linux/net/irda/irttp.c
Dave Jones 096895818c silence some noisy printks in irda
Fuzzing causes these printks to spew constantly.
Changing them to DEBUG statements is consistent with other usage in the file,
and makes them disappear when CONFIG_IRDA_DEBUG is disabled.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-04 15:53:48 -04:00

1915 lines
51 KiB
C

/*********************************************************************
*
* Filename: irttp.c
* Version: 1.2
* Description: Tiny Transport Protocol (TTP) implementation
* Status: Stable
* Author: Dag Brattli <dagb@cs.uit.no>
* Created at: Sun Aug 31 20:14:31 1997
* Modified at: Wed Jan 5 11:31:27 2000
* Modified by: Dag Brattli <dagb@cs.uit.no>
*
* Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
* 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/skbuff.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <net/irda/irda.h>
#include <net/irda/irlap.h>
#include <net/irda/irlmp.h>
#include <net/irda/parameters.h>
#include <net/irda/irttp.h>
static struct irttp_cb *irttp;
static void __irttp_close_tsap(struct tsap_cb *self);
static int irttp_data_indication(void *instance, void *sap,
struct sk_buff *skb);
static int irttp_udata_indication(void *instance, void *sap,
struct sk_buff *skb);
static void irttp_disconnect_indication(void *instance, void *sap,
LM_REASON reason, struct sk_buff *);
static void irttp_connect_indication(void *instance, void *sap,
struct qos_info *qos, __u32 max_sdu_size,
__u8 header_size, struct sk_buff *skb);
static void irttp_connect_confirm(void *instance, void *sap,
struct qos_info *qos, __u32 max_sdu_size,
__u8 header_size, struct sk_buff *skb);
static void irttp_run_tx_queue(struct tsap_cb *self);
static void irttp_run_rx_queue(struct tsap_cb *self);
static void irttp_flush_queues(struct tsap_cb *self);
static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
static void irttp_todo_expired(unsigned long data);
static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
int get);
static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
static void irttp_status_indication(void *instance,
LINK_STATUS link, LOCK_STATUS lock);
/* Information for parsing parameters in IrTTP */
static pi_minor_info_t pi_minor_call_table[] = {
{ NULL, 0 }, /* 0x00 */
{ irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
};
static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
/************************ GLOBAL PROCEDURES ************************/
/*
* Function irttp_init (void)
*
* Initialize the IrTTP layer. Called by module initialization code
*
*/
int __init irttp_init(void)
{
irttp = kzalloc(sizeof(struct irttp_cb), GFP_KERNEL);
if (irttp == NULL)
return -ENOMEM;
irttp->magic = TTP_MAGIC;
irttp->tsaps = hashbin_new(HB_LOCK);
if (!irttp->tsaps) {
IRDA_ERROR("%s: can't allocate IrTTP hashbin!\n",
__func__);
kfree(irttp);
return -ENOMEM;
}
return 0;
}
/*
* Function irttp_cleanup (void)
*
* Called by module destruction/cleanup code
*
*/
void irttp_cleanup(void)
{
/* Check for main structure */
IRDA_ASSERT(irttp->magic == TTP_MAGIC, return;);
/*
* Delete hashbin and close all TSAP instances in it
*/
hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
irttp->magic = 0;
/* De-allocate main structure */
kfree(irttp);
irttp = NULL;
}
/*************************** SUBROUTINES ***************************/
/*
* Function irttp_start_todo_timer (self, timeout)
*
* Start todo timer.
*
* Made it more effient and unsensitive to race conditions - Jean II
*/
static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
{
/* Set new value for timer */
mod_timer(&self->todo_timer, jiffies + timeout);
}
/*
* Function irttp_todo_expired (data)
*
* Todo timer has expired!
*
* One of the restriction of the timer is that it is run only on the timer
* interrupt which run every 10ms. This mean that even if you set the timer
* with a delay of 0, it may take up to 10ms before it's run.
* So, to minimise latency and keep cache fresh, we try to avoid using
* it as much as possible.
* Note : we can't use tasklets, because they can't be asynchronously
* killed (need user context), and we can't guarantee that here...
* Jean II
*/
static void irttp_todo_expired(unsigned long data)
{
struct tsap_cb *self = (struct tsap_cb *) data;
/* Check that we still exist */
if (!self || self->magic != TTP_TSAP_MAGIC)
return;
IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
/* Try to make some progress, especially on Tx side - Jean II */
irttp_run_rx_queue(self);
irttp_run_tx_queue(self);
/* Check if time for disconnect */
if (test_bit(0, &self->disconnect_pend)) {
/* Check if it's possible to disconnect yet */
if (skb_queue_empty(&self->tx_queue)) {
/* Make sure disconnect is not pending anymore */
clear_bit(0, &self->disconnect_pend); /* FALSE */
/* Note : self->disconnect_skb may be NULL */
irttp_disconnect_request(self, self->disconnect_skb,
P_NORMAL);
self->disconnect_skb = NULL;
} else {
/* Try again later */
irttp_start_todo_timer(self, HZ/10);
/* No reason to try and close now */
return;
}
}
/* Check if it's closing time */
if (self->close_pend)
/* Finish cleanup */
irttp_close_tsap(self);
}
/*
* Function irttp_flush_queues (self)
*
* Flushes (removes all frames) in transitt-buffer (tx_list)
*/
static void irttp_flush_queues(struct tsap_cb *self)
{
struct sk_buff* skb;
IRDA_DEBUG(4, "%s()\n", __func__);
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
/* Deallocate frames waiting to be sent */
while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
dev_kfree_skb(skb);
/* Deallocate received frames */
while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
dev_kfree_skb(skb);
/* Deallocate received fragments */
while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
dev_kfree_skb(skb);
}
/*
* Function irttp_reassemble (self)
*
* Makes a new (continuous) skb of all the fragments in the fragment
* queue
*
*/
static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
{
struct sk_buff *skb, *frag;
int n = 0; /* Fragment index */
IRDA_ASSERT(self != NULL, return NULL;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
IRDA_DEBUG(2, "%s(), self->rx_sdu_size=%d\n", __func__,
self->rx_sdu_size);
skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
if (!skb)
return NULL;
/*
* Need to reserve space for TTP header in case this skb needs to
* be requeued in case delivery failes
*/
skb_reserve(skb, TTP_HEADER);
skb_put(skb, self->rx_sdu_size);
/*
* Copy all fragments to a new buffer
*/
while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
skb_copy_to_linear_data_offset(skb, n, frag->data, frag->len);
n += frag->len;
dev_kfree_skb(frag);
}
IRDA_DEBUG(2,
"%s(), frame len=%d, rx_sdu_size=%d, rx_max_sdu_size=%d\n",
__func__, n, self->rx_sdu_size, self->rx_max_sdu_size);
/* Note : irttp_run_rx_queue() calculate self->rx_sdu_size
* by summing the size of all fragments, so we should always
* have n == self->rx_sdu_size, except in cases where we
* droped the last fragment (when self->rx_sdu_size exceed
* self->rx_max_sdu_size), where n < self->rx_sdu_size.
* Jean II */
IRDA_ASSERT(n <= self->rx_sdu_size, n = self->rx_sdu_size;);
/* Set the new length */
skb_trim(skb, n);
self->rx_sdu_size = 0;
return skb;
}
/*
* Function irttp_fragment_skb (skb)
*
* Fragments a frame and queues all the fragments for transmission
*
*/
static inline void irttp_fragment_skb(struct tsap_cb *self,
struct sk_buff *skb)
{
struct sk_buff *frag;
__u8 *frame;
IRDA_DEBUG(2, "%s()\n", __func__);
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
IRDA_ASSERT(skb != NULL, return;);
/*
* Split frame into a number of segments
*/
while (skb->len > self->max_seg_size) {
IRDA_DEBUG(2, "%s(), fragmenting ...\n", __func__);
/* Make new segment */
frag = alloc_skb(self->max_seg_size+self->max_header_size,
GFP_ATOMIC);
if (!frag)
return;
skb_reserve(frag, self->max_header_size);
/* Copy data from the original skb into this fragment. */
skb_copy_from_linear_data(skb, skb_put(frag, self->max_seg_size),
self->max_seg_size);
/* Insert TTP header, with the more bit set */
frame = skb_push(frag, TTP_HEADER);
frame[0] = TTP_MORE;
/* Hide the copied data from the original skb */
skb_pull(skb, self->max_seg_size);
/* Queue fragment */
skb_queue_tail(&self->tx_queue, frag);
}
/* Queue what is left of the original skb */
IRDA_DEBUG(2, "%s(), queuing last segment\n", __func__);
frame = skb_push(skb, TTP_HEADER);
frame[0] = 0x00; /* Clear more bit */
/* Queue fragment */
skb_queue_tail(&self->tx_queue, skb);
}
/*
* Function irttp_param_max_sdu_size (self, param)
*
* Handle the MaxSduSize parameter in the connect frames, this function
* will be called both when this parameter needs to be inserted into, and
* extracted from the connect frames
*/
static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
int get)
{
struct tsap_cb *self;
self = instance;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
if (get)
param->pv.i = self->tx_max_sdu_size;
else
self->tx_max_sdu_size = param->pv.i;
IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __func__, param->pv.i);
return 0;
}
/*************************** CLIENT CALLS ***************************/
/************************** LMP CALLBACKS **************************/
/* Everything is happily mixed up. Waiting for next clean up - Jean II */
/*
* Initialization, that has to be done on new tsap
* instance allocation and on duplication
*/
static void irttp_init_tsap(struct tsap_cb *tsap)
{
spin_lock_init(&tsap->lock);
init_timer(&tsap->todo_timer);
skb_queue_head_init(&tsap->rx_queue);
skb_queue_head_init(&tsap->tx_queue);
skb_queue_head_init(&tsap->rx_fragments);
}
/*
* Function irttp_open_tsap (stsap, notify)
*
* Create TSAP connection endpoint,
*/
struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
{
struct tsap_cb *self;
struct lsap_cb *lsap;
notify_t ttp_notify;
IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
/* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
* use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
* JeanII */
if((stsap_sel != LSAP_ANY) &&
((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
IRDA_DEBUG(0, "%s(), invalid tsap!\n", __func__);
return NULL;
}
self = kzalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
if (self == NULL) {
IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __func__);
return NULL;
}
/* Initialize internal objects */
irttp_init_tsap(self);
/* Initialise todo timer */
self->todo_timer.data = (unsigned long) self;
self->todo_timer.function = &irttp_todo_expired;
/* Initialize callbacks for IrLMP to use */
irda_notify_init(&ttp_notify);
ttp_notify.connect_confirm = irttp_connect_confirm;
ttp_notify.connect_indication = irttp_connect_indication;
ttp_notify.disconnect_indication = irttp_disconnect_indication;
ttp_notify.data_indication = irttp_data_indication;
ttp_notify.udata_indication = irttp_udata_indication;
ttp_notify.flow_indication = irttp_flow_indication;
if(notify->status_indication != NULL)
ttp_notify.status_indication = irttp_status_indication;
ttp_notify.instance = self;
strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
self->magic = TTP_TSAP_MAGIC;
self->connected = FALSE;
/*
* Create LSAP at IrLMP layer
*/
lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
if (lsap == NULL) {
IRDA_DEBUG(0, "%s: unable to allocate LSAP!!\n", __func__);
return NULL;
}
/*
* If user specified LSAP_ANY as source TSAP selector, then IrLMP
* will replace it with whatever source selector which is free, so
* the stsap_sel we have might not be valid anymore
*/
self->stsap_sel = lsap->slsap_sel;
IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __func__, self->stsap_sel);
self->notify = *notify;
self->lsap = lsap;
hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
if (credit > TTP_RX_MAX_CREDIT)
self->initial_credit = TTP_RX_MAX_CREDIT;
else
self->initial_credit = credit;
return self;
}
EXPORT_SYMBOL(irttp_open_tsap);
/*
* Function irttp_close (handle)
*
* Remove an instance of a TSAP. This function should only deal with the
* deallocation of the TSAP, and resetting of the TSAPs values;
*
*/
static void __irttp_close_tsap(struct tsap_cb *self)
{
/* First make sure we're connected. */
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
irttp_flush_queues(self);
del_timer(&self->todo_timer);
/* This one won't be cleaned up if we are disconnect_pend + close_pend
* and we receive a disconnect_indication */
if (self->disconnect_skb)
dev_kfree_skb(self->disconnect_skb);
self->connected = FALSE;
self->magic = ~TTP_TSAP_MAGIC;
kfree(self);
}
/*
* Function irttp_close (self)
*
* Remove TSAP from list of all TSAPs and then deallocate all resources
* associated with this TSAP
*
* Note : because we *free* the tsap structure, it is the responsibility
* of the caller to make sure we are called only once and to deal with
* possible race conditions. - Jean II
*/
int irttp_close_tsap(struct tsap_cb *self)
{
struct tsap_cb *tsap;
IRDA_DEBUG(4, "%s()\n", __func__);
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
/* Make sure tsap has been disconnected */
if (self->connected) {
/* Check if disconnect is not pending */
if (!test_bit(0, &self->disconnect_pend)) {
IRDA_WARNING("%s: TSAP still connected!\n",
__func__);
irttp_disconnect_request(self, NULL, P_NORMAL);
}
self->close_pend = TRUE;
irttp_start_todo_timer(self, HZ/10);
return 0; /* Will be back! */
}
tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
IRDA_ASSERT(tsap == self, return -1;);
/* Close corresponding LSAP */
if (self->lsap) {
irlmp_close_lsap(self->lsap);
self->lsap = NULL;
}
__irttp_close_tsap(self);
return 0;
}
EXPORT_SYMBOL(irttp_close_tsap);
/*
* Function irttp_udata_request (self, skb)
*
* Send unreliable data on this TSAP
*
*/
int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
{
int ret;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
IRDA_ASSERT(skb != NULL, return -1;);
IRDA_DEBUG(4, "%s()\n", __func__);
/* Take shortcut on zero byte packets */
if (skb->len == 0) {
ret = 0;
goto err;
}
/* Check that nothing bad happens */
if (!self->connected) {
IRDA_WARNING("%s(), Not connected\n", __func__);
ret = -ENOTCONN;
goto err;
}
if (skb->len > self->max_seg_size) {
IRDA_ERROR("%s(), UData is too large for IrLAP!\n", __func__);
ret = -EMSGSIZE;
goto err;
}
irlmp_udata_request(self->lsap, skb);
self->stats.tx_packets++;
return 0;
err:
dev_kfree_skb(skb);
return ret;
}
EXPORT_SYMBOL(irttp_udata_request);
/*
* Function irttp_data_request (handle, skb)
*
* Queue frame for transmission. If SAR is enabled, fragement the frame
* and queue the fragments for transmission
*/
int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
{
__u8 *frame;
int ret;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
IRDA_ASSERT(skb != NULL, return -1;);
IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
skb_queue_len(&self->tx_queue));
/* Take shortcut on zero byte packets */
if (skb->len == 0) {
ret = 0;
goto err;
}
/* Check that nothing bad happens */
if (!self->connected) {
IRDA_WARNING("%s: Not connected\n", __func__);
ret = -ENOTCONN;
goto err;
}
/*
* Check if SAR is disabled, and the frame is larger than what fits
* inside an IrLAP frame
*/
if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
__func__);
ret = -EMSGSIZE;
goto err;
}
/*
* Check if SAR is enabled, and the frame is larger than the
* TxMaxSduSize
*/
if ((self->tx_max_sdu_size != 0) &&
(self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
(skb->len > self->tx_max_sdu_size))
{
IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
__func__);
ret = -EMSGSIZE;
goto err;
}
/*
* Check if transmit queue is full
*/
if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
/*
* Give it a chance to empty itself
*/
irttp_run_tx_queue(self);
/* Drop packet. This error code should trigger the caller
* to resend the data in the client code - Jean II */
ret = -ENOBUFS;
goto err;
}
/* Queue frame, or queue frame segments */
if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
/* Queue frame */
IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
frame = skb_push(skb, TTP_HEADER);
frame[0] = 0x00; /* Clear more bit */
skb_queue_tail(&self->tx_queue, skb);
} else {
/*
* Fragment the frame, this function will also queue the
* fragments, we don't care about the fact the transmit
* queue may be overfilled by all the segments for a little
* while
*/
irttp_fragment_skb(self, skb);
}
/* Check if we can accept more data from client */
if ((!self->tx_sdu_busy) &&
(skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
/* Tx queue filling up, so stop client. */
if (self->notify.flow_indication) {
self->notify.flow_indication(self->notify.instance,
self, FLOW_STOP);
}
/* self->tx_sdu_busy is the state of the client.
* Update state after notifying client to avoid
* race condition with irttp_flow_indication().
* If the queue empty itself after our test but before
* we set the flag, we will fix ourselves below in
* irttp_run_tx_queue().
* Jean II */
self->tx_sdu_busy = TRUE;
}
/* Try to make some progress */
irttp_run_tx_queue(self);
return 0;
err:
dev_kfree_skb(skb);
return ret;
}
EXPORT_SYMBOL(irttp_data_request);
/*
* Function irttp_run_tx_queue (self)
*
* Transmit packets queued for transmission (if possible)
*
*/
static void irttp_run_tx_queue(struct tsap_cb *self)
{
struct sk_buff *skb;
unsigned long flags;
int n;
IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
__func__,
self->send_credit, skb_queue_len(&self->tx_queue));
/* Get exclusive access to the tx queue, otherwise don't touch it */
if (irda_lock(&self->tx_queue_lock) == FALSE)
return;
/* Try to send out frames as long as we have credits
* and as long as LAP is not full. If LAP is full, it will
* poll us through irttp_flow_indication() - Jean II */
while ((self->send_credit > 0) &&
(!irlmp_lap_tx_queue_full(self->lsap)) &&
(skb = skb_dequeue(&self->tx_queue)))
{
/*
* Since we can transmit and receive frames concurrently,
* the code below is a critical region and we must assure that
* nobody messes with the credits while we update them.
*/
spin_lock_irqsave(&self->lock, flags);
n = self->avail_credit;
self->avail_credit = 0;
/* Only room for 127 credits in frame */
if (n > 127) {
self->avail_credit = n-127;
n = 127;
}
self->remote_credit += n;
self->send_credit--;
spin_unlock_irqrestore(&self->lock, flags);
/*
* More bit must be set by the data_request() or fragment()
* functions
*/
skb->data[0] |= (n & 0x7f);
/* Detach from socket.
* The current skb has a reference to the socket that sent
* it (skb->sk). When we pass it to IrLMP, the skb will be
* stored in in IrLAP (self->wx_list). When we are within
* IrLAP, we lose the notion of socket, so we should not
* have a reference to a socket. So, we drop it here.
*
* Why does it matter ?
* When the skb is freed (kfree_skb), if it is associated
* with a socket, it release buffer space on the socket
* (through sock_wfree() and sock_def_write_space()).
* If the socket no longer exist, we may crash. Hard.
* When we close a socket, we make sure that associated packets
* in IrTTP are freed. However, we have no way to cancel
* the packet that we have passed to IrLAP. So, if a packet
* remains in IrLAP (retry on the link or else) after we
* close the socket, we are dead !
* Jean II */
if (skb->sk != NULL) {
/* IrSOCK application, IrOBEX, ... */
skb_orphan(skb);
}
/* IrCOMM over IrTTP, IrLAN, ... */
/* Pass the skb to IrLMP - done */
irlmp_data_request(self->lsap, skb);
self->stats.tx_packets++;
}
/* Check if we can accept more frames from client.
* We don't want to wait until the todo timer to do that, and we
* can't use tasklets (grr...), so we are obliged to give control
* to client. That's ok, this test will be true not too often
* (max once per LAP window) and we are called from places
* where we can spend a bit of time doing stuff. - Jean II */
if ((self->tx_sdu_busy) &&
(skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
(!self->close_pend))
{
if (self->notify.flow_indication)
self->notify.flow_indication(self->notify.instance,
self, FLOW_START);
/* self->tx_sdu_busy is the state of the client.
* We don't really have a race here, but it's always safer
* to update our state after the client - Jean II */
self->tx_sdu_busy = FALSE;
}
/* Reset lock */
self->tx_queue_lock = 0;
}
/*
* Function irttp_give_credit (self)
*
* Send a dataless flowdata TTP-PDU and give available credit to peer
* TSAP
*/
static inline void irttp_give_credit(struct tsap_cb *self)
{
struct sk_buff *tx_skb = NULL;
unsigned long flags;
int n;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
__func__,
self->send_credit, self->avail_credit, self->remote_credit);
/* Give credit to peer */
tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
if (!tx_skb)
return;
/* Reserve space for LMP, and LAP header */
skb_reserve(tx_skb, LMP_MAX_HEADER);
/*
* Since we can transmit and receive frames concurrently,
* the code below is a critical region and we must assure that
* nobody messes with the credits while we update them.
*/
spin_lock_irqsave(&self->lock, flags);
n = self->avail_credit;
self->avail_credit = 0;
/* Only space for 127 credits in frame */
if (n > 127) {
self->avail_credit = n - 127;
n = 127;
}
self->remote_credit += n;
spin_unlock_irqrestore(&self->lock, flags);
skb_put(tx_skb, 1);
tx_skb->data[0] = (__u8) (n & 0x7f);
irlmp_data_request(self->lsap, tx_skb);
self->stats.tx_packets++;
}
/*
* Function irttp_udata_indication (instance, sap, skb)
*
* Received some unit-data (unreliable)
*
*/
static int irttp_udata_indication(void *instance, void *sap,
struct sk_buff *skb)
{
struct tsap_cb *self;
int err;
IRDA_DEBUG(4, "%s()\n", __func__);
self = instance;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
IRDA_ASSERT(skb != NULL, return -1;);
self->stats.rx_packets++;
/* Just pass data to layer above */
if (self->notify.udata_indication) {
err = self->notify.udata_indication(self->notify.instance,
self,skb);
/* Same comment as in irttp_do_data_indication() */
if (!err)
return 0;
}
/* Either no handler, or handler returns an error */
dev_kfree_skb(skb);
return 0;
}
/*
* Function irttp_data_indication (instance, sap, skb)
*
* Receive segment from IrLMP.
*
*/
static int irttp_data_indication(void *instance, void *sap,
struct sk_buff *skb)
{
struct tsap_cb *self;
unsigned long flags;
int n;
self = instance;
n = skb->data[0] & 0x7f; /* Extract the credits */
self->stats.rx_packets++;
/* Deal with inbound credit
* Since we can transmit and receive frames concurrently,
* the code below is a critical region and we must assure that
* nobody messes with the credits while we update them.
*/
spin_lock_irqsave(&self->lock, flags);
self->send_credit += n;
if (skb->len > 1)
self->remote_credit--;
spin_unlock_irqrestore(&self->lock, flags);
/*
* Data or dataless packet? Dataless frames contains only the
* TTP_HEADER.
*/
if (skb->len > 1) {
/*
* We don't remove the TTP header, since we must preserve the
* more bit, so the defragment routing knows what to do
*/
skb_queue_tail(&self->rx_queue, skb);
} else {
/* Dataless flowdata TTP-PDU */
dev_kfree_skb(skb);
}
/* Push data to the higher layer.
* We do it synchronously because running the todo timer for each
* receive packet would be too much overhead and latency.
* By passing control to the higher layer, we run the risk that
* it may take time or grab a lock. Most often, the higher layer
* will only put packet in a queue.
* Anyway, packets are only dripping through the IrDA, so we can
* have time before the next packet.
* Further, we are run from NET_BH, so the worse that can happen is
* us missing the optimal time to send back the PF bit in LAP.
* Jean II */
irttp_run_rx_queue(self);
/* We now give credits to peer in irttp_run_rx_queue().
* We need to send credit *NOW*, otherwise we are going
* to miss the next Tx window. The todo timer may take
* a while before it's run... - Jean II */
/*
* If the peer device has given us some credits and we didn't have
* anyone from before, then we need to shedule the tx queue.
* We need to do that because our Tx have stopped (so we may not
* get any LAP flow indication) and the user may be stopped as
* well. - Jean II
*/
if (self->send_credit == n) {
/* Restart pushing stuff to LAP */
irttp_run_tx_queue(self);
/* Note : we don't want to schedule the todo timer
* because it has horrible latency. No tasklets
* because the tasklet API is broken. - Jean II */
}
return 0;
}
/*
* Function irttp_status_indication (self, reason)
*
* Status_indication, just pass to the higher layer...
*
*/
static void irttp_status_indication(void *instance,
LINK_STATUS link, LOCK_STATUS lock)
{
struct tsap_cb *self;
IRDA_DEBUG(4, "%s()\n", __func__);
self = instance;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
/* Check if client has already closed the TSAP and gone away */
if (self->close_pend)
return;
/*
* Inform service user if he has requested it
*/
if (self->notify.status_indication != NULL)
self->notify.status_indication(self->notify.instance,
link, lock);
else
IRDA_DEBUG(2, "%s(), no handler\n", __func__);
}
/*
* Function irttp_flow_indication (self, reason)
*
* Flow_indication : IrLAP tells us to send more data.
*
*/
static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
{
struct tsap_cb *self;
self = instance;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
/* We are "polled" directly from LAP, and the LAP want to fill
* its Tx window. We want to do our best to send it data, so that
* we maximise the window. On the other hand, we want to limit the
* amount of work here so that LAP doesn't hang forever waiting
* for packets. - Jean II */
/* Try to send some packets. Currently, LAP calls us every time
* there is one free slot, so we will send only one packet.
* This allow the scheduler to do its round robin - Jean II */
irttp_run_tx_queue(self);
/* Note regarding the interraction with higher layer.
* irttp_run_tx_queue() may call the client when its queue
* start to empty, via notify.flow_indication(). Initially.
* I wanted this to happen in a tasklet, to avoid client
* grabbing the CPU, but we can't use tasklets safely. And timer
* is definitely too slow.
* This will happen only once per LAP window, and usually at
* the third packet (unless window is smaller). LAP is still
* doing mtt and sending first packet so it's sort of OK
* to do that. Jean II */
/* If we need to send disconnect. try to do it now */
if(self->disconnect_pend)
irttp_start_todo_timer(self, 0);
}
/*
* Function irttp_flow_request (self, command)
*
* This function could be used by the upper layers to tell IrTTP to stop
* delivering frames if the receive queues are starting to get full, or
* to tell IrTTP to start delivering frames again.
*/
void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
{
IRDA_DEBUG(1, "%s()\n", __func__);
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
switch (flow) {
case FLOW_STOP:
IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
self->rx_sdu_busy = TRUE;
break;
case FLOW_START:
IRDA_DEBUG(1, "%s(), flow start\n", __func__);
self->rx_sdu_busy = FALSE;
/* Client say he can accept more data, try to free our
* queues ASAP - Jean II */
irttp_run_rx_queue(self);
break;
default:
IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
}
}
EXPORT_SYMBOL(irttp_flow_request);
/*
* Function irttp_connect_request (self, dtsap_sel, daddr, qos)
*
* Try to connect to remote destination TSAP selector
*
*/
int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
__u32 saddr, __u32 daddr,
struct qos_info *qos, __u32 max_sdu_size,
struct sk_buff *userdata)
{
struct sk_buff *tx_skb;
__u8 *frame;
__u8 n;
IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
IRDA_ASSERT(self != NULL, return -EBADR;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
if (self->connected) {
if(userdata)
dev_kfree_skb(userdata);
return -EISCONN;
}
/* Any userdata supplied? */
if (userdata == NULL) {
tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
GFP_ATOMIC);
if (!tx_skb)
return -ENOMEM;
/* Reserve space for MUX_CONTROL and LAP header */
skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
} else {
tx_skb = userdata;
/*
* Check that the client has reserved enough space for
* headers
*/
IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
{ dev_kfree_skb(userdata); return -1; } );
}
/* Initialize connection parameters */
self->connected = FALSE;
self->avail_credit = 0;
self->rx_max_sdu_size = max_sdu_size;
self->rx_sdu_size = 0;
self->rx_sdu_busy = FALSE;
self->dtsap_sel = dtsap_sel;
n = self->initial_credit;
self->remote_credit = 0;
self->send_credit = 0;
/*
* Give away max 127 credits for now
*/
if (n > 127) {
self->avail_credit=n-127;
n = 127;
}
self->remote_credit = n;
/* SAR enabled? */
if (max_sdu_size > 0) {
IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
{ dev_kfree_skb(tx_skb); return -1; } );
/* Insert SAR parameters */
frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
frame[0] = TTP_PARAMETERS | n;
frame[1] = 0x04; /* Length */
frame[2] = 0x01; /* MaxSduSize */
frame[3] = 0x02; /* Value length */
put_unaligned(cpu_to_be16((__u16) max_sdu_size),
(__be16 *)(frame+4));
} else {
/* Insert plain TTP header */
frame = skb_push(tx_skb, TTP_HEADER);
/* Insert initial credit in frame */
frame[0] = n & 0x7f;
}
/* Connect with IrLMP. No QoS parameters for now */
return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
tx_skb);
}
EXPORT_SYMBOL(irttp_connect_request);
/*
* Function irttp_connect_confirm (handle, qos, skb)
*
* Service user confirms TSAP connection with peer.
*
*/
static void irttp_connect_confirm(void *instance, void *sap,
struct qos_info *qos, __u32 max_seg_size,
__u8 max_header_size, struct sk_buff *skb)
{
struct tsap_cb *self;
int parameters;
int ret;
__u8 plen;
__u8 n;
IRDA_DEBUG(4, "%s()\n", __func__);
self = instance;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
IRDA_ASSERT(skb != NULL, return;);
self->max_seg_size = max_seg_size - TTP_HEADER;
self->max_header_size = max_header_size + TTP_HEADER;
/*
* Check if we have got some QoS parameters back! This should be the
* negotiated QoS for the link.
*/
if (qos) {
IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
qos->baud_rate.bits);
IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
qos->baud_rate.value);
}
n = skb->data[0] & 0x7f;
IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
self->send_credit = n;
self->tx_max_sdu_size = 0;
self->connected = TRUE;
parameters = skb->data[0] & 0x80;
IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
skb_pull(skb, TTP_HEADER);
if (parameters) {
plen = skb->data[0];
ret = irda_param_extract_all(self, skb->data+1,
IRDA_MIN(skb->len-1, plen),
&param_info);
/* Any errors in the parameter list? */
if (ret < 0) {
IRDA_WARNING("%s: error extracting parameters\n",
__func__);
dev_kfree_skb(skb);
/* Do not accept this connection attempt */
return;
}
/* Remove parameters */
skb_pull(skb, IRDA_MIN(skb->len, plen+1));
}
IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
self->send_credit, self->avail_credit, self->remote_credit);
IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
self->tx_max_sdu_size);
if (self->notify.connect_confirm) {
self->notify.connect_confirm(self->notify.instance, self, qos,
self->tx_max_sdu_size,
self->max_header_size, skb);
} else
dev_kfree_skb(skb);
}
/*
* Function irttp_connect_indication (handle, skb)
*
* Some other device is connecting to this TSAP
*
*/
static void irttp_connect_indication(void *instance, void *sap,
struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
struct sk_buff *skb)
{
struct tsap_cb *self;
struct lsap_cb *lsap;
int parameters;
int ret;
__u8 plen;
__u8 n;
self = instance;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
IRDA_ASSERT(skb != NULL, return;);
lsap = sap;
self->max_seg_size = max_seg_size - TTP_HEADER;
self->max_header_size = max_header_size+TTP_HEADER;
IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
/* Need to update dtsap_sel if its equal to LSAP_ANY */
self->dtsap_sel = lsap->dlsap_sel;
n = skb->data[0] & 0x7f;
self->send_credit = n;
self->tx_max_sdu_size = 0;
parameters = skb->data[0] & 0x80;
IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
skb_pull(skb, TTP_HEADER);
if (parameters) {
plen = skb->data[0];
ret = irda_param_extract_all(self, skb->data+1,
IRDA_MIN(skb->len-1, plen),
&param_info);
/* Any errors in the parameter list? */
if (ret < 0) {
IRDA_WARNING("%s: error extracting parameters\n",
__func__);
dev_kfree_skb(skb);
/* Do not accept this connection attempt */
return;
}
/* Remove parameters */
skb_pull(skb, IRDA_MIN(skb->len, plen+1));
}
if (self->notify.connect_indication) {
self->notify.connect_indication(self->notify.instance, self,
qos, self->tx_max_sdu_size,
self->max_header_size, skb);
} else
dev_kfree_skb(skb);
}
/*
* Function irttp_connect_response (handle, userdata)
*
* Service user is accepting the connection, just pass it down to
* IrLMP!
*
*/
int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
struct sk_buff *userdata)
{
struct sk_buff *tx_skb;
__u8 *frame;
int ret;
__u8 n;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
self->stsap_sel);
/* Any userdata supplied? */
if (userdata == NULL) {
tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
GFP_ATOMIC);
if (!tx_skb)
return -ENOMEM;
/* Reserve space for MUX_CONTROL and LAP header */
skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
} else {
tx_skb = userdata;
/*
* Check that the client has reserved enough space for
* headers
*/
IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
{ dev_kfree_skb(userdata); return -1; } );
}
self->avail_credit = 0;
self->remote_credit = 0;
self->rx_max_sdu_size = max_sdu_size;
self->rx_sdu_size = 0;
self->rx_sdu_busy = FALSE;
n = self->initial_credit;
/* Frame has only space for max 127 credits (7 bits) */
if (n > 127) {
self->avail_credit = n - 127;
n = 127;
}
self->remote_credit = n;
self->connected = TRUE;
/* SAR enabled? */
if (max_sdu_size > 0) {
IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
{ dev_kfree_skb(tx_skb); return -1; } );
/* Insert TTP header with SAR parameters */
frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
frame[0] = TTP_PARAMETERS | n;
frame[1] = 0x04; /* Length */
/* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1, */
/* TTP_SAR_HEADER, &param_info) */
frame[2] = 0x01; /* MaxSduSize */
frame[3] = 0x02; /* Value length */
put_unaligned(cpu_to_be16((__u16) max_sdu_size),
(__be16 *)(frame+4));
} else {
/* Insert TTP header */
frame = skb_push(tx_skb, TTP_HEADER);
frame[0] = n & 0x7f;
}
ret = irlmp_connect_response(self->lsap, tx_skb);
return ret;
}
EXPORT_SYMBOL(irttp_connect_response);
/*
* Function irttp_dup (self, instance)
*
* Duplicate TSAP, can be used by servers to confirm a connection on a
* new TSAP so it can keep listening on the old one.
*/
struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
{
struct tsap_cb *new;
unsigned long flags;
IRDA_DEBUG(1, "%s()\n", __func__);
/* Protect our access to the old tsap instance */
spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
/* Find the old instance */
if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
return NULL;
}
/* Allocate a new instance */
new = kmemdup(orig, sizeof(struct tsap_cb), GFP_ATOMIC);
if (!new) {
IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
return NULL;
}
spin_lock_init(&new->lock);
/* We don't need the old instance any more */
spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
/* Try to dup the LSAP (may fail if we were too slow) */
new->lsap = irlmp_dup(orig->lsap, new);
if (!new->lsap) {
IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
kfree(new);
return NULL;
}
/* Not everything should be copied */
new->notify.instance = instance;
/* Initialize internal objects */
irttp_init_tsap(new);
/* This is locked */
hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
return new;
}
EXPORT_SYMBOL(irttp_dup);
/*
* Function irttp_disconnect_request (self)
*
* Close this connection please! If priority is high, the queued data
* segments, if any, will be deallocated first
*
*/
int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
int priority)
{
int ret;
IRDA_ASSERT(self != NULL, return -1;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
/* Already disconnected? */
if (!self->connected) {
IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
if (userdata)
dev_kfree_skb(userdata);
return -1;
}
/* Disconnect already pending ?
* We need to use an atomic operation to prevent reentry. This
* function may be called from various context, like user, timer
* for following a disconnect_indication() (i.e. net_bh).
* Jean II */
if(test_and_set_bit(0, &self->disconnect_pend)) {
IRDA_DEBUG(0, "%s(), disconnect already pending\n",
__func__);
if (userdata)
dev_kfree_skb(userdata);
/* Try to make some progress */
irttp_run_tx_queue(self);
return -1;
}
/*
* Check if there is still data segments in the transmit queue
*/
if (!skb_queue_empty(&self->tx_queue)) {
if (priority == P_HIGH) {
/*
* No need to send the queued data, if we are
* disconnecting right now since the data will
* not have any usable connection to be sent on
*/
IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
irttp_flush_queues(self);
} else if (priority == P_NORMAL) {
/*
* Must delay disconnect until after all data segments
* have been sent and the tx_queue is empty
*/
/* We'll reuse this one later for the disconnect */
self->disconnect_skb = userdata; /* May be NULL */
irttp_run_tx_queue(self);
irttp_start_todo_timer(self, HZ/10);
return -1;
}
}
/* Note : we don't need to check if self->rx_queue is full and the
* state of self->rx_sdu_busy because the disconnect response will
* be sent at the LMP level (so even if the peer has its Tx queue
* full of data). - Jean II */
IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
self->connected = FALSE;
if (!userdata) {
struct sk_buff *tx_skb;
tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
if (!tx_skb)
return -ENOMEM;
/*
* Reserve space for MUX and LAP header
*/
skb_reserve(tx_skb, LMP_MAX_HEADER);
userdata = tx_skb;
}
ret = irlmp_disconnect_request(self->lsap, userdata);
/* The disconnect is no longer pending */
clear_bit(0, &self->disconnect_pend); /* FALSE */
return ret;
}
EXPORT_SYMBOL(irttp_disconnect_request);
/*
* Function irttp_disconnect_indication (self, reason)
*
* Disconnect indication, TSAP disconnected by peer?
*
*/
static void irttp_disconnect_indication(void *instance, void *sap,
LM_REASON reason, struct sk_buff *skb)
{
struct tsap_cb *self;
IRDA_DEBUG(4, "%s()\n", __func__);
self = instance;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
/* Prevent higher layer to send more data */
self->connected = FALSE;
/* Check if client has already tried to close the TSAP */
if (self->close_pend) {
/* In this case, the higher layer is probably gone. Don't
* bother it and clean up the remains - Jean II */
if (skb)
dev_kfree_skb(skb);
irttp_close_tsap(self);
return;
}
/* If we are here, we assume that is the higher layer is still
* waiting for the disconnect notification and able to process it,
* even if he tried to disconnect. Otherwise, it would have already
* attempted to close the tsap and self->close_pend would be TRUE.
* Jean II */
/* No need to notify the client if has already tried to disconnect */
if(self->notify.disconnect_indication)
self->notify.disconnect_indication(self->notify.instance, self,
reason, skb);
else
if (skb)
dev_kfree_skb(skb);
}
/*
* Function irttp_do_data_indication (self, skb)
*
* Try to deliver reassembled skb to layer above, and requeue it if that
* for some reason should fail. We mark rx sdu as busy to apply back
* pressure is necessary.
*/
static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
{
int err;
/* Check if client has already closed the TSAP and gone away */
if (self->close_pend) {
dev_kfree_skb(skb);
return;
}
err = self->notify.data_indication(self->notify.instance, self, skb);
/* Usually the layer above will notify that it's input queue is
* starting to get filled by using the flow request, but this may
* be difficult, so it can instead just refuse to eat it and just
* give an error back
*/
if (err) {
IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
/* Make sure we take a break */
self->rx_sdu_busy = TRUE;
/* Need to push the header in again */
skb_push(skb, TTP_HEADER);
skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
/* Put skb back on queue */
skb_queue_head(&self->rx_queue, skb);
}
}
/*
* Function irttp_run_rx_queue (self)
*
* Check if we have any frames to be transmitted, or if we have any
* available credit to give away.
*/
static void irttp_run_rx_queue(struct tsap_cb *self)
{
struct sk_buff *skb;
int more = 0;
IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
self->send_credit, self->avail_credit, self->remote_credit);
/* Get exclusive access to the rx queue, otherwise don't touch it */
if (irda_lock(&self->rx_queue_lock) == FALSE)
return;
/*
* Reassemble all frames in receive queue and deliver them
*/
while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
/* This bit will tell us if it's the last fragment or not */
more = skb->data[0] & 0x80;
/* Remove TTP header */
skb_pull(skb, TTP_HEADER);
/* Add the length of the remaining data */
self->rx_sdu_size += skb->len;
/*
* If SAR is disabled, or user has requested no reassembly
* of received fragments then we just deliver them
* immediately. This can be requested by clients that
* implements byte streams without any message boundaries
*/
if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
irttp_do_data_indication(self, skb);
self->rx_sdu_size = 0;
continue;
}
/* Check if this is a fragment, and not the last fragment */
if (more) {
/*
* Queue the fragment if we still are within the
* limits of the maximum size of the rx_sdu
*/
if (self->rx_sdu_size <= self->rx_max_sdu_size) {
IRDA_DEBUG(4, "%s(), queueing frag\n",
__func__);
skb_queue_tail(&self->rx_fragments, skb);
} else {
/* Free the part of the SDU that is too big */
dev_kfree_skb(skb);
}
continue;
}
/*
* This is the last fragment, so time to reassemble!
*/
if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
(self->rx_max_sdu_size == TTP_SAR_UNBOUND))
{
/*
* A little optimizing. Only queue the fragment if
* there are other fragments. Since if this is the
* last and only fragment, there is no need to
* reassemble :-)
*/
if (!skb_queue_empty(&self->rx_fragments)) {
skb_queue_tail(&self->rx_fragments,
skb);
skb = irttp_reassemble_skb(self);
}
/* Now we can deliver the reassembled skb */
irttp_do_data_indication(self, skb);
} else {
IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
/* Free the part of the SDU that is too big */
dev_kfree_skb(skb);
/* Deliver only the valid but truncated part of SDU */
skb = irttp_reassemble_skb(self);
irttp_do_data_indication(self, skb);
}
self->rx_sdu_size = 0;
}
/*
* It's not trivial to keep track of how many credits are available
* by incrementing at each packet, because delivery may fail
* (irttp_do_data_indication() may requeue the frame) and because
* we need to take care of fragmentation.
* We want the other side to send up to initial_credit packets.
* We have some frames in our queues, and we have already allowed it
* to send remote_credit.
* No need to spinlock, write is atomic and self correcting...
* Jean II
*/
self->avail_credit = (self->initial_credit -
(self->remote_credit +
skb_queue_len(&self->rx_queue) +
skb_queue_len(&self->rx_fragments)));
/* Do we have too much credits to send to peer ? */
if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
(self->avail_credit > 0)) {
/* Send explicit credit frame */
irttp_give_credit(self);
/* Note : do *NOT* check if tx_queue is non-empty, that
* will produce deadlocks. I repeat : send a credit frame
* even if we have something to send in our Tx queue.
* If we have credits, it means that our Tx queue is blocked.
*
* Let's suppose the peer can't keep up with our Tx. He will
* flow control us by not sending us any credits, and we
* will stop Tx and start accumulating credits here.
* Up to the point where the peer will stop its Tx queue,
* for lack of credits.
* Let's assume the peer application is single threaded.
* It will block on Tx and never consume any Rx buffer.
* Deadlock. Guaranteed. - Jean II
*/
}
/* Reset lock */
self->rx_queue_lock = 0;
}
#ifdef CONFIG_PROC_FS
struct irttp_iter_state {
int id;
};
static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
{
struct irttp_iter_state *iter = seq->private;
struct tsap_cb *self;
/* Protect our access to the tsap list */
spin_lock_irq(&irttp->tsaps->hb_spinlock);
iter->id = 0;
for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
self != NULL;
self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
if (iter->id == *pos)
break;
++iter->id;
}
return self;
}
static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct irttp_iter_state *iter = seq->private;
++*pos;
++iter->id;
return (void *) hashbin_get_next(irttp->tsaps);
}
static void irttp_seq_stop(struct seq_file *seq, void *v)
{
spin_unlock_irq(&irttp->tsaps->hb_spinlock);
}
static int irttp_seq_show(struct seq_file *seq, void *v)
{
const struct irttp_iter_state *iter = seq->private;
const struct tsap_cb *self = v;
seq_printf(seq, "TSAP %d, ", iter->id);
seq_printf(seq, "stsap_sel: %02x, ",
self->stsap_sel);
seq_printf(seq, "dtsap_sel: %02x\n",
self->dtsap_sel);
seq_printf(seq, " connected: %s, ",
self->connected? "TRUE":"FALSE");
seq_printf(seq, "avail credit: %d, ",
self->avail_credit);
seq_printf(seq, "remote credit: %d, ",
self->remote_credit);
seq_printf(seq, "send credit: %d\n",
self->send_credit);
seq_printf(seq, " tx packets: %lu, ",
self->stats.tx_packets);
seq_printf(seq, "rx packets: %lu, ",
self->stats.rx_packets);
seq_printf(seq, "tx_queue len: %u ",
skb_queue_len(&self->tx_queue));
seq_printf(seq, "rx_queue len: %u\n",
skb_queue_len(&self->rx_queue));
seq_printf(seq, " tx_sdu_busy: %s, ",
self->tx_sdu_busy? "TRUE":"FALSE");
seq_printf(seq, "rx_sdu_busy: %s\n",
self->rx_sdu_busy? "TRUE":"FALSE");
seq_printf(seq, " max_seg_size: %u, ",
self->max_seg_size);
seq_printf(seq, "tx_max_sdu_size: %u, ",
self->tx_max_sdu_size);
seq_printf(seq, "rx_max_sdu_size: %u\n",
self->rx_max_sdu_size);
seq_printf(seq, " Used by (%s)\n\n",
self->notify.name);
return 0;
}
static const struct seq_operations irttp_seq_ops = {
.start = irttp_seq_start,
.next = irttp_seq_next,
.stop = irttp_seq_stop,
.show = irttp_seq_show,
};
static int irttp_seq_open(struct inode *inode, struct file *file)
{
return seq_open_private(file, &irttp_seq_ops,
sizeof(struct irttp_iter_state));
}
const struct file_operations irttp_seq_fops = {
.owner = THIS_MODULE,
.open = irttp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
#endif /* PROC_FS */