tctildr: Add library to automate TCTI lifecycle.

Instantiating a TCTI context takes a bit of work. The default offered
by ESYS is a good start but this still leaves applications that need to
override the default with a lot of extra work. libtss2-tctildr will do
this work for you.
It provides:
- Tss2_TctiLdr_Initialize - Allocate and initialize a TCTI context for
  the caller. The 'name' parameter is a string that is either passed to
  dlopen, or mapped to an internal table of names to TCTIs linked
  directly into the loader.
- Tss2_TctiLdr_Finalize - The dual of 'Initialize'.

'Initialize' returns a TCTI instance that can be used by the existing
SYS & ESYS APIs. When no longer in use it must be freed using the paired
'Finalize' function.

This implementation reuses the esys_tcti_default module to preserve
existing behavior / default TCTI selection logic as much as possible.
The interface however is very different as callers may now search for
TCTIs using the 'name' parameter of Tss2_TctiLdr_Initialize. When this
parameter is NULL the old default selection logic is used to select a
default TCTI. When it is populated the library will attempt to load it.

On a system with 'dlopen' we simply pass the provided name through which
requires the caller provide the full name of the TCTI library (i.e.
libtss2-tcti-device.so.0). For the NO_DL case this commit introduces a
lookup mechanism for common TCTI names that we compare to the provided
'name'.

The ESYS unit tests have been updated and new unit tests added to cover
the dl & nodl, and tctildr modules. The build (both autotools and visual
studio) has been updated to include rules to build this new library and
to update dependencies:
- tss2-esys no longer depnds on the TCTIs directly
- tss2-esys now depends on tss2-tctildr

This includes a page in section 7 for the library itself as well as
individual pages in section 3 for the initialize and finalize functions.

Signed-off-by: Philip Tricca <philip.b.tricca@intel.com>

3 files changed, 22 insertions, 0 deletions

diff --git a/lib/tss2-tctildr.def b/lib/tss2-tctildr.def
new file mode 100644
index 00000000..56a1c8a8
--- /dev/null
+++ b/lib/tss2-tctildr.def
@@ -0,0 +1,4 @@
+LIBRARY tss2-tctildr
+EXPORTS
+    Tss2_TctiLdr_Finalize
+    Tss2_TctiLdr_Initialize
diff --git a/lib/tss2-tctildr.map b/lib/tss2-tctildr.map
new file mode 100644
index 00000000..f90dba4e
--- /dev/null
+++ b/lib/tss2-tctildr.map
@@ -0,0 +1,7 @@
+{
+    global:
+        Tss2_TctiLdr_Finalize;
+        Tss2_TctiLdr_Initialize;
+    local:
+        *;
+};
diff --git a/lib/tss2-tctildr.pc.in b/lib/tss2-tctildr.pc.in
new file mode 100644
index 00000000..0f18b75b
--- /dev/null
+++ b/lib/tss2-tctildr.pc.in
@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+includedir=@includedir@
+libdir=@libdir@
+
+Name: tss2-tctildr
+Description: Library to simplify management of TCTIs.
+URL: https://github.com/tpm2-software/tpm2-tss
+Version: @VERSION@
+Cflags: -I@includedir@
+Libs: -ltss2-tctildr -L@libdir@