Re: PATCH: Support binding to a local IPv4 address when mounting a server.

[Ben Greear <greearb@candelatech.com>]

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I re-worked the kernel nfs local-address-binding logic against 
2.6.29-rc5.  In quick testing,
this works with IPv4 and NFSv3 at least.  I changed the attribute to be 
called 'bindaddr'
as previously suggested.

I didn't actually make any further changes to the mount.nfs tool and it 
took the bindaddr=a.b.c.d
just fine, so maybe there are no changes at all needed in user-space.

Comments & suggestions welcome.

Thanks,
Ben

Signed-Off-By:  Ben Greear<greearb@candelatech.com>

-- 
Ben Greear <greearb@candelatech.com> 
Candela Technologies Inc  http://www.candelatech.com



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diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 3e634f2..1c7011e 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -213,7 +213,7 @@ static int nfs_callback_authenticate(struct svc_rqst *rqstp)
 	int ret = SVC_OK;
 
 	/* Don't talk to strangers */
-	clp = nfs_find_client(svc_addr(rqstp), 4);
+	clp = nfs_find_client(svc_daddr(rqstp), svc_addr(rqstp), 4);
 	if (clp == NULL)
 		return SVC_DROP;
 
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index bb25d21..94fd8b4 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -39,6 +39,7 @@ struct cb_compound_hdr_res {
 
 struct cb_getattrargs {
 	struct sockaddr *addr;
+	struct sockaddr *bindaddr;
 	struct nfs_fh fh;
 	uint32_t bitmap[2];
 };
@@ -54,6 +55,7 @@ struct cb_getattrres {
 
 struct cb_recallargs {
 	struct sockaddr *addr;
+	struct sockaddr *bindaddr;
 	struct nfs_fh fh;
 	nfs4_stateid stateid;
 	uint32_t truncate;
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index f7e83e2..cd75849 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -25,7 +25,7 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *
 
 	res->bitmap[0] = res->bitmap[1] = 0;
 	res->status = htonl(NFS4ERR_BADHANDLE);
-	clp = nfs_find_client(args->addr, 4);
+	clp = nfs_find_client(args->bindaddr, args->addr, 4);
 	if (clp == NULL)
 		goto out;
 
@@ -68,7 +68,7 @@ __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
 	__be32 res;
 	
 	res = htonl(NFS4ERR_BADHANDLE);
-	clp = nfs_find_client(args->addr, 4);
+	clp = nfs_find_client(args->bindaddr, args->addr, 4);
 	if (clp == NULL)
 		goto out;
 
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index dd0ef34..a342e8e 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -177,6 +177,7 @@ static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr
 	if (unlikely(status != 0))
 		goto out;
 	args->addr = svc_addr(rqstp);
+	args->bindaddr = svc_daddr(rqstp);
 	status = decode_bitmap(xdr, args->bitmap);
 out:
 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
@@ -189,6 +190,7 @@ static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	__be32 status;
 
 	args->addr = svc_addr(rqstp);
+	args->bindaddr = svc_daddr(rqstp);
 	status = decode_stateid(xdr, &args->stateid);
 	if (unlikely(status != 0))
 		goto out;
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 9b728f3..6cd8bd5 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -98,6 +98,7 @@ struct rpc_program		nfsacl_program = {
 struct nfs_client_initdata {
 	const char *hostname;
 	const struct sockaddr *addr;
+	const struct sockaddr *bindaddr;
 	size_t addrlen;
 	const struct nfs_rpc_ops *rpc_ops;
 	int proto;
@@ -130,7 +131,8 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
 
 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
 	clp->cl_addrlen = cl_init->addrlen;
-
+	memcpy(&clp->bindaddr, cl_init->bindaddr, cl_init->addrlen);
+	
 	if (cl_init->hostname) {
 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
 		if (!clp->cl_hostname)
@@ -276,7 +278,8 @@ static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
  * Find a client by IP address and protocol version
  * - returns NULL if no such client
  */
-struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
+struct nfs_client *nfs_find_client(const struct sockaddr *bindaddr,
+				   const struct sockaddr *addr, u32 nfsversion)
 {
 	struct nfs_client *clp;
 
@@ -293,6 +296,8 @@ struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
 			continue;
 
 		/* Match only the IP address, not the port number */
+		if (!nfs_sockaddr_match_ipaddr(bindaddr, (const struct sockaddr*)(&clp->bindaddr)))
+			continue;
 		if (!nfs_sockaddr_match_ipaddr(addr, clap))
 			continue;
 
@@ -357,6 +362,11 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
 		if (clp->cl_proto != data->proto)
 			continue;
 
+		/* Check to make sure local-IP bindings match, but just the IP-addr. */
+		if (!nfs_sockaddr_match_ipaddr((const struct sockaddr*)(&clp->bindaddr),
+					       data->bindaddr))
+			continue;
+		
 		/* Match the full socket address */
 		if (memcmp(&clp->cl_addr, data->addr, sizeof(clp->cl_addr)) != 0)
 			continue;
@@ -493,6 +503,7 @@ static int nfs_create_rpc_client(struct nfs_client *clp,
 	struct rpc_clnt		*clnt = NULL;
 	struct rpc_create_args args = {
 		.protocol	= clp->cl_proto,
+		.saddress	= (struct sockaddr *)&clp->bindaddr,
 		.address	= (struct sockaddr *)&clp->cl_addr,
 		.addrsize	= clp->cl_addrlen,
 		.timeout	= timeparms,
@@ -670,6 +681,7 @@ static int nfs_init_server(struct nfs_server *server,
 		.hostname = data->nfs_server.hostname,
 		.addr = (const struct sockaddr *)&data->nfs_server.address,
 		.addrlen = data->nfs_server.addrlen,
+		.bindaddr = (const struct sockaddr *)&data->bindaddr.address,
 		.rpc_ops = &nfs_v2_clientops,
 		.proto = data->nfs_server.protocol,
 	};
@@ -1035,6 +1047,7 @@ static int nfs4_set_client(struct nfs_server *server,
 		const struct sockaddr *addr,
 		const size_t addrlen,
 		const char *ip_addr,
+		const struct sockaddr* bindaddr,
 		rpc_authflavor_t authflavour,
 		int proto, const struct rpc_timeout *timeparms)
 {
@@ -1042,6 +1055,7 @@ static int nfs4_set_client(struct nfs_server *server,
 		.hostname = hostname,
 		.addr = addr,
 		.addrlen = addrlen,
+		.bindaddr = bindaddr,
 		.rpc_ops = &nfs_v4_clientops,
 		.proto = proto,
 	};
@@ -1096,6 +1110,7 @@ static int nfs4_init_server(struct nfs_server *server,
 			(const struct sockaddr *)&data->nfs_server.address,
 			data->nfs_server.addrlen,
 			data->client_address,
+			(const struct sockaddr *)&data->bindaddr.address,
 			data->auth_flavors[0],
 			data->nfs_server.protocol,
 			&timeparms);
@@ -1214,6 +1229,7 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
 				data->addr,
 				data->addrlen,
 				parent_client->cl_ipaddr,
+				(const struct sockaddr *)(&parent_client->bindaddr),
 				data->authflavor,
 				parent_server->client->cl_xprt->prot,
 				parent_server->client->cl_timeout);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 340ede8..330d10f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -41,6 +41,12 @@ struct nfs_parsed_mount_data {
 	unsigned int		auth_flavor_len;
 	rpc_authflavor_t	auth_flavors[1];
 	char			*client_address;
+	
+	struct {
+		struct sockaddr_storage	address;
+		size_t			addrlen;
+		char			*hostname;
+	} bindaddr;
 
 	struct {
 		struct sockaddr_storage	address;
@@ -66,6 +72,7 @@ struct nfs_parsed_mount_data {
 /* mount_clnt.c */
 struct nfs_mount_request {
 	struct sockaddr		*sap;
+	struct sockaddr		*bindaddr;
 	size_t			salen;
 	char			*hostname;
 	char			*dirpath;
@@ -81,7 +88,8 @@ extern int nfs_mount(struct nfs_mount_request *info);
 extern struct rpc_program nfs_program;
 
 extern void nfs_put_client(struct nfs_client *);
-extern struct nfs_client *nfs_find_client(const struct sockaddr *, u32);
+extern struct nfs_client *nfs_find_client(const struct sockaddr *,
+					  const struct sockaddr *, u32);
 extern struct nfs_client *nfs_find_client_next(struct nfs_client *);
 extern struct nfs_server *nfs_create_server(
 					const struct nfs_parsed_mount_data *,
diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index ca905a5..89acb0c 100644
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -44,6 +44,7 @@ int nfs_mount(struct nfs_mount_request *info)
 	};
 	struct rpc_create_args args = {
 		.protocol	= info->protocol,
+		.saddress	= info->bindaddr,
 		.address	= info->sap,
 		.addrsize	= info->salen,
 		.servername	= info->hostname,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index d6686f4..90f29bd 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -91,7 +91,7 @@ enum {
 
 	/* Mount options that take string arguments */
 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
-	Opt_addr, Opt_mountaddr, Opt_clientaddr,
+	Opt_addr, Opt_mountaddr, Opt_clientaddr, Opt_bindaddr,
 	Opt_lookupcache,
 
 	/* Special mount options */
@@ -155,6 +155,7 @@ static const match_table_t nfs_mount_option_tokens = {
 	{ Opt_mountproto, "mountproto=%s" },
 	{ Opt_addr, "addr=%s" },
 	{ Opt_clientaddr, "clientaddr=%s" },
+	{ Opt_bindaddr, "bindaddr=%s" },
 	{ Opt_mounthost, "mounthost=%s" },
 	{ Opt_mountaddr, "mountaddr=%s" },
 
@@ -563,6 +564,15 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 	if (clp->rpc_ops->version == 4)
 		seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
 #endif
+
+	if (clp->bindaddr.ss_family == AF_INET6) {
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)(&clp->bindaddr);
+		seq_printf(m, ",bindaddr=%pI6", &sin6->sin6_addr);
+	}
+	else {
+		struct sockaddr_in *sin = (struct sockaddr_in *)(&clp->bindaddr);
+		seq_printf(m, ",bindaddr=%pI4", &sin->sin_addr.s_addr);
+	}
 }
 
 /*
@@ -1251,6 +1261,16 @@ static int nfs_parse_mount_options(char *raw,
 			kfree(mnt->client_address);
 			mnt->client_address = string;
 			break;
+		case Opt_bindaddr:
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			nfs_parse_ip_address(string, strlen(string),
+					     (struct sockaddr *)&mnt->bindaddr.address,
+					     &mnt->bindaddr.addrlen);
+			kfree(mnt->bindaddr.hostname);
+			mnt->bindaddr.hostname = string;
+			break;
 		case Opt_mounthost:
 			string = match_strdup(args);
 			if (string == NULL)
@@ -1340,6 +1360,8 @@ static int nfs_try_mount(struct nfs_parsed_mount_data *args,
 	struct nfs_mount_request request = {
 		.sap		= (struct sockaddr *)
 						&args->mount_server.address,
+		.bindaddr	= (struct sockaddr *)&args->bindaddr.address,
+		.salen		= args->mount_server.addrlen,
 		.dirpath	= args->nfs_server.export_path,
 		.protocol	= args->mount_server.protocol,
 		.fh		= root_fh,
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 9bb81ae..ebe612f 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -64,6 +64,9 @@ struct nfs_client {
 	char			cl_ipaddr[48];
 	unsigned char		cl_id_uniquifier;
 #endif
+
+	/* If we should bind to a local IP, it should be specified below. */
+	struct sockaddr_storage	bindaddr;
 };
 
 /*