db: checksum installed files, protect config files

Checksum of installed is computed on the fly when extracting them
and it'll be saved to fdb. When installing config files those are
diverted with suffix .apk-new if earlier version of same file with
local changes exist.

1 files changed, 13 insertions, 19 deletions

diff --git a/src/archive.c b/src/archive.c
index 33e3428..6562297 100644
--- a/src/archive.c
+++ b/src/archive.c
@@ -53,6 +53,8 @@ struct apk_tar_entry_istream {
 	struct apk_istream is;
 	struct apk_istream *tar_is;
 	size_t bytes_left;
+	csum_ctx_t csum_ctx;
+	csum_p csum;
 };
 
 static size_t tar_entry_read(void *stream, void *ptr, size_t size)
@@ -63,33 +65,24 @@ static size_t tar_entry_read(void *stream, void *ptr, size_t size)
 	if (size > teis->bytes_left)
 		size = teis->bytes_left;
 	size = teis->tar_is->read(teis->tar_is, ptr, size);
-	if (size >= 0)
-		teis->bytes_left -= size;
-	return size;
-}
-
-static size_t tar_entry_splice(void *stream, int fd, size_t size)
-{
-	struct apk_tar_entry_istream *teis =
-		container_of(stream, struct apk_tar_entry_istream, is);
-
-	if (size > teis->bytes_left)
-		size = teis->bytes_left;
-	size = teis->tar_is->splice(teis->tar_is, fd, size);
-	if (size >= 0)
+	if (size > 0) {
 		teis->bytes_left -= size;
+		csum_process(&teis->csum_ctx, ptr, size);
+		if (teis->bytes_left == 0)
+			csum_finish(&teis->csum_ctx, teis->csum);
+	}
 	return size;
 }
 
 int apk_parse_tar(struct apk_istream *is, apk_archive_entry_parser parser,
 		  void *ctx)
 {
+	struct apk_file_info entry;
 	struct apk_tar_entry_istream teis = {
 		.is.read = tar_entry_read,
-		.is.splice = tar_entry_splice,
 		.tar_is = is,
+		.csum = entry.csum,
 	};
-	struct apk_archive_entry entry;
 	struct tar_header buf;
 	unsigned long offset = 0;
 	int end = 0, r;
@@ -107,7 +100,7 @@ int apk_parse_tar(struct apk_istream *is, apk_archive_entry_parser parser,
 			continue;
 		}
 
-		entry = (struct apk_archive_entry){
+		entry = (struct apk_file_info){
 			.size  = GET_OCTAL(buf.size),
 			.uid   = GET_OCTAL(buf.uid),
 			.gid   = GET_OCTAL(buf.gid),
@@ -160,6 +153,7 @@ int apk_parse_tar(struct apk_istream *is, apk_archive_entry_parser parser,
 				entry.name = strdup(buf.name);
 
 			/* callback parser function */
+			csum_init(&teis.csum_ctx);
 			r = parser(ctx, &entry, &teis.is);
 			if (r != 0)
 				return r;
@@ -191,7 +185,7 @@ int apk_parse_tar_gz(struct apk_bstream *bs, apk_archive_entry_parser parser,
 	return apk_parse_tar(apk_gunzip_bstream(bs), parser, ctx);
 }
 
-int apk_archive_entry_extract(const struct apk_archive_entry *ae,
+int apk_archive_entry_extract(const struct apk_file_info *ae,
 			      struct apk_istream *is,
 			      const char *fn)
 {
@@ -216,7 +210,7 @@ int apk_archive_entry_extract(const struct apk_archive_entry *ae,
 				r = -1;
 				break;
 			}
-			if (is->splice(is, fd, ae->size) == ae->size)
+			if (apk_istream_splice(is, fd, ae->size) == ae->size)
 				r = 0;
 			close(fd);
 		} else {