Remove use of ssize_t from library API

ssize_t is only available on POSIX platforms and even there it is
only defined to hold at least -1 in the range of negative numbers.

This commit replaces ssize_t return types with sqfs_s32 and the
coresponding function arguments with sqfs_u32. Because the range
of positiv numbers for a signed 32 bit number is only half that of
the unsigned version, additional checks have to be added.

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

1 files changed, 10 insertions, 4 deletions

diff --git a/lib/sqfs/comp/zstd.c b/lib/sqfs/comp/zstd.c
index 81e369b..b2e5d8b 100644
--- a/lib/sqfs/comp/zstd.c
+++ b/lib/sqfs/comp/zstd.c
@@ -51,12 +51,15 @@ static int zstd_read_options(sqfs_compressor_t *base, sqfs_file_t *file)
 	return 0;
 }
 
-static ssize_t zstd_comp_block(sqfs_compressor_t *base, const sqfs_u8 *in,
-			       size_t size, sqfs_u8 *out, size_t outsize)
+static sqfs_s32 zstd_comp_block(sqfs_compressor_t *base, const sqfs_u8 *in,
+				sqfs_u32 size, sqfs_u8 *out, sqfs_u32 outsize)
 {
 	zstd_compressor_t *zstd = (zstd_compressor_t *)base;
 	size_t ret;
 
+	if (size >= 0x7FFFFFFF)
+		return 0;
+
 	ret = ZSTD_compressCCtx(zstd->zctx, out, outsize, in, size,
 				zstd->level);
 
@@ -66,12 +69,15 @@ static ssize_t zstd_comp_block(sqfs_compressor_t *base, const sqfs_u8 *in,
 	return ret < size ? ret : 0;
 }
 
-static ssize_t zstd_uncomp_block(sqfs_compressor_t *base, const sqfs_u8 *in,
-				 size_t size, sqfs_u8 *out, size_t outsize)
+static sqfs_s32 zstd_uncomp_block(sqfs_compressor_t *base, const sqfs_u8 *in,
+				  sqfs_u32 size, sqfs_u8 *out, sqfs_u32 outsize)
 {
 	size_t ret;
 	(void)base;
 
+	if (outsize >= 0x7FFFFFFF)
+		return 0;
+
 	ret = ZSTD_decompress(out, outsize, in, size);
 
 	if (ZSTD_isError(ret))