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/*
* linux/net/sunrpc/rpcauth_unix.c
*
* UNIX-style authentication; no AUTH_SHORT support
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/auth.h>
#define NFS_NGROUPS 16
struct unx_cred {
struct rpc_cred uc_base;
uid_t uc_fsuid;
gid_t uc_gid, uc_fsgid;
gid_t uc_gids[NFS_NGROUPS];
};
#define uc_uid uc_base.cr_uid
#define uc_count uc_base.cr_count
#define uc_flags uc_base.cr_flags
#define uc_expire uc_base.cr_expire
#define UNX_CRED_EXPIRE (60 * HZ)
#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static struct rpc_credops unix_credops;
static struct rpc_auth *
unx_create(struct rpc_clnt *clnt)
{
struct rpc_auth *auth;
dprintk("RPC: creating UNIX authenticator for client %p\n", clnt);
if (!(auth = (struct rpc_auth *) rpc_allocate(0, sizeof(*auth))))
return NULL;
auth->au_cslack = UNX_WRITESLACK;
auth->au_rslack = 2; /* assume AUTH_NULL verf */
auth->au_expire = UNX_CRED_EXPIRE;
auth->au_ops = &authunix_ops;
rpcauth_init_credcache(auth);
return auth;
}
static void
unx_destroy(struct rpc_auth *auth)
{
dprintk("RPC: destroying UNIX authenticator %p\n", auth);
rpcauth_free_credcache(auth);
rpc_free(auth);
}
static struct rpc_cred *
unx_create_cred(int flags)
{
struct unx_cred *cred;
int i;
dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
current->uid, current->gid);
if (!(cred = (struct unx_cred *) rpc_allocate(flags, sizeof(*cred))))
return NULL;
atomic_set(&cred->uc_count, 0);
cred->uc_flags = RPCAUTH_CRED_UPTODATE;
if (flags & RPC_TASK_ROOTCREDS) {
cred->uc_uid = cred->uc_fsuid = 0;
cred->uc_gid = cred->uc_fsgid = 0;
cred->uc_gids[0] = NOGROUP;
} else {
int groups = current->ngroups;
if (groups > NFS_NGROUPS)
groups = NFS_NGROUPS;
cred->uc_uid = current->uid;
cred->uc_gid = current->gid;
cred->uc_fsuid = current->fsuid;
cred->uc_fsgid = current->fsgid;
for (i = 0; i < groups; i++)
cred->uc_gids[i] = (gid_t) current->groups[i];
if (i < NFS_NGROUPS)
cred->uc_gids[i] = NOGROUP;
}
cred->uc_base.cr_ops = &unix_credops;
return (struct rpc_cred *) cred;
}
struct rpc_cred *
authunix_fake_cred(struct rpc_task *task, uid_t uid, gid_t gid)
{
struct unx_cred *cred;
dprintk("RPC: allocating fake UNIX cred for uid %d gid %d\n",
uid, gid);
if (!(cred = (struct unx_cred *) rpc_malloc(task, sizeof(*cred))))
return NULL;
atomic_set(&cred->uc_count, 1);
cred->uc_flags = RPCAUTH_CRED_DEAD|RPCAUTH_CRED_UPTODATE;
cred->uc_uid = uid;
cred->uc_gid = gid;
cred->uc_fsuid = uid;
cred->uc_fsgid = gid;
cred->uc_gids[0] = (gid_t) NOGROUP;
return task->tk_msg.rpc_cred = (struct rpc_cred *) cred;
}
static void
unx_destroy_cred(struct rpc_cred *cred)
{
rpc_free(cred);
}
/*
* 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 rpc_cred *rcred, int taskflags)
{
struct unx_cred *cred = (struct unx_cred *) rcred;
int i;
if (!(taskflags & RPC_TASK_ROOTCREDS)) {
int groups;
if (cred->uc_uid != current->uid
|| cred->uc_gid != current->gid
|| cred->uc_fsuid != current->fsuid
|| cred->uc_fsgid != current->fsgid)
return 0;
groups = current->ngroups;
if (groups > NFS_NGROUPS)
groups = NFS_NGROUPS;
for (i = 0; i < groups ; i++)
if (cred->uc_gids[i] != (gid_t) current->groups[i])
return 0;
return 1;
}
return (cred->uc_uid == 0 && cred->uc_fsuid == 0
&& cred->uc_gid == 0 && cred->uc_fsgid == 0
&& cred->uc_gids[0] == (gid_t) NOGROUP);
}
/*
* Marshal credentials.
* Maybe we should keep a cached credential for performance reasons.
*/
static u32 *
unx_marshal(struct rpc_task *task, u32 *p, int ruid)
{
struct rpc_clnt *clnt = task->tk_client;
struct unx_cred *cred = (struct unx_cred *) task->tk_msg.rpc_cred;
u32 *base, *hold;
int i, n;
*p++ = htonl(RPC_AUTH_UNIX);
base = p++;
*p++ = htonl(jiffies/HZ);
/*
* Copy the UTS nodename captured when the client was created.
*/
n = clnt->cl_nodelen;
*p++ = htonl(n);
memcpy(p, clnt->cl_nodename, n);
p += (n + 3) >> 2;
/* Note: we don't use real uid if it involves raising priviledge */
if (ruid && cred->uc_uid != 0 && cred->uc_gid != 0) {
*p++ = htonl((u32) cred->uc_uid);
*p++ = htonl((u32) cred->uc_gid);
} else {
*p++ = htonl((u32) cred->uc_fsuid);
*p++ = htonl((u32) cred->uc_fsgid);
}
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;
}
/*
* Refresh credentials. This is a no-op for AUTH_UNIX
*/
static int
unx_refresh(struct rpc_task *task)
{
task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
return task->tk_status = -EACCES;
}
static u32 *
unx_validate(struct rpc_task *task, u32 *p)
{
u32 n = ntohl(*p++);
if (n != RPC_AUTH_NULL && n != RPC_AUTH_UNIX && n != RPC_AUTH_SHORT) {
printk("RPC: bad verf flavor: %ld\n", (unsigned long) n);
return NULL;
}
if ((n = ntohl(*p++)) > 400) {
printk("RPC: giant verf size: %ld\n", (unsigned long) n);
return NULL;
}
task->tk_auth->au_rslack = (n >> 2) + 2;
p += (n >> 2);
return p;
}
struct rpc_authops authunix_ops = {
RPC_AUTH_UNIX,
#ifdef RPC_DEBUG
"UNIX",
#endif
unx_create,
unx_destroy,
unx_create_cred
};
static
struct rpc_credops unix_credops = {
unx_destroy_cred,
unx_match,
unx_marshal,
unx_refresh,
unx_validate
};
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