Re: [PATCH 08/10] lockd: struct nlm_reboot should contain a full socket address

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Sep 17, 2008 at 11:18:11AM -0500, Chuck Lever wrote:
> The XDR decoders for the NSM NOTIFY procedure should construct a full
> socket address and store it in the nlm_reboot structure.  In addition
> to being able to store larger addresses, this means upper layer
> routines get an address family tag so they can distinguish between
> AF_INET and AF_INET6 addresses.
> 
> This also keeps potentially large socket addresses off the stack and
> instead in dynamically allocated storage.

So one way to think of this would be that you're extending the
kernel<->statd interface by using the address family of statd's notify
call to communicate the address family of the host that rebooted.

Do I have that right?

--b.

> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
> 
>  fs/lockd/svc4proc.c       |   10 +---------
>  fs/lockd/svcproc.c        |   10 +---------
>  fs/lockd/xdr.c            |   28 ++++++++++++++++++++++++++--
>  fs/lockd/xdr4.c           |   27 +++++++++++++++++++++++++--
>  include/linux/lockd/xdr.h |    3 ++-
>  5 files changed, 55 insertions(+), 23 deletions(-)
> 
> diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
> index 6a5ef9f..e61c05f 100644
> --- a/fs/lockd/svc4proc.c
> +++ b/fs/lockd/svc4proc.c
> @@ -430,8 +430,6 @@ static __be32
>  nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
>  					      void	        *resp)
>  {
> -	struct sockaddr_in	saddr;
> -
>  	dprintk("lockd: SM_NOTIFY     called\n");
>  
>  	if (!nlm_privileged_requester(rqstp)) {
> @@ -441,13 +439,7 @@ nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
>  		return rpc_system_err;
>  	}
>  
> -	/* Obtain the host pointer for this NFS server and try to
> -	 * reclaim all locks we hold on this server.
> -	 */
> -	memset(&saddr, 0, sizeof(saddr));
> -	saddr.sin_family = AF_INET;
> -	saddr.sin_addr.s_addr = argp->addr;
> -	nlm_host_rebooted((struct sockaddr *)&saddr, sizeof(saddr),
> +	nlm_host_rebooted((struct sockaddr *)&argp->addr, argp->addrlen,
>  			  argp->mon, argp->len, argp->state);
>  
>  	return rpc_success;
> diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
> index 62fcfdb..86a487a 100644
> --- a/fs/lockd/svcproc.c
> +++ b/fs/lockd/svcproc.c
> @@ -462,8 +462,6 @@ static __be32
>  nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
>  					      void	        *resp)
>  {
> -	struct sockaddr_in	saddr;
> -
>  	dprintk("lockd: SM_NOTIFY     called\n");
>  
>  	if (!nlm_privileged_requester(rqstp)) {
> @@ -473,13 +471,7 @@ nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
>  		return rpc_system_err;
>  	}
>  
> -	/* Obtain the host pointer for this NFS server and try to
> -	 * reclaim all locks we hold on this server.
> -	 */
> -	memset(&saddr, 0, sizeof(saddr));
> -	saddr.sin_family = AF_INET;
> -	saddr.sin_addr.s_addr = argp->addr;
> -	nlm_host_rebooted((struct sockaddr *)&saddr, sizeof(saddr),
> +	nlm_host_rebooted((struct sockaddr *)&argp->addr, argp->addrlen,
>  			  argp->mon, argp->len, argp->state);
>  
>  	return rpc_success;
> diff --git a/fs/lockd/xdr.c b/fs/lockd/xdr.c
> index 1f22629..92c5695 100644
> --- a/fs/lockd/xdr.c
> +++ b/fs/lockd/xdr.c
> @@ -9,6 +9,7 @@
>  #include <linux/types.h>
>  #include <linux/sched.h>
>  #include <linux/utsname.h>
> +#include <linux/in.h>
>  #include <linux/nfs.h>
>  
>  #include <linux/sunrpc/xdr.h>
> @@ -346,11 +347,34 @@ nlmsvc_decode_notify(struct svc_rqst *rqstp, __be32 *p, struct nlm_args *argp)
>  int
>  nlmsvc_decode_reboot(struct svc_rqst *rqstp, __be32 *p, struct nlm_reboot *argp)
>  {
> +	struct sockaddr_in *sin = (struct sockaddr_in *)&argp->addr;
> +	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&argp->addr;
> +
>  	if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
>  		return 0;
>  	argp->state = ntohl(*p++);
> -	/* Preserve the address in network byte order */
> -	argp->addr = *p++;
> +
> +	/* Decode the 16-byte private field */
> +	memset(&argp->addr, 0, sizeof(argp->addr));
> +	switch (svc_addr(rqstp)->sa_family) {
> +	case AF_INET:
> +		/* data in recv buffer is already in network byte order */
> +		sin->sin_family = AF_INET;
> +		sin->sin_addr.s_addr = *p++;
> +		argp->addrlen = sizeof(*sin);
> +		break;
> +	case AF_INET6:
> +		sin6->sin6_family = AF_INET6;
> +		sin6->sin6_addr.s6_addr32[0] = *p++;
> +		sin6->sin6_addr.s6_addr32[1] = *p++;
> +		sin6->sin6_addr.s6_addr32[2] = *p++;
> +		sin6->sin6_addr.s6_addr32[3] = *p++;
> +		argp->addrlen = sizeof(*sin6);
> +		break;
> +	default:
> +		return -EIO;
> +	}
> +
>  	return xdr_argsize_check(rqstp, p);
>  }
>  
> diff --git a/fs/lockd/xdr4.c b/fs/lockd/xdr4.c
> index 50c493a..2009020 100644
> --- a/fs/lockd/xdr4.c
> +++ b/fs/lockd/xdr4.c
> @@ -353,11 +353,34 @@ nlm4svc_decode_notify(struct svc_rqst *rqstp, __be32 *p, struct nlm_args *argp)
>  int
>  nlm4svc_decode_reboot(struct svc_rqst *rqstp, __be32 *p, struct nlm_reboot *argp)
>  {
> +	struct sockaddr_in *sin = (struct sockaddr_in *)&argp->addr;
> +	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&argp->addr;
> +
>  	if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
>  		return 0;
>  	argp->state = ntohl(*p++);
> -	/* Preserve the address in network byte order */
> -	argp->addr  = *p++;
> +
> +	/* Decode the 16-byte private field */
> +	memset(&argp->addr, 0, sizeof(argp->addr));
> +	switch (svc_addr(rqstp)->sa_family) {
> +	case AF_INET:
> +		/* address in recv buffer is already in network byte order */
> +		sin->sin_family = AF_INET;
> +		sin->sin_addr.s_addr = *p++;
> +		argp->addrlen = sizeof(*sin);
> +		break;
> +	case AF_INET6:
> +		sin6->sin6_family = AF_INET6;
> +		sin6->sin6_addr.s6_addr32[0] = *p++;
> +		sin6->sin6_addr.s6_addr32[1] = *p++;
> +		sin6->sin6_addr.s6_addr32[2] = *p++;
> +		sin6->sin6_addr.s6_addr32[3] = *p++;
> +		argp->addrlen = sizeof(*sin6);
> +		break;
> +	default:
> +		return -EIO;
> +	}
> +
>  	return xdr_argsize_check(rqstp, p);
>  }
>  
> diff --git a/include/linux/lockd/xdr.h b/include/linux/lockd/xdr.h
> index d6b3a80..6057b7e 100644
> --- a/include/linux/lockd/xdr.h
> +++ b/include/linux/lockd/xdr.h
> @@ -80,7 +80,8 @@ struct nlm_reboot {
>  	char *		mon;
>  	unsigned int	len;
>  	u32		state;
> -	__be32		addr;
> +	struct sockaddr_storage	addr;
> +	size_t		addrlen;
>  };
>  
>  /*
>