src/shctx.c - haproxy - Gitiles

 /*
  * shctx.c - shared context management functions for SSL
  *
  * Copyright (C) 2011-2012 EXCELIANCE
  *
  * Author: Emeric Brun - emeric@exceliance.fr
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */

 #include <sys/mman.h>
 #include <arpa/inet.h>
 #include <import/ebmbtree.h>
 #include <haproxy/list.h>
 #include <haproxy/shctx.h>

 int use_shared_mem = 0;

 /*
  * Reserve a new row if <first> is null, put it in the hotlist, set the refcount to 1
  * or append new blocks to the row with <first> as first block if non null.
  *
  * Reserve blocks in the avail list and put them in the hot list
  * Return the first block put in the hot list or NULL if not enough blocks available
  */
 struct shared_block *shctx_row_reserve_hot(struct shared_context *shctx,
                                            struct shared_block *first, int data_len)
 {
 	struct shared_block *last = NULL, *block, *sblock, *ret = NULL, *next;
 	int enough = 0;
 	int freed = 0;
 	int remain;

 	/* not enough usable blocks */
 	if (data_len > shctx->nbav * shctx->block_size)
 		goto out;

 	/* Check the object size limit. */
 	if (shctx->max_obj_size > 0) {
 		if ((first && first->len + data_len > shctx->max_obj_size) ||
 			(!first && data_len > shctx->max_obj_size))
 			goto out;
 	}

 	/* Note that <remain> is nul only if <first> is not nul. */
 	remain = 1;
 	if (first) {
 		/* Check that there is some block to reserve.
 		 * In this first block of code we compute the remaining room in the
 		 * current list of block already reserved for this object.
 		 * We return asap if there is enough room to copy <data_len> bytes.
 		 */
 		last = first->last_reserved;
 		/* Remaining room. */
 		remain = (shctx->block_size * first->block_count - first->len);
 		if (remain) {
 			if (remain > data_len) {
 				return last ? last : first;
 			} else {
 				data_len -= remain;
 				if (!data_len)
 					return last ? last : first;
 			}
 		}
 	}

 	while (!enough && !LIST_ISEMPTY(&shctx->avail)) {
 		int count = 0;
 		int first_count = 0, first_len = 0;

 		next = block = LIST_NEXT(&shctx->avail, struct shared_block *, list);
 		if (ret == NULL)
 			ret = next;

 		first_count = next->block_count;
 		first_len = next->len;
 		/*
 		Should never been set to 0.
 		if (next->block_count == 0)
 		next->block_count = 1;
 		*/

 		list_for_each_entry_safe_from(block, sblock, &shctx->avail, list) {

 			/* release callback */
 			if (first_len && shctx->free_block)
 				shctx->free_block(next, block);

 			block->block_count = 1;
 			block->len = 0;

 			freed++;
 			data_len -= shctx->block_size;

 			if (data_len > 0 || !enough) {
 				if (last) {
 					shctx_block_append_hot(shctx, &last->list, block);
 					last = block;
 				} else {
 					shctx_block_set_hot(shctx, block);
 				}
 				if (!remain) {
 					first->last_append = block;
 					remain = 1;
 				}
 				if (data_len <= 0) {
 					ret->block_count = freed;
 					ret->refcount = 1;
 					ret->last_reserved = block;
 					enough = 1;
 				}
 			}
 			count++;
 			if (count >= first_count)
 				break;
 		}
 	}

 	if (first) {
 		first->block_count += ret->block_count;
 		first->last_reserved = ret->last_reserved;
 		/* Reset this block. */
 		ret->last_reserved = NULL;
 		ret->block_count = 1;
 		ret->refcount = 0;
 		/* Return the first block. */
 		ret = first;
 	}

 out:
 	return ret;
 }

 /*
  * if the refcount is 0 move the row to the hot list. Increment the refcount
  */
 void shctx_row_inc_hot(struct shared_context *shctx, struct shared_block *first)
 {
 	struct shared_block *block, *sblock;
 	int count = 0;

 	if (first->refcount <= 0) {

 		block = first;

 		list_for_each_entry_safe_from(block, sblock, &shctx->avail, list) {

 			shctx_block_set_hot(shctx, block);

 			count++;
 			if (count >= first->block_count)
 				break;
 		}
 	}

 	first->refcount++;
 }

 /*
  * decrement the refcount and move the row at the end of the avail list if it reaches 0.
  */
 void shctx_row_dec_hot(struct shared_context *shctx, struct shared_block *first)
 {
 	struct shared_block *block, *sblock;
 	int count = 0;

 	first->refcount--;

 	if (first->refcount <= 0) {

 		block = first;

 		list_for_each_entry_safe_from(block, sblock, &shctx->hot, list) {

 			shctx_block_set_avail(shctx, block);

 			count++;
 			if (count >= first->block_count)
 				break;
 		}
 	}

 }


 /*
  * Append data in the row if there is enough space.
  * The row should be in the hot list
  *
  * Return the amount of appended data if ret >= 0
  * or how much more space it needs to contains the data if < 0.
  */
 int shctx_row_data_append(struct shared_context *shctx,
                           struct shared_block *first, struct shared_block *from,
                           unsigned char *data, int len)
 {
 	int remain, start;
 	struct shared_block *block;

 	/* return -<len> needed to work */
 	if (len > first->block_count * shctx->block_size - first->len)
 		return (first->block_count * shctx->block_size - first->len) - len;

 	block = from ? from : first;
 	list_for_each_entry_from(block, &shctx->hot, list) {
 		/* end of copy */
 		if (len <= 0)
 			break;

 		/* remaining written bytes in the current block. */
 		remain = (shctx->block_size * first->block_count - first->len) % shctx->block_size;
 		/* if remain == 0, previous buffers are full, or first->len == 0 */
 		if (!remain) {
 			remain = shctx->block_size;
 			start = 0;
 		}
 		else {
 			/* start must be calculated before remain is modified */
 			start = shctx->block_size - remain;
 		}

 		/* must not try to copy more than len */
 		remain = MIN(remain, len);

 		memcpy(block->data + start, data, remain);

 		data += remain;
 		len -= remain;
 		first->len += remain; /* update len in the head of the row */
 		first->last_append = block;
 	}

 	return len;
 }

 /*
  * Copy <len> data from a row of blocks, return the remaining data to copy
  * If 0 is returned, the full data has successfully been copied
  *
  * The row should be in the hot list
  */
 int shctx_row_data_get(struct shared_context *shctx, struct shared_block *first,
                        unsigned char *dst, int offset, int len)
 {
 	int count = 0, size = 0, start = -1;
 	struct shared_block *block;

 	/* can't copy more */
 	if (len > first->len)
 		len = first->len;

 	block = first;
 	count = 0;
 	/* Pass through the blocks to copy them */
 	list_for_each_entry_from(block, &shctx->hot, list) {
 		if (count >= first->block_count  || len <= 0)
 			break;

 		count++;
 		/* continue until we are in right block
 		   corresponding to the offset */
 		if (count < offset / shctx->block_size + 1)
 			continue;

 		/* on the first block, data won't possibly began at offset 0 */
 		if (start == -1)
 			start = offset - (count - 1) * shctx->block_size;

 		/* size can be lower than a block when copying the last block */
 		size = MIN(shctx->block_size - start, len);

 		memcpy(dst, block->data + start, size);
 		dst += size;
 		len -= size;
 		start = 0;
 	}
 	return len;
 }

 /* Allocate shared memory context.
  * <maxblocks> is maximum blocks.
  * If <maxblocks> is set to less or equal to 0, ssl cache is disabled.
  * Returns: -1 on alloc failure, <maxblocks> if it performs context alloc,
  * and 0 if cache is already allocated.
  */
 int shctx_init(struct shared_context **orig_shctx, int maxblocks, int blocksize,
                unsigned int maxobjsz, int extra, int shared)
 {
 	int i;
 	struct shared_context *shctx;
 	int ret;
 	void *cur;
 	int maptype = MAP_PRIVATE;

 	if (maxblocks <= 0)
 		return 0;

 	/* make sure to align the records on a pointer size */
 	blocksize = (blocksize + sizeof(void *) - 1) & -sizeof(void *);
 	extra     = (extra     + sizeof(void *) - 1) & -sizeof(void *);

 	if (shared) {
 		maptype = MAP_SHARED;
 		use_shared_mem = 1;
 	}

 	shctx = (struct shared_context *)mmap(NULL, sizeof(struct shared_context) + extra + (maxblocks * (sizeof(struct shared_block) + blocksize)),
 	                                      PROT_READ | PROT_WRITE, maptype | MAP_ANON, -1, 0);
 	if (!shctx || shctx == MAP_FAILED) {
 		shctx = NULL;
 		ret = SHCTX_E_ALLOC_CACHE;
 		goto err;
 	}

 	HA_SPIN_INIT(&shctx->lock);
 	shctx->nbav = 0;

 	LIST_INIT(&shctx->avail);
 	LIST_INIT(&shctx->hot);

 	shctx->block_size = blocksize;
 	shctx->max_obj_size = maxobjsz == (unsigned int)-1 ? 0 : maxobjsz;

 	/* init the free blocks after the shared context struct */
 	cur = (void *)shctx + sizeof(struct shared_context) + extra;
 	for (i = 0; i < maxblocks; i++) {
 		struct shared_block *cur_block = (struct shared_block *)cur;
 		cur_block->len = 0;
 		cur_block->refcount = 0;
 		cur_block->block_count = 1;
 		LIST_APPEND(&shctx->avail, &cur_block->list);
 		shctx->nbav++;
 		cur += sizeof(struct shared_block) + blocksize;
 	}
 	ret = maxblocks;

 err:
 	*orig_shctx = shctx;
 	return ret;
 }
	/*
	* shctx.c - shared context management functions for SSL
	*
	* Copyright (C) 2011-2012 EXCELIANCE
	*
	* Author: Emeric Brun - emeric@exceliance.fr
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/

	#include <sys/mman.h>
	#include <arpa/inet.h>
	#include <import/ebmbtree.h>
	#include <haproxy/list.h>
	#include <haproxy/shctx.h>

	int use_shared_mem = 0;

	/*
	* Reserve a new row if <first> is null, put it in the hotlist, set the refcount to 1
	* or append new blocks to the row with <first> as first block if non null.
	*
	* Reserve blocks in the avail list and put them in the hot list
	* Return the first block put in the hot list or NULL if not enough blocks available
	*/
	struct shared_block shctx_row_reserve_hot(struct shared_context shctx,
	struct shared_block *first, int data_len)
	{
	struct shared_block last = NULL, block, sblock, ret = NULL, *next;
	int enough = 0;
	int freed = 0;
	int remain;

	/* not enough usable blocks */
	if (data_len > shctx->nbav * shctx->block_size)
	goto out;

	/* Check the object size limit. */
	if (shctx->max_obj_size > 0) {
	if ((first && first->len + data_len > shctx->max_obj_size) \|\|
	(!first && data_len > shctx->max_obj_size))
	goto out;
	}

	/* Note that <remain> is nul only if <first> is not nul. */
	remain = 1;
	if (first) {
	/* Check that there is some block to reserve.
	* In this first block of code we compute the remaining room in the
	* current list of block already reserved for this object.
	* We return asap if there is enough room to copy <data_len> bytes.
	*/
	last = first->last_reserved;
	/* Remaining room. */
	remain = (shctx->block_size * first->block_count - first->len);
	if (remain) {
	if (remain > data_len) {
	return last ? last : first;
	} else {
	data_len -= remain;
	if (!data_len)
	return last ? last : first;
	}
	}
	}

	while (!enough && !LIST_ISEMPTY(&shctx->avail)) {
	int count = 0;
	int first_count = 0, first_len = 0;

	next = block = LIST_NEXT(&shctx->avail, struct shared_block *, list);
	if (ret == NULL)
	ret = next;

	first_count = next->block_count;
	first_len = next->len;
	/*
	Should never been set to 0.
	if (next->block_count == 0)
	next->block_count = 1;
	*/

	list_for_each_entry_safe_from(block, sblock, &shctx->avail, list) {

	/* release callback */
	if (first_len && shctx->free_block)
	shctx->free_block(next, block);

	block->block_count = 1;
	block->len = 0;

	freed++;
	data_len -= shctx->block_size;

	if (data_len > 0 \|\| !enough) {
	if (last) {
	shctx_block_append_hot(shctx, &last->list, block);
	last = block;
	} else {
	shctx_block_set_hot(shctx, block);
	}
	if (!remain) {
	first->last_append = block;
	remain = 1;
	}
	if (data_len <= 0) {
	ret->block_count = freed;
	ret->refcount = 1;
	ret->last_reserved = block;
	enough = 1;
	}
	}
	count++;
	if (count >= first_count)
	break;
	}
	}

	if (first) {
	first->block_count += ret->block_count;
	first->last_reserved = ret->last_reserved;
	/* Reset this block. */
	ret->last_reserved = NULL;
	ret->block_count = 1;
	ret->refcount = 0;
	/* Return the first block. */
	ret = first;
	}

	out:
	return ret;
	}

	/*
	* if the refcount is 0 move the row to the hot list. Increment the refcount
	*/
	void shctx_row_inc_hot(struct shared_context shctx, struct shared_block first)
	{
	struct shared_block block, sblock;
	int count = 0;

	if (first->refcount <= 0) {

	block = first;

	list_for_each_entry_safe_from(block, sblock, &shctx->avail, list) {

	shctx_block_set_hot(shctx, block);

	count++;
	if (count >= first->block_count)
	break;
	}
	}

	first->refcount++;
	}

	/*
	* decrement the refcount and move the row at the end of the avail list if it reaches 0.
	*/
	void shctx_row_dec_hot(struct shared_context shctx, struct shared_block first)
	{
	struct shared_block block, sblock;
	int count = 0;

	first->refcount--;

	if (first->refcount <= 0) {

	block = first;

	list_for_each_entry_safe_from(block, sblock, &shctx->hot, list) {

	shctx_block_set_avail(shctx, block);

	count++;
	if (count >= first->block_count)
	break;
	}
	}

	}


	/*
	* Append data in the row if there is enough space.
	* The row should be in the hot list
	*
	* Return the amount of appended data if ret >= 0
	* or how much more space it needs to contains the data if < 0.
	*/
	int shctx_row_data_append(struct shared_context *shctx,
	struct shared_block first, struct shared_block from,
	unsigned char *data, int len)
	{
	int remain, start;
	struct shared_block *block;

	/* return -<len> needed to work */
	if (len > first->block_count * shctx->block_size - first->len)
	return (first->block_count * shctx->block_size - first->len) - len;

	block = from ? from : first;
	list_for_each_entry_from(block, &shctx->hot, list) {
	/* end of copy */
	if (len <= 0)
	break;

	/* remaining written bytes in the current block. */
	remain = (shctx->block_size * first->block_count - first->len) % shctx->block_size;
	/* if remain == 0, previous buffers are full, or first->len == 0 */
	if (!remain) {
	remain = shctx->block_size;
	start = 0;
	}
	else {
	/* start must be calculated before remain is modified */
	start = shctx->block_size - remain;
	}

	/* must not try to copy more than len */
	remain = MIN(remain, len);

	memcpy(block->data + start, data, remain);

	data += remain;
	len -= remain;
	first->len += remain; /* update len in the head of the row */
	first->last_append = block;
	}

	return len;
	}

	/*
	* Copy <len> data from a row of blocks, return the remaining data to copy
	* If 0 is returned, the full data has successfully been copied
	*
	* The row should be in the hot list
	*/
	int shctx_row_data_get(struct shared_context shctx, struct shared_block first,
	unsigned char *dst, int offset, int len)
	{
	int count = 0, size = 0, start = -1;
	struct shared_block *block;

	/* can't copy more */
	if (len > first->len)
	len = first->len;

	block = first;
	count = 0;
	/* Pass through the blocks to copy them */
	list_for_each_entry_from(block, &shctx->hot, list) {
	if (count >= first->block_count \|\| len <= 0)
	break;

	count++;
	/* continue until we are in right block
	corresponding to the offset */
	if (count < offset / shctx->block_size + 1)
	continue;

	/* on the first block, data won't possibly began at offset 0 */
	if (start == -1)
	start = offset - (count - 1) * shctx->block_size;

	/* size can be lower than a block when copying the last block */
	size = MIN(shctx->block_size - start, len);

	memcpy(dst, block->data + start, size);
	dst += size;
	len -= size;
	start = 0;
	}
	return len;
	}

	/* Allocate shared memory context.
	* <maxblocks> is maximum blocks.
	* If <maxblocks> is set to less or equal to 0, ssl cache is disabled.
	* Returns: -1 on alloc failure, <maxblocks> if it performs context alloc,
	* and 0 if cache is already allocated.
	*/
	int shctx_init(struct shared_context **orig_shctx, int maxblocks, int blocksize,
	unsigned int maxobjsz, int extra, int shared)
	{
	int i;
	struct shared_context *shctx;
	int ret;
	void *cur;
	int maptype = MAP_PRIVATE;

	if (maxblocks <= 0)
	return 0;

	/* make sure to align the records on a pointer size */
	blocksize = (blocksize + sizeof(void ) - 1) & -sizeof(void );
	extra = (extra + sizeof(void ) - 1) & -sizeof(void );

	if (shared) {
	maptype = MAP_SHARED;
	use_shared_mem = 1;
	}

	shctx = (struct shared_context )mmap(NULL, sizeof(struct shared_context) + extra + (maxblocks (sizeof(struct shared_block) + blocksize)),
	PROT_READ \| PROT_WRITE, maptype \| MAP_ANON, -1, 0);
	if (!shctx \|\| shctx == MAP_FAILED) {
	shctx = NULL;
	ret = SHCTX_E_ALLOC_CACHE;
	goto err;
	}

	HA_SPIN_INIT(&shctx->lock);
	shctx->nbav = 0;

	LIST_INIT(&shctx->avail);
	LIST_INIT(&shctx->hot);

	shctx->block_size = blocksize;
	shctx->max_obj_size = maxobjsz == (unsigned int)-1 ? 0 : maxobjsz;

	/* init the free blocks after the shared context struct */
	cur = (void *)shctx + sizeof(struct shared_context) + extra;
	for (i = 0; i < maxblocks; i++) {
	struct shared_block cur_block = (struct shared_block )cur;
	cur_block->len = 0;
	cur_block->refcount = 0;
	cur_block->block_count = 1;
	LIST_APPEND(&shctx->avail, &cur_block->list);
	shctx->nbav++;
	cur += sizeof(struct shared_block) + blocksize;
	}
	ret = maxblocks;

	err:
	*orig_shctx = shctx;
	return ret;
	}