libvirt/tools/console.c

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/*
* console.c: A dumb serial console client
*
* Copyright (C) 2007, 2008 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Daniel Berrange <berrange@redhat.com>
*/
#include <config.h>
#ifndef __MINGW32__
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <poll.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include "console.h"
#include "internal.h"
#include "logging.h"
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#include "util.h"
/* ie Ctrl-] as per telnet */
#define CTRL_CLOSE_BRACKET '\35'
static int got_signal = 0;
static void do_signal(int sig ATTRIBUTE_UNUSED) {
got_signal = 1;
}
#ifndef HAVE_CFMAKERAW
static void
cfmakeraw (struct termios *attr)
{
attr->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
| INLCR | IGNCR | ICRNL | IXON);
attr->c_oflag &= ~OPOST;
attr->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
attr->c_cflag &= ~(CSIZE | PARENB);
attr->c_cflag |= CS8;
}
#endif /* !HAVE_CFMAKERAW */
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int vshRunConsole(const char *tty) {
int ttyfd, ret = -1;
struct termios ttyattr, rawattr;
void (*old_sigquit)(int);
void (*old_sigterm)(int);
void (*old_sigint)(int);
void (*old_sighup)(int);
void (*old_sigpipe)(int);
/* We do not want this to become the controlling TTY */
if ((ttyfd = open(tty, O_NOCTTY | O_RDWR)) < 0) {
VIR_ERROR(_("unable to open tty %s: %s\n"),
tty, strerror(errno));
return -1;
}
/* Put STDIN into raw mode so that stuff typed
does not echo to the screen (the TTY reads will
result in it being echoed back already), and
also ensure Ctrl-C, etc is blocked, and misc
other bits */
if (tcgetattr(STDIN_FILENO, &ttyattr) < 0) {
VIR_ERROR(_("unable to get tty attributes: %s\n"),
strerror(errno));
goto closetty;
}
rawattr = ttyattr;
cfmakeraw(&rawattr);
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &rawattr) < 0) {
VIR_ERROR(_("unable to set tty attributes: %s\n"),
strerror(errno));
goto closetty;
}
/* Trap all common signals so that we can safely restore
the original terminal settings on STDIN before the
process exits - people don't like being left with a
messed up terminal ! */
old_sigquit = signal(SIGQUIT, do_signal);
old_sigterm = signal(SIGTERM, do_signal);
old_sigint = signal(SIGINT, do_signal);
old_sighup = signal(SIGHUP, do_signal);
old_sigpipe = signal(SIGPIPE, do_signal);
got_signal = 0;
/* Now lets process STDIN & tty forever.... */
for (; !got_signal ;) {
unsigned int i;
struct pollfd fds[] = {
{ STDIN_FILENO, POLLIN, 0 },
{ ttyfd, POLLIN, 0 },
};
/* Wait for data to be available for reading on
STDIN or the tty */
if (poll(fds, (sizeof(fds)/sizeof(struct pollfd)), -1) < 0) {
if (got_signal)
goto cleanup;
if (errno == EINTR || errno == EAGAIN)
continue;
VIR_ERROR(_("failure waiting for I/O: %s\n"), strerror(errno));
goto cleanup;
}
for (i = 0 ; i < (sizeof(fds)/sizeof(struct pollfd)) ; i++) {
if (!fds[i].revents)
continue;
/* Process incoming data available for read */
if (fds[i].revents & POLLIN) {
char buf[4096];
int got, sent = 0, destfd;
if ((got = read(fds[i].fd, buf, sizeof(buf))) < 0) {
VIR_ERROR(_("failure reading input: %s\n"),
strerror(errno));
goto cleanup;
}
/* Quit if end of file, or we got the Ctrl-] key */
if (!got ||
(got == 1 &&
buf[0] == CTRL_CLOSE_BRACKET))
goto done;
/* Data from stdin goes to the TTY,
data from the TTY goes to STDOUT */
if (fds[i].fd == STDIN_FILENO)
destfd = ttyfd;
else
destfd = STDOUT_FILENO;
while (sent < got) {
int done;
if ((done = safewrite(destfd, buf + sent, got - sent))
<= 0) {
VIR_ERROR(_("failure writing output: %s\n"),
strerror(errno));
goto cleanup;
}
sent += done;
}
} else { /* Any other flag from poll is an error condition */
goto cleanup;
}
}
}
done:
ret = 0;
cleanup:
/* Restore original signal handlers */
signal(SIGQUIT, old_sigpipe);
signal(SIGQUIT, old_sighup);
signal(SIGQUIT, old_sigint);
signal(SIGQUIT, old_sigterm);
signal(SIGQUIT, old_sigquit);
/* Put STDIN back into the (sane?) state we found
it in before starting */
tcsetattr(STDIN_FILENO, TCSAFLUSH, &ttyattr);
closetty:
close(ttyfd);
return ret;
}
#endif /* !__MINGW32__ */