[lustre-devel] [PATCH 02/12] staging: lustre: libcfs: add documentation for cfs_crypto_hash_*()
James Simmons
jsimmons at infradead.org
Sat Mar 26 12:40:46 PDT 2016
From: Andreas Dilger <andreas.dilger at intel.com>
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 <andreas.dilger at intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5053
Reviewed-on: http://review.whamcloud.com/9990
Reviewed-by: Bob Glossman <bob.glossman at intel.com>
Reviewed-by: James Simmons <uja.ornl at gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin at intel.com>
---
.../lustre/include/linux/libcfs/libcfs_crypto.h | 101 ++++---------
.../lustre/lnet/libcfs/linux/linux-crypto.c | 153 ++++++++++++++++++--
2 files changed, 174 insertions(+), 80 deletions(-)
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)
--
1.7.1
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