/*
* linux/net/sunrpc/auth_unix.c
*
* UNIX-style authentication; no AUTH_SHORT support
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/auth.h>
#define NFS_NGROUPS 16
struct unx_cred {
struct rpc_cred uc_base;
gid_t uc_gid;
gid_t uc_gids[NFS_NGROUPS];
};
#define uc_uid uc_base.cr_uid
#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static struct rpc_auth unix_auth;
static const struct rpc_credops unix_credops;
static struct rpc_auth *
unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
dprintk("RPC: creating UNIX authenticator for client %p\n",
clnt);
atomic_inc(&unix_auth.au_count);
return &unix_auth;
}
static void
unx_destroy(struct rpc_auth *auth)
{
dprintk("RPC: destroying UNIX authenticator %p\n", auth);
rpcauth_clear_credcache(auth->au_credcache);
}
/*
* Lookup AUTH_UNIX creds for current process
*/
static struct rpc_cred *
unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
return rpcauth_lookup_credcache(auth, acred, flags);
}
static struct rpc_cred *
unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
{
struct unx_cred *cred;
unsigned int groups = 0;
unsigned int i;
dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
acred->uid, acred->gid);
if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
return ERR_PTR(-ENOMEM);
rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
if (acred->group_info != NULL)
groups = acred->group_info->ngroups;
if (groups > NFS_NGROUPS)
groups = NFS_NGROUPS;
cred->uc_gid = acred->gid;
for (i = 0; i < groups; i++)
cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
if (i < NFS_NGROUPS)
cred->uc_gids[i] = NOGROUP;
return &cred->uc_base;
}
static void
unx_free_cred(struct unx_cred *unx_cred)
{
dprintk("RPC: unx_free_cred %p\n", unx_cred);
kfree(unx_cred);
}
static void
unx_free_cred_callback(struct rcu_head *head)
{
struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
unx_free_cred(unx_cred);
}
static void
unx_destroy_cred(struct rpc_cred *cred)
{
call_rcu(&cred->cr_rcu, unx_free_cred_callback);
}
/*
* Match credentials against current process creds.
* The root_override argument takes care of cases where the caller may
* request root creds (e.g. for NFS swapping).
*/
static int
unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
{
struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
unsigned int groups = 0;
unsigned int i;
if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid)
return 0;
if (acred->group_info != NULL)
groups = acred->group_info->ngroups;
if (groups > NFS_NGROUPS)
groups = NFS_NGROUPS;
for (i = 0; i < groups ; i++)
if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
return 0;
return 1;
}
/*
* Marshal credentials.
* Maybe we should keep a cached credential for performance reasons.
*/
static __be32 *
unx_marshal(struct rpc_task *task, __be32 *p)
{
struct rpc_clnt *clnt = task->tk_client;
struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
__be32 *base, *hold;
int i;
*p++ = htonl(RPC_AUTH_UNIX);
base = p++;
*p++ = htonl(jiffies/HZ);
/*
* Copy the UTS nodename captured when the client was created.
*/
p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
*p++ = htonl((u32) cred->uc_uid);
*p++ = htonl((u32) cred->uc_gid);
hold = p++;
for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
*p++ = htonl((u32) cred->uc_gids[i]);
*hold = htonl(p - hold - 1); /* gid array length */
*base = htonl((p - base - 1) << 2); /* cred length */
*p++ = htonl(RPC_AUTH_NULL);
*p++ = htonl(0);
return p;
