attrs: New p11_attrs_merge() function

This takes one set of attributes and merges them into
another, without copying memory needlessly.

https://bugs.freedesktop.org/show_bug.cgi?id=62329

3 files changed, 153 insertions, 6 deletions

diff --git a/common/attrs.c b/common/attrs.c
index 759bb75..0ccf832 100644
--- a/common/attrs.c
+++ b/common/attrs.c
@@ -84,7 +84,8 @@ p11_attrs_free (void *attrs)
 static CK_ATTRIBUTE *
 attrs_build (CK_ATTRIBUTE *attrs,
              CK_ULONG count_to_add,
-             bool copy,
+             bool take_values,
+             bool override,
              CK_ATTRIBUTE * (*generator) (void *),
              void *state)
 {
@@ -116,18 +117,28 @@ attrs_build (CK_ATTRIBUTE *attrs,
 		for (j = 0; attr == NULL && j < current; j++) {
 			if (attrs[j].type == add->type) {
 				attr = attrs + j;
-				free (attrs[j].pValue);
 				break;
 			}
 		}
 
+		/* The attribute doesn't exist */
 		if (attr == NULL) {
 			attr = attrs + at;
 			at++;
+
+		/* The attribute exists and we're not overriding */
+		} else if (!override) {
+			if (take_values)
+				free (add->pValue);
+			continue;
+
+		/* The attribute exitss, and we're overriding */
+		} else {
+			free (attr->pValue);
 		}
 
 		memcpy (attr, add, sizeof (CK_ATTRIBUTE));
-		if (copy)
+		if (!take_values)
 			attr->pValue = memdup (attr->pValue, attr->ulValueLen);
 	}
 
@@ -158,7 +169,8 @@ p11_attrs_build (CK_ATTRIBUTE *attrs,
 	va_end (va);
 
 	va_start (va, attrs);
-	attrs = attrs_build (attrs, count, true, vararg_generator, &va);
+	attrs = attrs_build (attrs, count, false, true,
+	                     vararg_generator, &va);
 	va_end (va);
 
 	return attrs;
@@ -176,7 +188,8 @@ p11_attrs_buildn (CK_ATTRIBUTE *attrs,
                   const CK_ATTRIBUTE *add,
                   CK_ULONG count)
 {
-	return attrs_build (attrs, count, true, template_generator, &add);
+	return attrs_build (attrs, count, false, true,
+	                    template_generator, &add);
 }
 
 CK_ATTRIBUTE *
@@ -187,7 +200,34 @@ p11_attrs_take (CK_ATTRIBUTE *attrs,
 {
 	CK_ATTRIBUTE attr = { type, value, length };
 	CK_ATTRIBUTE *add = &attr;
-	return attrs_build (attrs, 1, false, template_generator, &add);
+	return attrs_build (attrs, 1, true, true,
+	                    template_generator, &add);
+}
+
+CK_ATTRIBUTE *
+p11_attrs_merge (CK_ATTRIBUTE *attrs,
+                 CK_ATTRIBUTE *merge,
+                 bool replace)
+{
+	CK_ATTRIBUTE *ptr;
+	CK_ULONG count;
+
+	if (attrs == NULL)
+		return merge;
+
+	ptr = merge;
+	count = p11_attrs_count (merge);
+
+	attrs = attrs_build (attrs, count, true, replace,
+	                     template_generator, &ptr);
+
+	/*
+	 * Since we're supposed to own the merge attributes,
+	 * free the container array.
+	 */
+	free (merge);
+
+	return attrs;
 }
 
 CK_ATTRIBUTE *
diff --git a/common/attrs.h b/common/attrs.h
index 870f0d1..4e3f46c 100644
--- a/common/attrs.h
+++ b/common/attrs.h
@@ -55,6 +55,10 @@ CK_ATTRIBUTE *      p11_attrs_take          (CK_ATTRIBUTE *attrs,
                                              CK_VOID_PTR value,
                                              CK_ULONG length);
 
+CK_ATTRIBUTE *      p11_attrs_merge         (CK_ATTRIBUTE *attrs,
+                                             CK_ATTRIBUTE *merge,
+                                             bool replace);
+
 bool                p11_attrs_is_empty      (const CK_ATTRIBUTE *attrs);
 
 CK_ULONG            p11_attrs_count         (const CK_ATTRIBUTE *attrs);
diff --git a/common/tests/test-attrs.c b/common/tests/test-attrs.c
index 09d0ace..49350be 100644
--- a/common/tests/test-attrs.c
+++ b/common/tests/test-attrs.c
@@ -290,6 +290,106 @@ test_take (CuTest *tc)
 	p11_attrs_free (attrs);
 }
 
+
+static void
+test_merge_replace (CuTest *tc)
+{
+	CK_ATTRIBUTE initial[] = {
+		{ CKA_LABEL, "label", 5 },
+		{ CKA_VALUE, "nine", 4 },
+	};
+
+	CK_ATTRIBUTE extra[] = {
+		{ CKA_LABEL, "boooyah", 7 },
+		{ CKA_APPLICATION, "disco", 5 },
+	};
+
+	CK_ATTRIBUTE *attrs;
+	CK_ATTRIBUTE *merge;
+
+	attrs = p11_attrs_buildn (NULL, initial, 2);
+	merge = p11_attrs_buildn (NULL, extra, 2);
+	attrs = p11_attrs_merge (attrs, merge, true);
+	CuAssertPtrNotNull (tc, attrs);
+
+	CuAssertTrue (tc, attrs[0].type == CKA_LABEL);
+	CuAssertIntEquals (tc, 7, attrs[0].ulValueLen);
+	CuAssertTrue (tc, memcmp (attrs[0].pValue, "boooyah", 7) == 0);
+
+	CuAssertPtrNotNull (tc, attrs);
+	CuAssertTrue (tc, attrs[1].type == CKA_VALUE);
+	CuAssertIntEquals (tc, 4, attrs[1].ulValueLen);
+	CuAssertTrue (tc, memcmp (attrs[1].pValue, "nine", 4) == 0);
+
+	CuAssertPtrNotNull (tc, attrs);
+	CuAssertTrue (tc, attrs[2].type == CKA_APPLICATION);
+	CuAssertIntEquals (tc, 5, attrs[2].ulValueLen);
+	CuAssertTrue (tc, memcmp (attrs[2].pValue, "disco", 5) == 0);
+
+	CuAssertTrue (tc, attrs[3].type == CKA_INVALID);
+
+	p11_attrs_free (attrs);
+}
+
+static void
+test_merge_empty (CuTest *tc)
+{
+	CK_ATTRIBUTE extra[] = {
+		{ CKA_LABEL, "boooyah", 7 },
+		{ CKA_APPLICATION, "disco", 5 },
+	};
+
+	CK_ATTRIBUTE *attrs = NULL;
+	CK_ATTRIBUTE *merge;
+
+	merge = p11_attrs_buildn (NULL, extra, 2);
+	attrs = p11_attrs_merge (attrs, merge, true);
+	CuAssertPtrNotNull (tc, attrs);
+	CuAssertPtrEquals (tc, merge, attrs);
+
+	p11_attrs_free (attrs);
+}
+
+static void
+test_merge_augment (CuTest *tc)
+{
+	CK_ATTRIBUTE initial[] = {
+		{ CKA_LABEL, "label", 5 },
+		{ CKA_VALUE, "nine", 4 },
+	};
+
+	CK_ATTRIBUTE extra[] = {
+		{ CKA_LABEL, "boooyah", 7 },
+		{ CKA_APPLICATION, "disco", 5 },
+	};
+
+	CK_ATTRIBUTE *attrs;
+	CK_ATTRIBUTE *merge;
+
+	attrs = p11_attrs_buildn (NULL, initial, 2);
+	merge = p11_attrs_buildn (NULL, extra, 2);
+	attrs = p11_attrs_merge (attrs, merge, false);
+	CuAssertPtrNotNull (tc, attrs);
+
+	CuAssertTrue (tc, attrs[0].type == CKA_LABEL);
+	CuAssertIntEquals (tc, 5, attrs[0].ulValueLen);
+	CuAssertTrue (tc, memcmp (attrs[0].pValue, "label", 5) == 0);
+
+	CuAssertPtrNotNull (tc, attrs);
+	CuAssertTrue (tc, attrs[1].type == CKA_VALUE);
+	CuAssertIntEquals (tc, 4, attrs[1].ulValueLen);
+	CuAssertTrue (tc, memcmp (attrs[1].pValue, "nine", 4) == 0);
+
+	CuAssertPtrNotNull (tc, attrs);
+	CuAssertTrue (tc, attrs[2].type == CKA_APPLICATION);
+	CuAssertIntEquals (tc, 5, attrs[2].ulValueLen);
+	CuAssertTrue (tc, memcmp (attrs[2].pValue, "disco", 5) == 0);
+
+	CuAssertTrue (tc, attrs[3].type == CKA_INVALID);
+
+	p11_attrs_free (attrs);
+}
+
 static void
 test_free_null (CuTest *tc)
 {
@@ -592,6 +692,9 @@ main (void)
 	SUITE_ADD_TEST (suite, test_build_null);
 	SUITE_ADD_TEST (suite, test_dup);
 	SUITE_ADD_TEST (suite, test_take);
+	SUITE_ADD_TEST (suite, test_merge_replace);
+	SUITE_ADD_TEST (suite, test_merge_augment);
+	SUITE_ADD_TEST (suite, test_merge_empty);
 	SUITE_ADD_TEST (suite, test_free_null);
 	SUITE_ADD_TEST (suite, test_match);
 	SUITE_ADD_TEST (suite, test_matchn);