[adns] / src / adns.c

/**/

#include <stdarg.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>

#include <netdb.h>
#include <arpa/nameser.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "adns-internal.h"

#define LIST_UNLINK_PART(list,node,part) \
  do { \
    if ((node)->back) (node)->back->part next= (node)->part next; \
      else                        (list).head= (node)->part next; \
    if ((node)->next) (node)->next->part back= (node)->part back; \
      else                        (list).tail= (node)->part back; \
  } while(0)

#define LIST_LINK_TAIL_PART(list,node,part) \
  do { \
    (node)->part back= 0; \
    (node)->part next= (list).tail; \
    if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \
    (list).tail= (node); \
  } while(0)

#define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
#define LIST_LINK_TAIL_PART(list,node) LIST_LINK_TAIL(list,node,)

static void vdebug(adns_state ads, const char *fmt, va_list al) {
  if (!(ads->iflags & adns_if_debug)) return;
  fputs("adns debug: ",stderr);
  vfprintf(stderr,fmt,al);
  fputc('\n',stderr);
}

static void debug(adns_state ads, const char *fmt, ...) {
  va_list al;

  va_start(al,fmt);
  vdebug(ads,fmt,al);
  va_end(al);
}

static void vdiag(adns_state ads, const char *fmt, va_list al) {
  if (ads->iflags & adns_if_noerrprint) return;
  fputs("adns: ",stderr);
  vfprintf(stderr,fmt,al);
  fputc('\n',stderr);
}

static void diag(adns_state ads, const char *fmt, ...) {
  va_list al;

  va_start(al,fmt);
  vdiag(ads,fmt,al);
  va_end(al);
}

static void addserver(adns_state ads, struct in_addr addr) {
  int i;
  struct server *ss;
  
  for (i=0; i<ads->nservers; i++) {
    if (ads->servers[i].addr.s_addr == addr.s_addr) {
      debug(ads,"duplicate nameserver %s ignored",inet_ntoa(addr));
      return;
    }
  }
  
  if (ads->nservers>=MAXSERVERS) {
    diag(ads,"too many nameservers, ignoring %s",inet_ntoa(addr));
    return;
  }

  ss= ads->servers+ads->nservers;
  ss->addr= addr;
  ss->state= server_disc;
  ss->connw.head= ss->connw.tail= 0;
  ads->nservers++;
}

static void configparseerr(adns_state ads, const char *fn, int lno,
			   const char *fmt, ...) {
  va_list al;
  
  if (ads->iflags & adns_if_noerrprint) return;
  if (lno==-1) fprintf(stderr,"adns: %s: ",fn);
  else fprintf(stderr,"adns: %s:%d: ",fn,lno);
  va_start(al,fmt);
  vfprintf(stderr,fmt,al);
  va_end(al);
  fputc('\n',stderr);
}

static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
  struct in_addr ia;
  
  if (!inet_aton(buf,&ia)) {
    configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
    return;
  }
  debug(ads,"using nameserver %s",inet_ntoa(ia));
  addserver(ads,ia);
}

static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
  if (!buf) return;
  diag(ads,"warning - `search' ignored FIXME");
}

static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
  diag(ads,"warning - `sortlist' ignored FIXME");
}

static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
  if (!buf) return;
  diag(ads,"warning - `options' ignored FIXME");
}

static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
  ads->nservers= 0;
}

static const struct configcommandinfo {
  const char *name;
  void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
} configcommandinfos[]= {
  { "nameserver",        ccf_nameserver  },
  { "domain",            ccf_search      },
  { "search",            ccf_search      },
  { "sortlist",          ccf_sortlist    },
  { "options",           ccf_options     },
  { "clearnameservers",  ccf_clearnss    },
  {  0                                   }
};

static int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
static int ctype_digit(int c) { return c>='0' && c<='9'; }

static void readconfig(adns_state ads, const char *filename) {
  char linebuf[2000], *p, *q;
  FILE *file;
  int lno, l, c;
  const struct configcommandinfo *ccip;

  file= fopen(filename,"r");
  if (!file) {
    if (errno == ENOENT) {
      debug(ads,"configuration file `%s' does not exist",filename);
      return;
    }
    diag(ads,"cannot open configuration file `%s': %s",filename,strerror(errno));
    return;
  }

  for (lno=1; fgets(linebuf,sizeof(linebuf),file); lno++) {
    l= strlen(linebuf);
    if (!l) continue;
    if (linebuf[l-1] != '\n' && !feof(file)) {
      diag(ads,"%s:%d: line too long",filename,lno);
      while ((c= getc(file)) != EOF && c != '\n') { }
      if (c == EOF) break;
      continue;
    }
    while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
    linebuf[l]= 0;
    p= linebuf;
    while (ctype_whitespace(*p)) p++;
    if (*p == '#' || *p == '\n') continue;
    q= p;
    while (*q && !ctype_whitespace(*q)) q++;
    for (ccip=configcommandinfos;
	 ccip->name && strncmp(ccip->name,p,q-p);
	 ccip++);
    if (!ccip->name) {
      diag(ads,"%s:%d: unknown configuration directive `%.*s'",filename,lno,q-p,p);
      continue;
    }
    while (ctype_whitespace(*q)) q++;
    ccip->fn(ads,filename,lno,q);
  }
  if (ferror(file)) {
    diag(ads,"%s:%d: read error: %s",filename,lno,strerror(errno));
  }
  fclose(file);
}

static const char *instrum_getenv(adns_state ads, const char *envvar) {
  const char *value;

  value= getenv(envvar);
  if (!value) debug(ads,"environment variable %s not set",envvar);
  else debug(ads,"environment variable %s set to `%s'",envvar,value);
  return value;
}

static void readconfigenv(adns_state ads, const char *envvar) {
  const char *filename;

  if (ads->iflags & adns_if_noenv) {
    debug(ads,"not checking environment variable `%s'",envvar);
    return;
  }
  filename= instrum_getenv(ads,envvar);
  if (filename) readconfig(ads,filename);
}
  
int adns_init(adns_state *ads_r, adns_initflags flags) {
  adns_state ads;
  const char *res_options, *adns_res_options;
  struct protoent *proto;
  int r;
  
  ads= malloc(sizeof(*ads)); if (!ads) return errno;
  ads->tosend.head= ads->tosend.tail= 0;
  ads->timew.head= ads->timew.tail= 0;
  ads->childw.head= ads->childw.tail= 0;
  ads->output.head= ads->output.tail= 0;
  ads->nextid= 0x311f;
  ads->udpsocket= -1;
  ads->qbufavail= 0;
  ads->qbuf= 0;
  ads->tcpbufavail= ads->tcpbufused= ads->tcpbufdone= 0;
  ads->tcpbuf= 0;
  ads->iflags= flags;
  ads->nservers= 0;
  ads->iflags= flags;

  res_options= instrum_getenv(ads,"RES_OPTIONS");
  adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
  ccf_options(ads,"RES_OPTIONS",-1,res_options);
  ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);

  readconfig(ads,"/etc/resolv.conf");
  readconfigenv(ads,"RES_CONF");
  readconfigenv(ads,"ADNS_RES_CONF");

  ccf_options(ads,"RES_OPTIONS",-1,res_options);
  ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);

  ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
  ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));

  if (!ads->nservers) {
    struct in_addr ia;
    if (ads->iflags & adns_if_debug)
      fprintf(stderr,"adns: no nameservers, using localhost\n");
    ia.s_addr= INADDR_LOOPBACK;
    addserver(ads,ia);
  }

  proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
  ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
  if (!ads->udpsocket) { r= errno; goto x_closeudp; }
  
  *ads_r= ads;
  return 0;

 x_closeudp:
  close(ads->udpsocket);
 x_free:
  free(ads);
  return r;
}

static void query_fail(adns_state ads, adns_query qu, adns_status stat) {
  adns_answer *ans;
  
  ans= qu->answer;
  if (!ans) ans= malloc(sizeof(*qu->answer));
  if (ans) {
    ans->status= stat;
    ans->cname= 0;
    ans->type= qu->type;
    ans->nrrs= 0;
  }
  qu->answer= ans;
  qu->id= -1;
  LIST_LINK_TAIL(ads->output,qu);
}

int adns_finish(adns_state ads) {
  abort(); /* FIXME */
}

static void autosys(adns_state ads, struct timeval now) {
  if (ads->iflags & adns_if_noautosys) return;
  adns_callback(ads,-1,0,0,0);
}

void adns_cancel(adns_state ads, adns_query query) {
  abort(); /* FIXME */
}

int adns_callback(adns_state ads, int maxfd,
		  const fd_set *readfds, const fd_set *writefds,
		  const fd_set *exceptfds) {
  abort(); /* FIXME */
}

static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf,
			struct timeval maxto) {
  struct timeval rbuf;

  rbuf= *tv_io;
  if (!rbuf) { *tvbuf= maxto; *tv_io= tvbuf; return; }
  if (timercmp(rbuf,&maxto,>)) *rbuf= maxto;
}

static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf,
			   struct timeval now, struct timeval maxtime) {
  ldiv_t dr;
  
  maxtime.tv_sec -= (now.tv_sec-1);
  maxtime.tv_usec += (1000-now.tv_usec);
  dr= ldiv(maxtime.tv_usec,1000);
  maxtime.tv_sec += dr.quot;
  maxtime.tv_usec -= dr.rem;
  inter_maxto(tv_io,tvbuf,maxtime);
}

static void localresourcerr(struct timeval **tv_io, struct timeval *tvbuf,
			    const char *syscall) {
  struct timeval tvto_lr;
  
  diag(ads,"local system resources scarce (during %s): %s",syscall,strerror(errno));
  timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS);
  inter_maxto(tv_io, tvbuf, tvto_lr);
  return;
}

static inline void timevaladd(struct timeval *tv_io, long ms) {
  struct timeval tmp;
  assert(ms>=0);
  tmp= *tv_io;
  tmp.tv_usec += (ms%1000)*1000;
  tmp.tv_sec += ms/1000;
  if (tmp.tv_usec >= 1000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
  *tv_io= tmp;
}    

void adns_interest(adns_state ads, int *maxfd,
		   fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
		   struct timeval **tv_io, struct timeval *tvbuf) {
  struct timeval now;
  adns_query qu;
  int r;
  
  r= gettimeofday(&now,0);
  if (r) { localresourcerr(tv_io,tvbuf,"gettimeofday"); return; }

  for (qu= ads->timew; qu; qu= nqu) {
    nqu= qu->next;
    if (timercmp(&now,qu->timeout,>)) {
      DLIST_UNLINK(ads->timew,qu);
      if (qu->nextudpserver == -1) {
	query_fail(ads,qu,adns_s_notresponding);
      } else {
	DLIST_LINKTAIL(ads->tosend,qu);
      }
    } else {
      inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
    }
  }
  
  for (qu= ads->tosend; qu; qu= nqu) {
    nqu= qu->next;
    quproc_tosend(ads,qu,now);
  }

  for (qu= ads->timew; qu; qu= qu->next) {
    if (qu->sentudp) {
      inter_addfd(maxfd,readfds,ads->udpsocket);
      break;
    }
  }
  switch (ads->tcpstate) {
  case server_disc:
    break;
  case server_connecting:
    inter_addfd(maxfd,readfds,ads->tcpsocket);
    inter_addfd(maxfd,writefds,ads->tcpsocket);
    inter_addfd(maxfd,exceptfds,ads->tcpsocket);
    break;
  case server_connected:
    inter_addfd(maxfd,readfds,ads->tcpsocket);
    inter_addfd(maxfd,exceptfds,ads->tcpsocket);
    if (ads->opbufused) inter_addfd(maxfd,writefds,ads->tcpsocket);
  default:
    abort();
  }
  
}

static int internal_check(adns_state ads,
			  adns_query *query_io,
			  adns_answer **answer,
			  void **context_r) {
  adns_query qu;

  qu= *query_io;
  if (!qu) {
    if (!ads->output.head) return EWOULDBLOCK;
    qu= ads->output.head;
  } else {
    if (qu->id>=0) return EWOULDBLOCK;
  }
  LIST_UNLINK(ads->output,qu);
  *answer= qu->answer;
  if (context_r) *context_r= qu->context;
  free(qu);
  return 0;
}

int adns_wait(adns_state ads,
	      adns_query *query_io,
	      adns_answer **answer_r,
	      void **context_r) {
  int r, maxfd, rsel, rcb;
  fd_set readfds, writefds, exceptfds;
  struct timeval tvbuf, *tvp;
  
  for (;;) {
    r= internal_check(ads,query_io,answer_r,context_r);
    if (r && r != EWOULDBLOCK) return r;
    FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
    maxfd= 0; tvp= 0;
    adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf);
    rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
    if (rsel==-1) return r;
    rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds);
    assert(rcb==rsel);
  }
}

int adns_check(adns_state ads,
	       adns_query *query_io,
	       adns_answer **answer_r,
	       void **context_r) {
  autosys(ads);
  return internal_check(ads,query_io,answer_r,context_r);
}

int adns_synchronous(adns_state ads,
		     const char *owner,
		     adns_rrtype type,
		     adns_queryflags flags,
		     adns_answer **answer_r) {
  adns_query qu;
  int r;
  
  r= adns_submit(ads,owner,type,flags,0,&qu);
  if (r) return r;

  do {
    r= adns_wait(ads,&qu,answer_r,0);
  } while (r==EINTR);
  if (r) adns_cancel(ads,qu);
  return r;
}

static adns_status mkquery(adns_state ads, const char *owner, int ol, int id,
			   adns_rrtype type, adns_queryflags flags, int *qml_r) {
  int ll, c, nlabs, qbufreq;
  unsigned char label[255], *nqbuf;
  const char *p, *pe;

#define MKQUERY_ADDB(b) *nqbuf++= (b)
#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))

  qbufreq= 12+strlen(owner)+3;
  if (ads->qbufavail < qbufreq) {
    nqbuf= realloc(ads->qbuf,qbufreq);
    if (!nqbuf) return adns_s_nolocalmem;
    ads->qbuf= nqbuf; ads->qbufavail= qbufreq;
  }
  nqbuf= ads->qbuf;
  
  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 */
  p= owner; pe= owner+ol;
  nlabs= 0;
  if (!*p) return adns_s_invaliddomain;
  do {
    ll= 0;
    while (p!=pe && (c= *p++)!='.') {
      if (c=='\\') {
	if (!(flags & adns_f_anyquote)) return adns_s_invaliddomain;
	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_invaliddomain;
	  } else {
	    return adns_s_invaliddomain;
	  }
	} else if (!(c= *p++)) {
	  return adns_s_invaliddomain;
	}
      }
      if (!(flags & adns_f_anyquote)) {
	if ((c >= '0' && c <= '9') || c == '-') {
	  if (!ll) return adns_s_invaliddomain;
	} else if ((c < 'a' || c > 'z') && (c < 'A' && c > 'Z')) {
	  return adns_s_invaliddomain;
	}
      }
      if (ll == sizeof(label)) return adns_s_invaliddomain;
      label[ll++]= c;
    }
    if (!ll) return adns_s_invaliddomain;
    if (nlabs++ > 63) return adns_s_invaliddomain;
    MKQUERY_ADDB(ll);
    memcpy(nqbuf,label,ll); nqbuf+= ll;
  } while (p!=pe);

  MKQUERY_ADDB(0);
  MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
  MKQUERY_ADDW(1); /* QCLASS=IN */

  *qml_r= nqbuf - ads->qbuf;
  
  return adns_s_ok;
}

static adns_query allocquery(adns_state ads, const char *owner, int ol,
			     int qml, int id, adns_rrtype type,
			     adns_queryflags flags, void *context) {
  adns_query qu;
  unsigned char *qm;
  
  qu= malloc(sizeof(*qu)+ol+1+qml); if (!qu) return 0;
  qu->next= qu->back= qu->parent= 0;
  qu->children.head= qu->children.tail= 0;
  qu->siblings.next= qu->siblings.back= 0;
  qu->id= id;
  qu->type= type;
  qu->answer= 0;
  qu->flags= flags;
  qu->context= context;
  qu->udpretries= 0;
  qu->sentudp= qu->senttcp= 0;
  qu->nextserver= 0;
  memcpy(qu->owner,owner,ol); qu->owner[ol]= 0;
  qu->querymsg= qm= qu->owner+ol+1;
  memcpy(qm,ads->qbuf,qml);
  qu->querylen= qml;
  return qu;
}

static int failsubmit(adns_state ads, void *context, adns_query *query_r,
		      adns_rrtype type, adns_queryflags flags,
		      int id, adns_status stat) {
  adns_query qu;

  qu= allocquery(ads,0,0,0,id,type,flags,context); if (!qu) return errno;
  query_fail(ads,qu,stat);
  *query_r= qu;
  return 0;
}

static void quproc_tosend(adns_state ads, adns_query qu, struct timeval now) {
  /* Query must be on the `tosend' queue, and guarantees to remove it. */
  struct sockaddr_in servaddr;
  int serv;

  if (qu->nextudpserver != -1) {
    if (qu->udpretries >= UDPMAXRETRIES) {
      DLIST_UNLINK(ads->tosend,qu);
      query_fail(ads,qu,adns_s_notresponding);
      return;
    }
    serv= qu->nextudpserver;
    memset(&servaddr,0,sizeof(servaddr));
    servaddr.sin_family= AF_INET;
    servaddr.sin_addr= ads->servers[serv].addr;
    servaddr.sin_port= htons(53);
    r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
    if (r<0 && errno == EMSGSIZE) {
      qu->nextudpserver= -1;
    } else {
      if (r<0) {
	diag("sendto %s failed: %s",inet_ntoa(servaddr.sin_addr),strerror(errno));
      }
      DLIST_UNLINK(ads->tosend,qu);
      timevaladd(&now,UDPRETRYMS);
      qu->timeout= now;
      qu->sentudp |= (1<<serv);
      qu->nextudpserver= (serv+1)%ads->nservers;
      qu->udpretries++;
      DLIST_LINKTAIL(ads->timew,qu);
      return;
    }
  }

  for (;;) {
    serv= tcpserver_get(ads);
    if (serv<0) { r=0; break; }
    if (ads->opbufused) { r=0; break; }
    r= write(ads->tcpsocket,qu->querymsg,qu->querylen);
    if (r >= 0) break;
    if (errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
	errno == ENOBUFS || errno == ENOMEM) {
      r= 0; break;
    }
    tcpserver_broken(serv);
  }
  if (r < qu->querylen) {
    newopbufused= qu->opbufused + (qu->querylen-r);
    if (newopbufused > ads->opbufavail) {
      newopbufavail= ads->newopbufused<<1;
      newopbuf= realloc(newopbufavail);
      if (!newopbuf) {
	DLIST_UNLINK(ads->tosend,qu);
	query_fail(ads,qu,adns_s_nolocalmem);
	return;
      }
      ads->opbuf= newopbuf;
      ads->opbufavail= newopbufavail;
    }
    memcpy(ads->opbuf+ads->opbufused,qu->querymsg+r,qu->querylen-r);
    ads->opbufused= newopbufused;
  }
  DLIST_UNLINK(ads->tosend,qu);
  timevaladd(&now,TCPMS);
  qu->timeout= now;
  qu->senttcp |= (1<<qu->nextserver);
  DLIST_LINKTAIL(ads->timew,qu);
}

int adns_submit(adns_state ads,
		const char *owner,
		adns_rrtype type,
		adns_queryflags flags,
		void *context,
		adns_query *query_r) {
  adns_query qu;
  adns_status stat;
  int ol, id, qml;

  id= ads->nextid++;

  ol= strlen(owner);
  if (ol<=1 || ol>MAXDNAME+1)
    return failsubmit(ads,context,query_r,type,flags,id,adns_s_invaliddomain);
  if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_f_search; ol--; }

  stat= mkquery(ads,owner,ol,id,type,flags,&qml);
  if (stat) return failsubmit(ads,context,query_r,type,flags,id,stat);

  qu= allocquery(ads,owner,ol,qml,id,type,flags,context); if (!qu) return errno;
  if (qu->flags & adns_f_usevc) qu->udpretries= -1;
  LIST_LINK_TAIL(ads->tosend,qu);
    
  r= gettimeofday(&now,0); if (r) return;
  quproc_tosend(ads,qu,now);
  autosys(ads,now);

  *query_r= qu;
  return 0;
}
Commit	Line	Data
a17d3a1d	1	/**/
a17d3a1d	2
964344fc	3	#include <stdarg.h>
	4	#include <stdio.h>
	5	#include <errno.h>
	6	#include <string.h>
	7	#include <stdlib.h>
e8c505a5	8	#include <assert.h>
80917fcc	9	#include <unistd.h>
964344fc	10
80917fcc	11	#include <netdb.h>
a17d3a1d	12	#include <arpa/nameser.h>
964344fc	13	#include <sys/socket.h>
	14	#include <netinet/in.h>
	15	#include <arpa/inet.h>
a17d3a1d	16
	17	#include "adns-internal.h"
	18
84fe28db	19	#define LIST_UNLINK_PART(list,node,part) \
a17d3a1d	20	do { \
84fe28db	21	if ((node)->back) (node)->back->part next= (node)->part next; \
	22	else (list).head= (node)->part next; \
	23	if ((node)->next) (node)->next->part back= (node)->part back; \
	24	else (list).tail= (node)->part back; \
a17d3a1d	25	} while(0)
a17d3a1d	26
84fe28db	27	#define LIST_LINK_TAIL_PART(list,node,part) \
a17d3a1d	28	do { \
84fe28db	29	(node)->part back= 0; \
	30	(node)->part next= (list).tail; \
	31	if ((list).tail) (list).tail->part back= (node); else (list).part head= (node); \
a17d3a1d	32	(list).tail= (node); \
	33	} while(0)
	34
84fe28db	35	#define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
	36	#define LIST_LINK_TAIL_PART(list,node) LIST_LINK_TAIL(list,node,)
	37
964344fc	38	static void vdebug(adns_state ads, const char *fmt, va_list al) {
	39	if (!(ads->iflags & adns_if_debug)) return;
	40	fputs("adns debug: ",stderr);
	41	vfprintf(stderr,fmt,al);
	42	fputc('\n',stderr);
	43	}
	44
	45	static void debug(adns_state ads, const char *fmt, ...) {
	46	va_list al;
	47
	48	va_start(al,fmt);
	49	vdebug(ads,fmt,al);
	50	va_end(al);
	51	}
	52
	53	static void vdiag(adns_state ads, const char *fmt, va_list al) {
	54	if (ads->iflags & adns_if_noerrprint) return;
	55	fputs("adns: ",stderr);
	56	vfprintf(stderr,fmt,al);
	57	fputc('\n',stderr);
	58	}
	59
	60	static void diag(adns_state ads, const char *fmt, ...) {
	61	va_list al;
	62
	63	va_start(al,fmt);
	64	vdiag(ads,fmt,al);
	65	va_end(al);
	66	}
	67
	68	static void addserver(adns_state ads, struct in_addr addr) {
e8c505a5	69	int i;
80917fcc	70	struct server *ss;
e8c505a5	71
	72	for (i=0; i<ads->nservers; i++) {
	73	if (ads->servers[i].addr.s_addr == addr.s_addr) {
	74	debug(ads,"duplicate nameserver %s ignored",inet_ntoa(addr));
	75	return;
	76	}
	77	}
	78
a17d3a1d	79	if (ads->nservers>=MAXSERVERS) {
964344fc	80	diag(ads,"too many nameservers, ignoring %s",inet_ntoa(addr));
e8c505a5	81	return;
a17d3a1d	82	}
e8c505a5	83
80917fcc	84	ss= ads->servers+ads->nservers;
	85	ss->addr= addr;
	86	ss->state= server_disc;
	87	ss->connw.head= ss->connw.tail= 0;
e8c505a5	88	ads->nservers++;
a17d3a1d	89	}
a17d3a1d	90
964344fc	91	static void configparseerr(adns_state ads, const char *fn, int lno,
	92	const char *fmt, ...) {
	93	va_list al;
	94
	95	if (ads->iflags & adns_if_noerrprint) return;
	96	if (lno==-1) fprintf(stderr,"adns: %s: ",fn);
	97	else fprintf(stderr,"adns: %s:%d: ",fn,lno);
	98	va_start(al,fmt);
	99	vfprintf(stderr,fmt,al);
	100	va_end(al);
	101	fputc('\n',stderr);
	102	}
	103
	104	static void ccf_nameserver(adns_state ads, const char fn, int lno, const char buf) {
	105	struct in_addr ia;
	106
	107	if (!inet_aton(buf,&ia)) {
	108	configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
	109	return;
	110	}
	111	debug(ads,"using nameserver %s",inet_ntoa(ia));
	112	addserver(ads,ia);
	113	}
	114
	115	static void ccf_search(adns_state ads, const char fn, int lno, const char buf) {
	116	if (!buf) return;
	117	diag(ads,"warning - `search' ignored FIXME");
	118	}
	119
	120	static void ccf_sortlist(adns_state ads, const char fn, int lno, const char buf) {
	121	diag(ads,"warning - `sortlist' ignored FIXME");
	122	}
	123
	124	static void ccf_options(adns_state ads, const char fn, int lno, const char buf) {
	125	if (!buf) return;
	126	diag(ads,"warning - `options' ignored FIXME");
	127	}
	128
	129	static void ccf_clearnss(adns_state ads, const char fn, int lno, const char buf) {
	130	ads->nservers= 0;
	131	}
	132
	133	static const struct configcommandinfo {
	134	const char *name;
	135	void (fn)(adns_state ads, const char fn, int lno, const char *buf);
	136	} configcommandinfos[]= {
	137	{ "nameserver", ccf_nameserver },
	138	{ "domain", ccf_search },
	139	{ "search", ccf_search },
	140	{ "sortlist", ccf_sortlist },
	141	{ "options", ccf_options },
	142	{ "clearnameservers", ccf_clearnss },
	143	{ 0 }
	144	};
	145
350d37d9	146	static int ctype_whitespace(int c) { return c==' ' \|\| c=='\n' \|\| c=='\t'; }
350d37d9	147	static int ctype_digit(int c) { return c>='0' && c<='9'; }
964344fc	148
	149	static void readconfig(adns_state ads, const char *filename) {
	150	char linebuf[2000], p, q;
	151	FILE *file;
	152	int lno, l, c;
	153	const struct configcommandinfo *ccip;
	154
	155	file= fopen(filename,"r");
	156	if (!file) {
	157	if (errno == ENOENT) {
	158	debug(ads,"configuration file `%s' does not exist",filename);
	159	return;
	160	}
	161	diag(ads,"cannot open configuration file `%s': %s",filename,strerror(errno));
	162	return;
	163	}
	164
	165	for (lno=1; fgets(linebuf,sizeof(linebuf),file); lno++) {
	166	l= strlen(linebuf);
	167	if (!l) continue;
	168	if (linebuf[l-1] != '\n' && !feof(file)) {
	169	diag(ads,"%s:%d: line too long",filename,lno);
	170	while ((c= getc(file)) != EOF && c != '\n') { }
	171	if (c == EOF) break;
	172	continue;
	173	}
350d37d9	174	while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
964344fc	175	linebuf[l]= 0;
964344fc	176	p= linebuf;
350d37d9	177	while (ctype_whitespace(*p)) p++;
964344fc	178	if (p == '#' \|\| p == '\n') continue;
964344fc	179	q= p;
350d37d9	180	while (q && !ctype_whitespace(q)) q++;
964344fc	181	for (ccip=configcommandinfos;
	182	ccip->name && strncmp(ccip->name,p,q-p);
	183	ccip++);
	184	if (!ccip->name) {
	185	diag(ads,"%s:%d: unknown configuration directive `%.*s'",filename,lno,q-p,p);
	186	continue;
	187	}
350d37d9	188	while (ctype_whitespace(*q)) q++;
964344fc	189	ccip->fn(ads,filename,lno,q);
	190	}
	191	if (ferror(file)) {
	192	diag(ads,"%s:%d: read error: %s",filename,lno,strerror(errno));
	193	}
	194	fclose(file);
	195	}
	196
	197	static const char instrum_getenv(adns_state ads, const char envvar) {
	198	const char *value;
	199
	200	value= getenv(envvar);
e8c505a5	201	if (!value) debug(ads,"environment variable %s not set",envvar);
e8c505a5	202	else debug(ads,"environment variable %s set to `%s'",envvar,value);
964344fc	203	return value;
a17d3a1d	204	}
a17d3a1d	205
964344fc	206	static void readconfigenv(adns_state ads, const char *envvar) {
a17d3a1d	207	const char *filename;
a17d3a1d	208
964344fc	209	if (ads->iflags & adns_if_noenv) {
	210	debug(ads,"not checking environment variable `%s'",envvar);
	211	return;
	212	}
	213	filename= instrum_getenv(ads,envvar);
	214	if (filename) readconfig(ads,filename);
a17d3a1d	215	}
a17d3a1d	216
964344fc	217	int adns_init(adns_state *ads_r, adns_initflags flags) {
a17d3a1d	218	adns_state ads;
964344fc	219	const char res_options, adns_res_options;
80917fcc	220	struct protoent *proto;
350d37d9	221	int r;
a17d3a1d	222
a17d3a1d	223	ads= malloc(sizeof(*ads)); if (!ads) return errno;
9d95094c	224	ads->tosend.head= ads->tosend.tail= 0;
a17d3a1d	225	ads->timew.head= ads->timew.tail= 0;
964344fc	226	ads->childw.head= ads->childw.tail= 0;
964344fc	227	ads->output.head= ads->output.tail= 0;
80917fcc	228	ads->nextid= 0x311f;
a17d3a1d	229	ads->udpsocket= -1;
	230	ads->qbufavail= 0;
	231	ads->qbuf= 0;
	232	ads->tcpbufavail= ads->tcpbufused= ads->tcpbufdone= 0;
	233	ads->tcpbuf= 0;
964344fc	234	ads->iflags= flags;
a17d3a1d	235	ads->nservers= 0;
964344fc	236	ads->iflags= flags;
	237
	238	res_options= instrum_getenv(ads,"RES_OPTIONS");
	239	adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
	240	ccf_options(ads,"RES_OPTIONS",-1,res_options);
	241	ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
a17d3a1d	242
	243	readconfig(ads,"/etc/resolv.conf");
	244	readconfigenv(ads,"RES_CONF");
	245	readconfigenv(ads,"ADNS_RES_CONF");
964344fc	246
	247	ccf_options(ads,"RES_OPTIONS",-1,res_options);
	248	ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
	249
	250	ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
	251	ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
	252
a17d3a1d	253	if (!ads->nservers) {
964344fc	254	struct in_addr ia;
964344fc	255	if (ads->iflags & adns_if_debug)
a17d3a1d	256	fprintf(stderr,"adns: no nameservers, using localhost\n");
964344fc	257	ia.s_addr= INADDR_LOOPBACK;
964344fc	258	addserver(ads,ia);
a17d3a1d	259	}
80917fcc	260
	261	proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
	262	ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
	263	if (!ads->udpsocket) { r= errno; goto x_closeudp; }
a17d3a1d	264
	265	*ads_r= ads;
	266	return 0;
80917fcc	267
	268	x_closeudp:
	269	close(ads->udpsocket);
	270	x_free:
	271	free(ads);
	272	return r;
a17d3a1d	273	}
a17d3a1d	274
964344fc	275	static void query_fail(adns_state ads, adns_query qu, adns_status stat) {
e8c505a5	276	adns_answer *ans;
a17d3a1d	277
	278	ans= qu->answer;
	279	if (!ans) ans= malloc(sizeof(*qu->answer));
	280	if (ans) {
	281	ans->status= stat;
	282	ans->cname= 0;
	283	ans->type= qu->type;
	284	ans->nrrs= 0;
	285	}
	286	qu->answer= ans;
9d95094c	287	qu->id= -1;
9d95094c	288	LIST_LINK_TAIL(ads->output,qu);
a17d3a1d	289	}
a17d3a1d	290
80917fcc	291	int adns_finish(adns_state ads) {
	292	abort(); /* FIXME */
	293	}
	294
84fe28db	295	static void autosys(adns_state ads, struct timeval now) {
e8c505a5	296	if (ads->iflags & adns_if_noautosys) return;
	297	adns_callback(ads,-1,0,0,0);
	298	}
	299
	300	void adns_cancel(adns_state ads, adns_query query) {
	301	abort(); /* FIXME */
	302	}
	303
	304	int adns_callback(adns_state ads, int maxfd,
	305	const fd_set readfds, const fd_set writefds,
	306	const fd_set *exceptfds) {
	307	abort(); /* FIXME */
	308	}
	309
84fe28db	310	static void inter_maxto(struct timeval *tv_io, struct timeval tvbuf,
	311	struct timeval maxto) {
	312	struct timeval rbuf;
	313
	314	rbuf= *tv_io;
	315	if (!rbuf) { tvbuf= maxto; tv_io= tvbuf; return; }
	316	if (timercmp(rbuf,&maxto,>)) *rbuf= maxto;
	317	}
	318
	319	static void inter_maxtoabs(struct timeval *tv_io, struct timeval tvbuf,
	320	struct timeval now, struct timeval maxtime) {
	321	ldiv_t dr;
	322
	323	maxtime.tv_sec -= (now.tv_sec-1);
	324	maxtime.tv_usec += (1000-now.tv_usec);
	325	dr= ldiv(maxtime.tv_usec,1000);
	326	maxtime.tv_sec += dr.quot;
	327	maxtime.tv_usec -= dr.rem;
	328	inter_maxto(tv_io,tvbuf,maxtime);
	329	}
	330
	331	static void localresourcerr(struct timeval *tv_io, struct timeval tvbuf,
	332	const char *syscall) {
	333	struct timeval tvto_lr;
	334
	335	diag(ads,"local system resources scarce (during %s): %s",syscall,strerror(errno));
	336	timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS);
	337	inter_maxto(tv_io, tvbuf, tvto_lr);
	338	return;
	339	}
	340
	341	static inline void timevaladd(struct timeval *tv_io, long ms) {
	342	struct timeval tmp;
	343	assert(ms>=0);
	344	tmp= *tv_io;
	345	tmp.tv_usec += (ms%1000)*1000;
	346	tmp.tv_sec += ms/1000;
	347	if (tmp.tv_usec >= 1000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
	348	*tv_io= tmp;
	349	}
	350
	351	void adns_interest(adns_state ads, int *maxfd,
	352	fd_set readfds, fd_set writefds, fd_set *exceptfds,
	353	struct timeval *tv_io, struct timeval tvbuf) {
	354	struct timeval now;
	355	adns_query qu;
	356	int r;
	357
	358	r= gettimeofday(&now,0);
	359	if (r) { localresourcerr(tv_io,tvbuf,"gettimeofday"); return; }
	360
	361	for (qu= ads->timew; qu; qu= nqu) {
	362	nqu= qu->next;
	363	if (timercmp(&now,qu->timeout,>)) {
	364	DLIST_UNLINK(ads->timew,qu);
	365	if (qu->nextudpserver == -1) {
	366	query_fail(ads,qu,adns_s_notresponding);
	367	} else {
	368	DLIST_LINKTAIL(ads->tosend,qu);
	369	}
	370	} else {
	371	inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
	372	}
	373	}
374
375	for (qu= ads->tosend; qu; qu= nqu) {
376	nqu= qu->next;
377	quproc_tosend(ads,qu,now);
378	}
379
380	for (qu= ads->timew; qu; qu= qu->next) {
381	if (qu->sentudp) {
382	inter_addfd(maxfd,readfds,ads->udpsocket);
383	break;
384	}
385	}
386	switch (ads->tcpstate) {
387	case server_disc:
388	break;
389	case server_connecting:
390	inter_addfd(maxfd,readfds,ads->tcpsocket);
391	inter_addfd(maxfd,writefds,ads->tcpsocket);
392	inter_addfd(maxfd,exceptfds,ads->tcpsocket);
393	break;
394	case server_connected:
395	inter_addfd(maxfd,readfds,ads->tcpsocket);
396	inter_addfd(maxfd,exceptfds,ads->tcpsocket);
397	if (ads->opbufused) inter_addfd(maxfd,writefds,ads->tcpsocket);
398	default:
399	abort();
400	}
401
402	}
403
e8c505a5	404	static int internal_check(adns_state ads,
e8c505a5	405	adns_query *query_io,
9d95094c	406	adns_answer **answer,
	407	void **context_r) {
	408	adns_query qu;
	409
	410	qu= *query_io;
	411	if (!qu) {
	412	if (!ads->output.head) return EWOULDBLOCK;
	413	qu= ads->output.head;
	414	} else {
	415	if (qu->id>=0) return EWOULDBLOCK;
	416	}
	417	LIST_UNLINK(ads->output,qu);
	418	*answer= qu->answer;
	419	if (context_r) *context_r= qu->context;
	420	free(qu);
	421	return 0;
e8c505a5	422	}
	423
	424	int adns_wait(adns_state ads,
	425	adns_query *query_io,
9d95094c	426	adns_answer **answer_r,
9d95094c	427	void **context_r) {
e8c505a5	428	int r, maxfd, rsel, rcb;
	429	fd_set readfds, writefds, exceptfds;
	430	struct timeval tvbuf, *tvp;
	431
	432	for (;;) {
9d95094c	433	r= internal_check(ads,query_io,answer_r,context_r);
e8c505a5	434	if (r && r != EWOULDBLOCK) return r;
	435	FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
	436	maxfd= 0; tvp= 0;
	437	adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf);
	438	rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
	439	if (rsel==-1) return r;
	440	rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds);
	441	assert(rcb==rsel);
	442	}
	443	}
	444
	445	int adns_check(adns_state ads,
	446	adns_query *query_io,
9d95094c	447	adns_answer **answer_r,
9d95094c	448	void **context_r) {
e8c505a5	449	autosys(ads);
9d95094c	450	return internal_check(ads,query_io,answer_r,context_r);
e8c505a5	451	}
	452
	453	int adns_synchronous(adns_state ads,
	454	const char *owner,
	455	adns_rrtype type,
72934832	456	adns_queryflags flags,
9d95094c	457	adns_answer **answer_r) {
e8c505a5	458	adns_query qu;
	459	int r;
	460
	461	r= adns_submit(ads,owner,type,flags,0,&qu);
	462	if (r) return r;
	463
72934832	464	do {
9d95094c	465	r= adns_wait(ads,&qu,answer_r,0);
72934832	466	} while (r==EINTR);
e8c505a5	467	if (r) adns_cancel(ads,qu);
	468	return r;
	469	}
	470
350d37d9	471	static adns_status mkquery(adns_state ads, const char *owner, int ol, int id,
	472	adns_rrtype type, adns_queryflags flags, int *qml_r) {
	473	int ll, c, nlabs, qbufreq;
	474	unsigned char label[255], *nqbuf;
	475	const char p, pe;
	476
	477	#define MKQUERY_ADDB(b) *nqbuf++= (b)
	478	#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
	479
	480	qbufreq= 12+strlen(owner)+3;
	481	if (ads->qbufavail < qbufreq) {
	482	nqbuf= realloc(ads->qbuf,qbufreq);
	483	if (!nqbuf) return adns_s_nolocalmem;
	484	ads->qbuf= nqbuf; ads->qbufavail= qbufreq;
	485	}
	486	nqbuf= ads->qbuf;
	487
	488	MKQUERY_ADDW(id);
	489	MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
	490	MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
	491	MKQUERY_ADDW(1); /* QDCOUNT=1 */
	492	MKQUERY_ADDW(0); /* ANCOUNT=0 */
	493	MKQUERY_ADDW(0); /* NSCOUNT=0 */
	494	MKQUERY_ADDW(0); /* ARCOUNT=0 */
	495	p= owner; pe= owner+ol;
	496	nlabs= 0;
	497	if (!*p) return adns_s_invaliddomain;
	498	do {
	499	ll= 0;
	500	while (p!=pe && (c= *p++)!='.') {
	501	if (c=='\\') {
	502	if (!(flags & adns_f_anyquote)) return adns_s_invaliddomain;
	503	if (ctype_digit(p[0])) {
	504	if (ctype_digit(p[1]) && ctype_digit(p[2])) {
	505	c= (p++ - '0')100 + (p++ - '0')10 + (*p++ - '0');
	506	if (c >= 256) return adns_s_invaliddomain;
	507	} else {
	508	return adns_s_invaliddomain;
	509	}
	510	} else if (!(c= *p++)) {
	511	return adns_s_invaliddomain;
	512	}
	513	}
	514	if (!(flags & adns_f_anyquote)) {
	515	if ((c >= '0' && c <= '9') \|\| c == '-') {
	516	if (!ll) return adns_s_invaliddomain;
	517	} else if ((c < 'a' \|\| c > 'z') && (c < 'A' && c > 'Z')) {
	518	return adns_s_invaliddomain;
	519	}
	520	}
	521	if (ll == sizeof(label)) return adns_s_invaliddomain;
	522	label[ll++]= c;
	523	}
	524	if (!ll) return adns_s_invaliddomain;
	525	if (nlabs++ > 63) return adns_s_invaliddomain;
	526	MKQUERY_ADDB(ll);
	527	memcpy(nqbuf,label,ll); nqbuf+= ll;
	528	} while (p!=pe);
	529
	530	MKQUERY_ADDB(0);
	531	MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
	532	MKQUERY_ADDW(1); /* QCLASS=IN */
	533
	534	*qml_r= nqbuf - ads->qbuf;
535
536	return adns_s_ok;
80917fcc	537	}
80917fcc	538
350d37d9	539	static adns_query allocquery(adns_state ads, const char *owner, int ol,
	540	int qml, int id, adns_rrtype type,
	541	adns_queryflags flags, void *context) {
a17d3a1d	542	adns_query qu;
350d37d9	543	unsigned char *qm;
	544
	545	qu= malloc(sizeof(*qu)+ol+1+qml); if (!qu) return 0;
84fe28db	546	qu->next= qu->back= qu->parent= 0;
	547	qu->children.head= qu->children.tail= 0;
	548	qu->siblings.next= qu->siblings.back= 0;
350d37d9	549	qu->id= id;
a17d3a1d	550	qu->type= type;
	551	qu->answer= 0;
	552	qu->flags= flags;
	553	qu->context= context;
964344fc	554	qu->udpretries= 0;
80917fcc	555	qu->sentudp= qu->senttcp= 0;
80917fcc	556	qu->nextserver= 0;
a17d3a1d	557	memcpy(qu->owner,owner,ol); qu->owner[ol]= 0;
350d37d9	558	qu->querymsg= qm= qu->owner+ol+1;
	559	memcpy(qm,ads->qbuf,qml);
	560	qu->querylen= qml;
	561	return qu;
	562	}
80917fcc	563
350d37d9	564	static int failsubmit(adns_state ads, void context, adns_query query_r,
	565	adns_rrtype type, adns_queryflags flags,
	566	int id, adns_status stat) {
	567	adns_query qu;
80917fcc	568
350d37d9	569	qu= allocquery(ads,0,0,0,id,type,flags,context); if (!qu) return errno;
	570	query_fail(ads,qu,stat);
	571	*query_r= qu;
	572	return 0;
	573	}
	574
84fe28db	575	static void quproc_tosend(adns_state ads, adns_query qu, struct timeval now) {
84fe28db	576	/* Query must be on the `tosend' queue, and guarantees to remove it. */
9d95094c	577	struct sockaddr_in servaddr;
84fe28db	578	int serv;
	579
	580	if (qu->nextudpserver != -1) {
	581	if (qu->udpretries >= UDPMAXRETRIES) {
	582	DLIST_UNLINK(ads->tosend,qu);
	583	query_fail(ads,qu,adns_s_notresponding);
	584	return;
	585	}
	586	serv= qu->nextudpserver;
	587	memset(&servaddr,0,sizeof(servaddr));
	588	servaddr.sin_family= AF_INET;
	589	servaddr.sin_addr= ads->servers[serv].addr;
	590	servaddr.sin_port= htons(53);
	591	r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
	592	if (r<0 && errno == EMSGSIZE) {
	593	qu->nextudpserver= -1;
	594	} else {
	595	if (r<0) {
	596	diag("sendto %s failed: %s",inet_ntoa(servaddr.sin_addr),strerror(errno));
	597	}
	598	DLIST_UNLINK(ads->tosend,qu);
	599	timevaladd(&now,UDPRETRYMS);
	600	qu->timeout= now;
	601	qu->sentudp \|= (1<<serv);
	602	qu->nextudpserver= (serv+1)%ads->nservers;
	603	qu->udpretries++;
	604	DLIST_LINKTAIL(ads->timew,qu);
	605	return;
	606	}
	607	}
	608
	609	for (;;) {
	610	serv= tcpserver_get(ads);
	611	if (serv<0) { r=0; break; }
	612	if (ads->opbufused) { r=0; break; }
	613	r= write(ads->tcpsocket,qu->querymsg,qu->querylen);
	614	if (r >= 0) break;
	615	if (errno == EAGAIN \|\| errno == EINTR \|\| errno == ENOSPC \|\|
	616	errno == ENOBUFS \|\| errno == ENOMEM) {
	617	r= 0; break;
	618	}
	619	tcpserver_broken(serv);
	620	}
	621	if (r < qu->querylen) {
	622	newopbufused= qu->opbufused + (qu->querylen-r);
	623	if (newopbufused > ads->opbufavail) {
	624	newopbufavail= ads->newopbufused<<1;
	625	newopbuf= realloc(newopbufavail);
	626	if (!newopbuf) {
	627	DLIST_UNLINK(ads->tosend,qu);
	628	query_fail(ads,qu,adns_s_nolocalmem);
	629	return;
	630	}
	631	ads->opbuf= newopbuf;
	632	ads->opbufavail= newopbufavail;
	633	}
	634	memcpy(ads->opbuf+ads->opbufused,qu->querymsg+r,qu->querylen-r);
	635	ads->opbufused= newopbufused;
	636	}
	637	DLIST_UNLINK(ads->tosend,qu);
	638	timevaladd(&now,TCPMS);
	639	qu->timeout= now;
	640	qu->senttcp \|= (1<<qu->nextserver);
	641	DLIST_LINKTAIL(ads->timew,qu);
9d95094c	642	}
9d95094c	643
350d37d9	644	int adns_submit(adns_state ads,
	645	const char *owner,
	646	adns_rrtype type,
	647	adns_queryflags flags,
	648	void *context,
	649	adns_query *query_r) {
	650	adns_query qu;
	651	adns_status stat;
	652	int ol, id, qml;
	653
	654	id= ads->nextid++;
	655
	656	ol= strlen(owner);
	657	if (ol<=1 \|\| ol>MAXDNAME+1)
	658	return failsubmit(ads,context,query_r,type,flags,id,adns_s_invaliddomain);
	659	if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_f_search; ol--; }
	660
	661	stat= mkquery(ads,owner,ol,id,type,flags,&qml);
	662	if (stat) return failsubmit(ads,context,query_r,type,flags,id,stat);
	663
	664	qu= allocquery(ads,owner,ol,qml,id,type,flags,context); if (!qu) return errno;
84fe28db	665	if (qu->flags & adns_f_usevc) qu->udpretries= -1;
9d95094c	666	LIST_LINK_TAIL(ads->tosend,qu);
84fe28db	667
	668	r= gettimeofday(&now,0); if (r) return;
	669	quproc_tosend(ads,qu,now);
	670	autosys(ads,now);
80917fcc	671
a17d3a1d	672	*query_r= qu;
e8c505a5	673	return 0;
a17d3a1d	674	}