From 020b02154d79e1e01f846da7a6beab59fd7c7840 Mon Sep 17 00:00:00 2001 From: Andreas Dilger Date: Sat, 26 Mar 2016 15:40:46 -0400 Subject: staging: lustre: libcfs: add documentation for cfs_crypto_hash_*() Add comment blocks for cfs_crypto_hash_*() in linux-crypto.c and libcfs_crypto.h. Delete obsolete comment about shash handling in cfs_crypto_hash_alloc(). Signed-off-by: Andreas Dilger Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5053 Reviewed-on: http://review.whamcloud.com/9990 Reviewed-by: Bob Glossman Reviewed-by: James Simmons Reviewed-by: Oleg Drokin Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs_crypto.h b/drivers/staging/lustre/include/linux/libcfs/libcfs_crypto.h index e866369..5182416 100644 --- a/drivers/staging/lustre/include/linux/libcfs/libcfs_crypto.h +++ b/drivers/staging/lustre/include/linux/libcfs/libcfs_crypto.h @@ -61,7 +61,14 @@ static struct cfs_crypto_hash_type hash_types[] = { [CFS_HASH_ALG_SHA512] = { "sha512", 0, 64 }, }; -/** Return pointer to type of hash for valid hash algorithm identifier */ +/** + * Return hash algorithm information for the specified algorithm identifier + * + * Hash information includes algorithm name, initial seed, hash size. + * + * \retval cfs_crypto_hash_type for valid ID (CFS_HASH_ALG_*) + * \retval NULL for unknown algorithm identifier + */ static inline const struct cfs_crypto_hash_type * cfs_crypto_hash_type(unsigned char hash_alg) { @@ -75,7 +82,14 @@ static inline const struct cfs_crypto_hash_type * return NULL; } -/** Return hash name for valid hash algorithm identifier or "unknown" */ +/** + * Return hash name for hash algorithm identifier + * + * \param[in] hash_alg hash alrgorithm id (CFS_HASH_ALG_*) + * + * \retval string name of known hash algorithm + * \retval "unknown" if hash algorithm is unknown + */ static inline const char *cfs_crypto_hash_name(unsigned char hash_alg) { const struct cfs_crypto_hash_type *ht; @@ -86,7 +100,14 @@ static inline const char *cfs_crypto_hash_name(unsigned char hash_alg) return "unknown"; } -/** Return digest size for valid algorithm identifier or 0 */ +/** + * Return digest size for hash algorithm type + * + * \param[in] hash_alg hash alrgorithm id (CFS_HASH_ALG_*) + * + * \retval hash algorithm digest size in bytes + * \retval 0 if hash algorithm type is unknown + */ static inline int cfs_crypto_hash_digestsize(unsigned char hash_alg) { const struct cfs_crypto_hash_type *ht; @@ -97,7 +118,12 @@ static inline int cfs_crypto_hash_digestsize(unsigned char hash_alg) return 0; } -/** Return hash identifier for valid hash algorithm name or 0xFF */ +/** + * Find hash algorithm ID for the specified algorithm name + * + * \retval hash algorithm ID for valid ID (CFS_HASH_ALG_*) + * \retval CFS_HASH_ALG_UNKNOWN for unknown algorithm name + */ static inline unsigned char cfs_crypto_hash_alg(const char *algname) { unsigned char i; @@ -108,24 +134,6 @@ static inline unsigned char cfs_crypto_hash_alg(const char *algname) return (i == CFS_HASH_ALG_MAX ? 0xFF : i); } -/** Calculate hash digest for buffer. - * @param alg id of hash algorithm - * @param buf buffer of data - * @param buf_len buffer len - * @param key initial value for algorithm, if it is NULL, - * default initial value should be used. - * @param key_len len of initial value - * @param hash [out] pointer to hash, if it is NULL, hash_len is - * set to valid digest size in bytes, retval -ENOSPC. - * @param hash_len [in,out] size of hash buffer - * @returns status of operation - * @retval -EINVAL if buf, buf_len, hash_len or alg_id is invalid - * @retval -ENODEV if this algorithm is unsupported - * @retval -ENOSPC if pointer to hash is NULL, or hash_len less than - * digest size - * @retval 0 for success - * @retval < 0 other errors from lower layers. - */ int cfs_crypto_hash_digest(unsigned char alg, const void *buf, unsigned int buf_len, unsigned char *key, unsigned int key_len, @@ -134,66 +142,17 @@ int cfs_crypto_hash_digest(unsigned char alg, /* cfs crypto hash descriptor */ struct cfs_crypto_hash_desc; -/** Allocate and initialize descriptor for hash algorithm. - * @param alg algorithm id - * @param key initial value for algorithm, if it is NULL, - * default initial value should be used. - * @param key_len len of initial value - * @returns pointer to descriptor of hash instance - * @retval ERR_PTR(error) when errors occurred. - */ struct cfs_crypto_hash_desc* cfs_crypto_hash_init(unsigned char alg, unsigned char *key, unsigned int key_len); - -/** Update digest by part of data. - * @param desc hash descriptor - * @param page data page - * @param offset data offset - * @param len data len - * @returns status of operation - * @retval 0 for success. - */ int cfs_crypto_hash_update_page(struct cfs_crypto_hash_desc *desc, struct page *page, unsigned int offset, unsigned int len); - -/** Update digest by part of data. - * @param desc hash descriptor - * @param buf pointer to data buffer - * @param buf_len size of data at buffer - * @returns status of operation - * @retval 0 for success. - */ int cfs_crypto_hash_update(struct cfs_crypto_hash_desc *desc, const void *buf, unsigned int buf_len); - -/** Finalize hash calculation, copy hash digest to buffer, destroy hash - * descriptor. - * @param desc hash descriptor - * @param hash buffer pointer to store hash digest - * @param hash_len pointer to hash buffer size, if NULL - * destroy hash descriptor - * @returns status of operation - * @retval -ENOSPC if hash is NULL, or *hash_len less than - * digest size - * @retval 0 for success - * @retval < 0 other errors from lower layers. - */ int cfs_crypto_hash_final(struct cfs_crypto_hash_desc *desc, unsigned char *hash, unsigned int *hash_len); -/** - * Register crypto hash algorithms - */ int cfs_crypto_register(void); - -/** - * Unregister - */ void cfs_crypto_unregister(void); - -/** Return hash speed in Mbytes per second for valid hash algorithm - * identifier. If test was unsuccessful -1 would be returned. - */ int cfs_crypto_hash_speed(unsigned char hash_alg); #endif diff --git a/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto.c b/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto.c index d4cb260..8960c3a 100644 --- a/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto.c +++ b/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto.c @@ -32,11 +32,31 @@ #include "../../../include/linux/libcfs/libcfs.h" #include "../../../include/linux/libcfs/libcfs_crypto.h" #include "linux-crypto.h" + /** - * Array of hash algorithm speed in MByte per second + * Array of hash algorithm speed in MByte per second */ static int cfs_crypto_hash_speeds[CFS_HASH_ALG_MAX]; +/** + * Initialize the state descriptor for the specified hash algorithm. + * + * An internal routine to allocate the hash-specific state in \a hdesc for + * use with cfs_crypto_hash_digest() to compute the hash of a single message, + * though possibly in multiple chunks. The descriptor internal state should + * be freed with cfs_crypto_hash_final(). + * + * \param[in] hash_alg hash algorithm id (CFS_HASH_ALG_*) + * \param[out] type pointer to the hash description in hash_types[] + * array + * \param[in,out] hdesc hash state descriptor to be initialized + * \param[in] key initial hash value/state, NULL to use default + * value + * \param[in] key_len length of \a key + * + * \retval 0 on success + * \retval negative errno on failure + */ static int cfs_crypto_hash_alloc(unsigned char alg_id, const struct cfs_crypto_hash_type **type, struct ahash_request **req, @@ -71,12 +91,6 @@ static int cfs_crypto_hash_alloc(unsigned char alg_id, ahash_request_set_callback(*req, 0, NULL, NULL); - /** Shash have different logic for initialization then digest - * shash: crypto_hash_setkey, crypto_hash_init - * digest: crypto_digest_init, crypto_digest_setkey - * Skip this function for digest, because we use shash logic at - * cfs_crypto_hash_alloc. - */ if (key) err = crypto_ahash_setkey(tfm, key, key_len); else if ((*type)->cht_key != 0) @@ -101,6 +115,32 @@ static int cfs_crypto_hash_alloc(unsigned char alg_id, return err; } +/** + * Calculate hash digest for the passed buffer. + * + * This should be used when computing the hash on a single contiguous buffer. + * It combines the hash initialization, computation, and cleanup. + * + * \param[in] hash_alg id of hash algorithm (CFS_HASH_ALG_*) + * \param[in] buf data buffer on which to compute hash + * \param[in] buf_len length of \a buf in bytes + * \param[in] key initial value/state for algorithm, + * if \a key = NULL use default initial value + * \param[in] key_len length of \a key in bytes + * \param[out] hash pointer to computed hash value, + * if \a hash = NULL then \a hash_len is to digest + * size in bytes, retval -ENOSPC + * \param[in,out] hash_len size of \a hash buffer + * + * \retval -EINVAL \a buf, \a buf_len, \a hash_len, + * \a alg_id invalid + * \retval -ENOENT \a hash_alg is unsupported + * \retval -ENOSPC \a hash is NULL, or \a hash_len less than + * digest size + * \retval 0 for success + * \retval negative errno for other errors from lower + * layers. + */ int cfs_crypto_hash_digest(unsigned char alg_id, const void *buf, unsigned int buf_len, unsigned char *key, unsigned int key_len, @@ -135,6 +175,23 @@ int cfs_crypto_hash_digest(unsigned char alg_id, } EXPORT_SYMBOL(cfs_crypto_hash_digest); +/** + * Allocate and initialize desriptor for hash algorithm. + * + * This should be used to initialize a hash descriptor for multiple calls + * to a single hash function when computing the hash across multiple + * separate buffers or pages using cfs_crypto_hash_update{,_page}(). + * + * The hash descriptor should be freed with cfs_crypto_hash_final(). + * + * \param[in] hash_alg algorithm id (CFS_HASH_ALG_*) + * \param[in] key initial value/state for algorithm, if \a key = NULL + * use default initial value + * \param[in] key_len length of \a key in bytes + * + * \retval pointer to descriptor of hash instance + * \retval ERR_PTR(errno) in case of error + */ struct cfs_crypto_hash_desc * cfs_crypto_hash_init(unsigned char alg_id, unsigned char *key, unsigned int key_len) @@ -151,6 +208,17 @@ struct cfs_crypto_hash_desc * } EXPORT_SYMBOL(cfs_crypto_hash_init); +/** + * Update hash digest computed on data within the given \a page + * + * \param[in] hdesc hash state descriptor + * \param[in] page data page on which to compute the hash + * \param[in] offset offset within \a page at which to start hash + * \param[in] len length of data on which to compute hash + * + * \retval 0 for success + * \retval negative errno on failure + */ int cfs_crypto_hash_update_page(struct cfs_crypto_hash_desc *hdesc, struct page *page, unsigned int offset, unsigned int len) @@ -166,6 +234,16 @@ int cfs_crypto_hash_update_page(struct cfs_crypto_hash_desc *hdesc, } EXPORT_SYMBOL(cfs_crypto_hash_update_page); +/** + * Update hash digest computed on the specified data + * + * \param[in] hdesc hash state descriptor + * \param[in] buf data buffer on which to compute the hash + * \param[in] buf_len length of \buf on which to compute hash + * + * \retval 0 for success + * \retval negative errno on failure + */ int cfs_crypto_hash_update(struct cfs_crypto_hash_desc *hdesc, const void *buf, unsigned int buf_len) { @@ -179,7 +257,18 @@ int cfs_crypto_hash_update(struct cfs_crypto_hash_desc *hdesc, } EXPORT_SYMBOL(cfs_crypto_hash_update); -/* If hash_len pointer is NULL - destroy descriptor. */ +/** + * Finish hash calculation, copy hash digest to buffer, clean up hash descriptor + * + * \param[in] hdesc hash descriptor + * \param[out] hash pointer to hash buffer to store hash digest + * \param[in,out] hash_len pointer to hash buffer size, if \a hdesc = NULL + * only free \a hdesc instead of computing the hash + * + * \retval -ENOSPC if \a hash = NULL, or \a hash_len < digest size + * \retval 0 for success + * \retval negative errno for other errors from lower layers + */ int cfs_crypto_hash_final(struct cfs_crypto_hash_desc *hdesc, unsigned char *hash, unsigned int *hash_len) { @@ -209,6 +298,17 @@ int cfs_crypto_hash_final(struct cfs_crypto_hash_desc *hdesc, } EXPORT_SYMBOL(cfs_crypto_hash_final); +/** + * Compute the speed of specified hash function + * + * Run a speed test on the given hash algorithm on buffer of the given size. + * The speed is stored internally in the cfs_crypto_hash_speeds[] array, and + * is available through the cfs_crypto_hash_speed() function. + * + * \param[in] hash_alg hash algorithm id (CFS_HASH_ALG_*) + * \param[in] buf data buffer on which to compute the hash + * \param[in] buf_len length of \buf on which to compute hash + */ static void cfs_crypto_performance_test(unsigned char alg_id, const unsigned char *buf, unsigned int buf_len) @@ -243,6 +343,18 @@ static void cfs_crypto_performance_test(unsigned char alg_id, cfs_crypto_hash_name(alg_id), cfs_crypto_hash_speeds[alg_id]); } +/** + * hash speed in Mbytes per second for valid hash algorithm + * + * Return the performance of the specified \a hash_alg that was previously + * computed using cfs_crypto_performance_test(). + * + * \param[in] hash_alg hash algorithm id (CFS_HASH_ALG_*) + * + * \retval positive speed of the hash function in MB/s + * \retval -ENOENT if \a hash_alg is unsupported + * \retval negative errno if \a hash_alg speed is unavailable + */ int cfs_crypto_hash_speed(unsigned char hash_alg) { if (hash_alg < CFS_HASH_ALG_MAX) @@ -252,7 +364,22 @@ int cfs_crypto_hash_speed(unsigned char hash_alg) EXPORT_SYMBOL(cfs_crypto_hash_speed); /** - * Do performance test for all hash algorithms. + * Run the performance test for all hash algorithms. + * + * Run the cfs_crypto_performance_test() benchmark for all of the available + * hash functions using a 1MB buffer size. This is a reasonable buffer size + * for Lustre RPCs, even if the actual RPC size is larger or smaller. + * + * Since the setup cost and computation speed of various hash algorithms is + * a function of the buffer size (and possibly internal contention of offload + * engines), this speed only represents an estimate of the actual speed under + * actual usage, but is reasonable for comparing available algorithms. + * + * The actual speeds are available via cfs_crypto_hash_speed() for later + * comparison. + * + * \retval 0 on success + * \retval -ENOMEM if no memory is available for test buffer */ static int cfs_crypto_test_hashes(void) { @@ -280,6 +407,11 @@ static int cfs_crypto_test_hashes(void) static int adler32; +/** + * Register available hash functions + * + * \retval 0 + */ int cfs_crypto_register(void) { request_module("crc32c"); @@ -291,6 +423,9 @@ int cfs_crypto_register(void) return 0; } +/** + * Unregister previously registered hash functions + */ void cfs_crypto_unregister(void) { if (adler32 == 0) -- cgit v0.10.2