1 files changed, 419 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_xdp_meta.c b/tools/testing/selftests/bpf/progs/test_xdp_meta.c
index fcf6ca14f2ea..d79cb74b571e 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_meta.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_meta.c
@@ -1,8 +1,11 @@
+#include <stdbool.h>
 #include <linux/bpf.h>
+#include <linux/errno.h>
 #include <linux/if_ether.h>
 #include <linux/pkt_cls.h>
 
 #include <bpf/bpf_helpers.h>
+#include "bpf_kfuncs.h"
 
 #define META_SIZE 32
 
@@ -23,6 +26,8 @@ struct {
 	__uint(value_size, META_SIZE);
 } test_result SEC(".maps");
 
+bool test_pass;
+
 SEC("tc")
 int ing_cls(struct __sk_buff *ctx)
 {
@@ -40,6 +45,231 @@ int ing_cls(struct __sk_buff *ctx)
 	return TC_ACT_SHOT;
 }
 
+/* Read from metadata using bpf_dynptr_read helper */
+SEC("tc")
+int ing_cls_dynptr_read(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr meta;
+	const __u32 zero = 0;
+	__u8 *dst;
+
+	dst = bpf_map_lookup_elem(&test_result, &zero);
+	if (!dst)
+		return TC_ACT_SHOT;
+
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	bpf_dynptr_read(dst, META_SIZE, &meta, 0, 0);
+
+	return TC_ACT_SHOT;
+}
+
+/* Write to metadata using bpf_dynptr_write helper */
+SEC("tc")
+int ing_cls_dynptr_write(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr data, meta;
+	__u8 *src;
+
+	bpf_dynptr_from_skb(ctx, 0, &data);
+	src = bpf_dynptr_slice(&data, sizeof(struct ethhdr), NULL, META_SIZE);
+	if (!src)
+		return TC_ACT_SHOT;
+
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	bpf_dynptr_write(&meta, 0, src, META_SIZE, 0);
+
+	return TC_ACT_UNSPEC; /* pass */
+}
+
+/* Read from metadata using read-only dynptr slice */
+SEC("tc")
+int ing_cls_dynptr_slice(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr meta;
+	const __u32 zero = 0;
+	__u8 *dst, *src;
+
+	dst = bpf_map_lookup_elem(&test_result, &zero);
+	if (!dst)
+		return TC_ACT_SHOT;
+
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	src = bpf_dynptr_slice(&meta, 0, NULL, META_SIZE);
+	if (!src)
+		return TC_ACT_SHOT;
+
+	__builtin_memcpy(dst, src, META_SIZE);
+
+	return TC_ACT_SHOT;
+}
+
+/* Write to metadata using writeable dynptr slice */
+SEC("tc")
+int ing_cls_dynptr_slice_rdwr(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr data, meta;
+	__u8 *src, *dst;
+
+	bpf_dynptr_from_skb(ctx, 0, &data);
+	src = bpf_dynptr_slice(&data, sizeof(struct ethhdr), NULL, META_SIZE);
+	if (!src)
+		return TC_ACT_SHOT;
+
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	dst = bpf_dynptr_slice_rdwr(&meta, 0, NULL, META_SIZE);
+	if (!dst)
+		return TC_ACT_SHOT;
+
+	__builtin_memcpy(dst, src, META_SIZE);
+
+	return TC_ACT_UNSPEC; /* pass */
+}
+
+/* Read skb metadata in chunks from various offsets in different ways. */
+SEC("tc")
+int ing_cls_dynptr_offset_rd(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr meta;
+	const __u32 chunk_len = META_SIZE / 4;
+	const __u32 zero = 0;
+	__u8 *dst, *src;
+
+	dst = bpf_map_lookup_elem(&test_result, &zero);
+	if (!dst)
+		return TC_ACT_SHOT;
+
+	/* 1. Regular read */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	bpf_dynptr_read(dst, chunk_len, &meta, 0, 0);
+	dst += chunk_len;
+
+	/* 2. Read from an offset-adjusted dynptr */
+	bpf_dynptr_adjust(&meta, chunk_len, bpf_dynptr_size(&meta));
+	bpf_dynptr_read(dst, chunk_len, &meta, 0, 0);
+	dst += chunk_len;
+
+	/* 3. Read at an offset */
+	bpf_dynptr_read(dst, chunk_len, &meta, chunk_len, 0);
+	dst += chunk_len;
+
+	/* 4. Read from a slice starting at an offset */
+	src = bpf_dynptr_slice(&meta, 2 * chunk_len, NULL, chunk_len);
+	if (!src)
+		return TC_ACT_SHOT;
+	__builtin_memcpy(dst, src, chunk_len);
+
+	return TC_ACT_SHOT;
+}
+
+/* Write skb metadata in chunks at various offsets in different ways. */
+SEC("tc")
+int ing_cls_dynptr_offset_wr(struct __sk_buff *ctx)
+{
+	const __u32 chunk_len = META_SIZE / 4;
+	__u8 payload[META_SIZE];
+	struct bpf_dynptr meta;
+	__u8 *dst, *src;
+
+	bpf_skb_load_bytes(ctx, sizeof(struct ethhdr), payload, sizeof(payload));
+	src = payload;
+
+	/* 1. Regular write */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	bpf_dynptr_write(&meta, 0, src, chunk_len, 0);
+	src += chunk_len;
+
+	/* 2. Write to an offset-adjusted dynptr */
+	bpf_dynptr_adjust(&meta, chunk_len, bpf_dynptr_size(&meta));
+	bpf_dynptr_write(&meta, 0, src, chunk_len, 0);
+	src += chunk_len;
+
+	/* 3. Write at an offset */
+	bpf_dynptr_write(&meta, chunk_len, src, chunk_len, 0);
+	src += chunk_len;
+
+	/* 4. Write to a slice starting at an offset */
+	dst = bpf_dynptr_slice_rdwr(&meta, 2 * chunk_len, NULL, chunk_len);
+	if (!dst)
+		return TC_ACT_SHOT;
+	__builtin_memcpy(dst, src, chunk_len);
+
+	return TC_ACT_UNSPEC; /* pass */
+}
+
+/* Pass an OOB offset to dynptr read, write, adjust, slice. */
+SEC("tc")
+int ing_cls_dynptr_offset_oob(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr meta;
+	__u8 md, *p;
+	int err;
+
+	err = bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (err)
+		goto fail;
+
+	/* read offset OOB */
+	err = bpf_dynptr_read(&md, sizeof(md), &meta, META_SIZE, 0);
+	if (err != -E2BIG)
+		goto fail;
+
+	/* write offset OOB */
+	err = bpf_dynptr_write(&meta, META_SIZE, &md, sizeof(md), 0);
+	if (err != -E2BIG)
+		goto fail;
+
+	/* adjust end offset OOB */
+	err = bpf_dynptr_adjust(&meta, 0, META_SIZE + 1);
+	if (err != -ERANGE)
+		goto fail;
+
+	/* adjust start offset OOB */
+	err = bpf_dynptr_adjust(&meta, META_SIZE + 1, META_SIZE + 1);
+	if (err != -ERANGE)
+		goto fail;
+
+	/* slice offset OOB */
+	p = bpf_dynptr_slice(&meta, META_SIZE, NULL, sizeof(*p));
+	if (p)
+		goto fail;
+
+	/* slice rdwr offset OOB */
+	p = bpf_dynptr_slice_rdwr(&meta, META_SIZE, NULL, sizeof(*p));
+	if (p)
+		goto fail;
+
+	return TC_ACT_UNSPEC;
+fail:
+	return TC_ACT_SHOT;
+}
+
+/* Reserve and clear space for metadata but don't populate it */
+SEC("xdp")
+int ing_xdp_zalloc_meta(struct xdp_md *ctx)
+{
+	struct ethhdr *eth = ctx_ptr(ctx, data);
+	__u8 *meta;
+	int ret;
+
+	/* Drop any non-test packets */
+	if (eth + 1 > ctx_ptr(ctx, data_end))
+		return XDP_DROP;
+	if (eth->h_proto != 0)
+		return XDP_DROP;
+
+	ret = bpf_xdp_adjust_meta(ctx, -META_SIZE);
+	if (ret < 0)
+		return XDP_DROP;
+
+	meta = ctx_ptr(ctx, data_meta);
+	if (meta + META_SIZE > ctx_ptr(ctx, data))
+		return XDP_DROP;
+
+	__builtin_memset(meta, 0, META_SIZE);
+
+	return XDP_PASS;
+}
+
 SEC("xdp")
 int ing_xdp(struct xdp_md *ctx)
 {
@@ -73,4 +303,193 @@ int ing_xdp(struct xdp_md *ctx)
 	return XDP_PASS;
 }
 
+/*
+ * Check that skb->data_meta..skb->data is empty if prog writes to packet
+ * _payload_ using packet pointers. Applies only to cloned skbs.
+ */
+SEC("tc")
+int clone_data_meta_empty_on_data_write(struct __sk_buff *ctx)
+{
+	struct ethhdr *eth = ctx_ptr(ctx, data);
+
+	if (eth + 1 > ctx_ptr(ctx, data_end))
+		goto out;
+	/* Ignore non-test packets */
+	if (eth->h_proto != 0)
+		goto out;
+
+	/* Expect no metadata */
+	if (ctx->data_meta != ctx->data)
+		goto out;
+
+	/* Packet write to trigger unclone in prologue */
+	eth->h_proto = 42;
+
+	test_pass = true;
+out:
+	return TC_ACT_SHOT;
+}
+
+/*
+ * Check that skb->data_meta..skb->data is empty if prog writes to packet
+ * _metadata_ using packet pointers. Applies only to cloned skbs.
+ */
+SEC("tc")
+int clone_data_meta_empty_on_meta_write(struct __sk_buff *ctx)
+{
+	struct ethhdr *eth = ctx_ptr(ctx, data);
+	__u8 *md = ctx_ptr(ctx, data_meta);
+
+	if (eth + 1 > ctx_ptr(ctx, data_end))
+		goto out;
+	/* Ignore non-test packets */
+	if (eth->h_proto != 0)
+		goto out;
+
+	if (md + 1 > ctx_ptr(ctx, data)) {
+		/* Expect no metadata */
+		test_pass = true;
+	} else {
+		/* Metadata write to trigger unclone in prologue */
+		*md = 42;
+	}
+out:
+	return TC_ACT_SHOT;
+}
+
+/*
+ * Check that skb_meta dynptr is writable but empty if prog writes to packet
+ * _payload_ using a dynptr slice. Applies only to cloned skbs.
+ */
+SEC("tc")
+int clone_dynptr_empty_on_data_slice_write(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr data, meta;
+	struct ethhdr *eth;
+
+	bpf_dynptr_from_skb(ctx, 0, &data);
+	eth = bpf_dynptr_slice_rdwr(&data, 0, NULL, sizeof(*eth));
+	if (!eth)
+		goto out;
+	/* Ignore non-test packets */
+	if (eth->h_proto != 0)
+		goto out;
+
+	/* Expect no metadata */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (bpf_dynptr_is_rdonly(&meta) || bpf_dynptr_size(&meta) > 0)
+		goto out;
+
+	/* Packet write to trigger unclone in prologue */
+	eth->h_proto = 42;
+
+	test_pass = true;
+out:
+	return TC_ACT_SHOT;
+}
+
+/*
+ * Check that skb_meta dynptr is writable but empty if prog writes to packet
+ * _metadata_ using a dynptr slice. Applies only to cloned skbs.
+ */
+SEC("tc")
+int clone_dynptr_empty_on_meta_slice_write(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr data, meta;
+	const struct ethhdr *eth;
+	__u8 *md;
+
+	bpf_dynptr_from_skb(ctx, 0, &data);
+	eth = bpf_dynptr_slice(&data, 0, NULL, sizeof(*eth));
+	if (!eth)
+		goto out;
+	/* Ignore non-test packets */
+	if (eth->h_proto != 0)
+		goto out;
+
+	/* Expect no metadata */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (bpf_dynptr_is_rdonly(&meta) || bpf_dynptr_size(&meta) > 0)
+		goto out;
+
+	/* Metadata write to trigger unclone in prologue */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	md = bpf_dynptr_slice_rdwr(&meta, 0, NULL, sizeof(*md));
+	if (md)
+		*md = 42;
+
+	test_pass = true;
+out:
+	return TC_ACT_SHOT;
+}
+
+/*
+ * Check that skb_meta dynptr is read-only before prog writes to packet payload
+ * using dynptr_write helper. Applies only to cloned skbs.
+ */
+SEC("tc")
+int clone_dynptr_rdonly_before_data_dynptr_write(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr data, meta;
+	const struct ethhdr *eth;
+
+	bpf_dynptr_from_skb(ctx, 0, &data);
+	eth = bpf_dynptr_slice(&data, 0, NULL, sizeof(*eth));
+	if (!eth)
+		goto out;
+	/* Ignore non-test packets */
+	if (eth->h_proto != 0)
+		goto out;
+
+	/* Expect read-only metadata before unclone */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (!bpf_dynptr_is_rdonly(&meta) || bpf_dynptr_size(&meta) != META_SIZE)
+		goto out;
+
+	/* Helper write to payload will unclone the packet */
+	bpf_dynptr_write(&data, offsetof(struct ethhdr, h_proto), "x", 1, 0);
+
+	/* Expect no metadata after unclone */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (bpf_dynptr_is_rdonly(&meta) || bpf_dynptr_size(&meta) != 0)
+		goto out;
+
+	test_pass = true;
+out:
+	return TC_ACT_SHOT;
+}
+
+/*
+ * Check that skb_meta dynptr is read-only if prog writes to packet
+ * metadata using dynptr_write helper. Applies only to cloned skbs.
+ */
+SEC("tc")
+int clone_dynptr_rdonly_before_meta_dynptr_write(struct __sk_buff *ctx)
+{
+	struct bpf_dynptr data, meta;
+	const struct ethhdr *eth;
+
+	bpf_dynptr_from_skb(ctx, 0, &data);
+	eth = bpf_dynptr_slice(&data, 0, NULL, sizeof(*eth));
+	if (!eth)
+		goto out;
+	/* Ignore non-test packets */
+	if (eth->h_proto != 0)
+		goto out;
+
+	/* Expect read-only metadata */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (!bpf_dynptr_is_rdonly(&meta) || bpf_dynptr_size(&meta) != META_SIZE)
+		goto out;
+
+	/* Metadata write. Expect failure. */
+	bpf_dynptr_from_skb_meta(ctx, 0, &meta);
+	if (bpf_dynptr_write(&meta, 0, "x", 1, 0) != -EINVAL)
+		goto out;
+
+	test_pass = true;
+out:
+	return TC_ACT_SHOT;
+}
+
 char _license[] SEC("license") = "GPL";