[PATCH 3/5] libkmod: Keep track of compression type

[Lucas De Marchi <lucas.de.marchi@xxxxxxxxx>]

Do not only set the type as direct, but also keep track of the
compression being used. This will allow using the in-kernel compression
in future.

Signed-off-by: Lucas De Marchi <lucas.de.marchi@xxxxxxxxx>
---
 libkmod/libkmod-file.c     | 27 +++++++++++++++------------
 libkmod/libkmod-internal.h |  7 +++++++
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index 1449c41..705770a 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -58,7 +58,7 @@ struct kmod_file {
 	gzFile gzf;
 #endif
 	int fd;
-	bool direct;
+	enum kmod_file_compression_type compression;
 	off_t size;
 	void *memory;
 	const struct file_ops *ops;
@@ -376,19 +376,20 @@ static const char magic_zlib[] = {0x1f, 0x8b};
 
 static const struct comp_type {
 	size_t magic_size;
+	enum kmod_file_compression_type compression;
 	const char *magic_bytes;
 	const struct file_ops ops;
 } comp_types[] = {
 #ifdef ENABLE_ZSTD
-	{sizeof(magic_zstd), magic_zstd, {load_zstd, unload_zstd}},
+	{sizeof(magic_zstd),	KMOD_FILE_COMPRESSION_ZSTD, magic_zstd, {load_zstd, unload_zstd}},
 #endif
 #ifdef ENABLE_XZ
-	{sizeof(magic_xz), magic_xz, {load_xz, unload_xz}},
+	{sizeof(magic_xz),	KMOD_FILE_COMPRESSION_XZ, magic_xz, {load_xz, unload_xz}},
 #endif
 #ifdef ENABLE_ZLIB
-	{sizeof(magic_zlib), magic_zlib, {load_zlib, unload_zlib}},
+	{sizeof(magic_zlib),	KMOD_FILE_COMPRESSION_ZLIB, magic_zlib, {load_zlib, unload_zlib}},
 #endif
-	{0, NULL, {NULL, NULL}}
+	{0,			KMOD_FILE_COMPRESSION_NONE, NULL, {NULL, NULL}}
 };
 
 static int load_reg(struct kmod_file *file)
@@ -403,7 +404,7 @@ static int load_reg(struct kmod_file *file)
 			    file->fd, 0);
 	if (file->memory == MAP_FAILED)
 		return -errno;
-	file->direct = true;
+
 	return 0;
 }
 
@@ -448,7 +449,6 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx,
 			magic_size_max = itr->magic_size;
 	}
 
-	file->direct = false;
 	if (magic_size_max > 0) {
 		char *buf = alloca(magic_size_max + 1);
 		ssize_t sz;
@@ -468,15 +468,18 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx,
 		}
 
 		for (itr = comp_types; itr->ops.load != NULL; itr++) {
-			if (memcmp(buf, itr->magic_bytes, itr->magic_size) == 0)
+			if (memcmp(buf, itr->magic_bytes, itr->magic_size) == 0) {
+				file->ops = &itr->ops;
+				file->compression = itr->compression;
 				break;
+			}
 		}
-		if (itr->ops.load != NULL)
-			file->ops = &itr->ops;
 	}
 
-	if (file->ops == NULL)
+	if (file->ops == NULL) {
 		file->ops = &reg_ops;
+		file->compression = KMOD_FILE_COMPRESSION_NONE;
+	}
 
 	file->ctx = ctx;
 
@@ -512,7 +515,7 @@ off_t kmod_file_get_size(const struct kmod_file *file)
 
 bool kmod_file_get_direct(const struct kmod_file *file)
 {
-	return file->direct;
+	return file->compression == KMOD_FILE_COMPRESSION_NONE;
 }
 
 int kmod_file_get_fd(const struct kmod_file *file)
diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index 4799ed5..7b8a158 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h
@@ -61,6 +61,13 @@ struct kmod_list {
 	void *data;
 };
 
+enum kmod_file_compression_type {
+	KMOD_FILE_COMPRESSION_NONE = 0,
+	KMOD_FILE_COMPRESSION_ZSTD,
+	KMOD_FILE_COMPRESSION_XZ,
+	KMOD_FILE_COMPRESSION_ZLIB,
+};
+
 struct kmod_list *kmod_list_append(struct kmod_list *list, const void *data) _must_check_ __attribute__((nonnull(2)));
 struct kmod_list *kmod_list_prepend(struct kmod_list *list, const void *data) _must_check_ __attribute__((nonnull(2)));
 struct kmod_list *kmod_list_remove(struct kmod_list *list) _must_check_;
-- 
2.40.1