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>

7 files changed, 64 insertions, 43 deletions

diff --git a/lib/tar/src/internal.h b/lib/tar/src/internal.h
index 56613d3..4671f0b 100644
--- a/lib/tar/src/internal.h
+++ b/lib/tar/src/internal.h
@@ -12,6 +12,8 @@
 #include "tar/tar.h"
 #include "tar/format.h"
 #include "util/util.h"
+#include "sqfs/error.h"
+#include "common.h"
 
 enum {
 	PAX_SIZE = 0x001,
diff --git a/lib/tar/src/iterator.c b/lib/tar/src/iterator.c
index 93c931c..ed35b73 100644
--- a/lib/tar/src/iterator.c
+++ b/lib/tar/src/iterator.c
@@ -231,7 +231,7 @@ retry:
 
 	return 0;
 fail:
-	tar->state = ret < 0 ? SQFS_ERROR_IO : 1;
+	tar->state = ret < 0 ? ret : 1;
 	return tar->state;
 }
 
diff --git a/lib/tar/src/read_header.c b/lib/tar/src/read_header.c
index 16fc9d7..df2f56c 100644
--- a/lib/tar/src/read_header.c
+++ b/lib/tar/src/read_header.c
@@ -176,8 +176,11 @@ int read_header(sqfs_istream_t *fp, tar_header_decoded_t *out)
 
 	for (;;) {
 		ret = sqfs_istream_read(fp, &hdr, sizeof(hdr));
-		if (ret < 0)
+		if (ret < 0) {
+			sqfs_perror(fp->get_filename(fp),
+				    "reading raw tar header", ret);
 			goto fail;
+		}
 
 		if ((size_t)ret < sizeof(hdr))
 			goto out_eof;
@@ -226,7 +229,12 @@ int read_header(sqfs_istream_t *fp, tar_header_decoded_t *out)
 				goto fail;
 			if (pax_size % 512)
 				pax_size += 512 - (pax_size % 512);
-			sqfs_istream_skip(fp, pax_size);
+			ret = sqfs_istream_skip(fp, pax_size);
+			if (ret) {
+				sqfs_perror(fp->get_filename(fp),
+					    "skipping padding", ret);
+				goto fail;
+			}
 			continue;
 		case TAR_TYPE_PAX:
 			clear_header(out);
diff --git a/lib/tar/src/read_sparse_map_new.c b/lib/tar/src/read_sparse_map_new.c
index 4e317a8..e42466c 100644
--- a/lib/tar/src/read_sparse_map_new.c
+++ b/lib/tar/src/read_sparse_map_new.c
@@ -42,8 +42,10 @@ sparse_map_t *read_gnu_new_sparse(sqfs_istream_t *fp, tar_header_decoded_t *out)
 		goto fail_format;
 
 	ret = sqfs_istream_read(fp, buffer, 512);
-	if (ret < 0)
+	if (ret < 0) {
+		sqfs_perror(fp->get_filename(fp), "reading sparse list", ret);
 		goto fail;
+	}
 
 	if (ret < 512)
 		goto fail_format;
@@ -69,8 +71,11 @@ sparse_map_t *read_gnu_new_sparse(sqfs_istream_t *fp, tar_header_decoded_t *out)
 				goto fail_format;
 
 			ret = sqfs_istream_read(fp, buffer + 512, 512);
-			if (ret < 0)
+			if (ret < 0) {
+				sqfs_perror(fp->get_filename(fp),
+					    "reading sparse list", ret);
 				goto fail;
+			}
 
 			if (ret < 512)
 				goto fail_format;
diff --git a/lib/tar/src/read_sparse_map_old.c b/lib/tar/src/read_sparse_map_old.c
index 1794073..0915214 100644
--- a/lib/tar/src/read_sparse_map_old.c
+++ b/lib/tar/src/read_sparse_map_old.c
@@ -60,8 +60,11 @@ sparse_map_t *read_gnu_old_sparse(sqfs_istream_t *fp, tar_header_t *hdr)
 
 	do {
 		ret = sqfs_istream_read(fp, &sph, sizeof(sph));
-		if (ret < 0)
+		if (ret < 0) {
+			sqfs_perror(fp->get_filename(fp),
+				    "reading old GNU sparse list", ret);
 			goto fail;
+		}
 
 		if ((size_t)ret < sizeof(sph))
 			goto fail_eof;
diff --git a/lib/tar/src/record_to_memory.c b/lib/tar/src/record_to_memory.c
index 597d6f8..84beaa3 100644
--- a/lib/tar/src/record_to_memory.c
+++ b/lib/tar/src/record_to_memory.c
@@ -19,8 +19,10 @@ char *record_to_memory(sqfs_istream_t *fp, size_t size)
 		goto fail_errno;
 
 	ret = sqfs_istream_read(fp, buffer, size);
-	if (ret < 0)
+	if (ret < 0) {
+		sqfs_perror(fp->get_filename(fp), "reading tar record", ret);
 		goto fail;
+	}
 
 	if ((size_t)ret < size) {
 		fputs("Reading tar record: unexpected end-of-file.\n", stderr);
@@ -28,8 +30,12 @@ char *record_to_memory(sqfs_istream_t *fp, size_t size)
 	}
 
 	if (size % 512) {
-		if (sqfs_istream_skip(fp, 512 - (size % 512)))
+		ret = sqfs_istream_skip(fp, 512 - (size % 512));
+		if (ret) {
+			sqfs_perror(fp->get_filename(fp),
+				    "skipping tar padding", ret);
 			goto fail;
+		}
 	}
 
 	buffer[size] = '\0';
diff --git a/lib/tar/src/write_header.c b/lib/tar/src/write_header.c
index 1183c9a..dda98b7 100644
--- a/lib/tar/src/write_header.c
+++ b/lib/tar/src/write_header.c
@@ -8,6 +8,7 @@
 
 #include "internal.h"
 #include "sqfs/xattr.h"
+#include "sqfs/error.h"
 #include <string.h>
 #include <stdlib.h>
 
@@ -106,16 +107,19 @@ static int write_ext_header(sqfs_ostream_t *fp, const struct stat *orig,
 			    int type, const char *name)
 {
 	struct stat sb;
+	int ret;
 
 	sb = *orig;
 	sb.st_mode = S_IFREG | 0644;
 	sb.st_size = payload_len;
 
-	if (write_header(fp, &sb, name, NULL, type))
-		return -1;
+	ret = write_header(fp, &sb, name, NULL, type);
+	if (ret)
+		return ret;
 
-	if (fp->append(fp, payload, payload_len))
-		return -1;
+	ret = fp->append(fp, payload, payload_len);
+	if (ret)
+		return ret;
 
 	return padd_file(fp, payload_len);
 }
@@ -159,11 +163,8 @@ static int write_schily_xattr(sqfs_ostream_t *fp, const struct stat *orig,
 	}
 
 	buffer = calloc(1, total_size + 1);
-	if (buffer == NULL) {
-		fprintf(stderr, "%s: generating xattr header: "
-			"out-of-memory\n", name);
-		return -1;
-	}
+	if (buffer == NULL)
+		return SQFS_ERROR_ALLOC;
 
 	ptr = buffer;
 
@@ -188,15 +189,15 @@ int write_tar_header(sqfs_ostream_t *fp,
 		     const char *slink_target, const sqfs_xattr_t *xattr,
 		     unsigned int counter)
 {
-	const char *reason;
 	char buffer[64];
-	int type;
+	int type, ret;
 
 	if (xattr != NULL) {
 		sprintf(buffer, "pax/xattr%u", counter);
 
-		if (write_schily_xattr(fp, sb, buffer, xattr))
-			return -1;
+		ret = write_schily_xattr(fp, sb, buffer, xattr);
+		if (ret)
+			return ret;
 	}
 
 	if (!S_ISLNK(sb->st_mode))
@@ -204,19 +205,20 @@ int write_tar_header(sqfs_ostream_t *fp,
 
 	if (S_ISLNK(sb->st_mode) && sb->st_size >= 100) {
 		sprintf(buffer, "gnu/target%u", counter);
-		if (write_ext_header(fp, sb, slink_target, sb->st_size,
-				     TAR_TYPE_GNU_SLINK, buffer))
-			return -1;
+		ret = write_ext_header(fp, sb, slink_target, sb->st_size,
+				       TAR_TYPE_GNU_SLINK, buffer);
+		if (ret)
+			return ret;
 		slink_target = NULL;
 	}
 
 	if (strlen(name) >= 100) {
 		sprintf(buffer, "gnu/name%u", counter);
 
-		if (write_ext_header(fp, sb, name, strlen(name),
-				     TAR_TYPE_GNU_PATH, buffer)) {
-			return -1;
-		}
+		ret = write_ext_header(fp, sb, name, strlen(name),
+				       TAR_TYPE_GNU_PATH, buffer);
+		if (ret)
+			return ret;
 
 		sprintf(buffer, "gnu/data%u", counter);
 		name = buffer;
@@ -229,18 +231,11 @@ int write_tar_header(sqfs_ostream_t *fp,
 	case S_IFREG: type = TAR_TYPE_FILE; break;
 	case S_IFDIR: type = TAR_TYPE_DIR; break;
 	case S_IFIFO: type = TAR_TYPE_FIFO; break;
-	case S_IFSOCK:
-		reason = "cannot pack socket";
-		goto out_skip;
 	default:
-		reason = "unknown type";
-		goto out_skip;
+		return SQFS_ERROR_UNSUPPORTED;
 	}
 
 	return write_header(fp, sb, name, slink_target, type);
-out_skip:
-	fprintf(stderr, "WARNING: %s: %s\n", name, reason);
-	return 1;
 }
 
 int write_hard_link(sqfs_ostream_t *fp, const struct stat *sb, const char *name,
@@ -249,15 +244,17 @@ int write_hard_link(sqfs_ostream_t *fp, const struct stat *sb, const char *name,
 	tar_header_t hdr;
 	char buffer[64];
 	size_t len;
+	int ret;
 
 	memset(&hdr, 0, sizeof(hdr));
 
 	len = strlen(target);
 	if (len >= 100) {
 		sprintf(buffer, "gnu/target%u", counter);
-		if (write_ext_header(fp, sb, target, len,
-				     TAR_TYPE_GNU_SLINK, buffer))
-			return -1;
+		ret = write_ext_header(fp, sb, target, len,
+				       TAR_TYPE_GNU_SLINK, buffer);
+		if (ret)
+			return ret;
 		sprintf(hdr.linkname, "hardlink_%u", counter);
 	} else {
 		memcpy(hdr.linkname, target, len);
@@ -266,10 +263,10 @@ int write_hard_link(sqfs_ostream_t *fp, const struct stat *sb, const char *name,
 	len = strlen(name);
 	if (len >= 100) {
 		sprintf(buffer, "gnu/name%u", counter);
-		if (write_ext_header(fp, sb, name, len,
-				     TAR_TYPE_GNU_PATH, buffer)) {
-			return -1;
-		}
+		ret = write_ext_header(fp, sb, name, len,
+				       TAR_TYPE_GNU_PATH, buffer);
+		if (ret)
+			return ret;
 		sprintf(hdr.name, "gnu/data%u", counter);
 	} else {
 		memcpy(hdr.name, name, len);