ustar: Make seek names struct opaque

Simplify main() a little and fix memory leak on success.

4 files changed, 80 insertions, 52 deletions

diff --git a/src/main.c b/src/main.c
index c3cea7c..7b18541 100644
--- a/src/main.c
+++ b/src/main.c
@@ -25,19 +25,16 @@
 int
 main(int argc, char *argv[])
 {
-	struct opkg_opk_ustar_seek_name *control_files_head;
-	struct opkg_opk_ustar_seek_name *control_files_tail;
+	struct opkg_opk_ustar_seek_name *control_files;
 	struct opkg_opk_opk             *opk;
 
-	control_files_head = control_files_tail = NULL;
-	if (opkg_opk_ustar_add_seek_name(
-				&control_files_head, &control_files_tail,
-				"control") != OPKG_OPK_OK) {
+	control_files = NULL;
+	if (opkg_opk_ustar_add_seek_name(&control_files, "control") !=
+			OPKG_OPK_OK) {
 		goto error0;
 	}
-	if (opkg_opk_ustar_add_seek_name(
-				&control_files_head, &control_files_tail,
-				"md5sums") != OPKG_OPK_OK) {
+	if (opkg_opk_ustar_add_seek_name(&control_files, "md5sums") !=
+			OPKG_OPK_OK) {
 		goto error0;
 	}
 
@@ -51,7 +48,7 @@ main(int argc, char *argv[])
 	if (opkg_opk_opk_init_inner(opk, "control.tar.gz") != OPKG_OPK_OK) {
 		goto error1;
 	}
-	if (opkg_opk_opk_read_control(opk, control_files_head) != OPKG_OPK_OK) {
+	if (opkg_opk_opk_read_control(opk, control_files) != OPKG_OPK_OK) {
 		goto error2;
 	}
 	opkg_opk_opk_free_inner(opk);
@@ -66,6 +63,7 @@ main(int argc, char *argv[])
 	opkg_opk_opk_free_inner(opk);
 
 	opkg_opk_opk_free_outer(opk);
+	opkg_opk_ustar_free_seek_names(control_files);
 	return EXIT_SUCCESS;
 
  error2:
@@ -73,10 +71,6 @@ main(int argc, char *argv[])
  error1:
 	opkg_opk_opk_free_outer(opk);
  error0:
-	while (control_files_head != NULL) {
-		control_files_tail = control_files_head;
-		control_files_head = control_files_head->next;
-		free(control_files_tail);
-	}
+	opkg_opk_ustar_free_seek_names(control_files);
 	return EXIT_FAILURE;
 }
diff --git a/src/opk.c b/src/opk.c
index cdb3f58..45da6fd 100644
--- a/src/opk.c
+++ b/src/opk.c
@@ -59,8 +59,7 @@ _opkg_opk_opk_file_read(void *user_data, char **buffer, size_t *size)
 struct opkg_opk_opk *
 opkg_opk_opk_init_outer(const char *file_name)
 {
-	struct opkg_opk_opk             *opk;
-	struct opkg_opk_ustar_seek_name  seek_name;
+	struct opkg_opk_opk *opk;
 
 	opk = malloc(sizeof(*opk));
 	if (opk == NULL) {
@@ -90,11 +89,8 @@ opkg_opk_opk_init_outer(const char *file_name)
 	}
 
 	/* Check package version. */
-	seek_name.name  = "debian-binary";
-	seek_name.found = 0;
-	seek_name.next  = NULL;
-	if (opkg_opk_ustar_seek(opk->outer_ustar, &seek_name) == OPKG_OPK_ERROR)
-	{
+	if (opkg_opk_ustar_seek_one(opk->outer_ustar, "debian-binary") !=
+			OPKG_OPK_OK) {
 		fputs("Error: Failed to find \"debian-binary\" in archive\n",
 				stderr);
 		goto error3;
@@ -129,8 +125,7 @@ opkg_opk_opk_init_outer(const char *file_name)
 int
 opkg_opk_opk_init_inner(struct opkg_opk_opk *opk, const char *member)
 {
-	int                              ret;
-	struct opkg_opk_ustar_seek_name  seek_name;
+	int ret;
 
 	/* Finish reading previous inner archive, if any. */
 	while ((ret = opkg_opk_ustar_read(opk->outer_ustar, NULL, NULL)) ==
@@ -141,11 +136,7 @@ opkg_opk_opk_init_inner(struct opkg_opk_opk *opk, const char *member)
 	}
 
 	/* Find requested inner archive. */
-	seek_name.name  = member;
-	seek_name.found = 0;
-	seek_name.next  = NULL;
-	if (opkg_opk_ustar_seek(opk->outer_ustar, &seek_name) == OPKG_OPK_ERROR)
-	{
+	if (opkg_opk_ustar_seek_one(opk->outer_ustar, member) != OPKG_OPK_OK) {
 		fprintf(stderr, "Error: Failed to find \"%s\" in archive\n",
 				member);
 		return OPKG_OPK_ERROR;
diff --git a/src/ustar.c b/src/ustar.c
index 9d95052..47e0dfa 100644
--- a/src/ustar.c
+++ b/src/ustar.c
@@ -53,6 +53,12 @@ struct opkg_opk_ustar {
 	char                  read_record[OPKG_OPK_USTAR_RECORD_SIZE];
 };
 
+struct opkg_opk_ustar_seek_name {
+	const char                      *name;
+	int                              found;
+	struct opkg_opk_ustar_seek_name *next;
+};
+
 struct opkg_opk_ustar *
 opkg_opk_ustar_init(struct opkg_opk_gzip *gzip)
 {
@@ -226,8 +232,8 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 }
 
 int
-opkg_opk_ustar_add_seek_name(struct opkg_opk_ustar_seek_name **head,
-		struct opkg_opk_ustar_seek_name **tail, const char *name)
+opkg_opk_ustar_add_seek_name(struct opkg_opk_ustar_seek_name **names,
+		const char *name)
 {
 	struct opkg_opk_ustar_seek_name *seek_name;
 
@@ -237,18 +243,24 @@ opkg_opk_ustar_add_seek_name(struct opkg_opk_ustar_seek_name **head,
 	}
 	seek_name->name  = name;
 	seek_name->found = 0;
-	seek_name->next  = NULL;
-
-	if (*head == NULL) {
-		*head = seek_name;
-	} else {
-		(*tail)->next = seek_name;
-	}
-	*tail = seek_name;
+	seek_name->next  = *names;
 
+	*names = seek_name;
 	return OPKG_OPK_OK;
 }
 
+void
+opkg_opk_ustar_free_seek_names(struct opkg_opk_ustar_seek_name *names)
+{
+	struct opkg_opk_ustar_seek_name *name;
+
+	while (names != NULL) {
+		name  = names;
+		names = names->next;
+		free(name);
+	}
+}
+
 int
 opkg_opk_ustar_seek(struct opkg_opk_ustar *ustar,
 		struct opkg_opk_ustar_seek_name *names)
@@ -321,6 +333,22 @@ opkg_opk_ustar_seek(struct opkg_opk_ustar *ustar,
 }
 
 int
+opkg_opk_ustar_seek_one(struct opkg_opk_ustar *ustar, const char *name)
+{
+	struct opkg_opk_ustar_seek_name  seek_name;
+
+	seek_name.name  = name;
+	seek_name.found = 0;
+	seek_name.next  = NULL;
+
+	if (opkg_opk_ustar_seek(ustar, &seek_name) == OPKG_OPK_END) {
+		return OPKG_OPK_OK;
+	} else {
+		return OPKG_OPK_ERROR;
+	}
+}
+
+int
 opkg_opk_ustar_read(struct opkg_opk_ustar *ustar, char **buffer, size_t *size)
 {
 	if (ustar->data_size_remaining == 0) {
diff --git a/src/ustar.h b/src/ustar.h
index a5bb461..3495d38 100644
--- a/src/ustar.h
+++ b/src/ustar.h
@@ -41,11 +41,7 @@ struct opkg_opk_ustar_member {
 	struct opkg_opk_ustar_member *next;
 };
 
-struct opkg_opk_ustar_seek_name {
-	const char                      *name;
-	int                              found;
-	struct opkg_opk_ustar_seek_name *next;
-};
+struct opkg_opk_ustar_seek_name;
 
 /*
  * Allocates and initializes an archive structure.
@@ -76,26 +72,32 @@ opkg_opk_ustar_list(struct opkg_opk_ustar *ustar,
 
 /*
  * Adds a name to a list of names to find with opkg_opk_ustar_seek().  List is
- * dynamically allocated; free with free().
+ * dynamically allocated; free with opkg_opk_ustar_free_seek_names().
  * Parameters:
- * - head: Address in which to store address of list head.
- * - tail: Address in which to store address of list tail.
- * - name: Name of member file to find.
+ * - names: Address in which to store address of list.
+ * - name:  Name of member file to find.
  * Returns:
  * - OPKG_OPK_OK if the name was added to the list.
  * - OPKG_OPK_ERROR on memory exhaustion.
  */
 int
-opkg_opk_ustar_add_seek_name(struct opkg_opk_ustar_seek_name **head,
-		struct opkg_opk_ustar_seek_name **tail, const char *name);
+opkg_opk_ustar_add_seek_name(struct opkg_opk_ustar_seek_name **names,
+		const char *name);
+
+/*
+ * Frees a list of names to find with opkg_opk_ustar_seek().
+ * Parameters:
+ * - names: List of names.
+ */
+void
+opkg_opk_ustar_free_seek_names(struct opkg_opk_ustar_seek_name *names);
 
 /*
  * Advances to a named member file.  May be called multiple times until all
  * requested members are found.
  * Parameters:
  * - ustar: Archive structure.
- * - names: Name(s) to find.  Member "found" will be set to "1" on the first
- *   name found.
+ * - names: Name(s) to find.
  * Returns:
  * - OPKG_OPK_OK if a member matching one of the requested names is found but
  *   more names remain to be found.
@@ -109,6 +111,19 @@ opkg_opk_ustar_seek(struct opkg_opk_ustar *ustar,
 		struct opkg_opk_ustar_seek_name *names);
 
 /*
+ * Advances to a named member file.
+ * Parameters:
+ * - ustar: Archive structure.
+ * - name:  Name to find.
+ * Returns:
+ * - OPKG_OPK_OK if a member matching the requested name is found.
+ * - OPKG_OPK_ERROR if no matching member is found or on decompression error, an
+ *   invalid header, or unsupported file type.
+ */
+int
+opkg_opk_ustar_seek_one(struct opkg_opk_ustar *ustar, const char *name);
+
+/*
  * Reads up to a record (512 octets) of member file data at a time.
  * Parameters:
  * - ustar:  Archive structure.