monero/external/unbound/libunbound/unbound-event.h
Erik de Castro Lopo a85b5759f3 Upgrade unbound library
These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).
2017-06-17 23:04:00 +10:00

264 lines
11 KiB
C

/*
* unbound-event.h - unbound validating resolver public API with events
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains the unbound interface for use with user defined
* pluggable event bases.
*
* Use ub_ctx_create_event_ub_base() to create an unbound context that uses
* the user provided event base API. Then, use the ub_resolve_event call
* to add DNS resolve queries to the context. Those then run whith the
* provided event_base, and when they are done you get a function callback.
*
* This method does not fork another process or create a thread, the effort
* is done by the unbound state machines that are connected to the event base.
*
* It is also possible to provide a libevent based event base by using
* ub_ctx_create_event_base(). But you have to use the same libevent that
* unbound was compiled with, otherwise it wouldn't work, the event and
* event_base structures would be different.
*/
#ifndef _UB_UNBOUND_EVENT_H
#define _UB_UNBOUND_EVENT_H
#ifdef __cplusplus
extern "C" {
#endif
struct ub_ctx;
struct ub_result;
struct event_base;
/** event timeout */
#define UB_EV_TIMEOUT 0x01
/** event fd readable */
#define UB_EV_READ 0x02
/** event fd writable */
#define UB_EV_WRITE 0x04
/** event signal */
#define UB_EV_SIGNAL 0x08
/** event must persist */
#define UB_EV_PERSIST 0x10
/** magic number to identify this version of the pluggable event api */
#define UB_EVENT_MAGIC 0x44d74d78
struct ub_event;
struct ub_event_base;
struct timeval;
/**
* The Virtual Method Table for and ub_event_base "object"
*/
struct ub_event_base_vmt {
/** Destructor for the ub_event_base object,
* (not called by libunbound) */
void (*free)(struct ub_event_base*);
/** Run the event loop
* (not called by libunbound when using ub_resolve_event) */
int (*dispatch)(struct ub_event_base*);
/** Exit the given event loop */
int (*loopexit)(struct ub_event_base*, struct timeval*);
/** Instantiate a new ub_event associated with this event base */
struct ub_event* (*new_event)(struct ub_event_base*,
int fd, short bits, void (*cb)(int, short, void*), void* arg);
/** Instantiate a new signal associated with this event base,
* (not called by libunbound) */
struct ub_event* (*new_signal)(struct ub_event_base*, int fd,
void (*cb)(int, short, void*), void* arg);
/** Create a new ub_event associated with the given wsaevent,
* (not called by libunbound) */
struct ub_event* (*winsock_register_wsaevent)(struct ub_event_base*,
void* wsaevent, void (*cb)(int, short, void*), void* arg);
};
/**
* A user defined pluggable event base is registered by providing a
* ub_event_base "object" with the ub_ctx_create_ub_event() function.
* The magic number must be correct and the Virtual Method Table must be
* fully equipped providing the event base API to be used by libunbound.
*/
struct ub_event_base {
/** magic must be UB_EVENT_MAGIC (0x44d74d78) */
unsigned long magic;
/** Virtual Method Table for ub_event_base */
struct ub_event_base_vmt* vmt;
};
/**
* The Virtual Method Table for and ub_event "object"
*/
struct ub_event_vmt {
/** Add event bits for this event to fire on.
* The event will be deactivated before this function is called. */
void (*add_bits)(struct ub_event*, short);
/** Configure the event so it will not longer fire on given bits
* The event will be deactivated before this function is called. */
void (*del_bits)(struct ub_event*, short);
/** Change or set the file descriptor on the event
* The event will be deactivated before this function is called. */
void (*set_fd)(struct ub_event*, int);
/** Destructor for the ub_event object */
void (*free)(struct ub_event*);
/** Activate the event. The given timeval is an timeout value. */
int (*add)(struct ub_event*, struct timeval*);
/** Deactivate the event */
int (*del)(struct ub_event*);
/** Reconfigure and activate a timeout event */
int (*add_timer)(struct ub_event*, struct ub_event_base*,
void (*cb)(int, short, void*), void* arg, struct timeval*);
/** Deactivate the timeout event */
int (*del_timer)(struct ub_event*);
/** Activate a signal event (not called by libunbound). */
int (*add_signal)(struct ub_event*, struct timeval*);
/** Deactivate a signal event (not called by libunbound). */
int (*del_signal)(struct ub_event*);
/** Destructor for a ub_event associated with a wsaevent,
* (not called by libunbound)
*/
void (*winsock_unregister_wsaevent)(struct ub_event* ev);
/** Libunbound will signal the eventloop when a TCP windows socket
* will block on next read or write (given by the eventbits), to work
* around edge trigger event behaviour of select on windows with TCP.
*/
void (*winsock_tcp_wouldblock)(struct ub_event*, int eventbit);
};
/**
* An "object" comprising a user defined pluggable event.
* The magic number must be correct and the Virtual Method Table must be
* fully equipped providing the ub_event API to be used by libunbound.
*/
struct ub_event {
/** magic must be UB_EVENT_MAGIC (0x44d74d78) */
unsigned long magic;
/** Virtual Method Table for ub_event */
struct ub_event_vmt* vmt;
};
typedef void (*ub_event_callback_type)(void*, int, void*, int, int, char*);
/**
* Create a resolving and validation context.
* The information from /etc/resolv.conf and /etc/hosts is not utilised by
* default. Use ub_ctx_resolvconf and ub_ctx_hosts to read them.
* @param base: the pluggable event base that the caller has created.
* The unbound context uses this event base.
* @return a new context. default initialisation.
* returns NULL on error.
* You must use ub_resolve_event with this context.
* Do not call ub_ctx_async, ub_poll, ub_wait, ub_process, this is all done
* with the event_base. Setup the options you like with the other functions.
*/
struct ub_ctx* ub_ctx_create_ub_event(struct ub_event_base* base);
/**
* Create a resolving and validation context.
* The information from /etc/resolv.conf and /etc/hosts is not utilised by
* default. Use ub_ctx_resolvconf and ub_ctx_hosts to read them.
* You have to use the same libevent that unbound was compiled with,
* otherwise it wouldn't work, the event and event_base structures would
* be different.
* @param base: the event base that the caller has created. The unbound
* context uses this event base.
* @return a new context. default initialisation.
* returns NULL on error.
* You must use ub_resolve_event with this context.
* Do not call ub_ctx_async, ub_poll, ub_wait, ub_process, this is all done
* with the event_base. Setup the options you like with the other functions.
*/
struct ub_ctx* ub_ctx_create_event(struct event_base* base);
/**
* Set a new libevent event_base on a context created with ub_ctx_create_event.
* You have to use the same libevent that unbound was compiled with,
* otherwise it wouldn't work, the event and event_base structures would
* be different.
* Any outbound queries will be canceled.
* @param ctx the ub_ctx to update. Must have been created with ub_ctx_create_event
* @param base the new event_base to attach to the ctx
* @return 0 if OK, else error
*/
int ub_ctx_set_event(struct ub_ctx* ctx, struct event_base* base);
/**
* Perform resolution and validation of the target name.
* Asynchronous, after a while, the callback will be called with your
* data and the result. Uses the event_base user installed by creating the
* context with ub_ctx_create_event().
* @param ctx: context with event_base in it.
* The context is finalized, and can no longer accept all config changes.
* @param name: domain name in text format (a string).
* @param rrtype: type of RR in host order, 1 is A.
* @param rrclass: class of RR in host order, 1 is IN (for internet).
* @param mydata: this data is your own data (you can pass NULL),
* and is passed on to the callback function.
* @param callback: this is called on completion of the resolution.
* It is called as:
* void callback(void* mydata, int rcode, void* packet, int packet_len,
* int sec, char* why_bogus)
* with mydata: the same as passed here, you may pass NULL,
* with rcode: 0 on no error, nonzero for mostly SERVFAIL situations,
* this is a DNS rcode.
* with packet: a buffer with DNS wireformat packet with the answer.
* do not inspect if rcode != 0.
* do not write or free the packet buffer, it is used internally
* in unbound (for other callbacks that want the same data).
* with packet_len: length in bytes of the packet buffer.
* with sec: 0 if insecure, 1 if bogus, 2 if DNSSEC secure.
* with why_bogus: text string explaining why it is bogus (or NULL).
* These point to buffers inside unbound; do not deallocate the packet or
* error string.
*
* If an error happens during processing, your callback will be called
* with error set to a nonzero value (and result==NULL).
* For localdata (etc/hosts) the callback is called immediately, before
* resolve_event returns, async_id=0 is returned.
* @param async_id: if you pass a non-NULL value, an identifier number is
* returned for the query as it is in progress. It can be used to
* cancel the query.
* @return 0 if OK, else error.
*/
int ub_resolve_event(struct ub_ctx* ctx, const char* name, int rrtype,
int rrclass, void* mydata, ub_event_callback_type callback,
int* async_id);
#ifdef __cplusplus
}
#endif
#endif /* _UB_UNBOUND_H */