lib/eggdrop/dns.h File Reference

Go to the source code of this file.

Defines
#define	DNS_IPV4   1
#define	DNS_IPV6   2
#define	DNS_REVERSE   3
#define	DNS_PORT   53
Typedefs
typedef int(*	dns_callback_t )(void *client_data, const char *query, char **result)
Functions
int	egg_dns_init (void)
int	egg_dns_shutdown (void)
void	egg_dns_send (char *query, int len)
int	egg_dns_lookup (const char *host, int timeout, dns_callback_t callback, void *client_data, event_owner_t *owner)
int	egg_dns_reverse (const char *ip, int timeout, dns_callback_t callback, void *client_data, event_owner_t *owner)
int	egg_dns_cancel (int id, int issue_callback)
int	egg_dns_cancel_by_owner (struct egg_module *module, void *script)

---

Define Documentation

#define DNS_IPV4   1

Definition at line 25 of file dns.h.

#define DNS_IPV6   2

Definition at line 26 of file dns.h.

#define DNS_PORT   53

Definition at line 29 of file dns.h.

Referenced by get_dns_idx().

#define DNS_REVERSE   3

Definition at line 27 of file dns.h.

---

Typedef Documentation

typedef int(* dns_callback_t)(void *client_data, const char *query, char **result)

Definition at line 31 of file dns.h.

---

Function Documentation

int egg_dns_cancel	(	int	id,
		int	issue_callback
	)

Definition at line 557 of file dns.c.

References dns_query::callback, dns_query::client_data, dns_query::id, dns_query::next, NULL, event_owner_b::on_delete, dns_query::owner, and dns_query::query.

Referenced by egg_connect_timeout(), egg_on_delete(), and kill_session().

{
  dns_query_t *q, *prev;

  prev = NULL;
  for (q = query_head; q; q = q->next) {
    if (q->id == id) break;
    prev = q;
  }
  if (!q) return(-1);
  if (prev) prev->next = q->next;
  else query_head = q->next;

  if (issue_callback) q->callback(q->client_data, q->query, NULL);
  if (q->owner && q->owner->on_delete) q->owner->on_delete(q->owner, q->client_data);
  free(q);
  return(0);
}

int egg_dns_cancel_by_owner	(	struct egg_module *	module,
		void *	script
	)

Definition at line 576 of file dns.c.

References dns_query::client_data, event_owner_b::client_data, event_owner_b::module, dns_query::next, NULL, event_owner_b::on_delete, and dns_query::owner.

Referenced by script_remove_events_by_owner().

{
  int removed = 0;
  dns_query_t *q, *prev= NULL, *next;

  for (q = query_head; q; q = next) {
    next = q->next;
    if (!q->owner || q->owner->module != module || (script && q->owner->client_data != script)) {
      prev = q;
      continue;
    }
    if (prev) prev->next = q->next;
    else query_head = q->next;
    ++removed;

    if (q->owner && q->owner->on_delete) q->owner->on_delete(q->owner, q->client_data);
    free(q);
  }
  return removed;
}

int egg_dns_init

(

void

)

Definition at line 398 of file dns.c.

References expire_queries(), dns_header_t::flags, read_hosts(), read_resolv(), and timer_create_secs().

Referenced by egg_net_init().

{
  _dns_header.flags = htons(1 << 8 | 1 << 7);
  read_resolv("/etc/resolv.conf");
  read_resolv(".resolv.conf");
  read_hosts("/etc/hosts");
  read_hosts(".hosts");
  timer_create_secs(1, "dns_check_expires", (Function) expire_queries);
  return(0);
}

int egg_dns_lookup	(	const char *	host,
		int	timeout,
		dns_callback_t	callback,
		void *	client_data,
		event_owner_t *	owner
	)

Definition at line 173 of file dns.c.

References dns_cache_t::answer, answer_add(), answer_free(), answer_init(), cache_find(), dns_query::callback, dns_query::client_data, cut_host(), egg_dns_send(), dns_query::id, dns_answer_t::len, dns_answer_t::list, make_header(), dns_query::next, nhosts, event_owner_b::on_delete, dns_query::owner, dns_query::query, query_id, dns_query::remaining, shuffleArray(), and socket_valid_ip().

Referenced by dcc_dns_set(), egg_client(), and script_dns_lookup().

{
  char buf[512];
  dns_query_t *q;
  int i, len, cache_id;

  if (socket_valid_ip(host)) {
    /* If it's already an ip, we're done. */
    dns_answer_t answer;

    answer_init(&answer);
    answer_add(&answer, host);
    callback(client_data, host, answer.list);
    answer_free(&answer);
    if (owner && owner->on_delete) owner->on_delete(owner, client_data);
    return(-1);
  }
  
  /* Search our cache for the same query */
  cache_id = cache_find(host);
  if (cache_id >= 0) {
    shuffleArray(cache[cache_id].answer.list, cache[cache_id].answer.len);
    callback(client_data, host, cache[cache_id].answer.list);
    if (owner && owner->on_delete) owner->on_delete(owner, client_data);
    return(-1);
  }

  /* Ok, now see if it's in our host cache. */
  for (i = 0; i < nhosts; i++) {
    if (!strcasecmp(host, hosts[i].host)) {
      dns_answer_t answer;

      answer_init(&answer);
      answer_add(&answer, hosts[i].ip);
      callback(client_data, host, answer.list);
      answer_free(&answer);
      if (owner && owner->on_delete) owner->on_delete(owner, client_data);
      return(-1);
    }
  }

  /* Allocate our query struct. */
  q = calloc(1, sizeof(*q));
  q->id = query_id;
  query_id++;
  q->query = strdup(host);
  q->callback = callback;
  q->client_data = client_data;
  q->owner = owner;
  q->next = query_head;
  query_head = q;

  /* Send the ipv4 query. */
  q->remaining = 1;
  len = make_header(buf, q->id);
  len += cut_host(host, buf + len);
  buf[len] = 0; len++; buf[len] = 1; len++;
  buf[len] = 0; len++; buf[len] = 1; len++;

  egg_dns_send(buf, len);

#ifdef IPV6
  /* Now send the ipv6 query. */
  q->remaining++;
  len = make_header(buf, q->id);
  len += cut_host(host, buf + len);
  buf[len] = 0; len++; buf[len] = 28; len++;
  buf[len] = 0; len++; buf[len] = 1; len++;

  egg_dns_send(buf, len);
#endif

  return(q->id);
}

int egg_dns_reverse	(	const char *	ip,
		int	timeout,
		dns_callback_t	callback,
		void *	client_data,
		event_owner_t *	owner
	)

Definition at line 251 of file dns.c.

References dns_cache_t::answer, answer_add(), answer_free(), answer_init(), cache_find(), dns_query::callback, dns_query::client_data, cut_host(), egg_dns_send(), dns_query::id, dns_answer_t::len, dns_answer_t::list, make_header(), dns_query::next, nhosts, NULL, event_owner_b::on_delete, dns_query::owner, dns_query::query, query_id, reverse_ip(), shuffleArray(), socket_ipv6_to_dots(), and socket_valid_ip().

Referenced by dcc_on_connect(), irc_on_newclient(), script_dns_reverse(), and telnet_on_newclient().

{
  dns_query_t *q;
  char buf[512], *reversed_ip;
  int i, len, cache_id;

  if (!socket_valid_ip(ip)) {
    /* If it's not a valid ip, don't even make the request. */
    callback(client_data, ip, NULL);
    if (owner && owner->on_delete) owner->on_delete(owner, client_data);
    return(-1);
  }

  /* Ok, see if we have it in our host cache. */
  for (i = 0; i < nhosts; i++) {
    if (!strcasecmp(hosts[i].ip, ip)) {
      dns_answer_t answer;

      answer_init(&answer);
      answer_add(&answer, hosts[i].host);
      callback(client_data, ip, answer.list);
      answer_free(&answer);
      if (owner && owner->on_delete) owner->on_delete(owner, client_data);
      return(-1);
    }
  }

  /* Search our cache for the same query */
  cache_id = cache_find(ip);
  if (cache_id >= 0) {
    shuffleArray(cache[cache_id].answer.list, cache[cache_id].answer.len);
    callback(client_data, ip, cache[cache_id].answer.list);
    if (owner && owner->on_delete) owner->on_delete(owner, client_data);
    return(-1);
  }

  /* We need to transform the ip address into the proper form
   * for reverse lookup. */
  if (strchr(ip, ':')) {
    char temp[64];

    socket_ipv6_to_dots(ip, temp);
    reversed_ip = malloc(strlen(temp) + 10);
    reverse_ip(temp, reversed_ip);
    strcat(reversed_ip, ".ip6.arpa");
  }
  else {
    reversed_ip = malloc(strlen(ip) + 14);
    reverse_ip(ip, reversed_ip);
    strcat(reversed_ip, ".in-addr.arpa");
  }

  len = make_header(buf, query_id);
  len += cut_host(reversed_ip, buf + len);
  buf[len] = 0; len++; buf[len] = 12; len++;
  buf[len] = 0; len++; buf[len] = 1; len++;

  free(reversed_ip);

  q = calloc(1, sizeof(*q));
  q->id = query_id;
  query_id++;
  q->query = strdup(ip);
  q->callback = callback;
  q->client_data = client_data;
  q->owner = owner;
  q->next = query_head;
  query_head = q;

  egg_dns_send(buf, len);

  return(q->id);
}

void egg_dns_send	(	char *	query,
		int	len
	)

Definition at line 161 of file dns.c.

References dns_idx, get_dns_idx(), and sockbuf_write().

Referenced by egg_dns_lookup(), and egg_dns_reverse().

{
  if (dns_idx < 0) {
    get_dns_idx();
    if (dns_idx < 0) return;
  }
  sockbuf_write(dns_idx, query, len);
}

int egg_dns_shutdown

(

void

)

Definition at line 409 of file dns.c.

References nhosts, nservers, and NULL.

Referenced by egg_net_shutdown().

{
  int i;

  if (nservers > 0) {
    for (i = 0; i < nservers; i++) {
      if (servers[i].ip) free(servers[i].ip);
    }
    free(servers); servers = NULL;
    nservers = 0;
  }
  
  if (nhosts > 0) {
    for (i = 0; i < nhosts; i++) {
      if (hosts[i].host) free(hosts[i].host);
      if (hosts[i].ip) free(hosts[i].ip);
    }
    free(hosts); hosts = NULL;
    nhosts = 0;
  }

  return (0);
}