[PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets

[PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets

[Thibaut Robert]

Use structs ethhdr, iphdr and tcphdr instead of manual parsing in
tcp_process.
This commit fix handling of ip packets containing options.
It also fixes the following sparse warning:

drivers/staging/wilc1000//wilc_wlan.c:201:19: warning: cast to restricted __be16

Signed-off-by: Thibaut Robert <thibaut.robert@gmail.com>
---
 drivers/staging/wilc1000/wilc_wlan.c | 44 +++++++++++-----------------
 1 file changed, 17 insertions(+), 27 deletions(-)

diff --git a/drivers/staging/wilc1000/wilc_wlan.c b/drivers/staging/wilc1000/wilc_wlan.c
index d4ebbf67e50b..28c93f3f846e 100644
--- a/drivers/staging/wilc1000/wilc_wlan.c
+++ b/drivers/staging/wilc1000/wilc_wlan.c
@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/if_ether.h>
+#include <linux/ip.h>
 #include "wilc_wfi_netdevice.h"
 #include "wilc_wlan_cfg.h"
 
@@ -184,9 +186,9 @@ static inline int add_tcp_pending_ack(u32 ack, u32 session_index,
 
 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;
-	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 (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);
+			total_length = ntohs(ip_hdr_ptr->tot_len);
+
+			data_offset = tcp_hdr_ptr->doff << 2;
 			if (total_length == (IHL + data_offset)) {
 				u32 seq_no, ack_no;
 
-				seq_no = ((u32)tcp_hdr_ptr[4] << 24) +
-					 ((u32)tcp_hdr_ptr[5] << 16) +
-					 ((u32)tcp_hdr_ptr[6] << 8) +
-					 (u32)tcp_hdr_ptr[7];
-
-				ack_no = ((u32)tcp_hdr_ptr[8] << 24) +
-					 ((u32)tcp_hdr_ptr[9] << 16) +
-					 ((u32)tcp_hdr_ptr[10] << 8) +
-					 (u32)tcp_hdr_ptr[11];
-
+				seq_no = ntohl(tcp_hdr_ptr->seq);
+				ack_no = ntohl(tcp_hdr_ptr->ack_seq);
 				for (i = 0; i < tcp_session; i++) {
 					u32 j = ack_session_info[i].seq_num;
 
-- 
2.17.0

Re: [PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets

[Dan Carpenter]

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

Re: [PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets

[Ajay Singh]

Thank you for submitting the patches.

The modification in this patch looks okay to me.
Please resend this by including changes as suggested by Dan.
I can do the modification and resubmit this patch by including review
comments, if its okay with you.


Regards,
Ajay

Re: [PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets

[Thibaut Robert]

Le lundi 04 juin 2018 à 10:55:49 (+0530), Ajay Singh a écrit :
> 
> Thank you for submitting the patches.
> 
> The modification in this patch looks okay to me.
> Please resend this by including changes as suggested by Dan.
> I can do the modification and resubmit this patch by including review
> comments, if its okay with you.
> 
Sorry, I would like to address the comments, but still had no time to do it correctly. I
am doing this as a hobby and am still learning so forgive me for the delay. 
If you can wait a little bit more, I'll resend an updated version.

Thanks for your time !
Thibaut

> 
> Regards,
> Ajay
> 
> 

Re: [PATCH 1/1] staging: wilc1000: Use common structs to parse ip packets

[Dan Carpenter]

On Mon, Jun 04, 2018 at 09:27:02PM +0200, Thibaut Robert wrote:
> Le lundi 04 juin 2018 à 10:55:49 (+0530), Ajay Singh a écrit :
> > 
> > Thank you for submitting the patches.
> > 
> > The modification in this patch looks okay to me.
> > Please resend this by including changes as suggested by Dan.
> > I can do the modification and resubmit this patch by including review
> > comments, if its okay with you.
> > 
> Sorry, I would like to address the comments, but still had no time to do it correctly. I
> am doing this as a hobby and am still learning so forgive me for the delay. 
> If you can wait a little bit more, I'll resend an updated version.
> 
> Thanks for your time !

When you're a kernel dev, you sometimes do get the feeling that everyone
is waiting for you.  We're not.  There is no rush.  We read through your
email and reply and then it's gone from our mind like dust in the wind.
There is never a rush and you will never run out of more work to do.

Plus the merge window is open so Greg won't even look at it for the next
several weeks.

Take all the time you need.

I normally write a patch, then wait until morning so I can review it
with fresh eyes before sending it.  If I wait longer than a day, though,
I forget what the issue is and I have to retest it from scratch.  After
one day in my outbox a patch gets old and boring so those are low
quality.  If it's a cleanup patch, I'll probably just delete it instead.

regards,
dan carpenter

[PATCH v2] staging: wilc1000: Use common structs to parse ip packets

[Thibaut Robert]

Use structs ethhdr, iphdr and tcphdr instead of manual parsing in
tcp_process.
This commit fix handling of ip packets containing options.
It also fixes the following sparse warning:

drivers/staging/wilc1000//wilc_wlan.c:201:19: warning: cast to restricted __be16

Signed-off-by: Thibaut Robert <thibaut.robert@gmail.com>
---
 drivers/staging/wilc1000/wilc_wlan.c | 43 ++++++++++------------------
 1 file changed, 15 insertions(+), 28 deletions(-)

diff --git a/drivers/staging/wilc1000/wilc_wlan.c b/drivers/staging/wilc1000/wilc_wlan.c
index 55755d7fbb30..85af36595e69 100644
--- a/drivers/staging/wilc1000/wilc_wlan.c
+++ b/drivers/staging/wilc1000/wilc_wlan.c
@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/if_ether.h>
+#include <linux/ip.h>
 #include "wilc_wfi_netdevice.h"
 #include "wilc_wlan_cfg.h"
 
@@ -150,9 +152,8 @@ static inline int add_tcp_pending_ack(u32 ack, u32 session_index,
 
 static inline void tcp_process(struct net_device *dev, struct txq_entry_t *tqe)
 {
-	u8 *eth_hdr_ptr;
-	u8 *buffer = tqe->buffer;
-	unsigned short h_proto;
+	void *buffer = tqe->buffer;
+	const struct ethhdr *eth_hdr_ptr = buffer;
 	int i;
 	unsigned long flags;
 	struct wilc_vif *vif;
@@ -163,37 +164,23 @@ 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;
+	if (eth_hdr_ptr->h_proto == htons(ETH_P_IP)) {
+		const struct iphdr *ip_hdr_ptr = buffer + ETH_HLEN;
 
-		ip_hdr_ptr = &buffer[ETHERNET_HDR_LEN];
-		protocol = ip_hdr_ptr[9];
-
-		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 = buffer + ETH_HLEN + IHL;
+			total_length = ntohs(ip_hdr_ptr->tot_len);
+
+			data_offset = tcp_hdr_ptr->doff << 2;
 			if (total_length == (IHL + data_offset)) {
 				u32 seq_no, ack_no;
 
-				seq_no = ((u32)tcp_hdr_ptr[4] << 24) +
-					 ((u32)tcp_hdr_ptr[5] << 16) +
-					 ((u32)tcp_hdr_ptr[6] << 8) +
-					 (u32)tcp_hdr_ptr[7];
-
-				ack_no = ((u32)tcp_hdr_ptr[8] << 24) +
-					 ((u32)tcp_hdr_ptr[9] << 16) +
-					 ((u32)tcp_hdr_ptr[10] << 8) +
-					 (u32)tcp_hdr_ptr[11];
-
+				seq_no = ntohl(tcp_hdr_ptr->seq);
+				ack_no = ntohl(tcp_hdr_ptr->ack_seq);
 				for (i = 0; i < tcp_session; i++) {
 					u32 j = ack_session_info[i].seq_num;
 
-- 
2.17.1

Re: [PATCH v2] staging: wilc1000: Use common structs to parse ip packets

[Dan Carpenter]

Nice...

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter

Re: [PATCH v2] staging: wilc1000: Use common structs to parse ip packets

[Claudiu Beznea]

Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>

On 19.06.2018 21:44, Thibaut Robert wrote:
> Use structs ethhdr, iphdr and tcphdr instead of manual parsing in
> tcp_process.
> This commit fix handling of ip packets containing options.
> It also fixes the following sparse warning:
> 
> drivers/staging/wilc1000//wilc_wlan.c:201:19: warning: cast to restricted __be16
> 
> Signed-off-by: Thibaut Robert <thibaut.robert@gmail.com>
> ---
>  drivers/staging/wilc1000/wilc_wlan.c | 43 ++++++++++------------------
>  1 file changed, 15 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/staging/wilc1000/wilc_wlan.c b/drivers/staging/wilc1000/wilc_wlan.c
> index 55755d7fbb30..85af36595e69 100644
> --- a/drivers/staging/wilc1000/wilc_wlan.c
> +++ b/drivers/staging/wilc1000/wilc_wlan.c
> @@ -1,4 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0
> +#include <linux/if_ether.h>
> +#include <linux/ip.h>
>  #include "wilc_wfi_netdevice.h"
>  #include "wilc_wlan_cfg.h"
>  
> @@ -150,9 +152,8 @@ static inline int add_tcp_pending_ack(u32 ack, u32 session_index,
>  
>  static inline void tcp_process(struct net_device *dev, struct txq_entry_t *tqe)
>  {
> -	u8 *eth_hdr_ptr;
> -	u8 *buffer = tqe->buffer;
> -	unsigned short h_proto;
> +	void *buffer = tqe->buffer;
> +	const struct ethhdr *eth_hdr_ptr = buffer;
>  	int i;
>  	unsigned long flags;
>  	struct wilc_vif *vif;
> @@ -163,37 +164,23 @@ 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;
> +	if (eth_hdr_ptr->h_proto == htons(ETH_P_IP)) {
> +		const struct iphdr *ip_hdr_ptr = buffer + ETH_HLEN;
>  
> -		ip_hdr_ptr = &buffer[ETHERNET_HDR_LEN];
> -		protocol = ip_hdr_ptr[9];
> -
> -		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 = buffer + ETH_HLEN + IHL;
> +			total_length = ntohs(ip_hdr_ptr->tot_len);
> +
> +			data_offset = tcp_hdr_ptr->doff << 2;
>  			if (total_length == (IHL + data_offset)) {
>  				u32 seq_no, ack_no;
>  
> -				seq_no = ((u32)tcp_hdr_ptr[4] << 24) +
> -					 ((u32)tcp_hdr_ptr[5] << 16) +
> -					 ((u32)tcp_hdr_ptr[6] << 8) +
> -					 (u32)tcp_hdr_ptr[7];
> -
> -				ack_no = ((u32)tcp_hdr_ptr[8] << 24) +
> -					 ((u32)tcp_hdr_ptr[9] << 16) +
> -					 ((u32)tcp_hdr_ptr[10] << 8) +
> -					 (u32)tcp_hdr_ptr[11];
> -
> +				seq_no = ntohl(tcp_hdr_ptr->seq);
> +				ack_no = ntohl(tcp_hdr_ptr->ack_seq);
>  				for (i = 0; i < tcp_session; i++) {
>  					u32 j = ack_session_info[i].seq_num;
>  
>