dnsmgr.h File Reference

Background DNS update manager. More...

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

Include dependency graph for dnsmgr.h:

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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. More...
struct ast_dnsmgr_entry *	ast_dnsmgr_get (const char *name, struct ast_sockaddr *result, const char *service)
	Allocate a new DNS manager entry. More...
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. More...
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. More...
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. More...
int	ast_dnsmgr_refresh (struct ast_dnsmgr_entry *entry)
	Force a refresh of a dnsmgr entry. More...
void	ast_dnsmgr_release (struct ast_dnsmgr_entry *entry)
	Free a DNS manager entry. More...

Detailed Description

Background DNS update manager.

Definition in file dnsmgr.h.

Typedef Documentation

dns_update_func

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

ast_dnsmgr_changed()

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 247 of file dnsmgr.c.

{
    int changed;
 
    ast_mutex_lock(&entry->lock);
 
    changed = entry->changed;
    entry->changed = 0;
 
    ast_mutex_unlock(&entry->lock);
 
    return changed;
}

References ast_mutex_lock, and ast_mutex_unlock.

Referenced by iax2_do_register().

ast_dnsmgr_get()

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

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 131 of file dnsmgr.c.

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

References ast_dnsmgr_get_family(), name, result, and service.

ast_dnsmgr_get_family()

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.

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 106 of file dnsmgr.c.

{
    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;
}

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

Referenced by ast_dnsmgr_get(), and internal_dnsmgr_lookup().

ast_dnsmgr_lookup()

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 191 of file dnsmgr.c.

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

References internal_dnsmgr_lookup(), name, NULL, result, and service.

Referenced by __iax2_do_register_s(), build_peer(), iax2_append_register(), and transport_apply().

ast_dnsmgr_lookup_cb()

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 196 of file dnsmgr.c.

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

References ast_dnsmgr_entry::data, internal_dnsmgr_lookup(), name, result, and service.

ast_dnsmgr_refresh()

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 239 of file dnsmgr.c.

{
    return dnsmgr_refresh(entry, 0);
}

References dnsmgr_refresh().

Referenced by build_peer(), and iax2_do_register().

ast_dnsmgr_release()

void ast_dnsmgr_release

(

struct ast_dnsmgr_entry *

entry

)

Free a DNS manager entry.

Parameters

entry

the DNS manager entry to free

Definition at line 136 of file dnsmgr.c.

{
    if (!entry) {
        return;
    }
 
    AST_RWLIST_WRLOCK(&entry_list);
    AST_RWLIST_REMOVE(&entry_list, entry, list);
    AST_RWLIST_UNLOCK(&entry_list);
    ast_debug(6, "removing dns manager for '%s'\n", entry->name);
 
    ast_mutex_destroy(&entry->lock);
    ast_free(entry);
}

References ast_debug, ast_free, ast_mutex_destroy, AST_RWLIST_REMOVE, AST_RWLIST_UNLOCK, and AST_RWLIST_WRLOCK.

Referenced by delete_users(), destroy_sip_transport_state(), and peer_destructor().