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 struct scomp_scratch {
  33         spinlock_t      lock;
  34         void            *src;
  35         void            *dst;
  36 };
  37
  38 static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
  39         .lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
  40 };
  41
  42 static const struct crypto_type crypto_scomp_type;
  43 static int scomp_scratch_users;
  44 static DEFINE_MUTEX(scomp_lock);
  45
  46 #ifdef CONFIG_NET
  47 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  48 {
  49         struct crypto_report_comp rscomp;
  50
  51         memset(&rscomp, 0, sizeof(rscomp));
  52
  53         strscpy(rscomp.type, "scomp", sizeof(rscomp.type));
  54
  55         return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
  56                        sizeof(rscomp), &rscomp);
  57 }
  58 #else
  59 static int crypto_scomp_report(struct sk_buff *skb, struct crypto_alg *alg)
  60 {
  61         return -ENOSYS;
  62 }
  63 #endif
  64
  65 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  66         __maybe_unused;
  67
  68 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
  69 {
  70         seq_puts(m, "type         : scomp\n");
  71 }
  72
  73 static void crypto_scomp_free_scratches(void)
  74 {
  75         struct scomp_scratch *scratch;
  76         int i;
  77
  78         for_each_possible_cpu(i) {
  79                 scratch = per_cpu_ptr(&scomp_scratch, i);
  80
  81                 vfree(scratch->src);
  82                 vfree(scratch->dst);
  83                 scratch->src = NULL;
  84                 scratch->dst = NULL;
  85         }
  86 }
  87
  88 static int crypto_scomp_alloc_scratches(void)
  89 {
  90         struct scomp_scratch *scratch;
  91         int i;
  92
  93         for_each_possible_cpu(i) {
  94                 void *mem;
  95
  96                 scratch = per_cpu_ptr(&scomp_scratch, i);
  97
  98                 mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
  99                 if (!mem)
 100                         goto error;
 101                 scratch->src = mem;
 102                 mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
 103                 if (!mem)
 104                         goto error;
 105                 scratch->dst = mem;
 106         }
 107         return 0;
 108 error:
 109         crypto_scomp_free_scratches();
 110         return -ENOMEM;
 111 }
 112
 113 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
 114 {
 115         int ret = 0;
 116
 117         mutex_lock(&scomp_lock);
 118         if (!scomp_scratch_users++)
 119                 ret = crypto_scomp_alloc_scratches();
 120         mutex_unlock(&scomp_lock);
 121
 122         return ret;
 123 }
 124
 125 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
 126 {
 127         struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
 128         void **tfm_ctx = acomp_tfm_ctx(tfm);
 129         struct crypto_scomp *scomp = *tfm_ctx;
 130         void **ctx = acomp_request_ctx(req);
 131         struct scomp_scratch *scratch;
 132         int ret;
 133
 134         if (!req->src || !req->slen || req->slen > SCOMP_SCRATCH_SIZE)
 135                 return -EINVAL;
 136
 137         if (req->dst && !req->dlen)
 138                 return -EINVAL;
 139
 140         if (!req->dlen || req->dlen > SCOMP_SCRATCH_SIZE)
 141                 req->dlen = SCOMP_SCRATCH_SIZE;
 142
 143         scratch = raw_cpu_ptr(&scomp_scratch);
 144         spin_lock(&scratch->lock);
 145
 146         scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0);
 147         if (dir)
 148                 ret = crypto_scomp_compress(scomp, scratch->src, req->slen,
 149                                             scratch->dst, &req->dlen, *ctx);
 150         else
 151                 ret = crypto_scomp_decompress(scomp, scratch->src, req->slen,
 152                                               scratch->dst, &req->dlen, *ctx);
 153         if (!ret) {
 154                 if (!req->dst) {
 155                         req->dst = sgl_alloc(req->dlen, GFP_ATOMIC, NULL);
 156                         if (!req->dst) {
 157                                 ret = -ENOMEM;
 158                                 goto out;
 159                         }
 160                 }
 161                 scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen,
 162                                          1);
 163         }
 164 out:
 165         spin_unlock(&scratch->lock);
 166         return ret;
 167 }
 168
 169 static int scomp_acomp_compress(struct acomp_req *req)
 170 {
 171         return scomp_acomp_comp_decomp(req, 1);
 172 }
 173
 174 static int scomp_acomp_decompress(struct acomp_req *req)
 175 {
 176         return scomp_acomp_comp_decomp(req, 0);
 177 }
 178
 179 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
 180 {
 181         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 182
 183         crypto_free_scomp(*ctx);
 184
 185         mutex_lock(&scomp_lock);
 186         if (!--scomp_scratch_users)
 187                 crypto_scomp_free_scratches();
 188         mutex_unlock(&scomp_lock);
 189 }
 190
 191 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
 192 {
 193         struct crypto_alg *calg = tfm->__crt_alg;
 194         struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
 195         struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
 196         struct crypto_scomp *scomp;
 197
 198         if (!crypto_mod_get(calg))
 199                 return -EAGAIN;
 200
 201         scomp = crypto_create_tfm(calg, &crypto_scomp_type);
 202         if (IS_ERR(scomp)) {
 203                 crypto_mod_put(calg);
 204                 return PTR_ERR(scomp);
 205         }
 206
 207         *ctx = scomp;
 208         tfm->exit = crypto_exit_scomp_ops_async;
 209
 210         crt->compress = scomp_acomp_compress;
 211         crt->decompress = scomp_acomp_decompress;
 212         crt->dst_free = sgl_free;
 213         crt->reqsize = sizeof(void *);
 214
 215         return 0;
 216 }
 217
 218 struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req)
 219 {
 220         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 221         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 222         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 223         struct crypto_scomp *scomp = *tfm_ctx;
 224         void *ctx;
 225
 226         ctx = crypto_scomp_alloc_ctx(scomp);
 227         if (IS_ERR(ctx)) {
 228                 kfree(req);
 229                 return NULL;
 230         }
 231
 232         *req->__ctx = ctx;
 233
 234         return req;
 235 }
 236
 237 void crypto_acomp_scomp_free_ctx(struct acomp_req *req)
 238 {
 239         struct crypto_acomp *acomp = crypto_acomp_reqtfm(req);
 240         struct crypto_tfm *tfm = crypto_acomp_tfm(acomp);
 241         struct crypto_scomp **tfm_ctx = crypto_tfm_ctx(tfm);
 242         struct crypto_scomp *scomp = *tfm_ctx;
 243         void *ctx = *req->__ctx;
 244
 245         if (ctx)
 246                 crypto_scomp_free_ctx(scomp, ctx);
 247 }
 248
 249 static const struct crypto_type crypto_scomp_type = {
 250         .extsize = crypto_alg_extsize,
 251         .init_tfm = crypto_scomp_init_tfm,
 252 #ifdef CONFIG_PROC_FS
 253         .show = crypto_scomp_show,
 254 #endif
 255         .report = crypto_scomp_report,
 256         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 257         .maskset = CRYPTO_ALG_TYPE_MASK,
 258         .type = CRYPTO_ALG_TYPE_SCOMPRESS,
 259         .tfmsize = offsetof(struct crypto_scomp, base),
 260 };
 261
 262 int crypto_register_scomp(struct scomp_alg *alg)
 263 {
 264         struct crypto_alg *base = &alg->base;
 265
 266         base->cra_type = &crypto_scomp_type;
 267         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 268         base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
 269
 270         return crypto_register_alg(base);
 271 }
 272 EXPORT_SYMBOL_GPL(crypto_register_scomp);
 273
 274 int crypto_unregister_scomp(struct scomp_alg *alg)
 275 {
 276         return crypto_unregister_alg(&alg->base);
 277 }
 278 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
 279
 280 int crypto_register_scomps(struct scomp_alg *algs, int count)
 281 {
 282         int i, ret;
 283
 284         for (i = 0; i < count; i++) {
 285                 ret = crypto_register_scomp(&algs[i]);
 286                 if (ret)
 287                         goto err;
 288         }
 289
 290         return 0;
 291
 292 err:
 293         for (--i; i >= 0; --i)
 294                 crypto_unregister_scomp(&algs[i]);
 295
 296         return ret;
 297 }
 298 EXPORT_SYMBOL_GPL(crypto_register_scomps);
 299
 300 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
 301 {
 302         int i;
 303
 304         for (i = count - 1; i >= 0; --i)
 305                 crypto_unregister_scomp(&algs[i]);
 306 }
 307 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
 308
 309 MODULE_LICENSE("GPL");
 310 MODULE_DESCRIPTION("Synchronous compression type");