linux/net/x25/x25_subr.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	X.25 Packet Layer release 002
 *
 *	This is ALPHA test software. This code may break your machine,
 *	randomly fail to work with new releases, misbehave and/or generally
 *	screw up. It might even work.
 *
 *	This code REQUIRES 2.1.15 or higher
 *
 *	History
 *	X.25 001	Jonathan Naylor	  Started coding.
 *	X.25 002	Jonathan Naylor	  Centralised disconnection processing.
 *	mar/20/00	Daniela Squassoni Disabling/enabling of facilities
 *					  negotiation.
 *	jun/24/01	Arnaldo C. Melo	  use skb_queue_purge, cleanups
 *	apr/04/15	Shaun Pereira		Fast select with no
 *						restriction on response.
 */

#define pr_fmt(fmt) …

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/x25.h>

/*
 *	This routine purges all of the queues of frames.
 */
void x25_clear_queues(struct sock *sk)
{ … }


/*
 * This routine purges the input queue of those frames that have been
 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
 * SDL diagram.
*/
void x25_frames_acked(struct sock *sk, unsigned short nr)
{ … }

void x25_requeue_frames(struct sock *sk)
{ … }

/*
 *	Validate that the value of nr is between va and vs. Return true or
 *	false for testing.
 */
int x25_validate_nr(struct sock *sk, unsigned short nr)
{ … }

/*
 *  This routine is called when the packet layer internally generates a
 *  control frame.
 */
void x25_write_internal(struct sock *sk, int frametype)
{ … }

/*
 *	Unpick the contents of the passed X.25 Packet Layer frame.
 */
int x25_decode(struct sock *sk, struct sk_buff *skb, int *ns, int *nr, int *q,
	       int *d, int *m)
{ … }

void x25_disconnect(struct sock *sk, int reason, unsigned char cause,
		    unsigned char diagnostic)
{ … }

/*
 * Clear an own-rx-busy condition and tell the peer about this, provided
 * that there is a significant amount of free receive buffer space available.
 */
void x25_check_rbuf(struct sock *sk)
{ … }