X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fadns.c;h=bde99e21a53852ab1120259fca56e6a13fcd8800;hb=9d95094ce421414fade949831eeb9dd3090328a7;hp=43a0daca34ef28f1c257a9c53af062a3417ef560;hpb=e8c505a56d42871fcfbc77e3c1f4d0a60686bab7;p=adns.git

diff --git a/src/adns.c b/src/adns.c
index 43a0dac..bde99e2 100644
--- a/src/adns.c
+++ b/src/adns.c
@@ -6,7 +6,9 @@
 #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>
@@ -62,6 +64,7 @@ static void diag(adns_state ads, const char *fmt, ...) {
 
 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) {
@@ -75,8 +78,10 @@ static void addserver(adns_state ads, struct in_addr addr) {
     return;
   }
 
-  ads->servers[ads->nservers].addr= addr;
-  ads->servers[ads->nservers].tcpsocket= -1;
+  ss= ads->servers+ads->nservers;
+  ss->addr= addr;
+  ss->state= server_disc;
+  ss->connw.head= ss->connw.tail= 0;
   ads->nservers++;
 }
 
@@ -135,9 +140,8 @@ static const struct configcommandinfo {
   {  0                                   }
 };
 
-static int whitespace(int c) {
-  return c==' ' || c=='\n' || c=='\t';
-}
+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;
@@ -164,13 +168,13 @@ static void readconfig(adns_state ads, const char *filename) {
       if (c == EOF) break;
       continue;
     }
-    while (l>0 && whitespace(linebuf[l-1])) l--;
+    while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
     linebuf[l]= 0;
     p= linebuf;
-    while (whitespace(*p)) p++;
+    while (ctype_whitespace(*p)) p++;
     if (*p == '#' || *p == '\n') continue;
     q= p;
-    while (*q && !whitespace(*q)) q++;
+    while (*q && !ctype_whitespace(*q)) q++;
     for (ccip=configcommandinfos;
 	 ccip->name && strncmp(ccip->name,p,q-p);
 	 ccip++);
@@ -178,7 +182,7 @@ static void readconfig(adns_state ads, const char *filename) {
       diag(ads,"%s:%d: unknown configuration directive `%.*s'",filename,lno,q-p,p);
       continue;
     }
-    while (whitespace(*q)) q++;
+    while (ctype_whitespace(*q)) q++;
     ccip->fn(ads,filename,lno,q);
   }
   if (ferror(file)) {
@@ -210,12 +214,15 @@ static void readconfigenv(adns_state ads, const char *envvar) {
 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->input.head= ads->input.tail= 0;
+  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;
@@ -247,9 +254,19 @@ int adns_init(adns_state *ads_r, adns_initflags flags) {
     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) {
@@ -264,7 +281,12 @@ static void query_fail(adns_state ads, adns_query qu, adns_status stat) {
     ans->nrrs= 0;
   }
   qu->answer= ans;
-  LIST_LINK_TAIL(ads->input,qu);
+  qu->id= -1;
+  LIST_LINK_TAIL(ads->output,qu);
+}
+
+int adns_finish(adns_state ads) {
+  abort(); /* FIXME */
 }
 
 void adns_interest(adns_state ads, int *maxfd,
@@ -290,21 +312,34 @@ int adns_callback(adns_state ads, int maxfd,
 
 static int internal_check(adns_state ads,
 			  adns_query *query_io,
-			  adns_answer *answer,
-			  void *context_r) {
-  abort(); /* FIXME */
+			  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,
-	      void *context_r) {
+	      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,context_r);
+    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;
@@ -318,57 +353,168 @@ int adns_wait(adns_state ads,
 
 int adns_check(adns_state ads,
 	       adns_query *query_io,
-	       adns_answer *answer,
-	       void *context_r) {
+	       adns_answer **answer_r,
+	       void **context_r) {
   autosys(ads);
-  return internal_check(ads,query_io,answer,context_r);
+  return internal_check(ads,query_io,answer_r,context_r);
 }
 
 int adns_synchronous(adns_state ads,
 		     const char *owner,
 		     adns_rrtype type,
-		     int flags,
-		     adns_answer *answer) {
+		     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;
 
-  r= adns_wait(ads,&qu,answer,0);
+  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= qu->child= 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 trysendudp(adns_state ads, adns_query qu) {
+  struct sockaddr_in servaddr;
+  /* FIXME: _f_usevc not implemented */
+  memset(&servaddr,0,sizeof(servaddr));
+  servaddr.sin_family= AF_INET;
+  servaddr.sin_addr= ads->servers[qu->nextserver].addr;
+  servaddr.sin_port= htons(53);
+  sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
+}
+
 int adns_submit(adns_state ads,
 		const char *owner,
 		adns_rrtype type,
-		int flags,
+		adns_queryflags flags,
 		void *context,
 		adns_query *query_r) {
   adns_query qu;
   adns_status stat;
-  int ol;
+  int ol, id, qml;
+
+  id= ads->nextid++;
 
-  stat= 0;
   ol= strlen(owner);
-  if (ol>MAXDNAME+1) { stat= adns_s_invaliddomain; ol= 0; }
-  if (ol>0 && owner[ol-1]=='.') { flags &= ~adns_f_search; ol--; }
-  qu= malloc(sizeof(*qu)+ol+1); if (!qu) return errno;
-  qu->next= qu->back= qu->parent= qu->child= 0;
-  qu->type= type;
-  qu->answer= 0;
-  qu->flags= flags;
-  qu->context= context;
-  qu->udpretries= 0;
-  qu->server= 0;
-  memcpy(qu->owner,owner,ol); qu->owner[ol]= 0;
-  if (stat) {
-    query_fail(ads,qu,stat);
-  } else {
-    LIST_LINK_TAIL(ads->input,qu);
-    autosys(ads);
-  }
+  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;
+
+  LIST_LINK_TAIL(ads->tosend,qu);
+  trysendudp(ads,qu);
+  autosys(ads);
+
   *query_r= qu;
   return 0;
 }