scd: Introduce a virtual reader table.

The vreader table makes the code more clear by explicitly talking
about APDU slots and reader indices.  It also accommodates for future
extensions.

* scd/scdaemon.h (server_control_s): Remove READER_SLOT.
* scd/scdaemon.c (scd_init_default_ctrl): Do not init READER_SLOT.
* scd/app.c (check_application_conflict): Add arg SLOT.
* scd/command.c (slot_status_s): Rename to vreader_s.
(server_local_s): Add field VREADER_IDX as replacement for
the READER_SLOT in server_control_s.  Change all users.
(slot_table): Rename to vreader_table.  Change all users.
(vreader_slot): New.
(do_reset, cmd_apdu): Map vreader to apdu slot.
(get_reader_slot): Rename to get_current_reader.  Return -1 on error.
(open_card): Map vreader toapdu slot.  Pass slot to
check_application_conflict.
(scd_command_handler): Init VREADER_IDX.
(update_reader_status_file): Reset SLOT field on error.

1 files changed, 2 insertions, 1 deletions

diff --git a/scd/app-common.h b/scd/app-common.h
index 6a1e2a763..e3d23c2b4 100644
--- a/scd/app-common.h
+++ b/scd/app-common.h
@@ -143,7 +143,8 @@ size_t app_help_read_length_of_cert (int slot, int fid, size_t *r_certoff);
 /*-- app.c --*/
 void app_dump_state (void);
 void application_notify_card_reset (int slot);
-gpg_error_t check_application_conflict (ctrl_t ctrl, const char *name);
+gpg_error_t check_application_conflict (ctrl_t ctrl, int slot,
+                                        const char *name);
 gpg_error_t select_application (ctrl_t ctrl, int slot, const char *name,
                                 app_t *r_app);
 char *get_supported_applications (void);