Remodel libtar/tar2sqfs to read data from an istream_t

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

9 files changed, 92 insertions, 122 deletions

diff --git a/lib/tar/Makemodule.am b/lib/tar/Makemodule.am
index 7ba0454..414aca1 100644
--- a/lib/tar/Makemodule.am
+++ b/lib/tar/Makemodule.am
@@ -1,9 +1,10 @@
-libtar_a_SOURCES = lib/tar/read_header.c lib/tar/write_header.c lib/tar/skip.c
+libtar_a_SOURCES = lib/tar/read_header.c lib/tar/write_header.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 lib/tar/read_retry.c include/tar.h
+libtar_a_SOURCES += lib/tar/padd_file.c lib/tar/record_to_memory.c
 libtar_a_SOURCES += lib/tar/pax_header.c lib/tar/read_sparse_map_new.c
+libtar_a_SOURCES += include/tar.h
 libtar_a_CFLAGS = $(AM_CFLAGS)
 libtar_a_CPPFLAGS = $(AM_CPPFLAGS)
 
diff --git a/lib/tar/internal.h b/lib/tar/internal.h
index bea863d..b7c4c34 100644
--- a/lib/tar/internal.h
+++ b/lib/tar/internal.h
@@ -59,9 +59,9 @@ bool is_checksum_valid(const tar_header_t *hdr);
 
 sparse_map_t *read_sparse_map(const char *line);
 
-sparse_map_t *read_gnu_old_sparse(FILE *fp, tar_header_t *hdr);
+sparse_map_t *read_gnu_old_sparse(istream_t *fp, tar_header_t *hdr);
 
-sparse_map_t *read_gnu_new_sparse(FILE *fp, tar_header_decoded_t *out);
+sparse_map_t *read_gnu_new_sparse(istream_t *fp, tar_header_decoded_t *out);
 
 void free_sparse_list(sparse_map_t *sparse);
 
@@ -69,9 +69,9 @@ size_t base64_decode(sqfs_u8 *out, const char *in, size_t len);
 
 void urldecode(char *str);
 
-char *record_to_memory(FILE *fp, sqfs_u64 size);
+char *record_to_memory(istream_t *fp, size_t size);
 
-int read_pax_header(FILE *fp, sqfs_u64 entsize, unsigned int *set_by_pax,
+int read_pax_header(istream_t *fp, sqfs_u64 entsize, unsigned int *set_by_pax,
 		    tar_header_decoded_t *out);
 
 #endif /* INTERNAL_H */
diff --git a/lib/tar/pax_header.c b/lib/tar/pax_header.c
index 448976d..a96a32f 100644
--- a/lib/tar/pax_header.c
+++ b/lib/tar/pax_header.c
@@ -25,7 +25,7 @@ static tar_xattr_t *mkxattr(const char *key, size_t keylen,
 	return xattr;
 }
 
-int read_pax_header(FILE *fp, sqfs_u64 entsize, unsigned int *set_by_pax,
+int read_pax_header(istream_t *fp, sqfs_u64 entsize, unsigned int *set_by_pax,
 		    tar_header_decoded_t *out)
 {
 	char *buffer, *line, *key, *ptr, *value, *end;
diff --git a/lib/tar/read_header.c b/lib/tar/read_header.c
index 14752ea..b332514 100644
--- a/lib/tar/read_header.c
+++ b/lib/tar/read_header.c
@@ -170,20 +170,24 @@ static int decode_header(const tar_header_t *hdr, unsigned int set_by_pax,
 	return 0;
 }
 
-int read_header(FILE *fp, tar_header_decoded_t *out)
+int read_header(istream_t *fp, tar_header_decoded_t *out)
 {
 	unsigned int set_by_pax = 0;
 	bool prev_was_zero = false;
 	sqfs_u64 pax_size;
 	tar_header_t hdr;
-	int version;
+	int version, ret;
 
 	memset(out, 0, sizeof(*out));
 
 	for (;;) {
-		if (read_retry("reading tar header", fp, &hdr, sizeof(hdr)))
+		ret = istream_read(fp, &hdr, sizeof(hdr));
+		if (ret < 0)
 			goto fail;
 
+		if ((size_t)ret < sizeof(hdr))
+			goto out_eof;
+
 		if (is_zero_block(&hdr)) {
 			if (prev_was_zero)
 				goto out_eof;
@@ -294,3 +298,17 @@ fail:
 	clear_header(out);
 	return -1;
 }
+
+int skip_padding(istream_t *fp, sqfs_u64 size)
+{
+	size_t tail = size % 512;
+
+	return tail ? istream_skip(fp, 512 - tail) : 0;
+}
+
+int skip_entry(istream_t *fp, sqfs_u64 size)
+{
+	size_t tail = size % 512;
+
+	return istream_skip(fp, tail ? (size + 512 - tail) : size);
+}
diff --git a/lib/tar/read_retry.c b/lib/tar/read_retry.c
deleted file mode 100644
index 2a2f82c..0000000
--- a/lib/tar/read_retry.c
+++ /dev/null
@@ -1,57 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * read_retry.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "tar.h"
-#include "internal.h"
-
-int read_retry(const char *errstr, FILE *fp, void *buffer, size_t size)
-{
-	size_t ret;
-
-	while (size > 0) {
-		if (ferror(fp)) {
-			fprintf(stderr, "%s: error reading from file\n",
-				errstr);
-			return -1;
-		}
-
-		if (feof(fp)) {
-			fprintf(stderr, "%s: short read\n", errstr);
-			return -1;
-		}
-
-		ret = fread(buffer, 1, size, fp);
-		size -= ret;
-		buffer = (char *)buffer + ret;
-	}
-
-	return 0;
-}
-
-char *record_to_memory(FILE *fp, sqfs_u64 size)
-{
-	char *buffer = malloc(size + 1);
-
-	if (buffer == NULL)
-		goto fail_errno;
-
-	if (read_retry("reading tar record", fp, buffer, size))
-		goto fail;
-
-	if (skip_padding(fp, size))
-		goto fail;
-
-	buffer[size] = '\0';
-	return buffer;
-fail_errno:
-	perror("reading tar record");
-	goto fail;
-fail:
-	free(buffer);
-	return NULL;
-}
diff --git a/lib/tar/read_sparse_map_new.c b/lib/tar/read_sparse_map_new.c
index f4f0f92..d9f6c6e 100644
--- a/lib/tar/read_sparse_map_new.c
+++ b/lib/tar/read_sparse_map_new.c
@@ -28,7 +28,7 @@ static int decode(const char *str, size_t len, size_t *out)
 	return (*str == '\n') ? ((int)count + 1) : -1;
 }
 
-sparse_map_t *read_gnu_new_sparse(FILE *fp, tar_header_decoded_t *out)
+sparse_map_t *read_gnu_new_sparse(istream_t *fp, tar_header_decoded_t *out)
 {
 	sparse_map_t *last = NULL, *list = NULL, *ent = NULL;
 	size_t i, count, value;
@@ -38,8 +38,12 @@ sparse_map_t *read_gnu_new_sparse(FILE *fp, tar_header_decoded_t *out)
 	if (out->record_size < 512)
 		goto fail_format;
 
-	if (read_retry("reading GNU sparse map", fp, buffer, 512))
-		return NULL;
+	ret = istream_read(fp, buffer, 512);
+	if (ret < 0)
+		goto fail;
+
+	if (ret < 512)
+		goto fail_format;
 
 	diff = decode(buffer, 512, &count);
 	if (diff <= 0)
@@ -61,10 +65,12 @@ sparse_map_t *read_gnu_new_sparse(FILE *fp, tar_header_decoded_t *out)
 			if (out->record_size < 512)
 				goto fail_format;
 
-			if (read_retry("reading GNU sparse map", fp,
-				       buffer + 512, 512)) {
-				return NULL;
-			}
+			ret = istream_read(fp, buffer + 512, 512);
+			if (ret < 0)
+				goto fail;
+
+			if (ret < 512)
+				goto fail_format;
 
 			ret = decode(buffer + diff, 1024 - diff, &value);
 			if (ret <= 0)
diff --git a/lib/tar/read_sparse_map_old.c b/lib/tar/read_sparse_map_old.c
index 84e1f9e..cd7177d 100644
--- a/lib/tar/read_sparse_map_old.c
+++ b/lib/tar/read_sparse_map_old.c
@@ -8,12 +8,12 @@
 
 #include "internal.h"
 
-sparse_map_t *read_gnu_old_sparse(FILE *fp, tar_header_t *hdr)
+sparse_map_t *read_gnu_old_sparse(istream_t *fp, tar_header_t *hdr)
 {
 	sparse_map_t *list = NULL, *end = NULL, *node;
 	gnu_sparse_t sph;
 	sqfs_u64 off, sz;
-	int i;
+	int i, ret;
 
 	for (i = 0; i < 4; ++i) {
 		if (!isdigit(hdr->tail.gnu.sparse[i].offset[0]))
@@ -47,8 +47,14 @@ sparse_map_t *read_gnu_old_sparse(FILE *fp, tar_header_t *hdr)
 		return list;
 
 	do {
-		if (read_retry("reading GNU sparse header",
-			       fp, &sph, sizeof(sph))) {
+		ret = istream_read(fp, &sph, sizeof(sph));
+		if (ret < 0)
+			goto fail;
+
+		if ((size_t)ret < sizeof(sph)) {
+			fputs("reading GNU sparse header: "
+			      "unexpected end-of-file\n",
+			      stderr);
 			goto fail;
 		}
 
diff --git a/lib/tar/record_to_memory.c b/lib/tar/record_to_memory.c
new file mode 100644
index 0000000..822608c
--- /dev/null
+++ b/lib/tar/record_to_memory.c
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * record_to_memory.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "tar.h"
+#include "internal.h"
+
+char *record_to_memory(istream_t *fp, size_t size)
+{
+	char *buffer = malloc(size + 1);
+	int ret;
+
+	if (buffer == NULL)
+		goto fail_errno;
+
+	ret = istream_read(fp, buffer, size);
+	if (ret < 0)
+		goto fail;
+
+	if ((size_t)ret < size) {
+		fputs("Reading tar record: unexpected end-of-file.\n", stderr);
+		goto fail;
+	}
+
+	if (skip_padding(fp, size))
+		goto fail;
+
+	buffer[size] = '\0';
+	return buffer;
+fail_errno:
+	perror("reading tar record");
+	goto fail;
+fail:
+	free(buffer);
+	return NULL;
+}
diff --git a/lib/tar/skip.c b/lib/tar/skip.c
deleted file mode 100644
index 36cd470..0000000
--- a/lib/tar/skip.c
+++ /dev/null
@@ -1,44 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * skip.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "tar.h"
-
-#include <stdio.h>
-
-static int skip_bytes(FILE *fp, sqfs_u64 size)
-{
-	unsigned char buffer[1024];
-	size_t diff;
-
-	while (size != 0) {
-		diff = sizeof(buffer);
-		if (diff > size)
-			diff = size;
-
-		if (read_retry("reading tar record padding", fp, buffer, diff))
-			return -1;
-
-		size -= diff;
-	}
-
-	return 0;
-}
-
-int skip_padding(FILE *fp, sqfs_u64 size)
-{
-	size_t tail = size % 512;
-
-	return tail ? skip_bytes(fp, 512 - tail) : 0;
-}
-
-int skip_entry(FILE *fp, sqfs_u64 size)
-{
-	size_t tail = size % 512;
-
-	return skip_bytes(fp, tail ? (size + 512 - tail) : size);
-}