Wed Apr 6 11:30:03 2011

Asterisk developer's documentation


dnsmgr.h File Reference

Background DNS update manager. More...

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

Go to the source code of this file.

Functions

int ast_dnsmgr_changed (struct ast_dnsmgr_entry *entry)
 Check is see if a dnsmgr entry has changed.
ast_dnsmgr_entryast_dnsmgr_get (const char *name, struct ast_sockaddr *result, const char *service)
 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_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.


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 193 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().

00194 {
00195    int changed;
00196 
00197    ast_mutex_lock(&entry->lock);
00198 
00199    changed = entry->changed;
00200    entry->changed = 0;
00201 
00202    ast_mutex_unlock(&entry->lock);
00203    
00204    return changed;
00205 }

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 86 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::list, ast_dnsmgr_entry::lock, ast_dnsmgr_entry::name, ast_dnsmgr_entry::result, and ast_dnsmgr_entry::service.

Referenced by ast_dnsmgr_lookup().

00087 {
00088    struct ast_dnsmgr_entry *entry;
00089    int total_size = sizeof(*entry) + strlen(name) + (service ? strlen(service) + 1 : 0);
00090 
00091    if (!result || ast_strlen_zero(name) || !(entry = ast_calloc(1, total_size))) {
00092       return NULL;
00093    }
00094 
00095    entry->result = result;
00096    ast_mutex_init(&entry->lock);
00097    strcpy(entry->name, name);
00098    if (service) {
00099       entry->service = ((char *) entry) + sizeof(*entry) + strlen(name);
00100       strcpy(entry->service, service);
00101    }
00102 
00103    AST_RWLIST_WRLOCK(&entry_list);
00104    AST_RWLIST_INSERT_HEAD(&entry_list, entry, list);
00105    AST_RWLIST_UNLOCK(&entry_list);
00106 
00107    return entry;
00108 }

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 adresses. if it is 0, both IPv4 * and IPv6 addresses can be returned.
dnsmgr Where to store the allocate DNS manager entry
service 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 124 of file dnsmgr.c.

References ast_dnsmgr_get(), ast_get_ip_or_srv(), ast_strlen_zero(), ast_verb, enabled, and ast_dnsmgr_entry::result.

Referenced by __sip_subscribe_mwi_do(), build_peer(), iax2_append_register(), and transmit_register().

00125 {
00126    if (ast_strlen_zero(name) || !result || !dnsmgr) {
00127       return -1;
00128    }
00129 
00130    if (*dnsmgr && !strcasecmp((*dnsmgr)->name, name)) {
00131       return 0;
00132    }
00133 
00134    ast_verb(4, "doing dnsmgr_lookup for '%s'\n", name);
00135 
00136    /* do a lookup now but add a manager so it will automagically get updated in the background */
00137    ast_get_ip_or_srv(result, name, service);
00138    
00139    /* if dnsmgr is not enable don't bother adding an entry */
00140    if (!enabled) {
00141       return 0;
00142    }
00143    
00144    ast_verb(3, "adding dns manager for '%s'\n", name);
00145    *dnsmgr = ast_dnsmgr_get(name, result, service);
00146    return !*dnsmgr;
00147 }

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 185 of file dnsmgr.c.

References dnsmgr_refresh().

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

00186 {
00187    return dnsmgr_refresh(entry, 0);
00188 }

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 110 of file dnsmgr.c.

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

Referenced by delete_users(), peer_destructor(), sip_destroy_peer(), sip_registry_destroy(), and sip_subscribe_mwi_destroy().

00111 {
00112    if (!entry)
00113       return;
00114 
00115    AST_RWLIST_WRLOCK(&entry_list);
00116    AST_RWLIST_REMOVE(&entry_list, entry, list);
00117    AST_RWLIST_UNLOCK(&entry_list);
00118    ast_verb(4, "removing dns manager for '%s'\n", entry->name);
00119 
00120    ast_mutex_destroy(&entry->lock);
00121    ast_free(entry);
00122 }


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