acinclude.m4

   1 # -*- autoconf -*-
   2
   3 # Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019 Nicira, Inc.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at:
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 dnl OVS_ENABLE_WERROR
  18 AC_DEFUN([OVS_ENABLE_WERROR],
  19   [AC_ARG_ENABLE(
  20      [Werror],
  21      [AC_HELP_STRING([--enable-Werror], [Add -Werror to CFLAGS])],
  22      [], [enable_Werror=no])
  23    AC_CONFIG_COMMANDS_PRE(
  24      [if test "X$enable_Werror" = Xyes; then
  25         OVS_CFLAGS="$OVS_CFLAGS -Werror"
  26       fi])
  27
  28    # Unless --enable-Werror is specified, report but do not fail the build
  29    # for errors reported by flake8.
  30    if test "X$enable_Werror" = Xyes; then
  31      FLAKE8_WERROR=
  32    else
  33      FLAKE8_WERROR=-
  34    fi
  35    AC_SUBST([FLAKE8_WERROR])
  36
  37    # If --enable-Werror is specified, fail the build on sparse warnings.
  38    if test "X$enable_Werror" = Xyes; then
  39      SPARSE_WERROR=-Wsparse-error
  40    else
  41      SPARSE_WERROR=
  42    fi
  43    AC_SUBST([SPARSE_WERROR])])
  44
  45 dnl OVS_CHECK_LINUX
  46 dnl
  47 dnl Configure linux kernel source tree
  48 AC_DEFUN([OVS_CHECK_LINUX], [
  49   AC_ARG_WITH([linux],
  50               [AC_HELP_STRING([--with-linux=/path/to/linux],
  51                               [Specify the Linux kernel build directory])])
  52   AC_ARG_WITH([linux-source],
  53               [AC_HELP_STRING([--with-linux-source=/path/to/linux-source],
  54                               [Specify the Linux kernel source directory
  55                                (usually figured out automatically from build
  56                                directory)])])
  57
  58   # Deprecated equivalents to --with-linux, --with-linux-source.
  59   AC_ARG_WITH([l26])
  60   AC_ARG_WITH([l26-source])
  61
  62   if test X"$with_linux" != X; then
  63     KBUILD=$with_linux
  64   elif test X"$with_l26" != X; then
  65     KBUILD=$with_l26
  66     AC_MSG_WARN([--with-l26 is deprecated, please use --with-linux instead])
  67   else
  68     KBUILD=
  69   fi
  70
  71   if test X"$KBUILD" != X; then
  72     if test X"$with_linux_source" != X; then
  73       KSRC=$with_linux_source
  74     elif test X"$with_l26_source" != X; then
  75       KSRC=$with_l26_source
  76       AC_MSG_WARN([--with-l26-source is deprecated, please use --with-linux-source instead])
  77     else
  78       KSRC=
  79     fi
  80   elif test X"$with_linux_source" != X || test X"$with_l26_source" != X; then
  81     AC_MSG_ERROR([Linux source directory may not be specified without Linux build directory])
  82   fi
  83
  84   if test -n "$KBUILD"; then
  85     KBUILD=`eval echo "$KBUILD"`
  86     case $KBUILD in
  87         /*) ;;
  88         *) KBUILD=`pwd`/$KBUILD ;;
  89     esac
  90
  91     # The build directory is what the user provided.
  92     # Make sure that it exists.
  93     AC_MSG_CHECKING([for Linux build directory])
  94     if test -d "$KBUILD"; then
  95         AC_MSG_RESULT([$KBUILD])
  96         AC_SUBST(KBUILD)
  97     else
  98         AC_MSG_RESULT([no])
  99         AC_ERROR([source dir $KBUILD doesn't exist])
 100     fi
 101
 102     # Debian breaks kernel headers into "source" header and "build" headers.
 103     # We want the source headers, but $KBUILD gives us the "build" headers.
 104     # Use heuristics to find the source headers.
 105     AC_MSG_CHECKING([for Linux source directory])
 106     if test -n "$KSRC"; then
 107       KSRC=`eval echo "$KSRC"`
 108       case $KSRC in
 109           /*) ;;
 110           *) KSRC=`pwd`/$KSRC ;;
 111       esac
 112       if test ! -e $KSRC/include/linux/kernel.h; then
 113         AC_MSG_ERROR([$KSRC is not a kernel source directory])
 114       fi
 115     else
 116       KSRC=$KBUILD
 117       if test ! -e $KSRC/include/linux/kernel.h; then
 118         # Debian kernel build Makefiles tend to include a line of the form:
 119         # MAKEARGS := -C /usr/src/linux-headers-3.2.0-1-common O=/usr/src/linux-headers-3.2.0-1-486
 120         # First try to extract the source directory from this line.
 121         KSRC=`sed -n 's/.*-C \([[^ ]]*\).*/\1/p' "$KBUILD"/Makefile`
 122         if test ! -e "$KSRC"/include/linux/kernel.h; then
 123           # Didn't work.  Fall back to name-based heuristics that used to work.
 124           case `echo "$KBUILD" | sed 's,/*$,,'` in # (
 125             */build)
 126               KSRC=`echo "$KBUILD" | sed 's,/build/*$,/source,'`
 127               ;; # (
 128             *)
 129               KSRC=`(cd $KBUILD && pwd -P) | sed 's,-[[^-]]*$,-common,'`
 130               ;;
 131           esac
 132         fi
 133       fi
 134       if test ! -e "$KSRC"/include/linux/kernel.h; then
 135         AC_MSG_ERROR([cannot find source directory (please use --with-linux-source)])
 136       fi
 137     fi
 138     AC_MSG_RESULT([$KSRC])
 139
 140     AC_MSG_CHECKING([for kernel version])
 141     version=`sed -n 's/^VERSION = //p' "$KSRC/Makefile"`
 142     patchlevel=`sed -n 's/^PATCHLEVEL = //p' "$KSRC/Makefile"`
 143     sublevel=`sed -n 's/^SUBLEVEL = //p' "$KSRC/Makefile"`
 144     if test X"$version" = X || test X"$patchlevel" = X; then
 145        AC_ERROR([cannot determine kernel version])
 146     elif test X"$sublevel" = X; then
 147        kversion=$version.$patchlevel
 148     else
 149        kversion=$version.$patchlevel.$sublevel
 150     fi
 151     AC_MSG_RESULT([$kversion])
 152
 153     if test "$version" -ge 5; then
 154        if test "$version" = 5 && test "$patchlevel" -le 0; then
 155           : # Linux 5.x
 156        else
 157           AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version newer than 5.0.x is not supported (please refer to the FAQ for advice)])
 158        fi
 159     elif test "$version" = 4; then
 160        : # Linux 4.x
 161     elif test "$version" = 3 && test "$patchlevel" -ge 10; then
 162        : # Linux 3.x
 163     else
 164        AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version 3.10 or later is required])
 165     fi
 166     if (test ! -e "$KBUILD"/include/linux/version.h && \
 167         test ! -e "$KBUILD"/include/generated/uapi/linux/version.h)|| \
 168        (test ! -e "$KBUILD"/include/linux/autoconf.h && \
 169         test ! -e "$KBUILD"/include/generated/autoconf.h); then
 170         AC_MSG_ERROR([Linux kernel source in $KBUILD is not configured])
 171     fi
 172     OVS_CHECK_LINUX_COMPAT
 173   fi
 174   AM_CONDITIONAL(LINUX_ENABLED, test -n "$KBUILD")
 175 ])
 176
 177 dnl OVS_CHECK_LINUX_TC
 178 dnl
 179 dnl Configure Linux tc compat.
 180 AC_DEFUN([OVS_CHECK_LINUX_TC], [
 181   AC_COMPILE_IFELSE([
 182     AC_LANG_PROGRAM([#include <linux/pkt_cls.h>], [
 183         int x = TCA_FLOWER_KEY_ENC_IP_TTL_MASK;
 184     ])],
 185     [AC_DEFINE([HAVE_TCA_FLOWER_KEY_ENC_IP_TTL_MASK], [1],
 186                [Define to 1 if TCA_FLOWER_KEY_ENC_IP_TTL_MASK is available.])])
 187
 188   AC_COMPILE_IFELSE([
 189     AC_LANG_PROGRAM([#include <linux/tc_act/tc_vlan.h>], [
 190         int x = TCA_VLAN_PUSH_VLAN_PRIORITY;
 191     ])],
 192     [AC_DEFINE([HAVE_TCA_VLAN_PUSH_VLAN_PRIORITY], [1],
 193                [Define to 1 if TCA_VLAN_PUSH_VLAN_PRIORITY is available.])])
 194
 195   AC_COMPILE_IFELSE([
 196     AC_LANG_PROGRAM([#include <linux/tc_act/tc_tunnel_key.h>], [
 197         int x = TCA_TUNNEL_KEY_ENC_TTL;
 198     ])],
 199     [AC_DEFINE([HAVE_TCA_TUNNEL_KEY_ENC_TTL], [1],
 200                [Define to 1 if TCA_TUNNEL_KEY_ENC_TTL is available.])])
 201
 202   AC_COMPILE_IFELSE([
 203     AC_LANG_PROGRAM([#include <linux/tc_act/tc_pedit.h>], [
 204         int x = TCA_PEDIT_KEY_EX_HDR_TYPE_UDP;
 205     ])],
 206     [AC_DEFINE([HAVE_TCA_PEDIT_KEY_EX_HDR_TYPE_UDP], [1],
 207                [Define to 1 if TCA_PEDIT_KEY_EX_HDR_TYPE_UDP is available.])])
 208
 209   AC_COMPILE_IFELSE([
 210     AC_LANG_PROGRAM([#include <linux/tc_act/tc_skbedit.h>], [
 211         int x = TCA_SKBEDIT_FLAGS;
 212     ])],
 213     [AC_DEFINE([HAVE_TCA_SKBEDIT_FLAGS], [1],
 214                [Define to 1 if TCA_SKBEDIT_FLAGS is available.])])
 215 ])
 216
 217 dnl OVS_CHECK_LINUX_SCTP_CT
 218 dnl
 219 dnl Checks for kernels which need additional SCTP state
 220 AC_DEFUN([OVS_CHECK_LINUX_SCTP_CT], [
 221   AC_COMPILE_IFELSE([
 222     AC_LANG_PROGRAM([#include <linux/netfilter/nfnetlink.h>
 223 #include <linux/netfilter/nfnetlink_conntrack.h>
 224 #include <linux/netfilter/nf_conntrack_common.h>
 225 #include <linux/netfilter/nf_conntrack_sctp.h>], [
 226         int x = SCTP_CONNTRACK_HEARTBEAT_SENT;
 227     ])],
 228     [AC_DEFINE([HAVE_SCTP_CONNTRACK_HEARTBEATS], [1],
 229                [Define to 1 if SCTP_CONNTRACK_HEARTBEAT_SENT is available.])])
 230 ])
 231
 232 dnl OVS_FIND_DEPENDENCY(FUNCTION, SEARCH_LIBS, NAME_TO_PRINT)
 233 dnl
 234 dnl Check for a function in a library list.
 235 AC_DEFUN([OVS_FIND_DEPENDENCY], [
 236   AC_SEARCH_LIBS([$1], [$2], [], [
 237     AC_MSG_ERROR([unable to find $3, install the dependency package])
 238   ])
 239 ])
 240
 241 dnl OVS_CHECK_LINUX_AF_XDP
 242 dnl
 243 dnl Check both Linux kernel AF_XDP and libbpf support
 244 AC_DEFUN([OVS_CHECK_LINUX_AF_XDP], [
 245   AC_ARG_ENABLE([afxdp],
 246                 [AC_HELP_STRING([--enable-afxdp], [Enable AF-XDP support])],
 247                 [], [enable_afxdp=no])
 248   AC_MSG_CHECKING([whether AF_XDP is enabled])
 249   if test "$enable_afxdp" != yes; then
 250     AC_MSG_RESULT([no])
 251     AF_XDP_ENABLE=false
 252   else
 253     AC_MSG_RESULT([yes])
 254     AF_XDP_ENABLE=true
 255
 256     AC_CHECK_HEADER([bpf/libbpf.h], [],
 257       [AC_MSG_ERROR([unable to find bpf/libbpf.h for AF_XDP support])])
 258
 259     AC_CHECK_HEADER([linux/if_xdp.h], [],
 260       [AC_MSG_ERROR([unable to find linux/if_xdp.h for AF_XDP support])])
 261
 262     AC_CHECK_HEADER([bpf/xsk.h], [],
 263       [AC_MSG_ERROR([unable to find bpf/xsk.h for AF_XDP support])])
 264
 265     AC_CHECK_FUNCS([pthread_spin_lock], [],
 266       [AC_MSG_ERROR([unable to find pthread_spin_lock for AF_XDP support])])
 267
 268     AC_DEFINE([HAVE_AF_XDP], [1],
 269               [Define to 1 if AF_XDP support is available and enabled.])
 270     LIBBPF_LDADD=" -lbpf -lelf"
 271     AC_SUBST([LIBBPF_LDADD])
 272   fi
 273   AM_CONDITIONAL([HAVE_AF_XDP], test "$AF_XDP_ENABLE" = true)
 274 ])
 275
 276 dnl OVS_CHECK_DPDK
 277 dnl
 278 dnl Configure DPDK source tree
 279 AC_DEFUN([OVS_CHECK_DPDK], [
 280   AC_ARG_WITH([dpdk],
 281               [AC_HELP_STRING([--with-dpdk=/path/to/dpdk],
 282                               [Specify the DPDK build directory])],
 283               [have_dpdk=true])
 284
 285   AC_MSG_CHECKING([whether dpdk datapath is enabled])
 286   if test "$have_dpdk" != true || test "$with_dpdk" = no; then
 287     AC_MSG_RESULT([no])
 288     DPDKLIB_FOUND=false
 289   else
 290     AC_MSG_RESULT([yes])
 291     case "$with_dpdk" in
 292       yes)
 293         DPDK_AUTO_DISCOVER="true"
 294         PKG_CHECK_MODULES_STATIC([DPDK], [libdpdk], [
 295             DPDK_INCLUDE="$DPDK_CFLAGS"
 296             DPDK_LIB="$DPDK_LIBS"], [
 297             DPDK_INCLUDE="-I/usr/local/include/dpdk -I/usr/include/dpdk"
 298             DPDK_LIB="-ldpdk"])
 299         ;;
 300       *)
 301         DPDK_AUTO_DISCOVER="false"
 302         DPDK_INCLUDE_PATH="$with_dpdk/include"
 303         # If 'with_dpdk' is passed install directory, point to headers
 304         # installed in $DESTDIR/$prefix/include/dpdk
 305         if test -e "$DPDK_INCLUDE_PATH/rte_config.h"; then
 306            DPDK_INCLUDE="-I$DPDK_INCLUDE_PATH"
 307         elif test -e "$DPDK_INCLUDE_PATH/dpdk/rte_config.h"; then
 308            DPDK_INCLUDE="-I$DPDK_INCLUDE_PATH/dpdk"
 309         fi
 310         DPDK_LIB_DIR="$with_dpdk/lib"
 311         DPDK_LIB="-ldpdk"
 312         ;;
 313     esac
 314
 315     ovs_save_CFLAGS="$CFLAGS"
 316     ovs_save_LDFLAGS="$LDFLAGS"
 317     CFLAGS="$CFLAGS $DPDK_INCLUDE"
 318     if test "$DPDK_AUTO_DISCOVER" = "false"; then
 319       LDFLAGS="$LDFLAGS -L${DPDK_LIB_DIR}"
 320     fi
 321
 322     AC_CHECK_HEADERS([rte_config.h], [], [
 323       AC_MSG_ERROR([unable to find rte_config.h in $with_dpdk])
 324     ], [AC_INCLUDES_DEFAULT])
 325
 326     AC_CHECK_DECLS([RTE_LIBRTE_VHOST_NUMA, RTE_EAL_NUMA_AWARE_HUGEPAGES], [
 327       OVS_FIND_DEPENDENCY([get_mempolicy], [numa], [libnuma])
 328     ], [], [[#include <rte_config.h>]])
 329
 330     AC_CHECK_DECL([RTE_LIBRTE_VHOST_NUMA], [
 331       AC_DEFINE([VHOST_NUMA], [1], [NUMA Aware vHost support detected in DPDK.])
 332     ], [], [[#include <rte_config.h>]])
 333
 334     AC_CHECK_DECL([RTE_LIBRTE_PMD_PCAP], [
 335       OVS_FIND_DEPENDENCY([pcap_dump], [pcap], [libpcap])
 336       AC_CHECK_DECL([RTE_LIBRTE_PDUMP], [
 337         AC_DEFINE([DPDK_PDUMP], [1], [DPDK pdump enabled in OVS.])
 338       ], [], [[#include <rte_config.h>]])
 339     ], [], [[#include <rte_config.h>]])
 340
 341     AC_CHECK_DECL([RTE_LIBRTE_MLX5_PMD], [dnl found
 342       OVS_FIND_DEPENDENCY([mnl_attr_put], [mnl], [libmnl])
 343       AC_CHECK_DECL([RTE_LIBRTE_MLX5_DLOPEN_DEPS], [], [dnl not found
 344         OVS_FIND_DEPENDENCY([mlx5dv_create_wq], [mlx5], [libmlx5])
 345         OVS_FIND_DEPENDENCY([verbs_init_cq], [ibverbs], [libibverbs])
 346       ], [[#include <rte_config.h>]])
 347     ], [], [[#include <rte_config.h>]])
 348
 349     AC_CHECK_DECL([RTE_LIBRTE_MLX4_PMD], [dnl found
 350       AC_CHECK_DECL([RTE_LIBRTE_MLX4_DLOPEN_DEPS], [], [dnl not found
 351         OVS_FIND_DEPENDENCY([mlx4dv_init_obj], [mlx4], [libmlx4])
 352         OVS_FIND_DEPENDENCY([verbs_init_cq], [ibverbs], [libibverbs])
 353       ], [[#include <rte_config.h>]])
 354     ], [], [[#include <rte_config.h>]])
 355
 356     # DPDK uses dlopen to load plugins.
 357     OVS_FIND_DEPENDENCY([dlopen], [dl], [libdl])
 358
 359     AC_MSG_CHECKING([whether linking with dpdk works])
 360     LIBS="$DPDK_LIB $LIBS"
 361     AC_LINK_IFELSE(
 362       [AC_LANG_PROGRAM([#include <rte_config.h>
 363                         #include <rte_eal.h>],
 364                        [int rte_argc; char ** rte_argv;
 365                         rte_eal_init(rte_argc, rte_argv);])],
 366       [AC_MSG_RESULT([yes])
 367        DPDKLIB_FOUND=true],
 368       [AC_MSG_RESULT([no])
 369        if test "$DPDK_AUTO_DISCOVER" = "true"; then
 370          AC_MSG_ERROR(m4_normalize([
 371             Could not find DPDK library in default search path, Use --with-dpdk
 372             to specify the DPDK library installed in non-standard location]))
 373        else
 374          AC_MSG_ERROR([Could not find DPDK libraries in $DPDK_LIB_DIR])
 375        fi
 376       ])
 377
 378     CFLAGS="$ovs_save_CFLAGS"
 379     LDFLAGS="$ovs_save_LDFLAGS"
 380     if test "$DPDK_AUTO_DISCOVER" = "false"; then
 381       OVS_LDFLAGS="$OVS_LDFLAGS -L$DPDK_LIB_DIR"
 382     fi
 383     OVS_CFLAGS="$OVS_CFLAGS $DPDK_INCLUDE"
 384     OVS_ENABLE_OPTION([-mssse3])
 385
 386     # DPDK pmd drivers are not linked unless --whole-archive is used.
 387     #
 388     # This happens because the rest of the DPDK code doesn't use any symbol in
 389     # the pmd driver objects, and the drivers register themselves using an
 390     # __attribute__((constructor)) function.
 391     #
 392     # These options are specified inside a single -Wl directive to prevent
 393     # autotools from reordering them.
 394     #
 395     # OTOH newer versions of dpdk pkg-config (generated with Meson)
 396     # will already have flagged just the right set of libs with
 397     # --whole-archive - in those cases do not wrap it once more.
 398     case "$DPDK_LIB" in
 399       *whole-archive*) DPDK_vswitchd_LDFLAGS=$DPDK_LIB;;
 400       *) DPDK_vswitchd_LDFLAGS=-Wl,--whole-archive,$DPDK_LIB,--no-whole-archive
 401     esac
 402     AC_SUBST([DPDK_vswitchd_LDFLAGS])
 403     AC_DEFINE([DPDK_NETDEV], [1], [System uses the DPDK module.])
 404   fi
 405
 406   AM_CONDITIONAL([DPDK_NETDEV], test "$DPDKLIB_FOUND" = true)
 407 ])
 408
 409 dnl OVS_GREP_IFELSE(FILE, REGEX, [IF-MATCH], [IF-NO-MATCH])
 410 dnl
 411 dnl Greps FILE for REGEX.  If it matches, runs IF-MATCH, otherwise IF-NO-MATCH.
 412 dnl If IF-MATCH is empty then it defines to OVS_DEFINE(HAVE_<REGEX>), with
 413 dnl <REGEX> translated to uppercase.
 414 AC_DEFUN([OVS_GREP_IFELSE], [
 415   AC_MSG_CHECKING([whether $2 matches in $1])
 416   if test -f $1; then
 417     grep '$2' $1 >/dev/null 2>&1
 418     status=$?
 419     case $status in
 420       0)
 421         AC_MSG_RESULT([yes])
 422         m4_if([$3], [], [OVS_DEFINE([HAVE_]m4_toupper([$2]))], [$3])
 423         ;;
 424       1)
 425         AC_MSG_RESULT([no])
 426         $4
 427         ;;
 428       *)
 429         AC_MSG_ERROR([grep exited with status $status])
 430         ;;
 431     esac
 432   else
 433     AC_MSG_RESULT([file not found])
 434     $4
 435   fi
 436 ])
 437
 438 dnl OVS_FIND_FIELD_IFELSE(FILE, STRUCTURE, REGEX, [IF-MATCH], [IF-NO-MATCH])
 439 dnl
 440 dnl Looks for STRUCTURE in FILE. If it is found, greps for REGEX within the
 441 dnl structure definition. If this is successful, runs IF-MATCH, otherwise
 442 dnl IF_NO_MATCH. If IF-MATCH is empty then it defines to
 443 dnl OVS_DEFINE(HAVE_<STRUCTURE>_WITH_<REGEX>), with <STRUCTURE> and <REGEX>
 444 dnl translated to uppercase.
 445 AC_DEFUN([OVS_FIND_FIELD_IFELSE], [
 446   AC_MSG_CHECKING([whether $2 has member $3 in $1])
 447   if test -f $1; then
 448     awk '/$2.{/,/^}/' $1 2>/dev/null | grep '$3' >/dev/null
 449     status=$?
 450     case $status in
 451       0)
 452         AC_MSG_RESULT([yes])
 453         m4_if([$4], [], [OVS_DEFINE([HAVE_]m4_toupper([$2])[_WITH_]m4_toupper([$3]))], [$4])
 454         ;;
 455       1)
 456         AC_MSG_RESULT([no])
 457         $5
 458         ;;
 459       *)
 460         AC_MSG_ERROR([grep exited with status $status])
 461         ;;
 462     esac
 463   else
 464     AC_MSG_RESULT([file not found])
 465     $5
 466   fi
 467 ])
 468
 469 dnl OVS_FIND_PARAM_IFELSE(FILE, FUNCTION, REGEX, [IF-MATCH], [IF-NO-MATCH])
 470 dnl
 471 dnl Looks for FUNCTION in FILE. If it is found, greps for REGEX within
 472 dnl the function signature starting from the line matching FUNCTION
 473 dnl and ending with the line containing the closing parenthesis.  If
 474 dnl this is successful, runs IF-MATCH, otherwise IF_NO_MATCH.  If
 475 dnl IF-MATCH is empty then it defines to
 476 dnl OVS_DEFINE(HAVE_<FUNCTION>_WITH_<REGEX>), with <FUNCTION> and
 477 dnl <REGEX> translated to uppercase.
 478 AC_DEFUN([OVS_FIND_PARAM_IFELSE], [
 479   AC_MSG_CHECKING([whether $2 has parameter $3 in $1])
 480   if test -f $1; then
 481     awk '/$2[[ \t\n]]*\(/,/\)/' $1 2>/dev/null | grep '$3' >/dev/null
 482     status=$?
 483     case $status in
 484       0)
 485         AC_MSG_RESULT([yes])
 486         m4_if([$4], [], [OVS_DEFINE([HAVE_]m4_toupper([$2])[_WITH_]m4_toupper([$3]))], [$4])
 487         ;;
 488       1)
 489         AC_MSG_RESULT([no])
 490         $5
 491         ;;
 492       *)
 493         AC_MSG_ERROR([grep exited with status $status])
 494         ;;
 495     esac
 496   else
 497     AC_MSG_RESULT([file not found])
 498     $5
 499   fi
 500 ])
 501
 502 dnl OVS_DEFINE(NAME)
 503 dnl
 504 dnl Defines NAME to 1 in kcompat.h.
 505 AC_DEFUN([OVS_DEFINE], [
 506   echo '#define $1 1' >> datapath/linux/kcompat.h.new
 507 ])
 508
 509 dnl OVS_CHECK_LINUX_COMPAT
 510 dnl
 511 dnl Runs various Autoconf checks on the Linux kernel source in
 512 dnl the directory in $KBUILD.
 513 AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
 514   rm -f datapath/linux/kcompat.h.new
 515   mkdir -p datapath/linux
 516   : > datapath/linux/kcompat.h.new
 517
 518   echo '#include <linux/version.h>
 519 #ifndef RHEL_RELEASE_CODE
 520 #define RHEL_RELEASE_CODE 0
 521 #define RHEL_RELEASE_VERSION(a, b) 0
 522 #endif' >> datapath/linux/kcompat.h.new
 523
 524   OVS_GREP_IFELSE([$KSRC/arch/x86/include/asm/checksum_32.h], [src_err,],
 525                   [OVS_DEFINE([HAVE_CSUM_COPY_DBG])])
 526
 527   OVS_GREP_IFELSE([$KSRC/include/net/ip6_fib.h], [rt6_get_cookie],
 528                   [OVS_DEFINE([HAVE_RT6_GET_COOKIE])])
 529
 530   OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_dst_lookup.*net],
 531                   [OVS_DEFINE([HAVE_IPV6_DST_LOOKUP_NET])])
 532   OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_stub])
 533
 534   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [ERR_CAST])
 535   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [IS_ERR_OR_NULL])
 536   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [PTR_ERR_OR_ZERO])
 537
 538   OVS_GREP_IFELSE([$KSRC/include/linux/jump_label.h], [static_branch_unlikely(],
 539                   [OVS_DEFINE([HAVE_UPSTREAM_STATIC_KEY])])
 540   OVS_GREP_IFELSE([$KSRC/include/linux/jump_label.h], [DEFINE_STATIC_KEY_FALSE],
 541                   [OVS_DEFINE([HAVE_DEFINE_STATIC_KEY])])
 542
 543   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [eth_hw_addr_random])
 544   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [ether_addr_copy])
 545
 546   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [IFLA_GENEVE_TOS])
 547   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [rtnl_link_stats64])
 548   OVS_GREP_IFELSE([$KSRC/include/linux/if_link.h], [rtnl_link_stats64])
 549   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_set_encap_proto])
 550   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_hwaccel_push_inside])
 551   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [__vlan_hwaccel_clear_tag])
 552
 553   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [ipv4_is_multicast])
 554   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [proto_ports_offset])
 555   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*dst_entry],
 556                   [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_DST_ENTRY])])
 557   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*net],
 558                   [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_NET])])
 559
 560   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [inet_get_local_port_range.*net],
 561                   [OVS_DEFINE([HAVE_INET_GET_LOCAL_PORT_RANGE_USING_NET])])
 562   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_defrag.*net],
 563                   [OVS_DEFINE([HAVE_IP_DEFRAG_TAKES_NET])])
 564   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/ip.h],
 565                         [ip_do_fragment], [net],
 566                         [OVS_DEFINE([HAVE_IP_DO_FRAGMENT_TAKES_NET])])
 567   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/ip.h],
 568                         [ip_local_out], [net],
 569                         [OVS_DEFINE([HAVE_IP_LOCAL_OUT_TAKES_NET])])
 570
 571   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_skb_dst_mtu])
 572
 573   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [IPSKB_FRAG_PMTU],
 574                   [OVS_DEFINE([HAVE_CORRECT_MRU_HANDLING])])
 575   OVS_GREP_IFELSE([$KSRC/include/net/ip_tunnels.h], [__ip_tunnel_change_mtu])
 576   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [hashfn.*const],
 577                   [OVS_DEFINE([HAVE_INET_FRAGS_CONST])])
 578   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [last_in],
 579                   [OVS_DEFINE([HAVE_INET_FRAGS_LAST_IN])])
 580   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_evicting])
 581   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_evictor])
 582   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
 583                         [frags_work])
 584   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
 585                         [rwlock])
 586   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_queue],
 587                         [list_evictor])
 588   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frag_lru_move])
 589   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/inet_frag.h],
 590                         [sub_frag_mem_limit], [struct.netns_frags],
 591                         [OVS_DEFINE([HAVE_SUB_FRAG_MEM_LIMIT_ARG_STRUCT_NETNS_FRAGS])])
 592   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [void.*inet_frags_init],
 593                   [OVS_DEFINE([HAVE_VOID_INET_FRAGS_INIT])])
 594   OVS_GREP_IFELSE([$KSRC/include/net/inetpeer.h], [vif],
 595                   [OVS_DEFINE([HAVE_INETPEER_VIF_SUPPORT])])
 596
 597   dnl Check for dst_cache and ipv6 lable to use backported tunnel infrastructure.
 598   dnl OVS does not really need ipv6 label field, but its presence signifies that
 599   dnl the stack has all required ipv6 support.
 600   dnl OVS also does not need dst_cache But this dependency allows us to write
 601   dnl much cleaner code.
 602
 603   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/ip_tunnels.h], [ip_tunnel_key],
 604                         [label],
 605                         [OVS_GREP_IFELSE([$KSRC/include/net/ip_tunnels.h],
 606                                          [iptunnel_pull_offloads],
 607                         [OVS_GREP_IFELSE([$KSRC/include/net/dst_cache.h], [dst_cache],
 608                         [OVS_GREP_IFELSE([$KSRC/include/net/erspan.h], [erspan_md2],
 609                                          [OVS_DEFINE([USE_UPSTREAM_TUNNEL])])])])])
 610
 611   OVS_GREP_IFELSE([$KSRC/include/net/dst_cache.h], [dst_cache],
 612                   [OVS_DEFINE([USE_BUILTIN_DST_CACHE])])
 613   OVS_GREP_IFELSE([$KSRC/include/net/mpls.h], [mpls_hdr],
 614                   [OVS_DEFINE([MPLS_HEADER_IS_L3])])
 615   OVS_GREP_IFELSE([$KSRC/include/linux/net.h], [sock_create_kern.*net],
 616                   [OVS_DEFINE([HAVE_SOCK_CREATE_KERN_NET])])
 617   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_fill_metadata_dst])
 618   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_disable_lro])
 619   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_stats])
 620   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_by_index_rcu])
 621   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_recursion_level])
 622   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [__skb_gso_segment])
 623   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [skb_gso_error_unwind])
 624   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [can_checksum_protocol])
 625   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_get_iflink])
 626   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_features_check],
 627                   [OVS_DEFINE([USE_UPSTREAM_TUNNEL_GSO])])
 628   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_add_vxlan_port])
 629   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_add_geneve_port])
 630   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_udp_tunnel_add])
 631   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_features_t])
 632   dnl Ubuntu kernel 3.13 has defined this struct but not used for netdev->tstats.
 633   dnl So check type of tstats.
 634   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [pcpu_sw_netstats.*tstats],
 635                   [OVS_DEFINE([HAVE_PCPU_SW_NETSTATS])])
 636   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netif_needs_gso.*net_device],
 637                   [OVS_DEFINE([HAVE_NETIF_NEEDS_GSO_NETDEV])])
 638   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [skb_csum_hwoffload_help])
 639   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload])
 640   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload.*uoff],
 641                   [OVS_DEFINE([HAVE_UDP_OFFLOAD_ARG_UOFF])])
 642   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [gro_remcsum])
 643   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [IFF_PHONY_HEADROOM])
 644   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device_ops],
 645                         [extended])
 646   OVS_FIND_PARAM_IFELSE([$KSRC/include/linux/netdevice.h],
 647                         [netdev_master_upper_dev_link], [upper_priv],
 648                         [OVS_DEFINE([HAVE_NETDEV_MASTER_UPPER_DEV_LINK_PRIV])])
 649   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h],
 650                   [netdev_master_upper_dev_link_rh],
 651                   [OVS_DEFINE([HAVE_NETDEV_MASTER_UPPER_DEV_LINK_RH])])
 652
 653   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device],
 654                         [max_mtu])
 655   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device_ops_extended],
 656                         [ndo_change_mtu], [OVS_DEFINE([HAVE_RHEL7_MAX_MTU])])
 657   OVS_FIND_PARAM_IFELSE([$KSRC/include/linux/netdevice.h],
 658                         [dev_change_flags], [extack],
 659                         [OVS_DEFINE([HAVE_DEV_CHANGE_FLAGS_TAKES_EXTACK])])
 660
 661   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_state])
 662   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_state],
 663                         [struct net ], [OVS_DEFINE([HAVE_NF_HOOK_STATE_NET])])
 664   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_register_net_hook])
 665   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hookfn.*nf_hook_ops],
 666                   [OVS_DEFINE([HAVE_NF_HOOKFN_ARG_OPS])])
 667   OVS_FIND_PARAM_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hookfn], [priv],
 668                   [OVS_DEFINE([HAVE_NF_HOOKFN_ARG_PRIV])])
 669   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_ops],
 670                         [owner], [OVS_DEFINE([HAVE_NF_HOOKS_OPS_OWNER])])
 671   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [NFPROTO_INET])
 672
 673
 674   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netfilter_ipv6.h], [nf_ipv6_ops],
 675                         [fragment.*sock], [OVS_DEFINE([HAVE_NF_IPV6_OPS_FRAGMENT])])
 676
 677   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 678                         [nf_conn], [struct timer_list[[ \t]]*timeout],
 679                         [OVS_DEFINE([HAVE_NF_CONN_TIMER])])
 680   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 681                   [nf_ct_delete(], [OVS_DEFINE([HAVE_NF_CT_DELETE])])
 682
 683   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 684                   [nf_ct_tmpl_alloc], [nf_conntrack_zone],
 685                   [OVS_DEFINE([HAVE_NF_CT_TMPL_ALLOC_TAKES_STRUCT_ZONE])])
 686   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 687                   [nf_ct_get_tuplepr], [struct.net],
 688                   [OVS_DEFINE([HAVE_NF_CT_GET_TUPLEPR_TAKES_STRUCT_NET])])
 689   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 690                   [nf_ct_set])
 691   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 692                   [nf_ct_is_untracked])
 693   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_zones.h],
 694                   [nf_ct_zone_init])
 695   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_l3proto.h],
 696                   [net_ns_get])
 697   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_labels.h],
 698                   [nf_connlabels_get])
 699   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_labels.h],
 700                   [nf_connlabels_get], [int bit],
 701                   [OVS_DEFINE([HAVE_NF_CONNLABELS_GET_TAKES_BIT])])
 702   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_labels.h],
 703                         [nf_conn_labels], [words])
 704   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h], [nf_ct_nat_ext_add])
 705   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h], [nf_nat_alloc_null_binding])
 706   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h], [nf_nat_range2])
 707   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_seqadj.h], [nf_ct_seq_adjust])
 708   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_count.h], [nf_conncount_gc_list],
 709                   [OVS_DEFINE([HAVE_UPSTREAM_NF_CONNCOUNT])])
 710
 711   OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32])
 712   OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32_max])
 713
 714   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [get_link_net])
 715   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [name_assign_type])
 716   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [rtnl_create_link.*src_net],
 717                   [OVS_DEFINE([HAVE_RTNL_CREATE_LINK_SRC_NET])])
 718   OVS_GREP_IFELSE([$KSRC/include/net/net_namespace.h], [possible_net_t])
 719
 720   OVS_GREP_IFELSE([$KSRC/include/linux/rcupdate.h], [rcu_read_lock_held], [],
 721                   [OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h],
 722                                    [rcu_read_lock_held])])
 723   OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h], [lockdep_rtnl_is_held])
 724   OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h], [net_rwsem])
 725   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/rtnetlink.h],
 726                         [rtnl_create_link], [extack],
 727                         [OVS_DEFINE([HAVE_RTNL_CREATE_LINK_TAKES_EXTACK])])
 728
 729   # Check for the proto_data_valid member in struct sk_buff.  The [^@]
 730   # is necessary because some versions of this header remove the
 731   # member but retain the kerneldoc comment that describes it (which
 732   # starts with @).  The brackets must be doubled because of m4
 733   # quoting rules.
 734   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
 735                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
 736   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_checksum_start_offset])
 737   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_protocol])
 738   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_protocol_type])
 739   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_inner_transport_offset])
 740   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [kfree_skb_list])
 741   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [rxhash])
 742   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u16.*rxhash],
 743                   [OVS_DEFINE([HAVE_U16_RXHASH])])
 744   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
 745                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
 746   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 747                   [skb_copy_from_linear_data_offset])
 748   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 749                   [skb_reset_tail_pointer])
 750   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
 751   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_warn_if_lro],
 752                   [OVS_DEFINE([HAVE_SKB_WARN_LRO])])
 753   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [consume_skb])
 754   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_frag_page])
 755   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_has_frag_list])
 756   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [__skb_fill_page_desc])
 757   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_reset_mac_len])
 758   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_unclone])
 759   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_orphan_frags])
 760   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_get_hash(],
 761                   [OVS_DEFINE([HAVE_SKB_GET_HASH])])
 762   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_clear_hash])
 763   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [int.skb_zerocopy(],
 764                   [OVS_DEFINE([HAVE_SKB_ZEROCOPY])])
 765   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u8.*l4_rxhash],
 766                   [OVS_DEFINE([HAVE_L4_RXHASH])])
 767   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_ensure_writable])
 768   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_vlan_pop])
 769   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [__skb_vlan_pop])
 770   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_vlan_push])
 771   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_clear_hash_if_not_l4])
 772   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_postpush_rcsum])
 773   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [lco_csum])
 774   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_nfct])
 775   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_put_zero])
 776
 777   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [bool],
 778                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
 779   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [__wsum],
 780                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
 781   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/types.h], [__wsum],
 782                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
 783
 784   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_replace4])
 785   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_unfold])
 786
 787   OVS_GREP_IFELSE([$KSRC/include/net/dst.h], [dst_discard_sk])
 788   OVS_GREP_IFELSE([$KSRC/include/net/dst.h], [__skb_dst_copy])
 789
 790   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genl_has_listeners])
 791   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [mcgrp_offset])
 792   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [parallel_ops])
 793   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [netlink_has_listeners(net->genl_sock],
 794                   [OVS_DEFINE([HAVE_GENL_HAS_LISTENERS_TAKES_NET])])
 795   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genlmsg_parse])
 796   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genl_notify.*family],
 797                   [OVS_DEFINE([HAVE_GENL_NOTIFY_TAKES_FAMILY])])
 798   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/genetlink.h],
 799                         [genl_notify], [net],
 800                         [OVS_DEFINE([HAVE_GENL_NOTIFY_TAKES_NET])])
 801
 802
 803   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/genetlink.h],
 804                         [genl_multicast_group], [id])
 805   OVS_GREP_IFELSE([$KSRC/include/net/geneve.h], [geneve_hdr])
 806
 807   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_cisco_register])
 808   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_handle_offloads])
 809   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [IP6_FH_F_SKIP_RH])
 810   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [ip6_local_out_sk])
 811   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [__ipv6_addr_jhash])
 812   OVS_GREP_IFELSE([$KSRC/include/net/ip6_fib.h], [rt6i.*u.dst],
 813                   [OVS_DEFINE([HAVE_RT6INFO_DST_UNION])])
 814   OVS_GREP_IFELSE([$KSRC/include/net/ip6_route.h], [ip6_frag.*sock],
 815                   [OVS_DEFINE([HAVE_IP_FRAGMENT_TAKES_SOCK])])
 816
 817   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_64bit])
 818   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_get_be16])
 819   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be16])
 820   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be32])
 821   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be64])
 822   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_in_addr])
 823   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
 824   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_is_last])
 825   OVS_GREP_IFELSE([$KSRC/include/linux/netlink.h], [void.*netlink_set_err],
 826                   [OVS_DEFINE([HAVE_VOID_NETLINK_SET_ERR])])
 827   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netlink.h],
 828                         [nla_parse], [netlink_ext_ack],
 829                         [OVS_DEFINE([HAVE_NETLINK_EXT_ACK])])
 830
 831   OVS_GREP_IFELSE([$KSRC/include/net/sctp/checksum.h], [sctp_compute_cksum])
 832
 833   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
 834                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
 835   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_insert_tag_set_proto])
 836   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [__vlan_insert_tag])
 837   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_get_protocol])
 838   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [skb_vlan_tagged])
 839   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [eth_type_vlan])
 840
 841   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/dst_metadata.h],
 842                         [metadata_dst_alloc], [metadata_type])
 843
 844   OVS_GREP_IFELSE([$KSRC/include/linux/u64_stats_sync.h], [u64_stats_fetch_begin_irq])
 845
 846   OVS_GREP_IFELSE([$KSRC/include/net/vxlan.h], [struct vxlan_metadata],
 847                   [OVS_DEFINE([HAVE_VXLAN_METADATA])])
 848   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_flow_src_port],
 849                   [OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [inet_get_local_port_range(net],
 850                                    [OVS_DEFINE([HAVE_UDP_FLOW_SRC_PORT])])])
 851   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_v4_check])
 852   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [udp_tunnel_gro_complete])
 853   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [sk_buff.*udp_tunnel_handle_offloads],
 854                   [OVS_DEFINE([HAVE_UDP_TUNNEL_HANDLE_OFFLOAD_RET_SKB])])
 855   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/udp_tunnel.h], [udp_tunnel_sock_cfg],
 856                         [gro_receive])
 857
 858   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [ignore_df],
 859                   [OVS_DEFINE([HAVE_IGNORE_DF_RENAME])])
 860   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/netdevice.h], [NET_NAME_UNKNOWN],
 861                   [OVS_DEFINE([HAVE_NET_NAME_UNKNOWN])])
 862
 863   OVS_GREP_IFELSE([$KSRC/include/net/sock.h], [sk_no_check_tx])
 864   OVS_GREP_IFELSE([$KSRC/include/linux/udp.h], [no_check6_tx])
 865   OVS_GREP_IFELSE([$KSRC/include/linux/utsrelease.h], [el6],
 866                   [OVS_DEFINE([HAVE_RHEL6_PER_CPU])])
 867   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/protocol.h],
 868                         [udp_add_offload], [net],
 869                         [OVS_DEFINE([HAVE_UDP_ADD_OFFLOAD_TAKES_NET])])
 870   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netfilter/ipv6/nf_defrag_ipv6.h],
 871                         [nf_defrag_ipv6_enable], [net],
 872                         [OVS_DEFINE([HAVE_DEFRAG_ENABLE_TAKES_NET])])
 873   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [family_list],
 874                         [OVS_DEFINE([HAVE_GENL_FAMILY_LIST])])
 875   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device],
 876                         [needs_free_netdev],
 877                         [OVS_DEFINE([HAVE_NEEDS_FREE_NETDEV])])
 878   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/vxlan.h], [vxlan_dev], [cfg],
 879                         [OVS_DEFINE([HAVE_VXLAN_DEV_CFG])])
 880   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_helper.h],
 881                   [nf_conntrack_helper_put],
 882                   [OVS_DEFINE(HAVE_NF_CONNTRACK_HELPER_PUT)])
 883   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],[[[[:space:]]]SKB_GSO_UDP[[[:space:]]]],
 884                   [OVS_DEFINE([HAVE_SKB_GSO_UDP])])
 885   OVS_GREP_IFELSE([$KSRC/include/net/dst.h],[DST_NOCACHE],
 886                   [OVS_DEFINE([HAVE_DST_NOCACHE])])
 887   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/rtnetlink.h], [rtnl_link_ops],
 888                         [extack],
 889                   [OVS_DEFINE([HAVE_EXT_ACK_IN_RTNL_LINKOPS])])
 890   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_ops],
 891                         [list],
 892                         [OVS_DEFINE([HAVE_LIST_IN_NF_HOOK_OPS])])
 893   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/netfilter/nf_conntrack_common.h],
 894                   [IP_CT_UNTRACKED])
 895   OVS_FIND_PARAM_IFELSE([$KSRC/include/linux/netdevice.h],
 896                         [netdev_master_upper_dev_link], [extack],
 897                         [OVS_DEFINE([HAVE_UPPER_DEV_LINK_EXTACK])])
 898   OVS_GREP_IFELSE([$KSRC/include/linux/compiler_types.h],
 899                   [__LINUX_COMPILER_TYPES_H],
 900                   [OVS_DEFINE([HAVE_LINUX_COMPILER_TYPES_H])])
 901   OVS_GREP_IFELSE([$KSRC/include/linux/timekeeping.h],
 902                   [ktime_get_ts64],
 903                   [OVS_DEFINE([HAVE_KTIME_GET_TS64])])
 904   OVS_GREP_IFELSE([$KSRC/include/net/net_namespace.h],
 905                   [EXPORT_SYMBOL_GPL(peernet2id_alloc)],
 906                   [OVS_DEFINE([HAVE_PEERNET2ID_ALLOC])])
 907   OVS_GREP_IFELSE([$KSRC/include/linux/timekeeping.h],
 908                   [ktime_get_ns],
 909                   [OVS_DEFINE([HAVE_KTIME_GET_NS])])
 910   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h],
 911                   frag_percpu_counter_batch[],
 912                   [OVS_DEFINE([HAVE_FRAG_PERCPU_COUNTER_BATCH])])
 913   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 914                   [null_compute_pseudo],
 915                   [OVS_DEFINE([HAVE_NULL_COMPUTE_PSEUDO])])
 916   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 917                   [__skb_checksum_convert],
 918                   [OVS_DEFINE([HAVE_SKB_CHECKSUM_CONVERT])])
 919   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device],
 920                         [max_mtu],
 921                         [OVS_DEFINE([HAVE_NET_DEVICE_MAX_MTU])])
 922   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/ip6_tunnel.h], [__ip6_tnl_parm],
 923                         [erspan_ver],
 924                         [OVS_DEFINE([HAVE_IP6_TNL_PARM_ERSPAN_VER])])
 925   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 926                   [SKB_GSO_IPXIP6],
 927                   [OVS_DEFINE([HAVE_SKB_GSO_IPXIP6])])
 928   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/ipv6.h],
 929                         [ip6_make_flowlabel], [fl6],
 930                         [OVS_DEFINE([HAVE_IP6_MAKE_FLOWLABEL_FL6])])
 931   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/ipv6.h], [netns_sysctl_ipv6],
 932                         [auto_flowlabels],
 933                         [OVS_DEFINE([HAVE_NETNS_SYSCTL_IPV6_AUTO_FLOWLABELS])])
 934   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h],
 935                   [netif_keep_dst],
 936                   [OVS_DEFINE([HAVE_NETIF_KEEP_DST])])
 937   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netdevice.h], [net_device_ops],
 938                         [ndo_get_iflink],
 939                         [OVS_DEFINE([HAVE_NDO_GET_IFLINK])])
 940   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 941                   [skb_set_inner_ipproto],
 942                   [OVS_DEFINE([HAVE_SKB_SET_INNER_IPPROTO])])
 943   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 944                   [tunnel_encap_types],
 945                   [OVS_DEFINE([HAVE_TUNNEL_ENCAP_TYPES])])
 946   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 947                   [IFLA_IPTUN_ENCAP_TYPE],
 948                   [OVS_DEFINE([HAVE_IFLA_IPTUN_ENCAP_TYPE])])
 949   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 950                   [IFLA_IPTUN_COLLECT_METADATA],
 951                   [OVS_DEFINE([HAVE_IFLA_IPTUN_COLLECT_METADATA])])
 952   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 953                   [IFLA_GRE_ENCAP_DPORT])
 954   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 955                   [IFLA_GRE_COLLECT_METADATA])
 956   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 957                   [IFLA_GRE_IGNORE_DF])
 958   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 959                   [IFLA_GRE_FWMARK])
 960   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 961                   [IFLA_GRE_ERSPAN_INDEX])
 962   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 963                   [IFLA_GRE_ERSPAN_HWID])
 964   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_tunnel.h],
 965                   [IFLA_IPTUN_FWMARK])
 966   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/skbuff.h], [sk_buff],
 967                         [csum_valid],
 968                         [OVS_DEFINE([HAVE_SKBUFF_CSUM_VALID])])
 969   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/skbuff.h], [sk_buff],
 970                         [vlan_present],
 971                         [OVS_DEFINE([HAVE_SKBUFF_VLAN_PRESENT])])
 972   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 973                   [skb_checksum_simple_validate])
 974   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h],
 975                   [void.*ndo_get_stats64],
 976                   [OVS_DEFINE([HAVE_VOID_NDO_GET_STATS64])])
 977   OVS_GREP_IFELSE([$KSRC/include/linux/timer.h], [init_timer_deferrable],
 978                   [OVS_DEFINE([HAVE_INIT_TIMER_DEFERRABLE])])
 979   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/ip_tunnels.h],
 980                         [ip_tunnel_info_opts_set], [flags],
 981                         [OVS_DEFINE([HAVE_IP_TUNNEL_INFO_OPTS_SET_FLAGS])])
 982   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
 983                         [rnd],
 984                         [OVS_DEFINE([HAVE_INET_FRAGS_RND])])
 985   OVS_GREP_IFELSE([$KSRC/include/linux/overflow.h], [__LINUX_OVERFLOW_H],
 986                   [OVS_DEFINE([HAVE_OVERFLOW_H])])
 987   OVS_GREP_IFELSE([$KSRC/include/linux/overflow.h], [struct_size],
 988                   [OVS_DEFINE([HAVE_STRUCT_SIZE])])
 989   OVS_GREP_IFELSE([$KSRC/include/linux/mm.h], [kvmalloc_array],
 990                   [OVS_DEFINE([HAVE_KVMALLOC_ARRAY])])
 991   OVS_GREP_IFELSE([$KSRC/include/linux/mm.h], [kvmalloc_node],
 992                   [OVS_DEFINE([HAVE_KVMALLOC_NODE])])
 993   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_l3proto.h],
 994                   [nf_conntrack_l3proto],
 995                   [OVS_DEFINE([HAVE_NF_CONNTRACK_L3PROATO_H])])
 996   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_core.h],
 997                         [nf_conntrack_in], [nf_hook_state],
 998                         [OVS_DEFINE([HAVE_NF_CONNTRACK_IN_TAKES_NF_HOOK_STATE])])
 999   OVS_GREP_IFELSE([$KSRC/include/net/ipv6_frag.h], [IP6_DEFRAG_CONNTRACK_IN],
1000                   [OVS_DEFINE([HAVE_IPV6_FRAG_H])])
1001   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_helper.h],
1002                         [nf_ct_helper_ext_add], [nf_conntrack_helper],
1003                         [OVS_DEFINE([HAVE_NF_CT_HELPER_EXT_ADD_TAKES_HELPER])])
1004   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_calc_hlen],
1005                   [OVS_DEFINE([HAVE_GRE_CALC_HLEN])])
1006   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [ip_gre_calc_hlen],
1007                   [OVS_DEFINE([HAVE_IP_GRE_CALC_HLEN])])
1008
1009   if cmp -s datapath/linux/kcompat.h.new \
1010             datapath/linux/kcompat.h >/dev/null 2>&1; then
1011     rm datapath/linux/kcompat.h.new
1012   else
1013     mv datapath/linux/kcompat.h.new datapath/linux/kcompat.h
1014   fi
1015 ])
1016
1017 dnl Checks for net/if_dl.h.
1018 dnl
1019 dnl (We use this as a proxy for checking whether we're building on FreeBSD
1020 dnl or NetBSD.)
1021 AC_DEFUN([OVS_CHECK_IF_DL],
1022   [AC_CHECK_HEADER([net/if_dl.h],
1023                    [HAVE_IF_DL=yes],
1024                    [HAVE_IF_DL=no])
1025    AM_CONDITIONAL([HAVE_IF_DL], [test "$HAVE_IF_DL" = yes])
1026    if test "$HAVE_IF_DL" = yes; then
1027       AC_DEFINE([HAVE_IF_DL], [1],
1028                 [Define to 1 if net/if_dl.h is available.])
1029
1030       # On these platforms we use libpcap to access network devices.
1031       AC_SEARCH_LIBS([pcap_open_live], [pcap])
1032    fi])
1033
1034 dnl Checks for buggy strtok_r.
1035 dnl
1036 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
1037 dnl with optimization that can cause segfaults:
1038 dnl
1039 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
1040 AC_DEFUN([OVS_CHECK_STRTOK_R],
1041   [AC_CACHE_CHECK(
1042      [whether strtok_r macro segfaults on some inputs],
1043      [ovs_cv_strtok_r_bug],
1044      [AC_RUN_IFELSE(
1045         [AC_LANG_PROGRAM([#include <stdio.h>
1046                           #include <string.h>
1047                          ],
1048                          [[#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
1049                            /* Assume bug is present, because relatively minor
1050                               changes in compiler settings (e.g. optimization
1051                               level) can make it crop up. */
1052                            return 1;
1053                            #else
1054                            char string[] = ":::";
1055                            char *save_ptr = (char *) 0xc0ffee;
1056                            char *token1, *token2;
1057                            token1 = strtok_r(string, ":", &save_ptr);
1058                            token2 = strtok_r(NULL, ":", &save_ptr);
1059                            freopen ("/dev/null", "w", stdout);
1060                            printf ("%s %s\n", token1, token2);
1061                            return 0;
1062                            #endif
1063                           ]])],
1064         [ovs_cv_strtok_r_bug=no],
1065         [ovs_cv_strtok_r_bug=yes],
1066         [ovs_cv_strtok_r_bug=yes])])
1067    if test $ovs_cv_strtok_r_bug = yes; then
1068      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
1069                [Define if strtok_r macro segfaults on some inputs])
1070    fi
1071 ])
1072
1073 dnl ----------------------------------------------------------------------
1074 dnl These macros are from GNU PSPP, with the following original license:
1075 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
1076 dnl This file is free software; the Free Software Foundation
1077 dnl gives unlimited permission to copy and/or distribute it,
1078 dnl with or without modifications, as long as this notice is preserved.
1079
1080 AC_DEFUN([_OVS_CHECK_CC_OPTION], [dnl
1081   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-= ], [__])])dnl
1082   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name],
1083     [ovs_save_CFLAGS="$CFLAGS"
1084      dnl Include -Werror in the compiler options, because without -Werror
1085      dnl clang's GCC-compatible compiler driver does not return a failure
1086      dnl exit status even though it complains about options it does not
1087      dnl understand.
1088      dnl
1089      dnl Also, check stderr as gcc exits with status 0 for options
1090      dnl rejected at getopt level.
1091      dnl    % touch /tmp/a.c
1092      dnl    % gcc -g -c -Werror -Qunused-arguments /tmp/a.c; echo $?
1093      dnl    gcc: unrecognized option '-Qunused-arguments'
1094      dnl    0
1095      dnl    %
1096      dnl
1097      dnl In addition, GCC does not complain about a -Wno-<foo> option that
1098      dnl it does not understand, unless it has another error to report, so
1099      dnl instead of testing for -Wno-<foo>, test for the positive version.
1100      CFLAGS="$CFLAGS $WERROR m4_bpatsubst([$1], [-Wno-], [-W])"
1101      AC_COMPILE_IFELSE(
1102        [AC_LANG_SOURCE([int x;])],
1103        [if test -s conftest.err && grep "unrecognized option" conftest.err
1104         then
1105           ovs_cv_name[]=no
1106         else
1107           ovs_cv_name[]=yes
1108         fi],
1109        [ovs_cv_name[]=no])
1110      CFLAGS="$ovs_save_CFLAGS"])
1111   if test $ovs_cv_name = yes; then
1112     m4_if([$2], [], [:], [$2])
1113   else
1114     m4_if([$3], [], [:], [$3])
1115   fi
1116 ])
1117
1118 dnl OVS_CHECK_WERROR
1119 dnl
1120 dnl Check whether the C compiler accepts -Werror.
1121 dnl Sets $WERROR to "-Werror", if so, and otherwise to the empty string.
1122 AC_DEFUN([OVS_CHECK_WERROR],
1123   [WERROR=
1124    _OVS_CHECK_CC_OPTION([-Werror], [WERROR=-Werror])])
1125
1126 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
1127 dnl Check whether the given C compiler OPTION is accepted.
1128 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
1129 AC_DEFUN([OVS_CHECK_CC_OPTION],
1130   [AC_REQUIRE([OVS_CHECK_WERROR])
1131    _OVS_CHECK_CC_OPTION([$1], [$2], [$3])])
1132
1133 dnl OVS_ENABLE_OPTION([OPTION])
1134 dnl Check whether the given C compiler OPTION is accepted.
1135 dnl If so, add it to WARNING_FLAGS.
1136 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
1137 AC_DEFUN([OVS_ENABLE_OPTION],
1138   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
1139    AC_SUBST([WARNING_FLAGS])])
1140
1141 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
1142 dnl Check whether the given C compiler OPTION is accepted.
1143 dnl If so, enable the given Automake CONDITIONAL.
1144
1145 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
1146 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
1147   [OVS_CHECK_CC_OPTION(
1148     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
1149    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
1150 dnl ----------------------------------------------------------------------
1151
1152 dnl Check for too-old XenServer.
1153 AC_DEFUN([OVS_CHECK_XENSERVER_VERSION],
1154   [AC_CACHE_CHECK([XenServer release], [ovs_cv_xsversion],
1155     [if test -e /etc/redhat-release; then
1156        ovs_cv_xsversion=`sed -n 's/^XenServer DDK release \([[^-]]*\)-.*/\1/p' /etc/redhat-release`
1157      fi
1158      if test -z "$ovs_cv_xsversion"; then
1159        ovs_cv_xsversion=none
1160      fi])
1161   case $ovs_cv_xsversion in
1162     none)
1163       ;;
1164
1165     [[1-9]][[0-9]]* |                    dnl XenServer 10 or later
1166     [[6-9]]* |                           dnl XenServer 6 or later
1167     5.[[7-9]]* |                         dnl XenServer 5.7 or later
1168     5.6.[[1-9]][[0-9]][[0-9]][[0-9]]* |  dnl XenServer 5.6.1000 or later
1169     5.6.[[2-9]][[0-9]][[0-9]]* |         dnl XenServer 5.6.200 or later
1170     5.6.1[[0-9]][[0-9]])                 dnl Xenserver 5.6.100 or later
1171       ;;
1172
1173     *)
1174       AC_MSG_ERROR([This appears to be XenServer $ovs_cv_xsversion, but only XenServer 5.6.100 or later is supported.  (If you are really using a supported version of XenServer, you may override this error message by specifying 'ovs_cv_xsversion=5.6.100' on the "configure" command line.)])
1175       ;;
1176   esac])
1177
1178 dnl OVS_CHECK_SPARSE_TARGET
1179 dnl
1180 dnl The "cgcc" script from "sparse" isn't very good at detecting the
1181 dnl target for which the code is being built.  This helps it out.
1182 AC_DEFUN([OVS_CHECK_SPARSE_TARGET],
1183   [AC_CACHE_CHECK(
1184     [target hint for cgcc],
1185     [ac_cv_sparse_target],
1186     [AS_CASE([`$CC -dumpmachine 2>/dev/null`],
1187        [i?86-* | athlon-*], [ac_cv_sparse_target=x86],
1188        [x86_64-*], [ac_cv_sparse_target=x86_64],
1189        [ac_cv_sparse_target=other])])
1190    AS_CASE([$ac_cv_sparse_target],
1191      [x86], [SPARSEFLAGS= CGCCFLAGS="-target=i86 -target=host_os_specs"],
1192      [x86_64], [SPARSEFLAGS=-m64 CGCCFLAGS="-target=x86_64 -target=host_os_specs"],
1193      [SPARSEFLAGS= CGCCFLAGS=])
1194
1195    dnl Get the the default defines for vector instructions from compiler to
1196    dnl allow "sparse" correctly check the same code that will be built.
1197    dnl Required for checking DPDK headers.
1198    AC_MSG_CHECKING([vector options for cgcc])
1199    VECTOR=$($CC -dM -E - < /dev/null | grep -E "MMX|SSE|AVX" | \
1200             cut -c 9- | sed 's/ /=/' | sed 's/^/-D/' | tr '\n' ' ')
1201    AC_MSG_RESULT([$VECTOR])
1202    CGCCFLAGS="$CGCCFLAGS $VECTOR"
1203
1204    AC_SUBST([SPARSEFLAGS])
1205    AC_SUBST([CGCCFLAGS])])
1206
1207 dnl OVS_SPARSE_EXTRA_INCLUDES
1208 dnl
1209 dnl The cgcc script from "sparse" does not search gcc's default
1210 dnl search path. Get the default search path from GCC and pass
1211 dnl them to sparse.
1212 AC_DEFUN([OVS_SPARSE_EXTRA_INCLUDES],
1213     AC_SUBST([SPARSE_EXTRA_INCLUDES],
1214            [`$CC -v -E - </dev/null 2>&1 >/dev/null | sed -n -e '/^#include.*search.*starts.*here:/,/^End.*of.*search.*list\./s/^ \(.*\)/-I \1/p' |grep -v /usr/lib | grep -x -v '\-I /usr/include' | tr \\\n ' ' `] ))
1215
1216 dnl OVS_ENABLE_SPARSE
1217 AC_DEFUN([OVS_ENABLE_SPARSE],
1218   [AC_REQUIRE([OVS_CHECK_SPARSE_TARGET])
1219    AC_REQUIRE([OVS_SPARSE_EXTRA_INCLUDES])
1220    : ${SPARSE=sparse}
1221    AC_SUBST([SPARSE])
1222    AC_CONFIG_COMMANDS_PRE(
1223      [CC='$(if $(C:0=),env REAL_CC="'"$CC"'" CHECK="$(SPARSE) $(SPARSE_WERROR) -I $(top_srcdir)/include/sparse $(SPARSEFLAGS) $(SPARSE_EXTRA_INCLUDES) " cgcc $(CGCCFLAGS),'"$CC"')'])
1224
1225    AC_ARG_ENABLE(
1226      [sparse],
1227      [AC_HELP_STRING([--enable-sparse], [Run "sparse" by default])],
1228      [], [enable_sparse=no])
1229    AM_CONDITIONAL([ENABLE_SPARSE_BY_DEFAULT], [test $enable_sparse = yes])])
1230
1231 dnl OVS_CTAGS_IDENTIFIERS
1232 dnl
1233 dnl ctags ignores symbols with extras identifiers. This builds a list of
1234 dnl specially handled identifiers to be ignored.
1235 AC_DEFUN([OVS_CTAGS_IDENTIFIERS],
1236     AC_SUBST([OVS_CTAGS_IDENTIFIERS_LIST],
1237            [`printf %s '-I "'; sed -n 's/^#define \(OVS_[A-Z_]\+\)(\.\.\.)$/\1+/p' ${srcdir}/include/openvswitch/compiler.h  | tr \\\n ' ' ; printf '"'`] ))
1238
1239 dnl OVS_PTHREAD_SET_NAME
1240 dnl
1241 dnl This checks for three known variants of pthreads functions for setting
1242 dnl the name of the current thread:
1243 dnl
1244 dnl   glibc: int pthread_setname_np(pthread_t, const char *name);
1245 dnl   NetBSD: int pthread_setname_np(pthread_t, const char *format, void *arg);
1246 dnl   FreeBSD: int pthread_set_name_np(pthread_t, const char *name);
1247 dnl
1248 dnl For glibc and FreeBSD, the arguments are just a thread and its name.  For
1249 dnl NetBSD, 'format' is a printf() format string and 'arg' is an argument to
1250 dnl provide to it.
1251 dnl
1252 dnl This macro defines:
1253 dnl
1254 dnl    glibc: HAVE_GLIBC_PTHREAD_SETNAME_NP
1255 dnl    NetBSD: HAVE_NETBSD_PTHREAD_SETNAME_NP
1256 dnl    FreeBSD: HAVE_PTHREAD_SET_NAME_NP
1257 AC_DEFUN([OVS_CHECK_PTHREAD_SET_NAME],
1258   [AC_CHECK_FUNCS([pthread_set_name_np])
1259    if test $ac_cv_func_pthread_set_name_np != yes; then
1260      AC_CACHE_CHECK(
1261        [for pthread_setname_np() variant],
1262        [ovs_cv_pthread_setname_np],
1263        [AC_LINK_IFELSE(
1264          [AC_LANG_PROGRAM([#include <pthread.h>
1265   ], [pthread_setname_np(pthread_self(), "name");])],
1266          [ovs_cv_pthread_setname_np=glibc],
1267          [AC_LINK_IFELSE(
1268            [AC_LANG_PROGRAM([#include <pthread.h>
1269 ], [pthread_setname_np(pthread_self(), "%s", "name");])],
1270            [ovs_cv_pthread_setname_np=netbsd],
1271            [ovs_cv_pthread_setname_np=none])])])
1272      case $ovs_cv_pthread_setname_np in # (
1273        glibc)
1274           AC_DEFINE(
1275             [HAVE_GLIBC_PTHREAD_SETNAME_NP], [1],
1276             [Define to 1 if pthread_setname_np() is available and takes 2 parameters (like glibc).])
1277           ;; # (
1278        netbsd)
1279           AC_DEFINE(
1280             [HAVE_NETBSD_PTHREAD_SETNAME_NP], [1],
1281             [Define to 1 if pthread_setname_np() is available and takes 3 parameters (like NetBSD).])
1282           ;;
1283      esac
1284    fi])
1285
1286 dnl OVS_CHECK_LINUX_HOST.
1287 dnl
1288 dnl Checks whether we're building for a Linux host, based on the presence of
1289 dnl the __linux__ preprocessor symbol, and sets up an Automake conditional
1290 dnl LINUX based on the result.
1291 AC_DEFUN([OVS_CHECK_LINUX_HOST],
1292   [AC_CACHE_CHECK(
1293      [whether __linux__ is defined],
1294      [ovs_cv_linux],
1295      [AC_COMPILE_IFELSE(
1296         [AC_LANG_PROGRAM([enum { LINUX = __linux__};], [])],
1297         [ovs_cv_linux=true],
1298         [ovs_cv_linux=false])])
1299    AM_CONDITIONAL([LINUX], [$ovs_cv_linux])])