cregit-Linux how code gets into the kernel

Release 4.11 net/irda/irlap_event.c

Directory: net/irda
/*********************************************************************
 *
 * Filename:      irlap_event.c
 * Version:       0.9
 * Description:   IrLAP state machine implementation
 * Status:        Experimental.
 * Author:        Dag Brattli <dag@brattli.net>
 * Created at:    Sat Aug 16 00:59:29 1997
 * Modified at:   Sat Dec 25 21:07:57 1999
 * Modified by:   Dag Brattli <dag@brattli.net>
 *
 *     Copyright (c) 1998-2000 Dag Brattli <dag@brattli.net>,
 *     Copyright (c) 1998      Thomas Davis <ratbert@radiks.net>
 *     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/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/skbuff.h>
#include <linux/slab.h>

#include <net/irda/irda.h>
#include <net/irda/irlap_event.h>

#include <net/irda/timer.h>
#include <net/irda/irlap.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/qos.h>
#include <net/irda/parameters.h>
#include <net/irda/irlmp.h>		/* irlmp_flow_indication(), ... */

#include <net/irda/irda_device.h>

#ifdef CONFIG_IRDA_FAST_RR

int sysctl_fast_poll_increase = 50;
#endif

static int irlap_state_ndm    (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_query  (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reply  (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_conn   (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_setup  (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_xmit_p (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_pclose (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_nrm_p  (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
				  struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset  (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_nrm_s  (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_xmit_s (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_sclose (struct irlap_cb *self, IRLAP_EVENT event,
			       struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset_check(struct irlap_cb *, IRLAP_EVENT event,
				   struct sk_buff *, struct irlap_info *);


static const char *const irlap_event[] __maybe_unused = {
	"DISCOVERY_REQUEST",
	"CONNECT_REQUEST",
	"CONNECT_RESPONSE",
	"DISCONNECT_REQUEST",
	"DATA_REQUEST",
	"RESET_REQUEST",
	"RESET_RESPONSE",
	"SEND_I_CMD",
	"SEND_UI_FRAME",
	"RECV_DISCOVERY_XID_CMD",
	"RECV_DISCOVERY_XID_RSP",
	"RECV_SNRM_CMD",
	"RECV_TEST_CMD",
	"RECV_TEST_RSP",
	"RECV_UA_RSP",
	"RECV_DM_RSP",
	"RECV_RD_RSP",
	"RECV_I_CMD",
	"RECV_I_RSP",
	"RECV_UI_FRAME",
	"RECV_FRMR_RSP",
	"RECV_RR_CMD",
	"RECV_RR_RSP",
	"RECV_RNR_CMD",
	"RECV_RNR_RSP",
	"RECV_REJ_CMD",
	"RECV_REJ_RSP",
	"RECV_SREJ_CMD",
	"RECV_SREJ_RSP",
	"RECV_DISC_CMD",
	"SLOT_TIMER_EXPIRED",
	"QUERY_TIMER_EXPIRED",
	"FINAL_TIMER_EXPIRED",
	"POLL_TIMER_EXPIRED",
	"DISCOVERY_TIMER_EXPIRED",
	"WD_TIMER_EXPIRED",
	"BACKOFF_TIMER_EXPIRED",
	"MEDIA_BUSY_TIMER_EXPIRED",
};


const char *const irlap_state[] = {
	"LAP_NDM",
	"LAP_QUERY",
	"LAP_REPLY",
	"LAP_CONN",
	"LAP_SETUP",
	"LAP_OFFLINE",
	"LAP_XMIT_P",
	"LAP_PCLOSE",
	"LAP_NRM_P",
	"LAP_RESET_WAIT",
	"LAP_RESET",
	"LAP_NRM_S",
	"LAP_XMIT_S",
	"LAP_SCLOSE",
	"LAP_RESET_CHECK",
};


static int (*state[])(struct irlap_cb *self, IRLAP_EVENT event,
		      struct sk_buff *skb, struct irlap_info *info) =
{
	irlap_state_ndm,
	irlap_state_query,
	irlap_state_reply,
	irlap_state_conn,
	irlap_state_setup,
	irlap_state_offline,
	irlap_state_xmit_p,
	irlap_state_pclose,
	irlap_state_nrm_p,
	irlap_state_reset_wait,
	irlap_state_reset,
	irlap_state_nrm_s,
	irlap_state_xmit_s,
	irlap_state_sclose,
	irlap_state_reset_check,
};

/*
 * Function irda_poll_timer_expired (data)
 *
 *    Poll timer has expired. Normally we must now send a RR frame to the
 *    remote device
 */

static void irlap_poll_timer_expired(void *data) { struct irlap_cb *self = (struct irlap_cb *) data; IRDA_ASSERT(self != NULL, return;); IRDA_ASSERT(self->magic == LAP_MAGIC, return;); irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4595.74%266.67%
Jean Tourrilhes24.26%133.33%
Total47100.00%3100.00%

/* * Calculate and set time before we will have to send back the pf bit * to the peer. Use in primary. * Make sure that state is XMIT_P/XMIT_S when calling this function * (and that nobody messed up with the state). - Jean II */
static void irlap_start_poll_timer(struct irlap_cb *self, int timeout) { IRDA_ASSERT(self != NULL, return;); IRDA_ASSERT(self->magic == LAP_MAGIC, return;); #ifdef CONFIG_IRDA_FAST_RR /* * Send out the RR frames faster if our own transmit queue is empty, or * if the peer is busy. The effect is a much faster conversation */ if (skb_queue_empty(&self->txq) || self->remote_busy) { if (self->fast_RR == TRUE) { /* * Assert that the fast poll timer has not reached the * normal poll timer yet */ if (self->fast_RR_timeout < timeout) { /* * FIXME: this should be a more configurable * function */ self->fast_RR_timeout += (sysctl_fast_poll_increase * HZ/1000); /* Use this fast(er) timeout instead */ timeout = self->fast_RR_timeout; } } else { self->fast_RR = TRUE; /* Start with just 0 ms */ self->fast_RR_timeout = 0; timeout = 0; } } else self->fast_RR = FALSE; pr_debug("%s(), timeout=%d (%ld)\n", __func__, timeout, jiffies); #endif /* CONFIG_IRDA_FAST_RR */ if (timeout == 0) irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL); else irda_start_timer(&self->poll_timer, timeout, self, irlap_poll_timer_expired); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)15394.44%436.36%
Jean Tourrilhes42.47%218.18%
David S. Miller10.62%19.09%
Harvey Harrison10.62%19.09%
Martin Dalecki10.62%19.09%
Joe Perches10.62%19.09%
Adrian Bunk10.62%19.09%
Total162100.00%11100.00%

/* * Function irlap_do_event (event, skb, info) * * Rushes through the state machine without any delay. If state == XMIT * then send queued data frames. */
void irlap_do_event(struct irlap_cb *self, IRLAP_EVENT event, struct sk_buff *skb, struct irlap_info *info) { int ret; if (!self || self->magic != LAP_MAGIC) return; pr_debug("%s(), event = %s, state = %s\n", __func__, irlap_event[event], irlap_state[self->state]); ret = (*state[self->state])(self, event, skb, info); /* * Check if there are any pending events that needs to be executed */ switch (self->state) { case LAP_XMIT_P: /* FALLTHROUGH */ case LAP_XMIT_S: /* * We just received the pf bit and are at the beginning * of a new LAP transmit window. * Check if there are any queued data frames, and do not * try to disconnect link if we send any data frames, since * that will change the state away form XMIT */ pr_debug("%s() : queue len = %d\n", __func__, skb_queue_len(&self->txq)); if (!skb_queue_empty(&self->txq)) { /* Prevent race conditions with irlap_data_request() */ self->local_busy = TRUE; /* Theory of operation. * We send frames up to when we fill the window or * reach line capacity. Those frames will queue up * in the device queue, and the driver will slowly * send them. * After each frame that we send, we poll the higher * layer for more data. It's the right time to do * that because the link layer need to perform the mtt * and then send the first frame, so we can afford * to send a bit of time in kernel space. * The explicit flow indication allow to minimise * buffers (== lower latency), to avoid higher layer * polling via timers (== less context switches) and * to implement a crude scheduler - Jean II */ /* Try to send away all queued data frames */ while ((skb = skb_dequeue(&self->txq)) != NULL) { /* Send one frame */ ret = (*state[self->state])(self, SEND_I_CMD, skb, NULL); /* Drop reference count. * It will be increase as needed in * irlap_send_data_xxx() */ kfree_skb(skb); /* Poll the higher layers for one more frame */ irlmp_flow_indication(self->notify.instance, FLOW_START); if (ret == -EPROTO) break; /* Try again later! */ } /* Finished transmitting */ self->local_busy = FALSE; } else if (self->disconnect_pending) { self->disconnect_pending = FALSE; ret = (*state[self->state])(self, DISCONNECT_REQUEST, NULL, NULL); } break; /* case LAP_NDM: */ /* case LAP_CONN: */ /* case LAP_RESET_WAIT: */ /* case LAP_RESET_CHECK: */ default: break; } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)19377.51%430.77%
Jean Tourrilhes4417.67%430.77%
Martin Dalecki52.01%17.69%
Harvey Harrison20.80%17.69%
David S. Miller20.80%17.69%
Joe Perches20.80%17.69%
Linus Torvalds10.40%17.69%
Total249100.00%13100.00%

/* * Function irlap_state_ndm (event, skb, frame) * * NDM (Normal Disconnected Mode) state * */
static int irlap_state_ndm(struct irlap_cb *self, IRLAP_EVENT event, struct sk_buff *skb, struct irlap_info *info) { discovery_t *discovery_rsp; int ret = 0; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); switch (event) { case CONNECT_REQUEST: IRDA_ASSERT(self->netdev != NULL, return -1;); if (self->media_busy) { /* Note : this will never happen, because we test * media busy in irlap_connect_request() and * postpone the event... - Jean II */ pr_debug("%s(), CONNECT_REQUEST: media busy!\n", __func__); /* Always switch state before calling upper layers */ irlap_next_state(self, LAP_NDM); irlap_disconnect_indication(self, LAP_MEDIA_BUSY); } else { irlap_send_snrm_frame(self, &self->qos_rx); /* Start Final-bit timer */ irlap_start_final_timer(self, self->final_timeout); self->retry_count = 0; irlap_next_state(self, LAP_SETUP); } break; case RECV_SNRM_CMD: /* Check if the frame contains and I field */ if (info) { self->daddr = info->daddr; self->caddr = info->caddr; irlap_next_state(self, LAP_CONN); irlap_connect_indication(self, skb); } else { pr_debug("%s(), SNRM frame does not contain an I field!\n", __func__); } break; case DISCOVERY_REQUEST: IRDA_ASSERT(info != NULL, return -1;); if (self->media_busy) { pr_debug("%s(), DISCOVERY_REQUEST: media busy!\n", __func__); /* irlap->log.condition = MEDIA_BUSY; */ /* This will make IrLMP try again */ irlap_discovery_confirm(self, NULL); /* Note : the discovery log is not cleaned up here, * it will be done in irlap_discovery_request() * Jean II */ return 0; } self->S = info->S; self->s = info->s; irlap_send_discovery_xid_frame(self, info->S, info->s, TRUE, info->discovery); self->frame_sent = FALSE; self->s++; irlap_start_slot_timer(self, self->slot_timeout); irlap_next_state(self, LAP_QUERY); break; case RECV_DISCOVERY_XID_CMD: IRDA_ASSERT(info != NULL, return -1;); /* Assert that this is not the final slot */ if (info->s <= info->S) { self->slot = irlap_generate_rand_time_slot(info->S, info->s); if (self->slot == info->s) { discovery_rsp = irlmp_get_discovery_response(); discovery_rsp->data.daddr = info->daddr; irlap_send_discovery_xid_frame(self, info->S, self->slot, FALSE, discovery_rsp); self->frame_sent = TRUE; } else self->frame_sent = FALSE; /* * Go to reply state until end of discovery to * inhibit our own transmissions. Set the timer * to not stay forever there... Jean II */ irlap_start_query_timer(self, info->S, info->s); irlap_next_state(self, LAP_REPLY); } else { /* This is the final slot. How is it possible ? * This would happen is both discoveries are just slightly * offset (if they are in sync, all packets are lost). * Most often, all the discovery requests will be received * in QUERY state (see my comment there), except for the * last frame that will come here. * The big trouble when it happen is that active discovery * doesn't happen, because nobody answer the discoveries * frame of the other guy, so the log shows up empty. * What should we do ? * Not much. It's too late to answer those discovery frames, * so we just pass the info to IrLMP who will put it in the * log (and post an event). * Another cause would be devices that do discovery much * slower than us, however the latest fixes should minimise * those cases... * Jean II */ pr_debug("%s(), Receiving final discovery request, missed the discovery slots :-(\n", __func__); /* Last discovery request -> in the log */ irlap_discovery_indication(self, info->discovery); } break; case MEDIA_BUSY_TIMER_EXPIRED: /* A bunch of events may be postponed because the media is * busy (usually immediately after we close a connection), * or while we are doing discovery (state query/reply). * In all those cases, the media busy flag will be cleared * when it's OK for us to process those postponed events. * This event is not mentioned in the state machines in the * IrLAP spec. It's because they didn't consider Ultra and * postponing connection request is optional. * Jean II */ #ifdef CONFIG_IRDA_ULTRA /* Send any pending Ultra frames if any */ if (!skb_queue_empty(&self->txq_ultra)) { /* We don't send the frame, just post an event. * Also, previously this code was in timer.c... * Jean II */ ret = (*state[self->state])(self, SEND_UI_FRAME, NULL, NULL); } #endif /* CONFIG_IRDA_ULTRA */ /* Check if we should try to connect. * This code was previously in irlap_do_event() */ if (self->connect_pending) { self->connect_pending = FALSE; /* This one *should* not pend in this state, except * if a socket try to connect and immediately * disconnect. - clear - Jean II */ if (self->disconnect_pending) irlap_disconnect_indication(self, LAP_DISC_INDICATION); else ret = (*state[self->state])(self, CONNECT_REQUEST, NULL, NULL); self->disconnect_pending = FALSE; } /* Note : one way to test if this code works well (including * media busy and small busy) is to create a user space * application generating an Ultra packet every 3.05 sec (or * 2.95 sec) and to see how it interact with discovery. * It's fairly easy to check that no packet is lost, that the * packets are postponed during discovery and that after * discovery indication you have a 100ms "gap". * As connection request and Ultra are now processed the same * way, this avoid the tedious job of trying IrLAP connection * in all those cases... * Jean II */ break; #ifdef CONFIG_IRDA_ULTRA case SEND_UI_FRAME: { int i; /* Only allowed to repeat an operation twice */ for (i=0; ((i<2) && (self->media_busy == FALSE)); i++) { skb = skb_dequeue(&self->txq_ultra); if (skb) irlap_send_ui_frame(self, skb, CBROADCAST, CMD_FRAME); else break; /* irlap_send_ui_frame() won't increase skb reference * count, so no dev_kfree_skb() - Jean II */ } if (i == 2) { /* Force us to listen 500 ms again */ irda_device_set_media_busy(self->netdev, TRUE); } break; } case RECV_UI_FRAME: /* Only accept broadcast frames in NDM mode */ if (info->caddr != CBROADCAST) { pr_debug("%s(), not a broadcast frame!\n", __func__); } else irlap_unitdata_indication(self, skb); break; #endif /* CONFIG_IRDA_ULTRA */ case RECV_TEST_CMD: /* Remove test frame header */ skb_pull(skb, sizeof(struct test_frame)); /* * Send response. This skb will not be sent out again, and * will only be used to send out the same info as the cmd */ irlap_send_test_frame(self, CBROADCAST, info->daddr, skb); break; case RECV_TEST_RSP: pr_debug("%s() not implemented!\n", __func__); break; default: pr_debug("%s(), Unknown event %s\n", __func__, irlap_event[event]); ret = -1; break; } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)56378.41%947.37%
Linus Torvalds11215.60%210.53%
Jean Tourrilhes273.76%526.32%
Joe Perches81.11%15.26%
Harvey Harrison70.97%15.26%
Martin Dalecki10.14%15.26%
Total718100.00%19100.00%

/* * Function irlap_state_query (event, skb, info) * * QUERY state * */
static int irlap_state_query(struct irlap_cb *self, IRLAP_EVENT event, struct sk_buff *skb, struct irlap_info *info) { int ret = 0; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); switch (event) { case RECV_DISCOVERY_XID_RSP: IRDA_ASSERT(info != NULL, return -1;); IRDA_ASSERT(info->discovery != NULL, return -1;); pr_debug("%s(), daddr=%08x\n", __func__, info->discovery->data.daddr); if (!self->discovery_log) { net_warn_ratelimited("%s: discovery log is gone! maybe the discovery timeout has been set too short?\n", __func__); break; } hashbin_insert(self->discovery_log, (irda_queue_t *) info->discovery, info->discovery->data.daddr, NULL); /* Keep state */ /* irlap_next_state(self, LAP_QUERY); */ break; case RECV_DISCOVERY_XID_CMD: /* Yes, it is possible to receive those frames in this mode. * Note that most often the last discovery request won't * occur here but in NDM state (see my comment there). * What should we do ? * Not much. We are currently performing our own discovery, * therefore we can't answer those frames. We don't want * to change state either. We just pass the info to * IrLMP who will put it in the log (and post an event). * Jean II */ IRDA_ASSERT(info != NULL, return -1;); pr_debug("%s(), Receiving discovery request (s = %d) while performing discovery :-(\n", __func__, info->s); /* Last discovery request ? */ if (info->s == 0xff) irlap_discovery_indication(self, info->discovery); break; case SLOT_TIMER_EXPIRED: /* * Wait a little longer if we detect an incoming frame. This * is not mentioned in the spec, but is a good thing to do, * since we want to work even with devices that violate the * timing requirements. */ if (irda_device_is_receiving(self->netdev) && !self->add_wait) { pr_debug("%s(), device is slow to answer, waiting some more!\n", __func__); irlap_start_slot_timer(self, msecs_to_jiffies(10)); self->add_wait = TRUE; return ret; } self->add_wait = FALSE; if (self->s < self->S) { irlap_send_discovery_xid_frame(self, self->S, self->s, TRUE, self->discovery_cmd); self->s++; irlap_start_slot_timer(self, self->slot_timeout); /* Keep state */ irlap_next_state(self, LAP_QUERY); } else { /* This is the final slot! */ irlap_send_discovery_xid_frame(self, self->S, 0xff, TRUE, self->discovery_cmd); /* Always switch state before calling upper layers */ irlap_next_state(self, LAP_NDM); /* * We are now finished with the discovery procedure, * so now we must return the results */ irlap_discovery_confirm(self, self->discovery_log); /* IrLMP should now have taken care of the log */ self->discovery_log = NULL; } break; default: pr_debug("%s(), Unknown event %s\n", __func__, irlap_event[event]); ret = -1; break; } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)31990.88%642.86%
Jean Tourrilhes164.56%321.43%
Joe Perches71.99%214.29%
Harvey Harrison51.42%17.14%
Martin Dalecki30.85%17.14%
Andrew Morton10.28%17.14%
Total351100.00%14100.00%

/* * Function irlap_state_reply (self, event, skb, info) * * REPLY, we have received a XID discovery frame from a device and we * are waiting for the right time slot to send a response XID frame * */
static int irlap_state_reply(struct irlap_cb *self, IRLAP_EVENT event, struct sk_buff *skb, struct irlap_info *info) { discovery_t *discovery_rsp; int ret=0; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); switch (event) { case QUERY_TIMER_EXPIRED: pr_debug("%s(), QUERY_TIMER_EXPIRED <%ld>\n", __func__, jiffies); irlap_next_state(self, LAP_NDM); break; case RECV_DISCOVERY_XID_CMD: IRDA_ASSERT(info != NULL, return -1;); /* Last frame? */ if (info->s == 0xff) { del_timer(&self->query_timer); /* info->log.condition = REMOTE; */ /* Always switch state before calling upper layers */ irlap_next_state(self, LAP_NDM); irlap_discovery_indication(self, info->discovery); } else { /* If it's our slot, send our reply */ if ((info->s >= self->slot) && (!self->frame_sent)) { discovery_rsp = irlmp_get_discovery_response(); discovery_rsp->data.daddr = info->daddr; irlap_send_discovery_xid_frame(self, info->S, self->slot, FALSE, discovery_rsp); self->frame_sent = TRUE; } /* Readjust our timer to accommodate devices * doing faster or slower discovery than us... * Jean II */ irlap_start_query_timer(self, info->S, info->s); /* Keep state */ //irlap_next_state(self, LAP_REPLY); } break; default: pr_debug("%s(), Unknown event %d, %s\n", __func__, event, irlap_event[event]); ret = -1; break; } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)20287.83%330.00%
Jean Tourrilhes2310.00%440.00%
Joe Perches20.87%110.00%
Harvey Harrison20.87%110.00%
Lucas De Marchi10.43%110.00%
Total230100.00%10100.00%

/* * Function irlap_state_conn (event, skb, info) * * CONN, we have received a SNRM command and is waiting for the upper * layer to accept or refuse connection * */
static int irlap_state_conn(struct irlap_cb *self, IRLAP_EVENT event, struct sk_buff *skb, struct irlap_info *info) { int ret = 0; pr_debug("%s(), event=%s\n", __func__, irlap_event[event]); IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); switch (event) { case CONNECT_RESPONSE: skb_pull(skb, sizeof(struct snrm_frame)); IRDA_ASSERT(self->netdev != NULL, return -1;); irlap_qos_negotiate(self, skb); irlap_initiate_connection_state(self); /* * Applying the parameters now will make sure we change speed * *after* we have sent the next frame */ irlap_apply_connection_parameters(self, FALSE); /* * Sending this frame will force a speed change after it has * been sent (i.e. the frame will be sent at 9600). */ irlap_send_ua_response_frame(self, &self->qos_rx); #if 0 /* * We are allowed to send two frames, but this may increase * the connect latency, so lets not do it for now. */ /* This is full of good intentions, but doesn't work in * practice. * After sending the first UA response, we switch the * dongle to the negotiated speed, which is usually * different than 9600 kb/s. * From there, there is two solutions : * 1) The other end has received the first UA response : * it will set up the connection, move to state LAP_NRM_P, * and will ignore and drop the second UA response. * Actually, it's even worse : the other side will almost * immediately send a RR that will likely collide with the * UA response (depending on negotiated turnaround). * 2) The other end has not received the first UA response, * will stay at 9600 and will never see the second UA response. * Jean II */ irlap_send_ua_response_frame(self, &self->qos_rx); #endif /* * The WD-timer could be set to the duration of the P-timer * for this case, but it is recommended to use twice the * value (note 3 IrLAP p. 60). */ irlap_start_wd_timer(self, self->wd_timeout); irlap_next_state(self, LAP_NRM_S); break; case RECV_DISCOVERY_XID_CMD: pr_debug("%s(), event RECV_DISCOVER_XID_CMD!\n", __func__); irlap_next_state(self, LAP_NDM); break; case DISCONNECT_REQUEST: pr_debug("%s(), Disconnect request!\n", __func__); irlap_send_dm_frame(self); irlap_next_state( self, LAP_NDM); irlap_disconnect_indication(self, LAP_DISC_INDICATION); break; default: pr_debug("%s(), Unknown event %d, %s\n", __func__, event, irlap_event[event]); ret = -1; break; } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)17480.18%538.46%
Linus Torvalds198.76%215.38%
Jean Tourrilhes115.07%215.38%
Harvey Harrison41.84%17.69%
Joe Perches41.84%17.69%
Martin Dalecki41.84%17.69%
Steven Cole10.46%17.69%
Total217100.00%13100.00%

/* * Function irlap_state_setup (event, skb, frame) * * SETUP state, The local layer has transmitted a SNRM command frame to * a remote peer layer and is awaiting a reply . * */
static int irlap_state_setup(struct irlap_cb *self, IRLAP_EVENT event, struct sk_buff *skb, struct irlap_info *info) { int ret = 0; IRDA_ASSERT(self != NULL, return -1;); IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); switch (event) { case FINAL_TIMER_EXPIRED: if (self->retry_count < self->N3) { /* * Perform random backoff, Wait a random number of time units, minimum * duration half the time taken to transmitt a SNRM frame, maximum duration * 1.5 times the time taken to transmit a SNRM frame. So this time should * between 15 msecs and 45 msecs. */ irlap_start_backoff_timer(self, msecs_to_jiffies(20 + (jiffies % 30))); } else { /* Always switch state before calling upper layers */ irlap_next_state(self, LAP_NDM); irlap_disconnect_indication(self, LAP_FOUND_NONE); } break; case BACKOFF_TIMER_EXPIRED: irlap_send_snrm_frame(self, &self->qos_rx); irlap_start_final_timer(self, self->final_timeout); self->retry_count++; break; case RECV_SNRM_CMD: pr_debug("%s(), SNRM battle!\n", __func__); IRDA_ASSERT(skb != NULL, return 0;); IRDA_ASSERT(info != NULL, return 0;); /* * The device with the largest device address wins the battle * (both have sent a SNRM command!) */ if (info &&(info->daddr > self->saddr)) { del_timer(&self->final_timer); irlap_initiate_connection_state(self); IRDA_ASSERT(self->netdev != NULL, return -1;); skb_pull(skb, sizeof(struct snrm_frame)); irlap_qos_negotiate(self, skb); /* Send UA frame and then change link settings */ irlap_apply_connection_parameters(self, FALSE); irlap_send_ua_response_frame(self, &self->qos_rx); irlap_next_state(self, LAP_NRM_S); irlap_connect_confirm(self, skb); /* * The WD-timer could be set to the duration of the * P-timer for this case, but it is recommended * to use twice the value (note 3 IrLAP p. 60). */ irlap_start_wd_timer(self, self->wd_timeout); } else { /* We just ignore the other device! */ irlap_next_state(self, LAP_SETUP); } break; case RECV_UA_RSP: /* Stop F-timer */ del_timer(&self->final_timer); /* Initiate connection state */ irlap_initiate_connection_state(self); /* Negotiate connection parameters */ IRDA_ASSERT(skb->len > 10, return -1;); skb_pull(skb, sizeof(struct ua_frame)); IRDA_ASSERT(self->netdev != NULL, return -1;); irlap_qos_negotiate