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// -*-c++-*-
/* $Id$ */
/*
*
* Copyright (C) 2003 David Mazieres (dm@uun.org)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
*/
#ifndef _ASYNC_DNSIMPL_H_
#define _ASYNC_DNSIMPL_H_ 1
#include "dnsparse.h"
#include "ihash.h"
#include "backoff.h"
class resolver;
class dnsreq {
int ntries;
int srchno;
public:
resolver *const resp;
bool usetcp;
private:
bool constructed;
bool intable;
protected:
void remove ();
public:
int error;
u_int16_t id; // DNS query ID
str basename; // Name for which to search
str name; // Name for which to query
u_int16_t type; // Type of query (T_A, T_PTR, etc.)
ihash_entry<dnsreq> hlink; // Per-id hash table link
tmoq_entry<dnsreq> tlink; // Retransmit queue link
dnsreq (resolver *, str, u_int16_t, bool search = false);
virtual ~dnsreq ();
void start (bool);
void xmit (int = 0);
virtual void readreply (dnsparse *) = 0;
void timeout ();
void fail (int);
};
class dnsreq_a : public dnsreq {
bool checkaddr; // Non-zero when arr_addr must be checked
in_addr addr; // Adress of inverse queries (for checking)
cbhent cb; // Callback for hostbyname/addr
dnsreq_a ();
public:
dnsreq_a (resolver *rp, str n, cbhent c, bool s = false)
: dnsreq (rp, n, T_A, s), checkaddr (false), cb (c) {}
dnsreq_a (resolver *rp, str n, cbhent c, const in_addr &a)
: dnsreq (rp, n, T_A), checkaddr (true), addr (a), cb (c) {}
void readreply (dnsparse *);
};
class dnsreq_mx : public dnsreq {
cbmxlist cb;
dnsreq_mx ();
public:
dnsreq_mx (resolver *rp, str n, cbmxlist c, bool s)
: dnsreq (rp, n, T_MX, s), cb (c) {}
void readreply (dnsparse *);
};
class dnsreq_srv : public dnsreq {
cbsrvlist cb;
dnsreq_srv ();
public:
dnsreq_srv (resolver *rp, str n, cbsrvlist c, bool s)
: dnsreq (rp, n, T_SRV, s), cb (c) {}
void readreply (dnsparse *);
};
class dnsreq_ptr : public dnsreq {
in_addr addr;
cbhent cb; // Callback for hostbyname/addr
int napending;
vec<str, 2> vnames;
vec<dnsreq_a *> vrfyv;
static void maybe_push (vec<str, 2> *sv, const char *s);
public:
static str inaddr_arpa (in_addr);
dnsreq_ptr (resolver *rp, in_addr a, cbhent c)
: dnsreq (rp, inaddr_arpa (a), T_PTR), addr (a), cb (c) {}
~dnsreq_ptr ();
void readreply (dnsparse *);
void readvrfy (int i, ptr<hostent> h, int err);
};
class dnsreq_txt : public dnsreq {
cbtxtlist cb;
public:
dnsreq_txt (resolver *rp, str n, cbtxtlist c, bool s = false)
: dnsreq (rp, n, T_TXT, s), cb (c) {}
void readreply (dnsparse *);
};
class dnssock {
public:
typedef callback<void, u_char *, ssize_t>::ref cb_t;
protected:
cb_t cb;
ref<bool> destroyed;
public:
const bool reliable;
dnssock (bool r, cb_t c)
: cb (c), destroyed (New refcounted<bool> (false)),
reliable (r) {}
virtual ~dnssock () { *destroyed = false; }
virtual void sendpkt (const u_char *pkt, size_t size) = 0;
};
class dnssock_udp : public dnssock {
int fd;
void rcb ();
public:
dnssock_udp (int f, cb_t cb);
~dnssock_udp ();
void sendpkt (const u_char *pkt, size_t size);
};
class dnssock_tcp : public dnssock {
int fd;
bool write_ok;
dnstcppkt tcpstate;
void rcb ();
void wcb (bool selected = false);
public:
dnssock_tcp (int f, cb_t cb);
~dnssock_tcp ();
void sendpkt (const u_char *pkt, size_t size);
};
class resolver {
protected:
ptr<dnssock> udpsock;
ptr<dnssock> tcpsock;
int nbump; // # of bumpsocks since last good reply
sockaddr *addr;
socklen_t addrlen;
dnsreq *udpcheck_req;
virtual bool bumpsock (bool failure) = 0;
bool udpinit ();
bool tcpinit ();
void cantsend ();
bool resend (bool udp, bool tcp);
static void failreq (int err, dnsreq *r) { r->fail (err); }
void pktready (bool tcp, u_char *qb, ssize_t size);
void udpcheck_cb (ptr<hostent> h, int err);
public:
time_t last_resp; // Last time of valid reply from this server
time_t last_bump;
ref<bool> destroyed;
ihash<u_int16_t, dnsreq, &dnsreq::id, &dnsreq::hlink> reqtab;
tmoq<dnsreq, &dnsreq::tlink, 1, 5> reqtoq;
resolver ();
virtual ~resolver ();
bool setsock (bool failure);
void sendreq (dnsreq *r);
virtual const char *srchlist (int n) { return n <= 0 ? "" : NULL; }
u_int16_t genid ();
void udpcheck ();
};
class resolv_conf : public resolver {
protected:
int ns_idx;
sockaddr_in srvaddr;
time_t last_reload;
bool reload_lock;
ifchgcb_t *ifc;
ref<bool> destroyed;
void reload (bool failure);
static void reload_dumpres (int fd);
void reload_cb (ref<bool> d, bool ifchange, str newres);
protected:
bool bumpsock (bool failure);
public:
resolv_conf ();
~resolv_conf ();
const char *srchlist (int n);
};
#endif /* _ASYNC_DNSIMPL_H_ */
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