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scd: Modify DEVINFO behavior to support looping forever. 

* scd/app.c (struct mrsw_lock): Add notify_cond member.
(notify_cond): Remove.
(card_list_r_lock, card_list_r_unlock): Rename.
(card_list_w_lock, card_list_w_unlock): Rename.
(card_list_signal, card_list_wait): New, fixing thinko about
notify/wakeup with MRSW lock.
(app_send_devinfo): Support looping.
(select_application): Notify app_send_devinfo thread for newly
detected device.
(initialize_module_command): Initialize notify_cond member.
(app_wait): Remove.
* scd/command.c (cmd_devinfo): Use new API of app_send_devinfo.
* scd/scdaemon.h (app_wait): Remove.

--

GnuPG-bug-id: 5359
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
This commit is contained in:
NIIBE Yutaka 2021-10-29 10:48:01 +09:00
parent 50e43af3f1
commit 48e824b6ea
3 changed files with 104 additions and 79 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

168
scd/app.c
View File

@ -49,11 +49,9 @@ struct mrsw_lock
int num_readers_active;
int num_writers_waiting;
int writer_active;
npth_cond_t notify_cond;
};
#define CARD_LIST_LOCK_WAIT 0
#define CARD_LIST_LOCK_UPDATE 1
/* MRSW lock to protect the list of cards.
*
* This structure is used for serializing access to the list of cards
@ -63,10 +61,9 @@ struct mrsw_lock
*
* Each use of a CARD (in the list) does "r" access.
*
* For "w" access, the app_wait function, which waits on any change of
* the list, it uses CARD_LIST_LOCK_WAIT. For other cases of "w"
* access (opening new card or removal of card), CARD_LIST_LOCK_UPDATE
* is used.
* For "w" access, the app_send_devinfo function may wait on any
* change of the list. For other cases of "w" access are opening new
* card or removal of card, updating the list of card.
*
* Note that for serializing access to each CARD (and its associated
* applications) itself, it is done separately by another mutex with
@ -74,9 +71,6 @@ struct mrsw_lock
*/
static struct mrsw_lock card_list_lock;
/* Notification to threads which keep watching the status change. */
static npth_cond_t notify_cond;
/* A list of card contexts. A card is a collection of applications
* (described by app_t) on the same physical token. */
static card_t card_top;
@ -325,7 +319,7 @@ unlock_card (card_t card)
static void
lock_r_card_list (void)
card_list_r_lock (void)
{
npth_mutex_lock (&card_list_lock.lock);
while (card_list_lock.num_writers_waiting
@ -336,7 +330,7 @@ lock_r_card_list (void)
}
static void
unlock_r_card_list (void)
card_list_r_unlock (void)
{
npth_mutex_lock (&card_list_lock.lock);
if (--card_list_lock.num_readers_active == 0)
@ -346,7 +340,7 @@ unlock_r_card_list (void)
static void
lock_w_card_list (int for_update)
card_list_w_lock (void)
{
npth_mutex_lock (&card_list_lock.lock);
card_list_lock.num_writers_waiting++;
@ -354,26 +348,46 @@ lock_w_card_list (int for_update)
|| card_list_lock.writer_active)
npth_cond_wait (&card_list_lock.cond, &card_list_lock.lock);
card_list_lock.num_writers_waiting--;
if (for_update)
{
card_list_lock.writer_active++;
npth_mutex_unlock (&card_list_lock.lock);
}
card_list_lock.writer_active++;
npth_mutex_unlock (&card_list_lock.lock);
}
static void
unlock_w_card_list (int for_update)
card_list_w_unlock (void)
{
if (for_update)
{
npth_mutex_lock (&card_list_lock.lock);
card_list_lock.writer_active--;
}
npth_mutex_lock (&card_list_lock.lock);
card_list_lock.writer_active--;
npth_cond_broadcast (&card_list_lock.cond);
npth_mutex_unlock (&card_list_lock.lock);
}
static void
card_list_signal (void)
{
npth_cond_broadcast (&card_list_lock.notify_cond);
}
static void
card_list_wait (void)
{
npth_mutex_lock (&card_list_lock.lock);
card_list_lock.writer_active--;
npth_cond_broadcast (&card_list_lock.cond);
npth_cond_wait (&card_list_lock.notify_cond, &card_list_lock.lock);
card_list_lock.num_writers_waiting++;
while (card_list_lock.num_readers_active
|| card_list_lock.writer_active)
npth_cond_wait (&card_list_lock.cond, &card_list_lock.lock);
card_list_lock.num_writers_waiting--;
card_list_lock.writer_active++;
npth_mutex_unlock (&card_list_lock.lock);
}
/* This function may be called to print information pertaining to the
* current state of this module to the log. */
void
@ -382,7 +396,7 @@ app_dump_state (void)
card_t c;
app_t a;
lock_r_card_list ();
card_list_r_lock ();
for (c = card_top; c; c = c->next)
{
log_info ("app_dump_state: card=%p slot=%d type=%s refcount=%u\n",
@ -392,37 +406,59 @@ app_dump_state (void)
log_info ("app_dump_state: app=%p type='%s'\n",
a, strapptype (a->apptype));
}
unlock_r_card_list ();
card_list_r_unlock ();
}
/*
* Send information for all available cards.
*
* With KEEP_LOOPING=0, it only outputs once.
* With KEEP_LOOPING<0, it keeps looping, until it detects no device.
* With KEEP_LOOPING>0, it keeps looping forever.
*/
gpg_error_t
app_send_devinfo (ctrl_t ctrl)
app_send_devinfo (ctrl_t ctrl, int keep_looping)
{
card_t c;
app_t a;
int no_device;
send_status_direct (ctrl, "DEVINFO_START", "");
lock_r_card_list ();
no_device = (card_top == NULL);
for (c = card_top; c; c = c->next)
while (1)
{
char *serialno;
char card_info[80];
card_list_w_lock ();
serialno = card_get_serialno (c);
snprintf (card_info, sizeof card_info, "DEVICE %s %s",
strcardtype (c->cardtype), serialno);
xfree (serialno);
no_device = (card_top == NULL);
if (no_device && keep_looping < 0)
{
card_list_w_unlock ();
break;
}
for (a = c->app; a; a = a->next)
send_status_direct (ctrl, card_info, strapptype (a->apptype));
send_status_direct (ctrl, "DEVINFO_START", "");
for (c = card_top; c; c = c->next)
{
char *serialno;
char card_info[80];
serialno = card_get_serialno (c);
snprintf (card_info, sizeof card_info, "DEVICE %s %s",
strcardtype (c->cardtype), serialno);
xfree (serialno);
for (a = c->app; a; a = a->next)
send_status_direct (ctrl, card_info, strapptype (a->apptype));
}
send_status_direct (ctrl, "DEVINFO_END", "");
if (no_device && !keep_looping)
{
card_list_w_unlock ();
break;
}
card_list_wait ();
card_list_w_unlock ();
}
unlock_r_card_list ();
send_status_direct (ctrl, "DEVINFO_END", "");
return no_device ? gpg_error (GPG_ERR_NOT_FOUND): 0;
}
@ -774,7 +810,7 @@ select_application (ctrl_t ctrl, const char *name,
gpg_error_t err = 0;
card_t card, card_prev = NULL;
lock_w_card_list (CARD_LIST_LOCK_UPDATE);
card_list_w_lock ();
ctrl->card_ctx = NULL;
@ -787,7 +823,7 @@ select_application (ctrl_t ctrl, const char *name,
err = apdu_dev_list_start (opt.reader_port, &l);
if (err)
{
unlock_w_card_list (CARD_LIST_LOCK_UPDATE);
card_list_w_unlock ();
return err;
}
@ -824,7 +860,11 @@ select_application (ctrl_t ctrl, const char *name,
/* If new device(s), kick the scdaemon loop. */
if (new_card)
scd_kick_the_loop ();
{
scd_kick_the_loop ();
/* Also notify watching by DEVINFO */
card_list_signal ();
}
}
for (card = card_top; card; card = card->next)
@ -874,7 +914,7 @@ select_application (ctrl_t ctrl, const char *name,
else
err = gpg_error (GPG_ERR_ENODEV);
unlock_w_card_list (CARD_LIST_LOCK_UPDATE);
card_list_w_unlock ();
return err;
}
@ -890,7 +930,7 @@ app_switch_current_card (ctrl_t ctrl,
gpg_error_t err;
card_t card, cardtmp;
lock_r_card_list ();
card_list_r_lock ();
cardtmp = ctrl->card_ctx;
if (!cardtmp)
@ -926,7 +966,7 @@ app_switch_current_card (ctrl_t ctrl,
err = send_serialno_and_app_status (ctrl->card_ctx, 0, ctrl);
leave:
unlock_r_card_list ();
card_list_r_unlock ();
return err;
}
@ -1244,14 +1284,14 @@ card_get (ctrl_t ctrl, const char *keygrip)
{
card_t card;
lock_r_card_list ();
card_list_r_lock ();
if (keygrip)
card = do_with_keygrip (ctrl, KEYGRIP_ACTION_LOOKUP, keygrip, 0);
else
card = ctrl->card_ctx;
if (!card)
{
unlock_r_card_list ();
card_list_r_unlock ();
return NULL;
}
@ -1268,7 +1308,7 @@ card_put (card_t card)
is using the card - this way the PIN cache and other cached data
are preserved. */
unlock_card (card);
unlock_r_card_list ();
card_list_r_unlock ();
}
@ -2348,7 +2388,7 @@ scd_update_reader_status_file (void)
int periodical_check_needed = 0;
int reported = 0;
lock_w_card_list (CARD_LIST_LOCK_UPDATE);
card_list_w_lock ();
for (card = card_top; card; card = card_next)
{
int sw;
@ -2412,9 +2452,9 @@ scd_update_reader_status_file (void)
}
if (reported)
npth_cond_broadcast (&notify_cond);
card_list_signal ();
unlock_w_card_list (CARD_LIST_LOCK_UPDATE);
card_list_w_unlock ();
return periodical_check_needed;
}
@ -2447,7 +2487,7 @@ initialize_module_command (void)
return err;
}
err = npth_cond_init (&notify_cond, NULL);
err = npth_cond_init (&card_list_lock.notify_cond, NULL);
if (err)
{
err = gpg_error_from_syserror ();
@ -2542,7 +2582,7 @@ send_card_and_app_list (ctrl_t ctrl, card_t wantcard, int with_apps)
card_t *cardlist = NULL;
int n, ncardlist;
lock_r_card_list ();
card_list_r_lock ();
for (n=0, c = card_top; c; c = c->next)
n++;
if (!n)
@ -2572,7 +2612,7 @@ send_card_and_app_list (ctrl_t ctrl, card_t wantcard, int with_apps)
err = 0;
leave:
unlock_r_card_list ();
card_list_r_unlock ();
xfree (cardlist);
return err;
}
@ -2665,16 +2705,8 @@ app_do_with_keygrip (ctrl_t ctrl, int action, const char *keygrip_str,
{
card_t card;
lock_r_card_list ();
card_list_r_lock ();
card = do_with_keygrip (ctrl, action, keygrip_str, capability);
unlock_r_card_list ();
card_list_r_unlock ();
return card;
}
void
app_wait (void)
{
lock_w_card_list (CARD_LIST_LOCK_WAIT);
npth_cond_wait (&notify_cond, &card_list_lock.lock);
unlock_w_card_list (CARD_LIST_LOCK_WAIT);
}

12
scd/command.c
View File

@ -2279,7 +2279,7 @@ cmd_devinfo (assuan_context_t ctx, char *line)
}
/* Firstly, send information of available devices. */
err = app_send_devinfo (ctrl);
err = app_send_devinfo (ctrl, 0);
/* If not watching, that's all. */
if (!watch)
@ -2311,16 +2311,10 @@ cmd_devinfo (assuan_context_t ctx, char *line)
}
/* Then, keep watching the status change. */
while (!err)
{
app_wait ();
/* Send information of available devices. */
err = app_send_devinfo (ctrl);
}
err = app_send_devinfo (ctrl, 1);
ctrl->server_local->watching_status = 0;
return 0;
return err;
}
/* Return true if the command CMD implements the option OPT. */

3
scd/scdaemon.h
View File

@ -155,7 +155,6 @@ int get_active_connection_count (void);
/*-- app.c --*/
int scd_update_reader_status_file (void);
void app_wait (void);
gpg_error_t app_send_devinfo (ctrl_t ctrl);
gpg_error_t app_send_devinfo (ctrl_t ctrl, int keep_looping);
#endif /*SCDAEMON_H*/