text: /*
   * GPL HEADER START
   *
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 only,
   * as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License version 2 for more details (a copy is included
   * in the LICENSE file that accompanied this code).
   *
   * You should have received a copy of the GNU General Public License
   * version 2 along with this program; If not, see
   * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
   *
   * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   * CA 95054 USA or visit www.sun.com if you need additional information or
   * have any questions.
   *
   * GPL HEADER END
   */
  /*
   * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
   * Use is subject to license terms.
   *
   * Copyright (c) 2011, 2012, Intel Corporation.
   */
  /*
   * This file is part of Lustre, http://www.lustre.org/
   * Lustre is a trademark of Sun Microsystems, Inc.
   *
   * lustre/ptlrpc/sec_bulk.c
   *
   * Author: Eric Mei <ericm@clusterfs.com>
   */
  
  #define DEBUG_SUBSYSTEM S_SEC
  
  #include "../../include/linux/libcfs/libcfs.h"
  #include <linux/crypto.h>
  
  #include "../include/obd.h"
  #include "../include/obd_cksum.h"
  #include "../include/obd_class.h"
  #include "../include/obd_support.h"
  #include "../include/lustre_net.h"
  #include "../include/lustre_import.h"
  #include "../include/lustre_dlm.h"
  #include "../include/lustre_sec.h"
  
  #include "ptlrpc_internal.h"
  
  /****************************************
   * bulk encryption page pools	   *
   ****************************************/
  
  #define POINTERS_PER_PAGE	(PAGE_CACHE_SIZE / sizeof(void *))
  #define PAGES_PER_POOL		(POINTERS_PER_PAGE)
  
  #define IDLE_IDX_MAX	 (100)
  #define IDLE_IDX_WEIGHT	 (3)
  
  #define CACHE_QUIESCENT_PERIOD  (20)
  
  static struct ptlrpc_enc_page_pool {
  	/*
  	 * constants
  	 */
  	unsigned long    epp_max_pages;   /* maximum pages can hold, const */
  	unsigned int     epp_max_pools;   /* number of pools, const */
  
  	/*
  	 * wait queue in case of not enough free pages.
  	 */
  	wait_queue_head_t      epp_waitq;       /* waiting threads */
  	unsigned int     epp_waitqlen;    /* wait queue length */
  	unsigned long    epp_pages_short; /* # of pages wanted of in-q users */
  	unsigned int     epp_growing:1;   /* during adding pages */
  
  	/*
  	 * indicating how idle the pools are, from 0 to MAX_IDLE_IDX
  	 * this is counted based on each time when getting pages from
  	 * the pools, not based on time. which means in case that system
  	 * is idled for a while but the idle_idx might still be low if no
  	 * activities happened in the pools.
  	 */
  	unsigned long    epp_idle_idx;
  
  	/* last shrink time due to mem tight */
  	time64_t         epp_last_shrink;
  	time64_t         epp_last_access;
  
  	/*
  	 * in-pool pages bookkeeping
  	 */
  	spinlock_t	 epp_lock;	   /* protect following fields */
  	unsigned long    epp_total_pages; /* total pages in pools */
  	unsigned long    epp_free_pages;  /* current pages available */
  
  	/*
  	 * statistics
  	 */
  	unsigned long    epp_st_max_pages;      /* # of pages ever reached */
  	unsigned int     epp_st_grows;	  /* # of grows */
  	unsigned int     epp_st_grow_fails;     /* # of add pages failures */
  	unsigned int     epp_st_shrinks;	/* # of shrinks */
  	unsigned long    epp_st_access;	 /* # of access */
  	unsigned long    epp_st_missings;       /* # of cache missing */
  	unsigned long    epp_st_lowfree;	/* lowest free pages reached */
  	unsigned int     epp_st_max_wqlen;      /* highest waitqueue length */
  	unsigned long       epp_st_max_wait;       /* in jiffies */
  	/*
  	 * pointers to pools
  	 */
  	struct page    ***epp_pools;
  } page_pools;
  
  /*
   * /proc/fs/lustre/sptlrpc/encrypt_page_pools
   */
  int sptlrpc_proc_enc_pool_seq_show(struct seq_file *m, void *v)
  {
  	spin_lock(&page_pools.epp_lock);
  
  	seq_printf(m,
  		   "physical pages:	  %lu\n"
  		   "pages per pool:	  %lu\n"
  		   "max pages:	       %lu\n"
  		   "max pools:	       %u\n"
  		   "total pages:	     %lu\n"
  		   "total free:	      %lu\n"
  		   "idle index:	      %lu/100\n"
  		   "last shrink:	     %lds\n"
  		   "last access:	     %lds\n"
  		   "max pages reached:       %lu\n"
  		   "grows:		   %u\n"
  		   "grows failure:	   %u\n"
  		   "shrinks:		 %u\n"
  		   "cache access:	    %lu\n"
  		   "cache missing:	   %lu\n"
  		   "low free mark:	   %lu\n"
  		   "max waitqueue depth:     %u\n"
  		   "max wait time:	   %ld/%u\n",
  		   totalram_pages,
  		   PAGES_PER_POOL,
  		   page_pools.epp_max_pages,
  		   page_pools.epp_max_pools,
  		   page_pools.epp_total_pages,
  		   page_pools.epp_free_pages,
  		   page_pools.epp_idle_idx,
  		   (long)(ktime_get_seconds() - page_pools.epp_last_shrink),
  		   (long)(ktime_get_seconds() - page_pools.epp_last_access),
  		   page_pools.epp_st_max_pages,
  		   page_pools.epp_st_grows,
  		   page_pools.epp_st_grow_fails,
  		   page_pools.epp_st_shrinks,
  		   page_pools.epp_st_access,
  		   page_pools.epp_st_missings,
  		   page_pools.epp_st_lowfree,
  		   page_pools.epp_st_max_wqlen,
  		   page_pools.epp_st_max_wait,
  		   HZ);
  
  	spin_unlock(&page_pools.epp_lock);
  
  	return 0;
  }
  
  static void enc_pools_release_free_pages(long npages)
  {
  	int p_idx, g_idx;
  	int p_idx_max1, p_idx_max2;
  
  	LASSERT(npages > 0);
  	LASSERT(npages <= page_pools.epp_free_pages);
  	LASSERT(page_pools.epp_free_pages <= page_pools.epp_total_pages);
  
  	/* max pool index before the release */
  	p_idx_max2 = (page_pools.epp_total_pages - 1) / PAGES_PER_POOL;
  
  	page_pools.epp_free_pages -= npages;
  	page_pools.epp_total_pages -= npages;
  
  	/* max pool index after the release */
  	p_idx_max1 = page_pools.epp_total_pages == 0 ? -1 :
  		     ((page_pools.epp_total_pages - 1) / PAGES_PER_POOL);
  
  	p_idx = page_pools.epp_free_pages / PAGES_PER_POOL;
  	g_idx = page_pools.epp_free_pages % PAGES_PER_POOL;
  	LASSERT(page_pools.epp_pools[p_idx]);
  
  	while (npages--) {
  		LASSERT(page_pools.epp_pools[p_idx]);
  		LASSERT(page_pools.epp_pools[p_idx][g_idx] != NULL);
  
  		__free_page(page_pools.epp_pools[p_idx][g_idx]);
  		page_pools.epp_pools[p_idx][g_idx] = NULL;
  
  		if (++g_idx == PAGES_PER_POOL) {
  			p_idx++;
  			g_idx = 0;
  		}
  	}
  
  	/* free unused pools */
  	while (p_idx_max1 < p_idx_max2) {
  		LASSERT(page_pools.epp_pools[p_idx_max2]);
  		kfree(page_pools.epp_pools[p_idx_max2]);
  		page_pools.epp_pools[p_idx_max2] = NULL;
  		p_idx_max2--;
  	}
  }
  
  /*
   * we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
   */
  static unsigned long enc_pools_shrink_count(struct shrinker *s,
  					    struct shrink_control *sc)
  {
  	/*
  	 * if no pool access for a long time, we consider it's fully idle.
  	 * a little race here is fine.
  	 */
  	if (unlikely(ktime_get_seconds() - page_pools.epp_last_access >
  		     CACHE_QUIESCENT_PERIOD)) {
  		spin_lock(&page_pools.epp_lock);
  		page_pools.epp_idle_idx = IDLE_IDX_MAX;
  		spin_unlock(&page_pools.epp_lock);
  	}
  
  	LASSERT(page_pools.epp_idle_idx <= IDLE_IDX_MAX);
  	return max((int)page_pools.epp_free_pages - PTLRPC_MAX_BRW_PAGES, 0) *
  		(IDLE_IDX_MAX - page_pools.epp_idle_idx) / IDLE_IDX_MAX;
  }
  
  /*
   * we try to keep at least PTLRPC_MAX_BRW_PAGES pages in the pool.
   */
  static unsigned long enc_pools_shrink_scan(struct shrinker *s,
  					   struct shrink_control *sc)
  {
  	spin_lock(&page_pools.epp_lock);
  	sc->nr_to_scan = min_t(unsigned long, sc->nr_to_scan,
  			      page_pools.epp_free_pages - PTLRPC_MAX_BRW_PAGES);
  	if (sc->nr_to_scan > 0) {
  		enc_pools_release_free_pages(sc->nr_to_scan);
  		CDEBUG(D_SEC, "released %ld pages, %ld left\n",
  		       (long)sc->nr_to_scan, page_pools.epp_free_pages);
  
  		page_pools.epp_st_shrinks++;
  		page_pools.epp_last_shrink = ktime_get_seconds();
  	}
  	spin_unlock(&page_pools.epp_lock);
  
  	/*
  	 * if no pool access for a long time, we consider it's fully idle.
  	 * a little race here is fine.
  	 */
  	if (unlikely(ktime_get_seconds() - page_pools.epp_last_access >
  		     CACHE_QUIESCENT_PERIOD)) {
  		spin_lock(&page_pools.epp_lock);
  		page_pools.epp_idle_idx = IDLE_IDX_MAX;
  		spin_unlock(&page_pools.epp_lock);
  	}
  
  	LASSERT(page_pools.epp_idle_idx <= IDLE_IDX_MAX);
  	return sc->nr_to_scan;
  }
  
  static inline
  int npages_to_npools(unsigned long npages)
  {
  	return (int) ((npages + PAGES_PER_POOL - 1) / PAGES_PER_POOL);
  }
  
  /*
   * return how many pages cleaned up.
   */
  static unsigned long enc_pools_cleanup(struct page ***pools, int npools)
  {
  	unsigned long cleaned = 0;
  	int i, j;
  
  	for (i = 0; i < npools; i++) {
  		if (pools[i]) {
  			for (j = 0; j < PAGES_PER_POOL; j++) {
  				if (pools[i][j]) {
  					__free_page(pools[i][j]);
  					cleaned++;
  				}
  			}
  			kfree(pools[i]);
  			pools[i] = NULL;
  		}
  	}
  
  	return cleaned;
  }
  
  static inline void enc_pools_wakeup(void)
  {
  	assert_spin_locked(&page_pools.epp_lock);
  	LASSERT(page_pools.epp_waitqlen >= 0);
  
  	if (unlikely(page_pools.epp_waitqlen)) {
  		LASSERT(waitqueue_active(&page_pools.epp_waitq));
  		wake_up_all(&page_pools.epp_waitq);
  	}
  }
  
  void sptlrpc_enc_pool_put_pages(struct ptlrpc_bulk_desc *desc)
  {
  	int p_idx, g_idx;
  	int i;
  
  	if (desc->bd_enc_iov == NULL)
  		return;
  
  	LASSERT(desc->bd_iov_count > 0);
  
  	spin_lock(&page_pools.epp_lock);
  
  	p_idx = page_pools.epp_free_pages / PAGES_PER_POOL;
  	g_idx = page_pools.epp_free_pages % PAGES_PER_POOL;
  
  	LASSERT(page_pools.epp_free_pages + desc->bd_iov_count <=
  		page_pools.epp_total_pages);
  	LASSERT(page_pools.epp_pools[p_idx]);
  
  	for (i = 0; i < desc->bd_iov_count; i++) {
  		LASSERT(desc->bd_enc_iov[i].kiov_page != NULL);
  		LASSERT(g_idx != 0 || page_pools.epp_pools[p_idx]);
  		LASSERT(page_pools.epp_pools[p_idx][g_idx] == NULL);
  
  		page_pools.epp_pools[p_idx][g_idx] =
  					desc->bd_enc_iov[i].kiov_page;
  
  		if (++g_idx == PAGES_PER_POOL) {
  			p_idx++;
  			g_idx = 0;
  		}
  	}
  
  	page_pools.epp_free_pages += desc->bd_iov_count;
  
  	enc_pools_wakeup();
  
  	spin_unlock(&page_pools.epp_lock);
  
  	kfree(desc->bd_enc_iov);
  	desc->bd_enc_iov = NULL;
  }
  EXPORT_SYMBOL(sptlrpc_enc_pool_put_pages);
  
  static inline void enc_pools_alloc(void)
  {
  	LASSERT(page_pools.epp_max_pools);
  	page_pools.epp_pools =
  		libcfs_kvzalloc(page_pools.epp_max_pools *
  				sizeof(*page_pools.epp_pools),
  				GFP_NOFS);
  }
  
  static inline void enc_pools_free(void)
  {
  	LASSERT(page_pools.epp_max_pools);
  	LASSERT(page_pools.epp_pools);
  
  	kvfree(page_pools.epp_pools);
  }
  
  static struct shrinker pools_shrinker = {
  	.count_objects	= enc_pools_shrink_count,
  	.scan_objects	= enc_pools_shrink_scan,
  	.seeks		= DEFAULT_SEEKS,
  };
  
  int sptlrpc_enc_pool_init(void)
  {
  	/*
  	 * maximum capacity is 1/8 of total physical memory.
  	 * is the 1/8 a good number?
  	 */
  	page_pools.epp_max_pages = totalram_pages / 8;
  	page_pools.epp_max_pools = npages_to_npools(page_pools.epp_max_pages);
  
  	init_waitqueue_head(&page_pools.epp_waitq);
  	page_pools.epp_waitqlen = 0;
  	page_pools.epp_pages_short = 0;
  
  	page_pools.epp_growing = 0;
  
  	page_pools.epp_idle_idx = 0;
  	page_pools.epp_last_shrink = ktime_get_seconds();
  	page_pools.epp_last_access = ktime_get_seconds();
  
  	spin_lock_init(&page_pools.epp_lock);
  	page_pools.epp_total_pages = 0;
  	page_pools.epp_free_pages = 0;
  
  	page_pools.epp_st_max_pages = 0;
  	page_pools.epp_st_grows = 0;
  	page_pools.epp_st_grow_fails = 0;
  	page_pools.epp_st_shrinks = 0;
  	page_pools.epp_st_access = 0;
  	page_pools.epp_st_missings = 0;
  	page_pools.epp_st_lowfree = 0;
  	page_pools.epp_st_max_wqlen = 0;
  	page_pools.epp_st_max_wait = 0;
  
  	enc_pools_alloc();
  	if (page_pools.epp_pools == NULL)
  		return -ENOMEM;
  
  	register_shrinker(&pools_shrinker);
  
  	return 0;
  }
  
  void sptlrpc_enc_pool_fini(void)
  {
  	unsigned long cleaned, npools;
  
  	LASSERT(page_pools.epp_pools);
  	LASSERT(page_pools.epp_total_pages == page_pools.epp_free_pages);
  
  	unregister_shrinker(&pools_shrinker);
  
  	npools = npages_to_npools(page_pools.epp_total_pages);
  	cleaned = enc_pools_cleanup(page_pools.epp_pools, npools);
  	LASSERT(cleaned == page_pools.epp_total_pages);
  
  	enc_pools_free();
  
  	if (page_pools.epp_st_access > 0) {
  		CDEBUG(D_SEC,
  		       "max pages %lu, grows %u, grow fails %u, shrinks %u, access %lu, missing %lu, max qlen %u, max wait %ld/%d\n",
  		       page_pools.epp_st_max_pages, page_pools.epp_st_grows,
  		       page_pools.epp_st_grow_fails,
  		       page_pools.epp_st_shrinks, page_pools.epp_st_access,
  		       page_pools.epp_st_missings, page_pools.epp_st_max_wqlen,
  		       page_pools.epp_st_max_wait, HZ);
  	}
  }
  
  static int cfs_hash_alg_id[] = {
  	[BULK_HASH_ALG_NULL]	= CFS_HASH_ALG_NULL,
  	[BULK_HASH_ALG_ADLER32]	= CFS_HASH_ALG_ADLER32,
  	[BULK_HASH_ALG_CRC32]	= CFS_HASH_ALG_CRC32,
  	[BULK_HASH_ALG_MD5]	= CFS_HASH_ALG_MD5,
  	[BULK_HASH_ALG_SHA1]	= CFS_HASH_ALG_SHA1,
  	[BULK_HASH_ALG_SHA256]	= CFS_HASH_ALG_SHA256,
  	[BULK_HASH_ALG_SHA384]	= CFS_HASH_ALG_SHA384,
  	[BULK_HASH_ALG_SHA512]	= CFS_HASH_ALG_SHA512,
  };
  
  const char *sptlrpc_get_hash_name(__u8 hash_alg)
  {
  	return cfs_crypto_hash_name(cfs_hash_alg_id[hash_alg]);
  }
  EXPORT_SYMBOL(sptlrpc_get_hash_name);
  
  __u8 sptlrpc_get_hash_alg(const char *algname)
  {
  	return cfs_crypto_hash_alg(algname);
  }
  EXPORT_SYMBOL(sptlrpc_get_hash_alg);
  
  int bulk_sec_desc_unpack(struct lustre_msg *msg, int offset, int swabbed)
  {
  	struct ptlrpc_bulk_sec_desc *bsd;
  	int			  size = msg->lm_buflens[offset];
  
  	bsd = lustre_msg_buf(msg, offset, sizeof(*bsd));
  	if (bsd == NULL) {
  		CERROR("Invalid bulk sec desc: size %d\n", size);
  		return -EINVAL;
  	}
  
  	if (swabbed)
  		__swab32s(&bsd->bsd_nob);
  
  	if (unlikely(bsd->bsd_version != 0)) {
  		CERROR("Unexpected version %u\n", bsd->bsd_version);
  		return -EPROTO;
  	}
  
  	if (unlikely(bsd->bsd_type >= SPTLRPC_BULK_MAX)) {
  		CERROR("Invalid type %u\n", bsd->bsd_type);
  		return -EPROTO;
  	}
  
  	/* FIXME more sanity check here */
  
  	if (unlikely(bsd->bsd_svc != SPTLRPC_BULK_SVC_NULL &&
  		     bsd->bsd_svc != SPTLRPC_BULK_SVC_INTG &&
  		     bsd->bsd_svc != SPTLRPC_BULK_SVC_PRIV)) {
  		CERROR("Invalid svc %u\n", bsd->bsd_svc);
  		return -EPROTO;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL(bulk_sec_desc_unpack);
  
  int sptlrpc_get_bulk_checksum(struct ptlrpc_bulk_desc *desc, __u8 alg,
  			      void *buf, int buflen)
  {
  	struct cfs_crypto_hash_desc *hdesc;
  	int hashsize;
  	char hashbuf[64];
  	unsigned int bufsize;
  	int i, err;
  
  	LASSERT(alg > BULK_HASH_ALG_NULL && alg < BULK_HASH_ALG_MAX);
  	LASSERT(buflen >= 4);
  
  	hdesc = cfs_crypto_hash_init(cfs_hash_alg_id[alg], NULL, 0);
  	if (IS_ERR(hdesc)) {
  		CERROR("Unable to initialize checksum hash %s\n",
  		       cfs_crypto_hash_name(cfs_hash_alg_id[alg]));
  		return PTR_ERR(hdesc);
  	}
  
  	hashsize = cfs_crypto_hash_digestsize(cfs_hash_alg_id[alg]);
  
  	for (i = 0; i < desc->bd_iov_count; i++) {
  		cfs_crypto_hash_update_page(hdesc, desc->bd_iov[i].kiov_page,
  				  desc->bd_iov[i].kiov_offset & ~CFS_PAGE_MASK,
  				  desc->bd_iov[i].kiov_len);
  	}
  	if (hashsize > buflen) {
  		bufsize = sizeof(hashbuf);
  		err = cfs_crypto_hash_final(hdesc, (unsigned char *)hashbuf,
  					    &bufsize);
  		memcpy(buf, hashbuf, buflen);
  	} else {
  		bufsize = buflen;
  		err = cfs_crypto_hash_final(hdesc, buf, &bufsize);
  	}
  
  	if (err)
  		cfs_crypto_hash_final(hdesc, NULL, NULL);
  	return err;
  }
  EXPORT_SYMBOL(sptlrpc_get_bulk_checksum);
  