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/* C-Ares integration to Quagga mainloop
* Copyright (c) 2014-2015 Timo Teräs
*
* This file is free software: you may copy, redistribute 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 <ares.h>
#include <ares_version.h>
#include "vector.h"
#include "thread.h"
#include "nhrpd.h"
struct resolver_state {
ares_channel channel;
struct thread *timeout;
vector read_threads, write_threads;
};
static struct resolver_state state;
#define THREAD_RUNNING ((struct thread *)-1)
static void resolver_update_timeouts(struct resolver_state *r);
static int resolver_cb_timeout(struct thread *t)
{
struct resolver_state *r = THREAD_ARG(t);
r->timeout = THREAD_RUNNING;
ares_process(r->channel, NULL, NULL);
r->timeout = NULL;
resolver_update_timeouts(r);
return 0;
}
static int resolver_cb_socket_readable(struct thread *t)
{
struct resolver_state *r = THREAD_ARG(t);
int fd = THREAD_FD(t);
vector_set_index(r->read_threads, fd, THREAD_RUNNING);
ares_process_fd(r->channel, fd, ARES_SOCKET_BAD);
if (vector_lookup(r->read_threads, fd) == THREAD_RUNNING) {
t = NULL;
thread_add_read(master, resolver_cb_socket_readable, r, fd, &t);
vector_set_index(r->read_threads, fd, t);
}
resolver_update_timeouts(r);
return 0;
}
static int resolver_cb_socket_writable(struct thread *t)
{
struct resolver_state *r = THREAD_ARG(t);
int fd = THREAD_FD(t);
vector_set_index(r->write_threads, fd, THREAD_RUNNING);
ares_process_fd(r->channel, ARES_SOCKET_BAD, fd);
if (vector_lookup(r->write_threads, fd) == THREAD_RUNNING) {
t = NULL;
thread_add_write(master, resolver_cb_socket_writable, r, fd,
&t);
vector_set_index(r->write_threads, fd, t);
}
resolver_update_timeouts(r);
return 0;
}
static void resolver_update_timeouts(struct resolver_state *r)
{
struct timeval *tv, tvbuf;
if (r->timeout == THREAD_RUNNING)
return;
THREAD_OFF(r->timeout);
tv = ares_timeout(r->channel, NULL, &tvbuf);
if (tv) {
unsigned int timeoutms = tv->tv_sec * 1000 + tv->tv_usec / 1000;
thread_add_timer_msec(master, resolver_cb_timeout, r, timeoutms,
&r->timeout);
}
}
static void ares_socket_cb(void *data, ares_socket_t fd, int readable,
int writable)
{
struct resolver_state *r = (struct resolver_state *)data;
struct thread *t;
if (readable) {
t = vector_lookup_ensure(r->read_threads, fd);
if (!t) {
thread_add_read(master, resolver_cb_socket_readable, r,
fd, &t);
vector_set_index(r->read_threads, fd, t);
}
} else {
t = vector_lookup(r->read_threads, fd);
if (t) {
if (t != THREAD_RUNNING) {
THREAD_OFF(t);
}
vector_unset(r->read_threads, fd);
}
}
if (writable) {
t = vector_lookup_ensure(r->write_threads, fd);
if (!t) {
thread_add_read(master, resolver_cb_socket_writable, r,
fd, &t);
vector_set_index(r->write_threads, fd, t);
}
} else {
t = vector_lookup(r->write_threads, fd);
if (t) {
if (t != THREAD_RUNNING) {
THREAD_OFF(t);
}
vector_unset(r->write_threads, fd);
}
}
}
void resolver_init(void)
{
struct ares_options ares_opts;
state.read_threads = vector_init(1);
state.write_threads = vector_init(1);
ares_opts = (struct ares_options){
.sock_state_cb = &ares_socket_cb,
.sock_state_cb_data = &state,
.timeout = 2,
.tries = 3,
};
ares_init_options(&state.channel, &ares_opts,
ARES_OPT_SOCK_STATE_CB | ARES_OPT_TIMEOUT
| ARES_OPT_TRIES);
}
static void ares_address_cb(void *arg, int status, int timeouts,
struct hostent *he)
{
struct resolver_query *query = (struct resolver_query *)arg;
union sockunion addr[16];
size_t i;
if (status != ARES_SUCCESS) {
debugf(NHRP_DEBUG_COMMON, "[%p] Resolving failed", query);
query->callback(query, -1, NULL);
query->callback = NULL;
return;
}
for (i = 0; i < ZEBRA_NUM_OF(addr) && he->h_addr_list[i] != NULL; i++) {
memset(&addr[i], 0, sizeof(addr[i]));
addr[i].sa.sa_family = he->h_addrtype;
switch (he->h_addrtype) {
case AF_INET:
memcpy(&addr[i].sin.sin_addr,
(uint8_t *)he->h_addr_list[i], he->h_length);
break;
case AF_INET6:
memcpy(&addr[i].sin6.sin6_addr,
(uint8_t *)he->h_addr_list[i], he->h_length);
break;
}
}
debugf(NHRP_DEBUG_COMMON, "[%p] Resolved with %d results", query,
(int)i);
query->callback(query, i, &addr[0]);
query->callback = NULL;
}
void resolver_resolve(struct resolver_query *query, int af,
const char *hostname,
void (*callback)(struct resolver_query *, int,
union sockunion *))
{
if (query->callback != NULL) {
zlog_err(
"Trying to resolve '%s', but previous query was not finished yet",
hostname);
return;
}
debugf(NHRP_DEBUG_COMMON, "[%p] Resolving '%s'", query, hostname);
query->callback = callback;
ares_gethostbyname(state.channel, hostname, af, ares_address_cb, query);
resolver_update_timeouts(&state);
}
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