NFS: add support for multiple sec= mount options
This patch adds support for multiple security options which can be
specified using a colon-delimited list of security flavors (the same
syntax as nfsd's exports file).
This is useful, for instance, when NFSv4.x mounts cross SECINFO
boundaries. With this patch a user can use "sec=krb5i,krb5p"
to mount a remote filesystem using krb5i, but can still cross
into krb5p-only exports.
New mounts will try all security options before failing. NFSv4.x
SECINFO results will be compared against the sec= flavors to
find the first flavor in both lists or if no match is found will
return -EPERM.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0eb8dc5..b02c4cc 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2873,11 +2873,24 @@
int status = -EPERM;
size_t i;
- for (i = 0; i < ARRAY_SIZE(flav_array); i++) {
- status = nfs4_lookup_root_sec(server, fhandle, info, flav_array[i]);
- if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
- continue;
- break;
+ if (server->auth_info.flavor_len > 0) {
+ /* try each flavor specified by user */
+ for (i = 0; i < server->auth_info.flavor_len; i++) {
+ status = nfs4_lookup_root_sec(server, fhandle, info,
+ server->auth_info.flavors[i]);
+ if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
+ continue;
+ break;
+ }
+ } else {
+ /* no flavors specified by user, try default list */
+ for (i = 0; i < ARRAY_SIZE(flav_array); i++) {
+ status = nfs4_lookup_root_sec(server, fhandle, info,
+ flav_array[i]);
+ if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
+ continue;
+ break;
+ }
}
/*
@@ -2919,9 +2932,6 @@
status = nfs4_lookup_root(server, fhandle, info);
if (status != -NFS4ERR_WRONGSEC)
break;
- /* Did user force a 'sec=' mount option? */
- if (server->auth_info.flavor_len > 0)
- break;
default:
status = nfs4_do_find_root_sec(server, fhandle, info);
}
@@ -3179,9 +3189,6 @@
err = -EPERM;
if (client != *clnt)
goto out;
- /* No security negotiation if the user specified 'sec=' */
- if (NFS_SERVER(dir)->auth_info.flavor_len > 0)
- goto out;
client = nfs4_create_sec_client(client, dir, name);
if (IS_ERR(client))
return PTR_ERR(client);
@@ -7942,6 +7949,9 @@
break;
}
+ if (!nfs_auth_info_match(&server->auth_info, flavor))
+ flavor = RPC_AUTH_MAXFLAVOR;
+
if (flavor != RPC_AUTH_MAXFLAVOR) {
err = nfs4_lookup_root_sec(server, fhandle,
info, flavor);