rework error handling for read streams

src/apk.c

@@ -524,7 +524,7 @@ int main(int argc, char **argv)
 	}
 	if (test_installed_db != NULL) {
 		struct apk_bstream *bs = apk_bstream_from_file(AT_FDCWD, test_installed_db);
-		if (bs != NULL) {
+		if (!IS_ERR_OR_NULL(bs)) {
 			apk_db_index_read(&db, bs, -1);
 			bs->close(bs, NULL);
 		}
@@ -548,7 +548,7 @@ int main(int argc, char **argv)
 		}
 
 		bs = apk_bstream_from_file(AT_FDCWD, name.ptr);
-		if (bs == NULL) {
+		if (IS_ERR_OR_NULL(bs)) {
 			apk_error("Failed to open repository: " BLOB_FMT, BLOB_PRINTF(name));
 			goto err;
 		}

src/database.c

@@ -698,6 +698,8 @@ int apk_db_read_overlay(struct apk_database *db, struct apk_bstream *bs)
 	struct apk_installed_package *ipkg;
 	apk_blob_t token = APK_BLOB_STR("\n"), line, bdir, bfile;
 
+	if (IS_ERR_OR_NULL(bs)) return -1;
+
 	pkg = apk_pkg_new();
 	if (pkg == NULL)
 		return -1;
@@ -1118,15 +1120,14 @@ static int apk_db_read_state(struct apk_database *db, int flags)
 
 	if (!(flags & APK_OPENF_NO_INSTALLED)) {
 		bs = apk_bstream_from_file(db->root_fd, apk_installed_file);
-		if (bs != NULL) {
+		if (!IS_ERR_OR_NULL(bs)) {
 			r = apk_db_index_read(db, bs, -1);
 			bs->close(bs, NULL);
-			if (r != 0)
+			if (r != 0) return -1;
-				return -1;
 		}
 
 		bs = apk_bstream_from_file(db->root_fd, apk_triggers_file);
-		if (bs != NULL) {
+		if (!IS_ERR_OR_NULL(bs)) {
 			apk_db_triggers_read(db, bs);
 			bs->close(bs, NULL);
 		}
@@ -1134,7 +1135,7 @@ static int apk_db_read_state(struct apk_database *db, int flags)
 
 	if (!(flags & APK_OPENF_NO_SCRIPTS)) {
 		is = apk_istream_from_file(db->root_fd, apk_scripts_file);
-		if (is != NULL) {
+		if (!IS_ERR_OR_NULL(is)) {
 			apk_tar_parse(is, apk_read_script_archive_entry, db,
 				      FALSE, &db->id_cache);
 			is->close(is);
@@ -1580,7 +1581,7 @@ int apk_db_open(struct apk_database *db, struct apk_db_options *dbopts)
 	if (!(dbopts->open_flags & APK_OPENF_NO_INSTALLED_REPO)) {
 		if (apk_db_cache_active(db)) {
 			bs = apk_bstream_from_file(db->cache_fd, "installed");
-			if (bs != NULL) {
+			if (!IS_ERR_OR_NULL(bs)) {
 				apk_db_index_read(db, bs, -2);
 				bs->close(bs, NULL);
 			}
@@ -2043,8 +2044,10 @@ static int load_apkindex(void *sctx, const struct apk_file_info *fi,
 	} else if (strcmp(fi->name, "APKINDEX") == 0) {
 		ctx->found = 1;
 		bs = apk_bstream_from_istream(is);
-		apk_db_index_read(ctx->db, bs, ctx->repo);
+		if (!IS_ERR_OR_NULL(bs)) {
-		bs->close(bs, NULL);
+			apk_db_index_read(ctx->db, bs, ctx->repo);
+			bs->close(bs, NULL);
+		}
 	}
 
 	return 0;
@@ -2055,6 +2058,8 @@ static int load_index(struct apk_database *db, struct apk_bstream *bs,
 {
 	int r = 0;
 
+	if (IS_ERR_OR_NULL(bs)) return bs ? PTR_ERR(bs) : -EINVAL;
+
 	if (targz) {
 		struct apk_istream *is;
 		struct apkindex_ctx ctx;
@@ -2072,8 +2077,10 @@ static int load_index(struct apk_database *db, struct apk_bstream *bs,
 			r = -ENOMSG;
 	} else {
 		bs = apk_bstream_from_istream(apk_bstream_gunzip(bs));
-		apk_db_index_read(db, bs, repo);
+		if (!IS_ERR_OR_NULL(bs)) {
-		bs->close(bs, NULL);
+			apk_db_index_read(db, bs, repo);
+			bs->close(bs, NULL);
+		}
 	}
 	return r;
 }
@@ -2145,10 +2152,10 @@ int apk_db_add_repository(apk_database_t _db, apk_blob_t _repository)
 	}
 	if (r == 0) {
 		bs = apk_bstream_from_fd_url(db->cache_fd, buf);
-		if (bs != NULL)
+		if (!IS_ERR_OR_NULL(bs))
 			r = load_index(db, bs, targz, repo_num);
 		else
-			r = -ENOENT;
+			r = PTR_ERR(bs);
 	}
 
 	if (r != 0) {
@@ -2564,8 +2571,8 @@ static int apk_db_unpack_pkg(struct apk_database *db,
 		need_copy = FALSE;
 
 	bs = apk_bstream_from_fd_url(filefd, file);
-	if (bs == NULL) {
+	if (IS_ERR_OR_NULL(bs)) {
-		r = -errno;
+		r = PTR_ERR(bs);
 		goto err_msg;
 	}
 	if (need_copy) {

src/fetch.c

@@ -169,8 +169,8 @@ static int fetch_package(apk_hash_item item, void *pctx)
 	}
 
 	is = apk_istream_from_fd_url(urlfd, url);
-	if (is == NULL) {
+	if (IS_ERR_OR_NULL(is)) {
-		r = -EIO;
+		r = PTR_ERR(is) ?: -EIO;
 		goto err;
 	}
 

src/gunzip.c

@@ -170,7 +170,7 @@ struct apk_istream *apk_bstream_gunzip_mpart(struct apk_bstream *bs,
 	return &gis->is;
 err:
 	bs->close(bs, NULL);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 
 struct apk_gzip_ostream {
@@ -236,8 +236,7 @@ struct apk_ostream *apk_ostream_gzip(struct apk_ostream *output)
 	if (IS_ERR_OR_NULL(output)) return ERR_CAST(output);
 
 	gos = malloc(sizeof(struct apk_gzip_ostream));
-	if (gos == NULL)
+	if (gos == NULL) goto err;
-		goto err;
 
 	*gos = (struct apk_gzip_ostream) {
 		.os.write = gzo_write,
@@ -254,6 +253,6 @@ struct apk_ostream *apk_ostream_gzip(struct apk_ostream *output)
 	return &gos->os;
 err:
 	output->close(output);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 

src/io.c

@@ -83,12 +83,12 @@ struct apk_istream *apk_istream_from_fd_pid(int fd, pid_t pid, int (*translate_s
 {
 	struct apk_fd_istream *fis;
 
-	if (fd < 0) return NULL;
+	if (fd < 0) return ERR_PTR(-EBADF);
 
 	fis = malloc(sizeof(struct apk_fd_istream));
 	if (fis == NULL) {
 		close(fd);
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	*fis = (struct apk_fd_istream) {
@@ -107,7 +107,7 @@ struct apk_istream *apk_istream_from_file(int atfd, const char *file)
 	int fd;
 
 	fd = openat(atfd, file, O_RDONLY | O_CLOEXEC);
-	if (fd < 0) return NULL;
+	if (fd < 0) return ERR_PTR(-errno);
 
 	return apk_istream_from_fd(fd);
 }
@@ -273,7 +273,7 @@ struct apk_bstream *apk_bstream_from_istream(struct apk_istream *istream)
 	if (IS_ERR_OR_NULL(istream)) return ERR_CAST(istream);
 
 	isbs = malloc(sizeof(struct apk_istream_bstream));
-	if (isbs == NULL) return NULL;
+	if (isbs == NULL) return ERR_PTR(-ENOMEM);
 
 	isbs->bs = (struct apk_bstream) {
 		.read = is_bs_read,
@@ -330,15 +330,15 @@ static struct apk_bstream *apk_mmap_bstream_from_fd(int fd)
 	struct stat st;
 	void *ptr;
 
-	if (fstat(fd, &st) < 0) return NULL;
+	if (fstat(fd, &st) < 0) return ERR_PTR(-errno);
 
 	ptr = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
-	if (ptr == MAP_FAILED) return NULL;
+	if (ptr == MAP_FAILED) return ERR_PTR(-errno);
 
 	mbs = malloc(sizeof(struct apk_mmap_bstream));
 	if (mbs == NULL) {
 		munmap(ptr, st.st_size);
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	mbs->bs = (struct apk_bstream) {
@@ -358,12 +358,11 @@ struct apk_bstream *apk_bstream_from_fd_pid(int fd, pid_t pid, int (*translate_s
 {
 	struct apk_bstream *bs;
 
-	if (fd < 0) return NULL;
+	if (fd < 0) return ERR_PTR(-EBADF);
 
 	if (pid == 0) {
 		bs = apk_mmap_bstream_from_fd(fd);
-		if (bs != NULL)
+		if (IS_ERR_OR_NULL(bs)) return ERR_CAST(bs);
-			return bs;
 	}
 
 	return apk_bstream_from_istream(apk_istream_from_fd_pid(fd, pid, translate_status));
@@ -374,7 +373,7 @@ struct apk_bstream *apk_bstream_from_file(int atfd, const char *file)
 	int fd;
 
 	fd = openat(atfd, file, O_RDONLY | O_CLOEXEC);
-	if (fd < 0) return NULL;
+	if (fd < 0) return ERR_PTR(-errno);
 
 	return apk_bstream_from_fd(fd);
 }
@@ -569,7 +568,7 @@ int apk_file_get_info(int atfd, const char *filename, unsigned int flags,
 	}
 
 	bs = apk_bstream_from_file(atfd, filename);
-	if (bs != NULL) {
+	if (!IS_ERR_OR_NULL(bs)) {
 		EVP_MD_CTX mdctx;
 		apk_blob_t blob;
 

src/package.c

@@ -903,8 +903,10 @@ int apk_pkg_read(struct apk_database *db, const char *file,
 	if (ctx.pkg == NULL)
 		goto err;
 	bs = apk_bstream_from_file(AT_FDCWD, file);
-	if (bs == NULL)
+	if (IS_ERR_OR_NULL(bs)) {
+		r = PTR_ERR(bs) ?: -EIO;
 		goto err;
+	}
 
 	ctx.db = db;
 	ctx.pkg->size = fi.size;

src/url.c

@@ -38,6 +38,34 @@ struct apk_fetch_istream {
 	fetchIO *fetchIO;
 };
 
+static int fetch_maperror(int ec)
+{
+	static const char map[] = {
+		[FETCH_ABORT] = -ECONNABORTED,
+		[FETCH_AUTH] = -EACCES,
+		[FETCH_DOWN] = -ECONNREFUSED,
+		[FETCH_EXISTS] = -EEXIST,
+		[FETCH_FULL] = -ENOSPC,
+		/* [FETCH_INFO] = , */
+		[FETCH_MEMORY] = -ENOMEM,
+		[FETCH_MOVED] = -ENOENT,
+		[FETCH_NETWORK] = -ENETUNREACH,
+		/* [FETCH_OK] = , */
+		[FETCH_PROTO] = -EPROTO,
+		[FETCH_RESOLV] = -ENXIO,
+		[FETCH_SERVER] = -EREMOTEIO,
+		[FETCH_TEMP] = -EAGAIN,
+		[FETCH_TIMEOUT] = -ETIMEDOUT,
+		[FETCH_UNAVAIL] = -ENOENT,
+		[FETCH_UNKNOWN] = -EIO,
+		[FETCH_URL] = -EINVAL,
+		[FETCH_UNCHANGED] = -EALREADY,
+	};
+
+	if (ec < 0 || ec >= ARRAY_SIZE(map) || !map[ec]) return -EIO;
+	return map[ec];
+}
+
 static ssize_t fetch_read(void *stream, void *ptr, size_t size)
 {
 	struct apk_fetch_istream *fis = container_of(stream, struct apk_fetch_istream, is);
@@ -70,14 +98,11 @@ static struct apk_istream *apk_istream_fetch(const char *url, time_t since)
 	fetchIO *io;
 
 	u = fetchParseURL(url);
-	if (!u) return NULL;
+	if (!u) return ERR_PTR(-ENOMEM);
 	u->last_modified = since;
 	io = fetchGet(u, "i");
 	fetchFreeURL(u);
-	if (!io) {
+	if (!io) return ERR_PTR(fetch_maperror(fetchLastErrCode));
-		if (fetchLastErrCode == FETCH_UNCHANGED) return ERR_PTR(-EALREADY);
-		return NULL;
-	}
 
 	fis = malloc(sizeof(*fis));
 	if (!fis) goto err;
@@ -91,7 +116,7 @@ static struct apk_istream *apk_istream_fetch(const char *url, time_t since)
 	return &fis->is;
 err:
 	if (io) fetchIO_close(io);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 
 struct apk_istream *apk_istream_from_fd_url_if_modified(int atfd, const char *url, time_t since)

src/verify.c

@@ -28,7 +28,7 @@ static int verify_main(void *ctx, struct apk_database *db, struct apk_string_arr
 		apk_sign_ctx_init(&sctx, APK_SIGN_VERIFY, NULL, db->keys_fd);
 		is = apk_bstream_gunzip_mpart(apk_bstream_from_file(AT_FDCWD, *parg),
 					      apk_sign_ctx_mpart_cb, &sctx);
-		if (is == NULL) {
+		if (IS_ERR_OR_NULL(is)) {
 			if (apk_verbosity >= 1)
 				apk_error("%s: %s", *parg, strerror(errno));
 			else