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SubjectRe: [PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets
On Tue, May 29, 2018 at 09:08:39PM +0200, Thibaut Robert wrote:
> static inline void tcp_process(struct net_device *dev, struct txq_entry_t *tqe)
> {
> - u8 *eth_hdr_ptr;
> + const struct ethhdr *eth_hdr_ptr = (const struct ethhdr *)tqe->buffer;
> +
> u8 *buffer = tqe->buffer;

No blank line, please.

> - unsigned short h_proto;
> int i;
> unsigned long flags;
> struct wilc_vif *vif;
> @@ -197,37 +199,25 @@ static inline void tcp_process(struct net_device *dev, struct txq_entry_t *tqe)
>
> spin_lock_irqsave(&wilc->txq_spinlock, flags);
>
> - eth_hdr_ptr = &buffer[0];
> - h_proto = ntohs(*((unsigned short *)&eth_hdr_ptr[12]));
> - if (h_proto == ETH_P_IP) {
> - u8 *ip_hdr_ptr;
> - u8 protocol;
> -
> - ip_hdr_ptr = &buffer[ETHERNET_HDR_LEN];
> - protocol = ip_hdr_ptr[9];
> + if (eth_hdr_ptr->h_proto == htons(ETH_P_IP)) {
> + const struct iphdr *ip_hdr_ptr = (const struct iphdr *)
> + (buffer + ETH_HLEN);

If you declared buffer as a void pointer you could remove this cast.

const struct iphdr *ip_hdr_ptr = buf + ETH_HLEN;


>
> - if (protocol == 0x06) {
> - u8 *tcp_hdr_ptr;
> + if (ip_hdr_ptr->protocol == IPPROTO_TCP) {
> + const struct tcphdr *tcp_hdr_ptr;
> u32 IHL, total_length, data_offset;
>
> - tcp_hdr_ptr = &ip_hdr_ptr[IP_HDR_LEN];
> - IHL = (ip_hdr_ptr[0] & 0xf) << 2;
> - total_length = ((u32)ip_hdr_ptr[2] << 8) +
> - (u32)ip_hdr_ptr[3];
> - data_offset = ((u32)tcp_hdr_ptr[12] & 0xf0) >> 2;
> + IHL = ip_hdr_ptr->ihl << 2;
> + tcp_hdr_ptr = (const struct tcphdr *)
> + ((u8 *)ip_hdr_ptr + IHL);

This alignment is a bit unfortunate... Perhaps?

tcp_hdr_ptr = buf + ETH_HLEN + IHL;

regards,
dan carpenter

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