| 1 | |
| 2 | |
| 3 | * Cryptographic API.
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| 4 | *
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| 5 | * Copyright (c) 2013 Chanho Min <[email protected]>
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| 6 |
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| 7 |
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| 8 | #include <linux/init.h>
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| 9 | #include <linux/module.h>
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| 10 | #include <linux/crypto.h>
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| 11 | #include <linux/vmalloc.h>
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| 12 | #include <linux/lz4.h>
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| 13 | #include <crypto/internal/scompress.h>
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| 14 |
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| 15 | static void *lz4_alloc_ctx(void)
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| 16 | {
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| 17 | void *ctx;
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| 18 |
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| 19 | ctx = vmalloc(LZ4_MEM_COMPRESS);
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| 20 | if (!ctx)
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| 21 | return ERR_PTR(-ENOMEM);
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| 22 |
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| 23 | return ctx;
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| 24 | }
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| 25 |
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| 26 | static void lz4_free_ctx(void *ctx)
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| 27 | {
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| 28 | vfree(ctx);
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| 29 | }
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| 30 |
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| 31 | static int __lz4_compress_crypto(const u8 *src, unsigned int slen,
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| 32 | u8 *dst, unsigned int *dlen, void *ctx)
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| 33 | {
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| 34 | int out_len = LZ4_compress_default(src, dst,
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| 35 | slen, *dlen, ctx);
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| 36 |
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| 37 | if (!out_len)
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| 38 | return -EINVAL;
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| 39 |
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| 40 | *dlen = out_len;
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| 41 | return 0;
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| 42 | }
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| 43 |
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| 44 | static int lz4_scompress(struct crypto_scomp *tfm, const u8 *src,
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| 45 | unsigned int slen, u8 *dst, unsigned int *dlen,
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| 46 | void *ctx)
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| 47 | {
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| 48 | return __lz4_compress_crypto(src, slen, dst, dlen, ctx);
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| 49 | }
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| 50 |
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| 51 | static int __lz4_decompress_crypto(const u8 *src, unsigned int slen,
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| 52 | u8 *dst, unsigned int *dlen, void *ctx)
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| 53 | {
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| 54 | int out_len = LZ4_decompress_safe(src, dst, slen, *dlen);
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| 55 |
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| 56 | if (out_len < 0)
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| 57 | return -EINVAL;
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| 58 |
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| 59 | *dlen = out_len;
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| 60 | return 0;
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| 61 | }
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| 62 |
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| 63 | static int lz4_sdecompress(struct crypto_scomp *tfm, const u8 *src,
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| 64 | unsigned int slen, u8 *dst, unsigned int *dlen,
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| 65 | void *ctx)
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| 66 | {
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| 67 | return __lz4_decompress_crypto(src, slen, dst, dlen, NULL);
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| 68 | }
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| 69 |
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| 70 | static struct scomp_alg scomp = {
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| 71 | .streams = {
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| 72 | .alloc_ctx = lz4_alloc_ctx,
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| 73 | .free_ctx = lz4_free_ctx,
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| 74 | },
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| 75 | .compress = lz4_scompress,
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| 76 | .decompress = lz4_sdecompress,
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| 77 | .base = {
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| 78 | .cra_name = "lz4",
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| 79 | .cra_driver_name = "lz4-scomp",
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| 80 | .cra_module = THIS_MODULE,
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| 81 | }
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| 82 | };
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| 83 |
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| 84 | static int __init lz4_mod_init(void)
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| 85 | {
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| 86 | return crypto_register_scomp(&scomp);
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| 87 | }
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| 88 |
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| 89 | static void __exit lz4_mod_fini(void)
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| 90 | {
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| 91 | crypto_unregister_scomp(&scomp);
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| 92 | }
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| 93 |
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| 94 | module_init(lz4_mod_init);
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| 95 | module_exit(lz4_mod_fini);
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| 96 |
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| 97 | MODULE_LICENSE("GPL");
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| 98 | MODULE_DESCRIPTION("LZ4 Compression Algorithm");
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| 99 | MODULE_ALIAS_CRYPTO("lz4");
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