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/sched.h>
  21 #include <linux/string.h>
  22 #include <linux/workqueue.h>
  23
  24 #include "internal.h"
  25
  26 struct cryptomgr_param {
  27         struct work_struct work;
  28
  29         struct {
  30                 struct rtattr attr;
  31                 struct crypto_attr_alg data;
  32         } alg;
  33
  34         struct {
  35                 u32 type;
  36                 u32 mask;
  37                 char name[CRYPTO_MAX_ALG_NAME];
  38         } larval;
  39
  40         char template[CRYPTO_MAX_ALG_NAME];
  41 };
  42
  43 static void cryptomgr_probe(void *data)
  44 {
  45         struct cryptomgr_param *param = data;
  46         struct crypto_template *tmpl;
  47         struct crypto_instance *inst;
  48         int err;
  49
  50         tmpl = crypto_lookup_template(param->template);
  51         if (!tmpl)
  52                 goto err;
  53
  54         do {
  55                 inst = tmpl->alloc(&param->alg, sizeof(param->alg));
  56                 if (IS_ERR(inst))
  57                         err = PTR_ERR(inst);
  58                 else if ((err = crypto_register_instance(tmpl, inst)))
  59                         tmpl->free(inst);
  60         } while (err == -EAGAIN && !signal_pending(current));
  61
  62         crypto_tmpl_put(tmpl);
  63
  64         if (err)
  65                 goto err;
  66
  67 out:
  68         kfree(param);
  69         return;
  70
  71 err:
  72         crypto_larval_error(param->larval.name, param->larval.type,
  73                             param->larval.mask);
  74         goto out;
  75 }
  76
  77 static int cryptomgr_schedule_probe(struct crypto_larval *larval)
  78 {
  79         struct cryptomgr_param *param;
  80         const char *name = larval->alg.cra_name;
  81         const char *p;
  82         unsigned int len;
  83
  84         param = kmalloc(sizeof(*param), GFP_KERNEL);
  85         if (!param)
  86                 goto err;
  87
  88         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
  89                 ;
  90
  91         len = p - name;
  92         if (!len || *p != '(')
  93                 goto err_free_param;
  94
  95         memcpy(param->template, name, len);
  96         param->template[len] = 0;
  97
  98         name = p + 1;
  99         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
 100                 ;
 101
 102         len = p - name;
 103         if (!len || *p != ')' || p[1])
 104                 goto err_free_param;
 105
 106         param->alg.attr.rta_len = sizeof(param->alg);
 107         param->alg.attr.rta_type = CRYPTOA_ALG;
 108         memcpy(param->alg.data.name, name, len);
 109         param->alg.data.name[len] = 0;
 110
 111         memcpy(param->larval.name, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);
 112         param->larval.type = larval->alg.cra_flags;
 113         param->larval.mask = larval->mask;
 114
 115         INIT_WORK(&param->work, cryptomgr_probe, param);
 116         schedule_work(&param->work);
 117
 118         return NOTIFY_STOP;
 119
 120 err_free_param:
 121         kfree(param);
 122 err:
 123         return NOTIFY_OK;
 124 }
 125
 126 static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
 127                             void *data)
 128 {
 129         switch (msg) {
 130         case CRYPTO_MSG_ALG_REQUEST:
 131                 return cryptomgr_schedule_probe(data);
 132         }
 133
 134         return NOTIFY_DONE;
 135 }
 136
 137 static struct notifier_block cryptomgr_notifier = {
 138         .notifier_call = cryptomgr_notify,
 139 };
 140
 141 static int __init cryptomgr_init(void)
 142 {
 143         return crypto_register_notifier(&cryptomgr_notifier);
 144 }
 145
 146 static void __exit cryptomgr_exit(void)
 147 {
 148         int err = crypto_unregister_notifier(&cryptomgr_notifier);
 149         BUG_ON(err);
 150 }
 151
 152 module_init(cryptomgr_init);
 153 module_exit(cryptomgr_exit);
 154
 155 MODULE_LICENSE("GPL");
 156 MODULE_DESCRIPTION("Crypto Algorithm Manager");