include/fileeq: add functions to compare files content

Signed-off-by: Karel Zak <kzak@redhat.com>

include/all-io.h

@@ -111,5 +111,4 @@ static inline ssize_t sendfile_all(int out, int in, off_t *off, size_t count)
 	return -1;
 #endif
 }
-
 #endif /* UTIL_LINUX_ALL_IO_H */

include/fileeq.h

@@ -0,0 +1,53 @@
+#ifndef UTIL_LINUX_FILEEQ
+#define UTIL_LINUX_FILEEQ
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+/* Number of bytes from the beginnning of the file we always
+ * compare by memcmp() */
+#define UL_FILEEQ_INTROSIZ	32
+
+struct ul_fileeq_data {
+	unsigned char intro[UL_FILEEQ_INTROSIZ];
+	unsigned char *blocks;
+	size_t nblocks;
+	size_t maxblocks;
+	int fd;
+	const char *name;
+	bool is_eof;
+};
+
+struct ul_fileeq {
+	int fd_api;	/* Crypto socket */
+	int fd_cip;	/* Cipher handler */
+
+	size_t readsiz;
+	uint64_t filesiz;
+	uint64_t blocksmax;
+	const struct ul_fileeq_method *method;
+
+	/* UL_FILEEQ_MEMCMP buffers */
+	unsigned char *buf_a;
+	unsigned char *buf_b;
+	unsigned char *buf_last;
+};
+
+extern int ul_fileeq_init(struct ul_fileeq *eq, const char *method);
+extern void ul_fileeq_deinit(struct ul_fileeq *eq);
+
+
+extern int ul_fileeq_data_associated(struct ul_fileeq_data *data);
+extern void ul_fileeq_data_close_file(struct ul_fileeq_data *data);
+extern void ul_fileeq_data_init(struct ul_fileeq_data *data);
+extern void ul_fileeq_data_deinit(struct ul_fileeq_data *data);
+extern void ul_fileeq_data_set_file(struct ul_fileeq_data *data,
+				    const char *name);
+extern size_t ul_fileeq_set_size(struct ul_fileeq *eq, uint64_t filesiz,
+                                 size_t readsiz, size_t memsiz);
+
+extern int ul_fileeq(struct ul_fileeq *eq,
+              struct ul_fileeq_data *a, struct ul_fileeq_data *b);
+
+#endif /* UTIL_LINUX_FILEEQ */

lib/Makemodule.am

@@ -84,6 +84,7 @@ check_PROGRAMS += \
 	test_buffer \
 	test_canonicalize \
 	test_colors \
+	test_fileeq \
 	test_fileutils \
 	test_ismounted \
 	test_pwdutils \
@@ -188,6 +189,9 @@ test_linux_version_SOURCES = lib/linux_version.c
 test_linux_version_CFLAGS = $(AM_CFLAGS) -DTEST_PROGRAM_LINUXVERSION
 endif
 
+test_fileeq_SOURCES = lib/fileeq.c
+test_fileeq_CFLAGS = $(AM_CFLAGS) -DTEST_PROGRAM_FILEEQ
+
 test_fileutils_SOURCES = lib/fileutils.c
 test_fileutils_CFLAGS = $(AM_CFLAGS) -DTEST_PROGRAM_FILEUTILS