[RFC] iproute: Support cross-compiling.

[RFC] iproute: Support cross-compiling.

[greearb]

From: Ben Greear <greearb@candelatech.com>

This lets users use their own compiler instead of
hard-coding to use gcc.

Also adds tests to disable some things that were not supported
in my ARM cross-compile toolchain.

Signed-off-by: Ben Greear <greearb@candelatech.com>
---
:100644 100644 c6e4943... 3b00076... M	Makefile
:100755 100755 f5c3d40... 680fdcb... M	configure
:100644 100644 8d03993... 5c91e18... M	ip/Makefile
:100644 100644 e41a598... 773f7cb... M	ip/ipnetns.c
:100644 100644 8c25381... d04358d... M	misc/Makefile
 Makefile      |    2 +-
 configure     |   88 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 ip/Makefile   |    8 +++++
 ip/ipnetns.c  |   17 +++++++++++
 misc/Makefile |    5 +++
 5 files changed, 114 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index c6e4943..3b00076 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@ ADDLIB+=dnet_ntop.o dnet_pton.o
 #options for ipx
 ADDLIB+=ipx_ntop.o ipx_pton.o
 
-CC = gcc
+CC ?= gcc
 HOSTCC = gcc
 CCOPTS = -D_GNU_SOURCE -O2 -Wstrict-prototypes -Wall
 CFLAGS = $(CCOPTS) -I../include $(DEFINES)
diff --git a/configure b/configure
index f5c3d40..680fdcb 100755
--- a/configure
+++ b/configure
@@ -3,6 +3,11 @@
 #
 INCLUDE=${1:-"$PWD/include"}
 
+if [ "_$CC" == "_" ]
+then
+    CC=gcc
+fi
+
 check_atm()
 {
 cat >/tmp/atmtest.c <<EOF
@@ -13,7 +18,7 @@ int main(int argc, char **argv) {
 	return 0;
 }
 EOF
-gcc -I$INCLUDE -o /tmp/atmtest /tmp/atmtest.c -latm >/dev/null 2>&1 
+${CC} -I$INCLUDE -o /tmp/atmtest /tmp/atmtest.c -latm >/dev/null 2>&1
 if [ $? -eq 0 ]
 then
     echo "TC_CONFIG_ATM:=y" >>Config
@@ -47,7 +52,7 @@ int main(int argc, char **argv)
 
 EOF
 
-if gcc -I$INCLUDE $IPTC -o /tmp/ipttest /tmp/ipttest.c $IPTL -ldl -lxtables >/dev/null 2>&1
+if ${CC} -I$INCLUDE $IPTC -o /tmp/ipttest /tmp/ipttest.c $IPTL -ldl -lxtables >/dev/null 2>&1
 then
 	echo "TC_CONFIG_XT:=y" >>Config
 	echo "using xtables"
@@ -84,7 +89,7 @@ int main(int argc, char **argv) {
 }
 
 EOF
-gcc -I$INCLUDE $IPTC -o /tmp/ipttest /tmp/ipttest.c $IPTL -ldl >/dev/null 2>&1
+${CC} -I$INCLUDE $IPTC -o /tmp/ipttest /tmp/ipttest.c $IPTL -ldl >/dev/null 2>&1
 
 if [ $? -eq 0 ]
 then
@@ -124,7 +129,7 @@ int main(int argc, char **argv) {
 }
 
 EOF
-gcc -I$INCLUDE $IPTC -o /tmp/ipttest /tmp/ipttest.c $IPTL -ldl >/dev/null 2>&1
+${CC} -I$INCLUDE $IPTC -o /tmp/ipttest /tmp/ipttest.c $IPTL -ldl >/dev/null 2>&1
 
 if [ $? -eq 0 ]
 then
@@ -168,7 +173,7 @@ int main(int argc, char **argv)
 	return 0;
 }
 EOF
-gcc -I$INCLUDE -o /tmp/setnstest /tmp/setnstest.c >/dev/null 2>&1
+${CC} -I$INCLUDE -o /tmp/setnstest /tmp/setnstest.c >/dev/null 2>&1
 if [ $? -eq 0 ]
 then
 	echo "IP_CONFIG_SETNS:=y" >>Config
@@ -179,6 +184,70 @@ fi
 rm -f /tmp/setnstest.c /tmp/setnstest
 }
 
+check_inotify()
+{
+cat >/tmp/inotify_test.c <<EOF
+#include <sys/inotify.h>
+int main(int argc, char **argv)
+{
+	return 0;
+}
+EOF
+${CC} -I$INCLUDE -o /tmp/inotify_test /tmp/inotify_test.c >/dev/null 2>&1
+if [ $? -eq 0 ]
+then
+	echo "yes"
+else
+	echo "IP_CONFIG_DISABLE_INOTIFY:=y" >>Config
+	echo "no"
+fi
+rm -f /tmp/inotify_test.c /tmp/inotify_test
+}
+
+
+check_unshare()
+{
+cat >/tmp/unshare_test.c <<EOF
+#define _GNU_SOURCE             /* See feature_test_macros(7) */
+#include <sched.h>
+int main(int argc, char **argv)
+{
+	return unshare(0); /* 0 == no op */
+}
+EOF
+${CC} -I$INCLUDE -o /tmp/unshare_test /tmp/unshare_test.c >/dev/null 2>&1
+if [ $? -eq 0 ]
+then
+	echo "yes"
+else
+	echo "IP_CONFIG_DISABLE_UNSHARE:=y" >>Config
+	echo "no"
+fi
+rm -f /tmp/unshare_test.c /tmp/unshare_test
+}
+
+
+check_db185()
+{
+cat >/tmp/db185_test.c <<EOF
+#include <db_185.h>
+int main(int argc, char **argv)
+{
+	return 0;
+}
+EOF
+${CC} -I$INCLUDE -o /tmp/db185_test /tmp/db185_test.c >/dev/null 2>&1
+if [ $? -eq 0 ]
+then
+	echo "yes"
+else
+	echo "IP_CONFIG_DISABLE_DB185:=y" >>Config
+	echo "no"
+fi
+rm -f /tmp/db185_test.c /tmp/db185_test
+}
+
+
 echo "# Generated config based on" $INCLUDE >Config
 
 echo "TC schedulers"
@@ -197,3 +266,12 @@ check_ipt_lib_dir
 
 echo -n "libc has setns: "
 check_setns
+
+echo -n "libc has inotify support: "
+check_inotify
+
+echo -n "libc has unshare support: "
+check_unshare
+
+echo -n "libc has db_185 support: "
+check_db185
diff --git a/ip/Makefile b/ip/Makefile
index 8d03993..5c91e18 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -13,6 +13,14 @@ ifeq ($(IP_CONFIG_SETNS),y)
 	CFLAGS += -DHAVE_SETNS
 endif
 
+ifeq ($(IP_CONFIG_DISABLE_INOTIFY),y)
+	CFLAGS += -DDISABLE_INOTIFY
+endif
+
+ifeq ($(IP_CONFIG_DISABLE_UNSHARE),y)
+	CFLAGS += -DCONFIG_IP_NO_UNSHARE
+endif
+
 ALLOBJ=$(IPOBJ) $(RTMONOBJ)
 SCRIPTS=ifcfg rtpr routel routef
 TARGETS=ip rtmon
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index e41a598..773f7cb 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -2,7 +2,9 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#ifndef DISABLE_INOTIFY
 #include <sys/inotify.h>
+#endif
 #include <sys/mount.h>
 #include <sys/param.h>
 #include <sys/syscall.h>
@@ -118,6 +120,10 @@ static void bind_etc(const char *name)
 
 static int netns_exec(int argc, char **argv)
 {
+#ifdef CONFIG_IP_NO_UNSHARE
+	fprintf(stderr, "No unshare on this platform, cannod do netns_exec\n");
+	return -1;
+#else
 	/* Setup the proper environment for apps that are not netns
 	 * aware, and execute a program in that environment.
 	 */
@@ -169,6 +175,7 @@ static int netns_exec(int argc, char **argv)
 		fprintf(stderr, "exec of %s failed: %s\n",
 			cmd, strerror(errno));
 	exit(-1);
+#endif
 }
 
 static int netns_delete(int argc, char **argv)
@@ -194,6 +201,10 @@ static int netns_delete(int argc, char **argv)
 
 static int netns_add(int argc, char **argv)
 {
+#ifdef CONFIG_IP_NO_UNSHARE
+	fprintf(stderr, "No unshare on this platform, cannod do netns_add\n");
+	return -1;
+#else
 	/* This function creates a new network namespace and
 	 * a new mount namespace and bind them into a well known
 	 * location in the filesystem based on the name provided.
@@ -242,11 +253,16 @@ out_delete:
 	netns_delete(argc, argv);
 	exit(-1);
 	return -1;
+#endif
 }
 
 
 static int netns_monitor(int argc, char **argv)
 {
+#ifdef DISABLE_INOTIFY
+	fprintf(stderr, "inotify not supported (compiled out)\n");
+	return -1;
+#else
 	char buf[4096];
 	struct inotify_event *event;
 	int fd;
@@ -278,6 +294,7 @@ static int netns_monitor(int argc, char **argv)
 		}
 	}
 	return 0;
+#endif
 }
 
 int do_netns(int argc, char **argv)
diff --git a/misc/Makefile b/misc/Makefile
index 8c25381..d04358d 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -18,8 +18,13 @@ ifstat: ifstat.c
 rtacct: rtacct.c
 	$(CC) $(CFLAGS) $(LDFLAGS) -o rtacct rtacct.c $(LIBNETLINK) -lm
 
+ifeq ($(IP_CONFIG_DISABLE_DB185),y)
+arpd:
+	@echo "Cannot build arpd on this system, no db_185.h file."
+else
 arpd: arpd.c
 	$(CC) $(CFLAGS) -I$(DBM_INCLUDE) $(LDFLAGS) -o arpd arpd.c $(LIBNETLINK) -ldb -lpthread
+endif
 
 ssfilter.c: ssfilter.y
 	bison ssfilter.y -o ssfilter.c
-- 
1.7.3.4

Re: [RFC] iproute: Support cross-compiling.

[Stephen Hemminger]

On Tue, 15 Nov 2011 17:04:42 -0800
greearb@candelatech.com wrote:

> From: Ben Greear <greearb@candelatech.com>
> 
> This lets users use their own compiler instead of
> hard-coding to use gcc.
> 
> Also adds tests to disable some things that were not supported
> in my ARM cross-compile toolchain.
> 
> Signed-off-by: Ben Greear <greearb@candelatech.com>

Can't you do this by setting up the compile environment better?
I would rather have the tools work with all features and handle
errors from kernel rather than neutering it.

Re: [RFC] iproute: Support cross-compiling.

[Ben Greear]

On 11/15/2011 05:17 PM, Stephen Hemminger wrote:
> On Tue, 15 Nov 2011 17:04:42 -0800
> greearb@candelatech.com wrote:
>
>> From: Ben Greear<greearb@candelatech.com>
>>
>> This lets users use their own compiler instead of
>> hard-coding to use gcc.
>>
>> Also adds tests to disable some things that were not supported
>> in my ARM cross-compile toolchain.
>>
>> Signed-off-by: Ben Greear<greearb@candelatech.com>
>
> Can't you do this by setting up the compile environment better?
> I would rather have the tools work with all features and handle
> errors from kernel rather than neutering it.

At the least, the parts that let you use your own CC could
be split out and applied?

I've no interest in trying to fix whatever is wrong with my
tool chain..just not worth the effort since I don't need
network namespaces and I don't need the arp daemon.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

Re: [RFC] iproute: Support cross-compiling.

[Eric Dumazet]

Le mardi 15 novembre 2011 à 17:17 -0800, Stephen Hemminger a écrit :
> On Tue, 15 Nov 2011 17:04:42 -0800
> greearb@candelatech.com wrote:
> 
> > From: Ben Greear <greearb@candelatech.com>
> > 
> > This lets users use their own compiler instead of
> > hard-coding to use gcc.
> > 
> > Also adds tests to disable some things that were not supported
> > in my ARM cross-compile toolchain.
> > 
> > Signed-off-by: Ben Greear <greearb@candelatech.com>
> 
> Can't you do this by setting up the compile environment better?
> I would rather have the tools work with all features and handle
> errors from kernel rather than neutering it.

I have roughly same errors when compiling on RHEL4

glibc-2.3.4-2.36 doesnt contain unshare() call, but my dev kernel
certainly have it ;)

Re: [RFC] iproute: Support cross-compiling.

[Pádraig Brady]

On 11/16/2011 01:04 AM, greearb@candelatech.com wrote:
> From: Ben Greear <greearb@candelatech.com>
> 
> This lets users use their own compiler instead of
> hard-coding to use gcc.
> 
> Also adds tests to disable some things that were not supported
> in my ARM cross-compile toolchain.
> 
> Signed-off-by: Ben Greear <greearb@candelatech.com>
> ---
> :100644 100644 c6e4943... 3b00076... M	Makefile
> :100755 100755 f5c3d40... 680fdcb... M	configure
> :100644 100644 8d03993... 5c91e18... M	ip/Makefile
> :100644 100644 e41a598... 773f7cb... M	ip/ipnetns.c
> :100644 100644 8c25381... d04358d... M	misc/Makefile
>  Makefile      |    2 +-
>  configure     |   88 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
>  ip/Makefile   |    8 +++++
>  ip/ipnetns.c  |   17 +++++++++++
>  misc/Makefile |    5 +++
>  5 files changed, 114 insertions(+), 6 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index c6e4943..3b00076 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -27,7 +27,7 @@ ADDLIB+=dnet_ntop.o dnet_pton.o
>  #options for ipx
>  ADDLIB+=ipx_ntop.o ipx_pton.o
>  
> -CC = gcc
> +CC ?= gcc

Right that allows one to override at build time,
supporting clang, ccache, ...

>  HOSTCC = gcc
>  CCOPTS = -D_GNU_SOURCE -O2 -Wstrict-prototypes -Wall
>  CFLAGS = $(CCOPTS) -I../include $(DEFINES)
> diff --git a/configure b/configure
> index f5c3d40..680fdcb 100755
> --- a/configure
> +++ b/configure
> @@ -3,6 +3,11 @@
>  #
>  INCLUDE=${1:-"$PWD/include"}
>  
> +if [ "_$CC" == "_" ]
> +then
> +    CC=gcc
> +fi

Ditto at configure time.
Note the shell idiom for this is
: ${var:="value"}
Note the leading : is required for portability.
Not applicable here, but if you want to set only if unset
(rather than the above which also handles empty), do:
: ${var="value"}

cheers,
Pádraig.