agent: Terminate pinentry process gracefully, by watching socket.

* agent/call-pinentry.c (watch_sock): New.
(do_getpin): Spawn the watching thread.

--

While we don't have npth_cancel (and it's difficult to implement it
correctly), this is a kind of best compromise allowing a thread's
polling when pinentry is active.

GnuPG-bug-id: 2011
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
This commit is contained in:
NIIBE Yutaka 2019-02-19 14:36:50 +09:00
parent 99aa54323f
commit c395f83153
1 changed files with 81 additions and 4 deletions

View File

@ -942,16 +942,88 @@ build_cmd_setdesc (char *line, size_t linelen, const char *desc)
/* Ask pinentry to get a pin by "GETPIN" command.
* FIXME: Support EOF detection of the socket: ctrl->thread_startup.fd
/* Watch the socket's EOF condition, while checking finish of
foreground thread. When EOF condition is detected, terminate
the pinentry process behind the assuan pipe.
*/
static void *
watch_sock (void *arg)
{
gnupg_fd_t *p = (gnupg_fd_t *)arg;
pid_t pid = assuan_get_pid (entry_ctx);
while (1)
{
int err;
gnupg_fd_t sock = *p;
fd_set fdset;
struct timeval timeout = { 0, 500000 };
if (sock == GNUPG_INVALID_FD)
return NULL;
FD_ZERO (&fdset);
FD_SET (FD2INT (sock), &fdset);
err = npth_select (FD2INT (sock)+1, &fdset, NULL, NULL, &timeout);
if (err < 0)
{
if (errno == EINTR)
continue;
else
return NULL;
}
/* Possibly, it's EOF. */
if (err > 0)
break;
}
if (pid == (pid_t)(-1))
; /* No pid available can't send a kill. */
#ifdef HAVE_W32_SYSTEM
/* Older versions of assuan set PID to 0 on Windows to indicate an
invalid value. */
else if (pid != (pid_t) INVALID_HANDLE_VALUE && pid != 0)
TerminateProcess ((HANDLE)pid, 1);
#else
else if (pid > 0)
kill (pid, SIGINT);
#endif
return NULL;
}
/* Ask pinentry to get a pin by "GETPIN" command, spawning a thread
detecting the socket's EOF.
*/
static gpg_error_t
do_getpin (ctrl_t ctrl, struct entry_parm_s *parm)
{
int rc;
npth_attr_t tattr;
gpg_error_t rc;
int err;
npth_t thread;
int saveflag = assuan_get_flag (entry_ctx, ASSUAN_CONFIDENTIAL);
gnupg_fd_t sock_watched = ctrl->thread_startup.fd;
err = npth_attr_init (&tattr);
if (err)
{
log_error ("do_getpin: error npth_attr_init: %s\n", strerror (err));
return gpg_error_from_errno (err);
}
npth_attr_setdetachstate (&tattr, NPTH_CREATE_JOINABLE);
err = npth_create (&thread, &tattr, watch_sock, (void *)&sock_watched);
npth_attr_destroy (&tattr);
if (err)
{
log_error ("do_getpin: error spawning thread: %s\n", strerror (err));
return gpg_error_from_errno (err);
}
(void)ctrl;
assuan_begin_confidential (entry_ctx);
rc = assuan_transact (entry_ctx, "GETPIN", getpin_cb, parm,
inq_quality, entry_ctx,
@ -968,6 +1040,11 @@ do_getpin (ctrl_t ctrl, struct entry_parm_s *parm)
&& gpg_err_code (rc) == GPG_ERR_CANCELED)
rc = gpg_err_make (gpg_err_source (rc), GPG_ERR_FULLY_CANCELED);
sock_watched = GNUPG_INVALID_FD;
err = npth_join (thread, NULL);
if (err)
log_error ("do_getpin: error joining thread: %s\n", strerror (err));
return rc;
}