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>

3 files changed, 22 insertions, 8 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 9b569af695ab..ac225a79376c 100644
--- a/fs/nfsd/export.c
+++ b/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);
 }
 
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index 45aa21ce6784..2cf9a9a2d89c 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/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);
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 180e068ea064..22cb5be79ad0 100644
--- a/fs/nfsd/nfsfh.c
+++ b/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)