Tweak 7d915a0bb9

A downstream query may have gone to TCP, not just DNSSEC queries.

src/cache.c

@@ -479,7 +479,7 @@ static struct crec *cache_scan_free(char *name, union all_addr *addr, unsigned s
 	  if ((crecp->flags & F_FORWARD) && hostname_isequal(cache_get_name(crecp), name))
 	    {
 	      int rrmatch = 0;
-	      if (crecp->flags & flags & F_RR)
+	      if (addr && (crecp->flags & flags & F_RR))
 		{
 		  unsigned short rrc = (crecp->flags & F_KEYTAG) ? crecp->addr.rrblock.rrtype : crecp->addr.rrdata.rrtype;
 		  unsigned short rra = (flags & F_KEYTAG) ? addr->rrblock.rrtype : addr->rrdata.rrtype;

src/dnsmasq.c

@@ -32,6 +32,7 @@ static volatile int pipewrite;
 static void set_dns_listeners(void);
 static void set_tftp_listeners(void);
 static void check_dns_listeners(time_t now);
+static void do_tcp_connection(struct listener *listener, time_t now, int slot);
 static void sig_handler(int sig);
 static void async_event(int pipe, time_t now);
 static void fatal_event(struct event_desc *ev, char *msg);
@@ -961,8 +962,15 @@ int main (int argc, char **argv)
 	my_syslog(LOG_WARNING, _("warning: ignoring resolv-file flag because no-resolv is set"));
       daemon->resolv_files = NULL;
       if (!daemon->servers)
+	{
+#ifdef HAVE_DBUS
+	  if (option_bool(OPT_DBUS))
+	    my_syslog(LOG_INFO, _("no upstream servers configured - please set them from DBus"));
+	  else
+#endif
 	  my_syslog(LOG_WARNING, _("warning: no upstream servers configured"));
 	}
+    } 
 
   if (daemon->max_logs != 0)
     my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs);
@@ -1476,7 +1484,7 @@ static void async_event(int pipe, time_t now)
 {
   pid_t p;
   struct event_desc ev;
-  int i, check = 0;
+  int wstatus, i, check = 0;
   char *msg;
   
   /* NOTE: the memory used to return msg is leaked: use msgs in events only
@@ -1539,7 +1547,7 @@ static void async_event(int pipe, time_t now)
 		
       case EVENT_CHILD:
 	/* See Stevens 5.10 */
-	while ((p = waitpid(-1, NULL, WNOHANG)) != 0)
+	while ((p = waitpid(-1, &wstatus, WNOHANG)) != 0)
 	  if (p == -1)
 	    {
 	      if (errno != EINTR)
@@ -1550,6 +1558,20 @@ static void async_event(int pipe, time_t now)
 	      if (daemon->tcp_pids[i] == p)
 		{
 		  daemon->tcp_pids[i] = 0;
+
+		  if (!WIFEXITED(wstatus))
+		    {
+		      /* If a helper process dies, (eg with SIGSEV)
+			 log that and attempt to patch things up so that the 
+			 parent can continue to function. */
+		      my_syslog(LOG_WARNING, _("TCP helper process %u died unexpectedly"), (unsigned int)p);
+		      if (daemon->tcp_pipes[i] != -1)
+			{
+			  close(daemon->tcp_pipes[i]);
+			  daemon->tcp_pipes[i] = -1;
+			}
+		    }
+		  
 		  /* tcp_pipes == -1 && tcp_pids == 0 required to free slot */
 		  if (daemon->tcp_pipes[i] == -1)
 		    daemon->metrics[METRIC_TCP_CONNECTIONS]--;
@@ -1832,22 +1854,17 @@ static void check_dns_listeners(time_t now)
   struct listener *listener;
   struct randfd_list *rfl;
   int i;
-  int pipefd[2];
   
-  for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
+  /* Note that handling events here can create or destroy fds and
-    if (poll_check(serverfdp->fd, POLLIN))
+     render the result of the last poll() call invalid. Once
-      reply_query(serverfdp->fd, now);
+     we find an fd that needs service, do it, then return to go around the
-  
+     poll() loop again. This avoid really, really, wierd bugs. */
-  for (i = 0; i < daemon->numrrand; i++)
-    if (daemon->randomsocks[i].refcount != 0 && 
-	poll_check(daemon->randomsocks[i].fd, POLLIN))
-      reply_query(daemon->randomsocks[i].fd, now);
-
-  /* Check overflow random sockets too. */
-  for (rfl = daemon->rfl_poll; rfl; rfl = rfl->next)
-    if (poll_check(rfl->rfd->fd, POLLIN))
-      reply_query(rfl->rfd->fd, now);
 
+  if (!option_bool(OPT_DEBUG))
+    for (i = 0; i < daemon->max_procs; i++)
+      if (daemon->tcp_pipes[i] != -1 &&
+	  poll_check(daemon->tcp_pipes[i], POLLIN | POLLHUP))
+	{
 	   /* Races. The child process can die before we read all of the data from the
 	      pipe, or vice versa. Therefore send tcp_pids to zero when we wait() the 
 	      process, and tcp_pipes to -1 and close the FD when we read the last
@@ -1855,11 +1872,7 @@ static void check_dns_listeners(time_t now)
 	      The order of these events is indeterminate, and both are needed
 	      to free the process slot. Once the child process has gone, poll()
 	      returns POLLHUP, not POLLIN, so have to check for both here. */
-  if (!option_bool(OPT_DEBUG))
+	  if (!cache_recv_insert(now, daemon->tcp_pipes[i]))
-    for (i = 0; i < daemon->max_procs; i++)
-      if (daemon->tcp_pipes[i] != -1 &&
-	  poll_check(daemon->tcp_pipes[i], POLLIN | POLLHUP) &&
-	  !cache_recv_insert(now, daemon->tcp_pipes[i]))
 	    {
 	      close(daemon->tcp_pipes[i]);
 	      daemon->tcp_pipes[i] = -1;	
@@ -1867,11 +1880,38 @@ static void check_dns_listeners(time_t now)
 	      if (daemon->tcp_pids[i] == 0)
 		daemon->metrics[METRIC_TCP_CONNECTIONS]--;
 	    }
+	  return;
+	}
+
+  for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
+    if (poll_check(serverfdp->fd, POLLIN))
+      {
+	reply_query(serverfdp->fd, now);
+	return;
+      }
+  
+  for (i = 0; i < daemon->numrrand; i++)
+    if (daemon->randomsocks[i].refcount != 0 && 
+	poll_check(daemon->randomsocks[i].fd, POLLIN))
+      {
+	reply_query(daemon->randomsocks[i].fd, now);
+	return;
+      }
+  
+  /* Check overflow random sockets too. */
+  for (rfl = daemon->rfl_poll; rfl; rfl = rfl->next)
+    if (poll_check(rfl->rfd->fd, POLLIN))
+      {
+	reply_query(rfl->rfd->fd, now);
+	return;
+      }
   
   for (listener = daemon->listeners; listener; listener = listener->next)
-    {
     if (listener->fd != -1 && poll_check(listener->fd, POLLIN))
+      {
 	receive_query(listener, now); 
+	return;
+      }
   
   /* check to see if we have a free tcp process slot.
      Note that we can't assume that because we had
@@ -1882,23 +1922,39 @@ static void check_dns_listeners(time_t now)
     if (daemon->tcp_pids[i] == 0 && daemon->tcp_pipes[i] == -1)
       break;
 
-      if (listener->tcpfd != -1 && i >= 0 && poll_check(listener->tcpfd, POLLIN))
+  if (i >= 0)
+    for (listener = daemon->listeners; listener; listener = listener->next)
+      if (listener->tcpfd != -1 && poll_check(listener->tcpfd, POLLIN))
+	{
+	  do_tcp_connection(listener, now, i);
+	  return;
+	}
+}
+
+static void do_tcp_connection(struct listener *listener, time_t now, int slot)
 {
   int confd, client_ok = 1;
   struct irec *iface = NULL;
   pid_t p;
   union mysockaddr tcp_addr;
   socklen_t tcp_len = sizeof(union mysockaddr);
+  unsigned char a = 0, *buff;
+  struct server *s; 
+  int flags, auth_dns;
+  struct in_addr netmask;
+  int pipefd[2];
 
   while ((confd = accept(listener->tcpfd, NULL, NULL)) == -1 && errno == EINTR);
   
   if (confd == -1)
-	    continue;
+    return;
   
   if (getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1)
     {
+    closeconandreturn:
+      shutdown(confd, SHUT_RDWR);
       close(confd);
-	      continue;
+      return;
     }
   
   /* Make sure that the interface list is up-to-date.
@@ -1961,17 +2017,26 @@ static void check_dns_listeners(time_t now)
     }
   
   if (!client_ok)
+    goto closeconandreturn;
+  
+  if (!option_bool(OPT_DEBUG))
     {
-	      shutdown(confd, SHUT_RDWR);
+      if (pipe(pipefd) == -1)
-	      close(confd);
+	goto closeconandreturn; /* pipe failed */
-	    }
+            
-	  else if (!option_bool(OPT_DEBUG) && pipe(pipefd) == 0 && (p = fork()) != 0)
+      if ((p = fork()) == -1)
 	{
-	      close(pipefd[1]); /* parent needs read pipe end. */
+	  /* fork failed */
-	      if (p == -1)
 	  close(pipefd[0]);
-	      else
+	  close(pipefd[1]);
+	  goto closeconandreturn;
+	}
+
+      if (p != 0)
 	{
+	  /* fork() done: parent side */
+	  close(pipefd[1]); /* parent needs read pipe end. */
+      
 #ifdef HAVE_LINUX_NETWORK
 	  /* The child process inherits the netlink socket, 
 	     which it never uses, but when the parent (us) 
@@ -1987,17 +2052,16 @@ static void check_dns_listeners(time_t now)
 	     is sent by the child after it has closed the
 	     netlink socket. */
 	  
-		  unsigned char a;
 	  read_write(pipefd[0], &a, 1, RW_READ);
 #endif
 	  
-		  /* i holds index of free slot */
+
-		  daemon->tcp_pids[i] = p;
+	  daemon->tcp_pids[slot] = p;
-		  daemon->tcp_pipes[i] = pipefd[0];
+	  daemon->tcp_pipes[slot] = pipefd[0];
 	  daemon->metrics[METRIC_TCP_CONNECTIONS]++;
 	  if (daemon->metrics[METRIC_TCP_CONNECTIONS] > daemon->max_procs_used)
 	    daemon->max_procs_used = daemon->metrics[METRIC_TCP_CONNECTIONS];
-		}
+	
 	  close(confd);
 	  
 	  /* The child can use up to TCP_MAX_QUERIES ids, so skip that many. */
@@ -2007,14 +2071,10 @@ static void check_dns_listeners(time_t now)
 	  if (option_bool(OPT_DNSSEC_VALID))
 	    daemon->log_id += daemon->limit[LIMIT_WORK];
 #endif
+	  
+	  return;
+	}
     }
-	  else
-	    {
-	      unsigned char *buff;
-	      struct server *s; 
-	      int flags;
-	      struct in_addr netmask;
-	      int auth_dns;
          
   if (iface)
     {
@@ -2033,8 +2093,6 @@ static void check_dns_listeners(time_t now)
     {
 #ifdef HAVE_LINUX_NETWORK
       /* See comment above re: netlink socket. */
-		  unsigned char a = 0;
-
       close(daemon->netlinkfd);
       read_write(pipefd[1], &a, 1, RW_WRITE);
 #endif		  
@@ -2069,9 +2127,7 @@ static void check_dns_listeners(time_t now)
       _exit(0);
     }
 }
-	}
+
-    }
-}
 
 #ifdef HAVE_DNSSEC
 /* If a DNSSEC query over UDP returns a truncated answer,

src/forward.c

@@ -163,7 +163,7 @@ static int domain_no_rebind(char *domain)
   return 0;
 }
 
-static int forward_query(int udpfd, union mysockaddr *udpaddr,
+static void forward_query(int udpfd, union mysockaddr *udpaddr,
 			  union all_addr *dst_addr, unsigned int dst_iface,
 			  struct dns_header *header, size_t plen,  size_t replylimit, time_t now, 
 			  struct frec *forward, unsigned int fwd_flags, int fast_retry)
@@ -190,6 +190,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
     {
       old_src = 1;
       old_reply = 1;
+      fwd_flags = forward->flags;
     }
   else if (gotname && (forward = lookup_frec(daemon->namebuff, C_IN, (int)rrtype, -1, fwd_flags,
 					     FREC_CHECKING_DISABLED | FREC_AD_QUESTION | FREC_DO_QUESTION |
@@ -253,7 +254,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 	     it's safe to wait for the reply from the first without
 	     forwarding the second. */
 	  if (difftime(now, forward->time) < 2)
-	    return 0;
+	    return;
 	}
       
       /* use our id when resending */
@@ -373,6 +374,10 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
       while (forward->blocking_query)
 	forward = forward->blocking_query;
 
+      /* Don't retry if we've already sent it via TCP. */
+      if (forward->flags & FREC_GONE_TO_TCP)
+	return;
+      
       if (forward->flags & (FREC_DNSKEY_QUERY | FREC_DS_QUERY))
 	{
 	  /* log_id should match previous DNSSEC query. */
@@ -385,7 +390,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 	  
 	  /* Find suitable servers: should never fail. */
 	  if (!filter_servers(forward->sentto->arrayposn, F_DNSSECOK, &first, &last))
-	    return 0;
+	    return;
 	  
 	  is_dnssec = 1;
 	  forward->forwardall = 1;
@@ -501,8 +506,9 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
   
   if (forwarded || is_dnssec)
     {
+      daemon->metrics[METRIC_DNS_QUERIES_FORWARDED]++;
       forward->forward_timestamp = dnsmasq_milliseconds();
-      return 1;
+      return;
     }
   
   /* could not send on, prepare to return */ 
@@ -514,9 +520,9 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
   if (udpfd != -1)
     {
       if (!(plen = make_local_answer(flags, gotname, plen, header, daemon->namebuff, (char *)(header + replylimit), first, last, ede)))
-	return 0;
+	return;
       
-      if (forward->flags & FREC_HAS_PHEADER)
+      if (fwd_flags & FREC_HAS_PHEADER)
 	{
 	  u16 swap = htons((u16)ede);
 
@@ -542,7 +548,8 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
       send_from(udpfd, option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND), (char *)header, plen, udpaddr, dst_addr, dst_iface);
     }
   
-  return 0;
+  daemon->metrics[METRIC_DNS_LOCAL_ANSWERED]++;
+  return;
 }
 
 /* Check if any frecs need to do a retry, and action that if so. 
@@ -779,10 +786,9 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
 	      header->ancount = htons(0);
 	      header->nscount = htons(0);
 	      header->arcount = htons(0);
-	      ede = EDE_DNSSEC_BOGUS;
 	    }
 	}
-      else if (!(header->hb4 & HB4_CD) && ad_reqd && cache_secure)
+      else if (ad_reqd && cache_secure)
 	header->hb4 |= HB4_AD;
       
       /* If the requestor didn't set the DO bit, don't return DNSSEC info. */
@@ -1243,20 +1249,25 @@ void return_reply(time_t now, struct frec *forward, struct dns_header *header, s
 	  char *result, *domain = "result";
 	  union all_addr a;
 
-	  a.log.ede = ede = errflags_to_ede(status);
+	  ede = errflags_to_ede(status);
 	  
 	  if (STAT_ISEQUAL(status, STAT_ABANDONED))
 	    {
 	      result = "ABANDONED";
 	      status = STAT_BOGUS;
+	      if (ede == EDE_UNSET)
+		ede = EDE_OTHER;
 	    }
 	  else
 	    result = (STAT_ISEQUAL(status, STAT_SECURE) ? "SECURE" : (STAT_ISEQUAL(status, STAT_INSECURE) ? "INSECURE" : "BOGUS"));
 
+	  
 	  if (STAT_ISEQUAL(status, STAT_SECURE))
 	    cache_secure = 1;
 	  else if (STAT_ISEQUAL(status, STAT_BOGUS))
 	    {
+	      if (ede == EDE_UNSET)
+		ede = EDE_DNSSEC_BOGUS;
 	      no_cache_dnssec = 1;
 	      bogusanswer = 1;
 	      
@@ -1264,6 +1275,7 @@ void return_reply(time_t now, struct frec *forward, struct dns_header *header, s
 		domain = daemon->namebuff;
 	    }
       
+	  a.log.ede = ede;
 	  log_query(F_SECSTAT, domain, &a, result, 0);
 	}
     }
@@ -1845,11 +1857,8 @@ void receive_query(struct listener *listen, time_t now)
       blockdata_free(saved_question);
       saved_question = NULL;
 
-      if (forward_query(fd, &source_addr, &dst_addr, if_index, header, (size_t)n,
+      forward_query(fd, &source_addr, &dst_addr, if_index, header, (size_t)n,
-			udp_size, now, NULL, fwd_flags, 0))
+		    udp_size, now, NULL, fwd_flags, 0);
-	daemon->metrics[METRIC_DNS_QUERIES_FORWARDED]++;
-      else
-	daemon->metrics[METRIC_DNS_LOCAL_ANSWERED]++;
     }
 
   blockdata_free(saved_question);
@@ -2394,8 +2403,7 @@ unsigned char *tcp_request(int confd, time_t now,
 	  size = saved_size;
 
 	  /* save state of "cd" flag in query */
-	  if ((checking_disabled = header->hb4 & HB4_CD))
+	  checking_disabled = header->hb4 & HB4_CD;
-	    no_cache_dnssec = 1;
 	  
 	  if (lookup_domain(daemon->namebuff, gotname, &first, &last))
 	    flags = is_local_answer(now, first, daemon->namebuff);
@@ -2447,7 +2455,9 @@ unsigned char *tcp_request(int confd, time_t now,
 			  /* Clear this in case we don't call tcp_key_recurse() below */
 			  memset(daemon->rr_status, 0, sizeof(*daemon->rr_status) * daemon->rr_status_sz);
 			  
-			  if (!checking_disabled && (master->flags & SERV_DO_DNSSEC))
+			  if (checking_disabled || (header->hb4 & HB4_CD))
+			    no_cache_dnssec = 1;
+			  else if (master->flags & SERV_DO_DNSSEC)
 			    {
 			      int keycount = daemon->limit[LIMIT_WORK]; /* Limit to number of DNSSEC questions, to catch loops and avoid filling cache. */
 			      int validatecount = daemon->limit[LIMIT_CRYPTO]; 
@@ -2456,12 +2466,14 @@ unsigned char *tcp_request(int confd, time_t now,
 			      char *result, *domain = "result";
 			      
 			      union all_addr a;
-			      a.log.ede = ede = errflags_to_ede(status);
+			      ede = errflags_to_ede(status);
 			      
 			      if (STAT_ISEQUAL(status, STAT_ABANDONED))
 				{
 				  result = "ABANDONED";
 				  status = STAT_BOGUS;
+				  if (ede == EDE_UNSET)
+				    ede = EDE_OTHER;
 				}
 			      else
 				result = (STAT_ISEQUAL(status, STAT_SECURE) ? "SECURE" : (STAT_ISEQUAL(status, STAT_INSECURE) ? "INSECURE" : "BOGUS"));
@@ -2470,6 +2482,8 @@ unsigned char *tcp_request(int confd, time_t now,
 				cache_secure = 1;
 			      else if (STAT_ISEQUAL(status, STAT_BOGUS))
 				{
+				  if (ede == EDE_UNSET)
+				    ede = EDE_DNSSEC_BOGUS;
 				  no_cache_dnssec = 1;
 				  bogusanswer = 1;
 				  
@@ -2477,6 +2491,7 @@ unsigned char *tcp_request(int confd, time_t now,
 				    domain = daemon->namebuff;
 				}
 			      
+			      a.log.ede = ede;
 			      log_query(F_SECSTAT, domain, &a, result, 0);
 			      
 			      if ((daemon->limit[LIMIT_CRYPTO] - validatecount) > (int)daemon->metrics[METRIC_CRYPTO_HWM])