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, 7 insertions, 4 deletions

diff --git a/lib/sqfs/comp/gzip.c b/lib/sqfs/comp/gzip.c
index 3dd8d10..3886e60 100644
--- a/lib/sqfs/comp/gzip.c
+++ b/lib/sqfs/comp/gzip.c
@@ -107,7 +107,7 @@ static int flag_to_zlib_strategy(int flag)
 }
 
 static int find_strategy(gzip_compressor_t *gzip, const sqfs_u8 *in,
-			 size_t size, sqfs_u8 *out, size_t outsize)
+			 sqfs_u32 size, sqfs_u8 *out, sqfs_u32 outsize)
 {
 	int ret, strategy, selected = Z_DEFAULT_STRATEGY;
 	size_t i, length, minlength = 0;
@@ -148,13 +148,16 @@ static int find_strategy(gzip_compressor_t *gzip, const sqfs_u8 *in,
 	return selected;
 }
 
-static ssize_t gzip_do_block(sqfs_compressor_t *base, const sqfs_u8 *in,
-			     size_t size, sqfs_u8 *out, size_t outsize)
+static sqfs_s32 gzip_do_block(sqfs_compressor_t *base, const sqfs_u8 *in,
+			      sqfs_u32 size, sqfs_u8 *out, sqfs_u32 outsize)
 {
 	gzip_compressor_t *gzip = (gzip_compressor_t *)base;
 	int ret, strategy = 0;
 	size_t written;
 
+	if (size >= 0x7FFFFFFF)
+		return 0;
+
 	if (gzip->compress && gzip->opt.strategies != 0) {
 		strategy = find_strategy(gzip, in, size, out, outsize);
 		if (strategy < 0)
@@ -193,7 +196,7 @@ static ssize_t gzip_do_block(sqfs_compressor_t *base, const sqfs_u8 *in,
 		if (gzip->compress && written >= size)
 			return 0;
 
-		return (ssize_t)written;
+		return written;
 	}
 
 	if (ret != Z_OK && ret != Z_BUF_ERROR)