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SOURCE.ARC
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AX25USER.C
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C/C++ Source or Header
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1989-09-25
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6KB
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260 lines
/* User subroutines for AX.25 */
#include "global.h"
#include "mbuf.h"
#include "timer.h"
#include "iface.h"
#include "ax25.h"
#include "lapb.h"
#include <ctype.h>
/* Open an AX.25 connection */
struct ax25_cb *
open_ax25(addr,window,r_upcall,t_upcall,s_upcall,iface,user)
struct ax25 *addr; /* Addresses */
int16 window; /* Window size in bytes */
void (*r_upcall)(); /* Receiver upcall handler */
void (*t_upcall)(); /* Transmitter upcall handler */
void (*s_upcall)(); /* State-change upcall handler */
struct interface *iface; /* Hardware interface structure */
char *user; /* User linkage area */
{
register struct ax25_cb *axp;
struct ax25_call *axc;
struct ax25_cb *cr_ax25();
void lapbstate();
if((axc = find_axcall(ax25_excl,&addr->dest)) != NULLAXCALL &&
((axc->flags & MULTI_IF) || axc->interface == iface))
return NULLAX25;
if((axp = cr_ax25(&addr->dest,&addr->source)) == NULLAX25)
return NULLAX25;
ASSIGN(axp->addr,*addr);
if(addr->ndigis != 0){
axp->t1.start *= (addr->ndigis + 1);
axp->t2.start *= (addr->ndigis + 1);
/*axp->t3.start *= (addr->ndigis + 1);
axp->t4.start *= (addr->ndigis + 1);*/
}
axp->window = window;
axp->r_upcall = r_upcall;
axp->t_upcall = t_upcall;
axp->s_upcall = s_upcall;
axp->interface = iface;
axp->user = user;
if (axp->state == DISCONNECTED){
/* Don't send anything if the connection already exists */
lapbstate(axp,SETUP,LAPBNOMS);
sendctl(axp,COMMAND,SABM|PF);
}
return axp;
}
/* Send data on an AX.25 connection. Caller must provide PID */
int
send_ax25(axp,bp)
struct ax25_cb *axp;
struct mbuf *bp;
{
if(axp == NULLAX25 || bp == NULLBUF || axp->fin){
free_p(bp);
return -1;
}
enqueue(&axp->txq,bp);
return lapb_output(axp);
}
/* Send data on an AX.25 connection, creating packets sized "paclen" */
sendp_ax25(axp,bp,pid)
register struct ax25_cb *axp;
struct mbuf *bp;
char pid;
{
register struct mbuf *tbp;
int16 bsize;
if(axp == NULLAX25 || bp == NULLBUF)
return;
bsize = len_mbuf(bp);
while(bsize != 0){
if (bsize <= axp->paclen) {
if((tbp = pushdown(bp,1)) == NULLBUF) {/* make space for PID */
free_p(bp);
break; /* out of memory! */
}
bsize = 0;
} else {
/* Allocate buffer, allowing space for PID */
if((tbp = alloc_mbuf(axp->paclen + 1)) == NULLBUF) {
free_p(bp);
break; /* out of memory! */
}
tbp->cnt = 1 + pullup(&bp,tbp->data + 1,axp->paclen);
bsize -= axp->paclen;
}
*tbp->data = pid;
send_ax25(axp,tbp);
}
}
/* Send UI frames to an AX.25-type iface, creating packets sized "paclen" */
sendui_ax25(ifp,addr,bp,pid)
struct interface *ifp;
struct ax25 *addr;
struct mbuf *bp;
char pid;
{
register struct mbuf *tbp;
int16 bsize;
extern int16 paclen;
if(ifp == NULLIF || bp == NULLBUF)
return;
bsize = len_mbuf(bp);
while(bsize != 0){
if (bsize <= paclen) {
if((tbp = pushdown(bp,1)) == NULLBUF) {/* make space for PID */
free_p(bp);
break; /* out of memory! */
}
bsize = 0;
} else {
/* Allocate buffer, allowing space for PID */
if((tbp = alloc_mbuf(paclen + 1)) == NULLBUF) {
free_p(bp);
break; /* out of memory! */
}
tbp->cnt = 1 + pullup(&bp,tbp->data + 1,paclen);
bsize -= paclen;
}
*tbp->data = pid;
senduiframe(ifp,addr,tbp);
}
}
/* Receive incoming data on an AX.25 connection */
struct mbuf *
recv_ax25(axp,cnt)
register struct ax25_cb *axp;
int16 cnt;
{
struct mbuf *bp;
unsigned rxqlen;
if(axp->rxq == NULLBUF)
return NULLBUF;
if ((rxqlen = len_mbuf(axp->rxq)) <= cnt || cnt == 0){
bp = axp->rxq;
axp->rxq = NULLBUF;
cnt = rxqlen;
} else {
if ((bp = alloc_mbuf(cnt)) == NULLBUF)
return NULLBUF;
cnt = bp->cnt = pullup(&axp->rxq,bp->data,cnt);
}
/* If this has un-busied us, send a RR to reopen the window */
if(rxqlen >= axp->window && (rxqlen - cnt) < axp->window)
sendctl(axp,RESPONSE,RR);
return bp;
}
/* Get a line of text from an AX.25 connection (up to \r) */
/* The textline may span multiple incoming packets, so NULLBUF is returned */
/* as long as the line is incomplete (and it is saved) */
struct mbuf *
recvl_ax25(axp,cnt)
register struct ax25_cb *axp;
int16 cnt;
{
struct mbuf *bp;
unsigned rxqlen;
if(axp->rxq == NULLBUF)
return NULLBUF;
rxqlen = len_mbuf(axp->rxq);
if ((bp = pullline(&axp->rxq,cnt)) != NULLBUF){
/* If this has un-busied us, send a RR to reopen the window */
if(rxqlen >= axp->window && (rxqlen - bp->cnt) < axp->window)
sendctl(axp,RESPONSE,RR);
}
return bp;
}
/* "Gracefully Close" an AX.25 connection */
close_ax25(axp)
struct ax25_cb *axp;
{
axp->fin = YES; /* set FIN flag */
if (axp->txq == NULLBUF && /* no outstanding frames? */
axp->state != DISCPENDING) /* not already disconnecting? */
disc_ax25(axp); /* start disconnecting now */
}
/* Close an AX.25 connection */
disc_ax25(axp)
struct ax25_cb *axp;
{
void lapbstate();
switch (axp->state)
{
case DISCONNECTED:
break; /* Ignored */
case DISCPENDING: /* was pending, just drop it */
lapbstate(axp,DISCONNECTED,LAPBDISC);
del_ax25(axp);
break;
case CONNECTED: /* was connected, full retries */
lapbstate(axp,DISCPENDING,LAPBNOMS);
sendctl(axp,COMMAND,DISC|PF);
break;
default: /* SETUP */
lapbstate(axp,DISCPENDING,LAPBNOMS);
axp->retries = axp->n2 - 2; /* try 3 times only */
sendctl(axp,COMMAND,DISC|PF);
break;
}
}
/* Verify that axp points to a valid ax25 control block */
ax25val(axp)
struct ax25_cb *axp;
{
register struct ax25_cb *axp1;
register int i;
if(axp == NULLAX25)
return 0; /* Null pointer can't be valid */
for(i=0; i < NHASH; i++)
for(axp1 = ax25_cb[i];axp1 != NULLAX25; axp1 = axp1->next)
if(axp1 == axp)
return 1;
return 0;
}
/* Force a retransmission */
kick_ax25(axp)
struct ax25_cb *axp;
{
void recover();
if(!ax25val(axp))
return -1;
recover((int *)axp);
return 0;
}
/* Abruptly terminate an AX.25 connection */
reset_ax25(axp)
struct ax25_cb *axp;
{
void lapbstate();
lapbstate(axp,DISCONNECTED,LAPBNOMS);
del_ax25(axp);
}