crypto/scompress.c

   1 /*
   2  * Synchronous Compression operations
   3  *
   4  * Copyright 2015 LG Electronics Inc.
   5  * Copyright (c) 2016, Intel Corporation
   6  * Author: Giovanni Cabiddu <[email protected]>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/slab.h>
  19 #include <linux/string.h>
  20 #include <linux/crypto.h>
  21 #include <linux/compiler.h>
  22 #include <linux/vmalloc.h>
  23 #include <crypto/algapi.h>
  24 #include <linux/cryptouser.h>
  25 #include <net/netlink.h>
  26 #include <linux/scatterlist.h>
  27 #include <crypto/scatterwalk.h>
  28 #include <crypto/internal/acompress.h>
  29 #include <crypto/internal/scompress.h>
  30 #include "internal.h"
  31
  32 static const struct crypto_type crypto_scomp_type;
  33 static void * __percpu *scomp_src_scratches;
  34 static void * __percpu *scomp_dst_scratches;
  35 static int scomp_scratch_users;
  36 static DEFINE_MUTEX(scomp_lock);
  37
  38 #ifdef CONFIG_NET
  39 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  40 {
  41         struct crypto_report_comp rscomp;
  42
  43         memset(&rscomp, 0, sizeof(rscomp));
  44
  45         strscpy(rscomp.type, "scomp", sizeof(rscomp.type));
  46
  47         return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
  48                        sizeof(rscomp), &rscomp);
  49 }
  50 #else
  51 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  52 {
  53         return -ENOSYS;
  54 }
  55 #endif
  56
  57 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  58         __maybe_unused;
  59
  60 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  61 {
  62         seq_puts(m, "type         : scomp\n");
  63 }
  64
  65 static void crypto_scomp_free_scratches(void * __percpu *scratches)
  66 {
  67         int i;
  68
  69         if (!scratches)
  70                 return;
  71
  72         for_each_possible_cpu(i)
  73                 vfree(*per_cpu_ptr(scratches, i));
  74
  75         free_percpu(scratches);
  76 }
  77
  78 static void * __percpu *crypto_scomp_alloc_scratches(void)
  79 {
  80         void * __percpu *scratches;
  81         int i;
  82
  83         scratches = alloc_percpu(void *);
  84         if (!scratches)
  85                 return NULL;
  86
  87         for_each_possible_cpu(i) {
  88                 void *scratch;
  89
  90                 scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  91                 if (!scratch)
  92                         goto error;
  93                 *per_cpu_ptr(scratches, i) = scratch;
  94         }
  95
  96         return scratches;
  97
  98 error:
  99         crypto_scomp_free_scratches(scratches);
 100         return NULL;
 101 }
 102
 103 static void crypto_scomp_free_all_scratches(void)
 104 {
 105         if (!--scomp_scratch_users) {
 106                 crypto_scomp_free_scratches(scomp_src_scratches);
 107                 crypto_scomp_free_scratches(scomp_dst_scratches);
 108                 scomp_src_scratches = NULL;
 109                 scomp_dst_scratches = NULL;
 110         }
 111 }
 112
 113 static int crypto_scomp_alloc_all_scratches(void)
 114 {
 115         if (!scomp_scratch_users++) {
 116                 scomp_src_scratches = crypto_scomp_alloc_scratches();
 117                 if (!scomp_src_scratches)
 118                         return -ENOMEM;
 119                 scomp_dst_scratches = crypto_scomp_alloc_scratches();
 120                 if (!scomp_dst_scratches) {
 121                         crypto_scomp_free_scratches(scomp_src_scratches);
 122                         scomp_src_scratches = NULL;
 123                         return -ENOMEM;
 124                 }
 125         }
 126         return 0;
 127 }
 128
 129 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
 130 {
 131         int ret;
 132
 133         mutex_lock(&scomp_lock);
 134         ret = crypto_scomp_alloc_all_scratches();
 135         mutex_unlock(&scomp_lock);
 136
 137         return ret;
 138 }
 139
 140 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 141 {
 142         struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 143         void **tfm_ctx = acomp_tfm_ctx(tfm);
 144         struct crypto_scomp *scomp = *tfm_ctx;
 145         void **ctx = acomp_request_ctx(req);
 146         const int cpu = get_cpu();
 147         u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
 148         u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
 149         int ret;
 150
 151         if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
 152                 ret = -EINVAL;
 153                 goto out;
 154         }
 155
 156         if (req->dst && !req->dlen) {
 157                 ret = -EINVAL;
 158                 goto out;
 159         }
 160
 161         if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
 162                 req->dlen = SCOMP_SCRATCH_SIZE;
 163
 164         scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
 165         if (dir)
 166                 ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
 167                                             scratch_dst, &req->dlen, *ctx);
 168         else
 169                 ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
 170                                               scratch_dst, &req->dlen, *ctx);
 171         if (!ret) {
 172                 if (!req->dst) {
 173                         req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
 174                         if (!req->dst)
 175                                 goto out;
 176                 }
 177                 scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
 178                                          1);
 179         }
 180 out:
 181         put_cpu();
 182         return ret;
 183 }
 184
 185 static int scomp_acomp_compress(struct acomp_req *req)
 186 {
 187         return scomp_acomp_comp_decomp(req, 1);
 188 }
 189
 190 static int scomp_acomp_decompress(struct acomp_req *req)
 191 {
 192         return scomp_acomp_comp_decomp(req, 0);
 193 }
 194
 195 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
 196 {
 197         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 198
 199         crypto_free_scomp(*ctx);
 200
 201         mutex_lock(&scomp_lock);
 202         crypto_scomp_free_all_scratches();
 203         mutex_unlock(&scomp_lock);
 204 }
 205
 206 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
 207 {
 208         struct crypto_alg *calg = tfm->__crt_alg;
 209         struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
 210         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 211         struct crypto_scomp *scomp;
 212
 213         if (!crypto_mod_get(calg))
 214                 return -EAGAIN;
 215
 216         scomp = crypto_create_tfm(calg, &crypto_scomp_type);
 217         if (IS_ERR(scomp)) {
 218                 crypto_mod_put(calg);
 219                 return PTR_ERR(scomp);
 220         }
 221
 222         *ctx = scomp;
 223         tfm->exit = crypto_exit_scomp_ops_async;
 224
 225         crt->compress = scomp_acomp_compress;
 226         crt->decompress = scomp_acomp_decompress;
 227         crt->dst_free = sgl_free;
 228         crt->reqsize = sizeof(void *);
 229
 230         return 0;
 231 }
 232
 233 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
 234 {
 235         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 236         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 237         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 238         struct crypto_scomp *scomp = *tfm_ctx;
 239         void *ctx;
 240
 241         ctx = crypto_scomp_alloc_ctx(scomp);
 242         if (IS_ERR(ctx)) {
 243                 kfree(req);
 244                 return NULL;
 245         }
 246
 247         *req->__ctx = ctx;
 248
 249         return req;
 250 }
 251
 252 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
 253 {
 254         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 255         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 256         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 257         struct crypto_scomp *scomp = *tfm_ctx;
 258         void *ctx = *req->__ctx;
 259
 260         if (ctx)
 261                 crypto_scomp_free_ctx(scomp, ctx);
 262 }
 263
 264 static const struct crypto_type crypto_scomp_type = {
 265         .extsize = crypto_alg_extsize,
 266         .init_tfm = crypto_scomp_init_tfm,
 267 #ifdef CONFIG_PROC_FS
 268         .show = crypto_scomp_show,
 269 #endif
 270         .report = crypto_scomp_report,
 271         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 272         .maskset = CRYPTO_ALG_TYPE_MASK,
 273         .type = CRYPTO_ALG_TYPE_SCOMPRESS,
 274         .tfmsize = offsetof(struct crypto_scomp, base),
 275 };
 276
 277 int crypto_register_scomp(struct scomp_alg *alg)
 278 {
 279         struct crypto_alg *base = &alg->base;
 280
 281         base->cra_type = &crypto_scomp_type;
 282         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 283         base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
 284
 285         return crypto_register_alg(base);
 286 }
 287 EXPORT_SYMBOL_GPL(crypto_register_scomp);
 288
 289 int crypto_unregister_scomp(struct scomp_alg *alg)
 290 {
 291         return crypto_unregister_alg(&alg->base);
 292 }
 293 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
 294
 295 int crypto_register_scomps(struct scomp_alg *algs, int count)
 296 {
 297         int i, ret;
 298
 299         for (i = 0; i < count; i++) {
 300                 ret = crypto_register_scomp(&algs[i]);
 301                 if (ret)
 302                         goto err;
 303         }
 304
 305         return 0;
 306
 307 err:
 308         for (--i; i >= 0; --i)
 309                 crypto_unregister_scomp(&algs[i]);
 310
 311         return ret;
 312 }
 313 EXPORT_SYMBOL_GPL(crypto_register_scomps);
 314
 315 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
 316 {
 317         int i;
 318
 319         for (i = count - 1; i >= 0; --i)
 320                 crypto_unregister_scomp(&algs[i]);
 321 }
 322 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
 323
 324 MODULE_LICENSE("GPL");
 325 MODULE_DESCRIPTION("Synchronous compression type");