[adns] / src / transmit.c

/*
 * 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. 
 */

#include <errno.h>

#include <sys/types.h>
#include <sys/uio.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];
  struct iovec iov[2];
  int wr, 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 {
    iov[0].iov_base= length;
    iov[0].iov_len= 2;
    iov[1].iov_base= qu->query_dgram;
    iov[1].iov_len= qu->query_dglen;
    adns__sigpipe_protect(qu->ads);
    wr= writev(qu->ads->tcpsocket,iov,2);
    adns__sigpipe_unprotect(qu->ads);
    if (wr < 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->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);
}
Commit	Line	Data
e576be50	1	/*
	2	* transmit.c
	3	* - construct queries
	4	* - send queries
	5	*/
	6	/*
d942707d	7	* This file is
3d5cde09	8	* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
d942707d	9	*
d942707d	10	* It is part of adns, which is
3d5cde09	11	* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
bef232ae	12	* Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
e576be50	13	*
	14	* This program is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2, or (at your option)
	17	* any later version.
	18	*
	19	* This program is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with this program; if not, write to the Free Software Foundation,
	26	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	27	*/
	28
3955725c	29	#include <errno.h>
3955725c	30
71a6ff46	31	#include <sys/types.h>
3955725c	32	#include <sys/uio.h>
3955725c	33
e576be50	34	#include "internal.h"
2953d358	35	#include "tvarith.h"
e576be50	36
e062dcae	37	#define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
e576be50	38	#define MKQUERY_ADDB(b) *rqp++= (b)
e576be50	39	#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
e062dcae	40	#define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
e576be50	41
609133ee	42	static adns_status mkquery_header(adns_state ads, vbuf *vb,
609133ee	43	int *id_r, int qdlen) {
e062dcae	44	int id;
	45	byte *rqp;
	46
ea1e31e3	47	if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory;
e576be50	48
e062dcae	49	vb->used= 0;
	50	MKQUERY_START(vb);
	51
660d7d3b	52	*id_r= id= (ads->nextid++) & 0x0ffff;
e576be50	53	MKQUERY_ADDW(id);
	54	MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
	55	MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
	56	MKQUERY_ADDW(1); /* QDCOUNT=1 */
	57	MKQUERY_ADDW(0); /* ANCOUNT=0 */
	58	MKQUERY_ADDW(0); /* NSCOUNT=0 */
	59	MKQUERY_ADDW(0); /* ARCOUNT=0 */
e062dcae	60
	61	MKQUERY_STOP(vb);
	62
	63	return adns_s_ok;
	64	}
	65
	66	static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) {
	67	byte *rqp;
	68
	69	MKQUERY_START(vb);
	70	MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
	71	MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
	72	MKQUERY_STOP(vb);
	73	assert(vb->used <= vb->avail);
	74
	75	return adns_s_ok;
	76	}
	77
	78	adns_status adns__mkquery(adns_state ads, vbuf vb, int id_r,
	79	const char *owner, int ol,
	80	const typeinfo *typei, adns_queryflags flags) {
4b2c4f8a	81	int ll, c, nbytes;
e062dcae	82	byte label[255], *rqp;
	83	const char p, pe;
	84	adns_status st;
	85
914a5ff5	86	st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st;
e062dcae	87
	88	MKQUERY_START(vb);
	89
e576be50	90	p= owner; pe= owner+ol;
4b2c4f8a	91	nbytes= 0;
e9e53c73	92	while (p!=pe) {
e576be50	93	ll= 0;
	94	while (p!=pe && (c= *p++)!='.') {
	95	if (c=='\\') {
ea1e31e3	96	if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
e576be50	97	if (ctype_digit(p[0])) {
e576be50	98	if (ctype_digit(p[1]) && ctype_digit(p[2])) {
0d66e373	99	c= (p++ - '0')100;
	100	c += (p++ - '0')10;
	101	c += (*p++ - '0');
ea1e31e3	102	if (c >= 256) return adns_s_querydomaininvalid;
e576be50	103	} else {
ea1e31e3	104	return adns_s_querydomaininvalid;
e576be50	105	}
e576be50	106	} else if (!(c= *p++)) {
ea1e31e3	107	return adns_s_querydomaininvalid;
e576be50	108	}
e576be50	109	}
828d89bd	110	if (!(flags & adns_qf_quoteok_query)) {
ffbda80c	111	if (c == '-') {
ea1e31e3	112	if (!ll) return adns_s_querydomaininvalid;
ffbda80c	113	} else if (!ctype_alpha(c) && !ctype_digit(c)) {
ea1e31e3	114	return adns_s_querydomaininvalid;
e576be50	115	}
e576be50	116	}
ea1e31e3	117	if (ll == sizeof(label)) return adns_s_querydomaininvalid;
e576be50	118	label[ll++]= c;
e576be50	119	}
ea1e31e3	120	if (!ll) return adns_s_querydomaininvalid;
5b9dd636	121	if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong;
4b2c4f8a	122	nbytes+= ll+1;
5b9dd636	123	if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong;
e576be50	124	MKQUERY_ADDB(ll);
e576be50	125	memcpy(rqp,label,ll); rqp+= ll;
e9e53c73	126	}
e062dcae	127	MKQUERY_ADDB(0);
	128
	129	MKQUERY_STOP(vb);
	130
	131	st= mkquery_footer(vb,typei->type);
	132
	133	return adns_s_ok;
	134	}
e576be50	135
e062dcae	136	adns_status adns__mkquery_frdgram(adns_state ads, vbuf vb, int id_r,
609133ee	137	const byte *qd_dgram, int qd_dglen,
609133ee	138	int qd_begin,
e062dcae	139	adns_rrtype type, adns_queryflags flags) {
	140	byte *rqp;
	141	findlabel_state fls;
	142	int lablen, labstart;
	143	adns_status st;
	144
	145	st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
	146
	147	MKQUERY_START(vb);
	148
	149	adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
	150	for (;;) {
	151	st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
	152	if (!lablen) break;
	153	assert(lablen<255);
	154	MKQUERY_ADDB(lablen);
	155	memcpy(rqp,qd_dgram+labstart,lablen);
	156	rqp+= lablen;
	157	}
e576be50	158	MKQUERY_ADDB(0);
e576be50	159
e062dcae	160	MKQUERY_STOP(vb);
	161
	162	st= mkquery_footer(vb,type);
e576be50	163
	164	return adns_s_ok;
	165	}
	166
f7f83b4a	167	void adns__querysend_tcp(adns_query qu, struct timeval now) {
e576be50	168	byte length[2];
	169	struct iovec iov[2];
	170	int wr, r;
3955725c	171	adns_state ads;
e576be50	172
3955725c	173	if (qu->ads->tcpstate != server_ok) return;
e576be50	174
f7f83b4a	175	assert(qu->state == query_tcpw);
f7f83b4a	176
e576be50	177	length[0]= (qu->query_dglen&0x0ff00U) >>8;
e576be50	178	length[1]= (qu->query_dglen&0x0ff);
3955725c	179
3955725c	180	ads= qu->ads;
609133ee	181	if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2))
609133ee	182	return;
e576be50	183
f7f83b4a	184	qu->retries++;
	185
	186	/* Reset idle timeout. */
	187	ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0;
e576be50	188
	189	if (ads->tcpsend.used) {
	190	wr= 0;
	191	} else {
	192	iov[0].iov_base= length;
	193	iov[0].iov_len= 2;
	194	iov[1].iov_base= qu->query_dgram;
	195	iov[1].iov_len= qu->query_dglen;
ac868fa8	196	adns__sigpipe_protect(qu->ads);
3955725c	197	wr= writev(qu->ads->tcpsocket,iov,2);
ac868fa8	198	adns__sigpipe_unprotect(qu->ads);
e576be50	199	if (wr < 0) {
	200	if (!(errno == EAGAIN \|\| errno == EINTR \|\| errno == ENOSPC \|\|
	201	errno == ENOBUFS \|\| errno == ENOMEM)) {
	202	adns__tcp_broken(ads,"write",strerror(errno));
	203	return;
	204	}
	205	wr= 0;
	206	}
	207	}
	208
	209	if (wr<2) {
	210	r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
	211	wr= 0;
	212	} else {
	213	wr-= 2;
	214	}
	215	if (wr<qu->query_dglen) {
609133ee	216	r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr);
609133ee	217	assert(r);
e576be50	218	}
	219	}
	220
3955725c	221	static void query_usetcp(adns_query qu, struct timeval now) {
f7f83b4a	222	qu->state= query_tcpw;
e576be50	223	qu->timeout= now;
f7f83b4a	224	timevaladd(&qu->timeout,TCPWAITMS);
	225	LIST_LINK_TAIL(qu->ads->tcpw,qu);
	226	adns__querysend_tcp(qu,now);
3955725c	227	adns__tcp_tryconnect(qu->ads,now);
e576be50	228	}
e576be50	229
d8c062fa	230	void adns__query_send(adns_query qu, struct timeval now) {
e576be50	231	struct sockaddr_in servaddr;
e576be50	232	int serv, r;
3955725c	233	adns_state ads;
e576be50	234
d8c062fa	235	assert(qu->state == query_tosend);
e576be50	236	if ((qu->flags & adns_qf_usevc) \|\| (qu->query_dglen > DNS_MAXUDP)) {
3955725c	237	query_usetcp(qu,now);
e576be50	238	return;
	239	}
	240
f7f83b4a	241	if (qu->retries >= UDPMAXRETRIES) {
3955725c	242	adns__query_fail(qu,adns_s_timeout);
e576be50	243	return;
	244	}
	245
	246	serv= qu->udpnextserver;
	247	memset(&servaddr,0,sizeof(servaddr));
3955725c	248
3955725c	249	ads= qu->ads;
e576be50	250	servaddr.sin_family= AF_INET;
	251	servaddr.sin_addr= ads->servers[serv].addr;
	252	servaddr.sin_port= htons(DNS_PORT);
	253
71a6ff46	254	r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,
71a6ff46	255	(const struct sockaddr*)&servaddr,sizeof(servaddr));
609133ee	256	if (r<0 && errno == EMSGSIZE) {
	257	qu->retries= 0;
	258	query_usetcp(qu,now);
	259	return;
	260	}
	261	if (r<0 && errno != EAGAIN)
	262	adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
e576be50	263
e576be50	264	qu->timeout= now;
f7f83b4a	265	timevaladd(&qu->timeout,UDPRETRYMS);
e576be50	266	qu->udpsent \|= (1<<serv);
e576be50	267	qu->udpnextserver= (serv+1)%ads->nservers;
f7f83b4a	268	qu->retries++;
f7f83b4a	269	LIST_LINK_TAIL(ads->udpw,qu);
e576be50	270	}