/********************************************************************* * * 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) */ 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 = (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 * */ 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 = (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)); 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 = (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. */ 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: %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 */