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BSD 4_2 release
[unix-history] / usr / src / ucb / telnet.c
#ifndef lint
static char sccsid[] = "@(#)telnet.c 4.24 (Berkeley) 7/20/83";
#endif
/*
* User telnet program.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#define TELOPTS
#include <arpa/telnet.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <setjmp.h>
#include <netdb.h>
#define strip(x) ((x)&0177)
char ttyobuf[BUFSIZ], *tfrontp = ttyobuf, *tbackp = ttyobuf;
char netobuf[BUFSIZ], *nfrontp = netobuf, *nbackp = netobuf;
char hisopts[256];
char myopts[256];
char doopt[] = { IAC, DO, '%', 'c', 0 };
char dont[] = { IAC, DONT, '%', 'c', 0 };
char will[] = { IAC, WILL, '%', 'c', 0 };
char wont[] = { IAC, WONT, '%', 'c', 0 };
int connected;
int net;
int showoptions = 0;
int options;
int debug = 0;
int crmod = 0;
char *prompt;
char escape = CTRL(]);
char line[200];
int margc;
char *margv[20];
jmp_buf toplevel;
jmp_buf peerdied;
extern int errno;
int tn(), quit(), suspend(), bye(), help();
int setescape(), status(), toggle(), setoptions();
int setcrmod(), setdebug();
#define HELPINDENT (sizeof ("connect"))
struct cmd {
char *name; /* command name */
char *help; /* help string */
int (*handler)(); /* routine which executes command */
};
char openhelp[] = "connect to a site";
char closehelp[] = "close current connection";
char quithelp[] = "exit telnet";
char zhelp[] = "suspend telnet";
char debughelp[] = "toggle debugging";
char escapehelp[] = "set escape character";
char statushelp[] = "print status information";
char helphelp[] = "print help information";
char optionshelp[] = "toggle viewing of options processing";
char crmodhelp[] = "toggle mapping of received carriage returns";
struct cmd cmdtab[] = {
{ "open", openhelp, tn },
{ "close", closehelp, bye },
{ "quit", quithelp, quit },
{ "z", zhelp, suspend },
{ "escape", escapehelp, setescape },
{ "status", statushelp, status },
{ "options", optionshelp, setoptions },
{ "crmod", crmodhelp, setcrmod },
{ "debug", debughelp, setdebug },
{ "?", helphelp, help },
0
};
struct sockaddr_in sin;
int intr(), deadpeer();
char *control();
struct cmd *getcmd();
struct servent *sp;
struct tchars otc;
struct ltchars oltc;
struct sgttyb ottyb;
main(argc, argv)
int argc;
char *argv[];
{
sp = getservbyname("telnet", "tcp");
if (sp == 0) {
fprintf(stderr, "telnet: tcp/telnet: unknown service\n");
exit(1);
}
ioctl(0, TIOCGETP, (char *)&ottyb);
ioctl(0, TIOCGETC, (char *)&otc);
ioctl(0, TIOCGLTC, (char *)&oltc);
setbuf(stdin, 0);
setbuf(stdout, 0);
prompt = argv[0];
if (argc > 1 && !strcmp(argv[1], "-d"))
debug = SO_DEBUG, argv++, argc--;
if (argc != 1) {
if (setjmp(toplevel) != 0)
exit(0);
tn(argc, argv);
}
setjmp(toplevel);
for (;;)
command(1);
}
char *hostname;
char hnamebuf[32];
tn(argc, argv)
int argc;
char *argv[];
{
register int c;
register struct hostent *host;
if (connected) {
printf("?Already connected to %s\n", hostname);
return;
}
if (argc < 2) {
strcpy(line, "Connect ");
printf("(to) ");
gets(&line[strlen(line)]);
makeargv();
argc = margc;
argv = margv;
}
if (argc > 3) {
printf("usage: %s host-name [port]\n", argv[0]);
return;
}
host = gethostbyname(argv[1]);
if (host) {
sin.sin_family = host->h_addrtype;
bcopy(host->h_addr, (caddr_t)&sin.sin_addr, host->h_length);
hostname = host->h_name;
} else {
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = inet_addr(argv[1]);
if (sin.sin_addr.s_addr == -1) {
printf("%s: unknown host\n", argv[1]);
return;
}
strcpy(hnamebuf, argv[1]);
hostname = hnamebuf;
}
sin.sin_port = sp->s_port;
if (argc == 3) {
sin.sin_port = atoi(argv[2]);
if (sin.sin_port < 0) {
printf("%s: bad port number\n", argv[2]);
return;
}
sin.sin_port = htons(sin.sin_port);
}
net = socket(AF_INET, SOCK_STREAM, 0, 0);
if (net < 0) {
perror("telnet: socket");
return;
}
if (debug && setsockopt(net, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
perror("setsockopt (SO_DEBUG)");
signal(SIGINT, intr);
signal(SIGPIPE, deadpeer);
printf("Trying...\n");
if (connect(net, (caddr_t)&sin, sizeof (sin), 0) < 0) {
perror("telnet: connect");
signal(SIGINT, SIG_DFL);
return;
}
connected++;
call(status, "status", 0);
if (setjmp(peerdied) == 0)
telnet(net);
fprintf(stderr, "Connection closed by foreign host.\n");
exit(1);
}
/*
* Print status about the connection.
*/
/*VARARGS*/
status()
{
if (connected)
printf("Connected to %s.\n", hostname);
else
printf("No connection.\n");
printf("Escape character is '%s'.\n", control(escape));
fflush(stdout);
}
makeargv()
{
register char *cp;
register char **argp = margv;
margc = 0;
for (cp = line; *cp;) {
while (isspace(*cp))
cp++;
if (*cp == '\0')
break;
*argp++ = cp;
margc += 1;
while (*cp != '\0' && !isspace(*cp))
cp++;
if (*cp == '\0')
break;
*cp++ = '\0';
}
*argp++ = 0;
}
/*VARARGS*/
suspend()
{
register int save;
save = mode(0);
kill(0, SIGTSTP);
/* reget parameters in case they were changed */
ioctl(0, TIOCGETP, (char *)&ottyb);
ioctl(0, TIOCGETC, (char *)&otc);
ioctl(0, TIOCGLTC, (char *)&oltc);
(void) mode(save);
}
/*VARARGS*/
bye()
{
register char *op;
(void) mode(0);
if (connected) {
shutdown(net, 2);
printf("Connection closed.\n");
close(net);
connected = 0;
/* reset his options */
for (op = hisopts; op < &hisopts[256]; op++)
*op = 0;
}
}
/*VARARGS*/
quit()
{
call(bye, "bye", 0);
exit(0);
}
/*
* Help command.
*/
help(argc, argv)
int argc;
char *argv[];
{
register struct cmd *c;
if (argc == 1) {
printf("Commands may be abbreviated. Commands are:\n\n");
for (c = cmdtab; c->name; c++)
printf("%-*s\t%s\n", HELPINDENT, c->name, c->help);
return;
}
while (--argc > 0) {
register char *arg;
arg = *++argv;
c = getcmd(arg);
if (c == (struct cmd *)-1)
printf("?Ambiguous help command %s\n", arg);
else if (c == (struct cmd *)0)
printf("?Invalid help command %s\n", arg);
else
printf("%s\n", c->help);
}
}
/*
* Call routine with argc, argv set from args (terminated by 0).
* VARARGS2
*/
call(routine, args)
int (*routine)();
int args;
{
register int *argp;
register int argc;
for (argc = 0, argp = &args; *argp++ != 0; argc++)
;
(*routine)(argc, &args);
}
struct tchars notc = { -1, -1, -1, -1, -1, -1 };
struct ltchars noltc = { -1, -1, -1, -1, -1, -1 };
mode(f)
register int f;
{
static int prevmode = 0;
struct tchars *tc;
struct ltchars *ltc;
struct sgttyb sb;
int onoff, old;
if (prevmode == f)
return (f);
old = prevmode;
prevmode = f;
sb = ottyb;
switch (f) {
case 0:
onoff = 0;
tc = &otc;
ltc = &oltc;
break;
case 1:
case 2:
sb.sg_flags |= CBREAK;
if (f == 1)
sb.sg_flags &= ~(ECHO|CRMOD);
else
sb.sg_flags |= ECHO|CRMOD;
sb.sg_erase = sb.sg_kill = -1;
tc = &notc;
ltc = &noltc;
onoff = 1;
break;
default:
return;
}
ioctl(fileno(stdin), TIOCSLTC, (char *)ltc);
ioctl(fileno(stdin), TIOCSETC, (char *)tc);
ioctl(fileno(stdin), TIOCSETP, (char *)&sb);
ioctl(fileno(stdin), FIONBIO, &onoff);
ioctl(fileno(stdout), FIONBIO, &onoff);
return (old);
}
char sibuf[BUFSIZ], *sbp;
char tibuf[BUFSIZ], *tbp;
int scc, tcc;
/*
* Select from tty and network...
*/
telnet(s)
int s;
{
register int c;
int tin = fileno(stdin), tout = fileno(stdout);
int on = 1;
(void) mode(2);
ioctl(s, FIONBIO, &on);
for (;;) {
int ibits = 0, obits = 0;
if (nfrontp - nbackp)
obits |= (1 << s);
else
ibits |= (1 << tin);
if (tfrontp - tbackp)
obits |= (1 << tout);
else
ibits |= (1 << s);
if (scc < 0 && tcc < 0)
break;
select(16, &ibits, &obits, 0, 0);
if (ibits == 0 && obits == 0) {
sleep(5);
continue;
}
/*
* Something to read from the network...
*/
if (ibits & (1 << s)) {
scc = read(s, sibuf, sizeof (sibuf));
if (scc < 0 && errno == EWOULDBLOCK)
scc = 0;
else {
if (scc <= 0)
break;
sbp = sibuf;
}
}
/*
* Something to read from the tty...
*/
if (ibits & (1 << tin)) {
tcc = read(tin, tibuf, sizeof (tibuf));
if (tcc < 0 && errno == EWOULDBLOCK)
tcc = 0;
else {
if (tcc <= 0)
break;
tbp = tibuf;
}
}
while (tcc > 0) {
register int c;
if ((&netobuf[BUFSIZ] - nfrontp) < 2)
break;
c = *tbp++ & 0377, tcc--;
if (strip(c) == escape) {
command(0);
tcc = 0;
break;
}
if (c == IAC)
*nfrontp++ = c;
*nfrontp++ = c;
}
if ((obits & (1 << s)) && (nfrontp - nbackp) > 0)
netflush(s);
if (scc > 0)
telrcv();
if ((obits & (1 << tout)) && (tfrontp - tbackp) > 0)
ttyflush(tout);
}
(void) mode(0);
}
command(top)
int top;
{
register struct cmd *c;
int oldmode, wasopen;
oldmode = mode(0);
if (!top)
putchar('\n');
else
signal(SIGINT, SIG_DFL);
for (;;) {
printf("%s> ", prompt);
if (gets(line) == 0) {
if (feof(stdin)) {
clearerr(stdin);
putchar('\n');
}
break;
}
if (line[0] == 0)
break;
makeargv();
c = getcmd(margv[0]);
if (c == (struct cmd *)-1) {
printf("?Ambiguous command\n");
continue;
}
if (c == 0) {
printf("?Invalid command\n");
continue;
}
(*c->handler)(margc, margv);
if (c->handler != help)
break;
}
if (!top) {
if (!connected)
longjmp(toplevel, 1);
(void) mode(oldmode);
}
}
/*
* Telnet receiver states for fsm
*/
#define TS_DATA 0
#define TS_IAC 1
#define TS_WILL 2
#define TS_WONT 3
#define TS_DO 4
#define TS_DONT 5
telrcv()
{
register int c;
static int state = TS_DATA;
while (scc > 0) {
c = *sbp++ & 0377, scc--;
switch (state) {
case TS_DATA:
if (c == IAC) {
state = TS_IAC;
continue;
}
*tfrontp++ = c;
/*
* This hack is needed since we can't set
* CRMOD on output only. Machines like MULTICS
* like to send \r without \n; since we must
* turn off CRMOD to get proper input, the mapping
* is done here (sigh).
*/
if (c == '\r' && crmod)
*tfrontp++ = '\n';
continue;
case TS_IAC:
switch (c) {
case WILL:
state = TS_WILL;
continue;
case WONT:
state = TS_WONT;
continue;
case DO:
state = TS_DO;
continue;
case DONT:
state = TS_DONT;
continue;
case DM:
ioctl(fileno(stdout), TIOCFLUSH, 0);
break;
case NOP:
case GA:
break;
default:
break;
}
state = TS_DATA;
continue;
case TS_WILL:
printoption("RCVD", will, c, !hisopts[c]);
if (!hisopts[c])
willoption(c);
state = TS_DATA;
continue;
case TS_WONT:
printoption("RCVD", wont, c, hisopts[c]);
if (hisopts[c])
wontoption(c);
state = TS_DATA;
continue;
case TS_DO:
printoption("RCVD", doopt, c, !myopts[c]);
if (!myopts[c])
dooption(c);
state = TS_DATA;
continue;
case TS_DONT:
printoption("RCVD", dont, c, myopts[c]);
if (myopts[c]) {
myopts[c] = 0;
sprintf(nfrontp, wont, c);
nfrontp += sizeof (wont) - 2;
printoption("SENT", wont, c);
}
state = TS_DATA;
continue;
}
}
}
willoption(option)
int option;
{
char *fmt;
switch (option) {
case TELOPT_ECHO:
(void) mode(1);
case TELOPT_SGA:
hisopts[option] = 1;
fmt = doopt;
break;
case TELOPT_TM:
fmt = dont;
break;
default:
fmt = dont;
break;
}
sprintf(nfrontp, fmt, option);
nfrontp += sizeof (dont) - 2;
printoption("SENT", fmt, option);
}
wontoption(option)
int option;
{
char *fmt;
switch (option) {
case TELOPT_ECHO:
(void) mode(2);
case TELOPT_SGA:
hisopts[option] = 0;
fmt = dont;
break;
default:
fmt = dont;
}
sprintf(nfrontp, fmt, option);
nfrontp += sizeof (doopt) - 2;
printoption("SENT", fmt, option);
}
dooption(option)
int option;
{
char *fmt;
switch (option) {
case TELOPT_TM:
fmt = wont;
break;
case TELOPT_ECHO:
(void) mode(2);
fmt = will;
hisopts[option] = 0;
break;
case TELOPT_SGA:
fmt = will;
break;
default:
fmt = wont;
break;
}
sprintf(nfrontp, fmt, option);
nfrontp += sizeof (doopt) - 2;
printoption("SENT", fmt, option);
}
/*
* Set the escape character.
*/
setescape(argc, argv)
int argc;
char *argv[];
{
register char *arg;
char buf[50];
if (argc > 2)
arg = argv[1];
else {
printf("new escape character: ");
gets(buf);
arg = buf;
}
if (arg[0] != '\0')
escape = arg[0];
printf("Escape character is '%s'.\n", control(escape));
fflush(stdout);
}
/*VARARGS*/
setoptions()
{
showoptions = !showoptions;
printf("%s show option processing.\n", showoptions ? "Will" : "Wont");
fflush(stdout);
}
/*VARARGS*/
setcrmod()
{
crmod = !crmod;
printf("%s map carriage return on output.\n", crmod ? "Will" : "Wont");
fflush(stdout);
}
/*VARARGS*/
setdebug()
{
debug = !debug;
printf("%s turn on socket level debugging.\n",
debug ? "Will" : "Wont");
fflush(stdout);
if (debug && net > 0 && setsockopt(net, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
perror("setsockopt (SO_DEBUG)");
}
/*
* Construct a control character sequence
* for a special character.
*/
char *
control(c)
register int c;
{
static char buf[3];
if (c == 0177)
return ("^?");
if (c >= 040) {
buf[0] = c;
buf[1] = 0;
} else {
buf[0] = '^';
buf[1] = '@'+c;
buf[2] = 0;
}
return (buf);
}
struct cmd *
getcmd(name)
register char *name;
{
register char *p, *q;
register struct cmd *c, *found;
register int nmatches, longest;
longest = 0;
nmatches = 0;
found = 0;
for (c = cmdtab; p = c->name; c++) {
for (q = name; *q == *p++; q++)
if (*q == 0) /* exact match? */
return (c);
if (!*q) { /* the name was a prefix */
if (q - name > longest) {
longest = q - name;
nmatches = 1;
found = c;
} else if (q - name == longest)
nmatches++;
}
}
if (nmatches > 1)
return ((struct cmd *)-1);
return (found);
}
deadpeer()
{
(void) mode(0);
longjmp(peerdied, -1);
}
intr()
{
(void) mode(0);
longjmp(toplevel, -1);
}
ttyflush(fd)
{
int n;
if ((n = tfrontp - tbackp) > 0)
n = write(fd, tbackp, n);
if (n < 0)
return;
tbackp += n;
if (tbackp == tfrontp)
tbackp = tfrontp = ttyobuf;
}
netflush(fd)
{
int n;
if ((n = nfrontp - nbackp) > 0)
n = write(fd, nbackp, n);
if (n < 0) {
if (errno != ENOBUFS && errno != EWOULDBLOCK) {
(void) mode(0);
perror(hostname);
close(fd);
longjmp(peerdied, -1);
/*NOTREACHED*/
}
n = 0;
}
nbackp += n;
if (nbackp == nfrontp)
nbackp = nfrontp = netobuf;
}
/*VARARGS*/
printoption(direction, fmt, option, what)
char *direction, *fmt;
int option, what;
{
if (!showoptions)
return;
printf("%s ", direction);
if (fmt == doopt)
fmt = "do";
else if (fmt == dont)
fmt = "dont";
else if (fmt == will)
fmt = "will";
else if (fmt == wont)
fmt = "wont";
else
fmt = "???";
if (option < TELOPT_SUPDUP)
printf("%s %s", fmt, telopts[option]);
else
printf("%s %d", fmt, option);
if (*direction == '<') {
printf("\r\n");
return;
}
printf(" (%s)\r\n", what ? "reply" : "don't reply");
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.