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/*
* NET An implementation of the IEEE 802.2 LLC protocol for the
* LINUX operating system. LLC is implemented as a set of
* state machines and callbacks for higher networking layers.
*
* Class 2 llc algorithm.
* Pseudocode interpreter, transition table lookup,
* data_request & indicate primitives...
*
* Code for initialization, termination, registration and
* MAC layer glue.
*
* Copyright Tim Alpaerts,
* <Tim_Alpaerts@toyota-motor-europe.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.
*
* Changes
* Alan Cox : Chainsawed into Linux format
* Modified to use llc_ names
* Changed callbacks
*
* This file must be processed by sed before it can be compiled.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/p8022.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <asm/byteorder.h>
#include "pseudo/pseudocode.h"
#include "transit/pdutr.h"
#include "transit/timertr.h"
#include <net/llc_frame.h>
#include <net/llc.h>
/*
* Data_request() is called by the client to present a data unit
* to the llc for transmission.
* In the future this function should also check if the transmit window
* allows the sending of another pdu, and if not put the skb on the atq
* for deferred sending.
*/
int llc_data_request(llcptr lp, struct sk_buff *skb)
{
if (skb_headroom(skb) < (lp->dev->hard_header_len +4)){
printk("cl2llc: data_request() not enough headroom in skb\n");
return -1;
};
skb_push(skb, 4);
if ((lp->state != NORMAL) && (lp->state != BUSY) && (lp->state != REJECT))
{
printk("cl2llc: data_request() while no llc connection\n");
return -1;
}
if (lp->remote_busy)
{ /* if the remote llc is BUSY, */
ADD_TO_ATQ(skb); /* save skb in the await transmit queue */
return 0;
}
else
{
/*
* Else proceed with xmit
*/
switch(lp->state)
{
case NORMAL:
if(lp->p_flag)
llc_interpret_pseudo_code(lp, NORMAL2, skb, NO_FRAME);
else
llc_interpret_pseudo_code(lp, NORMAL1, skb, NO_FRAME);
break;
case BUSY:
if (lp->p_flag)
llc_interpret_pseudo_code(lp, BUSY2, skb, NO_FRAME);
else
llc_interpret_pseudo_code(lp, BUSY1, skb, NO_FRAME);
break;
case REJECT:
if (lp->p_flag)
llc_interpret_pseudo_code(lp, REJECT2, skb, NO_FRAME);
else
llc_interpret_pseudo_code(lp, REJECT1, skb, NO_FRAME);
break;
default:;
}
if(lp->llc_callbacks)
{
lp->llc_event(lp);
lp->llc_callbacks=0;
}
return 0;
}
}
/*
* Disconnect_request() requests that the llc to terminate a connection
*/
void disconnect_request(llcptr lp)
{
if ((lp->state == NORMAL) ||
(lp->state == BUSY) ||
(lp->state == REJECT) ||
(lp->state == AWAIT) ||
(lp->state == AWAIT_BUSY) ||
(lp->state == AWAIT_REJECT))
{
lp->state = D_CONN;
llc_interpret_pseudo_code(lp, SH1, NULL, NO_FRAME);
if(lp->llc_callbacks)
{
lp->llc_event(lp);
lp->llc_callbacks=0;
}
/*
* lp may be invalid after the callback
*/
}
}
/*
* Connect_request() requests that the llc to start a connection
*/
void connect_request(llcptr lp)
{
if (lp->state == ADM)
{
lp->state = SETUP;
llc_interpret_pseudo_code(lp, ADM1, NULL, NO_FRAME);
if(lp->llc_callbacks)
{
lp->llc_event(lp);
lp->llc_callbacks=0;
}
/*
* lp may be invalid after the callback
*/
}
}
/*
* Interpret_pseudo_code() executes the actions in the connection component
* state transition table. Table 4 in document on p88.
*
* If this function is called to handle an incoming pdu, skb will point
* to the buffer with the pdu and type will contain the decoded pdu type.
*
* If called by data_request skb points to an skb that was skb_alloc-ed by
* the llc client to hold the information unit to be transmitted, there is
* no valid type in this case.
*
* If called because a timer expired no skb is passed, and there is no
* type.
*/
void llc_interpret_pseudo_code(llcptr lp, int pc_label, struct sk_buff *skb,
char type)
{
short int pc; /* program counter in pseudo code array */
char p_flag_received;
frameptr fr;
int resend_count; /* number of pdus resend by llc_resend_ipdu() */
int ack_count; /* number of pdus acknowledged */
struct sk_buff *skb2;
if (skb != NULL)
{
fr = (frameptr) skb->data;
}
else
fr = NULL;
pc = pseudo_code_idx[pc_label];
while(pseudo_code[pc])
{
switch(pseudo_code[pc])
{
case 9:
if ((type != I_CMD) || (fr->i_hdr.i_pflag == 0))
break;
case 1:
lp->remote_busy = 0;
llc_stop_timer(lp, BUSY_TIMER);
if ((lp->state == NORMAL) ||
(lp->state == REJECT) ||
(lp->state == BUSY))
{
skb2 = llc_pull_from_atq(lp);
if (skb2 != NULL)
llc_start_timer(lp, ACK_TIMER);
while (skb2 != NULL)
{
llc_sendipdu( lp, I_CMD, 0, skb2);
skb2 = llc_pull_from_atq(lp);
}
}
break;
case 2:
lp->state = NORMAL; /* needed to eliminate connect_response() */
lp->llc_mode = MODE_ABM;
lp->llc_callbacks|=LLC_CONN_INDICATION;
break;
case 3:
lp->llc_mode = MODE_ABM;
lp->llc_callbacks|=LLC_CONN_CONFIRM;
break;
case 4:
skb_pull(skb, 4);
lp->inc_skb=skb;
lp->llc_callbacks|=LLC_DATA_INDIC;
break;
case 5:
lp->llc_mode = MODE_ADM;
lp->llc_callbacks|=LLC_DISC_INDICATION;
break;
case 70:
lp->llc_callbacks|=LLC_RESET_INDIC_LOC;
break;
case 71:
lp->llc_callbacks|=LLC_RESET_INDIC_REM;
break;
case 7:
lp->llc_callbacks|=LLC_RST_CONFIRM;
break;
case 66:
lp->llc_callbacks|=LLC_FRMR_RECV;
break;
case 67:
lp->llc_callbacks|=LLC_FRMR_SENT;
break;
case 68:
lp->llc_callbacks|=LLC_REMOTE_BUSY;
break;
case 69:
lp->llc_callbacks|=LLC_REMOTE_NOTBUSY;
break;
case 11:
llc_sendpdu(lp, DISC_CMD, lp->f_flag, 0, NULL);
break;
case 12:
llc_sendpdu(lp, DM_RSP, 0, 0, NULL);
break;
case 13:
lp->frmr_info_fld.cntl1 = fr->pdu_cntl.byte1;
lp->frmr_info_fld.cntl2 = fr->pdu_cntl.byte2;
lp->frmr_info_fld.vs = lp->vs;
lp->frmr_info_fld.vr_cr = lp->vr;
llc_sendpdu(lp, FRMR_RSP, 0, 5, (char *) &lp->frmr_info_fld);
break;
case 14:
llc_sendpdu(lp, FRMR_RSP, 0, 5, (char *) &lp->frmr_info_fld);
break;
case 15:
llc_sendpdu(lp, FRMR_RSP, lp->p_flag,
5, (char *) &lp->frmr_info_fld);
break;
case 16:
llc_sendipdu(lp, I_CMD, 1, skb);
break;
case 17:
resend_count = llc_resend_ipdu(lp, fr->i_hdr.nr, I_CMD, 1);
break;
case 18:
resend_count = llc_resend_ipdu(lp, fr->i_hdr.nr, I_CMD, 1);
if (resend_count == 0)
{
llc_sendpdu(lp, RR_CMD, 1, 0, NULL);
}
break;
case 19:
llc_sendipdu(lp, I_CMD, 0, skb);
break;
case 20:
resend_count = llc_resend_ipdu(lp, fr->i_hdr.nr, I_CMD, 0);
break;
case 21:
resend_count = llc_resend_ipdu(lp, fr->i_hdr.nr, I_CMD, 0);
if (resend_count == 0)
{
llc_sendpdu(lp, RR_CMD, 0, 0, NULL);
}
break;
case 22:
resend_count = llc_resend_ipdu(lp, fr->i_hdr.nr, I_RSP, 1);
break;
case 23:
llc_sendpdu(lp, REJ_CMD, 1, 0, NULL);
break;
case 24:
llc_sendpdu(lp, REJ_RSP, 1, 0, NULL);
break;
case 25:
if (IS_RSP(fr))
llc_sendpdu(lp, REJ_CMD, 0, 0, NULL);
else
llc_sendpdu(lp, REJ_RSP, 0, 0, NULL);
break;
case 26:
llc_sendpdu(lp, RNR_CMD, 1, 0, NULL);
break;
case 27:
llc_sendpdu(lp, RNR_RSP, 1, 0, NULL);
break;
case 28:
if (IS_RSP(fr))
llc_sendpdu(lp, RNR_CMD, 0, 0, NULL);
else
llc_sendpdu(lp, RNR_RSP, 0, 0, NULL);
break;
case 29:
if (lp->remote_busy == 0)
{
lp->remote_busy = 1;
llc_start_timer(lp, BUSY_TIMER);
lp->llc_callbacks|=LLC_REMOTE_BUSY;
}
else if (lp->timer_state[BUSY_TIMER] == TIMER_IDLE)
{
llc_start_timer(lp, BUSY_TIMER);
}
break;
case 30:
if (IS_RSP(fr))
llc_sendpdu(lp, RNR_CMD, 0, 0, NULL);
else
llc_sendpdu(lp, RNR_RSP, 0, 0, NULL);
break;
case 31:
llc_sendpdu(lp, RR_CMD, 1, 0, NULL);
break;
case 32:
llc_sendpdu(lp, RR_CMD, 1, 0, NULL);
break;
case 33:
llc_sendpdu(lp, RR_RSP, 1, 0, NULL);
break;
case 34:
llc_sendpdu(lp, RR_RSP, 1, 0, NULL);
break;
case 35:
llc_sendpdu(lp, RR_RSP, 0, 0, NULL);
break;
case 36:
if (IS_RSP(fr))
llc_sendpdu(lp, RR_CMD, 0, 0, NULL);
else
llc_sendpdu(lp, RR_RSP, 0, 0, NULL);
break;
case 37:
llc_sendpdu(lp, SABME_CMD, 0, 0, NULL);
lp->f_flag = 0;
break;
case 38:
llc_sendpdu(lp, UA_RSP, lp->f_flag, 0, NULL);
break;
case 39:
lp->s_flag = 0;
break;
case 40:
lp->s_flag = 1;
break;
case 41:
if(lp->timer_state[P_TIMER] == TIMER_RUNNING)
llc_stop_timer(lp, P_TIMER);
llc_start_timer(lp, P_TIMER);
if (lp->p_flag == 0)
{
lp->retry_count = 0;
lp->p_flag = 1;
}
break;
case 44:
if (lp->timer_state[ACK_TIMER] == TIMER_IDLE)
llc_start_timer(lp, ACK_TIMER);
break;
case 42:
llc_start_timer(lp, ACK_TIMER);
break;
case 43:
llc_start_timer(lp, REJ_TIMER);
break;
case 45:
llc_stop_timer(lp, ACK_TIMER);
break;
case 46:
llc_stop_timer(lp, ACK_TIMER);
lp->p_flag = 0;
break;
case 10:
if (lp->data_flag == 2)
llc_stop_timer(lp, REJ_TIMER);
break;
case 47:
llc_stop_timer(lp, REJ_TIMER);
break;
case 48:
llc_stop_timer(lp, ACK_TIMER);
llc_stop_timer(lp, P_TIMER);
llc_stop_timer(lp, REJ_TIMER);
llc_stop_timer(lp, BUSY_TIMER);
break;
case 49:
llc_stop_timer(lp, P_TIMER);
llc_stop_timer(lp, REJ_TIMER);
llc_stop_timer(lp, BUSY_TIMER);
break;
case 50:
ack_count = llc_free_acknowledged_skbs(lp,
(unsigned char) fr->s_hdr.nr);
if (ack_count > 0)
{
lp->retry_count = 0;
llc_stop_timer(lp, ACK_TIMER);
if (skb_peek(&lp->rtq) != NULL)
{
/*
* Re-transmit queue not empty
*/
llc_start_timer(lp, ACK_TIMER);
}
}
break;
case 51:
if (IS_UFRAME(fr))
p_flag_received = fr->u_hdr.u_pflag;
else
p_flag_received = fr->i_hdr.i_pflag;
if ((fr->pdu_hdr.ssap & 0x01) && (p_flag_received))
{
lp->p_flag = 0;
llc_stop_timer(lp, P_TIMER);
}
break;
case 52:
lp->data_flag = 2;
break;
case 53:
lp->data_flag = 0;
break;
case 54:
lp->data_flag = 1;
break;
case 55:
if (lp->data_flag == 0)
lp->data_flag = 1;
break;
case 56:
lp->p_flag = 0;
break;
case 57:
lp->p_flag = lp->f_flag;
break;
case 58:
lp->remote_busy = 0;
break;
case 59:
lp->retry_count = 0;
break;
case 60:
lp->retry_count++;
break;
case 61:
lp->vr = 0;
break;
case 62:
lp->vr++;
break;
case 63:
lp->vs = 0;
break;
case 64:
lp->vs = fr->i_hdr.nr;
break;
case 65:
if (IS_UFRAME(fr))
lp->f_flag = fr->u_hdr.u_pflag;
else
lp->f_flag = fr->i_hdr.i_pflag;
break;
default:;
}
pc++;
}
}
/*
* Process_otype2_frame will handle incoming frames
* for 802.2 Type 2 Procedure.
*/
void llc_process_otype2_frame(llcptr lp, struct sk_buff *skb, char type)
{
int idx; /* index in transition table */
int pc_label; /* action to perform, from tr tbl */
int validation; /* result of validate_seq_nos */
int p_flag_received; /* p_flag in received frame */
frameptr fr;
fr = (frameptr) skb->data;
if (IS_UFRAME(fr))
p_flag_received = fr->u_hdr.u_pflag;
else
p_flag_received = fr->i_hdr.i_pflag;
switch(lp->state)
{
/* Compute index in transition table: */
case ADM:
idx = type;
idx = (idx << 1) + p_flag_received;
break;
case CONN:
case RESET_WAIT:
case RESET_CHECK:
case ERROR:
idx = type;
break;
case SETUP:
case RESET:
case D_CONN:
idx = type;
idx = (idx << 1) + lp->p_flag;
break;
case NORMAL:
case BUSY:
case REJECT:
case AWAIT:
case AWAIT_BUSY:
case AWAIT_REJECT:
validation = llc_validate_seq_nos(lp, fr);
if (validation > 3)
type = BAD_FRAME;
idx = type;
idx = (idx << 1);
if (validation & 1)
idx = idx +1;
idx = (idx << 1) + p_flag_received;
idx = (idx << 1) + lp->p_flag;
default:
printk("llc_proc: bad state\n");
return;
}
idx = (idx << 1) + pdutr_offset[lp->state];
lp->state = pdutr_entry[idx +1];
pc_label = pdutr_entry[idx];
if (pc_label != 0)
{
llc_interpret_pseudo_code(lp, pc_label, skb, type);
if(lp->llc_callbacks)
{
lp->llc_event(lp);
lp->llc_callbacks=0;
}
/*
* lp may no longer be valid after this point. Be
* careful what is added!
*/
}
}
void llc_timer_expired(llcptr lp, int t)
{
int idx; /* index in transition table */
int pc_label; /* action to perform, from tr tbl */
lp->timer_state[t] = TIMER_EXPIRED;
idx = lp->state; /* Compute index in transition table: */
idx = (idx << 2) + t;
idx = idx << 1;
if (lp->retry_count >= lp->n2)
idx = idx + 1;
idx = (idx << 1) + lp->s_flag;
idx = (idx << 1) + lp->p_flag;
idx = idx << 1; /* 2 bytes per entry: action & newstate */
pc_label = timertr_entry[idx];
if (pc_label != 0)
{
llc_interpret_pseudo_code(lp, pc_label, NULL, NO_FRAME);
lp->state = timertr_entry[idx +1];
}
lp->timer_state[t] = TIMER_IDLE;
if(lp->llc_callbacks)
{
lp->llc_event(lp);
lp->llc_callbacks=0;
}
/*
* And lp may have vanished in the event callback
*/
}
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