[PATCH 5/6] UML - Network and pcap cleanup

[PATCH 5/6] UML - Network and pcap cleanup

[Jeff Dike]

[ Paolo - could you eyeball the globally valid MAC piece of this and
see if you think it's OK? ]

Some network device cleanup.

When setup_etheraddr found a globally valid MAC being assigned to an
interface, it went ahead and used it rather than assigning a random
MAC like the other cases do.  This isn't really an error like the
others, but it seems consistent to make it behave the same.

We were getting some duplicate kfree() in the error case in
eth_configure because platform_device_unregister frees buffers that
the error cases following tried to free again.

The pcap initialization routine wasn't doing the proper printk of its
information, causing a printk of the first part of that line to be
unterminated by a newline.

The pcap code had a bunch of style violations, which are now fixed.

pcap_setup wasn't returning false when it detected an unrecognized
option.

The printks in pcap_user all got UM_KERN_BLAH prepended to their
format strings.

pcap_remove now checks for a non-NULL pcap structure before it calls
pcap_close.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
--
 arch/um/drivers/net_kern.c  |   15 +++++++++------
 arch/um/drivers/pcap_kern.c |   25 ++++++++++++++++---------
 arch/um/drivers/pcap_user.c |   23 +++++++++++++----------
 3 files changed, 38 insertions(+), 25 deletions(-)

Index: linux-2.6.21-mm/arch/um/drivers/net_kern.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/net_kern.c	2007-04-27 16:23:31.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/net_kern.c	2007-04-27 16:24:12.000000000 -0400
@@ -316,12 +316,14 @@ static void setup_etheraddr(char *str, u
 	}
 	if (!is_local_ether_addr(addr)) {
 		printk(KERN_WARNING
-		       "Warning: attempt to assign a globally valid ethernet address to a "
-		       "device\n");
-		printk(KERN_WARNING "You should better enable the 2nd rightmost bit "
-		      "in the first byte of the MAC, i.e. "
-		      "%02x:%02x:%02x:%02x:%02x:%02x\n",
-		      addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4], addr[5]);
+		       "Warning: attempt to assign a globally valid ethernet "
+		       "address to a device\n");
+		printk(KERN_WARNING "You should better enable the 2nd "
+		       "rightmost bit in the first byte of the MAC,\n");
+		printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
+		       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
+		       addr[5]);
+		goto random;
 	}
 	return;
 
@@ -478,6 +480,7 @@ out_undo_user_init:
 		(*transport->user->remove)(&lp->user);
 out_unregister:
 	platform_device_unregister(&device->pdev);
+	return; /* platform_device_unregister frees dev and device */
 out_free_netdev:
 	free_netdev(dev);
 out_free_device:
Index: linux-2.6.21-mm/arch/um/drivers/pcap_kern.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/pcap_kern.c	2007-04-27 16:24:05.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/pcap_kern.c	2007-04-27 16:24:22.000000000 -0400
@@ -29,21 +29,25 @@ void pcap_init(struct net_device *dev, v
 	ppri->promisc = init->promisc;
 	ppri->optimize = init->optimize;
 	ppri->filter = init->filter;
+
+	printk("pcap backend, host interface %s\n", ppri->host_if);
 }
 
-static int pcap_read(int fd, struct sk_buff **skb, 
+static int pcap_read(int fd, struct sk_buff **skb,
 		       struct uml_net_private *lp)
 {
 	*skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
-	if(*skb == NULL) return(-ENOMEM);
-	return(pcap_user_read(fd, skb_mac_header(*skb),
+	if(*skb == NULL)
+		return -ENOMEM;
+
+	return pcap_user_read(fd, skb_mac_header(*skb),
 			      (*skb)->dev->mtu + ETH_HEADER_OTHER,
-			      (struct pcap_data *) &lp->user));
+			      (struct pcap_data *) &lp->user);
 }
 
 static int pcap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
 {
-	return(-EPERM);
+	return -EPERM;
 }
 
 static const struct net_kern_info pcap_kern_info = {
@@ -65,12 +69,12 @@ int pcap_setup(char *str, char **mac_out
 		  .optimize 	= 0,
 		  .filter 	= NULL });
 
-	remain = split_if_spec(str, &host_if, &init->filter, 
+	remain = split_if_spec(str, &host_if, &init->filter,
 			       &options[0], &options[1], NULL);
 	if(remain != NULL){
 		printk(KERN_ERR "pcap_setup - Extra garbage on "
 		       "specification : '%s'\n", remain);
-		return(0);
+		return 0;
 	}
 
 	if(host_if != NULL)
@@ -87,10 +91,13 @@ int pcap_setup(char *str, char **mac_out
 			init->optimize = 1;
 		else if(!strcmp(options[i], "nooptimize"))
 			init->optimize = 0;
-		else printk("pcap_setup : bad option - '%s'\n", options[i]);
+		else {
+			printk("pcap_setup : bad option - '%s'\n", options[i]);
+			return 0;
+		}
 	}
 
-	return(1);
+	return 1;
 }
 
 static struct transport pcap_transport = {
Index: linux-2.6.21-mm/arch/um/drivers/pcap_user.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/pcap_user.c	2007-04-27 16:24:05.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/pcap_user.c	2007-04-27 16:24:12.000000000 -0400
@@ -13,6 +13,7 @@
 #include "pcap_user.h"
 #include "user.h"
 #include "um_malloc.h"
+#include "kern_constants.h"
 
 #define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
 
@@ -26,8 +27,8 @@ static int pcap_user_init(void *data, vo
 
 	p = pcap_open_live(pri->host_if, MAX_PACKET, pri->promisc, 0, errors);
 	if(p == NULL){
-		printk("pcap_user_init : pcap_open_live failed - '%s'\n", 
-		       errors);
+		printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - "
+		       "'%s'\n", errors);
 		return -EINVAL;
 	}
 
@@ -48,13 +49,13 @@ static int pcap_open(void *data)
 	if(pri->filter != NULL){
 		err = dev_netmask(pri->dev, &netmask);
 		if(err < 0){
-			printk("pcap_open : dev_netmask failed\n");
+			printk(UM_KERN_ERR "pcap_open : dev_netmask failed\n");
 			return -EIO;
 		}
 
 		pri->compiled = um_kmalloc(sizeof(struct bpf_program));
 		if(pri->compiled == NULL){
-			printk("pcap_open : kmalloc failed\n");
+			printk(UM_KERN_ERR "pcap_open : kmalloc failed\n");
 			return -ENOMEM;
 		}
 
@@ -62,15 +63,15 @@ static int pcap_open(void *data)
 				   (struct bpf_program *) pri->compiled, 
 				   pri->filter, pri->optimize, netmask);
 		if(err < 0){
-			printk("pcap_open : pcap_compile failed - '%s'\n", 
-			       pcap_geterr(pri->pcap));
+			printk(UM_KERN_ERR "pcap_open : pcap_compile failed - "
+			       "'%s'\n", pcap_geterr(pri->pcap));
 			return -EIO;
 		}
 
 		err = pcap_setfilter(pri->pcap, pri->compiled);
 		if(err < 0){
-			printk("pcap_open : pcap_setfilter failed - '%s'\n", 
-			       pcap_geterr(pri->pcap));
+			printk(UM_KERN_ERR "pcap_open : pcap_setfilter "
+			       "failed - '%s'\n", pcap_geterr(pri->pcap));
 			return -EIO;
 		}
 	}
@@ -85,7 +86,8 @@ static void pcap_remove(void *data)
 	if(pri->compiled != NULL)
 		pcap_freecode(pri->compiled);
 
-	pcap_close(pri->pcap);
+	if(pri->pcap != NULL)
+		pcap_close(pri->pcap);
 }
 
 struct pcap_handler_data {
@@ -114,7 +116,8 @@ int pcap_user_read(int fd, void *buffer,
 
 	n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);
 	if(n < 0){
-		printk("pcap_dispatch failed - %s\n", pcap_geterr(pri->pcap));
+		printk(UM_KERN_ERR "pcap_dispatch failed - %s\n",
+		       pcap_geterr(pri->pcap));
 		return -EIO;
 	}
 	else if(n == 0) 

Re: [PATCH 5/6] UML - Network and pcap cleanup

[Blaisorblade]

On martedì 1 maggio 2007, Jeff Dike wrote:
> [ Paolo - could you eyeball the globally valid MAC piece of this and
> see if you think it's OK? ]

Done, the patch can be accepted (I've not looked at the PCAP part). I've a 
note on the other fix there (the additional return).

> Some network device cleanup.
>
> When setup_etheraddr found a globally valid MAC being assigned to an
> interface, it went ahead and used it rather than assigning a random
> MAC like the other cases do.  This isn't really an error like the
> others, but it seems consistent to make it behave the same.
Fine, agreed. For this, you can add my Acked-by. Probably at that time MAC 
randomization wasn't implemented.

> We were getting some duplicate kfree() in the error case in
> eth_configure because platform_device_unregister frees buffers that
> the error cases following tried to free again.

This is due to patch:
"uml: drivers get release methods"
this could be useful to check whether other such changes are needed, by 
grepping for platform_device_unregister in exit paths, also for ubd driver.

That patch only fixed net_remove() and ubd_remove().
-- 
Inform me of my mistakes, so I can add them to my list!
Paolo Giarrusso, aka Blaisorblade
http://www.user-mode-linux.org/~blaisorblade

Re: [PATCH 5/6] UML - Network and pcap cleanup

[Jeff Dike]

On Thu, May 03, 2007 at 03:32:43PM +0200, Blaisorblade wrote:
> This is due to patch:
> "uml: drivers get release methods"
> this could be useful to check whether other such changes are needed, by 
> grepping for platform_device_unregister in exit paths, also for ubd driver.
> 
> That patch only fixed net_remove() and ubd_remove().

Yeah, good point - I'll have a look.

				Jeff

-- 
Work email - jdike at linux dot intel dot com