Do not check for MSG_WAITFORONE as it is not used anymore.

Reverted to usual recvmmsg/sendmmsg availability check.

configure.ac

@@ -116,33 +116,19 @@ AC_ARG_ENABLE([debuglevel],
         ;;
     esac], [])
 
-AX_MSG_WAITFORONE
 # recvmmsg() (valgrind doesn't support it, so disable for debugging)
 AC_ARG_ENABLE([recvmmsg],
     AS_HELP_STRING([--enable-recvmmsg=yes|no], [enable recvmmsg() network API under Linux (kernel support required) (set to 'no' if you have trouble running server under valgrind) [default=yes]]),
     [case "${enableval}" in
       yes)
-	  if test "$ax_cv_have_msg_waitforone" = "yes"; then
-	      AC_DEFINE([ENABLE_RECVMMSG], [1], [recvmmsg enabled])
-	      recvmmsg=true
-	  else
-	      recvmmsg=false
-	  fi
+	  AC_CHECK_FUNCS([recvmmsg sendmmsg])
           ;;
       no)
-          recvmmsg=false
           ;;
       *)
           AC_MSG_ERROR([bad value ${enableval} for --enable-recvmmsg])
           ;;
-    esac], [
-    if test "$ax_cv_have_msg_waitforone" = "yes"; then
-        AC_DEFINE([ENABLE_RECVMMSG], [1], [recvmmsg enabled])
-        recvmmsg=true
-    else
-        recvmmsg=false
-    fi
-    ])
+    esac], [ AC_CHECK_FUNCS([recvmmsg sendmmsg]) ])
 
 # Enable integrity check
 AC_ARG_ENABLE([integrity-check],
@@ -302,7 +288,7 @@ AC_TYPE_SSIZE_T
 AC_DEFINE([DSFMT_MEXP], [521], [DSFMT parameters])
 
 # Checks for library functions.
-AC_CHECK_FUNCS([clock_gettime gettimeofday fgetln getline madvise poll posix_memalign pselect pthread_setaffinity_np regcomp select sendmmsg setgroups])
+AC_CHECK_FUNCS([clock_gettime gettimeofday fgetln getline madvise poll posix_memalign pselect pthread_setaffinity_np regcomp select setgroups])
 
 # Check for cpu_set_t/cpuset_t compatibility
 AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]], [[cpu_set_t set; CPU_ZERO(&set);]])],

m4/ax_recvmmsg.m4

-dnl @synopsis AX_MSG_WAITFORONE
-dnl @summary Test if the libc/kernel have working recvmmsg MSG_WAITFORONE implementation
-dnl @category Misc
-dnl
-dnl We need recvmmsg to support MSG_WAITFORONE.  RHEL 6 (and derivates)
-dnl are know for broken implementation
-dnl
-dnl @version 2013-03-12
-dnl @license GPL
-dnl @author Ondřej Surý <ondrej@sury.org> and Marek Vavruša <marek@vavrusa.com>
-
-AC_DEFUN([AX_MSG_WAITFORONE],
-[
-  AC_REQUIRE([AC_PROG_CC])
-
-  AC_LANG_PUSH([C])
-
-  AC_CACHE_CHECK([for recv_mmsg support], [ax_cv_have_msg_waitforone],
-  [
-    AC_RUN_IFELSE(
-    [
-      AC_LANG_PROGRAM(
-      [[
-#ifndef _GNU_SOURCE
-  #define _GNU_SOURCE
-#endif
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <netinet/ip.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <signal.h>
-
-volatile int _intr = 0;
-void sighandle(int s) {
-     _intr = 1;
-}
-      ]],[[
-#ifndef MSG_WAITFORONE
-  return 3; /* Not supported. */
-#else
-  int port = 35353;
-  int fd = socket(AF_INET, SOCK_DGRAM, 0);
-  if (fd < 0) return 1;
-  struct mmsghdr msgs[2];
-  struct iovec iovecs[2];
-  char bufs[2][64];
-  unsigned i = 0;
-  memset(msgs, 0, sizeof(msgs));
-  for (i = 0; i < 2; i++) {
-    iovecs[i].iov_base = bufs[i];
-    iovecs[i].iov_len = 64;
-    msgs[i].msg_hdr.msg_iov = &iovecs[i];
-    msgs[i].msg_hdr.msg_iovlen = 1;
-  }
-
-  struct sockaddr_in sa; /* Bind to socket. */
-  sa.sin_family = AF_INET;
-  sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-  sa.sin_port = htons(port); /* Find free port. */
-  while (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
-  if (errno == EADDRINUSE) sa.sin_port = ++port;
-  else break;
-  }
-
-  int cfd = socket(AF_INET, SOCK_DGRAM, 0); /* Send datagram. */
-  char pkt[32] = { '\xdf' };
-  sendto(cfd, pkt, sizeof(pkt), 0, (struct sockaddr*)&sa, sizeof(sa));
-
-  /* Broken implementation doesn't respect recvmmsg timeout. */
-  struct sigaction aset;
-  memset(&aset, 0, sizeof(struct sigaction));
-  aset.sa_handler = sighandle;
-  sigaction(SIGALRM, &aset, NULL);
-  alarm(1);
-
-  int ret = recvmmsg(fd, msgs, 2, MSG_WAITFORONE, NULL);
-  close(cfd);
-  close(fd);
-  if (ret < 0) { /* Completely failed. */
-    return 2;
-  }
-
-  return _intr; /* OK if not interrupted. */
-#endif
-    ]])],
-  [ax_cv_have_msg_waitforone=yes],
-  [ax_cv_have_msg_waitforone=no],
-  [ax_cv_have_msg_waitforone=no])])
-
-  AC_LANG_POP([C])
-])

src/knot/server/udp-handler.c

@@ -340,7 +340,7 @@ static int udp_recvfrom_send(void *d)
 	return 0;
 }
 
-#ifdef ENABLE_RECVMMSG
+#ifdef HAVE_RECVMMSG
 
 /*! \brief Pointer to selected UDP send implementation. */
 static int (*_send_mmsg)(int, sockaddr_t *, struct mmsghdr *, size_t) = 0;
@@ -370,7 +370,7 @@ static inline int sendmmsg(int fd, struct mmsghdr *mmsg, unsigned vlen,
 {
 	return syscall(SYS_sendmmsg, fd, mmsg, vlen, flags, NULL);
 }
-#endif
+#endif /* HAVE_SENDMMSG */
 
 /*!
  * \brief Send multiple packets.
@@ -382,7 +382,7 @@ int udp_sendmmsg(int sock, sockaddr_t *_, struct mmsghdr *msgs, size_t count)
 	UNUSED(_);
 	return sendmmsg(sock, msgs, count, 0);
 }
-#endif
+#endif /* ENABLE_SENDMMSG */
 
 /* UDP recvmmsg() request struct. */
 struct udp_recvmmsg {
@@ -483,7 +483,7 @@ static int udp_recvmmsg_send(void *d)
 	}
 	return rc;
 }
-#endif
+#endif /* HAVE_RECVMMSG */
 
 /*! \brief Initialize UDP master routine on run-time. */
 void __attribute__ ((constructor)) udp_master_init()
@@ -496,7 +496,7 @@ void __attribute__ ((constructor)) udp_master_init()
 	_udp_handle = udp_recvfrom_handle;
 
 	/* Optimized functions. */
-#ifdef ENABLE_RECVMMSG
+#ifdef HAVE_RECVMMSG
 	/* Check for recvmmsg() support. */
 	if (dlsym(RTLD_DEFAULT, "recvmmsg") != 0) {
 		recvmmsg(0, NULL, 0, 0, 0);
@@ -517,7 +517,7 @@ void __attribute__ ((constructor)) udp_master_init()
 		_send_mmsg = udp_sendmmsg;
 	}
 #endif /* ENABLE_SENDMMSG */
-#endif /* ENABLE_RECVMMSG */
+#endif /* HAVE_RECVMMSG */
 }
 
 int udp_reader(iohandler_t *h, dthread_t *thread)