dnsmgr.h File Reference

Background DNS update manager. More...

#include "asterisk/netsock2.h"
#include "asterisk/srv.h"

Include dependency graph for dnsmgr.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Typedefs
typedef void(*	dns_update_func )(struct ast_sockaddr *old_addr, struct ast_sockaddr *new_addr, void *data)
Functions
int	ast_dnsmgr_changed (struct ast_dnsmgr_entry *entry)
	Check is see if a dnsmgr entry has changed.
struct ast_dnsmgr_entry *	ast_dnsmgr_get (const char *name, struct ast_sockaddr *result, const char *service)
	Allocate a new DNS manager entry.
struct ast_dnsmgr_entry *	ast_dnsmgr_get_family (const char *name, struct ast_sockaddr *result, const char *service, unsigned int family)
	Allocate a new DNS manager entry.
int	ast_dnsmgr_lookup (const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service)
	Allocate and initialize a DNS manager entry.
int	ast_dnsmgr_lookup_cb (const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service, dns_update_func func, void *data)
	Allocate and initialize a DNS manager entry, with update callback.
int	ast_dnsmgr_refresh (struct ast_dnsmgr_entry *entry)
	Force a refresh of a dnsmgr entry.
void	ast_dnsmgr_release (struct ast_dnsmgr_entry *entry)
	Free a DNS manager entry.

---

Detailed Description

Background DNS update manager.

Definition in file dnsmgr.h.

---

Typedef Documentation

typedef void(* dns_update_func)(struct ast_sockaddr *old_addr, struct ast_sockaddr *new_addr, void *data)

Definition at line 40 of file dnsmgr.h.

---

Function Documentation

int ast_dnsmgr_changed

(

struct ast_dnsmgr_entry *

entry

)

Check is see if a dnsmgr entry has changed.

Return values:

	non-zero	if the dnsmgr entry has changed since the last call to this function
	zero	if the dnsmgr entry has not changed since the last call to this function

Definition at line 235 of file dnsmgr.c.

References ast_mutex_lock, ast_mutex_unlock, ast_dnsmgr_entry::changed, and ast_dnsmgr_entry::lock.

Referenced by iax2_do_register().

{
   int changed;

   ast_mutex_lock(&entry->lock);

   changed = entry->changed;
   entry->changed = 0;

   ast_mutex_unlock(&entry->lock);

   return changed;
}

struct ast_dnsmgr_entry* ast_dnsmgr_get	(	const char *	name,
		struct ast_sockaddr *	result,
		const char *	service
	)			[read]

Allocate a new DNS manager entry.

Parameters:

	name	the hostname
	result	where the DNS manager should store the IP address as it refreshes it.
	service

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function does not force an initial lookup of the IP address. So, generally, this should be used when the initial address is already known.

Returns:

a DNS manager entry

Version:

1.6.1 result changed from struct in_addr to struct sockaddr_in to store port number

1.8.0 result changed from struct ast_sockaddr_in to ast_sockaddr for IPv6 support

Definition at line 117 of file dnsmgr.c.

References ast_dnsmgr_get_family().

{
   return ast_dnsmgr_get_family(name, result, service, 0);
}

struct ast_dnsmgr_entry* ast_dnsmgr_get_family	(	const char *	name,
		struct ast_sockaddr *	result,
		const char *	service,
		unsigned int	family
	)			[read]

Allocate a new DNS manager entry.

Parameters:

	name	the hostname
	result	where the DNS manager should store the IP address as it refreshes it.
	service
	family	Address family to filter DNS addresses.

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function does not force an initial lookup of the IP address. So, generally, this should be used when the initial address is already known.

Returns:

a DNS manager entry

Definition at line 92 of file dnsmgr.c.

References ast_calloc, ast_mutex_init, AST_RWLIST_INSERT_HEAD, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, ast_strlen_zero(), ast_dnsmgr_entry::family, ast_dnsmgr_entry::lock, ast_dnsmgr_entry::name, ast_dnsmgr_entry::result, and ast_dnsmgr_entry::service.

Referenced by ast_dnsmgr_get(), and internal_dnsmgr_lookup().

{
   struct ast_dnsmgr_entry *entry;
   int total_size = sizeof(*entry) + strlen(name) + (service ? strlen(service) + 1 : 0);

   if (!result || ast_strlen_zero(name) || !(entry = ast_calloc(1, total_size))) {
      return NULL;
   }

   entry->result = result;
   ast_mutex_init(&entry->lock);
   strcpy(entry->name, name);
   if (service) {
      entry->service = ((char *) entry) + sizeof(*entry) + strlen(name);
      strcpy(entry->service, service);
   }
   entry->family = family;

   AST_RWLIST_WRLOCK(&entry_list);
   AST_RWLIST_INSERT_HEAD(&entry_list, entry, list);
   AST_RWLIST_UNLOCK(&entry_list);

   return entry;
}

int ast_dnsmgr_lookup	(	const char *	name,
		struct ast_sockaddr *	result,
		struct ast_dnsmgr_entry **	dnsmgr,
		const char *	service
	)

Allocate and initialize a DNS manager entry.

Parameters:

	name	the hostname
	result	where to store the IP address as the DNS manager refreshes it. The address family is used as an input parameter to filter the returned addresses. If it is 0, both IPv4 and IPv6 addresses can be returned.
	dnsmgr	Where to store the allocate DNS manager entry
	service

Note:

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function _does_ force an initial lookup, so it may block for some period of time.

Return values:

	0	success
	non-zero	failure

Version:

1.6.1 result changed from struct in_addr to struct aockaddr_in to store port number

Definition at line 177 of file dnsmgr.c.

References internal_dnsmgr_lookup().

Referenced by build_peer(), and iax2_append_register().

{
   return internal_dnsmgr_lookup(name, result, dnsmgr, service, NULL, NULL);
}

int ast_dnsmgr_lookup_cb	(	const char *	name,
		struct ast_sockaddr *	result,
		struct ast_dnsmgr_entry **	dnsmgr,
		const char *	service,
		dns_update_func	func,
		void *	data
	)

Allocate and initialize a DNS manager entry, with update callback.

Parameters:

	name	the hostname
	result	The addr which is intended to be updated in the update callback when DNS manager calls it on refresh. The address family is used as an input parameter to filter the returned addresses. If it is 0, both IPv4 and IPv6 addresses can be returned.
	dnsmgr	Where to store the allocate DNS manager entry
	service
	func	The update callback function The update callback will be called when DNS manager detects that an IP address has been changed. Instead of updating the addr itself, DNS manager will call this callback function with the old and new addresses. It is the responsibility of the callback to perform any updates
	data	A pointer to data that will be passed through to the callback function

Note:

This function allocates a new DNS manager entry object, and fills it with the provided hostname and IP address. This function _does_ force an initial lookup, so it may block for some period of time.

Return values:

	0	success
	non-zero	failure

Definition at line 182 of file dnsmgr.c.

References internal_dnsmgr_lookup().

Referenced by __sip_subscribe_mwi_do(), build_peer(), and transmit_register().

{
   return internal_dnsmgr_lookup(name, result, dnsmgr, service, func, data);
}

int ast_dnsmgr_refresh

(

struct ast_dnsmgr_entry *

entry

)

Force a refresh of a dnsmgr entry.

Return values:

	non-zero	if the result is different than the previous result
	zero	if the result is the same as the previous result

Definition at line 227 of file dnsmgr.c.

References dnsmgr_refresh().

Referenced by build_peer(), iax2_do_register(), and sip_reg_timeout().

{
   return dnsmgr_refresh(entry, 0);
}

void ast_dnsmgr_release

(

struct ast_dnsmgr_entry *

entry

)

Free a DNS manager entry.

Parameters:

entry

the DNS manager entry to free

Returns:

nothing

Definition at line 122 of file dnsmgr.c.

References ast_free, ast_mutex_destroy, AST_RWLIST_REMOVE, AST_RWLIST_UNLOCK, AST_RWLIST_WRLOCK, ast_verb, ast_dnsmgr_entry::lock, and ast_dnsmgr_entry::name.

Referenced by cleanup_all_regs(), delete_users(), match_and_cleanup_peer_sched(), peer_destructor(), and unload_module().

{
   if (!entry) {
      return;
   }

   AST_RWLIST_WRLOCK(&entry_list);
   AST_RWLIST_REMOVE(&entry_list, entry, list);
   AST_RWLIST_UNLOCK(&entry_list);
   ast_verb(4, "removing dns manager for '%s'\n", entry->name);

   ast_mutex_destroy(&entry->lock);
   ast_free(entry);
}