freebsd-dev/crypto/kerberosIV/appl/telnet/telnetd/telnetd.c
2000-12-29 21:00:22 +00:00

1400 lines
34 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "telnetd.h"
RCSID("$Id: telnetd.c,v 1.58.2.1 2000/10/10 13:12:08 assar Exp $");
#ifdef _SC_CRAY_SECURE_SYS
#include <sys/sysv.h>
#include <sys/secdev.h>
#include <sys/secparm.h>
#include <sys/usrv.h>
int secflag;
char tty_dev[16];
struct secdev dv;
struct sysv sysv;
struct socksec ss;
#endif /* _SC_CRAY_SECURE_SYS */
#ifdef AUTHENTICATION
int auth_level = 0;
#endif
extern int utmp_len;
int registerd_host_only = 0;
#ifdef STREAMSPTY
# include <stropts.h>
# include <termios.h>
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif /* HAVE_SYS_UIO_H */
#ifdef HAVE_SYS_STREAM_H
#include <sys/stream.h>
#endif
#ifdef _AIX
#include <sys/termio.h>
#endif
# ifdef HAVE_SYS_STRTTY_H
# include <sys/strtty.h>
# endif
# ifdef HAVE_SYS_STR_TTY_H
# include <sys/str_tty.h>
# endif
/* make sure we don't get the bsd version */
/* what is this here for? solaris? /joda */
# ifdef HAVE_SYS_TTY_H
# include "/usr/include/sys/tty.h"
# endif
# ifdef HAVE_SYS_PTYVAR_H
# include <sys/ptyvar.h>
# endif
/*
* Because of the way ptyibuf is used with streams messages, we need
* ptyibuf+1 to be on a full-word boundary. The following wierdness
* is simply to make that happen.
*/
long ptyibufbuf[BUFSIZ/sizeof(long)+1];
char *ptyibuf = ((char *)&ptyibufbuf[1])-1;
char *ptyip = ((char *)&ptyibufbuf[1])-1;
char ptyibuf2[BUFSIZ];
unsigned char ctlbuf[BUFSIZ];
struct strbuf strbufc, strbufd;
int readstream(int, char*, int);
#else /* ! STREAMPTY */
/*
* I/O data buffers,
* pointers, and counters.
*/
char ptyibuf[BUFSIZ], *ptyip = ptyibuf;
char ptyibuf2[BUFSIZ];
#endif /* ! STREAMPTY */
int hostinfo = 1; /* do we print login banner? */
#ifdef _CRAY
extern int newmap; /* nonzero if \n maps to ^M^J */
int lowpty = 0, highpty; /* low, high pty numbers */
#endif /* CRAY */
int debug = 0;
int keepalive = 1;
char *progname;
static void usage (void);
/*
* The string to pass to getopt(). We do it this way so
* that only the actual options that we support will be
* passed off to getopt().
*/
char valid_opts[] = "Bd:hklnS:u:UL:y"
#ifdef AUTHENTICATION
"a:X:z"
#endif
#ifdef DIAGNOSTICS
"D:"
#endif
#ifdef _CRAY
"r:"
#endif
;
static void doit(struct sockaddr*, int);
int
main(int argc, char **argv)
{
struct sockaddr_storage __ss;
struct sockaddr *sa = (struct sockaddr *)&__ss;
int on = 1, sa_size;
int ch;
#if defined(IPPROTO_IP) && defined(IP_TOS)
int tos = -1;
#endif
#ifdef ENCRYPTION
extern int des_check_key;
des_check_key = 1; /* Kludge for Mac NCSA telnet 2.6 /bg */
#endif
pfrontp = pbackp = ptyobuf;
netip = netibuf;
nfrontp = nbackp = netobuf;
progname = *argv;
#ifdef ENCRYPTION
nclearto = 0;
#endif
#ifdef _CRAY
/*
* Get number of pty's before trying to process options,
* which may include changing pty range.
*/
highpty = getnpty();
#endif /* CRAY */
while ((ch = getopt(argc, argv, valid_opts)) != -1) {
switch(ch) {
#ifdef AUTHENTICATION
case 'a':
/*
* Check for required authentication level
*/
if (strcmp(optarg, "debug") == 0) {
auth_debug_mode = 1;
} else if (strcasecmp(optarg, "none") == 0) {
auth_level = 0;
} else if (strcasecmp(optarg, "otp") == 0) {
auth_level = 0;
require_otp = 1;
} else if (strcasecmp(optarg, "other") == 0) {
auth_level = AUTH_OTHER;
} else if (strcasecmp(optarg, "user") == 0) {
auth_level = AUTH_USER;
} else if (strcasecmp(optarg, "valid") == 0) {
auth_level = AUTH_VALID;
} else if (strcasecmp(optarg, "off") == 0) {
/*
* This hack turns off authentication
*/
auth_level = -1;
} else {
fprintf(stderr,
"telnetd: unknown authorization level for -a\n");
}
break;
#endif /* AUTHENTICATION */
case 'B': /* BFTP mode is not supported any more */
break;
case 'd':
if (strcmp(optarg, "ebug") == 0) {
debug++;
break;
}
usage();
/* NOTREACHED */
break;
#ifdef DIAGNOSTICS
case 'D':
/*
* Check for desired diagnostics capabilities.
*/
if (!strcmp(optarg, "report")) {
diagnostic |= TD_REPORT|TD_OPTIONS;
} else if (!strcmp(optarg, "exercise")) {
diagnostic |= TD_EXERCISE;
} else if (!strcmp(optarg, "netdata")) {
diagnostic |= TD_NETDATA;
} else if (!strcmp(optarg, "ptydata")) {
diagnostic |= TD_PTYDATA;
} else if (!strcmp(optarg, "options")) {
diagnostic |= TD_OPTIONS;
} else {
usage();
/* NOT REACHED */
}
break;
#endif /* DIAGNOSTICS */
case 'h':
hostinfo = 0;
break;
case 'k': /* Linemode is not supported any more */
case 'l':
break;
case 'n':
keepalive = 0;
break;
#ifdef _CRAY
case 'r':
{
char *strchr();
char *c;
/*
* Allow the specification of alterations
* to the pty search range. It is legal to
* specify only one, and not change the
* other from its default.
*/
c = strchr(optarg, '-');
if (c) {
*c++ = '\0';
highpty = atoi(c);
}
if (*optarg != '\0')
lowpty = atoi(optarg);
if ((lowpty > highpty) || (lowpty < 0) ||
(highpty > 32767)) {
usage();
/* NOT REACHED */
}
break;
}
#endif /* CRAY */
case 'S':
#ifdef HAVE_PARSETOS
if ((tos = parsetos(optarg, "tcp")) < 0)
fprintf(stderr, "%s%s%s\n",
"telnetd: Bad TOS argument '", optarg,
"'; will try to use default TOS");
#else
fprintf(stderr, "%s%s\n", "TOS option unavailable; ",
"-S flag not supported\n");
#endif
break;
case 'u':
utmp_len = atoi(optarg);
break;
case 'U':
registerd_host_only = 1;
break;
#ifdef AUTHENTICATION
case 'X':
/*
* Check for invalid authentication types
*/
auth_disable_name(optarg);
break;
#endif
case 'y':
no_warn = 1;
break;
#ifdef AUTHENTICATION
case 'z':
log_unauth = 1;
break;
#endif /* AUTHENTICATION */
case 'L':
new_login = optarg;
break;
default:
fprintf(stderr, "telnetd: %c: unknown option\n", ch);
/* FALLTHROUGH */
case '?':
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
if (debug) {
int port = 0;
struct servent *sp;
if (argc > 1) {
usage ();
} else if (argc == 1) {
sp = roken_getservbyname (*argv, "tcp");
if (sp)
port = sp->s_port;
else
port = htons(atoi(*argv));
} else {
#ifdef KRB5
port = krb5_getportbyname (NULL, "telnet", "tcp", 23);
#else
port = k_getportbyname("telnet", "tcp", htons(23));
#endif
}
mini_inetd (port);
} else if (argc > 0) {
usage();
/* NOT REACHED */
}
#ifdef _SC_CRAY_SECURE_SYS
secflag = sysconf(_SC_CRAY_SECURE_SYS);
/*
* Get socket's security label
*/
if (secflag) {
int szss = sizeof(ss);
int sock_multi;
int szi = sizeof(int);
memset(&dv, 0, sizeof(dv));
if (getsysv(&sysv, sizeof(struct sysv)) != 0)
fatalperror(net, "getsysv");
/*
* Get socket security label and set device values
* {security label to be set on ttyp device}
*/
#ifdef SO_SEC_MULTI /* 8.0 code */
if ((getsockopt(0, SOL_SOCKET, SO_SECURITY,
(void *)&ss, &szss) < 0) ||
(getsockopt(0, SOL_SOCKET, SO_SEC_MULTI,
(void *)&sock_multi, &szi) < 0))
fatalperror(net, "getsockopt");
else {
dv.dv_actlvl = ss.ss_actlabel.lt_level;
dv.dv_actcmp = ss.ss_actlabel.lt_compart;
if (!sock_multi) {
dv.dv_minlvl = dv.dv_maxlvl = dv.dv_actlvl;
dv.dv_valcmp = dv.dv_actcmp;
} else {
dv.dv_minlvl = ss.ss_minlabel.lt_level;
dv.dv_maxlvl = ss.ss_maxlabel.lt_level;
dv.dv_valcmp = ss.ss_maxlabel.lt_compart;
}
dv.dv_devflg = 0;
}
#else /* SO_SEC_MULTI */ /* 7.0 code */
if (getsockopt(0, SOL_SOCKET, SO_SECURITY,
(void *)&ss, &szss) >= 0) {
dv.dv_actlvl = ss.ss_slevel;
dv.dv_actcmp = ss.ss_compart;
dv.dv_minlvl = ss.ss_minlvl;
dv.dv_maxlvl = ss.ss_maxlvl;
dv.dv_valcmp = ss.ss_maxcmp;
}
#endif /* SO_SEC_MULTI */
}
#endif /* _SC_CRAY_SECURE_SYS */
roken_openlog("telnetd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
sa_size = sizeof (__ss);
if (getpeername(STDIN_FILENO, sa, &sa_size) < 0) {
fprintf(stderr, "%s: ", progname);
perror("getpeername");
_exit(1);
}
if (keepalive &&
setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE,
(void *)&on, sizeof (on)) < 0) {
syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
}
#if defined(IPPROTO_IP) && defined(IP_TOS) && defined(HAVE_SETSOCKOPT)
{
# ifdef HAVE_GETTOSBYNAME
struct tosent *tp;
if (tos < 0 && (tp = gettosbyname("telnet", "tcp")))
tos = tp->t_tos;
# endif
if (tos < 0)
tos = 020; /* Low Delay bit */
if (tos
&& sa->sa_family == AF_INET
&& (setsockopt(STDIN_FILENO, IPPROTO_IP, IP_TOS,
(void *)&tos, sizeof(tos)) < 0)
&& (errno != ENOPROTOOPT) )
syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
}
#endif /* defined(IPPROTO_IP) && defined(IP_TOS) */
net = STDIN_FILENO;
doit(sa, sa_size);
/* NOTREACHED */
return 0;
} /* end of main */
static void
usage(void)
{
fprintf(stderr, "Usage: telnetd");
#ifdef AUTHENTICATION
fprintf(stderr, " [-a (debug|other|otp|user|valid|off|none)]\n\t");
#endif
fprintf(stderr, " [-debug]");
#ifdef DIAGNOSTICS
fprintf(stderr, " [-D (options|report|exercise|netdata|ptydata)]\n\t");
#endif
#ifdef AUTHENTICATION
fprintf(stderr, " [-edebug]");
#endif
fprintf(stderr, " [-h]");
fprintf(stderr, " [-L login]");
fprintf(stderr, " [-n]");
#ifdef _CRAY
fprintf(stderr, " [-r[lowpty]-[highpty]]");
#endif
fprintf(stderr, "\n\t");
#ifdef HAVE_GETTOSBYNAME
fprintf(stderr, " [-S tos]");
#endif
#ifdef AUTHENTICATION
fprintf(stderr, " [-X auth-type] [-y] [-z]");
#endif
fprintf(stderr, " [-u utmp_hostname_length] [-U]");
fprintf(stderr, " [port]\n");
exit(1);
}
/*
* getterminaltype
*
* Ask the other end to send along its terminal type and speed.
* Output is the variable terminaltype filled in.
*/
static unsigned char ttytype_sbbuf[] = {
IAC, SB, TELOPT_TTYPE, TELQUAL_SEND, IAC, SE
};
int
getterminaltype(char *name, size_t name_sz)
{
int retval = -1;
void _gettermname();
settimer(baseline);
#ifdef AUTHENTICATION
/*
* Handle the Authentication option before we do anything else.
*/
send_do(TELOPT_AUTHENTICATION, 1);
while (his_will_wont_is_changing(TELOPT_AUTHENTICATION))
ttloop();
if (his_state_is_will(TELOPT_AUTHENTICATION)) {
retval = auth_wait(name, name_sz);
}
#endif
#ifdef ENCRYPTION
send_will(TELOPT_ENCRYPT, 1);
send_do(TELOPT_ENCRYPT, 1); /* esc@magic.fi */
#endif
send_do(TELOPT_TTYPE, 1);
send_do(TELOPT_TSPEED, 1);
send_do(TELOPT_XDISPLOC, 1);
send_do(TELOPT_NEW_ENVIRON, 1);
send_do(TELOPT_OLD_ENVIRON, 1);
while (
#ifdef ENCRYPTION
his_do_dont_is_changing(TELOPT_ENCRYPT) ||
#endif
his_will_wont_is_changing(TELOPT_TTYPE) ||
his_will_wont_is_changing(TELOPT_TSPEED) ||
his_will_wont_is_changing(TELOPT_XDISPLOC) ||
his_will_wont_is_changing(TELOPT_NEW_ENVIRON) ||
his_will_wont_is_changing(TELOPT_OLD_ENVIRON)) {
ttloop();
}
#ifdef ENCRYPTION
/*
* Wait for the negotiation of what type of encryption we can
* send with. If autoencrypt is not set, this will just return.
*/
if (his_state_is_will(TELOPT_ENCRYPT)) {
encrypt_wait();
}
#endif
if (his_state_is_will(TELOPT_TSPEED)) {
static unsigned char sb[] =
{ IAC, SB, TELOPT_TSPEED, TELQUAL_SEND, IAC, SE };
telnet_net_write (sb, sizeof sb);
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
}
if (his_state_is_will(TELOPT_XDISPLOC)) {
static unsigned char sb[] =
{ IAC, SB, TELOPT_XDISPLOC, TELQUAL_SEND, IAC, SE };
telnet_net_write (sb, sizeof sb);
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
}
if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
static unsigned char sb[] =
{ IAC, SB, TELOPT_NEW_ENVIRON, TELQUAL_SEND, IAC, SE };
telnet_net_write (sb, sizeof sb);
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
}
else if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
static unsigned char sb[] =
{ IAC, SB, TELOPT_OLD_ENVIRON, TELQUAL_SEND, IAC, SE };
telnet_net_write (sb, sizeof sb);
DIAG(TD_OPTIONS, printsub('>', sb + 2, sizeof sb - 2););
}
if (his_state_is_will(TELOPT_TTYPE)) {
telnet_net_write (ttytype_sbbuf, sizeof ttytype_sbbuf);
DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
sizeof ttytype_sbbuf - 2););
}
if (his_state_is_will(TELOPT_TSPEED)) {
while (sequenceIs(tspeedsubopt, baseline))
ttloop();
}
if (his_state_is_will(TELOPT_XDISPLOC)) {
while (sequenceIs(xdisplocsubopt, baseline))
ttloop();
}
if (his_state_is_will(TELOPT_NEW_ENVIRON)) {
while (sequenceIs(environsubopt, baseline))
ttloop();
}
if (his_state_is_will(TELOPT_OLD_ENVIRON)) {
while (sequenceIs(oenvironsubopt, baseline))
ttloop();
}
if (his_state_is_will(TELOPT_TTYPE)) {
char first[256], last[256];
while (sequenceIs(ttypesubopt, baseline))
ttloop();
/*
* If the other side has already disabled the option, then
* we have to just go with what we (might) have already gotten.
*/
if (his_state_is_will(TELOPT_TTYPE) && !terminaltypeok(terminaltype)) {
strlcpy(first, terminaltype, sizeof(first));
for(;;) {
/*
* Save the unknown name, and request the next name.
*/
strlcpy(last, terminaltype, sizeof(last));
_gettermname();
if (terminaltypeok(terminaltype))
break;
if ((strncmp(last, terminaltype, sizeof(last)) == 0) ||
his_state_is_wont(TELOPT_TTYPE)) {
/*
* We've hit the end. If this is the same as
* the first name, just go with it.
*/
if (strncmp(first, terminaltype, sizeof(first)) == 0)
break;
/*
* Get the terminal name one more time, so that
* RFC1091 compliant telnets will cycle back to
* the start of the list.
*/
_gettermname();
if (strncmp(first, terminaltype, sizeof(first)) != 0)
strcpy(terminaltype, first);
break;
}
}
}
}
return(retval);
} /* end of getterminaltype */
void
_gettermname()
{
/*
* If the client turned off the option,
* we can't send another request, so we
* just return.
*/
if (his_state_is_wont(TELOPT_TTYPE))
return;
settimer(baseline);
telnet_net_write (ttytype_sbbuf, sizeof ttytype_sbbuf);
DIAG(TD_OPTIONS, printsub('>', ttytype_sbbuf + 2,
sizeof ttytype_sbbuf - 2););
while (sequenceIs(ttypesubopt, baseline))
ttloop();
}
int
terminaltypeok(char *s)
{
return 1;
}
char *hostname;
char host_name[MaxHostNameLen];
char remote_host_name[MaxHostNameLen];
/*
* Get a pty, scan input lines.
*/
static void
doit(struct sockaddr *who, int who_len)
{
char *host = NULL;
struct hostent *hp = NULL;
int level;
int ptynum;
char user_name[256];
int error;
char host_addr[256];
void *addr;
int addr_sz;
const char *tmp;
int af;
/*
* Find an available pty to use.
*/
ourpty = getpty(&ptynum);
if (ourpty < 0)
fatal(net, "All network ports in use");
#ifdef _SC_CRAY_SECURE_SYS
/*
* set ttyp line security label
*/
if (secflag) {
char slave_dev[16];
snprintf(tty_dev, sizeof(tty_dev), "/dev/pty/%03d", ptynum);
if (setdevs(tty_dev, &dv) < 0)
fatal(net, "cannot set pty security");
snprintf(slave_dev, sizeof(slave_dev), "/dev/ttyp%03d", ptynum);
if (setdevs(slave_dev, &dv) < 0)
fatal(net, "cannot set tty security");
}
#endif /* _SC_CRAY_SECURE_SYS */
af = who->sa_family;
switch (af) {
case AF_INET : {
struct sockaddr_in *sin = (struct sockaddr_in *)who;
addr = &sin->sin_addr;
addr_sz = sizeof(sin->sin_addr);
break;
}
#ifdef HAVE_IPV6
case AF_INET6 : {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)who;
addr = &sin6->sin6_addr;
addr_sz = sizeof(sin6->sin6_addr);
break;
}
#endif
default :
fatal (net, "Unknown address family\r\n");
break;
}
hp = getipnodebyaddr (addr, addr_sz, af, &error);
if (hp == NULL && registerd_host_only) {
fatal(net, "Couldn't resolve your address into a host name.\r\n\
Please contact your net administrator");
} else if (hp != NULL) {
host = hp->h_name;
}
tmp = inet_ntop(af, addr, host_addr, sizeof(host_addr));
if (tmp == NULL)
strlcpy (host_addr, "unknown address", sizeof(host_addr));
if (host == NULL)
host = host_addr;
/*
* We must make a copy because Kerberos is probably going
* to also do a gethost* and overwrite the static data...
*/
strlcpy(remote_host_name, host, sizeof(remote_host_name));
if (hp != NULL)
freehostent (hp);
host = remote_host_name;
/* XXX - should be k_gethostname? */
gethostname(host_name, sizeof (host_name));
hostname = host_name;
/* Only trim if too long (and possible) */
if (strlen(remote_host_name) > abs(utmp_len)) {
char *domain = strchr(host_name, '.');
char *p = strchr(remote_host_name, '.');
if (domain && p && (strcmp(p, domain) == 0))
*p = 0; /* remove domain part */
}
/*
* If hostname still doesn't fit utmp, use ipaddr.
*/
if (strlen(remote_host_name) > abs(utmp_len))
strlcpy(remote_host_name,
host_addr,
sizeof(remote_host_name));
#ifdef AUTHENTICATION
auth_encrypt_init(hostname, host, "TELNETD", 1);
#endif
init_env();
/*
* get terminal type.
*/
*user_name = 0;
level = getterminaltype(user_name, sizeof(user_name));
setenv("TERM", terminaltype ? terminaltype : "network", 1);
#ifdef _SC_CRAY_SECURE_SYS
if (secflag) {
if (setulvl(dv.dv_actlvl) < 0)
fatal(net,"cannot setulvl()");
if (setucmp(dv.dv_actcmp) < 0)
fatal(net, "cannot setucmp()");
}
#endif /* _SC_CRAY_SECURE_SYS */
/* begin server processing */
my_telnet(net, ourpty, host, level, user_name);
/*NOTREACHED*/
} /* end of doit */
/* output contents of /etc/issue.net, or /etc/issue */
static void
show_issue(void)
{
FILE *f;
char buf[128];
f = fopen("/etc/issue.net", "r");
if(f == NULL)
f = fopen("/etc/issue", "r");
if(f){
while(fgets(buf, sizeof(buf)-2, f)){
strcpy(buf + strcspn(buf, "\r\n"), "\r\n");
writenet((unsigned char*)buf, strlen(buf));
}
fclose(f);
}
}
/*
* Main loop. Select from pty and network, and
* hand data to telnet receiver finite state machine.
*/
void
my_telnet(int f, int p, char *host, int level, char *autoname)
{
int on = 1;
char *he;
char *IM;
int nfd;
int startslave_called = 0;
time_t timeout;
/*
* Initialize the slc mapping table.
*/
get_slc_defaults();
/*
* Do some tests where it is desireable to wait for a response.
* Rather than doing them slowly, one at a time, do them all
* at once.
*/
if (my_state_is_wont(TELOPT_SGA))
send_will(TELOPT_SGA, 1);
/*
* Is the client side a 4.2 (NOT 4.3) system? We need to know this
* because 4.2 clients are unable to deal with TCP urgent data.
*
* To find out, we send out a "DO ECHO". If the remote system
* answers "WILL ECHO" it is probably a 4.2 client, and we note
* that fact ("WILL ECHO" ==> that the client will echo what
* WE, the server, sends it; it does NOT mean that the client will
* echo the terminal input).
*/
send_do(TELOPT_ECHO, 1);
/*
* Send along a couple of other options that we wish to negotiate.
*/
send_do(TELOPT_NAWS, 1);
send_will(TELOPT_STATUS, 1);
flowmode = 1; /* default flow control state */
restartany = -1; /* uninitialized... */
send_do(TELOPT_LFLOW, 1);
/*
* Spin, waiting for a response from the DO ECHO. However,
* some REALLY DUMB telnets out there might not respond
* to the DO ECHO. So, we spin looking for NAWS, (most dumb
* telnets so far seem to respond with WONT for a DO that
* they don't understand...) because by the time we get the
* response, it will already have processed the DO ECHO.
* Kludge upon kludge.
*/
while (his_will_wont_is_changing(TELOPT_NAWS))
ttloop();
/*
* But...
* The client might have sent a WILL NAWS as part of its
* startup code; if so, we'll be here before we get the
* response to the DO ECHO. We'll make the assumption
* that any implementation that understands about NAWS
* is a modern enough implementation that it will respond
* to our DO ECHO request; hence we'll do another spin
* waiting for the ECHO option to settle down, which is
* what we wanted to do in the first place...
*/
if (his_want_state_is_will(TELOPT_ECHO) &&
his_state_is_will(TELOPT_NAWS)) {
while (his_will_wont_is_changing(TELOPT_ECHO))
ttloop();
}
/*
* On the off chance that the telnet client is broken and does not
* respond to the DO ECHO we sent, (after all, we did send the
* DO NAWS negotiation after the DO ECHO, and we won't get here
* until a response to the DO NAWS comes back) simulate the
* receipt of a will echo. This will also send a WONT ECHO
* to the client, since we assume that the client failed to
* respond because it believes that it is already in DO ECHO
* mode, which we do not want.
*/
if (his_want_state_is_will(TELOPT_ECHO)) {
DIAG(TD_OPTIONS,
{output_data("td: simulating recv\r\n");
});
willoption(TELOPT_ECHO);
}
/*
* Finally, to clean things up, we turn on our echo. This
* will break stupid 4.2 telnets out of local terminal echo.
*/
if (my_state_is_wont(TELOPT_ECHO))
send_will(TELOPT_ECHO, 1);
#ifdef TIOCPKT
#ifdef STREAMSPTY
if (!really_stream)
#endif
/*
* Turn on packet mode
*/
ioctl(p, TIOCPKT, (char *)&on);
#endif
/*
* Call telrcv() once to pick up anything received during
* terminal type negotiation, 4.2/4.3 determination, and
* linemode negotiation.
*/
telrcv();
ioctl(f, FIONBIO, (char *)&on);
ioctl(p, FIONBIO, (char *)&on);
#if defined(SO_OOBINLINE) && defined(HAVE_SETSOCKOPT)
setsockopt(net, SOL_SOCKET, SO_OOBINLINE,
(void *)&on, sizeof on);
#endif /* defined(SO_OOBINLINE) */
#ifdef SIGTSTP
signal(SIGTSTP, SIG_IGN);
#endif
#ifdef SIGTTOU
/*
* Ignoring SIGTTOU keeps the kernel from blocking us
* in ttioct() in /sys/tty.c.
*/
signal(SIGTTOU, SIG_IGN);
#endif
signal(SIGCHLD, cleanup);
#ifdef TIOCNOTTY
{
int t;
t = open(_PATH_TTY, O_RDWR);
if (t >= 0) {
ioctl(t, TIOCNOTTY, (char *)0);
close(t);
}
}
#endif
show_issue();
/*
* Show banner that getty never gave.
*
* We put the banner in the pty input buffer. This way, it
* gets carriage return null processing, etc., just like all
* other pty --> client data.
*/
if (getenv("USER"))
hostinfo = 0;
IM = DEFAULT_IM;
he = 0;
edithost(he, host_name);
if (hostinfo && *IM)
putf(IM, ptyibuf2);
if (pcc)
strncat(ptyibuf2, ptyip, pcc+1);
ptyip = ptyibuf2;
pcc = strlen(ptyip);
DIAG(TD_REPORT, {
output_data("td: Entering processing loop\r\n");
});
nfd = ((f > p) ? f : p) + 1;
timeout = time(NULL) + 5;
for (;;) {
fd_set ibits, obits, xbits;
int c;
/* wait for encryption to be turned on, but don't wait
indefinitely */
if(!startslave_called && (!encrypt_delay() || timeout > time(NULL))){
startslave_called = 1;
startslave(host, level, autoname);
}
if (ncc < 0 && pcc < 0)
break;
FD_ZERO(&ibits);
FD_ZERO(&obits);
FD_ZERO(&xbits);
if (f >= FD_SETSIZE
|| p >= FD_SETSIZE)
fatal(net, "fd too large");
/*
* Never look for input if there's still
* stuff in the corresponding output buffer
*/
if (nfrontp - nbackp || pcc > 0) {
FD_SET(f, &obits);
} else {
FD_SET(p, &ibits);
}
if (pfrontp - pbackp || ncc > 0) {
FD_SET(p, &obits);
} else {
FD_SET(f, &ibits);
}
if (!SYNCHing) {
FD_SET(f, &xbits);
}
if ((c = select(nfd, &ibits, &obits, &xbits,
(struct timeval *)0)) < 1) {
if (c == -1) {
if (errno == EINTR) {
continue;
}
}
sleep(5);
continue;
}
/*
* Any urgent data?
*/
if (FD_ISSET(net, &xbits)) {
SYNCHing = 1;
}
/*
* Something to read from the network...
*/
if (FD_ISSET(net, &ibits)) {
#ifndef SO_OOBINLINE
/*
* In 4.2 (and 4.3 beta) systems, the
* OOB indication and data handling in the kernel
* is such that if two separate TCP Urgent requests
* come in, one byte of TCP data will be overlaid.
* This is fatal for Telnet, but we try to live
* with it.
*
* In addition, in 4.2 (and...), a special protocol
* is needed to pick up the TCP Urgent data in
* the correct sequence.
*
* What we do is: if we think we are in urgent
* mode, we look to see if we are "at the mark".
* If we are, we do an OOB receive. If we run
* this twice, we will do the OOB receive twice,
* but the second will fail, since the second
* time we were "at the mark", but there wasn't
* any data there (the kernel doesn't reset
* "at the mark" until we do a normal read).
* Once we've read the OOB data, we go ahead
* and do normal reads.
*
* There is also another problem, which is that
* since the OOB byte we read doesn't put us
* out of OOB state, and since that byte is most
* likely the TELNET DM (data mark), we would
* stay in the TELNET SYNCH (SYNCHing) state.
* So, clocks to the rescue. If we've "just"
* received a DM, then we test for the
* presence of OOB data when the receive OOB
* fails (and AFTER we did the normal mode read
* to clear "at the mark").
*/
if (SYNCHing) {
int atmark;
ioctl(net, SIOCATMARK, (char *)&atmark);
if (atmark) {
ncc = recv(net, netibuf, sizeof (netibuf), MSG_OOB);
if ((ncc == -1) && (errno == EINVAL)) {
ncc = read(net, netibuf, sizeof (netibuf));
if (sequenceIs(didnetreceive, gotDM)) {
SYNCHing = stilloob(net);
}
}
} else {
ncc = read(net, netibuf, sizeof (netibuf));
}
} else {
ncc = read(net, netibuf, sizeof (netibuf));
}
settimer(didnetreceive);
#else /* !defined(SO_OOBINLINE)) */
ncc = read(net, netibuf, sizeof (netibuf));
#endif /* !defined(SO_OOBINLINE)) */
if (ncc < 0 && errno == EWOULDBLOCK)
ncc = 0;
else {
if (ncc <= 0) {
break;
}
netip = netibuf;
}
DIAG((TD_REPORT | TD_NETDATA), {
output_data("td: netread %d chars\r\n", ncc);
});
DIAG(TD_NETDATA, printdata("nd", netip, ncc));
}
/*
* Something to read from the pty...
*/
if (FD_ISSET(p, &ibits)) {
#ifdef STREAMSPTY
if (really_stream)
pcc = readstream(p, ptyibuf, BUFSIZ);
else
#endif
pcc = read(p, ptyibuf, BUFSIZ);
/*
* On some systems, if we try to read something
* off the master side before the slave side is
* opened, we get EIO.
*/
if (pcc < 0 && (errno == EWOULDBLOCK ||
#ifdef EAGAIN
errno == EAGAIN ||
#endif
errno == EIO)) {
pcc = 0;
} else {
if (pcc <= 0)
break;
if (ptyibuf[0] & TIOCPKT_FLUSHWRITE) {
netclear(); /* clear buffer back */
#ifndef NO_URGENT
/*
* There are client telnets on some
* operating systems get screwed up
* royally if we send them urgent
* mode data.
*/
output_data ("%c%c", IAC, DM);
neturg = nfrontp-1; /* off by one XXX */
DIAG(TD_OPTIONS,
printoption("td: send IAC", DM));
#endif
}
if (his_state_is_will(TELOPT_LFLOW) &&
(ptyibuf[0] &
(TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))) {
int newflow =
ptyibuf[0] & TIOCPKT_DOSTOP ? 1 : 0;
if (newflow != flowmode) {
flowmode = newflow;
output_data("%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
flowmode ? LFLOW_ON
: LFLOW_OFF,
IAC, SE);
DIAG(TD_OPTIONS, printsub('>',
(unsigned char *)nfrontp-4,
4););
}
}
pcc--;
ptyip = ptyibuf+1;
}
}
while (pcc > 0) {
if ((&netobuf[BUFSIZ] - nfrontp) < 3)
break;
c = *ptyip++ & 0377, pcc--;
if (c == IAC)
*nfrontp++ = c;
*nfrontp++ = c;
if ((c == '\r') && (my_state_is_wont(TELOPT_BINARY))) {
if (pcc > 0 && ((*ptyip & 0377) == '\n')) {
*nfrontp++ = *ptyip++ & 0377;
pcc--;
} else
*nfrontp++ = '\0';
}
}
if (FD_ISSET(f, &obits) && (nfrontp - nbackp) > 0)
netflush();
if (ncc > 0)
telrcv();
if (FD_ISSET(p, &obits) && (pfrontp - pbackp) > 0)
ptyflush();
}
cleanup(0);
}
#ifndef TCSIG
# ifdef TIOCSIG
# define TCSIG TIOCSIG
# endif
#endif
#ifdef STREAMSPTY
int flowison = -1; /* current state of flow: -1 is unknown */
int
readstream(int p, char *ibuf, int bufsize)
{
int flags = 0;
int ret = 0;
struct termios *tsp;
#if 0
struct termio *tp;
#endif
struct iocblk *ip;
char vstop, vstart;
int ixon;
int newflow;
strbufc.maxlen = BUFSIZ;
strbufc.buf = (char *)ctlbuf;
strbufd.maxlen = bufsize-1;
strbufd.len = 0;
strbufd.buf = ibuf+1;
ibuf[0] = 0;
ret = getmsg(p, &strbufc, &strbufd, &flags);
if (ret < 0) /* error of some sort -- probably EAGAIN */
return(-1);
if (strbufc.len <= 0 || ctlbuf[0] == M_DATA) {
/* data message */
if (strbufd.len > 0) { /* real data */
return(strbufd.len + 1); /* count header char */
} else {
/* nothing there */
errno = EAGAIN;
return(-1);
}
}
/*
* It's a control message. Return 1, to look at the flag we set
*/
switch (ctlbuf[0]) {
case M_FLUSH:
if (ibuf[1] & FLUSHW)
ibuf[0] = TIOCPKT_FLUSHWRITE;
return(1);
case M_IOCTL:
ip = (struct iocblk *) (ibuf+1);
switch (ip->ioc_cmd) {
#ifdef TCSETS
case TCSETS:
case TCSETSW:
case TCSETSF:
tsp = (struct termios *)
(ibuf+1 + sizeof(struct iocblk));
vstop = tsp->c_cc[VSTOP];
vstart = tsp->c_cc[VSTART];
ixon = tsp->c_iflag & IXON;
break;
#endif
#if 0
case TCSETA:
case TCSETAW:
case TCSETAF:
tp = (struct termio *) (ibuf+1 + sizeof(struct iocblk));
vstop = tp->c_cc[VSTOP];
vstart = tp->c_cc[VSTART];
ixon = tp->c_iflag & IXON;
break;
#endif
default:
errno = EAGAIN;
return(-1);
}
newflow = (ixon && (vstart == 021) && (vstop == 023)) ? 1 : 0;
if (newflow != flowison) { /* it's a change */
flowison = newflow;
ibuf[0] = newflow ? TIOCPKT_DOSTOP : TIOCPKT_NOSTOP;
return(1);
}
}
/* nothing worth doing anything about */
errno = EAGAIN;
return(-1);
}
#endif /* STREAMSPTY */
/*
* Send interrupt to process on other side of pty.
* If it is in raw mode, just write NULL;
* otherwise, write intr char.
*/
void
interrupt()
{
ptyflush(); /* half-hearted */
#if defined(STREAMSPTY) && defined(TIOCSIGNAL)
/* Streams PTY style ioctl to post a signal */
if (really_stream)
{
int sig = SIGINT;
ioctl(ourpty, TIOCSIGNAL, &sig);
ioctl(ourpty, I_FLUSH, FLUSHR);
}
#else
#ifdef TCSIG
ioctl(ourpty, TCSIG, (char *)SIGINT);
#else /* TCSIG */
init_termbuf();
*pfrontp++ = slctab[SLC_IP].sptr ?
(unsigned char)*slctab[SLC_IP].sptr : '\177';
#endif /* TCSIG */
#endif
}
/*
* Send quit to process on other side of pty.
* If it is in raw mode, just write NULL;
* otherwise, write quit char.
*/
void
sendbrk()
{
ptyflush(); /* half-hearted */
#ifdef TCSIG
ioctl(ourpty, TCSIG, (char *)SIGQUIT);
#else /* TCSIG */
init_termbuf();
*pfrontp++ = slctab[SLC_ABORT].sptr ?
(unsigned char)*slctab[SLC_ABORT].sptr : '\034';
#endif /* TCSIG */
}
void
sendsusp()
{
#ifdef SIGTSTP
ptyflush(); /* half-hearted */
# ifdef TCSIG
ioctl(ourpty, TCSIG, (char *)SIGTSTP);
# else /* TCSIG */
*pfrontp++ = slctab[SLC_SUSP].sptr ?
(unsigned char)*slctab[SLC_SUSP].sptr : '\032';
# endif /* TCSIG */
#endif /* SIGTSTP */
}
/*
* When we get an AYT, if ^T is enabled, use that. Otherwise,
* just send back "[Yes]".
*/
void
recv_ayt()
{
#if defined(SIGINFO) && defined(TCSIG)
if (slctab[SLC_AYT].sptr && *slctab[SLC_AYT].sptr != _POSIX_VDISABLE) {
ioctl(ourpty, TCSIG, (char *)SIGINFO);
return;
}
#endif
output_data("\r\n[Yes]\r\n");
}
void
doeof()
{
init_termbuf();
*pfrontp++ = slctab[SLC_EOF].sptr ?
(unsigned char)*slctab[SLC_EOF].sptr : '\004';
}