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/* $NetBSD: res_data.c,v 1.8 2004/06/09 18:07:03 christos Exp $ */
/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1995-1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "resolv_private.h"
#include <pthread.h>
extern "C" int res_ourserver_p(const res_state, const struct sockaddr*);
extern "C" int __res_vinit(res_state, int);
class GlobalStateAccessor {
public:
GlobalStateAccessor() {
pthread_mutex_lock(&mutex);
if (!initialized) {
init();
initialized = true;
}
}
~GlobalStateAccessor() {
pthread_mutex_unlock(&mutex);
}
__res_state* get() {
return &state;
}
int init();
private:
static __res_state state;
static bool initialized;
static pthread_mutex_t mutex;
};
__res_state GlobalStateAccessor::state;
bool GlobalStateAccessor::initialized = false;
pthread_mutex_t GlobalStateAccessor::mutex = PTHREAD_MUTEX_INITIALIZER;
int GlobalStateAccessor::init() {
// These three fields used to be statically initialized. This made
// it hard to use this code in a shared library. It is necessary,
// now that we're doing dynamic initialization here, that we preserve
// the old semantics: if an application modifies one of these three
// fields of _res before res_init() is called, res_init() will not
// alter them. Of course, if an application is setting them to
// _zero_ before calling res_init(), hoping to override what used
// to be the static default, we can't detect it and unexpected results
// will follow. Zero for any of these fields would make no sense,
// so one can safely assume that the applications were already getting
// unexpected results.
// g_nres.options is tricky since some apps were known to diddle the bits
// before res_init() was first called. We can't replicate that semantic
// with dynamic initialization (they may have turned bits off that are
// set in RES_DEFAULT). Our solution is to declare such applications
// "broken". They could fool us by setting RES_INIT but none do (yet).
if (!state.retrans) state.retrans = RES_TIMEOUT;
if (!state.retry) state.retry = 4;
if (!(state.options & RES_INIT)) state.options = RES_DEFAULT;
// This one used to initialize implicitly to zero, so unless the app
// has set it to something in particular, we can randomize it now.
if (!state.id) state.id = res_randomid();
return __res_vinit(&state, 1);
}
int res_init(void) {
GlobalStateAccessor gsa;
return gsa.init();
}
void p_query(const u_char* msg) {
fp_query(msg, stdout);
}
void fp_query(const u_char* msg, FILE* file) {
fp_nquery(msg, PACKETSZ, file);
}
void fp_nquery(const u_char* msg, int len, FILE* file) {
GlobalStateAccessor gsa;
res_pquery(gsa.get(), msg, len, file);
}
int
res_mkquery(int op, const char* dname, int klass, int type, const u_char* data,
int datalen, const u_char* newrr_in, u_char* buf, int buflen) {
GlobalStateAccessor gsa;
return res_nmkquery(gsa.get(), op, dname, klass, type, data, datalen, newrr_in, buf, buflen);
}
int res_query(const char* name, int klass, int type, u_char* answer, int anslen) {
GlobalStateAccessor gsa;
return res_nquery(gsa.get(), name, klass, type, answer, anslen);
}
void res_send_setqhook(res_send_qhook hook) {
GlobalStateAccessor gsa;
gsa.get()->qhook = hook;
}
void res_send_setrhook(res_send_rhook hook) {
GlobalStateAccessor gsa;
gsa.get()->rhook = hook;
}
int res_isourserver(const struct sockaddr_in* inp) {
GlobalStateAccessor gsa;
return res_ourserver_p(gsa.get(), reinterpret_cast<const sockaddr*>(inp));
}
int res_send(const u_char* buf, int buflen, u_char* ans, int anssiz) {
GlobalStateAccessor gsa;
return res_nsend(gsa.get(), buf, buflen, ans, anssiz);
}
void res_close(void) {
GlobalStateAccessor gsa;
res_nclose(gsa.get());
}
int res_search(const char* name, int klass, int type, u_char* answer, int anslen) {
GlobalStateAccessor gsa;
return res_nsearch(gsa.get(), name, klass, type, answer, anslen);
}
int res_querydomain(const char* name, const char* domain, int klass, int type, u_char* answer,
int anslen) {
GlobalStateAccessor gsa;
return res_nquerydomain(gsa.get(), name, domain, klass, type, answer, anslen);
}
int res_opt(int a, u_char* b, int c, int d) {
GlobalStateAccessor gsa;
return res_nopt(gsa.get(), a, b, c, d);
}
const char* hostalias(const char* name) {
return NULL;
}
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