bpf: fix link info netfilter flags to populate defrag flag

PATCH Applied Tyrone Wu 4 participants 5 messages Oct 11, 2024 – Oct 16, 2024

Subsystems (6)

Networking Network drivers Kselftest netfilter +2 more subsystems

lore

Share & tools

lore

Tyrone Wu

author

2024-10-11 19:33 UTC #0 lore raw

PATCH 1/2 bpf: fix link info netfilter flags to populate defrag flag

This patch correctly populates the bpf_link_info.netfilter.flags field when user passes the BPF_F_NETFILTER_IP_DEFRAG flag.

Fixes 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs")

Signed-off-by Tyrone Wu <[email protected]>

---
 net/netfilter/nf_bpf_link.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

net/netfilter/nf_bpf_link.c +2 -1

index 5257d5e7eb09..797fe8a9971e 100644
@@ -150,11 +150,12 @@ static int bpf_nf_link_fill_link_info(const struct bpf_link *link,
 				      struct bpf_link_info *info)
 {
 	struct bpf_nf_link *nf_link = container_of(link, struct bpf_nf_link, link);
+	const struct nf_defrag_hook *hook = nf_link->defrag_hook;
 
 	info->netfilter.pf = nf_link->hook_ops.pf;
 	info->netfilter.hooknum = nf_link->hook_ops.hooknum;
 	info->netfilter.priority = nf_link->hook_ops.priority;
-	info->netfilter.flags = 0;
+	info->netfilter.flags = hook ? BPF_F_NETFILTER_IP_DEFRAG : 0;
 
 	return 0;
 }

Signature · 1 line

2.43.0

Tyrone Wu

author

2024-10-11 19:33 UTC #1 lore raw

PATCH 2/2 selftests/bpf: add asserts for netfilter link info

Add assertions/tests to verify bpf_link_info fields for netfilter link are correctly populated.

Signed-off-by Tyrone Wu <[email protected]>

---
 .../bpf/prog_tests/netfilter_link_attach.c    | 40 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 2 deletions(-)

tools/testing/selftests/bpf/prog_tests/netfilter_link_attach.c +38 -2

index 4297a2a4cb11..5bf98ab2e17f 100644
@@ -26,10 +26,43 @@ static const struct nf_link_test nf_hook_link_tests[] = {
 
 	{ .pf = NFPROTO_INET, .priority = 1, .name = "invalid-inet-not-supported", },
 
-	{ .pf = NFPROTO_IPV4, .priority = -10000, .expect_success = true, .name = "attach ipv4", },
-	{ .pf = NFPROTO_IPV6, .priority =  10001, .expect_success = true, .name = "attach ipv6", },
+	{
+		.pf = NFPROTO_IPV4,
+		.hooknum = NF_INET_POST_ROUTING,
+		.priority = -10000,
+		.flags = 0,
+		.expect_success = true,
+		.name = "attach ipv4",
+	},
+	{
+		.pf = NFPROTO_IPV6,
+		.hooknum = NF_INET_FORWARD,
+		.priority =  10001,
+		.flags = BPF_F_NETFILTER_IP_DEFRAG,
+		.expect_success = true,
+		.name = "attach ipv6",
+	},
 };
 
+static void verify_netfilter_link_info(struct bpf_link *link, const struct nf_link_test nf_expected)
+{
+	struct bpf_link_info info;
+	__u32 len = sizeof(info);
+	int err, fd;
+
+	memset(&info, 0, len);
+
+	fd = bpf_link__fd(link);
+	err = bpf_link_get_info_by_fd(fd, &info, &len);
+	ASSERT_OK(err, "get_link_info");
+
+	ASSERT_EQ(info.type, BPF_LINK_TYPE_NETFILTER, "info link type");
+	ASSERT_EQ(info.netfilter.pf, nf_expected.pf, "info nf protocol family");
+	ASSERT_EQ(info.netfilter.hooknum, nf_expected.hooknum, "info nf hooknum");
+	ASSERT_EQ(info.netfilter.priority, nf_expected.priority, "info nf priority");
+	ASSERT_EQ(info.netfilter.flags, nf_expected.flags, "info nf flags");
+}
+
 void test_netfilter_link_attach(void)
 {
 	struct test_netfilter_link_attach *skel;

@@ -63,6 +96,7 @@ void test_netfilter_link_attach(void)
 
 			if (!ASSERT_OK_PTR(link, "program attach successful"))
 				continue;
+			verify_netfilter_link_info(link, nf_hook_link_tests[i]);
 
 			link2 = bpf_program__attach_netfilter(prog, &opts);
 			ASSERT_ERR_PTR(link2, "attach program with same pf/hook/priority");

@@ -73,6 +107,8 @@ void test_netfilter_link_attach(void)
 			link2 = bpf_program__attach_netfilter(prog, &opts);
 			if (!ASSERT_OK_PTR(link2, "program reattach successful"))
 				continue;
+			verify_netfilter_link_info(link2, nf_hook_link_tests[i]);
+
 			if (!ASSERT_OK(bpf_link__destroy(link2), "link destroy"))
 				break;
 		} else {

Signature · 1 line

2.43.0

Florian Westphal

maintainer Acked-by on v1 1/2

2024-10-15 15:25 UTC #2 lore raw

In reply to Tyrone Wu

Quoted 2 lines · Tyrone Wu

This patch correctly populates the bpf_link_info.netfilter.flags field when user passes the BPF_F_NETFILTER_IP_DEFRAG flag.

Indeed, thanks for fixing this.
Patch and testcase look good, but one nit:

Quoted 1 line

Fixes 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs")

BPF_F_NETFILTER_IP_DEFRAG flag was added in
91721c2d02d3 ("netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link"), that was a bit later than the initial support.

Other than that,

Acked-by Florian Westphal <[email protected]>

Daniel Borkmann

maintainer

2024-10-16 15:13 UTC #3 lore raw

Quoted 7 lines · Florian Westphal

Quoted 2 lines · Tyrone Wu
This patch correctly populates the bpf_link_info.netfilter.flags field when user passes the BPF_F_NETFILTER_IP_DEFRAG flag.
Indeed, thanks for fixing this.
Patch and testcase look good, but one nit:

Quoted 7 lines

Quoted 1 line
Fixes 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs")
BPF_F_NETFILTER_IP_DEFRAG flag was added in
91721c2d02d3 ("netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link"), that was a bit later than the initial support.
Other than that,
Acked-by Florian Westphal <[email protected]>

Thanks Florian & Tyrone, fixed up Fixes tag while applying.

[email protected]

CI Applied

2024-10-16 15:10 UTC #4 lore raw

In reply to Tyrone Wu

This series was applied to bpf/bpf.git (master) by Daniel Borkmann <[email protected]>:

Hello:

This series was applied to bpf/bpf.git (master)
by Daniel Borkmann <[email protected]>:

Quoted 8 lines · On Fri, 11 Oct 2024 19:32:51 +0000 you wrote:

This patch correctly populates the bpf_link_info.netfilter.flags field when user passes the BPF_F_NETFILTER_IP_DEFRAG flag.
Fixes 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs")
Signed-off-by Tyrone Wu <[email protected]>
---
 net/netfilter/nf_bpf_link.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Here is the summary with links:
- [bpf,v1,1/2] bpf: fix link info netfilter flags to populate defrag flag

    https://git.kernel.org/bpf/bpf/c/92f3715e1eba
  - [bpf,v1,2/2] selftests/bpf: add asserts for netfilter link info
    https://git.kernel.org/bpf/bpf/c/2aa587fd6659

You are awesome, thank you!

Signature · 2 lines

Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html