[adns] / src / transmit.c

/*
 * transmit.c
 * - construct queries
 * - send queries
 */
/*
 *  This file is part of adns, which is
 *    Copyright (C) 1997-2000,2003,2006  Ian Jackson
 *    Copyright (C) 1999-2000,2003,2006  Tony Finch
 *    Copyright (C) 1991 Massachusetts Institute of Technology
 *  (See the file INSTALL for full details.)
 *  
 *  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__qdpl_normal(adns_state ads,
			      const char **p_io, const char *pe, int labelnum,
			      char label_r[], int *ll_io,
			      adns_queryflags flags,
			      const typeinfo *typei) {
  int ll, c;
  const char *p;

  ll= 0;
  p= *p_io;
  
  while (p!=pe && (c= *p++)!='.') {
    if (c=='\\') {
      if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
      if (ctype_digit(p[0])) {
	if (p+1==pe || p+2==pe) return adns_s_querydomaininvalid;
	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 == *ll_io) return adns_s_querydomaininvalid;
    label_r[ll++]= c;
  }
  
  *p_io= p;
  *ll_io= ll;
  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_rrtype type,
			  adns_queryflags flags) {
  int labelnum, ll, nbytes;
  byte label[255];
  byte *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;
  labelnum= 0;
  while (p!=pe) {
    ll= sizeof(label);
    st= typei->qdparselabel(ads, &p,pe, labelnum++, label, &ll, flags, typei);
    if (st) return st;
    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,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	/*
ae8cc977	7	* This file is part of adns, which is
	8	* Copyright (C) 1997-2000,2003,2006 Ian Jackson
	9	* Copyright (C) 1999-2000,2003,2006 Tony Finch
	10	* Copyright (C) 1991 Massachusetts Institute of Technology
	11	* (See the file INSTALL for full details.)
e576be50	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2, or (at your option)
	16	* any later version.
	17	*
	18	* This program is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	21	* GNU General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU General Public License
	24	* along with this program; if not, write to the Free Software Foundation,
	25	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	26	*/
	27
3955725c	28	#include <errno.h>
3955725c	29
71a6ff46	30	#include <sys/types.h>
3955725c	31	#include <sys/uio.h>
3955725c	32
e576be50	33	#include "internal.h"
2953d358	34	#include "tvarith.h"
e576be50	35
e062dcae	36	#define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
e576be50	37	#define MKQUERY_ADDB(b) *rqp++= (b)
e576be50	38	#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
e062dcae	39	#define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
e576be50	40
609133ee	41	static adns_status mkquery_header(adns_state ads, vbuf *vb,
609133ee	42	int *id_r, int qdlen) {
e062dcae	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);
2c6eb096	69	MKQUERY_ADDW(type & adns_rrt_typemask); /* QTYPE */
e062dcae	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
d19b03d0	77	adns_status adns__qdpl_normal(adns_state ads,
	78	const char *p_io, const char pe, int labelnum,
	79	char label_r[], int *ll_io,
	80	adns_queryflags flags,
	81	const typeinfo *typei) {
	82	int ll, c;
	83	const char *p;
	84
	85	ll= 0;
	86	p= *p_io;
	87
	88	while (p!=pe && (c= *p++)!='.') {
	89	if (c=='\\') {
	90	if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
	91	if (ctype_digit(p[0])) {
	92	if (p+1==pe \|\| p+2==pe) return adns_s_querydomaininvalid;
	93	if (ctype_digit(p[1]) && ctype_digit(p[2])) {
	94	c= (p++ - '0')100;
	95	c += (p++ - '0')10;
	96	c += (*p++ - '0');
	97	if (c >= 256) return adns_s_querydomaininvalid;
	98	} else {
	99	return adns_s_querydomaininvalid;
	100	}
	101	} else if (!(c= *p++)) {
	102	return adns_s_querydomaininvalid;
	103	}
	104	}
	105	if (!(flags & adns_qf_quoteok_query)) {
	106	if (c == '-') {
	107	if (!ll) return adns_s_querydomaininvalid;
	108	} else if (!ctype_alpha(c) && !ctype_digit(c)) {
	109	return adns_s_querydomaininvalid;
	110	}
	111	}
	112	if (ll == *ll_io) return adns_s_querydomaininvalid;
	113	label_r[ll++]= c;
	114	}
	115
	116	*p_io= p;
	117	*ll_io= ll;
	118	return adns_s_ok;
	119	}
	120
e062dcae	121	adns_status adns__mkquery(adns_state ads, vbuf vb, int id_r,
e062dcae	122	const char *owner, int ol,
2c6eb096	123	const typeinfo *typei, adns_rrtype type,
2c6eb096	124	adns_queryflags flags) {
d19b03d0	125	int labelnum, ll, nbytes;
	126	byte label[255];
	127	byte *rqp;
e062dcae	128	const char p, pe;
	129	adns_status st;
	130
914a5ff5	131	st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st;
e062dcae	132
	133	MKQUERY_START(vb);
	134
e576be50	135	p= owner; pe= owner+ol;
4b2c4f8a	136	nbytes= 0;
d19b03d0	137	labelnum= 0;
e9e53c73	138	while (p!=pe) {
d19b03d0	139	ll= sizeof(label);
	140	st= typei->qdparselabel(ads, &p,pe, labelnum++, label, &ll, flags, typei);
	141	if (st) return st;
ea1e31e3	142	if (!ll) return adns_s_querydomaininvalid;
5b9dd636	143	if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong;
4b2c4f8a	144	nbytes+= ll+1;
5b9dd636	145	if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong;
e576be50	146	MKQUERY_ADDB(ll);
e576be50	147	memcpy(rqp,label,ll); rqp+= ll;
e9e53c73	148	}
e062dcae	149	MKQUERY_ADDB(0);
	150
	151	MKQUERY_STOP(vb);
	152
2c6eb096	153	st= mkquery_footer(vb,type);
e062dcae	154
	155	return adns_s_ok;
	156	}
e576be50	157
e062dcae	158	adns_status adns__mkquery_frdgram(adns_state ads, vbuf vb, int id_r,
609133ee	159	const byte *qd_dgram, int qd_dglen,
609133ee	160	int qd_begin,
e062dcae	161	adns_rrtype type, adns_queryflags flags) {
	162	byte *rqp;
	163	findlabel_state fls;
	164	int lablen, labstart;
	165	adns_status st;
	166
	167	st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
	168
	169	MKQUERY_START(vb);
	170
	171	adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
	172	for (;;) {
	173	st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
	174	if (!lablen) break;
	175	assert(lablen<255);
	176	MKQUERY_ADDB(lablen);
	177	memcpy(rqp,qd_dgram+labstart,lablen);
	178	rqp+= lablen;
	179	}
e576be50	180	MKQUERY_ADDB(0);
e576be50	181
e062dcae	182	MKQUERY_STOP(vb);
	183
	184	st= mkquery_footer(vb,type);
e576be50	185
	186	return adns_s_ok;
	187	}
	188
f7f83b4a	189	void adns__querysend_tcp(adns_query qu, struct timeval now) {
e576be50	190	byte length[2];
	191	struct iovec iov[2];
	192	int wr, r;
3955725c	193	adns_state ads;
e576be50	194
3955725c	195	if (qu->ads->tcpstate != server_ok) return;
e576be50	196
f7f83b4a	197	assert(qu->state == query_tcpw);
f7f83b4a	198
e576be50	199	length[0]= (qu->query_dglen&0x0ff00U) >>8;
e576be50	200	length[1]= (qu->query_dglen&0x0ff);
3955725c	201
3955725c	202	ads= qu->ads;
609133ee	203	if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2))
609133ee	204	return;
e576be50	205
f7f83b4a	206	qu->retries++;
	207
	208	/* Reset idle timeout. */
	209	ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0;
e576be50	210
	211	if (ads->tcpsend.used) {
	212	wr= 0;
	213	} else {
	214	iov[0].iov_base= length;
	215	iov[0].iov_len= 2;
	216	iov[1].iov_base= qu->query_dgram;
	217	iov[1].iov_len= qu->query_dglen;
ac868fa8	218	adns__sigpipe_protect(qu->ads);
3955725c	219	wr= writev(qu->ads->tcpsocket,iov,2);
ac868fa8	220	adns__sigpipe_unprotect(qu->ads);
e576be50	221	if (wr < 0) {
	222	if (!(errno == EAGAIN \|\| errno == EINTR \|\| errno == ENOSPC \|\|
	223	errno == ENOBUFS \|\| errno == ENOMEM)) {
	224	adns__tcp_broken(ads,"write",strerror(errno));
	225	return;
	226	}
	227	wr= 0;
	228	}
	229	}
	230
	231	if (wr<2) {
	232	r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
	233	wr= 0;
	234	} else {
	235	wr-= 2;
	236	}
	237	if (wr<qu->query_dglen) {
609133ee	238	r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr);
609133ee	239	assert(r);
e576be50	240	}
	241	}
	242
3955725c	243	static void query_usetcp(adns_query qu, struct timeval now) {
f7f83b4a	244	qu->state= query_tcpw;
e576be50	245	qu->timeout= now;
f7f83b4a	246	timevaladd(&qu->timeout,TCPWAITMS);
	247	LIST_LINK_TAIL(qu->ads->tcpw,qu);
	248	adns__querysend_tcp(qu,now);
3955725c	249	adns__tcp_tryconnect(qu->ads,now);
e576be50	250	}
e576be50	251
d8c062fa	252	void adns__query_send(adns_query qu, struct timeval now) {
e576be50	253	struct sockaddr_in servaddr;
e576be50	254	int serv, r;
3955725c	255	adns_state ads;
e576be50	256
d8c062fa	257	assert(qu->state == query_tosend);
e576be50	258	if ((qu->flags & adns_qf_usevc) \|\| (qu->query_dglen > DNS_MAXUDP)) {
3955725c	259	query_usetcp(qu,now);
e576be50	260	return;
	261	}
	262
f7f83b4a	263	if (qu->retries >= UDPMAXRETRIES) {
3955725c	264	adns__query_fail(qu,adns_s_timeout);
e576be50	265	return;
	266	}
	267
	268	serv= qu->udpnextserver;
	269	memset(&servaddr,0,sizeof(servaddr));
3955725c	270
3955725c	271	ads= qu->ads;
e576be50	272	servaddr.sin_family= AF_INET;
	273	servaddr.sin_addr= ads->servers[serv].addr;
	274	servaddr.sin_port= htons(DNS_PORT);
	275
71a6ff46	276	r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,
71a6ff46	277	(const struct sockaddr*)&servaddr,sizeof(servaddr));
609133ee	278	if (r<0 && errno == EMSGSIZE) {
	279	qu->retries= 0;
	280	query_usetcp(qu,now);
	281	return;
	282	}
	283	if (r<0 && errno != EAGAIN)
	284	adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
e576be50	285
e576be50	286	qu->timeout= now;
f7f83b4a	287	timevaladd(&qu->timeout,UDPRETRYMS);
e576be50	288	qu->udpsent \|= (1<<serv);
e576be50	289	qu->udpnextserver= (serv+1)%ads->nservers;
f7f83b4a	290	qu->retries++;
f7f83b4a	291	LIST_LINK_TAIL(ads->udpw,qu);
e576be50	292	}