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Diffstat (limited to 'net/irda/irlap_event.c')
| -rw-r--r-- | net/irda/irlap_event.c | 2334 |
1 files changed, 2334 insertions, 0 deletions
diff --git a/net/irda/irlap_event.c b/net/irda/irlap_event.c new file mode 100644 index 000000000000..1cd89f5f3b75 --- /dev/null +++ b/net/irda/irlap_event.c @@ -0,0 +1,2334 @@ +/********************************************************************* + * + * 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 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/string.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/skbuff.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 *); + +#ifdef CONFIG_IRDA_DEBUG +static const char *irlap_event[] = { + "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", +}; +#endif /* CONFIG_IRDA_DEBUG */ + +const char *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); +} + +/* + * 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_len(&self->txq) == 0) || (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; + + IRDA_DEBUG(3, "%s(), timeout=%d (%ld)\n", __FUNCTION__, 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); +} + +/* + * 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; + + IRDA_DEBUG(3, "%s(), event = %s, state = %s\n", __FUNCTION__, + 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 + */ + IRDA_DEBUG(2, "%s() : queue len = %d\n", __FUNCTION__, + skb_queue_len(&self->txq)); + + if (skb_queue_len(&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; + } +} + +/* + * Function irlap_next_state (self, state) + * + * Switches state and provides debug information + * + */ +static inline void irlap_next_state(struct irlap_cb *self, IRLAP_STATE state) +{ + /* + if (!self || self->magic != LAP_MAGIC) + return; + + IRDA_DEBUG(4, "next LAP state = %s\n", irlap_state[state]); + */ + self->state = state; +} + +/* + * 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 */ + IRDA_DEBUG(0, "%s(), CONNECT_REQUEST: media busy!\n", + __FUNCTION__); + + /* 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 { + IRDA_DEBUG(0, "%s(), SNRM frame does not " + "contain an I field!\n", __FUNCTION__); + } + break; + case DISCOVERY_REQUEST: + IRDA_ASSERT(info != NULL, return -1;); + + if (self->media_busy) { + IRDA_DEBUG(1, "%s(), DISCOVERY_REQUEST: media busy!\n", + __FUNCTION__); + /* 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 + */ + IRDA_DEBUG(1, "%s(), Receiving final discovery request, missed the discovery slots :-(\n", __FUNCTION__); + + /* 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) { + IRDA_DEBUG(0, "%s(), not a broadcast frame!\n", + __FUNCTION__); + } 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: + IRDA_DEBUG(0, "%s() not implemented!\n", __FUNCTION__); + break; + default: + IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__, + irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * 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;); + + IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__, + info->discovery->data.daddr); + + if (!self->discovery_log) { + IRDA_WARNING("%s: discovery log is gone! " + "maybe the discovery timeout has been set" + " to short?\n", __FUNCTION__); + 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;); + + IRDA_DEBUG(1, "%s(), Receiving discovery request (s = %d) while performing discovery :-(\n", __FUNCTION__, 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) { + IRDA_DEBUG(2, "%s(), device is slow to answer, " + "waiting some more!\n", __FUNCTION__); + 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: + IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__, + irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * 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_DEBUG(4, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return -1;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); + + switch (event) { + case QUERY_TIMER_EXPIRED: + IRDA_DEBUG(0, "%s(), QUERY_TIMER_EXPIRED <%ld>\n", + __FUNCTION__, 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 accomodate 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: + IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__, + event, irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * 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; + + IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, 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: + IRDA_DEBUG(3, "%s(), event RECV_DISCOVER_XID_CMD!\n", + __FUNCTION__); + irlap_next_state(self, LAP_NDM); + + break; + case DISCONNECT_REQUEST: + IRDA_DEBUG(0, "%s(), Disconnect request!\n", __FUNCTION__); + irlap_send_dm_frame(self); + irlap_next_state( self, LAP_NDM); + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__, + event, irlap_event[event]); + + ret = -1; + break; + } + + return ret; +} + +/* + * 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_DEBUG(4, "%s()\n", __FUNCTION__); + + 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: + IRDA_DEBUG(4, "%s(), SNRM battle!\n", __FUNCTION__); + + 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(self, skb); + + /* Set the new link setting *now* (before the rr frame) */ + irlap_apply_connection_parameters(self, TRUE); + self->retry_count = 0; + + /* Wait for turnaround time to give a chance to the other + * device to be ready to receive us. + * Note : the time to switch speed is typically larger + * than the turnaround time, but as we don't have the other + * side speed switch time, that's our best guess... + * Jean II */ + irlap_wait_min_turn_around(self, &self->qos_tx); + + /* This frame will actually be sent at the new speed */ + irlap_send_rr_frame(self, CMD_FRAME); + + /* The timer is set to half the normal timer to quickly + * detect a failure to negociate the new connection + * parameters. IrLAP 6.11.3.2, note 3. + * Note that currently we don't process this failure + * properly, as we should do a quick disconnect. + * Jean II */ + irlap_start_final_timer(self, self->final_timeout/2); + irlap_next_state(self, LAP_NRM_P); + + irlap_connect_confirm(self, skb); + break; + case RECV_DM_RSP: /* FALLTHROUGH */ + case RECV_DISC_CMD: + del_timer(&self->final_timer); + irlap_next_state(self, LAP_NDM); + + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__, + event, irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * Function irlap_state_offline (self, event, skb, info) + * + * OFFLINE state, not used for now! + * + */ +static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + IRDA_DEBUG( 0, "%s(), Unknown event\n", __FUNCTION__); + + return -1; +} + +/* + * Function irlap_state_xmit_p (self, event, skb, info) + * + * XMIT, Only the primary station has right to transmit, and we + * therefore do not expect to receive any transmissions from other + * stations. + * + */ +static int irlap_state_xmit_p(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + + switch (event) { + case SEND_I_CMD: + /* + * Only send frame if send-window > 0. + */ + if ((self->window > 0) && (!self->remote_busy)) { + int nextfit; +#ifdef CONFIG_IRDA_DYNAMIC_WINDOW + struct sk_buff *skb_next; + + /* With DYNAMIC_WINDOW, we keep the window size + * maximum, and adapt on the packets we are sending. + * At 115k, we can send only 2 packets of 2048 bytes + * in a 500 ms turnaround. Without this option, we + * would always limit the window to 2. With this + * option, if we send smaller packets, we can send + * up to 7 of them (always depending on QoS). + * Jean II */ + + /* Look at the next skb. This is safe, as we are + * the only consumer of the Tx queue (if we are not, + * we have other problems) - Jean II */ + skb_next = skb_peek(&self->txq); + + /* Check if a subsequent skb exist and would fit in + * the current window (with respect to turnaround + * time). + * This allow us to properly mark the current packet + * with the pf bit, to avoid falling back on the + * second test below, and avoid waiting the + * end of the window and sending a extra RR. + * Note : (skb_next != NULL) <=> (skb_queue_len() > 0) + * Jean II */ + nextfit = ((skb_next != NULL) && + ((skb_next->len + skb->len) <= + self->bytes_left)); + + /* + * The current packet may not fit ! Because of test + * above, this should not happen any more !!! + * Test if we have transmitted more bytes over the + * link than its possible to do with the current + * speed and turn-around-time. + */ + if((!nextfit) && (skb->len > self->bytes_left)) { + IRDA_DEBUG(0, "%s(), Not allowed to transmit" + " more bytes!\n", __FUNCTION__); + /* Requeue the skb */ + skb_queue_head(&self->txq, skb_get(skb)); + /* + * We should switch state to LAP_NRM_P, but + * that is not possible since we must be sure + * that we poll the other side. Since we have + * used up our time, the poll timer should + * trigger anyway now, so we just wait for it + * DB + */ + /* + * Sorry, but that's not totally true. If + * we send 2000B packets, we may wait another + * 1000B until our turnaround expire. That's + * why we need to be proactive in avoiding + * coming here. - Jean II + */ + return -EPROTO; + } + + /* Substract space used by this skb */ + self->bytes_left -= skb->len; +#else /* CONFIG_IRDA_DYNAMIC_WINDOW */ + /* Window has been adjusted for the max packet + * size, so much simpler... - Jean II */ + nextfit = (skb_queue_len(&self->txq) > 0); +#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */ + /* + * Send data with poll bit cleared only if window > 1 + * and there is more frames after this one to be sent + */ + if ((self->window > 1) && (nextfit)) { + /* More packet to send in current window */ + irlap_send_data_primary(self, skb); + irlap_next_state(self, LAP_XMIT_P); + } else { + /* Final packet of window */ + irlap_send_data_primary_poll(self, skb); + irlap_next_state(self, LAP_NRM_P); + + /* + * Make sure state machine does not try to send + * any more frames + */ + ret = -EPROTO; + } +#ifdef CONFIG_IRDA_FAST_RR + /* Peer may want to reply immediately */ + self->fast_RR = FALSE; +#endif /* CONFIG_IRDA_FAST_RR */ + } else { + IRDA_DEBUG(4, "%s(), Unable to send! remote busy?\n", + __FUNCTION__); + skb_queue_head(&self->txq, skb_get(skb)); + + /* + * The next ret is important, because it tells + * irlap_next_state _not_ to deliver more frames + */ + ret = -EPROTO; + } + break; + case POLL_TIMER_EXPIRED: + IRDA_DEBUG(3, "%s(), POLL_TIMER_EXPIRED <%ld>\n", + __FUNCTION__, jiffies); + irlap_send_rr_frame(self, CMD_FRAME); + /* Return to NRM properly - Jean II */ + self->window = self->window_size; +#ifdef CONFIG_IRDA_DYNAMIC_WINDOW + /* Allowed to transmit a maximum number of bytes again. */ + self->bytes_left = self->line_capacity; +#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */ + irlap_start_final_timer(self, self->final_timeout); + irlap_next_state(self, LAP_NRM_P); + break; + case DISCONNECT_REQUEST: + del_timer(&self->poll_timer); + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_disc_frame(self); + irlap_flush_all_queues(self); + irlap_start_final_timer(self, self->final_timeout); + self->retry_count = 0; + irlap_next_state(self, LAP_PCLOSE); + break; + case DATA_REQUEST: + /* Nothing to do, irlap_do_event() will send the packet + * when we return... - Jean II */ + break; + default: + IRDA_DEBUG(0, "%s(), Unknown event %s\n", + __FUNCTION__, irlap_event[event]); + + ret = -EINVAL; + break; + } + return ret; +} + +/* + * Function irlap_state_pclose (event, skb, info) + * + * PCLOSE state + */ +static int irlap_state_pclose(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + + IRDA_DEBUG(1, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return -1;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); + + switch (event) { + case RECV_UA_RSP: /* FALLTHROUGH */ + case RECV_DM_RSP: + del_timer(&self->final_timer); + + /* Set new link parameters */ + irlap_apply_default_connection_parameters(self); + + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + case FINAL_TIMER_EXPIRED: + if (self->retry_count < self->N3) { + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_disc_frame(self); + irlap_start_final_timer(self, self->final_timeout); + self->retry_count++; + /* Keep state */ + } else { + irlap_apply_default_connection_parameters(self); + + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + irlap_disconnect_indication(self, LAP_NO_RESPONSE); + } + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %d\n", __FUNCTION__, event); + + ret = -1; + break; + } + return ret; +} + +/* + * Function irlap_state_nrm_p (self, event, skb, info) + * + * NRM_P (Normal Response Mode as Primary), The primary station has given + * permissions to a secondary station to transmit IrLAP resonse frames + * (by sending a frame with the P bit set). The primary station will not + * transmit any frames and is expecting to receive frames only from the + * secondary to which transmission permissions has been given. + */ +static int irlap_state_nrm_p(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + int ns_status; + int nr_status; + + switch (event) { + case RECV_I_RSP: /* Optimize for the common case */ + /* FIXME: must check for remote_busy below */ +#ifdef CONFIG_IRDA_FAST_RR + /* + * Reset the fast_RR so we can use the fast RR code with + * full speed the next time since peer may have more frames + * to transmitt + */ + self->fast_RR = FALSE; +#endif /* CONFIG_IRDA_FAST_RR */ + IRDA_ASSERT( info != NULL, return -1;); + + ns_status = irlap_validate_ns_received(self, info->ns); + nr_status = irlap_validate_nr_received(self, info->nr); + + /* + * Check for expected I(nformation) frame + */ + if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) { + + /* Update Vr (next frame for us to receive) */ + self->vr = (self->vr + 1) % 8; + + /* Update Nr received, cleanup our retry queue */ + irlap_update_nr_received(self, info->nr); + + /* + * Got expected NR, so reset the + * retry_count. This is not done by IrLAP spec, + * which is strange! + */ + self->retry_count = 0; + self->ack_required = TRUE; + + /* poll bit cleared? */ + if (!info->pf) { + /* Keep state, do not move this line */ + irlap_next_state(self, LAP_NRM_P); + + irlap_data_indication(self, skb, FALSE); + } else { + /* No longer waiting for pf */ + del_timer(&self->final_timer); + + irlap_wait_min_turn_around(self, &self->qos_tx); + + /* Call higher layer *before* changing state + * to give them a chance to send data in the + * next LAP frame. + * Jean II */ + irlap_data_indication(self, skb, FALSE); + + /* XMIT states are the most dangerous state + * to be in, because user requests are + * processed directly and may change state. + * On the other hand, in NDM_P, those + * requests are queued and we will process + * them when we return to irlap_do_event(). + * Jean II + */ + irlap_next_state(self, LAP_XMIT_P); + + /* This is the last frame. + * Make sure it's always called in XMIT state. + * - Jean II */ + irlap_start_poll_timer(self, self->poll_timeout); + } + break; + + } + /* Unexpected next to send (Ns) */ + if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED)) + { + if (!info->pf) { + irlap_update_nr_received(self, info->nr); + + /* + * Wait until the last frame before doing + * anything + */ + + /* Keep state */ + irlap_next_state(self, LAP_NRM_P); + } else { + IRDA_DEBUG(4, + "%s(), missing or duplicate frame!\n", + __FUNCTION__); + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, CMD_FRAME); + + self->ack_required = FALSE; + + irlap_start_final_timer(self, self->final_timeout); + irlap_next_state(self, LAP_NRM_P); + } + break; + } + /* + * Unexpected next to receive (Nr) + */ + if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED)) + { + if (info->pf) { + self->vr = (self->vr + 1) % 8; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + /* Resend rejected frames */ + irlap_resend_rejected_frames(self, CMD_FRAME); + + self->ack_required = FALSE; + + /* Make sure we account for the time + * to transmit our frames. See comemnts + * in irlap_send_data_primary_poll(). + * Jean II */ + irlap_start_final_timer(self, 2 * self->final_timeout); + + /* Keep state, do not move this line */ + irlap_next_state(self, LAP_NRM_P); + + irlap_data_indication(self, skb, FALSE); + } else { + /* + * Do not resend frames until the last + * frame has arrived from the other + * device. This is not documented in + * IrLAP!! + */ + self->vr = (self->vr + 1) % 8; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + self->ack_required = FALSE; + + /* Keep state, do not move this line!*/ + irlap_next_state(self, LAP_NRM_P); + + irlap_data_indication(self, skb, FALSE); + } + break; + } + /* + * Unexpected next to send (Ns) and next to receive (Nr) + * Not documented by IrLAP! + */ + if ((ns_status == NS_UNEXPECTED) && + (nr_status == NR_UNEXPECTED)) + { + IRDA_DEBUG(4, "%s(), unexpected nr and ns!\n", + __FUNCTION__); + if (info->pf) { + /* Resend rejected frames */ + irlap_resend_rejected_frames(self, CMD_FRAME); + + /* Give peer some time to retransmit! + * But account for our own Tx. */ + irlap_start_final_timer(self, 2 * self->final_timeout); + + /* Keep state, do not move this line */ + irlap_next_state(self, LAP_NRM_P); + } else { + /* Update Nr received */ + /* irlap_update_nr_received( info->nr); */ + + self->ack_required = FALSE; + } + break; + } + + /* + * Invalid NR or NS + */ + if ((nr_status == NR_INVALID) || (ns_status == NS_INVALID)) { + if (info->pf) { + del_timer(&self->final_timer); + + irlap_next_state(self, LAP_RESET_WAIT); + + irlap_disconnect_indication(self, LAP_RESET_INDICATION); + self->xmitflag = TRUE; + } else { + del_timer(&self->final_timer); + + irlap_disconnect_indication(self, LAP_RESET_INDICATION); + + self->xmitflag = FALSE; + } + break; + } + IRDA_DEBUG(1, "%s(), Not implemented!\n", __FUNCTION__); + IRDA_DEBUG(1, "%s(), event=%s, ns_status=%d, nr_status=%d\n", + __FUNCTION__, irlap_event[event], ns_status, nr_status); + break; + case RECV_UI_FRAME: + /* Poll bit cleared? */ + if (!info->pf) { + irlap_data_indication(self, skb, TRUE); + irlap_next_state(self, LAP_NRM_P); + } else { + del_timer(&self->final_timer); + irlap_data_indication(self, skb, TRUE); + irlap_next_state(self, LAP_XMIT_P); + IRDA_DEBUG(1, "%s: RECV_UI_FRAME: next state %s\n", __FUNCTION__, irlap_state[self->state]); + irlap_start_poll_timer(self, self->poll_timeout); + } + break; + case RECV_RR_RSP: + /* + * If you get a RR, the remote isn't busy anymore, + * no matter what the NR + */ + self->remote_busy = FALSE; + + /* + * Nr as expected? + */ + ret = irlap_validate_nr_received(self, info->nr); + if (ret == NR_EXPECTED) { + /* Stop final timer */ + del_timer(&self->final_timer); + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + /* + * Got expected NR, so reset the retry_count. This + * is not done by the IrLAP standard , which is + * strange! DB. + */ + self->retry_count = 0; + irlap_wait_min_turn_around(self, &self->qos_tx); + + irlap_next_state(self, LAP_XMIT_P); + + /* Start poll timer */ + irlap_start_poll_timer(self, self->poll_timeout); + } else if (ret == NR_UNEXPECTED) { + IRDA_ASSERT(info != NULL, return -1;); + /* + * Unexpected nr! + */ + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + IRDA_DEBUG(4, "RECV_RR_FRAME: Retrans:%d, nr=%d, va=%d, " + "vs=%d, vr=%d\n", + self->retry_count, info->nr, self->va, + self->vs, self->vr); + + /* Resend rejected frames */ + irlap_resend_rejected_frames(self, CMD_FRAME); + + /* Final timer ??? Jean II */ + + irlap_next_state(self, LAP_NRM_P); + } else if (ret == NR_INVALID) { + IRDA_DEBUG(1, "%s(), Received RR with " + "invalid nr !\n", __FUNCTION__); + del_timer(&self->final_timer); + + irlap_next_state(self, LAP_RESET_WAIT); + + irlap_disconnect_indication(self, LAP_RESET_INDICATION); + self->xmitflag = TRUE; + } + break; + case RECV_RNR_RSP: + IRDA_ASSERT(info != NULL, return -1;); + + /* Stop final timer */ + del_timer(&self->final_timer); + self->remote_busy = TRUE; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + irlap_next_state(self, LAP_XMIT_P); + + /* Start poll timer */ + irlap_start_poll_timer(self, self->poll_timeout); + break; + case RECV_FRMR_RSP: + del_timer(&self->final_timer); + self->xmitflag = TRUE; + irlap_next_state(self, LAP_RESET_WAIT); + irlap_reset_indication(self); + break; + case FINAL_TIMER_EXPIRED: + /* + * We are allowed to wait for additional 300 ms if + * final timer expires when we are in the middle + * of receiving a frame (page 45, IrLAP). Check that + * we only do this once for each frame. + */ + if (irda_device_is_receiving(self->netdev) && !self->add_wait) { + IRDA_DEBUG(1, "FINAL_TIMER_EXPIRED when receiving a " + "frame! Waiting a little bit more!\n"); + irlap_start_final_timer(self, msecs_to_jiffies(300)); + + /* + * Don't allow this to happen one more time in a row, + * or else we can get a pretty tight loop here if + * if we only receive half a frame. DB. + */ + self->add_wait = TRUE; + break; + } + self->add_wait = FALSE; + + /* N2 is the disconnect timer. Until we reach it, we retry */ + if (self->retry_count < self->N2) { + /* Retry sending the pf bit to the secondary */ + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, CMD_FRAME); + + irlap_start_final_timer(self, self->final_timeout); + self->retry_count++; + IRDA_DEBUG(4, "irlap_state_nrm_p: FINAL_TIMER_EXPIRED:" + " retry_count=%d\n", self->retry_count); + + /* Early warning event. I'm using a pretty liberal + * interpretation of the spec and generate an event + * every time the timer is multiple of N1 (and not + * only the first time). This allow application + * to know precisely if connectivity restart... + * Jean II */ + if((self->retry_count % self->N1) == 0) + irlap_status_indication(self, + STATUS_NO_ACTIVITY); + + /* Keep state */ + } else { + irlap_apply_default_connection_parameters(self); + + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + irlap_disconnect_indication(self, LAP_NO_RESPONSE); + } + break; + case RECV_REJ_RSP: + irlap_update_nr_received(self, info->nr); + if (self->remote_busy) { + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, CMD_FRAME); + } else + irlap_resend_rejected_frames(self, CMD_FRAME); + irlap_start_final_timer(self, 2 * self->final_timeout); + break; + case RECV_SREJ_RSP: + irlap_update_nr_received(self, info->nr); + if (self->remote_busy) { + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, CMD_FRAME); + } else + irlap_resend_rejected_frame(self, CMD_FRAME); + irlap_start_final_timer(self, 2 * self->final_timeout); + break; + case RECV_RD_RSP: + IRDA_DEBUG(1, "%s(), RECV_RD_RSP\n", __FUNCTION__); + + irlap_flush_all_queues(self); + irlap_next_state(self, LAP_XMIT_P); + /* Call back the LAP state machine to do a proper disconnect */ + irlap_disconnect_request(self); + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %s\n", + __FUNCTION__, irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * Function irlap_state_reset_wait (event, skb, info) + * + * We have informed the service user of a reset condition, and is + * awaiting reset of disconnect request. + * + */ +static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + + IRDA_DEBUG(3, "%s(), event = %s\n", __FUNCTION__, irlap_event[event]); + + IRDA_ASSERT(self != NULL, return -1;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); + + switch (event) { + case RESET_REQUEST: + if (self->xmitflag) { + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_snrm_frame(self, NULL); + irlap_start_final_timer(self, self->final_timeout); + irlap_next_state(self, LAP_RESET); + } else { + irlap_start_final_timer(self, self->final_timeout); + irlap_next_state(self, LAP_RESET); + } + break; + case DISCONNECT_REQUEST: + irlap_wait_min_turn_around( self, &self->qos_tx); + irlap_send_disc_frame( self); + irlap_flush_all_queues( self); + irlap_start_final_timer( self, self->final_timeout); + self->retry_count = 0; + irlap_next_state( self, LAP_PCLOSE); + break; + default: + IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__, + irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * Function irlap_state_reset (self, event, skb, info) + * + * We have sent a SNRM reset command to the peer layer, and is awaiting + * reply. + * + */ +static int irlap_state_reset(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + + IRDA_DEBUG(3, "%s(), event = %s\n", __FUNCTION__, irlap_event[event]); + + IRDA_ASSERT(self != NULL, return -1;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); + + switch (event) { + case RECV_DISC_CMD: + del_timer(&self->final_timer); + + irlap_apply_default_connection_parameters(self); + + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + irlap_disconnect_indication(self, LAP_NO_RESPONSE); + + break; + case RECV_UA_RSP: + del_timer(&self->final_timer); + + /* Initiate connection state */ + irlap_initiate_connection_state(self); + + irlap_reset_confirm(); + + self->remote_busy = FALSE; + + irlap_next_state(self, LAP_XMIT_P); + + irlap_start_poll_timer(self, self->poll_timeout); + + break; + case FINAL_TIMER_EXPIRED: + if (self->retry_count < 3) { + irlap_wait_min_turn_around(self, &self->qos_tx); + + IRDA_ASSERT(self->netdev != NULL, return -1;); + irlap_send_snrm_frame(self, self->qos_dev); + + self->retry_count++; /* Experimental!! */ + + irlap_start_final_timer(self, self->final_timeout); + irlap_next_state(self, LAP_RESET); + } else if (self->retry_count >= self->N3) { + irlap_apply_default_connection_parameters(self); + + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + irlap_disconnect_indication(self, LAP_NO_RESPONSE); + } + break; + case RECV_SNRM_CMD: + /* + * SNRM frame is not allowed to contain an I-field in this + * state + */ + if (!info) { + IRDA_DEBUG(3, "%s(), RECV_SNRM_CMD\n", __FUNCTION__); + irlap_initiate_connection_state(self); + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_ua_response_frame(self, &self->qos_rx); + irlap_reset_confirm(); + irlap_start_wd_timer(self, self->wd_timeout); + irlap_next_state(self, LAP_NDM); + } else { + IRDA_DEBUG(0, + "%s(), SNRM frame contained an I field!\n", + __FUNCTION__); + } + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %s\n", + __FUNCTION__, irlap_event[event]); + + ret = -1; + break; + } + return ret; +} + +/* + * Function irlap_state_xmit_s (event, skb, info) + * + * XMIT_S, The secondary station has been given the right to transmit, + * and we therefor do not expect to receive any transmissions from other + * stations. + */ +static int irlap_state_xmit_s(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + + IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[event]); + + IRDA_ASSERT(self != NULL, return -ENODEV;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;); + + switch (event) { + case SEND_I_CMD: + /* + * Send frame only if send window > 0 + */ + if ((self->window > 0) && (!self->remote_busy)) { + int nextfit; +#ifdef CONFIG_IRDA_DYNAMIC_WINDOW + struct sk_buff *skb_next; + + /* + * Same deal as in irlap_state_xmit_p(), so see + * the comments at that point. + * We are the secondary, so there are only subtle + * differences. - Jean II + */ + + /* Check if a subsequent skb exist and would fit in + * the current window (with respect to turnaround + * time). - Jean II */ + skb_next = skb_peek(&self->txq); + nextfit = ((skb_next != NULL) && + ((skb_next->len + skb->len) <= + self->bytes_left)); + + /* + * Test if we have transmitted more bytes over the + * link than its possible to do with the current + * speed and turn-around-time. + */ + if((!nextfit) && (skb->len > self->bytes_left)) { + IRDA_DEBUG(0, "%s(), Not allowed to transmit" + " more bytes!\n", __FUNCTION__); + /* Requeue the skb */ + skb_queue_head(&self->txq, skb_get(skb)); + + /* + * Switch to NRM_S, this is only possible + * when we are in secondary mode, since we + * must be sure that we don't miss any RR + * frames + */ + self->window = self->window_size; + self->bytes_left = self->line_capacity; + irlap_start_wd_timer(self, self->wd_timeout); + + irlap_next_state(self, LAP_NRM_S); + /* Slight difference with primary : + * here we would wait for the other side to + * expire the turnaround. - Jean II */ + + return -EPROTO; /* Try again later */ + } + /* Substract space used by this skb */ + self->bytes_left -= skb->len; +#else /* CONFIG_IRDA_DYNAMIC_WINDOW */ + /* Window has been adjusted for the max packet + * size, so much simpler... - Jean II */ + nextfit = (skb_queue_len(&self->txq) > 0); +#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */ + /* + * Send data with final bit cleared only if window > 1 + * and there is more frames to be sent + */ + if ((self->window > 1) && (nextfit)) { + irlap_send_data_secondary(self, skb); + irlap_next_state(self, LAP_XMIT_S); + } else { + irlap_send_data_secondary_final(self, skb); + irlap_next_state(self, LAP_NRM_S); + + /* + * Make sure state machine does not try to send + * any more frames + */ + ret = -EPROTO; + } + } else { + IRDA_DEBUG(2, "%s(), Unable to send!\n", __FUNCTION__); + skb_queue_head(&self->txq, skb_get(skb)); + ret = -EPROTO; + } + break; + case DISCONNECT_REQUEST: + irlap_send_rd_frame(self); + irlap_flush_all_queues(self); + irlap_start_wd_timer(self, self->wd_timeout); + irlap_next_state(self, LAP_SCLOSE); + break; + case DATA_REQUEST: + /* Nothing to do, irlap_do_event() will send the packet + * when we return... - Jean II */ + break; + default: + IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__, + irlap_event[event]); + + ret = -EINVAL; + break; + } + return ret; +} + +/* + * Function irlap_state_nrm_s (event, skb, info) + * + * NRM_S (Normal Response Mode as Secondary) state, in this state we are + * expecting to receive frames from the primary station + * + */ +static int irlap_state_nrm_s(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ns_status; + int nr_status; + int ret = 0; + + IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[ event]); + + IRDA_ASSERT(self != NULL, return -1;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;); + + switch (event) { + case RECV_I_CMD: /* Optimize for the common case */ + /* FIXME: must check for remote_busy below */ + IRDA_DEBUG(4, "%s(), event=%s nr=%d, vs=%d, ns=%d, " + "vr=%d, pf=%d\n", __FUNCTION__, + irlap_event[event], info->nr, + self->vs, info->ns, self->vr, info->pf); + + self->retry_count = 0; + + ns_status = irlap_validate_ns_received(self, info->ns); + nr_status = irlap_validate_nr_received(self, info->nr); + /* + * Check for expected I(nformation) frame + */ + if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) { + + /* Update Vr (next frame for us to receive) */ + self->vr = (self->vr + 1) % 8; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + /* + * poll bit cleared? + */ + if (!info->pf) { + + self->ack_required = TRUE; + + /* + * Starting WD-timer here is optional, but + * not recommended. Note 6 IrLAP p. 83 + */ +#if 0 + irda_start_timer(WD_TIMER, self->wd_timeout); +#endif + /* Keep state, do not move this line */ + irlap_next_state(self, LAP_NRM_S); + + irlap_data_indication(self, skb, FALSE); + break; + } else { + /* + * We should wait before sending RR, and + * also before changing to XMIT_S + * state. (note 1, IrLAP p. 82) + */ + irlap_wait_min_turn_around(self, &self->qos_tx); + + /* + * Give higher layers a chance to + * immediately reply with some data before + * we decide if we should send a RR frame + * or not + */ + irlap_data_indication(self, skb, FALSE); + + /* Any pending data requests? */ + if ((skb_queue_len(&self->txq) > 0) && + (self->window > 0)) + { + self->ack_required = TRUE; + + del_timer(&self->wd_timer); + + irlap_next_state(self, LAP_XMIT_S); + } else { + irlap_send_rr_frame(self, RSP_FRAME); + irlap_start_wd_timer(self, + self->wd_timeout); + + /* Keep the state */ + irlap_next_state(self, LAP_NRM_S); + } + break; + } + } + /* + * Check for Unexpected next to send (Ns) + */ + if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED)) + { + /* Unexpected next to send, with final bit cleared */ + if (!info->pf) { + irlap_update_nr_received(self, info->nr); + + irlap_start_wd_timer(self, self->wd_timeout); + } else { + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, RSP_FRAME); + + irlap_start_wd_timer(self, self->wd_timeout); + } + break; + } + + /* + * Unexpected Next to Receive(NR) ? + */ + if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED)) + { + if (info->pf) { + IRDA_DEBUG(4, "RECV_I_RSP: frame(s) lost\n"); + + self->vr = (self->vr + 1) % 8; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + /* Resend rejected frames */ + irlap_resend_rejected_frames(self, RSP_FRAME); + + /* Keep state, do not move this line */ + irlap_next_state(self, LAP_NRM_S); + + irlap_data_indication(self, skb, FALSE); + irlap_start_wd_timer(self, self->wd_timeout); + break; + } + /* + * This is not documented in IrLAP!! Unexpected NR + * with poll bit cleared + */ + if (!info->pf) { + self->vr = (self->vr + 1) % 8; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + + /* Keep state, do not move this line */ + irlap_next_state(self, LAP_NRM_S); + + irlap_data_indication(self, skb, FALSE); + irlap_start_wd_timer(self, self->wd_timeout); + } + break; + } + + if (ret == NR_INVALID) { + IRDA_DEBUG(0, "NRM_S, NR_INVALID not implemented!\n"); + } + if (ret == NS_INVALID) { + IRDA_DEBUG(0, "NRM_S, NS_INVALID not implemented!\n"); + } + break; + case RECV_UI_FRAME: + /* + * poll bit cleared? + */ + if (!info->pf) { + irlap_data_indication(self, skb, TRUE); + irlap_next_state(self, LAP_NRM_S); /* Keep state */ + } else { + /* + * Any pending data requests? + */ + if ((skb_queue_len(&self->txq) > 0) && + (self->window > 0) && !self->remote_busy) + { + irlap_data_indication(self, skb, TRUE); + + del_timer(&self->wd_timer); + + irlap_next_state(self, LAP_XMIT_S); + } else { + irlap_data_indication(self, skb, TRUE); + + irlap_wait_min_turn_around(self, &self->qos_tx); + + irlap_send_rr_frame(self, RSP_FRAME); + self->ack_required = FALSE; + + irlap_start_wd_timer(self, self->wd_timeout); + + /* Keep the state */ + irlap_next_state(self, LAP_NRM_S); + } + } + break; + case RECV_RR_CMD: + self->retry_count = 0; + + /* + * Nr as expected? + */ + nr_status = irlap_validate_nr_received(self, info->nr); + if (nr_status == NR_EXPECTED) { + if ((skb_queue_len( &self->txq) > 0) && + (self->window > 0)) { + self->remote_busy = FALSE; + + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + del_timer(&self->wd_timer); + + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_next_state(self, LAP_XMIT_S); + } else { + self->remote_busy = FALSE; + /* Update Nr received */ + irlap_update_nr_received(self, info->nr); + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_start_wd_timer(self, self->wd_timeout); + + /* Note : if the link is idle (this case), + * we never go in XMIT_S, so we never get a + * chance to process any DISCONNECT_REQUEST. + * Do it now ! - Jean II */ + if (self->disconnect_pending) { + /* Disconnect */ + irlap_send_rd_frame(self); + irlap_flush_all_queues(self); + + irlap_next_state(self, LAP_SCLOSE); + } else { + /* Just send back pf bit */ + irlap_send_rr_frame(self, RSP_FRAME); + + irlap_next_state(self, LAP_NRM_S); + } + } + } else if (nr_status == NR_UNEXPECTED) { + self->remote_busy = FALSE; + irlap_update_nr_received(self, info->nr); + irlap_resend_rejected_frames(self, RSP_FRAME); + + irlap_start_wd_timer(self, self->wd_timeout); + + /* Keep state */ + irlap_next_state(self, LAP_NRM_S); + } else { + IRDA_DEBUG(1, "%s(), invalid nr not implemented!\n", + __FUNCTION__); + } + break; + case RECV_SNRM_CMD: + /* SNRM frame is not allowed to contain an I-field */ + if (!info) { + del_timer(&self->wd_timer); + IRDA_DEBUG(1, "%s(), received SNRM cmd\n", __FUNCTION__); + irlap_next_state(self, LAP_RESET_CHECK); + + irlap_reset_indication(self); + } else { + IRDA_DEBUG(0, + "%s(), SNRM frame contained an I-field!\n", + __FUNCTION__); + + } + break; + case RECV_REJ_CMD: + irlap_update_nr_received(self, info->nr); + if (self->remote_busy) { + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, RSP_FRAME); + } else + irlap_resend_rejected_frames(self, RSP_FRAME); + irlap_start_wd_timer(self, self->wd_timeout); + break; + case RECV_SREJ_CMD: + irlap_update_nr_received(self, info->nr); + if (self->remote_busy) { + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, RSP_FRAME); + } else + irlap_resend_rejected_frame(self, RSP_FRAME); + irlap_start_wd_timer(self, self->wd_timeout); + break; + case WD_TIMER_EXPIRED: + /* + * Wait until retry_count * n matches negotiated threshold/ + * disconnect time (note 2 in IrLAP p. 82) + * + * Similar to irlap_state_nrm_p() -> FINAL_TIMER_EXPIRED + * Note : self->wd_timeout = (self->final_timeout * 2), + * which explain why we use (self->N2 / 2) here !!! + * Jean II + */ + IRDA_DEBUG(1, "%s(), retry_count = %d\n", __FUNCTION__, + self->retry_count); + + if (self->retry_count < (self->N2 / 2)) { + /* No retry, just wait for primary */ + irlap_start_wd_timer(self, self->wd_timeout); + self->retry_count++; + + if((self->retry_count % (self->N1 / 2)) == 0) + irlap_status_indication(self, + STATUS_NO_ACTIVITY); + } else { + irlap_apply_default_connection_parameters(self); + + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + irlap_disconnect_indication(self, LAP_NO_RESPONSE); + } + break; + case RECV_DISC_CMD: + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + /* Send disconnect response */ + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_ua_response_frame(self, NULL); + + del_timer(&self->wd_timer); + irlap_flush_all_queues(self); + /* Set default link parameters */ + irlap_apply_default_connection_parameters(self); + + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + case RECV_DISCOVERY_XID_CMD: + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rr_frame(self, RSP_FRAME); + self->ack_required = TRUE; + irlap_start_wd_timer(self, self->wd_timeout); + irlap_next_state(self, LAP_NRM_S); + + break; + case RECV_TEST_CMD: + /* Remove test frame header (only LAP header in NRM) */ + skb_pull(skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER); + + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_start_wd_timer(self, self->wd_timeout); + + /* Send response (info will be copied) */ + irlap_send_test_frame(self, self->caddr, info->daddr, skb); + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__, + event, irlap_event[event]); + + ret = -EINVAL; + break; + } + return ret; +} + +/* + * Function irlap_state_sclose (self, event, skb, info) + */ +static int irlap_state_sclose(struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, struct irlap_info *info) +{ + int ret = 0; + + IRDA_DEBUG(1, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return -ENODEV;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;); + + switch (event) { + case RECV_DISC_CMD: + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + /* Send disconnect response */ + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_ua_response_frame(self, NULL); + + del_timer(&self->wd_timer); + /* Set default link parameters */ + irlap_apply_default_connection_parameters(self); + + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + case RECV_DM_RSP: + /* IrLAP-1.1 p.82: in SCLOSE, S and I type RSP frames + * shall take us down into default NDM state, like DM_RSP + */ + case RECV_RR_RSP: + case RECV_RNR_RSP: + case RECV_REJ_RSP: + case RECV_SREJ_RSP: + case RECV_I_RSP: + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + del_timer(&self->wd_timer); + irlap_apply_default_connection_parameters(self); + + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + case WD_TIMER_EXPIRED: + /* Always switch state before calling upper layers */ + irlap_next_state(self, LAP_NDM); + + irlap_apply_default_connection_parameters(self); + + irlap_disconnect_indication(self, LAP_DISC_INDICATION); + break; + default: + /* IrLAP-1.1 p.82: in SCLOSE, basically any received frame + * with pf=1 shall restart the wd-timer and resend the rd:rsp + */ + if (info != NULL && info->pf) { + del_timer(&self->wd_timer); + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rd_frame(self); + irlap_start_wd_timer(self, self->wd_timeout); + break; /* stay in SCLOSE */ + } + + IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__, + event, irlap_event[event]); + + ret = -EINVAL; + break; + } + + return -1; +} + +static int irlap_state_reset_check( struct irlap_cb *self, IRLAP_EVENT event, + struct sk_buff *skb, + struct irlap_info *info) +{ + int ret = 0; + + IRDA_DEBUG(1, "%s(), event=%s\n", __FUNCTION__, irlap_event[event]); + + IRDA_ASSERT(self != NULL, return -ENODEV;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;); + + switch (event) { + case RESET_RESPONSE: + irlap_send_ua_response_frame(self, &self->qos_rx); + irlap_initiate_connection_state(self); + irlap_start_wd_timer(self, WD_TIMEOUT); + irlap_flush_all_queues(self); + + irlap_next_state(self, LAP_NRM_S); + break; + case DISCONNECT_REQUEST: + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_send_rd_frame(self); + irlap_start_wd_timer(self, WD_TIMEOUT); + irlap_next_state(self, LAP_SCLOSE); + break; + default: + IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__, + event, irlap_event[event]); + + ret = -EINVAL; + break; + } + return ret; +} |