[adns] / src / transmit.c

/*
 * transmit.c
 * - construct queries
 * - send queries
 */
/*
 *  This file is
 *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
 *
 *  It is part of adns, which is
 *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
 *    Copyright (C) 1999 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 + (*p++ - '0')*10 + (*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 > 63) return adns_s_querydomaintoolong;
    nbytes+= ll+1;
    if (nbytes > 254) 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) 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
	8	* Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
	9	*
	10	* It is part of adns, which is
	11	* Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
	12	* Copyright (C) 1999 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
e062dcae	42	static adns_status mkquery_header(adns_state ads, vbuf vb, int id_r, int qdlen) {
	43	int id;
	44	byte *rqp;
	45
ea1e31e3	46	if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory;
e576be50	47
e062dcae	48	vb->used= 0;
	49	MKQUERY_START(vb);
	50
660d7d3b	51	*id_r= id= (ads->nextid++) & 0x0ffff;
e576be50	52	MKQUERY_ADDW(id);
	53	MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
	54	MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
	55	MKQUERY_ADDW(1); /* QDCOUNT=1 */
	56	MKQUERY_ADDW(0); /* ANCOUNT=0 */
	57	MKQUERY_ADDW(0); /* NSCOUNT=0 */
	58	MKQUERY_ADDW(0); /* ARCOUNT=0 */
e062dcae	59
	60	MKQUERY_STOP(vb);
	61
	62	return adns_s_ok;
	63	}
	64
	65	static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) {
	66	byte *rqp;
	67
	68	MKQUERY_START(vb);
	69	MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
	70	MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
	71	MKQUERY_STOP(vb);
	72	assert(vb->used <= vb->avail);
	73
	74	return adns_s_ok;
	75	}
	76
	77	adns_status adns__mkquery(adns_state ads, vbuf vb, int id_r,
	78	const char *owner, int ol,
	79	const typeinfo *typei, adns_queryflags flags) {
4b2c4f8a	80	int ll, c, nbytes;
e062dcae	81	byte label[255], *rqp;
	82	const char p, pe;
	83	adns_status st;
	84
914a5ff5	85	st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st;
e062dcae	86
	87	MKQUERY_START(vb);
	88
e576be50	89	p= owner; pe= owner+ol;
4b2c4f8a	90	nbytes= 0;
e9e53c73	91	while (p!=pe) {
e576be50	92	ll= 0;
	93	while (p!=pe && (c= *p++)!='.') {
	94	if (c=='\\') {
ea1e31e3	95	if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
e576be50	96	if (ctype_digit(p[0])) {
	97	if (ctype_digit(p[1]) && ctype_digit(p[2])) {
	98	c= (p++ - '0')100 + (p++ - '0')10 + (*p++ - '0');
ea1e31e3	99	if (c >= 256) return adns_s_querydomaininvalid;
e576be50	100	} else {
ea1e31e3	101	return adns_s_querydomaininvalid;
e576be50	102	}
e576be50	103	} else if (!(c= *p++)) {
ea1e31e3	104	return adns_s_querydomaininvalid;
e576be50	105	}
e576be50	106	}
828d89bd	107	if (!(flags & adns_qf_quoteok_query)) {
ffbda80c	108	if (c == '-') {
ea1e31e3	109	if (!ll) return adns_s_querydomaininvalid;
ffbda80c	110	} else if (!ctype_alpha(c) && !ctype_digit(c)) {
ea1e31e3	111	return adns_s_querydomaininvalid;
e576be50	112	}
e576be50	113	}
ea1e31e3	114	if (ll == sizeof(label)) return adns_s_querydomaininvalid;
e576be50	115	label[ll++]= c;
e576be50	116	}
ea1e31e3	117	if (!ll) return adns_s_querydomaininvalid;
4b2c4f8a	118	if (ll > 63) return adns_s_querydomaintoolong;
	119	nbytes+= ll+1;
	120	if (nbytes > 254) return adns_s_querydomaintoolong;
e576be50	121	MKQUERY_ADDB(ll);
e576be50	122	memcpy(rqp,label,ll); rqp+= ll;
e9e53c73	123	}
e062dcae	124	MKQUERY_ADDB(0);
	125
	126	MKQUERY_STOP(vb);
	127
	128	st= mkquery_footer(vb,typei->type);
	129
	130	return adns_s_ok;
	131	}
e576be50	132
e062dcae	133	adns_status adns__mkquery_frdgram(adns_state ads, vbuf vb, int id_r,
	134	const byte *qd_dgram, int qd_dglen, int qd_begin,
	135	adns_rrtype type, adns_queryflags flags) {
	136	byte *rqp;
	137	findlabel_state fls;
	138	int lablen, labstart;
	139	adns_status st;
	140
	141	st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
	142
	143	MKQUERY_START(vb);
	144
	145	adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
	146	for (;;) {
	147	st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
	148	if (!lablen) break;
	149	assert(lablen<255);
	150	MKQUERY_ADDB(lablen);
	151	memcpy(rqp,qd_dgram+labstart,lablen);
	152	rqp+= lablen;
	153	}
e576be50	154	MKQUERY_ADDB(0);
e576be50	155
e062dcae	156	MKQUERY_STOP(vb);
	157
	158	st= mkquery_footer(vb,type);
e576be50	159
	160	return adns_s_ok;
	161	}
	162
f7f83b4a	163	void adns__querysend_tcp(adns_query qu, struct timeval now) {
e576be50	164	byte length[2];
	165	struct iovec iov[2];
	166	int wr, r;
3955725c	167	adns_state ads;
e576be50	168
3955725c	169	if (qu->ads->tcpstate != server_ok) return;
e576be50	170
f7f83b4a	171	assert(qu->state == query_tcpw);
f7f83b4a	172
e576be50	173	length[0]= (qu->query_dglen&0x0ff00U) >>8;
e576be50	174	length[1]= (qu->query_dglen&0x0ff);
3955725c	175
3955725c	176	ads= qu->ads;
e576be50	177	if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return;
e576be50	178
f7f83b4a	179	qu->retries++;
	180
	181	/* Reset idle timeout. */
	182	ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0;
e576be50	183
	184	if (ads->tcpsend.used) {
	185	wr= 0;
	186	} else {
	187	iov[0].iov_base= length;
	188	iov[0].iov_len= 2;
	189	iov[1].iov_base= qu->query_dgram;
	190	iov[1].iov_len= qu->query_dglen;
ac868fa8	191	adns__sigpipe_protect(qu->ads);
3955725c	192	wr= writev(qu->ads->tcpsocket,iov,2);
ac868fa8	193	adns__sigpipe_unprotect(qu->ads);
e576be50	194	if (wr < 0) {
	195	if (!(errno == EAGAIN \|\| errno == EINTR \|\| errno == ENOSPC \|\|
	196	errno == ENOBUFS \|\| errno == ENOMEM)) {
	197	adns__tcp_broken(ads,"write",strerror(errno));
	198	return;
	199	}
	200	wr= 0;
	201	}
	202	}
	203
	204	if (wr<2) {
	205	r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
	206	wr= 0;
	207	} else {
	208	wr-= 2;
	209	}
	210	if (wr<qu->query_dglen) {
	211	r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r);
	212	}
	213	}
	214
3955725c	215	static void query_usetcp(adns_query qu, struct timeval now) {
f7f83b4a	216	qu->state= query_tcpw;
e576be50	217	qu->timeout= now;
f7f83b4a	218	timevaladd(&qu->timeout,TCPWAITMS);
	219	LIST_LINK_TAIL(qu->ads->tcpw,qu);
	220	adns__querysend_tcp(qu,now);
3955725c	221	adns__tcp_tryconnect(qu->ads,now);
e576be50	222	}
e576be50	223
d8c062fa	224	void adns__query_send(adns_query qu, struct timeval now) {
e576be50	225	struct sockaddr_in servaddr;
e576be50	226	int serv, r;
3955725c	227	adns_state ads;
e576be50	228
d8c062fa	229	assert(qu->state == query_tosend);
e576be50	230	if ((qu->flags & adns_qf_usevc) \|\| (qu->query_dglen > DNS_MAXUDP)) {
3955725c	231	query_usetcp(qu,now);
e576be50	232	return;
	233	}
	234
f7f83b4a	235	if (qu->retries >= UDPMAXRETRIES) {
3955725c	236	adns__query_fail(qu,adns_s_timeout);
e576be50	237	return;
	238	}
	239
	240	serv= qu->udpnextserver;
	241	memset(&servaddr,0,sizeof(servaddr));
3955725c	242
3955725c	243	ads= qu->ads;
e576be50	244	servaddr.sin_family= AF_INET;
	245	servaddr.sin_addr= ads->servers[serv].addr;
	246	servaddr.sin_port= htons(DNS_PORT);
	247
71a6ff46	248	r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,
71a6ff46	249	(const struct sockaddr*)&servaddr,sizeof(servaddr));
f7f83b4a	250	if (r<0 && errno == EMSGSIZE) { qu->retries= 0; query_usetcp(qu,now); return; }
e576be50	251	if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
e576be50	252
e576be50	253	qu->timeout= now;
f7f83b4a	254	timevaladd(&qu->timeout,UDPRETRYMS);
e576be50	255	qu->udpsent \|= (1<<serv);
e576be50	256	qu->udpnextserver= (serv+1)%ads->nservers;
f7f83b4a	257	qu->retries++;
f7f83b4a	258	LIST_LINK_TAIL(ads->udpw,qu);
e576be50	259	}