1266077Sdes/* 2266077Sdes * unbound-event.h - unbound validating resolver public API with events 3266077Sdes * 4266077Sdes * Copyright (c) 2007, NLnet Labs. All rights reserved. 5266077Sdes * 6266077Sdes * This software is open source. 7266077Sdes * 8266077Sdes * Redistribution and use in source and binary forms, with or without 9266077Sdes * modification, are permitted provided that the following conditions 10266077Sdes * are met: 11266077Sdes * 12266077Sdes * Redistributions of source code must retain the above copyright notice, 13266077Sdes * this list of conditions and the following disclaimer. 14266077Sdes * 15266077Sdes * Redistributions in binary form must reproduce the above copyright notice, 16266077Sdes * this list of conditions and the following disclaimer in the documentation 17266077Sdes * and/or other materials provided with the distribution. 18266077Sdes * 19266077Sdes * Neither the name of the NLNET LABS nor the names of its contributors may 20266077Sdes * be used to endorse or promote products derived from this software without 21266077Sdes * specific prior written permission. 22266077Sdes * 23266077Sdes * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24266077Sdes * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25266077Sdes * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26266077Sdes * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27266077Sdes * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28266077Sdes * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29266077Sdes * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30266077Sdes * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31266077Sdes * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32266077Sdes * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33266077Sdes * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34266077Sdes */ 35266077Sdes 36266077Sdes/** 37266077Sdes * \file 38266077Sdes * 39266077Sdes * This file contains the unbound interface for use with libevent. 40266077Sdes * You have to use the same libevent that unbound was compiled with, 41266077Sdes * otherwise it wouldn't work, the event and event_base structures would 42266077Sdes * be different. If unbound is compiled without libevent support then 43266077Sdes * this header file is not supposed to be installed on the system. 44266077Sdes * 45266077Sdes * Use ub_ctx_create_event_base() to create an unbound context that uses 46266077Sdes * the event base that you have made. Then, use the ub_resolve_event call 47266077Sdes * to add DNS resolve queries to the context. Those then run when you 48266077Sdes * call event_dispatch() on your event_base, and when they are done you 49266077Sdes * get a function callback. 50266077Sdes * 51266077Sdes * This method does not fork another process or create a thread, the effort 52266077Sdes * is done by the unbound state machines that are connected to the event_base. 53266077Sdes */ 54266077Sdes#ifndef _UB_UNBOUND_EVENT_H 55266077Sdes#define _UB_UNBOUND_EVENT_H 56266077Sdes 57266077Sdes#ifdef __cplusplus 58266077Sdesextern "C" { 59266077Sdes#endif 60266077Sdes 61266077Sdesstruct ub_ctx; 62266077Sdesstruct ub_result; 63266077Sdesstruct event_base; 64266077Sdes 65266077Sdestypedef void (*ub_event_callback_t)(void*, int, void*, int, int, char*); 66266077Sdes 67266077Sdes/** 68266077Sdes * Create a resolving and validation context. 69266077Sdes * The information from /etc/resolv.conf and /etc/hosts is not utilised by 70266077Sdes * default. Use ub_ctx_resolvconf and ub_ctx_hosts to read them. 71266077Sdes * @param base: the event base that the caller has created. The unbound 72266077Sdes * context uses this event base. 73266077Sdes * @return a new context. default initialisation. 74266077Sdes * returns NULL on error. 75266077Sdes * You must use ub_resolve_event with this context. 76266077Sdes * Do not call ub_ctx_async, ub_poll, ub_wait, ub_process, this is all done 77266077Sdes * with the event_base. Setup the options you like with the other functions. 78266077Sdes */ 79266077Sdesstruct ub_ctx* ub_ctx_create_event(struct event_base* base); 80266077Sdes 81266077Sdes/** 82266077Sdes * Set a new event_base on a context created with ub_ctx_create_event. 83266077Sdes * Any outbound queries will be canceled. 84266077Sdes * @param ctx the ub_ctx to update. Must have been created with ub_ctx_create_event 85266077Sdes * @param base the new event_base to attach to the ctx 86266077Sdes * @return 0 if OK, else error 87266077Sdes */ 88266077Sdesint ub_ctx_set_event(struct ub_ctx* ctx, struct event_base* base); 89266077Sdes 90266077Sdes/** 91266077Sdes * Perform resolution and validation of the target name. 92266077Sdes * Asynchronous, after a while, the callback will be called with your 93266077Sdes * data and the result. Uses the event_base user installed by creating the 94266077Sdes * context with ub_ctx_create_event(). 95266077Sdes * @param ctx: context with event_base in it. 96266077Sdes * The context is finalized, and can no longer accept all config changes. 97266077Sdes * @param name: domain name in text format (a string). 98266077Sdes * @param rrtype: type of RR in host order, 1 is A. 99266077Sdes * @param rrclass: class of RR in host order, 1 is IN (for internet). 100266077Sdes * @param mydata: this data is your own data (you can pass NULL), 101266077Sdes * and is passed on to the callback function. 102266077Sdes * @param callback: this is called on completion of the resolution. 103266077Sdes * It is called as: 104266077Sdes * void callback(void* mydata, int rcode, void* packet, int packet_len, 105266077Sdes * int sec, char* why_bogus) 106266077Sdes * with mydata: the same as passed here, you may pass NULL, 107266077Sdes * with rcode: 0 on no error, nonzero for mostly SERVFAIL situations, 108266077Sdes * this is a DNS rcode. 109266077Sdes * with packet: a buffer with DNS wireformat packet with the answer. 110266077Sdes * do not inspect if rcode != 0. 111266077Sdes * do not write or free the packet buffer, it is used internally 112266077Sdes * in unbound (for other callbacks that want the same data). 113266077Sdes * with packet_len: length in bytes of the packet buffer. 114266077Sdes * with sec: 0 if insecure, 1 if bogus, 2 if DNSSEC secure. 115266077Sdes * with why_bogus: text string explaining why it is bogus (or NULL). 116266077Sdes * These point to buffers inside unbound; do not deallocate the packet or 117266077Sdes * error string. 118266077Sdes * 119266077Sdes * If an error happens during processing, your callback will be called 120266077Sdes * with error set to a nonzero value (and result==NULL). 121266077Sdes * For localdata (etc/hosts) the callback is called immediately, before 122266077Sdes * resolve_event returns, async_id=0 is returned. 123266077Sdes * @param async_id: if you pass a non-NULL value, an identifier number is 124266077Sdes * returned for the query as it is in progress. It can be used to 125266077Sdes * cancel the query. 126266077Sdes * @return 0 if OK, else error. 127266077Sdes */ 128266077Sdesint ub_resolve_event(struct ub_ctx* ctx, const char* name, int rrtype, 129266077Sdes int rrclass, void* mydata, ub_event_callback_t callback, int* async_id); 130266077Sdes 131266077Sdes#ifdef __cplusplus 132266077Sdes} 133266077Sdes#endif 134266077Sdes 135266077Sdes#endif /* _UB_UNBOUND_H */ 136