bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff
@ 2021-09-04  0:18 Vadim Fedorenko
  2021-09-04  0:19 ` [PATCH bpf-next v2 1/2] bpf: add hardware timestamp field " Vadim Fedorenko
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Vadim Fedorenko @ 2021-09-04  0:18 UTC (permalink / raw)
  To: Martin KaFai Lau, Daniel Borkmann
  Cc: Vadim Fedorenko, Alexei Starovoitov, Song Liu, Yonghong Song,
	John Fastabend, Jakub Kicinski, netdev, bpf

This patch set adds hardware timestamps to __sk_buff. The first patch
implements feature, the second one adds a selftest.

v1 -> v2:

* Fixed bpf_skb_is_valid_access() to provide correct access to field
* Added explicit test to deny access to padding area
* Added verifier selftest to check for denied access to padding area

Vadim Fedorenko (2):
  bpf: add hardware timestamp field to __sk_buff
  selftests/bpf: test new __sk_buff field hwtstamp

 include/uapi/linux/bpf.h                      |  2 +
 lib/test_bpf.c                                |  1 +
 net/bpf/test_run.c                            |  8 +++
 net/core/filter.c                             | 21 +++++++
 tools/include/uapi/linux/bpf.h                |  2 +
 .../selftests/bpf/prog_tests/skb_ctx.c        |  1 +
 .../selftests/bpf/progs/test_skb_ctx.c        |  2 +
 .../testing/selftests/bpf/verifier/ctx_skb.c  | 60 +++++++++++++++++++
 8 files changed, 97 insertions(+)

-- 
2.18.4


^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH bpf-next v2 1/2] bpf: add hardware timestamp field to __sk_buff
  2021-09-04  0:18 [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Vadim Fedorenko
@ 2021-09-04  0:19 ` Vadim Fedorenko
  2021-09-04  0:19 ` [PATCH bpf-next v2 2/2] selftests/bpf: test new __sk_buff field hwtstamp Vadim Fedorenko
  2021-09-07 19:09 ` [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Martin KaFai Lau
  2 siblings, 0 replies; 5+ messages in thread
From: Vadim Fedorenko @ 2021-09-04  0:19 UTC (permalink / raw)
  To: Martin KaFai Lau, Daniel Borkmann
  Cc: Vadim Fedorenko, Alexei Starovoitov, Song Liu, Yonghong Song,
	John Fastabend, Jakub Kicinski, netdev, bpf

BPF programs may want to know hardware timestamps if NIC supports
such timestamping.

Expose this data as hwtstamp field of __sk_buff the same way as
gso_segs/gso_size. This field could be accessed from the same
programs as tstamp field, but it's read-only field. Explicit test
to deny access to padding data is added to bpf_skb_is_valid_access.

Also update BPF_PROG_TEST_RUN tests of the feature.

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
---
 include/uapi/linux/bpf.h       |  2 ++
 net/core/filter.c              | 21 +++++++++++++++++++++
 tools/include/uapi/linux/bpf.h |  2 ++
 3 files changed, 25 insertions(+)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 791f31dd0abe..51cfd91cc387 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5284,6 +5284,8 @@ struct __sk_buff {
 	__u32 gso_segs;
 	__bpf_md_ptr(struct bpf_sock *, sk);
 	__u32 gso_size;
+	__u32 :32;		/* Padding, future use. */
+	__u64 hwtstamp;
 };
 
 struct bpf_tunnel_key {
diff --git a/net/core/filter.c b/net/core/filter.c
index 2e32cee2c469..4bace37a6a44 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7765,6 +7765,10 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type
 		break;
 	case bpf_ctx_range_ptr(struct __sk_buff, flow_keys):
 		return false;
+	case bpf_ctx_range(struct __sk_buff, hwtstamp):
+		if (type == BPF_WRITE || size != sizeof(__u64))
+			return false;
+		break;
 	case bpf_ctx_range(struct __sk_buff, tstamp):
 		if (size != sizeof(__u64))
 			return false;
@@ -7774,6 +7778,9 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type
 			return false;
 		info->reg_type = PTR_TO_SOCK_COMMON_OR_NULL;
 		break;
+	case offsetofend(struct __sk_buff, gso_size) ... offsetof(struct __sk_buff, hwtstamp) - 1:
+		/* Explicitly prohibit access to padding in __sk_buff. */
+		return false;
 	default:
 		/* Only narrow read access allowed for now. */
 		if (type == BPF_WRITE) {
@@ -7802,6 +7809,7 @@ static bool sk_filter_is_valid_access(int off, int size,
 	case bpf_ctx_range_till(struct __sk_buff, family, local_port):
 	case bpf_ctx_range(struct __sk_buff, tstamp):
 	case bpf_ctx_range(struct __sk_buff, wire_len):
+	case bpf_ctx_range(struct __sk_buff, hwtstamp):
 		return false;
 	}
 
@@ -7872,6 +7880,7 @@ static bool lwt_is_valid_access(int off, int size,
 	case bpf_ctx_range(struct __sk_buff, data_meta):
 	case bpf_ctx_range(struct __sk_buff, tstamp):
 	case bpf_ctx_range(struct __sk_buff, wire_len):
+	case bpf_ctx_range(struct __sk_buff, hwtstamp):
 		return false;
 	}
 
@@ -8373,6 +8382,7 @@ static bool sk_skb_is_valid_access(int off, int size,
 	case bpf_ctx_range(struct __sk_buff, data_meta):
 	case bpf_ctx_range(struct __sk_buff, tstamp):
 	case bpf_ctx_range(struct __sk_buff, wire_len):
+	case bpf_ctx_range(struct __sk_buff, hwtstamp):
 		return false;
 	}
 
@@ -8884,6 +8894,17 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
 				      si->dst_reg, si->src_reg,
 				      offsetof(struct sk_buff, sk));
 		break;
+	case offsetof(struct __sk_buff, hwtstamp):
+		BUILD_BUG_ON(sizeof_field(struct skb_shared_hwtstamps, hwtstamp) != 8);
+		BUILD_BUG_ON(offsetof(struct skb_shared_hwtstamps, hwtstamp) != 0);
+
+		insn = bpf_convert_shinfo_access(si, insn);
+		*insn++ = BPF_LDX_MEM(BPF_DW,
+				      si->dst_reg, si->dst_reg,
+				      bpf_target_off(struct skb_shared_info,
+						     hwtstamps, 8,
+						     target_size));
+		break;
 	}
 
 	return insn - insn_buf;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 791f31dd0abe..51cfd91cc387 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5284,6 +5284,8 @@ struct __sk_buff {
 	__u32 gso_segs;
 	__bpf_md_ptr(struct bpf_sock *, sk);
 	__u32 gso_size;
+	__u32 :32;		/* Padding, future use. */
+	__u64 hwtstamp;
 };
 
 struct bpf_tunnel_key {
-- 
2.18.4


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* [PATCH bpf-next v2 2/2] selftests/bpf: test new __sk_buff field hwtstamp
  2021-09-04  0:18 [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Vadim Fedorenko
  2021-09-04  0:19 ` [PATCH bpf-next v2 1/2] bpf: add hardware timestamp field " Vadim Fedorenko
@ 2021-09-04  0:19 ` Vadim Fedorenko
  2021-09-07 19:09 ` [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Martin KaFai Lau
  2 siblings, 0 replies; 5+ messages in thread
From: Vadim Fedorenko @ 2021-09-04  0:19 UTC (permalink / raw)
  To: Martin KaFai Lau, Daniel Borkmann
  Cc: Vadim Fedorenko, Alexei Starovoitov, Song Liu, Yonghong Song,
	John Fastabend, Jakub Kicinski, netdev, bpf

Analogous to the gso_segs selftests introduced in commit d9ff286a0f59
("bpf: allow BPF programs access skb_shared_info->gso_segs field")

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
---
 lib/test_bpf.c                                |  1 +
 net/bpf/test_run.c                            |  8 +++
 .../selftests/bpf/prog_tests/skb_ctx.c        |  1 +
 .../selftests/bpf/progs/test_skb_ctx.c        |  2 +
 .../testing/selftests/bpf/verifier/ctx_skb.c  | 60 +++++++++++++++++++
 5 files changed, 72 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 830a18ecffc8..0018d51b93b0 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -8800,6 +8800,7 @@ static __init struct sk_buff *build_test_skb(void)
 	skb_shinfo(skb[0])->gso_type |= SKB_GSO_DODGY;
 	skb_shinfo(skb[0])->gso_segs = 0;
 	skb_shinfo(skb[0])->frag_list = skb[1];
+	skb_shinfo(skb[0])->hwtstamps.hwtstamp = 1000;
 
 	/* adjust skb[0]'s len */
 	skb[0]->len += skb[1]->len;
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 2eb0e55ef54d..1232dd839d7a 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -511,6 +511,12 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
 	/* gso_size is allowed */
 
 	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_size),
+			   offsetof(struct __sk_buff, hwtstamp)))
+		return -EINVAL;
+
+	/* hwtstamp is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, hwtstamp),
 			   sizeof(struct __sk_buff)))
 		return -EINVAL;
 
@@ -532,6 +538,7 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
 		return -EINVAL;
 	skb_shinfo(skb)->gso_segs = __skb->gso_segs;
 	skb_shinfo(skb)->gso_size = __skb->gso_size;
+	skb_shinfo(skb)->hwtstamps.hwtstamp = __skb->hwtstamp;
 
 	return 0;
 }
@@ -550,6 +557,7 @@ static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
 	memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);
 	__skb->wire_len = cb->pkt_len;
 	__skb->gso_segs = skb_shinfo(skb)->gso_segs;
+	__skb->hwtstamp = skb_shinfo(skb)->hwtstamps.hwtstamp;
 }
 
 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
diff --git a/tools/testing/selftests/bpf/prog_tests/skb_ctx.c b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
index fafeddaad6a9..87ca95e8442b 100644
--- a/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
+++ b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
@@ -17,6 +17,7 @@ void test_skb_ctx(void)
 		.gso_segs = 8,
 		.mark = 9,
 		.gso_size = 10,
+		.hwtstamp = 11,
 	};
 	struct bpf_prog_test_run_attr tattr = {
 		.data_in = &pkt_v4,
diff --git a/tools/testing/selftests/bpf/progs/test_skb_ctx.c b/tools/testing/selftests/bpf/progs/test_skb_ctx.c
index b02ea589ce7e..5cfa91cf0f08 100644
--- a/tools/testing/selftests/bpf/progs/test_skb_ctx.c
+++ b/tools/testing/selftests/bpf/progs/test_skb_ctx.c
@@ -25,6 +25,8 @@ int process(struct __sk_buff *skb)
 		return 1;
 	if (skb->gso_size != 10)
 		return 1;
+	if (skb->hwtstamp != 11)
+		return 1;
 
 	return 0;
 }
diff --git a/tools/testing/selftests/bpf/verifier/ctx_skb.c b/tools/testing/selftests/bpf/verifier/ctx_skb.c
index 2022c0f2cd75..9e1a30b94197 100644
--- a/tools/testing/selftests/bpf/verifier/ctx_skb.c
+++ b/tools/testing/selftests/bpf/verifier/ctx_skb.c
@@ -1057,6 +1057,66 @@
 	.result = ACCEPT,
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 },
+{
+	"padding after gso_size is not accessible",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+		    offsetofend(struct __sk_buff, gso_size)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.result_unpriv = REJECT,
+	.errstr = "invalid bpf_context access off=180 size=4",
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+},
+{
+	"read hwtstamp from CGROUP_SKB",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
+		    offsetof(struct __sk_buff, hwtstamp)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+},
+{
+	"read hwtstamp from CGROUP_SKB",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1,
+		    offsetof(struct __sk_buff, hwtstamp)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+},
+{
+	"write hwtstamp from CGROUP_SKB",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+		    offsetof(struct __sk_buff, hwtstamp)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = REJECT,
+	.result_unpriv = REJECT,
+	.errstr = "invalid bpf_context access off=184 size=8",
+	.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+},
+{
+	"read hwtstamp from CLS",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
+		    offsetof(struct __sk_buff, hwtstamp)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+},
 {
 	"check wire_len is not readable by sockets",
 	.insns = {
-- 
2.18.4


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff
  2021-09-04  0:18 [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Vadim Fedorenko
  2021-09-04  0:19 ` [PATCH bpf-next v2 1/2] bpf: add hardware timestamp field " Vadim Fedorenko
  2021-09-04  0:19 ` [PATCH bpf-next v2 2/2] selftests/bpf: test new __sk_buff field hwtstamp Vadim Fedorenko
@ 2021-09-07 19:09 ` Martin KaFai Lau
  2021-09-09  4:08   ` Andrii Nakryiko
  2 siblings, 1 reply; 5+ messages in thread
From: Martin KaFai Lau @ 2021-09-07 19:09 UTC (permalink / raw)
  To: Vadim Fedorenko
  Cc: Daniel Borkmann, Alexei Starovoitov, Song Liu, Yonghong Song,
	John Fastabend, Jakub Kicinski, netdev, bpf

On Sat, Sep 04, 2021 at 03:18:59AM +0300, Vadim Fedorenko wrote:
> This patch set adds hardware timestamps to __sk_buff. The first patch
> implements feature, the second one adds a selftest.
> 
> v1 -> v2:
> 
> * Fixed bpf_skb_is_valid_access() to provide correct access to field
> * Added explicit test to deny access to padding area
> * Added verifier selftest to check for denied access to padding area
Acked-by: Martin KaFai Lau <kafai@fb.com>

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff
  2021-09-07 19:09 ` [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Martin KaFai Lau
@ 2021-09-09  4:08   ` Andrii Nakryiko
  0 siblings, 0 replies; 5+ messages in thread
From: Andrii Nakryiko @ 2021-09-09  4:08 UTC (permalink / raw)
  To: Martin KaFai Lau
  Cc: Vadim Fedorenko, Daniel Borkmann, Alexei Starovoitov, Song Liu,
	Yonghong Song, John Fastabend, Jakub Kicinski, Networking, bpf

On Tue, Sep 7, 2021 at 12:11 PM Martin KaFai Lau <kafai@fb.com> wrote:
>
> On Sat, Sep 04, 2021 at 03:18:59AM +0300, Vadim Fedorenko wrote:
> > This patch set adds hardware timestamps to __sk_buff. The first patch
> > implements feature, the second one adds a selftest.
> >
> > v1 -> v2:
> >
> > * Fixed bpf_skb_is_valid_access() to provide correct access to field
> > * Added explicit test to deny access to padding area
> > * Added verifier selftest to check for denied access to padding area
> Acked-by: Martin KaFai Lau <kafai@fb.com>

This patch set doesn't apply cleanly anymore ([0]). Please collect
Acks, rebase, and resubmit. Thanks!

  [0] https://github.com/kernel-patches/bpf/pull/1718#issuecomment-914717959

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-09-09  4:08 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-04  0:18 [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Vadim Fedorenko
2021-09-04  0:19 ` [PATCH bpf-next v2 1/2] bpf: add hardware timestamp field " Vadim Fedorenko
2021-09-04  0:19 ` [PATCH bpf-next v2 2/2] selftests/bpf: test new __sk_buff field hwtstamp Vadim Fedorenko
2021-09-07 19:09 ` [PATCH bpf-next v2 0/2] add hwtstamp to __sk_buff Martin KaFai Lau
2021-09-09  4:08   ` Andrii Nakryiko

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).