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/module.h>
  18 #include <linux/notifier.h>
  19 #include <linux/rtnetlink.h>
  20 #include <linux/string.h>
  21 #include <linux/workqueue.h>
  22
  23 #include "internal.h"
  24
  25 struct cryptomgr_param {
  26         struct work_struct work;
  27
  28         struct {
  29                 struct rtattr attr;
  30                 struct crypto_attr_alg data;
  31         } alg;
  32
  33         struct {
  34                 char name[CRYPTO_MAX_ALG_NAME];
  35         } larval;
  36
  37         char template[CRYPTO_MAX_ALG_NAME];
  38 };
  39
  40 static void cryptomgr_probe(void *data)
  41 {
  42         struct cryptomgr_param *param = data;
  43         struct crypto_template *tmpl;
  44         struct crypto_instance *inst;
  45
  46         tmpl = crypto_lookup_template(param->template);
  47         if (!tmpl)
  48                 goto err;
  49
  50         inst = tmpl->alloc(&param->alg, sizeof(param->alg));
  51         if (IS_ERR(inst))
  52                 goto err;
  53         else if ((err = crypto_register_instance(tmpl, inst))) {
  54                 tmpl->free(inst);
  55                 goto err;
  56         }
  57
  58         crypto_tmpl_put(tmpl);
  59
  60 out:
  61         kfree(param);
  62         return;
  63
  64 err:
  65         crypto_larval_error(param->larval.name);
  66         goto out;
  67 }
  68
  69 static int cryptomgr_schedule_probe(struct crypto_larval *larval)
  70 {
  71         struct cryptomgr_param *param;
  72         const char *name = larval->alg.cra_name;
  73         const char *p;
  74         unsigned int len;
  75
  76         param = kmalloc(sizeof(*param), GFP_KERNEL);
  77         if (!param)
  78                 goto err;
  79
  80         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
  81                 ;
  82
  83         len = p - name;
  84         if (!len || *p != '(')
  85                 goto err_free_param;
  86
  87         memcpy(param->template, name, len);
  88         param->template[len] = 0;
  89
  90         name = p + 1;
  91         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
  92                 ;
  93
  94         len = p - name;
  95         if (!len || *p != ')' || p[1])
  96                 goto err_free_param;
  97
  98         param->alg.attr.rta_len = sizeof(param->alg);
  99         param->alg.attr.rta_type = CRYPTOA_ALG;
 100         memcpy(param->alg.data.name, name, len);
 101         param->alg.data.name[len] = 0;
 102
 103         memcpy(param->larval.name, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);
 104
 105         INIT_WORK(&param->work, cryptomgr_probe, param);
 106         schedule_work(&param->work);
 107
 108         return NOTIFY_STOP;
 109
 110 err_free_param:
 111         kfree(param);
 112 err:
 113         return NOTIFY_OK;
 114 }
 115
 116 static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
 117                             void *data)
 118 {
 119         switch (msg) {
 120         case CRYPTO_MSG_ALG_REQUEST:
 121                 return cryptomgr_schedule_probe(data);
 122         }
 123
 124         return NOTIFY_DONE;
 125 }
 126
 127 static struct notifier_block cryptomgr_notifier = {
 128         .notifier_call = cryptomgr_notify,
 129 };
 130
 131 static int __init cryptomgr_init(void)
 132 {
 133         return crypto_register_notifier(&cryptomgr_notifier);
 134 }
 135
 136 static void __exit cryptomgr_exit(void)
 137 {
 138         int err = crypto_unregister_notifier(&cryptomgr_notifier);
 139         BUG_ON(err);
 140 }
 141
 142 module_init(cryptomgr_init);
 143 module_exit(cryptomgr_exit);
 144
 145 MODULE_LICENSE("GPL");
 146 MODULE_DESCRIPTION("Crypto Algorithm Manager");