[adns] / src / transmit.c

/*
 * transmit.c
 * - construct queries
 * - send queries
 */
/*
 *  This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
 *  
 *  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 <string.h>

#include <sys/uio.h>

#include "internal.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, nlabs;
  byte label[255], *rqp;
  const char *p, *pe;
  adns_status st;

  st= mkquery_header(ads,vb,id_r,strlen(owner)+2); if (st) return st;
  
  MKQUERY_START(vb);

  p= owner; pe= owner+ol;
  nlabs= 0;
  if (!*p) return adns_s_querydomaininvalid;
  do {
    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 (nlabs++ > 63) return adns_s_querydomaintoolong;
    MKQUERY_ADDB(ll);
    memcpy(rqp,label,ll); rqp+= ll;
  } while (p!=pe);
  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__query_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;

  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;

  timevaladd(&now,TCPMS);
  qu->timeout= now;
  qu->state= query_tcpsent;

  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) {
  timevaladd(&now,TCPMS);
  qu->timeout= now;
  qu->state= query_tcpwait;
  LIST_LINK_TAIL(qu->ads->timew,qu);
  adns__query_tcp(qu,now);
  adns__tcp_tryconnect(qu->ads,now);
}

void adns__query_udp(adns_query qu, struct timeval now) {
  struct sockaddr_in servaddr;
  int serv, r;
  adns_state ads;

  assert(qu->state == query_udp);
  if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) {
    query_usetcp(qu,now);
    return;
  }

  if (qu->udpretries >= 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,&servaddr,sizeof(servaddr));
  if (r<0 && errno == EMSGSIZE) { query_usetcp(qu,now); return; }
  if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
  
  timevaladd(&now,UDPRETRYMS);
  qu->timeout= now;
  qu->udpsent |= (1<<serv);
  qu->udpnextserver= (serv+1)%ads->nservers;
  qu->udpretries++;
  LIST_LINK_TAIL(ads->timew,qu);
}
Commit	Line	Data
e576be50	1	/*
	2	* transmit.c
	3	* - construct queries
	4	* - send queries
	5	*/
	6	/*
a719a4be	7	* This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
e576be50	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2, or (at your option)
	12	* any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software Foundation,
	21	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	22	*/
	23
3955725c	24	#include <errno.h>
	25	#include <string.h>
	26
	27	#include <sys/uio.h>
	28
e576be50	29	#include "internal.h"
e576be50	30
e062dcae	31	#define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
e576be50	32	#define MKQUERY_ADDB(b) *rqp++= (b)
e576be50	33	#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
e062dcae	34	#define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
e576be50	35
e062dcae	36	static adns_status mkquery_header(adns_state ads, vbuf vb, int id_r, int qdlen) {
	37	int id;
	38	byte *rqp;
	39
ea1e31e3	40	if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory;
e576be50	41
e062dcae	42	vb->used= 0;
	43	MKQUERY_START(vb);
	44
660d7d3b	45	*id_r= id= (ads->nextid++) & 0x0ffff;
e576be50	46	MKQUERY_ADDW(id);
	47	MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
	48	MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
	49	MKQUERY_ADDW(1); /* QDCOUNT=1 */
	50	MKQUERY_ADDW(0); /* ANCOUNT=0 */
	51	MKQUERY_ADDW(0); /* NSCOUNT=0 */
	52	MKQUERY_ADDW(0); /* ARCOUNT=0 */
e062dcae	53
	54	MKQUERY_STOP(vb);
	55
	56	return adns_s_ok;
	57	}
	58
	59	static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) {
	60	byte *rqp;
	61
	62	MKQUERY_START(vb);
	63	MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
	64	MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
	65	MKQUERY_STOP(vb);
	66	assert(vb->used <= vb->avail);
	67
	68	return adns_s_ok;
	69	}
	70
	71	adns_status adns__mkquery(adns_state ads, vbuf vb, int id_r,
	72	const char *owner, int ol,
	73	const typeinfo *typei, adns_queryflags flags) {
	74	int ll, c, nlabs;
	75	byte label[255], *rqp;
	76	const char p, pe;
	77	adns_status st;
	78
	79	st= mkquery_header(ads,vb,id_r,strlen(owner)+2); if (st) return st;
	80
	81	MKQUERY_START(vb);
	82
e576be50	83	p= owner; pe= owner+ol;
e576be50	84	nlabs= 0;
ea1e31e3	85	if (!*p) return adns_s_querydomaininvalid;
e576be50	86	do {
	87	ll= 0;
	88	while (p!=pe && (c= *p++)!='.') {
	89	if (c=='\\') {
ea1e31e3	90	if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
e576be50	91	if (ctype_digit(p[0])) {
	92	if (ctype_digit(p[1]) && ctype_digit(p[2])) {
	93	c= (p++ - '0')100 + (p++ - '0')10 + (*p++ - '0');
ea1e31e3	94	if (c >= 256) return adns_s_querydomaininvalid;
e576be50	95	} else {
ea1e31e3	96	return adns_s_querydomaininvalid;
e576be50	97	}
e576be50	98	} else if (!(c= *p++)) {
ea1e31e3	99	return adns_s_querydomaininvalid;
e576be50	100	}
e576be50	101	}
828d89bd	102	if (!(flags & adns_qf_quoteok_query)) {
ffbda80c	103	if (c == '-') {
ea1e31e3	104	if (!ll) return adns_s_querydomaininvalid;
ffbda80c	105	} else if (!ctype_alpha(c) && !ctype_digit(c)) {
ea1e31e3	106	return adns_s_querydomaininvalid;
e576be50	107	}
e576be50	108	}
ea1e31e3	109	if (ll == sizeof(label)) return adns_s_querydomaininvalid;
e576be50	110	label[ll++]= c;
e576be50	111	}
ea1e31e3	112	if (!ll) return adns_s_querydomaininvalid;
ea1e31e3	113	if (nlabs++ > 63) return adns_s_querydomaintoolong;
e576be50	114	MKQUERY_ADDB(ll);
	115	memcpy(rqp,label,ll); rqp+= ll;
	116	} while (p!=pe);
e062dcae	117	MKQUERY_ADDB(0);
	118
	119	MKQUERY_STOP(vb);
	120
	121	st= mkquery_footer(vb,typei->type);
	122
	123	return adns_s_ok;
	124	}
e576be50	125
e062dcae	126	adns_status adns__mkquery_frdgram(adns_state ads, vbuf vb, int id_r,
	127	const byte *qd_dgram, int qd_dglen, int qd_begin,
	128	adns_rrtype type, adns_queryflags flags) {
	129	byte *rqp;
	130	findlabel_state fls;
	131	int lablen, labstart;
	132	adns_status st;
	133
	134	st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
	135
	136	MKQUERY_START(vb);
	137
	138	adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
	139	for (;;) {
	140	st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
	141	if (!lablen) break;
	142	assert(lablen<255);
	143	MKQUERY_ADDB(lablen);
	144	memcpy(rqp,qd_dgram+labstart,lablen);
	145	rqp+= lablen;
	146	}
e576be50	147	MKQUERY_ADDB(0);
e576be50	148
e062dcae	149	MKQUERY_STOP(vb);
	150
	151	st= mkquery_footer(vb,type);
e576be50	152
	153	return adns_s_ok;
	154	}
	155
3955725c	156	void adns__query_tcp(adns_query qu, struct timeval now) {
e576be50	157	byte length[2];
	158	struct iovec iov[2];
	159	int wr, r;
3955725c	160	adns_state ads;
e576be50	161
3955725c	162	if (qu->ads->tcpstate != server_ok) return;
e576be50	163
	164	length[0]= (qu->query_dglen&0x0ff00U) >>8;
	165	length[1]= (qu->query_dglen&0x0ff);
3955725c	166
3955725c	167	ads= qu->ads;
e576be50	168	if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return;
	169
	170	timevaladd(&now,TCPMS);
	171	qu->timeout= now;
	172	qu->state= query_tcpsent;
e576be50	173
	174	if (ads->tcpsend.used) {
	175	wr= 0;
	176	} else {
	177	iov[0].iov_base= length;
	178	iov[0].iov_len= 2;
	179	iov[1].iov_base= qu->query_dgram;
	180	iov[1].iov_len= qu->query_dglen;
ac868fa8	181	adns__sigpipe_protect(qu->ads);
3955725c	182	wr= writev(qu->ads->tcpsocket,iov,2);
ac868fa8	183	adns__sigpipe_unprotect(qu->ads);
e576be50	184	if (wr < 0) {
	185	if (!(errno == EAGAIN \|\| errno == EINTR \|\| errno == ENOSPC \|\|
	186	errno == ENOBUFS \|\| errno == ENOMEM)) {
	187	adns__tcp_broken(ads,"write",strerror(errno));
	188	return;
	189	}
	190	wr= 0;
	191	}
	192	}
	193
	194	if (wr<2) {
	195	r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
	196	wr= 0;
	197	} else {
	198	wr-= 2;
	199	}
	200	if (wr<qu->query_dglen) {
	201	r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r);
	202	}
	203	}
	204
3955725c	205	static void query_usetcp(adns_query qu, struct timeval now) {
e576be50	206	timevaladd(&now,TCPMS);
	207	qu->timeout= now;
	208	qu->state= query_tcpwait;
3955725c	209	LIST_LINK_TAIL(qu->ads->timew,qu);
	210	adns__query_tcp(qu,now);
	211	adns__tcp_tryconnect(qu->ads,now);
e576be50	212	}
e576be50	213
3955725c	214	void adns__query_udp(adns_query qu, struct timeval now) {
e576be50	215	struct sockaddr_in servaddr;
e576be50	216	int serv, r;
3955725c	217	adns_state ads;
e576be50	218
	219	assert(qu->state == query_udp);
	220	if ((qu->flags & adns_qf_usevc) \|\| (qu->query_dglen > DNS_MAXUDP)) {
3955725c	221	query_usetcp(qu,now);
e576be50	222	return;
	223	}
	224
	225	if (qu->udpretries >= UDPMAXRETRIES) {
3955725c	226	adns__query_fail(qu,adns_s_timeout);
e576be50	227	return;
	228	}
	229
	230	serv= qu->udpnextserver;
	231	memset(&servaddr,0,sizeof(servaddr));
3955725c	232
3955725c	233	ads= qu->ads;
e576be50	234	servaddr.sin_family= AF_INET;
	235	servaddr.sin_addr= ads->servers[serv].addr;
	236	servaddr.sin_port= htons(DNS_PORT);
	237
	238	r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,&servaddr,sizeof(servaddr));
3955725c	239	if (r<0 && errno == EMSGSIZE) { query_usetcp(qu,now); return; }
e576be50	240	if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
	241
	242	timevaladd(&now,UDPRETRYMS);
	243	qu->timeout= now;
	244	qu->udpsent \|= (1<<serv);
	245	qu->udpnextserver= (serv+1)%ads->nservers;
	246	qu->udpretries++;
	247	LIST_LINK_TAIL(ads->timew,qu);
	248	}