[PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Artem Savkov]

Without CONFIG_NET_FOU bpf selftests are unable to build because of
missing definitions. Add ___local versions of struct bpf_fou_encap and
enum bpf_fou_encap_type to fix the issue.

Signed-off-by: Artem Savkov <asavkov@redhat.com>
---
 .../selftests/bpf/progs/test_tunnel_kern.c    | 24 +++++++++++++------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
index 3f5abcf3ff136..0913ec384b159 100644
--- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
@@ -26,10 +26,20 @@
  */
 #define ASSIGNED_ADDR_VETH1 0xac1001c8
 
+struct bpf_fou_encap___local {
+       __be16 sport;
+       __be16 dport;
+};
+
+enum bpf_fou_encap_type___local {
+       FOU_BPF_ENCAP_FOU___local,
+       FOU_BPF_ENCAP_GUE___local,
+};
+
 int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
-			  struct bpf_fou_encap *encap, int type) __ksym;
+			  struct bpf_fou_encap___local *encap, int type) __ksym;
 int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
-			  struct bpf_fou_encap *encap) __ksym;
+			  struct bpf_fou_encap___local *encap) __ksym;
 struct xfrm_state *
 bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts,
 		       u32 opts__sz) __ksym;
@@ -745,7 +755,7 @@ SEC("tc")
 int ipip_gue_set_tunnel(struct __sk_buff *skb)
 {
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 	void *data = (void *)(long)skb->data;
 	struct iphdr *iph = data;
 	void *data_end = (void *)(long)skb->data_end;
@@ -769,7 +779,7 @@ int ipip_gue_set_tunnel(struct __sk_buff *skb)
 	encap.sport = 0;
 	encap.dport = bpf_htons(5555);
 
-	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE);
+	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
@@ -782,7 +792,7 @@ SEC("tc")
 int ipip_fou_set_tunnel(struct __sk_buff *skb)
 {
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 	void *data = (void *)(long)skb->data;
 	struct iphdr *iph = data;
 	void *data_end = (void *)(long)skb->data_end;
@@ -806,7 +816,7 @@ int ipip_fou_set_tunnel(struct __sk_buff *skb)
 	encap.sport = 0;
 	encap.dport = bpf_htons(5555);
 
-	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU);
+	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU___local);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
@@ -820,7 +830,7 @@ int ipip_encap_get_tunnel(struct __sk_buff *skb)
 {
 	int ret;
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 
 	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
 	if (ret < 0) {
-- 
2.45.2

Re: [PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Daniel Borkmann]

Hi Artem,

On 7/18/24 4:31 PM, Artem Savkov wrote:
> Without CONFIG_NET_FOU bpf selftests are unable to build because of
> missing definitions. Add ___local versions of struct bpf_fou_encap and
> enum bpf_fou_encap_type to fix the issue.
> 
> Signed-off-by: Artem Savkov <asavkov@redhat.com>

This breaks BPF CI, ptal:

https://github.com/kernel-patches/bpf/actions/runs/9999691294/job/27641198557

   [...]
     CLNG-BPF [test_maps] btf__core_reloc_existence___wrong_field_defs.bpf.o
     CLNG-BPF [test_maps] verifier_bswap.bpf.o
     CLNG-BPF [test_maps] test_core_reloc_existence.bpf.o
     CLNG-BPF [test_maps] test_global_func8.bpf.o
     CLNG-BPF [test_maps] verifier_bitfield_write.bpf.o
     CLNG-BPF [test_maps] local_storage_bench.bpf.o
     CLNG-BPF [test_maps] verifier_runtime_jit.bpf.o
     CLNG-BPF [test_maps] test_pkt_access.bpf.o
   progs/test_tunnel_kern.c:39:5: error: conflicting types for 'bpf_skb_set_fou_encap'
      39 | int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
         |     ^
   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:12: note: previous declaration is here
    107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
           |            ^
   progs/test_tunnel_kern.c:41:5: error: conflicting types for 'bpf_skb_get_fou_encap'
      41 | int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
         |     ^
   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:12: note: previous declaration is here
    107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
           |            ^
     CLNG-BPF [test_maps] verifier_typedef.bpf.o
     CLNG-BPF [test_maps] user_ringbuf_fail.bpf.o
     CLNG-BPF [test_maps] verifier_map_in_map.bpf.o
   progs/test_tunnel_kern.c:782:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
     782 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
         |                                          ^~~~~~
   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
    107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
           |                                                                                   ^
   progs/test_tunnel_kern.c:819:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
     819 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU___local);
         |                                          ^~~~~~
   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
    107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
           |                                                                                   ^
   progs/test_tunnel_kern.c:841:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
     841 |         ret = bpf_skb_get_fou_encap(skb, &encap);
         |                                          ^~~~~~
   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:83: note: passing argument to parameter 'encap' here
    107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
           |                                                                                   ^
   5 errors generated.
     CLNG-BPF [test_maps] verifier_bounds_deduction.bpf.o
     CLNG-BPF [test_maps] test_netfilter_link_attach.bpf.o
     CLNG-BPF [test_maps] verifier_jeq_infer_not_null.bpf.o
   make: *** [Makefile:654: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/test_tunnel_kern.bpf.o] Error 1
   make: *** Waiting for unfinished jobs....
   make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'
   Error: Process completed with exit code 2.

Re: [PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Alexei Starovoitov]

On Fri, Jul 19, 2024 at 8:45 AM Daniel Borkmann <daniel@iogearbox.net> wrote:
>
> Hi Artem,
>
> On 7/18/24 4:31 PM, Artem Savkov wrote:
> > Without CONFIG_NET_FOU bpf selftests are unable to build because of
> > missing definitions. Add ___local versions of struct bpf_fou_encap and
> > enum bpf_fou_encap_type to fix the issue.
> >
> > Signed-off-by: Artem Savkov <asavkov@redhat.com>
>
> This breaks BPF CI, ptal:
>
> https://github.com/kernel-patches/bpf/actions/runs/9999691294/job/27641198557
>
>    [...]
>      CLNG-BPF [test_maps] btf__core_reloc_existence___wrong_field_defs.bpf.o
>      CLNG-BPF [test_maps] verifier_bswap.bpf.o
>      CLNG-BPF [test_maps] test_core_reloc_existence.bpf.o
>      CLNG-BPF [test_maps] test_global_func8.bpf.o
>      CLNG-BPF [test_maps] verifier_bitfield_write.bpf.o
>      CLNG-BPF [test_maps] local_storage_bench.bpf.o
>      CLNG-BPF [test_maps] verifier_runtime_jit.bpf.o
>      CLNG-BPF [test_maps] test_pkt_access.bpf.o
>    progs/test_tunnel_kern.c:39:5: error: conflicting types for 'bpf_skb_set_fou_encap'
>       39 | int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
>          |     ^
>    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:12: note: previous declaration is here
>     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
>            |            ^
>    progs/test_tunnel_kern.c:41:5: error: conflicting types for 'bpf_skb_get_fou_encap'
>       41 | int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
>          |     ^
>    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:12: note: previous declaration is here
>     107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
>            |            ^
>      CLNG-BPF [test_maps] verifier_typedef.bpf.o
>      CLNG-BPF [test_maps] user_ringbuf_fail.bpf.o
>      CLNG-BPF [test_maps] verifier_map_in_map.bpf.o
>    progs/test_tunnel_kern.c:782:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
>      782 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
>          |                                          ^~~~~~
>    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
>     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;

It's a good idea to introduce struct bpf_fou_encap___local
for !FOU builds, but kfunc signature needs to stay and
__local variable needs to be type casted to (struct bpf_fou_encap *)
when calling kfunc.

Re: [PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Andrii Nakryiko]

On Fri, Jul 19, 2024 at 10:09 AM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Fri, Jul 19, 2024 at 8:45 AM Daniel Borkmann <daniel@iogearbox.net> wrote:
> >
> > Hi Artem,
> >
> > On 7/18/24 4:31 PM, Artem Savkov wrote:
> > > Without CONFIG_NET_FOU bpf selftests are unable to build because of
> > > missing definitions. Add ___local versions of struct bpf_fou_encap and
> > > enum bpf_fou_encap_type to fix the issue.
> > >
> > > Signed-off-by: Artem Savkov <asavkov@redhat.com>
> >
> > This breaks BPF CI, ptal:
> >
> > https://github.com/kernel-patches/bpf/actions/runs/9999691294/job/27641198557
> >
> >    [...]
> >      CLNG-BPF [test_maps] btf__core_reloc_existence___wrong_field_defs.bpf.o
> >      CLNG-BPF [test_maps] verifier_bswap.bpf.o
> >      CLNG-BPF [test_maps] test_core_reloc_existence.bpf.o
> >      CLNG-BPF [test_maps] test_global_func8.bpf.o
> >      CLNG-BPF [test_maps] verifier_bitfield_write.bpf.o
> >      CLNG-BPF [test_maps] local_storage_bench.bpf.o
> >      CLNG-BPF [test_maps] verifier_runtime_jit.bpf.o
> >      CLNG-BPF [test_maps] test_pkt_access.bpf.o
> >    progs/test_tunnel_kern.c:39:5: error: conflicting types for 'bpf_skb_set_fou_encap'
> >       39 | int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
> >          |     ^
> >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:12: note: previous declaration is here
> >     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
> >            |            ^
> >    progs/test_tunnel_kern.c:41:5: error: conflicting types for 'bpf_skb_get_fou_encap'
> >       41 | int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
> >          |     ^
> >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:12: note: previous declaration is here
> >     107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
> >            |            ^
> >      CLNG-BPF [test_maps] verifier_typedef.bpf.o
> >      CLNG-BPF [test_maps] user_ringbuf_fail.bpf.o
> >      CLNG-BPF [test_maps] verifier_map_in_map.bpf.o
> >    progs/test_tunnel_kern.c:782:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
> >      782 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
> >          |                                          ^~~~~~
> >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
> >     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
>
> It's a good idea to introduce struct bpf_fou_encap___local
> for !FOU builds, but kfunc signature needs to stay and
> __local variable needs to be type casted to (struct bpf_fou_encap *)
> when calling kfunc.

Given we specify

CONFIG_NET_FOU=y (not =m)

in selftests/bpf/config, do we really need to work around this? I bet
we have a bunch of other missing types if we don't set all the
settings as required by selftests/bpf/config.

Re: [PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Artem Savkov]

On Fri, Jul 19, 2024 at 11:44:34AM -0700, Andrii Nakryiko wrote:
> On Fri, Jul 19, 2024 at 10:09 AM Alexei Starovoitov
> <alexei.starovoitov@gmail.com> wrote:
> >
> > On Fri, Jul 19, 2024 at 8:45 AM Daniel Borkmann <daniel@iogearbox.net> wrote:
> > >
> > > Hi Artem,
> > >
> > > On 7/18/24 4:31 PM, Artem Savkov wrote:
> > > > Without CONFIG_NET_FOU bpf selftests are unable to build because of
> > > > missing definitions. Add ___local versions of struct bpf_fou_encap and
> > > > enum bpf_fou_encap_type to fix the issue.
> > > >
> > > > Signed-off-by: Artem Savkov <asavkov@redhat.com>
> > >
> > > This breaks BPF CI, ptal:
> > >
> > > https://github.com/kernel-patches/bpf/actions/runs/9999691294/job/27641198557
> > >
> > >    [...]
> > >      CLNG-BPF [test_maps] btf__core_reloc_existence___wrong_field_defs.bpf.o
> > >      CLNG-BPF [test_maps] verifier_bswap.bpf.o
> > >      CLNG-BPF [test_maps] test_core_reloc_existence.bpf.o
> > >      CLNG-BPF [test_maps] test_global_func8.bpf.o
> > >      CLNG-BPF [test_maps] verifier_bitfield_write.bpf.o
> > >      CLNG-BPF [test_maps] local_storage_bench.bpf.o
> > >      CLNG-BPF [test_maps] verifier_runtime_jit.bpf.o
> > >      CLNG-BPF [test_maps] test_pkt_access.bpf.o
> > >    progs/test_tunnel_kern.c:39:5: error: conflicting types for 'bpf_skb_set_fou_encap'
> > >       39 | int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
> > >          |     ^
> > >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:12: note: previous declaration is here
> > >     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
> > >            |            ^
> > >    progs/test_tunnel_kern.c:41:5: error: conflicting types for 'bpf_skb_get_fou_encap'
> > >       41 | int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
> > >          |     ^
> > >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:12: note: previous declaration is here
> > >     107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
> > >            |            ^
> > >      CLNG-BPF [test_maps] verifier_typedef.bpf.o
> > >      CLNG-BPF [test_maps] user_ringbuf_fail.bpf.o
> > >      CLNG-BPF [test_maps] verifier_map_in_map.bpf.o
> > >    progs/test_tunnel_kern.c:782:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
> > >      782 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
> > >          |                                          ^~~~~~
> > >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
> > >     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
> >
> > It's a good idea to introduce struct bpf_fou_encap___local
> > for !FOU builds, but kfunc signature needs to stay and
> > __local variable needs to be type casted to (struct bpf_fou_encap *)
> > when calling kfunc.
> 
> Given we specify
> 
> CONFIG_NET_FOU=y (not =m)
> 
> in selftests/bpf/config, do we really need to work around this? I bet
> we have a bunch of other missing types if we don't set all the
> settings as required by selftests/bpf/config.

We do have other missing types and a lot of them (not all) are fixed
the same way with ___local versions by interested parties.

-- 
 Artem

Re: [PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Artem Savkov]

On Fri, Jul 19, 2024 at 10:09:35AM -0700, Alexei Starovoitov wrote:
> On Fri, Jul 19, 2024 at 8:45 AM Daniel Borkmann <daniel@iogearbox.net> wrote:
> >
> > Hi Artem,
> >
> > On 7/18/24 4:31 PM, Artem Savkov wrote:
> > > Without CONFIG_NET_FOU bpf selftests are unable to build because of
> > > missing definitions. Add ___local versions of struct bpf_fou_encap and
> > > enum bpf_fou_encap_type to fix the issue.
> > >
> > > Signed-off-by: Artem Savkov <asavkov@redhat.com>
> >
> > This breaks BPF CI, ptal:
> >
> > https://github.com/kernel-patches/bpf/actions/runs/9999691294/job/27641198557
> >
> >    [...]
> >      CLNG-BPF [test_maps] btf__core_reloc_existence___wrong_field_defs.bpf.o
> >      CLNG-BPF [test_maps] verifier_bswap.bpf.o
> >      CLNG-BPF [test_maps] test_core_reloc_existence.bpf.o
> >      CLNG-BPF [test_maps] test_global_func8.bpf.o
> >      CLNG-BPF [test_maps] verifier_bitfield_write.bpf.o
> >      CLNG-BPF [test_maps] local_storage_bench.bpf.o
> >      CLNG-BPF [test_maps] verifier_runtime_jit.bpf.o
> >      CLNG-BPF [test_maps] test_pkt_access.bpf.o
> >    progs/test_tunnel_kern.c:39:5: error: conflicting types for 'bpf_skb_set_fou_encap'
> >       39 | int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
> >          |     ^
> >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:12: note: previous declaration is here
> >     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
> >            |            ^
> >    progs/test_tunnel_kern.c:41:5: error: conflicting types for 'bpf_skb_get_fou_encap'
> >       41 | int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
> >          |     ^
> >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:12: note: previous declaration is here
> >     107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
> >            |            ^
> >      CLNG-BPF [test_maps] verifier_typedef.bpf.o
> >      CLNG-BPF [test_maps] user_ringbuf_fail.bpf.o
> >      CLNG-BPF [test_maps] verifier_map_in_map.bpf.o
> >    progs/test_tunnel_kern.c:782:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
> >      782 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
> >          |                                          ^~~~~~
> >    /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
> >     107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
> 
> It's a good idea to introduce struct bpf_fou_encap___local
> for !FOU builds, but kfunc signature needs to stay and
> __local variable needs to be type casted to (struct bpf_fou_encap *)
> when calling kfunc.

Casting won't work as the compiler still have no idea about struct
bpf_fou_encap.

I think I'll need to fix this by adding '#define
BPF_NO_KDUNC_PROTOTYPES' to the test. Daniel has done this for other
cases like this in the series introducing bpftool kfunc prototype
dumping (https://lore.kernel.org/all/cover.1718207789.git.dxu@dxuuu.xyz/)

-- 
 Artem

[PATCH bpf-next v2] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Artem Savkov]

Without CONFIG_NET_FOU bpf selftests are unable to build because of
missing definitions. Add ___local versions of struct bpf_fou_encap and
enum bpf_fou_encap_type to fix the issue.

Signed-off-by: Artem Savkov <asavkov@redhat.com>

---
v2: added BPF_NO_KFUNC_PROTOTYPES define to avoid issues when
CONFIG_NET_FOU is set.
---
 .../selftests/bpf/progs/test_tunnel_kern.c    | 25 +++++++++++++------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
index 3f5abcf3ff136..4d526fc73f2bb 100644
--- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
@@ -6,6 +6,7 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
+#define BPF_NO_KFUNC_PROTOTYPES
 #include "vmlinux.h"
 #include <bpf/bpf_core_read.h>
 #include <bpf/bpf_helpers.h>
@@ -26,10 +27,20 @@
  */
 #define ASSIGNED_ADDR_VETH1 0xac1001c8
 
+struct bpf_fou_encap___local {
+       __be16 sport;
+       __be16 dport;
+};
+
+enum bpf_fou_encap_type___local {
+       FOU_BPF_ENCAP_FOU___local,
+       FOU_BPF_ENCAP_GUE___local,
+};
+
 int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
-			  struct bpf_fou_encap *encap, int type) __ksym;
+			  struct bpf_fou_encap___local *encap, int type) __ksym;
 int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
-			  struct bpf_fou_encap *encap) __ksym;
+			  struct bpf_fou_encap___local *encap) __ksym;
 struct xfrm_state *
 bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts,
 		       u32 opts__sz) __ksym;
@@ -745,7 +756,7 @@ SEC("tc")
 int ipip_gue_set_tunnel(struct __sk_buff *skb)
 {
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 	void *data = (void *)(long)skb->data;
 	struct iphdr *iph = data;
 	void *data_end = (void *)(long)skb->data_end;
@@ -769,7 +780,7 @@ int ipip_gue_set_tunnel(struct __sk_buff *skb)
 	encap.sport = 0;
 	encap.dport = bpf_htons(5555);
 
-	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE);
+	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
@@ -782,7 +793,7 @@ SEC("tc")
 int ipip_fou_set_tunnel(struct __sk_buff *skb)
 {
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 	void *data = (void *)(long)skb->data;
 	struct iphdr *iph = data;
 	void *data_end = (void *)(long)skb->data_end;
@@ -806,7 +817,7 @@ int ipip_fou_set_tunnel(struct __sk_buff *skb)
 	encap.sport = 0;
 	encap.dport = bpf_htons(5555);
 
-	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU);
+	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU___local);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
@@ -820,7 +831,7 @@ int ipip_encap_get_tunnel(struct __sk_buff *skb)
 {
 	int ret;
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 
 	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
 	if (ret < 0) {
-- 
2.45.2

Re: [PATCH bpf-next v2] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Alexei Starovoitov]

On Mon, Jul 22, 2024 at 6:53 AM Artem Savkov <asavkov@redhat.com> wrote:
>
>  bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts,
>                        u32 opts__sz) __ksym;
> @@ -745,7 +756,7 @@ SEC("tc")
>  int ipip_gue_set_tunnel(struct __sk_buff *skb)
>  {
>         struct bpf_tunnel_key key = {};
> -       struct bpf_fou_encap encap = {};
> +       struct bpf_fou_encap___local encap = {};
>         void *data = (void *)(long)skb->data;
>         struct iphdr *iph = data;
>         void *data_end = (void *)(long)skb->data_end;
> @@ -769,7 +780,7 @@ int ipip_gue_set_tunnel(struct __sk_buff *skb)
>         encap.sport = 0;
>         encap.dport = bpf_htons(5555);
>
> -       ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE);
> +       ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);

> Casting won't work as the compiler still have no idea about struct
> bpf_fou_encap.


struct bpf_fou_encap;

(struct bpf_fou_encap *)&encap

works just fine.

pw-bot: cr

[PATCH bpf-next v3] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Artem Savkov]

Without CONFIG_NET_FOU bpf selftests are unable to build because of
missing definitions. Add ___local versions of struct bpf_fou_encap and
enum bpf_fou_encap_type to fix the issue.

Signed-off-by: Artem Savkov <asavkov@redhat.com>

---
v3: swith from using BPF_NO_KFUNC_PROTOTYPES to casting to keep kfunc
prototype intact.

v2: added BPF_NO_KFUNC_PROTOTYPES define to avoid issues when
CONFIG_NET_FOU is set.
---
 .../selftests/bpf/progs/test_tunnel_kern.c    | 26 ++++++++++++++-----
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
index 3f5abcf3ff136..fcff3010d8a60 100644
--- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
@@ -26,6 +26,18 @@
  */
 #define ASSIGNED_ADDR_VETH1 0xac1001c8
 
+struct bpf_fou_encap___local {
+       __be16 sport;
+       __be16 dport;
+};
+
+enum bpf_fou_encap_type___local {
+       FOU_BPF_ENCAP_FOU___local,
+       FOU_BPF_ENCAP_GUE___local,
+};
+
+struct bpf_fou_encap;
+
 int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
 			  struct bpf_fou_encap *encap, int type) __ksym;
 int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
@@ -745,7 +757,7 @@ SEC("tc")
 int ipip_gue_set_tunnel(struct __sk_buff *skb)
 {
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 	void *data = (void *)(long)skb->data;
 	struct iphdr *iph = data;
 	void *data_end = (void *)(long)skb->data_end;
@@ -769,7 +781,8 @@ int ipip_gue_set_tunnel(struct __sk_buff *skb)
 	encap.sport = 0;
 	encap.dport = bpf_htons(5555);
 
-	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE);
+	ret = bpf_skb_set_fou_encap(skb, (struct bpf_fou_encap *)&encap,
+				    FOU_BPF_ENCAP_GUE___local);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
@@ -782,7 +795,7 @@ SEC("tc")
 int ipip_fou_set_tunnel(struct __sk_buff *skb)
 {
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 	void *data = (void *)(long)skb->data;
 	struct iphdr *iph = data;
 	void *data_end = (void *)(long)skb->data_end;
@@ -806,7 +819,8 @@ int ipip_fou_set_tunnel(struct __sk_buff *skb)
 	encap.sport = 0;
 	encap.dport = bpf_htons(5555);
 
-	ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU);
+	ret = bpf_skb_set_fou_encap(skb, (struct bpf_fou_encap *)&encap,
+				    FOU_BPF_ENCAP_FOU___local);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
@@ -820,7 +834,7 @@ int ipip_encap_get_tunnel(struct __sk_buff *skb)
 {
 	int ret;
 	struct bpf_tunnel_key key = {};
-	struct bpf_fou_encap encap = {};
+	struct bpf_fou_encap___local encap = {};
 
 	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
 	if (ret < 0) {
@@ -828,7 +842,7 @@ int ipip_encap_get_tunnel(struct __sk_buff *skb)
 		return TC_ACT_SHOT;
 	}
 
-	ret = bpf_skb_get_fou_encap(skb, &encap);
+	ret = bpf_skb_get_fou_encap(skb, (struct bpf_fou_encap *)&encap);
 	if (ret < 0) {
 		log_err(ret);
 		return TC_ACT_SHOT;
-- 
2.45.2

Re: [PATCH bpf-next v3] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Simon Horman]

On Tue, Jul 23, 2024 at 09:10:31AM +0200, Artem Savkov wrote:
> Without CONFIG_NET_FOU bpf selftests are unable to build because of
> missing definitions. Add ___local versions of struct bpf_fou_encap and
> enum bpf_fou_encap_type to fix the issue.
> 
> Signed-off-by: Artem Savkov <asavkov@redhat.com>
> 
> ---
> v3: swith from using BPF_NO_KFUNC_PROTOTYPES to casting to keep kfunc
> prototype intact.
> 
> v2: added BPF_NO_KFUNC_PROTOTYPES define to avoid issues when
> CONFIG_NET_FOU is set.
> ---
>  .../selftests/bpf/progs/test_tunnel_kern.c    | 26 ++++++++++++++-----
>  1 file changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
> index 3f5abcf3ff136..fcff3010d8a60 100644
> --- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
> +++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
> @@ -26,6 +26,18 @@
>   */
>  #define ASSIGNED_ADDR_VETH1 0xac1001c8
>  
> +struct bpf_fou_encap___local {
> +       __be16 sport;
> +       __be16 dport;
> +};
> +
> +enum bpf_fou_encap_type___local {
> +       FOU_BPF_ENCAP_FOU___local,
> +       FOU_BPF_ENCAP_GUE___local,
> +};

nit: The above use spaces rather than tabs for indentation.

Re: [PATCH bpf-next v3] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Andrii Nakryiko]

On Tue, Jul 23, 2024 at 12:10 AM Artem Savkov <asavkov@redhat.com> wrote:
>
> Without CONFIG_NET_FOU bpf selftests are unable to build because of
> missing definitions. Add ___local versions of struct bpf_fou_encap and
> enum bpf_fou_encap_type to fix the issue.
>
> Signed-off-by: Artem Savkov <asavkov@redhat.com>
>
> ---
> v3: swith from using BPF_NO_KFUNC_PROTOTYPES to casting to keep kfunc
> prototype intact.
>
> v2: added BPF_NO_KFUNC_PROTOTYPES define to avoid issues when
> CONFIG_NET_FOU is set.
> ---
>  .../selftests/bpf/progs/test_tunnel_kern.c    | 26 ++++++++++++++-----
>  1 file changed, 20 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
> index 3f5abcf3ff136..fcff3010d8a60 100644
> --- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
> +++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
> @@ -26,6 +26,18 @@
>   */
>  #define ASSIGNED_ADDR_VETH1 0xac1001c8
>
> +struct bpf_fou_encap___local {
> +       __be16 sport;
> +       __be16 dport;
> +};
> +
> +enum bpf_fou_encap_type___local {
> +       FOU_BPF_ENCAP_FOU___local,
> +       FOU_BPF_ENCAP_GUE___local,
> +};

both of the above are internal kernel types (not UAPI ones), so I
added preserve_access_index to the struct and ...

> +
> +struct bpf_fou_encap;
> +
>  int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
>                           struct bpf_fou_encap *encap, int type) __ksym;
>  int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
> @@ -745,7 +757,7 @@ SEC("tc")
>  int ipip_gue_set_tunnel(struct __sk_buff *skb)
>  {
>         struct bpf_tunnel_key key = {};
> -       struct bpf_fou_encap encap = {};
> +       struct bpf_fou_encap___local encap = {};
>         void *data = (void *)(long)skb->data;
>         struct iphdr *iph = data;
>         void *data_end = (void *)(long)skb->data_end;
> @@ -769,7 +781,8 @@ int ipip_gue_set_tunnel(struct __sk_buff *skb)
>         encap.sport = 0;
>         encap.dport = bpf_htons(5555);
>
> -       ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE);
> +       ret = bpf_skb_set_fou_encap(skb, (struct bpf_fou_encap *)&encap,
> +                                   FOU_BPF_ENCAP_GUE___local);
>         if (ret < 0) {
>                 log_err(ret);
>                 return TC_ACT_SHOT;
> @@ -782,7 +795,7 @@ SEC("tc")
>  int ipip_fou_set_tunnel(struct __sk_buff *skb)
>  {
>         struct bpf_tunnel_key key = {};
> -       struct bpf_fou_encap encap = {};
> +       struct bpf_fou_encap___local encap = {};
>         void *data = (void *)(long)skb->data;
>         struct iphdr *iph = data;
>         void *data_end = (void *)(long)skb->data_end;
> @@ -806,7 +819,8 @@ int ipip_fou_set_tunnel(struct __sk_buff *skb)
>         encap.sport = 0;
>         encap.dport = bpf_htons(5555);
>
> -       ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU);
> +       ret = bpf_skb_set_fou_encap(skb, (struct bpf_fou_encap *)&encap,
> +                                   FOU_BPF_ENCAP_FOU___local);


use bpf_core_enum_value() here for getting enum value in CO-RE-relocatable way

(also fixed spaces vs tabs issue that were pointed out)

pushed to bpf-next


>         if (ret < 0) {
>                 log_err(ret);
>                 return TC_ACT_SHOT;
> @@ -820,7 +834,7 @@ int ipip_encap_get_tunnel(struct __sk_buff *skb)
>  {
>         int ret;
>         struct bpf_tunnel_key key = {};
> -       struct bpf_fou_encap encap = {};
> +       struct bpf_fou_encap___local encap = {};
>
>         ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
>         if (ret < 0) {
> @@ -828,7 +842,7 @@ int ipip_encap_get_tunnel(struct __sk_buff *skb)
>                 return TC_ACT_SHOT;
>         }
>
> -       ret = bpf_skb_get_fou_encap(skb, &encap);
> +       ret = bpf_skb_get_fou_encap(skb, (struct bpf_fou_encap *)&encap);
>         if (ret < 0) {
>                 log_err(ret);
>                 return TC_ACT_SHOT;
> --
> 2.45.2
>

Re: [PATCH bpf-next v3] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <andrii@kernel.org>:

On Tue, 23 Jul 2024 09:10:31 +0200 you wrote:
> Without CONFIG_NET_FOU bpf selftests are unable to build because of
> missing definitions. Add ___local versions of struct bpf_fou_encap and
> enum bpf_fou_encap_type to fix the issue.
> 
> Signed-off-by: Artem Savkov <asavkov@redhat.com>
> 
> 
> [...]

Here is the summary with links:
  - [bpf-next,v3] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y
    https://git.kernel.org/bpf/bpf-next/c/c67b2a6f3b84

You are awesome, thank you!
-- 
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