chiark / gitweb /
More reply stuff.
[adns.git] / src / event.c
index 33998a8..7ed12f6 100644 (file)
 /**/
 
-static void autosys(adns_state ads, struct timeval now) {
-  if (ads->iflags & adns_if_noautosys) return;
-  adns_callback(ads,-1,0,0,0);
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include <netdb.h>
+#include <arpa/inet.h>
+
+#include "internal.h"
+
+/* TCP connection management */
+
+void adns__tcp_broken(adns_state ads, const char *what, const char *why) {
+  int serv;
+  adns_query qu, nqu;
+  
+  assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok);
+  serv= ads->tcpserver;
+  adns__warn(ads,serv,"TCP connection lost: %s: %s",what,why);
+  close(ads->tcpsocket);
+  ads->tcpstate= server_disconnected;
+  
+  for (qu= ads->timew.head; qu; qu= nqu) {
+    nqu= qu->next;
+    if (qu->state == query_udp) continue;
+    assert(qu->state == query_tcpwait || qu->state == query_tcpsent);
+    qu->state= query_tcpwait;
+    qu->tcpfailed |= (1<<serv);
+    if (qu->tcpfailed == (1<<ads->nservers)-1) {
+      LIST_UNLINK(ads->timew,qu);
+      adns__query_fail(ads,qu,adns_s_allservfail);
+    }
+  }
+
+  ads->tcprecv.used= ads->tcpsend.used= 0;
+  ads->tcpserver= (serv+1)%ads->nservers;
+}
+
+static void tcp_connected(adns_state ads, struct timeval now) {
+  adns_query qu, nqu;
+  
+  adns__debug(ads,ads->tcpserver,"TCP connected");
+  ads->tcpstate= server_ok;
+  for (qu= ads->timew.head; qu; qu= nqu) {
+    nqu= qu->next;
+    if (qu->state == query_udp) continue;
+    assert (qu->state == query_tcpwait);
+    adns__query_tcp(ads,qu,now);
+  }
+}
+
+void adns__tcp_tryconnect(adns_state ads, struct timeval now) {
+  int r, fd, tries;
+  struct sockaddr_in addr;
+  struct protoent *proto;
+  /* fixme: single TCP timeout, not once per server */
+
+  for (tries=0; tries<ads->nservers; tries++) {
+    if (ads->tcpstate == server_connecting || ads->tcpstate == server_ok) return;
+    assert(ads->tcpstate == server_disconnected);
+    assert(!ads->tcpsend.used);
+    assert(!ads->tcprecv.used);
+
+    proto= getprotobyname("tcp");
+    if (!proto) { adns__diag(ads,-1,"unable to find protocol no. for TCP !"); return; }
+    fd= socket(AF_INET,SOCK_STREAM,proto->p_proto);
+    if (fd<0) {
+      adns__diag(ads,-1,"cannot create TCP socket: %s",strerror(errno));
+      return;
+    }
+    r= adns__setnonblock(ads,fd);
+    if (r) {
+      adns__diag(ads,-1,"cannot make TCP socket nonblocking: %s",strerror(r));
+      close(fd);
+      return;
+    }
+    memset(&addr,0,sizeof(addr));
+    addr.sin_family= AF_INET;
+    addr.sin_port= htons(NSPORT);
+    addr.sin_addr= ads->servers[ads->tcpserver].addr;
+    r= connect(fd,&addr,sizeof(addr));
+    ads->tcpsocket= fd;
+    ads->tcpstate= server_connecting;
+    if (r==0) { tcp_connected(ads,now); continue; }
+    if (errno == EWOULDBLOCK || errno == EINPROGRESS) return;
+    adns__tcp_broken(ads,"connect",strerror(errno));
+  }
+}
+
+/* `Interest' functions - find out which fd's we might be interested in,
+ * and when we want to be called back for a timeout.
+ */
+
+static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf,
+                       struct timeval maxto) {
+  struct timeval *rbuf;
+
+  if (!tv_io) return;
+  rbuf= *tv_io;
+  if (!rbuf) {
+    *tvbuf= maxto; *tv_io= tvbuf;
+  } else {
+    if (timercmp(rbuf,&maxto,>)) *rbuf= maxto;
+  }
+fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n",
+       maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);
+}
+
+static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf,
+                          struct timeval now, struct timeval maxtime) {
+  ldiv_t dr;
+
+fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n",
+       now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);
+  if (!tv_io) return;
+  maxtime.tv_sec -= (now.tv_sec+2);
+  maxtime.tv_usec -= (now.tv_usec-2000000);
+  dr= ldiv(maxtime.tv_usec,1000000);
+  maxtime.tv_sec += dr.quot;
+  maxtime.tv_usec -= dr.quot*1000000;
+  if (maxtime.tv_sec<0) timerclear(&maxtime);
+  inter_maxto(tv_io,tvbuf,maxtime);
 }
 
+static void inter_addfd(int *maxfd, fd_set *fds, int fd) {
+  if (!maxfd || !fds) return;
+  if (fd>=*maxfd) *maxfd= fd+1;
+  FD_SET(fd,fds);
+}
+
+static void checktimeouts(adns_state ads, struct timeval now,
+                         struct timeval **tv_io, struct timeval *tvbuf) {
+  adns_query qu, nqu;
+  
+  for (qu= ads->timew.head; qu; qu= nqu) {
+    nqu= qu->next;
+    if (timercmp(&now,&qu->timeout,>)) {
+      LIST_UNLINK(ads->timew,qu);
+      if (qu->state != query_udp) {
+       adns__query_fail(ads,qu,adns_s_timeout);
+      } else {
+       adns__query_udp(ads,qu,now);
+      }
+    } else {
+      inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
+    }
+  }
+}  
+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;
+  struct timeval tvto_lr;
+  int r;
+  
+fprintf(stderr,"adns_interest\n");
+
+r= gettimeofday(&now,0);
+  if (r) {
+    adns__warn(ads,-1,"gettimeofday failed - will sleep for a bit: %s",strerror(errno));
+    timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS);
+    inter_maxto(tv_io, tvbuf, tvto_lr);
+  } else {
+    checktimeouts(ads,now,tv_io,tvbuf);
+  }
+  
+  inter_addfd(maxfd,readfds,ads->udpsocket);
+
+  switch (ads->tcpstate) {
+  case server_disconnected:
+    break;
+  case server_connecting:
+    inter_addfd(maxfd,writefds,ads->tcpsocket);
+    break;
+  case server_ok:
+    inter_addfd(maxfd,readfds,ads->tcpsocket);
+    inter_addfd(maxfd,exceptfds,ads->tcpsocket);
+    if (ads->tcpsend.used) inter_addfd(maxfd,writefds,ads->tcpsocket);
+  default:
+    abort();
+  }
+}
+
+/* Callback procedures - these do the real work of reception and timeout, etc. */
+
 static int callb_checkfd(int maxfd, const fd_set *fds, int fd) {
   return maxfd<0 || !fds ? 1 :
          fd<maxfd && FD_ISSET(fd,fds);
 }
 
-int adns_callback(adns_state ads, int maxfd,
-                 const fd_set *readfds, const fd_set *writefds,
-                 const fd_set *exceptfds) {
-  int skip, dgramlen, count;
-  enum adns__tcpstate oldtcpstate;
+static int internal_callback(adns_state ads, int maxfd,
+                            const fd_set *readfds, const fd_set *writefds,
+                            const fd_set *exceptfds,
+                            struct timeval now) {
+  int skip, want, dgramlen, count, udpaddrlen, r, serv;
+  byte udpbuf[MAXUDPDGRAM];
+  struct sockaddr_in udpaddr;
 
   count= 0;
-  oldtcpstate= ads->tcpstate;
-  
-  if (ads->tcpstate == server_connecting) {
+
+  switch (ads->tcpstate) {
+  case server_disconnected:
+    break;
+  case server_connecting:
     if (callb_checkfd(maxfd,writefds,ads->tcpsocket)) {
       count++;
       assert(ads->tcprecv.used==0);
-      vbuf_ensure(&ads->tcprecv,1);
+      adns__vbuf_ensure(&ads->tcprecv,1);
       if (ads->tcprecv.buf) {
        r= read(ads->tcpsocket,&ads->tcprecv.buf,1);
        if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) {
-         diag("nameserver %s TCP connection made",
-              inet_ntoa(ads->servers[ads->tcpserver].addr));
-         ads->tcpstate= server_connected;
+         tcp_connected(ads,now);
        } else if (r>0) {
-         tcpserver_broken(ads,"connect/read","sent data before first request");
+         adns__tcp_broken(ads,"connect/read","sent data before first request");
        } else if (errno!=EINTR) {
-         tcpserver_broken(ads,"connect",strerror(errno));
+         adns__tcp_broken(ads,"connect/read",strerror(errno));
        }
       }
     }
-  }
-  if (ads->tcpstate == server_connected) {
-    if (oldtcpstate == server_connected)
-      count+= callb_checkfd(maxfd,readfds,ads->tcpsocket) +
-             callb_checkfd(maxfd,exceptfds,ads->tcpsocket) +
-       (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket));
-    if (oldtcpstate != server_connected || callb_checkfd(maxfd,readfds,ads->tcpsocket)) {
+    break;
+  case server_ok:
+    count+= callb_checkfd(maxfd,readfds,ads->tcpsocket) +
+            callb_checkfd(maxfd,exceptfds,ads->tcpsocket) +
+      (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket));
+    if (callb_checkfd(maxfd,readfds,ads->tcpsocket)) {
       skip= 0;
       for (;;) {
        if (ads->tcprecv.used<skip+2) {
@@ -53,13 +234,13 @@ int adns_callback(adns_state ads, int maxfd,
          if (ads->tcprecv.used<skip+2+dgramlen) {
            want= 2+dgramlen;
          } else {
-           procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,-1);
+           adns__procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,ads->tcpserver);
            skip+= 2+dgramlen; continue;
          }
        }
-       Ads->tcprecv.used -= skip;
+       ads->tcprecv.used -= skip;
        memmove(ads->tcprecv.buf,ads->tcprecv.buf+skip,ads->tcprecv.used);
-       vbuf_ensure(&ads->tcprecv,want);
+       adns__vbuf_ensure(&ads->tcprecv,want);
        if (ads->tcprecv.used >= ads->tcprecv.avail) break;
        r= read(ads->tcpsocket,
                ads->tcprecv.buf+ads->tcprecv.used,
@@ -71,139 +252,84 @@ int adns_callback(adns_state ads, int maxfd,
            if (errno==EAGAIN || errno==EWOULDBLOCK || errno==ENOMEM) break;
            if (errno==EINTR) continue;
          }
-         tcpserver_broken(ads->tcpserver,"read",r?strerror(errno):"closed");
+         adns__tcp_broken(ads,"read",r?strerror(errno):"closed");
          break;
        }
       }
     } else if (callb_checkfd(maxfd,exceptfds,ads->tcpsocket)) {
-      tcpserver_broken(ads->tcpserver,"select","exceptional condition detected");
+      adns__tcp_broken(ads,"select","exceptional condition detected");
     } else if (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)) {
       r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used);
       if (r<0) {
        if (errno!=EAGAIN && errno!=EWOULDBLOCK && errno!=ENOMEM && errno!=EINTR) {
-         tcpserver_broken(ads->tcpserver,"write",strerror(errno));
+         adns__tcp_broken(ads,"write",strerror(errno));
        }
       } else if (r>0) {
        ads->tcpsend.used -= r;
        memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used);
       }
     }
+  default:
+    abort();
   }
 
-  if (
-    break;
-       
-      
-       }
-         
-  tcpserver_broken(
-               
-           if (ads-
-         used= 0;
-         for (;;) {
-         vbuf_ensure(&ads->tcprecv,2);
-         vbuf_ensure(&ads->tcprecv,
-         if (ads->tcprecv.avail<2) break;
-      if (ads->tcprecv.used
-      
-      if (ads->tcprecv.used<2 && ads->tcprecv.avail
-      if (ads->tcprecv.used<2 && ads->tcprecv.avail
-      r= read(ads->tcpsocket,
-      if (adns->tcprecv.used<2) {
-       if (
-         
-  if (ads->tcpstate != server_disc) {
-    
-      
+  if (callb_checkfd(maxfd,readfds,ads->udpsocket)) {
+    count++;
+    for (;;) {
+      udpaddrlen= sizeof(udpaddr);
+      r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0,&udpaddr,&udpaddrlen);
+      if (r<0) {
+       if (!(errno == EAGAIN || errno == EWOULDBLOCK ||
+             errno == EINTR || errno == ENOMEM || errno == ENOBUFS))
+         adns__warn(ads,-1,"datagram receive error: %s",strerror(errno));
+       break;
+      }
+      if (udpaddrlen != sizeof(udpaddr)) {
+       adns__diag(ads,-1,"datagram received with wrong address length %d (expected %d)",
+                  udpaddrlen,sizeof(udpaddr));
+       continue;
+      }
+      if (udpaddr.sin_family != AF_INET) {
+       adns__diag(ads,-1,"datagram received with wrong protocol family"
+                  " %u (expected %u)",udpaddr.sin_family,AF_INET);
+       continue;
+      }
+      if (ntohs(udpaddr.sin_port) != NSPORT) {
+       adns__diag(ads,-1,"datagram received from wrong port %u (expected %u)",
+                  ntohs(udpaddr.sin_port),NSPORT);
+       continue;
+      }
+      for (serv= 0;
+          serv < ads->nservers &&
+            ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr;
+          serv++);
+      if (serv >= ads->nservers) {
+       adns__warn(ads,-1,"datagram received from unknown nameserver %s",
+                  inet_ntoa(udpaddr.sin_addr));
+       continue;
+      }
+      adns__procdgram(ads,udpbuf,r,serv);
     }
-  if (maxfd<0 || !readfds || (FD_ISSET
-      ads->
-      
-  abort(); /* FIXME */
-}
-         diag("nameserver #%d (%s) TCP connection died: %s",
-              inet_ntoa(ads->servers[tcpserver].addr),
-
-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 void inter_addfd(int *maxfd, fd_set *fds, int fd) {
-  if (fd>=*maxfd) *maxfd= fd+1;
-  FD_SET(fd,fds);
+  }
+  return count;
 }
 
-void adns_interest(adns_state ads, int *maxfd,
-                  fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
-                  struct timeval **tv_io, struct timeval *tvbuf) {
+int adns_callback(adns_state ads, int maxfd,
+                 const fd_set *readfds, const fd_set *writefds,
+                 const fd_set *exceptfds) {
   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);
-  }
+  r= gettimeofday(&now,0); if (r) return -1;
+  checktimeouts(ads,now,0,0);
+  return internal_callback(ads,maxfd,readfds,writefds,exceptfds,now);
+}
 
-  inter_addfd(maxfd,readfds,ads->udpsocket);
-  switch (ads->tcpstate) {
-  case server_disc:
-    break;
-  case server_connecting:
-    inter_addfd(maxfd,writefds,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();
-  }
-  
+/* User-visible functions and their implementation. */
+
+void adns__autosys(adns_state ads, struct timeval now) {
+  if (ads->iflags & adns_if_noautosys) return;
+  adns_callback(ads,-1,0,0,0);
 }
 
 static int internal_check(adns_state ads,
@@ -220,8 +346,8 @@ static int internal_check(adns_state ads,
     if (qu->id>=0) return EWOULDBLOCK;
   }
   LIST_UNLINK(ads->output,qu);
-  *answer= qu->answer;
-  if (context_r) *context_r= qu->context;
+  *answer= (adns_answer*)qu->answer.buf;
+  if (context_r) *context_r= qu->context.ext;
   free(qu);
   return 0;
 }
@@ -236,9 +362,9 @@ int adns_wait(adns_state ads,
   
   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);
+    if (r != EWOULDBLOCK) return r;
     maxfd= 0; tvp= 0;
+    FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
     adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf);
     rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
     if (rsel==-1) return r;
@@ -251,6 +377,10 @@ int adns_check(adns_state ads,
               adns_query *query_io,
               adns_answer **answer_r,
               void **context_r) {
-  autosys(ads);
+  struct timeval now;
+  int r;
+  
+  r= gettimeofday(&now,0); if (r) return errno;
+  adns__autosys(ads,now);
   return internal_check(ads,query_io,answer_r,context_r);
 }