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>
This commit is contained in:
Weston Andros Adamson
2013-10-18 15:15:19 -04:00
committed by Trond Myklebust
parent 5837f6dfcb
commit 4d4b69dd84
6 changed files with 145 additions and 71 deletions

View File

@@ -497,7 +497,8 @@ static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
static const struct {
rpc_authflavor_t flavour;
const char *str;
} sec_flavours[] = {
} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
{ RPC_AUTH_NULL, "null" },
{ RPC_AUTH_UNIX, "sys" },
{ RPC_AUTH_GSS_KRB5, "krb5" },
@@ -1018,6 +1019,52 @@ static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
}
}
/*
* Add 'flavor' to 'auth_info' if not already present.
* Returns true if 'flavor' ends up in the list, false otherwise
*/
static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
rpc_authflavor_t flavor)
{
unsigned int i;
unsigned int max_flavor_len = (sizeof(auth_info->flavors) /
sizeof(auth_info->flavors[0]));
/* make sure this flavor isn't already in the list */
for (i = 0; i < auth_info->flavor_len; i++) {
if (flavor == auth_info->flavors[i])
return true;
}
if (auth_info->flavor_len + 1 >= max_flavor_len) {
dfprintk(MOUNT, "NFS: too many sec= flavors\n");
return false;
}
auth_info->flavors[auth_info->flavor_len++] = flavor;
return true;
}
/*
* Return true if 'match' is in auth_info or auth_info is empty.
* Return false otherwise.
*/
bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
rpc_authflavor_t match)
{
int i;
if (!auth_info->flavor_len)
return true;
for (i = 0; i < auth_info->flavor_len; i++) {
if (auth_info->flavors[i] == match)
return true;
}
return false;
}
EXPORT_SYMBOL_GPL(nfs_auth_info_match);
/*
* Parse the value of the 'sec=' option.
*/
@@ -1026,49 +1073,55 @@ static int nfs_parse_security_flavors(char *value,
{
substring_t args[MAX_OPT_ARGS];
rpc_authflavor_t pseudoflavor;
char *p;
dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
switch (match_token(value, nfs_secflavor_tokens, args)) {
case Opt_sec_none:
pseudoflavor = RPC_AUTH_NULL;
break;
case Opt_sec_sys:
pseudoflavor = RPC_AUTH_UNIX;
break;
case Opt_sec_krb5:
pseudoflavor = RPC_AUTH_GSS_KRB5;
break;
case Opt_sec_krb5i:
pseudoflavor = RPC_AUTH_GSS_KRB5I;
break;
case Opt_sec_krb5p:
pseudoflavor = RPC_AUTH_GSS_KRB5P;
break;
case Opt_sec_lkey:
pseudoflavor = RPC_AUTH_GSS_LKEY;
break;
case Opt_sec_lkeyi:
pseudoflavor = RPC_AUTH_GSS_LKEYI;
break;
case Opt_sec_lkeyp:
pseudoflavor = RPC_AUTH_GSS_LKEYP;
break;
case Opt_sec_spkm:
pseudoflavor = RPC_AUTH_GSS_SPKM;
break;
case Opt_sec_spkmi:
pseudoflavor = RPC_AUTH_GSS_SPKMI;
break;
case Opt_sec_spkmp:
pseudoflavor = RPC_AUTH_GSS_SPKMP;
break;
default:
return 0;
while ((p = strsep(&value, ":")) != NULL) {
switch (match_token(p, nfs_secflavor_tokens, args)) {
case Opt_sec_none:
pseudoflavor = RPC_AUTH_NULL;
break;
case Opt_sec_sys:
pseudoflavor = RPC_AUTH_UNIX;
break;
case Opt_sec_krb5:
pseudoflavor = RPC_AUTH_GSS_KRB5;
break;
case Opt_sec_krb5i:
pseudoflavor = RPC_AUTH_GSS_KRB5I;
break;
case Opt_sec_krb5p:
pseudoflavor = RPC_AUTH_GSS_KRB5P;
break;
case Opt_sec_lkey:
pseudoflavor = RPC_AUTH_GSS_LKEY;
break;
case Opt_sec_lkeyi:
pseudoflavor = RPC_AUTH_GSS_LKEYI;
break;
case Opt_sec_lkeyp:
pseudoflavor = RPC_AUTH_GSS_LKEYP;
break;
case Opt_sec_spkm:
pseudoflavor = RPC_AUTH_GSS_SPKM;
break;
case Opt_sec_spkmi:
pseudoflavor = RPC_AUTH_GSS_SPKMI;
break;
case Opt_sec_spkmp:
pseudoflavor = RPC_AUTH_GSS_SPKMP;
break;
default:
dfprintk(MOUNT,
"NFS: sec= option '%s' not recognized\n", p);
return 0;
}
if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
return 0;
}
mnt->auth_info.flavors[0] = pseudoflavor;
mnt->auth_info.flavor_len = 1;
return 1;
}
@@ -1615,12 +1668,14 @@ out_security_failure:
}
/*
* Ensure that the specified authtype in args->auth_info is supported by
* the server. Returns 0 if it's ok, and -EACCES if not.
* Ensure that a specified authtype in args->auth_info is supported by
* the server. Returns 0 and sets args->selected_flavor if it's ok, and
* -EACCES if not.
*/
static int nfs_verify_authflavor(struct nfs_parsed_mount_data *args,
static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
rpc_authflavor_t *server_authlist, unsigned int count)
{
rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
unsigned int i;
/*
@@ -1632,17 +1687,19 @@ static int nfs_verify_authflavor(struct nfs_parsed_mount_data *args,
* can be used.
*/
for (i = 0; i < count; i++) {
if (args->auth_info.flavors[0] == server_authlist[i] ||
server_authlist[i] == RPC_AUTH_NULL)
flavor = server_authlist[i];
if (nfs_auth_info_match(&args->auth_info, flavor) ||
flavor == RPC_AUTH_NULL)
goto out;
}
dfprintk(MOUNT, "NFS: auth flavor %u not supported by server\n",
args->auth_info.flavors[0]);
dfprintk(MOUNT,
"NFS: specified auth flavors not supported by server\n");
return -EACCES;
out:
args->selected_flavor = args->auth_info.flavors[0];
args->selected_flavor = flavor;
dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
return 0;
}
@@ -1732,7 +1789,7 @@ static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_inf
* whether the server supports it, and then just try to use it if so.
*/
if (args->auth_info.flavor_len > 0) {
status = nfs_verify_authflavor(args, authlist, authlist_len);
status = nfs_verify_authflavors(args, authlist, authlist_len);
dfprintk(MOUNT, "NFS: using auth flavor %u\n",
args->selected_flavor);
if (status)
@@ -2102,9 +2159,6 @@ static int nfs_validate_text_mount_data(void *options,
nfs_set_port(sap, &args->nfs_server.port, port);
if (args->auth_info.flavor_len > 1)
goto out_bad_auth;
return nfs_parse_devname(dev_name,
&args->nfs_server.hostname,
max_namelen,
@@ -2124,10 +2178,6 @@ out_invalid_transport_udp:
out_no_address:
dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
return -EINVAL;
out_bad_auth:
dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
return -EINVAL;
}
static int