Change memory managment from a fixed size array to a list.

This is needed to avoid running into out of buffer situations
where we cannot alloc a new buffer because we hit the array size
limit (ZBUF).
Use a combined allocation for the struct and the actual data buffer
to not increase the number of malloc calls. [1]

Defer initialization of zbuf until we actually need it.

Make sure the output buffer will be large enough in all cases.

Details discussed with:	kib [1]
Reviewed by:		kib [1]
MFC after:		6 days

1 files changed, 7 insertions, 3 deletions

diff --git a/sys/opencrypto/deflate.h b/sys/opencrypto/deflate.h
index 5c8ebd4..dcf7a84 100644
--- a/sys/opencrypto/deflate.h
+++ b/sys/opencrypto/deflate.h
@@ -47,10 +47,14 @@ u_int32_t deflate_global(u_int8_t *, u_int32_t, int, u_int8_t **);
 void *z_alloc(void *, u_int, u_int);
 void z_free(void *, void *);
 
+/*
+ * We are going to use a combined allocation to hold the metadata
+ * from the struct immediately followed by the real application data.
+ */
 struct deflate_buf {
-	u_int8_t *out;
-	u_int32_t size;
-	int flag;
+	struct deflate_buf *next;
+	uint32_t size;
+	uint8_t data[];
 };
 
 #endif /* _CRYPTO_DEFLATE_H_ */