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linux_dsm_epyc7002/net/irda/irlap_event.c
Robie Basak 5d780cd658 [IrDA]: Frame length validation. 
When using a stir4200-based USB adaptor to talk to a device that uses
an mcp2150, the stir4200 sometimes drops an incoming frame causing the
mcp2150 to try and retransmit the lost frame. In this combination, the
next frame received from the mcp2150 is often invalid - either an
empty i:rsp or an IrCOMM i:rsp with an invalid clen. These corner
cases are now checked.

Signed-off-by: Robie Basak <rb-oss-1@justgohome.co.uk>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:08:09 -08:00

2333 lines
65 KiB
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/*********************************************************************
*
* Filename: irlap_event.c
* Version: 0.9
* Description: IrLAP state machine implementation
* Status: Experimental.
* Author: Dag Brattli <dag@brattli.net>
* Created at: Sat Aug 16 00:59:29 1997
* Modified at: Sat Dec 25 21:07:57 1999
* Modified by: Dag Brattli <dag@brattli.net>
*
* Copyright (c) 1998-2000 Dag Brattli <dag@brattli.net>,
* Copyright (c) 1998 Thomas Davis <ratbert@radiks.net>
* All Rights Reserved.
* Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
*
* 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.
*
* Neither Dag Brattli nor University of Tromsø admit liability nor
* provide warranty for any of this software. This material is
* provided "AS-IS" and at no charge.
*
********************************************************************/
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/skbuff.h>
#include <net/irda/irda.h>
#include <net/irda/irlap_event.h>
#include <net/irda/timer.h>
#include <net/irda/irlap.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/qos.h>
#include <net/irda/parameters.h>
#include <net/irda/irlmp.h> /* irlmp_flow_indication(), ... */
#include <net/irda/irda_device.h>
#ifdef CONFIG_IRDA_FAST_RR
int sysctl_fast_poll_increase = 50;
#endif
static int irlap_state_ndm (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_query (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reply (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_conn (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_setup (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_xmit_p (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_pclose (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_nrm_p (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_nrm_s (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_xmit_s (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_sclose (struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset_check(struct irlap_cb *, IRLAP_EVENT event,
struct sk_buff *, struct irlap_info *);
#ifdef CONFIG_IRDA_DEBUG
static const char *irlap_event[] = {
"DISCOVERY_REQUEST",
"CONNECT_REQUEST",
"CONNECT_RESPONSE",
"DISCONNECT_REQUEST",
"DATA_REQUEST",
"RESET_REQUEST",
"RESET_RESPONSE",
"SEND_I_CMD",
"SEND_UI_FRAME",
"RECV_DISCOVERY_XID_CMD",
"RECV_DISCOVERY_XID_RSP",
"RECV_SNRM_CMD",
"RECV_TEST_CMD",
"RECV_TEST_RSP",
"RECV_UA_RSP",
"RECV_DM_RSP",
"RECV_RD_RSP",
"RECV_I_CMD",
"RECV_I_RSP",
"RECV_UI_FRAME",
"RECV_FRMR_RSP",
"RECV_RR_CMD",
"RECV_RR_RSP",
"RECV_RNR_CMD",
"RECV_RNR_RSP",
"RECV_REJ_CMD",
"RECV_REJ_RSP",
"RECV_SREJ_CMD",
"RECV_SREJ_RSP",
"RECV_DISC_CMD",
"SLOT_TIMER_EXPIRED",
"QUERY_TIMER_EXPIRED",
"FINAL_TIMER_EXPIRED",
"POLL_TIMER_EXPIRED",
"DISCOVERY_TIMER_EXPIRED",
"WD_TIMER_EXPIRED",
"BACKOFF_TIMER_EXPIRED",
"MEDIA_BUSY_TIMER_EXPIRED",
};
#endif /* CONFIG_IRDA_DEBUG */
const char *irlap_state[] = {
"LAP_NDM",
"LAP_QUERY",
"LAP_REPLY",
"LAP_CONN",
"LAP_SETUP",
"LAP_OFFLINE",
"LAP_XMIT_P",
"LAP_PCLOSE",
"LAP_NRM_P",
"LAP_RESET_WAIT",
"LAP_RESET",
"LAP_NRM_S",
"LAP_XMIT_S",
"LAP_SCLOSE",
"LAP_RESET_CHECK",
};
static int (*state[])(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info) =
{
irlap_state_ndm,
irlap_state_query,
irlap_state_reply,
irlap_state_conn,
irlap_state_setup,
irlap_state_offline,
irlap_state_xmit_p,
irlap_state_pclose,
irlap_state_nrm_p,
irlap_state_reset_wait,
irlap_state_reset,
irlap_state_nrm_s,
irlap_state_xmit_s,
irlap_state_sclose,
irlap_state_reset_check,
};
/*
* Function irda_poll_timer_expired (data)
*
* Poll timer has expired. Normally we must now send a RR frame to the
* remote device
*/
static void irlap_poll_timer_expired(void *data)
{
struct irlap_cb *self = (struct irlap_cb *) data;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
}
/*
* Calculate and set time before we will have to send back the pf bit
* to the peer. Use in primary.
* Make sure that state is XMIT_P/XMIT_S when calling this function
* (and that nobody messed up with the state). - Jean II
*/
static void irlap_start_poll_timer(struct irlap_cb *self, int timeout)
{
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
#ifdef CONFIG_IRDA_FAST_RR
/*
* Send out the RR frames faster if our own transmit queue is empty, or
* if the peer is busy. The effect is a much faster conversation
*/
if (skb_queue_empty(&self->txq) || self->remote_busy) {
if (self->fast_RR == TRUE) {
/*
* Assert that the fast poll timer has not reached the
* normal poll timer yet
*/
if (self->fast_RR_timeout < timeout) {
/*
* FIXME: this should be a more configurable
* function
*/
self->fast_RR_timeout +=
(sysctl_fast_poll_increase * HZ/1000);
/* Use this fast(er) timeout instead */
timeout = self->fast_RR_timeout;
}
} else {
self->fast_RR = TRUE;
/* Start with just 0 ms */
self->fast_RR_timeout = 0;
timeout = 0;
}
} else
self->fast_RR = FALSE;
IRDA_DEBUG(3, "%s(), timeout=%d (%ld)\n", __FUNCTION__, timeout, jiffies);
#endif /* CONFIG_IRDA_FAST_RR */
if (timeout == 0)
irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
else
irda_start_timer(&self->poll_timer, timeout, self,
irlap_poll_timer_expired);
}
/*
* Function irlap_do_event (event, skb, info)
*
* Rushes through the state machine without any delay. If state == XMIT
* then send queued data frames.
*/
void irlap_do_event(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret;
if (!self || self->magic != LAP_MAGIC)
return;
IRDA_DEBUG(3, "%s(), event = %s, state = %s\n", __FUNCTION__,
irlap_event[event], irlap_state[self->state]);
ret = (*state[self->state])(self, event, skb, info);
/*
* Check if there are any pending events that needs to be executed
*/
switch (self->state) {
case LAP_XMIT_P: /* FALLTHROUGH */
case LAP_XMIT_S:
/*
* We just received the pf bit and are at the beginning
* of a new LAP transmit window.
* Check if there are any queued data frames, and do not
* try to disconnect link if we send any data frames, since
* that will change the state away form XMIT
*/
IRDA_DEBUG(2, "%s() : queue len = %d\n", __FUNCTION__,
skb_queue_len(&self->txq));
if (!skb_queue_empty(&self->txq)) {
/* Prevent race conditions with irlap_data_request() */
self->local_busy = TRUE;
/* Theory of operation.
* We send frames up to when we fill the window or
* reach line capacity. Those frames will queue up
* in the device queue, and the driver will slowly
* send them.
* After each frame that we send, we poll the higher
* layer for more data. It's the right time to do
* that because the link layer need to perform the mtt
* and then send the first frame, so we can afford
* to send a bit of time in kernel space.
* The explicit flow indication allow to minimise
* buffers (== lower latency), to avoid higher layer
* polling via timers (== less context switches) and
* to implement a crude scheduler - Jean II */
/* Try to send away all queued data frames */
while ((skb = skb_dequeue(&self->txq)) != NULL) {
/* Send one frame */
ret = (*state[self->state])(self, SEND_I_CMD,
skb, NULL);
/* Drop reference count.
* It will be increase as needed in
* irlap_send_data_xxx() */
kfree_skb(skb);
/* Poll the higher layers for one more frame */
irlmp_flow_indication(self->notify.instance,
FLOW_START);
if (ret == -EPROTO)
break; /* Try again later! */
}
/* Finished transmitting */
self->local_busy = FALSE;
} else if (self->disconnect_pending) {
self->disconnect_pending = FALSE;
ret = (*state[self->state])(self, DISCONNECT_REQUEST,
NULL, NULL);
}
break;
/* case LAP_NDM: */
/* case LAP_CONN: */
/* case LAP_RESET_WAIT: */
/* case LAP_RESET_CHECK: */
default:
break;
}
}
/*
* Function irlap_state_ndm (event, skb, frame)
*
* NDM (Normal Disconnected Mode) state
*
*/
static int irlap_state_ndm(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
discovery_t *discovery_rsp;
int ret = 0;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case CONNECT_REQUEST:
IRDA_ASSERT(self->netdev != NULL, return -1;);
if (self->media_busy) {
/* Note : this will never happen, because we test
* media busy in irlap_connect_request() and
* postpone the event... - Jean II */
IRDA_DEBUG(0, "%s(), CONNECT_REQUEST: media busy!\n",
__FUNCTION__);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_MEDIA_BUSY);
} else {
irlap_send_snrm_frame(self, &self->qos_rx);
/* Start Final-bit timer */
irlap_start_final_timer(self, self->final_timeout);
self->retry_count = 0;
irlap_next_state(self, LAP_SETUP);
}
break;
case RECV_SNRM_CMD:
/* Check if the frame contains and I field */
if (info) {
self->daddr = info->daddr;
self->caddr = info->caddr;
irlap_next_state(self, LAP_CONN);
irlap_connect_indication(self, skb);
} else {
IRDA_DEBUG(0, "%s(), SNRM frame does not "
"contain an I field!\n", __FUNCTION__);
}
break;
case DISCOVERY_REQUEST:
IRDA_ASSERT(info != NULL, return -1;);
if (self->media_busy) {
IRDA_DEBUG(1, "%s(), DISCOVERY_REQUEST: media busy!\n",
__FUNCTION__);
/* irlap->log.condition = MEDIA_BUSY; */
/* This will make IrLMP try again */
irlap_discovery_confirm(self, NULL);
/* Note : the discovery log is not cleaned up here,
* it will be done in irlap_discovery_request()
* Jean II */
return 0;
}
self->S = info->S;
self->s = info->s;
irlap_send_discovery_xid_frame(self, info->S, info->s, TRUE,
info->discovery);
self->frame_sent = FALSE;
self->s++;
irlap_start_slot_timer(self, self->slot_timeout);
irlap_next_state(self, LAP_QUERY);
break;
case RECV_DISCOVERY_XID_CMD:
IRDA_ASSERT(info != NULL, return -1;);
/* Assert that this is not the final slot */
if (info->s <= info->S) {
self->slot = irlap_generate_rand_time_slot(info->S,
info->s);
if (self->slot == info->s) {
discovery_rsp = irlmp_get_discovery_response();
discovery_rsp->data.daddr = info->daddr;
irlap_send_discovery_xid_frame(self, info->S,
self->slot,
FALSE,
discovery_rsp);
self->frame_sent = TRUE;
} else
self->frame_sent = FALSE;
/*
* Go to reply state until end of discovery to
* inhibit our own transmissions. Set the timer
* to not stay forever there... Jean II
*/
irlap_start_query_timer(self, info->S, info->s);
irlap_next_state(self, LAP_REPLY);
} else {
/* This is the final slot. How is it possible ?
* This would happen is both discoveries are just slightly
* offset (if they are in sync, all packets are lost).
* Most often, all the discovery requests will be received
* in QUERY state (see my comment there), except for the
* last frame that will come here.
* The big trouble when it happen is that active discovery
* doesn't happen, because nobody answer the discoveries
* frame of the other guy, so the log shows up empty.
* What should we do ?
* Not much. It's too late to answer those discovery frames,
* so we just pass the info to IrLMP who will put it in the
* log (and post an event).
* Another cause would be devices that do discovery much
* slower than us, however the latest fixes should minimise
* those cases...
* Jean II
*/
IRDA_DEBUG(1, "%s(), Receiving final discovery request, missed the discovery slots :-(\n", __FUNCTION__);
/* Last discovery request -> in the log */
irlap_discovery_indication(self, info->discovery);
}
break;
case MEDIA_BUSY_TIMER_EXPIRED:
/* A bunch of events may be postponed because the media is
* busy (usually immediately after we close a connection),
* or while we are doing discovery (state query/reply).
* In all those cases, the media busy flag will be cleared
* when it's OK for us to process those postponed events.
* This event is not mentioned in the state machines in the
* IrLAP spec. It's because they didn't consider Ultra and
* postponing connection request is optional.
* Jean II */
#ifdef CONFIG_IRDA_ULTRA
/* Send any pending Ultra frames if any */
if (!skb_queue_empty(&self->txq_ultra)) {
/* We don't send the frame, just post an event.
* Also, previously this code was in timer.c...
* Jean II */
ret = (*state[self->state])(self, SEND_UI_FRAME,
NULL, NULL);
}
#endif /* CONFIG_IRDA_ULTRA */
/* Check if we should try to connect.
* This code was previously in irlap_do_event() */
if (self->connect_pending) {
self->connect_pending = FALSE;
/* This one *should* not pend in this state, except
* if a socket try to connect and immediately
* disconnect. - clear - Jean II */
if (self->disconnect_pending)
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
else
ret = (*state[self->state])(self,
CONNECT_REQUEST,
NULL, NULL);
self->disconnect_pending = FALSE;
}
/* Note : one way to test if this code works well (including
* media busy and small busy) is to create a user space
* application generating an Ultra packet every 3.05 sec (or
* 2.95 sec) and to see how it interact with discovery.
* It's fairly easy to check that no packet is lost, that the
* packets are postponed during discovery and that after
* discovery indication you have a 100ms "gap".
* As connection request and Ultra are now processed the same
* way, this avoid the tedious job of trying IrLAP connection
* in all those cases...
* Jean II */
break;
#ifdef CONFIG_IRDA_ULTRA
case SEND_UI_FRAME:
{
int i;
/* Only allowed to repeat an operation twice */
for (i=0; ((i<2) && (self->media_busy == FALSE)); i++) {
skb = skb_dequeue(&self->txq_ultra);
if (skb)
irlap_send_ui_frame(self, skb, CBROADCAST,
CMD_FRAME);
else
break;
/* irlap_send_ui_frame() won't increase skb reference
* count, so no dev_kfree_skb() - Jean II */
}
if (i == 2) {
/* Force us to listen 500 ms again */
irda_device_set_media_busy(self->netdev, TRUE);
}
break;
}
case RECV_UI_FRAME:
/* Only accept broadcast frames in NDM mode */
if (info->caddr != CBROADCAST) {
IRDA_DEBUG(0, "%s(), not a broadcast frame!\n",
__FUNCTION__);
} else
irlap_unitdata_indication(self, skb);
break;
#endif /* CONFIG_IRDA_ULTRA */
case RECV_TEST_CMD:
/* Remove test frame header */
skb_pull(skb, sizeof(struct test_frame));
/*
* Send response. This skb will not be sent out again, and
* will only be used to send out the same info as the cmd
*/
irlap_send_test_frame(self, CBROADCAST, info->daddr, skb);
break;
case RECV_TEST_RSP:
IRDA_DEBUG(0, "%s() not implemented!\n", __FUNCTION__);
break;
default:
IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_query (event, skb, info)
*
* QUERY state
*
*/
static int irlap_state_query(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case RECV_DISCOVERY_XID_RSP:
IRDA_ASSERT(info != NULL, return -1;);
IRDA_ASSERT(info->discovery != NULL, return -1;);
IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__,
info->discovery->data.daddr);
if (!self->discovery_log) {
IRDA_WARNING("%s: discovery log is gone! "
"maybe the discovery timeout has been set"
" too short?\n", __FUNCTION__);
break;
}
hashbin_insert(self->discovery_log,
(irda_queue_t *) info->discovery,
info->discovery->data.daddr, NULL);
/* Keep state */
/* irlap_next_state(self, LAP_QUERY); */
break;
case RECV_DISCOVERY_XID_CMD:
/* Yes, it is possible to receive those frames in this mode.
* Note that most often the last discovery request won't
* occur here but in NDM state (see my comment there).
* What should we do ?
* Not much. We are currently performing our own discovery,
* therefore we can't answer those frames. We don't want
* to change state either. We just pass the info to
* IrLMP who will put it in the log (and post an event).
* Jean II
*/
IRDA_ASSERT(info != NULL, return -1;);
IRDA_DEBUG(1, "%s(), Receiving discovery request (s = %d) while performing discovery :-(\n", __FUNCTION__, info->s);
/* Last discovery request ? */
if (info->s == 0xff)
irlap_discovery_indication(self, info->discovery);
break;
case SLOT_TIMER_EXPIRED:
/*
* Wait a little longer if we detect an incoming frame. This
* is not mentioned in the spec, but is a good thing to do,
* since we want to work even with devices that violate the
* timing requirements.
*/
if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
IRDA_DEBUG(2, "%s(), device is slow to answer, "
"waiting some more!\n", __FUNCTION__);
irlap_start_slot_timer(self, msecs_to_jiffies(10));
self->add_wait = TRUE;
return ret;
}
self->add_wait = FALSE;
if (self->s < self->S) {
irlap_send_discovery_xid_frame(self, self->S,
self->s, TRUE,
self->discovery_cmd);
self->s++;
irlap_start_slot_timer(self, self->slot_timeout);
/* Keep state */
irlap_next_state(self, LAP_QUERY);
} else {
/* This is the final slot! */
irlap_send_discovery_xid_frame(self, self->S, 0xff,
TRUE,
self->discovery_cmd);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
/*
* We are now finished with the discovery procedure,
* so now we must return the results
*/
irlap_discovery_confirm(self, self->discovery_log);
/* IrLMP should now have taken care of the log */
self->discovery_log = NULL;
}
break;
default:
IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_reply (self, event, skb, info)
*
* REPLY, we have received a XID discovery frame from a device and we
* are waiting for the right time slot to send a response XID frame
*
*/
static int irlap_state_reply(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
discovery_t *discovery_rsp;
int ret=0;
IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case QUERY_TIMER_EXPIRED:
IRDA_DEBUG(0, "%s(), QUERY_TIMER_EXPIRED <%ld>\n",
__FUNCTION__, jiffies);
irlap_next_state(self, LAP_NDM);
break;
case RECV_DISCOVERY_XID_CMD:
IRDA_ASSERT(info != NULL, return -1;);
/* Last frame? */
if (info->s == 0xff) {
del_timer(&self->query_timer);
/* info->log.condition = REMOTE; */
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_discovery_indication(self, info->discovery);
} else {
/* If it's our slot, send our reply */
if ((info->s >= self->slot) && (!self->frame_sent)) {
discovery_rsp = irlmp_get_discovery_response();
discovery_rsp->data.daddr = info->daddr;
irlap_send_discovery_xid_frame(self, info->S,
self->slot,
FALSE,
discovery_rsp);
self->frame_sent = TRUE;
}
/* Readjust our timer to accomodate devices
* doing faster or slower discovery than us...
* Jean II */
irlap_start_query_timer(self, info->S, info->s);
/* Keep state */
//irlap_next_state(self, LAP_REPLY);
}
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__,
event, irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_conn (event, skb, info)
*
* CONN, we have received a SNRM command and is waiting for the upper
* layer to accept or refuse connection
*
*/
static int irlap_state_conn(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[ event]);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case CONNECT_RESPONSE:
skb_pull(skb, sizeof(struct snrm_frame));
IRDA_ASSERT(self->netdev != NULL, return -1;);
irlap_qos_negotiate(self, skb);
irlap_initiate_connection_state(self);
/*
* Applying the parameters now will make sure we change speed
* *after* we have sent the next frame
*/
irlap_apply_connection_parameters(self, FALSE);
/*
* Sending this frame will force a speed change after it has
* been sent (i.e. the frame will be sent at 9600).
*/
irlap_send_ua_response_frame(self, &self->qos_rx);
#if 0
/*
* We are allowed to send two frames, but this may increase
* the connect latency, so lets not do it for now.
*/
/* This is full of good intentions, but doesn't work in
* practice.
* After sending the first UA response, we switch the
* dongle to the negotiated speed, which is usually
* different than 9600 kb/s.
* From there, there is two solutions :
* 1) The other end has received the first UA response :
* it will set up the connection, move to state LAP_NRM_P,
* and will ignore and drop the second UA response.
* Actually, it's even worse : the other side will almost
* immediately send a RR that will likely collide with the
* UA response (depending on negotiated turnaround).
* 2) The other end has not received the first UA response,
* will stay at 9600 and will never see the second UA response.
* Jean II */
irlap_send_ua_response_frame(self, &self->qos_rx);
#endif
/*
* The WD-timer could be set to the duration of the P-timer
* for this case, but it is recommended to use twice the
* value (note 3 IrLAP p. 60).
*/
irlap_start_wd_timer(self, self->wd_timeout);
irlap_next_state(self, LAP_NRM_S);
break;
case RECV_DISCOVERY_XID_CMD:
IRDA_DEBUG(3, "%s(), event RECV_DISCOVER_XID_CMD!\n",
__FUNCTION__);
irlap_next_state(self, LAP_NDM);
break;
case DISCONNECT_REQUEST:
IRDA_DEBUG(0, "%s(), Disconnect request!\n", __FUNCTION__);
irlap_send_dm_frame(self);
irlap_next_state( self, LAP_NDM);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__,
event, irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_setup (event, skb, frame)
*
* SETUP state, The local layer has transmitted a SNRM command frame to
* a remote peer layer and is awaiting a reply .
*
*/
static int irlap_state_setup(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case FINAL_TIMER_EXPIRED:
if (self->retry_count < self->N3) {
/*
* Perform random backoff, Wait a random number of time units, minimum
* duration half the time taken to transmitt a SNRM frame, maximum duration
* 1.5 times the time taken to transmit a SNRM frame. So this time should
* between 15 msecs and 45 msecs.
*/
irlap_start_backoff_timer(self, msecs_to_jiffies(20 +
(jiffies % 30)));
} else {
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_FOUND_NONE);
}
break;
case BACKOFF_TIMER_EXPIRED:
irlap_send_snrm_frame(self, &self->qos_rx);
irlap_start_final_timer(self, self->final_timeout);
self->retry_count++;
break;
case RECV_SNRM_CMD:
IRDA_DEBUG(4, "%s(), SNRM battle!\n", __FUNCTION__);
IRDA_ASSERT(skb != NULL, return 0;);
IRDA_ASSERT(info != NULL, return 0;);
/*
* The device with the largest device address wins the battle
* (both have sent a SNRM command!)
*/
if (info &&(info->daddr > self->saddr)) {
del_timer(&self->final_timer);
irlap_initiate_connection_state(self);
IRDA_ASSERT(self->netdev != NULL, return -1;);
skb_pull(skb, sizeof(struct snrm_frame));
irlap_qos_negotiate(self, skb);
/* Send UA frame and then change link settings */
irlap_apply_connection_parameters(self, FALSE);
irlap_send_ua_response_frame(self, &self->qos_rx);
irlap_next_state(self, LAP_NRM_S);
irlap_connect_confirm(self, skb);
/*
* The WD-timer could be set to the duration of the
* P-timer for this case, but it is recommended
* to use twice the value (note 3 IrLAP p. 60).
*/
irlap_start_wd_timer(self, self->wd_timeout);
} else {
/* We just ignore the other device! */
irlap_next_state(self, LAP_SETUP);
}
break;
case RECV_UA_RSP:
/* Stop F-timer */
del_timer(&self->final_timer);
/* Initiate connection state */
irlap_initiate_connection_state(self);
/* Negotiate connection parameters */
IRDA_ASSERT(skb->len > 10, return -1;);
skb_pull(skb, sizeof(struct ua_frame));
IRDA_ASSERT(self->netdev != NULL, return -1;);
irlap_qos_negotiate(self, skb);
/* Set the new link setting *now* (before the rr frame) */
irlap_apply_connection_parameters(self, TRUE);
self->retry_count = 0;
/* Wait for turnaround time to give a chance to the other
* device to be ready to receive us.
* Note : the time to switch speed is typically larger
* than the turnaround time, but as we don't have the other
* side speed switch time, that's our best guess...
* Jean II */
irlap_wait_min_turn_around(self, &self->qos_tx);
/* This frame will actually be sent at the new speed */
irlap_send_rr_frame(self, CMD_FRAME);
/* The timer is set to half the normal timer to quickly
* detect a failure to negociate the new connection
* parameters. IrLAP 6.11.3.2, note 3.
* Note that currently we don't process this failure
* properly, as we should do a quick disconnect.
* Jean II */
irlap_start_final_timer(self, self->final_timeout/2);
irlap_next_state(self, LAP_NRM_P);
irlap_connect_confirm(self, skb);
break;
case RECV_DM_RSP: /* FALLTHROUGH */
case RECV_DISC_CMD:
del_timer(&self->final_timer);
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__,
event, irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_offline (self, event, skb, info)
*
* OFFLINE state, not used for now!
*
*/
static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
IRDA_DEBUG( 0, "%s(), Unknown event\n", __FUNCTION__);
return -1;
}
/*
* Function irlap_state_xmit_p (self, event, skb, info)
*
* XMIT, Only the primary station has right to transmit, and we
* therefore do not expect to receive any transmissions from other
* stations.
*
*/
static int irlap_state_xmit_p(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
switch (event) {
case SEND_I_CMD:
/*
* Only send frame if send-window > 0.
*/
if ((self->window > 0) && (!self->remote_busy)) {
int nextfit;
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
struct sk_buff *skb_next;
/* With DYNAMIC_WINDOW, we keep the window size
* maximum, and adapt on the packets we are sending.
* At 115k, we can send only 2 packets of 2048 bytes
* in a 500 ms turnaround. Without this option, we
* would always limit the window to 2. With this
* option, if we send smaller packets, we can send
* up to 7 of them (always depending on QoS).
* Jean II */
/* Look at the next skb. This is safe, as we are
* the only consumer of the Tx queue (if we are not,
* we have other problems) - Jean II */
skb_next = skb_peek(&self->txq);
/* Check if a subsequent skb exist and would fit in
* the current window (with respect to turnaround
* time).
* This allow us to properly mark the current packet
* with the pf bit, to avoid falling back on the
* second test below, and avoid waiting the
* end of the window and sending a extra RR.
* Note : (skb_next != NULL) <=> (skb_queue_len() > 0)
* Jean II */
nextfit = ((skb_next != NULL) &&
((skb_next->len + skb->len) <=
self->bytes_left));
/*
* The current packet may not fit ! Because of test
* above, this should not happen any more !!!
* Test if we have transmitted more bytes over the
* link than its possible to do with the current
* speed and turn-around-time.
*/
if((!nextfit) && (skb->len > self->bytes_left)) {
IRDA_DEBUG(0, "%s(), Not allowed to transmit"
" more bytes!\n", __FUNCTION__);
/* Requeue the skb */
skb_queue_head(&self->txq, skb_get(skb));
/*
* We should switch state to LAP_NRM_P, but
* that is not possible since we must be sure
* that we poll the other side. Since we have
* used up our time, the poll timer should
* trigger anyway now, so we just wait for it
* DB
*/
/*
* Sorry, but that's not totally true. If
* we send 2000B packets, we may wait another
* 1000B until our turnaround expire. That's
* why we need to be proactive in avoiding
* coming here. - Jean II
*/
return -EPROTO;
}
/* Substract space used by this skb */
self->bytes_left -= skb->len;
#else /* CONFIG_IRDA_DYNAMIC_WINDOW */
/* Window has been adjusted for the max packet
* size, so much simpler... - Jean II */
nextfit = !skb_queue_empty(&self->txq);
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
/*
* Send data with poll bit cleared only if window > 1
* and there is more frames after this one to be sent
*/
if ((self->window > 1) && (nextfit)) {
/* More packet to send in current window */
irlap_send_data_primary(self, skb);
irlap_next_state(self, LAP_XMIT_P);
} else {
/* Final packet of window */
irlap_send_data_primary_poll(self, skb);
/*
* Make sure state machine does not try to send
* any more frames
*/
ret = -EPROTO;
}
#ifdef CONFIG_IRDA_FAST_RR
/* Peer may want to reply immediately */
self->fast_RR = FALSE;
#endif /* CONFIG_IRDA_FAST_RR */
} else {
IRDA_DEBUG(4, "%s(), Unable to send! remote busy?\n",
__FUNCTION__);
skb_queue_head(&self->txq, skb_get(skb));
/*
* The next ret is important, because it tells
* irlap_next_state _not_ to deliver more frames
*/
ret = -EPROTO;
}
break;
case POLL_TIMER_EXPIRED:
IRDA_DEBUG(3, "%s(), POLL_TIMER_EXPIRED <%ld>\n",
__FUNCTION__, jiffies);
irlap_send_rr_frame(self, CMD_FRAME);
/* Return to NRM properly - Jean II */
self->window = self->window_size;
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
/* Allowed to transmit a maximum number of bytes again. */
self->bytes_left = self->line_capacity;
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
irlap_start_final_timer(self, self->final_timeout);
irlap_next_state(self, LAP_NRM_P);
break;
case DISCONNECT_REQUEST:
del_timer(&self->poll_timer);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_disc_frame(self);
irlap_flush_all_queues(self);
irlap_start_final_timer(self, self->final_timeout);
self->retry_count = 0;
irlap_next_state(self, LAP_PCLOSE);
break;
case DATA_REQUEST:
/* Nothing to do, irlap_do_event() will send the packet
* when we return... - Jean II */
break;
default:
IRDA_DEBUG(0, "%s(), Unknown event %s\n",
__FUNCTION__, irlap_event[event]);
ret = -EINVAL;
break;
}
return ret;
}
/*
* Function irlap_state_pclose (event, skb, info)
*
* PCLOSE state
*/
static int irlap_state_pclose(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case RECV_UA_RSP: /* FALLTHROUGH */
case RECV_DM_RSP:
del_timer(&self->final_timer);
/* Set new link parameters */
irlap_apply_default_connection_parameters(self);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
case FINAL_TIMER_EXPIRED:
if (self->retry_count < self->N3) {
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_disc_frame(self);
irlap_start_final_timer(self, self->final_timeout);
self->retry_count++;
/* Keep state */
} else {
irlap_apply_default_connection_parameters(self);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_NO_RESPONSE);
}
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %d\n", __FUNCTION__, event);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_nrm_p (self, event, skb, info)
*
* NRM_P (Normal Response Mode as Primary), The primary station has given
* permissions to a secondary station to transmit IrLAP resonse frames
* (by sending a frame with the P bit set). The primary station will not
* transmit any frames and is expecting to receive frames only from the
* secondary to which transmission permissions has been given.
*/
static int irlap_state_nrm_p(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
int ns_status;
int nr_status;
switch (event) {
case RECV_I_RSP: /* Optimize for the common case */
if (unlikely(skb->len <= LAP_ADDR_HEADER + LAP_CTRL_HEADER)) {
/*
* Input validation check: a stir4200/mcp2150
* combination sometimes results in an empty i:rsp.
* This makes no sense; we can just ignore the frame
* and send an rr:cmd immediately. This happens before
* changing nr or ns so triggers a retransmit
*/
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, CMD_FRAME);
/* Keep state */
break;
}
/* FIXME: must check for remote_busy below */
#ifdef CONFIG_IRDA_FAST_RR
/*
* Reset the fast_RR so we can use the fast RR code with
* full speed the next time since peer may have more frames
* to transmitt
*/
self->fast_RR = FALSE;
#endif /* CONFIG_IRDA_FAST_RR */
IRDA_ASSERT( info != NULL, return -1;);
ns_status = irlap_validate_ns_received(self, info->ns);
nr_status = irlap_validate_nr_received(self, info->nr);
/*
* Check for expected I(nformation) frame
*/
if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {
/* Update Vr (next frame for us to receive) */
self->vr = (self->vr + 1) % 8;
/* Update Nr received, cleanup our retry queue */
irlap_update_nr_received(self, info->nr);
/*
* Got expected NR, so reset the
* retry_count. This is not done by IrLAP spec,
* which is strange!
*/
self->retry_count = 0;
self->ack_required = TRUE;
/* poll bit cleared? */
if (!info->pf) {
/* Keep state, do not move this line */
irlap_next_state(self, LAP_NRM_P);
irlap_data_indication(self, skb, FALSE);
} else {
/* No longer waiting for pf */
del_timer(&self->final_timer);
irlap_wait_min_turn_around(self, &self->qos_tx);
/* Call higher layer *before* changing state
* to give them a chance to send data in the
* next LAP frame.
* Jean II */
irlap_data_indication(self, skb, FALSE);
/* XMIT states are the most dangerous state
* to be in, because user requests are
* processed directly and may change state.
* On the other hand, in NDM_P, those
* requests are queued and we will process
* them when we return to irlap_do_event().
* Jean II
*/
irlap_next_state(self, LAP_XMIT_P);
/* This is the last frame.
* Make sure it's always called in XMIT state.
* - Jean II */
irlap_start_poll_timer(self, self->poll_timeout);
}
break;
}
/* Unexpected next to send (Ns) */
if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
{
if (!info->pf) {
irlap_update_nr_received(self, info->nr);
/*
* Wait until the last frame before doing
* anything
*/
/* Keep state */
irlap_next_state(self, LAP_NRM_P);
} else {
IRDA_DEBUG(4,
"%s(), missing or duplicate frame!\n",
__FUNCTION__);
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, CMD_FRAME);
self->ack_required = FALSE;
irlap_start_final_timer(self, self->final_timeout);
irlap_next_state(self, LAP_NRM_P);
}
break;
}
/*
* Unexpected next to receive (Nr)
*/
if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
{
if (info->pf) {
self->vr = (self->vr + 1) % 8;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
/* Resend rejected frames */
irlap_resend_rejected_frames(self, CMD_FRAME);
self->ack_required = FALSE;
/* Make sure we account for the time
* to transmit our frames. See comemnts
* in irlap_send_data_primary_poll().
* Jean II */
irlap_start_final_timer(self, 2 * self->final_timeout);
/* Keep state, do not move this line */
irlap_next_state(self, LAP_NRM_P);
irlap_data_indication(self, skb, FALSE);
} else {
/*
* Do not resend frames until the last
* frame has arrived from the other
* device. This is not documented in
* IrLAP!!
*/
self->vr = (self->vr + 1) % 8;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
self->ack_required = FALSE;
/* Keep state, do not move this line!*/
irlap_next_state(self, LAP_NRM_P);
irlap_data_indication(self, skb, FALSE);
}
break;
}
/*
* Unexpected next to send (Ns) and next to receive (Nr)
* Not documented by IrLAP!
*/
if ((ns_status == NS_UNEXPECTED) &&
(nr_status == NR_UNEXPECTED))
{
IRDA_DEBUG(4, "%s(), unexpected nr and ns!\n",
__FUNCTION__);
if (info->pf) {
/* Resend rejected frames */
irlap_resend_rejected_frames(self, CMD_FRAME);
/* Give peer some time to retransmit!
* But account for our own Tx. */
irlap_start_final_timer(self, 2 * self->final_timeout);
/* Keep state, do not move this line */
irlap_next_state(self, LAP_NRM_P);
} else {
/* Update Nr received */
/* irlap_update_nr_received( info->nr); */
self->ack_required = FALSE;
}
break;
}
/*
* Invalid NR or NS
*/
if ((nr_status == NR_INVALID) || (ns_status == NS_INVALID)) {
if (info->pf) {
del_timer(&self->final_timer);
irlap_next_state(self, LAP_RESET_WAIT);
irlap_disconnect_indication(self, LAP_RESET_INDICATION);
self->xmitflag = TRUE;
} else {
del_timer(&self->final_timer);
irlap_disconnect_indication(self, LAP_RESET_INDICATION);
self->xmitflag = FALSE;
}
break;
}
IRDA_DEBUG(1, "%s(), Not implemented!\n", __FUNCTION__);
IRDA_DEBUG(1, "%s(), event=%s, ns_status=%d, nr_status=%d\n",
__FUNCTION__, irlap_event[event], ns_status, nr_status);
break;
case RECV_UI_FRAME:
/* Poll bit cleared? */
if (!info->pf) {
irlap_data_indication(self, skb, TRUE);
irlap_next_state(self, LAP_NRM_P);
} else {
del_timer(&self->final_timer);
irlap_data_indication(self, skb, TRUE);
irlap_next_state(self, LAP_XMIT_P);
IRDA_DEBUG(1, "%s: RECV_UI_FRAME: next state %s\n", __FUNCTION__, irlap_state[self->state]);
irlap_start_poll_timer(self, self->poll_timeout);
}
break;
case RECV_RR_RSP:
/*
* If you get a RR, the remote isn't busy anymore,
* no matter what the NR
*/
self->remote_busy = FALSE;
/* Stop final timer */
del_timer(&self->final_timer);
/*
* Nr as expected?
*/
ret = irlap_validate_nr_received(self, info->nr);
if (ret == NR_EXPECTED) {
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
/*
* Got expected NR, so reset the retry_count. This
* is not done by the IrLAP standard , which is
* strange! DB.
*/
self->retry_count = 0;
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_next_state(self, LAP_XMIT_P);
/* Start poll timer */
irlap_start_poll_timer(self, self->poll_timeout);
} else if (ret == NR_UNEXPECTED) {
IRDA_ASSERT(info != NULL, return -1;);
/*
* Unexpected nr!
*/
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
IRDA_DEBUG(4, "RECV_RR_FRAME: Retrans:%d, nr=%d, va=%d, "
"vs=%d, vr=%d\n",
self->retry_count, info->nr, self->va,
self->vs, self->vr);
/* Resend rejected frames */
irlap_resend_rejected_frames(self, CMD_FRAME);
irlap_start_final_timer(self, self->final_timeout * 2);
irlap_next_state(self, LAP_NRM_P);
} else if (ret == NR_INVALID) {
IRDA_DEBUG(1, "%s(), Received RR with "
"invalid nr !\n", __FUNCTION__);
irlap_next_state(self, LAP_RESET_WAIT);
irlap_disconnect_indication(self, LAP_RESET_INDICATION);
self->xmitflag = TRUE;
}
break;
case RECV_RNR_RSP:
IRDA_ASSERT(info != NULL, return -1;);
/* Stop final timer */
del_timer(&self->final_timer);
self->remote_busy = TRUE;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
irlap_next_state(self, LAP_XMIT_P);
/* Start poll timer */
irlap_start_poll_timer(self, self->poll_timeout);
break;
case RECV_FRMR_RSP:
del_timer(&self->final_timer);
self->xmitflag = TRUE;
irlap_next_state(self, LAP_RESET_WAIT);
irlap_reset_indication(self);
break;
case FINAL_TIMER_EXPIRED:
/*
* We are allowed to wait for additional 300 ms if
* final timer expires when we are in the middle
* of receiving a frame (page 45, IrLAP). Check that
* we only do this once for each frame.
*/
if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
IRDA_DEBUG(1, "FINAL_TIMER_EXPIRED when receiving a "
"frame! Waiting a little bit more!\n");
irlap_start_final_timer(self, msecs_to_jiffies(300));
/*
* Don't allow this to happen one more time in a row,
* or else we can get a pretty tight loop here if
* if we only receive half a frame. DB.
*/
self->add_wait = TRUE;
break;
}
self->add_wait = FALSE;
/* N2 is the disconnect timer. Until we reach it, we retry */
if (self->retry_count < self->N2) {
if (skb_peek(&self->wx_list) == NULL) {
/* Retry sending the pf bit to the secondary */
IRDA_DEBUG(4, "nrm_p: resending rr");
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, CMD_FRAME);
} else {
IRDA_DEBUG(4, "nrm_p: resend frames");
irlap_resend_rejected_frames(self, CMD_FRAME);
}
irlap_start_final_timer(self, self->final_timeout);
self->retry_count++;
IRDA_DEBUG(4, "irlap_state_nrm_p: FINAL_TIMER_EXPIRED:"
" retry_count=%d\n", self->retry_count);
/* Early warning event. I'm using a pretty liberal
* interpretation of the spec and generate an event
* every time the timer is multiple of N1 (and not
* only the first time). This allow application
* to know precisely if connectivity restart...
* Jean II */
if((self->retry_count % self->N1) == 0)
irlap_status_indication(self,
STATUS_NO_ACTIVITY);
/* Keep state */
} else {
irlap_apply_default_connection_parameters(self);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_NO_RESPONSE);
}
break;
case RECV_REJ_RSP:
irlap_update_nr_received(self, info->nr);
if (self->remote_busy) {
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, CMD_FRAME);
} else
irlap_resend_rejected_frames(self, CMD_FRAME);
irlap_start_final_timer(self, 2 * self->final_timeout);
break;
case RECV_SREJ_RSP:
irlap_update_nr_received(self, info->nr);
if (self->remote_busy) {
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, CMD_FRAME);
} else
irlap_resend_rejected_frame(self, CMD_FRAME);
irlap_start_final_timer(self, 2 * self->final_timeout);
break;
case RECV_RD_RSP:
IRDA_DEBUG(1, "%s(), RECV_RD_RSP\n", __FUNCTION__);
irlap_flush_all_queues(self);
irlap_next_state(self, LAP_XMIT_P);
/* Call back the LAP state machine to do a proper disconnect */
irlap_disconnect_request(self);
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %s\n",
__FUNCTION__, irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_reset_wait (event, skb, info)
*
* We have informed the service user of a reset condition, and is
* awaiting reset of disconnect request.
*
*/
static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(3, "%s(), event = %s\n", __FUNCTION__, irlap_event[event]);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case RESET_REQUEST:
if (self->xmitflag) {
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_snrm_frame(self, NULL);
irlap_start_final_timer(self, self->final_timeout);
irlap_next_state(self, LAP_RESET);
} else {
irlap_start_final_timer(self, self->final_timeout);
irlap_next_state(self, LAP_RESET);
}
break;
case DISCONNECT_REQUEST:
irlap_wait_min_turn_around( self, &self->qos_tx);
irlap_send_disc_frame( self);
irlap_flush_all_queues( self);
irlap_start_final_timer( self, self->final_timeout);
self->retry_count = 0;
irlap_next_state( self, LAP_PCLOSE);
break;
default:
IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_reset (self, event, skb, info)
*
* We have sent a SNRM reset command to the peer layer, and is awaiting
* reply.
*
*/
static int irlap_state_reset(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(3, "%s(), event = %s\n", __FUNCTION__, irlap_event[event]);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case RECV_DISC_CMD:
del_timer(&self->final_timer);
irlap_apply_default_connection_parameters(self);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_NO_RESPONSE);
break;
case RECV_UA_RSP:
del_timer(&self->final_timer);
/* Initiate connection state */
irlap_initiate_connection_state(self);
irlap_reset_confirm();
self->remote_busy = FALSE;
irlap_next_state(self, LAP_XMIT_P);
irlap_start_poll_timer(self, self->poll_timeout);
break;
case FINAL_TIMER_EXPIRED:
if (self->retry_count < 3) {
irlap_wait_min_turn_around(self, &self->qos_tx);
IRDA_ASSERT(self->netdev != NULL, return -1;);
irlap_send_snrm_frame(self, self->qos_dev);
self->retry_count++; /* Experimental!! */
irlap_start_final_timer(self, self->final_timeout);
irlap_next_state(self, LAP_RESET);
} else if (self->retry_count >= self->N3) {
irlap_apply_default_connection_parameters(self);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_NO_RESPONSE);
}
break;
case RECV_SNRM_CMD:
/*
* SNRM frame is not allowed to contain an I-field in this
* state
*/
if (!info) {
IRDA_DEBUG(3, "%s(), RECV_SNRM_CMD\n", __FUNCTION__);
irlap_initiate_connection_state(self);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_ua_response_frame(self, &self->qos_rx);
irlap_reset_confirm();
irlap_start_wd_timer(self, self->wd_timeout);
irlap_next_state(self, LAP_NDM);
} else {
IRDA_DEBUG(0,
"%s(), SNRM frame contained an I field!\n",
__FUNCTION__);
}
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %s\n",
__FUNCTION__, irlap_event[event]);
ret = -1;
break;
}
return ret;
}
/*
* Function irlap_state_xmit_s (event, skb, info)
*
* XMIT_S, The secondary station has been given the right to transmit,
* and we therefor do not expect to receive any transmissions from other
* stations.
*/
static int irlap_state_xmit_s(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[event]);
IRDA_ASSERT(self != NULL, return -ENODEV;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
switch (event) {
case SEND_I_CMD:
/*
* Send frame only if send window > 0
*/
if ((self->window > 0) && (!self->remote_busy)) {
int nextfit;
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
struct sk_buff *skb_next;
/*
* Same deal as in irlap_state_xmit_p(), so see
* the comments at that point.
* We are the secondary, so there are only subtle
* differences. - Jean II
*/
/* Check if a subsequent skb exist and would fit in
* the current window (with respect to turnaround
* time). - Jean II */
skb_next = skb_peek(&self->txq);
nextfit = ((skb_next != NULL) &&
((skb_next->len + skb->len) <=
self->bytes_left));
/*
* Test if we have transmitted more bytes over the
* link than its possible to do with the current
* speed and turn-around-time.
*/
if((!nextfit) && (skb->len > self->bytes_left)) {
IRDA_DEBUG(0, "%s(), Not allowed to transmit"
" more bytes!\n", __FUNCTION__);
/* Requeue the skb */
skb_queue_head(&self->txq, skb_get(skb));
/*
* Switch to NRM_S, this is only possible
* when we are in secondary mode, since we
* must be sure that we don't miss any RR
* frames
*/
self->window = self->window_size;
self->bytes_left = self->line_capacity;
irlap_start_wd_timer(self, self->wd_timeout);
irlap_next_state(self, LAP_NRM_S);
/* Slight difference with primary :
* here we would wait for the other side to
* expire the turnaround. - Jean II */
return -EPROTO; /* Try again later */
}
/* Substract space used by this skb */
self->bytes_left -= skb->len;
#else /* CONFIG_IRDA_DYNAMIC_WINDOW */
/* Window has been adjusted for the max packet
* size, so much simpler... - Jean II */
nextfit = !skb_queue_empty(&self->txq);
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
/*
* Send data with final bit cleared only if window > 1
* and there is more frames to be sent
*/
if ((self->window > 1) && (nextfit)) {
irlap_send_data_secondary(self, skb);
irlap_next_state(self, LAP_XMIT_S);
} else {
irlap_send_data_secondary_final(self, skb);
irlap_next_state(self, LAP_NRM_S);
/*
* Make sure state machine does not try to send
* any more frames
*/
ret = -EPROTO;
}
} else {
IRDA_DEBUG(2, "%s(), Unable to send!\n", __FUNCTION__);
skb_queue_head(&self->txq, skb_get(skb));
ret = -EPROTO;
}
break;
case DISCONNECT_REQUEST:
irlap_send_rd_frame(self);
irlap_flush_all_queues(self);
irlap_start_wd_timer(self, self->wd_timeout);
irlap_next_state(self, LAP_SCLOSE);
break;
case DATA_REQUEST:
/* Nothing to do, irlap_do_event() will send the packet
* when we return... - Jean II */
break;
default:
IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
irlap_event[event]);
ret = -EINVAL;
break;
}
return ret;
}
/*
* Function irlap_state_nrm_s (event, skb, info)
*
* NRM_S (Normal Response Mode as Secondary) state, in this state we are
* expecting to receive frames from the primary station
*
*/
static int irlap_state_nrm_s(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ns_status;
int nr_status;
int ret = 0;
IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[ event]);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
switch (event) {
case RECV_I_CMD: /* Optimize for the common case */
/* FIXME: must check for remote_busy below */
IRDA_DEBUG(4, "%s(), event=%s nr=%d, vs=%d, ns=%d, "
"vr=%d, pf=%d\n", __FUNCTION__,
irlap_event[event], info->nr,
self->vs, info->ns, self->vr, info->pf);
self->retry_count = 0;
ns_status = irlap_validate_ns_received(self, info->ns);
nr_status = irlap_validate_nr_received(self, info->nr);
/*
* Check for expected I(nformation) frame
*/
if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {
/* Update Vr (next frame for us to receive) */
self->vr = (self->vr + 1) % 8;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
/*
* poll bit cleared?
*/
if (!info->pf) {
self->ack_required = TRUE;
/*
* Starting WD-timer here is optional, but
* not recommended. Note 6 IrLAP p. 83
*/
#if 0
irda_start_timer(WD_TIMER, self->wd_timeout);
#endif
/* Keep state, do not move this line */
irlap_next_state(self, LAP_NRM_S);
irlap_data_indication(self, skb, FALSE);
break;
} else {
/*
* We should wait before sending RR, and
* also before changing to XMIT_S
* state. (note 1, IrLAP p. 82)
*/
irlap_wait_min_turn_around(self, &self->qos_tx);
/*
* Give higher layers a chance to
* immediately reply with some data before
* we decide if we should send a RR frame
* or not
*/
irlap_data_indication(self, skb, FALSE);
/* Any pending data requests? */
if (!skb_queue_empty(&self->txq) &&
(self->window > 0))
{
self->ack_required = TRUE;
del_timer(&self->wd_timer);
irlap_next_state(self, LAP_XMIT_S);
} else {
irlap_send_rr_frame(self, RSP_FRAME);
irlap_start_wd_timer(self,
self->wd_timeout);
/* Keep the state */
irlap_next_state(self, LAP_NRM_S);
}
break;
}
}
/*
* Check for Unexpected next to send (Ns)
*/
if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
{
/* Unexpected next to send, with final bit cleared */
if (!info->pf) {
irlap_update_nr_received(self, info->nr);
irlap_start_wd_timer(self, self->wd_timeout);
} else {
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, RSP_FRAME);
irlap_start_wd_timer(self, self->wd_timeout);
}
break;
}
/*
* Unexpected Next to Receive(NR) ?
*/
if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
{
if (info->pf) {
IRDA_DEBUG(4, "RECV_I_RSP: frame(s) lost\n");
self->vr = (self->vr + 1) % 8;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
/* Resend rejected frames */
irlap_resend_rejected_frames(self, RSP_FRAME);
/* Keep state, do not move this line */
irlap_next_state(self, LAP_NRM_S);
irlap_data_indication(self, skb, FALSE);
irlap_start_wd_timer(self, self->wd_timeout);
break;
}
/*
* This is not documented in IrLAP!! Unexpected NR
* with poll bit cleared
*/
if (!info->pf) {
self->vr = (self->vr + 1) % 8;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
/* Keep state, do not move this line */
irlap_next_state(self, LAP_NRM_S);
irlap_data_indication(self, skb, FALSE);
irlap_start_wd_timer(self, self->wd_timeout);
}
break;
}
if (ret == NR_INVALID) {
IRDA_DEBUG(0, "NRM_S, NR_INVALID not implemented!\n");
}
if (ret == NS_INVALID) {
IRDA_DEBUG(0, "NRM_S, NS_INVALID not implemented!\n");
}
break;
case RECV_UI_FRAME:
/*
* poll bit cleared?
*/
if (!info->pf) {
irlap_data_indication(self, skb, TRUE);
irlap_next_state(self, LAP_NRM_S); /* Keep state */
} else {
/*
* Any pending data requests?
*/
if (!skb_queue_empty(&self->txq) &&
(self->window > 0) && !self->remote_busy)
{
irlap_data_indication(self, skb, TRUE);
del_timer(&self->wd_timer);
irlap_next_state(self, LAP_XMIT_S);
} else {
irlap_data_indication(self, skb, TRUE);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, RSP_FRAME);
self->ack_required = FALSE;
irlap_start_wd_timer(self, self->wd_timeout);
/* Keep the state */
irlap_next_state(self, LAP_NRM_S);
}
}
break;
case RECV_RR_CMD:
self->retry_count = 0;
/*
* Nr as expected?
*/
nr_status = irlap_validate_nr_received(self, info->nr);
if (nr_status == NR_EXPECTED) {
if (!skb_queue_empty(&self->txq) &&
(self->window > 0)) {
self->remote_busy = FALSE;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
del_timer(&self->wd_timer);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_next_state(self, LAP_XMIT_S);
} else {
self->remote_busy = FALSE;
/* Update Nr received */
irlap_update_nr_received(self, info->nr);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_start_wd_timer(self, self->wd_timeout);
/* Note : if the link is idle (this case),
* we never go in XMIT_S, so we never get a
* chance to process any DISCONNECT_REQUEST.
* Do it now ! - Jean II */
if (self->disconnect_pending) {
/* Disconnect */
irlap_send_rd_frame(self);
irlap_flush_all_queues(self);
irlap_next_state(self, LAP_SCLOSE);
} else {
/* Just send back pf bit */
irlap_send_rr_frame(self, RSP_FRAME);
irlap_next_state(self, LAP_NRM_S);
}
}
} else if (nr_status == NR_UNEXPECTED) {
self->remote_busy = FALSE;
irlap_update_nr_received(self, info->nr);
irlap_resend_rejected_frames(self, RSP_FRAME);
irlap_start_wd_timer(self, self->wd_timeout);
/* Keep state */
irlap_next_state(self, LAP_NRM_S);
} else {
IRDA_DEBUG(1, "%s(), invalid nr not implemented!\n",
__FUNCTION__);
}
break;
case RECV_SNRM_CMD:
/* SNRM frame is not allowed to contain an I-field */
if (!info) {
del_timer(&self->wd_timer);
IRDA_DEBUG(1, "%s(), received SNRM cmd\n", __FUNCTION__);
irlap_next_state(self, LAP_RESET_CHECK);
irlap_reset_indication(self);
} else {
IRDA_DEBUG(0,
"%s(), SNRM frame contained an I-field!\n",
__FUNCTION__);
}
break;
case RECV_REJ_CMD:
irlap_update_nr_received(self, info->nr);
if (self->remote_busy) {
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, RSP_FRAME);
} else
irlap_resend_rejected_frames(self, RSP_FRAME);
irlap_start_wd_timer(self, self->wd_timeout);
break;
case RECV_SREJ_CMD:
irlap_update_nr_received(self, info->nr);
if (self->remote_busy) {
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, RSP_FRAME);
} else
irlap_resend_rejected_frame(self, RSP_FRAME);
irlap_start_wd_timer(self, self->wd_timeout);
break;
case WD_TIMER_EXPIRED:
/*
* Wait until retry_count * n matches negotiated threshold/
* disconnect time (note 2 in IrLAP p. 82)
*
* Similar to irlap_state_nrm_p() -> FINAL_TIMER_EXPIRED
* Note : self->wd_timeout = (self->final_timeout * 2),
* which explain why we use (self->N2 / 2) here !!!
* Jean II
*/
IRDA_DEBUG(1, "%s(), retry_count = %d\n", __FUNCTION__,
self->retry_count);
if (self->retry_count < (self->N2 / 2)) {
/* No retry, just wait for primary */
irlap_start_wd_timer(self, self->wd_timeout);
self->retry_count++;
if((self->retry_count % (self->N1 / 2)) == 0)
irlap_status_indication(self,
STATUS_NO_ACTIVITY);
} else {
irlap_apply_default_connection_parameters(self);
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_disconnect_indication(self, LAP_NO_RESPONSE);
}
break;
case RECV_DISC_CMD:
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
/* Send disconnect response */
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_ua_response_frame(self, NULL);
del_timer(&self->wd_timer);
irlap_flush_all_queues(self);
/* Set default link parameters */
irlap_apply_default_connection_parameters(self);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
case RECV_DISCOVERY_XID_CMD:
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rr_frame(self, RSP_FRAME);
self->ack_required = TRUE;
irlap_start_wd_timer(self, self->wd_timeout);
irlap_next_state(self, LAP_NRM_S);
break;
case RECV_TEST_CMD:
/* Remove test frame header (only LAP header in NRM) */
skb_pull(skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_start_wd_timer(self, self->wd_timeout);
/* Send response (info will be copied) */
irlap_send_test_frame(self, self->caddr, info->daddr, skb);
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__,
event, irlap_event[event]);
ret = -EINVAL;
break;
}
return ret;
}
/*
* Function irlap_state_sclose (self, event, skb, info)
*/
static int irlap_state_sclose(struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb, struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
IRDA_ASSERT(self != NULL, return -ENODEV;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
switch (event) {
case RECV_DISC_CMD:
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
/* Send disconnect response */
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_ua_response_frame(self, NULL);
del_timer(&self->wd_timer);
/* Set default link parameters */
irlap_apply_default_connection_parameters(self);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
case RECV_DM_RSP:
/* IrLAP-1.1 p.82: in SCLOSE, S and I type RSP frames
* shall take us down into default NDM state, like DM_RSP
*/
case RECV_RR_RSP:
case RECV_RNR_RSP:
case RECV_REJ_RSP:
case RECV_SREJ_RSP:
case RECV_I_RSP:
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
del_timer(&self->wd_timer);
irlap_apply_default_connection_parameters(self);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
case WD_TIMER_EXPIRED:
/* Always switch state before calling upper layers */
irlap_next_state(self, LAP_NDM);
irlap_apply_default_connection_parameters(self);
irlap_disconnect_indication(self, LAP_DISC_INDICATION);
break;
default:
/* IrLAP-1.1 p.82: in SCLOSE, basically any received frame
* with pf=1 shall restart the wd-timer and resend the rd:rsp
*/
if (info != NULL && info->pf) {
del_timer(&self->wd_timer);
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rd_frame(self);
irlap_start_wd_timer(self, self->wd_timeout);
break; /* stay in SCLOSE */
}
IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__,
event, irlap_event[event]);
ret = -EINVAL;
break;
}
return -1;
}
static int irlap_state_reset_check( struct irlap_cb *self, IRLAP_EVENT event,
struct sk_buff *skb,
struct irlap_info *info)
{
int ret = 0;
IRDA_DEBUG(1, "%s(), event=%s\n", __FUNCTION__, irlap_event[event]);
IRDA_ASSERT(self != NULL, return -ENODEV;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
switch (event) {
case RESET_RESPONSE:
irlap_send_ua_response_frame(self, &self->qos_rx);
irlap_initiate_connection_state(self);
irlap_start_wd_timer(self, WD_TIMEOUT);
irlap_flush_all_queues(self);
irlap_next_state(self, LAP_NRM_S);
break;
case DISCONNECT_REQUEST:
irlap_wait_min_turn_around(self, &self->qos_tx);
irlap_send_rd_frame(self);
irlap_start_wd_timer(self, WD_TIMEOUT);
irlap_next_state(self, LAP_SCLOSE);
break;
default:
IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__,
event, irlap_event[event]);
ret = -EINVAL;
break;
}
return ret;
}
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