* [PATCH bpf-next 1/3] bpf: add gso_size to __sk_buff
2020-03-03 20:05 [PATCH bpf-next 0/3] add gso_size to __sk_buff Willem de Bruijn
@ 2020-03-03 20:05 ` Willem de Bruijn
2020-03-03 20:05 ` [PATCH bpf-next 2/3] bpf: Sync uapi bpf.h to tools/ Willem de Bruijn
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Willem de Bruijn @ 2020-03-03 20:05 UTC (permalink / raw)
To: bpf; +Cc: netdev, daniel, ast, Willem de Bruijn
From: Willem de Bruijn <willemb@google.com>
BPF programs may want to know whether an skb is gso. The canonical
answer is skb_is_gso(skb), which tests that gso_size != 0.
Expose this field in the same manner as gso_segs. That field itself
is not a sufficient signal, as the comment in skb_shared_info makes
clear: gso_segs may be zero, e.g., from dodgy sources.
Also prepare net/bpf/test_run for upcoming BPF_PROG_TEST_RUN tests
of the feature.
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
include/uapi/linux/bpf.h | 1 +
net/bpf/test_run.c | 7 +++++++
net/core/filter.c | 44 +++++++++++++++++++++++++++-------------
3 files changed, 38 insertions(+), 14 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 8e98ced0963b..180337fae97e 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3176,6 +3176,7 @@ struct __sk_buff {
__u32 wire_len;
__u32 gso_segs;
__bpf_md_ptr(struct bpf_sock *, sk);
+ __u32 gso_size;
};
struct bpf_tunnel_key {
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 562443f94133..1cd7a1c2f8b2 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -277,6 +277,12 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
/* gso_segs is allowed */
if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs),
+ offsetof(struct __sk_buff, gso_size)))
+ return -EINVAL;
+
+ /* gso_size is allowed */
+
+ if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_size),
sizeof(struct __sk_buff)))
return -EINVAL;
@@ -297,6 +303,7 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
if (__skb->gso_segs > GSO_MAX_SEGS)
return -EINVAL;
skb_shinfo(skb)->gso_segs = __skb->gso_segs;
+ skb_shinfo(skb)->gso_size = __skb->gso_size;
return 0;
}
diff --git a/net/core/filter.c b/net/core/filter.c
index 4a08c9fb2be7..cd0a532db4e7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7139,6 +7139,27 @@ static u32 flow_dissector_convert_ctx_access(enum bpf_access_type type,
return insn - insn_buf;
}
+static struct bpf_insn *bpf_convert_shinfo_access(const struct bpf_insn *si,
+ struct bpf_insn *insn)
+{
+ /* si->dst_reg = skb_shinfo(SKB); */
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end),
+ BPF_REG_AX, si->src_reg,
+ offsetof(struct sk_buff, end));
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, head),
+ si->dst_reg, si->src_reg,
+ offsetof(struct sk_buff, head));
+ *insn++ = BPF_ALU64_REG(BPF_ADD, si->dst_reg, BPF_REG_AX);
+#else
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end),
+ si->dst_reg, si->src_reg,
+ offsetof(struct sk_buff, end));
+#endif
+
+ return insn;
+}
+
static u32 bpf_convert_ctx_access(enum bpf_access_type type,
const struct bpf_insn *si,
struct bpf_insn *insn_buf,
@@ -7461,26 +7482,21 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
break;
case offsetof(struct __sk_buff, gso_segs):
- /* si->dst_reg = skb_shinfo(SKB); */
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
- *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end),
- BPF_REG_AX, si->src_reg,
- offsetof(struct sk_buff, end));
- *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, head),
- si->dst_reg, si->src_reg,
- offsetof(struct sk_buff, head));
- *insn++ = BPF_ALU64_REG(BPF_ADD, si->dst_reg, BPF_REG_AX);
-#else
- *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end),
- si->dst_reg, si->src_reg,
- offsetof(struct sk_buff, end));
-#endif
+ insn = bpf_convert_shinfo_access(si, insn);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct skb_shared_info, gso_segs),
si->dst_reg, si->dst_reg,
bpf_target_off(struct skb_shared_info,
gso_segs, 2,
target_size));
break;
+ case offsetof(struct __sk_buff, gso_size):
+ insn = bpf_convert_shinfo_access(si, insn);
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct skb_shared_info, gso_size),
+ si->dst_reg, si->dst_reg,
+ bpf_target_off(struct skb_shared_info,
+ gso_size, 2,
+ target_size));
+ break;
case offsetof(struct __sk_buff, wire_len):
BUILD_BUG_ON(sizeof_field(struct qdisc_skb_cb, pkt_len) != 4);
--
2.25.0.265.gbab2e86ba0-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH bpf-next 2/3] bpf: Sync uapi bpf.h to tools/
2020-03-03 20:05 [PATCH bpf-next 0/3] add gso_size to __sk_buff Willem de Bruijn
2020-03-03 20:05 ` [PATCH bpf-next 1/3] bpf: " Willem de Bruijn
@ 2020-03-03 20:05 ` Willem de Bruijn
2020-03-03 20:05 ` [PATCH bpf-next 3/3] selftests/bpf: test new __sk_buff field gso_size Willem de Bruijn
2020-03-03 22:56 ` [PATCH bpf-next 0/3] add gso_size to __sk_buff Petar Penkov
3 siblings, 0 replies; 6+ messages in thread
From: Willem de Bruijn @ 2020-03-03 20:05 UTC (permalink / raw)
To: bpf; +Cc: netdev, daniel, ast, Willem de Bruijn
From: Willem de Bruijn <willemb@google.com>
sync tools/include/uapi/linux/bpf.h to match include/uapi/linux/bpf.h
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
tools/include/uapi/linux/bpf.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 906e9f2752db..7c689f4552dd 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3176,6 +3176,7 @@ struct __sk_buff {
__u32 wire_len;
__u32 gso_segs;
__bpf_md_ptr(struct bpf_sock *, sk);
+ __u32 gso_size;
};
struct bpf_tunnel_key {
--
2.25.0.265.gbab2e86ba0-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH bpf-next 3/3] selftests/bpf: test new __sk_buff field gso_size
2020-03-03 20:05 [PATCH bpf-next 0/3] add gso_size to __sk_buff Willem de Bruijn
2020-03-03 20:05 ` [PATCH bpf-next 1/3] bpf: " Willem de Bruijn
2020-03-03 20:05 ` [PATCH bpf-next 2/3] bpf: Sync uapi bpf.h to tools/ Willem de Bruijn
@ 2020-03-03 20:05 ` Willem de Bruijn
2020-03-03 22:56 ` [PATCH bpf-next 0/3] add gso_size to __sk_buff Petar Penkov
3 siblings, 0 replies; 6+ messages in thread
From: Willem de Bruijn @ 2020-03-03 20:05 UTC (permalink / raw)
To: bpf; +Cc: netdev, daniel, ast, Willem de Bruijn
From: Willem de Bruijn <willemb@google.com>
Analogous to the gso_segs selftests introduced in commit d9ff286a0f59
("bpf: allow BPF programs access skb_shared_info->gso_segs field").
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
.../selftests/bpf/prog_tests/skb_ctx.c | 1 +
.../selftests/bpf/progs/test_skb_ctx.c | 2 +
.../testing/selftests/bpf/verifier/ctx_skb.c | 47 +++++++++++++++++++
3 files changed, 50 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/skb_ctx.c b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
index c6d6b685a946..4538bd08203f 100644
--- a/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
+++ b/tools/testing/selftests/bpf/prog_tests/skb_ctx.c
@@ -14,6 +14,7 @@ void test_skb_ctx(void)
.wire_len = 100,
.gso_segs = 8,
.mark = 9,
+ .gso_size = 10,
};
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 202de3938494..b02ea589ce7e 100644
--- a/tools/testing/selftests/bpf/progs/test_skb_ctx.c
+++ b/tools/testing/selftests/bpf/progs/test_skb_ctx.c
@@ -23,6 +23,8 @@ int process(struct __sk_buff *skb)
return 1;
if (skb->gso_segs != 8)
return 1;
+ if (skb->gso_size != 10)
+ 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 d438193804b2..2e16b8e268f2 100644
--- a/tools/testing/selftests/bpf/verifier/ctx_skb.c
+++ b/tools/testing/selftests/bpf/verifier/ctx_skb.c
@@ -1010,6 +1010,53 @@
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
+{
+ "read gso_size from CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, gso_size)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+},
+{
+ "read gso_size from CGROUP_SKB",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1,
+ offsetof(struct __sk_buff, gso_size)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+},
+{
+ "write gso_size from CGROUP_SKB",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(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=176 size=4",
+ .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+},
+{
+ "read gso_size from CLS",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, gso_size)),
+ 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 = {
--
2.25.0.265.gbab2e86ba0-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH bpf-next 0/3] add gso_size to __sk_buff
2020-03-03 20:05 [PATCH bpf-next 0/3] add gso_size to __sk_buff Willem de Bruijn
` (2 preceding siblings ...)
2020-03-03 20:05 ` [PATCH bpf-next 3/3] selftests/bpf: test new __sk_buff field gso_size Willem de Bruijn
@ 2020-03-03 22:56 ` Petar Penkov
2020-03-04 0:31 ` Alexei Starovoitov
3 siblings, 1 reply; 6+ messages in thread
From: Petar Penkov @ 2020-03-03 22:56 UTC (permalink / raw)
To: Willem de Bruijn
Cc: bpf, Networking, Daniel Borkmann, Alexei Starovoitov, Willem de Bruijn
For the series: Acked-by: Petar Penkov <ppenkov@google.com>
On Tue, Mar 3, 2020 at 1:46 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> From: Willem de Bruijn <willemb@google.com>
>
> See first patch for details.
>
> Patch split across three parts { kernel feature, uapi header, tools }
> following the custom for such __sk_buff changes.
>
> Willem de Bruijn (3):
> bpf: add gso_size to __sk_buff
> bpf: Sync uapi bpf.h to tools/
> selftests/bpf: test new __sk_buff field gso_size
>
> include/uapi/linux/bpf.h | 1 +
> net/bpf/test_run.c | 7 +++
> net/core/filter.c | 44 +++++++++++------
> tools/include/uapi/linux/bpf.h | 1 +
> .../selftests/bpf/prog_tests/skb_ctx.c | 1 +
> .../selftests/bpf/progs/test_skb_ctx.c | 2 +
> .../testing/selftests/bpf/verifier/ctx_skb.c | 47 +++++++++++++++++++
> 7 files changed, 89 insertions(+), 14 deletions(-)
>
> --
> 2.25.0.265.gbab2e86ba0-goog
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH bpf-next 0/3] add gso_size to __sk_buff
2020-03-03 22:56 ` [PATCH bpf-next 0/3] add gso_size to __sk_buff Petar Penkov
@ 2020-03-04 0:31 ` Alexei Starovoitov
0 siblings, 0 replies; 6+ messages in thread
From: Alexei Starovoitov @ 2020-03-04 0:31 UTC (permalink / raw)
To: Petar Penkov
Cc: Willem de Bruijn, bpf, Networking, Daniel Borkmann,
Alexei Starovoitov, Willem de Bruijn
On Tue, Mar 3, 2020 at 2:56 PM Petar Penkov <ppenkov.kernel@gmail.com> wrote:
>
> For the series: Acked-by: Petar Penkov <ppenkov@google.com>
please don't top post.
> On Tue, Mar 3, 2020 at 1:46 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > From: Willem de Bruijn <willemb@google.com>
> >
> > See first patch for details.
> >
> > Patch split across three parts { kernel feature, uapi header, tools }
> > following the custom for such __sk_buff changes.
Applied. Thanks
^ permalink raw reply [flat|nested] 6+ messages in thread