[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230605131445.32016-1-fw@strlen.de>
Date: Mon, 5 Jun 2023 15:14:45 +0200
From: Florian Westphal <fw@...len.de>
To: <bpf@...r.kernel.org>
Cc: netdev@...r.kernel.org,
ast@...nel.org,
Florian Westphal <fw@...len.de>,
Andrii Nakryiko <andrii.nakryiko@...il.com>
Subject: [PATCH bpf v2] bpf: netfilter: add BPF_NETFILTER bpf_attach_type
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@...il.com>
Link: https://lore.kernel.org/bpf/CAEf4BzZ69YgrQW7DHCJUT_X+GqMq_ZQQPBwopaJJVGFD5=d5Vg@mail.gmail.com/
Signed-off-by: Florian Westphal <fw@...len.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(-)
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;
--
2.39.3
Powered by blists - more mailing lists