/*********************************************************************
*
* 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 Tromsø 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 <linux/slab.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_reset_mac_header(skb);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
skb->protocol = htons(ETH_P_IRDA);
skb->priority = TC_PRIO_BESTEFFORT;
irlap_insert_info(self, skb);
if (unlikely(self->mode & IRDA_MODE_MONITOR)) {
IRDA_DEBUG(3, "%s(): %s is in monitor mode\n", __func__,
self->netdev->name);
dev_kfree_skb(skb);
return;
}
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 = alloc_skb(sizeof(struct snrm_frame) +
IRLAP_NEGOCIATION_PARAMS_LEN,
GFP_ATOMIC);
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 parameters
*/
if (qos) {
skb_put(tx_skb, 9); /* 25 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",
__func__);
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",
__func__);
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", __func__, jiffies);
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
/* Allocate frame */
tx_skb = alloc_skb(sizeof(struct ua_frame) +
IRLAP_NEGOCIATION_PARAMS_LEN,
GFP_ATOMIC);
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;
struct dm_frame *frame;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
tx_skb = alloc_skb(sizeof(struct dm_frame), GFP_ATOMIC);
if (!tx_skb)
return;
frame = (struct dm_frame *)skb_put(tx_skb, 2);
if (self->state == LAP_NDM)
frame->caddr = CBROADCAST;
else
frame->caddr = self->caddr;
frame->control = 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;
struct disc_frame *frame;
IRDA_DEBUG(3, "%s()\n", __func__);
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
tx_skb = alloc_skb(sizeof(struct disc_frame), GFP_ATOMIC);
if (!tx_skb)
return;
frame = (struct disc_frame *)skb_put(tx_skb, 2);
frame->caddr = self->caddr | CMD_FRAME;
frame->control = 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", __func__,
s, S, command);
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
IRDA_ASSERT(discovery != NULL, return;);
tx_skb = alloc_skb(sizeof(struct xid_frame) + IRLAP_DISCOVERY_INFO_LEN,
GFP_ATOMIC);
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", __func__);
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 too short!\n", __func__);
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",
__func__);
return;
}
if ((discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) {
IRDA_WARNING("%s: kmalloc failed!\n", __func__);
return;
}
discovery->data.daddr = info->daddr;
discovery->data.saddr = self->saddr;
discovery->timestamp = jiffies;
IRDA_DEBUG(4, "%s(), daddr=%08x\n", __func__,
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 too short!\n", __func__);
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",
__func__);
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 too short!\n",
__func__);
return;
}
/*
* We now have some discovery info to deliver!
*/
discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC);
if (!discovery) {
IRDA_WARNING("%s: unable to malloc!\n", __func__);
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;
struct rr_frame *frame;
tx_skb = alloc_skb(sizeof(struct rr_frame), GFP_ATOMIC);
if (!tx_skb)
return;
frame = (struct rr_frame *)skb_put(tx_skb, 2);
frame->caddr = self->caddr;
frame->caddr |= (command) ? CMD_FRAME : 0;
frame->control = 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;
struct rd_frame *frame;
tx_skb = alloc_skb(sizeof(struct rd_frame), GFP_ATOMIC);
if (!tx_skb)
return;
frame = (struct rd_frame *)skb_put(tx_skb, 2);
frame->caddr = self->caddr;
frame->caddr = 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", __func__, 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", __func__);
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", __func__);
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", __func__);
/* 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", __func__);
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_next_state(self, LAP_NRM_P);
irlap_send_i_frame(self, tx_skb, CMD_FRAME);
} else {
IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __func__);
if (self->ack_required) {
irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
irlap_next_state(self, LAP_NRM_P);
irlap_send_rr_frame(self, CMD_FRAME);
self->ack_required = FALSE;
} else {
skb->data[1] |= PF_BIT;
irlap_next_state(self, LAP_NRM_P);
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", __func__, 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 beginning 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;
IRDA_ASSERT(self != NULL, return;);
IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
/* Resend unacknowledged frame(s) */
skb_queue_walk(&self->wx_list, skb) {
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", __func__);
return;
}
/* Clear old Nr field + poll bit */
tx_skb->data[1] &= 0x0f;
/*
* Set poll bit on the last frame retransmitted
*/
if (skb_queue_is_last(&self->wx_list, skb))
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 0 /* Not yet */
/*
* We can now fill the window with additional data frames
*/
while (!skb_queue_empty(&self->txq)) {
IRDA_DEBUG(0, "%s(), sending additional frames!\n", __func__);
if (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_empty(&self->txq)) {
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", __func__);
return;
}
/* 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", __func__);
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", __func__);
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", __func__);
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 too short!\n", __func__);
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 = alloc_skb(cmd->len + sizeof(struct test_frame), GFP_ATOMIC);
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", __func__);
if (!pskb_may_pull(skb, sizeof(*frame))) {
IRDA_ERROR("%s: frame too short!\n", __func__);
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 too short!\n",
__func__);
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 net_device *orig_dev)
{
struct irlap_info info;
struct irlap_cb *self;
int command;
__u8 control;
int ret = -1;
if (!net_eq(dev_net(dev), &init_net))
goto out;
/* 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)
goto err;
/* 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", __func__);
goto err;
}
/* Check if frame is large enough for parsing */
if (!pskb_may_pull(skb, 2)) {
IRDA_ERROR("%s: frame too short!\n", __func__);
goto err;
}
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",
__func__);
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",
__func__, 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",
__func__, info.control);
break;
}
out:
ret = 0;
err:
/* Always drop our reference on the skb */
dev_kfree_skb(skb);
return ret;
}