crypto/cryptomgr.c

   1 /*
   2  * Create default crypto algorithm instances.
   3  *
   4  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <linux/crypto.h>
  14 #include <linux/ctype.h>
  15 #include <linux/err.h>
  16 #include <linux/init.h>
  17 #include <linux/kthread.h>
  18 #include <linux/module.h>
  19 #include <linux/notifier.h>
  20 #include <linux/rtnetlink.h>
  21 #include <linux/sched.h>
  22 #include <linux/string.h>
  23
  24 #include "internal.h"
  25
  26 struct cryptomgr_param {
  27         struct task_struct *thread;
  28
  29         struct rtattr *tb[CRYPTOA_MAX];
  30
  31         struct {
  32                 struct rtattr attr;
  33                 struct crypto_attr_type data;
  34         } type;
  35
  36         struct {
  37                 struct rtattr attr;
  38                 struct crypto_attr_alg data;
  39         } alg;
  40
  41         struct {
  42                 char name[CRYPTO_MAX_ALG_NAME];
  43         } larval;
  44
  45         char template[CRYPTO_MAX_ALG_NAME];
  46 };
  47
  48 static int cryptomgr_probe(void *data)
  49 {
  50         struct cryptomgr_param *param = data;
  51         struct crypto_template *tmpl;
  52         struct crypto_instance *inst;
  53         int err;
  54
  55         tmpl = crypto_lookup_template(param->template);
  56         if (!tmpl)
  57                 goto err;
  58
  59         do {
  60                 inst = tmpl->alloc(param->tb);
  61                 if (IS_ERR(inst))
  62                         err = PTR_ERR(inst);
  63                 else if ((err = crypto_register_instance(tmpl, inst)))
  64                         tmpl->free(inst);
  65         } while (err == -EAGAIN && !signal_pending(current));
  66
  67         crypto_tmpl_put(tmpl);
  68
  69         if (err)
  70                 goto err;
  71
  72 out:
  73         kfree(param);
  74         module_put_and_exit(0);
  75
  76 err:
  77         crypto_larval_error(param->larval.name, param->type.data.type,
  78                             param->type.data.mask);
  79         goto out;
  80 }
  81
  82 static int cryptomgr_schedule_probe(struct crypto_larval *larval)
  83 {
  84         struct cryptomgr_param *param;
  85         const char *name = larval->alg.cra_name;
  86         const char *p;
  87         unsigned int len;
  88
  89         if (!try_module_get(THIS_MODULE))
  90                 goto err;
  91
  92         param = kzalloc(sizeof(*param), GFP_KERNEL);
  93         if (!param)
  94                 goto err_put_module;
  95
  96         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
  97                 ;
  98
  99         len = p - name;
 100         if (!len || *p != '(')
 101                 goto err_free_param;
 102
 103         memcpy(param->template, name, len);
 104
 105         name = p + 1;
 106         len = 0;
 107         for (p = name; *p; p++) {
 108                 for (; isalnum(*p) || *p == '-' || *p == '_' || *p == '('; p++)
 109                         ;
 110
 111                 if (*p != ')')
 112                         goto err_free_param;
 113
 114                 len = p - name;
 115         }
 116
 117         if (!len || name[len + 1])
 118                 goto err_free_param;
 119
 120         param->type.attr.rta_len = sizeof(param->type);
 121         param->type.attr.rta_type = CRYPTOA_TYPE;
 122         param->type.data.type = larval->alg.cra_flags;
 123         param->type.data.mask = larval->mask;
 124         param->tb[CRYPTOA_TYPE - 1] = &param->type.attr;
 125
 126         param->alg.attr.rta_len = sizeof(param->alg);
 127         param->alg.attr.rta_type = CRYPTOA_ALG;
 128         memcpy(param->alg.data.name, name, len);
 129         param->tb[CRYPTOA_ALG - 1] = &param->alg.attr;
 130
 131         memcpy(param->larval.name, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);
 132
 133         param->thread = kthread_run(cryptomgr_probe, param, "cryptomgr");
 134         if (IS_ERR(param->thread))
 135                 goto err_free_param;
 136
 137         return NOTIFY_STOP;
 138
 139 err_free_param:
 140         kfree(param);
 141 err_put_module:
 142         module_put(THIS_MODULE);
 143 err:
 144         return NOTIFY_OK;
 145 }
 146
 147 static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
 148                             void *data)
 149 {
 150         switch (msg) {
 151         case CRYPTO_MSG_ALG_REQUEST:
 152                 return cryptomgr_schedule_probe(data);
 153         }
 154
 155         return NOTIFY_DONE;
 156 }
 157
 158 static struct notifier_block cryptomgr_notifier = {
 159         .notifier_call = cryptomgr_notify,
 160 };
 161
 162 static int __init cryptomgr_init(void)
 163 {
 164         return crypto_register_notifier(&cryptomgr_notifier);
 165 }
 166
 167 static void __exit cryptomgr_exit(void)
 168 {
 169         int err = crypto_unregister_notifier(&cryptomgr_notifier);
 170         BUG_ON(err);
 171 }
 172
 173 module_init(cryptomgr_init);
 174 module_exit(cryptomgr_exit);
 175
 176 MODULE_LICENSE("GPL");
 177 MODULE_DESCRIPTION("Crypto Algorithm Manager");