SRI-NOSC/ncpp/tel-s/svrtel.c
#/*
Module Name:
N N EEEEEEE TTTTTTT GGGGG RRRRRR FFFFFFF
NN N E T G G R R F
N N N E T G G R R F
N N N EEEEEE T G RRRRR FFFFFF
N N N E T G GGG R R F
N NN E T G G R R F
N N EEEEEEE T GGGGG R R F
Network Graphics Server for UNIX
Installation:
if $1x = finalx goto final
cc -c svrtel.c
if ! -r svrtel.o exit
cc svrtel.o /usr/net/hnumcvt.c -lj
rm -f svrtel.o hnumcvt.o
exit
: final
cc -O -c svrtel.c
if ! -r svrtel.o exit
cc -O -n -s svrtel.o /usr/net/hnumcvt.c -lj
if ! -r a.out exit
if ! -r ncpp/tel-s/svrtel.c goto same
if { cmp -s svrtel.c ncpp/tel-s/svrtel.c } goto same
su cp svrtel.c ncpp/tel-s/svrtel.c
rm -f svrtel.c
: same
if -r /usr/net/etc/svrtel su rm -f /usr/net/etc/svrtel
su cp a.out /usr/net/etc/svrtel
e - ncpp/tel-s/svrtel.c
1i
#define OLDTLNT
.
w /tmp/svrtel.c
q
cc -O -s -n /tmp/svrtel.c hnumcvt.o -lj
if -r /usr/net/etc/srvrtelnet su rm -f /usr/net/etc/srvrtelnet
su cp a.out /usr/net/etc/srvrtelnet
rm -f a.out svrtel.o hnumcvt.o /tmp/svrtel.c
chdir /usr/net/etc
su chmod 744 svrtel srvrtelnet
su chown root svrtel srvrtelnet
su chgrp system svrtel srvrtelnet
Synopsis:
Function:
Restrictions:
Diagnostics:
Files:
See Also:
Bugs:
Globals contained:
Routines contained:
Modules referenced:
Modules referencing:
Compile time parameters and effects:
Module History:
*/
/* Parameters */
#define SIGINR 15 /* Interrupt-by-sender (INS) */
#define NETBUFSIZE 60 /* Number of characters in network buffer */
char ptys[] "ABCEDFGH"; /* Suffix characters of psuedo-teletypes */
/* TELNET Opcodes */
#define SE 0360 /* Subnegotiation_end */
#define NOP 0361 /* Nop */
#define DATAM 0362 /* Data_mark */
#define BREAK 0363 /* Break */
#define IP 0364 /* Interrupt_Process */
#define AO 0365 /* Abort_Output */
#define AYT 0366 /* Are_You_There */
#define EC 0367 /* Erase_Character */
#define EL 0370 /* Erase_Line */
#define GA 0371 /* Go_Ahead */
#define SB 0372 /* Subnegotiation_Begin */
#define WILL 0373 /* Will */
#define WONT 0374 /* Wont */
#define DO 0375 /* Do */
#define DONT 0376 /* Dont */
#define IAC 0377 /* Interpet_As_Command */
#ifdef OLDTLNT
/* Old TELNET Opcodes */
#define ODATAM 128 /* Data_mark */
#define OBREAK 129 /* Break */
#define ONOP 130 /* Nop */
#define OIECHO 131 /* I echo */
#define OUECHO 132 /* You echo */
#define OHYI 133 /* Hide your input */
#endif
/* TELNET Options
TELOPT($BINO,0,Transmit_binary);
TELOPT($ECHO,1,Echo);
TELOPT($RCP,2,Prepare_to_reconnect);
TELOPT($SGA,3,Suppress_go_ahead);
TELOPT($NAMS,4,Negotiate_approximate_message_size);
TELOPT($STATUS,5,Status_of_TELNET_options);
TELOPT($TIMRK,6,Timing_Mark);
TELOPT($RCTE,7,Remote_Controled_Transmission_and_Echoing);
TELOPT($NAOL,10,Negotiate_About_Output_Line_width);
TELOPT($NAOP,11,Negotiate_About_Output_Page_Size);
TELOPT($EXTASC,17,Extended_ASCII);
TELOPT($EXOPL,377,Extended_Options_List);
*/
/*
Global variables */
int pid; /* Process ID of subsidiary fork */
int netchan; /* Channel descriptor for network */
/* channel used for TELNET data */
int ptychan; /* Channel number of PTY */
char echoflag; /* Indicates 'will echo' has been sent */
int junk; /* Somewhere to throw away things */
int pty; /* Pty name */
char *arg1p; /* Pointer to arg[1] */
int inter; /* Indication that an interrupt came in */
int ins(); /* INS interrupt routine */
struct openparams /* struct for parameterized network opens */
{
char o_op; /* opcode for kernel & daemon - unused here */
char o_type; /* Type for connection. See defines below */
int o_id; /* ID of file for kernel & daemon, unused here */
int o_lskt; /* Local socket number either abs or rel */
int o_fskt[2]; /* Foreign socket either abs or rel */
char o_frnhost; /* Foreign host number */
char o_bsize; /* bytesize for the connection */
int o_nomall; /* nominal allocation for the connection */
int o_timeo; /* Number of seconds before time out */
int o_relid; /* fid of file to base a data connection on */
} openparams;
#define o_direct 01 /* icp |~ direct */
#define o_server 02 /* user | server */
#define o_init 04 /* listen | init */
#define o_specific 010 /* general | specific */
#define o_duplex 020 /* simplex | duplex */
#define o_relative 040 /* absolute | relative */
struct ttymode
{ char ispeed, ospeed;
char erase, kill;
int mode;
};
/*
main - Handles new connections */
int foochan; /* Due to crock in close */
main(argcnt,argvec)
int argcnt;
char *argvec[];
{
log("Awaiting connection\n");
signal(1,1); /* Ignore quits */
signal(2,1); /* Ignore hangups */
signal(SIGINR,1); /* Ignore ins interrupts */
if(argcnt > 1) arg1p = argvec[1];
for (;;) {
openparams.o_type = o_server; /* Server ICP */
openparams.o_fskt[0] = 0; /* Clear any crud */
openparams.o_fskt[1] = 0;
#ifndef OLDTLNT
openparams.o_lskt = 23; /* Use socket 23 */
#endif
#ifdef OLDTLNT
openparams.o_lskt = 1; /* Use socket 1 */
#endif
netchan = open("/dev/net/anyhost",&openparams);
if (netchan < 0) {
log("Open failure.\n");
continue;
}
foochan = dup(netchan); /* Bagbiting close!!! */
if ((pid = fork())<0) {
log("No processes left!\n"); }
else if (pid==0) {
netgrf();
exit(0);
}
else { /* More logger */
wait(&junk); /* Wait for server to become orphan */
close(foochan); /* Flush extra channel */
close(netchan); /* And real channel, then wait for */
} /* another user */
}
}
/*
netgrf - Sets up processes for NGP server */
netgrf()
{
/* Fork another level deep so parent can die and leave the server as */
/* an orphan to be inherited by /etc/init. Otherwise, zombies are */
/* left lying around because the logger (i.e. main) cannot afford to */
/* do a wait. */
switch(pid=fork()) {
case -1:
log("No processes left!\n");
write(netchan,"Sorry, not enough resources available.\r\n",41);
exit(1); /* Failure return */
default:
exit(0); /* Continues logger */
case 0: /* child continues on.... */
break;
}
if (openpty()<0) {
log("No ptys\n");
write(netchan,"Sorry, no ptys\r\n",16);
exit(1); /* Failure return */
}
setss();
if ((pid = fork()) < 0) {
log("No processes left!\n");
write(netchan,"Sorry, no processes\r\n",21);
exit(1); /* Failure return */
}
close(foochan); /* Two process have it open now (bagbitting close!) */
if (pid==0)
telxmt(); /* Child handles transmit side */
else
telrcv(); /* Parent handles recieve side */
}
/*
telrcv - TELNET recieve side */
telrcv()
{
int c;
/* signal(SIGINR,&ins); ***/
sleep(2); /* Give getty a chance to do stty */
for(;;) {
c = telgetc(); /* Fetch a character */
if (c==IAC) /* IAC? */
telcmd(); /* Yes, handle special command */
#ifdef OLDTLNT
else if (c >=128 )
otelcmd(c);
#endif
else {
write(ptychan,&c,1); /* Otherwise, just enter it */
if (c=='\r') { /* Special case? */
c = telgetc(); /* Yes, look for LF */
if (c && c!='\n') /* If different, enter */
write(ptychan,&c,1); /* it too! */
}
}
}
}
#ifdef OLDTLNT
/*
otelcmd - Handle old TELNET commands */
otelcmd(c)
int c;
{
struct ttymode status; /* Buffer for stty and gtty */
switch(c) {
case OBREAK:
gtty(ptychan,&status); /* return NUL in raw mode, else DEL */
write(ptychan,(status.mode&040) ? "\0" : "\177",1);
break;
case OIECHO:
case OUECHO:
gtty(ptychan,&status);
status.ispeed = status.ospeed = ( (c == OIECHO) ? 4 : 11 );
stty(ptychan,&status);
break;
}
}
#endif
/*
telcmd - Handle new TELNET commands */
telcmd()
{
char negbuf[3];
int command;
struct ttymode status; /* Buffer for stty and gtty */
command = telgetc(); /* Get a character */
switch(command) {
case BREAK:
case IP:
gtty(ptychan,&status); /* output NUL in raw mode, else DEL */
write(ptychan,(status.mode&040) ? "\0" : "\177",1);
break;
case AYT:
write(netchan,"\007",1);
break;
case EC:
case EL:
gtty(ptychan,&status);
write(ptychan,(command == EC) ? &status.erase : &status.kill, 1);
break;
case SB: /* Begin subnegotiation? */
/* Look for end of subnegotiation */
do {
while(command != IAC)
command = telgetc();
} while telgetc() != SE;
break;
case WILL:
case WONT:
case DO:
case DONT:
/* Negotiate. Always give negative acknowledgement */
negbuf[0] = IAC; /* Interpete As Command */
negbuf[1] = DONT+WONT-((command+1)&0376); /* Negative ack. */
negbuf[2] = telgetc(); /* Set code for option */
if (negbuf[2]==1 && /* Echo option? */
(negbuf[1]&0377) == WONT) {
gtty(ptychan,&status);
if (command == DO) { /* User wants us to echo */
status.ispeed = status.ospeed = 11; /* 2400 baud echos */
negbuf[1] = WILL;
} else { /* User doesn't want us to echo */
status.ispeed = status.ospeed = 4; /* 134.5 baud doesn't echo */
negbuf[1] = WONT;
}
stty(ptychan,&status); /* Set desired echo mode */
if (echoflag == 0) { /* Was this a response to our WILL ECHO? */
echoflag++; /* If so don't do anything */
break;
}
}
write(netchan,negbuf,3); /* Send off confirmation/denial to net */
break;
case IAC: /* Not really a command */
write(ptychan,&command,1); /* but a character */
break;
}
}
/*
telxmt - TELNET transmit side */
char ttybuf[NETBUFSIZE+1]; /* This size is best for NetUNIX */
telxmt()
{
register int bytcnt;
register char *s1,*s2;
int retries;
struct ttymode status;
/* Send 'WILL ECHO' and a reminder */
#ifdef OLDTLNT
write(netchan,"\203\r\n",3);
#endif
#ifndef OLDTLNT
write(netchan,"\377\373\001\r\n",5);
#endif
log("connection on tty%c", pty);
if(arg1p) printf(" from %s", &arg1p[10]);
printf(".\n"); flush();
/* Copy characters from output buffer to network */
retries = 10;
for(;;) switch(bytcnt = read(ptychan,ttybuf,sizeof ttybuf)) {
case -1: /* error returned; time to quit! */
exit(0);
case 0: /* EOF -- other side closed */
gtty(ptychan, &status);
if(status.mode&1 || --retries == 0)
exit(0);
sleep(1); /* give a chance to re-open */
continue;
default:
retries = 5;
for (s1 = s2 = ttybuf, ttybuf[bytcnt] = 0; *s1; s1++)
if (*s1 == IAC) {
write(netchan,s2,s1-s2+1);
s2 = s1;
}
write(netchan,s2,s1-s2);
}
}
/*
openpty- Find a usable PTY */
char *ptyname "/dev/ptyx"; /* Where to look for pseudo-teletypes */
int openpty() /* Find an available pseudo-teletype */
{
register char *p;
for (p = ptys; ptyname[8] = *p++;) {
ptychan = open(ptyname,2); /* Try this PTY */
if (ptychan>=0) {
pty = ptyname[8]&0177;
return(ptychan);
}
}
return -1;
}
/*setss - Set arguments to appear in ss */
char argstr[] "ttyX host ";
setss()
{ register char *p, *q;
struct openparams statparams;
if ((q=arg1p) == 0) return;
argstr[3] = pty;
p = argstr;
while (*p) { if (*q) *q++ = *p++; else return; }
if (fstat(netchan,&statparams) >= 0) {
p = hnumcnv(statparams.o_frnhost&0377);
while (*p) { if (*q) *q++ = *p++; else return; }
}
*q = '\0';
}
/*
telgetc- Get a character from TELNET stream */
telgetc()
{
char c;
register int i;
int ttytype[3];
i = read(netchan,&c,1);
if (inter) { /* check for interrupts */
inter = 0; /* DM will be ignored */
gtty(ptychan,ttytype); /* return NUL in raw mode, else DEL */
return( (ttytype[2]&040) ? 0 : 0177);
}
if (i != 1) {
/*DEBUG*/if(pid==0)log("PID not set! This can't happen!\n");else
kill(pid,9); /* Kill other side */
exit(1);
} else {
return(c&0377);
}
}
ins()
{ inter++; /* note that an interrupt has occurred */
signal(SIGINR,&ins);
}
log(txt, a, b, c, d)
char *txt;
{
long t; /* gets the result from time */
time(&t); /* get system time */
#ifndef OLDTLNT
printf ("%-16.16sNew Telnet server: ",
#endif
#ifdef OLDTLNT
printf ("%-16.16sOld Telnet server: ",
#endif
ctime(&t)+4); /* Mmm dd hh:mm:ss */
printf(txt, a, b, c, d);
flush();
}