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Diffstat (limited to 'net/irda/irlap_frame.c')
| -rw-r--r-- | net/irda/irlap_frame.c | 1437 |
1 files changed, 1437 insertions, 0 deletions
diff --git a/net/irda/irlap_frame.c b/net/irda/irlap_frame.c new file mode 100644 index 0000000..040abe7 --- /dev/null +++ b/net/irda/irlap_frame.c @@ -0,0 +1,1437 @@ +/********************************************************************* + * + * Filename: irlap_frame.c + * Version: 1.0 + * Description: Build and transmit IrLAP frames + * Status: Stable + * Author: Dag Brattli <dagb@cs.uit.no> + * Created at: Tue Aug 19 10:27:26 1997 + * Modified at: Wed Jan 5 08:59:04 2000 + * Modified by: Dag Brattli <dagb@cs.uit.no> + * + * Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>, + * All Rights Reserved. + * Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * Neither Dag Brattli nor University of Tromsų admit liability nor + * provide warranty for any of this software. This material is + * provided "AS-IS" and at no charge. + * + ********************************************************************/ + +#include <linux/skbuff.h> +#include <linux/if.h> +#include <linux/if_ether.h> +#include <linux/netdevice.h> +#include <linux/irda.h> + +#include <net/pkt_sched.h> +#include <net/sock.h> + +#include <asm/byteorder.h> + +#include <net/irda/irda.h> +#include <net/irda/irda_device.h> +#include <net/irda/irlap.h> +#include <net/irda/wrapper.h> +#include <net/irda/timer.h> +#include <net/irda/irlap_frame.h> +#include <net/irda/qos.h> + +static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb, + int command); + +/* + * Function irlap_insert_info (self, skb) + * + * Insert minimum turnaround time and speed information into the skb. We + * need to do this since it's per packet relevant information. Safe to + * have this function inlined since it's only called from one place + */ +static inline void irlap_insert_info(struct irlap_cb *self, + struct sk_buff *skb) +{ + struct irda_skb_cb *cb = (struct irda_skb_cb *) skb->cb; + + /* + * Insert MTT (min. turn time) and speed into skb, so that the + * device driver knows which settings to use + */ + cb->magic = LAP_MAGIC; + cb->mtt = self->mtt_required; + cb->next_speed = self->speed; + + /* Reset */ + self->mtt_required = 0; + + /* + * Delay equals negotiated BOFs count, plus the number of BOFs to + * force the negotiated minimum turnaround time + */ + cb->xbofs = self->bofs_count; + cb->next_xbofs = self->next_bofs; + cb->xbofs_delay = self->xbofs_delay; + + /* Reset XBOF's delay (used only for getting min turn time) */ + self->xbofs_delay = 0; + /* Put the correct xbofs value for the next packet */ + self->bofs_count = self->next_bofs; +} + +/* + * Function irlap_queue_xmit (self, skb) + * + * A little wrapper for dev_queue_xmit, so we can insert some common + * code into it. + */ +void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb) +{ + /* Some common init stuff */ + skb->dev = self->netdev; + skb->h.raw = skb->nh.raw = skb->mac.raw = skb->data; + skb->protocol = htons(ETH_P_IRDA); + skb->priority = TC_PRIO_BESTEFFORT; + + irlap_insert_info(self, skb); + + dev_queue_xmit(skb); +} + +/* + * Function irlap_send_snrm_cmd (void) + * + * Transmits a connect SNRM command frame + */ +void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos) +{ + struct sk_buff *tx_skb; + struct snrm_frame *frame; + int ret; + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + /* Allocate frame */ + tx_skb = dev_alloc_skb(64); + if (!tx_skb) + return; + + frame = (struct snrm_frame *) skb_put(tx_skb, 2); + + /* Insert connection address field */ + if (qos) + frame->caddr = CMD_FRAME | CBROADCAST; + else + frame->caddr = CMD_FRAME | self->caddr; + + /* Insert control field */ + frame->control = SNRM_CMD | PF_BIT; + + /* + * If we are establishing a connection then insert QoS paramerters + */ + if (qos) { + skb_put(tx_skb, 9); /* 21 left */ + frame->saddr = cpu_to_le32(self->saddr); + frame->daddr = cpu_to_le32(self->daddr); + + frame->ncaddr = self->caddr; + + ret = irlap_insert_qos_negotiation_params(self, tx_skb); + if (ret < 0) { + dev_kfree_skb(tx_skb); + return; + } + } + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_recv_snrm_cmd (skb, info) + * + * Received SNRM (Set Normal Response Mode) command frame + * + */ +static void irlap_recv_snrm_cmd(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info) +{ + struct snrm_frame *frame; + + if (pskb_may_pull(skb,sizeof(struct snrm_frame))) { + frame = (struct snrm_frame *) skb->data; + + /* Copy the new connection address ignoring the C/R bit */ + info->caddr = frame->ncaddr & 0xFE; + + /* Check if the new connection address is valid */ + if ((info->caddr == 0x00) || (info->caddr == 0xfe)) { + IRDA_DEBUG(3, "%s(), invalid connection address!\n", + __FUNCTION__); + return; + } + + /* Copy peer device address */ + info->daddr = le32_to_cpu(frame->saddr); + info->saddr = le32_to_cpu(frame->daddr); + + /* Only accept if addressed directly to us */ + if (info->saddr != self->saddr) { + IRDA_DEBUG(2, "%s(), not addressed to us!\n", + __FUNCTION__); + return; + } + irlap_do_event(self, RECV_SNRM_CMD, skb, info); + } else { + /* Signal that this SNRM frame does not contain and I-field */ + irlap_do_event(self, RECV_SNRM_CMD, skb, NULL); + } +} + +/* + * Function irlap_send_ua_response_frame (qos) + * + * Send UA (Unnumbered Acknowledgement) frame + * + */ +void irlap_send_ua_response_frame(struct irlap_cb *self, struct qos_info *qos) +{ + struct sk_buff *tx_skb; + struct ua_frame *frame; + int ret; + + IRDA_DEBUG(2, "%s() <%ld>\n", __FUNCTION__, jiffies); + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + /* Allocate frame */ + tx_skb = dev_alloc_skb(64); + if (!tx_skb) + return; + + frame = (struct ua_frame *) skb_put(tx_skb, 10); + + /* Build UA response */ + frame->caddr = self->caddr; + frame->control = UA_RSP | PF_BIT; + + frame->saddr = cpu_to_le32(self->saddr); + frame->daddr = cpu_to_le32(self->daddr); + + /* Should we send QoS negotiation parameters? */ + if (qos) { + ret = irlap_insert_qos_negotiation_params(self, tx_skb); + if (ret < 0) { + dev_kfree_skb(tx_skb); + return; + } + } + + irlap_queue_xmit(self, tx_skb); +} + + +/* + * Function irlap_send_dm_frame (void) + * + * Send disconnected mode (DM) frame + * + */ +void irlap_send_dm_frame( struct irlap_cb *self) +{ + struct sk_buff *tx_skb = NULL; + __u8 *frame; + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + tx_skb = dev_alloc_skb(32); + if (!tx_skb) + return; + + frame = skb_put(tx_skb, 2); + + if (self->state == LAP_NDM) + frame[0] = CBROADCAST; + else + frame[0] = self->caddr; + + frame[1] = DM_RSP | PF_BIT; + + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_send_disc_frame (void) + * + * Send disconnect (DISC) frame + * + */ +void irlap_send_disc_frame(struct irlap_cb *self) +{ + struct sk_buff *tx_skb = NULL; + __u8 *frame; + + IRDA_DEBUG(3, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + tx_skb = dev_alloc_skb(16); + if (!tx_skb) + return; + + frame = skb_put(tx_skb, 2); + + frame[0] = self->caddr | CMD_FRAME; + frame[1] = DISC_CMD | PF_BIT; + + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_send_discovery_xid_frame (S, s, command) + * + * Build and transmit a XID (eXchange station IDentifier) discovery + * frame. + */ +void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s, + __u8 command, discovery_t *discovery) +{ + struct sk_buff *tx_skb = NULL; + struct xid_frame *frame; + __u32 bcast = BROADCAST; + __u8 *info; + + IRDA_DEBUG(4, "%s(), s=%d, S=%d, command=%d\n", __FUNCTION__, + s, S, command); + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + IRDA_ASSERT(discovery != NULL, return;); + + tx_skb = dev_alloc_skb(64); + if (!tx_skb) + return; + + skb_put(tx_skb, 14); + frame = (struct xid_frame *) tx_skb->data; + + if (command) { + frame->caddr = CBROADCAST | CMD_FRAME; + frame->control = XID_CMD | PF_BIT; + } else { + frame->caddr = CBROADCAST; + frame->control = XID_RSP | PF_BIT; + } + frame->ident = XID_FORMAT; + + frame->saddr = cpu_to_le32(self->saddr); + + if (command) + frame->daddr = cpu_to_le32(bcast); + else + frame->daddr = cpu_to_le32(discovery->data.daddr); + + switch (S) { + case 1: + frame->flags = 0x00; + break; + case 6: + frame->flags = 0x01; + break; + case 8: + frame->flags = 0x02; + break; + case 16: + frame->flags = 0x03; + break; + default: + frame->flags = 0x02; + break; + } + + frame->slotnr = s; + frame->version = 0x00; + + /* + * Provide info for final slot only in commands, and for all + * responses. Send the second byte of the hint only if the + * EXTENSION bit is set in the first byte. + */ + if (!command || (frame->slotnr == 0xff)) { + int len; + + if (discovery->data.hints[0] & HINT_EXTENSION) { + info = skb_put(tx_skb, 2); + info[0] = discovery->data.hints[0]; + info[1] = discovery->data.hints[1]; + } else { + info = skb_put(tx_skb, 1); + info[0] = discovery->data.hints[0]; + } + info = skb_put(tx_skb, 1); + info[0] = discovery->data.charset; + + len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb)); + info = skb_put(tx_skb, len); + memcpy(info, discovery->data.info, len); + } + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_recv_discovery_xid_rsp (skb, info) + * + * Received a XID discovery response + * + */ +static void irlap_recv_discovery_xid_rsp(struct irlap_cb *self, + struct sk_buff *skb, + struct irlap_info *info) +{ + struct xid_frame *xid; + discovery_t *discovery = NULL; + __u8 *discovery_info; + char *text; + + IRDA_DEBUG(4, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + if (!pskb_may_pull(skb, sizeof(struct xid_frame))) { + IRDA_ERROR("%s: frame to short!\n", __FUNCTION__); + return; + } + + xid = (struct xid_frame *) skb->data; + + info->daddr = le32_to_cpu(xid->saddr); + info->saddr = le32_to_cpu(xid->daddr); + + /* Make sure frame is addressed to us */ + if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) { + IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n", + __FUNCTION__); + return; + } + + if ((discovery = kmalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) { + IRDA_WARNING("%s: kmalloc failed!\n", __FUNCTION__); + return; + } + memset(discovery, 0, sizeof(discovery_t)); + + discovery->data.daddr = info->daddr; + discovery->data.saddr = self->saddr; + discovery->timestamp = jiffies; + + IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__, + discovery->data.daddr); + + discovery_info = skb_pull(skb, sizeof(struct xid_frame)); + + /* Get info returned from peer */ + discovery->data.hints[0] = discovery_info[0]; + if (discovery_info[0] & HINT_EXTENSION) { + IRDA_DEBUG(4, "EXTENSION\n"); + discovery->data.hints[1] = discovery_info[1]; + discovery->data.charset = discovery_info[2]; + text = (char *) &discovery_info[3]; + } else { + discovery->data.hints[1] = 0; + discovery->data.charset = discovery_info[1]; + text = (char *) &discovery_info[2]; + } + /* + * Terminate info string, should be safe since this is where the + * FCS bytes resides. + */ + skb->data[skb->len] = '\0'; + strncpy(discovery->data.info, text, NICKNAME_MAX_LEN); + discovery->name_len = strlen(discovery->data.info); + + info->discovery = discovery; + + irlap_do_event(self, RECV_DISCOVERY_XID_RSP, skb, info); +} + +/* + * Function irlap_recv_discovery_xid_cmd (skb, info) + * + * Received a XID discovery command + * + */ +static void irlap_recv_discovery_xid_cmd(struct irlap_cb *self, + struct sk_buff *skb, + struct irlap_info *info) +{ + struct xid_frame *xid; + discovery_t *discovery = NULL; + __u8 *discovery_info; + char *text; + + if (!pskb_may_pull(skb, sizeof(struct xid_frame))) { + IRDA_ERROR("%s: frame to short!\n", __FUNCTION__); + return; + } + + xid = (struct xid_frame *) skb->data; + + info->daddr = le32_to_cpu(xid->saddr); + info->saddr = le32_to_cpu(xid->daddr); + + /* Make sure frame is addressed to us */ + if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) { + IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n", + __FUNCTION__); + return; + } + + switch (xid->flags & 0x03) { + case 0x00: + info->S = 1; + break; + case 0x01: + info->S = 6; + break; + case 0x02: + info->S = 8; + break; + case 0x03: + info->S = 16; + break; + default: + /* Error!! */ + return; + } + info->s = xid->slotnr; + + discovery_info = skb_pull(skb, sizeof(struct xid_frame)); + + /* + * Check if last frame + */ + if (info->s == 0xff) { + /* Check if things are sane at this point... */ + if((discovery_info == NULL) || + !pskb_may_pull(skb, 3)) { + IRDA_ERROR("%s: discovery frame to short!\n", + __FUNCTION__); + return; + } + + /* + * We now have some discovery info to deliver! + */ + discovery = kmalloc(sizeof(discovery_t), GFP_ATOMIC); + if (!discovery) { + IRDA_WARNING("%s: unable to malloc!\n", __FUNCTION__); + return; + } + + discovery->data.daddr = info->daddr; + discovery->data.saddr = self->saddr; + discovery->timestamp = jiffies; + + discovery->data.hints[0] = discovery_info[0]; + if (discovery_info[0] & HINT_EXTENSION) { + discovery->data.hints[1] = discovery_info[1]; + discovery->data.charset = discovery_info[2]; + text = (char *) &discovery_info[3]; + } else { + discovery->data.hints[1] = 0; + discovery->data.charset = discovery_info[1]; + text = (char *) &discovery_info[2]; + } + /* + * Terminate string, should be safe since this is where the + * FCS bytes resides. + */ + skb->data[skb->len] = '\0'; + strncpy(discovery->data.info, text, NICKNAME_MAX_LEN); + discovery->name_len = strlen(discovery->data.info); + + info->discovery = discovery; + } else + info->discovery = NULL; + + irlap_do_event(self, RECV_DISCOVERY_XID_CMD, skb, info); +} + +/* + * Function irlap_send_rr_frame (self, command) + * + * Build and transmit RR (Receive Ready) frame. Notice that it is currently + * only possible to send RR frames with the poll bit set. + */ +void irlap_send_rr_frame(struct irlap_cb *self, int command) +{ + struct sk_buff *tx_skb; + __u8 *frame; + + tx_skb = dev_alloc_skb(16); + if (!tx_skb) + return; + + frame = skb_put(tx_skb, 2); + + frame[0] = self->caddr; + frame[0] |= (command) ? CMD_FRAME : 0; + + frame[1] = RR | PF_BIT | (self->vr << 5); + + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_send_rd_frame (self) + * + * Request disconnect. Used by a secondary station to request the + * disconnection of the link. + */ +void irlap_send_rd_frame(struct irlap_cb *self) +{ + struct sk_buff *tx_skb; + __u8 *frame; + + tx_skb = dev_alloc_skb(16); + if (!tx_skb) + return; + + frame = skb_put(tx_skb, 2); + + frame[0] = self->caddr; + frame[1] = RD_RSP | PF_BIT; + + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_recv_rr_frame (skb, info) + * + * Received RR (Receive Ready) frame from peer station, no harm in + * making it inline since its called only from one single place + * (irlap_driver_rcv). + */ +static inline void irlap_recv_rr_frame(struct irlap_cb *self, + struct sk_buff *skb, + struct irlap_info *info, int command) +{ + info->nr = skb->data[1] >> 5; + + /* Check if this is a command or a response frame */ + if (command) + irlap_do_event(self, RECV_RR_CMD, skb, info); + else + irlap_do_event(self, RECV_RR_RSP, skb, info); +} + +/* + * Function irlap_recv_rnr_frame (self, skb, info) + * + * Received RNR (Receive Not Ready) frame from peer station + * + */ +static void irlap_recv_rnr_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info, int command) +{ + info->nr = skb->data[1] >> 5; + + IRDA_DEBUG(4, "%s(), nr=%d, %ld\n", __FUNCTION__, info->nr, jiffies); + + if (command) + irlap_do_event(self, RECV_RNR_CMD, skb, info); + else + irlap_do_event(self, RECV_RNR_RSP, skb, info); +} + +static void irlap_recv_rej_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info, int command) +{ + IRDA_DEBUG(0, "%s()\n", __FUNCTION__); + + info->nr = skb->data[1] >> 5; + + /* Check if this is a command or a response frame */ + if (command) + irlap_do_event(self, RECV_REJ_CMD, skb, info); + else + irlap_do_event(self, RECV_REJ_RSP, skb, info); +} + +static void irlap_recv_srej_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info, int command) +{ + IRDA_DEBUG(0, "%s()\n", __FUNCTION__); + + info->nr = skb->data[1] >> 5; + + /* Check if this is a command or a response frame */ + if (command) + irlap_do_event(self, RECV_SREJ_CMD, skb, info); + else + irlap_do_event(self, RECV_SREJ_RSP, skb, info); +} + +static void irlap_recv_disc_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info, int command) +{ + IRDA_DEBUG(2, "%s()\n", __FUNCTION__); + + /* Check if this is a command or a response frame */ + if (command) + irlap_do_event(self, RECV_DISC_CMD, skb, info); + else + irlap_do_event(self, RECV_RD_RSP, skb, info); +} + +/* + * Function irlap_recv_ua_frame (skb, frame) + * + * Received UA (Unnumbered Acknowledgement) frame + * + */ +static inline void irlap_recv_ua_frame(struct irlap_cb *self, + struct sk_buff *skb, + struct irlap_info *info) +{ + irlap_do_event(self, RECV_UA_RSP, skb, info); +} + +/* + * Function irlap_send_data_primary(self, skb) + * + * Send I-frames as the primary station but without the poll bit set + * + */ +void irlap_send_data_primary(struct irlap_cb *self, struct sk_buff *skb) +{ + struct sk_buff *tx_skb; + + if (skb->data[1] == I_FRAME) { + + /* + * Insert frame sequence number (Vs) in control field before + * inserting into transmit window queue. + */ + skb->data[1] = I_FRAME | (self->vs << 1); + + /* + * Insert frame in store, in case of retransmissions + * Increase skb reference count, see irlap_do_event() + */ + skb_get(skb); + skb_queue_tail(&self->wx_list, skb); + + /* Copy buffer */ + tx_skb = skb_clone(skb, GFP_ATOMIC); + if (tx_skb == NULL) { + return; + } + + self->vs = (self->vs + 1) % 8; + self->ack_required = FALSE; + self->window -= 1; + + irlap_send_i_frame( self, tx_skb, CMD_FRAME); + } else { + IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__); + irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME); + self->window -= 1; + } +} +/* + * Function irlap_send_data_primary_poll (self, skb) + * + * Send I(nformation) frame as primary with poll bit set + */ +void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb) +{ + struct sk_buff *tx_skb; + int transmission_time; + + /* Stop P timer */ + del_timer(&self->poll_timer); + + /* Is this reliable or unreliable data? */ + if (skb->data[1] == I_FRAME) { + + /* + * Insert frame sequence number (Vs) in control field before + * inserting into transmit window queue. + */ + skb->data[1] = I_FRAME | (self->vs << 1); + + /* + * Insert frame in store, in case of retransmissions + * Increase skb reference count, see irlap_do_event() + */ + skb_get(skb); + skb_queue_tail(&self->wx_list, skb); + + /* Copy buffer */ + tx_skb = skb_clone(skb, GFP_ATOMIC); + if (tx_skb == NULL) { + return; + } + + /* + * Set poll bit if necessary. We do this to the copied + * skb, since retransmitted need to set or clear the poll + * bit depending on when they are sent. + */ + tx_skb->data[1] |= PF_BIT; + + self->vs = (self->vs + 1) % 8; + self->ack_required = FALSE; + + irlap_send_i_frame(self, tx_skb, CMD_FRAME); + } else { + IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__); + + if (self->ack_required) { + irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME); + irlap_send_rr_frame(self, CMD_FRAME); + self->ack_required = FALSE; + } else { + skb->data[1] |= PF_BIT; + irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME); + } + } + + /* How much time we took for transmission of all frames. + * We don't know, so let assume we used the full window. Jean II */ + transmission_time = self->final_timeout; + + /* Reset parameter so that we can fill next window */ + self->window = self->window_size; + +#ifdef CONFIG_IRDA_DYNAMIC_WINDOW + /* Remove what we have not used. Just do a prorata of the + * bytes left in window to window capacity. + * See max_line_capacities[][] in qos.c for details. Jean II */ + transmission_time -= (self->final_timeout * self->bytes_left + / self->line_capacity); + IRDA_DEBUG(4, "%s() adjusting transmission_time : ft=%d, bl=%d, lc=%d -> tt=%d\n", __FUNCTION__, self->final_timeout, self->bytes_left, self->line_capacity, transmission_time); + + /* We are allowed to transmit a maximum number of bytes again. */ + self->bytes_left = self->line_capacity; +#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */ + + /* + * The network layer has a intermediate buffer between IrLAP + * and the IrDA driver which can contain 8 frames. So, even + * though IrLAP is currently sending the *last* frame of the + * tx-window, the driver most likely has only just started + * sending the *first* frame of the same tx-window. + * I.e. we are always at the very begining of or Tx window. + * Now, we are supposed to set the final timer from the end + * of our tx-window to let the other peer reply. So, we need + * to add extra time to compensate for the fact that we + * are really at the start of tx-window, otherwise the final timer + * might expire before he can answer... + * Jean II + */ + irlap_start_final_timer(self, self->final_timeout + transmission_time); + + /* + * The clever amongst you might ask why we do this adjustement + * only here, and not in all the other cases in irlap_event.c. + * In all those other case, we only send a very short management + * frame (few bytes), so the adjustement would be lost in the + * noise... + * The exception of course is irlap_resend_rejected_frame(). + * Jean II */ +} + +/* + * Function irlap_send_data_secondary_final (self, skb) + * + * Send I(nformation) frame as secondary with final bit set + * + */ +void irlap_send_data_secondary_final(struct irlap_cb *self, + struct sk_buff *skb) +{ + struct sk_buff *tx_skb = NULL; + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + IRDA_ASSERT(skb != NULL, return;); + + /* Is this reliable or unreliable data? */ + if (skb->data[1] == I_FRAME) { + + /* + * Insert frame sequence number (Vs) in control field before + * inserting into transmit window queue. + */ + skb->data[1] = I_FRAME | (self->vs << 1); + + /* + * Insert frame in store, in case of retransmissions + * Increase skb reference count, see irlap_do_event() + */ + skb_get(skb); + skb_queue_tail(&self->wx_list, skb); + + tx_skb = skb_clone(skb, GFP_ATOMIC); + if (tx_skb == NULL) { + return; + } + + tx_skb->data[1] |= PF_BIT; + + self->vs = (self->vs + 1) % 8; + self->ack_required = FALSE; + + irlap_send_i_frame(self, tx_skb, RSP_FRAME); + } else { + if (self->ack_required) { + irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME); + irlap_send_rr_frame(self, RSP_FRAME); + self->ack_required = FALSE; + } else { + skb->data[1] |= PF_BIT; + irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME); + } + } + + self->window = self->window_size; +#ifdef CONFIG_IRDA_DYNAMIC_WINDOW + /* We are allowed to transmit a maximum number of bytes again. */ + self->bytes_left = self->line_capacity; +#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */ + + irlap_start_wd_timer(self, self->wd_timeout); +} + +/* + * Function irlap_send_data_secondary (self, skb) + * + * Send I(nformation) frame as secondary without final bit set + * + */ +void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb) +{ + struct sk_buff *tx_skb = NULL; + + /* Is this reliable or unreliable data? */ + if (skb->data[1] == I_FRAME) { + + /* + * Insert frame sequence number (Vs) in control field before + * inserting into transmit window queue. + */ + skb->data[1] = I_FRAME | (self->vs << 1); + + /* + * Insert frame in store, in case of retransmissions + * Increase skb reference count, see irlap_do_event() + */ + skb_get(skb); + skb_queue_tail(&self->wx_list, skb); + + tx_skb = skb_clone(skb, GFP_ATOMIC); + if (tx_skb == NULL) { + return; + } + + self->vs = (self->vs + 1) % 8; + self->ack_required = FALSE; + self->window -= 1; + + irlap_send_i_frame(self, tx_skb, RSP_FRAME); + } else { + irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME); + self->window -= 1; + } +} + +/* + * Function irlap_resend_rejected_frames (nr) + * + * Resend frames which has not been acknowledged. Should be safe to + * traverse the list without locking it since this function will only be + * called from interrupt context (BH) + */ +void irlap_resend_rejected_frames(struct irlap_cb *self, int command) +{ + struct sk_buff *tx_skb; + struct sk_buff *skb; + int count; + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + /* Initialize variables */ + count = skb_queue_len(&self->wx_list); + + /* Resend unacknowledged frame(s) */ + skb = skb_peek(&self->wx_list); + while (skb != NULL) { + irlap_wait_min_turn_around(self, &self->qos_tx); + + /* We copy the skb to be retransmitted since we will have to + * modify it. Cloning will confuse packet sniffers + */ + /* tx_skb = skb_clone( skb, GFP_ATOMIC); */ + tx_skb = skb_copy(skb, GFP_ATOMIC); + if (!tx_skb) { + IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__); + return; + } + /* Unlink tx_skb from list */ + tx_skb->next = tx_skb->prev = NULL; + tx_skb->list = NULL; + + /* Clear old Nr field + poll bit */ + tx_skb->data[1] &= 0x0f; + + /* + * Set poll bit on the last frame retransmitted + */ + if (count-- == 1) + tx_skb->data[1] |= PF_BIT; /* Set p/f bit */ + else + tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */ + + irlap_send_i_frame(self, tx_skb, command); + + /* + * If our skb is the last buffer in the list, then + * we are finished, if not, move to the next sk-buffer + */ + if (skb == skb_peek_tail(&self->wx_list)) + skb = NULL; + else + skb = skb->next; + } +#if 0 /* Not yet */ + /* + * We can now fill the window with additional data frames + */ + while (skb_queue_len( &self->txq) > 0) { + + IRDA_DEBUG(0, "%s(), sending additional frames!\n", __FUNCTION__); + if ((skb_queue_len( &self->txq) > 0) && + (self->window > 0)) { + skb = skb_dequeue( &self->txq); + IRDA_ASSERT(skb != NULL, return;); + + /* + * If send window > 1 then send frame with pf + * bit cleared + */ + if ((self->window > 1) && + skb_queue_len(&self->txq) > 0) + { + irlap_send_data_primary(self, skb); + } else { + irlap_send_data_primary_poll(self, skb); + } + kfree_skb(skb); + } + } +#endif +} + +void irlap_resend_rejected_frame(struct irlap_cb *self, int command) +{ + struct sk_buff *tx_skb; + struct sk_buff *skb; + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + + /* Resend unacknowledged frame(s) */ + skb = skb_peek(&self->wx_list); + if (skb != NULL) { + irlap_wait_min_turn_around(self, &self->qos_tx); + + /* We copy the skb to be retransmitted since we will have to + * modify it. Cloning will confuse packet sniffers + */ + /* tx_skb = skb_clone( skb, GFP_ATOMIC); */ + tx_skb = skb_copy(skb, GFP_ATOMIC); + if (!tx_skb) { + IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__); + return; + } + /* Unlink tx_skb from list */ + tx_skb->next = tx_skb->prev = NULL; + tx_skb->list = NULL; + + /* Clear old Nr field + poll bit */ + tx_skb->data[1] &= 0x0f; + + /* Set poll/final bit */ + tx_skb->data[1] |= PF_BIT; /* Set p/f bit */ + + irlap_send_i_frame(self, tx_skb, command); + } +} + +/* + * Function irlap_send_ui_frame (self, skb, command) + * + * Contruct and transmit an Unnumbered Information (UI) frame + * + */ +void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb, + __u8 caddr, int command) +{ + IRDA_DEBUG(4, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + IRDA_ASSERT(skb != NULL, return;); + + /* Insert connection address */ + skb->data[0] = caddr | ((command) ? CMD_FRAME : 0); + + irlap_queue_xmit(self, skb); +} + +/* + * Function irlap_send_i_frame (skb) + * + * Contruct and transmit Information (I) frame + */ +static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb, + int command) +{ + /* Insert connection address */ + skb->data[0] = self->caddr; + skb->data[0] |= (command) ? CMD_FRAME : 0; + + /* Insert next to receive (Vr) */ + skb->data[1] |= (self->vr << 5); /* insert nr */ + + irlap_queue_xmit(self, skb); +} + +/* + * Function irlap_recv_i_frame (skb, frame) + * + * Receive and parse an I (Information) frame, no harm in making it inline + * since it's called only from one single place (irlap_driver_rcv). + */ +static inline void irlap_recv_i_frame(struct irlap_cb *self, + struct sk_buff *skb, + struct irlap_info *info, int command) +{ + info->nr = skb->data[1] >> 5; /* Next to receive */ + info->pf = skb->data[1] & PF_BIT; /* Final bit */ + info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */ + + /* Check if this is a command or a response frame */ + if (command) + irlap_do_event(self, RECV_I_CMD, skb, info); + else + irlap_do_event(self, RECV_I_RSP, skb, info); +} + +/* + * Function irlap_recv_ui_frame (self, skb, info) + * + * Receive and parse an Unnumbered Information (UI) frame + * + */ +static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info) +{ + IRDA_DEBUG( 4, "%s()\n", __FUNCTION__); + + info->pf = skb->data[1] & PF_BIT; /* Final bit */ + + irlap_do_event(self, RECV_UI_FRAME, skb, info); +} + +/* + * Function irlap_recv_frmr_frame (skb, frame) + * + * Received Frame Reject response. + * + */ +static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info) +{ + __u8 *frame; + int w, x, y, z; + + IRDA_DEBUG(0, "%s()\n", __FUNCTION__); + + IRDA_ASSERT(self != NULL, return;); + IRDA_ASSERT(self->magic == LAP_MAGIC, return;); + IRDA_ASSERT(skb != NULL, return;); + IRDA_ASSERT(info != NULL, return;); + + if (!pskb_may_pull(skb, 4)) { + IRDA_ERROR("%s: frame to short!\n", __FUNCTION__); + return; + } + + frame = skb->data; + + info->nr = frame[2] >> 5; /* Next to receive */ + info->pf = frame[2] & PF_BIT; /* Final bit */ + info->ns = (frame[2] >> 1) & 0x07; /* Next to send */ + + w = frame[3] & 0x01; + x = frame[3] & 0x02; + y = frame[3] & 0x04; + z = frame[3] & 0x08; + + if (w) { + IRDA_DEBUG(0, "Rejected control field is undefined or not " + "implemented.\n"); + } + if (x) { + IRDA_DEBUG(0, "Rejected control field was invalid because it " + "contained a non permitted I field.\n"); + } + if (y) { + IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated " + "for the existing connection or exceeded the maximum " + "this station supports if no connection exists.\n"); + } + if (z) { + IRDA_DEBUG(0, "Rejected control field control field contained an " + "invalid Nr count.\n"); + } + irlap_do_event(self, RECV_FRMR_RSP, skb, info); +} + +/* + * Function irlap_send_test_frame (self, daddr) + * + * Send a test frame response + * + */ +void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr, + struct sk_buff *cmd) +{ + struct sk_buff *tx_skb; + struct test_frame *frame; + __u8 *info; + + tx_skb = dev_alloc_skb(cmd->len+sizeof(struct test_frame)); + if (!tx_skb) + return; + + /* Broadcast frames must include saddr and daddr fields */ + if (caddr == CBROADCAST) { + frame = (struct test_frame *) + skb_put(tx_skb, sizeof(struct test_frame)); + + /* Insert the swapped addresses */ + frame->saddr = cpu_to_le32(self->saddr); + frame->daddr = cpu_to_le32(daddr); + } else + frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER); + + frame->caddr = caddr; + frame->control = TEST_RSP | PF_BIT; + + /* Copy info */ + info = skb_put(tx_skb, cmd->len); + memcpy(info, cmd->data, cmd->len); + + /* Return to sender */ + irlap_wait_min_turn_around(self, &self->qos_tx); + irlap_queue_xmit(self, tx_skb); +} + +/* + * Function irlap_recv_test_frame (self, skb) + * + * Receive a test frame + * + */ +static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb, + struct irlap_info *info, int command) +{ + struct test_frame *frame; + + IRDA_DEBUG(2, "%s()\n", __FUNCTION__); + + if (!pskb_may_pull(skb, sizeof(*frame))) { + IRDA_ERROR("%s: frame to short!\n", __FUNCTION__); + return; + } + frame = (struct test_frame *) skb->data; + + /* Broadcast frames must carry saddr and daddr fields */ + if (info->caddr == CBROADCAST) { + if (skb->len < sizeof(struct test_frame)) { + IRDA_DEBUG(0, "%s() test frame to short!\n", + __FUNCTION__); + return; + } + + /* Read and swap addresses */ + info->daddr = le32_to_cpu(frame->saddr); + info->saddr = le32_to_cpu(frame->daddr); + + /* Make sure frame is addressed to us */ + if ((info->saddr != self->saddr) && + (info->saddr != BROADCAST)) { + return; + } + } + + if (command) + irlap_do_event(self, RECV_TEST_CMD, skb, info); + else + irlap_do_event(self, RECV_TEST_RSP, skb, info); +} + +/* + * Function irlap_driver_rcv (skb, netdev, ptype) + * + * Called when a frame is received. Dispatches the right receive function + * for processing of the frame. + * + * Note on skb management : + * After calling the higher layers of the IrDA stack, we always + * kfree() the skb, which drop the reference count (and potentially + * destroy it). + * If a higher layer of the stack want to keep the skb around (to put + * in a queue or pass it to the higher layer), it will need to use + * skb_get() to keep a reference on it. This is usually done at the + * LMP level in irlmp.c. + * Jean II + */ +int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *ptype) +{ + struct irlap_info info; + struct irlap_cb *self; + int command; + __u8 control; + + /* FIXME: should we get our own field? */ + self = (struct irlap_cb *) dev->atalk_ptr; + + /* If the net device is down, then IrLAP is gone! */ + if (!self || self->magic != LAP_MAGIC) { + dev_kfree_skb(skb); + return -1; + } + + /* We are no longer an "old" protocol, so we need to handle + * share and non linear skbs. This should never happen, so + * we don't need to be clever about it. Jean II */ + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { + IRDA_ERROR("%s: can't clone shared skb!\n", __FUNCTION__); + dev_kfree_skb(skb); + return -1; + } + + /* Check if frame is large enough for parsing */ + if (!pskb_may_pull(skb, 2)) { + IRDA_ERROR("%s: frame to short!\n", __FUNCTION__); + dev_kfree_skb(skb); + return -1; + } + + command = skb->data[0] & CMD_FRAME; + info.caddr = skb->data[0] & CBROADCAST; + + info.pf = skb->data[1] & PF_BIT; + info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */ + + control = info.control; + + /* First we check if this frame has a valid connection address */ + if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) { + IRDA_DEBUG(0, "%s(), wrong connection address!\n", + __FUNCTION__); + goto out; + } + /* + * Optimize for the common case and check if the frame is an + * I(nformation) frame. Only I-frames have bit 0 set to 0 + */ + if (~control & 0x01) { + irlap_recv_i_frame(self, skb, &info, command); + goto out; + } + /* + * We now check is the frame is an S(upervisory) frame. Only + * S-frames have bit 0 set to 1 and bit 1 set to 0 + */ + if (~control & 0x02) { + /* + * Received S(upervisory) frame, check which frame type it is + * only the first nibble is of interest + */ + switch (control & 0x0f) { + case RR: + irlap_recv_rr_frame(self, skb, &info, command); + break; + case RNR: + irlap_recv_rnr_frame(self, skb, &info, command); + break; + case REJ: + irlap_recv_rej_frame(self, skb, &info, command); + break; + case SREJ: + irlap_recv_srej_frame(self, skb, &info, command); + break; + default: + IRDA_WARNING("%s: Unknown S-frame %02x received!\n", + __FUNCTION__, info.control); + break; + } + goto out; + } + /* + * This must be a C(ontrol) frame + */ + switch (control) { + case XID_RSP: + irlap_recv_discovery_xid_rsp(self, skb, &info); + break; + case XID_CMD: + irlap_recv_discovery_xid_cmd(self, skb, &info); + break; + case SNRM_CMD: + irlap_recv_snrm_cmd(self, skb, &info); + break; + case DM_RSP: + irlap_do_event(self, RECV_DM_RSP, skb, &info); + break; + case DISC_CMD: /* And RD_RSP since they have the same value */ + irlap_recv_disc_frame(self, skb, &info, command); + break; + case TEST_CMD: + irlap_recv_test_frame(self, skb, &info, command); + break; + case UA_RSP: + irlap_recv_ua_frame(self, skb, &info); + break; + case FRMR_RSP: + irlap_recv_frmr_frame(self, skb, &info); + break; + case UI_FRAME: + irlap_recv_ui_frame(self, skb, &info); + break; + default: + IRDA_WARNING("%s: Unknown frame %02x received!\n", + __FUNCTION__, info.control); + break; + } +out: + /* Always drop our reference on the skb */ + dev_kfree_skb(skb); + return 0; +} |
