On Thu, Jul 25, 2024 at 3:39 AM Tony Ambardar <tony.ambardar@xxxxxxxxx> wrote:
>
> From: Tony Ambardar <tony.ambardar@xxxxxxxxx>
>
> Fix redefinition errors seen compiling lwt_reroute.c for mips64el/musl-libc
> by adjusting the order of includes in lwt_helpers.h. The ordering required
> is:
> <net/if.h> --> <arpa/inet.h> (from "test_progs.h") --> <linux/icmp.h>.
>
> Because of the complexity and large number of includes, ordering appears to
> be fragile however. Previously, with "test_progs.h" at the end of this
> sequence, compiling with GCC 12.3 for mips64el/musl-libc yields errors:
>
> In file included from .../include/arpa/inet.h:9,
> from ./test_progs.h:18,
> from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:11,
> from tools/testing/selftests/bpf/prog_tests/lwt_reroute.c:52:
> .../include/netinet/in.h:23:8: error: redefinition of 'struct in6_addr'
> 23 | struct in6_addr {
> | ^~~~~~~~
> In file included from .../include/linux/icmp.h:24,
> from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:9:
> .../include/linux/in6.h:33:8: note: originally defined here
> 33 | struct in6_addr {
> | ^~~~~~~~
> .../include/netinet/in.h:34:8: error: redefinition of 'struct sockaddr_in6'
> 34 | struct sockaddr_in6 {
> | ^~~~~~~~~~~~
> .../include/linux/in6.h:50:8: note: originally defined here
> 50 | struct sockaddr_in6 {
> | ^~~~~~~~~~~~
> .../include/netinet/in.h:42:8: error: redefinition of 'struct ipv6_mreq'
> 42 | struct ipv6_mreq {
> | ^~~~~~~~~
> .../include/linux/in6.h:60:8: note: originally defined here
> 60 | struct ipv6_mreq {
> | ^~~~~~~~~
>
> Similarly, with "test_progs.h" at the beginning of this sequence, compiling
> with GCC 12.3 for x86_64 using glibc would fail like this:
>
> In file included from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:8,
> from tools/testing/selftests/bpf/prog_tests/lwt_reroute.c:52:
> /usr/include/linux/if.h:83:9: error: redeclaration of enumerator ‘IFF_UP’
> 83 | IFF_UP = 1<<0, /* sysfs */
> | ^~~~~~
> /usr/include/net/if.h:44:5: note: previous definition of ‘IFF_UP’ with type ‘enum <anonymous>’
> 44 | IFF_UP = 0x1, /* Interface is up. */
> | ^~~~~~
> /usr/include/linux/if.h:84:9: error: redeclaration of enumerator ‘IFF_BROADCAST’
> 84 | IFF_BROADCAST = 1<<1, /* __volatile__ */
> | ^~~~~~~~~~~~~
> /usr/include/net/if.h:46:5: note: previous definition of ‘IFF_BROADCAST’ with type ‘enum <anonymous>’
> 46 | IFF_BROADCAST = 0x2, /* Broadcast address valid. */
> | ^~~~~~~~~~~~~
>
> ...
>
> In file included from /usr/include/linux/icmp.h:23,
> from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:10,
> from tools/testing/selftests/bpf/prog_tests/lwt_reroute.c:52:
> /usr/include/linux/if.h:194:8: error: redefinition of ‘struct ifmap’
> 194 | struct ifmap {
> | ^~~~~
> In file included from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:8,
> from tools/testing/selftests/bpf/prog_tests/lwt_reroute.c:52:
> /usr/include/net/if.h:111:8: note: originally defined here
> 111 | struct ifmap
> | ^~~~~
> In file included from /usr/include/linux/icmp.h:23,
> from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:10,
> from tools/testing/selftests/bpf/prog_tests/lwt_reroute.c:52:
> /usr/include/linux/if.h:232:8: error: redefinition of ‘struct ifreq’
> 232 | struct ifreq {
> | ^~~~~
> In file included from tools/testing/selftests/bpf/prog_tests/lwt_helpers.h:8,
> from tools/testing/selftests/bpf/prog_tests/lwt_reroute.c:52:
> /usr/include/net/if.h:126:8: note: originally defined here
> 126 | struct ifreq
> | ^~~~~
>
> Fixes: 43a7c3ef8a15 ("selftests/bpf: Add lwt_xmit tests for BPF_REDIRECT")
> Signed-off-by: Tony Ambardar <tony.ambardar@xxxxxxxxx>
> ---
> tools/testing/selftests/bpf/prog_tests/lwt_helpers.h | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h b/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
> index fb1eb8c67361..8e5e28af03c5 100644
> --- a/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
> +++ b/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
> @@ -6,10 +6,9 @@
> #include <time.h>
> #include <net/if.h>
> #include <linux/if_tun.h>
> +#include "test_progs.h" /* between <net/if.h> and <linux/icmp.h> or errors */
Now we'll be papering over the real issue. Can you see if you can
untangle this mess and ensure that we consistently use either net/if.h
or linux/if.h headers?
pw-bot: cr
> #include <linux/icmp.h>
>
> -#include "test_progs.h"
> -
> #define log_err(MSG, ...) \
> fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
> __FILE__, __LINE__, strerror(errno), ##__VA_ARGS__)
> --
> 2.34.1
>
