pkt_len = uml_vector_writev(
  		vp->fds->tx_fd,
  		(struct iovec *) &iov,
  		iov_count
  	);
  
  	if (pkt_len < 0)
  		goto drop;
  
  	netif_trans_update(vp->dev);
  	netif_wake_queue(vp->dev);
  
  	if (pkt_len > 0) {
  		vp->dev->stats.tx_bytes += skb->len;
  		vp->dev->stats.tx_packets++;
  	} else {
  		vp->dev->stats.tx_dropped++;
  	}
  	consume_skb(skb);
  	return pkt_len;
  drop:
  	vp->dev->stats.tx_dropped++;
  	consume_skb(skb);
  	if (pkt_len < 0)
  		vp->in_error = true;
  	return pkt_len;
  }
  
  /*
   * Receive as many messages as we can in one call using the special
   * mmsg vector matched to an skb vector which we prepared earlier.
   */
  
  static int vector_mmsg_rx(struct vector_private *vp)
  {
  	int packet_count, i;
  	struct vector_queue *qi = vp->rx_queue;
  	struct sk_buff *skb;
  	struct mmsghdr *mmsg_vector = qi->mmsg_vector;
  	void **skbuff_vector = qi->skbuff_vector;
  	int header_check;
  
  	/* Refresh the vector and make sure it is with new skbs and the
  	 * iovs are updated to point to them.
  	 */
  
  	prep_queue_for_rx(qi);
  
  	/* Fire the Lazy Gun - get as many packets as we can in one go. */
  
  	packet_count = uml_vector_recvmmsg(
  		vp->fds->rx_fd, qi->mmsg_vector, qi->max_depth, 0);
  
  	if (packet_count < 0)
  		vp->in_error = true;
  
  	if (packet_count <= 0)
  		return packet_count;
  
  	/* We treat packet processing as enqueue, buffer refresh as dequeue
  	 * The queue_depth tells us how many buffers have been used and how
  	 * many do we need to prep the next time prep_queue_for_rx() is called.
  	 */
  
  	qi->queue_depth = packet_count;
  
  	for (i = 0; i < packet_count; i++) {
  		skb = (*skbuff_vector);
  		if (mmsg_vector->msg_len > vp->header_size) {
  			if (vp->header_size > 0) {
  				header_check = vp->verify_header(
  					mmsg_vector->msg_hdr.msg_iov->iov_base,
  					skb,
  					vp
  				);
  				if (header_check < 0) {
  				/* Overlay header failed to verify - discard.
  				 * We can actually keep this skb and reuse it,
  				 * but that will make the prep logic too
  				 * complex.
  				 */
  					dev_kfree_skb_irq(skb);
  					vp->estats.rx_encaps_errors++;
  					continue;
  				}
  				if (header_check > 0) {
  					vp->estats.rx_csum_offload_good++;
  					skb->ip_summed = CHECKSUM_UNNECESSARY;
  				}
  			}
  			pskb_trim(skb,
  				mmsg_vector->msg_len - vp->rx_header_size);
  			skb->protocol = eth_type_trans(skb, skb->dev);
  			/*
  			 * We do not need to lock on updating stats here
  			 * The interrupt loop is non-reentrant.
  			 */
  			vp->dev->stats.rx_bytes += skb->len;
  			vp->dev->stats.rx_packets++;
  			netif_rx(skb);
  		} else {
  			/* Overlay header too short to do anything - discard.
  			 * We can actually keep this skb and reuse it,
  			 * but that will make the prep logic too complex.
  			 */
  			if (skb != NULL)
  				dev_kfree_skb_irq(skb);
  		}
  		(*skbuff_vector) = NULL;
  		/* Move to the next buffer element */
  		mmsg_vector++;
  		skbuff_vector++;
  	}
  	if (packet_count > 0) {
  		if (vp->estats.rx_queue_max < packet_count)
  			vp->estats.rx_queue_max = packet_count;
  		vp->estats.rx_queue_running_average =
  			(vp->estats.rx_queue_running_average + packet_count) >> 1;
  	}
  	return packet_count;
  }
  
  static void vector_rx(struct vector_private *vp)
  {
  	int err;
  	int iter = 0;
  
  	if ((vp->options & VECTOR_RX) > 0)
  		while (((err = vector_mmsg_rx(vp)) > 0) && (iter < MAX_ITERATIONS))
  			iter++;
  	else
  		while (((err = vector_legacy_rx(vp)) > 0) && (iter < MAX_ITERATIONS))
  			iter++;
  	if ((err != 0) && net_ratelimit())
  		netdev_err(vp->dev, "vector_rx: error(%d)\n", err);
  	if (iter == MAX_ITERATIONS)
  		netdev_err(vp->dev, "vector_rx: device stuck, remote end may have closed the connection\n");
  }
  
  static int vector_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	struct vector_private *vp = netdev_priv(dev);
  	int queue_depth = 0;
  
  	if (vp->in_error) {
  		deactivate_fd(vp->fds->rx_fd, vp->rx_irq);
  		if ((vp->fds->rx_fd != vp->fds->tx_fd) && (vp->tx_irq != 0))
  			deactivate_fd(vp->fds->tx_fd, vp->tx_irq);
  		return NETDEV_TX_BUSY;
  	}
  
  	if ((vp->options & VECTOR_TX) == 0) {
  		writev_tx(vp, skb);
  		return NETDEV_TX_OK;
  	}
  
  	/* We do BQL only in the vector path, no point doing it in
  	 * packet at a time mode as there is no device queue
  	 */
  
  	netdev_sent_queue(vp->dev, skb->len);
  	queue_depth = vector_enqueue(vp->tx_queue, skb);
  
  	/* if the device queue is full, stop the upper layers and
  	 * flush it.
  	 */
  
  	if (queue_depth >= vp->tx_queue->max_depth - 1) {
  		vp->estats.tx_kicks++;
  		netif_stop_queue(dev);
  		vector_send(vp->tx_queue);
  		return NETDEV_TX_OK;
  	}
  	if (netdev_xmit_more()) {
  		mod_timer(&vp->tl, vp->coalesce);
  		return NETDEV_TX_OK;
  	}
  	if (skb->len < TX_SMALL_PACKET) {
  		vp->estats.tx_kicks++;
  		vector_send(vp->tx_queue);
  	} else
  		tasklet_schedule(&vp->tx_poll);
  	return NETDEV_TX_OK;
  }
  
  static irqreturn_t vector_rx_interrupt(int irq, void *dev_id)
  {
  	struct net_device *dev = dev_id;
  	struct vector_private *vp = netdev_priv(dev);
  
  	if (!netif_running(dev))
  		return IRQ_NONE;
  	vector_rx(vp);
  	return IRQ_HANDLED;
  
  }
  
  static irqreturn_t vector_tx_interrupt(int irq, void *dev_id)
  {
  	struct net_device *dev = dev_id;
  	struct vector_private *vp = netdev_priv(dev);
  
  	if (!netif_running(dev))
  		return IRQ_NONE;
  	/* We need to pay attention to it only if we got
  	 * -EAGAIN or -ENOBUFFS from sendmmsg. Otherwise
  	 * we ignore it. In the future, it may be worth
  	 * it to improve the IRQ controller a bit to make
  	 * tweaking the IRQ mask less costly
  	 */
  
  	if (vp->in_write_poll)
  		tasklet_schedule(&vp->tx_poll);
  	return IRQ_HANDLED;
  
  }
  
  static int irq_rr;
  
  static int vector_net_close(struct net_device *dev)
  {
  	struct vector_private *vp = netdev_priv(dev);
  	unsigned long flags;
  
  	netif_stop_queue(dev);
  	del_timer(&vp->tl);
  
  	if (vp->fds == NULL)
  		return 0;
  
  	/* Disable and free all IRQS */
  	if (vp->rx_irq > 0) {
  		um_free_irq(vp->rx_irq, dev);
  		vp->rx_irq = 0;
  	}
  	if (vp->tx_irq > 0) {
  		um_free_irq(vp->tx_irq, dev);
  		vp->tx_irq = 0;
  	}
  	tasklet_kill(&vp->tx_poll);
  	if (vp->fds->rx_fd > 0) {
  		if (vp->bpf)
  			uml_vector_detach_bpf(vp->fds->rx_fd, vp->bpf);
  		os_close_file(vp->fds->rx_fd);
  		vp->fds->rx_fd = -1;
  	}
  	if (vp->fds->tx_fd > 0) {
  		os_close_file(vp->fds->tx_fd);
  		vp->fds->tx_fd = -1;
  	}
  	if (vp->bpf != NULL)
  		kfree(vp->bpf->filter);
  	kfree(vp->bpf);
  	vp->bpf = NULL;
  	kfree(vp->fds->remote_addr);
  	kfree(vp->transport_data);
  	kfree(vp->header_rxbuffer);
  	kfree(vp->header_txbuffer);
  	if (vp->rx_queue != NULL)
  		destroy_queue(vp->rx_queue);
  	if (vp->tx_queue != NULL)
  		destroy_queue(vp->tx_queue);
  	kfree(vp->fds);
  	vp->fds = NULL;
  	spin_lock_irqsave(&vp->lock, flags);
  	vp->opened = false;
  	vp->in_error = false;
  	spin_unlock_irqrestore(&vp->lock, flags);
  	return 0;
  }
  
  /* TX tasklet */
  
  static void vector_tx_poll(struct tasklet_struct *t)
  {
  	struct vector_private *vp = from_tasklet(vp, t, tx_poll);
  
  	vp->estats.tx_kicks++;
  	vector_send(vp->tx_queue);
  }
  static void vector_reset_tx(struct work_struct *work)
  {
  	struct vector_private *vp =
  		container_of(work, struct vector_private, reset_tx);
  	netdev_reset_queue(vp->dev);
  	netif_start_queue(vp->dev);
  	netif_wake_queue(vp->dev);
  }
  
  static int vector_net_open(struct net_device *dev)
  {
  	struct vector_private *vp = netdev_priv(dev);
  	unsigned long flags;
  	int err = -EINVAL;
  	struct vector_device *vdevice;
  
  	spin_lock_irqsave(&vp->lock, flags);
  	if (vp->opened) {
  		spin_unlock_irqrestore(&vp->lock, flags);
  		return -ENXIO;
  	}
  	vp->opened = true;
  	spin_unlock_irqrestore(&vp->lock, flags);
  
  	vp->bpf = uml_vector_user_bpf(get_bpf_file(vp->parsed));
  
  	vp->fds = uml_vector_user_open(vp->unit, vp->parsed);
  
  	if (vp->fds == NULL)
  		goto out_close;
  
  	if (build_transport_data(vp) < 0)
  		goto out_close;
  
  	if ((vp->options & VECTOR_RX) > 0) {
  		vp->rx_queue = create_queue(
  			vp,
  			get_depth(vp->parsed),
  			vp->rx_header_size,
  			MAX_IOV_SIZE
  		);
  		vp->rx_queue->queue_depth = get_depth(vp->parsed);
  	} else {
  		vp->header_rxbuffer = kmalloc(
  			vp->rx_header_size,
  			GFP_KERNEL
  		);
  		if (vp->header_rxbuffer == NULL)
  			goto out_close;
  	}
  	if ((vp->options & VECTOR_TX) > 0) {
  		vp->tx_queue = create_queue(
  			vp,
  			get_depth(vp->parsed),
  			vp->header_size,
  			MAX_IOV_SIZE
  		);
  	} else {
  		vp->header_txbuffer = kmalloc(vp->header_size, GFP_KERNEL);
  		if (vp->header_txbuffer == NULL)
  			goto out_close;
  	}
  
  	/* READ IRQ */
  	err = um_request_irq(
  		irq_rr + VECTOR_BASE_IRQ, vp->fds->rx_fd,
  			IRQ_READ, vector_rx_interrupt,
  			IRQF_SHARED, dev->name, dev);
  	if (err < 0) {
  		netdev_err(dev, "vector_open: failed to get rx irq(%d)\n", err);
  		err = -ENETUNREACH;
  		goto out_close;
  	}
  	vp->rx_irq = irq_rr + VECTOR_BASE_IRQ;
  	dev->irq = irq_rr + VECTOR_BASE_IRQ;
  	irq_rr = (irq_rr + 1) % VECTOR_IRQ_SPACE;
  
  	/* WRITE IRQ - we need it only if we have vector TX */
  	if ((vp->options & VECTOR_TX) > 0) {
  		err = um_request_irq(
  			irq_rr + VECTOR_BASE_IRQ, vp->fds->tx_fd,
  				IRQ_WRITE, vector_tx_interrupt,
  				IRQF_SHARED, dev->name, dev);
  		if (err < 0) {
  			netdev_err(dev,
  				"vector_open: failed to get tx irq(%d)\n", err);
  			err = -ENETUNREACH;
  			goto out_close;
  		}
  		vp->tx_irq = irq_rr + VECTOR_BASE_IRQ;
  		irq_rr = (irq_rr + 1) % VECTOR_IRQ_SPACE;
  	}
  
  	if ((vp->options & VECTOR_QDISC_BYPASS) != 0) {
  		if (!uml_raw_enable_qdisc_bypass(vp->fds->rx_fd))
  			vp->options |= VECTOR_BPF;
  	}
  	if (((vp->options & VECTOR_BPF) != 0) && (vp->bpf == NULL))
  		vp->bpf = uml_vector_default_bpf(dev->dev_addr);
  
  	if (vp->bpf != NULL)
  		uml_vector_attach_bpf(vp->fds->rx_fd, vp->bpf);
  
  	netif_start_queue(dev);
  
  	/* clear buffer - it can happen that the host side of the interface
  	 * is full when we get here. In this case, new data is never queued,
  	 * SIGIOs never arrive, and the net never works.
  	 */
  
  	vector_rx(vp);
  
  	vector_reset_stats(vp);
  	vdevice = find_device(vp->unit);
  	vdevice->opened = 1;
  
  	if ((vp->options & VECTOR_TX) != 0)
  		add_timer(&vp->tl);
  	return 0;
  out_close:
  	vector_net_close(dev);
  	return err;
  }
  
  
  static void vector_net_set_multicast_list(struct net_device *dev)
  {
  	/* TODO: - we can do some BPF games here */
  	return;
  }
  
  static void vector_net_tx_timeout(struct net_device *dev, unsigned int txqueue)
  {
  	struct vector_private *vp = netdev_priv(dev);
  
  	vp->estats.tx_timeout_count++;
  	netif_trans_update(dev);
  	schedule_work(&vp->reset_tx);
  }
  
  static netdev_features_t vector_fix_features(struct net_device *dev,
  	netdev_features_t features)
  {
  	features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
  	return features;
  }
  
  static int vector_set_features(struct net_device *dev,
  	netdev_features_t features)
  {
  	struct vector_private *vp = netdev_priv(dev);
  	/* Adjust buffer sizes for GSO/GRO. Unfortunately, there is
  	 * no way to negotiate it on raw sockets, so we can change
  	 * only our side.
  	 */
  	if (features & NETIF_F_GRO)
  		/* All new frame buffers will be GRO-sized */
  		vp->req_size = 65536;
  	else
  		/* All new frame buffers will be normal sized */
  		vp->req_size = vp->max_packet + vp->headroom + SAFETY_MARGIN;
  	return 0;
  }
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
  static void vector_net_poll_controller(struct net_device *dev)
  {
  	disable_irq(dev->irq);
  	vector_rx_interrupt(dev->irq, dev);
  	enable_irq(dev->irq);
  }
  #endif
  
  static void vector_net_get_drvinfo(struct net_device *dev,
  				struct ethtool_drvinfo *info)
  {
  	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
  }
  
  static int vector_net_load_bpf_flash(struct net_device *dev,
  				struct ethtool_flash *efl)
  {
  	struct vector_private *vp = netdev_priv(dev);
  	struct vector_device *vdevice;
  	const struct firmware *fw;
  	int result = 0;
  
  	if (!(vp->options & VECTOR_BPF_FLASH)) {
  		netdev_err(dev, "loading firmware not permitted: %s\n", efl->data);
  		return -1;
  	}
  
  	spin_lock(&vp->lock);
  
  	if (vp->bpf != NULL) {
  		if (vp->opened)
  			uml_vector_detach_bpf(vp->fds->rx_fd, vp->bpf);
  		kfree(vp->bpf->filter);
  		vp->bpf->filter = NULL;
  	} else {
  		vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_ATOMIC);
  		if (vp->bpf == NULL) {
  			netdev_err(dev, "failed to allocate memory for firmware\n");
  			goto flash_fail;
  		}
  	}
  
  	vdevice = find_device(vp->unit);
  
  	if (request_firmware(&fw, efl->data, &vdevice->pdev.dev))
  		goto flash_fail;
  
  	vp->bpf->filter = kmemdup(fw->data, fw->size, GFP_ATOMIC);
  	if (!vp->bpf->filter)
  		goto free_buffer;
  
  	vp->bpf->len = fw->size / sizeof(struct sock_filter);
  	release_firmware(fw);
  
  	if (vp->opened)
  		result = uml_vector_attach_bpf(vp->fds->rx_fd, vp->bpf);
  
  	spin_unlock(&vp->lock);
  
  	return result;
  
  free_buffer:
  	release_firmware(fw);
  
  flash_fail:
  	spin_unlock(&vp->lock);
  	if (vp->bpf != NULL)
  		kfree(vp->bpf->filter);
  	kfree(vp->bpf);
  	vp->bpf = NULL;
  	return -1;
  }
  
  static void vector_get_ringparam(struct net_device *netdev,
  				struct ethtool_ringparam *ring)
  {
  	struct vector_private *vp = netdev_priv(netdev);
  
  	ring->rx_max_pending = vp->rx_queue->max_depth;
  	ring->tx_max_pending = vp->tx_queue->max_depth;
  	ring->rx_pending = vp->rx_queue->max_depth;
  	ring->tx_pending = vp->tx_queue->max_depth;
  }
  
  static void vector_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
  {
  	switch (stringset) {
  	case ETH_SS_TEST:
  		*buf = '\0';
  		break;
  	case ETH_SS_STATS:
  		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
  		break;
  	default:
  		WARN_ON(1);
  		break;
  	}
  }
  
  static int vector_get_sset_count(struct net_device *dev, int sset)
  {
  	switch (sset) {
  	case ETH_SS_TEST:
  		return 0;
  	case ETH_SS_STATS:
  		return VECTOR_NUM_STATS;
  	default:
  		return -EOPNOTSUPP;
  	}
  }
  
  static void vector_get_ethtool_stats(struct net_device *dev,
  	struct ethtool_stats *estats,
  	u64 *tmp_stats)
  {
  	struct vector_private *vp = netdev_priv(dev);
  
  	memcpy(tmp_stats, &vp->estats, sizeof(struct vector_estats));
  }
  
  static int vector_get_coalesce(struct net_device *netdev,
  			       struct ethtool_coalesce *ec,
  			       struct kernel_ethtool_coalesce *kernel_coal,
  			       struct netlink_ext_ack *extack)
  {
  	struct vector_private *vp = netdev_priv(netdev);
  
  	ec->tx_coalesce_usecs = (vp->coalesce * 1000000) / HZ;
  	return 0;
  }
  
  static int vector_set_coalesce(struct net_device *netdev,
  			       struct ethtool_coalesce *ec,
  			       struct kernel_ethtool_coalesce *kernel_coal,
  			       struct netlink_ext_ack *extack)
  {
  	struct vector_private *vp = netdev_priv(netdev);
  
  	vp->coalesce = (ec->tx_coalesce_usecs * HZ) / 1000000;
  	if (vp->coalesce == 0)
  		vp->coalesce = 1;
  	return 0;
  }
  
  static const struct ethtool_ops vector_net_ethtool_ops = {
  	.supported_coalesce_params = ETHTOOL_COALESCE_TX_USECS,
  	.get_drvinfo	= vector_net_get_drvinfo,
  	.get_link	= ethtool_op_get_link,
  	.get_ts_info	= ethtool_op_get_ts_info,
  	.get_ringparam	= vector_get_ringparam,
  	.get_strings	= vector_get_strings,
  	.get_sset_count	= vector_get_sset_count,
  	.get_ethtool_stats = vector_get_ethtool_stats,
  	.get_coalesce	= vector_get_coalesce,
  	.set_coalesce	= vector_set_coalesce,
  	.flash_device	= vector_net_load_bpf_flash,
  };
  
  
  static const struct net_device_ops vector_netdev_ops = {
  	.ndo_open		= vector_net_open,
  	.ndo_stop		= vector_net_close,
  	.ndo_start_xmit		= vector_net_start_xmit,
  	.ndo_set_rx_mode	= vector_net_set_multicast_list,
  	.ndo_tx_timeout		= vector_net_tx_timeout,
  	.ndo_set_mac_address	= eth_mac_addr,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_fix_features	= vector_fix_features,
  	.ndo_set_features	= vector_set_features,
  #ifdef CONFIG_NET_POLL_CONTROLLER
  	.ndo_poll_controller = vector_net_poll_controller,
  #endif
  };
  
  
  static void vector_timer_expire(struct timer_list *t)
  {
  	struct vector_private *vp = from_timer(vp, t, tl);
  
  	vp->estats.tx_kicks++;
  	vector_send(vp->tx_queue);
  }
  
  static void vector_eth_configure(
  		int n,
  		struct arglist *def
  	)
  {
  	struct vector_device *device;
  	struct net_device *dev;
  	struct vector_private *vp;
  	int err;
  
  	device = kzalloc(sizeof(*device), GFP_KERNEL);
  	if (device == NULL) {
  		printk(KERN_ERR "eth_configure failed to allocate struct "
  				 "vector_device\n");
  		return;
  	}
  	dev = alloc_etherdev(sizeof(struct vector_private));
  	if (dev == NULL) {
  		printk(KERN_ERR "eth_configure: failed to allocate struct "
  				 "net_device for vec%d\n", n);
  		goto out_free_device;
  	}
  
  	dev->mtu = get_mtu(def);
  
  	INIT_LIST_HEAD(&device->list);
  	device->unit = n;
  
  	/* If this name ends up conflicting with an existing registered
  	 * netdevice, that is OK, register_netdev{,ice}() will notice this
  	 * and fail.
  	 */
  	snprintf(dev->name, sizeof(dev->name), "vec%d", n);
  	uml_net_setup_etheraddr(dev, uml_vector_fetch_arg(def, "mac"));
  	vp = netdev_priv(dev);
  
  	/* sysfs register */
  	if (!driver_registered) {
  		platform_driver_register(&uml_net_driver);
  		driver_registered = 1;
  	}
  	device->pdev.id = n;
  	device->pdev.name = DRIVER_NAME;
  	device->pdev.dev.release = vector_device_release;
  	dev_set_drvdata(&device->pdev.dev, device);
  	if (platform_device_register(&device->pdev))
  		goto out_free_netdev;
  	SET_NETDEV_DEV(dev, &device->pdev.dev);
  
  	device->dev = dev;
  
  	*vp = ((struct vector_private)
  		{
  		.list			= LIST_HEAD_INIT(vp->list),
  		.dev			= dev,
  		.unit			= n,
  		.options		= get_transport_options(def),
  		.rx_irq			= 0,
  		.tx_irq			= 0,
  		.parsed			= def,
  		.max_packet		= get_mtu(def) + ETH_HEADER_OTHER,
  		/* TODO - we need to calculate headroom so that ip header
  		 * is 16 byte aligned all the time
  		 */
  		.headroom		= get_headroom(def),
  		.form_header		= NULL,
  		.verify_header		= NULL,
  		.header_rxbuffer	= NULL,
  		.header_txbuffer	= NULL,
  		.header_size		= 0,
  		.rx_header_size		= 0,
  		.rexmit_scheduled	= false,
  		.opened			= false,
  		.transport_data		= NULL,
  		.in_write_poll		= false,
  		.coalesce		= 2,
  		.req_size		= get_req_size(def),
  		.in_error		= false,
  		.bpf			= NULL
  	});
  
  	dev->features = dev->hw_features = (NETIF_F_SG | NETIF_F_FRAGLIST);
  	tasklet_setup(&vp->tx_poll, vector_tx_poll);
  	INIT_WORK(&vp->reset_tx, vector_reset_tx);
  
  	timer_setup(&vp->tl, vector_timer_expire, 0);
  	spin_lock_init(&vp->lock);
  
  	/* FIXME */
  	dev->netdev_ops = &vector_netdev_ops;
  	dev->ethtool_ops = &vector_net_ethtool_ops;
  	dev->watchdog_timeo = (HZ >> 1);
  	/* primary IRQ - fixme */
  	dev->irq = 0; /* we will adjust this once opened */
  
  	rtnl_lock();
  	err = register_netdevice(dev);
  	rtnl_unlock();
  	if (err)
  		goto out_undo_user_init;
  
  	spin_lock(&vector_devices_lock);
  	list_add(&device->list, &vector_devices);
  	spin_unlock(&vector_devices_lock);
  
  	return;
  
  out_undo_user_init:
  	return;
  out_free_netdev:
  	free_netdev(dev);
  out_free_device:
  	kfree(device);
  }
  
  
  
  
  /*
   * Invoked late in the init
   */
  
  static int __init vector_init(void)
  {
  	struct list_head *ele;
  	struct vector_cmd_line_arg *def;
  	struct arglist *parsed;
  
  	list_for_each(ele, &vec_cmd_line) {
  		def = list_entry(ele, struct vector_cmd_line_arg, list);
  		parsed = uml_parse_vector_ifspec(def->arguments);
  		if (parsed != NULL)
  			vector_eth_configure(def->unit, parsed);
  	}
  	return 0;
  }
  
  
  /* Invoked at initial argument parsing, only stores
   * arguments until a proper vector_init is called
   * later
   */
  
  static int __init vector_setup(char *str)
  {
  	char *error;
  	int n, err;
  	struct vector_cmd_line_arg *new;
  
  	err = vector_parse(str, &n, &str, &error);
  	if (err) {
  		printk(KERN_ERR "vector_setup - Couldn't parse '%s' : %s\n",
  				 str, error);
  		return 1;
  	}
  	new = memblock_alloc(sizeof(*new), SMP_CACHE_BYTES);
  	if (!new)
  		panic("%s: Failed to allocate %zu bytes\n", __func__,
  		      sizeof(*new));
  	INIT_LIST_HEAD(&new->list);
  	new->unit = n;
  	new->arguments = str;
  	list_add_tail(&new->list, &vec_cmd_line);
  	return 1;
  }
  
  __setup("vec", vector_setup);
  __uml_help(vector_setup,
  "vec[0-9]+:<option>=<value>,<option>=<value>\n"
  "	 Configure a vector io network device.\n\n"
  );
  
  late_initcall(vector_init);
  
  static struct mc_device vector_mc = {
  	.list		= LIST_HEAD_INIT(vector_mc.list),
  	.name		= "vec",
  	.config		= vector_config,
  	.get_config	= NULL,
  	.id		= vector_id,
  	.remove		= vector_remove,
  };
  
  #ifdef CONFIG_INET
  static int vector_inetaddr_event(
  	struct notifier_block *this,
  	unsigned long event,
  	void *ptr)
  {
  	return NOTIFY_DONE;
  }
  
  static struct notifier_block vector_inetaddr_notifier = {
  	.notifier_call		= vector_inetaddr_event,
  };
  
  static void inet_register(void)
  {
  	register_inetaddr_notifier(&vector_inetaddr_notifier);
  }
  #else
  static inline void inet_register(void)
  {
  }
  #endif
  
  static int vector_net_init(void)
  {
  	mconsole_register_dev(&vector_mc);
  	inet_register();
  	return 0;
  }
  
  __initcall(vector_net_init);
  
  
  
  