Date: Mon, 18 May 1998 16:43:28 -0700 From: Paul Traina <pst@juniper.net> To: Greg Lehey <grog@lemis.com> Cc: Bruce Evans <bde@zeta.org.au>, regnauld@deepo.prosa.dk, current@FreeBSD.ORG, julian@whistle.com, scrappy@hub.org Subject: Re: Serial console, system hangs and DDB... Message-ID: <199805182343.QAA00587@base.juniper.net> In-Reply-To: Your message of "Tue, 19 May 1998 08:54:27 %2B0930." <19980519085427.E427@freebie.lemis.com>
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In message <19980519085427.E427@freebie.lemis.com>, Greg Lehey writes:
> On Mon, 18 May 1998 at 13:31:44 -0700, Paul Traina wrote:
> > I modified ours to send { IAC, BREAK } on a particular key sequence,
> > which made the terminal server send a break.
> >
> > If you're right on a tty line, I think you just have it set baudrate to 0
> > for a moment.
>
> That's right.
>
> Do you have code?
> Greg
> --
> See complete headers for address and phone numbers
> finger grog@lemis.com for PGP public key
/* Serial interface for raw TCP connections on Un*x like systems
Copyright 1992, 1993 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "serial.h"
#include <sys/types.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include "signals.h"
#include "gdb_string.h"
#include "gdbcmd.h"
#define TELCMDS
#include <arpa/telnet.h>
static int tcp_telnet_mode = 0;
struct tcp_ttystate
{
int bogus;
};
static int tcp_open PARAMS ((serial_t scb, const char *name));
static void tcp_raw PARAMS ((serial_t scb));
static int wait_for PARAMS ((serial_t scb, int timeout));
static int tcp_readchar PARAMS ((serial_t scb, int timeout));
static int tcp_setbaudrate PARAMS ((serial_t scb, int rate));
static int tcp_setstopbits PARAMS ((serial_t scb, int num));
static int tcp_write PARAMS ((serial_t scb, const char *str, int len));
/* FIXME: static void tcp_restore PARAMS ((serial_t scb)); */
static void tcp_close PARAMS ((serial_t scb));
static serial_ttystate tcp_get_tty_state PARAMS ((serial_t scb));
static int tcp_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
/* Open up a raw tcp socket */
static int
tcp_open(scb, name)
serial_t scb;
const char *name;
{
char *port_str;
int port;
struct hostent *hostent;
struct sockaddr_in sockaddr;
int tmp;
char hostname[100];
struct protoent *protoent;
int i;
port_str = strchr (name, ':');
if (!port_str)
error ("tcp_open: No colon in host name!"); /* Shouldn't ever happen */
tmp = min (port_str - name, (int) sizeof hostname - 1);
strncpy (hostname, name, tmp); /* Don't want colon */
hostname[tmp] = '\000'; /* Tie off host name */
port = atoi (port_str + 1);
hostent = gethostbyname (hostname);
if (!hostent)
{
fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
errno = ENOENT;
return -1;
}
for (i = 1; i <= 15; i++)
{
scb->fd = socket (PF_INET, SOCK_STREAM, 0);
if (scb->fd < 0)
return -1;
/* Allow rapid reuse of this port. */
tmp = 1;
setsockopt (scb->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&tmp, sizeof(tmp));
/* Enable TCP keep alive process. */
tmp = 1;
setsockopt (scb->fd, SOL_SOCKET, SO_KEEPALIVE, (char *)&tmp, sizeof(tmp));
sockaddr.sin_family = PF_INET;
sockaddr.sin_port = htons(port);
memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
sizeof (struct in_addr));
if (!connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof(sockaddr)))
break;
close (scb->fd);
scb->fd = -1;
/* We retry for ECONNREFUSED because that is often a temporary condition, which
happens when the server is being restarted. */
if (errno != ECONNREFUSED)
return -1;
sleep (1);
}
protoent = getprotobyname ("tcp");
if (!protoent)
return -1;
tmp = 1;
if (setsockopt (scb->fd, protoent->p_proto, TCP_NODELAY,
(char *)&tmp, sizeof(tmp)))
return -1;
signal(SIGPIPE, SIG_IGN); /* If we don't do this, then GDB simply exits
when the remote side dies. */
return 0;
}
static serial_ttystate
tcp_get_tty_state(scb)
serial_t scb;
{
struct tcp_ttystate *state;
state = (struct tcp_ttystate *)xmalloc(sizeof *state);
return (serial_ttystate)state;
}
static int
tcp_set_tty_state(scb, ttystate)
serial_t scb;
serial_ttystate ttystate;
{
struct tcp_ttystate *state;
state = (struct tcp_ttystate *)ttystate;
return 0;
}
static int
tcp_return_0 (scb)
serial_t scb;
{
return 0;
}
static void
tcp_raw(scb)
serial_t scb;
{
return; /* Always in raw mode */
}
/* Wait for input on scb, with timeout seconds. Returns 0 on success,
otherwise SERIAL_TIMEOUT or SERIAL_ERROR.
For termio{s}, we actually just setup VTIME if necessary, and let the
timeout occur in the read() in tcp_read().
*/
static int
wait_for(scb, timeout)
serial_t scb;
int timeout;
{
int numfds;
struct timeval tv;
fd_set readfds, exceptfds;
FD_ZERO (&readfds);
FD_ZERO (&exceptfds);
tv.tv_sec = timeout;
tv.tv_usec = 0;
FD_SET(scb->fd, &readfds);
FD_SET(scb->fd, &exceptfds);
while (1)
{
if (timeout >= 0)
numfds = select(scb->fd+1, &readfds, 0, &exceptfds, &tv);
else
numfds = select(scb->fd+1, &readfds, 0, &exceptfds, 0);
if (numfds <= 0)
if (numfds == 0)
return SERIAL_TIMEOUT;
else if (errno == EINTR)
continue;
else
return SERIAL_ERROR; /* Got an error from select or poll */
return 0;
}
}
static int
telnet_cleanup_char (u_char c, int *state)
{
if (*state == 0) { /* starting out */
if (c == IAC) {
*state = IAC; /* in IAC start */
return 0;
}
return 1; /* move write pointer one character */
} else if (*state == IAC) {
if (c == IAC) {
*state = 0; /* IAC IAC = quoted real IAC char */
return 1; /* don't move write pointer at all */
}
if (!TELCMD_OK(c) || (c < SB))
*state = 0; /* illegal or a 2 byte IAC */
else
*state = c;
return 0;
} else { /* inside a 3 byte command */
*state = 0;
return 0; /* back up over IAC, COMMAND, and byte */
}
}
static int
telnet_cleanse (char *dst, int dstlen, const char *src, int srclen)
{
static int state = 0;
const char *sp;
char *dp;
for (sp = src, dp = dst; (dp - dst >= dstlen) && srclen--; sp++) {
*dp = *sp;
dp += telnet_cleanup_char((u_char) *sp, &state);
}
return dp - dst;
}
/* Read a character with user-specified timeout. TIMEOUT is number of seconds
to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns
char if successful. Returns -2 if timeout expired, EOF if line dropped
dead, or -3 for any other error (see errno in that case). */
static int
tcp_readchar(scb, timeout)
serial_t scb;
int timeout;
{
int status;
if (scb->bufcnt-- > 0)
return *scb->bufp++;
status = wait_for(scb, timeout);
if (status < 0)
return status;
while (1)
{
scb->bufcnt = read(scb->fd, scb->buf, BUFSIZ);
if (scb->bufcnt != -1 || errno != EINTR)
break;
}
if (scb->bufcnt <= 0)
if (scb->bufcnt == 0)
return SERIAL_TIMEOUT; /* 0 chars means timeout [may need to
distinguish between EOF & timeouts
someday] */
else
return SERIAL_ERROR; /* Got an error from read */
if (tcp_telnet_mode)
scb->bufcnt = telnet_cleanse(scb->buf, BUFSIZ, scb->buf, scb->bufcnt);
scb->bufcnt--;
scb->bufp = scb->buf;
return *scb->bufp++;
}
static int
tcp_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
serial_t scb;
serial_ttystate new_ttystate;
serial_ttystate old_ttystate;
{
return 0;
}
static void
tcp_print_tty_state (scb, ttystate)
serial_t scb;
serial_ttystate ttystate;
{
/* Nothing to print. */
return;
}
static int
tcp_setbaudrate(scb, rate)
serial_t scb;
int rate;
{
return 0; /* Never fails! */
}
static int
tcp_setstopbits(scb, num)
serial_t scb;
int num;
{
return 0; /* Never fails! */
}
static int
tcp_write(scb, str, len)
serial_t scb;
const char *str;
int len;
{
int cc;
while (len > 0)
{
cc = write(scb->fd, str, len);
if (cc < 0)
return 1;
len -= cc;
str += cc;
}
return 0;
}
static int
tcp_send_break(scb)
serial_t scb;
{
static const char iac_brk[] = { IAC, BREAK };
fprintf(stderr, "\n[TCP BREAK SENT]\n");
return (write(scb->fd, iac_brk, sizeof(iac_brk)) != sizeof(iac_brk));
}
static void
tcp_close(scb)
serial_t scb;
{
if (scb->fd < 0)
return;
close(scb->fd);
scb->fd = -1;
}
static struct serial_ops tcp_ops =
{
"tcp",
0,
tcp_open,
tcp_close,
tcp_readchar,
tcp_write,
tcp_return_0, /* flush output */
tcp_return_0, /* flush input */
tcp_send_break, /* send break */
tcp_raw,
tcp_get_tty_state,
tcp_set_tty_state,
tcp_print_tty_state,
tcp_noflush_set_tty_state,
tcp_setbaudrate,
tcp_setstopbits,
};
void
_initialize_ser_tcp ()
{
serial_add_interface (&tcp_ops);
add_show_from_set (add_set_cmd ("remotetcptelnet", no_class,
var_zinteger, (char *)&tcp_telnet_mode,
"Set whether tcp socket understands telnet protocol.\n",
&setlist), &showlist);
}
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