+++ /dev/null
-/*********************************************************************
- *
- * Filename: irlmp_frame.c
- * Version: 0.9
- * Description: IrLMP frame implementation
- * Status: Experimental.
- * Author: Dag Brattli <dagb@cs.uit.no>
- * Created at: Tue Aug 19 02:09:59 1997
- * Modified at: Mon Dec 13 13:41:12 1999
- * Modified by: Dag Brattli <dagb@cs.uit.no>
- *
- * Copyright (c) 1998-1999 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/kernel.h>
-
-#include <net/irda/irda.h>
-#include <net/irda/irlap.h>
-#include <net/irda/timer.h>
-#include <net/irda/irlmp.h>
-#include <net/irda/irlmp_frame.h>
-#include <net/irda/discovery.h>
-
-static struct lsap_cb *irlmp_find_lsap(struct lap_cb *self, __u8 dlsap,
- __u8 slsap, int status, hashbin_t *);
-
-inline void irlmp_send_data_pdu(struct lap_cb *self, __u8 dlsap, __u8 slsap,
- int expedited, struct sk_buff *skb)
-{
- skb->data[0] = dlsap;
- skb->data[1] = slsap;
-
- if (expedited) {
- pr_debug("%s(), sending expedited data\n", __func__);
- irlap_data_request(self->irlap, skb, TRUE);
- } else
- irlap_data_request(self->irlap, skb, FALSE);
-}
-
-/*
- * Function irlmp_send_lcf_pdu (dlsap, slsap, opcode,skb)
- *
- * Send Link Control Frame to IrLAP
- */
-void irlmp_send_lcf_pdu(struct lap_cb *self, __u8 dlsap, __u8 slsap,
- __u8 opcode, struct sk_buff *skb)
-{
- __u8 *frame;
-
- IRDA_ASSERT(self != NULL, return;);
- IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
- IRDA_ASSERT(skb != NULL, return;);
-
- frame = skb->data;
-
- frame[0] = dlsap | CONTROL_BIT;
- frame[1] = slsap;
-
- frame[2] = opcode;
-
- if (opcode == DISCONNECT)
- frame[3] = 0x01; /* Service user request */
- else
- frame[3] = 0x00; /* rsvd */
-
- irlap_data_request(self->irlap, skb, FALSE);
-}
-
-/*
- * Function irlmp_input (skb)
- *
- * Used by IrLAP to pass received data frames to IrLMP layer
- *
- */
-void irlmp_link_data_indication(struct lap_cb *self, struct sk_buff *skb,
- int unreliable)
-{
- struct lsap_cb *lsap;
- __u8 slsap_sel; /* Source (this) LSAP address */
- __u8 dlsap_sel; /* Destination LSAP address */
- __u8 *fp;
-
- IRDA_ASSERT(self != NULL, return;);
- IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
- IRDA_ASSERT(skb->len > 2, return;);
-
- fp = skb->data;
-
- /*
- * The next statements may be confusing, but we do this so that
- * destination LSAP of received frame is source LSAP in our view
- */
- slsap_sel = fp[0] & LSAP_MASK;
- dlsap_sel = fp[1];
-
- /*
- * Check if this is an incoming connection, since we must deal with
- * it in a different way than other established connections.
- */
- if ((fp[0] & CONTROL_BIT) && (fp[2] == CONNECT_CMD)) {
- pr_debug("%s(), incoming connection, source LSAP=%d, dest LSAP=%d\n",
- __func__, slsap_sel, dlsap_sel);
-
- /* Try to find LSAP among the unconnected LSAPs */
- lsap = irlmp_find_lsap(self, dlsap_sel, slsap_sel, CONNECT_CMD,
- irlmp->unconnected_lsaps);
-
- /* Maybe LSAP was already connected, so try one more time */
- if (!lsap) {
- pr_debug("%s(), incoming connection for LSAP already connected\n",
- __func__);
- lsap = irlmp_find_lsap(self, dlsap_sel, slsap_sel, 0,
- self->lsaps);
- }
- } else
- lsap = irlmp_find_lsap(self, dlsap_sel, slsap_sel, 0,
- self->lsaps);
-
- if (lsap == NULL) {
- pr_debug("IrLMP, Sorry, no LSAP for received frame!\n");
- pr_debug("%s(), slsap_sel = %02x, dlsap_sel = %02x\n",
- __func__, slsap_sel, dlsap_sel);
- if (fp[0] & CONTROL_BIT) {
- pr_debug("%s(), received control frame %02x\n",
- __func__, fp[2]);
- } else {
- pr_debug("%s(), received data frame\n", __func__);
- }
- return;
- }
-
- /*
- * Check if we received a control frame?
- */
- if (fp[0] & CONTROL_BIT) {
- switch (fp[2]) {
- case CONNECT_CMD:
- lsap->lap = self;
- irlmp_do_lsap_event(lsap, LM_CONNECT_INDICATION, skb);
- break;
- case CONNECT_CNF:
- irlmp_do_lsap_event(lsap, LM_CONNECT_CONFIRM, skb);
- break;
- case DISCONNECT:
- pr_debug("%s(), Disconnect indication!\n",
- __func__);
- irlmp_do_lsap_event(lsap, LM_DISCONNECT_INDICATION,
- skb);
- break;
- case ACCESSMODE_CMD:
- pr_debug("Access mode cmd not implemented!\n");
- break;
- case ACCESSMODE_CNF:
- pr_debug("Access mode cnf not implemented!\n");
- break;
- default:
- pr_debug("%s(), Unknown control frame %02x\n",
- __func__, fp[2]);
- break;
- }
- } else if (unreliable) {
- /* Optimize and bypass the state machine if possible */
- if (lsap->lsap_state == LSAP_DATA_TRANSFER_READY)
- irlmp_udata_indication(lsap, skb);
- else
- irlmp_do_lsap_event(lsap, LM_UDATA_INDICATION, skb);
- } else {
- /* Optimize and bypass the state machine if possible */
- if (lsap->lsap_state == LSAP_DATA_TRANSFER_READY)
- irlmp_data_indication(lsap, skb);
- else
- irlmp_do_lsap_event(lsap, LM_DATA_INDICATION, skb);
- }
-}
-
-/*
- * Function irlmp_link_unitdata_indication (self, skb)
- *
- *
- *
- */
-#ifdef CONFIG_IRDA_ULTRA
-void irlmp_link_unitdata_indication(struct lap_cb *self, struct sk_buff *skb)
-{
- struct lsap_cb *lsap;
- __u8 slsap_sel; /* Source (this) LSAP address */
- __u8 dlsap_sel; /* Destination LSAP address */
- __u8 pid; /* Protocol identifier */
- __u8 *fp;
- unsigned long flags;
-
- IRDA_ASSERT(self != NULL, return;);
- IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
- IRDA_ASSERT(skb->len > 2, return;);
-
- fp = skb->data;
-
- /*
- * The next statements may be confusing, but we do this so that
- * destination LSAP of received frame is source LSAP in our view
- */
- slsap_sel = fp[0] & LSAP_MASK;
- dlsap_sel = fp[1];
- pid = fp[2];
-
- if (pid & 0x80) {
- pr_debug("%s(), extension in PID not supp!\n",
- __func__);
- return;
- }
-
- /* Check if frame is addressed to the connectionless LSAP */
- if ((slsap_sel != LSAP_CONNLESS) || (dlsap_sel != LSAP_CONNLESS)) {
- pr_debug("%s(), dropping frame!\n", __func__);
- return;
- }
-
- /* Search the connectionless LSAP */
- spin_lock_irqsave(&irlmp->unconnected_lsaps->hb_spinlock, flags);
- lsap = (struct lsap_cb *) hashbin_get_first(irlmp->unconnected_lsaps);
- while (lsap != NULL) {
- /*
- * Check if source LSAP and dest LSAP selectors and PID match.
- */
- if ((lsap->slsap_sel == slsap_sel) &&
- (lsap->dlsap_sel == dlsap_sel) &&
- (lsap->pid == pid))
- {
- break;
- }
- lsap = (struct lsap_cb *) hashbin_get_next(irlmp->unconnected_lsaps);
- }
- spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags);
-
- if (lsap)
- irlmp_connless_data_indication(lsap, skb);
- else {
- pr_debug("%s(), found no matching LSAP!\n", __func__);
- }
-}
-#endif /* CONFIG_IRDA_ULTRA */
-
-/*
- * Function irlmp_link_disconnect_indication (reason, userdata)
- *
- * IrLAP has disconnected
- *
- */
-void irlmp_link_disconnect_indication(struct lap_cb *lap,
- struct irlap_cb *irlap,
- LAP_REASON reason,
- struct sk_buff *skb)
-{
- IRDA_ASSERT(lap != NULL, return;);
- IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, return;);
-
- lap->reason = reason;
- lap->daddr = DEV_ADDR_ANY;
-
- /* FIXME: must do something with the skb if any */
-
- /*
- * Inform station state machine
- */
- irlmp_do_lap_event(lap, LM_LAP_DISCONNECT_INDICATION, NULL);
-}
-
-/*
- * Function irlmp_link_connect_indication (qos)
- *
- * Incoming LAP connection!
- *
- */
-void irlmp_link_connect_indication(struct lap_cb *self, __u32 saddr,
- __u32 daddr, struct qos_info *qos,
- struct sk_buff *skb)
-{
- /* Copy QoS settings for this session */
- self->qos = qos;
-
- /* Update destination device address */
- self->daddr = daddr;
- IRDA_ASSERT(self->saddr == saddr, return;);
-
- irlmp_do_lap_event(self, LM_LAP_CONNECT_INDICATION, skb);
-}
-
-/*
- * Function irlmp_link_connect_confirm (qos)
- *
- * LAP connection confirmed!
- *
- */
-void irlmp_link_connect_confirm(struct lap_cb *self, struct qos_info *qos,
- struct sk_buff *skb)
-{
- IRDA_ASSERT(self != NULL, return;);
- IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
- IRDA_ASSERT(qos != NULL, return;);
-
- /* Don't need use the skb for now */
-
- /* Copy QoS settings for this session */
- self->qos = qos;
-
- irlmp_do_lap_event(self, LM_LAP_CONNECT_CONFIRM, NULL);
-}
-
-/*
- * Function irlmp_link_discovery_indication (self, log)
- *
- * Device is discovering us
- *
- * It's not an answer to our own discoveries, just another device trying
- * to perform discovery, but we don't want to miss the opportunity
- * to exploit this information, because :
- * o We may not actively perform discovery (just passive discovery)
- * o This type of discovery is much more reliable. In some cases, it
- * seem that less than 50% of our discoveries get an answer, while
- * we always get ~100% of these.
- * o Make faster discovery, statistically divide time of discovery
- * events by 2 (important for the latency aspect and user feel)
- * o Even is we do active discovery, the other node might not
- * answer our discoveries (ex: Palm). The Palm will just perform
- * one active discovery and connect directly to us.
- *
- * However, when both devices discover each other, they might attempt to
- * connect to each other following the discovery event, and it would create
- * collisions on the medium (SNRM battle).
- * The "fix" for that is to disable all connection requests in IrLAP
- * for 100ms after a discovery indication by setting the media_busy flag.
- * Previously, we used to postpone the event which was quite ugly. Now
- * that IrLAP takes care of this problem, just pass the event up...
- *
- * Jean II
- */
-void irlmp_link_discovery_indication(struct lap_cb *self,
- discovery_t *discovery)
-{
- IRDA_ASSERT(self != NULL, return;);
- IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
-
- /* Add to main log, cleanup */
- irlmp_add_discovery(irlmp->cachelog, discovery);
-
- /* Just handle it the same way as a discovery confirm,
- * bypass the LM_LAP state machine (see below) */
- irlmp_discovery_confirm(irlmp->cachelog, DISCOVERY_PASSIVE);
-}
-
-/*
- * Function irlmp_link_discovery_confirm (self, log)
- *
- * Called by IrLAP with a list of discoveries after the discovery
- * request has been carried out. A NULL log is received if IrLAP
- * was unable to carry out the discovery request
- *
- */
-void irlmp_link_discovery_confirm(struct lap_cb *self, hashbin_t *log)
-{
- IRDA_ASSERT(self != NULL, return;);
- IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
-
- /* Add to main log, cleanup */
- irlmp_add_discovery_log(irlmp->cachelog, log);
-
- /* Propagate event to various LSAPs registered for it.
- * We bypass the LM_LAP state machine because
- * 1) We do it regardless of the LM_LAP state
- * 2) It doesn't affect the LM_LAP state
- * 3) Faster, slimer, simpler, ...
- * Jean II */
- irlmp_discovery_confirm(irlmp->cachelog, DISCOVERY_ACTIVE);
-}
-
-#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
-static inline void irlmp_update_cache(struct lap_cb *lap,
- struct lsap_cb *lsap)
-{
- /* Prevent concurrent read to get garbage */
- lap->cache.valid = FALSE;
- /* Update cache entry */
- lap->cache.dlsap_sel = lsap->dlsap_sel;
- lap->cache.slsap_sel = lsap->slsap_sel;
- lap->cache.lsap = lsap;
- lap->cache.valid = TRUE;
-}
-#endif
-
-/*
- * Function irlmp_find_handle (self, dlsap_sel, slsap_sel, status, queue)
- *
- * Find handle associated with destination and source LSAP
- *
- * Any IrDA connection (LSAP/TSAP) is uniquely identified by
- * 3 parameters, the local lsap, the remote lsap and the remote address.
- * We may initiate multiple connections to the same remote service
- * (they will have different local lsap), a remote device may initiate
- * multiple connections to the same local service (they will have
- * different remote lsap), or multiple devices may connect to the same
- * service and may use the same remote lsap (and they will have
- * different remote address).
- * So, where is the remote address ? Each LAP connection is made with
- * a single remote device, so imply a specific remote address.
- * Jean II
- */
-static struct lsap_cb *irlmp_find_lsap(struct lap_cb *self, __u8 dlsap_sel,
- __u8 slsap_sel, int status,
- hashbin_t *queue)
-{
- struct lsap_cb *lsap;
- unsigned long flags;
-
- /*
- * Optimize for the common case. We assume that the last frame
- * received is in the same connection as the last one, so check in
- * cache first to avoid the linear search
- */
-#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
- if ((self->cache.valid) &&
- (self->cache.slsap_sel == slsap_sel) &&
- (self->cache.dlsap_sel == dlsap_sel))
- {
- return self->cache.lsap;
- }
-#endif
-
- spin_lock_irqsave(&queue->hb_spinlock, flags);
-
- lsap = (struct lsap_cb *) hashbin_get_first(queue);
- while (lsap != NULL) {
- /*
- * If this is an incoming connection, then the destination
- * LSAP selector may have been specified as LM_ANY so that
- * any client can connect. In that case we only need to check
- * if the source LSAP (in our view!) match!
- */
- if ((status == CONNECT_CMD) &&
- (lsap->slsap_sel == slsap_sel) &&
- (lsap->dlsap_sel == LSAP_ANY)) {
- /* This is where the dest lsap sel is set on incoming
- * lsaps */
- lsap->dlsap_sel = dlsap_sel;
- break;
- }
- /*
- * Check if source LSAP and dest LSAP selectors match.
- */
- if ((lsap->slsap_sel == slsap_sel) &&
- (lsap->dlsap_sel == dlsap_sel))
- break;
-
- lsap = (struct lsap_cb *) hashbin_get_next(queue);
- }
-#ifdef CONFIG_IRDA_CACHE_LAST_LSAP
- if(lsap)
- irlmp_update_cache(self, lsap);
-#endif
- spin_unlock_irqrestore(&queue->hb_spinlock, flags);
-
- /* Return what we've found or NULL */
- return lsap;
-}
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