build error: redefinition of 'struct ethhdr' about owl

[WhyNotHugo]

So I understand the issue: both files being included define struct ethhdr. However, both of them defined other types which are used, so removing either of them is not an option.

[WhyNotHugo]

I tired hacking around this with this horrible patch:

diff --git a/daemon/io.c b/daemon/io.c
index 42688f5..b41e8fb 100644
--- a/daemon/io.c
+++ b/daemon/io.c
@@ -25,7 +25,10 @@
 #include <net/if.h>
 #include <sys/ioctl.h>
 #ifndef __APPLE__
-#include <linux/if_tun.h>
+/* #include <linux/if_tun.h> */
+#define IFF_NO_PI	0x1000
+#define IFF_TAP		0x0002
+#define TUNSETIFF     _IOW('T', 202, int)
 #else
 #include <sys/sys_domain.h>
 #include <sys/kern_control.h>

But build now fails with another unrelated error:

> make
[  5%] Built target radiotap
[ 51%] Built target awdl
[ 64%] Built target owl
[ 67%] Building CXX object googletest/googletest/CMakeFiles/gtest.dir/src/gtest-all.cc.o
In file included from /home/hugo/clones/github.com/seemoo-lab/owl/googletest/googletest/src/gtest-all.cc:42:
/home/hugo/clones/github.com/seemoo-lab/owl/googletest/googletest/src/gtest-death-test.cc: In function 'bool testing::internal::StackGrowsDown()':
/home/hugo/clones/github.com/seemoo-lab/owl/googletest/googletest/src/gtest-death-test.cc:1301:24: error: 'dummy' may be used uninitialized [-Werror=maybe-uninitialized]
 1301 |   StackLowerThanAddress(&dummy, &result);
      |   ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/home/hugo/clones/github.com/seemoo-lab/owl/googletest/googletest/src/gtest-death-test.cc:1290:13: note: by argument 1 of type 'const void*' to 'void testing::internal::StackLowerThanAddress(const void*, bool*)' declared here
 1290 | static void StackLowerThanAddress(const void* ptr, bool* result) {
      |             ^~~~~~~~~~~~~~~~~~~~~
/home/hugo/clones/github.com/seemoo-lab/owl/googletest/googletest/src/gtest-death-test.cc:1299:7: note: 'dummy' declared here
 1299 |   int dummy;
      |       ^~~~~
cc1plus: all warnings being treated as errors
make[2]: *** [googletest/googletest/CMakeFiles/gtest.dir/build.make:76: googletest/googletest/CMakeFiles/gtest.dir/src/gtest-all.cc.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:322: googletest/googletest/CMakeFiles/gtest.dir/all] Error 2
make: *** [Makefile:136: all] Error 2

[rela81]

Thanks to your "horrible" patch I was able to compile owl on Alpine successfully. I didn't get any further errors. You could also try to update googletest as described in issue #50

[WhyNotHugo]

Thanks for the pointer to #50. I've submitted #80 which fixes that other issue.

I'm still unsure what to do about this patch of mine, it doesn't seem clean enough to include on the project, but I also can't think of any cleaner approach.