1 files changed, 80 insertions, 88 deletions

diff --git a/lib/sqfs/xattr_reader.c b/lib/sqfs/xattr_reader.c
index aeee574..80731ba 100644
--- a/lib/sqfs/xattr_reader.c
+++ b/lib/sqfs/xattr_reader.c
@@ -10,12 +10,12 @@
 #include "sqfs/meta_reader.h"
 #include "sqfs/super.h"
 #include "sqfs/xattr.h"
+#include "sqfs/error.h"
 #include "sqfs/data.h"
 #include "util.h"
 
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
 #include <errno.h>
 
 struct sqfs_xattr_reader_t {
@@ -29,24 +29,28 @@ struct sqfs_xattr_reader_t {
 	sqfs_meta_reader_t *idrd;
 	sqfs_meta_reader_t *kvrd;
 	sqfs_super_t *super;
+	int sqfsfd;
 };
 
-static int get_id_block_locations(sqfs_xattr_reader_t *xr, int sqfsfd,
-				  sqfs_super_t *super)
+int sqfs_xattr_reader_load_locations(sqfs_xattr_reader_t *xr)
 {
 	sqfs_xattr_id_table_t idtbl;
 	size_t i;
+	int err;
 
-	if (super->xattr_id_table_start >= super->bytes_used) {
-		fputs("xattr ID location table is after end of filesystem\n",
-		      stderr);
-		return -1;
-	}
+	if (xr->super->flags & SQFS_FLAG_NO_XATTRS)
+		return 0;
+
+	if (xr->super->xattr_id_table_start == 0xFFFFFFFFFFFFFFFF)
+		return 0;
+
+	if (xr->super->xattr_id_table_start >= xr->super->bytes_used)
+		return SQFS_ERROR_OUT_OF_BOUNDS;
 
 	if (read_data_at("reading xattr ID location table",
-			 super->xattr_id_table_start,
-			 sqfsfd, &idtbl, sizeof(idtbl))) {
-		return -1;
+			 xr->super->xattr_id_table_start,
+			 xr->sqfsfd, &idtbl, sizeof(idtbl))) {
+		return SQFS_ERROR_IO;
 	}
 
 	xr->xattr_start = le64toh(idtbl.xattr_table_start);
@@ -59,23 +63,24 @@ static int get_id_block_locations(sqfs_xattr_reader_t *xr, int sqfsfd,
 
 	xr->id_block_starts = alloc_array(sizeof(uint64_t), xr->num_id_blocks);
 	if (xr->id_block_starts == NULL) {
-		perror("allocating xattr ID location table");
-		return -1;
+		if (errno == EOVERFLOW)
+			return SQFS_ERROR_OVERFLOW;
+		return SQFS_ERROR_ALLOC;
 	}
 
 	if (read_data_at("reading xattr ID block locations",
-			 super->xattr_id_table_start + sizeof(idtbl),
-			 sqfsfd, xr->id_block_starts,
+			 xr->super->xattr_id_table_start + sizeof(idtbl),
+			 xr->sqfsfd, xr->id_block_starts,
 			 sizeof(uint64_t) * xr->num_id_blocks)) {
+		err = SQFS_ERROR_IO;
 		goto fail;
 	}
 
 	for (i = 0; i < xr->num_id_blocks; ++i) {
 		xr->id_block_starts[i] = le64toh(xr->id_block_starts[i]);
 
-		if (xr->id_block_starts[i] > super->bytes_used) {
-			fputs("found xattr ID block that is past "
-			      "end of filesystem\n", stderr);
+		if (xr->id_block_starts[i] > xr->super->bytes_used) {
+			err = SQFS_ERROR_OUT_OF_BOUNDS;
 			goto fail;
 		}
 	}
@@ -84,119 +89,113 @@ static int get_id_block_locations(sqfs_xattr_reader_t *xr, int sqfsfd,
 fail:
 	free(xr->id_block_starts);
 	xr->id_block_starts = NULL;
-	return -1;
+	return err;
 }
 
-sqfs_xattr_entry_t *sqfs_xattr_reader_read_key(sqfs_xattr_reader_t *xr)
+int sqfs_xattr_reader_read_key(sqfs_xattr_reader_t *xr,
+			       sqfs_xattr_entry_t **key_out)
 {
 	sqfs_xattr_entry_t key, *out;
 	const char *prefix;
 	size_t plen, total;
+	int ret;
 
-	if (sqfs_meta_reader_read(xr->kvrd, &key, sizeof(key)))
-		return NULL;
+	ret = sqfs_meta_reader_read(xr->kvrd, &key, sizeof(key));
+	if (ret)
+		return ret;
 
 	key.type = le16toh(key.type);
 	key.size = le16toh(key.size);
 
 	prefix = sqfs_get_xattr_prefix(key.type & SQFS_XATTR_PREFIX_MASK);
-	if (prefix == NULL) {
-		fprintf(stderr, "found unknown xattr type %u\n",
-			key.type & SQFS_XATTR_PREFIX_MASK);
-		return NULL;
-	}
+	if (prefix == NULL)
+		return SQFS_ERROR_UNSUPPORTED;
 
 	plen = strlen(prefix);
 
 	if (SZ_ADD_OV(plen, key.size, &total) || SZ_ADD_OV(total, 1, &total) ||
 	    SZ_ADD_OV(sizeof(*out), total, &total)) {
-		errno = EOVERFLOW;
-		goto fail_alloc;
+		return SQFS_ERROR_OVERFLOW;
 	}
 
 	out = calloc(1, total);
-	if (out == NULL) {
-		goto fail_alloc;
-	}
+	if (out == NULL)
+		return SQFS_ERROR_ALLOC;
 
 	*out = key;
 	memcpy(out->key, prefix, plen);
 
-	if (sqfs_meta_reader_read(xr->kvrd, out->key + plen, key.size)) {
+	ret = sqfs_meta_reader_read(xr->kvrd, out->key + plen, key.size);
+	if (ret) {
 		free(out);
-		return NULL;
+		return ret;
 	}
 
-	return out;
-fail_alloc:
-	perror("allocating xattr key");
-	return NULL;
+	*key_out = out;
+	return 0;
 }
 
-sqfs_xattr_value_t *sqfs_xattr_reader_read_value(sqfs_xattr_reader_t *xr,
-						 const sqfs_xattr_entry_t *key)
+int sqfs_xattr_reader_read_value(sqfs_xattr_reader_t *xr,
+				 const sqfs_xattr_entry_t *key,
+				 sqfs_xattr_value_t **val_out)
 {
 	size_t offset, new_offset, size;
 	sqfs_xattr_value_t value, *out;
 	uint64_t ref, start, new_start;
+	int ret;
 
-	if (sqfs_meta_reader_read(xr->kvrd, &value, sizeof(value)))
-		return NULL;
+	ret = sqfs_meta_reader_read(xr->kvrd, &value, sizeof(value));
+	if (ret)
+		return ret;
 
 	if (key->type & SQFS_XATTR_FLAG_OOL) {
-		if (sqfs_meta_reader_read(xr->kvrd, &ref, sizeof(ref)))
-			return NULL;
+		ret = sqfs_meta_reader_read(xr->kvrd, &ref, sizeof(ref));
+		if (ret)
+			return ret;
 
 		sqfs_meta_reader_get_position(xr->kvrd, &start, &offset);
 
 		new_start = xr->xattr_start + (ref >> 16);
-		new_offset = ref & 0xFFFF;
-
-		if (new_start > xr->super->bytes_used) {
-			fputs("OOL xattr reference points past end of "
-			      "filesystem\n", stderr);
-			return NULL;
-		}
+		if (new_start >= xr->super->bytes_used)
+			return SQFS_ERROR_OUT_OF_BOUNDS;
 
-		if (new_offset >= SQFS_META_BLOCK_SIZE) {
-			fputs("OOL xattr reference points outside "
-			      "metadata block\n", stderr);
-			return NULL;
-		}
+		new_offset = ref & 0xFFFF;
+		if (new_offset >= SQFS_META_BLOCK_SIZE)
+			return SQFS_ERROR_OUT_OF_BOUNDS;
 
-		if (sqfs_meta_reader_seek(xr->kvrd, new_start, new_offset))
-			return NULL;
+		ret = sqfs_meta_reader_seek(xr->kvrd, new_start, new_offset);
+		if (ret)
+			return ret;
 	}
 
 	value.size = le32toh(value.size);
 
 	if (SZ_ADD_OV(sizeof(*out), value.size, &size) ||
 	    SZ_ADD_OV(size, 1, &size)) {
-		errno = EOVERFLOW;
-		goto fail_alloc;
+		return SQFS_ERROR_OVERFLOW;
 	}
 
 	out = calloc(1, size);
 	if (out == NULL)
-		goto fail_alloc;
+		return SQFS_ERROR_ALLOC;
 
 	*out = value;
 
-	if (sqfs_meta_reader_read(xr->kvrd, out->value, value.size))
+	ret = sqfs_meta_reader_read(xr->kvrd, out->value, value.size);
+	if (ret)
 		goto fail;
 
 	if (key->type & SQFS_XATTR_FLAG_OOL) {
-		if (sqfs_meta_reader_seek(xr->kvrd, start, offset))
+		ret = sqfs_meta_reader_seek(xr->kvrd, start, offset);
+		if (ret)
 			goto fail;
 	}
 
-	return out;
-fail_alloc:
-	perror("allocating xattr value");
-	return NULL;
+	*val_out = out;
+	return 0;
 fail:
 	free(out);
-	return NULL;
+	return ret;
 }
 
 int sqfs_xattr_reader_seek_kv(sqfs_xattr_reader_t *xr,
@@ -212,38 +211,35 @@ int sqfs_xattr_reader_get_desc(sqfs_xattr_reader_t *xr, uint32_t idx,
 			       sqfs_xattr_id_t *desc)
 {
 	size_t block, offset;
+	int ret;
 
 	memset(desc, 0, sizeof(*desc));
 
 	if (idx == 0xFFFFFFFF)
 		return 0;
 
-	if (xr->kvrd == NULL || xr->idrd == NULL) {
-		if (idx != 0)
-			goto fail_bounds;
-		return 0;
-	}
+	if (xr->kvrd == NULL || xr->idrd == NULL)
+		return idx == 0 ? 0 : SQFS_ERROR_OUT_OF_BOUNDS;
 
 	if (idx >= xr->num_ids)
-		goto fail_bounds;
+		return SQFS_ERROR_OUT_OF_BOUNDS;
 
 	offset = (idx * sizeof(*desc)) % SQFS_META_BLOCK_SIZE;
 	block = (idx * sizeof(*desc)) / SQFS_META_BLOCK_SIZE;
 
-	if (sqfs_meta_reader_seek(xr->idrd, xr->id_block_starts[block], offset))
-		return -1;
+	ret = sqfs_meta_reader_seek(xr->idrd, xr->id_block_starts[block],
+				    offset);
+	if (ret)
+		return ret;
 
-	if (sqfs_meta_reader_read(xr->idrd, desc, sizeof(*desc)))
-		return -1;
+	ret = sqfs_meta_reader_read(xr->idrd, desc, sizeof(*desc));
+	if (ret)
+		return ret;
 
 	desc->xattr = le64toh(desc->xattr);
 	desc->count = le32toh(desc->count);
 	desc->size = le32toh(desc->size);
 	return 0;
-fail_bounds:
-	fprintf(stderr, "Tried to access out of bounds "
-		"xattr index: 0x%08X\n", idx);
-	return -1;
 }
 
 void sqfs_xattr_reader_destroy(sqfs_xattr_reader_t *xr)
@@ -263,10 +259,8 @@ sqfs_xattr_reader_t *sqfs_xattr_reader_create(int sqfsfd, sqfs_super_t *super,
 {
 	sqfs_xattr_reader_t *xr = calloc(1, sizeof(*xr));
 
-	if (xr == NULL) {
-		perror("creating xattr reader");
+	if (xr == NULL)
 		return NULL;
-	}
 
 	if (super->flags & SQFS_FLAG_NO_XATTRS)
 		return xr;
@@ -274,9 +268,6 @@ sqfs_xattr_reader_t *sqfs_xattr_reader_create(int sqfsfd, sqfs_super_t *super,
 	if (super->xattr_id_table_start == 0xFFFFFFFFFFFFFFFF)
 		return xr;
 
-	if (get_id_block_locations(xr, sqfsfd, super))
-		goto fail;
-
 	xr->idrd = sqfs_meta_reader_create(sqfsfd, cmp,
 					   super->id_table_start,
 					   super->bytes_used);
@@ -289,6 +280,7 @@ sqfs_xattr_reader_t *sqfs_xattr_reader_create(int sqfsfd, sqfs_super_t *super,
 	if (xr->kvrd == NULL)
 		goto fail;
 
+	xr->sqfsfd = sqfsfd;
 	xr->super = super;
 	return xr;
 fail: