[PATCH] staging: rtl8188eu: Replace a custom function with crc32_le()

From: Fabio M. De Francesco
Date: Thu Jul 01 2021 - 09:38:18 EST


Use crc32_le in place of the custom getcrc32. This change makes GCC
to warn about incorrect castings to the restricted type __le32, but
they can be safely ignored because crc32_le calculates bitwise
little-endian Ethernet AUTODIN II CRC32.

Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
---
drivers/staging/rtl8188eu/core/rtw_security.c | 22 ++++---------------
1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_security.c b/drivers/staging/rtl8188eu/core/rtw_security.c
index 1b2cb6196463..5f010cb66970 100644
--- a/drivers/staging/rtl8188eu/core/rtw_security.c
+++ b/drivers/staging/rtl8188eu/core/rtw_security.c
@@ -111,21 +111,6 @@ static void crc32_init(void)
bcrc32initialized = 1;
}

-static __le32 getcrc32(u8 *buf, int len)
-{
- u8 *p;
- u32 crc;
-
- if (bcrc32initialized == 0)
- crc32_init();
-
- crc = 0xffffffff; /* preload shift register, per CRC-32 spec */
-
- for (p = buf; len > 0; ++p, --len)
- crc = crc32_table[(crc ^ *p) & 0xff] ^ (crc >> 8);
- return cpu_to_le32(~crc); /* transmit complement, per CRC-32 spec */
-}
-
/* Need to consider the fragment situation */
void rtw_wep_encrypt(struct adapter *padapter, struct xmit_frame *pxmitframe)
{
@@ -609,14 +594,15 @@ u32 rtw_tkip_encrypt(struct adapter *padapter, struct xmit_frame *pxmitframe)

if ((curfragnum + 1) == pattrib->nr_frags) { /* 4 the last fragment */
length = pattrib->last_txcmdsz - pattrib->hdrlen - pattrib->iv_len - pattrib->icv_len;
- *((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/
+ *((__le32 *)crc) = ~crc32_le(~0, payload, length);

arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
arcfour_encrypt(&mycontext, payload + length, crc, 4);
} else {
length = pxmitpriv->frag_len - pattrib->hdrlen - pattrib->iv_len - pattrib->icv_len;
- *((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/
+ *((__le32 *)crc) = ~crc32_le(~0, payload, length);
+
arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
arcfour_encrypt(&mycontext, payload + length, crc, 4);
@@ -682,7 +668,7 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, struct recv_frame *precvframe)
arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);

- *((__le32 *)crc) = getcrc32(payload, length - 4);
+ *((__le32 *)crc) = ~crc32_le(~0, payload, length - 4);

if (crc[3] != payload[length - 1] ||
crc[2] != payload[length - 2] ||
--
2.32.0