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 rtattr *tb[CRYPTOA_MAX];
  28
  29         struct {
  30                 struct rtattr attr;
  31                 struct crypto_attr_type data;
  32         } type;
  33
  34         struct {
  35                 struct rtattr attr;
  36                 struct crypto_attr_alg data;
  37         } alg;
  38
  39         struct {
  40                 char name[CRYPTO_MAX_ALG_NAME];
  41         } larval;
  42
  43         char template[CRYPTO_MAX_ALG_NAME];
  44 };
  45
  46 static int cryptomgr_probe(void *data)
  47 {
  48         struct cryptomgr_param *param = data;
  49         struct crypto_template *tmpl;
  50         struct crypto_instance *inst;
  51         int err;
  52
  53         tmpl = crypto_lookup_template(param->template);
  54         if (!tmpl)
  55                 goto err;
  56
  57         do {
  58                 inst = tmpl->alloc(param->tb);
  59                 if (IS_ERR(inst))
  60                         err = PTR_ERR(inst);
  61                 else if ((err = crypto_register_instance(tmpl, inst)))
  62                         tmpl->free(inst);
  63         } while (err == -EAGAIN && !signal_pending(current));
  64
  65         crypto_tmpl_put(tmpl);
  66
  67         if (err)
  68                 goto err;
  69
  70 out:
  71         kfree(param);
  72         module_put_and_exit(0);
  73
  74 err:
  75         crypto_larval_error(param->larval.name, param->type.data.type,
  76                             param->type.data.mask);
  77         goto out;
  78 }
  79
  80 static int cryptomgr_schedule_probe(struct crypto_larval *larval)
  81 {
  82         struct task_struct *thread;
  83         struct cryptomgr_param *param;
  84         const char *name = larval->alg.cra_name;
  85         const char *p;
  86         unsigned int len;
  87
  88         if (!try_module_get(THIS_MODULE))
  89                 goto err;
  90
  91         param = kzalloc(sizeof(*param), GFP_KERNEL);
  92         if (!param)
  93                 goto err_put_module;
  94
  95         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
  96                 ;
  97
  98         len = p - name;
  99         if (!len || *p != '(')
 100                 goto err_free_param;
 101
 102         memcpy(param->template, name, len);
 103
 104         name = p + 1;
 105         len = 0;
 106         for (p = name; *p; p++) {
 107                 for (; isalnum(*p) || *p == '-' || *p == '_' || *p == '('; p++)
 108                         ;
 109
 110                 if (*p != ')')
 111                         goto err_free_param;
 112
 113                 len = p - name;
 114         }
 115
 116         if (!len || name[len + 1])
 117                 goto err_free_param;
 118
 119         param->type.attr.rta_len = sizeof(param->type);
 120         param->type.attr.rta_type = CRYPTOA_TYPE;
 121         param->type.data.type = larval->alg.cra_flags;
 122         param->type.data.mask = larval->mask;
 123         param->tb[CRYPTOA_TYPE - 1] = &param->type.attr;
 124
 125         param->alg.attr.rta_len = sizeof(param->alg);
 126         param->alg.attr.rta_type = CRYPTOA_ALG;
 127         memcpy(param->alg.data.name, name, len);
 128         param->tb[CRYPTOA_ALG - 1] = &param->alg.attr;
 129
 130         memcpy(param->larval.name, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);
 131
 132         thread = kthread_run(cryptomgr_probe, param, "cryptomgr");
 133         if (IS_ERR(thread))
 134                 goto err_free_param;
 135
 136         return NOTIFY_STOP;
 137
 138 err_free_param:
 139         kfree(param);
 140 err_put_module:
 141         module_put(THIS_MODULE);
 142 err:
 143         return NOTIFY_OK;
 144 }
 145
 146 static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
 147                             void *data)
 148 {
 149         switch (msg) {
 150         case CRYPTO_MSG_ALG_REQUEST:
 151                 return cryptomgr_schedule_probe(data);
 152         }
 153
 154         return NOTIFY_DONE;
 155 }
 156
 157 static struct notifier_block cryptomgr_notifier = {
 158         .notifier_call = cryptomgr_notify,
 159 };
 160
 161 static int __init cryptomgr_init(void)
 162 {
 163         return crypto_register_notifier(&cryptomgr_notifier);
 164 }
 165
 166 static void __exit cryptomgr_exit(void)
 167 {
 168         int err = crypto_unregister_notifier(&cryptomgr_notifier);
 169         BUG_ON(err);
 170 }
 171
 172 module_init(cryptomgr_init);
 173 module_exit(cryptomgr_exit);
 174
 175 MODULE_LICENSE("GPL");
 176 MODULE_DESCRIPTION("Crypto Algorithm Manager");