| Message ID | 20230605131445.32016-1-fw@strlen.de (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf,v2] bpf: netfilter: add BPF_NETFILTER bpf_attach_type | expand |
On Mon, Jun 5, 2023 at 6:15 AM Florian Westphal <fw@strlen.de> wrote: > > Andrii Nakryiko writes: > > And we currently don't have an attach type for NETLINK BPF link. > Thankfully it's not too late to add it. I see that link_create() in > kernel/bpf/syscall.c just bypasses attach_type check. We shouldn't > have done that. Instead we need to add BPF_NETLINK attach type to enum > bpf_attach_type. And wire all that properly throughout the kernel and > libbpf itself. > > This adds BPF_NETFILTER and uses it. This breaks uabi but this > wasn't in any non-rc release yet, so it should be fine. > > v2: check link_attack prog type in link_create too > > Fixes: 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs") > Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> > Link: https://lore.kernel.org/bpf/CAEf4BzZ69YgrQW7DHCJUT_X+GqMq_ZQQPBwopaJJVGFD5=d5Vg@mail.gmail.com/ > Signed-off-by: Florian Westphal <fw@strlen.de> > --- There was one more place that needed adjustment in tools/lib/bpf/libbpf_probes.c and another in tools/lib/bpf/libbpf.c for BPF_NETLINK -> "netlink" string representation. I fixed it up and pushed it to the bpf tree, but for future submissions please make sure to run all selftests locally and make sure they all pass. > include/uapi/linux/bpf.h | 1 + > kernel/bpf/syscall.c | 9 +++++++++ > tools/include/uapi/linux/bpf.h | 1 + > tools/lib/bpf/libbpf.c | 2 +- > 4 files changed, 12 insertions(+), 1 deletion(-) > [...]
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1bb11a6ee667..c994ff5b157c 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1035,6 +1035,7 @@ enum bpf_attach_type { BPF_TRACE_KPROBE_MULTI, BPF_LSM_CGROUP, BPF_STRUCT_OPS, + BPF_NETFILTER, __MAX_BPF_ATTACH_TYPE }; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 14f39c1e573e..0c21d0d8efe4 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2433,6 +2433,10 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type, default: return -EINVAL; } + case BPF_PROG_TYPE_NETFILTER: + if (expected_attach_type == BPF_NETFILTER) + return 0; + return -EINVAL; case BPF_PROG_TYPE_SYSCALL: case BPF_PROG_TYPE_EXT: if (expected_attach_type) @@ -4590,7 +4594,12 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) switch (prog->type) { case BPF_PROG_TYPE_EXT: + break; case BPF_PROG_TYPE_NETFILTER: + if (attr->link_create.attach_type != BPF_NETFILTER) { + ret = -EINVAL; + goto out; + } break; case BPF_PROG_TYPE_PERF_EVENT: case BPF_PROG_TYPE_TRACEPOINT: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1bb11a6ee667..c994ff5b157c 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1035,6 +1035,7 @@ enum bpf_attach_type { BPF_TRACE_KPROBE_MULTI, BPF_LSM_CGROUP, BPF_STRUCT_OPS, + BPF_NETFILTER, __MAX_BPF_ATTACH_TYPE }; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ad1ec893b41b..532a97cf1cc1 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8712,7 +8712,7 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("struct_ops+", STRUCT_OPS, 0, SEC_NONE), SEC_DEF("struct_ops.s+", STRUCT_OPS, 0, SEC_SLEEPABLE), SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE), - SEC_DEF("netfilter", NETFILTER, 0, SEC_NONE), + SEC_DEF("netfilter", NETFILTER, BPF_NETFILTER, SEC_NONE), }; static size_t custom_sec_def_cnt;
Andrii Nakryiko writes: And we currently don't have an attach type for NETLINK BPF link. Thankfully it's not too late to add it. I see that link_create() in kernel/bpf/syscall.c just bypasses attach_type check. We shouldn't have done that. Instead we need to add BPF_NETLINK attach type to enum bpf_attach_type. And wire all that properly throughout the kernel and libbpf itself. This adds BPF_NETFILTER and uses it. This breaks uabi but this wasn't in any non-rc release yet, so it should be fine. v2: check link_attack prog type in link_create too Fixes: 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs") Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Link: https://lore.kernel.org/bpf/CAEf4BzZ69YgrQW7DHCJUT_X+GqMq_ZQQPBwopaJJVGFD5=d5Vg@mail.gmail.com/ Signed-off-by: Florian Westphal <fw@strlen.de> --- include/uapi/linux/bpf.h | 1 + kernel/bpf/syscall.c | 9 +++++++++ tools/include/uapi/linux/bpf.h | 1 + tools/lib/bpf/libbpf.c | 2 +- 4 files changed, 12 insertions(+), 1 deletion(-)