nes-proj/os/services/ip64/ip64-addrmap.c
2017-09-22 17:09:54 +02:00

255 lines
7.3 KiB
C

/*
* Copyright (c) 2012, Thingsquare, http://www.thingsquare.com/.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "ip64/ip64-addrmap.h"
#include "lib/memb.h"
#include "lib/list.h"
#include "ip64-conf.h"
#include "lib/random.h"
#include <string.h>
#ifdef IP64_ADDRMAP_CONF_ENTRIES
#define NUM_ENTRIES IP64_ADDRMAP_CONF_ENTRIES
#else /* IP64_ADDRMAP_CONF_ENTRIES */
#define NUM_ENTRIES 32
#endif /* IP64_ADDRMAP_CONF_ENTRIES */
MEMB(entrymemb, struct ip64_addrmap_entry, NUM_ENTRIES);
LIST(entrylist);
#define FIRST_MAPPED_PORT 10000
#define LAST_MAPPED_PORT 20000
static uint16_t mapped_port = FIRST_MAPPED_PORT;
#define printf(...)
/*---------------------------------------------------------------------------*/
struct ip64_addrmap_entry *
ip64_addrmap_list(void)
{
return list_head(entrylist);
}
/*---------------------------------------------------------------------------*/
void
ip64_addrmap_init(void)
{
memb_init(&entrymemb);
list_init(entrylist);
mapped_port = FIRST_MAPPED_PORT;
}
/*---------------------------------------------------------------------------*/
static void
check_age(void)
{
struct ip64_addrmap_entry *m;
/* Walk through the list of address mappings, throw away the ones
that are too old. */
m = list_head(entrylist);
while(m != NULL) {
if(timer_expired(&m->timer)) {
list_remove(entrylist, m);
memb_free(&entrymemb, m);
m = list_head(entrylist);
} else {
m = list_item_next(m);
}
}
}
/*---------------------------------------------------------------------------*/
static int
recycle(void)
{
/* Find the oldest recyclable mapping and remove it. */
struct ip64_addrmap_entry *m, *oldest;
/* Walk through the list of address mappings, throw away the ones
that are too old. */
oldest = NULL;
for(m = list_head(entrylist);
m != NULL;
m = list_item_next(m)) {
if(m->flags & FLAGS_RECYCLABLE) {
if(oldest == NULL) {
oldest = m;
} else {
if(timer_remaining(&m->timer) <
timer_remaining(&oldest->timer)) {
oldest = m;
}
}
}
}
/* If we found an oldest recyclable entry, remove it and return
non-zero. */
if(oldest != NULL) {
list_remove(entrylist, oldest);
memb_free(&entrymemb, oldest);
return 1;
}
return 0;
}
/*---------------------------------------------------------------------------*/
struct ip64_addrmap_entry *
ip64_addrmap_lookup(const uip_ip6addr_t *ip6addr,
uint16_t ip6port,
const uip_ip4addr_t *ip4addr,
uint16_t ip4port,
uint8_t protocol)
{
struct ip64_addrmap_entry *m;
printf("lookup ip4port %d ip6port %d\n", uip_htons(ip4port),
uip_htons(ip6port));
check_age();
for(m = list_head(entrylist); m != NULL; m = list_item_next(m)) {
printf("protocol %d %d, ip4port %d %d, ip6port %d %d, ip4 %d ip6 %d\n",
m->protocol, protocol,
m->ip4port, ip4port,
m->ip6port, ip6port,
uip_ip4addr_cmp(&m->ip4addr, ip4addr),
uip_ip6addr_cmp(&m->ip6addr, ip6addr));
if(m->protocol == protocol &&
m->ip4port == ip4port &&
m->ip6port == ip6port &&
uip_ip4addr_cmp(&m->ip4addr, ip4addr) &&
uip_ip6addr_cmp(&m->ip6addr, ip6addr)) {
m->ip6to4++;
return m;
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
struct ip64_addrmap_entry *
ip64_addrmap_lookup_port(uint16_t mapped_port, uint8_t protocol)
{
struct ip64_addrmap_entry *m;
check_age();
for(m = list_head(entrylist); m != NULL; m = list_item_next(m)) {
printf("mapped port %d %d, protocol %d %d\n",
m->mapped_port, mapped_port,
m->protocol, protocol);
if(m->mapped_port == mapped_port &&
m->protocol == protocol) {
m->ip4to6++;
return m;
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
static void
increase_mapped_port(void)
{
mapped_port = (random_rand() % (LAST_MAPPED_PORT - FIRST_MAPPED_PORT)) +
FIRST_MAPPED_PORT;
}
/*---------------------------------------------------------------------------*/
struct ip64_addrmap_entry *
ip64_addrmap_create(const uip_ip6addr_t *ip6addr,
uint16_t ip6port,
const uip_ip4addr_t *ip4addr,
uint16_t ip4port,
uint8_t protocol)
{
struct ip64_addrmap_entry *m;
check_age();
m = memb_alloc(&entrymemb);
if(m == NULL) {
/* We could not allocate an entry, try to recycle one and try to
allocate again. */
if(recycle()) {
m = memb_alloc(&entrymemb);
}
}
if(m != NULL) {
uip_ip4addr_copy(&m->ip4addr, ip4addr);
m->ip4port = ip4port;
uip_ip6addr_copy(&m->ip6addr, ip6addr);
m->ip6port = ip6port;
m->protocol = protocol;
m->flags = FLAGS_NONE;
m->ip6to4 = 1;
m->ip4to6 = 0;
timer_set(&m->timer, 0);
/* Pick a new, unused local port. First make sure that the
mapped_port number does not belong to any active connection. If
so, we keep increasing the mapped_port until we're free. */
{
struct ip64_addrmap_entry *n;
n = list_head(entrylist);
while(n != NULL) {
if(n->mapped_port == mapped_port) {
increase_mapped_port();
n = list_head(entrylist);
} else {
n = list_item_next(m);
}
}
}
m->mapped_port = mapped_port;
increase_mapped_port();
list_add(entrylist, m);
return m;
}
return NULL;
}
/*---------------------------------------------------------------------------*/
void
ip64_addrmap_set_lifetime(struct ip64_addrmap_entry *e,
clock_time_t time)
{
if(e != NULL) {
timer_set(&e->timer, time);
}
}
/*---------------------------------------------------------------------------*/
void
ip64_addrmap_set_recycleble(struct ip64_addrmap_entry *e)
{
if(e != NULL) {
e->flags |= FLAGS_RECYCLABLE;
}
}
/*---------------------------------------------------------------------------*/