X-Git-Url: https://git.distorted.org.uk/~mdw/adns/blobdiff_plain/a17d3a1d960ca40434205a80aa106ca4c7224ec9..9d95094ce421414fade949831eeb9dd3090328a7:/src/adns.c

diff --git a/src/adns.c b/src/adns.c
index 381105d..bde99e2 100644
--- a/src/adns.c
+++ b/src/adns.c
@@ -1,6 +1,18 @@
 /**/
 
+#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"
 
@@ -16,65 +28,249 @@
   do { \
     (node)->back= 0; \
     (node)->next= (list).tail; \
-    if (list).tail (list).tail->back= (node); else (list).head= (node); \
+    if ((list).tail) (list).tail->back= (node); else (list).head= (node); \
     (list).tail= (node); \
   } while(0)
 
-void addserver(adns_state ads, struct in_addr addr) {
+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) {
-    if (ads->flags & adns_if_debug)
-      fprintf(stderr,"adns: too many nameservers, ignoring %s",
-	      inet_ntoa(addr));
-  } else {
-    ads->servers[ads->nservers].addr= addr;
-    ads->servers[ads->nservers].tcpsocket= -1;
-    ads->nservers++;
+    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);
 }
 
-void readconfig(adns_state ads, const char *filename) {
+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;
 }
 
-void readconfigenv(adns_state ads, const char *envvar) {
+static void readconfigenv(adns_state ads, const char *envvar) {
   const char *filename;
 
-  if (flags & adns_if_noenv) return;
-  filename= getenv(envvar); if (!filename) return;
-  readconfig(ads,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, int flags) {
+int adns_init(adns_state *ads_r, adns_initflags flags) {
   adns_state ads;
-  const char *cfile;
+  const char *res_options, *adns_res_options;
+  struct protoent *proto;
+  int r;
   
   ads= malloc(sizeof(*ads)); if (!ads) return errno;
-  ads->queue.head= ads->queue.tail= 0;
+  ads->tosend.head= ads->tosend.tail= 0;
   ads->timew.head= ads->timew.tail= 0;
-  ads->child.head= ads->child.tail= 0;
-  ads->ready.head= ads->ready.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->flags= flags;
+  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) {
-    if (ads->flags & adns_if_debug)
+    struct in_addr ia;
+    if (ads->iflags & adns_if_debug)
       fprintf(stderr,"adns: no nameservers, using localhost\n");
-    addserver(ads,INADDR_LOOPBACK);
+    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;
 }
 
-void query_fail(adns_state ads, adns_query qu, ands_status stat) {
-  struct adns_answer ans;
+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));
@@ -85,43 +281,240 @@ void query_fail(adns_state ads, adns_query qu, ands_status stat) {
     ans->nrrs= 0;
   }
   qu->answer= ans;
-  LIST_LINK_TAIL(ads.ready,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,
+		   fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+		   struct timeval **tv_io, struct timeval *tvbuf) {
+  abort(); /* FIXME */
+}
+
+static void autosys(adns_state ads) {
+  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 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= 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;
 }
 
-void adns_event(adns_state ads,
-		fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
-		int *maxfd, struct timeval *tv) {
-  for (
+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, r;
+  int ol, id, qml;
+
+  id= ads->nextid++;
 
-  stat= 0;
   ol= strlen(owner);
-  if (ol>MAXDNAME+1) { stat= ands_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->retries= 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);
-    adns_event(ads,0,0,0,0,0);
-  }
+  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;
 }