From f8b8b6aac2ca1cb34d7a346aee1d874e7650557b Mon Sep 17 00:00:00 2001
From: NIIBE Yutaka <gniibe@fsij.org>
Date: Thu, 8 Mar 2018 16:51:51 +0900
Subject: [PATCH] scd: Fix status check when using PC/SC.

* scd/apdu.c (struct reader_table_s): Add field of current_state.
(new_reader_slot): Initialize current_state.
(pcsc_get_status): Keep the status in READER_TABLE array.
Return SW_HOST_NO_READER when PCSC_STATE_CHANGED.
* scd/scdaemon.c (handle_connections): Silence a warning.

--

To detect some change of card status, including suspend/resume
possibly, SCardGetStatusChange should be used keeping the
dwCurrentState field.

This change could improve situation for suspend/resume with Yubikey on
Windows.  Even not, this is doing the Right Thing.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
---
 scd/apdu.c     | 15 ++++++++++++---
 scd/scdaemon.c |  2 ++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/scd/apdu.c b/scd/apdu.c
index c50afbde2..6758e69e8 100644
--- a/scd/apdu.c
+++ b/scd/apdu.c
@@ -119,6 +119,7 @@ struct reader_table_s {
     pcsc_dword_t modify_ioctl;
     int pinmin;
     int pinmax;
+    pcsc_dword_t current_state;
   } pcsc;
 #ifdef USE_G10CODE_RAPDU
   struct {
@@ -453,6 +454,7 @@ new_reader_slot (void)
   reader_table[reader].pcsc.modify_ioctl = 0;
   reader_table[reader].pcsc.pinmin = -1;
   reader_table[reader].pcsc.pinmax = -1;
+  reader_table[reader].pcsc.current_state = PCSC_STATE_UNAWARE;
 
   return reader;
 }
@@ -652,12 +654,12 @@ pcsc_get_status (int slot, unsigned int *status, int on_wire)
   (void)on_wire;
   memset (rdrstates, 0, sizeof *rdrstates);
   rdrstates[0].reader = reader_table[slot].rdrname;
-  rdrstates[0].current_state = PCSC_STATE_UNAWARE;
+  rdrstates[0].current_state = reader_table[slot].pcsc.current_state;
   err = pcsc_get_status_change (reader_table[slot].pcsc.context,
                                 0,
                                 rdrstates, 1);
   if (err == PCSC_E_TIMEOUT)
-    err = 0; /* Timeout is no error error here. */
+    err = 0; /* Timeout is no error here.  */
   if (err)
     {
       log_error ("pcsc_get_status_change failed: %s (0x%lx)\n",
@@ -665,6 +667,9 @@ pcsc_get_status (int slot, unsigned int *status, int on_wire)
       return pcsc_error_to_sw (err);
     }
 
+  reader_table[slot].pcsc.current_state =
+    (rdrstates[0].event_state & ~PCSC_STATE_CHANGED);
+
   /*   log_debug  */
   /*     ("pcsc_get_status_change: %s%s%s%s%s%s%s%s%s%s\n", */
   /*      (rdrstates[0].event_state & PCSC_STATE_IGNORE)? " ignore":"", */
@@ -701,7 +706,11 @@ pcsc_get_status (int slot, unsigned int *status, int on_wire)
     *status |= APDU_CARD_USABLE;
 #endif
 
-  return 0;
+  if (!on_wire && (rdrstates[0].event_state & PCSC_STATE_CHANGED))
+    /* Event like sleep/resume occurs, which requires RESET.  */
+    return SW_HOST_NO_READER;
+  else
+    return 0;
 }
 
 
diff --git a/scd/scdaemon.c b/scd/scdaemon.c
index cebeea9d3..91b559925 100644
--- a/scd/scdaemon.c
+++ b/scd/scdaemon.c
@@ -1348,6 +1348,8 @@ handle_connections (int listen_fd)
       FD_SET (pipe_fd[0], &read_fdset);
       if (max_fd < pipe_fd[0])
         max_fd = pipe_fd[0];
+#else
+      (void)max_fd;
 #endif
 
 #ifndef HAVE_W32_SYSTEM