compat: Detect and use __skb_dst_copy().
[cascardo/ovs.git] / 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$DPDK_INCLUDE"
220     OVS_ENABLE_OPTION([-mssse3])
221
222     # DPDK pmd drivers are not linked unless --whole-archive is used.
223     #
224     # This happens because the rest of the DPDK code doesn't use any symbol in
225     # the pmd driver objects, and the drivers register themselves using an
226     # __attribute__((constructor)) function.
227     #
228     # These options are specified inside a single -Wl directive to prevent
229     # autotools from reordering them.
230     DPDK_vswitchd_LDFLAGS=-Wl,--whole-archive,$DPDK_LIB,--no-whole-archive
231     AC_SUBST([DPDK_vswitchd_LDFLAGS])
232     AC_DEFINE([DPDK_NETDEV], [1], [System uses the DPDK module.])
233
234   else
235     RTE_SDK=
236   fi
237
238   AM_CONDITIONAL([DPDK_NETDEV], test -n "$RTE_SDK")
239 ])
240
241 dnl OVS_GREP_IFELSE(FILE, REGEX, [IF-MATCH], [IF-NO-MATCH])
242 dnl
243 dnl Greps FILE for REGEX.  If it matches, runs IF-MATCH, otherwise IF-NO-MATCH.
244 dnl If IF-MATCH is empty then it defines to OVS_DEFINE(HAVE_<REGEX>), with
245 dnl <REGEX> translated to uppercase.
246 AC_DEFUN([OVS_GREP_IFELSE], [
247   AC_MSG_CHECKING([whether $2 matches in $1])
248   if test -f $1; then
249     grep '$2' $1 >/dev/null 2>&1
250     status=$?
251     case $status in
252       0) 
253         AC_MSG_RESULT([yes])
254         m4_if([$3], [], [OVS_DEFINE([HAVE_]m4_toupper([$2]))], [$3])
255         ;;
256       1) 
257         AC_MSG_RESULT([no])
258         $4
259         ;;
260       *) 
261         AC_MSG_ERROR([grep exited with status $status])
262         ;;
263     esac
264   else
265     AC_MSG_RESULT([file not found])
266     $4
267   fi
268 ])
269
270 dnl OVS_FIND_FIELD_IFELSE(FILE, STRUCTURE, REGEX, [IF-MATCH], [IF-NO-MATCH])
271 dnl
272 dnl Looks for STRUCTURE in FILE. If it is found, greps for REGEX within the
273 dnl structure definition. If this is successful, runs IF-MATCH, otherwise
274 dnl IF_NO_MATCH. If IF-MATCH is empty then it defines to
275 dnl OVS_DEFINE(HAVE_<STRUCTURE>_WITH_<REGEX>), with <STRUCTURE> and <REGEX>
276 dnl translated to uppercase.
277 AC_DEFUN([OVS_FIND_FIELD_IFELSE], [
278   AC_MSG_CHECKING([whether $2 has member $3 in $1])
279   if test -f $1; then
280     awk '/$2.{/,/^}/' $1 2>/dev/null | grep '$3' >/dev/null
281     status=$?
282     case $status in
283       0)
284         AC_MSG_RESULT([yes])
285         m4_if([$4], [], [OVS_DEFINE([HAVE_]m4_toupper([$2])[_WITH_]m4_toupper([$3]))], [$4])
286         ;;
287       1)
288         AC_MSG_RESULT([no])
289         $5
290         ;;
291       *)
292         AC_MSG_ERROR([grep exited with status $status])
293         ;;
294     esac
295   else
296     AC_MSG_RESULT([file not found])
297     $5
298   fi
299 ])
300
301 dnl OVS_DEFINE(NAME)
302 dnl
303 dnl Defines NAME to 1 in kcompat.h.
304 AC_DEFUN([OVS_DEFINE], [
305   echo '#define $1 1' >> datapath/linux/kcompat.h.new
306 ])
307
308 dnl OVS_CHECK_LINUX_COMPAT
309 dnl
310 dnl Runs various Autoconf checks on the Linux 2.6 kernel source in
311 dnl the directory in $KBUILD.
312 AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
313   rm -f datapath/linux/kcompat.h.new
314   mkdir -p datapath/linux
315   : > datapath/linux/kcompat.h.new
316
317   echo '#include <linux/version.h>
318 #ifndef RHEL_RELEASE_CODE
319 #define RHEL_RELEASE_CODE 0
320 #define RHEL_RELEASE_VERSION(a, b) 0
321 #endif' >> datapath/linux/kcompat.h.new
322
323   OVS_GREP_IFELSE([$KSRC/arch/x86/include/asm/checksum_32.h], [src_err,],
324                   [OVS_DEFINE([HAVE_CSUM_COPY_DBG])])
325
326   OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_dst_lookup.*net],
327                   [OVS_DEFINE([HAVE_IPV6_DST_LOOKUP_NET])])
328   OVS_GREP_IFELSE([$KSRC/include/net/addrconf.h], [ipv6_stub])
329
330   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [ERR_CAST])
331   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [IS_ERR_OR_NULL])
332
333   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [eth_hw_addr_random])
334   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [ether_addr_copy])
335
336   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [IFLA_GENEVE_TOS])
337   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/if_link.h], [rtnl_link_stats64])
338   OVS_GREP_IFELSE([$KSRC/include/linux/if_link.h], [rtnl_link_stats64])
339   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_set_encap_proto])
340   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_hwaccel_push_inside])
341
342   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [ipv4_is_multicast])
343   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [proto_ports_offset])
344   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*dst_entry],
345                   [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_DST_ENTRY])])
346   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [__ip_select_ident.*net],
347                   [OVS_DEFINE([HAVE_IP_SELECT_IDENT_USING_NET])])
348
349   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [inet_get_local_port_range.*net],
350                   [OVS_DEFINE([HAVE_INET_GET_LOCAL_PORT_RANGE_USING_NET])])
351   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_do_fragment])
352   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_is_fragment])
353   OVS_GREP_IFELSE([$KSRC/include/net/ip.h], [ip_skb_dst_mtu])
354   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [hashfn.*const],
355                   [OVS_DEFINE([HAVE_INET_FRAGS_CONST])])
356   OVS_GREP_IFELSE([$KSRC/include/net/inet_frag.h], [last_in],
357                   [OVS_DEFINE([HAVE_INET_FRAGS_LAST_IN])])
358   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
359                         [frags_work])
360   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/inet_frag.h], [inet_frags],
361                         [rwlock])
362
363   OVS_GREP_IFELSE([$KSRC/include/net/dst_metadata.h], [metadata_dst])
364
365   OVS_GREP_IFELSE([$KSRC/include/linux/net.h], [sock_create_kern.*net],
366                   [OVS_DEFINE([HAVE_SOCK_CREATE_KERN_NET])])
367   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_disable_lro])
368   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_stats])
369   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_by_index_rcu])
370   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_recursion_level])
371   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [__skb_gso_segment])
372   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [can_checksum_protocol])
373   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [ndo_get_iflink])
374   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_features_t])
375   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [pcpu_sw_netstats])
376   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netdev_rx_handler_register])
377   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [net_device_extended])
378   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [rx_handler_func_t.*pskb],
379                   [OVS_DEFINE([HAVE_RX_HANDLER_PSKB])])
380   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netif_needs_gso.*net_device],
381                   [OVS_DEFINE([HAVE_NETIF_NEEDS_GSO_NETDEV])])
382   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload])
383   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload.*uoff],
384                   [OVS_DEFINE([HAVE_UDP_OFFLOAD_ARG_UOFF])])
385   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [gro_remcsum])
386
387   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hook_state])
388   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_register_net_hook])
389   OVS_GREP_IFELSE([$KSRC/include/linux/netfilter.h], [nf_hookfn.*nf_hook_ops],
390                   [OVS_DEFINE([HAVE_NF_HOOKFN_ARG_OPS])])
391   OVS_FIND_FIELD_IFELSE([$KSRC/include/linux/netfilter_ipv6.h], [nf_ipv6_ops],
392                         [fragment], [OVS_DEFINE([HAVE_NF_IPV6_OPS_FRAGMENT])])
393
394   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack.h],
395                   [tmpl_alloc.*conntrack_zone],
396                   [OVS_DEFINE([HAVE_NF_CT_TMPL_ALLOC_TAKES_STRUCT_ZONE])])
397   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_zones.h],
398                   [nf_ct_zone_init])
399   OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_labels.h],
400                   [nf_connlabels_get])
401
402   OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32])
403   OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32_max])
404
405   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [get_link_net])
406   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [name_assign_type])
407   OVS_GREP_IFELSE([$KSRC/include/net/rtnetlink.h], [rtnl_create_link.*src_net],
408                   [OVS_DEFINE([HAVE_RTNL_CREATE_LINK_SRC_NET])])
409   OVS_GREP_IFELSE([$KSRC/include/net/net_namespace.h], [possible_net_t])
410
411   OVS_GREP_IFELSE([$KSRC/include/linux/rcupdate.h], [rcu_read_lock_held], [],
412                   [OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h],
413                                    [rcu_read_lock_held])])
414   OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h], [lockdep_rtnl_is_held])
415   
416   # Check for the proto_data_valid member in struct sk_buff.  The [^@]
417   # is necessary because some versions of this header remove the
418   # member but retain the kerneldoc comment that describes it (which
419   # starts with @).  The brackets must be doubled because of m4
420   # quoting rules.
421   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
422                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
423   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_checksum_start_offset])
424   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_protocol])
425   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_mac_header])
426   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [inner_network_header])
427   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [kfree_skb_list])
428   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_scrub_packet.*xnet],
429                   [OVS_DEFINE([HAVE_SKB_SCRUB_PACKET_XNET])])
430   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [rxhash])
431   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u16.*rxhash],
432                   [OVS_DEFINE([HAVE_U16_RXHASH])])
433   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
434                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
435   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], 
436                   [skb_copy_from_linear_data_offset])
437   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
438                   [skb_reset_tail_pointer])
439   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
440   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_transport_header],
441                   [OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
442   OVS_GREP_IFELSE([$KSRC/include/linux/icmpv6.h], [icmp6_hdr],
443                   [OVS_DEFINE([HAVE_ICMP6_HDR])])
444   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_warn_if_lro],
445                   [OVS_DEFINE([HAVE_SKB_WARN_LRO])])
446   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [consume_skb])
447   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_frag_page])
448   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_has_frag_list])
449   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [__skb_fill_page_desc])
450   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_reset_mac_len])
451   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_unclone])
452   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_orphan_frags])
453   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_get_hash])
454   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_clear_hash])
455   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [int.skb_zerocopy(],
456                   [OVS_DEFINE([HAVE_SKB_ZEROCOPY])])
457   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [u8.*l4_rxhash],
458                   [OVS_DEFINE([HAVE_L4_RXHASH])])
459   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_ensure_writable])
460   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_vlan_pop])
461   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_vlan_push])
462
463   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [bool],
464                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
465   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [__wsum],
466                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
467   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/types.h], [__wsum],
468                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
469
470   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_replace4])
471   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_unfold])
472
473   OVS_GREP_IFELSE([$KSRC/include/net/dst.h], [dst_discard_sk])
474   OVS_GREP_IFELSE([$KSRC/include/net/dst.h], [__skb_dst_copy])
475
476   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genl_has_listeners])
477   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [mcgrp_offset])
478   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [parallel_ops])
479   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genlmsg_new_unicast])
480   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [netlink_has_listeners(net->genl_sock],
481                   [OVS_DEFINE([HAVE_GENL_HAS_LISTENERS_TAKES_NET])])
482   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genlmsg_parse])
483   OVS_GREP_IFELSE([$KSRC/include/net/genetlink.h], [genl_notify.*family],
484                   [OVS_DEFINE([HAVE_GENL_NOTIFY_TAKES_FAMILY])])
485
486   OVS_FIND_FIELD_IFELSE([$KSRC/include/net/genetlink.h],
487                         [genl_multicast_group], [id])
488   OVS_GREP_IFELSE([$KSRC/include/net/geneve.h], [geneve_hdr])
489
490   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_cisco_register])
491   OVS_GREP_IFELSE([$KSRC/include/net/gre.h], [gre_handle_offloads])
492   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [IP6_FH_F_SKIP_RH])
493   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [ip6_local_out_sk])
494   OVS_GREP_IFELSE([$KSRC/include/net/ipv6.h], [__ipv6_addr_jhash])
495   OVS_GREP_IFELSE([$KSRC/include/net/ip6_fib.h], [rt6i.*u.dst],
496                   [OVS_DEFINE([HAVE_RT6INFO_DST_UNION])])
497   OVS_GREP_IFELSE([$KSRC/include/net/ip6_route.h], [ip6_frag.*sock],
498                   [OVS_DEFINE([HAVE_IP_FRAGMENT_TAKES_SOCK])])
499
500   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_get_be16])
501   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be16])
502   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be32])
503   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be64])
504   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_in_addr])
505   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
506   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_is_last])
507   OVS_GREP_IFELSE([$KSRC/include/linux/netlink.h], [void.*netlink_set_err],
508                   [OVS_DEFINE([HAVE_VOID_NETLINK_SET_ERR])])
509
510   OVS_GREP_IFELSE([$KSRC/include/net/sctp/checksum.h], [sctp_compute_cksum])
511
512   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
513                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
514   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_insert_tag_set_proto])
515   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [__vlan_insert_tag])
516   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_get_protocol])
517
518   OVS_GREP_IFELSE([$KSRC/include/linux/u64_stats_sync.h], [u64_stats_fetch_begin_irq])
519
520   OVS_GREP_IFELSE([$KSRC/include/linux/openvswitch.h], [openvswitch_handle_frame_hook],
521                   [OVS_DEFINE([HAVE_RHEL_OVS_HOOK])])
522   OVS_GREP_IFELSE([$KSRC/include/net/vxlan.h], [struct vxlan_metadata],
523                   [OVS_DEFINE([HAVE_VXLAN_METADATA])])
524   OVS_GREP_IFELSE([$KSRC/include/net/vxlan.h], [VXLAN_HF_RCO])
525   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_flow_src_port],
526                   [OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [inet_get_local_port_range(net],
527                                    [OVS_DEFINE([HAVE_UDP_FLOW_SRC_PORT])])])
528   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_v4_check])
529   OVS_GREP_IFELSE([$KSRC/include/net/udp.h], [udp_set_csum])
530   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [udp_tunnel_gro_complete])
531   OVS_GREP_IFELSE([$KSRC/include/net/udp_tunnel.h], [ipv6_v6only],
532                   [OVS_DEFINE([HAVE_UDP_TUNNEL_IPV6])])
533
534   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [ignore_df],
535                   [OVS_DEFINE([HAVE_IGNORE_DF_RENAME])])
536   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/netdevice.h], [NET_NAME_UNKNOWN],
537                   [OVS_DEFINE([HAVE_NET_NAME_UNKNOWN])])
538
539   OVS_GREP_IFELSE([$KSRC/include/linux/utsrelease.h], [el6],
540                   [OVS_DEFINE([HAVE_RHEL6_PER_CPU])])
541
542   if test "$version" = 4 && test "$patchlevel" -le 2; then
543         OVS_DEFINE([OVS_FRAGMENT_BACKPORT])
544   elif test "$version" = 3 && test "$patchlevel" -ge 10; then
545         OVS_DEFINE([OVS_FRAGMENT_BACKPORT])
546   fi
547
548   if cmp -s datapath/linux/kcompat.h.new \
549             datapath/linux/kcompat.h >/dev/null 2>&1; then
550     rm datapath/linux/kcompat.h.new
551   else
552     mv datapath/linux/kcompat.h.new datapath/linux/kcompat.h
553   fi
554 ])
555
556 dnl Checks for net/if_packet.h.
557 AC_DEFUN([OVS_CHECK_IF_PACKET],
558   [AC_CHECK_HEADER([net/if_packet.h],
559                    [HAVE_IF_PACKET=yes],
560                    [HAVE_IF_PACKET=no])
561    AM_CONDITIONAL([HAVE_IF_PACKET], [test "$HAVE_IF_PACKET" = yes])
562    if test "$HAVE_IF_PACKET" = yes; then
563       AC_DEFINE([HAVE_IF_PACKET], [1],
564                 [Define to 1 if net/if_packet.h is available.])
565    fi])
566
567 dnl Checks for net/if_dl.h.
568 dnl
569 dnl (We use this as a proxy for checking whether we're building on FreeBSD
570 dnl or NetBSD.)
571 AC_DEFUN([OVS_CHECK_IF_DL],
572   [AC_CHECK_HEADER([net/if_dl.h],
573                    [HAVE_IF_DL=yes],
574                    [HAVE_IF_DL=no])
575    AM_CONDITIONAL([HAVE_IF_DL], [test "$HAVE_IF_DL" = yes])
576    if test "$HAVE_IF_DL" = yes; then
577       AC_DEFINE([HAVE_IF_DL], [1],
578                 [Define to 1 if net/if_dl.h is available.])
579
580       # On these platforms we use libpcap to access network devices.
581       AC_SEARCH_LIBS([pcap_open_live], [pcap])
582    fi])
583
584 dnl Checks for buggy strtok_r.
585 dnl
586 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
587 dnl with optimization that can cause segfaults:
588 dnl
589 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
590 AC_DEFUN([OVS_CHECK_STRTOK_R],
591   [AC_CACHE_CHECK(
592      [whether strtok_r macro segfaults on some inputs],
593      [ovs_cv_strtok_r_bug],
594      [AC_RUN_IFELSE(
595         [AC_LANG_PROGRAM([#include <stdio.h>
596                           #include <string.h>
597                          ],
598                          [[#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
599                            /* Assume bug is present, because relatively minor
600                               changes in compiler settings (e.g. optimization
601                               level) can make it crop up. */
602                            return 1;
603                            #else
604                            char string[] = ":::";
605                            char *save_ptr = (char *) 0xc0ffee;
606                            char *token1, *token2;
607                            token1 = strtok_r(string, ":", &save_ptr);
608                            token2 = strtok_r(NULL, ":", &save_ptr);
609                            freopen ("/dev/null", "w", stdout);
610                            printf ("%s %s\n", token1, token2);
611                            return 0;
612                            #endif
613                           ]])],
614         [ovs_cv_strtok_r_bug=no],
615         [ovs_cv_strtok_r_bug=yes],
616         [ovs_cv_strtok_r_bug=yes])])
617    if test $ovs_cv_strtok_r_bug = yes; then
618      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
619                [Define if strtok_r macro segfaults on some inputs])
620    fi
621 ])
622
623 dnl ----------------------------------------------------------------------
624 dnl These macros are from GNU PSPP, with the following original license:
625 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
626 dnl This file is free software; the Free Software Foundation
627 dnl gives unlimited permission to copy and/or distribute it,
628 dnl with or without modifications, as long as this notice is preserved.
629
630 AC_DEFUN([_OVS_CHECK_CC_OPTION], [dnl
631   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-=], [__])])dnl
632   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name], 
633     [ovs_save_CFLAGS="$CFLAGS"
634      dnl Include -Werror in the compiler options, because without -Werror
635      dnl clang's GCC-compatible compiler driver does not return a failure
636      dnl exit status even though it complains about options it does not
637      dnl understand.
638      dnl
639      dnl Also, check stderr as gcc exits with status 0 for options
640      dnl rejected at getopt level.
641      dnl    % touch /tmp/a.c
642      dnl    % gcc -g -c -Werror -Qunused-arguments /tmp/a.c; echo $?
643      dnl    gcc: unrecognized option '-Qunused-arguments'
644      dnl    0
645      dnl    %
646      CFLAGS="$CFLAGS $WERROR $1"
647      AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,)], [if test -s conftest.err && grep "unrecognized option" conftest.err; then ovs_cv_name[]=no; else ovs_cv_name[]=yes; fi], [ovs_cv_name[]=no])
648      CFLAGS="$ovs_save_CFLAGS"])
649   if test $ovs_cv_name = yes; then
650     m4_if([$2], [], [:], [$2])
651   else
652     m4_if([$3], [], [:], [$3])
653   fi
654 ])
655
656 dnl OVS_CHECK_WERROR
657 dnl
658 dnl Check whether the C compiler accepts -Werror.
659 dnl Sets $WERROR to "-Werror", if so, and otherwise to the empty string.
660 AC_DEFUN([OVS_CHECK_WERROR],
661   [WERROR=
662    _OVS_CHECK_CC_OPTION([-Werror], [WERROR=-Werror])])
663
664 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
665 dnl Check whether the given C compiler OPTION is accepted.
666 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
667 AC_DEFUN([OVS_CHECK_CC_OPTION],
668   [AC_REQUIRE([OVS_CHECK_WERROR])
669    _OVS_CHECK_CC_OPTION([$1], [$2], [$3])])
670
671 dnl OVS_ENABLE_OPTION([OPTION])
672 dnl Check whether the given C compiler OPTION is accepted.
673 dnl If so, add it to WARNING_FLAGS.
674 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
675 AC_DEFUN([OVS_ENABLE_OPTION], 
676   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
677    AC_SUBST([WARNING_FLAGS])])
678
679 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
680 dnl Check whether the given C compiler OPTION is accepted.
681 dnl If so, enable the given Automake CONDITIONAL.
682
683 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
684 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
685   [OVS_CHECK_CC_OPTION(
686     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
687    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
688 dnl ----------------------------------------------------------------------
689
690 dnl Check for too-old XenServer.
691 AC_DEFUN([OVS_CHECK_XENSERVER_VERSION],
692   [AC_CACHE_CHECK([XenServer release], [ovs_cv_xsversion],
693     [if test -e /etc/redhat-release; then
694        ovs_cv_xsversion=`sed -n 's/^XenServer DDK release \([[^-]]*\)-.*/\1/p' /etc/redhat-release`
695      fi
696      if test -z "$ovs_cv_xsversion"; then
697        ovs_cv_xsversion=none
698      fi])
699   case $ovs_cv_xsversion in
700     none)
701       ;;
702
703     [[1-9]][[0-9]]* |                    dnl XenServer 10 or later
704     [[6-9]]* |                           dnl XenServer 6 or later
705     5.[[7-9]]* |                         dnl XenServer 5.7 or later
706     5.6.[[1-9]][[0-9]][[0-9]][[0-9]]* |  dnl XenServer 5.6.1000 or later
707     5.6.[[2-9]][[0-9]][[0-9]]* |         dnl XenServer 5.6.200 or later
708     5.6.1[[0-9]][[0-9]])                 dnl Xenserver 5.6.100 or later
709       ;;
710
711     *)
712       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.)])
713       ;;
714   esac])
715
716 dnl OVS_MAKE_HAS_IF([if-true], [if-false])
717 dnl
718 dnl Checks whether make has the GNU make $(if condition,then,else) extension.
719 dnl Runs 'if-true' if so, 'if-false' otherwise.
720 AC_DEFUN([OVS_CHECK_MAKE_IF],
721   [AC_CACHE_CHECK(
722      [whether ${MAKE-make} has GNU make \$(if) extension],
723      [ovs_cv_gnu_make_if],
724      [cat <<'EOF' > conftest.mk
725 conftest.out:
726         echo $(if x,y,z) > conftest.out
727 .PHONY: all
728 EOF
729       rm -f conftest.out
730       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} -f conftest.mk all:"]) >&AS_MESSAGE_LOG_FD 2>&1
731       ${MAKE-make} -f conftest.mk conftest.out >&AS_MESSAGE_LOG_FD 2>&1
732       AS_ECHO(["$as_me:$LINENO: conftest.out contains:"]) >&AS_MESSAGE_LOG_FD 2>&1
733       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
734       result=`cat conftest.out`
735       rm -f conftest.mk conftest.out
736       if test "X$result" = "Xy"; then
737         ovs_cv_gnu_make_if=yes
738       else
739         ovs_cv_gnu_make_if=no
740       fi])])
741
742 dnl OVS_CHECK_GNU_MAKE
743 dnl
744 dnl Checks whether make is GNU make (because Linux kernel Makefiles
745 dnl only work with GNU make).
746 AC_DEFUN([OVS_CHECK_GNU_MAKE],
747   [AC_CACHE_CHECK(
748      [whether ${MAKE-make} is GNU make],
749      [ovs_cv_gnu_make],
750      [rm -f conftest.out
751       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} --version:"]) >&AS_MESSAGE_LOG_FD 2>&1
752       ${MAKE-make} --version >conftest.out 2>&1
753       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
754       result=`cat conftest.out`
755       rm -f conftest.mk conftest.out
756
757       case $result in # (
758         GNU*) ovs_cv_gnu_make=yes ;; # (
759         *) ovs_cv_gnu_make=no ;;
760       esac])
761    AM_CONDITIONAL([GNU_MAKE], [test $ovs_cv_gnu_make = yes])])
762
763 dnl OVS_CHECK_SPARSE_TARGET
764 dnl
765 dnl The "cgcc" script from "sparse" isn't very good at detecting the
766 dnl target for which the code is being built.  This helps it out.
767 AC_DEFUN([OVS_CHECK_SPARSE_TARGET],
768   [AC_CACHE_CHECK(
769     [target hint for cgcc],
770     [ac_cv_sparse_target],
771     [AS_CASE([`$CC -dumpmachine 2>/dev/null`],
772        [i?86-* | athlon-*], [ac_cv_sparse_target=x86],
773        [x86_64-*], [ac_cv_sparse_target=x86_64],
774        [ac_cv_sparse_target=other])])
775    AS_CASE([$ac_cv_sparse_target],
776      [x86], [SPARSEFLAGS= CGCCFLAGS=-target=i86],
777      [x86_64], [SPARSEFLAGS=-m64 CGCCFLAGS=-target=x86_64],
778      [SPARSEFLAGS= CGCCFLAGS=])
779    AC_SUBST([SPARSEFLAGS])
780    AC_SUBST([CGCCFLAGS])])
781
782 dnl OVS_SPARSE_EXTRA_INCLUDES
783 dnl
784 dnl The cgcc script from "sparse" does not search gcc's default
785 dnl search path. Get the default search path from GCC and pass
786 dnl them to sparse.
787 AC_DEFUN([OVS_SPARSE_EXTRA_INCLUDES],
788     AC_SUBST([SPARSE_EXTRA_INCLUDES],
789            [`$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 ' ' `] ))
790
791 dnl OVS_ENABLE_SPARSE
792 AC_DEFUN([OVS_ENABLE_SPARSE],
793   [AC_REQUIRE([OVS_CHECK_SPARSE_TARGET])
794    AC_REQUIRE([OVS_CHECK_MAKE_IF])
795    AC_REQUIRE([OVS_SPARSE_EXTRA_INCLUDES])
796    : ${SPARSE=sparse}
797    AC_SUBST([SPARSE])
798    AC_CONFIG_COMMANDS_PRE(
799      [if test $ovs_cv_gnu_make_if = yes; then
800         CC='$(if $(C),env REAL_CC="'"$CC"'" CHECK="$(SPARSE) -I $(top_srcdir)/include/sparse $(SPARSEFLAGS) $(SPARSE_EXTRA_INCLUDES) " cgcc $(CGCCFLAGS),'"$CC"')'
801       fi])])
802
803 dnl OVS_PTHREAD_SET_NAME
804 dnl
805 dnl This checks for three known variants of pthreads functions for setting
806 dnl the name of the current thread:
807 dnl
808 dnl   glibc: int pthread_setname_np(pthread_t, const char *name);
809 dnl   NetBSD: int pthread_setname_np(pthread_t, const char *format, void *arg);
810 dnl   FreeBSD: int pthread_set_name_np(pthread_t, const char *name);
811 dnl
812 dnl For glibc and FreeBSD, the arguments are just a thread and its name.  For
813 dnl NetBSD, 'format' is a printf() format string and 'arg' is an argument to
814 dnl provide to it.
815 dnl
816 dnl This macro defines:
817 dnl
818 dnl    glibc: HAVE_GLIBC_PTHREAD_SETNAME_NP
819 dnl    NetBSD: HAVE_NETBSD_PTHREAD_SETNAME_NP
820 dnl    FreeBSD: HAVE_PTHREAD_SET_NAME_NP
821 AC_DEFUN([OVS_CHECK_PTHREAD_SET_NAME],
822   [AC_CHECK_FUNCS([pthread_set_name_np])
823    if test $ac_cv_func_pthread_set_name_np != yes; then
824      AC_CACHE_CHECK(
825        [for pthread_setname_np() variant],
826        [ovs_cv_pthread_setname_np],
827        [AC_LINK_IFELSE(
828          [AC_LANG_PROGRAM([#include <pthread.h>
829   ], [pthread_setname_np(pthread_self(), "name");])],
830          [ovs_cv_pthread_setname_np=glibc],
831          [AC_LINK_IFELSE(
832            [AC_LANG_PROGRAM([#include <pthread.h>
833 ], [pthread_setname_np(pthread_self(), "%s", "name");])],
834            [ovs_cv_pthread_setname_np=netbsd],
835            [ovs_cv_pthread_setname_np=none])])])
836      case $ovs_cv_pthread_setname_np in # (
837        glibc)
838           AC_DEFINE(
839             [HAVE_GLIBC_PTHREAD_SETNAME_NP], [1],
840             [Define to 1 if pthread_setname_np() is available and takes 2 parameters (like glibc).])
841           ;; # (
842        netbsd)
843           AC_DEFINE(
844             [HAVE_NETBSD_PTHREAD_SETNAME_NP], [1],
845             [Define to 1 if pthread_setname_np() is available and takes 3 parameters (like NetBSD).])
846           ;;
847      esac
848    fi])
849
850 dnl OVS_CHECK_LINUX_HOST.
851 dnl
852 dnl Checks whether we're building for a Linux host, based on the presence of
853 dnl the __linux__ preprocessor symbol, and sets up an Automake conditional
854 dnl LINUX based on the result.
855 AC_DEFUN([OVS_CHECK_LINUX_HOST],
856   [AC_CACHE_CHECK(
857      [whether __linux__ is defined],
858      [ovs_cv_linux],
859      [AC_COMPILE_IFELSE(
860         [AC_LANG_PROGRAM([enum { LINUX = __linux__};], [])],
861         [ovs_cv_linux=true],
862         [ovs_cv_linux=false])])
863    AM_CONDITIONAL([LINUX], [$ovs_cv_linux])])