diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_xdp_meta.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_xdp_meta.c | 658 |
1 files changed, 639 insertions, 19 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_meta.c b/tools/testing/selftests/bpf/progs/test_xdp_meta.c index a7c4a7d49fe6..0a0f371a2dec 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_meta.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_meta.c @@ -1,40 +1,320 @@ +#include <stdbool.h> #include <linux/bpf.h> +#include <linux/errno.h> #include <linux/if_ether.h> #include <linux/pkt_cls.h> +#include <bpf/bpf_endian.h> #include <bpf/bpf_helpers.h> +#include "bpf_kfuncs.h" + +#define META_SIZE 32 -#define __round_mask(x, y) ((__typeof__(x))((y) - 1)) -#define round_up(x, y) ((((x) - 1) | __round_mask(x, y)) + 1) #define ctx_ptr(ctx, mem) (void *)(unsigned long)ctx->mem -SEC("t") +/* Demonstrate passing metadata from XDP to TC using bpf_xdp_adjust_meta. + * + * The XDP program extracts a fixed-size payload following the Ethernet header + * and stores it as packet metadata to test the driver's metadata support. The + * TC program then verifies if the passed metadata is correct. + */ + +bool test_pass; + +static const __u8 smac_want[ETH_ALEN] = { + 0x12, 0x34, 0xDE, 0xAD, 0xBE, 0xEF, +}; + +static const __u8 meta_want[META_SIZE] = { + 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, + 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, + 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, + 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, +}; + +static bool check_smac(const struct ethhdr *eth) +{ + return !__builtin_memcmp(eth->h_source, smac_want, ETH_ALEN); +} + +static bool check_metadata(const char *file, int line, __u8 *meta_have) +{ + if (!__builtin_memcmp(meta_have, meta_want, META_SIZE)) + return true; + + bpf_stream_printk(BPF_STREAM_STDERR, + "FAIL:%s:%d: metadata mismatch\n" + " have:\n %pI6\n %pI6\n" + " want:\n %pI6\n %pI6\n", + file, line, + &meta_have[0x00], &meta_have[0x10], + &meta_want[0x00], &meta_want[0x10]); + return false; +} + +#define check_metadata(meta_have) check_metadata(__FILE__, __LINE__, meta_have) + +static bool check_skb_metadata(const char *file, int line, struct __sk_buff *skb) +{ + __u8 *data_meta = ctx_ptr(skb, data_meta); + __u8 *data = ctx_ptr(skb, data); + + return data_meta + META_SIZE <= data && (check_metadata)(file, line, data_meta); +} + +#define check_skb_metadata(skb) check_skb_metadata(__FILE__, __LINE__, skb) + +SEC("tc") int ing_cls(struct __sk_buff *ctx) { - __u8 *data, *data_meta, *data_end; - __u32 diff = 0; + __u8 *meta_have = ctx_ptr(ctx, data_meta); + __u8 *data = ctx_ptr(ctx, data); - data_meta = ctx_ptr(ctx, data_meta); - data_end = ctx_ptr(ctx, data_end); - data = ctx_ptr(ctx, data); + if (meta_have + META_SIZE > data) + goto out; + + if (!check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +/* Read from metadata using bpf_dynptr_read helper */ +SEC("tc") +int ing_cls_dynptr_read(struct __sk_buff *ctx) +{ + __u8 meta_have[META_SIZE]; + struct bpf_dynptr meta; + + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + bpf_dynptr_read(meta_have, META_SIZE, &meta, 0, 0); + + if (!check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + 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; + __u8 *meta_have; + + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + meta_have = bpf_dynptr_slice(&meta, 0, NULL, META_SIZE); + if (!meta_have) + goto out; + + if (!check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + 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; - if (data + ETH_ALEN > data_end || - data_meta + round_up(ETH_ALEN, 4) > data) + bpf_dynptr_from_skb(ctx, 0, &data); + src = bpf_dynptr_slice(&data, sizeof(struct ethhdr), NULL, META_SIZE); + if (!src) return TC_ACT_SHOT; - diff |= ((__u32 *)data_meta)[0] ^ ((__u32 *)data)[0]; - diff |= ((__u16 *)data_meta)[2] ^ ((__u16 *)data)[2]; + 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) +{ + const __u32 chunk_len = META_SIZE / 4; + __u8 meta_have[META_SIZE]; + struct bpf_dynptr meta; + __u8 *dst, *src; + + dst = meta_have; + + /* 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) + goto out; + __builtin_memcpy(dst, src, chunk_len); + + if (!check_metadata(meta_have)) + goto out; - return diff ? TC_ACT_SHOT : TC_ACT_OK; + test_pass = true; +out: + return TC_ACT_SHOT; } -SEC("x") +/* 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 (!check_smac(eth)) + 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) { - __u8 *data, *data_meta, *data_end; + __u8 *data, *data_meta, *data_end, *payload; + struct ethhdr *eth; int ret; - ret = bpf_xdp_adjust_meta(ctx, -round_up(ETH_ALEN, 4)); + ret = bpf_xdp_adjust_meta(ctx, -META_SIZE); if (ret < 0) return XDP_DROP; @@ -42,12 +322,352 @@ int ing_xdp(struct xdp_md *ctx) data_end = ctx_ptr(ctx, data_end); data = ctx_ptr(ctx, data); - if (data + ETH_ALEN > data_end || - data_meta + round_up(ETH_ALEN, 4) > data) + eth = (struct ethhdr *)data; + payload = data + sizeof(struct ethhdr); + + if (payload + META_SIZE > data_end || + data_meta + META_SIZE > data) + return XDP_DROP; + + /* The Linux networking stack may send other packets on the test + * interface that interfere with the test. Just drop them. + * The test packets can be recognized by their source MAC address. + */ + if (!check_smac(eth)) return XDP_DROP; - __builtin_memcpy(data_meta, data, ETH_ALEN); + __builtin_memcpy(data_meta, payload, META_SIZE); return XDP_PASS; } +/* + * Check that, when operating on a cloned packet, skb->data_meta..skb->data is + * kept intact if prog writes to packet _payload_ using packet pointers. + */ +SEC("tc") +int clone_data_meta_survives_data_write(struct __sk_buff *ctx) +{ + __u8 *meta_have = ctx_ptr(ctx, data_meta); + struct ethhdr *eth = ctx_ptr(ctx, data); + + if (eth + 1 > ctx_ptr(ctx, data_end)) + goto out; + /* Ignore non-test packets */ + if (!check_smac(eth)) + goto out; + + if (meta_have + META_SIZE > eth) + goto out; + + if (!check_metadata(meta_have)) + goto out; + + /* Packet write to trigger unclone in prologue */ + eth->h_proto = 42; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +/* + * Check that, when operating on a cloned packet, skb->data_meta..skb->data is + * kept intact if prog writes to packet _metadata_ using packet pointers. + */ +SEC("tc") +int clone_data_meta_survives_meta_write(struct __sk_buff *ctx) +{ + __u8 *meta_have = ctx_ptr(ctx, data_meta); + struct ethhdr *eth = ctx_ptr(ctx, data); + + if (eth + 1 > ctx_ptr(ctx, data_end)) + goto out; + /* Ignore non-test packets */ + if (!check_smac(eth)) + goto out; + + if (meta_have + META_SIZE > eth) + goto out; + + if (!check_metadata(meta_have)) + goto out; + + /* Metadata write to trigger unclone in prologue */ + *meta_have = 42; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +/* + * Check that, when operating on a cloned packet, metadata remains intact if + * prog creates a r/w slice to packet _payload_. + */ +SEC("tc") +int clone_meta_dynptr_survives_data_slice_write(struct __sk_buff *ctx) +{ + struct bpf_dynptr data, meta; + __u8 meta_have[META_SIZE]; + 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 (!check_smac(eth)) + goto out; + + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + bpf_dynptr_read(meta_have, META_SIZE, &meta, 0, 0); + if (!check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +/* + * Check that, when operating on a cloned packet, metadata remains intact if + * prog creates an r/w slice to packet _metadata_. + */ +SEC("tc") +int clone_meta_dynptr_survives_meta_slice_write(struct __sk_buff *ctx) +{ + struct bpf_dynptr data, meta; + const struct ethhdr *eth; + __u8 *meta_have; + + 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 (!check_smac(eth)) + goto out; + + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + meta_have = bpf_dynptr_slice_rdwr(&meta, 0, NULL, META_SIZE); + if (!meta_have) + goto out; + + if (!check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +/* + * Check that, when operating on a cloned packet, skb_meta dynptr is read-write + * before prog writes to packet _payload_ using dynptr_write helper and metadata + * remains intact before and after the write. + */ +SEC("tc") +int clone_meta_dynptr_rw_before_data_dynptr_write(struct __sk_buff *ctx) +{ + struct bpf_dynptr data, meta; + __u8 meta_have[META_SIZE]; + const struct ethhdr *eth; + int err; + + 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 (!check_smac(eth)) + goto out; + + /* Expect read-write metadata before unclone */ + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + if (bpf_dynptr_is_rdonly(&meta)) + goto out; + + err = bpf_dynptr_read(meta_have, META_SIZE, &meta, 0, 0); + if (err || !check_metadata(meta_have)) + goto out; + + /* Helper write to payload will unclone the packet */ + bpf_dynptr_write(&data, offsetof(struct ethhdr, h_proto), "x", 1, 0); + + err = bpf_dynptr_read(meta_have, META_SIZE, &meta, 0, 0); + if (err || !check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +/* + * Check that, when operating on a cloned packet, skb_meta dynptr is read-write + * before prog writes to packet _metadata_ using dynptr_write helper and + * metadata remains intact before and after the write. + */ +SEC("tc") +int clone_meta_dynptr_rw_before_meta_dynptr_write(struct __sk_buff *ctx) +{ + struct bpf_dynptr data, meta; + __u8 meta_have[META_SIZE]; + const struct ethhdr *eth; + int err; + + 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 (!check_smac(eth)) + goto out; + + /* Expect read-write metadata before unclone */ + bpf_dynptr_from_skb_meta(ctx, 0, &meta); + if (bpf_dynptr_is_rdonly(&meta)) + goto out; + + err = bpf_dynptr_read(meta_have, META_SIZE, &meta, 0, 0); + if (err || !check_metadata(meta_have)) + goto out; + + /* Helper write to metadata will unclone the packet */ + bpf_dynptr_write(&meta, 0, &meta_have[0], 1, 0); + + err = bpf_dynptr_read(meta_have, META_SIZE, &meta, 0, 0); + if (err || !check_metadata(meta_have)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +SEC("tc") +int helper_skb_vlan_push_pop(struct __sk_buff *ctx) +{ + int err; + + /* bpf_skb_vlan_push assumes HW offload for primary VLAN tag. Only + * secondary tag push triggers an actual MAC header modification. + */ + err = bpf_skb_vlan_push(ctx, 0, 42); + if (err) + goto out; + err = bpf_skb_vlan_push(ctx, 0, 207); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + err = bpf_skb_vlan_pop(ctx); + if (err) + goto out; + err = bpf_skb_vlan_pop(ctx); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +SEC("tc") +int helper_skb_adjust_room(struct __sk_buff *ctx) +{ + int err; + + /* Grow a 1 byte hole after the MAC header */ + err = bpf_skb_adjust_room(ctx, 1, BPF_ADJ_ROOM_MAC, 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + /* Shrink a 1 byte hole after the MAC header */ + err = bpf_skb_adjust_room(ctx, -1, BPF_ADJ_ROOM_MAC, 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + /* Grow a 256 byte hole to trigger head reallocation */ + err = bpf_skb_adjust_room(ctx, 256, BPF_ADJ_ROOM_MAC, 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +SEC("tc") +int helper_skb_change_head_tail(struct __sk_buff *ctx) +{ + int err; + + /* Reserve 1 extra in the front for packet data */ + err = bpf_skb_change_head(ctx, 1, 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + /* Reserve 256 extra bytes in the front to trigger head reallocation */ + err = bpf_skb_change_head(ctx, 256, 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + /* Reserve 4k extra bytes in the back to trigger head reallocation */ + err = bpf_skb_change_tail(ctx, ctx->len + 4096, 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + +SEC("tc") +int helper_skb_change_proto(struct __sk_buff *ctx) +{ + int err; + + err = bpf_skb_change_proto(ctx, bpf_htons(ETH_P_IPV6), 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + err = bpf_skb_change_proto(ctx, bpf_htons(ETH_P_IP), 0); + if (err) + goto out; + + if (!check_skb_metadata(ctx)) + goto out; + + test_pass = true; +out: + return TC_ACT_SHOT; +} + char _license[] SEC("license") = "GPL"; |