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[CRYPTO_MAX_ATTRS + 2];
  28
  29         struct {
  30                 struct rtattr attr;
  31                 struct crypto_attr_type data;
  32         } type;
  33
  34         union {
  35                 struct rtattr attr;
  36                 struct {
  37                         struct rtattr attr;
  38                         struct crypto_attr_alg data;
  39                 } alg;
  40                 struct {
  41                         struct rtattr attr;
  42                         struct crypto_attr_u32 data;
  43                 } nu32;
  44         } attrs[CRYPTO_MAX_ATTRS];
  45
  46         char larval[CRYPTO_MAX_ALG_NAME];
  47         char template[CRYPTO_MAX_ALG_NAME];
  48 };
  49
  50 static int cryptomgr_probe(void *data)
  51 {
  52         struct cryptomgr_param *param = data;
  53         struct crypto_template *tmpl;
  54         struct crypto_instance *inst;
  55         int err;
  56
  57         tmpl = crypto_lookup_template(param->template);
  58         if (!tmpl)
  59                 goto err;
  60
  61         do {
  62                 inst = tmpl->alloc(param->tb);
  63                 if (IS_ERR(inst))
  64                         err = PTR_ERR(inst);
  65                 else if ((err = crypto_register_instance(tmpl, inst)))
  66                         tmpl->free(inst);
  67         } while (err == -EAGAIN && !signal_pending(current));
  68
  69         crypto_tmpl_put(tmpl);
  70
  71         if (err)
  72                 goto err;
  73
  74 out:
  75         kfree(param);
  76         module_put_and_exit(0);
  77
  78 err:
  79         crypto_larval_error(param->larval, param->type.data.type,
  80                             param->type.data.mask);
  81         goto out;
  82 }
  83
  84 static int cryptomgr_schedule_probe(struct crypto_larval *larval)
  85 {
  86         struct task_struct *thread;
  87         struct cryptomgr_param *param;
  88         const char *name = larval->alg.cra_name;
  89         const char *p;
  90         unsigned int len;
  91         int i;
  92
  93         if (!try_module_get(THIS_MODULE))
  94                 goto err;
  95
  96         param = kzalloc(sizeof(*param), GFP_KERNEL);
  97         if (!param)
  98                 goto err_put_module;
  99
 100         for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
 101                 ;
 102
 103         len = p - name;
 104         if (!len || *p != '(')
 105                 goto err_free_param;
 106
 107         memcpy(param->template, name, len);
 108
 109         i = 0;
 110         for (;;) {
 111                 int notnum = 0;
 112
 113                 name = ++p;
 114                 len = 0;
 115
 116                 for (; isalnum(*p) || *p == '-' || *p == '_'; p++)
 117                         notnum |= !isdigit(*p);
 118
 119                 if (*p == '(') {
 120                         int recursion = 0;
 121
 122                         for (;;) {
 123                                 if (!*++p)
 124                                         goto err_free_param;
 125                                 if (*p == '(')
 126                                         recursion++;
 127                                 else if (*p == ')' && !recursion--)
 128                                         break;
 129                         }
 130
 131                         notnum = 1;
 132                         p++;
 133                 }
 134
 135                 len = p - name;
 136                 if (!len)
 137                         goto err_free_param;
 138
 139                 if (notnum) {
 140                         param->attrs[i].alg.attr.rta_len =
 141                                 sizeof(param->attrs[i].alg);
 142                         param->attrs[i].alg.attr.rta_type = CRYPTOA_ALG;
 143                         memcpy(param->attrs[i].alg.data.name, name, len);
 144                 } else {
 145                         param->attrs[i].nu32.attr.rta_len =
 146                                 sizeof(param->attrs[i].nu32);
 147                         param->attrs[i].nu32.attr.rta_type = CRYPTOA_U32;
 148                         param->attrs[i].nu32.data.num =
 149                                 simple_strtol(name, NULL, 0);
 150                 }
 151
 152                 param->tb[i + 1] = &param->attrs[i].attr;
 153                 i++;
 154
 155                 if (i >= CRYPTO_MAX_ATTRS)
 156                         goto err_free_param;
 157
 158                 if (*p == ')')
 159                         break;
 160
 161                 if (*p != ',')
 162                         goto err_free_param;
 163         }
 164
 165         if (!i)
 166                 goto err_free_param;
 167
 168         param->tb[i + 1] = NULL;
 169
 170         param->type.attr.rta_len = sizeof(param->type);
 171         param->type.attr.rta_type = CRYPTOA_TYPE;
 172         param->type.data.type = larval->alg.cra_flags;
 173         param->type.data.mask = larval->mask;
 174         param->tb[0] = &param->type.attr;
 175
 176         memcpy(param->larval, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);
 177
 178         thread = kthread_run(cryptomgr_probe, param, "cryptomgr");
 179         if (IS_ERR(thread))
 180                 goto err_free_param;
 181
 182         return NOTIFY_STOP;
 183
 184 err_free_param:
 185         kfree(param);
 186 err_put_module:
 187         module_put(THIS_MODULE);
 188 err:
 189         return NOTIFY_OK;
 190 }
 191
 192 static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
 193                             void *data)
 194 {
 195         switch (msg) {
 196         case CRYPTO_MSG_ALG_REQUEST:
 197                 return cryptomgr_schedule_probe(data);
 198         }
 199
 200         return NOTIFY_DONE;
 201 }
 202
 203 static struct notifier_block cryptomgr_notifier = {
 204         .notifier_call = cryptomgr_notify,
 205 };
 206
 207 static int __init cryptomgr_init(void)
 208 {
 209         return crypto_register_notifier(&cryptomgr_notifier);
 210 }
 211
 212 static void __exit cryptomgr_exit(void)
 213 {
 214         int err = crypto_unregister_notifier(&cryptomgr_notifier);
 215         BUG_ON(err);
 216 }
 217
 218 module_init(cryptomgr_init);
 219 module_exit(cryptomgr_exit);
 220
 221 MODULE_LICENSE("GPL");
 222 MODULE_DESCRIPTION("Crypto Algorithm Manager");