diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/irda/irlmp_frame.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/irda/irlmp_frame.c')
-rw-r--r-- | net/irda/irlmp_frame.c | 491 |
1 files changed, 491 insertions, 0 deletions
diff --git a/net/irda/irlmp_frame.c b/net/irda/irlmp_frame.c new file mode 100644 index 00000000000..91cd268172f --- /dev/null +++ b/net/irda/irlmp_frame.c @@ -0,0 +1,491 @@ +/********************************************************************* + * + * 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 Tromsų admit liability nor + * provide warranty for any of this software. This material is + * provided "AS-IS" and at no charge. + * + ********************************************************************/ + +#include <linux/config.h> +#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) { + IRDA_DEBUG(4, "%s(), sending expedited data\n", __FUNCTION__); + 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_DEBUG(2, "%s()\n", __FUNCTION__); + + 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_DEBUG(4, "%s()\n", __FUNCTION__); + + 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)) { + IRDA_DEBUG(3, "%s(), incoming connection, " + "source LSAP=%d, dest LSAP=%d\n", + __FUNCTION__, 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) { + IRDA_DEBUG(1, "%s(), incoming connection for LSAP already connected\n", __FUNCTION__); + 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) { + IRDA_DEBUG(2, "IrLMP, Sorry, no LSAP for received frame!\n"); + IRDA_DEBUG(2, "%s(), slsap_sel = %02x, dlsap_sel = %02x\n", + __FUNCTION__, slsap_sel, dlsap_sel); + if (fp[0] & CONTROL_BIT) { + IRDA_DEBUG(2, "%s(), received control frame %02x\n", + __FUNCTION__, fp[2]); + } else { + IRDA_DEBUG(2, "%s(), received data frame\n", __FUNCTION__); + } + 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: + IRDA_DEBUG(4, "%s(), Disconnect indication!\n", + __FUNCTION__); + irlmp_do_lsap_event(lsap, LM_DISCONNECT_INDICATION, + skb); + break; + case ACCESSMODE_CMD: + IRDA_DEBUG(0, "Access mode cmd not implemented!\n"); + break; + case ACCESSMODE_CNF: + IRDA_DEBUG(0, "Access mode cnf not implemented!\n"); + break; + default: + IRDA_DEBUG(0, "%s(), Unknown control frame %02x\n", + __FUNCTION__, 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_DEBUG(4, "%s()\n", __FUNCTION__); + + 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) { + IRDA_DEBUG(0, "%s(), extension in PID not supp!\n", + __FUNCTION__); + return; + } + + /* Check if frame is addressed to the connectionless LSAP */ + if ((slsap_sel != LSAP_CONNLESS) || (dlsap_sel != LSAP_CONNLESS)) { + IRDA_DEBUG(0, "%s(), dropping frame!\n", __FUNCTION__); + 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 { + IRDA_DEBUG(0, "%s(), found no matching LSAP!\n", __FUNCTION__); + } +} +#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_DEBUG(2, "%s()\n", __FUNCTION__); + + 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) +{ + IRDA_DEBUG(4, "%s()\n", __FUNCTION__); + + /* 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_DEBUG(4, "%s()\n", __FUNCTION__); + + 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_DEBUG(4, "%s()\n", __FUNCTION__); + + 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; +} |