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 <giovanni.cabiddu@intel.com>
   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         strncpy(rscomp.type, "scomp", sizeof(rscomp.type));
  44
  45         if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
  46                     sizeof(struct crypto_report_comp), &rscomp))
  47                 goto nla_put_failure;
  48         return 0;
  49
  50 nla_put_failure:
  51         return -EMSGSIZE;
  52 }
  53 #else
  54 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  55 {
  56         return -ENOSYS;
  57 }
  58 #endif
  59
  60 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  61         __maybe_unused;
  62
  63 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  64 {
  65         seq_puts(m, "type         : scomp\n");
  66 }
  67
  68 static void crypto_scomp_free_scratches(void * __percpu *scratches)
  69 {
  70         int i;
  71
  72         if (!scratches)
  73                 return;
  74
  75         for_each_possible_cpu(i)
  76                 vfree(*per_cpu_ptr(scratches, i));
  77
  78         free_percpu(scratches);
  79 }
  80
  81 static void * __percpu *crypto_scomp_alloc_scratches(void)
  82 {
  83         void * __percpu *scratches;
  84         int i;
  85
  86         scratches = alloc_percpu(void *);
  87         if (!scratches)
  88                 return NULL;
  89
  90         for_each_possible_cpu(i) {
  91                 void *scratch;
  92
  93                 scratch = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  94                 if (!scratch)
  95                         goto error;
  96                 *per_cpu_ptr(scratches, i) = scratch;
  97         }
  98
  99         return scratches;
 100
 101 error:
 102         crypto_scomp_free_scratches(scratches);
 103         return NULL;
 104 }
 105
 106 static void crypto_scomp_free_all_scratches(void)
 107 {
 108         if (!--scomp_scratch_users) {
 109                 crypto_scomp_free_scratches(scomp_src_scratches);
 110                 crypto_scomp_free_scratches(scomp_dst_scratches);
 111                 scomp_src_scratches = NULL;
 112                 scomp_dst_scratches = NULL;
 113         }
 114 }
 115
 116 static int crypto_scomp_alloc_all_scratches(void)
 117 {
 118         if (!scomp_scratch_users++) {
 119                 scomp_src_scratches = crypto_scomp_alloc_scratches();
 120                 if (!scomp_src_scratches)
 121                         return -ENOMEM;
 122                 scomp_dst_scratches = crypto_scomp_alloc_scratches();
 123                 if (!scomp_dst_scratches) {
 124                         crypto_scomp_free_scratches(scomp_src_scratches);
 125                         scomp_src_scratches = NULL;
 126                         return -ENOMEM;
 127                 }
 128         }
 129         return 0;
 130 }
 131
 132 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
 133 {
 134         int ret;
 135
 136         mutex_lock(&scomp_lock);
 137         ret = crypto_scomp_alloc_all_scratches();
 138         mutex_unlock(&scomp_lock);
 139
 140         return ret;
 141 }
 142
 143 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 144 {
 145         struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 146         void **tfm_ctx = acomp_tfm_ctx(tfm);
 147         struct crypto_scomp *scomp = *tfm_ctx;
 148         void **ctx = acomp_request_ctx(req);
 149         const int cpu = get_cpu();
 150         u8 *scratch_src = *per_cpu_ptr(scomp_src_scratches, cpu);
 151         u8 *scratch_dst = *per_cpu_ptr(scomp_dst_scratches, cpu);
 152         int ret;
 153
 154         if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE) {
 155                 ret = -EINVAL;
 156                 goto out;
 157         }
 158
 159         if (req->dst && !req->dlen) {
 160                 ret = -EINVAL;
 161                 goto out;
 162         }
 163
 164         if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
 165                 req->dlen = SCOMP_SCRATCH_SIZE;
 166
 167         scatterwalk_map_and_copy(scratch_src, req->src, 0, req->slen, 0);
 168         if (dir)
 169                 ret = crypto_scomp_compress(scomp, scratch_src, req->slen,
 170                                             scratch_dst, &req->dlen, *ctx);
 171         else
 172                 ret = crypto_scomp_decompress(scomp, scratch_src, req->slen,
 173                                               scratch_dst, &req->dlen, *ctx);
 174         if (!ret) {
 175                 if (!req->dst) {
 176                         req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
 177                         if (!req->dst)
 178                                 goto out;
 179                 }
 180                 scatterwalk_map_and_copy(scratch_dst, req->dst, 0, req->dlen,
 181                                          1);
 182         }
 183 out:
 184         put_cpu();
 185         return ret;
 186 }
 187
 188 static int scomp_acomp_compress(struct acomp_req *req)
 189 {
 190         return scomp_acomp_comp_decomp(req, 1);
 191 }
 192
 193 static int scomp_acomp_decompress(struct acomp_req *req)
 194 {
 195         return scomp_acomp_comp_decomp(req, 0);
 196 }
 197
 198 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
 199 {
 200         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 201
 202         crypto_free_scomp(*ctx);
 203
 204         mutex_lock(&scomp_lock);
 205         crypto_scomp_free_all_scratches();
 206         mutex_unlock(&scomp_lock);
 207 }
 208
 209 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
 210 {
 211         struct crypto_alg *calg = tfm->__crt_alg;
 212         struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
 213         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 214         struct crypto_scomp *scomp;
 215
 216         if (!crypto_mod_get(calg))
 217                 return -EAGAIN;
 218
 219         scomp = crypto_create_tfm(calg, &crypto_scomp_type);
 220         if (IS_ERR(scomp)) {
 221                 crypto_mod_put(calg);
 222                 return PTR_ERR(scomp);
 223         }
 224
 225         *ctx = scomp;
 226         tfm->exit = crypto_exit_scomp_ops_async;
 227
 228         crt->compress = scomp_acomp_compress;
 229         crt->decompress = scomp_acomp_decompress;
 230         crt->dst_free = sgl_free;
 231         crt->reqsize = sizeof(void *);
 232
 233         return 0;
 234 }
 235
 236 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
 237 {
 238         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 239         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 240         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 241         struct crypto_scomp *scomp = *tfm_ctx;
 242         void *ctx;
 243
 244         ctx = crypto_scomp_alloc_ctx(scomp);
 245         if (IS_ERR(ctx)) {
 246                 kfree(req);
 247                 return NULL;
 248         }
 249
 250         *req->__ctx = ctx;
 251
 252         return req;
 253 }
 254
 255 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
 256 {
 257         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 258         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 259         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 260         struct crypto_scomp *scomp = *tfm_ctx;
 261         void *ctx = *req->__ctx;
 262
 263         if (ctx)
 264                 crypto_scomp_free_ctx(scomp, ctx);
 265 }
 266
 267 static const struct crypto_type crypto_scomp_type = {
 268         .extsize = crypto_alg_extsize,
 269         .init_tfm = crypto_scomp_init_tfm,
 270 #ifdef CONFIG_PROC_FS
 271         .show = crypto_scomp_show,
 272 #endif
 273         .report = crypto_scomp_report,
 274         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 275         .maskset = CRYPTO_ALG_TYPE_MASK,
 276         .type = CRYPTO_ALG_TYPE_SCOMPRESS,
 277         .tfmsize = offsetof(struct crypto_scomp, base),
 278 };
 279
 280 int crypto_register_scomp(struct scomp_alg *alg)
 281 {
 282         struct crypto_alg *base = &alg->base;
 283
 284         base->cra_type = &crypto_scomp_type;
 285         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 286         base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
 287
 288         return crypto_register_alg(base);
 289 }
 290 EXPORT_SYMBOL_GPL(crypto_register_scomp);
 291
 292 int crypto_unregister_scomp(struct scomp_alg *alg)
 293 {
 294         return crypto_unregister_alg(&alg->base);
 295 }
 296 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
 297
 298 int crypto_register_scomps(struct scomp_alg *algs, int count)
 299 {
 300         int i, ret;
 301
 302         for (i = 0; i < count; i++) {
 303                 ret = crypto_register_scomp(&algs[i]);
 304                 if (ret)
 305                         goto err;
 306         }
 307
 308         return 0;
 309
 310 err:
 311         for (--i; i >= 0; --i)
 312                 crypto_unregister_scomp(&algs[i]);
 313
 314         return ret;
 315 }
 316 EXPORT_SYMBOL_GPL(crypto_register_scomps);
 317
 318 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
 319 {
 320         int i;
 321
 322         for (i = count - 1; i >= 0; --i)
 323                 crypto_unregister_scomp(&algs[i]);
 324 }
 325 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
 326
 327 MODULE_LICENSE("GPL");
 328 MODULE_DESCRIPTION("Synchronous compression type");