/*
   * net/core/gen_stats.c
   *
   *             This program is free software; you can redistribute it and/or
   *             modify it under the terms of the GNU General Public License
   *             as published by the Free Software Foundation; either version
   *             2 of the License, or (at your option) any later version.
   *
   * Authors:  Thomas Graf <tgraf@suug.ch>
   *           Jamal Hadi Salim
   *           Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   *
   * See Documentation/networking/gen_stats.txt
   */
  
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/socket.h>
  #include <linux/rtnetlink.h>
  #include <linux/gen_stats.h>

  #include <net/netlink.h>

  #include <net/gen_stats.h>
  
  
  static inline int
  gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size)
  {

  	NLA_PUT(d->skb, type, size, buf);

  	return 0;

  nla_put_failure:

  	spin_unlock_bh(d->lock);
  	return -1;
  }
  
  /**
   * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
   * @skb: socket buffer to put statistics TLVs into
   * @type: TLV type for top level statistic TLV
   * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
   * @xstats_type: TLV type for backward compatibility xstats TLV
   * @lock: statistics lock
   * @d: dumping handle
   *
   * Initializes the dumping handle, grabs the statistic lock and appends
   * an empty TLV header to the socket buffer for use a container for all
   * other statistic TLVS.
   *
   * The dumping handle is marked to be in backward compatibility mode telling
   * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
   *
   * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
   */
  int
  gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
  	int xstats_type, spinlock_t *lock, struct gnet_dump *d)

  	__acquires(lock)

  {
  	memset(d, 0, sizeof(*d));

  	spin_lock_bh(lock);
  	d->lock = lock;
  	if (type)

  		d->tail = (struct nlattr *)skb_tail_pointer(skb);

  	d->skb = skb;
  	d->compat_tc_stats = tc_stats_type;
  	d->compat_xstats = xstats_type;
  
  	if (d->tail)
  		return gnet_stats_copy(d, type, NULL, 0);
  
  	return 0;
  }

  EXPORT_SYMBOL(gnet_stats_start_copy_compat);

  
  /**
   * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
   * @skb: socket buffer to put statistics TLVs into
   * @type: TLV type for top level statistic TLV
   * @lock: statistics lock
   * @d: dumping handle
   *
   * Initializes the dumping handle, grabs the statistic lock and appends
   * an empty TLV header to the socket buffer for use a container for all
   * other statistic TLVS.
   *
   * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
   */
  int
  gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
  	struct gnet_dump *d)
  {
  	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
  }

  EXPORT_SYMBOL(gnet_stats_start_copy);

  
  /**
   * gnet_stats_copy_basic - copy basic statistics into statistic TLV
   * @d: dumping handle
   * @b: basic statistics
   *
   * Appends the basic statistics to the top level TLV created by
   * gnet_stats_start_copy().
   *
   * Returns 0 on success or -1 with the statistic lock released
   * if the room in the socket buffer was not sufficient.
   */
  int

  gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)

  {
  	if (d->compat_tc_stats) {
  		d->tc_stats.bytes = b->bytes;
  		d->tc_stats.packets = b->packets;
  	}

  	if (d->tail) {
  		struct gnet_stats_basic sb;

  		memset(&sb, 0, sizeof(sb));
  		sb.bytes = b->bytes;
  		sb.packets = b->packets;
  		return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
  	}

  	return 0;
  }

  EXPORT_SYMBOL(gnet_stats_copy_basic);

  
  /**
   * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
   * @d: dumping handle

   * @b: basic statistics

   * @r: rate estimator statistics
   *
   * Appends the rate estimator statistics to the top level TLV created by
   * gnet_stats_start_copy().
   *
   * Returns 0 on success or -1 with the statistic lock released
   * if the room in the socket buffer was not sufficient.
   */
  int

  gnet_stats_copy_rate_est(struct gnet_dump *d,
  			 const struct gnet_stats_basic_packed *b,
  			 struct gnet_stats_rate_est *r)

  {

  	if (b && !gen_estimator_active(b, r))
  		return 0;

  	if (d->compat_tc_stats) {
  		d->tc_stats.bps = r->bps;
  		d->tc_stats.pps = r->pps;
  	}
  
  	if (d->tail)
  		return gnet_stats_copy(d, TCA_STATS_RATE_EST, r, sizeof(*r));
  
  	return 0;
  }

  EXPORT_SYMBOL(gnet_stats_copy_rate_est);

  
  /**
   * gnet_stats_copy_queue - copy queue statistics into statistics TLV
   * @d: dumping handle
   * @q: queue statistics
   *
   * Appends the queue statistics to the top level TLV created by
   * gnet_stats_start_copy().
   *
   * Returns 0 on success or -1 with the statistic lock released
   * if the room in the socket buffer was not sufficient.
   */
  int
  gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q)
  {
  	if (d->compat_tc_stats) {
  		d->tc_stats.drops = q->drops;
  		d->tc_stats.qlen = q->qlen;
  		d->tc_stats.backlog = q->backlog;
  		d->tc_stats.overlimits = q->overlimits;
  	}
  
  	if (d->tail)
  		return gnet_stats_copy(d, TCA_STATS_QUEUE, q, sizeof(*q));
  
  	return 0;
  }

  EXPORT_SYMBOL(gnet_stats_copy_queue);

  
  /**
   * gnet_stats_copy_app - copy application specific statistics into statistics TLV
   * @d: dumping handle
   * @st: application specific statistics data
   * @len: length of data
   *
   * Appends the application sepecific statistics to the top level TLV created by
   * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
   * handle is in backward compatibility mode.
   *
   * Returns 0 on success or -1 with the statistic lock released
   * if the room in the socket buffer was not sufficient.
   */
  int
  gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
  {
  	if (d->compat_xstats) {
  		d->xstats = st;
  		d->xstats_len = len;
  	}
  
  	if (d->tail)
  		return gnet_stats_copy(d, TCA_STATS_APP, st, len);
  
  	return 0;
  }

  EXPORT_SYMBOL(gnet_stats_copy_app);

  
  /**
   * gnet_stats_finish_copy - finish dumping procedure
   * @d: dumping handle
   *
   * Corrects the length of the top level TLV to include all TLVs added
   * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
   * if gnet_stats_start_copy_compat() was used and releases the statistics
   * lock.
   *
   * Returns 0 on success or -1 with the statistic lock released
   * if the room in the socket buffer was not sufficient.
   */
  int
  gnet_stats_finish_copy(struct gnet_dump *d)
  {
  	if (d->tail)

  		d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;

  
  	if (d->compat_tc_stats)
  		if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
  			sizeof(d->tc_stats)) < 0)
  			return -1;
  
  	if (d->compat_xstats && d->xstats) {
  		if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
  			d->xstats_len) < 0)
  			return -1;
  	}
  
  	spin_unlock_bh(d->lock);
  	return 0;
  }

  EXPORT_SYMBOL(gnet_stats_finish_copy);