Root/crypto/pcrypt.c

1/*
2 * pcrypt - Parallel crypto wrapper.
3 *
4 * Copyright (C) 2009 secunet Security Networks AG
5 * Copyright (C) 2009 Steffen Klassert <steffen.klassert@secunet.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21#include <crypto/algapi.h>
22#include <crypto/internal/aead.h>
23#include <linux/err.h>
24#include <linux/init.h>
25#include <linux/module.h>
26#include <linux/slab.h>
27#include <linux/notifier.h>
28#include <linux/kobject.h>
29#include <linux/cpu.h>
30#include <crypto/pcrypt.h>
31
32struct padata_pcrypt {
33    struct padata_instance *pinst;
34    struct workqueue_struct *wq;
35
36    /*
37     * Cpumask for callback CPUs. It should be
38     * equal to serial cpumask of corresponding padata instance,
39     * so it is updated when padata notifies us about serial
40     * cpumask change.
41     *
42     * cb_cpumask is protected by RCU. This fact prevents us from
43     * using cpumask_var_t directly because the actual type of
44     * cpumsak_var_t depends on kernel configuration(particularly on
45     * CONFIG_CPUMASK_OFFSTACK macro). Depending on the configuration
46     * cpumask_var_t may be either a pointer to the struct cpumask
47     * or a variable allocated on the stack. Thus we can not safely use
48     * cpumask_var_t with RCU operations such as rcu_assign_pointer or
49     * rcu_dereference. So cpumask_var_t is wrapped with struct
50     * pcrypt_cpumask which makes possible to use it with RCU.
51     */
52    struct pcrypt_cpumask {
53        cpumask_var_t mask;
54    } *cb_cpumask;
55    struct notifier_block nblock;
56};
57
58static struct padata_pcrypt pencrypt;
59static struct padata_pcrypt pdecrypt;
60static struct kset *pcrypt_kset;
61
62struct pcrypt_instance_ctx {
63    struct crypto_spawn spawn;
64    unsigned int tfm_count;
65};
66
67struct pcrypt_aead_ctx {
68    struct crypto_aead *child;
69    unsigned int cb_cpu;
70};
71
72static int pcrypt_do_parallel(struct padata_priv *padata, unsigned int *cb_cpu,
73                  struct padata_pcrypt *pcrypt)
74{
75    unsigned int cpu_index, cpu, i;
76    struct pcrypt_cpumask *cpumask;
77
78    cpu = *cb_cpu;
79
80    rcu_read_lock_bh();
81    cpumask = rcu_dereference_bh(pcrypt->cb_cpumask);
82    if (cpumask_test_cpu(cpu, cpumask->mask))
83            goto out;
84
85    if (!cpumask_weight(cpumask->mask))
86            goto out;
87
88    cpu_index = cpu % cpumask_weight(cpumask->mask);
89
90    cpu = cpumask_first(cpumask->mask);
91    for (i = 0; i < cpu_index; i++)
92        cpu = cpumask_next(cpu, cpumask->mask);
93
94    *cb_cpu = cpu;
95
96out:
97    rcu_read_unlock_bh();
98    return padata_do_parallel(pcrypt->pinst, padata, cpu);
99}
100
101static int pcrypt_aead_setkey(struct crypto_aead *parent,
102                  const u8 *key, unsigned int keylen)
103{
104    struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
105
106    return crypto_aead_setkey(ctx->child, key, keylen);
107}
108
109static int pcrypt_aead_setauthsize(struct crypto_aead *parent,
110                   unsigned int authsize)
111{
112    struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
113
114    return crypto_aead_setauthsize(ctx->child, authsize);
115}
116
117static void pcrypt_aead_serial(struct padata_priv *padata)
118{
119    struct pcrypt_request *preq = pcrypt_padata_request(padata);
120    struct aead_request *req = pcrypt_request_ctx(preq);
121
122    aead_request_complete(req->base.data, padata->info);
123}
124
125static void pcrypt_aead_giv_serial(struct padata_priv *padata)
126{
127    struct pcrypt_request *preq = pcrypt_padata_request(padata);
128    struct aead_givcrypt_request *req = pcrypt_request_ctx(preq);
129
130    aead_request_complete(req->areq.base.data, padata->info);
131}
132
133static void pcrypt_aead_done(struct crypto_async_request *areq, int err)
134{
135    struct aead_request *req = areq->data;
136    struct pcrypt_request *preq = aead_request_ctx(req);
137    struct padata_priv *padata = pcrypt_request_padata(preq);
138
139    padata->info = err;
140    req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
141
142    padata_do_serial(padata);
143}
144
145static void pcrypt_aead_enc(struct padata_priv *padata)
146{
147    struct pcrypt_request *preq = pcrypt_padata_request(padata);
148    struct aead_request *req = pcrypt_request_ctx(preq);
149
150    padata->info = crypto_aead_encrypt(req);
151
152    if (padata->info == -EINPROGRESS)
153        return;
154
155    padata_do_serial(padata);
156}
157
158static int pcrypt_aead_encrypt(struct aead_request *req)
159{
160    int err;
161    struct pcrypt_request *preq = aead_request_ctx(req);
162    struct aead_request *creq = pcrypt_request_ctx(preq);
163    struct padata_priv *padata = pcrypt_request_padata(preq);
164    struct crypto_aead *aead = crypto_aead_reqtfm(req);
165    struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
166    u32 flags = aead_request_flags(req);
167
168    memset(padata, 0, sizeof(struct padata_priv));
169
170    padata->parallel = pcrypt_aead_enc;
171    padata->serial = pcrypt_aead_serial;
172
173    aead_request_set_tfm(creq, ctx->child);
174    aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
175                  pcrypt_aead_done, req);
176    aead_request_set_crypt(creq, req->src, req->dst,
177                   req->cryptlen, req->iv);
178    aead_request_set_assoc(creq, req->assoc, req->assoclen);
179
180    err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
181    if (!err)
182        return -EINPROGRESS;
183
184    return err;
185}
186
187static void pcrypt_aead_dec(struct padata_priv *padata)
188{
189    struct pcrypt_request *preq = pcrypt_padata_request(padata);
190    struct aead_request *req = pcrypt_request_ctx(preq);
191
192    padata->info = crypto_aead_decrypt(req);
193
194    if (padata->info == -EINPROGRESS)
195        return;
196
197    padata_do_serial(padata);
198}
199
200static int pcrypt_aead_decrypt(struct aead_request *req)
201{
202    int err;
203    struct pcrypt_request *preq = aead_request_ctx(req);
204    struct aead_request *creq = pcrypt_request_ctx(preq);
205    struct padata_priv *padata = pcrypt_request_padata(preq);
206    struct crypto_aead *aead = crypto_aead_reqtfm(req);
207    struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
208    u32 flags = aead_request_flags(req);
209
210    memset(padata, 0, sizeof(struct padata_priv));
211
212    padata->parallel = pcrypt_aead_dec;
213    padata->serial = pcrypt_aead_serial;
214
215    aead_request_set_tfm(creq, ctx->child);
216    aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
217                  pcrypt_aead_done, req);
218    aead_request_set_crypt(creq, req->src, req->dst,
219                   req->cryptlen, req->iv);
220    aead_request_set_assoc(creq, req->assoc, req->assoclen);
221
222    err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
223    if (!err)
224        return -EINPROGRESS;
225
226    return err;
227}
228
229static void pcrypt_aead_givenc(struct padata_priv *padata)
230{
231    struct pcrypt_request *preq = pcrypt_padata_request(padata);
232    struct aead_givcrypt_request *req = pcrypt_request_ctx(preq);
233
234    padata->info = crypto_aead_givencrypt(req);
235
236    if (padata->info == -EINPROGRESS)
237        return;
238
239    padata_do_serial(padata);
240}
241
242static int pcrypt_aead_givencrypt(struct aead_givcrypt_request *req)
243{
244    int err;
245    struct aead_request *areq = &req->areq;
246    struct pcrypt_request *preq = aead_request_ctx(areq);
247    struct aead_givcrypt_request *creq = pcrypt_request_ctx(preq);
248    struct padata_priv *padata = pcrypt_request_padata(preq);
249    struct crypto_aead *aead = aead_givcrypt_reqtfm(req);
250    struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
251    u32 flags = aead_request_flags(areq);
252
253    memset(padata, 0, sizeof(struct padata_priv));
254
255    padata->parallel = pcrypt_aead_givenc;
256    padata->serial = pcrypt_aead_giv_serial;
257
258    aead_givcrypt_set_tfm(creq, ctx->child);
259    aead_givcrypt_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
260                   pcrypt_aead_done, areq);
261    aead_givcrypt_set_crypt(creq, areq->src, areq->dst,
262                areq->cryptlen, areq->iv);
263    aead_givcrypt_set_assoc(creq, areq->assoc, areq->assoclen);
264    aead_givcrypt_set_giv(creq, req->giv, req->seq);
265
266    err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
267    if (!err)
268        return -EINPROGRESS;
269
270    return err;
271}
272
273static int pcrypt_aead_init_tfm(struct crypto_tfm *tfm)
274{
275    int cpu, cpu_index;
276    struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
277    struct pcrypt_instance_ctx *ictx = crypto_instance_ctx(inst);
278    struct pcrypt_aead_ctx *ctx = crypto_tfm_ctx(tfm);
279    struct crypto_aead *cipher;
280
281    ictx->tfm_count++;
282
283    cpu_index = ictx->tfm_count % cpumask_weight(cpu_online_mask);
284
285    ctx->cb_cpu = cpumask_first(cpu_online_mask);
286    for (cpu = 0; cpu < cpu_index; cpu++)
287        ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
288
289    cipher = crypto_spawn_aead(crypto_instance_ctx(inst));
290
291    if (IS_ERR(cipher))
292        return PTR_ERR(cipher);
293
294    ctx->child = cipher;
295    tfm->crt_aead.reqsize = sizeof(struct pcrypt_request)
296        + sizeof(struct aead_givcrypt_request)
297        + crypto_aead_reqsize(cipher);
298
299    return 0;
300}
301
302static void pcrypt_aead_exit_tfm(struct crypto_tfm *tfm)
303{
304    struct pcrypt_aead_ctx *ctx = crypto_tfm_ctx(tfm);
305
306    crypto_free_aead(ctx->child);
307}
308
309static struct crypto_instance *pcrypt_alloc_instance(struct crypto_alg *alg)
310{
311    struct crypto_instance *inst;
312    struct pcrypt_instance_ctx *ctx;
313    int err;
314
315    inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
316    if (!inst) {
317        inst = ERR_PTR(-ENOMEM);
318        goto out;
319    }
320
321    err = -ENAMETOOLONG;
322    if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
323             "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
324        goto out_free_inst;
325
326    memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
327
328    ctx = crypto_instance_ctx(inst);
329    err = crypto_init_spawn(&ctx->spawn, alg, inst,
330                CRYPTO_ALG_TYPE_MASK);
331    if (err)
332        goto out_free_inst;
333
334    inst->alg.cra_priority = alg->cra_priority + 100;
335    inst->alg.cra_blocksize = alg->cra_blocksize;
336    inst->alg.cra_alignmask = alg->cra_alignmask;
337
338out:
339    return inst;
340
341out_free_inst:
342    kfree(inst);
343    inst = ERR_PTR(err);
344    goto out;
345}
346
347static struct crypto_instance *pcrypt_alloc_aead(struct rtattr **tb,
348                         u32 type, u32 mask)
349{
350    struct crypto_instance *inst;
351    struct crypto_alg *alg;
352
353    alg = crypto_get_attr_alg(tb, type, (mask & CRYPTO_ALG_TYPE_MASK));
354    if (IS_ERR(alg))
355        return ERR_CAST(alg);
356
357    inst = pcrypt_alloc_instance(alg);
358    if (IS_ERR(inst))
359        goto out_put_alg;
360
361    inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
362    inst->alg.cra_type = &crypto_aead_type;
363
364    inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
365    inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
366    inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
367
368    inst->alg.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
369
370    inst->alg.cra_init = pcrypt_aead_init_tfm;
371    inst->alg.cra_exit = pcrypt_aead_exit_tfm;
372
373    inst->alg.cra_aead.setkey = pcrypt_aead_setkey;
374    inst->alg.cra_aead.setauthsize = pcrypt_aead_setauthsize;
375    inst->alg.cra_aead.encrypt = pcrypt_aead_encrypt;
376    inst->alg.cra_aead.decrypt = pcrypt_aead_decrypt;
377    inst->alg.cra_aead.givencrypt = pcrypt_aead_givencrypt;
378
379out_put_alg:
380    crypto_mod_put(alg);
381    return inst;
382}
383
384static struct crypto_instance *pcrypt_alloc(struct rtattr **tb)
385{
386    struct crypto_attr_type *algt;
387
388    algt = crypto_get_attr_type(tb);
389    if (IS_ERR(algt))
390        return ERR_CAST(algt);
391
392    switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
393    case CRYPTO_ALG_TYPE_AEAD:
394        return pcrypt_alloc_aead(tb, algt->type, algt->mask);
395    }
396
397    return ERR_PTR(-EINVAL);
398}
399
400static void pcrypt_free(struct crypto_instance *inst)
401{
402    struct pcrypt_instance_ctx *ctx = crypto_instance_ctx(inst);
403
404    crypto_drop_spawn(&ctx->spawn);
405    kfree(inst);
406}
407
408static int pcrypt_cpumask_change_notify(struct notifier_block *self,
409                    unsigned long val, void *data)
410{
411    struct padata_pcrypt *pcrypt;
412    struct pcrypt_cpumask *new_mask, *old_mask;
413    struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
414
415    if (!(val & PADATA_CPU_SERIAL))
416        return 0;
417
418    pcrypt = container_of(self, struct padata_pcrypt, nblock);
419    new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
420    if (!new_mask)
421        return -ENOMEM;
422    if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
423        kfree(new_mask);
424        return -ENOMEM;
425    }
426
427    old_mask = pcrypt->cb_cpumask;
428
429    cpumask_copy(new_mask->mask, cpumask->cbcpu);
430    rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
431    synchronize_rcu_bh();
432
433    free_cpumask_var(old_mask->mask);
434    kfree(old_mask);
435    return 0;
436}
437
438static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
439{
440    int ret;
441
442    pinst->kobj.kset = pcrypt_kset;
443    ret = kobject_add(&pinst->kobj, NULL, name);
444    if (!ret)
445        kobject_uevent(&pinst->kobj, KOBJ_ADD);
446
447    return ret;
448}
449
450static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
451                  const char *name)
452{
453    int ret = -ENOMEM;
454    struct pcrypt_cpumask *mask;
455
456    get_online_cpus();
457
458    pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
459                     1, name);
460    if (!pcrypt->wq)
461        goto err;
462
463    pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
464    if (!pcrypt->pinst)
465        goto err_destroy_workqueue;
466
467    mask = kmalloc(sizeof(*mask), GFP_KERNEL);
468    if (!mask)
469        goto err_free_padata;
470    if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
471        kfree(mask);
472        goto err_free_padata;
473    }
474
475    cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
476    rcu_assign_pointer(pcrypt->cb_cpumask, mask);
477
478    pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
479    ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
480    if (ret)
481        goto err_free_cpumask;
482
483    ret = pcrypt_sysfs_add(pcrypt->pinst, name);
484    if (ret)
485        goto err_unregister_notifier;
486
487    put_online_cpus();
488
489    return ret;
490
491err_unregister_notifier:
492    padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
493err_free_cpumask:
494    free_cpumask_var(mask->mask);
495    kfree(mask);
496err_free_padata:
497    padata_free(pcrypt->pinst);
498err_destroy_workqueue:
499    destroy_workqueue(pcrypt->wq);
500err:
501    put_online_cpus();
502
503    return ret;
504}
505
506static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
507{
508    free_cpumask_var(pcrypt->cb_cpumask->mask);
509    kfree(pcrypt->cb_cpumask);
510
511    padata_stop(pcrypt->pinst);
512    padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
513    destroy_workqueue(pcrypt->wq);
514    padata_free(pcrypt->pinst);
515}
516
517static struct crypto_template pcrypt_tmpl = {
518    .name = "pcrypt",
519    .alloc = pcrypt_alloc,
520    .free = pcrypt_free,
521    .module = THIS_MODULE,
522};
523
524static int __init pcrypt_init(void)
525{
526    int err = -ENOMEM;
527
528    pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
529    if (!pcrypt_kset)
530        goto err;
531
532    err = pcrypt_init_padata(&pencrypt, "pencrypt");
533    if (err)
534        goto err_unreg_kset;
535
536    err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
537    if (err)
538        goto err_deinit_pencrypt;
539
540    padata_start(pencrypt.pinst);
541    padata_start(pdecrypt.pinst);
542
543    return crypto_register_template(&pcrypt_tmpl);
544
545err_deinit_pencrypt:
546    pcrypt_fini_padata(&pencrypt);
547err_unreg_kset:
548    kset_unregister(pcrypt_kset);
549err:
550    return err;
551}
552
553static void __exit pcrypt_exit(void)
554{
555    pcrypt_fini_padata(&pencrypt);
556    pcrypt_fini_padata(&pdecrypt);
557
558    kset_unregister(pcrypt_kset);
559    crypto_unregister_template(&pcrypt_tmpl);
560}
561
562module_init(pcrypt_init);
563module_exit(pcrypt_exit);
564
565MODULE_LICENSE("GPL");
566MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
567MODULE_DESCRIPTION("Parallel crypto wrapper");
568

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