From: Wouter Wijngaards <wouter@nlnetlabs.nl>
Date: Fri, 7 Nov 2008 14:28:06 +0000 (+0000)
Subject: detect nonblocking broken.
X-Git-Tag: release-1.1.0~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=847107403ff8a843428aee1a4dbe228cd9b0d913;p=thirdparty%2Funbound.git

detect nonblocking broken.


git-svn-id: file:///svn/unbound/trunk@1338 be551aaa-1e26-0410-a405-d3ace91eadb9
---

diff --git a/config.h.in b/config.h.in
index 308718c00..973856ac0 100644
--- a/config.h.in
+++ b/config.h.in
@@ -272,6 +272,10 @@
 /* Define if mkdir has one argument. */
 #undef MKDIR_HAS_ONE_ARG
 
+/* Define if the network stack does not fully support nonblocking io (causes
+   lower performance). */
+#undef NONBLOCKING_IS_BROKEN
+
 /* Define to the address where bug reports for this package should be sent. */
 #undef PACKAGE_BUGREPORT
 
diff --git a/configure b/configure
index 5dcea7ea9..69c5cffad 100755
--- a/configure
+++ b/configure
@@ -25012,6 +25012,192 @@ _ACEOF
 
 fi
 
+# check if select and nonblocking sockets actually work.
+{ echo "$as_me:$LINENO: checking if nonblocking sockets work" >&5
+echo $ECHO_N "checking if nonblocking sockets work... $ECHO_C" >&6; }
+if test "$cross_compiling" = yes; then
+
+	{ echo "$as_me:$LINENO: result: crosscompile(yes)" >&5
+echo "${ECHO_T}crosscompile(yes)" >&6; }
+
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_TIME_H
+#include <time.h>
+#endif
+
+int
+main ()
+{
+
+	int port;
+	int sfd, cfd;
+	int num = 10;
+	int i, p;
+	struct sockaddr_in a;
+	/* test if select and nonblocking reads work well together */
+	/* open port.
+	   fork child to send 10 messages.
+	   select to read.
+	   then try to nonblocking read the 10 messages
+	   then, nonblocking read must give EAGAIN
+	*/
+
+	port = 12345 + (time(0)%32);
+	sfd = socket(PF_INET, SOCK_DGRAM, 0);
+	if(sfd == -1) {
+		perror("socket");
+		return 1;
+	}
+	memset(&a, 0, sizeof(a));
+	a.sin_family = AF_INET;
+	a.sin_port = htons(port);
+	a.sin_addr.s_addr = inet_addr("127.0.0.1");
+	if(bind(sfd, (struct sockaddr*)&a, sizeof(a)) < 0) {
+		perror("bind");
+		return 1;
+	}
+	if(fcntl(sfd, F_SETFL, O_NONBLOCK) == -1) {
+		perror("fcntl");
+		return 1;
+	}
+
+	cfd = socket(PF_INET, SOCK_DGRAM, 0);
+	if(cfd == -1) {
+		perror("client socket");
+		return 1;
+	}
+	a.sin_port = 0;
+	if(bind(cfd, (struct sockaddr*)&a, sizeof(a)) < 0) {
+		perror("client bind");
+		return 1;
+	}
+	a.sin_port = htons(port);
+
+	/* no handler, causes exit in 10 seconds */
+	alarm(10);
+
+	/* send and receive on the socket */
+	if((p=fork()) == 0) {
+		for(i=0; i<num; i++) {
+			if(sendto(cfd, &i, sizeof(i), 0,
+				(struct sockaddr*)&a, sizeof(a)) < 0) {
+				perror("sendto");
+				return 1;
+			}
+		}
+	} else {
+		/* parent */
+		fd_set rset;
+		int x;
+		if(p == -1) {
+			perror("fork");
+			return 1;
+		}
+		FD_ZERO(&rset);
+		FD_SET(sfd, &rset);
+		if(select(sfd+1, &rset, NULL, NULL, NULL) < 1) {
+			perror("select");
+			return 1;
+		}
+		i = 0;
+		while(i < num) {
+			if(recv(sfd, &x, sizeof(x), 0) != sizeof(x)) {
+				if(errno == EAGAIN)
+					continue;
+				perror("recv");
+				return 1;
+			}
+			i++;
+		}
+		/* now we want to get EAGAIN: nonblocking goodness */
+		errno = 0;
+		recv(sfd, &x, sizeof(x), 0);
+		if(errno != EAGAIN) {
+			perror("trying to recv again");
+			return 1;
+		}
+		/* EAGAIN encountered */
+	}
+
+	close(sfd);
+	close(cfd);
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+
+	{ echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+
+else
+  echo "$as_me: program exited with status $ac_status" >&5
+echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+( exit $ac_status )
+
+	{ echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define NONBLOCKING_IS_BROKEN 1
+_ACEOF
+
+
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
+fi
+
+
+
 # check mkdir
 { echo "$as_me:$LINENO: checking whether mkdir has one arg" >&5
 echo $ECHO_N "checking whether mkdir has one arg... $ECHO_C" >&6; }
diff --git a/configure.ac b/configure.ac
index a0c0ff8a5..d7c26e901 100644
--- a/configure.ac
+++ b/configure.ac
@@ -802,6 +802,134 @@ if echo $build_os | grep darwin8 > /dev/null; then
 	AC_DEFINE(DARWIN_BROKEN_SETREUID, 1, [Define this if on macOSX10.4-darwin8 and setreuid and setregid do not work])
 fi
 
+# check if select and nonblocking sockets actually work.
+AC_MSG_CHECKING([if nonblocking sockets work])
+AC_RUN_IFELSE(AC_LANG_PROGRAM([
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_TIME_H
+#include <time.h>
+#endif
+],[[
+	int port;
+	int sfd, cfd;
+	int num = 10;
+	int i, p;
+	struct sockaddr_in a;
+	/* test if select and nonblocking reads work well together */
+	/* open port.
+	   fork child to send 10 messages.
+	   select to read.
+	   then try to nonblocking read the 10 messages
+	   then, nonblocking read must give EAGAIN
+	*/
+
+	port = 12345 + (time(0)%32);
+	sfd = socket(PF_INET, SOCK_DGRAM, 0);
+	if(sfd == -1) {
+		perror("socket");
+		return 1;
+	}
+	memset(&a, 0, sizeof(a));
+	a.sin_family = AF_INET;
+	a.sin_port = htons(port);
+	a.sin_addr.s_addr = inet_addr("127.0.0.1");
+	if(bind(sfd, (struct sockaddr*)&a, sizeof(a)) < 0) {
+		perror("bind");
+		return 1;
+	}
+	if(fcntl(sfd, F_SETFL, O_NONBLOCK) == -1) {
+		perror("fcntl");
+		return 1;
+	}
+
+	cfd = socket(PF_INET, SOCK_DGRAM, 0);
+	if(cfd == -1) {
+		perror("client socket");
+		return 1;
+	}
+	a.sin_port = 0;
+	if(bind(cfd, (struct sockaddr*)&a, sizeof(a)) < 0) {
+		perror("client bind");
+		return 1;
+	}
+	a.sin_port = htons(port);
+
+	/* no handler, causes exit in 10 seconds */
+	alarm(10);
+
+	/* send and receive on the socket */
+	if((p=fork()) == 0) {
+		for(i=0; i<num; i++) {
+			if(sendto(cfd, &i, sizeof(i), 0, 
+				(struct sockaddr*)&a, sizeof(a)) < 0) {
+				perror("sendto");
+				return 1;
+			}
+		}
+	} else {
+		/* parent */
+		fd_set rset;
+		int x;
+		if(p == -1) {
+			perror("fork");
+			return 1;
+		}
+		FD_ZERO(&rset);
+		FD_SET(sfd, &rset);
+		if(select(sfd+1, &rset, NULL, NULL, NULL) < 1) {
+			perror("select");
+			return 1;
+		}
+		i = 0;
+		while(i < num) {
+			if(recv(sfd, &x, sizeof(x), 0) != sizeof(x)) {
+				if(errno == EAGAIN)
+					continue;
+				perror("recv");
+				return 1;
+			}
+			i++;
+		}
+		/* now we want to get EAGAIN: nonblocking goodness */
+		errno = 0;
+		recv(sfd, &x, sizeof(x), 0);
+		if(errno != EAGAIN) {
+			perror("trying to recv again");
+			return 1;
+		}
+		/* EAGAIN encountered */
+	}
+
+	close(sfd);
+	close(cfd);
+]]), [
+	AC_MSG_RESULT([yes])
+], [
+	AC_MSG_RESULT([no])
+	AC_DEFINE([NONBLOCKING_IS_BROKEN], 1, [Define if the network stack does not fully support nonblocking io (causes lower performance).])
+], [
+	AC_MSG_RESULT([crosscompile(yes)])
+])
+
 # check mkdir
 AC_MSG_CHECKING([whether mkdir has one arg])
 AC_TRY_COMPILE([
diff --git a/doc/Changelog b/doc/Changelog
index 894bcc6a8..a38c3f243 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,5 +1,6 @@
 7 November 2008: Wouter
 	- fix bug 217: fixed, setreuid and setregid do not work on MacOSX10.4.
+	- detect nonblocking problems in network stack in configure script.
 
 6 November 2008: Wouter
 	- dname_priv must decompress the name before comparison.
diff --git a/util/netevent.c b/util/netevent.c
index edbd14484..8fc9a576d 100644
--- a/util/netevent.c
+++ b/util/netevent.c
@@ -48,8 +48,12 @@
 /** The TCP reading or writing query timeout in seconds */
 #define TCP_QUERY_TIMEOUT 120 
 
+#ifndef NONBLOCKING_IS_BROKEN
 /** number of UDP reads to perform per read indication from select */
 #define NUM_UDP_PER_SELECT 100
+#else
+#define NUM_UDP_PER_SELECT 1
+#endif
 
 /* We define libevent structures here to hide the libevent stuff. */