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|
/*
* 802.2 Class 2 LLC service.
*/
int llc_rx_adm(struct sock *sk,struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(type==CMD)
{
if(cmd==DISC)
send_response(sk,DM|pf);
else if(cmd==SABM)
{
if(sk->state!=TCP_LISTEN)
send_response(sk. DM|pf);
else
{
sk=ll_rx_accept(sk);
if(sk!=NULL)
{
send_response(sk, UA|pf);
sk->llc.vs=0;
sk->llc.vr=0;
sk->llc.p_flag=0;
sk->llc.remote_busy=0;
llc_state(sk,LLC_NORMAL);
}
}
}
else if(pf)
send_response(sk, DM|PF);
}
return 0;
}
int llc_rx_setup(struct sock *sk, struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(type==CMD)
{
if(cmd==SABM)
{
sk->llc.vs=0;
sk->llc.vr=0;
send_response(sk, UA|pf);
}
if(cmd==DISC)
{
send_response(sk, DM|pf);
llc_error(sk,ECONNRESET);
llc_state(sk, LLC_ADM);
}
}
else
{
if(cmd==UA && pf==sk->llc.p_flag)
{
del_timer(&sk->llc.t1);
sk->llc.vs=0;
llc_update_p_flag(sk,pf);
llc_state(sk,LLC_NORMAL);
}
if(cmd==DM)
{
llc_error(sk, ECONNRESET);
llc_state(sk, LLC_ADM);
}
}
}
int llc_rx_reset(struct sock *sk, struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(type==CMD)
{
if(cmd==SABM)
{
sk->llc.vr=0;
sk->llc.vs=0;
send_response(sk, UA|pf);
}
else if(cmd==DISC)
{
if(sk->llc.cause_flag==1)
llc_shutdown(sk,SHUTDOWN_MASK);
else
llc_eror(sk, ECONNREFUSED);
send_response(sk, DM|pf);
llc_state(sk, LLC_ADM);
}
}
else
{
if(cmd==UA)
{
if(sk->llc.p_flag==pf)
{
del_timer(&sk->llc.t1);
sk->llc.vs=0;
sk->llc.vr=0;
llc_update_p_flag(sk,pf);
llc_confirm_reset(sk, sk->llc.cause_flag);
sk->llc.remote_busy=0;
llc_state(sk, LLC_NORMAL);
}
}
if(cmd==DM)
{ /* Should check cause_flag */
llc_shutdown(sk, SHUTDOWN_MASK);
llc_state(sk, LLC_ADM);
}
}
return 0;
}
int llc_rx_d_conn(struct sock *sk, struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(type==CMD)
{
if(cmd==SABM)
{
llc_error(sk, ECONNRESET);
llc_state(sk, ADM);
}
else if(cmd==DISC)
{
send_response(UA|pf);
llc_state(sk, LLC_D_CONN);
}
else if(pf)
send_response(sk, DM|PF);
}
else
{
if(cmd==UA && pf==sk->llc.p_flag)
{
del_timer(&sk->llc.t1);
llc_state(sk, ADM);
llc_confirm_reset(sk, sk->llc.cause_flag);
}
if(cmd==DM)
{
del_timer(&sk->llc.t1);
/*if(sk->llc.cause_flag)*/
llc_shutdown(sk, SHUTDOWN_MASK);
}
}
return 0;
}
int llc_rx_error(struct sock *sk, struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(type==CMD)
{
if(cmd==SABM)
{
sk->llc.vs=0;
sk->llc.vr=0;
send_response(sk, UA|pf);
llc_error(sk,ECONNRESET);
sk->llc.p_flag=0;
sk->llc.remote_busy=0;
llc_state(sk, LLC_NORMAL);
}
else if(cmd==DISC)
{
send_response(sk, UA|pf);
llc_shutdown(sk, SHUTDOWN_MASK);
llc_state(sk, LLC_ADM);
}
else
llc_resend_frmr_rsp(sk,pf);
}
else
{
if(cmd==DM)
{
llc_error(sk, ECONNRESET);
del_timer(&sk->llc.t1);
llc_state(sk, LLC_ADM);
}
if(cmd==FRMR)
{
send_command(sk, SABM);
sk->llc.p_flag=pf;
llc_start_t1();
sk->llc.retry_count=0;
sk->llc.cause_flag=0;
llc_error(sk, EPROTO);
llc_state(sk, LLC_RESET);
}
}
}
/*
* Subroutine for handling the shared cases of the data modes.
*/
int llc_rx_nr_shared(struct sock *sk, struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(type==CMD)
{
if(cmd==SABM)
{
/*
* Optional reset processing. We decline resets.
*/
send_response(sk,DM|pf);
llc_error(sk, ECONNRESET);
llc_state(sk, LLC_ADM);
}
else if(cmd==DISC)
{
send_response(sk,UA|pf);
llc_state(sk, LLC_ADM);
llc_shutdown(sk, SHUTDOWN_MASK);
}
/*
* We only ever use windows of 7, so there is no illegal NR/NS value
* otherwise we would FRMR here and go to ERROR state
*/
else if(cmd==ILLEGAL)
{
llc_send_frmr_response(sk, ILLEGAL_TYPE,pf);
llc_state(sk, LLC_ERROR);
llc_error(sk, EPROTO);
}
else
/*
* Not covered by general rule
*/
return 0;
}
else
{
/*
* We close on errors
*/
if(cmd==FRMR)
{
send_command(sk, DM|pf);
sk->llc.p_flag=pf;
llc_start_t1(sk);
llc_error(sk, EPROTO);
sk->llc.cause_flag=0;
llc_state(sk, LLC_D_CONN):
}
else if(cmd==DM)
{
llc_state(sk, LLC_ADM);
llc_error(sk, ECONNREFUSED);
}
/*
* We always use a window of 7 so can't get I resp
* with invalid NS, or any resp with invalid NR. If
* we add this they do the same as..
*/
else if(cmd==UA)
{
llc_send_frmr_response(sk, UNEXPECTED_CONTROL, pf);
llc_state(sk, LLC_ERROR);
llc_error(sk, EPROTO);
}
else if(pf==1 && sk->llc.p_flag==0)
{
llc_send_frmr_response(sk, UNEXPECTED_RESPONSE, pf);
llc_state(sk, LLC_ERROR);
llc_error(sk, EPROTO);
}
else if(cmd==ILLEGAL)
{
llc_send_frmr_response(sk, ILLEGAL_TYPE,pf);
llc_state(sk, LLC_ERROR);
llc_error(sk, EPROTO);
}
else
/*
* Not covered by general rule
*/
return 0
}
/*
* Processed.
*/
return 1;
}
int llc_rx_normal(struct sock *sk, struct sk_buff *skb, int type, int cmd, int pf, int nr, int ns)
{
if(llc_rx_nr_shared(sk, skb, type, cmd, pf, nr, ns))
return 0;
if(cmd==I)
{
if(llc_invalid_ns(sk,ns))
{
if((type==RESP && sk->llc.p_flag==pf)||(type==CMD && pf==0 && sk->llc.p_flag==0))
{
llc_command(sk, REJ|PF);
llc_ack_frames(sk,nr); /* Ack frames and update N(R) */
sk->llc.p_flag=PF;
llc_state(sk, LLC_REJECT);
sk->llc.retry_count=0;
llc_start_t1(sk);
sk->llc.remote_busy=0;
}
else if((type==CMD && !pf && sk->llc.p_flag==1) || (type==RESP && !pf && sk->llc.p_flag==1))
{
if(type==CMD)
llc_response(sk, REJ);
else
llc_command(sk, REJ);
llc_ack_frames(sk,nr);
sk->llc.retry_count=0;
llc_state(sk, LLC_REJECT);
llc_start_t1(sk);
}
else if(pf && type==CMD)
{
llc_response(sk, REJ|PF);
llc_ack_frames(sk,nr);
sk->llc.retry_count=0;
llc_start_t1(sk);
}
}
else
{
/*
* Valid I frame cases
*/
if(sk->llc.p_flag==pf && !(type==CMD && pf))
{
sk->llc.vr=(sk->llc.vr+1)&7;
llc_queue_rr_cmd(sk, PF);
sk->llc.retry_count=0;
llc_start_t1(sk);
sk->llc.p_flag=1;
llc_ack_frames(sk,nr);
sk->llc.remote_busy=0;
}
else if(sk->ppc.p_flag!=pf)
{
sk->llc.vr=(sk->llc.vr+1)&7;
if(type==CMD)
llc_queue_rr_resp(sk, 0);
else
llc_queue_rr_cmd(sk, 0);
if(sk->llc.nr!=nr)
{
llc_ack_frames(sk,nr);
llc_reset_t1(sk);
}
}
else if(pf)
{
sk->llc.vr=(sk->llc.vr+1)&7;
llc_queue_rr_resp(sk,PF);
if(sk->llc.nr!=nr)
{
llc_ack_frames(sk,nr);
llc_reset_t1(sk);
}
}
llc_queue_data(sk,skb);
return 1;
}
}
else if(cmd==RR||cmd==RNR)
{
if(type==CMD || (type==RESP && (!pf || pf==1 && sk->llc.p_flag==1)))
{
llc_update_p_flag(sk,pf);
if(sk->llc.nr!=nr)
{
llc_ack_frames(sk,nr);
llc_reset_t1(sk);
}
if(cmd==RR)
sk->llc.remote_busy=0;
else
{ sk->llc.remote_busy=1;
if(!llc_t1_running(sk))
llc_start_t1(sk);
}
}
else if(type==cmd && pf)
{
if(cmd==RR)
llc_queue_rr_resp(sk,PF);
else
{
send_response(sk, RR|PF);
if(!llc_t1_running(sk))
llc_start_t1(sk);
}
if(sk->llc.nr!=nr)
{
llc_ack_frames(sk,nr);
llc_reset_t1(sk);
}
if(cmd==RR)
sk->llc.remote_busy=0;
else
sk->llc.remote_busy=1;
}
}
else if(cmd==REJ)
{
}
}
|
