This fixes the main issues in virt-rescue and is usable. There are some enhancements which could be made (in follow up work): - An escape sequence and escape commands that could be handled by virt-rescue, eg. to shut down the appliance, mount or unmount filesystems. - `virt-rescue -i' could be implemented cleanly by performing the right API calls before handing control to the rescue shell. Rich.
Richard W.M. Jones
2017-Mar-03 12:27 UTC
[Libguestfs] [PATCH 1/5] generator: Deprecate direct mode (guestfs_set_direct, guestfs_get_direct).
---
generator/actions_properties.ml | 28 ----------------------------
generator/actions_properties_deprecated.ml | 30 ++++++++++++++++++++++++++++++
rescue/rescue.c | 3 +++
test-tool/test-tool.c | 1 -
4 files changed, 33 insertions(+), 29 deletions(-)
diff --git a/generator/actions_properties.ml b/generator/actions_properties.ml
index 8f6455b..87144b1 100644
--- a/generator/actions_properties.ml
+++ b/generator/actions_properties.ml
@@ -260,34 +260,6 @@ C<guestfs_set_event_callback>)." };
Return the command trace flag." };
{ defaults with
- name = "set_direct"; added = (1, 0, 72);
- style = RErr, [Bool "direct"], [];
- fish_alias = ["direct"]; config_only = true;
- blocking = false;
- shortdesc = "enable or disable direct appliance mode";
- longdesc = "\
-If the direct appliance mode flag is enabled, then stdin and
-stdout are passed directly through to the appliance once it
-is launched.
-
-One consequence of this is that log messages aren't caught
-by the library and handled by C<guestfs_set_log_message_callback>,
-but go straight to stdout.
-
-You probably don't want to use this unless you know what you
-are doing.
-
-The default is disabled." };
-
- { defaults with
- name = "get_direct"; added = (1, 0, 72);
- style = RBool "direct", [], [];
- blocking = false;
- shortdesc = "get direct appliance mode flag";
- longdesc = "\
-Return the direct appliance mode flag." };
-
- { defaults with
name = "set_recovery_proc"; added = (1, 0, 77);
style = RErr, [Bool "recoveryproc"], [];
fish_alias = ["recovery-proc"]; config_only = true;
diff --git a/generator/actions_properties_deprecated.ml
b/generator/actions_properties_deprecated.ml
index def17b9..5327782 100644
--- a/generator/actions_properties_deprecated.ml
+++ b/generator/actions_properties_deprecated.ml
@@ -125,6 +125,36 @@ Return the current backend.
See C<guestfs_set_backend> and L<guestfs(3)/BACKEND>." };
+ { defaults with
+ name = "set_direct"; added = (1, 0, 72);
+ style = RErr, [Bool "direct"], [];
+ deprecated_by = Deprecated_no_replacement;
+ fish_alias = ["direct"]; config_only = true;
+ blocking = false;
+ shortdesc = "enable or disable direct appliance mode";
+ longdesc = "\
+If the direct appliance mode flag is enabled, then stdin and
+stdout are passed directly through to the appliance once it
+is launched.
+
+One consequence of this is that log messages aren't caught
+by the library and handled by C<guestfs_set_log_message_callback>,
+but go straight to stdout.
+
+You probably don't want to use this unless you know what you
+are doing.
+
+The default is disabled." };
+
+ { defaults with
+ name = "get_direct"; added = (1, 0, 72);
+ style = RBool "direct", [], [];
+ deprecated_by = Deprecated_no_replacement;
+ blocking = false;
+ shortdesc = "get direct appliance mode flag";
+ longdesc = "\
+Return the direct appliance mode flag." };
+
]
let daemon_functions = [
diff --git a/rescue/rescue.c b/rescue/rescue.c
index ed40ba6..572a844 100644
--- a/rescue/rescue.c
+++ b/rescue/rescue.c
@@ -295,9 +295,12 @@ main (int argc, char *argv[])
usage (EXIT_FAILURE);
}
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
/* Setting "direct mode" is required for the rescue appliance. */
if (guestfs_set_direct (g, 1) == -1)
exit (EXIT_FAILURE);
+#pragma GCC diagnostic pop
{
/* The libvirt backend doesn't support direct mode. As a temporary
diff --git a/test-tool/test-tool.c b/test-tool/test-tool.c
index 20e2a32..2ae266d 100644
--- a/test-tool/test-tool.c
+++ b/test-tool/test-tool.c
@@ -224,7 +224,6 @@ main (int argc, char *argv[])
p = guestfs_get_cachedir (g);
printf ("guestfs_get_cachedir: %s\n", p ? : "(null)");
free (p);
- printf ("guestfs_get_direct: %d\n", guestfs_get_direct (g));
p = guestfs_get_hv (g);
printf ("guestfs_get_hv: %s\n", p);
free (p);
--
2.9.3
Richard W.M. Jones
2017-Mar-03 12:27 UTC
[Libguestfs] [PATCH 2/5] New API: internal-get-console-socket to support virt-rescue.
This API intended for use by virt-rescue only gets the file descriptor
of the console socket.
---
generator/actions_core.ml | 11 +++++++
generator/actions_properties_deprecated.ml | 4 +--
lib/Makefile.am | 1 +
lib/conn-socket.c | 16 +++++++++-
lib/guestfs-internal.h | 3 ++
lib/rescue.c | 47 ++++++++++++++++++++++++++++++
6 files changed, 79 insertions(+), 3 deletions(-)
create mode 100644 lib/rescue.c
diff --git a/generator/actions_core.ml b/generator/actions_core.ml
index ed89f74..765a7fe 100644
--- a/generator/actions_core.ml
+++ b/generator/actions_core.ml
@@ -1722,6 +1722,17 @@ call it returns a simple true/false boolean result,
instead
of throwing an exception if a feature is not found. For
other documentation see C<guestfs_available>." };
+ { defaults with
+ name = "internal_get_console_socket"; added = (1, 37, 1);
+ style = RInt "fd", [], [];
+ visibility = VInternal;
+ test_excuse = "writing to the socket may block";
+ shortdesc = "get the appliance console socket";
+ longdesc = "\
+This call is used by L<virt-rescue(1)> to write directly to
+appliance console (for passing through keystrokes). It should
+not normally be used by other libguestfs users." };
+
]
let daemon_functions = [
diff --git a/generator/actions_properties_deprecated.ml
b/generator/actions_properties_deprecated.ml
index 5327782..f36509e 100644
--- a/generator/actions_properties_deprecated.ml
+++ b/generator/actions_properties_deprecated.ml
@@ -128,7 +128,7 @@ See C<guestfs_set_backend> and
L<guestfs(3)/BACKEND>." };
{ defaults with
name = "set_direct"; added = (1, 0, 72);
style = RErr, [Bool "direct"], [];
- deprecated_by = Deprecated_no_replacement;
+ deprecated_by = Replaced_by "internal_get_console_socket";
fish_alias = ["direct"]; config_only = true;
blocking = false;
shortdesc = "enable or disable direct appliance mode";
@@ -149,7 +149,7 @@ The default is disabled." };
{ defaults with
name = "get_direct"; added = (1, 0, 72);
style = RBool "direct", [], [];
- deprecated_by = Deprecated_no_replacement;
+ deprecated_by = Replaced_by "internal_get_console_socket";
blocking = false;
shortdesc = "get direct appliance mode flag";
longdesc = "\
diff --git a/lib/Makefile.am b/lib/Makefile.am
index e1ab1bf..774274b 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -116,6 +116,7 @@ libguestfs_la_SOURCES = \
private-data.c \
proto.c \
qemu.c \
+ rescue.c \
stringsbuf.c \
structs-compare.c \
structs-copy.c \
diff --git a/lib/conn-socket.c b/lib/conn-socket.c
index 4e1f781..43f5e67 100644
--- a/lib/conn-socket.c
+++ b/lib/conn-socket.c
@@ -1,5 +1,5 @@
/* libguestfs
- * Copyright (C) 2013 Red Hat Inc.
+ * Copyright (C) 2013-2017 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
@@ -396,6 +396,19 @@ handle_log_message (guestfs_h *g,
return 1;
}
+static int
+get_console_sock (guestfs_h *g, struct connection *connv)
+{
+ struct connection_socket *conn = (struct connection_socket *) connv;
+
+ if (conn->console_sock == -1) {
+ error (g, _("console socket not connected"));
+ return -1;
+ }
+
+ return conn->console_sock;
+}
+
static void
free_conn_socket (guestfs_h *g, struct connection *connv)
{
@@ -417,6 +430,7 @@ static struct connection_ops ops = {
.read_data = read_data,
.write_data = write_data,
.can_read_data = can_read_data,
+ .get_console_sock = get_console_sock,
};
/**
diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
index 7126b88..5e9d97c 100644
--- a/lib/guestfs-internal.h
+++ b/lib/guestfs-internal.h
@@ -373,6 +373,9 @@ struct connection_ops {
* Returns: 1 = yes, 0 = no, -1 = error
*/
int (*can_read_data) (guestfs_h *g, struct connection *);
+
+ /* Get the console socket (to support virt-rescue). */
+ int (*get_console_sock) (guestfs_h *g, struct connection *);
};
/**
diff --git a/lib/rescue.c b/lib/rescue.c
new file mode 100644
index 0000000..ae7811a
--- /dev/null
+++ b/lib/rescue.c
@@ -0,0 +1,47 @@
+/* libguestfs
+ * Copyright (C) 2017 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 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * Support for virt-rescue(1).
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <libintl.h>
+
+#include "guestfs.h"
+#include "guestfs-internal.h"
+#include "guestfs-internal-actions.h"
+
+int
+guestfs_impl_internal_get_console_socket (guestfs_h *g)
+{
+ if (!g->conn) {
+ error (g, _("no console socket, the handle must be launched"));
+ return -1;
+ }
+
+ if (!g->conn->ops->get_console_sock)
+ NOT_SUPPORTED (g, -1,
+ _("connection class does not support getting the console
socket"));
+
+ return g->conn->ops->get_console_sock (g, g->conn);
+}
--
2.9.3
Richard W.M. Jones
2017-Mar-03 12:27 UTC
[Libguestfs] [PATCH 3/5] appliance: Fix job control in virt-rescue.
See comment and link to busybox FAQ for explanation.
---
appliance/init | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/appliance/init b/appliance/init
index 8be27a2..bb8b709 100755
--- a/appliance/init
+++ b/appliance/init
@@ -177,6 +177,10 @@ if ! test "$guestfs_rescue" = 1; then
else
# Run virt-rescue shell.
+ # Get name of the serial port, from console= passed by libguestfs.
+ guestfs_serial=$(grep -Eo 'console=[^[:space:]]+' /proc/cmdline |
+ sed s/console=//)
+
# Remove LD_PRELOAD=libSegFault set above.
unset LD_PRELOAD
@@ -185,6 +189,16 @@ else
echo "PS1='><rescue> '" >> $HOME/.bashrc
echo "export TERM PS1" >> $HOME/.bashrc
+ # The shell is opened by default on /dev/console, which (on Linux)
+ # is not a controlling terminal, causing job control to fail. For
+ # how we work around this, see:
+ # https://busybox.net/FAQ.html#job_control
+ run_bash_with_ctty ()
+ {
+ setsid bash -c \
+ "exec bash </dev/$guestfs_serial >/dev/$guestfs_serial
2>&1"
+ }
+
echo
echo "------------------------------------------------------------"
echo
@@ -194,7 +208,7 @@ else
echo "You have to mount the guest's partitions under /sysroot"
echo "before you can examine them."
echo
- bash -i
+ run_bash_with_ctty
echo
echo "virt-rescue: Syncing the disk now before exiting ..."
echo
--
2.9.3
Richard W.M. Jones
2017-Mar-03 12:27 UTC
[Libguestfs] [PATCH 4/5] lib: Return EPIPE for "appliance closed the connection unexpectedly".
---
lib/errors.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/lib/errors.c b/lib/errors.c
index c2af611..ace6a89 100644
--- a/lib/errors.c
+++ b/lib/errors.c
@@ -358,12 +358,15 @@ void
guestfs_int_unexpected_close_error (guestfs_h *g)
{
if (g->verbose)
- error (g, _("appliance closed the connection unexpectedly, see earlier
error messages"));
+ guestfs_int_error_errno (g, EPIPE,
+ _("appliance closed the connection
unexpectedly, "
+ "see earlier error messages"));
else
- error (g, _(
- "appliance closed the connection unexpectedly.\n"
- "This usually means the libguestfs appliance crashed.\n"
- DEBUG_ADVICE));
+ guestfs_int_error_errno (g, EPIPE,
+ _("appliance closed the connection
unexpectedly.\n"
+ "This usually means the libguestfs
appliance "
+ "crashed.\n"
+ DEBUG_ADVICE));
}
/**
--
2.9.3
Richard W.M. Jones
2017-Mar-03 12:27 UTC
[Libguestfs] [PATCH 5/5] rescue: Modify virt-rescue so it doesn't use direct mode (RHBZ#1152819, RHBZ#1171654).
Instead of using "direct mode" (which was basically a quick hack),
virt-rescue now launches the appliance with a running daemon.
The daemon doesn't do much -- there is still a bash shell which the
user interacts with. The daemon is there simply to provide the
initial GUESTFS_LAUNCH_FLAG message and to handle shutdown a bit more
gracefully.
To interact with the shell, and replacing direct mode, virt-rescue now
prints out log messages (the output of the shell), and sends input
typed by the user directly to the console socket. This uses the
guestfs_internal_get_console_socket API added previously. Most of the
complexity behind this is hidden in virt-rescue.
This fully fixes the handling of ^C (RHBZ#1152819). Also there were
earlier reports that full screen commands like 'vim' didn't work
well,
(RHBZ#1171654), but in this version vim appears to work fine, albeit
only using 80x24 of the screen because of the serial console.
---
appliance/init | 101 ++++++++++-----------
rescue/Makefile.am | 1 +
rescue/rescue.c | 253 ++++++++++++++++++++++++++++++++++++++++++++---------
3 files changed, 263 insertions(+), 92 deletions(-)
diff --git a/appliance/init b/appliance/init
index bb8b709..fa42c2b 100755
--- a/appliance/init
+++ b/appliance/init
@@ -159,59 +159,62 @@ if test "$guestfs_verbose" = 1 && test
"$guestfs_boot_analysis" != 1; then
echo -n "uptime: "; cat /proc/uptime
fi
-if ! test "$guestfs_rescue" = 1; then
- # Run the daemon.
- cmd="guestfsd"
- eval `grep -Eo 'guestfs_channel=[^[:space:]]+' /proc/cmdline`
- if test "x$guestfs_channel" != "x"; then
+# Run the daemon.
+cmd="guestfsd"
+eval `grep -Eo 'guestfs_channel=[^[:space:]]+' /proc/cmdline`
+if test "x$guestfs_channel" != "x"; then
cmd="$cmd --channel $guestfs_channel"
- fi
- if test "$guestfs_verbose" = 1; then
+fi
+if test "$guestfs_verbose" = 1; then
cmd="$cmd --verbose"
- fi
- if test "$guestfs_network" = 1; then
+fi
+if test "$guestfs_network" = 1; then
cmd="$cmd --network"
- fi
- echo $cmd
- $cmd
+fi
+if ! test "$guestfs_rescue" = 1; then
+ echo $cmd
+ $cmd
else
- # Run virt-rescue shell.
-
- # Get name of the serial port, from console= passed by libguestfs.
- guestfs_serial=$(grep -Eo 'console=[^[:space:]]+' /proc/cmdline |
- sed s/console=//)
-
- # Remove LD_PRELOAD=libSegFault set above.
- unset LD_PRELOAD
-
- :> $HOME/.bashrc
- grep -Eo 'TERM=[^[:space:]]+' /proc/cmdline >> $HOME/.bashrc
- echo "PS1='><rescue> '" >> $HOME/.bashrc
- echo "export TERM PS1" >> $HOME/.bashrc
-
- # The shell is opened by default on /dev/console, which (on Linux)
- # is not a controlling terminal, causing job control to fail. For
- # how we work around this, see:
- # https://busybox.net/FAQ.html#job_control
- run_bash_with_ctty ()
- {
- setsid bash -c \
- "exec bash </dev/$guestfs_serial >/dev/$guestfs_serial
2>&1"
- }
-
- echo
- echo "------------------------------------------------------------"
- echo
- echo "Welcome to virt-rescue, the libguestfs rescue shell."
- echo
- echo "Note: The contents of / are the rescue appliance."
- echo "You have to mount the guest's partitions under /sysroot"
- echo "before you can examine them."
- echo
- run_bash_with_ctty
- echo
- echo "virt-rescue: Syncing the disk now before exiting ..."
- echo
+ # Run virt-rescue shell.
+
+ # We need a daemon, even in virt-rescue.
+ $cmd &
+
+ # Get name of the serial port, from console= passed by libguestfs.
+ guestfs_serial=$(grep -Eo 'console=[^[:space:]]+' /proc/cmdline |
+ sed s/console=//)
+
+ # Remove LD_PRELOAD=libSegFault set above.
+ unset LD_PRELOAD
+
+ :> $HOME/.bashrc
+ grep -Eo 'TERM=[^[:space:]]+' /proc/cmdline >> $HOME/.bashrc
+ echo "PS1='><rescue> '" >> $HOME/.bashrc
+ echo "export TERM PS1" >> $HOME/.bashrc
+
+ # The shell is opened by default on /dev/console, which (on Linux)
+ # is not a controlling terminal, causing job control to fail. For
+ # how we work around this, see:
+ # https://busybox.net/FAQ.html#job_control
+ run_bash_with_ctty ()
+ {
+ setsid bash -c \
+ "exec bash </dev/$guestfs_serial >/dev/$guestfs_serial
2>&1"
+ }
+
+ echo
+ echo
"------------------------------------------------------------"
+ echo
+ echo "Welcome to virt-rescue, the libguestfs rescue shell."
+ echo
+ echo "Note: The contents of / (root) are the rescue appliance."
+ echo "You have to mount the guest's partitions under
/sysroot"
+ echo "before you can examine them."
+ echo
+ run_bash_with_ctty
+ echo
+ echo "virt-rescue: Syncing the disk now before exiting ..."
+ echo
fi
sync
diff --git a/rescue/Makefile.am b/rescue/Makefile.am
index 7919aaf..99d4b79 100644
--- a/rescue/Makefile.am
+++ b/rescue/Makefile.am
@@ -30,6 +30,7 @@ virt_rescue_SOURCES = \
virt_rescue_CPPFLAGS = \
-DGUESTFS_WARN_DEPRECATED=1 \
+ -DGUESTFS_PRIVATE=1 \
-DLOCALEBASEDIR=\""$(datadir)/locale"\" \
-I$(top_srcdir)/common/utils -I$(top_builddir)/common/utils \
-I$(top_srcdir)/lib -I$(top_builddir)/lib \
diff --git a/rescue/rescue.c b/rescue/rescue.c
index 572a844..8c8bced 100644
--- a/rescue/rescue.c
+++ b/rescue/rescue.c
@@ -26,18 +26,24 @@
#include <getopt.h>
#include <errno.h>
#include <error.h>
+#include <termios.h>
+#include <poll.h>
#include <locale.h>
#include <assert.h>
#include <libintl.h>
+#include "full-write.h"
+#include "getprogname.h"
#include "ignore-value.h"
#include "xvasprintf.h"
-#include "getprogname.h"
#include "guestfs.h"
#include "options.h"
#include "display-options.h"
+static void log_message_callback (guestfs_h *g, void *opaque, uint64_t event,
int event_handle, int flags, const char *buf, size_t buf_len, const uint64_t
*array, size_t array_len);
+static void do_rescue (int sock);
+static void restore_tty (void);
static void add_scratch_disks (int n, struct drv **drvs);
static void do_suggestion (struct drv *drvs);
@@ -54,6 +60,9 @@ int inspector = 0;
int in_guestfish = 0;
int in_virt_rescue = 1;
+/* Old terminal settings. */
+static struct termios old_termios;
+
static void __attribute__((noreturn))
usage (int status)
{
@@ -135,6 +144,9 @@ main (int argc, char *argv[])
int memsize = 0;
int smp = 0;
int suggest = 0;
+ char *append_full;
+ int sock;
+ struct termios termios;
g = guestfs_create ();
if (g == NULL)
@@ -295,30 +307,6 @@ main (int argc, char *argv[])
usage (EXIT_FAILURE);
}
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
- /* Setting "direct mode" is required for the rescue appliance. */
- if (guestfs_set_direct (g, 1) == -1)
- exit (EXIT_FAILURE);
-#pragma GCC diagnostic pop
-
- {
- /* The libvirt backend doesn't support direct mode. As a temporary
- * workaround, force the appliance backend, but warn about it.
- */
- CLEANUP_FREE char *backend = guestfs_get_backend (g);
- if (backend) {
- if (STREQ (backend, "libvirt") ||
- STRPREFIX (backend, "libvirt:")) {
- fprintf (stderr, _("%s: warning: virt-rescue doesn't work with
the libvirt backend\n"
- "at the moment. As a workaround, forcing
backend = 'direct'.\n"),
- getprogname ());
- if (guestfs_set_backend (g, "direct") == -1)
- exit (EXIT_FAILURE);
- }
- }
- }
-
/* Set other features. */
if (memsize > 0)
if (guestfs_set_memsize (g, memsize) == -1)
@@ -330,16 +318,15 @@ main (int argc, char *argv[])
if (guestfs_set_smp (g, smp) == -1)
exit (EXIT_FAILURE);
- {
- /* Kernel command line must include guestfs_rescue=1 (see
- * appliance/init) as well as other options.
- */
- CLEANUP_FREE char *append_full = xasprintf
("guestfs_rescue=1%s%s",
- append ? " " :
"",
- append ? append :
"");
- if (guestfs_set_append (g, append_full) == -1)
- exit (EXIT_FAILURE);
- }
+ /* Kernel command line must include guestfs_rescue=1 (see
+ * appliance/init) as well as other options.
+ */
+ append_full = xasprintf ("guestfs_rescue=1%s%s",
+ append ? " " : "",
+ append ? append : "");
+ if (guestfs_set_append (g, append_full) == -1)
+ exit (EXIT_FAILURE);
+ free (append_full);
/* Add drives. */
add_drives (drvs, 'a');
@@ -347,20 +334,200 @@ main (int argc, char *argv[])
/* Free up data structures, no longer needed after this point. */
free_drives (drvs);
- /* Run the appliance. This won't return until the user quits the
- * appliance.
+ /* Add an event handler to print "log messages". These will be the
+ * output of the appliance console during launch and shutdown.
+ * After launch, we will read the console messages directly from the
+ * socket and they won't be passed through the event callback.
*/
- if (!verbose)
- guestfs_set_error_handler (g, NULL, NULL);
+ if (guestfs_set_event_callback (g, log_message_callback,
+ GUESTFS_EVENT_APPLIANCE, 0, NULL) == -1)
+ exit (EXIT_FAILURE);
- /* We expect launch to fail, so ignore the return value, and don't
- * bother with explicit guestfs_shutdown either.
+ /* Run the appliance. */
+ if (guestfs_launch (g) == -1)
+ exit (EXIT_FAILURE);
+
+ sock = guestfs_internal_get_console_socket (g);
+ if (sock == -1)
+ exit (EXIT_FAILURE);
+
+ /* Put stdin in raw mode so that we can receive ^C and other
+ * special keys.
*/
- ignore_value (guestfs_launch (g));
+ if (tcgetattr (STDIN_FILENO, &termios) == -1) {
+ perror ("tcgetattr: stdin");
+ exit (EXIT_FAILURE);
+ }
+ old_termios = termios;
+ cfmakeraw (&termios);
+ if (tcsetattr (STDIN_FILENO, TCSANOW, &termios) == -1) {
+ perror ("tcsetattr: stdin");
+ exit (EXIT_FAILURE);
+ }
+ /* Restore the tty settings when the process exits. */
+ atexit (restore_tty);
+
+ do_rescue (sock);
+
+ /* Shut down the appliance. */
+ guestfs_push_error_handler (g, NULL, NULL);
+ if (guestfs_shutdown (g) == -1) {
+ const char *err;
+
+ /* Ignore "appliance closed the connection unexpectedly" since
+ * this can happen if the user reboots the appliance.
+ */
+ if (guestfs_last_errno (g) == EPIPE)
+ goto next;
+
+ /* Otherwise it's a real error. */
+ err = guestfs_last_error (g);
+ fprintf (stderr, "libguestfs: error: %s\n", err);
+ exit (EXIT_FAILURE);
+ }
+ next:
+ guestfs_pop_error_handler (g);
guestfs_close (g);
- exit (EXIT_SUCCESS);
+ exit (EXIT_SUCCESS); /* implicitly calls restore_tty */
+}
+
+static void
+log_message_callback (guestfs_h *g, void *opaque, uint64_t event,
+ int event_handle, int flags,
+ const char *buf, size_t buf_len,
+ const uint64_t *array, size_t array_len)
+{
+ if (buf_len > 0) {
+ ignore_value (full_write (STDOUT_FILENO, buf, buf_len));
+ }
+}
+
+/* This is the main loop for virt-rescue. We read and write
+ * directly to the console socket.
+ */
+#define BUFSIZE 4096
+static char rbuf[BUFSIZE]; /* appliance -> local tty */
+static char wbuf[BUFSIZE]; /* local tty -> appliance */
+
+static void
+do_rescue (int sock)
+{
+ size_t rlen = 0;
+ size_t wlen = 0;
+
+ while (sock >= 0 || rlen > 0) {
+ struct pollfd fds[3];
+ nfds_t nfds = 2;
+ int r;
+ ssize_t n;
+
+ fds[0].fd = STDIN_FILENO;
+ fds[0].events = 0;
+ if (BUFSIZE-wlen > 0)
+ fds[0].events = POLLIN;
+ fds[0].revents = 0;
+
+ fds[1].fd = STDOUT_FILENO;
+ fds[1].events = 0;
+ if (rlen > 0)
+ fds[1].events |= POLLOUT;
+ fds[1].revents = 0;
+
+ if (sock >= 0) {
+ fds[2].fd = sock;
+ fds[2].events = 0;
+ if (BUFSIZE-rlen > 0)
+ fds[2].events |= POLLIN;
+ if (wlen > 0)
+ fds[2].events |= POLLOUT;
+ fds[2].revents = 0;
+ nfds++;
+ }
+
+ r = poll (fds, nfds, -1);
+ if (r == -1) {
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ perror ("poll");
+ return;
+ }
+
+ /* Input from local tty. */
+ if ((fds[0].revents & POLLIN) != 0) {
+ assert (BUFSIZE-wlen > 0);
+ n = read (STDIN_FILENO, wbuf+wlen, BUFSIZE-wlen);
+ if (n == -1) {
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ perror ("read");
+ return;
+ }
+ if (n == 0) {
+ /* We don't expect this to happen. Maybe the whole tty went away?
+ * Anyway, we should exit as soon as possible.
+ */
+ return;
+ }
+ if (n > 0)
+ wlen += n;
+ }
+
+ /* Log message from appliance. */
+ if (nfds > 2 && (fds[2].revents & POLLIN) != 0) {
+ assert (BUFSIZE-rlen > 0);
+ n = read (sock, rbuf+rlen, BUFSIZE-rlen);
+ if (n == -1) {
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ if (errno == ECONNRESET)
+ goto appliance_closed;
+ perror ("read");
+ return;
+ }
+ if (n == 0) {
+ appliance_closed:
+ sock = -1;
+ /* Don't actually close the socket, because it's owned by
+ * the guestfs handle.
+ */
+ continue;
+ }
+ if (n > 0)
+ rlen += n;
+ }
+
+ /* Write log messages to local tty. */
+ if ((fds[1].revents & POLLOUT) != 0) {
+ assert (rlen > 0);
+ n = write (STDOUT_FILENO, rbuf, rlen);
+ if (n == -1) {
+ perror ("write");
+ continue;
+ }
+ rlen -= n;
+ memmove (rbuf, rbuf+n, rlen);
+ }
+
+ /* Write commands to the appliance. */
+ if (nfds > 2 && (fds[2].revents & POLLOUT) != 0) {
+ assert (wlen > 0);
+ n = write (sock, wbuf, wlen);
+ if (n == -1) {
+ perror ("write");
+ continue;
+ }
+ wlen -= n;
+ memmove (wbuf, wbuf+n, wlen);
+ }
+ }
+}
+
+static void
+restore_tty (void)
+{
+ tcsetattr (STDIN_FILENO, TCSANOW, &old_termios);
}
static void suggest_filesystems (void);
--
2.9.3