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DEFINITIONS
This source file includes following definitions.
- gss_get_ctx
- gss_put_ctx
- gss_cred_set_ctx
- simple_get_bytes
- simple_get_netobj
- gss_cred_get_ctx
- gss_alloc_context
- gss_fill_context
- gss_release_msg
- __gss_find_upcall
- gss_add_msg
- __gss_unhash_msg
- gss_unhash_msg
- gss_upcall_callback
- gss_alloc_msg
- gss_setup_upcall
- gss_refresh_upcall
- gss_create_upcall
- gss_pipe_upcall
- gss_pipe_downcall
- gss_pipe_release
- gss_pipe_destroy_msg
- gss_create
- gss_free
- gss_free_callback
- gss_destroy
- gss_destroying_context
- gss_do_free_ctx
- gss_free_ctx_callback
- gss_free_ctx
- gss_free_cred
- gss_free_cred_callback
- gss_destroy_cred
- gss_lookup_cred
- gss_create_cred
- gss_cred_init
- gss_match
- gss_marshal
- gss_renew_cred
- gss_refresh
- gss_refresh_null
- gss_validate
- gss_wrap_req_integ
- priv_release_snd_buf
- alloc_enc_pages
- gss_wrap_req_priv
- gss_wrap_req
- gss_unwrap_resp_integ
- gss_unwrap_resp_priv
- gss_unwrap_resp
- init_rpcsec_gss
- exit_rpcsec_gss
/*
* linux/net/sunrpc/auth_gss/auth_gss.c
*
* RPCSEC_GSS client authentication.
*
* Copyright (c) 2000 The Regents of the University of Michigan.
* All rights reserved.
*
* Dug Song <dugsong@monkey.org>
* Andy Adamson <andros@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/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/auth_gss.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/gss_err.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/gss_api.h>
#include <asm/uaccess.h>
static const struct rpc_authops authgss_ops;
static const struct rpc_credops gss_credops;
static const struct rpc_credops gss_nullops;
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
#define GSS_CRED_SLACK 1024
/* length of a krb5 verifier (48), plus data added before arguments when
* using integrity (two 4-byte integers): */
#define GSS_VERF_SLACK 100
struct gss_auth {
struct kref kref;
struct rpc_auth rpc_auth;
struct gss_api_mech *mech;
enum rpc_gss_svc service;
struct rpc_clnt *client;
struct dentry *dentry;
};
static void gss_free_ctx(struct gss_cl_ctx *);
static struct rpc_pipe_ops gss_upcall_ops;
static inline struct gss_cl_ctx *
gss_get_ctx(struct gss_cl_ctx *ctx)
{
atomic_inc(&ctx->count);
return ctx;
}
static inline void
gss_put_ctx(struct gss_cl_ctx *ctx)
{
if (atomic_dec_and_test(&ctx->count))
gss_free_ctx(ctx);
}
/* gss_cred_set_ctx:
* called by gss_upcall_callback and gss_create_upcall in order
* to set the gss context. The actual exchange of an old context
* and a new one is protected by the inode->i_lock.
*/
static void
gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
{
struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
return;
gss_get_ctx(ctx);
rcu_assign_pointer(gss_cred->gc_ctx, ctx);
set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
smp_mb__before_clear_bit();
clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
}
static const void *
simple_get_bytes(const void *p, const void *end, void *res, size_t len)
{
const void *q = (const void *)((const char *)p + len);
if (unlikely(q > end || q < p))
return ERR_PTR(-EFAULT);
memcpy(res, p, len);
return q;
}
static inline const void *
simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
{
const void *q;
unsigned int len;
p = simple_get_bytes(p, end, &len, sizeof(len));
if (IS_ERR(p))
return p;
q = (const void *)((const char *)p + len);
if (unlikely(q > end || q < p))
return ERR_PTR(-EFAULT);
dest->data = kmemdup(p, len, GFP_NOFS);
if (unlikely(dest->data == NULL))
return ERR_PTR(-ENOMEM);
dest->len = len;
return q;
}
static struct gss_cl_ctx *
gss_cred_get_ctx(struct rpc_cred *cred)
{
struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
struct gss_cl_ctx *ctx = NULL;
rcu_read_lock();
if (gss_cred->gc_ctx)
ctx = gss_get_ctx(gss_cred->gc_ctx);
rcu_read_unlock();
return ctx;
}
static struct gss_cl_ctx *
gss_alloc_context(void)
{
struct gss_cl_ctx *ctx;
ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
if (ctx != NULL) {
ctx->gc_proc = RPC_GSS_PROC_DATA;
ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */
spin_lock_init(&ctx->gc_seq_lock);
atomic_set(&ctx->count,1);
}
return ctx;
}
#define GSSD_MIN_TIMEOUT (60 * 60)
static const void *
gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
{
const void *q;
unsigned int seclen;
unsigned int timeout;
u32 window_size;
int ret;
/* First unsigned int gives the lifetime (in seconds) of the cred */
p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
if (IS_ERR(p))
goto err;
if (timeout == 0)
timeout = GSSD_MIN_TIMEOUT;
ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
/* Sequence number window. Determines the maximum number of simultaneous requests */
p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
if (IS_ERR(p))
goto err;
ctx->gc_win = window_size;
/* gssd signals an error by passing ctx->gc_win = 0: */
if (ctx->gc_win == 0) {
/* in which case, p points to an error code which we ignore */
p = ERR_PTR(-EACCES);
goto err;
}
/* copy the opaque wire context */
p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
if (IS_ERR(p))
goto err;
/* import the opaque security context */
p = simple_get_bytes(p, end, &seclen, sizeof(seclen));
if (IS_ERR(p))
goto err;
q = (const void *)((const char *)p + seclen);
if (unlikely(q > end || q < p)) {
p = ERR_PTR(-EFAULT);
goto err;
}
ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
if (ret < 0) {
p = ERR_PTR(ret);
goto err;
}
return q;
err:
dprintk("RPC: gss_fill_context returning %ld\n", -PTR_ERR(p));
return p;
}
struct gss_upcall_msg {
atomic_t count;
uid_t uid;
struct rpc_pipe_msg msg;
struct list_head list;
struct gss_auth *auth;
struct rpc_wait_queue rpc_waitqueue;
wait_queue_head_t waitqueue;
struct gss_cl_ctx *ctx;
};
static void
gss_release_msg(struct gss_upcall_msg *gss_msg)
{
if (!atomic_dec_and_test(&gss_msg->count))
return;
BUG_ON(!list_empty(&gss_msg->list));
if (gss_msg->ctx != NULL)
gss_put_ctx(gss_msg->ctx);
rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
kfree(gss_msg);
}
static struct gss_upcall_msg *
__gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
{
struct gss_upcall_msg *pos;
list_for_each_entry(pos, &rpci->in_downcall, list) {
if (pos->uid != uid)
continue;
atomic_inc(&pos->count);
dprintk("RPC: gss_find_upcall found msg %p\n", pos);
return pos;
}
dprintk("RPC: gss_find_upcall found nothing\n");
return NULL;
}
/* Try to add an upcall to the pipefs queue.
* If an upcall owned by our uid already exists, then we return a reference
* to that upcall instead of adding the new upcall.
*/
static inline struct gss_upcall_msg *
gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
{
struct inode *inode = gss_auth->dentry->d_inode;
struct rpc_inode *rpci = RPC_I(inode);
struct gss_upcall_msg *old;
spin_lock(&inode->i_lock);
old = __gss_find_upcall(rpci, gss_msg->uid);
if (old == NULL) {
atomic_inc(&gss_msg->count);
list_add(&gss_msg->list, &rpci->in_downcall);
} else
gss_msg = old;
spin_unlock(&inode->i_lock);
return gss_msg;
}
static void
__gss_unhash_msg(struct gss_upcall_msg *gss_msg)
{
list_del_init(&gss_msg->list);
rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
wake_up_all(&gss_msg->waitqueue);
atomic_dec(&gss_msg->count);
}
static void
gss_unhash_msg(struct gss_upcall_msg *gss_msg)
{
struct gss_auth *gss_auth = gss_msg->auth;
struct inode *inode = gss_auth->dentry->d_inode;
if (list_empty(&gss_msg->list))
return;
spin_lock(&inode->i_lock);
if (!list_empty(&gss_msg->list))
__gss_unhash_msg(gss_msg);
spin_unlock(&inode->i_lock);
}
static void
gss_upcall_callback(struct rpc_task *task)
{
struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
struct gss_cred, gc_base);
struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
struct inode *inode = gss_msg->auth->dentry->d_inode;
spin_lock(&inode->i_lock);
if (gss_msg->ctx)
gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
else
task->tk_status = gss_msg->msg.errno;
gss_cred->gc_upcall = NULL;
rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
spin_unlock(&inode->i_lock);
gss_release_msg(gss_msg);
}
static inline struct gss_upcall_msg *
gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
{
struct gss_upcall_msg *gss_msg;
gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
if (gss_msg != NULL) {
INIT_LIST_HEAD(&gss_msg->list);
rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
init_waitqueue_head(&gss_msg->waitqueue);
atomic_set(&gss_msg->count, 1);
gss_msg->msg.data = &gss_msg->uid;
gss_msg->msg.len = sizeof(gss_msg->uid);
gss_msg->uid = uid;
gss_msg->auth = gss_auth;
}
return gss_msg;
}
static struct gss_upcall_msg *
gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
{
struct gss_cred *gss_cred = container_of(cred,
struct gss_cred, gc_base);
struct gss_upcall_msg *gss_new, *gss_msg;
uid_t uid = cred->cr_uid;
/* Special case: rpc.gssd assumes that uid == 0 implies machine creds */
if (gss_cred->gc_machine_cred != 0)
uid = 0;
gss_new = gss_alloc_msg(gss_auth, uid);
if (gss_new == NULL)
return ERR_PTR(-ENOMEM);
gss_msg = gss_add_msg(gss_auth, gss_new);
if (gss_msg == gss_new) {
int res = rpc_queue_upcall(gss_auth->dentry->d_inode, &gss_new->msg);
if (res) {
gss_unhash_msg(gss_new);
gss_msg = ERR_PTR(res);
}
} else
gss_release_msg(gss_new);
return gss_msg;
}
static inline int
gss_refresh_upcall(struct rpc_task *task)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
struct gss_auth *gss_auth = container_of(cred->cr_auth,
struct gss_auth, rpc_auth);
struct gss_cred *gss_cred = container_of(cred,
struct gss_cred, gc_base);
struct gss_upcall_msg *gss_msg;
struct inode *inode = gss_auth->dentry->d_inode;
int err = 0;
dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
cred->cr_uid);
gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
if (IS_ERR(gss_msg)) {
err = PTR_ERR(gss_msg);
goto out;
}
spin_lock(&inode->i_lock);
if (gss_cred->gc_upcall != NULL)
rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
else if (gss_msg->ctx != NULL) {
gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
gss_cred->gc_upcall = NULL;
rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
} else if (gss_msg->msg.errno >= 0) {
task->tk_timeout = 0;
gss_cred->gc_upcall = gss_msg;
/* gss_upcall_callback will release the reference to gss_upcall_msg */
atomic_inc(&gss_msg->count);
rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
} else
err = gss_msg->msg.errno;
spin_unlock(&inode->i_lock);
gss_release_msg(gss_msg);
out:
dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
task->tk_pid, cred->cr_uid, err);
return err;
}
static inline int
gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
{
struct inode *inode = gss_auth->dentry->d_inode;
struct rpc_cred *cred = &gss_cred->gc_base;
struct gss_upcall_msg *gss_msg;
DEFINE_WAIT(wait);
int err = 0;
dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid);
gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
if (IS_ERR(gss_msg)) {
err = PTR_ERR(gss_msg);
goto out;
}
for (;;) {
prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
spin_lock(&inode->i_lock);
if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
break;
}
spin_unlock(&inode->i_lock);
if (signalled()) {
err = -ERESTARTSYS;
goto out_intr;
}
schedule();
}
if (gss_msg->ctx)
gss_cred_set_ctx(cred, gss_msg->ctx);
else
err = gss_msg->msg.errno;
spin_unlock(&inode->i_lock);
out_intr:
finish_wait(&gss_msg->waitqueue, &wait);
gss_release_msg(gss_msg);
out:
dprintk("RPC: gss_create_upcall for uid %u result %d\n",
cred->cr_uid, err);
return err;
}
static ssize_t
gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
char __user *dst, size_t buflen)
{
char *data = (char *)msg->data + msg->copied;
size_t mlen = min(msg->len, buflen);
unsigned long left;
left = copy_to_user(dst, data, mlen);
if (left == mlen) {
msg->errno = -EFAULT;
return -EFAULT;
}
mlen -= left;
msg->copied += mlen;
msg->errno = 0;
return mlen;
}
#define MSG_BUF_MAXSIZE 1024
static ssize_t
gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
{
const void *p, *end;
void *buf;
struct gss_upcall_msg *gss_msg;
struct inode *inode = filp->f_path.dentry->d_inode;
struct gss_cl_ctx *ctx;
uid_t uid;
ssize_t err = -EFBIG;
if (mlen > MSG_BUF_MAXSIZE)
goto out;
err = -ENOMEM;
buf = kmalloc(mlen, GFP_NOFS);
if (!buf)
goto out;
err = -EFAULT;
if (copy_from_user(buf, src, mlen))
goto err;
end = (const void *)((char *)buf + mlen);
p = simple_get_bytes(buf, end, &uid, sizeof(uid));
if (IS_ERR(p)) {
err = PTR_ERR(p);
goto err;
}
err = -ENOMEM;
ctx = gss_alloc_context();
if (ctx == NULL)
goto err;
err = -ENOENT;
/* Find a matching upcall */
spin_lock(&inode->i_lock);
gss_msg = __gss_find_upcall(RPC_I(inode), uid);
if (gss_msg == NULL) {
spin_unlock(&inode->i_lock);
goto err_put_ctx;
}
list_del_init(&gss_msg->list);
spin_unlock(&inode->i_lock);
p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
if (IS_ERR(p)) {
err = PTR_ERR(p);
gss_msg->msg.errno = (err == -EAGAIN) ? -EAGAIN : -EACCES;
goto err_release_msg;
}
gss_msg->ctx = gss_get_ctx(ctx);
err = mlen;
err_release_msg:
spin_lock(&inode->i_lock);
__gss_unhash_msg(gss_msg);
spin_unlock(&inode->i_lock);
gss_release_msg(gss_msg);
err_put_ctx:
gss_put_ctx(ctx);
err:
kfree(buf);
out:
dprintk("RPC: gss_pipe_downcall returning %Zd\n", err);
return err;
}
static void
gss_pipe_release(struct inode *inode)
{
struct rpc_inode *rpci = RPC_I(inode);
struct gss_upcall_msg *gss_msg;
spin_lock(&inode->i_lock);
while (!list_empty(&rpci->in_downcall)) {
gss_msg = list_entry(rpci->in_downcall.next,
struct gss_upcall_msg, list);
gss_msg->msg.errno = -EPIPE;
atomic_inc(&gss_msg->count);
__gss_unhash_msg(gss_msg);
spin_unlock(&inode->i_lock);
gss_release_msg(gss_msg);
spin_lock(&inode->i_lock);
}
spin_unlock(&inode->i_lock);
}
static void
gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
static unsigned long ratelimit;
if (msg->errno < 0) {
dprintk("RPC: gss_pipe_destroy_msg releasing msg %p\n",
gss_msg);
atomic_inc(&gss_msg->count);
gss_unhash_msg(gss_msg);
if (msg->errno == -ETIMEDOUT) {
unsigned long now = jiffies;
if (time_after(now, ratelimit)) {
printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
"Please check user daemon is running!\n");
ratelimit = now + 15*HZ;
}
}
gss_release_msg(gss_msg);
}
}
/*
* NOTE: we have the opportunity to use different
* parameters based on the input flavor (which must be a pseudoflavor)
*/
static struct rpc_auth *
gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
struct gss_auth *gss_auth;
struct rpc_auth * auth;
int err = -ENOMEM; /* XXX? */
dprintk("RPC: creating GSS authenticator for client %p\n", clnt);
if (!try_module_get(THIS_MODULE))
return ERR_PTR(err);
if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
goto out_dec;
gss_auth->client = clnt;
err = -EINVAL;
gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
if (!gss_auth->mech) {
printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
__func__, flavor);
goto err_free;
}
gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
if (gss_auth->service == 0)
goto err_put_mech;
auth = &gss_auth->rpc_auth;
auth->au_cslack = GSS_CRED_SLACK >> 2;
auth->au_rslack = GSS_VERF_SLACK >> 2;
auth->au_ops = &authgss_ops;
auth->au_flavor = flavor;
atomic_set(&auth->au_count, 1);
kref_init(&gss_auth->kref);
gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
if (IS_ERR(gss_auth->dentry)) {
err = PTR_ERR(gss_auth->dentry);
goto err_put_mech;
}
err = rpcauth_init_credcache(auth);
if (err)
goto err_unlink_pipe;
return auth;
err_unlink_pipe:
rpc_unlink(gss_auth->dentry);
err_put_mech:
gss_mech_put(gss_auth->mech);
err_free:
kfree(gss_auth);
out_dec:
module_put(THIS_MODULE);
return ERR_PTR(err);
}
static void
gss_free(struct gss_auth *gss_auth)
{
rpc_unlink(gss_auth->dentry);
gss_auth->dentry = NULL;
gss_mech_put(gss_auth->mech);
kfree(gss_auth);
module_put(THIS_MODULE);
}
static void
gss_free_callback(struct kref *kref)
{
struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
gss_free(gss_auth);
}
static void
gss_destroy(struct rpc_auth *auth)
{
struct gss_auth *gss_auth;
dprintk("RPC: destroying GSS authenticator %p flavor %d\n",
auth, auth->au_flavor);
rpcauth_destroy_credcache(auth);
gss_auth = container_of(auth, struct gss_auth, rpc_auth);
kref_put(&gss_auth->kref, gss_free_callback);
}
/*
* gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
* to the server with the GSS control procedure field set to
* RPC_GSS_PROC_DESTROY. This should normally cause the server to release
* all RPCSEC_GSS state associated with that context.
*/
static int
gss_destroying_context(struct rpc_cred *cred)
{
struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
struct rpc_task *task;
if (gss_cred->gc_ctx == NULL ||
test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
return 0;
gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
cred->cr_ops = &gss_nullops;
/* Take a reference to ensure the cred will be destroyed either
* by the RPC call or by the put_rpccred() below */
get_rpccred(cred);
task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
if (!IS_ERR(task))
rpc_put_task(task);
put_rpccred(cred);
return 1;
}
/* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
* to create a new cred or context, so they check that things have been
* allocated before freeing them. */
static void
gss_do_free_ctx(struct gss_cl_ctx *ctx)
{
dprintk("RPC: gss_free_ctx\n");
kfree(ctx->gc_wire_ctx.data);
kfree(ctx);
}
static void
gss_free_ctx_callback(struct rcu_head *head)
{
struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
gss_do_free_ctx(ctx);
}
static void
gss_free_ctx(struct gss_cl_ctx *ctx)
{
struct gss_ctx *gc_gss_ctx;
gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
if (gc_gss_ctx)
gss_delete_sec_context(&gc_gss_ctx);
}
static void
gss_free_cred(struct gss_cred *gss_cred)
{
dprintk("RPC: gss_free_cred %p\n", gss_cred);
kfree(gss_cred);
}
static void
gss_free_cred_callback(struct rcu_head *head)
{
struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
gss_free_cred(gss_cred);
}
static void
gss_destroy_cred(struct rpc_cred *cred)
{
struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
if (gss_destroying_context(cred))
return;
rcu_assign_pointer(gss_cred->gc_ctx, NULL);
call_rcu(&cred->cr_rcu, gss_free_cred_callback);
if (ctx)
gss_put_ctx(ctx);
kref_put(&gss_auth->kref, gss_free_callback);
}
/*
* Lookup RPCSEC_GSS cred for the current process
*/
static struct rpc_cred *
gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
return rpcauth_lookup_credcache(auth, acred, flags);
}
static struct rpc_cred *
gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
struct gss_cred *cred = NULL;
int err = -ENOMEM;
dprintk("RPC: gss_create_cred for uid %d, flavor %d\n",
acred->uid, auth->au_flavor);
if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
goto out_err;
rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
/*
* Note: in order to force a call to call_refresh(), we deliberately
* fail to flag the credential as RPCAUTH_CRED_UPTODATE.
*/
cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
cred->gc_service = gss_auth->service;
cred->gc_machine_cred = acred->machine_cred;
kref_get(&gss_auth->kref);
return &cred->gc_base;
out_err:
dprintk("RPC: gss_create_cred failed with error %d\n", err);
return ERR_PTR(err);
}
static int
gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
{
struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
int err;
do {
err = gss_create_upcall(gss_auth, gss_cred);
} while (err == -EAGAIN);
return err;
}
static int
gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
{
struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
goto out;
/* Don't match with creds that have expired. */
if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
return 0;
if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
return 0;
out:
if (acred->machine_cred != gss_cred->gc_machine_cred)
return 0;
return (rc->cr_uid == acred->uid);
}
/*
* Marshal credentials.
* Maybe we should keep a cached credential for performance reasons.
*/
static __be32 *
gss_marshal(struct rpc_task *task, __be32 *p)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
gc_base);
struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
__be32 *cred_len;
struct rpc_rqst *req = task->tk_rqstp;
u32 maj_stat = 0;
struct xdr_netobj mic;
struct kvec iov;
struct xdr_buf verf_buf;
dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
*p++ = htonl(RPC_AUTH_GSS);
cred_len = p++;
spin_lock(&ctx->gc_seq_lock);
req->rq_seqno = ctx->gc_seq++;
spin_unlock(&ctx->gc_seq_lock);
*p++ = htonl((u32) RPC_GSS_VERSION);
*p++ = htonl((u32) ctx->gc_proc);
*p++ = htonl((u32) req->rq_seqno);
*p++ = htonl((u32) gss_cred->gc_service);
p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
*cred_len = htonl((p - (cred_len + 1)) << 2);
/* We compute the checksum for the verifier over the xdr-encoded bytes
* starting with the xid and ending at the end of the credential: */
iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
req->rq_snd_buf.head[0].iov_base);
iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
xdr_buf_from_iov(&iov, &verf_buf);
/* set verifier flavor*/
*p++ = htonl(RPC_AUTH_GSS);
mic.data = (u8 *)(p + 1);
maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
} else if (maj_stat != 0) {
printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
goto out_put_ctx;
}
p = xdr_encode_opaque(p, NULL, mic.len);
gss_put_ctx(ctx);
return p;
out_put_ctx:
gss_put_ctx(ctx);
return NULL;
}
static int gss_renew_cred(struct rpc_task *task)
{
struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
struct gss_cred *gss_cred = container_of(oldcred,
struct gss_cred,
gc_base);
struct rpc_auth *auth = oldcred->cr_auth;
struct auth_cred acred = {
.uid = oldcred->cr_uid,
.machine_cred = gss_cred->gc_machine_cred,
};
struct rpc_cred *new;
new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
if (IS_ERR(new))
return PTR_ERR(new);
task->tk_msg.rpc_cred = new;
put_rpccred(oldcred);
return 0;
}
/*
* Refresh credentials. XXX - finish
*/
static int
gss_refresh(struct rpc_task *task)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
int ret = 0;
if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
ret = gss_renew_cred(task);
if (ret < 0)
goto out;
cred = task->tk_msg.rpc_cred;
}
if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
ret = gss_refresh_upcall(task);
out:
return ret;
}
/* Dummy refresh routine: used only when destroying the context */
static int
gss_refresh_null(struct rpc_task *task)
{
return -EACCES;
}
static __be32 *
gss_validate(struct rpc_task *task, __be32 *p)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
__be32 seq;
struct kvec iov;
struct xdr_buf verf_buf;
struct xdr_netobj mic;
u32 flav,len;
u32 maj_stat;
dprintk("RPC: %5u gss_validate\n", task->tk_pid);
flav = ntohl(*p++);
if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
goto out_bad;
if (flav != RPC_AUTH_GSS)
goto out_bad;
seq = htonl(task->tk_rqstp->rq_seqno);
iov.iov_base = &seq;
iov.iov_len = sizeof(seq);
xdr_buf_from_iov(&iov, &verf_buf);
mic.data = (u8 *)p;
mic.len = len;
maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
if (maj_stat == GSS_S_CONTEXT_EXPIRED)
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
if (maj_stat) {
dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
"error 0x%08x\n", task->tk_pid, maj_stat);
goto out_bad;
}
/* We leave it to unwrap to calculate au_rslack. For now we just
* calculate the length of the verifier: */
cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
gss_put_ctx(ctx);
dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
task->tk_pid);
return p + XDR_QUADLEN(len);
out_bad:
gss_put_ctx(ctx);
dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
return NULL;
}
static inline int
gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
{
struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
struct xdr_buf integ_buf;
__be32 *integ_len = NULL;
struct xdr_netobj mic;
u32 offset;
__be32 *q;
struct kvec *iov;
u32 maj_stat = 0;
int status = -EIO;
integ_len = p++;
offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
*p++ = htonl(rqstp->rq_seqno);
status = rpc_call_xdrproc(encode, rqstp, p, obj);
if (status)
return status;
if (xdr_buf_subsegment(snd_buf, &integ_buf,
offset, snd_buf->len - offset))
return status;
*integ_len = htonl(integ_buf.len);
/* guess whether we're in the head or the tail: */
if (snd_buf->page_len || snd_buf->tail[0].iov_len)
iov = snd_buf->tail;
else
iov = snd_buf->head;
p = iov->iov_base + iov->iov_len;
mic.data = (u8 *)(p + 1);
maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
status = -EIO; /* XXX? */
if (maj_stat == GSS_S_CONTEXT_EXPIRED)
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
else if (maj_stat)
return status;
q = xdr_encode_opaque(p, NULL, mic.len);
offset = (u8 *)q - (u8 *)p;
iov->iov_len += offset;
snd_buf->len += offset;
return 0;
}
static void
priv_release_snd_buf(struct rpc_rqst *rqstp)
{
int i;
for (i=0; i < rqstp->rq_enc_pages_num; i++)
__free_page(rqstp->rq_enc_pages[i]);
kfree(rqstp->rq_enc_pages);
}
static int
alloc_enc_pages(struct rpc_rqst *rqstp)
{
struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
int first, last, i;
if (snd_buf->page_len == 0) {
rqstp->rq_enc_pages_num = 0;
return 0;
}
first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
rqstp->rq_enc_pages_num = last - first + 1 + 1;
rqstp->rq_enc_pages
= kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
GFP_NOFS);
if (!rqstp->rq_enc_pages)
goto out;
for (i=0; i < rqstp->rq_enc_pages_num; i++) {
rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
if (rqstp->rq_enc_pages[i] == NULL)
goto out_free;
}
rqstp->rq_release_snd_buf = priv_release_snd_buf;
return 0;
out_free:
for (i--; i >= 0; i--) {
__free_page(rqstp->rq_enc_pages[i]);
}
out:
return -EAGAIN;
}
static inline int
gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
{
struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
u32 offset;
u32 maj_stat;
int status;
__be32 *opaque_len;
struct page **inpages;
int first;
int pad;
struct kvec *iov;
char *tmp;
opaque_len = p++;
offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
*p++ = htonl(rqstp->rq_seqno);
status = rpc_call_xdrproc(encode, rqstp, p, obj);
if (status)
return status;
status = alloc_enc_pages(rqstp);
if (status)
return status;
first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
inpages = snd_buf->pages + first;
snd_buf->pages = rqstp->rq_enc_pages;
snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
/* Give the tail its own page, in case we need extra space in the
* head when wrapping: */
if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
snd_buf->tail[0].iov_base = tmp;
}
maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
/* RPC_SLACK_SPACE should prevent this ever happening: */
BUG_ON(snd_buf->len > snd_buf->buflen);
status = -EIO;
/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
* done anyway, so it's safe to put the request on the wire: */
if (maj_stat == GSS_S_CONTEXT_EXPIRED)
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
else if (maj_stat)
return status;
*opaque_len = htonl(snd_buf->len - offset);
/* guess whether we're in the head or the tail: */
if (snd_buf->page_len || snd_buf->tail[0].iov_len)
iov = snd_buf->tail;
else
iov = snd_buf->head;
p = iov->iov_base + iov->iov_len;
pad = 3 - ((snd_buf->len - offset - 1) & 3);
memset(p, 0, pad);
iov->iov_len += pad;
snd_buf->len += pad;
return 0;
}
static int
gss_wrap_req(struct rpc_task *task,
kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
gc_base);
struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
int status = -EIO;
dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
/* The spec seems a little ambiguous here, but I think that not
* wrapping context destruction requests makes the most sense.
*/
status = rpc_call_xdrproc(encode, rqstp, p, obj);
goto out;
}
switch (gss_cred->gc_service) {
case RPC_GSS_SVC_NONE:
status = rpc_call_xdrproc(encode, rqstp, p, obj);
break;
case RPC_GSS_SVC_INTEGRITY:
status = gss_wrap_req_integ(cred, ctx, encode,
rqstp, p, obj);
break;
case RPC_GSS_SVC_PRIVACY:
status = gss_wrap_req_priv(cred, ctx, encode,
rqstp, p, obj);
break;
}
out:
gss_put_ctx(ctx);
dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
return status;
}
static inline int
gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
struct rpc_rqst *rqstp, __be32 **p)
{
struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf;
struct xdr_buf integ_buf;
struct xdr_netobj mic;
u32 data_offset, mic_offset;
u32 integ_len;
u32 maj_stat;
int status = -EIO;
integ_len = ntohl(*(*p)++);
if (integ_len & 3)
return status;
data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
mic_offset = integ_len + data_offset;
if (mic_offset > rcv_buf->len)
return status;
if (ntohl(*(*p)++) != rqstp->rq_seqno)
return status;
if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
mic_offset - data_offset))
return status;
if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
return status;
maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
if (maj_stat == GSS_S_CONTEXT_EXPIRED)
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
if (maj_stat != GSS_S_COMPLETE)
return status;
return 0;
}
static inline int
gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
struct rpc_rqst *rqstp, __be32 **p)
{
struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf;
u32 offset;
u32 opaque_len;
u32 maj_stat;
int status = -EIO;
opaque_len = ntohl(*(*p)++);
offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
if (offset + opaque_len > rcv_buf->len)
return status;
/* remove padding: */
rcv_buf->len = offset + opaque_len;
maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
if (maj_stat == GSS_S_CONTEXT_EXPIRED)
clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
if (maj_stat != GSS_S_COMPLETE)
return status;
if (ntohl(*(*p)++) != rqstp->rq_seqno)
return status;
return 0;
}
static int
gss_unwrap_resp(struct rpc_task *task,
kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
{
struct rpc_cred *cred = task->tk_msg.rpc_cred;
struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
gc_base);
struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
__be32 *savedp = p;
struct kvec *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
int savedlen = head->iov_len;
int status = -EIO;
if (ctx->gc_proc != RPC_GSS_PROC_DATA)
goto out_decode;
switch (gss_cred->gc_service) {
case RPC_GSS_SVC_NONE:
break;
case RPC_GSS_SVC_INTEGRITY:
status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
if (status)
goto out;
break;
case RPC_GSS_SVC_PRIVACY:
status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
if (status)
goto out;
break;
}
/* take into account extra slack for integrity and privacy cases: */
cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
+ (savedlen - head->iov_len);
out_decode:
status = rpc_call_xdrproc(decode, rqstp, p, obj);
out:
gss_put_ctx(ctx);
dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
status);
return status;
}
static const struct rpc_authops authgss_ops = {
.owner = THIS_MODULE,
.au_flavor = RPC_AUTH_GSS,
.au_name = "RPCSEC_GSS",
.create = gss_create,
.destroy = gss_destroy,
.lookup_cred = gss_lookup_cred,
.crcreate = gss_create_cred
};
static const struct rpc_credops gss_credops = {
.cr_name = "AUTH_GSS",
.crdestroy = gss_destroy_cred,
.cr_init = gss_cred_init,
.crbind = rpcauth_generic_bind_cred,
.crmatch = gss_match,
.crmarshal = gss_marshal,
.crrefresh = gss_refresh,
.crvalidate = gss_validate,
.crwrap_req = gss_wrap_req,
.crunwrap_resp = gss_unwrap_resp,
};
static const struct rpc_credops gss_nullops = {
.cr_name = "AUTH_GSS",
.crdestroy = gss_destroy_cred,
.crbind = rpcauth_generic_bind_cred,
.crmatch = gss_match,
.crmarshal = gss_marshal,
.crrefresh = gss_refresh_null,
.crvalidate = gss_validate,
.crwrap_req = gss_wrap_req,
.crunwrap_resp = gss_unwrap_resp,
};
static struct rpc_pipe_ops gss_upcall_ops = {
.upcall = gss_pipe_upcall,
.downcall = gss_pipe_downcall,
.destroy_msg = gss_pipe_destroy_msg,
.release_pipe = gss_pipe_release,
};
/*
* Initialize RPCSEC_GSS module
*/
static int __init init_rpcsec_gss(void)
{
int err = 0;
err = rpcauth_register(&authgss_ops);
if (err)
goto out;
err = gss_svc_init();
if (err)
goto out_unregister;
return 0;
out_unregister:
rpcauth_unregister(&authgss_ops);
out:
return err;
}
static void __exit exit_rpcsec_gss(void)
{
gss_svc_shutdown();
rpcauth_unregister(&authgss_ops);
}
MODULE_LICENSE("GPL");
module_init(init_rpcsec_gss)
module_exit(exit_rpcsec_gss)