[PATCH v4 1/2] staging: rtl8188eu: Replace a custom function with crc32_le()

Fabio M. De Francesco
2021-07-23T19:26:49Z

Use crc32_le() in place of the custom getcrc32().

Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
---

v3 --> v4:
According to a suggestion of David Laight, kill the casts of crc to __le32.

v2 --> v3:
Join two related patches in a series because they must be applied in
order (first 1/2, then 2/2). Rebase to the current Greg K-H's tree and resend.

v1 --> v2:
Use cpu_to_le32() to assign native endian return value of crc32_le to
crc in little endian byte order.

drivers/staging/rtl8188eu/core/rtw_security.c | 45 ++++++++-----------
1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_security.c b/drivers/staging/rtl8188eu/core/rtw_security.c
index 1b2cb6196463..7001f24f118d 100644
--- a/drivers/staging/rtl8188eu/core/rtw_security.c
+++ b/drivers/staging/rtl8188eu/core/rtw_security.c
@@ -11,6 +11,7 @@
#include <wifi.h>
#include <osdep_intf.h>
#include <net/lib80211.h>
+#include <linux/types.h>

/* WEP related ===== */

@@ -111,21 +112,6 @@ 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)
{
@@ -564,7 +550,10 @@ u32 rtw_tkip_encrypt(struct adapter *padapter, struct xmit_frame *pxmitframe)
u32 pnh;
u8 rc4key[16];
u8 ttkey[16];
- u8 crc[4];
+ union {
+ __le32 f0;
+ u8 f1[4];
+ } crc;
u8 hw_hdr_offset = 0;
struct arc4context mycontext;
int curfragnum, length;
@@ -609,17 +598,18 @@ 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*/
+ crc.f0 = cpu_to_le32(~crc32_le(~0, payload, length));

arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
- arcfour_encrypt(&mycontext, payload + length, crc, 4);
+ arcfour_encrypt(&mycontext, payload + length, crc.f1, 4);
} else {
length = pxmitpriv->frag_len - pattrib->hdrlen - pattrib->iv_len - pattrib->icv_len;
- *((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/
+ crc.f0 = cpu_to_le32(~crc32_le(~0, payload, length));
+
arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
- arcfour_encrypt(&mycontext, payload + length, crc, 4);
+ arcfour_encrypt(&mycontext, payload + length, crc.f1, 4);

pframe += pxmitpriv->frag_len;
pframe = (u8 *)round_up((size_t)(pframe), 4);
@@ -639,7 +629,10 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, struct recv_frame *precvframe)
u32 pnh;
u8 rc4key[16];
u8 ttkey[16];
- u8 crc[4];
+ union {
+ __le32 f0;
+ u8 f1[4];
+ } crc;
struct arc4context mycontext;
int length;
u8 *pframe, *payload, *iv, *prwskey;
@@ -682,12 +675,12 @@ 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);
+ crc.f0 = cpu_to_le32(~crc32_le(~0, payload, length - 4));

- if (crc[3] != payload[length - 1] ||
- crc[2] != payload[length - 2] ||
- crc[1] != payload[length - 3] ||
- crc[0] != payload[length - 4])
+ if (crc.f1[3] != payload[length - 1] ||
+ crc.f1[2] != payload[length - 2] ||
+ crc.f1[1] != payload[length - 3] ||
+ crc.f1[0] != payload[length - 4])
res = _FAIL;
} else {
res = _FAIL;
--
2.32.0