/*
 *  net/dccp/qpolicy.c
 *
 *  Policy-based packet dequeueing interface for DCCP.
 *
 *  Copyright (c) 2008 Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License v2
 *  as published by the Free Software Foundation.
 */
#include "dccp.h"

/*
 *	Simple Dequeueing Policy:
 *	If tx_qlen is different from 0, enqueue up to tx_qlen elements.
 */
static void qpolicy_simple_push(struct sock *sk, struct sk_buff *skb)
{
	skb_queue_tail(&sk->sk_write_queue, skb);
}

static bool qpolicy_simple_full(struct sock *sk)
{
	return dccp_sk(sk)->dccps_tx_qlen &&
	       sk->sk_write_queue.qlen >= dccp_sk(sk)->dccps_tx_qlen;
}

static struct sk_buff *qpolicy_simple_top(struct sock *sk)
{
	return skb_peek(&sk->sk_write_queue);
}

/*
 *	Priority-based Dequeueing Policy:
 *	If tx_qlen is different from 0 and the queue has reached its upper bound
 *	of tx_qlen elements, replace older packets lowest-priority-first.
 */
static struct sk_buff *qpolicy_prio_best_skb(struct sock *sk)
{
	struct sk_buff *skb, *best = NULL;

	skb_queue_walk(&sk->sk_write_queue, skb)
		if (best == NULL || skb->priority > best->priority)
			best = skb;
	return best;
}

static struct sk_buff *qpolicy_prio_worst_skb(struct sock *sk)
{
	struct sk_buff *skb, *worst = NULL;

	skb_queue_walk(&sk->sk_write_queue, skb)
		if (worst == NULL || skb->priority < worst->priority)
			worst = skb;
	return worst;
}

static bool qpolicy_prio_full(struct sock *sk)
{
	if (qpolicy_simple_full(sk))
		dccp_qpolicy_drop(sk, qpolicy_prio_worst_skb(sk));
	return false;
}

/**
 * struct dccp_qpolicy_operations  -  TX Packet Dequeueing Interface
 * @push: add a new @skb to the write queue
 * @full: indicates that no more packets will be admitted
 * @top:  peeks at whatever the queueing policy defines as its `top'
 */
static struct dccp_qpolicy_operations {
	void		(*push)	(struct sock *sk, struct sk_buff *skb);
	bool		(*full) (struct sock *sk);
	struct sk_buff*	(*top)  (struct sock *sk);
	__be32		params;

} qpol_table[DCCPQ_POLICY_MAX] = {
	[DCCPQ_POLICY_SIMPLE] = {
		.push   = qpolicy_simple_push,
		.full   = qpolicy_simple_full,
		.top    = qpolicy_simple_top,
		.params = 0,
	},
	[DCCPQ_POLICY_PRIO] = {
		.push   = qpolicy_simple_push,
		.full   = qpolicy_prio_full,
		.top    = qpolicy_prio_best_skb,
		.params = DCCP_SCM_PRIORITY,
	},
};

/*
 *	Externally visible interface
 */
void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb)
{
	qpol_table[dccp_sk(sk)->dccps_qpolicy].push(sk, skb);
}

bool dccp_qpolicy_full(struct sock *sk)
{
	return qpol_table[dccp_sk(sk)->dccps_qpolicy].full(sk);
}

void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb)
{
	if (skb != NULL) {
		skb_unlink(skb, &sk->sk_write_queue);
		kfree_skb(skb);
	}
}

struct sk_buff *dccp_qpolicy_top(struct sock *sk)
{
	return qpol_table[dccp_sk(sk)->dccps_qpolicy].top(sk);
}

struct sk_buff *dccp_qpolicy_pop(struct sock *sk)
{
	struct sk_buff *skb = dccp_qpolicy_top(sk);

	if (skb != NULL) {
		/* Clear any skb fields that we used internally */
		skb->priority = 0;
		skb_unlink(skb, &sk->sk_write_queue);
	}
	return skb;
}

bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param)
{
	/* check if exactly one bit is set */
	if (!param || (param & (param - 1)))
		return false;
	return (qpol_table[dccp_sk(sk)->dccps_qpolicy].params & param) == param;
}
ion value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-30 15:47:19 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-30 15:47:19 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/oss/sb_card.c?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/oss/sb_card.c?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>4078d3ae27d4ebb85bdcd4d84e9b9a4d059f22bb</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/oss/sb_card.c?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>sound/oss/sb_card.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/oss/sb_card.c?id=751321b3dd5040dc5be19bd23f985e80c914621a'>751321b3dd5040dc5be19bd23f985e80c914621a</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/oss/sb_card.c?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b&amp;id2=751321b3dd5040dc5be19bd23f985e80c914621a'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/oss/sb_card.c?id=54791b276b4000b307339f269d3bf7db877d536f'>54791b276b4000b307339f269d3bf7db877d536f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/oss/sb_card.c?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b&amp;id2=54791b276b4000b307339f269d3bf7db877d536f'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc</div><div class='commit-msg'>Pull sparc fixes from David Miller:
 "Several small bug fixes and tidies, along with a fix for non-resumable
  memory errors triggered by userspace"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Handle PIO &amp; MEM non-resumable errors.
  sparc64: Zero pages on allocation for mondo and error queues.
  sparc: Fixed typo in sstate.c. Replaced panicing with panicking
  sparc: use symbolic names for tsb indexing
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>Diffstat</a> (limited to 'sound/oss/sb_card.c')</div><table summary='diffstat' class='diffstat'>