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freebsd-dev/libexec/telnetd/utility.c
Mark Murray aa71cb52b5 Feature merging and diff reduction between this code and crypto telnet. 
Also remove conditional (AUTHENTICATION) code as we have never compiled
it here, and it is doubtful that it even works in this scenario.
2001-08-20 12:12:27 +00:00

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/*
* 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.
*/
#ifndef lint
#if 0
static const char sccsid[] = "@(#)utility.c 8.4 (Berkeley) 5/30/95";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#ifdef __FreeBSD__
#include <locale.h>
#include <sys/utsname.h>
#endif
#include <string.h>
#define PRINTOPTIONS
#include "telnetd.h"
/*
* utility functions performing io related tasks
*/
/*
* ttloop
*
* A small subroutine to flush the network output buffer, get some data
* from the network, and pass it through the telnet state machine. We
* also flush the pty input buffer (by dropping its data) if it becomes
* too full.
*/
void
ttloop()
{
DIAG(TD_REPORT, output_data("td: ttloop\r\n"));
if (nfrontp - nbackp > 0) {
netflush();
}
ncc = read(net, netibuf, sizeof netibuf);
if (ncc < 0) {
syslog(LOG_INFO, "ttloop: read: %m");
exit(1);
} else if (ncc == 0) {
syslog(LOG_INFO, "ttloop: peer died: %m");
exit(1);
}
DIAG(TD_REPORT, output_data("td: ttloop read %d chars\r\n", ncc));
netip = netibuf;
telrcv(); /* state machine */
if (ncc > 0) {
pfrontp = pbackp = ptyobuf;
telrcv();
}
} /* end of ttloop */
/*
* Check a descriptor to see if out of band data exists on it.
*/
int
stilloob(s)
int s; /* socket number */
{
static struct timeval timeout = { 0 };
fd_set excepts;
int value;
do {
FD_ZERO(&excepts);
FD_SET(s, &excepts);
memset((char *)&timeout, 0, sizeof timeout);
value = select(s+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
} while ((value == -1) && (errno == EINTR));
if (value < 0) {
fatalperror(pty, "select");
}
if (FD_ISSET(s, &excepts)) {
return 1;
} else {
return 0;
}
}
void
ptyflush()
{
int n;
if ((n = pfrontp - pbackp) > 0) {
DIAG(TD_REPORT | TD_PTYDATA,
output_data("td: ptyflush %d chars\r\n", n));
DIAG(TD_PTYDATA, printdata("pd", pbackp, n));
n = write(pty, pbackp, n);
}
if (n < 0) {
if (errno == EWOULDBLOCK || errno == EINTR)
return;
cleanup(0);
}
pbackp += n;
if (pbackp == pfrontp)
pbackp = pfrontp = ptyobuf;
}
/*
* nextitem()
*
* Return the address of the next "item" in the TELNET data
* stream. This will be the address of the next character if
* the current address is a user data character, or it will
* be the address of the character following the TELNET command
* if the current address is a TELNET IAC ("I Am a Command")
* character.
*/
char *
nextitem(current)
char *current;
{
if ((*current&0xff) != IAC) {
return current+1;
}
switch (*(current+1)&0xff) {
case DO:
case DONT:
case WILL:
case WONT:
return current+3;
case SB: /* loop forever looking for the SE */
{
register char *look = current+2;
for (;;) {
if ((*look++&0xff) == IAC) {
if ((*look++&0xff) == SE) {
return look;
}
}
}
}
default:
return current+2;
}
} /* end of nextitem */
/*
* netclear()
*
* We are about to do a TELNET SYNCH operation. Clear
* the path to the network.
*
* Things are a bit tricky since we may have sent the first
* byte or so of a previous TELNET command into the network.
* So, we have to scan the network buffer from the beginning
* until we are up to where we want to be.
*
* A side effect of what we do, just to keep things
* simple, is to clear the urgent data pointer. The principal
* caller should be setting the urgent data pointer AFTER calling
* us in any case.
*/
void
netclear()
{
register char *thisitem, *next;
char *good;
#define wewant(p) ((nfrontp > p) && ((*p&0xff) == IAC) && \
((*(p+1)&0xff) != EC) && ((*(p+1)&0xff) != EL))
thisitem = netobuf;
while ((next = nextitem(thisitem)) <= nbackp) {
thisitem = next;
}
/* Now, thisitem is first before/at boundary. */
good = netobuf; /* where the good bytes go */
while (nfrontp > thisitem) {
if (wewant(thisitem)) {
int length;
next = thisitem;
do {
next = nextitem(next);
} while (wewant(next) && (nfrontp > next));
length = next-thisitem;
memmove(good, thisitem, length);
good += length;
thisitem = next;
} else {
thisitem = nextitem(thisitem);
}
}
nbackp = netobuf;
nfrontp = good; /* next byte to be sent */
neturg = 0;
} /* end of netclear */
/*
* netflush
* Send as much data as possible to the network,
* handling requests for urgent data.
*/
void
netflush()
{
int n;
extern int not42;
while ((n = nfrontp - nbackp) > 0) {
#if 0
/* XXX This causes output_data() to recurse and die */
DIAG(TD_REPORT, {
n += output_data("td: netflush %d chars\r\n", n);
});
#endif
/*
* if no urgent data, or if the other side appears to be an
* old 4.2 client (and thus unable to survive TCP urgent data),
* write the entire buffer in non-OOB mode.
*/
if ((neturg == 0) || (not42 == 0)) {
n = write(net, nbackp, n); /* normal write */
} else {
n = neturg - nbackp;
/*
* In 4.2 (and 4.3) systems, there is some question about
* what byte in a sendOOB operation is the "OOB" data.
* To make ourselves compatible, we only send ONE byte
* out of band, the one WE THINK should be OOB (though
* we really have more the TCP philosophy of urgent data
* rather than the Unix philosophy of OOB data).
*/
if (n > 1) {
n = send(net, nbackp, n-1, 0); /* send URGENT all by itself */
} else {
n = send(net, nbackp, n, MSG_OOB); /* URGENT data */
}
}
if (n == -1) {
if (errno == EWOULDBLOCK || errno == EINTR)
continue;
cleanup(0);
/* NOTREACHED */
}
nbackp += n;
if (nbackp >= neturg) {
neturg = 0;
}
if (nbackp == nfrontp) {
nbackp = nfrontp = netobuf;
}
}
return;
} /* end of netflush */
/*
* miscellaneous functions doing a variety of little jobs follow ...
*/
void
fatal(f, msg)
int f;
char *msg;
{
char buf[BUFSIZ];
(void) snprintf(buf, sizeof(buf), "telnetd: %s.\r\n", msg);
(void) write(f, buf, (int)strlen(buf));
sleep(1); /*XXX*/
exit(1);
}
void
fatalperror(f, msg)
int f;
char *msg;
{
char buf[BUFSIZ], *strerror();
(void) snprintf(buf, sizeof(buf), "%s: %s", msg, strerror(errno));
fatal(f, buf);
}
char editedhost[32];
void
edithost(pat, host)
register char *pat;
register char *host;
{
register char *res = editedhost;
if (!pat)
pat = "";
while (*pat) {
switch (*pat) {
case '#':
if (*host)
host++;
break;
case '@':
if (*host)
*res++ = *host++;
break;
default:
*res++ = *pat;
break;
}
if (res == &editedhost[sizeof editedhost - 1]) {
*res = '\0';
return;
}
pat++;
}
if (*host)
(void) strncpy(res, host,
sizeof editedhost - (res - editedhost) -1);
else
*res = '\0';
editedhost[sizeof editedhost - 1] = '\0';
}
static char *putlocation;
void
putstr(s)
register char *s;
{
while (*s)
putchr(*s++);
}
void
putchr(cc)
int cc;
{
*putlocation++ = cc;
}
#ifdef __FreeBSD__
static char fmtstr[] = { "%+" };
#else
/*
* This is split on two lines so that SCCS will not see the M
* between two % signs and expand it...
*/
static char fmtstr[] = { "%l:%M\
%P on %A, %d %B %Y" };
#endif
void
putf(cp, where)
register char *cp;
char *where;
{
char *slash;
time_t t;
char db[100];
#ifdef __FreeBSD__
static struct utsname kerninfo;
if (!*kerninfo.sysname)
uname(&kerninfo);
#endif
putlocation = where;
while (*cp) {
if (*cp =='\n') {
putstr("\r\n");
cp++;
continue;
} else if (*cp != '%') {
putchr(*cp++);
continue;
}
switch (*++cp) {
case 't':
#ifdef STREAMSPTY
/* names are like /dev/pts/2 -- we want pts/2 */
slash = strchr(line+1, '/');
#else
slash = strrchr(line, '/');
#endif
if (slash == (char *) 0)
putstr(line);
else
putstr(&slash[1]);
break;
case 'h':
putstr(editedhost);
break;
case 'd':
#ifdef __FreeBSD__
setlocale(LC_TIME, "");
#endif
(void)time(&t);
(void)strftime(db, sizeof(db), fmtstr, localtime(&t));
putstr(db);
break;
#ifdef __FreeBSD__
case 's':
putstr(kerninfo.sysname);
break;
case 'm':
putstr(kerninfo.machine);
break;
case 'r':
putstr(kerninfo.release);
break;
case 'v':
putstr(kerninfo.version);
break;
#endif
case '%':
putchr('%');
break;
}
cp++;
}
}
#ifdef DIAGNOSTICS
/*
* Print telnet options and commands in plain text, if possible.
*/
void
printoption(fmt, option)
register char *fmt;
register int option;
{
if (TELOPT_OK(option))
output_data("%s %s\r\n", fmt, TELOPT(option));
else if (TELCMD_OK(option))
output_data("%s %s\r\n", fmt, TELCMD(option));
else
output_data("%s %d\r\n", fmt, option);
return;
}
void
printsub(direction, pointer, length)
char direction; /* '<' or '>' */
unsigned char *pointer; /* where suboption data sits */
int length; /* length of suboption data */
{
register int i = 0;
if (!(diagnostic & TD_OPTIONS))
return;
if (direction) {
output_data("td: %s suboption ",
direction == '<' ? "recv" : "send");
if (length >= 3) {
register int j;
i = pointer[length-2];
j = pointer[length-1];
if (i != IAC || j != SE) {
output_data("(terminated by ");
if (TELOPT_OK(i))
output_data("%s ", TELOPT(i));
else if (TELCMD_OK(i))
output_data("%s ", TELCMD(i));
else
output_data("%d ", i);
if (TELOPT_OK(j))
output_data("%s", TELOPT(j));
else if (TELCMD_OK(j))
output_data("%s", TELCMD(j));
else
output_data("%d", j);
output_data(", not IAC SE!) ");
}
}
length -= 2;
}
if (length < 1) {
output_data("(Empty suboption??\?)");
return;
}
switch (pointer[0]) {
case TELOPT_TTYPE:
output_data("TERMINAL-TYPE ");
switch (pointer[1]) {
case TELQUAL_IS:
output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
break;
case TELQUAL_SEND:
output_data("SEND");
break;
default:
output_data(
"- unknown qualifier %d (0x%x).",
pointer[1], pointer[1]);
}
break;
case TELOPT_TSPEED:
output_data("TERMINAL-SPEED");
if (length < 2) {
output_data(" (empty suboption??\?)");
break;
}
switch (pointer[1]) {
case TELQUAL_IS:
output_data(" IS %.*s", length-2, (char *)pointer+2);
break;
default:
if (pointer[1] == 1)
output_data(" SEND");
else
output_data(" %d (unknown)", pointer[1]);
for (i = 2; i < length; i++) {
output_data(" ?%d?", pointer[i]);
}
break;
}
break;
case TELOPT_LFLOW:
output_data("TOGGLE-FLOW-CONTROL");
if (length < 2) {
output_data(" (empty suboption??\?)");
break;
}
switch (pointer[1]) {
case LFLOW_OFF:
output_data(" OFF"); break;
case LFLOW_ON:
output_data(" ON"); break;
case LFLOW_RESTART_ANY:
output_data(" RESTART-ANY"); break;
case LFLOW_RESTART_XON:
output_data(" RESTART-XON"); break;
default:
output_data(" %d (unknown)", pointer[1]);
}
for (i = 2; i < length; i++) {
output_data(" ?%d?", pointer[i]);
}
break;
case TELOPT_NAWS:
output_data("NAWS");
if (length < 2) {
output_data(" (empty suboption??\?)");
break;
}
if (length == 2) {
output_data(" ?%d?", pointer[1]);
break;
}
output_data(" %d %d (%d)",
pointer[1], pointer[2],
(int)((((unsigned int)pointer[1])<<8)|((unsigned int)pointer[2])));
if (length == 4) {
output_data(" ?%d?", pointer[3]);
break;
}
output_data(" %d %d (%d)",
pointer[3], pointer[4],
(int)((((unsigned int)pointer[3])<<8)|((unsigned int)pointer[4])));
for (i = 5; i < length; i++) {
output_data(" ?%d?", pointer[i]);
}
break;
case TELOPT_LINEMODE:
output_data("LINEMODE ");
if (length < 2) {
output_data(" (empty suboption??\?)");
break;
}
switch (pointer[1]) {
case WILL:
output_data("WILL ");
goto common;
case WONT:
output_data("WONT ");
goto common;
case DO:
output_data("DO ");
goto common;
case DONT:
output_data("DONT ");
common:
if (length < 3) {
output_data("(no option??\?)");
break;
}
switch (pointer[2]) {
case LM_FORWARDMASK:
output_data("Forward Mask");
for (i = 3; i < length; i++) {
output_data(" %x", pointer[i]);
}
break;
default:
output_data("%d (unknown)", pointer[2]);
for (i = 3; i < length; i++) {
output_data(" %d", pointer[i]);
}
break;
}
break;
case LM_SLC:
output_data("SLC");
for (i = 2; i < length - 2; i += 3) {
if (SLC_NAME_OK(pointer[i+SLC_FUNC]))
output_data(" %s", SLC_NAME(pointer[i+SLC_FUNC]));
else
output_data(" %d", pointer[i+SLC_FUNC]);
switch (pointer[i+SLC_FLAGS]&SLC_LEVELBITS) {
case SLC_NOSUPPORT:
output_data(" NOSUPPORT"); break;
case SLC_CANTCHANGE:
output_data(" CANTCHANGE"); break;
case SLC_VARIABLE:
output_data(" VARIABLE"); break;
case SLC_DEFAULT:
output_data(" DEFAULT"); break;
}
output_data("%s%s%s",
pointer[i+SLC_FLAGS]&SLC_ACK ? "|ACK" : "",
pointer[i+SLC_FLAGS]&SLC_FLUSHIN ? "|FLUSHIN" : "",
pointer[i+SLC_FLAGS]&SLC_FLUSHOUT ? "|FLUSHOUT" : "");
if (pointer[i+SLC_FLAGS]& ~(SLC_ACK|SLC_FLUSHIN|
SLC_FLUSHOUT| SLC_LEVELBITS)) {
output_data("(0x%x)", pointer[i+SLC_FLAGS]);
}
output_data(" %d;", pointer[i+SLC_VALUE]);
if ((pointer[i+SLC_VALUE] == IAC) &&
(pointer[i+SLC_VALUE+1] == IAC))
i++;
}
for (; i < length; i++) {
output_data(" ?%d?", pointer[i]);
}
break;
case LM_MODE:
output_data("MODE ");
if (length < 3) {
output_data("(no mode??\?)");
break;
}
{
char tbuf[32];
sprintf(tbuf, "%s%s%s%s%s",
pointer[2]&MODE_EDIT ? "|EDIT" : "",
pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "",
pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
pointer[2]&MODE_LIT_ECHO ? "|LIT_ECHO" : "",
pointer[2]&MODE_ACK ? "|ACK" : "");
output_data("%s", tbuf[1] ? &tbuf[1] : "0");
}
if (pointer[2]&~(MODE_EDIT|MODE_TRAPSIG|MODE_ACK)) {
output_data(" (0x%x)", pointer[2]);
}
for (i = 3; i < length; i++) {
output_data(" ?0x%x?", pointer[i]);
}
break;
default:
output_data("%d (unknown)", pointer[1]);
for (i = 2; i < length; i++) {
output_data(" %d", pointer[i]);
}
}
break;
case TELOPT_STATUS: {
register char *cp;
register int j, k;
output_data("STATUS");
switch (pointer[1]) {
default:
if (pointer[1] == TELQUAL_SEND)
output_data(" SEND");
else
output_data(" %d (unknown)", pointer[1]);
for (i = 2; i < length; i++) {
output_data(" ?%d?", pointer[i]);
}
break;
case TELQUAL_IS:
output_data(" IS\r\n");
for (i = 2; i < length; i++) {
switch(pointer[i]) {
case DO: cp = "DO"; goto common2;
case DONT: cp = "DONT"; goto common2;
case WILL: cp = "WILL"; goto common2;
case WONT: cp = "WONT"; goto common2;
common2:
i++;
if (TELOPT_OK(pointer[i]))
output_data(" %s %s", cp, TELOPT(pointer[i]));
else
output_data(" %s %d", cp, pointer[i]);
output_data("\r\n");
break;
case SB:
output_data(" SB ");
i++;
j = k = i;
while (j < length) {
if (pointer[j] == SE) {
if (j+1 == length)
break;
if (pointer[j+1] == SE)
j++;
else
break;
}
pointer[k++] = pointer[j++];
}
printsub(0, &pointer[i], k - i);
if (i < length) {
output_data(" SE");
i = j;
} else
i = j - 1;
output_data("\r\n");
break;
default:
output_data(" %d", pointer[i]);
break;
}
}
break;
}
break;
}
case TELOPT_XDISPLOC:
output_data("X-DISPLAY-LOCATION ");
switch (pointer[1]) {
case TELQUAL_IS:
output_data("IS \"%.*s\"", length-2, (char *)pointer+2);
break;
case TELQUAL_SEND:
output_data("SEND");
break;
default:
output_data("- unknown qualifier %d (0x%x).",
pointer[1], pointer[1]);
}
break;
case TELOPT_NEW_ENVIRON:
output_data("NEW-ENVIRON ");
goto env_common1;
case TELOPT_OLD_ENVIRON:
output_data("OLD-ENVIRON");
env_common1:
switch (pointer[1]) {
case TELQUAL_IS:
output_data("IS ");
goto env_common;
case TELQUAL_SEND:
output_data("SEND ");
goto env_common;
case TELQUAL_INFO:
output_data("INFO ");
env_common:
{
register int noquote = 2;
for (i = 2; i < length; i++ ) {
switch (pointer[i]) {
case NEW_ENV_VAR:
output_data("\" VAR " + noquote);
noquote = 2;
break;
case NEW_ENV_VALUE:
output_data("\" VALUE " + noquote);
noquote = 2;
break;
case ENV_ESC:
output_data("\" ESC " + noquote);
noquote = 2;
break;
case ENV_USERVAR:
output_data("\" USERVAR " + noquote);
noquote = 2;
break;
default:
if (isprint(pointer[i]) && pointer[i] != '"') {
if (noquote) {
output_data("\"");
noquote = 0;
}
output_data("%c", pointer[i]);
} else {
output_data("\" %03o " + noquote,
pointer[i]);
noquote = 2;
}
break;
}
}
if (!noquote)
output_data("\"");
break;
}
}
break;
default:
if (TELOPT_OK(pointer[0]))
output_data("%s (unknown)", TELOPT(pointer[0]));
else
output_data("%d (unknown)", pointer[i]);
for (i = 1; i < length; i++) {
output_data(" %d", pointer[i]);
}
break;
}
output_data("\r\n");
}
/*
* Dump a data buffer in hex and ascii to the output data stream.
*/
void
printdata(tag, ptr, cnt)
register char *tag;
register char *ptr;
register int cnt;
{
register int i;
char xbuf[30];
while (cnt) {
/* flush net output buffer if no room for new data) */
if ((&netobuf[BUFSIZ] - nfrontp) < 80) {
netflush();
}
/* add a line of output */
output_data("%s: ", tag);
for (i = 0; i < 20 && cnt; i++) {
output_data("%02x", *ptr);
if (isprint(*ptr)) {
xbuf[i] = *ptr;
} else {
xbuf[i] = '.';
}
if (i % 2) {
output_data(" ");
}
cnt--;
ptr++;
}
xbuf[i] = '\0';
output_data(" %s\r\n", xbuf );
}
}
#endif /* DIAGNOSTICS */
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