linux/net/sunrpc/auth_gss/gss_mech_switch.c
J. Bruce Fields 058c5c9999 rpc: allow autoloading of gss mechanisms
Remove the need for an explicit modprobe of rpcsec_gss_krb5.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-07-15 18:58:45 -04:00

406 lines
9.7 KiB
C

/*
* linux/net/sunrpc/gss_mech_switch.c
*
* Copyright (c) 2001 The Regents of the University of Michigan.
* All rights reserved.
*
* J. Bruce Fields <bfields@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/gss_asn1.h>
#include <linux/sunrpc/auth_gss.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/gss_err.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/gss_api.h>
#include <linux/sunrpc/clnt.h>
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static LIST_HEAD(registered_mechs);
static DEFINE_SPINLOCK(registered_mechs_lock);
static void
gss_mech_free(struct gss_api_mech *gm)
{
struct pf_desc *pf;
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
pf = &gm->gm_pfs[i];
kfree(pf->auth_domain_name);
pf->auth_domain_name = NULL;
}
}
static inline char *
make_auth_domain_name(char *name)
{
static char *prefix = "gss/";
char *new;
new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
if (new) {
strcpy(new, prefix);
strcat(new, name);
}
return new;
}
static int
gss_mech_svc_setup(struct gss_api_mech *gm)
{
struct pf_desc *pf;
int i, status;
for (i = 0; i < gm->gm_pf_num; i++) {
pf = &gm->gm_pfs[i];
pf->auth_domain_name = make_auth_domain_name(pf->name);
status = -ENOMEM;
if (pf->auth_domain_name == NULL)
goto out;
status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
pf->auth_domain_name);
if (status)
goto out;
}
return 0;
out:
gss_mech_free(gm);
return status;
}
int
gss_mech_register(struct gss_api_mech *gm)
{
int status;
status = gss_mech_svc_setup(gm);
if (status)
return status;
spin_lock(&registered_mechs_lock);
list_add(&gm->gm_list, &registered_mechs);
spin_unlock(&registered_mechs_lock);
dprintk("RPC: registered gss mechanism %s\n", gm->gm_name);
return 0;
}
EXPORT_SYMBOL_GPL(gss_mech_register);
void
gss_mech_unregister(struct gss_api_mech *gm)
{
spin_lock(&registered_mechs_lock);
list_del(&gm->gm_list);
spin_unlock(&registered_mechs_lock);
dprintk("RPC: unregistered gss mechanism %s\n", gm->gm_name);
gss_mech_free(gm);
}
EXPORT_SYMBOL_GPL(gss_mech_unregister);
struct gss_api_mech *
gss_mech_get(struct gss_api_mech *gm)
{
__module_get(gm->gm_owner);
return gm;
}
EXPORT_SYMBOL_GPL(gss_mech_get);
struct gss_api_mech *
_gss_mech_get_by_name(const char *name)
{
struct gss_api_mech *pos, *gm = NULL;
spin_lock(&registered_mechs_lock);
list_for_each_entry(pos, &registered_mechs, gm_list) {
if (0 == strcmp(name, pos->gm_name)) {
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
}
spin_unlock(&registered_mechs_lock);
return gm;
}
struct gss_api_mech * gss_mech_get_by_name(const char *name)
{
struct gss_api_mech *gm = NULL;
gm = _gss_mech_get_by_name(name);
if (!gm) {
request_module("rpc-auth-gss-%s", name);
gm = _gss_mech_get_by_name(name);
}
return gm;
}
EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
struct gss_api_mech *
gss_mech_get_by_OID(struct xdr_netobj *obj)
{
struct gss_api_mech *pos, *gm = NULL;
spin_lock(&registered_mechs_lock);
list_for_each_entry(pos, &registered_mechs, gm_list) {
if (obj->len == pos->gm_oid.len) {
if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
}
}
spin_unlock(&registered_mechs_lock);
return gm;
}
EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
static inline int
mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
return 1;
}
return 0;
}
struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
{
struct gss_api_mech *gm = NULL, *pos;
spin_lock(&registered_mechs_lock);
list_for_each_entry(pos, &registered_mechs, gm_list) {
if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
module_put(pos->gm_owner);
continue;
}
if (try_module_get(pos->gm_owner))
gm = pos;
break;
}
spin_unlock(&registered_mechs_lock);
return gm;
}
struct gss_api_mech *
gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
{
struct gss_api_mech *gm;
gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
if (!gm) {
request_module("rpc-auth-gss-%u", pseudoflavor);
gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
}
return gm;
}
EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
{
struct gss_api_mech *pos = NULL;
int i = 0;
spin_lock(&registered_mechs_lock);
list_for_each_entry(pos, &registered_mechs, gm_list) {
array_ptr[i] = pos->gm_pfs->pseudoflavor;
i++;
}
spin_unlock(&registered_mechs_lock);
return i;
}
EXPORT_SYMBOL_GPL(gss_mech_list_pseudoflavors);
u32
gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].service == service) {
return gm->gm_pfs[i].pseudoflavor;
}
}
return RPC_AUTH_MAXFLAVOR; /* illegal value */
}
EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
u32
gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
return gm->gm_pfs[i].service;
}
return 0;
}
EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
char *
gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
{
int i;
for (i = 0; i < gm->gm_pf_num; i++) {
if (gm->gm_pfs[i].service == service)
return gm->gm_pfs[i].auth_domain_name;
}
return NULL;
}
EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
void
gss_mech_put(struct gss_api_mech * gm)
{
if (gm)
module_put(gm->gm_owner);
}
EXPORT_SYMBOL_GPL(gss_mech_put);
/* The mech could probably be determined from the token instead, but it's just
* as easy for now to pass it in. */
int
gss_import_sec_context(const void *input_token, size_t bufsize,
struct gss_api_mech *mech,
struct gss_ctx **ctx_id,
gfp_t gfp_mask)
{
if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
return -ENOMEM;
(*ctx_id)->mech_type = gss_mech_get(mech);
return mech->gm_ops
->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
}
/* gss_get_mic: compute a mic over message and return mic_token. */
u32
gss_get_mic(struct gss_ctx *context_handle,
struct xdr_buf *message,
struct xdr_netobj *mic_token)
{
return context_handle->mech_type->gm_ops
->gss_get_mic(context_handle,
message,
mic_token);
}
/* gss_verify_mic: check whether the provided mic_token verifies message. */
u32
gss_verify_mic(struct gss_ctx *context_handle,
struct xdr_buf *message,
struct xdr_netobj *mic_token)
{
return context_handle->mech_type->gm_ops
->gss_verify_mic(context_handle,
message,
mic_token);
}
/*
* This function is called from both the client and server code.
* Each makes guarantees about how much "slack" space is available
* for the underlying function in "buf"'s head and tail while
* performing the wrap.
*
* The client and server code allocate RPC_MAX_AUTH_SIZE extra
* space in both the head and tail which is available for use by
* the wrap function.
*
* Underlying functions should verify they do not use more than
* RPC_MAX_AUTH_SIZE of extra space in either the head or tail
* when performing the wrap.
*/
u32
gss_wrap(struct gss_ctx *ctx_id,
int offset,
struct xdr_buf *buf,
struct page **inpages)
{
return ctx_id->mech_type->gm_ops
->gss_wrap(ctx_id, offset, buf, inpages);
}
u32
gss_unwrap(struct gss_ctx *ctx_id,
int offset,
struct xdr_buf *buf)
{
return ctx_id->mech_type->gm_ops
->gss_unwrap(ctx_id, offset, buf);
}
/* gss_delete_sec_context: free all resources associated with context_handle.
* Note this differs from the RFC 2744-specified prototype in that we don't
* bother returning an output token, since it would never be used anyway. */
u32
gss_delete_sec_context(struct gss_ctx **context_handle)
{
dprintk("RPC: gss_delete_sec_context deleting %p\n",
*context_handle);
if (!*context_handle)
return GSS_S_NO_CONTEXT;
if ((*context_handle)->internal_ctx_id)
(*context_handle)->mech_type->gm_ops
->gss_delete_sec_context((*context_handle)
->internal_ctx_id);
gss_mech_put((*context_handle)->mech_type);
kfree(*context_handle);
*context_handle=NULL;
return GSS_S_COMPLETE;
}