acinclude.m4

   1 # -*- autoconf -*-
   2
   3 # Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 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 dnl OVS_CHECK_LINUX
  29 dnl
  30 dnl Configure linux kernel source tree
  31 AC_DEFUN([OVS_CHECK_LINUX], [
  32   AC_ARG_WITH([linux],
  33               [AC_HELP_STRING([--with-linux=/path/to/linux],
  34                               [Specify the Linux kernel build directory])])
  35   AC_ARG_WITH([linux-source],
  36               [AC_HELP_STRING([--with-linux-source=/path/to/linux-source],
  37                               [Specify the Linux kernel source directory
  38                                (usually figured out automatically from build
  39                                directory)])])
  40
  41   # Deprecated equivalents to --with-linux, --with-linux-source.
  42   AC_ARG_WITH([l26])
  43   AC_ARG_WITH([l26-source])
  44
  45   if test X"$with_linux" != X; then
  46     KBUILD=$with_linux
  47   elif test X"$with_l26" != X; then
  48     KBUILD=$with_l26
  49     AC_MSG_WARN([--with-l26 is deprecated, please use --with-linux instead])
  50   else
  51     KBUILD=
  52   fi
  53
  54   if test X"$KBUILD" != X; then
  55     if test X"$with_linux_source" != X; then
  56       KSRC=$with_linux_source
  57     elif test X"$with_l26_source" != X; then
  58       KSRC=$with_l26_source
  59       AC_MSG_WARN([--with-l26-source is deprecated, please use --with-linux-source instead])
  60     else
  61       KSRC=
  62     fi
  63   elif test X"$with_linux_source" != X || test X"$with_l26_source" != X; then
  64     AC_MSG_ERROR([Linux source directory may not be specified without Linux build directory])
  65   fi
  66
  67   if test -n "$KBUILD"; then
  68     KBUILD=`eval echo "$KBUILD"`
  69     case $KBUILD in
  70         /*) ;;
  71         *) KBUILD=`pwd`/$KBUILD ;;
  72     esac
  73
  74     # The build directory is what the user provided.
  75     # Make sure that it exists.
  76     AC_MSG_CHECKING([for Linux build directory])
  77     if test -d "$KBUILD"; then
  78         AC_MSG_RESULT([$KBUILD])
  79         AC_SUBST(KBUILD)
  80     else
  81         AC_MSG_RESULT([no])
  82         AC_ERROR([source dir $KBUILD doesn't exist])
  83     fi
  84
  85     # Debian breaks kernel headers into "source" header and "build" headers.
  86     # We want the source headers, but $KBUILD gives us the "build" headers.
  87     # Use heuristics to find the source headers.
  88     AC_MSG_CHECKING([for Linux source directory])
  89     if test -n "$KSRC"; then
  90       KSRC=`eval echo "$KSRC"`
  91       case $KSRC in
  92           /*) ;;
  93           *) KSRC=`pwd`/$KSRC ;;
  94       esac
  95       if test ! -e $KSRC/include/linux/kernel.h; then
  96         AC_MSG_ERROR([$KSRC is not a kernel source directory])
  97       fi
  98     else
  99       KSRC=$KBUILD
 100       if test ! -e $KSRC/include/linux/kernel.h; then
 101         # Debian kernel build Makefiles tend to include a line of the form:
 102         # MAKEARGS := -C /usr/src/linux-headers-3.2.0-1-common O=/usr/src/linux-headers-3.2.0-1-486
 103         # First try to extract the source directory from this line.
 104         KSRC=`sed -n 's/.*-C \([[^ ]]*\).*/\1/p' "$KBUILD"/Makefile`
 105         if test ! -e "$KSRC"/include/linux/kernel.h; then
 106           # Didn't work.  Fall back to name-based heuristics that used to work.
 107           case `echo "$KBUILD" | sed 's,/*$,,'` in # (
 108             */build)
 109               KSRC=`echo "$KBUILD" | sed 's,/build/*$,/source,'`
 110               ;; # (
 111             *)
 112               KSRC=`(cd $KBUILD && pwd -P) | sed 's,-[[^-]]*$,-common,'`
 113               ;;
 114           esac
 115         fi
 116       fi
 117       if test ! -e "$KSRC"/include/linux/kernel.h; then
 118         AC_MSG_ERROR([cannot find source directory (please use --with-linux-source)])
 119       fi
 120     fi
 121     AC_MSG_RESULT([$KSRC])
 122
 123     AC_MSG_CHECKING([for kernel version])
 124     version=`sed -n 's/^VERSION = //p' "$KSRC/Makefile"`
 125     patchlevel=`sed -n 's/^PATCHLEVEL = //p' "$KSRC/Makefile"`
 126     sublevel=`sed -n 's/^SUBLEVEL = //p' "$KSRC/Makefile"`
 127     if test X"$version" = X || test X"$patchlevel" = X; then
 128        AC_ERROR([cannot determine kernel version])
 129     elif test X"$sublevel" = X; then
 130        kversion=$version.$patchlevel
 131     else
 132        kversion=$version.$patchlevel.$sublevel
 133     fi
 134     AC_MSG_RESULT([$kversion])
 135
 136     if test "$version" -ge 4; then
 137        if test "$version" = 4 && test "$patchlevel" -le 3; then
 138           : # Linux 4.x
 139        else
 140           AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version newer than 4.3.x is not supported (please refer to the FAQ for advice)])
 141        fi
 142     elif test "$version" = 3; then
 143        : # Linux 3.x
 144     else
 145        if test "$version" -le 1 || test "$patchlevel" -le 5 || test "$sublevel" -le 31; then
 146          AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version 2.6.32 or later is required])
 147        else
 148          : # Linux 2.6.x
 149        fi
 150     fi
 151     if (test ! -e "$KBUILD"/include/linux/version.h && \
 152         test ! -e "$KBUILD"/include/generated/uapi/linux/version.h)|| \
 153        (test ! -e "$KBUILD"/include/linux/autoconf.h && \
 154         test ! -e "$KBUILD"/include/generated/autoconf.h); then
 155         AC_MSG_ERROR([Linux kernel source in $KBUILD is not configured])
 156     fi
 157     OVS_CHECK_LINUX_COMPAT
 158   fi
 159   AM_CONDITIONAL(LINUX_ENABLED, test -n "$KBUILD")
 160 ])
 161
 162 dnl OVS_CHECK_DPDK
 163 dnl
 164 dnl Configure DPDK source tree
 165 AC_DEFUN([OVS_CHECK_DPDK], [
 166   AC_ARG_WITH([dpdk],
 167               [AC_HELP_STRING([--with-dpdk=/path/to/dpdk],
 168                               [Specify the DPDK build directory])])
 169
 170   if test X"$with_dpdk" != X; then
 171     RTE_SDK=$with_dpdk
 172
 173     DPDK_INCLUDE=$RTE_SDK/include
 174     DPDK_LIB_DIR=$RTE_SDK/lib
 175     DPDK_LIB="-ldpdk"
 176     DPDK_EXTRA_LIB=""
 177     RTE_SDK_FULL=`readlink -f $RTE_SDK`
 178
 179     AC_COMPILE_IFELSE(
 180       [AC_LANG_PROGRAM([#include <$RTE_SDK_FULL/include/rte_config.h>
 181 #if !RTE_LIBRTE_VHOST_USER
 182 #error
 183 #endif], [])],
 184                     [], [AC_DEFINE([VHOST_CUSE], [1], [DPDK vhost-cuse support enabled, vhost-user disabled.])
 185                          DPDK_EXTRA_LIB="-lfuse"])
 186
 187     ovs_save_CFLAGS="$CFLAGS"
 188     ovs_save_LDFLAGS="$LDFLAGS"
 189     LDFLAGS="$LDFLAGS -L$DPDK_LIB_DIR"
 190     CFLAGS="$CFLAGS -I$DPDK_INCLUDE"
 191
 192     # On some systems we have to add -ldl to link with dpdk
 193     #
 194     # This code, at first, tries to link without -ldl (""),
 195     # then adds it and tries again.
 196     # Before each attempt the search cache must be unset,
 197     # otherwise autoconf will stick with the old result
 198
 199     found=false
 200     save_LIBS=$LIBS
 201     for extras in "" "-ldl"; do
 202         LIBS="$DPDK_LIB $extras $save_LIBS $DPDK_EXTRA_LIB"
 203         AC_LINK_IFELSE(
 204            [AC_LANG_PROGRAM([#include <rte_config.h>
 205                              #include <rte_eal.h>],
 206                             [int rte_argc; char ** rte_argv;
 207                              rte_eal_init(rte_argc, rte_argv);])],
 208            [found=true])
 209         if $found; then
 210             break
 211         fi
 212     done
 213     if $found; then :; else
 214         AC_MSG_ERROR([cannot link with dpdk])
 215     fi
 216     CFLAGS="$ovs_save_CFLAGS"
 217     LDFLAGS="$ovs_save_LDFLAGS"
 218     OVS_LDFLAGS="$OVS_LDFLAGS -L$DPDK_LIB_DIR"
 219     OVS_CFLAGS="$OVS_CFLAGS -I$DPDK_INCLUDE -mssse3"
 220
 221     # DPDK pmd drivers are not linked unless --whole-archive is used.
 222     #
 223     # This happens because the rest of the DPDK code doesn't use any symbol in
 224     # the pmd driver objects, and the drivers register themselves using an
 225     # __attribute__((constructor)) function.
 226     #
 227     # These options are specified inside a single -Wl directive to prevent
 228     # autotools from reordering them.
 229     DPDK_vswitchd_LDFLAGS=-Wl,--whole-archive,$DPDK_LIB,--no-whole-archive
 230     AC_SUBST([DPDK_vswitchd_LDFLAGS])
 231     AC_DEFINE([DPDK_NETDEV], [1], [System uses the DPDK module.])
 232
 233   else
 234     RTE_SDK=
 235   fi
 236
 237   AM_CONDITIONAL([DPDK_NETDEV], test -n "$RTE_SDK")
 238 ])
 239
 240 dnl OVS_GREP_IFELSE(FILE, REGEX, [IF-MATCH], [IF-NO-MATCH])
 241 dnl
 242 dnl Greps FILE for REGEX.  If it matches, runs IF-MATCH, otherwise IF-NO-MATCH.
 243 dnl If IF-MATCH is empty then it defines to OVS_DEFINE(HAVE_<REGEX>), with
 244 dnl <REGEX> translated to uppercase.
 245 AC_DEFUN([OVS_GREP_IFELSE], [
 246   AC_MSG_CHECKING([whether $2 matches in $1])
 247   if test -f $1; then
 248     grep '$2' $1 >/dev/null 2>&1
 249     status=$?
 250     case $status in
 251       0)
 252         AC_MSG_RESULT([yes])
 253         m4_if([$3], [], [OVS_DEFINE([HAVE_]m4_toupper([$2]))], [$3])
 254         ;;
 255       1)
 256         AC_MSG_RESULT([no])
 257         $4
 258         ;;
 259       *)
 260         AC_MSG_ERROR([grep exited with status $status])
 261         ;;
 262     esac
 263   else
 264     AC_MSG_RESULT([file not found])
 265     $4
 266   fi
 267 ])
 268
 269 dnl OVS_FIND_FIELD_IFELSE(FILE, STRUCTURE, REGEX, [IF-MATCH], [IF-NO-MATCH])
 270 dnl
 271 dnl Looks for STRUCTURE in FILE. If it is found, greps for REGEX within the
 272 dnl structure definition. If this is successful, runs IF-MATCH, otherwise
 273 dnl IF_NO_MATCH. If IF-MATCH is empty then it defines to
 274 dnl OVS_DEFINE(HAVE_<STRUCTURE>_WITH_<REGEX>), with <STRUCTURE> and <REGEX>
 275 dnl translated to uppercase.
 276 AC_DEFUN([OVS_FIND_FIELD_IFELSE], [
 277   AC_MSG_CHECKING([whether $2 has member $3 in $1])
 278   if test -f $1; then
 279     awk '/$2.{/,/^}/' $1 2>/dev/null | grep '$3' >/dev/null
 280     status=$?
 281     case $status in
 282       0)
 283         AC_MSG_RESULT([yes])
 284         m4_if([$4], [], [OVS_DEFINE([HAVE_]m4_toupper([$2])[_WITH_]m4_toupper([$3]))], [$4])
 285         ;;
 286       1)
 287         AC_MSG_RESULT([no])
 288         $5
 289         ;;
 290       *)
 291         AC_MSG_ERROR([grep exited with status $status])
 292         ;;
 293     esac
 294   else
 295     AC_MSG_RESULT([file not found])
 296     $5
 297   fi
 298 ])
 299
 300 dnl OVS_DEFINE(NAME)
 301 dnl
 302 dnl Defines NAME to 1 in kcompat.h.
 303 AC_DEFUN([OVS_DEFINE], [
 304   echo '#define $1 1' >> datapath/linux/kcompat.h.new
 305 ])
 306
 307 dnl OVS_CHECK_LINUX_COMPAT
 308 dnl
 309 dnl Runs various Autoconf checks on the Linux 2.6 kernel source in
 310 dnl the directory in $KBUILD.
 311 AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
 312   rm -f datapath/linux/kcompat.h.new
 313   mkdir -p datapath/linux
 314   : > datapath/linux/kcompat.h.new
 315
 316   echo '#include <linux/version.h>
 317 #ifndef RHEL_RELEASE_CODE
 318 #define RHEL_RELEASE_CODE 0
 319 #define RHEL_RELEASE_VERSION(a, b) 0
 320 #endif' >> datapath/linux/kcompat.h.new
 321
 322   OVS_GREP_IFELSE([$KSRC/arch/x86/include/asm/checksum_32.h], [src_err,],
 323                   [OVS_DEFINE([HAVE_CSUM_COPY_DBG])])
 324
 325   OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_dst_lookup.*net],
 326                   [OVS_DEFINE([HAVE_IPV6_DST_LOOKUP_NET])])
 327   OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_stub])
 328
 329   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [ERR_CAST])
 330   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [IS_ERR_OR_NULL])
 331
 332   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [eth_hw_addr_random])
 333   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [ether_addr_copy])
 334
 335   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [IFLA_GENEVE_TOS])
 336   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [rtnl_link_stats64])
 337   OVS_GREP_IFELSE([$KSRC/include/linux/if_link.h], [rtnl_link_stats64])
 338   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_set_encap_proto])
 339   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_hwaccel_push_inside])
 340
 341   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [ipv4_is_multicast])
 342   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [proto_ports_offset])
 343   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*dst_entry],
 344                   [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_DST_ENTRY])])
 345   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*net],
 346                   [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_NET])])
 347
 348   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [inet_get_local_port_range.*net],
 349                   [OVS_DEFINE([HAVE_INET_GET_LOCAL_PORT_RANGE_USING_NET])])
 350   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_do_fragment])
 351   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_is_fragment])
 352   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_skb_dst_mtu])
 353   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [hashfn.*const],
 354                   [OVS_DEFINE([HAVE_INET_FRAGS_CONST])])
 355   OVS_GREP_IFELSE([$KSRC/include/net/dst_metadata.h], [metadata_dst])
 356
 357   OVS_GREP_IFELSE([$KSRC/include/linux/net.h], [sock_create_kern.*net],
 358                   [OVS_DEFINE([HAVE_SOCK_CREATE_KERN_NET])])
 359   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_disable_lro])
 360   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_stats])
 361   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_by_index_rcu])
 362   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_recursion_level])
 363   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [__skb_gso_segment])
 364   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [can_checksum_protocol])
 365   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_get_iflink])
 366   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_features_t])
 367   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [pcpu_sw_netstats])
 368   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_rx_handler_register])
 369   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [net_device_extended])
 370   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [rx_handler_func_t.*pskb],
 371                   [OVS_DEFINE([HAVE_RX_HANDLER_PSKB])])
 372   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netif_needs_gso.*net_device],
 373                   [OVS_DEFINE([HAVE_NETIF_NEEDS_GSO_NETDEV])])
 374   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload])
 375   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload.*uoff],
 376                   [OVS_DEFINE([HAVE_UDP_OFFLOAD_ARG_UOFF])])
 377   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [gro_remcsum])
 378
 379   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_state])
 380   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_register_net_hook])
 381   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hookfn.*nf_hook_ops],
 382                   [OVS_DEFINE([HAVE_NF_HOOKFN_ARG_OPS])])
 383
 384   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
 385                   [tmpl_alloc.*conntrack_zone],
 386                   [OVS_DEFINE([HAVE_NF_CT_TMPL_ALLOC_TAKES_STRUCT_ZONE])])
 387
 388   OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32])
 389   OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32_max])
 390
 391   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [get_link_net])
 392   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [name_assign_type])
 393   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [rtnl_create_link.*src_net],
 394                   [OVS_DEFINE([HAVE_RTNL_CREATE_LINK_SRC_NET])])
 395   OVS_GREP_IFELSE([$KSRC/include/net/net_namespace.h], [possible_net_t])
 396
 397   OVS_GREP_IFELSE([$KSRC/include/linux/rcupdate.h], [rcu_read_lock_held], [],
 398                   [OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h],
 399                                    [rcu_read_lock_held])])
 400   OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h], [lockdep_rtnl_is_held])
 401
 402   # Check for the proto_data_valid member in struct sk_buff.  The [^@]
 403   # is necessary because some versions of this header remove the
 404   # member but retain the kerneldoc comment that describes it (which
 405   # starts with @).  The brackets must be doubled because of m4
 406   # quoting rules.
 407   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
 408                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
 409   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_checksum_start_offset])
 410   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_protocol])
 411   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_mac_header])
 412   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_network_header])
 413   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [kfree_skb_list])
 414   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_scrub_packet.*xnet],
 415                   [OVS_DEFINE([HAVE_SKB_SCRUB_PACKET_XNET])])
 416   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [rxhash])
 417   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u16.*rxhash],
 418                   [OVS_DEFINE([HAVE_U16_RXHASH])])
 419   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
 420                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
 421   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 422                   [skb_copy_from_linear_data_offset])
 423   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 424                   [skb_reset_tail_pointer])
 425   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
 426   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_transport_header],
 427                   [OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
 428   OVS_GREP_IFELSE([$KSRC/include/linux/icmpv6.h], [icmp6_hdr],
 429                   [OVS_DEFINE([HAVE_ICMP6_HDR])])
 430   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_warn_if_lro],
 431                   [OVS_DEFINE([HAVE_SKB_WARN_LRO])])
 432   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [consume_skb])
 433   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_frag_page])
 434   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_has_frag_list])
 435   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [__skb_fill_page_desc])
 436   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_reset_mac_len])
 437   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_unclone])
 438   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_orphan_frags])
 439   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_get_hash])
 440   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_clear_hash])
 441   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [int.skb_zerocopy(],
 442                   [OVS_DEFINE([HAVE_SKB_ZEROCOPY])])
 443   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u8.*l4_rxhash],
 444                   [OVS_DEFINE([HAVE_L4_RXHASH])])
 445   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_ensure_writable])
 446   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_vlan_pop])
 447   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_vlan_push])
 448
 449   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [bool],
 450                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
 451   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [__wsum],
 452                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
 453   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/types.h], [__wsum],
 454                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
 455
 456   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_replace4])
 457   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_unfold])
 458
 459   OVS_GREP_IFELSE([$KSRC/include/net/dst.h], [dst_discard_sk])
 460
 461   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genl_has_listeners])
 462   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [mcgrp_offset])
 463   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [parallel_ops])
 464   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genlmsg_new_unicast])
 465   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [netlink_has_listeners(net->genl_sock],
 466                   [OVS_DEFINE([HAVE_GENL_HAS_LISTENERS_TAKES_NET])])
 467   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genlmsg_parse])
 468   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genl_notify.*family],
 469                   [OVS_DEFINE([HAVE_GENL_NOTIFY_TAKES_FAMILY])])
 470
 471   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/genetlink.h],
 472                         [genl_multicast_group], [id])
 473   OVS_GREP_IFELSE([$KSRC/include/net/geneve.h], [geneve_hdr])
 474
 475   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_cisco_register])
 476   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_handle_offloads])
 477   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [IP6_FH_F_SKIP_RH])
 478   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [ip6_local_out_sk])
 479   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [__ipv6_addr_jhash])
 480   OVS_GREP_IFELSE([$KSRC/include/net/ip6_fib.h], [rt6i.*u.dst],
 481                   [OVS_DEFINE([HAVE_RT6INFO_DST_UNION])])
 482   OVS_GREP_IFELSE([$KSRC/include/net/ip6_route.h], [ip6_frag.*sock],
 483                   [OVS_DEFINE([HAVE_IP_FRAGMENT_TAKES_SOCK])])
 484
 485   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_get_be16])
 486   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be16])
 487   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be32])
 488   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be64])
 489   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_in_addr])
 490   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
 491   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_is_last])
 492
 493   OVS_GREP_IFELSE([$KSRC/include/net/sctp/checksum.h], [sctp_compute_cksum])
 494
 495   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
 496                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
 497   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_insert_tag_set_proto])
 498   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [__vlan_insert_tag])
 499   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_get_protocol])
 500
 501   OVS_GREP_IFELSE([$KSRC/include/linux/u64_stats_sync.h], [u64_stats_fetch_begin_irq])
 502
 503   OVS_GREP_IFELSE([$KSRC/include/linux/openvswitch.h], [openvswitch_handle_frame_hook],
 504                   [OVS_DEFINE([HAVE_RHEL_OVS_HOOK])])
 505   OVS_GREP_IFELSE([$KSRC/include/net/vxlan.h], [struct vxlan_metadata],
 506                   [OVS_DEFINE([HAVE_VXLAN_METADATA])])
 507   OVS_GREP_IFELSE([$KSRC/include/net/vxlan.h], [VXLAN_HF_RCO])
 508   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_flow_src_port],
 509                   [OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [inet_get_local_port_range(net],
 510                                    [OVS_DEFINE([HAVE_UDP_FLOW_SRC_PORT])])])
 511   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_v4_check])
 512   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_set_csum])
 513   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [udp_tunnel_gro_complete])
 514   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [ipv6_v6only],
 515                   [OVS_DEFINE([HAVE_UDP_TUNNEL_IPV6])])
 516
 517   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [ignore_df],
 518                   [OVS_DEFINE([HAVE_IGNORE_DF_RENAME])])
 519   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/netdevice.h], [NET_NAME_UNKNOWN],
 520                   [OVS_DEFINE([HAVE_NET_NAME_UNKNOWN])])
 521
 522   OVS_GREP_IFELSE([$KSRC/include/linux/utsrelease.h], [el6],
 523                   [OVS_DEFINE([HAVE_RHEL6_PER_CPU])])
 524
 525   if test "$version" = 4 && test "$patchlevel" -le 2; then
 526         OVS_DEFINE([OVS_FRAGMENT_BACKPORT])
 527   elif test "$version" = 3 && test "$patchlevel" -ge 10; then
 528         OVS_DEFINE([OVS_FRAGMENT_BACKPORT])
 529   fi
 530
 531   if cmp -s datapath/linux/kcompat.h.new \
 532             datapath/linux/kcompat.h >/dev/null 2>&1; then
 533     rm datapath/linux/kcompat.h.new
 534   else
 535     mv datapath/linux/kcompat.h.new datapath/linux/kcompat.h
 536   fi
 537 ])
 538
 539 dnl Checks for net/if_packet.h.
 540 AC_DEFUN([OVS_CHECK_IF_PACKET],
 541   [AC_CHECK_HEADER([net/if_packet.h],
 542                    [HAVE_IF_PACKET=yes],
 543                    [HAVE_IF_PACKET=no])
 544    AM_CONDITIONAL([HAVE_IF_PACKET], [test "$HAVE_IF_PACKET" = yes])
 545    if test "$HAVE_IF_PACKET" = yes; then
 546       AC_DEFINE([HAVE_IF_PACKET], [1],
 547                 [Define to 1 if net/if_packet.h is available.])
 548    fi])
 549
 550 dnl Checks for net/if_dl.h.
 551 dnl
 552 dnl (We use this as a proxy for checking whether we're building on FreeBSD
 553 dnl or NetBSD.)
 554 AC_DEFUN([OVS_CHECK_IF_DL],
 555   [AC_CHECK_HEADER([net/if_dl.h],
 556                    [HAVE_IF_DL=yes],
 557                    [HAVE_IF_DL=no])
 558    AM_CONDITIONAL([HAVE_IF_DL], [test "$HAVE_IF_DL" = yes])
 559    if test "$HAVE_IF_DL" = yes; then
 560       AC_DEFINE([HAVE_IF_DL], [1],
 561                 [Define to 1 if net/if_dl.h is available.])
 562
 563       # On these platforms we use libpcap to access network devices.
 564       AC_SEARCH_LIBS([pcap_open_live], [pcap])
 565    fi])
 566
 567 dnl Checks for buggy strtok_r.
 568 dnl
 569 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
 570 dnl with optimization that can cause segfaults:
 571 dnl
 572 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
 573 AC_DEFUN([OVS_CHECK_STRTOK_R],
 574   [AC_CACHE_CHECK(
 575      [whether strtok_r macro segfaults on some inputs],
 576      [ovs_cv_strtok_r_bug],
 577      [AC_RUN_IFELSE(
 578         [AC_LANG_PROGRAM([#include <stdio.h>
 579                           #include <string.h>
 580                          ],
 581                          [[#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
 582                            /* Assume bug is present, because relatively minor
 583                               changes in compiler settings (e.g. optimization
 584                               level) can make it crop up. */
 585                            return 1;
 586                            #else
 587                            char string[] = ":::";
 588                            char *save_ptr = (char *) 0xc0ffee;
 589                            char *token1, *token2;
 590                            token1 = strtok_r(string, ":", &save_ptr);
 591                            token2 = strtok_r(NULL, ":", &save_ptr);
 592                            freopen ("/dev/null", "w", stdout);
 593                            printf ("%s %s\n", token1, token2);
 594                            return 0;
 595                            #endif
 596                           ]])],
 597         [ovs_cv_strtok_r_bug=no],
 598         [ovs_cv_strtok_r_bug=yes],
 599         [ovs_cv_strtok_r_bug=yes])])
 600    if test $ovs_cv_strtok_r_bug = yes; then
 601      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
 602                [Define if strtok_r macro segfaults on some inputs])
 603    fi
 604 ])
 605
 606 dnl ----------------------------------------------------------------------
 607 dnl These macros are from GNU PSPP, with the following original license:
 608 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
 609 dnl This file is free software; the Free Software Foundation
 610 dnl gives unlimited permission to copy and/or distribute it,
 611 dnl with or without modifications, as long as this notice is preserved.
 612
 613 AC_DEFUN([_OVS_CHECK_CC_OPTION], [dnl
 614   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-=], [__])])dnl
 615   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name],
 616     [ovs_save_CFLAGS="$CFLAGS"
 617      dnl Include -Werror in the compiler options, because without -Werror
 618      dnl clang's GCC-compatible compiler driver does not return a failure
 619      dnl exit status even though it complains about options it does not
 620      dnl understand.
 621      dnl
 622      dnl Also, check stderr as gcc exits with status 0 for options
 623      dnl rejected at getopt level.
 624      dnl    % touch /tmp/a.c
 625      dnl    % gcc -g -c -Werror -Qunused-arguments /tmp/a.c; echo $?
 626      dnl    gcc: unrecognized option '-Qunused-arguments'
 627      dnl    0
 628      dnl    %
 629      CFLAGS="$CFLAGS $WERROR $1"
 630      AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,)], [if test -s conftest.err && grep "unrecognized option" conftest.err; then ovs_cv_name[]=no; else ovs_cv_name[]=yes; fi], [ovs_cv_name[]=no])
 631      CFLAGS="$ovs_save_CFLAGS"])
 632   if test $ovs_cv_name = yes; then
 633     m4_if([$2], [], [:], [$2])
 634   else
 635     m4_if([$3], [], [:], [$3])
 636   fi
 637 ])
 638
 639 dnl OVS_CHECK_WERROR
 640 dnl
 641 dnl Check whether the C compiler accepts -Werror.
 642 dnl Sets $WERROR to "-Werror", if so, and otherwise to the empty string.
 643 AC_DEFUN([OVS_CHECK_WERROR],
 644   [WERROR=
 645    _OVS_CHECK_CC_OPTION([-Werror], [WERROR=-Werror])])
 646
 647 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
 648 dnl Check whether the given C compiler OPTION is accepted.
 649 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
 650 AC_DEFUN([OVS_CHECK_CC_OPTION],
 651   [AC_REQUIRE([OVS_CHECK_WERROR])
 652    _OVS_CHECK_CC_OPTION([$1], [$2], [$3])])
 653
 654 dnl OVS_ENABLE_OPTION([OPTION])
 655 dnl Check whether the given C compiler OPTION is accepted.
 656 dnl If so, add it to WARNING_FLAGS.
 657 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
 658 AC_DEFUN([OVS_ENABLE_OPTION],
 659   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
 660    AC_SUBST([WARNING_FLAGS])])
 661
 662 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
 663 dnl Check whether the given C compiler OPTION is accepted.
 664 dnl If so, enable the given Automake CONDITIONAL.
 665
 666 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
 667 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
 668   [OVS_CHECK_CC_OPTION(
 669     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
 670    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
 671 dnl ----------------------------------------------------------------------
 672
 673 dnl Check for too-old XenServer.
 674 AC_DEFUN([OVS_CHECK_XENSERVER_VERSION],
 675   [AC_CACHE_CHECK([XenServer release], [ovs_cv_xsversion],
 676     [if test -e /etc/redhat-release; then
 677        ovs_cv_xsversion=`sed -n 's/^XenServer DDK release \([[^-]]*\)-.*/\1/p' /etc/redhat-release`
 678      fi
 679      if test -z "$ovs_cv_xsversion"; then
 680        ovs_cv_xsversion=none
 681      fi])
 682   case $ovs_cv_xsversion in
 683     none)
 684       ;;
 685
 686     [[1-9]][[0-9]]* |                    dnl XenServer 10 or later
 687     [[6-9]]* |                           dnl XenServer 6 or later
 688     5.[[7-9]]* |                         dnl XenServer 5.7 or later
 689     5.6.[[1-9]][[0-9]][[0-9]][[0-9]]* |  dnl XenServer 5.6.1000 or later
 690     5.6.[[2-9]][[0-9]][[0-9]]* |         dnl XenServer 5.6.200 or later
 691     5.6.1[[0-9]][[0-9]])                 dnl Xenserver 5.6.100 or later
 692       ;;
 693
 694     *)
 695       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.)])
 696       ;;
 697   esac])
 698
 699 dnl OVS_MAKE_HAS_IF([if-true], [if-false])
 700 dnl
 701 dnl Checks whether make has the GNU make $(if condition,then,else) extension.
 702 dnl Runs 'if-true' if so, 'if-false' otherwise.
 703 AC_DEFUN([OVS_CHECK_MAKE_IF],
 704   [AC_CACHE_CHECK(
 705      [whether ${MAKE-make} has GNU make \$(if) extension],
 706      [ovs_cv_gnu_make_if],
 707      [cat <<'EOF' > conftest.mk
 708 conftest.out:
 709         echo $(if x,y,z) > conftest.out
 710 .PHONY: all
 711 EOF
 712       rm -f conftest.out
 713       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} -f conftest.mk all:"]) >&AS_MESSAGE_LOG_FD 2>&1
 714       ${MAKE-make} -f conftest.mk conftest.out >&AS_MESSAGE_LOG_FD 2>&1
 715       AS_ECHO(["$as_me:$LINENO: conftest.out contains:"]) >&AS_MESSAGE_LOG_FD 2>&1
 716       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
 717       result=`cat conftest.out`
 718       rm -f conftest.mk conftest.out
 719       if test "X$result" = "Xy"; then
 720         ovs_cv_gnu_make_if=yes
 721       else
 722         ovs_cv_gnu_make_if=no
 723       fi])])
 724
 725 dnl OVS_CHECK_GNU_MAKE
 726 dnl
 727 dnl Checks whether make is GNU make (because Linux kernel Makefiles
 728 dnl only work with GNU make).
 729 AC_DEFUN([OVS_CHECK_GNU_MAKE],
 730   [AC_CACHE_CHECK(
 731      [whether ${MAKE-make} is GNU make],
 732      [ovs_cv_gnu_make],
 733      [rm -f conftest.out
 734       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} --version:"]) >&AS_MESSAGE_LOG_FD 2>&1
 735       ${MAKE-make} --version >conftest.out 2>&1
 736       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
 737       result=`cat conftest.out`
 738       rm -f conftest.mk conftest.out
 739
 740       case $result in # (
 741         GNU*) ovs_cv_gnu_make=yes ;; # (
 742         *) ovs_cv_gnu_make=no ;;
 743       esac])
 744    AM_CONDITIONAL([GNU_MAKE], [test $ovs_cv_gnu_make = yes])])
 745
 746 dnl OVS_CHECK_SPARSE_TARGET
 747 dnl
 748 dnl The "cgcc" script from "sparse" isn't very good at detecting the
 749 dnl target for which the code is being built.  This helps it out.
 750 AC_DEFUN([OVS_CHECK_SPARSE_TARGET],
 751   [AC_CACHE_CHECK(
 752     [target hint for cgcc],
 753     [ac_cv_sparse_target],
 754     [AS_CASE([`$CC -dumpmachine 2>/dev/null`],
 755        [i?86-* | athlon-*], [ac_cv_sparse_target=x86],
 756        [x86_64-*], [ac_cv_sparse_target=x86_64],
 757        [ac_cv_sparse_target=other])])
 758    AS_CASE([$ac_cv_sparse_target],
 759      [x86], [SPARSEFLAGS= CGCCFLAGS=-target=i86],
 760      [x86_64], [SPARSEFLAGS=-m64 CGCCFLAGS=-target=x86_64],
 761      [SPARSEFLAGS= CGCCFLAGS=])
 762    AC_SUBST([SPARSEFLAGS])
 763    AC_SUBST([CGCCFLAGS])])
 764
 765 dnl OVS_SPARSE_EXTRA_INCLUDES
 766 dnl
 767 dnl The cgcc script from "sparse" does not search gcc's default
 768 dnl search path. Get the default search path from GCC and pass
 769 dnl them to sparse.
 770 AC_DEFUN([OVS_SPARSE_EXTRA_INCLUDES],
 771     AC_SUBST([SPARSE_EXTRA_INCLUDES],
 772            [`$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 ' ' `] ))
 773
 774 dnl OVS_ENABLE_SPARSE
 775 AC_DEFUN([OVS_ENABLE_SPARSE],
 776   [AC_REQUIRE([OVS_CHECK_SPARSE_TARGET])
 777    AC_REQUIRE([OVS_CHECK_MAKE_IF])
 778    AC_REQUIRE([OVS_SPARSE_EXTRA_INCLUDES])
 779    : ${SPARSE=sparse}
 780    AC_SUBST([SPARSE])
 781    AC_CONFIG_COMMANDS_PRE(
 782      [if test $ovs_cv_gnu_make_if = yes; then
 783         CC='$(if $(C),env REAL_CC="'"$CC"'" CHECK="$(SPARSE) -I $(top_srcdir)/include/sparse $(SPARSEFLAGS) $(SPARSE_EXTRA_INCLUDES) " cgcc $(CGCCFLAGS),'"$CC"')'
 784       fi])])
 785
 786 dnl OVS_PTHREAD_SET_NAME
 787 dnl
 788 dnl This checks for three known variants of pthreads functions for setting
 789 dnl the name of the current thread:
 790 dnl
 791 dnl   glibc: int pthread_setname_np(pthread_t, const char *name);
 792 dnl   NetBSD: int pthread_setname_np(pthread_t, const char *format, void *arg);
 793 dnl   FreeBSD: int pthread_set_name_np(pthread_t, const char *name);
 794 dnl
 795 dnl For glibc and FreeBSD, the arguments are just a thread and its name.  For
 796 dnl NetBSD, 'format' is a printf() format string and 'arg' is an argument to
 797 dnl provide to it.
 798 dnl
 799 dnl This macro defines:
 800 dnl
 801 dnl    glibc: HAVE_GLIBC_PTHREAD_SETNAME_NP
 802 dnl    NetBSD: HAVE_NETBSD_PTHREAD_SETNAME_NP
 803 dnl    FreeBSD: HAVE_PTHREAD_SET_NAME_NP
 804 AC_DEFUN([OVS_CHECK_PTHREAD_SET_NAME],
 805   [AC_CHECK_FUNCS([pthread_set_name_np])
 806    if test $ac_cv_func_pthread_set_name_np != yes; then
 807      AC_CACHE_CHECK(
 808        [for pthread_setname_np() variant],
 809        [ovs_cv_pthread_setname_np],
 810        [AC_LINK_IFELSE(
 811          [AC_LANG_PROGRAM([#include <pthread.h>
 812   ], [pthread_setname_np(pthread_self(), "name");])],
 813          [ovs_cv_pthread_setname_np=glibc],
 814          [AC_LINK_IFELSE(
 815            [AC_LANG_PROGRAM([#include <pthread.h>
 816 ], [pthread_setname_np(pthread_self(), "%s", "name");])],
 817            [ovs_cv_pthread_setname_np=netbsd],
 818            [ovs_cv_pthread_setname_np=none])])])
 819      case $ovs_cv_pthread_setname_np in # (
 820        glibc)
 821           AC_DEFINE(
 822             [HAVE_GLIBC_PTHREAD_SETNAME_NP], [1],
 823             [Define to 1 if pthread_setname_np() is available and takes 2 parameters (like glibc).])
 824           ;; # (
 825        netbsd)
 826           AC_DEFINE(
 827             [HAVE_NETBSD_PTHREAD_SETNAME_NP], [1],
 828             [Define to 1 if pthread_setname_np() is available and takes 3 parameters (like NetBSD).])
 829           ;;
 830      esac
 831    fi])
 832
 833 dnl OVS_CHECK_LINUX_HOST.
 834 dnl
 835 dnl Checks whether we're building for a Linux host, based on the presence of
 836 dnl the __linux__ preprocessor symbol, and sets up an Automake conditional
 837 dnl LINUX based on the result.
 838 AC_DEFUN([OVS_CHECK_LINUX_HOST],
 839   [AC_CACHE_CHECK(
 840      [whether __linux__ is defined],
 841      [ovs_cv_linux],
 842      [AC_COMPILE_IFELSE(
 843         [AC_LANG_PROGRAM([enum { LINUX = __linux__};], [])],
 844         [ovs_cv_linux=true],
 845         [ovs_cv_linux=false])])
 846    AM_CONDITIONAL([LINUX], [$ovs_cv_linux])])