/********************************************************************* * * 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); } /* * 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); } /* * 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; } } /* * 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; } /* * 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; } /* * 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; } /* * 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; } /* * 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(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 negotiate 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: pr_debug("%s(), Unknown event %d, %s\n", __func__, 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) { pr_debug("%s(), Unknown event\n", __func__); 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)) { pr_debug("%s(), Not allowed to transmit more bytes!\n", __func__); /* 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; } /* Subtract 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_empty(&self->txq); #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); /* * 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 { pr_debug("%s(), Unable to send! remote busy?\n", __func__); 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: pr_debug("%s(), POLL_TIMER_EXPIRED <%ld>\n", __func__, 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: pr_debug("%s(), Unknown event %s\n", __func__, 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_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: pr_debug("%s(), Unknown event %d\n", __func__, 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 */ if (unlikely(skb->len <= LAP_ADDR_HEADER + LAP_CTRL_HEADER)) { /* * Input validation check: a stir4200/mcp2150 * combination sometimes results in an empty i:rsp. * This makes no sense; we can just ignore the frame * and send an rr:cmd immediately. This happens before * changing nr or ns so triggers a retransmit */ irlap_wait_min_turn_around(self, &self->qos_tx); irlap_send_rr_frame(self, CMD_FRAME); /* Keep state */ break; } /* 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 { pr_debug("%s(), missing or duplicate frame!\n", __func__); /* 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)) { pr_debug("%s(), unexpected nr and ns!\n", __func__); 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; } pr_debug("%s(), Not implemented!\n", __func__); pr_debug("%s(), event=%s, ns_status=%d, nr_status=%d\n", __func__, 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); pr_debug("%s: RECV_UI_FRAME: next state %s\n", __func__, 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; /* Stop final timer */ del_timer(&self->final_timer); /* * Nr as expected? */ ret = irlap_validate_nr_received(self, info->nr); if (ret == NR_EXPECTED) { /* 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); pr_debug("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); irlap_start_final_timer(self, self->final_timeout * 2); irlap_next_state(self, LAP_NRM_P); } else if (ret == NR_INVALID) { pr_debug("%s(), Received RR with invalid nr !\n", __func__); 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) { pr_debug("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) { if (skb_peek(&self->wx_list) == NULL) { /* Retry sending the pf bit to the secondary */ pr_debug("nrm_p: resending rr"); irlap_wait_min_turn_around(self, &self->qos_tx); irlap_send_rr_frame(self, CMD_FRAME); } else { pr_debug("nrm_p: resend frames"); irlap_resend_rejected_frames(self, CMD_FRAME); } irlap_start_final_timer(self, self->final_timeout); self->retry_count++; pr_debug("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: pr_debug("%s(), RECV_RD_RSP\n", __func__); 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: pr_debug("%s(), Unknown event %s\n", __func__, 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; 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 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: pr_debug("%s(), Unknown event %s\n", __func__, 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; 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 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) { pr_debug("%s(), RECV_SNRM_CMD\n", __func__); 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 { pr_debug("%s(), SNRM frame contained an I field!\n", __func__); } break; default: pr_debug("%s(), Unknown event %s\n", __func__, 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 therefore 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; pr_debug("%s(), event=%s\n", __func__, 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)) { pr_debug("%s(), Not allowed to transmit more bytes!\n", __func__); /* 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 */ } /* Subtract 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_empty(&self->txq); #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 { pr_debug("%s(), Unable to send!\n", __func__); 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: pr_debug("%s(), Unknown event %s\n", __func__, 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; 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 RECV_I_CMD: /* Optimize for the common case */ /* FIXME: must check for remote_busy below */ pr_debug("%s(), event=%s nr=%d, vs=%d, ns=%d, vr=%d, pf=%d\n", __func__, 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_empty(&self->txq) && (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) { pr_debug("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) { pr_debug("NRM_S, NR_INVALID not implemented!\n"); } if (ret == NS_INVALID) { pr_debug("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_empty(&self->txq) && (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_empty(&self->txq) && (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 { pr_debug("%s(), invalid nr not implemented!\n", __func__); } break; case RECV_SNRM_CMD: /* SNRM frame is not allowed to contain an I-field */ if (!info) { del_timer(&self->wd_timer); pr_debug("%s(), received SNRM cmd\n", __func__); irlap_next_state(self, LAP_RESET_CHECK); irlap_reset_indication(self); } else { pr_debug("%s(), SNRM frame contained an I-field!\n", __func__); } 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 */ pr_debug("%s(), retry_count = %d\n", __func__, 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: pr_debug("%s(), Unknown event %d, (%s)\n", __func__, 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) { 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 */ } pr_debug("%s(), Unknown event %d, (%s)\n", __func__, event, irlap_event[event]); 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; pr_debug("%s(), event=%s\n", __func__, 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: pr_debug("%s(), Unknown event %d, (%s)\n", __func__, event, irlap_event[event]); ret = -EINVAL; break; } return ret; }