blob: bfca085bb9693e696574076d879d0c8da8ce86e0 [file] [log] [blame]
/*
* 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 <types/global.h>
#include <common/mini-clist.h>
#include "proto/shctx.h"
#if !defined (USE_PRIVATE_CACHE)
int use_shared_mem = 0;
#endif
/*
* 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;
#ifndef USE_PRIVATE_CACHE
#ifdef USE_PTHREAD_PSHARED
pthread_mutexattr_t attr;
#endif
#endif
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 *);
#ifndef USE_PRIVATE_CACHE
if (shared)
maptype = MAP_SHARED;
#endif
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;
}
shctx->nbav = 0;
#ifndef USE_PRIVATE_CACHE
if (maptype == MAP_SHARED) {
#ifdef USE_PTHREAD_PSHARED
if (pthread_mutexattr_init(&attr)) {
munmap(shctx, sizeof(struct shared_context) + extra + (maxblocks * (sizeof(struct shared_block) + blocksize)));
shctx = NULL;
ret = SHCTX_E_INIT_LOCK;
goto err;
}
if (pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED)) {
pthread_mutexattr_destroy(&attr);
munmap(shctx, sizeof(struct shared_context) + extra + (maxblocks * (sizeof(struct shared_block) + blocksize)));
shctx = NULL;
ret = SHCTX_E_INIT_LOCK;
goto err;
}
if (pthread_mutex_init(&shctx->mutex, &attr)) {
pthread_mutexattr_destroy(&attr);
munmap(shctx, sizeof(struct shared_context) + extra + (maxblocks * (sizeof(struct shared_block) + blocksize)));
shctx = NULL;
ret = SHCTX_E_INIT_LOCK;
goto err;
}
#else
shctx->waiters = 0;
#endif
use_shared_mem = 1;
}
#endif
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_ADDQ(&shctx->avail, &cur_block->list);
shctx->nbav++;
cur += sizeof(struct shared_block) + blocksize;
}
ret = maxblocks;
err:
*orig_shctx = shctx;
return ret;
}