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/*
* linux/fs/nfs/rpcauth.c
*
* Generic RPC authentication API.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/sunrpc/clnt.h>
#include <linux/spinlock.h>
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
#define RPC_MAXFLAVOR 8
static struct rpc_authops * auth_flavors[RPC_MAXFLAVOR] = {
&authnull_ops, /* AUTH_NULL */
&authunix_ops, /* AUTH_UNIX */
NULL, /* others can be loadable modules */
};
int
rpcauth_register(struct rpc_authops *ops)
{
unsigned int flavor;
if ((flavor = ops->au_flavor) >= RPC_MAXFLAVOR)
return -EINVAL;
if (auth_flavors[flavor] != NULL)
return -EPERM; /* what else? */
auth_flavors[flavor] = ops;
return 0;
}
int
rpcauth_unregister(struct rpc_authops *ops)
{
unsigned int flavor;
if ((flavor = ops->au_flavor) >= RPC_MAXFLAVOR)
return -EINVAL;
if (auth_flavors[flavor] != ops)
return -EPERM; /* what else? */
auth_flavors[flavor] = NULL;
return 0;
}
struct rpc_auth *
rpcauth_create(unsigned int flavor, struct rpc_clnt *clnt)
{
struct rpc_authops *ops;
if (flavor >= RPC_MAXFLAVOR || !(ops = auth_flavors[flavor]))
return NULL;
clnt->cl_auth = ops->create(clnt);
return clnt->cl_auth;
}
void
rpcauth_destroy(struct rpc_auth *auth)
{
auth->au_ops->destroy(auth);
}
static spinlock_t rpc_credcache_lock = SPIN_LOCK_UNLOCKED;
/*
* Initialize RPC credential cache
*/
void
rpcauth_init_credcache(struct rpc_auth *auth)
{
memset(auth->au_credcache, 0, sizeof(auth->au_credcache));
auth->au_nextgc = jiffies + (auth->au_expire >> 1);
}
/*
* Destroy an unreferenced credential
*/
static inline void
rpcauth_crdestroy(struct rpc_cred *cred)
{
#ifdef RPC_DEBUG
if (cred->cr_magic != RPCAUTH_CRED_MAGIC)
BUG();
cred->cr_magic = 0;
if (atomic_read(&cred->cr_count) || cred->cr_auth)
BUG();
#endif
cred->cr_ops->crdestroy(cred);
}
/*
* Destroy a list of credentials
*/
static inline
void rpcauth_destroy_credlist(struct rpc_cred *head)
{
struct rpc_cred *cred;
while ((cred = head) != NULL) {
head = cred->cr_next;
rpcauth_crdestroy(cred);
}
}
/*
* Clear the RPC credential cache, and delete those credentials
* that are not referenced.
*/
void
rpcauth_free_credcache(struct rpc_auth *auth)
{
struct rpc_cred **q, *cred, *free = NULL;
int i;
spin_lock(&rpc_credcache_lock);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
q = &auth->au_credcache[i];
while ((cred = *q) != NULL) {
*q = cred->cr_next;
cred->cr_auth = NULL;
if (atomic_read(&cred->cr_count) == 0) {
cred->cr_next = free;
free = cred;
} else
cred->cr_next = NULL;
}
}
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(free);
}
/*
* Remove stale credentials. Avoid sleeping inside the loop.
*/
static void
rpcauth_gc_credcache(struct rpc_auth *auth)
{
struct rpc_cred **q, *cred, *free = NULL;
int i;
dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
spin_lock(&rpc_credcache_lock);
for (i = 0; i < RPC_CREDCACHE_NR; i++) {
q = &auth->au_credcache[i];
while ((cred = *q) != NULL) {
if (!atomic_read(&cred->cr_count) &&
time_before(cred->cr_expire, jiffies)) {
*q = cred->cr_next;
cred->cr_auth = NULL;
cred->cr_next = free;
free = cred;
continue;
}
q = &cred->cr_next;
}
}
spin_unlock(&rpc_credcache_lock);
rpcauth_destroy_credlist(free);
auth->au_nextgc = jiffies + auth->au_expire;
}
/*
* Insert credential into cache
*/
void
rpcauth_insert_credcache(struct rpc_auth *auth, struct rpc_cred *cred)
{
int nr;
nr = (cred->cr_uid & RPC_CREDCACHE_MASK);
spin_lock(&rpc_credcache_lock);
cred->cr_next = auth->au_credcache[nr];
auth->au_credcache[nr] = cred;
cred->cr_auth = auth;
get_rpccred(cred);
spin_unlock(&rpc_credcache_lock);
}
/*
* Look up a process' credentials in the authentication cache
*/
static struct rpc_cred *
rpcauth_lookup_credcache(struct rpc_auth *auth, int taskflags)
{
struct rpc_cred **q, *cred = NULL;
int nr = 0;
if (!(taskflags & RPC_TASK_ROOTCREDS))
nr = current->uid & RPC_CREDCACHE_MASK;
if (time_before(auth->au_nextgc, jiffies))
rpcauth_gc_credcache(auth);
spin_lock(&rpc_credcache_lock);
q = &auth->au_credcache[nr];
while ((cred = *q) != NULL) {
if (!(cred->cr_flags & RPCAUTH_CRED_DEAD) &&
cred->cr_ops->crmatch(cred, taskflags)) {
*q = cred->cr_next;
break;
}
q = &cred->cr_next;
}
spin_unlock(&rpc_credcache_lock);
if (!cred) {
cred = auth->au_ops->crcreate(taskflags);
#ifdef RPC_DEBUG
if (cred)
cred->cr_magic = RPCAUTH_CRED_MAGIC;
#endif
}
if (cred)
rpcauth_insert_credcache(auth, cred);
return (struct rpc_cred *) cred;
}
/*
* Remove cred handle from cache
*/
static void
rpcauth_remove_credcache(struct rpc_cred *cred)
{
struct rpc_auth *auth = cred->cr_auth;
struct rpc_cred **q, *cr;
int nr;
nr = (cred->cr_uid & RPC_CREDCACHE_MASK);
q = &auth->au_credcache[nr];
while ((cr = *q) != NULL) {
if (cred == cr) {
*q = cred->cr_next;
cred->cr_next = NULL;
cred->cr_auth = NULL;
break;
}
q = &cred->cr_next;
}
}
struct rpc_cred *
rpcauth_lookupcred(struct rpc_auth *auth, int taskflags)
{
dprintk("RPC: looking up %s cred\n",
auth->au_ops->au_name);
return rpcauth_lookup_credcache(auth, taskflags);
}
struct rpc_cred *
rpcauth_bindcred(struct rpc_task *task)
{
struct rpc_auth *auth = task->tk_auth;
dprintk("RPC: %4d looking up %s cred\n",
task->tk_pid, task->tk_auth->au_ops->au_name);
task->tk_msg.rpc_cred = rpcauth_lookup_credcache(auth, task->tk_flags);
if (task->tk_msg.rpc_cred == 0)
task->tk_status = -ENOMEM;
return task->tk_msg.rpc_cred;
}
int
rpcauth_matchcred(struct rpc_auth *auth, struct rpc_cred *cred, int taskflags)
{
dprintk("RPC: matching %s cred %d\n",
auth->au_ops->au_name, taskflags);
return cred->cr_ops->crmatch(cred, taskflags);
}
void
rpcauth_holdcred(struct rpc_task *task)
{
dprintk("RPC: %4d holding %s cred %p\n",
task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
if (task->tk_msg.rpc_cred)
get_rpccred(task->tk_msg.rpc_cred);
}
void
put_rpccred(struct rpc_cred *cred)
{
if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
return;
if (cred->cr_auth && cred->cr_flags & RPCAUTH_CRED_DEAD)
rpcauth_remove_credcache(cred);
if (!cred->cr_auth) {
spin_unlock(&rpc_credcache_lock);
rpcauth_crdestroy(cred);
return;
}
cred->cr_expire = jiffies + cred->cr_auth->au_expire;
spin_unlock(&rpc_credcache_lock);
}
void
rpcauth_unbindcred(struct rpc_task *task)
{
struct rpc_auth *auth = task->tk_auth;
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %4d releasing %s cred %p\n",
task->tk_pid, auth->au_ops->au_name, cred);
put_rpccred(cred);
task->tk_msg.rpc_cred = NULL;
}
u32 *
rpcauth_marshcred(struct rpc_task *task, u32 *p)
{
struct rpc_auth *auth = task->tk_auth;
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %4d marshaling %s cred %p\n",
task->tk_pid, auth->au_ops->au_name, cred);
return cred->cr_ops->crmarshal(task, p,
task->tk_flags & RPC_CALL_REALUID);
}
u32 *
rpcauth_checkverf(struct rpc_task *task, u32 *p)
{
struct rpc_auth *auth = task->tk_auth;
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %4d validating %s cred %p\n",
task->tk_pid, auth->au_ops->au_name, cred);
return cred->cr_ops->crvalidate(task, p);
}
int
rpcauth_refreshcred(struct rpc_task *task)
{
struct rpc_auth *auth = task->tk_auth;
struct rpc_cred *cred = task->tk_msg.rpc_cred;
dprintk("RPC: %4d refreshing %s cred %p\n",
task->tk_pid, auth->au_ops->au_name, cred);
task->tk_status = cred->cr_ops->crrefresh(task);
return task->tk_status;
}
void
rpcauth_invalcred(struct rpc_task *task)
{
dprintk("RPC: %4d invalidating %s cred %p\n",
task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
spin_lock(&rpc_credcache_lock);
if (task->tk_msg.rpc_cred)
task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
spin_unlock(&rpc_credcache_lock);
}
int
rpcauth_uptodatecred(struct rpc_task *task)
{
int retval;
spin_lock(&rpc_credcache_lock);
retval = !(task->tk_msg.rpc_cred) ||
(task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
spin_unlock(&rpc_credcache_lock);
return retval;
}
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