linux/net/sunrpc/auth_generic.c
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   1/*
   2 * Generic RPC credential
   3 *
   4 * Copyright (C) 2008, Trond Myklebust <Trond.Myklebust@netapp.com>
   5 */
   6
   7#include <linux/err.h>
   8#include <linux/types.h>
   9#include <linux/module.h>
  10#include <linux/sched.h>
  11#include <linux/sunrpc/auth.h>
  12#include <linux/sunrpc/clnt.h>
  13#include <linux/sunrpc/debug.h>
  14#include <linux/sunrpc/sched.h>
  15
  16#ifdef RPC_DEBUG
  17# define RPCDBG_FACILITY        RPCDBG_AUTH
  18#endif
  19
  20#define RPC_MACHINE_CRED_USERID         ((uid_t)0)
  21#define RPC_MACHINE_CRED_GROUPID        ((gid_t)0)
  22
  23struct generic_cred {
  24        struct rpc_cred gc_base;
  25        struct auth_cred acred;
  26};
  27
  28static struct rpc_auth generic_auth;
  29static struct rpc_cred_cache generic_cred_cache;
  30static const struct rpc_credops generic_credops;
  31
  32/*
  33 * Public call interface
  34 */
  35struct rpc_cred *rpc_lookup_cred(void)
  36{
  37        return rpcauth_lookupcred(&generic_auth, 0);
  38}
  39EXPORT_SYMBOL_GPL(rpc_lookup_cred);
  40
  41/*
  42 * Public call interface for looking up machine creds.
  43 */
  44struct rpc_cred *rpc_lookup_machine_cred(void)
  45{
  46        struct auth_cred acred = {
  47                .uid = RPC_MACHINE_CRED_USERID,
  48                .gid = RPC_MACHINE_CRED_GROUPID,
  49                .machine_cred = 1,
  50        };
  51
  52        dprintk("RPC:       looking up machine cred\n");
  53        return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
  54}
  55EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
  56
  57static void
  58generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred)
  59{
  60        struct rpc_auth *auth = task->tk_client->cl_auth;
  61        struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
  62        struct rpc_cred *ret;
  63
  64        ret = auth->au_ops->lookup_cred(auth, acred, 0);
  65        if (!IS_ERR(ret))
  66                task->tk_msg.rpc_cred = ret;
  67        else
  68                task->tk_status = PTR_ERR(ret);
  69}
  70
  71/*
  72 * Lookup generic creds for current process
  73 */
  74static struct rpc_cred *
  75generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
  76{
  77        return rpcauth_lookup_credcache(&generic_auth, acred, flags);
  78}
  79
  80static struct rpc_cred *
  81generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
  82{
  83        struct generic_cred *gcred;
  84
  85        gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
  86        if (gcred == NULL)
  87                return ERR_PTR(-ENOMEM);
  88
  89        rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
  90        gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
  91
  92        gcred->acred.uid = acred->uid;
  93        gcred->acred.gid = acred->gid;
  94        gcred->acred.group_info = acred->group_info;
  95        if (gcred->acred.group_info != NULL)
  96                get_group_info(gcred->acred.group_info);
  97        gcred->acred.machine_cred = acred->machine_cred;
  98
  99        dprintk("RPC:       allocated %s cred %p for uid %d gid %d\n",
 100                        gcred->acred.machine_cred ? "machine" : "generic",
 101                        gcred, acred->uid, acred->gid);
 102        return &gcred->gc_base;
 103}
 104
 105static void
 106generic_free_cred(struct rpc_cred *cred)
 107{
 108        struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
 109
 110        dprintk("RPC:       generic_free_cred %p\n", gcred);
 111        if (gcred->acred.group_info != NULL)
 112                put_group_info(gcred->acred.group_info);
 113        kfree(gcred);
 114}
 115
 116static void
 117generic_free_cred_callback(struct rcu_head *head)
 118{
 119        struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
 120        generic_free_cred(cred);
 121}
 122
 123static void
 124generic_destroy_cred(struct rpc_cred *cred)
 125{
 126        call_rcu(&cred->cr_rcu, generic_free_cred_callback);
 127}
 128
 129/*
 130 * Match credentials against current process creds.
 131 */
 132static int
 133generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
 134{
 135        struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
 136        int i;
 137
 138        if (gcred->acred.uid != acred->uid ||
 139            gcred->acred.gid != acred->gid ||
 140            gcred->acred.machine_cred != acred->machine_cred)
 141                goto out_nomatch;
 142
 143        /* Optimisation in the case where pointers are identical... */
 144        if (gcred->acred.group_info == acred->group_info)
 145                goto out_match;
 146
 147        /* Slow path... */
 148        if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
 149                goto out_nomatch;
 150        for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
 151                if (GROUP_AT(gcred->acred.group_info, i) !=
 152                                GROUP_AT(acred->group_info, i))
 153                        goto out_nomatch;
 154        }
 155out_match:
 156        return 1;
 157out_nomatch:
 158        return 0;
 159}
 160
 161void __init rpc_init_generic_auth(void)
 162{
 163        spin_lock_init(&generic_cred_cache.lock);
 164}
 165
 166void __exit rpc_destroy_generic_auth(void)
 167{
 168        rpcauth_clear_credcache(&generic_cred_cache);
 169}
 170
 171static struct rpc_cred_cache generic_cred_cache = {
 172        {{ NULL, },},
 173};
 174
 175static const struct rpc_authops generic_auth_ops = {
 176        .owner = THIS_MODULE,
 177        .au_name = "Generic",
 178        .lookup_cred = generic_lookup_cred,
 179        .crcreate = generic_create_cred,
 180};
 181
 182static struct rpc_auth generic_auth = {
 183        .au_ops = &generic_auth_ops,
 184        .au_count = ATOMIC_INIT(0),
 185        .au_credcache = &generic_cred_cache,
 186};
 187
 188static const struct rpc_credops generic_credops = {
 189        .cr_name = "Generic cred",
 190        .crdestroy = generic_destroy_cred,
 191        .crbind = generic_bind_cred,
 192        .crmatch = generic_match,
 193};
 194