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