[NFS] [PATCH] NFS: Add support for AF_INET6 addresses in nfs_compare_super()

[NFS] [PATCH] NFS: Add support for AF_INET6 addresses in nfs_compare_super()

[Chuck Lever]

Refactor nfs_compare_super() and add AF_INET6 support.

Replace the generic memcmp() to document explicitly what parts of the
addresses must match in this check, and make the comparison independent
of the lengths of both addresses.

A side benefit is both tests are more computationally efficient than a
memcmp().

Note the "void *" casts are temporary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/super.c |   41 ++++++++++++++++++++++++++++++++++++++---
 1 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6b004d8..e5646a9 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -45,6 +45,8 @@
 #include <linux/nfs_idmap.h>
 #include <linux/vfs.h>
 #include <linux/inet.h>
+#include <linux/in6.h>
+#include <net/ipv6.h>
 #include <linux/nfs_xdr.h>
 #include <linux/magic.h>
 #include <linux/parser.h>
@@ -1302,15 +1304,48 @@ static int nfs_set_super(struct super_block *s, void *data)
 	return ret;
 }
 
+static int nfs_compare_super_address(struct nfs_server *server1,
+				     struct nfs_server *server2)
+{
+	struct sockaddr_storage *ssp1 = (void *)&server1->nfs_client->cl_addr;
+	struct sockaddr_storage *ssp2 = (void *)&server2->nfs_client->cl_addr;
+
+	if (ssp1->ss_family != ssp2->ss_family)
+		return 0;
+
+	switch (ssp1->ss_family) {
+	case AF_INET: {
+		struct sockaddr_in *sin1 = (struct sockaddr_in *)ssp1;
+		struct sockaddr_in *sin2 = (struct sockaddr_in *)ssp2;
+		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
+			return 0;
+		if (sin1->sin_port != sin2->sin_port)
+			return 0;
+		break;
+	}
+	case AF_INET6: {
+		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)ssp1;
+		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)ssp2;
+		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
+			return 0;
+		if (sin1->sin6_port != sin2->sin6_port)
+			return 0;
+		break;
+	}
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
 static int nfs_compare_super(struct super_block *sb, void *data)
 {
 	struct nfs_sb_mountdata *sb_mntdata = data;
 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
 	int mntflags = sb_mntdata->mntflags;
 
-	if (memcmp(&old->nfs_client->cl_addr,
-				&server->nfs_client->cl_addr,
-				sizeof(old->nfs_client->cl_addr)) != 0)
+	if (!nfs_compare_super_address(old, server))
 		return 0;
 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
 	if (old->flags & NFS_MOUNT_UNSHARED)


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Re: [NFS] [PATCH] NFS: Add support for AF_INET6 addresses in nfs_compare_super()

[Trond Myklebust]

On Fri, 2007-11-30 at 14:12 -0500, Chuck Lever wrote:
> Refactor nfs_compare_super() and add AF_INET6 support.
> 
> Replace the generic memcmp() to document explicitly what parts of the
> addresses must match in this check, and make the comparison independent
> of the lengths of both addresses.
> 
> A side benefit is both tests are more computationally efficient than a
> memcmp().
> 
> Note the "void *" casts are temporary.
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
> 
>  fs/nfs/super.c |   41 ++++++++++++++++++++++++++++++++++++++---
>  1 files changed, 38 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 6b004d8..e5646a9 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -45,6 +45,8 @@
>  #include <linux/nfs_idmap.h>
>  #include <linux/vfs.h>
>  #include <linux/inet.h>
> +#include <linux/in6.h>
> +#include <net/ipv6.h>
>  #include <linux/nfs_xdr.h>
>  #include <linux/magic.h>
>  #include <linux/parser.h>
> @@ -1302,15 +1304,48 @@ static int nfs_set_super(struct super_block *s, void *data)
>  	return ret;
>  }
>  
> +static int nfs_compare_super_address(struct nfs_server *server1,
> +				     struct nfs_server *server2)
> +{
> +	struct sockaddr_storage *ssp1 = (void *)&server1->nfs_client->cl_addr;
> +	struct sockaddr_storage *ssp2 = (void *)&server2->nfs_client->cl_addr;
> +
> +	if (ssp1->ss_family != ssp2->ss_family)
> +		return 0;
> +
> +	switch (ssp1->ss_family) {
> +	case AF_INET: {
> +		struct sockaddr_in *sin1 = (struct sockaddr_in *)ssp1;
> +		struct sockaddr_in *sin2 = (struct sockaddr_in *)ssp2;
> +		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
> +			return 0;
> +		if (sin1->sin_port != sin2->sin_port)

What if sin2->sin_port == 0?

> +			return 0;
> +		break;
> +	}
> +	case AF_INET6: {
> +		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)ssp1;
> +		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)ssp2;
> +		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
> +			return 0;
> +		if (sin1->sin6_port != sin2->sin6_port)
> +			return 0;
> +		break;
> +	}
> +	default:
> +		return 0;
> +	}
> +
> +	return 1;
> +}
> +
>  static int nfs_compare_super(struct super_block *sb, void *data)
>  {
>  	struct nfs_sb_mountdata *sb_mntdata = data;
>  	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
>  	int mntflags = sb_mntdata->mntflags;
>  
> -	if (memcmp(&old->nfs_client->cl_addr,
> -				&server->nfs_client->cl_addr,
> -				sizeof(old->nfs_client->cl_addr)) != 0)
> +	if (!nfs_compare_super_address(old, server))
>  		return 0;
>  	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
>  	if (old->flags & NFS_MOUNT_UNSHARED)
> 


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Re: [NFS] [PATCH] NFS: Add support for AF_INET6 addresses in nfs_compare_super()

[Chuck Lever]

On Nov 30, 2007, at 2:17 PM, Trond Myklebust wrote:

>
> On Fri, 2007-11-30 at 14:12 -0500, Chuck Lever wrote:
>> Refactor nfs_compare_super() and add AF_INET6 support.
>>
>> Replace the generic memcmp() to document explicitly what parts of the
>> addresses must match in this check, and make the comparison  
>> independent
>> of the lengths of both addresses.
>>
>> A side benefit is both tests are more computationally efficient  
>> than a
>> memcmp().
>>
>> Note the "void *" casts are temporary.
>>
>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>> ---
>>
>>  fs/nfs/super.c |   41 ++++++++++++++++++++++++++++++++++++++---
>>  1 files changed, 38 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>> index 6b004d8..e5646a9 100644
>> --- a/fs/nfs/super.c
>> +++ b/fs/nfs/super.c
>> @@ -45,6 +45,8 @@
>>  #include <linux/nfs_idmap.h>
>>  #include <linux/vfs.h>
>>  #include <linux/inet.h>
>> +#include <linux/in6.h>
>> +#include <net/ipv6.h>
>>  #include <linux/nfs_xdr.h>
>>  #include <linux/magic.h>
>>  #include <linux/parser.h>
>> @@ -1302,15 +1304,48 @@ static int nfs_set_super(struct  
>> super_block *s, void *data)
>>  	return ret;
>>  }
>>
>> +static int nfs_compare_super_address(struct nfs_server *server1,
>> +				     struct nfs_server *server2)
>> +{
>> +	struct sockaddr_storage *ssp1 = (void *)&server1->nfs_client- 
>> >cl_addr;
>> +	struct sockaddr_storage *ssp2 = (void *)&server2->nfs_client- 
>> >cl_addr;
>> +
>> +	if (ssp1->ss_family != ssp2->ss_family)
>> +		return 0;
>> +
>> +	switch (ssp1->ss_family) {
>> +	case AF_INET: {
>> +		struct sockaddr_in *sin1 = (struct sockaddr_in *)ssp1;
>> +		struct sockaddr_in *sin2 = (struct sockaddr_in *)ssp2;
>> +		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
>> +			return 0;
>> +		if (sin1->sin_port != sin2->sin_port)
>
> What if sin2->sin_port == 0?

The original comparison in nfs_compare_super() uses a memcmp() to  
compare sizeof(struct sockaddr_in) bytes, which would include the  
sin_port field of both addresses, right?  Thus the original  
comparison would find a match when sin2->sin_port is zero only if  
sin1->sin_port is also zero.

AFAICT, the comparisons in nfs_compare_super_address() provide  
precisely the same check as the memcmp() in the original.

>> +			return 0;
>> +		break;
>> +	}
>> +	case AF_INET6: {
>> +		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)ssp1;
>> +		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)ssp2;
>> +		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
>> +			return 0;
>> +		if (sin1->sin6_port != sin2->sin6_port)
>> +			return 0;
>> +		break;
>> +	}
>> +	default:
>> +		return 0;
>> +	}
>> +
>> +	return 1;
>> +}
>> +
>>  static int nfs_compare_super(struct super_block *sb, void *data)
>>  {
>>  	struct nfs_sb_mountdata *sb_mntdata = data;
>>  	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
>>  	int mntflags = sb_mntdata->mntflags;
>>
>> -	if (memcmp(&old->nfs_client->cl_addr,
>> -				&server->nfs_client->cl_addr,
>> -				sizeof(old->nfs_client->cl_addr)) != 0)
>> +	if (!nfs_compare_super_address(old, server))
>>  		return 0;
>>  	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
>>  	if (old->flags & NFS_MOUNT_UNSHARED)
>>
>

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com




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