dovecot-2.2: lib-fs: Added support for giving a hash of the writ...

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.2/rev/7e0ebc2faf3c
changeset: 16721:7e0ebc2faf3c
user:      Timo Sirainen <tss at iki.fi>
date:      Tue Sep 10 00:27:12 2013 +0300
description:
lib-fs: Added support for giving a hash of the written data to be verified by storage.

diffstat:

 src/lib-fs/fs-api-private.h |   3 +++
 src/lib-fs/fs-api.c         |  17 +++++++++++++++++
 src/lib-fs/fs-api.h         |  13 ++++++++++++-
 3 files changed, 32 insertions(+), 1 deletions(-)

diffs (105 lines):

diff -r f73c388ad360 -r 7e0ebc2faf3c src/lib-fs/fs-api-private.h
--- a/src/lib-fs/fs-api-private.h	Mon Sep 09 04:34:58 2013 +0300
+++ b/src/lib-fs/fs-api-private.h	Tue Sep 10 00:27:12 2013 +0300
@@ -75,6 +75,9 @@
 	struct istream *pending_read_input;
 	bool write_pending;
 
+	const struct hash_method *write_digest_method;
+	void *write_digest;
+
 	pool_t metadata_pool;
 	ARRAY_TYPE(fs_metadata) metadata;
 
diff -r f73c388ad360 -r 7e0ebc2faf3c src/lib-fs/fs-api.c
--- a/src/lib-fs/fs-api.c	Mon Sep 09 04:34:58 2013 +0300
+++ b/src/lib-fs/fs-api.c	Tue Sep 10 00:27:12 2013 +0300
@@ -4,6 +4,7 @@
 #include "array.h"
 #include "module-dir.h"
 #include "str.h"
+#include "hash-method.h"
 #include "istream.h"
 #include "istream-seekable.h"
 #include "ostream.h"
@@ -199,6 +200,7 @@
 		i_stream_unref(&file->copy_input);
 		(void)fs_write_stream_abort(file, &file->copy_output);
 	}
+	i_free_and_null(file->write_digest);
 	if (file->fs->v.file_close != NULL) T_BEGIN {
 		file->fs->v.file_close(file);
 	} T_END;
@@ -251,6 +253,11 @@
 		file->fs->v.get_path(file);
 }
 
+struct fs *fs_file_fs(struct fs_file *file)
+{
+	return file->fs;
+}
+
 static void ATTR_FORMAT(2, 0)
 fs_set_verror(struct fs *fs, const char *fmt, va_list args)
 {
@@ -475,6 +482,16 @@
 	} T_END;
 }
 
+void fs_write_set_hash(struct fs_file *file, const struct hash_method *method,
+		       const void *digest)
+{
+	file->write_digest_method = method;
+
+	i_free(file->write_digest);
+	file->write_digest = i_malloc(method->digest_size);
+	memcpy(file->write_digest, digest, method->digest_size);
+}
+
 void fs_file_set_async_callback(struct fs_file *file,
 				fs_file_async_callback_t *callback,
 				void *context)
diff -r f73c388ad360 -r 7e0ebc2faf3c src/lib-fs/fs-api.h
--- a/src/lib-fs/fs-api.h	Mon Sep 09 04:34:58 2013 +0300
+++ b/src/lib-fs/fs-api.h	Tue Sep 10 00:27:12 2013 +0300
@@ -5,6 +5,7 @@
 struct fs;
 struct fs_file;
 struct fs_lock;
+struct hash_method;
 
 enum fs_properties {
 	FS_PROPERTY_METADATA	= 0x01,
@@ -19,7 +20,9 @@
 	FS_PROPERTY_RELIABLEITER= 0x40,
 	/* Backend uses directories, which aren't automatically deleted
 	   when its children are deleted. */
-	FS_PROPERTY_DIRECTORIES	= 0x80
+	FS_PROPERTY_DIRECTORIES	= 0x80,
+	FS_PROPERTY_WRITE_HASH_MD5	= 0x100,
+	FS_PROPERTY_WRITE_HASH_SHA256	= 0x200
 };
 
 enum fs_open_mode {
@@ -115,6 +118,8 @@
    FS_OPEN_MODE_CREATE_UNIQUE_128 and the write has already finished,
    return the path including the generated filename. */
 const char *fs_file_path(struct fs_file *file);
+/* Returns the file's fs. */
+struct fs *fs_file_fs(struct fs_file *file);
 
 /* Return the error message for the last failed operation. */
 const char *fs_last_error(struct fs *fs);
@@ -151,6 +156,12 @@
 /* Abort writing via stream. Anything written to the stream is discarded. */
 void fs_write_stream_abort(struct fs_file *file, struct ostream **output);
 
+/* Set a hash to the following write. The storage can then verify that the
+   input data matches the specified hash, or fail if it doesn't. Typically
+   implemented by Content-MD5 header. */
+void fs_write_set_hash(struct fs_file *file, const struct hash_method *method,
+		       const void *digest);
+
 /* Call the specified callback whenever the file can be read/written to.
    May call the callback immediately. */
 void fs_file_set_async_callback(struct fs_file *file,