[PATCH v2] staging: rtl8192e: Replace strcpy with strcat in rtl819x_translate_scan

[PATCH v2] staging: rtl8192e: Replace strcpy with strcat in rtl819x_translate_scan

[Abhishek Tamboli]

Replace strcpy() with strcat() in rtl819x_translate_scan()
Also Fix proto_name[] buffer size issue to accommodate all
network modes.

Signed-off-by: Abhishek Tamboli <abhishektamboli9@gmail.com>
---
Changes in v2:
- Revert the use of strscpy and replaced it with strcat.
- Remove the 'pname' and replace it's usage with direct
operations on 'proto_name' buffer.

 drivers/staging/rtl8192e/rtllib_wx.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/rtl8192e/rtllib_wx.c b/drivers/staging/rtl8192e/rtllib_wx.c
index fbd4ec824084..ec0c4c5bade7 100644
--- a/drivers/staging/rtl8192e/rtllib_wx.c
+++ b/drivers/staging/rtl8192e/rtllib_wx.c
@@ -23,14 +23,14 @@ static const char * const rtllib_modes[] = {
 };

 #define MAX_CUSTOM_LEN 64
+#define MAX_PROTO_NAME_LEN 10
 static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
 					   char *start, char *stop,
 					   struct rtllib_network *network,
 					   struct iw_request_info *info)
 {
 	char custom[MAX_CUSTOM_LEN];
-	char proto_name[6];
-	char *pname = proto_name;
+	char proto_name[MAX_PROTO_NAME_LEN];
 	char *p;
 	struct iw_event iwe;
 	int i, j;
@@ -59,13 +59,12 @@ static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
 	}
 	/* Add the protocol name */
 	iwe.cmd = SIOCGIWNAME;
+	/* Initialise proto_name as an empty string*/
+	memset(proto_name, '\0', sizeof(proto_name));
 	for (i = 0; i < ARRAY_SIZE(rtllib_modes); i++) {
-		if (network->mode & BIT(i)) {
-			strcpy(pname, rtllib_modes[i]);
-			pname += strlen(rtllib_modes[i]);
+		if (network->mode & BIT(i))
+			strcat(proto_name, rtllib_modes[i]);
 		}
-	}
-	*pname = '\0';
 	snprintf(iwe.u.name, IFNAMSIZ, "IEEE802.11%s", proto_name);
 	start = iwe_stream_add_event(info, start, stop, &iwe, IW_EV_CHAR_LEN);
 	/* Add mode */
--
2.34.1

Re: [PATCH v2] staging: rtl8192e: Replace strcpy with strcat in rtl819x_translate_scan

[Greg KH]

On Fri, Aug 23, 2024 at 09:04:11PM +0530, Abhishek Tamboli wrote:
> Replace strcpy() with strcat() in rtl819x_translate_scan()
> Also Fix proto_name[] buffer size issue to accommodate all
> network modes.

When you say "also" in a changelog text, that's a huge hint that this
should probably be split up into multiple changes.  Please do that here.

More comments below.

> Signed-off-by: Abhishek Tamboli <abhishektamboli9@gmail.com>
> ---
> Changes in v2:
> - Revert the use of strscpy and replaced it with strcat.
> - Remove the 'pname' and replace it's usage with direct
> operations on 'proto_name' buffer.
> 
>  drivers/staging/rtl8192e/rtllib_wx.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/staging/rtl8192e/rtllib_wx.c b/drivers/staging/rtl8192e/rtllib_wx.c
> index fbd4ec824084..ec0c4c5bade7 100644
> --- a/drivers/staging/rtl8192e/rtllib_wx.c
> +++ b/drivers/staging/rtl8192e/rtllib_wx.c
> @@ -23,14 +23,14 @@ static const char * const rtllib_modes[] = {
>  };
> 
>  #define MAX_CUSTOM_LEN 64
> +#define MAX_PROTO_NAME_LEN 10

Where did this "10" come from?  What sets this limit?  Why not 100?
1000?  2?  You get the idea :)


>  static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
>  					   char *start, char *stop,
>  					   struct rtllib_network *network,
>  					   struct iw_request_info *info)
>  {
>  	char custom[MAX_CUSTOM_LEN];
> -	char proto_name[6];
> -	char *pname = proto_name;
> +	char proto_name[MAX_PROTO_NAME_LEN];
>  	char *p;
>  	struct iw_event iwe;
>  	int i, j;
> @@ -59,13 +59,12 @@ static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
>  	}
>  	/* Add the protocol name */
>  	iwe.cmd = SIOCGIWNAME;
> +	/* Initialise proto_name as an empty string*/
> +	memset(proto_name, '\0', sizeof(proto_name));
>  	for (i = 0; i < ARRAY_SIZE(rtllib_modes); i++) {
> -		if (network->mode & BIT(i)) {
> -			strcpy(pname, rtllib_modes[i]);
> -			pname += strlen(rtllib_modes[i]);
> +		if (network->mode & BIT(i))
> +			strcat(proto_name, rtllib_modes[i]);
>  		}
> -	}

I think the } placement is now incorrect, right?  Did you run checkpatch
on this change?

thanks,

greg k-h

Re: [PATCH v2] staging: rtl8192e: Replace strcpy with strcat in rtl819x_translate_scan

[Dan Carpenter]

On Fri, Aug 23, 2024 at 09:04:11PM +0530, Abhishek Tamboli wrote:
> diff --git a/drivers/staging/rtl8192e/rtllib_wx.c b/drivers/staging/rtl8192e/rtllib_wx.c
> index fbd4ec824084..ec0c4c5bade7 100644
> --- a/drivers/staging/rtl8192e/rtllib_wx.c
> +++ b/drivers/staging/rtl8192e/rtllib_wx.c
> @@ -23,14 +23,14 @@ static const char * const rtllib_modes[] = {
>  };
> 
>  #define MAX_CUSTOM_LEN 64
> +#define MAX_PROTO_NAME_LEN 10
>  static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
>  					   char *start, char *stop,
>  					   struct rtllib_network *network,
>  					   struct iw_request_info *info)
>  {
>  	char custom[MAX_CUSTOM_LEN];
> -	char proto_name[6];
> -	char *pname = proto_name;
> +	char proto_name[MAX_PROTO_NAME_LEN];

In the end I think we don't want to make this buffer larger.  But if we did
this define is really vague and slightly confusing.  I assumed it was something
else when I read it.  It hurts readability.  It would probably be better to just
leave it as 6 instead and add a comment.  /* Large enough to hold "N-24G" */

>  	char *p;
>  	struct iw_event iwe;
>  	int i, j;
> @@ -59,13 +59,12 @@ static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
>  	}
>  	/* Add the protocol name */
>  	iwe.cmd = SIOCGIWNAME;
> +	/* Initialise proto_name as an empty string*/

This comment doesn't add any information.  Every kernel developer knows what
memset() does.

> +	memset(proto_name, '\0', sizeof(proto_name));

Normally we would just say 0 instead of '\0'.  The other way to do this would
be to initialize it at the start:

	char proto_name[6] = "";

regards,
dan carpenter

Re: [PATCH v2] staging: rtl8192e: Replace strcpy with strcat in rtl819x_translate_scan

[Abhishek Tamboli]

On Sat, Aug 24, 2024 at 01:45:00PM +0800, Greg KH wrote:
> On Fri, Aug 23, 2024 at 09:04:11PM +0530, Abhishek Tamboli wrote:
> > Replace strcpy() with strcat() in rtl819x_translate_scan()
> > Also Fix proto_name[] buffer size issue to accommodate all
> > network modes.
> 
> When you say "also" in a changelog text, that's a huge hint that this
> should probably be split up into multiple changes.  Please do that here.
Sure, I'll do it.
> More comments below.
> 
> > Signed-off-by: Abhishek Tamboli <abhishektamboli9@gmail.com>
> > ---
> > Changes in v2:
> > - Revert the use of strscpy and replaced it with strcat.
> > - Remove the 'pname' and replace it's usage with direct
> > operations on 'proto_name' buffer.
> > 
> >  drivers/staging/rtl8192e/rtllib_wx.c | 13 ++++++-------
> >  1 file changed, 6 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/staging/rtl8192e/rtllib_wx.c b/drivers/staging/rtl8192e/rtllib_wx.c
> > index fbd4ec824084..ec0c4c5bade7 100644
> > --- a/drivers/staging/rtl8192e/rtllib_wx.c
> > +++ b/drivers/staging/rtl8192e/rtllib_wx.c
> > @@ -23,14 +23,14 @@ static const char * const rtllib_modes[] = {
> >  };
> > 
> >  #define MAX_CUSTOM_LEN 64
> > +#define MAX_PROTO_NAME_LEN 10
> 
> Where did this "10" come from?  What sets this limit?  Why not 100?
> 1000?  2?  You get the idea :)
> 
yes, I got it.
> >  static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
> >  					   char *start, char *stop,
> >  					   struct rtllib_network *network,
> >  					   struct iw_request_info *info)
> >  {
> >  	char custom[MAX_CUSTOM_LEN];
> > -	char proto_name[6];
> > -	char *pname = proto_name;
> > +	char proto_name[MAX_PROTO_NAME_LEN];
> >  	char *p;
> >  	struct iw_event iwe;
> >  	int i, j;
> > @@ -59,13 +59,12 @@ static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
> >  	}
> >  	/* Add the protocol name */
> >  	iwe.cmd = SIOCGIWNAME;
> > +	/* Initialise proto_name as an empty string*/
> > +	memset(proto_name, '\0', sizeof(proto_name));
> >  	for (i = 0; i < ARRAY_SIZE(rtllib_modes); i++) {
> > -		if (network->mode & BIT(i)) {
> > -			strcpy(pname, rtllib_modes[i]);
> > -			pname += strlen(rtllib_modes[i]);
> > +		if (network->mode & BIT(i))
> > +			strcat(proto_name, rtllib_modes[i]);
> >  		}
> > -	}
> 
> I think the } placement is now incorrect, right?  Did you run checkpatch
> on this change?
Yes, I do run the checkpatch on this change and didn't get any warnings
or errors.

Thanks, for the feedback. I'll do the changes.

Regards,
Abhishek

Re: [PATCH v2] staging: rtl8192e: Replace strcpy with strcat in rtl819x_translate_scan

[Abhishek Tamboli]

On Sat, Aug 24, 2024 at 02:21:47PM +0300, Dan Carpenter wrote:
> On Fri, Aug 23, 2024 at 09:04:11PM +0530, Abhishek Tamboli wrote:
> > diff --git a/drivers/staging/rtl8192e/rtllib_wx.c b/drivers/staging/rtl8192e/rtllib_wx.c
> > index fbd4ec824084..ec0c4c5bade7 100644
> > --- a/drivers/staging/rtl8192e/rtllib_wx.c
> > +++ b/drivers/staging/rtl8192e/rtllib_wx.c
> > @@ -23,14 +23,14 @@ static const char * const rtllib_modes[] = {
> >  };
> > 
> >  #define MAX_CUSTOM_LEN 64
> > +#define MAX_PROTO_NAME_LEN 10
> >  static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
> >  					   char *start, char *stop,
> >  					   struct rtllib_network *network,
> >  					   struct iw_request_info *info)
> >  {
> >  	char custom[MAX_CUSTOM_LEN];
> > -	char proto_name[6];
> > -	char *pname = proto_name;
> > +	char proto_name[MAX_PROTO_NAME_LEN];
> 
> In the end I think we don't want to make this buffer larger.  But if we did
> this define is really vague and slightly confusing.  I assumed it was something
> else when I read it.  It hurts readability.  It would probably be better to just
> leave it as 6 instead and add a comment.  /* Large enough to hold "N-24G" */
Okay, I'll revert the buffer size to 6.
> 
> >  	char *p;
> >  	struct iw_event iwe;
> >  	int i, j;
> > @@ -59,13 +59,12 @@ static inline char *rtl819x_translate_scan(struct rtllib_device *ieee,
> >  	}
> >  	/* Add the protocol name */
> >  	iwe.cmd = SIOCGIWNAME;
> > +	/* Initialise proto_name as an empty string*/
> 
> This comment doesn't add any information.  Every kernel developer knows what
> memset() does.
Sure, I'll remove it.
> > +	memset(proto_name, '\0', sizeof(proto_name));
> 
> Normally we would just say 0 instead of '\0'.  The other way to do this would
> be to initialize it at the start:
> 
> 	char proto_name[6] = "";
> 
Thanks, for the feedback. I'll do the changes.

Regards,
Abhishek