knfsd: nfsd: set rq_client to ip-address-determined-domain

We want it to be possible for users to restrict exports both by IP address and
by pseudoflavor.  The pseudoflavor information has previously been passed
using special auth_domains stored in the rq_client field.  After the preceding
patch that stored the pseudoflavor in rq_pflavor, that's now superfluous; so
now we use rq_client for the ip information, as auth_null and auth_unix do.

However, we keep around the special auth_domain in the rq_gssclient field for
backwards compatibility purposes, so we can still do upcalls using the old
"gss/pseudoflavor" auth_domain if upcalls using the unix domain to give us an
appropriate export.  This allows us to continue supporting old mountd.

In fact, for this first patch, we always use the "gss/pseudoflavor"
auth_domain (and only it) if it is available; thus rq_client is ignored in the
auth_gss case, and this patch on its own makes no change in behavior; that
will be left to later patches.

Note on idmap: I'm almost tempted to just replace the auth_domain in the idmap
upcall by a dummy value--no version of idmapd has ever used it, and it's
unlikely anyone really wants to perform idmapping differently depending on the
where the client is (they may want to perform *credential* mapping
differently, but that's a different matter--the idmapper just handles id's
used in getattr and setattr).  But I'm updating the idmapd code anyway, just
out of general backwards-compatibility paranoia.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nfsd/export.c

@@ -1237,21 +1237,28 @@ struct svc_export *
 rqst_exp_get_by_name(struct svc_rqst *rqstp, struct vfsmount *mnt,
 		struct dentry *dentry)
 {
-	return exp_get_by_name(rqstp->rq_client, mnt, dentry,
-						&rqstp->rq_chandle);
+	struct auth_domain *clp;
+
+	clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
+	return exp_get_by_name(clp, mnt, dentry, &rqstp->rq_chandle);
 }
 
 struct svc_export *
 rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
 {
-	return exp_find(rqstp->rq_client, fsid_type, fsidv,
-						&rqstp->rq_chandle);
+	struct auth_domain *clp;
+
+	clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
+	return exp_find(clp, fsid_type, fsidv, &rqstp->rq_chandle);
 }
 
 struct svc_export *
 rqst_exp_parent(struct svc_rqst *rqstp, struct vfsmount *mnt,
 		struct dentry *dentry)
 {
+	struct auth_domain *clp;
+
+	clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 	return exp_parent(rqstp->rq_client, mnt, dentry, &rqstp->rq_chandle);
 }
 

fs/nfsd/nfs4idmap.c

@@ -587,6 +587,15 @@ idmap_lookup(struct svc_rqst *rqstp,
 	return ret;
 }
 
+static char *
+rqst_authname(struct svc_rqst *rqstp)
+{
+	struct auth_domain *clp;
+
+	clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
+	return clp->name;
+}
+
 static int
 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 		uid_t *id)
@@ -600,7 +609,7 @@ idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen
 		return -EINVAL;
 	memcpy(key.name, name, namelen);
 	key.name[namelen] = '\0';
-	strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
+	strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 	ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 	if (ret == -ENOENT)
 		ret = -ESRCH; /* nfserr_badname */
@@ -620,7 +629,7 @@ idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 	};
 	int ret;
 
-	strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
+	strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 	ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 	if (ret == -ENOENT)
 		return sprintf(name, "%u", id);

fs/nfsd/nfsfh.c

@@ -120,8 +120,6 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
 		int data_left = fh->fh_size/4;
 
 		error = nfserr_stale;
-		if (rqstp->rq_client == NULL)
-			goto out;
 		if (rqstp->rq_vers > 2)
 			error = nfserr_badhandle;
 		if (rqstp->rq_vers == 4 && fh->fh_size == 0)

include/linux/sunrpc/svc.h

@@ -249,6 +249,7 @@ struct svc_rqst {
 						 */
 	/* Catering to nfsd */
 	struct auth_domain *	rq_client;	/* RPC peer info */
+	struct auth_domain *	rq_gssclient;	/* "gss/"-style peer info */
 	struct svc_cacherep *	rq_cacherep;	/* cache info */
 	struct knfsd_fh *	rq_reffh;	/* Referrence filehandle, used to
 						 * determine what device number

include/linux/sunrpc/svcauth.h

@@ -127,6 +127,7 @@ extern struct auth_domain *auth_unix_lookup(struct in_addr addr);
 extern int auth_unix_forget_old(struct auth_domain *dom);
 extern void svcauth_unix_purge(void);
 extern void svcauth_unix_info_release(void *);
+extern int svcauth_unix_set_client(struct svc_rqst *rqstp);
 
 static inline unsigned long hash_str(char *name, int bits)
 {

net/sunrpc/auth_gss/svcauth_gss.c

@@ -913,10 +913,23 @@ svcauth_gss_set_client(struct svc_rqst *rqstp)
 	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
 	struct rsc *rsci = svcdata->rsci;
 	struct rpc_gss_wire_cred *gc = &svcdata->clcred;
+	int stat;
 
-	rqstp->rq_client = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
-	if (rqstp->rq_client == NULL)
+	/*
+	 * A gss export can be specified either by:
+	 * 	export	*(sec=krb5,rw)
+	 * or by
+	 * 	export gss/krb5(rw)
+	 * The latter is deprecated; but for backwards compatibility reasons
+	 * the nfsd code will still fall back on trying it if the former
+	 * doesn't work; so we try to make both available to nfsd, below.
+	 */
+	rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
+	if (rqstp->rq_gssclient == NULL)
 		return SVC_DENIED;
+	stat = svcauth_unix_set_client(rqstp);
+	if (stat == SVC_DROP)
+		return stat;
 	return SVC_OK;
 }
 
@@ -1088,7 +1101,6 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 			svc_putnl(resv, GSS_SEQ_WIN);
 			if (svc_safe_putnetobj(resv, &rsip->out_token))
 				goto drop;
-			rqstp->rq_client = NULL;
 		}
 		goto complete;
 	case RPC_GSS_PROC_DESTROY:
@@ -1319,6 +1331,9 @@ svcauth_gss_release(struct svc_rqst *rqstp)
 	if (rqstp->rq_client)
 		auth_domain_put(rqstp->rq_client);
 	rqstp->rq_client = NULL;
+	if (rqstp->rq_gssclient)
+		auth_domain_put(rqstp->rq_gssclient);
+	rqstp->rq_gssclient = NULL;
 	if (rqstp->rq_cred.cr_group_info)
 		put_group_info(rqstp->rq_cred.cr_group_info);
 	rqstp->rq_cred.cr_group_info = NULL;

net/sunrpc/svcauth_unix.c

@@ -638,7 +638,7 @@ static int unix_gid_find(uid_t uid, struct group_info **gip,
 	}
 }
 
-static int
+int
 svcauth_unix_set_client(struct svc_rqst *rqstp)
 {
 	struct sockaddr_in *sin = svc_addr_in(rqstp);
@@ -673,6 +673,8 @@ svcauth_unix_set_client(struct svc_rqst *rqstp)
 	return SVC_OK;
 }
 
+EXPORT_SYMBOL(svcauth_unix_set_client);
+
 static int
 svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
 {