[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__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
98db6da3	1	/*
	2	* transmit.c
	3	* - construct queries
	4	* - send queries
	5	*/
	6	/*
a79ac5ba	7	* This file is
89435c42	8	* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
a79ac5ba	9	*
a79ac5ba	10	* It is part of adns, which is
89435c42	11	* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
c6826df6	12	* Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
98db6da3	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
11c8bf9b	29	#include <errno.h>
11c8bf9b	30
763d28b9	31	#include <sys/types.h>
11c8bf9b	32	#include <sys/uio.h>
11c8bf9b	33
98db6da3	34	#include "internal.h"
83e1be2f	35	#include "tvarith.h"
98db6da3	36
f2ad23ee	37	#define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
98db6da3	38	#define MKQUERY_ADDB(b) *rqp++= (b)
98db6da3	39	#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
f2ad23ee	40	#define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
98db6da3	41
9c344a42	42	static adns_status mkquery_header(adns_state ads, vbuf *vb,
9c344a42	43	int *id_r, int qdlen) {
f2ad23ee	44	int id;
	45	byte *rqp;
	46
9b86645c	47	if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory;
98db6da3	48
f2ad23ee	49	vb->used= 0;
	50	MKQUERY_START(vb);
	51
7e6a84a1	52	*id_r= id= (ads->nextid++) & 0x0ffff;
98db6da3	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 */
f2ad23ee	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);
7d0aaee4	70	MKQUERY_ADDW(type & adns_rrt_typemask); /* QTYPE */
f2ad23ee	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
bddb4c18	78	adns_status adns__qdpl_normal(adns_state ads,
	79	const char *p_io, const char pe, int labelnum,
	80	char label_r[], int *ll_io,
	81	adns_queryflags flags,
	82	const typeinfo *typei) {
	83	int ll, c;
	84	const char *p;
	85
	86	ll= 0;
	87	p= *p_io;
	88
	89	while (p!=pe && (c= *p++)!='.') {
	90	if (c=='\\') {
	91	if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
	92	if (ctype_digit(p[0])) {
	93	if (p+1==pe \|\| p+2==pe) return adns_s_querydomaininvalid;
	94	if (ctype_digit(p[1]) && ctype_digit(p[2])) {
	95	c= (p++ - '0')100;
	96	c += (p++ - '0')10;
	97	c += (*p++ - '0');
	98	if (c >= 256) return adns_s_querydomaininvalid;
	99	} else {
	100	return adns_s_querydomaininvalid;
	101	}
	102	} else if (!(c= *p++)) {
	103	return adns_s_querydomaininvalid;
	104	}
	105	}
	106	if (!(flags & adns_qf_quoteok_query)) {
	107	if (c == '-') {
	108	if (!ll) return adns_s_querydomaininvalid;
	109	} else if (!ctype_alpha(c) && !ctype_digit(c)) {
	110	return adns_s_querydomaininvalid;
	111	}
	112	}
	113	if (ll == *ll_io) return adns_s_querydomaininvalid;
	114	label_r[ll++]= c;
	115	}
	116
	117	*p_io= p;
	118	*ll_io= ll;
	119	return adns_s_ok;
	120	}
	121
f2ad23ee	122	adns_status adns__mkquery(adns_state ads, vbuf vb, int id_r,
f2ad23ee	123	const char *owner, int ol,
7d0aaee4	124	const typeinfo *typei, adns_rrtype type,
7d0aaee4	125	adns_queryflags flags) {
bddb4c18	126	int labelnum, ll, nbytes;
	127	byte label[255];
	128	byte *rqp;
f2ad23ee	129	const char p, pe;
	130	adns_status st;
	131
fc86e61f	132	st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st;
f2ad23ee	133
	134	MKQUERY_START(vb);
	135
98db6da3	136	p= owner; pe= owner+ol;
f57665b9	137	nbytes= 0;
bddb4c18	138	labelnum= 0;
7683abe2	139	while (p!=pe) {
bddb4c18	140	ll= sizeof(label);
	141	st= typei->qdparselabel(ads, &p,pe, labelnum++, label, &ll, flags, typei);
	142	if (st) return st;
9b86645c	143	if (!ll) return adns_s_querydomaininvalid;
3d75057b	144	if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong;
f57665b9	145	nbytes+= ll+1;
3d75057b	146	if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong;
98db6da3	147	MKQUERY_ADDB(ll);
98db6da3	148	memcpy(rqp,label,ll); rqp+= ll;
7683abe2	149	}
f2ad23ee	150	MKQUERY_ADDB(0);
	151
	152	MKQUERY_STOP(vb);
	153
7d0aaee4	154	st= mkquery_footer(vb,type);
f2ad23ee	155
	156	return adns_s_ok;
	157	}
98db6da3	158
f2ad23ee	159	adns_status adns__mkquery_frdgram(adns_state ads, vbuf vb, int id_r,
9c344a42	160	const byte *qd_dgram, int qd_dglen,
9c344a42	161	int qd_begin,
f2ad23ee	162	adns_rrtype type, adns_queryflags flags) {
	163	byte *rqp;
	164	findlabel_state fls;
	165	int lablen, labstart;
	166	adns_status st;
	167
	168	st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
	169
	170	MKQUERY_START(vb);
	171
	172	adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
	173	for (;;) {
	174	st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
	175	if (!lablen) break;
	176	assert(lablen<255);
	177	MKQUERY_ADDB(lablen);
	178	memcpy(rqp,qd_dgram+labstart,lablen);
	179	rqp+= lablen;
	180	}
98db6da3	181	MKQUERY_ADDB(0);
98db6da3	182
f2ad23ee	183	MKQUERY_STOP(vb);
	184
	185	st= mkquery_footer(vb,type);
98db6da3	186
	187	return adns_s_ok;
	188	}
	189
d0a057ac	190	void adns__querysend_tcp(adns_query qu, struct timeval now) {
98db6da3	191	byte length[2];
	192	struct iovec iov[2];
	193	int wr, r;
11c8bf9b	194	adns_state ads;
98db6da3	195
11c8bf9b	196	if (qu->ads->tcpstate != server_ok) return;
98db6da3	197
d0a057ac	198	assert(qu->state == query_tcpw);
d0a057ac	199
98db6da3	200	length[0]= (qu->query_dglen&0x0ff00U) >>8;
98db6da3	201	length[1]= (qu->query_dglen&0x0ff);
11c8bf9b	202
11c8bf9b	203	ads= qu->ads;
9c344a42	204	if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2))
9c344a42	205	return;
98db6da3	206
d0a057ac	207	qu->retries++;
	208
	209	/* Reset idle timeout. */
	210	ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0;
98db6da3	211
	212	if (ads->tcpsend.used) {
	213	wr= 0;
	214	} else {
	215	iov[0].iov_base= length;
	216	iov[0].iov_len= 2;
	217	iov[1].iov_base= qu->query_dgram;
	218	iov[1].iov_len= qu->query_dglen;
87e46054	219	adns__sigpipe_protect(qu->ads);
11c8bf9b	220	wr= writev(qu->ads->tcpsocket,iov,2);
87e46054	221	adns__sigpipe_unprotect(qu->ads);
98db6da3	222	if (wr < 0) {
	223	if (!(errno == EAGAIN \|\| errno == EINTR \|\| errno == ENOSPC \|\|
	224	errno == ENOBUFS \|\| errno == ENOMEM)) {
	225	adns__tcp_broken(ads,"write",strerror(errno));
	226	return;
	227	}
	228	wr= 0;
	229	}
	230	}
	231
	232	if (wr<2) {
	233	r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
	234	wr= 0;
	235	} else {
	236	wr-= 2;
	237	}
	238	if (wr<qu->query_dglen) {
9c344a42	239	r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr);
9c344a42	240	assert(r);
98db6da3	241	}
	242	}
	243
11c8bf9b	244	static void query_usetcp(adns_query qu, struct timeval now) {
d0a057ac	245	qu->state= query_tcpw;
98db6da3	246	qu->timeout= now;
d0a057ac	247	timevaladd(&qu->timeout,TCPWAITMS);
	248	LIST_LINK_TAIL(qu->ads->tcpw,qu);
	249	adns__querysend_tcp(qu,now);
11c8bf9b	250	adns__tcp_tryconnect(qu->ads,now);
98db6da3	251	}
98db6da3	252
24d52b13	253	void adns__query_send(adns_query qu, struct timeval now) {
98db6da3	254	struct sockaddr_in servaddr;
98db6da3	255	int serv, r;
11c8bf9b	256	adns_state ads;
98db6da3	257
24d52b13	258	assert(qu->state == query_tosend);
98db6da3	259	if ((qu->flags & adns_qf_usevc) \|\| (qu->query_dglen > DNS_MAXUDP)) {
11c8bf9b	260	query_usetcp(qu,now);
98db6da3	261	return;
	262	}
	263
d0a057ac	264	if (qu->retries >= UDPMAXRETRIES) {
11c8bf9b	265	adns__query_fail(qu,adns_s_timeout);
98db6da3	266	return;
	267	}
	268
	269	serv= qu->udpnextserver;
	270	memset(&servaddr,0,sizeof(servaddr));
11c8bf9b	271
11c8bf9b	272	ads= qu->ads;
98db6da3	273	servaddr.sin_family= AF_INET;
	274	servaddr.sin_addr= ads->servers[serv].addr;
	275	servaddr.sin_port= htons(DNS_PORT);
	276
763d28b9	277	r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,
763d28b9	278	(const struct sockaddr*)&servaddr,sizeof(servaddr));
9c344a42	279	if (r<0 && errno == EMSGSIZE) {
	280	qu->retries= 0;
	281	query_usetcp(qu,now);
	282	return;
	283	}
	284	if (r<0 && errno != EAGAIN)
	285	adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
98db6da3	286
98db6da3	287	qu->timeout= now;
d0a057ac	288	timevaladd(&qu->timeout,UDPRETRYMS);
98db6da3	289	qu->udpsent \|= (1<<serv);
98db6da3	290	qu->udpnextserver= (serv+1)%ads->nservers;
d0a057ac	291	qu->retries++;
d0a057ac	292	LIST_LINK_TAIL(ads->udpw,qu);
98db6da3	293	}