monitor: Rework early disk password inquiry (Jan Kiszka)

Reading the passwords for encrypted hard disks during early startup is
broken (I guess for quiet a while now):
 - No monitor terminal is ready for input at this point
 - Forcing all mux'ed terminals into monitor mode can confuse other
   users of that channels

To overcome these issues and to lay the ground for a clean decoupling of
monitor terminals, this patch changes the initial password inquiry as
follows:
 - Prevent autostart if there is some encrypted disk
 - Once the user tries to resume the VM, prompt for all missing
   passwords
 - Only resume if all passwords were accepted

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6707 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aliguori 2009-03-05 23:01:01 +00:00
parent 430eb509d2
commit c0f4ce7751
8 changed files with 85 additions and 65 deletions

14
block.c
View File

@ -336,6 +336,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
bs->read_only = 0;
bs->is_temporary = 0;
bs->encrypted = 0;
bs->valid_key = 0;
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
@ -966,6 +967,15 @@ int bdrv_is_encrypted(BlockDriverState *bs)
return bs->encrypted;
}
int bdrv_key_required(BlockDriverState *bs)
{
BlockDriverState *backing_hd = bs->backing_hd;
if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
return 1;
return (bs->encrypted && !bs->valid_key);
}
int bdrv_set_key(BlockDriverState *bs, const char *key)
{
int ret;
@ -978,7 +988,9 @@ int bdrv_set_key(BlockDriverState *bs, const char *key)
}
if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
return -1;
return bs->drv->bdrv_set_key(bs, key);
ret = bs->drv->bdrv_set_key(bs, key);
bs->valid_key = (ret == 0);
return ret;
}
void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)

View File

@ -103,8 +103,6 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
BlockDriverCompletionFunc *cb, void *opaque);
void bdrv_aio_cancel(BlockDriverAIOCB *acb);
int qemu_key_check(BlockDriverState *bs, const char *name);
/* Ensure contents are flushed to disk. */
void bdrv_flush(BlockDriverState *bs);
void bdrv_flush_all(void);
@ -144,7 +142,9 @@ BlockDriverState *bdrv_find(const char *name);
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs),
void *opaque);
int bdrv_is_encrypted(BlockDriverState *bs);
int bdrv_key_required(BlockDriverState *bs);
int bdrv_set_key(BlockDriverState *bs, const char *key);
int bdrv_query_missing_keys(void);
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
void *opaque);
const char *bdrv_get_device_name(BlockDriverState *bs);

View File

@ -96,6 +96,7 @@ struct BlockDriverState {
int removable; /* if true, the media can be removed */
int locked; /* if true, the media cannot temporarily be ejected */
int encrypted; /* if true, the media is encrypted */
int valid_key; /* if true, a valid encryption key has been set */
int sg; /* if true, the device is a /dev/sg* */
/* event callback when inserting/removing */
void (*change_cb)(void *opaque);

View File

@ -302,10 +302,9 @@ void term_printf(const char *fmt, ...) __attribute__ ((__format__ (__printf__, 1
void term_print_filename(const char *filename);
void term_flush(void);
void term_print_help(void);
void monitor_readline(const char *prompt, int is_password,
char *buf, int buf_size);
void monitor_suspend(void);
void monitor_resume(void);
int monitor_read_bdrv_key(BlockDriverState *bs);
/* readline.c */
typedef void ReadLineFunc(void *opaque, const char *str);

View File

@ -11,6 +11,7 @@
#include "usb.h"
#include "block.h"
#include "scsi-disk.h"
#include "console.h"
//#define DEBUG_MSD
@ -513,7 +514,7 @@ static void usb_msd_handle_destroy(USBDevice *dev)
qemu_free(s);
}
USBDevice *usb_msd_init(const char *filename)
USBDevice *usb_msd_init(const char *filename, BlockDriverState **pbs)
{
MSDState *s;
BlockDriverState *bdrv;
@ -552,9 +553,8 @@ USBDevice *usb_msd_init(const char *filename)
bdrv = bdrv_new("usb");
if (bdrv_open2(bdrv, filename, 0, drv) < 0)
goto fail;
if (qemu_key_check(bdrv, filename))
goto fail;
s->bs = bdrv;
*pbs = bdrv;
s->dev.speed = USB_SPEED_FULL;
s->dev.handle_packet = usb_generic_handle_packet;

View File

@ -21,6 +21,9 @@
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "block.h"
#define USB_TOKEN_SETUP 0x2d
#define USB_TOKEN_IN 0x69 /* device -> host */
#define USB_TOKEN_OUT 0xe1 /* host -> device */
@ -250,7 +253,7 @@ USBDevice *usb_keyboard_init(void);
void usb_hid_datain_cb(USBDevice *dev, void *opaque, void (*datain)(void *));
/* usb-msd.c */
USBDevice *usb_msd_init(const char *filename);
USBDevice *usb_msd_init(const char *filename, BlockDriverState **pbs);
/* usb-net.c */
USBDevice *usb_net_init(NICInfo *nd);

View File

@ -76,6 +76,8 @@ static uint8_t term_outbuf[1024];
static int term_outbuf_index;
static void monitor_start_input(void);
static void monitor_readline(const char *prompt, int is_password,
char *buf, int buf_size);
static CPUState *mon_cpu = NULL;
@ -433,7 +435,7 @@ static void do_change_block(const char *device, const char *filename, const char
if (eject_device(bs, 0) < 0)
return;
bdrv_open2(bs, filename, 0, drv);
qemu_key_check(bs, filename);
monitor_read_bdrv_key(bs);
}
static void do_change_vnc(const char *target, const char *arg)
@ -494,9 +496,24 @@ static void do_stop(void)
vm_stop(EXCP_INTERRUPT);
}
static void encrypted_bdrv_it(void *opaque, BlockDriverState *bs)
{
int *err = opaque;
if (bdrv_key_required(bs))
*err = monitor_read_bdrv_key(bs);
else
*err = 0;
}
static void do_cont(void)
{
vm_start();
int err = 0;
bdrv_iterate(encrypted_bdrv_it, &err);
/* only resume the vm if all keys are set and valid */
if (!err)
vm_start();
}
#ifdef CONFIG_GDBSTUB
@ -2892,8 +2909,8 @@ static void monitor_readline_cb(void *opaque, const char *input)
monitor_readline_started = 0;
}
void monitor_readline(const char *prompt, int is_password,
char *buf, int buf_size)
static void monitor_readline(const char *prompt, int is_password,
char *buf, int buf_size)
{
int i;
int old_focus[MAX_MON];
@ -2923,3 +2940,22 @@ void monitor_readline(const char *prompt, int is_password,
monitor_hd[i]->focus = old_focus[i];
}
}
int monitor_read_bdrv_key(BlockDriverState *bs)
{
char password[256];
int i;
if (!bdrv_is_encrypted(bs))
return 0;
term_printf("%s (%s) is encrypted.\n", bdrv_get_device_name(bs),
bdrv_get_encrypted_filename(bs));
for(i = 0; i < 3; i++) {
monitor_readline("Password: ", 1, password, sizeof(password));
if (bdrv_set_key(bs, password) == 0)
return 0;
term_printf("invalid password\n");
}
return -EPERM;
}

73
vl.c
View File

@ -201,6 +201,7 @@ ram_addr_t ram_size;
int nb_nics;
NICInfo nd_table[MAX_NICS];
int vm_running;
static int autostart;
static int rtc_utc = 1;
static int rtc_date_offset = -1; /* -1 means no change */
int cirrus_vga_enabled = 1;
@ -2607,11 +2608,13 @@ int drive_init(struct drive_opt *arg, int snapshot, void *opaque)
bdrv_flags |= BDRV_O_CACHE_WB;
else if (cache == 3) /* not specified */
bdrv_flags |= BDRV_O_CACHE_DEF;
if (bdrv_open2(bdrv, file, bdrv_flags, drv) < 0 || qemu_key_check(bdrv, file)) {
if (bdrv_open2(bdrv, file, bdrv_flags, drv) < 0) {
fprintf(stderr, "qemu: could not open disk image %s\n",
file);
return -1;
}
if (bdrv_key_required(bdrv))
autostart = 0;
return drives_table_idx;
}
@ -2658,7 +2661,7 @@ int usb_device_add_dev(USBDevice *dev)
return 0;
}
static int usb_device_add(const char *devname)
static int usb_device_add(const char *devname, int is_hotplug)
{
const char *p;
USBDevice *dev;
@ -2675,7 +2678,18 @@ static int usb_device_add(const char *devname)
} else if (!strcmp(devname, "keyboard")) {
dev = usb_keyboard_init();
} else if (strstart(devname, "disk:", &p)) {
dev = usb_msd_init(p);
BlockDriverState *bs;
dev = usb_msd_init(p, &bs);
if (!dev)
return -1;
if (bdrv_key_required(bs)) {
autostart = 0;
if (is_hotplug && monitor_read_bdrv_key(bs) < 0) {
dev->handle_destroy(dev);
return -1;
}
}
} else if (!strcmp(devname, "wacom-tablet")) {
dev = usb_wacom_init();
} else if (strstart(devname, "serial:", &p)) {
@ -2756,7 +2770,7 @@ static int usb_device_del(const char *devname)
void do_usb_add(const char *devname)
{
usb_device_add(devname);
usb_device_add(devname, 1);
}
void do_usb_del(const char *devname)
@ -4334,45 +4348,6 @@ static const QEMUOption qemu_options[] = {
{ NULL },
};
/* password input */
int qemu_key_check(BlockDriverState *bs, const char *name)
{
char password[256];
int i;
if (!bdrv_is_encrypted(bs))
return 0;
term_printf("%s is encrypted.\n", name);
for(i = 0; i < 3; i++) {
monitor_readline("Password: ", 1, password, sizeof(password));
if (bdrv_set_key(bs, password) == 0)
return 0;
term_printf("invalid password\n");
}
return -EPERM;
}
static BlockDriverState *get_bdrv(int index)
{
if (index > nb_drives)
return NULL;
return drives_table[index].bdrv;
}
static void read_passwords(void)
{
BlockDriverState *bs;
int i;
for(i = 0; i < 6; i++) {
bs = get_bdrv(i);
if (bs)
qemu_key_check(bs, bdrv_get_device_name(bs));
}
}
#ifdef HAS_AUDIO
struct soundhw soundhw[] = {
#ifdef HAS_AUDIO_CHOICE
@ -4639,7 +4614,6 @@ int main(int argc, char **argv, char **envp)
int fds[2];
int tb_size;
const char *pid_file = NULL;
int autostart;
const char *incoming = NULL;
int fd = 0;
struct passwd *pwd = NULL;
@ -5637,7 +5611,7 @@ int main(int argc, char **argv, char **envp)
/* init USB devices */
if (usb_enabled) {
for(i = 0; i < usb_devices_index; i++) {
if (usb_device_add(usb_devices[i]) < 0) {
if (usb_device_add(usb_devices[i], 0) < 0) {
fprintf(stderr, "Warning: could not add USB device %s\n",
usb_devices[i]);
}
@ -5748,13 +5722,8 @@ int main(int argc, char **argv, char **envp)
qemu_start_incoming_migration(incoming);
}
{
/* XXX: simplify init */
read_passwords();
if (autostart) {
vm_start();
}
}
if (autostart)
vm_start();
if (daemonize) {
uint8_t status = 0;