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/**
* @file libnatpmp.c NAT-PMP Client library
*
* Copyright (C) 2010 Creytiv.com
*/
#include <string.h>
#include <re.h>
#include <baresip.h>
#include "libnatpmp.h"
enum {
NATPMP_DELAY = 250,
NATPMP_MAXTX = 9,
};
struct natpmp_req {
struct natpmp_req **npp;
struct udp_sock *us;
struct tmr tmr;
struct mbuf *mb;
struct sa srv;
unsigned n;
natpmp_resp_h *resph;
void *arg;
};
static void completed(struct natpmp_req *np, int err,
const struct natpmp_resp *resp)
{
natpmp_resp_h *resph = np->resph;
void *arg = np->arg;
tmr_cancel(&np->tmr);
if (np->npp) {
*np->npp = NULL;
np->npp = NULL;
}
np->resph = NULL;
/* must be destroyed before calling handler */
mem_deref(np);
if (resph)
resph(err, resp, arg);
}
static void destructor(void *arg)
{
struct natpmp_req *np = arg;
tmr_cancel(&np->tmr);
mem_deref(np->us);
mem_deref(np->mb);
}
static void timeout(void *arg)
{
struct natpmp_req *np = arg;
int err;
if (np->n > NATPMP_MAXTX) {
completed(np, ETIMEDOUT, NULL);
return;
}
tmr_start(&np->tmr, NATPMP_DELAY<<np->n, timeout, arg);
#if 1
debug("natpmp: {n=%u} tx %u bytes\n", np->n, np->mb->end);
#endif
np->n++;
np->mb->pos = 0;
err = udp_send(np->us, &np->srv, np->mb);
if (err) {
completed(np, err, NULL);
}
}
static int resp_decode(struct natpmp_resp *resp, struct mbuf *mb)
{
resp->vers = mbuf_read_u8(mb);
resp->op = mbuf_read_u8(mb);
resp->result = ntohs(mbuf_read_u16(mb));
resp->epoch = ntohl(mbuf_read_u32(mb));
if (!(resp->op & 0x80))
return EPROTO;
resp->op &= ~0x80;
switch (resp->op) {
case NATPMP_OP_EXTERNAL:
resp->u.ext_addr = ntohl(mbuf_read_u32(mb));
break;
case NATPMP_OP_MAPPING_UDP:
case NATPMP_OP_MAPPING_TCP:
resp->u.map.int_port = ntohs(mbuf_read_u16(mb));
resp->u.map.ext_port = ntohs(mbuf_read_u16(mb));
resp->u.map.lifetime = ntohl(mbuf_read_u32(mb));
break;
default:
warning("natmap: unknown opcode %d\n", resp->op);
return EBADMSG;
}
return 0;
}
static void udp_recv(const struct sa *src, struct mbuf *mb, void *arg)
{
struct natpmp_req *np = arg;
struct natpmp_resp resp;
if (!sa_cmp(src, &np->srv, SA_ALL))
return;
if (resp_decode(&resp, mb))
return;
completed(np, 0, &resp);
}
static int natpmp_init(struct natpmp_req *np, const struct sa *srv,
uint8_t opcode, natpmp_resp_h *resph, void *arg)
{
int err;
if (!np || !srv)
return EINVAL;
/* a new UDP socket for each NAT-PMP request */
err = udp_listen(&np->us, NULL, udp_recv, np);
if (err)
return err;
np->srv = *srv;
np->resph = resph;
np->arg = arg;
udp_connect(np->us, srv);
np->mb = mbuf_alloc(512);
if (!np->mb)
return ENOMEM;
err |= mbuf_write_u8(np->mb, NATPMP_VERSION);
err |= mbuf_write_u8(np->mb, opcode);
return err;
}
int natpmp_external_request(struct natpmp_req **npp, const struct sa *srv,
natpmp_resp_h *resph, void *arg)
{
struct natpmp_req *np;
int err;
np = mem_zalloc(sizeof(*np), destructor);
if (!np)
return ENOMEM;
err = natpmp_init(np, srv, NATPMP_OP_EXTERNAL, resph, arg);
if (err)
goto out;
timeout(np);
out:
if (err)
mem_deref(np);
else if (npp) {
np->npp = npp;
*npp = np;
}
else {
/* Destroy the transaction now */
mem_deref(np);
}
return err;
}
int natpmp_mapping_request(struct natpmp_req **npp, const struct sa *srv,
uint16_t int_port, uint16_t ext_port,
uint32_t lifetime, natpmp_resp_h *resph, void *arg)
{
struct natpmp_req *np;
int err;
np = mem_zalloc(sizeof(*np), destructor);
if (!np)
return ENOMEM;
err = natpmp_init(np, srv, NATPMP_OP_MAPPING_UDP, resph, arg);
if (err)
goto out;
err |= mbuf_write_u16(np->mb, 0x0000);
err |= mbuf_write_u16(np->mb, htons(int_port));
err |= mbuf_write_u16(np->mb, htons(ext_port));
err |= mbuf_write_u32(np->mb, htonl(lifetime));
if (err)
goto out;
timeout(np);
out:
if (err)
mem_deref(np);
else if (npp) {
np->npp = npp;
*npp = np;
}
else {
/* Destroy the transaction now */
mem_deref(np);
}
return err;
}
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