Re: [PATCH] staging: r8188eu: simplify complex pointer casting

From: Philipp Hortmann
Date: Sun Nov 06 2022 - 03:36:01 EST


On 11/6/22 09:26, Deepak R Varma wrote:
Pointers to structures udphdr and dhcpMessage are derived by casting
adjacent pointers with size_t. Such typecast of pointer using size_t
is not preferred. The code looks complex and delicate. Simplify such
casting by utilizing generic "void *" casting.
While at this change, remove the unnecessary __be32 casting for member
variable "cookie".

Suggested-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Deepak R Varma <drv@xxxxxxxxx>
---
drivers/staging/r8188eu/core/rtw_br_ext.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_br_ext.c b/drivers/staging/r8188eu/core/rtw_br_ext.c
index a23f7df373ed..e9b0906d0d74 100644
--- a/drivers/staging/r8188eu/core/rtw_br_ext.c
+++ b/drivers/staging/r8188eu/core/rtw_br_ext.c
@@ -610,13 +610,15 @@ void dhcp_flag_bcast(struct adapter *priv, struct sk_buff *skb)
struct iphdr *iph = (struct iphdr *)(skb->data + ETH_HLEN);

if (iph->protocol == IPPROTO_UDP) { /* UDP */
- struct udphdr *udph = (struct udphdr *)((size_t)iph + (iph->ihl << 2));
+ struct udphdr *udph = (void *)iph + (iph->ihl << 2);

if ((udph->source == htons(CLIENT_PORT)) &&
(udph->dest == htons(SERVER_PORT))) { /* DHCP request */
- struct dhcpMessage *dhcph =
- (struct dhcpMessage *)((size_t)udph + sizeof(struct udphdr));
- u32 cookie = be32_to_cpu((__be32)dhcph->cookie);
+ u32 cookie;
+ struct dhcpMessage *dhcph;
+
+ dhcph = (void *)udph + sizeof(struct udphdr);
+ cookie = be32_to_cpu(dhcph->cookie);

if (cookie == DHCP_MAGIC) { /* match magic word */
if (!(dhcph->flags & htons(BROADCAST_FLAG))) {
--
2.34.1




Tested-by: Philipp Hortmann <philipp.g.hortmann@xxxxxxxxx> # Edimax N150