00001 /* 00002 * Asterisk -- An open source telephony toolkit. 00003 * 00004 * Copyright (C) 1999 - 2005, Digium, Inc. 00005 * 00006 * Kevin P. Fleming <kpfleming@digium.com> 00007 * 00008 * See http://www.asterisk.org for more information about 00009 * the Asterisk project. Please do not directly contact 00010 * any of the maintainers of this project for assistance; 00011 * the project provides a web site, mailing lists and IRC 00012 * channels for your use. 00013 * 00014 * This program is free software, distributed under the terms of 00015 * the GNU General Public License Version 2. See the LICENSE file 00016 * at the top of the source tree. 00017 */ 00018 00019 /*! \file 00020 * \brief Background DNS update manager 00021 */ 00022 00023 #ifndef _ASTERISK_DNSMGR_H 00024 #define _ASTERISK_DNSMGR_H 00025 00026 #if defined(__cplusplus) || defined(c_plusplus) 00027 extern "C" { 00028 #endif 00029 00030 #include "asterisk/netsock2.h" 00031 #include "asterisk/srv.h" 00032 00033 /*! 00034 * \brief A DNS manager entry 00035 * 00036 * This is an opaque type. 00037 */ 00038 struct ast_dnsmgr_entry; 00039 00040 typedef void (*dns_update_func)(struct ast_sockaddr *old_addr, struct ast_sockaddr *new_addr, void *data); 00041 00042 /*! 00043 * \brief Allocate a new DNS manager entry 00044 * 00045 * \param name the hostname 00046 * \param result where the DNS manager should store the IP address as it refreshes it. 00047 * \param service 00048 * 00049 * \details 00050 * This function allocates a new DNS manager entry object, and fills it with the 00051 * provided hostname and IP address. This function does not force an initial lookup 00052 * of the IP address. So, generally, this should be used when the initial address 00053 * is already known. 00054 * 00055 * \return a DNS manager entry 00056 * \version 1.6.1 result changed from struct in_addr to struct sockaddr_in to store port number 00057 * \version 1.8.0 result changed from struct ast_sockaddr_in to ast_sockaddr for IPv6 support 00058 */ 00059 struct ast_dnsmgr_entry *ast_dnsmgr_get(const char *name, struct ast_sockaddr *result, const char *service); 00060 00061 /*! 00062 * \brief Allocate a new DNS manager entry 00063 * 00064 * \param name the hostname 00065 * \param result where the DNS manager should store the IP address as it refreshes it. 00066 * \param service 00067 * \param family Address family to filter DNS addresses. 00068 * 00069 * \details 00070 * This function allocates a new DNS manager entry object, and fills it with the 00071 * provided hostname and IP address. This function does not force an initial lookup 00072 * of the IP address. So, generally, this should be used when the initial address 00073 * is already known. 00074 * 00075 * \return a DNS manager entry 00076 */ 00077 struct ast_dnsmgr_entry *ast_dnsmgr_get_family(const char *name, struct ast_sockaddr *result, const char *service, unsigned int family); 00078 00079 /*! 00080 * \brief Free a DNS manager entry 00081 * 00082 * \param entry the DNS manager entry to free 00083 * 00084 * \return nothing 00085 */ 00086 void ast_dnsmgr_release(struct ast_dnsmgr_entry *entry); 00087 00088 /*! 00089 * \brief Allocate and initialize a DNS manager entry 00090 * 00091 * \param name the hostname 00092 * \param result where to store the IP address as the DNS manager refreshes it. 00093 * The address family is used as an input parameter to filter the returned addresses. 00094 * If it is 0, both IPv4 and IPv6 addresses can be returned. 00095 * \param dnsmgr Where to store the allocate DNS manager entry 00096 * \param service 00097 * 00098 * \note 00099 * This function allocates a new DNS manager entry object, and fills it with 00100 * the provided hostname and IP address. This function _does_ force an initial 00101 * lookup, so it may block for some period of time. 00102 * 00103 * \retval 0 success 00104 * \retval non-zero failure 00105 * \version 1.6.1 result changed from struct in_addr to struct aockaddr_in to store port number 00106 */ 00107 int ast_dnsmgr_lookup(const char *name, struct ast_sockaddr *result, struct ast_dnsmgr_entry **dnsmgr, const char *service); 00108 00109 /*! 00110 * \brief Allocate and initialize a DNS manager entry, with update callback 00111 * 00112 * \param name the hostname 00113 * \param result The addr which is intended to be updated in the update callback when DNS manager calls it on refresh. 00114 * The address family is used as an input parameter to filter the returned addresses. 00115 * If it is 0, both IPv4 and IPv6 addresses can be returned. 00116 * \param dnsmgr Where to store the allocate DNS manager entry 00117 * \param service 00118 * \param func The update callback function 00119 * The update callback will be called when DNS manager detects that an IP address has been changed. 00120 * Instead of updating the addr itself, DNS manager will call this callback function with the old 00121 * and new addresses. It is the responsibility of the callback to perform any updates 00122 * \param data A pointer to data that will be passed through to the callback function 00123 * 00124 * \note 00125 * This function allocates a new DNS manager entry object, and fills it with 00126 * the provided hostname and IP address. This function _does_ force an initial 00127 * lookup, so it may block for some period of time. 00128 * 00129 * \retval 0 success 00130 * \retval non-zero failure 00131 */ 00132 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); 00133 00134 /*! 00135 * \brief Force a refresh of a dnsmgr entry 00136 * 00137 * \retval non-zero if the result is different than the previous result 00138 * \retval zero if the result is the same as the previous result 00139 */ 00140 int ast_dnsmgr_refresh(struct ast_dnsmgr_entry *entry); 00141 00142 /*! 00143 * \brief Check is see if a dnsmgr entry has changed 00144 * 00145 * \retval non-zero if the dnsmgr entry has changed since the last call to 00146 * this function 00147 * \retval zero if the dnsmgr entry has not changed since the last call to 00148 * this function 00149 */ 00150 int ast_dnsmgr_changed(struct ast_dnsmgr_entry *entry); 00151 00152 #if defined(__cplusplus) || defined(c_plusplus) 00153 } 00154 #endif /* c_plusplus */ 00155 00156 #endif /* ASTERISK_DNSMGR_H */