END_TEST
START_TEST (encode_supports_telnet_iac_test) {
register unsigned int i;
int res;
const char *charset, *encoding;
const char *non_iac_encodings[] = {
"cp1251",
"cp866",
"iso-8859-1",
"koi8-r",
"windows-1251",
NULL
};
res = pr_encode_supports_telnet_iac();
fail_unless(res == TRUE, "Expected TRUE, got %d", res);
charset = "us-ascii";
for (i = 0; non_iac_encodings[i]; i++) {
encoding = non_iac_encodings[i];
res = pr_encode_set_charset_encoding(charset, encoding);
fail_unless(res == 0, "Failed to set charset '%s', encoding '%s': %s",
charset, encoding, strerror(errno));
res = pr_encode_supports_telnet_iac();
fail_unless(res == FALSE, "Expected FALSE, got %d", res);
}
encoding = "utf-8";
res = pr_encode_set_charset_encoding(charset, encoding);
fail_unless(res == 0, "Failed to set charset '%s', encoding '%s': %s",
charset, encoding, strerror(errno));
}
char *pr_netio_telnet_gets(char *buf, size_t buflen,
pr_netio_stream_t *in_nstrm, pr_netio_stream_t *out_nstrm) {
char *bp = buf;
unsigned char cp;
int toread, handle_iac = TRUE, saw_newline = FALSE;
pr_buffer_t *pbuf = NULL;
if (buflen == 0 ||
in_nstrm == NULL ||
out_nstrm == NULL) {
errno = EINVAL;
return NULL;
}
#ifdef PR_USE_NLS
handle_iac = pr_encode_supports_telnet_iac();
#endif /* PR_USE_NLS */
buflen--;
if (in_nstrm->strm_buf) {
pbuf = in_nstrm->strm_buf;
} else {
pbuf = pr_netio_buffer_alloc(in_nstrm);
}
while (buflen > 0) {
pr_signals_handle();
/* Is the buffer empty? */
if (pbuf->current == NULL ||
pbuf->remaining == pbuf->buflen) {
toread = pr_netio_read(in_nstrm, pbuf->buf,
(buflen < pbuf->buflen ? buflen : pbuf->buflen), 1);
if (toread <= 0) {
if (bp != buf) {
*bp = '\0';
return buf;
}
return NULL;
}
pbuf->remaining = pbuf->buflen - toread;
pbuf->current = pbuf->buf;
/* Before we begin iterating through the data read in from the
* network, handing any Telnet characters and such, generate an event
* for any listeners which may want to examine this data as well.
*/
pr_event_generate("core.ctrl-read", pbuf);
}
toread = pbuf->buflen - pbuf->remaining;
while (buflen > 0 &&
toread > 0 &&
*pbuf->current != '\n' &&
toread--) {
pr_signals_handle();
cp = *pbuf->current++;
pbuf->remaining++;
if (handle_iac == TRUE) {
switch (telnet_mode) {
case TELNET_IAC:
switch (cp) {
case TELNET_WILL:
case TELNET_WONT:
case TELNET_DO:
case TELNET_DONT:
case TELNET_IP:
case TELNET_DM:
/* Why do we do this crazy thing where we set the "telnet mode"
* to be the action, and let the while loop, on the next pass,
* handle that action? It's because we don't know, right now,
* whether there actually a "next byte" in the input buffer.
* There _should_ be -- but we can't be sure. And that next
* byte is needed for properly responding with WONT/DONT
* responses.
*/
telnet_mode = cp;
continue;
case TELNET_IAC:
/* In this case, we know that the previous byte was TELNET_IAC,
* and that the current byte is another TELNET_IAC. The
* first TELNET_IAC thus "escapes" the second, telling us
* that the current byte (TELNET_IAC) should be written out
* as is (Bug#3697).
*/
telnet_mode = 0;
break;
default:
/* In this case, we know that the previous byte was TELNET_IAC,
* but the current byte is not a value we care about. So
* write the TELNET_IAC into the output buffer, break out of
* of the switch, and let that handle the writing of the
* current byte into the output buffer.
*/
*bp++ = TELNET_IAC;
buflen--;
telnet_mode = 0;
break;
}
break;
case TELNET_WILL:
case TELNET_WONT:
pr_netio_printf(out_nstrm, "%c%c%c", TELNET_IAC, TELNET_DONT, cp);
telnet_mode = 0;
continue;
case TELNET_DO:
case TELNET_DONT:
pr_netio_printf(out_nstrm, "%c%c%c", TELNET_IAC, TELNET_WONT, cp);
telnet_mode = 0;
continue;
case TELNET_IP:
case TELNET_DM:
default:
if (cp == TELNET_IAC) {
telnet_mode = cp;
continue;
}
break;
}
}
/* In the situation where the previous byte was an IAC, we wrote IAC
* into the output buffer, and decremented buflen (size of the output
* buffer remaining). Thus we need to check here if buflen is zero,
* before trying to decrement buflen again (and possibly underflowing
* the buflen size_t data type).
*/
if (buflen == 0) {
break;
}
*bp++ = cp;
buflen--;
}
if (buflen > 0 &&
toread > 0 &&
*pbuf->current == '\n') {
buflen--;
toread--;
*bp++ = *pbuf->current++;
pbuf->remaining++;
saw_newline = TRUE;
break;
}
if (toread == 0) {
/* No more input? Set pbuf->current to null, so that at the top of
* the loop, we read more.
*/
pbuf->current = NULL;
}
}
if (!saw_newline) {
/* If we haven't seen a newline, then assume the client is deliberately
* sending a too-long command, trying to exploit buffer sizes and make
* the server make some possibly bad assumptions.
*/
properly_terminated_prev_command = FALSE;
errno = E2BIG;
return NULL;
}
if (!properly_terminated_prev_command) {
properly_terminated_prev_command = TRUE;
pr_log_pri(PR_LOG_NOTICE, "client sent too-long command, ignoring");
errno = E2BIG;
return NULL;
}
properly_terminated_prev_command = TRUE;
*bp = '\0';
return buf;
}
