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/*
* Stick tables management functions.
*
* Copyright 2009-2010 EXCELIANCE, Emeric Brun <ebrun@exceliance.fr>
* Copyright (C) 2010 Willy Tarreau <w@1wt.eu>
*
* 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 <string.h>
#include <common/config.h>
#include <common/memory.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <common/time.h>
#include <ebmbtree.h>
#include <ebsttree.h>
#include <proto/pattern.h>
#include <proto/proxy.h>
#include <proto/session.h>
#include <proto/stick_table.h>
#include <proto/task.h>
/* static structure used to return a table key built from a pattern */
static struct stktable_key static_table_key;
/*
* Free an allocated sticky session <ts>, and decrease sticky sessions counter
* in table <t>.
*/
void stksess_free(struct stktable *t, struct stksess *ts)
{
t->current--;
pool_free2(t->pool, (void *)ts - t->data_size);
}
/*
* Initialize or update the key in the sticky session <ts> present in table <t>
* from the value present in <key>.
*/
void stksess_setkey(struct stktable *t, struct stksess *ts, struct stktable_key *key)
{
if (t->type != STKTABLE_TYPE_STRING)
memcpy(ts->key.key, key->key, t->key_size);
else {
memcpy(ts->key.key, key->key, MIN(t->key_size - 1, key->key_len));
ts->key.key[MIN(t->key_size - 1, key->key_len)] = 0;
}
}
/*
* Init sticky session <ts> of table <t>. The data parts are cleared and <ts>
* is returned.
*/
static struct stksess *stksess_init(struct stktable *t, struct stksess * ts)
{
memset((void *)ts - t->data_size, 0, t->data_size);
ts->key.node.leaf_p = NULL;
ts->exp.node.leaf_p = NULL;
return ts;
}
/*
* Trash oldest <to_batch> sticky sessions from table <t>
* Returns number of trashed sticky sessions.
*/
static int stktable_trash_oldest(struct stktable *t, int to_batch)
{
struct stksess *ts;
struct eb32_node *eb;
int batched = 0;
eb = eb32_lookup_ge(&t->exps, now_ms - TIMER_LOOK_BACK);
while (batched < to_batch) {
if (unlikely(!eb)) {
/* we might have reached the end of the tree, typically because
* <now_ms> is in the first half and we're first scanning the last
* half. Let's loop back to the beginning of the tree now.
*/
eb = eb32_first(&t->exps);
if (likely(!eb))
break;
}
/* timer looks expired, detach it from the queue */
ts = eb32_entry(eb, struct stksess, exp);
eb = eb32_next(eb);
eb32_delete(&ts->exp);
if (ts->expire != ts->exp.key) {
if (!tick_isset(ts->expire))
continue;
ts->exp.key = ts->expire;
eb32_insert(&t->exps, &ts->exp);
if (!eb || eb->key > ts->exp.key)
eb = &ts->exp;
continue;
}
/* session expired, trash it */
ebmb_delete(&ts->key);
stksess_free(t, ts);
batched++;
}
return batched;
}
/*
* Allocate and initialise a new sticky session.
* The new sticky session is returned or NULL in case of lack of memory.
* Sticky sessions should only be allocated this way, and must be freed using
* stksess_free(). Increase table <t> sticky session counter.
*/
struct stksess *stksess_new(struct stktable *t, struct stktable_key *key)
{
struct stksess *ts;
if (unlikely(t->current == t->size)) {
if ( t->nopurge )
return NULL;
if (!stktable_trash_oldest(t, t->size >> 8))
return NULL;
}
ts = pool_alloc2(t->pool) + t->data_size;
if (ts) {
t->current++;
stksess_init(t, ts);
stksess_setkey(t, ts, key);
}
return ts;
}
/*
* Looks in table <t> for a sticky session matching key <key>.
* Returns pointer on requested sticky session or NULL if none was found.
*/
struct stksess *stktable_lookup_key(struct stktable *t, struct stktable_key *key)
{
struct ebmb_node *eb;
if (t->type == STKTABLE_TYPE_STRING)
eb = ebst_lookup_len(&t->keys, key->key, key->key_len);
else
eb = ebmb_lookup(&t->keys, key->key, t->key_size);
if (unlikely(!eb)) {
/* no session found */
return NULL;
}
return ebmb_entry(eb, struct stksess, key);
}
/*
* Looks in table <t> for a sticky session with same key as <ts>.
* Returns pointer on requested sticky session or NULL if none was found.
*/
struct stksess *stktable_lookup(struct stktable *t, struct stksess *ts)
{
struct ebmb_node *eb;
if (t->type == STKTABLE_TYPE_STRING)
eb = ebst_lookup(&(t->keys), (char *)ts->key.key);
else
eb = ebmb_lookup(&(t->keys), ts->key.key, t->key_size);
if (unlikely(!eb))
return NULL;
return ebmb_entry(eb, struct stksess, key);
}
/* Insert new sticky session <ts> in the table. It is assumed that it does not
* yet exist (the caller must check this). The table's timeout is updated if it
* is set. <ts> is returned.
*/
struct stksess *stktable_store(struct stktable *t, struct stksess *ts)
{
ebmb_insert(&t->keys, &ts->key, t->key_size);
ts->exp.key = ts->expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
eb32_insert(&t->exps, &ts->exp);
if (t->expire) {
t->exp_task->expire = t->exp_next = tick_first(ts->expire, t->exp_next);
task_queue(t->exp_task);
}
return ts;
}
/*
* Trash expired sticky sessions from table <t>. The next expiration date is
* returned.
*/
static int stktable_trash_expired(struct stktable *t)
{
struct stksess *ts;
struct eb32_node *eb;
eb = eb32_lookup_ge(&t->exps, now_ms - TIMER_LOOK_BACK);
while (1) {
if (unlikely(!eb)) {
/* we might have reached the end of the tree, typically because
* <now_ms> is in the first half and we're first scanning the last
* half. Let's loop back to the beginning of the tree now.
*/
eb = eb32_first(&t->exps);
if (likely(!eb))
break;
}
if (likely(tick_is_lt(now_ms, eb->key))) {
/* timer not expired yet, revisit it later */
t->exp_next = eb->key;
return t->exp_next;
}
/* timer looks expired, detach it from the queue */
ts = eb32_entry(eb, struct stksess, exp);
eb = eb32_next(eb);
eb32_delete(&ts->exp);
if (!tick_is_expired(ts->expire, now_ms)) {
if (!tick_isset(ts->expire))
continue;
ts->exp.key = ts->expire;
eb32_insert(&t->exps, &ts->exp);
if (!eb || eb->key > ts->exp.key)
eb = &ts->exp;
continue;
}
/* session expired, trash it */
ebmb_delete(&ts->key);
stksess_free(t, ts);
}
/* We have found no task to expire in any tree */
t->exp_next = TICK_ETERNITY;
return t->exp_next;
}
/*
* Task processing function to trash expired sticky sessions. A pointer to the
* task itself is returned since it never dies.
*/
static struct task *process_table_expire(struct task *task)
{
struct stktable *t = (struct stktable *)task->context;
task->expire = stktable_trash_expired(t);
return task;
}
/* Perform minimal stick table intializations, report 0 in case of error, 1 if OK. */
int stktable_init(struct stktable *t)
{
if (t->size) {
memset(&t->keys, 0, sizeof(t->keys));
memset(&t->exps, 0, sizeof(t->exps));
t->pool = create_pool("sticktables", sizeof(struct stksess) + t->data_size + t->key_size, MEM_F_SHARED);
t->exp_next = TICK_ETERNITY;
if ( t->expire ) {
t->exp_task = task_new();
t->exp_task->process = process_table_expire;
t->exp_task->expire = TICK_ETERNITY;
t->exp_task->context = (void *)t;
}
return t->pool != NULL;
}
return 1;
}
/*
* Configuration keywords of known table types
*/
struct stktable_type stktable_types[STKTABLE_TYPES] = { { "ip", 0, 4 } ,
{ "integer", 0, 4 },
{ "string", STK_F_CUSTOM_KEYSIZE, 32 } };
/*
* Parse table type configuration.
* Returns 0 on successful parsing, else 1.
* <myidx> is set at next configuration <args> index.
*/
int stktable_parse_type(char **args, int *myidx, unsigned long *type, size_t *key_size)
{
for (*type = 0; *type < STKTABLE_TYPES; (*type)++) {
if (strcmp(args[*myidx], stktable_types[*type].kw) != 0)
continue;
*key_size = stktable_types[*type].default_size;
(*myidx)++;
if (stktable_types[*type].flags & STK_F_CUSTOM_KEYSIZE) {
if (strcmp("len", args[*myidx]) == 0) {
(*myidx)++;
*key_size = atol(args[*myidx]);
if ( !*key_size )
break;
/* null terminated string needs +1 for '\0'. */
(*key_size)++;
(*myidx)++;
}
}
return 0;
}
return 1;
}
/*****************************************************************/
/* typed pattern to typed table key functions */
/*****************************************************************/
static void *k_int2int(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
return (void *)&pdata->integer;
}
static void *k_ip2ip(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
return (void *)&pdata->ip.s_addr;
}
static void *k_ip2int(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
kdata->integer = ntohl(pdata->ip.s_addr);
return (void *)&kdata->integer;
}
static void *k_int2ip(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
kdata->ip.s_addr = htonl(pdata->integer);
return (void *)&kdata->ip.s_addr;
}
static void *k_str2str(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
*len = pdata->str.len;
return (void *)pdata->str.str;
}
static void *k_ip2str(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
if (!inet_ntop(AF_INET, &pdata->ip, kdata->buf, sizeof(kdata->buf)))
return NULL;
*len = strlen((const char *)kdata->buf);
return (void *)kdata->buf;
}
static void *k_int2str(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
void *key;
key = (void *)ultoa_r(pdata->integer, kdata->buf, sizeof(kdata->buf));
if (!key)
return NULL;
*len = strlen((const char *)key);
return key;
}
static void *k_str2ip(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
if (!buf2ip(pdata->str.str, pdata->str.len, &kdata->ip))
return NULL;
return (void *)&kdata->ip.s_addr;
}
static void *k_str2int(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
int i;
kdata->integer = 0;
for (i = 0; i < pdata->str.len; i++) {
uint32_t val = pdata->str.str[i] - '0';
if (val > 9)
break;
kdata->integer = kdata->integer * 10 + val;
}
return (void *)&kdata->integer;
}
/*****************************************************************/
/* typed pattern to typed table key matrix: */
/* pattern_to_key[from pattern type][to table key type] */
/* NULL pointer used for impossible pattern casts */
/*****************************************************************/
typedef void *(*pattern_to_key_fct)(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len);
static pattern_to_key_fct pattern_to_key[PATTERN_TYPES][STKTABLE_TYPES] = {
{ k_ip2ip, k_ip2int, k_ip2str },
{ k_int2ip, k_int2int, k_int2str },
{ k_str2ip, k_str2int, k_str2str },
};
/*
* Process a fetch + format conversion as defined by the pattern expression <expr>
* on request or response considering the <dir> parameter. Returns either NULL if
* no key could be extracted, or a pointer to the converted result stored in
* static_table_key in format <table_type>.
*/
struct stktable_key *stktable_fetch_key(struct proxy *px, struct session *l4, void *l7, int dir,
struct pattern_expr *expr, unsigned long table_type)
{
struct pattern *ptrn;
ptrn = pattern_process(px, l4, l7, dir, expr, NULL);
if (!ptrn)
return NULL;
static_table_key.key_len = (size_t)-1;
static_table_key.key = pattern_to_key[ptrn->type][table_type](&ptrn->data, &static_table_key.data, &static_table_key.key_len);
if (!static_table_key.key)
return NULL;
return &static_table_key;
}
/*
* Returns 1 if pattern expression <expr> result can be converted to table key of
* type <table_type>, otherwise zero. Used in configuration check.
*/
int stktable_compatible_pattern(struct pattern_expr *expr, unsigned long table_type)
{
if (table_type >= STKTABLE_TYPES)
return 0;
if (LIST_ISEMPTY(&expr->conv_exprs)) {
if (!pattern_to_key[expr->fetch->out_type][table_type])
return 0;
} else {
struct pattern_conv_expr *conv_expr;
conv_expr = LIST_PREV(&expr->conv_exprs, typeof(conv_expr), list);
if (!pattern_to_key[conv_expr->conv->out_type][table_type])
return 0;
}
return 1;
}
/* Extra data types processing */
struct stktable_data_type stktable_data_types[STKTABLE_DATA_TYPES] = {
[STKTABLE_DT_CONN_CUM] = { .name = "conn_cum", .data_length = stktable_data_size(conn_cum) },
[STKTABLE_DT_SERVER_ID] = { .name = "server_id", .data_length = stktable_data_size(server_id) },
};
/*
* Returns the data type number for the stktable_data_type whose name is <name>,
* or <0 if not found.
*/
int stktable_get_data_type(char *name)
{
int type;
for (type = 0; type < STKTABLE_DATA_TYPES; type++) {
if (strcmp(name, stktable_data_types[type].name) == 0)
return type;
}
return -1;
}