[ETH]: Combine format_addr() with print_mac().

[ETH]: Combine format_addr() with print_mac().

[Michael Chan]

[ETH]: Combine format_addr() with print_mac().

print_mac() used by most net drivers and format_addr() used by
net-sysfs.c are very similar and they can be integrated.

format_addr() is also identically redefined in the qla4xxx iscsi
driver.

Export a new function format_mac_addr() to be used by net-sysfs,
qla4xxx and others in the future.  Both print_mac() and
format_mac_addr() call _format_mac_addr() to do the formatting.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Cc: Joe Perches <joe@perches.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: David Somayajulu <david.somayajulu@qlogic.com>

diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 89460d2..0f4562b 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -173,18 +173,6 @@ static void qla4xxx_conn_stop(struct iscsi_cls_conn *conn, int flag)
 		printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
 }
 
-static ssize_t format_addr(char *buf, const unsigned char *addr, int len)
-{
-	int i;
-	char *cp = buf;
-
-	for (i = 0; i < len; i++)
-		cp += sprintf(cp, "%02x%c", addr[i],
-			      i == (len - 1) ? '\n' : ':');
-	return cp - buf;
-}
-
-
 static int qla4xxx_host_get_param(struct Scsi_Host *shost,
 				  enum iscsi_host_param param, char *buf)
 {
@@ -193,7 +181,7 @@ static int qla4xxx_host_get_param(struct Scsi_Host *shost,
 
 	switch (param) {
 	case ISCSI_HOST_PARAM_HWADDRESS:
-		len = format_addr(buf, ha->my_mac, MAC_ADDR_LEN);
+		len = format_mac_addr(buf, ha->my_mac, MAC_ADDR_LEN);
 		break;
 	case ISCSI_HOST_PARAM_IPADDRESS:
 		len = sprintf(buf, "%d.%d.%d.%d\n", ha->ip_address[0],
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index cc002cb..d20512c 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -124,10 +124,11 @@ int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
 extern struct ctl_table ether_table[];
 #endif
 
+extern ssize_t format_mac_addr(char *buf, const unsigned char *addr, int len);
+
 /*
  *	Display a 6 byte device address (MAC) in a readable format.
  */
-#define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
 extern char *print_mac(char *buf, const u8 *addr);
 #define DECLARE_MAC_BUF(var) char var[18] __maybe_unused
 
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index e41f4b9..e72993b 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -95,17 +95,6 @@ NETDEVICE_SHOW(type, fmt_dec);
 NETDEVICE_SHOW(link_mode, fmt_dec);
 
 /* use same locking rules as GIFHWADDR ioctl's */
-static ssize_t format_addr(char *buf, const unsigned char *addr, int len)
-{
-	int i;
-	char *cp = buf;
-
-	for (i = 0; i < len; i++)
-		cp += sprintf(cp, "%02x%c", addr[i],
-			      i == (len - 1) ? '\n' : ':');
-	return cp - buf;
-}
-
 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
@@ -114,7 +103,7 @@ static ssize_t show_address(struct device *dev, struct device_attribute *attr,
 
 	read_lock(&dev_base_lock);
 	if (dev_isalive(net))
-	    ret = format_addr(buf, net->dev_addr, net->addr_len);
+		ret = format_mac_addr(buf, net->dev_addr, net->addr_len);
 	read_unlock(&dev_base_lock);
 	return ret;
 }
@@ -124,7 +113,7 @@ static ssize_t show_broadcast(struct device *dev,
 {
 	struct net_device *net = to_net_dev(dev);
 	if (dev_isalive(net))
-		return format_addr(buf, net->broadcast, net->addr_len);
+		return format_mac_addr(buf, net->broadcast, net->addr_len);
 	return -EINVAL;
 }
 
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 6b2e454..f760d41 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -359,10 +359,33 @@ struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count)
 }
 EXPORT_SYMBOL(alloc_etherdev_mq);
 
+static ssize_t _format_mac_addr(char *buf, const unsigned char *addr, int len)
+{
+	int i;
+	char *cp = buf;
+
+	for (i = 0; i < len; i++) {
+		cp += sprintf(cp, "%02x", addr[i]);
+		if (i == len - 1)
+			break;
+		*cp++ = ':';
+	}
+	return cp - buf;
+}
+
+ssize_t format_mac_addr(char *buf, const unsigned char *addr, int len)
+{
+	ssize_t l;
+
+	l = _format_mac_addr(buf, addr, len);
+	strcpy(buf + l, "\n");
+	return l + 1;
+}
+EXPORT_SYMBOL(format_mac_addr);
+
 char *print_mac(char *buf, const u8 *addr)
 {
-	sprintf(buf, MAC_FMT,
-		addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+	_format_mac_addr(buf, addr, ETH_ALEN);
 	return buf;
 }
 EXPORT_SYMBOL(print_mac);

Re: [ETH]: Combine format_addr() with print_mac().

[Joe Perches]

On Fri, 2007-12-21 at 14:05 -0800, Michael Chan wrote:
> [ETH]: Combine format_addr() with print_mac().
> print_mac() used by most net drivers and format_addr() used by
> net-sysfs.c are very similar and they can be integrated.
> format_addr() is also identically redefined in the qla4xxx iscsi
> driver.
> diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
> index 6b2e454..f760d41 100644
> --- a/net/ethernet/eth.c
> +++ b/net/ethernet/eth.c
> @@ -359,10 +359,33 @@ struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count)
>  }
>  EXPORT_SYMBOL(alloc_etherdev_mq);
>  
> +static ssize_t _format_mac_addr(char *buf, const unsigned char *addr, int len)
> +{
> +	int i;
> +	char *cp = buf;
> +
> +	for (i = 0; i < len; i++) {
> +		cp += sprintf(cp, "%02x", addr[i]);
> +		if (i == len - 1)
> +			break;
> +		*cp++ = ':';
> +	}
> +	return cp - buf;
> +}
> +
> +ssize_t format_mac_addr(char *buf, const unsigned char *addr, int len)
> +{
> +	ssize_t l;
> +
> +	l = _format_mac_addr(buf, addr, len);
> +	strcpy(buf + l, "\n");
> +	return l + 1;
> +}
> +EXPORT_SYMBOL(format_mac_addr);
> +
>  char *print_mac(char *buf, const u8 *addr)
>  {
> -	sprintf(buf, MAC_FMT,
> -		addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
> +	_format_mac_addr(buf, addr, ETH_ALEN);
>  	return buf;
>  }
>  EXPORT_SYMBOL(print_mac);

I think const unsigned char *addr should be const u8 *addr
ssize_t? shouldn't it be size_t?
Indexing buf by int len is unchecked.
That could lead to unintended buffer overruns.
Maybe add a buflen argument and use snprintf?

I had a patch that added some type-safety to print_mac
and prevented this unintended buffer overrun.

It seems it wasn't applied.

---------------------------------------

Subject: Re: [PATCH net-2.6.24] introduce MAC_FMT/MAC_ARG
Date: Mon, 24 Sep 2007 10:28:36 -0700

Here is a patch that adds some type safety to print_mac
by using a struct print_mac_buf * instead of char *.

It also reduces the defconfig vmlinux size by 8 bytes.

Signed-off-by:  Joe Perches <joe@perches.com>

--

 include/linux/if_ether.h |   12 ++++++++++--
 net/ethernet/eth.c       |    6 +++---
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index 57abca1..620d6b1 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -126,7 +126,15 @@ extern struct ctl_table ether_table[];
  *     Display a 6 byte device address (MAC) in a readable format.
  */
 #define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
-extern char *print_mac(char *buf, const u8 *addr);
-#define DECLARE_MAC_BUF(var) char var[18] __maybe_unused
+
+struct print_mac_buf {
+       char formatted_mac_addr[18];
+};
+
+#define DECLARE_MAC_BUF(var) \
+       struct print_mac_buf __maybe_unused _##var; \
+       struct print_mac_buf __maybe_unused *var = &_##var
+
+extern char *print_mac(struct print_mac_buf *buf, const u8 *addr);
 
 #endif /* _LINUX_IF_ETHER_H */
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 2aaf6fa..ad82613 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -338,10 +338,10 @@ struct net_device *alloc_etherdev_mq(int
sizeof_priv, unsigned int queue_count)
 }
 EXPORT_SYMBOL(alloc_etherdev_mq);
 
-char *print_mac(char *buf, const u8 *addr)
+char *print_mac(struct print_mac_buf *buf, const u8 *addr)
 {
-       sprintf(buf, MAC_FMT,
+       sprintf(buf->formatted_mac_addr, MAC_FMT,
                addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
-       return buf;
+       return buf->formatted_mac_addr;
 }
 EXPORT_SYMBOL(print_mac);

Re: [ETH]: Combine format_addr() with print_mac().

[Michael Chan]

On Fri, 2007-12-21 at 14:36 -0800, Joe Perches wrote:
> On Fri, 2007-12-21 at 14:05 -0800, Michael Chan wrote:
> > diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
> > index 6b2e454..f760d41 100644
> > --- a/net/ethernet/eth.c
> > +++ b/net/ethernet/eth.c
> > @@ -359,10 +359,33 @@ struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count)
> >  }
> >  EXPORT_SYMBOL(alloc_etherdev_mq);
> >  
> > +static ssize_t _format_mac_addr(char *buf, const unsigned char *addr, int len)
> > +{
> > +	int i;
> > +	char *cp = buf;
> > +
> > +	for (i = 0; i < len; i++) {
> > +		cp += sprintf(cp, "%02x", addr[i]);
> > +		if (i == len - 1)
> > +			break;
> > +		*cp++ = ':';
> > +	}
> > +	return cp - buf;
> > +}
> > +
> > +ssize_t format_mac_addr(char *buf, const unsigned char *addr, int len)
> > +{
> > +	ssize_t l;
> > +
> > +	l = _format_mac_addr(buf, addr, len);
> > +	strcpy(buf + l, "\n");
> > +	return l + 1;
> > +}
> > +EXPORT_SYMBOL(format_mac_addr);
> > +
> >  char *print_mac(char *buf, const u8 *addr)
> >  {
> > -	sprintf(buf, MAC_FMT,
> > -		addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
> > +	_format_mac_addr(buf, addr, ETH_ALEN);
> >  	return buf;
> >  }
> >  EXPORT_SYMBOL(print_mac);
> 
> I think const unsigned char *addr should be const u8 *addr

The dev_addr is declared as unsigned char* in struct net_device.  To be
consistent, can we change print_mac() and MAC_BUF to use unsigned char*?
They are really the same.

> ssize_t? shouldn't it be size_t?

I'm just keeping the prototype unchanged as originally defined in net-
sysfs.c

> Indexing buf by int len is unchecked.
> That could lead to unintended buffer overruns.
> Maybe add a buflen argument and use snprintf?

Again, I kept the semantics the same as the original, but will be happy
to add a buflen for better checking.

> 
> I had a patch that added some type-safety to print_mac
> and prevented this unintended buffer overrun.
> 
> It seems it wasn't applied.
> 
> ---------------------------------------
> 
> Subject: Re: [PATCH net-2.6.24] introduce MAC_FMT/MAC_ARG
> Date: Mon, 24 Sep 2007 10:28:36 -0700
> 
> Here is a patch that adds some type safety to print_mac
> by using a struct print_mac_buf * instead of char *.
> 
> It also reduces the defconfig vmlinux size by 8 bytes.
> 
> Signed-off-by:  Joe Perches <joe@perches.com>
> 
> --
> 
>  include/linux/if_ether.h |   12 ++++++++++--
>  net/ethernet/eth.c       |    6 +++---
>  2 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
> index 57abca1..620d6b1 100644
> --- a/include/linux/if_ether.h
> +++ b/include/linux/if_ether.h
> @@ -126,7 +126,15 @@ extern struct ctl_table ether_table[];
>   *     Display a 6 byte device address (MAC) in a readable format.
>   */
>  #define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
> -extern char *print_mac(char *buf, const u8 *addr);
> -#define DECLARE_MAC_BUF(var) char var[18] __maybe_unused
> +
> +struct print_mac_buf {
> +       char formatted_mac_addr[18];
> +};
> +
> +#define DECLARE_MAC_BUF(var) \
> +       struct print_mac_buf __maybe_unused _##var; \
> +       struct print_mac_buf __maybe_unused *var = &_##var
> +
> +extern char *print_mac(struct print_mac_buf *buf, const u8 *addr);
>  
>  #endif /* _LINUX_IF_ETHER_H */
> diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
> index 2aaf6fa..ad82613 100644
> --- a/net/ethernet/eth.c
> +++ b/net/ethernet/eth.c
> @@ -338,10 +338,10 @@ struct net_device *alloc_etherdev_mq(int
> sizeof_priv, unsigned int queue_count)
>  }
>  EXPORT_SYMBOL(alloc_etherdev_mq);
>  
> -char *print_mac(char *buf, const u8 *addr)
> +char *print_mac(struct print_mac_buf *buf, const u8 *addr)
>  {
> -       sprintf(buf, MAC_FMT,
> +       sprintf(buf->formatted_mac_addr, MAC_FMT,
>                 addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
> -       return buf;
> +       return buf->formatted_mac_addr;
>  }
>  EXPORT_SYMBOL(print_mac);
> 
> 
> 
> 

Re: [ETH]: Combine format_addr() with print_mac().

[Joe Perches]

On Fri, 2007-12-21 at 19:58 -0800, Michael Chan wrote:
> The dev_addr is declared as unsigned char* in struct net_device.  To be
> consistent, can we change print_mac() and MAC_BUF to use unsigned char*?
> They are really the same.

That's fine by me.  I like consistency.
I don't remember why it was u8 and not unsigned char.

> > ssize_t? shouldn't it be size_t?
> I'm just keeping the prototype unchanged as originally defined in net-
> sysfs.c

It's painless to change the prototype.
size_t seems more sensible.

> > Indexing buf by int len is unchecked.
> > That could lead to unintended buffer overruns.
> > Maybe add a buflen argument and use snprintf?
> Again, I kept the semantics the same as the original, but will be happy
> to add a buflen for better checking.

That sounds good.

cheers, Joe

Re: [ETH]: Combine format_addr() with print_mac().

[Michael Chan]

On Fri, 2007-12-21 at 23:02 -0800, Joe Perches wrote:
> On Fri, 2007-12-21 at 19:58 -0800, Michael Chan wrote:
> > > ssize_t? shouldn't it be size_t?
> > I'm just keeping the prototype unchanged as originally defined in net-
> > sysfs.c
> 
> It's painless to change the prototype.
> size_t seems more sensible.
> 

I'll change the internal function to use size_t, but the exported
function for sysfs use will be ssize_t since sysfs uses ssize_t.

Here's the revised patch:

[ETH]: Combine format_addr() with print_mac().

print_mac() used many most net drivers and format_addr() used by
net-sysfs.c are very similar and they can be intergrated.

format_addr() is also identically redefined in the qla4xxx iscsi
driver.

Export a new function sysfs_format_mac() to be used by net-sysfs,
qla4xxx and others in the future.  Both print_mac() and
sysfs_format_mac() call _format_mac_addr() to do the formatting.

Changed print_mac() to use unsigned char * to be consistent with
net_device struct's dev_addr.  Added buffer length overrun checking
as suggested by Joe Perches.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Cc: Joe Perches <joe@perches.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: David Somayajulu <david.somayajulu@qlogic.com>

diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 89460d2..4e9cf18 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -173,18 +173,6 @@ static void qla4xxx_conn_stop(struct iscsi_cls_conn *conn, int flag)
 		printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
 }
 
-static ssize_t format_addr(char *buf, const unsigned char *addr, int len)
-{
-	int i;
-	char *cp = buf;
-
-	for (i = 0; i < len; i++)
-		cp += sprintf(cp, "%02x%c", addr[i],
-			      i == (len - 1) ? '\n' : ':');
-	return cp - buf;
-}
-
-
 static int qla4xxx_host_get_param(struct Scsi_Host *shost,
 				  enum iscsi_host_param param, char *buf)
 {
@@ -193,7 +181,7 @@ static int qla4xxx_host_get_param(struct Scsi_Host *shost,
 
 	switch (param) {
 	case ISCSI_HOST_PARAM_HWADDRESS:
-		len = format_addr(buf, ha->my_mac, MAC_ADDR_LEN);
+		len = sysfs_format_mac(buf, ha->my_mac, MAC_ADDR_LEN);
 		break;
 	case ISCSI_HOST_PARAM_IPADDRESS:
 		len = sprintf(buf, "%d.%d.%d.%d\n", ha->ip_address[0],
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index cc002cb..7a1e011 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -124,12 +124,14 @@ int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
 extern struct ctl_table ether_table[];
 #endif
 
+extern ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len);
+
 /*
  *	Display a 6 byte device address (MAC) in a readable format.
  */
-#define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
-extern char *print_mac(char *buf, const u8 *addr);
-#define DECLARE_MAC_BUF(var) char var[18] __maybe_unused
+extern char *print_mac(char *buf, const unsigned char *addr);
+#define MAC_BUF_SIZE	18
+#define DECLARE_MAC_BUF(var) char var[MAC_BUF_SIZE] __maybe_unused
 
 #endif
 
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index e41f4b9..7635d3f 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -95,17 +95,6 @@ NETDEVICE_SHOW(type, fmt_dec);
 NETDEVICE_SHOW(link_mode, fmt_dec);
 
 /* use same locking rules as GIFHWADDR ioctl's */
-static ssize_t format_addr(char *buf, const unsigned char *addr, int len)
-{
-	int i;
-	char *cp = buf;
-
-	for (i = 0; i < len; i++)
-		cp += sprintf(cp, "%02x%c", addr[i],
-			      i == (len - 1) ? '\n' : ':');
-	return cp - buf;
-}
-
 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
@@ -114,7 +103,7 @@ static ssize_t show_address(struct device *dev, struct device_attribute *attr,
 
 	read_lock(&dev_base_lock);
 	if (dev_isalive(net))
-	    ret = format_addr(buf, net->dev_addr, net->addr_len);
+		ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
 	read_unlock(&dev_base_lock);
 	return ret;
 }
@@ -124,7 +113,7 @@ static ssize_t show_broadcast(struct device *dev,
 {
 	struct net_device *net = to_net_dev(dev);
 	if (dev_isalive(net))
-		return format_addr(buf, net->broadcast, net->addr_len);
+		return sysfs_format_mac(buf, net->broadcast, net->addr_len);
 	return -EINVAL;
 }
 
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 6b2e454..a7b4175 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -359,10 +359,34 @@ struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count)
 }
 EXPORT_SYMBOL(alloc_etherdev_mq);
 
-char *print_mac(char *buf, const u8 *addr)
+static size_t _format_mac_addr(char *buf, int buflen,
+				const unsigned char *addr, int len)
 {
-	sprintf(buf, MAC_FMT,
-		addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+	int i;
+	char *cp = buf;
+
+	for (i = 0; i < len; i++) {
+		cp += scnprintf(cp, buflen - (cp - buf), "%02x", addr[i]);
+		if (i == len - 1)
+			break;
+		cp += strlcpy(cp, ":", buflen - (cp - buf));
+	}
+	return cp - buf;
+}
+
+ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
+{
+	size_t l;
+
+	l = _format_mac_addr(buf, PAGE_SIZE, addr, len);
+	l += strlcpy(buf + l, "\n", PAGE_SIZE - l);
+	return ((ssize_t) l);
+}
+EXPORT_SYMBOL(sysfs_format_mac);
+
+char *print_mac(char *buf, const unsigned char *addr)
+{
+	_format_mac_addr(buf, MAC_BUF_SIZE, addr, ETH_ALEN);
 	return buf;
 }
 EXPORT_SYMBOL(print_mac);

Re: [ETH]: Combine format_addr() with print_mac().

[David Miller]

From: "Michael Chan" <mchan@broadcom.com>
Date: Sun, 23 Dec 2007 16:20:35 -0800

> Here's the revised patch:
> 
> [ETH]: Combine format_addr() with print_mac().
> 
> print_mac() used many most net drivers and format_addr() used by
> net-sysfs.c are very similar and they can be intergrated.
> 
> format_addr() is also identically redefined in the qla4xxx iscsi
> driver.
> 
> Export a new function sysfs_format_mac() to be used by net-sysfs,
> qla4xxx and others in the future.  Both print_mac() and
> sysfs_format_mac() call _format_mac_addr() to do the formatting.
> 
> Changed print_mac() to use unsigned char * to be consistent with
> net_device struct's dev_addr.  Added buffer length overrun checking
> as suggested by Joe Perches.
> 
> Signed-off-by: Michael Chan <mchan@broadcom.com>

Applied to net-2.6.25, thanks Michael.