可调试(vs2012编译)libevent 2.1.8

/* Copyright 2006-2007 Niels Provos * Copyright 2007-2012 Nick Mathewson and Niels Provos * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. */ /* Based on software by Adam Langly. Adam's original message: * * Async DNS Library * Adam Langley <agl@imperialviolet.org> * http://www.imperialviolet.org/eventdns.html * Public Domain code * * This software is Public Domain. To view a copy of the public domain dedication, * visit http://creativecommons.org/licenses/publicdomain/ or send a letter to * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA. * * I ask and expect, but do not require, that all derivative works contain an * attribution similar to: * Parts developed by Adam Langley <agl@imperialviolet.org> * * You may wish to replace the word "Parts" with something else depending on * the amount of original code. * * (Derivative works does not include programs which link against, run or include * the source verbatim in their source distributions) * * Version: 0.1b */ #include "event2/event-config.h" #include "evconfig-private.h" #include <sys/types.h> #ifndef _FORTIFY_SOURCE #define _FORTIFY_SOURCE 3 #endif #include <string.h> #include <fcntl.h> #ifdef EVENT__HAVE_SYS_TIME_H #include <sys/time.h> #endif #ifdef EVENT__HAVE_STDINT_H #include <stdint.h> #endif #include <stdlib.h> #include <string.h> #include <errno.h> #ifdef EVENT__HAVE_UNISTD_H #include <unistd.h> #endif #include <limits.h> #include <sys/stat.h> #include <stdio.h> #include <stdarg.h> #ifdef _WIN32 #include <winsock2.h> #include <ws2tcpip.h> #ifndef _WIN32_IE #define _WIN32_IE 0x400 #endif #include <shlobj.h> #endif #include "event2/dns.h" #include "event2/dns_struct.h" #include "event2/dns_compat.h" #include "event2/util.h" #include "event2/event.h" #include "event2/event_struct.h" #include "event2/thread.h" #include "defer-internal.h" #include "log-internal.h" #include "mm-internal.h" #include "strlcpy-internal.h" #include "ipv6-internal.h" #include "util-internal.h" #include "evthread-internal.h" #ifdef _WIN32 #include <ctype.h> #include <winsock2.h> #include <windows.h> #include <iphlpapi.h> #include <io.h> #else #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #endif #ifdef EVENT__HAVE_NETINET_IN6_H #include <netinet/in6.h> #endif #define EVDNS_LOG_DEBUG EVENT_LOG_DEBUG #define EVDNS_LOG_WARN EVENT_LOG_WARN #define EVDNS_LOG_MSG EVENT_LOG_MSG #ifndef HOST_NAME_MAX #define HOST_NAME_MAX 255 #endif #include <stdio.h> #undef MIN #define MIN(a,b) ((a)<(b)?(a):(b)) #define ASSERT_VALID_REQUEST(req) \ EVUTIL_ASSERT((req)->handle && (req)->handle->current_req == (req)) #define u64 ev_uint64_t #define u32 ev_uint32_t #define u16 ev_uint16_t #define u8 ev_uint8_t /* maximum number of addresses from a single packet */ /* that we bother recording */ #define MAX_V4_ADDRS 32 #define MAX_V6_ADDRS 32 #define TYPE_A EVDNS_TYPE_A #define TYPE_CNAME 5 #define TYPE_PTR EVDNS_TYPE_PTR #define TYPE_SOA EVDNS_TYPE_SOA #define TYPE_AAAA EVDNS_TYPE_AAAA #define CLASS_INET EVDNS_CLASS_INET /* Persistent handle. We keep this separate from 'struct request' since we * need some object to last for as long as an evdns_request is outstanding so * that it can be canceled, whereas a search request can lead to multiple * 'struct request' instances being created over its lifetime. */ struct evdns_request { struct request *current_req; struct evdns_base *base; int pending_cb; /* Waiting for its callback to be invoked; not * owned by event base any more. */ /* elements used by the searching code */ int search_index; struct search_state *search_state; char *search_origname; /* needs to be free()ed */ int search_flags; }; struct request { u8 *request; /* the dns packet data */ u8 request_type; /* TYPE_PTR or TYPE_A or TYPE_AAAA */ unsigned int request_len; int reissue_count; int tx_count; /* the number of times that this packet has been sent */ void *user_pointer; /* the pointer given to us for this request */ evdns_callback_type user_callback; struct nameserver *ns; /* the server which we last sent it */ /* these objects are kept in a circular list */ /* XXX We could turn this into a CIRCLEQ. */ struct request *next, *prev; struct event timeout_event; u16 trans_id; /* the transaction id */ unsigned request_appended :1; /* true if the request pointer is data which follows this struct */ unsigned transmit_me :1; /* needs to be transmitted */ /* XXXX This is a horrible hack. */ char **put_cname_in_ptr; /* store the cname here if we get one. */ struct evdns_base *base; struct evdns_request *handle; }; struct reply { unsigned int type; unsigned int have_answer : 1; union { struct { u32 addrcount; u32 addresses[MAX_V4_ADDRS]; } a; struct { u32 addrcount; struct in6_addr addresses[MAX_V6_ADDRS]; } aaaa; struct { char name[HOST_NAME_MAX]; } ptr; } data; }; struct nameserver { evutil_socket_t socket; /* a connected UDP socket */ struct sockaddr_storage address; ev_socklen_t addrlen; int failed_times; /* number of times which we have given this server a chance */ int timedout; /* number of times in a row a request has timed out */ struct event event; /* these objects are kept in a circular list */ struct nameserver *next, *prev; struct event timeout_event; /* used to keep the timeout for */ /* when we next probe this server. */ /* Valid if state == 0 */ /* Outstanding probe request for this nameserver, if any */ struct evdns_request *probe_request; char state; /* zero if we think that this server is down */ char choked; /* true if we have an EAGAIN from this server's socket */ char write_waiting; /* true if we are waiting for EV_WRITE events */ struct evdns_base *base; /* Number of currently inflight requests: used * to track when we should add/del the event. */ int requests_inflight; }; /* Represents a local port where we're listening for DNS requests. Right now, */ /* only UDP is supported. */ struct evdns_server_port { evutil_socket_t socket; /* socket we use to read queries and write replies. */ int refcnt; /* reference count. */ char choked; /* Are we currently blocked from writing? */ char closing; /* Are we trying to close this port, pending writes? */ evdns_request_callback_fn_type user_callback; /* Fn to handle requests */ void *user_data; /* Opaque pointer passed to user_callback */ struct event event; /* Read/write event */ /* circular list of replies that we want to write. */ struct server_request *pending_replies; struct event_base *eve