Cleanup: move read_data function to libtar

Its the only user. The other code doesn't touch raw file
descriptors anymore.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

5 files changed, 43 insertions, 6 deletions

diff --git a/lib/tar/Makemodule.am b/lib/tar/Makemodule.am
index 129d66f..f0945ff 100644
--- a/lib/tar/Makemodule.am
+++ b/lib/tar/Makemodule.am
@@ -2,7 +2,7 @@ libtar_a_SOURCES = lib/tar/read_header.c lib/tar/write_header.c lib/tar/skip.c
 libtar_a_SOURCES += lib/tar/number.c lib/tar/checksum.c lib/tar/cleanup.c
 libtar_a_SOURCES += lib/tar/read_sparse_map.c lib/tar/read_sparse_map_old.c
 libtar_a_SOURCES += lib/tar/base64.c lib/tar/urldecode.c lib/tar/internal.h
-libtar_a_SOURCES += lib/tar/padd_file.c include/tar.h
+libtar_a_SOURCES += lib/tar/padd_file.c lib/tar/read_retry.c include/tar.h
 libtar_a_CFLAGS = $(AM_CFLAGS)
 libtar_a_CPPFLAGS = $(AM_CPPFLAGS)
 
diff --git a/lib/tar/read_header.c b/lib/tar/read_header.c
index f6d746b..760d36a 100644
--- a/lib/tar/read_header.c
+++ b/lib/tar/read_header.c
@@ -42,7 +42,7 @@ static char *record_to_memory(int fd, sqfs_u64 size)
 	if (buffer == NULL)
 		goto fail_errno;
 
-	if (read_data("reading tar record", fd, buffer, size))
+	if (read_retry("reading tar record", fd, buffer, size))
 		goto fail;
 
 	if (skip_padding(fd, size))
@@ -368,7 +368,7 @@ int read_header(int fd, tar_header_decoded_t *out)
 	memset(out, 0, sizeof(*out));
 
 	for (;;) {
-		if (read_data("reading tar header", fd, &hdr, sizeof(hdr)))
+		if (read_retry("reading tar header", fd, &hdr, sizeof(hdr)))
 			goto fail;
 
 		if (is_zero_block(&hdr)) {
diff --git a/lib/tar/read_retry.c b/lib/tar/read_retry.c
new file mode 100644
index 0000000..5d06595
--- /dev/null
+++ b/lib/tar/read_retry.c
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * read_retry.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include "tar.h"
+
+int read_retry(const char *errstr, int fd, void *buffer, size_t size)
+{
+	ssize_t ret;
+
+	while (size > 0) {
+		ret = read(fd, buffer, size);
+		if (ret < 0) {
+			if (errno == EINTR)
+				continue;
+			perror(errstr);
+			return -1;
+		}
+		if (ret == 0) {
+			fprintf(stderr, "%s: short read\n", errstr);
+			return -1;
+		}
+
+		size -= ret;
+		buffer = (char *)buffer + ret;
+	}
+
+	return 0;
+}
diff --git a/lib/tar/read_sparse_map_old.c b/lib/tar/read_sparse_map_old.c
index fb79eca..959c9a8 100644
--- a/lib/tar/read_sparse_map_old.c
+++ b/lib/tar/read_sparse_map_old.c
@@ -47,8 +47,8 @@ sparse_map_t *read_gnu_old_sparse(int fd, tar_header_t *hdr)
 		return list;
 
 	do {
-		if (read_data("reading GNU sparse header",
-			      fd, &sph, sizeof(sph))) {
+		if (read_retry("reading GNU sparse header",
+			       fd, &sph, sizeof(sph))) {
 			goto fail;
 		}
 
diff --git a/lib/tar/skip.c b/lib/tar/skip.c
index eb91416..0ebe013 100644
--- a/lib/tar/skip.c
+++ b/lib/tar/skip.c
@@ -21,7 +21,7 @@ static int skip_bytes(int fd, sqfs_u64 size)
 		if (diff > size)
 			diff = size;
 
-		if (read_data("reading tar record padding", fd, buffer, diff))
+		if (read_retry("reading tar record padding", fd, buffer, diff))
 			return -1;
 
 		size -= diff;