Removing the --disable-nbdns config option.

- Asynchronous DNS resolver support assumed by default
- HAVE_ASYNC_DNS, HAVE_NB_DNS, and USE_NB_DNS preprocessor definitions
  removed
- In the process, I added FindBIND and CheckNameserCompat CMake modules

BuildOptions.cmake

@@ -37,16 +37,16 @@ set(ENABLE_DEBUG false
 set(ENABLE_PERFTOOLS false
     CACHE STRING "use Google's perftools" FORCE)
 
-set(USE_NB_DNS true
-    CACHE BOOL "Use non-blocking DNS support" FORCE)
-
 ##
 ## Configure Dependencies for Non-Standard Paths
 ##
 
-# Uncomment to specific a custom prefix containing the OpenSSL installation.
+# Uncomment to specify a custom prefix containing the OpenSSL installation.
 #set(OPENSSL_ROOT_DIR path/to/your/openssl)
 
+# Uncomment to specify a custom prefix containing the BIND installation.
+#set(BIND_ROOT_DIR path/to/your/bind)
+
 # Uncomment to specify a custom prefix that contains the libpcap installation.
 #set(PCAP_ROOT path/to/your/pcap)
 
@@ -59,7 +59,6 @@ set(USE_NB_DNS true
 # TODO: more dependencies:
 # Flex
 # Bison
-# BIND8
 # Perl?
 # BinPAC
 #

CMakeLists.txt

@@ -43,11 +43,13 @@ file(STRINGS "${CMAKE_SOURCE_DIR}/VERSION" VERSION LIMIT_COUNT 1)
 find_package(FLEX REQUIRED)
 find_package(BISON REQUIRED)
 find_package(PCAP REQUIRED)
-include_directories(BEFORE ${PCAP_INCLUDE_DIR})
 find_package(OpenSSL REQUIRED)
-include_directories(BEFORE ${OPENSSL_INCLUDE_DIR})
+find_package(BIND REQUIRED)
+include_directories(BEFORE
+                    ${PCAP_INCLUDE_DIR}
+                    ${OPENSSL_INCLUDE_DIR}
+                    ${BIND_INCLUDE_DIR})
 
-# TODO: find bind8 lib?
 # TODO: optional libmagic
 # TODO: optional libGeoIP
 # TODO: optional libz
@@ -64,12 +66,8 @@ include(CheckHeaders)
 include(CheckFunctions)
 include(MiscTests)
 include(PCAPTests)
-#TODO: use/integrate find_package(OpenSSL)
 include(OpenSSLTests)
-
-#TODO: NB_DNS tests
-set(HAVE_NB_DNS ${USE_NB_DNS})
-set(HAVE_ASYNC_DNS ${USE_NB_DNS}) #TODO: should make consistent w/ HAVE_NB_DNS
+include(CheckNameserCompat)
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/config.h.in
                ${CMAKE_CURRENT_BINARY_DIR}/config.h)

cmake/CheckNameserCompat.cmake

@@ -0,0 +1,21 @@
+include(CheckCSourcecompiles)
+
+# Check whether the namser compatibility header is required
+# This can be the case on the Darwin platform
+
+check_c_source_compiles("
+    #include <arpa/nameser.h>
+    int main() { HEADER *hdr; int d = NS_IN6ADDRSZ; return 0; }"
+    have_nameser_header)
+
+if (NOT have_nameser_header)
+    check_c_source_compiles("
+        #include <arpa/nameser.h>
+        #include <arpa/nameser_compat.h>
+        int main() { HEADER *hdr; int d = NS_IN6ADDRSZ; return 0; }"
+        NEED_NAMESER_COMPAT_H)
+    if (NOT NEED_NAMESER_COMPAT_H)
+        message(FATAL_ERROR
+            "Asynchronous DNS support compatibility check failed.")
+    endif ()
+endif ()

cmake/FindBIND.cmake

@@ -0,0 +1,77 @@
+# - Try to find libpcap include dirs and libraries 
+#
+# Usage of this module as follows:
+#
+#     find_package(BIND)
+#
+# Variables used by this module, they can change the default behaviour and need
+# to be set before calling find_package:
+#
+#  BIND_ROOT_DIR             Set this variable to the root installation of BIND
+#                            if the module has problems finding the proper
+#                            installation path.
+#
+# Variables defined by this module:
+#
+#  BIND_FOUND                System has BIND, include and library dirs found
+#  BIND_INCLUDE_DIR          The BIND include directories. 
+#  BIND_LIBRARIES            All BIND libraries found.
+#  BIND_LIBRARY              The BIND library required for ns_inittab and
+#                            res_mkquery symbols.
+
+find_path(BIND_ROOT_DIR
+    NAMES include/resolv.h
+)
+mark_as_advanced(BIND_ROOT_DIR)
+
+if (BIND_ROOT_DIR)
+    set(BIND_INCLUDE_DIR ${BIND_ROOT_DIR}/include)
+endif ()
+
+find_library(BIND_LIBRARIES
+    NAMES resolv bind
+    HINTS ${BIND_ROOT_DIR}/lib
+)
+
+include(CheckCSourceCompiles)
+
+# Find which library has the res_mkquery and ns_initparse symbols
+set(CMAKE_REQUIRED_INCLUDES ${BIND_INCLUDE_DIR})
+foreach (bindlib ${BIND_LIBRARIES})
+    set(CMAKE_REQUIRED_LIBRARIES ${bindlib})
+
+    check_c_source_compiles("
+        #include <arpa/nameser.h>
+        int main() {
+            ns_initparse(0, 0, 0);
+            return 0;
+        }
+" ns_initparse_works)
+
+    check_c_source_compiles("
+        #include <sys/types.h>
+        #include <sys/socket.h>
+        #include <netinet/in.h>
+        #include <arpa/nameser.h>
+        #include <resolv.h>
+        int main() {
+            int (*p)() = res_mkquery;
+        }
+" res_mkquery_works)
+
+    unset(CMAKE_REQUIRED_LIBRARIES)
+
+    if (ns_initparse_works AND res_mkquery_works)
+        set(BIND_LIBRARY ${bindlib})
+        break ()
+    endif ()
+endforeach ()
+unset(CMAKE_REQUIRED_INCLUDES)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(BIND DEFAULT_MSG
+    BIND_LIBRARY
+    BIND_INCLUDE_DIR
+)
+
+mark_as_advanced(BIND_LIBRARIES BIND_LIBRARY BIND_INCLUDE_DIR)

cmake/OSSpecific.cmake

@@ -6,29 +6,6 @@ elseif (${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
     set(USE_NMALLOC true)
 
 elseif (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-    if (USE_NB_DNS)
-        include(CheckCSourceCompiles)
-        check_c_source_compiles("
-        #include <arpa/nameser.h>
-        int main() {
-            HEADER *hdr; int d = NS_IN6ADDRSZ; return 0;
-        }
-        " ns_header_defined)
-        if (NOT ns_header_defined)
-            check_c_source_compiles("
-            #include <arpa/nameser.h>
-            #include <arpa/nameser_compat.h>
-            int main() {
-                HEADER *hdr; int d = NS_IN6ADDRSZ; return 0;
-            }
-            " NEED_NAMESER_COMPAT_H)
-            if (NOT NEED_NAMESER_COMPAT_H)
-                message(WARNING "Darwin nameser compatibility check failed."
-                        "Non-blocking DNS support disabled.")
-                set(USE_NB_DNS false)
-            endif ()
-        endif ()
-    endif ()
 
 elseif (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
     set(HAVE_LINUX true)

config.h.in

@@ -38,9 +38,6 @@
 /* Define if you have the <memory.h> header file. */
 #cmakedefine HAVE_MEMORY_H
 
-/* async dns support */
-#cmakedefine HAVE_NB_DNS
-
 /* Define if you have the <netinet/ether.h> header file. */
 #cmakedefine HAVE_NETINET_ETHER_H
 

src/CMakeLists.txt

@@ -189,9 +189,7 @@ endforeach(binpact)
 
 ########### next target ###############
 
-if (HAVE_NB_DNS)
-    set(dns_SRCS nb_dns.c nb_dns.h)
-endif ()
+set(dns_SRCS nb_dns.c nb_dns.h)
 
 set(openssl_SRCS X509.cc SSLCiphers.cc SSLInterpreter.cc SSLProxy.cc
                  SSLv2.cc SSLv3.cc SSLv3Automaton.cc)
@@ -382,10 +380,10 @@ add_dependencies(bro make_dbg_constants)
 
 target_link_libraries(bro
                       m
-                      resolv
                       binpac_lib
                       ${PCAP_LIBRARY}
                       ${OPENSSL_LIBRARIES}
+                      ${BIND_LIBRARY}
 )
 
 install(TARGETS bro DESTINATION bin)

src/DNS_Mgr.cc

@@ -53,9 +53,7 @@ public:
 	const char* ReqHost() const	{ return host; }
 	uint32 ReqAddr() const		{ return addr; }
 
-#ifdef HAVE_NB_DNS
 	int MakeRequest(nb_dns_info* nb_dns);
-#endif
 	int RequestPending() const	{ return request_pending; }
 	void RequestDone()	{ request_pending = 0; }
 
@@ -66,7 +64,6 @@ protected:
 	int request_pending;
 };
 
-#ifdef HAVE_NB_DNS
 int DNS_Mgr_Request::MakeRequest(nb_dns_info* nb_dns)
 	{
 	if ( ! nb_dns )
@@ -80,7 +77,6 @@ int DNS_Mgr_Request::MakeRequest(nb_dns_info* nb_dns)
 	else
 		return nb_dns_addr_request(nb_dns, addr, (void*) this, err) >= 0;
 	}
-#endif
 
 class DNS_Mapping {
 public:
@@ -350,13 +346,11 @@ DNS_Mgr::DNS_Mgr(DNS_MgrMode arg_mode)
 	host_mappings.SetDeleteFunc(DNS_Mgr_mapping_delete_func);
 	addr_mappings.SetDeleteFunc(DNS_Mgr_mapping_delete_func);
 
-#ifdef HAVE_NB_DNS
 	char err[NB_DNS_ERRSIZE];
 	nb_dns = nb_dns_init(err);
 
 	if ( ! nb_dns )
 		warn(fmt("problem initializing NB-DNS: %s", err));
-#endif
 
 	dns_mapping_valid = dns_mapping_unverified = dns_mapping_new_name =
 		dns_mapping_lost_name = dns_mapping_name_changed =
@@ -372,10 +366,8 @@ DNS_Mgr::DNS_Mgr(DNS_MgrMode arg_mode)
 
 DNS_Mgr::~DNS_Mgr()
 	{
-#ifdef HAVE_NB_DNS
 	if ( nb_dns )
 		nb_dns_finish(nb_dns);
-#endif
 
 	delete [] cache_name;
 	delete [] dir;
@@ -410,14 +402,12 @@ bool DNS_Mgr::Init()
 
 	did_init = 1;
 
-#ifdef HAVE_NB_DNS
 	io_sources.Register(this, true);
 
 	// We never set idle to false, having the main loop only calling us from
 	// time to time. If we're issuing more DNS requests than we can handle
 	// in this way, we are having problems anyway ...
 	idle = true;
-#endif
 
 	return true;
 	}
@@ -531,7 +521,6 @@ void DNS_Mgr::Resolve()
 
 	int i;
 
-#ifdef HAVE_NB_DNS
 	int first_req = 0;
 	int num_pending = min(requests.length(), MAX_PENDING_REQUESTS);
 	int last_req = num_pending - 1;
@@ -597,7 +586,6 @@ void DNS_Mgr::Resolve()
 				--num_pending;
 			}
 		}
-#endif
 
 	// All done with the list of requests.
 	for ( i = requests.length() - 1; i >= 0; --i )
@@ -860,7 +848,6 @@ TableVal* DNS_Mgr::LookupNameInCache(string name)
 	return d->AddrsSet();
 	}
 
-#ifdef HAVE_NB_DNS
 void DNS_Mgr::AsyncLookupAddr(dns_mgr_addr_type host, LookupCallback* callback)
 	{
 	if ( ! did_init )
@@ -956,13 +943,10 @@ void DNS_Mgr::IssueAsyncRequests()
 		++asyncs_pending;
 		}
 	}
-#endif
 
 void  DNS_Mgr::GetFds(int* read, int* write, int* except)
 	{
-#ifdef HAVE_NB_DNS
 	*read = nb_dns_fd(nb_dns);
-#endif
 	}
 
 double DNS_Mgr::NextTimestamp(double* network_time)
@@ -971,7 +955,6 @@ double DNS_Mgr::NextTimestamp(double* network_time)
 	return asyncs_timeouts.size() ? timer_mgr->Time() : -1.0;
 	}
 
-#ifdef HAVE_NB_DNS
 void DNS_Mgr::CheckAsyncAddrRequest(dns_mgr_addr_type addr, bool timeout)
 	{
 	// Note that this code is a mirror of that for CheckAsyncHostRequest.
@@ -1030,13 +1013,9 @@ void DNS_Mgr::CheckAsyncHostRequest(const char* host, bool timeout)
 		// eventually times out.
 		}
 	}
-#endif
 
 void  DNS_Mgr::Process()
 	{
-#ifndef HAVE_NB_DNS
-	internal_error("DNS_Mgr::Process(): should never be reached");
-#else
 
 	while ( asyncs_timeouts.size() > 0 )
 		{
@@ -1084,9 +1063,8 @@ void  DNS_Mgr::Process()
 
 		IssueAsyncRequests();
 		}
-#endif
 	}
-#ifdef HAVE_NB_DNS
+
 int DNS_Mgr::AnswerAvailable(int timeout)
 	{
 	int fd = nb_dns_fd(nb_dns);
@@ -1116,4 +1094,3 @@ int DNS_Mgr::AnswerAvailable(int timeout)
 
 	return status;
 	}
-#endif

src/DNS_Mgr.h

@@ -79,10 +79,8 @@ public:
 		virtual void Timeout() = 0;
 	};
 
-#ifdef HAVE_NB_DNS
 	void AsyncLookupAddr(dns_mgr_addr_type host, LookupCallback* callback);
 	void AsyncLookupName(string name, LookupCallback* callback);
-#endif
 
 protected:
 	friend class LookupCallback;
@@ -102,7 +100,6 @@ protected:
 	void LoadCache(FILE* f);
 	void Save(FILE* f, PDict(DNS_Mapping)& m);
 
-#ifdef HAVE_NB_DNS
 	// Selects on the fd to see if there is an answer available (timeout is
 	// secs). Returns 0 on timeout, -1 on EINTR, and 1 if answer is ready.
 	int AnswerAvailable(int timeout);
@@ -115,8 +112,6 @@ protected:
 	void CheckAsyncAddrRequest(dns_mgr_addr_type addr, bool timeout);
 	void CheckAsyncHostRequest(const char* host, bool timeout);
 
-#endif
-
 	// IOSource interface.
 	virtual void GetFds(int* read, int* write, int* except);
 	virtual double NextTimestamp(double* network_time);

src/bro.bif

@@ -2808,10 +2808,6 @@ private:
 # function result.  Therefore, they can only be called inside a when-condition.
 function lookup_addr%(host: addr%) : string
 	%{
-#ifndef HAVE_NB_DNS
-	run_time("lookup_addr(): not configured for asynchronous DNS lookups");
-	return new StringVal("<error>");
-#else
 	// FIXME: Is should be easy to adapt the function to synchronous
 	// lookups if we're reading a trace.
 	Trigger* trigger = frame->GetTrigger();
@@ -2839,15 +2835,10 @@ function lookup_addr%(host: addr%) : string
 			new LookupHostCallback(trigger, frame->GetCall(), true));
 #endif
 	return 0;
-#endif
 	%}
 
 function lookup_hostname%(host: string%) : addr_set
 	%{
-#ifndef HAVE_NB_DNS
-	run_time("lookup_hostname(): not configured for asynchronous DNS lookups");
-	return new StringVal("<error>");
-#else
 	// FIXME: Is should be easy to adapt the function to synchronous
 	// lookups if we're reading a trace.
 	Trigger* trigger = frame->GetTrigger();
@@ -2864,7 +2855,6 @@ function lookup_hostname%(host: string%) : addr_set
 	dns_mgr->AsyncLookupName(host->CheckString(),
 			new LookupHostCallback(trigger, frame->GetCall(), false));
 	return 0;
-#endif
 	%}
 
 # Stop Bro's packet processing.

src/main.cc

@@ -406,11 +406,7 @@ int main(int argc, char** argv)
 
 	enum DNS_MgrMode dns_type = DNS_DEFAULT;
 
-#ifdef HAVE_NB_DNS
 	dns_type = getenv("BRO_DNS_FAKE") ? DNS_FAKE : DNS_DEFAULT;
-#else
-	dns_type = DNS_FAKE;
-#endif
 
 	RETSIGTYPE (*oldhandler)(int);