/*
 *	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
 *
 *	This module:
 *		This module 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.
 *
 *	History
 *	X.25 001	Jonathan Naylor	Started coding.
 *	X.25 002	Jonathan Naylor	New timer architecture.
 *					Centralised disconnection processing.
 */

#include <linux/errno.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/x25.h>

static void x25_heartbeat_expiry(unsigned long);
static void x25_timer_expiry(unsigned long);

void x25_init_timers(struct sock *sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	setup_timer(&x25->timer, x25_timer_expiry, (unsigned long)sk);

	/* initialized by sock_init_data */
	sk->sk_timer.data     = (unsigned long)sk;
	sk->sk_timer.function = &x25_heartbeat_expiry;
}

void x25_start_heartbeat(struct sock *sk)
{
	mod_timer(&sk->sk_timer, jiffies + 5 * HZ);
}

void x25_stop_heartbeat(struct sock *sk)
{
	del_timer(&sk->sk_timer);
}

void x25_start_t2timer(struct sock *sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	mod_timer(&x25->timer, jiffies + x25->t2);
}

void x25_start_t21timer(struct sock *sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	mod_timer(&x25->timer, jiffies + x25->t21);
}

void x25_start_t22timer(struct sock *sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	mod_timer(&x25->timer, jiffies + x25->t22);
}

void x25_start_t23timer(struct sock *sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	mod_timer(&x25->timer, jiffies + x25->t23);
}

void x25_stop_timer(struct sock *sk)
{
	del_timer(&x25_sk(sk)->timer);
}

unsigned long x25_display_timer(struct sock *sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	if (!timer_pending(&x25->timer))
		return 0;

	return x25->timer.expires - jiffies;
}

static void x25_heartbeat_expiry(unsigned long param)
{
	struct sock *sk = (struct sock *)param;

	bh_lock_sock(sk);
	if (sock_owned_by_user(sk)) /* can currently only occur in state 3 */
		goto restart_heartbeat;

	switch (x25_sk(sk)->state) {

		case X25_STATE_0:
			/*
			 * Magic here: If we listen() and a new link dies
			 * before it is accepted() it isn't 'dead' so doesn't
			 * get removed.
			 */
			if (sock_flag(sk, SOCK_DESTROY) ||
			    (sk->sk_state == TCP_LISTEN &&
			     sock_flag(sk, SOCK_DEAD))) {
				bh_unlock_sock(sk);
				x25_destroy_socket_from_timer(sk);
				return;
			}
			break;

		case X25_STATE_3:
			/*
			 * Check for the state of the receive buffer.
			 */
			x25_check_rbuf(sk);
			break;
	}
restart_heartbeat:
	x25_start_heartbeat(sk);
	bh_unlock_sock(sk);
}

/*
 *	Timer has expired, it may have been T2, T21, T22, or T23. We can tell
 *	by the state machine state.
 */
static inline void x25_do_timer_expiry(struct sock * sk)
{
	struct x25_sock *x25 = x25_sk(sk);

	switch (x25->state) {

		case X25_STATE_3:	/* T2 */
			if (x25->condition & X25_COND_ACK_PENDING) {
				x25->condition &= ~X25_COND_ACK_PENDING;
				x25_enquiry_response(sk);
			}
			break;

		case X25_STATE_1:	/* T21 */
		case X25_STATE_4:	/* T22 */
			x25_write_internal(sk, X25_CLEAR_REQUEST);
			x25->state = X25_STATE_2;
			x25_start_t23timer(sk);
			break;

		case X25_STATE_2:	/* T23 */
			x25_disconnect(sk, ETIMEDOUT, 0, 0);
			break;
	}
}

static void x25_timer_expiry(unsigned long param)
{
	struct sock *sk = (struct sock *)param;

	bh_lock_sock(sk);
	if (sock_owned_by_user(sk)) { /* can currently only occur in state 3 */
		if (x25_sk(sk)->state == X25_STATE_3)
			x25_start_t2timer(sk);
	} else
		x25_do_timer_expiry(sk);
	bh_unlock_sock(sk);
}
</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>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-02-09 16:57:39 -0500</td></tr>
<tr><th>committer</th><td>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-02-09 16:57:39 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>2cbf5b4212b1595449548f189a8fb2df0b25a03f</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/sctp?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>cda37b0df90dff6a18070f3330da80183f6456e5</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/sctp?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>net/sctp</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp?id=caa2858cd51c54fabd48c486b1b150ead539b872'>caa2858cd51c54fabd48c486b1b150ead539b872</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/sctp?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f&amp;id2=caa2858cd51c54fabd48c486b1b150ead539b872'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp?id=242bd2d519d7194633e309286ba7ba29a1ad63e8'>242bd2d519d7194633e309286ba7ba29a1ad63e8</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/sctp?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f&amp;id2=242bd2d519d7194633e309286ba7ba29a1ad63e8'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'sctp-sender-stream-reconf-reset-add-streams'</div><div class='commit-msg'>Xin Long says:

====================
sctp: add sender-side procedures for stream reconf asoc reset and add streams

Patch 4/6 is to implement sender-side procedures for the SSN/TSN Reset
Request Parameter described in rfc6525 section 5.1.4, patch 3/6 is
ahead of it to define a function to make the request chunk for it.

Patch 6/6 is to implement sender-side procedures for the Add Incoming
and Outgoing Streams Request Parameter Request Parameter described in
rfc6525 section 5.1.5 and 5.1.6, patch 5/6 is ahead of it to define a
function to make the request chunk for it.

Patch 2/6 is a fix to recover streams states when it fails to send
request and Patch 1/6 is to drop some unncessary __packed from some
old structures.

v1-&gt;v2:
  - put these into a smaller group.
  - rename some temporary variables in the codes.
  - rename the titles of the commits and improve some changelogs.
v2-&gt;v3:
  - re-split the patchset and make sure it has no dead codes for review.
  - move some codes into stream.c from socket.c.
v3-&gt;v4:
  - add one more patch to fix a send reset stream request issue.
  - doing actual work only when request is sent successfully.
  - reduce some indents in sctp_send_add_streams.
v4-&gt;v5:
  - close streams before sending request and recover them when sending
    fails in patch 1/5 and patch 3/5
v5-&gt;v6:
  - add patch 1/6 to drop some unncessary __packed from some old structures.
  - remove __packed from some new structures in patch 3/6 and 5/6.
  - define unsigned int outcnt and incnt to make codes smaller in patch 6/6.
  - use krealloc instead of kcalloc and remove ksize check in patch 6/6, as
    ksize check is acutally used in krealloc already.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>Diffstat</a> (limited to 'net/sctp')</div><table summary='diffstat' class='diffstat'><tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/cgit.cgi/linux/net-next.git/diff/net/sctp/sm_make_chunk.c?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>net/sctp/sm_make_chunk.c</a></td><td class='right'>75</td><td class='graph'><table summary='file diffstat' width='100%'><tr><td class='add' style='width: 56.0%;'/><td class='rem' style='width: 0.0%;'/><td class='none' style='width: 44.0%;'/></tr></table></td></tr>
<tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/cgit.cgi/linux/net-next.git/diff/net/sctp/socket.c?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>net/sctp/socket.c</a></td><td class='right'>58</td><td class='graph'><table summary='file diffstat' width='100%'><tr><td class='add' style='width: 43.3%;'/><td class='rem' style='width: 0.0%;'/><td class='none' style='width: 56.7%;'/></tr></table></td></tr>
<tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/cgit.cgi/linux/net-next.git/diff/net/sctp/stream.c?id=2cbf5b4212b1595449548f189a8fb2df0b25a03f'>net/sctp/stream.c</a></td><td class='right'>134</td><td class='graph'><table summary='file diffstat' width='100%'><tr><td class='add' style='width: 99.3%;'/><td class='rem' style='width: 0.7%;'/><td class='none' style='width: 0.0%;'/></tr></table></td></tr>
</table><div class='diffstat-summary'>3 files changed, 266 insertions, 1 deletions</div><table summary='diff' class='diff'><tr><td><div class='head'>diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c