From 6fcc263c182fc49d9ba2d1bd7649b4af1e9f3e3a Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Thu, 10 Sep 2020 12:14:02 +0200
Subject: [PATCH] keyboxd: Use D-lines instead of a separate thread.

* kbx/kbx-client-util.c (kbx_client_data_new): Add arg 'dlines'.
* g10/call-keyboxd.c (open_context): Set DLINES to true.
* sm/keydb.c (open_context): Ditto.
--

This allows to compile time switch between the D-line and the
fd-passing data communication between gpg/gpgsm and keyboxd. A quick
test with about 3000 OpenPGP keys showed that D-lines are only 10%
slower than the fd-passing based implementation.  Given that the
thread adds extra complexity we go for now with the D-line approach.

Signed-off-by: Werner Koch <wk@gnupg.org>
---
 g10/call-keyboxd.c    |  2 +-
 kbx/kbx-client-util.c | 12 +++++++++---
 kbx/kbx-client-util.h |  2 +-
 sm/keydb.c            |  2 +-
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/g10/call-keyboxd.c b/g10/call-keyboxd.c
index e0ee26e6b..e75b786a0 100644
--- a/g10/call-keyboxd.c
+++ b/g10/call-keyboxd.c
@@ -190,7 +190,7 @@ open_context (ctrl_t ctrl, keyboxd_local_t *r_kbl)
           return err;
         }
 
-      err = kbx_client_data_new (&kbl->kcd, kbl->ctx);
+      err = kbx_client_data_new (&kbl->kcd, kbl->ctx, 1);
       if (err)
         {
           assuan_release (kbl->ctx);
diff --git a/kbx/kbx-client-util.c b/kbx/kbx-client-util.c
index ba356b3c5..910050372 100644
--- a/kbx/kbx-client-util.c
+++ b/kbx/kbx-client-util.c
@@ -270,10 +270,12 @@ datastream_thread (void *arg)
 
 
 /* Create a new keyboxd client data object and return it at R_KCD.
- * CTX is the assuan context to be used for connecting the
- * keyboxd.  */
+ * CTX is the assuan context to be used for connecting the keyboxd.
+ * If dlines is set, communication is done without fd passing via
+ * D-lines.  */
 gpg_error_t
-kbx_client_data_new (kbx_client_data_t *r_kcd, assuan_context_t ctx)
+kbx_client_data_new (kbx_client_data_t *r_kcd, assuan_context_t ctx,
+                     int dlines)
 {
   kbx_client_data_t kcd;
   int rc;
@@ -285,6 +287,9 @@ kbx_client_data_new (kbx_client_data_t *r_kcd, assuan_context_t ctx)
 
   kcd->ctx = ctx;
 
+  if (dlines)
+    goto leave;
+
   rc = npth_mutex_init (&kcd->mutex, NULL);
   if (rc)
     {
@@ -312,6 +317,7 @@ kbx_client_data_new (kbx_client_data_t *r_kcd, assuan_context_t ctx)
       return err;
     }
 
+ leave:
   *r_kcd = kcd;
   return 0;
 }
diff --git a/kbx/kbx-client-util.h b/kbx/kbx-client-util.h
index db6cb9475..1cc68b5a0 100644
--- a/kbx/kbx-client-util.h
+++ b/kbx/kbx-client-util.h
@@ -26,7 +26,7 @@ struct kbx_client_data_s;
 typedef struct kbx_client_data_s *kbx_client_data_t;
 
 gpg_error_t kbx_client_data_new (kbx_client_data_t *r_kcd,
-                                 assuan_context_t ctx);
+                                 assuan_context_t ctx, int dlines);
 void kbx_client_data_release (kbx_client_data_t kcd);
 gpg_error_t kbx_client_data_cmd (kbx_client_data_t kcd, const char *command,
                                  gpg_error_t (*status_cb)(void *opaque,
diff --git a/sm/keydb.c b/sm/keydb.c
index ca32162d1..d7525bd76 100644
--- a/sm/keydb.c
+++ b/sm/keydb.c
@@ -570,7 +570,7 @@ open_context (ctrl_t ctrl, keydb_local_t *r_kbl)
           return err;
         }
 
-      err = kbx_client_data_new (&kbl->kcd, kbl->ctx);
+      err = kbx_client_data_new (&kbl->kcd, kbl->ctx, 1);
       if (err)
         {
           assuan_release (kbl->ctx);