db: fix change detection for symlinks

apk_fileinfo_get() special cases symlink digest calculation.
Convert apk_fsdir_ops.file_digest to .file_info to fix symlink
change detection.

fixes #10853

src/apk_fs.h

@@ -42,7 +42,7 @@ struct apk_fsdir_ops {
 
 	int (*file_extract)(struct apk_ctx *, const struct apk_file_info *, struct apk_istream *, apk_progress_cb, void *, unsigned int, apk_blob_t);
 	int (*file_control)(struct apk_fsdir *, apk_blob_t, int);
-	int (*file_digest)(struct apk_fsdir *, apk_blob_t, uint8_t alg, struct apk_digest *);
+	int (*file_info)(struct apk_fsdir *, apk_blob_t, unsigned int, struct apk_file_info *);
 };
 
 #define APK_FSEXTRACTF_NO_CHOWN		0x0001
@@ -72,8 +72,8 @@ static inline int apk_fsdir_update_perms(struct apk_fsdir *fs, mode_t mode, uid_
 static inline int apk_fsdir_file_control(struct apk_fsdir *fs, apk_blob_t filename, int ctrl) {
 	return fs->ops->file_control(fs, filename, ctrl);
 }
-static inline int apk_fsdir_file_digest(struct apk_fsdir *fs, apk_blob_t filename, uint8_t alg, struct apk_digest *dgst) {
+static inline int apk_fsdir_file_info(struct apk_fsdir *fs, apk_blob_t filename, unsigned int flags, struct apk_file_info *fi) {
-	return fs->ops->file_digest(fs, filename, alg, dgst);
+	return fs->ops->file_info(fs, filename, flags, fi);
 }
 
 #endif

src/database.c

@@ -2757,6 +2757,18 @@ static const struct apk_extract_ops extract_installer = {
 	.file = apk_db_install_file,
 };
 
+static int apk_db_audit_file(struct apk_fsdir *d, apk_blob_t filename, struct apk_db_file *dbf)
+{
+	struct apk_file_info fi;
+	int r;
+
+	// Check file first
+	r = apk_fsdir_file_info(d, filename, APK_FI_NOFOLLOW | APK_FI_DIGEST(apk_dbf_digest(dbf)), &fi);
+	if (r != 0 || !dbf || dbf->csum.type == APK_CHECKSUM_NONE) return r != -ENOENT;
+	if (apk_digest_cmp_csum(&fi.digest, &dbf->csum) != 0) return 1;
+	return 0;
+}
+
 static void apk_db_purge_pkg(struct apk_database *db,
 			     struct apk_installed_package *ipkg,
 			     int is_installed)
@@ -2766,7 +2778,6 @@ static void apk_db_purge_pkg(struct apk_database *db,
 	struct apk_db_file *file;
 	struct apk_db_file_hash_key key;
 	struct apk_fsdir d;
-	struct apk_digest dgst;
 	struct hlist_node *dc, *dn, *fc, *fn;
 	unsigned long hash;
 	int ctrl = is_installed ? APK_FS_CTRL_DELETE : APK_FS_CTRL_CANCEL;
@@ -2785,9 +2796,7 @@ static void apk_db_purge_pkg(struct apk_database *db,
 			if (!is_installed ||
 			    (diri->dir->protect_mode == APK_PROTECT_NONE) ||
 			    (db->ctx->flags & APK_PURGE) ||
-			    (file->csum.type != APK_CHECKSUM_NONE &&
+			    apk_db_audit_file(&d, key.filename, file) == 0)
-			     apk_fsdir_file_digest(&d, key.filename, apk_dbf_digest(file), &dgst) == 0 &&
-			     apk_digest_cmp_csum(&dgst, &file->csum) == 0))
 				apk_fsdir_file_control(&d, key.filename, ctrl);
 
 			apk_dbg2(out, DIR_FILE_FMT, DIR_FILE_PRINTF(diri->dir, file));
@@ -2813,7 +2822,6 @@ static uint8_t apk_db_migrate_files_for_priority(struct apk_database *db,
 	struct apk_db_file_hash_key key;
 	struct hlist_node *dc, *dn, *fc, *fn;
 	struct apk_fsdir d;
-	struct apk_digest dgst;
 	unsigned long hash;
 	apk_blob_t dirname;
 	int r, ctrl;
@@ -2848,21 +2856,17 @@ static uint8_t apk_db_migrate_files_for_priority(struct apk_database *db,
 				// File was from overlay, delete the package's version
 				ctrl = APK_FS_CTRL_CANCEL;
 			} else if (diri->dir->protect_mode != APK_PROTECT_NONE &&
-				   apk_fsdir_file_digest(&d, key.filename, apk_dbf_digest(ofile), &dgst) == 0 &&
+				   apk_db_audit_file(&d, key.filename, ofile) != 0) {
-				   (!ofile || ofile->csum.type == APK_CHECKSUM_NONE ||
-				    apk_digest_cmp_csum(&dgst, &ofile->csum) != 0)) {
 				// Protected directory, and a file without db entry
 				// or with local modifications. Keep the filesystem file.
 				// Determine if the package's file should be kept as .apk-new
 				if ((db->ctx->flags & APK_CLEAN_PROTECTED) ||
-				    (file->csum.type != APK_CHECKSUM_NONE &&
+				    apk_db_audit_file(&d, key.filename, file) == 0) {
-				     (apk_fsdir_file_digest(&d, key.filename, apk_dbf_digest(file), &dgst) == 0 &&
-				      apk_digest_cmp_csum(&dgst, &file->csum) == 0))) {
 					// No .apk-new files allowed, or the file on disk has the same
 					// hash as the file from new package. Keep the on disk one.
 					ctrl = APK_FS_CTRL_CANCEL;
 				} else {
-					// All files difference. Use the package's file as .apk-new.
+					// All files differ. Use the package's file as .apk-new.
 					ctrl = APK_FS_CTRL_APKNEW;
 				}
 			}

src/fs_fsys.c

@@ -12,6 +12,7 @@
 
 #include "apk_fs.h"
 #include "apk_xattr.h"
+#include "apk_database.h" // for db->atoms
 
 #define TMPNAME_MAX (PATH_MAX + 64)
 
@@ -265,23 +266,16 @@ static int fsys_file_control(struct apk_fsdir *d, apk_blob_t filename, int ctrl)
 	return rc;
 }
 
-static int fsys_file_digest(struct apk_fsdir *d, apk_blob_t filename, uint8_t alg, struct apk_digest *dgst)
+static int fsys_file_info(struct apk_fsdir *d, apk_blob_t filename,
+			  unsigned int flags, struct apk_file_info *fi)
 {
 	struct apk_ctx *ac = d->ac;
-	struct apk_istream *is;
+	int n, r;
-	apk_blob_t blob;
-	int n;
 
 	n = apk_pathbuilder_pushb(&d->pb, filename);
-	is = apk_istream_from_file(apk_ctx_fd_dest(ac), apk_pathbuilder_cstr(&d->pb));
+	r = apk_fileinfo_get(apk_ctx_fd_dest(ac), apk_pathbuilder_cstr(&d->pb), flags, fi, &ac->db->atoms);
 	apk_pathbuilder_pop(&d->pb, n);
-	if (IS_ERR(is)) return PTR_ERR(is);
+	return r;
-
-	apk_digest_ctx_reset(&ac->dctx, alg);
-	while (apk_istream_get_all(is, &blob) == 0)
-		apk_digest_ctx_update(&ac->dctx, blob.ptr, blob.len);
-	apk_digest_ctx_final(&ac->dctx, dgst);
-	return apk_istream_close(is);
 }
 
 static const struct apk_fsdir_ops fsdir_ops_fsys = {
@@ -292,7 +286,7 @@ static const struct apk_fsdir_ops fsdir_ops_fsys = {
 	.dir_update_perms = fsys_dir_update_perms,
 	.file_extract = fsys_file_extract,
 	.file_control = fsys_file_control,
-	.file_digest = fsys_file_digest,
+	.file_info = fsys_file_info,
 };
 
 static const struct apk_fsdir_ops *apk_fsops_get(apk_blob_t dir)

src/fs_uvol.c

@@ -150,7 +150,7 @@ static int uvol_file_control(struct apk_fsdir *d, apk_blob_t filename, int ctrl)
 	}
 }
 
-static int uvol_file_digest(struct apk_fsdir *d, apk_blob_t filename, uint8_t alg, struct apk_digest *dgst)
+static int uvol_file_info(struct apk_fsdir *d, apk_blob_t filename, unsigned int flags, struct apk_file_info *fi)
 {
 	return -APKE_UVOL_ERROR;
 }
@@ -163,5 +163,5 @@ const struct apk_fsdir_ops fsdir_ops_uvol = {
 	.dir_update_perms = uvol_dir_update_perms,
 	.file_extract = uvol_file_extract,
 	.file_control = uvol_file_control,
-	.file_digest = uvol_file_digest,
+	.file_info = uvol_file_info,
 };