libvirt/tools/console.c
Peter Krempa e3b8808ba7 virsh: console: Avoid using stream after being freed.
The stream object wasn't set to NULL after freeing causing a double free
attempt on the cleanup path.
2012-08-03 13:33:18 +02:00

427 lines
12 KiB
C

/*
* console.c: A dumb serial console client
*
* Copyright (C) 2007-2008, 2010-2011 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, see
* <http://www.gnu.org/licenses/>.
*
* Daniel Berrange <berrange@redhat.com>
*/
#include <config.h>
#ifndef WIN32
# 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 <c-ctype.h>
# include "internal.h"
# include "console.h"
# include "logging.h"
# include "util.h"
# include "virfile.h"
# include "memory.h"
# include "threads.h"
# include "virterror_internal.h"
/*
* Convert given character to control character.
* Basically, we assume ASCII, and take lower 6 bits.
*/
# define CONTROL(c) ((c) ^ 0x40)
# define VIR_FROM_THIS VIR_FROM_NONE
struct virConsoleBuffer {
size_t length;
size_t offset;
char *data;
};
typedef struct virConsole virConsole;
typedef virConsole *virConsolePtr;
struct virConsole {
virStreamPtr st;
bool quit;
virMutex lock;
virCond cond;
int stdinWatch;
int stdoutWatch;
struct virConsoleBuffer streamToTerminal;
struct virConsoleBuffer terminalToStream;
char escapeChar;
};
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 */
static void
virConsoleShutdown(virConsolePtr con)
{
if (con->st) {
virStreamEventRemoveCallback(con->st);
virStreamAbort(con->st);
virStreamFree(con->st);
con->st = NULL;
}
VIR_FREE(con->streamToTerminal.data);
VIR_FREE(con->terminalToStream.data);
if (con->stdinWatch != -1)
virEventRemoveHandle(con->stdinWatch);
if (con->stdoutWatch != -1)
virEventRemoveHandle(con->stdoutWatch);
con->stdinWatch = -1;
con->stdoutWatch = -1;
con->quit = true;
virCondSignal(&con->cond);
}
static void
virConsoleEventOnStream(virStreamPtr st,
int events, void *opaque)
{
virConsolePtr con = opaque;
if (events & VIR_STREAM_EVENT_READABLE) {
size_t avail = con->streamToTerminal.length -
con->streamToTerminal.offset;
int got;
if (avail < 1024) {
if (VIR_REALLOC_N(con->streamToTerminal.data,
con->streamToTerminal.length + 1024) < 0) {
virReportOOMError();
virConsoleShutdown(con);
return;
}
con->streamToTerminal.length += 1024;
avail += 1024;
}
got = virStreamRecv(st,
con->streamToTerminal.data +
con->streamToTerminal.offset,
avail);
if (got == -2)
return; /* blocking */
if (got <= 0) {
virConsoleShutdown(con);
return;
}
con->streamToTerminal.offset += got;
if (con->streamToTerminal.offset)
virEventUpdateHandle(con->stdoutWatch,
VIR_EVENT_HANDLE_WRITABLE);
}
if (events & VIR_STREAM_EVENT_WRITABLE &&
con->terminalToStream.offset) {
ssize_t done;
size_t avail;
done = virStreamSend(con->st,
con->terminalToStream.data,
con->terminalToStream.offset);
if (done == -2)
return; /* blocking */
if (done < 0) {
virConsoleShutdown(con);
return;
}
memmove(con->terminalToStream.data,
con->terminalToStream.data + done,
con->terminalToStream.offset - done);
con->terminalToStream.offset -= done;
avail = con->terminalToStream.length - con->terminalToStream.offset;
if (avail > 1024) {
if (VIR_REALLOC_N(con->terminalToStream.data,
con->terminalToStream.offset + 1024) < 0)
{}
con->terminalToStream.length = con->terminalToStream.offset + 1024;
}
}
if (!con->terminalToStream.offset)
virStreamEventUpdateCallback(con->st,
VIR_STREAM_EVENT_READABLE);
if (events & VIR_STREAM_EVENT_ERROR ||
events & VIR_STREAM_EVENT_HANGUP) {
virConsoleShutdown(con);
}
}
static void
virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED,
int fd ATTRIBUTE_UNUSED,
int events,
void *opaque)
{
virConsolePtr con = opaque;
if (events & VIR_EVENT_HANDLE_READABLE) {
size_t avail = con->terminalToStream.length -
con->terminalToStream.offset;
int got;
if (avail < 1024) {
if (VIR_REALLOC_N(con->terminalToStream.data,
con->terminalToStream.length + 1024) < 0) {
virReportOOMError();
virConsoleShutdown(con);
return;
}
con->terminalToStream.length += 1024;
avail += 1024;
}
got = read(fd,
con->terminalToStream.data +
con->terminalToStream.offset,
avail);
if (got < 0) {
if (errno != EAGAIN) {
virConsoleShutdown(con);
}
return;
}
if (got == 0) {
virConsoleShutdown(con);
return;
}
if (con->terminalToStream.data[con->terminalToStream.offset] == con->escapeChar) {
virConsoleShutdown(con);
return;
}
con->terminalToStream.offset += got;
if (con->terminalToStream.offset)
virStreamEventUpdateCallback(con->st,
VIR_STREAM_EVENT_READABLE |
VIR_STREAM_EVENT_WRITABLE);
}
if (events & VIR_EVENT_HANDLE_ERROR ||
events & VIR_EVENT_HANDLE_HANGUP) {
virConsoleShutdown(con);
}
}
static void
virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED,
int fd,
int events,
void *opaque)
{
virConsolePtr con = opaque;
if (events & VIR_EVENT_HANDLE_WRITABLE &&
con->streamToTerminal.offset) {
ssize_t done;
size_t avail;
done = write(fd,
con->streamToTerminal.data,
con->streamToTerminal.offset);
if (done < 0) {
if (errno != EAGAIN) {
virConsoleShutdown(con);
}
return;
}
memmove(con->streamToTerminal.data,
con->streamToTerminal.data + done,
con->streamToTerminal.offset - done);
con->streamToTerminal.offset -= done;
avail = con->streamToTerminal.length - con->streamToTerminal.offset;
if (avail > 1024) {
if (VIR_REALLOC_N(con->streamToTerminal.data,
con->streamToTerminal.offset + 1024) < 0)
{}
con->streamToTerminal.length = con->streamToTerminal.offset + 1024;
}
}
if (!con->streamToTerminal.offset)
virEventUpdateHandle(con->stdoutWatch, 0);
if (events & VIR_EVENT_HANDLE_ERROR ||
events & VIR_EVENT_HANDLE_HANGUP) {
virConsoleShutdown(con);
}
}
static char
vshGetEscapeChar(const char *s)
{
if (*s == '^')
return CONTROL(c_toupper(s[1]));
return *s;
}
int vshMakeStdinRaw(struct termios *ttyattr, bool report_errors) {
struct termios rawattr;
if (tcgetattr(STDIN_FILENO, ttyattr) < 0) {
if (report_errors)
VIR_ERROR(_("unable to get tty attributes: %s"),
strerror(errno));
return -1;
}
rawattr = *ttyattr;
cfmakeraw(&rawattr);
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &rawattr) < 0) {
if (report_errors)
VIR_ERROR(_("unable to set tty attributes: %s"),
strerror(errno));
return -1;
}
return 0;
}
int vshRunConsole(virDomainPtr dom,
const char *dev_name,
const char *escape_seq,
unsigned int flags)
{
int ret = -1;
struct termios ttyattr;
void (*old_sigquit)(int);
void (*old_sigterm)(int);
void (*old_sigint)(int);
void (*old_sighup)(int);
void (*old_sigpipe)(int);
virConsolePtr con = NULL;
/* 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 (vshMakeStdinRaw(&ttyattr, true) < 0)
goto resettty;
/* 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;
if (VIR_ALLOC(con) < 0) {
virReportOOMError();
goto cleanup;
}
con->escapeChar = vshGetEscapeChar(escape_seq);
con->st = virStreamNew(virDomainGetConnect(dom),
VIR_STREAM_NONBLOCK);
if (!con->st)
goto cleanup;
if (virDomainOpenConsole(dom, dev_name, con->st, flags) < 0)
goto cleanup;
if (virCondInit(&con->cond) < 0 || virMutexInit(&con->lock) < 0)
goto cleanup;
con->stdinWatch = virEventAddHandle(STDIN_FILENO,
VIR_EVENT_HANDLE_READABLE,
virConsoleEventOnStdin,
con,
NULL);
con->stdoutWatch = virEventAddHandle(STDOUT_FILENO,
0,
virConsoleEventOnStdout,
con,
NULL);
virStreamEventAddCallback(con->st,
VIR_STREAM_EVENT_READABLE,
virConsoleEventOnStream,
con,
NULL);
while (!con->quit) {
if (virCondWait(&con->cond, &con->lock) < 0) {
VIR_ERROR(_("unable to wait on console condition"));
goto cleanup;
}
}
ret = 0;
cleanup:
if (con) {
if (con->st)
virStreamFree(con->st);
virMutexDestroy(&con->lock);
ignore_value(virCondDestroy(&con->cond));
VIR_FREE(con);
}
/* Restore original signal handlers */
signal(SIGPIPE, old_sigpipe);
signal(SIGHUP, old_sighup);
signal(SIGINT, old_sigint);
signal(SIGTERM, old_sigterm);
signal(SIGQUIT, old_sigquit);
resettty:
/* Put STDIN back into the (sane?) state we found
it in before starting */
tcsetattr(STDIN_FILENO, TCSAFLUSH, &ttyattr);
return ret;
}
#endif /* !WIN32 */