Overhaul sqfs_istream_t/sqfs_ostream_t error handling

Report an error number from the implementations, change the users to
forward that error number (which also means libtar write header/link
now returns an error code) and all subsequent binaries to use
sqfs_perror() instead of relying on the function to print an error
internally.

Also, make sure to preserve errno/GetLastError() in the implementations
and print out a stringified error in sqfs_perror() if the error code
indicates an I/O error.

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

10 files changed, 62 insertions, 25 deletions

diff --git a/bin/gensquashfs/Makemodule.am b/bin/gensquashfs/Makemodule.am
index 98153cb..dd32d5a 100644
--- a/bin/gensquashfs/Makemodule.am
+++ b/bin/gensquashfs/Makemodule.am
@@ -26,7 +26,7 @@ test_filemap_xattr_SOURCES = bin/gensquashfs/test/filemap_xattr.c \
 test_filemap_xattr_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/bin/gensquashfs/src
 test_filemap_xattr_CPPFLAGS += -DTESTPATH=$(GENDATADIR)/xattr1.txt
 test_filemap_xattr_LDADD = libio.a libsquashfs.la libfstree.a libutil.a
-test_filemap_xattr_LDADD += libcompat.a
+test_filemap_xattr_LDADD += libcommon.a libcompat.a
 
 test_fstree_from_file_SOURCES = bin/gensquashfs/test/fstree_from_file.c \
 				bin/gensquashfs/src/fstree_from_file.c \
diff --git a/bin/gensquashfs/src/filemap_xattr.c b/bin/gensquashfs/src/filemap_xattr.c
index 89624f4..8843c46 100644
--- a/bin/gensquashfs/src/filemap_xattr.c
+++ b/bin/gensquashfs/src/filemap_xattr.c
@@ -159,8 +159,12 @@ xattr_open_map_file(const char *path) {
 	struct XattrMap *map;
 	size_t line_num = 1;
 	char *p = NULL;
-	sqfs_istream_t *file = istream_open_file(path);
-	if (file == NULL) {
+	sqfs_istream_t *file = NULL;
+	int ret;
+
+	ret = istream_open_file(&file, path);
+	if (ret) {
+		sqfs_perror(path, NULL, ret);
 		return NULL;
 	}
 
diff --git a/bin/gensquashfs/src/fstree_from_file.c b/bin/gensquashfs/src/fstree_from_file.c
index efb5d43..f392b34 100644
--- a/bin/gensquashfs/src/fstree_from_file.c
+++ b/bin/gensquashfs/src/fstree_from_file.c
@@ -313,9 +313,11 @@ int fstree_from_file(fstree_t *fs, const char *filename, const char *basepath)
 	sqfs_istream_t *fp;
 	int ret;
 
-	fp = istream_open_file(filename);
-	if (fp == NULL)
+	ret = istream_open_file(&fp, filename);
+	if (ret) {
+		sqfs_perror(filename, NULL, ret);
 		return -1;
+	}
 
 	ret = fstree_from_file_stream(fs, fp, basepath);
 
diff --git a/bin/gensquashfs/src/mkfs.c b/bin/gensquashfs/src/mkfs.c
index cdef359..de291fa 100644
--- a/bin/gensquashfs/src/mkfs.c
+++ b/bin/gensquashfs/src/mkfs.c
@@ -160,9 +160,11 @@ int main(int argc, char **argv)
 	}
 
 	if (opt.sortfile != NULL) {
-		sortfile = istream_open_file(opt.sortfile);
-		if (sortfile == NULL)
+		int ret = istream_open_file(&sortfile, opt.sortfile);
+		if (ret) {
+			sqfs_perror(opt.sortfile, NULL, ret);
 			goto out;
+		}
 	}
 
 	if (opt.infile == NULL) {
diff --git a/bin/rdsquashfs/src/fill_files.c b/bin/rdsquashfs/src/fill_files.c
index e692ee3..f0ad7e2 100644
--- a/bin/rdsquashfs/src/fill_files.c
+++ b/bin/rdsquashfs/src/fill_files.c
@@ -145,9 +145,11 @@ static int fill_files(sqfs_data_reader_t *data, int flags)
 		openflags |= SQFS_FILE_OPEN_NO_SPARSE;
 
 	for (i = 0; i < num_files; ++i) {
-		fp = ostream_open_file(files[i].path, openflags);
-		if (fp == NULL)
+		ret = ostream_open_file(&fp, files[i].path, openflags);
+		if (ret) {
+			sqfs_perror(files[i].path, NULL, ret);
 			return -1;
+		}
 
 		if (!(flags & UNPACK_QUIET))
 			printf("unpacking %s\n", files[i].path);
@@ -157,9 +159,13 @@ static int fill_files(sqfs_data_reader_t *data, int flags)
 		if (ret == 0)
 			ret = fp->flush(fp);
 
-		sqfs_drop(fp);
-		if (ret)
+		if (ret) {
+			sqfs_perror(files[i].path, "unpacking", ret);
+			sqfs_drop(fp);
 			return -1;
+		}
+
+		sqfs_drop(fp);
 	}
 
 	return 0;
diff --git a/bin/rdsquashfs/src/rdsquashfs.c b/bin/rdsquashfs/src/rdsquashfs.c
index ad85e68..77dc5ba 100644
--- a/bin/rdsquashfs/src/rdsquashfs.c
+++ b/bin/rdsquashfs/src/rdsquashfs.c
@@ -208,6 +208,7 @@ int main(int argc, char **argv)
 		break;
 	case OP_CAT: {
 		sqfs_ostream_t *fp;
+		int ret;
 
 		if (!S_ISREG(n->inode->base.mode)) {
 			fprintf(stderr, "/%s: not a regular file\n",
@@ -215,9 +216,11 @@ int main(int argc, char **argv)
 			goto out;
 		}
 
-		fp = ostream_open_stdout();
-		if (fp == NULL)
+		ret = ostream_open_stdout(&fp);
+		if (ret) {
+			sqfs_perror("stdout", "creating stream wrapper", ret);
 			goto out;
+		}
 
 		ret = sqfs_data_reader_dump(opt.cmdpath, data, n->inode,
 					    fp, super.block_size);
diff --git a/bin/sqfs2tar/src/sqfs2tar.c b/bin/sqfs2tar/src/sqfs2tar.c
index e90aa56..714f6db 100644
--- a/bin/sqfs2tar/src/sqfs2tar.c
+++ b/bin/sqfs2tar/src/sqfs2tar.c
@@ -117,9 +117,9 @@ int main(int argc, char **argv)
 
 	process_args(argc, argv);
 
-	out_file = ostream_open_stdout();
-	if (out_file == NULL) {
-		perror("changing stdout to binary mode");
+	ret = ostream_open_stdout(&out_file);
+	if (ret) {
+		sqfs_perror("stdout", "creating stream wrapper", ret);
 		goto out;
 	}
 
@@ -253,8 +253,11 @@ int main(int argc, char **argv)
 	if (terminate_archive())
 		goto out;
 
-	if (out_file->flush(out_file))
+	ret = out_file->flush(out_file);
+	if (ret) {
+		sqfs_perror(out_file->get_filename(out_file), NULL, ret);
 		goto out;
+	}
 
 	status = EXIT_SUCCESS;
 out:
diff --git a/bin/sqfs2tar/src/write_tree.c b/bin/sqfs2tar/src/write_tree.c
index e578a9f..dc3ac72 100644
--- a/bin/sqfs2tar/src/write_tree.c
+++ b/bin/sqfs2tar/src/write_tree.c
@@ -119,6 +119,8 @@ static int write_tree_dfs(const sqfs_tree_node_t *n)
 		if (lnk != NULL) {
 			ret = write_hard_link(out_file, &sb, name, lnk->target,
 					      record_counter++);
+			if (ret != 0)
+				sqfs_perror(name, "writing hard link", ret);
 			sqfs_free(name);
 			return ret;
 		}
@@ -143,10 +145,13 @@ static int write_tree_dfs(const sqfs_tree_node_t *n)
 			       record_counter++);
 	sqfs_xattr_list_free(xattr);
 
-	if (ret > 0)
+	if (ret == SQFS_ERROR_UNSUPPORTED) {
+		fprintf(stderr, "WARNING: %s: unsupported file type\n", name);
 		goto out_skip;
+	}
 
 	if (ret < 0) {
+		sqfs_perror(name, "writing tar header", ret);
 		sqfs_free(name);
 		return -1;
 	}
@@ -158,7 +163,9 @@ static int write_tree_dfs(const sqfs_tree_node_t *n)
 			return -1;
 		}
 
-		if (padd_file(out_file, sb.st_size)) {
+		ret = padd_file(out_file, sb.st_size);
+		if (ret) {
+			sqfs_perror(name, NULL, ret);
 			sqfs_free(name);
 			return -1;
 		}
diff --git a/bin/sqfsdiff/src/extract.c b/bin/sqfsdiff/src/extract.c
index 43e9b97..d51096f 100644
--- a/bin/sqfsdiff/src/extract.c
+++ b/bin/sqfsdiff/src/extract.c
@@ -11,6 +11,7 @@ static int extract(sqfs_data_reader_t *data, const sqfs_inode_generic_t *inode,
 {
 	char *ptr, *temp;
 	sqfs_ostream_t *fp;
+	int ret;
 
 	temp = alloca(strlen(prefix) + strlen(path) + 2);
 	sprintf(temp, "%s/%s", prefix, path);
@@ -21,9 +22,9 @@ static int extract(sqfs_data_reader_t *data, const sqfs_inode_generic_t *inode,
 		return -1;
 	*ptr = '/';
 
-	fp = ostream_open_file(temp, SQFS_FILE_OPEN_OVERWRITE);
-	if (fp == NULL) {
-		perror(temp);
+	ret = ostream_open_file(&fp, temp, SQFS_FILE_OPEN_OVERWRITE);
+	if (ret) {
+		sqfs_perror(temp, NULL, ret);
 		return -1;
 	}
 
@@ -32,7 +33,13 @@ static int extract(sqfs_data_reader_t *data, const sqfs_inode_generic_t *inode,
 		return -1;
 	}
 
-	fp->flush(fp);
+	ret = fp->flush(fp);
+	if (ret) {
+		sqfs_perror(fp->get_filename(fp), NULL, ret);
+		sqfs_drop(fp);
+		return -1;
+	}
+
 	sqfs_drop(fp);
 	return 0;
 }
diff --git a/bin/tar2sqfs/src/tar2sqfs.c b/bin/tar2sqfs/src/tar2sqfs.c
index f7ed060..ed671f5 100644
--- a/bin/tar2sqfs/src/tar2sqfs.c
+++ b/bin/tar2sqfs/src/tar2sqfs.c
@@ -12,12 +12,15 @@ int main(int argc, char **argv)
 	sqfs_istream_t *input_file = NULL;
 	dir_iterator_t *tar = NULL;
 	sqfs_writer_t sqfs;
+	int ret;
 
 	process_args(argc, argv);
 
-	input_file = istream_open_stdin();
-	if (input_file == NULL)
+	ret = istream_open_stdin(&input_file);
+	if (ret) {
+		sqfs_perror("stdint", "creating stream wrapper", ret);
 		return EXIT_FAILURE;
+	}
 
 	tar = tar_open_stream(input_file);
 	sqfs_drop(input_file);