/*
* transmit.c
* - construct queries
* - send queries
*/
/*
* This file is
* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
*
* It is part of adns, which is
* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
* Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
*
* 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.
*
* $Id: transmit.c,v 1.2 2003/06/14 13:55:50 tr-ircd Exp $
*/
#include "struct.h"
#include "fileio.h"
#include "internal.h"
#include "tvarith.h"
#define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
#define MKQUERY_ADDB(b) *rqp++= (b)
#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
#define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
static adns_status mkquery_header(adns_state ads, vbuf * vb, int *id_r, int qdlen)
{
int id;
byte *rqp;
if (!adns__vbuf_ensure(vb, DNS_HDRSIZE + qdlen + 4))
return adns_s_nomemory;
vb->used = 0;
MKQUERY_START(vb);
*id_r = id = (ads->nextid++) & 0x0ffff;
MKQUERY_ADDW(id);
MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
MKQUERY_ADDW(1); /* QDCOUNT=1 */
MKQUERY_ADDW(0); /* ANCOUNT=0 */
MKQUERY_ADDW(0); /* NSCOUNT=0 */
MKQUERY_ADDW(0); /* ARCOUNT=0 */
MKQUERY_STOP(vb);
return adns_s_ok;
}
static adns_status mkquery_footer(vbuf * vb, adns_rrtype type)
{
byte *rqp;
MKQUERY_START(vb);
MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
MKQUERY_STOP(vb);
assert(vb->used <= vb->avail);
return adns_s_ok;
}
adns_status adns__mkquery(adns_state ads, vbuf * vb, int *id_r,
const char *owner, int ol, const typeinfo * typei, adns_queryflags flags)
{
int ll, c, nbytes;
byte label[255], *rqp;
const char *p, *pe;
adns_status st;
st = mkquery_header(ads, vb, id_r, ol + 2);
if (st)
return st;
MKQUERY_START(vb);
p = owner;
pe = owner + ol;
nbytes = 0;
while (p != pe) {
ll = 0;
while (p != pe && (c = *p++) != '.') {
if (c == '\\') {
if (!(flags & adns_qf_quoteok_query))
return adns_s_querydomaininvalid;
if (ctype_digit(p[0])) {
if (ctype_digit(p[1]) && ctype_digit(p[2])) {
c = (*p++ - '0') * 100;
c += (*p++ - '0') * 10;
c += (*p++ - '0');
if (c >= 256)
return adns_s_querydomaininvalid;
} else {
return adns_s_querydomaininvalid;
}
} else if (!(c = *p++)) {
return adns_s_querydomaininvalid;
}
}
if (!(flags & adns_qf_quoteok_query)) {
if (c == '-') {
if (!ll)
return adns_s_querydomaininvalid;
} else if (!ctype_alpha(c) && !ctype_digit(c)) {
return adns_s_querydomaininvalid;
}
}
if (ll == sizeof(label))
return adns_s_querydomaininvalid;
label[ll++] = c;
}
if (!ll)
return adns_s_querydomaininvalid;
if (ll > DNS_MAXLABEL)
return adns_s_querydomaintoolong;
nbytes += ll + 1;
if (nbytes >= DNS_MAXDOMAIN)
return adns_s_querydomaintoolong;
MKQUERY_ADDB(ll);
memcpy(rqp, label, ll);
rqp += ll;
}
MKQUERY_ADDB(0);
MKQUERY_STOP(vb);
st = mkquery_footer(vb, typei->type);
return adns_s_ok;
}
adns_status adns__mkquery_frdgram(adns_state ads, vbuf * vb, int *id_r,
const byte * qd_dgram, int qd_dglen,
int qd_begin, adns_rrtype type, adns_queryflags flags)
{
byte *rqp;
findlabel_state fls;
int lablen, labstart;
adns_status st;
st = mkquery_header(ads, vb, id_r, qd_dglen);
if (st)
return st;
MKQUERY_START(vb);
adns__findlabel_start(&fls, ads, -1, 0, qd_dgram, qd_dglen, qd_dglen, qd_begin, 0);
for (;;) {
st = adns__findlabel_next(&fls, &lablen, &labstart);
assert(!st);
if (!lablen)
break;
assert(lablen < 255);
MKQUERY_ADDB(lablen);
memcpy(rqp, qd_dgram + labstart, lablen);
rqp += lablen;
}
MKQUERY_ADDB(0);
MKQUERY_STOP(vb);
st = mkquery_footer(vb, type);
return adns_s_ok;
}
void adns__querysend_tcp(adns_query qu, struct timeval now)
{
byte length[2];
#if 0
struct iovec iov[2];
#endif
int wr, wr2 = 0, r;
adns_state ads;
if (qu->ads->tcpstate != server_ok)
return;
assert(qu->state == query_tcpw);
length[0] = (qu->query_dglen & 0x0ff00U) >> 8;
length[1] = (qu->query_dglen & 0x0ff);
ads = qu->ads;
if (!adns__vbuf_ensure(&ads->tcpsend, ads->tcpsend.used + qu->query_dglen + 2))
return;
qu->retries++;
/* Reset idle timeout. */
ads->tcptimeout.tv_sec = ads->tcptimeout.tv_usec = 0;
if (ads->tcpsend.used) {
wr = 0;
} else {
#if 0
iov[0].iov_base = (char *) length;
iov[0].iov_len = 2;
iov[1].iov_base = (char *) qu->query_dgram;
iov[1].iov_len = qu->query_dglen;
wr = writev(qu->ads->tcpsocket, iov, 2);
#endif
wr = write(qu->ads->tcpsocket, (char *) length, 2);
if (wr > 0)
wr2 = write(qu->ads->tcpsocket, (char *) qu->query_dgram, qu->query_dglen);
if (wr < 0 || wr2 < 0) {
if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
errno == ENOBUFS || errno == ENOMEM)) {
adns__tcp_broken(ads, "write", strerror(errno));
return;
}
wr = 0;
}
}
if (wr < 2) {
r = adns__vbuf_append(&ads->tcpsend, length, 2 - wr);
assert(r);
wr = 0;
} else {
wr -= 2;
}
if (wr < qu->query_dglen) {
r = adns__vbuf_append(&ads->tcpsend, qu->query_dgram + wr, qu->query_dglen - wr);
assert(r);
}
}
static void query_usetcp(adns_query qu, struct timeval now)
{
qu->state = query_tcpw;
qu->timeout = now;
timevaladd(&qu->timeout, TCPWAITMS);
LIST_LINK_TAIL(qu->ads->tcpw, qu);
adns__querysend_tcp(qu, now);
adns__tcp_tryconnect(qu->ads, now);
}
void adns__query_send(adns_query qu, struct timeval now)
{
struct sockaddr_in servaddr;
int serv, r;
adns_state ads;
assert(qu->state == query_tosend);
if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) {
query_usetcp(qu, now);
return;
}
if (qu->query_dglen > DNS_MAXUDP) {
adns__query_fail(qu, adns_s_systemfail);
return;
}
if (qu->retries >= UDPMAXRETRIES) {
adns__query_fail(qu, adns_s_timeout);
return;
}
serv = qu->udpnextserver;
memset(&servaddr, 0, sizeof(servaddr));
ads = qu->ads;
servaddr.sin_family = AF_INET;
servaddr.sin_addr = ads->servers[serv].addr;
servaddr.sin_port = htons(DNS_PORT);
r = sendto(ads->udpsocket, qu->query_dgram, qu->query_dglen, 0,
(const struct sockaddr *) &servaddr, sizeof(servaddr));
if (r < 0 && errno == EMSGSIZE) {
qu->retries = 0;
query_usetcp(qu, now);
return;
}
if (r < 0 && errno != EAGAIN)
adns__warn(ads, serv, 0, "sendto failed: %s", strerror(errno));
qu->timeout = now;
timevaladd(&qu->timeout, UDPRETRYMS);
qu->udpsent |= (1 << serv);
qu->udpnextserver = (serv + 1) % ads->nservers;
qu->retries++;
LIST_LINK_TAIL(ads->udpw, qu);
}
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