From 3a634eef021c2af94918746df37b523fc491910d Mon Sep 17 00:00:00 2001
From: Johannes Holland <joh.ho@gmx.de>
Date: Sun, 8 Oct 2023 11:41:54 +0200
Subject: [PATCH] tctildr: refactor loading to use list of file name formats

Signed-off-by: Johannes Holland <joh.ho@gmx.de>
---
 src/tss2-tcti/tctildr-dl.c | 73 ++++++++++++--------------------------
 src/tss2-tcti/tctildr.h    | 15 ++++----
 test/unit/tctildr-dl.c     |  4 +--
 3 files changed, 32 insertions(+), 60 deletions(-)

diff --git a/src/tss2-tcti/tctildr-dl.c b/src/tss2-tcti/tctildr-dl.c
index 363d32b66..491d404bc 100644
--- a/src/tss2-tcti/tctildr-dl.c
+++ b/src/tss2-tcti/tctildr-dl.c
@@ -78,65 +78,36 @@ TSS2_RC
 handle_from_name(const char *file,
                  void **handle)
 {
-    char *file_xfrm = NULL;
     size_t size;
-    size_t len;
+    char file_xfrm[PATH_MAX];
+    const char *formats[] = {
+        /* <name> */
+        "%s",
+        /* libtss2-tcti-<name>.so.0 */
+        FMT_TCTI_PREFIX "%s" FMT_LIB_SUFFIX_0,
+        /* libtss2-tcti-<name>.so */
+        FMT_TCTI_PREFIX "%s" FMT_LIB_SUFFIX,
+    };
 
     if (handle == NULL) {
         return TSS2_TCTI_RC_BAD_REFERENCE;
     }
-    *handle = dlopen(file, RTLD_NOW);
-    if (*handle != NULL) {
-        return TSS2_RC_SUCCESS;
-    } else {
-        LOG_DEBUG("Could not load TCTI file: \"%s\": %s", file, dlerror());
-    }
 
-    len = snprintf(NULL, 0, TCTI_NAME_TEMPLATE_0, file);
-    if (len >= PATH_MAX) {
-        LOG_ERROR("TCTI name truncated in transform.");
-        return TSS2_TCTI_RC_BAD_VALUE;
-    }
-    file_xfrm = calloc(len + 1, sizeof(char));
-    if (file_xfrm == NULL) {
-        return TSS2_TCTI_RC_MEMORY;
-    }
-    /* 'name' alone didn't work, try libtss2-tcti-<name>.so.0 */
-    size = snprintf(file_xfrm,
-                    len + 1,
-                    TCTI_NAME_TEMPLATE_0,
-                    file);
-    if (size >= (len + 1)) {
-        LOG_ERROR("TCTI name truncated in transform.");
-        SAFE_FREE(file_xfrm);
-        return TSS2_TCTI_RC_BAD_VALUE;
-    }
-    *handle = dlopen(file_xfrm, RTLD_NOW);
-    if (*handle != NULL) {
-        SAFE_FREE(file_xfrm);
-        return TSS2_RC_SUCCESS;
-    } else {
-        LOG_DEBUG("Could not load TCTI file \"%s\": %s", file, dlerror());
-    }
-    /* libtss2-tcti-<name>.so.0 didn't work, try libtss2-tcti-<name>.so */
-    size = snprintf(file_xfrm,
-                    len + 1,
-                    TCTI_NAME_TEMPLATE,
-                    file);
-    if (size >= (len + 1)) {
-        LOG_ERROR("TCTI name truncated in transform.");
-        SAFE_FREE(file_xfrm);
-        return TSS2_TCTI_RC_BAD_VALUE;
-    }
-    *handle = dlopen(file_xfrm, RTLD_NOW);
-    if (*handle == NULL) {
-        LOG_DEBUG("Failed to load TCTI for name \"%s\": %s", file, dlerror());
-        SAFE_FREE(file_xfrm);
-        return TSS2_TCTI_RC_NOT_SUPPORTED;
+    for (size_t i = 0; i < ARRAY_SIZE(formats); i++) {
+        size = snprintf(file_xfrm, sizeof(file_xfrm), formats[i], file);
+        if (size >= sizeof(file_xfrm)) {
+            LOG_ERROR("TCTI name truncated in transform.");
+            return TSS2_TCTI_RC_BAD_VALUE;
+        }
+        *handle = dlopen(file_xfrm, RTLD_NOW);
+        if (*handle != NULL) {
+            return TSS2_RC_SUCCESS;
+        } else {
+            LOG_DEBUG("Could not load TCTI file \"%s\": %s", file, dlerror());
+        }
     }
 
-    SAFE_FREE(file_xfrm);
-    return TSS2_RC_SUCCESS;
+    return TSS2_TCTI_RC_NOT_SUPPORTED;
 }
 TSS2_RC
 tcti_from_file(const char *file,
diff --git a/src/tss2-tcti/tctildr.h b/src/tss2-tcti/tctildr.h
index 12bab3035..02cd39405 100644
--- a/src/tss2-tcti/tctildr.h
+++ b/src/tss2-tcti/tctildr.h
@@ -9,13 +9,14 @@
 #include "tss2_tpm2_types.h"
 #include "tss2_tcti.h"
 
-#define TCTI_SUFFIX ".so"
-#define TCTI_SUFFIX_0 TCTI_SUFFIX".0"
-#define LIB_PREFIX "lib"
-#define TCTI_PREFIX LIB_PREFIX"tss2-tcti"
-#define TCTI_NAME_TEMPLATE TCTI_PREFIX"-%s"TCTI_SUFFIX
-#define TCTI_NAME_TEMPLATE_0 TCTI_PREFIX"-%s"TCTI_SUFFIX_0
-#define DEFAULT_TCTI_LIBRARY_NAME TCTI_PREFIX"-default"TCTI_SUFFIX
+#define FMT_LIB_PREFIX "lib"
+#define FMT_TSS_PREFIX FMT_LIB_PREFIX"tss2-"
+#define FMT_TCTI_PREFIX FMT_TSS_PREFIX"tcti-"
+
+#define FMT_LIB_SUFFIX_0 FMT_LIB_SUFFIX".0"
+#define FMT_LIB_SUFFIX ".so"
+
+#define DEFAULT_TCTI_LIBRARY_NAME FMT_TCTI_PREFIX"-default"TCTI_SUFFIX
 
 #define TCTILDR_MAGIC 0xbc44a31ca74b4aafULL
 
diff --git a/test/unit/tctildr-dl.c b/test/unit/tctildr-dl.c
index 4279baee5..ab62aa74b 100644
--- a/test/unit/tctildr-dl.c
+++ b/test/unit/tctildr-dl.c
@@ -152,7 +152,7 @@ test_handle_from_name_first_dlopen_success (void **state)
     assert_int_equal (handle, TEST_HANDLE);
 }
 
-#define TEST_TCTI_NAME_SO_0 TCTI_PREFIX"-"TEST_TCTI_NAME""TCTI_SUFFIX_0
+#define TEST_TCTI_NAME_SO_0 FMT_TCTI_PREFIX TEST_TCTI_NAME""FMT_LIB_SUFFIX_0
 static void
 test_handle_from_name_second_dlopen_success (void **state)
 {
@@ -171,7 +171,7 @@ test_handle_from_name_second_dlopen_success (void **state)
     assert_int_equal (rc, TSS2_RC_SUCCESS);
     assert_int_equal (handle, TEST_HANDLE);
 }
-#define TEST_TCTI_NAME_SO TCTI_PREFIX"-"TEST_TCTI_NAME""TCTI_SUFFIX
+#define TEST_TCTI_NAME_SO FMT_TCTI_PREFIX TEST_TCTI_NAME""FMT_LIB_SUFFIX
 static void
 test_handle_from_name_third_dlopen_success (void **state)
 {