datapath: Avoid backported csum_replace4() on RHEL 5.
[openvswitch] / acinclude.m4
1 # -*- autoconf -*-
2
3 # Copyright (c) 2008, 2009, 2010 Nicira Networks.
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_CHECK_LINUX26
18 dnl
19 dnl Configure linux kernel source tree 
20 AC_DEFUN([OVS_CHECK_LINUX26], [
21   AC_ARG_WITH([l26],
22               [AC_HELP_STRING([--with-l26=/path/to/linux-2.6],
23                               [Specify the linux 2.6 kernel build directory])],
24               [KBUILD26="$withval"], [KBUILD26=])dnl
25   AC_ARG_WITH([l26-source],
26               [AC_HELP_STRING([--with-l26-source=/path/to/linux-2.6-source],
27                               [Specify the linux 2.6 kernel source directory
28                                (usually figured out automatically from build
29                                directory)])],
30               [KSRC26="$withval"], [KSRC26=])dnl
31   if test -n "$KBUILD26"; then
32     KBUILD26=`eval echo "$KBUILD26"`
33     case $KBUILD26 in
34         /*) ;;
35         *) KBUILD26=`pwd`/$KBUILD26 ;;
36     esac
37
38     # The build directory is what the user provided.
39     # Make sure that it exists.
40     AC_MSG_CHECKING([for Linux 2.6 build directory])
41     if test -d "$KBUILD26"; then
42         AC_MSG_RESULT([$KBUILD26])
43         AC_SUBST(KBUILD26)
44     else
45         AC_MSG_RESULT([no])
46         AC_ERROR([source dir $KBUILD26 doesn't exist])
47     fi
48
49     # Debian breaks kernel headers into "source" header and "build" headers.
50     # We want the source headers, but $KBUILD26 gives us the "build" headers.
51     # Use heuristics to find the source headers.
52     AC_MSG_CHECKING([for Linux 2.6 source directory])
53     if test -n "$KSRC26"; then
54       KSRC26=`eval echo "$KSRC26"`
55       case $KSRC26 in
56           /*) ;;
57           *) KSRC26=`pwd`/$KSRC26 ;;
58       esac
59       if test ! -e $KSRC26/include/linux/kernel.h; then
60         AC_MSG_ERROR([$KSRC26 is not a kernel source directory)])
61       fi
62     else
63       KSRC26=$KBUILD26
64       if test ! -e $KSRC26/include/linux/kernel.h; then
65         case `echo "$KBUILD26" | sed 's,/*$,,'` in # (
66           */build)
67             KSRC26=`echo "$KBUILD26" | sed 's,/build/*$,/source,'`
68             ;; # (
69           *)
70             KSRC26=`(cd $KBUILD26 && pwd -P) | sed 's,-[[^-]]*$,-common,'`
71             ;;
72         esac
73       fi
74       if test ! -e $KSRC26/include/linux/kernel.h; then
75         AC_MSG_ERROR([cannot find source directory (please use --with-l26-source)])
76       fi
77     fi
78     AC_MSG_RESULT([$KSRC26])
79
80     AC_MSG_CHECKING([for kernel version])
81     patchlevel=`sed -n 's/^PATCHLEVEL = //p' "$KSRC26/Makefile"`
82     sublevel=`sed -n 's/^SUBLEVEL = //p' "$KSRC26/Makefile"`
83     if test -z "$patchlevel" || test -z "$sublevel"; then
84        AC_ERROR([cannot determine kernel version])
85     fi
86     AC_MSG_RESULT([2.$patchlevel.$sublevel])
87     if test "2.$patchlevel" != '2.6'; then
88        if test "$BUILD26" = "$KSRC26"; then
89          AC_ERROR([Linux kernel in $KBUILD26 is not version 2.6])
90        else
91          AC_ERROR([Linux kernel in build tree $KBUILD26 (source tree $KSRC26) is not version 2.6])
92        fi
93     fi
94     if test ! -e "$KBUILD26"/include/linux/version.h || \
95        (test ! -e "$KBUILD26"/include/linux/autoconf.h && \
96         test ! -e "$KBUILD26"/include/generated/autoconf.h); then
97         AC_MSG_ERROR([Linux kernel source in $KBUILD26 is not configured])
98     fi
99     OVS_CHECK_LINUX26_COMPAT
100   elif test -n "$KSRC26"; then
101     AC_MSG_ERROR([--with-l26-source may not be specified without --with-l26])
102   fi
103   AM_CONDITIONAL(L26_ENABLED, test -n "$KBUILD26")
104 ])
105
106 dnl OVS_GREP_IFELSE(FILE, REGEX, [IF-MATCH], [IF-NO-MATCH])
107 dnl
108 dnl Greps FILE for REGEX.  If it matches, runs IF-MATCH, otherwise IF-NO-MATCH.
109 dnl If IF-MATCH is empty then it defines to OVS_DEFINE(HAVE_<REGEX>), with
110 dnl <REGEX> translated to uppercase.
111 AC_DEFUN([OVS_GREP_IFELSE], [
112   AC_MSG_CHECKING([whether $2 matches in $1])
113   if test -f $1; then
114     grep '$2' $1 >/dev/null 2>&1
115     status=$?
116     case $status in
117       0) 
118         AC_MSG_RESULT([yes])
119         m4_if([$3], [], [OVS_DEFINE([HAVE_]m4_toupper([$2]))], [$3])
120         ;;
121       1) 
122         AC_MSG_RESULT([no])
123         $4
124         ;;
125       *) 
126         AC_MSG_ERROR([grep exited with status $status])
127         ;;
128     esac
129   else
130     AC_MSG_RESULT([file not found])
131     $4
132   fi
133 ])
134
135 dnl OVS_DEFINE(NAME)
136 dnl
137 dnl Defines NAME to 1 in kcompat.h.
138 AC_DEFUN([OVS_DEFINE], [
139   echo '#define $1 1' >> datapath/linux-2.6/kcompat.h.new
140 ])
141
142 AC_DEFUN([OVS_CHECK_LOG2_H], [
143   AC_MSG_CHECKING([for $KSRC26/include/linux/log2.h])
144   if test -e $KSRC26/include/linux/log2.h; then
145     AC_MSG_RESULT([yes])
146     OVS_DEFINE([HAVE_LOG2_H])
147   else
148     AC_MSG_RESULT([no])
149   fi
150 ])
151
152 dnl OVS_CHECK_LINUX26_COMPAT
153 dnl
154 dnl Runs various Autoconf checks on the Linux 2.6 kernel source in
155 dnl the directory in $KBUILD26.
156 AC_DEFUN([OVS_CHECK_LINUX26_COMPAT], [
157   rm -f datapath/linux-2.6/kcompat.h.new
158   mkdir -p datapath/linux-2.6
159   : > datapath/linux-2.6/kcompat.h.new
160
161   OVS_GREP_IFELSE([$KSRC26/arch/x86/include/asm/checksum_32.h], [src_err,],
162                   [OVS_DEFINE([HAVE_CSUM_COPY_DBG])])
163
164   OVS_GREP_IFELSE([$KSRC26/include/linux/err.h], [ERR_CAST])
165
166   OVS_GREP_IFELSE([$KSRC26/include/linux/in.h], [ipv4_is_multicast])
167
168   OVS_GREP_IFELSE([$KSRC26/include/linux/netdevice.h], [dev_disable_lro])
169   OVS_GREP_IFELSE([$KSRC26/include/linux/netdevice.h], [dev_get_stats])
170
171   # Check for the proto_data_valid member in struct sk_buff.  The [^@]
172   # is necessary because some versions of this header remove the
173   # member but retain the kerneldoc comment that describes it (which
174   # starts with @).  The brackets must be doubled because of m4
175   # quoting rules.
176   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [[[^@]]proto_data_valid],
177                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
178   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [raw],
179                   [OVS_DEFINE([HAVE_MAC_RAW])])
180   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_dst(],
181                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
182   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], 
183                   [skb_copy_from_linear_data_offset])
184   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_cow_head])
185   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_transport_header],
186                   [OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
187   OVS_GREP_IFELSE([$KSRC26/include/linux/skbuff.h], [skb_warn_if_lro],
188                   [OVS_DEFINE([HAVE_SKB_WARN_LRO])])
189
190   OVS_GREP_IFELSE([$KSRC26/include/linux/string.h], [kmemdup], [],
191                   [OVS_GREP_IFELSE([$KSRC26/include/linux/slab.h], [kmemdup])])
192
193   OVS_GREP_IFELSE([$KSRC26/include/linux/types.h], [bool],
194                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
195   OVS_GREP_IFELSE([$KSRC26/include/linux/types.h], [__wsum],
196                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
197
198   OVS_GREP_IFELSE([$KSRC26/include/net/checksum.h], [csum_replace4])
199   OVS_GREP_IFELSE([$KSRC26/include/net/checksum.h], [csum_unfold])
200
201   OVS_GREP_IFELSE([$KSRC26/include/net/netlink.h], [NLA_NUL_STRING])
202   OVS_GREP_IFELSE([$KSRC26/include/net/netlink.h], [nla_get_be16])
203
204   OVS_CHECK_LOG2_H
205
206   if cmp -s datapath/linux-2.6/kcompat.h.new \
207             datapath/linux-2.6/kcompat.h >/dev/null 2>&1; then
208     rm datapath/linux-2.6/kcompat.h.new
209   else
210     mv datapath/linux-2.6/kcompat.h.new datapath/linux-2.6/kcompat.h
211   fi
212 ])
213
214 dnl Checks for net/if_packet.h.
215 AC_DEFUN([OVS_CHECK_IF_PACKET],
216   [AC_CHECK_HEADER([net/if_packet.h],
217                    [HAVE_IF_PACKET=yes],
218                    [HAVE_IF_PACKET=no])
219    AM_CONDITIONAL([HAVE_IF_PACKET], [test "$HAVE_IF_PACKET" = yes])
220    if test "$HAVE_IF_PACKET" = yes; then
221       AC_DEFINE([HAVE_IF_PACKET], [1],
222                 [Define to 1 if net/if_packet.h is available.])
223    fi])
224
225 dnl Checks for buggy strtok_r.
226 dnl
227 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
228 dnl with optimization that can cause segfaults:
229 dnl
230 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
231 AC_DEFUN([OVS_CHECK_STRTOK_R],
232   [AC_CACHE_CHECK(
233      [whether strtok_r macro segfaults on some inputs],
234      [ovs_cv_strtok_r_bug],
235      [AC_RUN_IFELSE(
236         [AC_LANG_PROGRAM([#include <stdio.h>
237                           #include <string.h>
238                          ],
239                          [[char string[] = ":::";
240                            char *save_ptr = (char *) 0xc0ffee;
241                            char *token1, *token2;
242                            token1 = strtok_r(string, ":", &save_ptr);
243                            token2 = strtok_r(NULL, ":", &save_ptr);
244                            freopen ("/dev/null", "w", stdout);
245                            printf ("%s %s\n", token1, token2);
246                            return 0;
247                           ]])],
248         [ovs_cv_strtok_r_bug=no],
249         [ovs_cv_strtok_r_bug=yes],
250         [ovs_cv_strtok_r_bug=yes])])
251    if test $ovs_cv_strtok_r_bug = yes; then
252      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
253                [Define if strtok_r macro segfaults on some inputs])
254    fi
255 ])
256
257 dnl ----------------------------------------------------------------------
258 dnl These macros are from GNU PSPP, with the following original license:
259 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
260 dnl This file is free software; the Free Software Foundation
261 dnl gives unlimited permission to copy and/or distribute it,
262 dnl with or without modifications, as long as this notice is preserved.
263
264 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
265 dnl Check whether the given C compiler OPTION is accepted.
266 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
267 AC_DEFUN([OVS_CHECK_CC_OPTION],
268 [
269   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-], [_])])dnl
270   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name], 
271     [ovs_save_CFLAGS="$CFLAGS"
272      CFLAGS="$CFLAGS $1"
273      AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,)], [ovs_cv_name[]=yes], [ovs_cv_name[]=no])
274      CFLAGS="$ovs_save_CFLAGS"])
275   if test $ovs_cv_name = yes; then
276     m4_if([$2], [], [:], [$2])
277   else
278     m4_if([$3], [], [:], [$3])
279   fi
280 ])
281
282 dnl OVS_ENABLE_OPTION([OPTION])
283 dnl Check whether the given C compiler OPTION is accepted.
284 dnl If so, add it to WARNING_FLAGS.
285 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
286 AC_DEFUN([OVS_ENABLE_OPTION], 
287   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
288    AC_SUBST([WARNING_FLAGS])])
289
290 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
291 dnl Check whether the given C compiler OPTION is accepted.
292 dnl If so, enable the given Automake CONDITIONAL.
293
294 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
295 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
296   [OVS_CHECK_CC_OPTION(
297     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
298    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
299 dnl ----------------------------------------------------------------------