reader: transform get_bidder into register_bidder

There's a notable duplication across all the read bidder code.

Check the archive magic/state, set the bidder private data (to NULL in
all but one case), name and vtable.

Change the helper to do the actual registration, keeping things simpler
in the dozen+ filters. This also allows us to enforce the bidder ::bid
and ::init dispatch are non NULL. The final one ::free is optional.

NOTE: some of the bidders do _not_ set a name, which I suspect is a
pre-existing bug. I've left them as-is, but we might want to fix and
enforce that somehow.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

1 files changed, 13 insertions, 27 deletions

diff --git a/libarchive/archive_read_support_filter_program.c b/libarchive/archive_read_support_filter_program.c
index 85540387..5d9d0719 100644
--- a/libarchive/archive_read_support_filter_program.c
+++ b/libarchive/archive_read_support_filter_program.c
@@ -130,40 +130,14 @@ program_bidder_vtable = {
 	.free = program_bidder_free,
 };
 
-static int
-set_bidder_signature(struct archive_read_filter_bidder *bidder,
-    struct program_bidder *state, const void *signature, size_t signature_len)
-{
-
-	if (signature != NULL && signature_len > 0) {
-		state->signature_len = signature_len;
-		state->signature = malloc(signature_len);
-		memcpy(state->signature, signature, signature_len);
-	}
-
-	/*
-	 * Fill in the bidder object.
-	 */
-	bidder->data = state;
-	bidder->vtable = &program_bidder_vtable;
-	return (ARCHIVE_OK);
-}
-
 int
 archive_read_support_filter_program_signature(struct archive *_a,
     const char *cmd, const void *signature, size_t signature_len)
 {
 	struct archive_read *a = (struct archive_read *)_a;
-	struct archive_read_filter_bidder *bidder;
 	struct program_bidder *state;
 
 	/*
-	 * Get a bidder object from the read core.
-	 */
-	if (__archive_read_get_bidder(a, &bidder) != ARCHIVE_OK)
-		return (ARCHIVE_FATAL);
-
-	/*
 	 * Allocate our private state.
 	 */
 	state = (struct program_bidder *)calloc(1, sizeof (*state));
@@ -173,7 +147,19 @@ archive_read_support_filter_program_signature(struct archive *_a,
 	if (state->cmd == NULL)
 		goto memerr;
 
-	return set_bidder_signature(bidder, state, signature, signature_len);
+	if (signature != NULL && signature_len > 0) {
+		state->signature_len = signature_len;
+		state->signature = malloc(signature_len);
+		memcpy(state->signature, signature, signature_len);
+	}
+
+	if (__archive_read_register_bidder(a, state, NULL,
+				&program_bidder_vtable) != ARCHIVE_OK) {
+		free_state(state);
+		return (ARCHIVE_FATAL);
+	}
+	return (ARCHIVE_OK);
+
 memerr:
 	free_state(state);
 	archive_set_error(_a, ENOMEM, "Can't allocate memory");