diff options
Diffstat (limited to 'net/irda/irttp.c')
| -rw-r--r-- | net/irda/irttp.c | 1899 |
1 files changed, 1899 insertions, 0 deletions
diff --git a/net/irda/irttp.c b/net/irda/irttp.c new file mode 100644 index 0000000..74e439e --- /dev/null +++ b/net/irda/irttp.c @@ -0,0 +1,1899 @@ +/********************************************************************* + * + * 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 <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) + */ +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 = (struct tsap_cb *) 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_WARNING("%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) +{ + 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__); + + /* Check that nothing bad happens */ + if ((skb->len == 0) || (!self->connected)) { + IRDA_DEBUG(1, "%s(), No data, or not connected\n", + __func__); + goto err; + } + + if (skb->len > self->max_seg_size) { + IRDA_DEBUG(1, "%s(), UData is too large for IrLAP!\n", + __func__); + goto err; + } + + irlmp_udata_request(self->lsap, skb); + self->stats.tx_packets++; + + return 0; + +err: + dev_kfree_skb(skb); + return -1; +} +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)); + + /* Check that nothing bad happens */ + if ((skb->len == 0) || (!self->connected)) { + IRDA_WARNING("%s: No data, or 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 = (struct tsap_cb *) 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 = (struct tsap_cb *) 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 = (struct tsap_cb *) 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 = (struct tsap_cb *) 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) + * + * Sevice 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 = (struct tsap_cb *) 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), + ¶m_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 + * + */ +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 = (struct tsap_cb *) instance; + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;); + IRDA_ASSERT(skb != NULL, return;); + + lsap = (struct lsap_cb *) 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), + ¶m_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, ¶m_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 = kmalloc(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; + } + /* Dup */ + memcpy(new, orig, sizeof(struct tsap_cb)); + + /* 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? + * + */ +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 = (struct tsap_cb *) 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. + */ +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: %ld, ", + self->stats.tx_packets); + seq_printf(seq, "rx packets: %ld, ", + self->stats.rx_packets); + seq_printf(seq, "tx_queue len: %d ", + skb_queue_len(&self->tx_queue)); + seq_printf(seq, "rx_queue len: %d\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: %d, ", + self->max_seg_size); + seq_printf(seq, "tx_max_sdu_size: %d, ", + self->tx_max_sdu_size); + seq_printf(seq, "rx_max_sdu_size: %d\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 */ |
