[PATCH bpf-next v2 5/8] selftests/bpf: Verify xdp_metadata xdp->af_xdp path

Stanislav Fomichev
2022-11-21T18:26:23Z

- create new netns
- create veth pair (veTX+veRX)
- setup AF_XDP socket for both interfaces
- attach bpf to veRX
- send packet via veTX
- verify the packet has expected metadata at veRX

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/testing/selftests/bpf/Makefile | 2 +-
.../selftests/bpf/prog_tests/xdp_metadata.c | 365 ++++++++++++++++++
.../selftests/bpf/progs/xdp_metadata.c | 57 +++
tools/testing/selftests/bpf/xdp_metadata.h | 7 +
4 files changed, 430 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
create mode 100644 tools/testing/selftests/bpf/progs/xdp_metadata.c
create mode 100644 tools/testing/selftests/bpf/xdp_metadata.h

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 6a0f043dc410..4eed22fa3681 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -527,7 +527,7 @@ TRUNNER_BPF_PROGS_DIR := progs
TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \
network_helpers.c testing_helpers.c \
btf_helpers.c flow_dissector_load.h \
- cap_helpers.c
+ cap_helpers.c xsk.c
TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko \
$(OUTPUT)/liburandom_read.so \
$(OUTPUT)/xdp_synproxy \
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
new file mode 100644
index 000000000000..01035ff7d783
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <network_helpers.h>
+#include "xdp_metadata.skel.h"
+#include "xdp_metadata.h"
+#include "xsk.h"
+
+#include <bpf/btf.h>
+#include <linux/errqueue.h>
+#include <linux/if_link.h>
+#include <linux/net_tstamp.h>
+#include <linux/udp.h>
+#include <sys/mman.h>
+#include <net/if.h>
+#include <poll.h>
+
+#define TX_NAME "veTX"
+#define RX_NAME "veRX"
+
+#define UDP_PAYLOAD_BYTES 4
+
+#define AF_XDP_SOURCE_PORT 1234
+#define AF_XDP_CONSUMER_PORT 8080
+
+#define UMEM_NUM 16
+#define UMEM_FRAME_SIZE XSK_UMEM__DEFAULT_FRAME_SIZE
+#define UMEM_SIZE (UMEM_FRAME_SIZE * UMEM_NUM)
+#define XDP_FLAGS XDP_FLAGS_DRV_MODE
+#define QUEUE_ID 0
+
+#define TX_ADDR "10.0.0.1"
+#define RX_ADDR "10.0.0.2"
+#define PREFIX_LEN "8"
+#define FAMILY AF_INET
+
+#define SYS(cmd) ({ \
+ if (!ASSERT_OK(system(cmd), (cmd))) \
+ goto out; \
+})
+
+struct xsk {
+ void *umem_area;
+ struct xsk_umem *umem;
+ struct xsk_ring_prod fill;
+ struct xsk_ring_cons comp;
+ struct xsk_ring_prod tx;
+ struct xsk_ring_cons rx;
+ struct xsk_socket *socket;
+};
+
+static int open_xsk(const char *ifname, struct xsk *xsk)
+{
+ int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
+ const struct xsk_socket_config socket_config = {
+ .rx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .libbpf_flags = XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD,
+ .xdp_flags = XDP_FLAGS,
+ .bind_flags = XDP_COPY,
+ };
+ const struct xsk_umem_config umem_config = {
+ .fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+ .comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
+ .frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE,
+ .flags = XDP_UMEM_UNALIGNED_CHUNK_FLAG,
+ };
+ __u32 idx;
+ u64 addr;
+ int ret;
+ int i;
+
+ xsk->umem_area = mmap(NULL, UMEM_SIZE, PROT_READ | PROT_WRITE, mmap_flags, -1, 0);
+ if (!ASSERT_NEQ(xsk->umem_area, MAP_FAILED, "mmap"))
+ return -1;
+
+ ret = xsk_umem__create(&xsk->umem,
+ xsk->umem_area, UMEM_SIZE,
+ &xsk->fill,
+ &xsk->comp,
+ &umem_config);
+ if (!ASSERT_OK(ret, "xsk_umem__create"))
+ return ret;
+
+ ret = xsk_socket__create(&xsk->socket, ifname, QUEUE_ID,
+ xsk->umem,
+ &xsk->rx,
+ &xsk->tx,
+ &socket_config);
+ if (!ASSERT_OK(ret, "xsk_socket__create"))
+ return ret;
+
+ /* First half of umem is for TX. This way address matches 1-to-1
+ * to the completion queue index.
+ */
+
+ for (i = 0; i < UMEM_NUM / 2; i++) {
+ addr = i * UMEM_FRAME_SIZE;
+ printf("%p: tx_desc[%d] -> %lx\n", xsk, i, addr);
+ }
+
+ /* Second half of umem is for RX. */
+
+ ret = xsk_ring_prod__reserve(&xsk->fill, UMEM_NUM / 2, &idx);
+ if (!ASSERT_EQ(UMEM_NUM / 2, ret, "xsk_ring_prod__reserve"))
+ return ret;
+ if (!ASSERT_EQ(idx, 0, "fill idx != 0"))
+ return -1;
+
+ for (i = 0; i < UMEM_NUM / 2; i++) {
+ addr = (UMEM_NUM / 2 + i) * UMEM_FRAME_SIZE;
+ printf("%p: rx_desc[%d] -> %lx\n", xsk, i, addr);
+ *xsk_ring_prod__fill_addr(&xsk->fill, i) = addr;
+ }
+ xsk_ring_prod__submit(&xsk->fill, ret);
+
+ return 0;
+}
+
+static void close_xsk(struct xsk *xsk)
+{
+ if (xsk->umem)
+ xsk_umem__delete(xsk->umem);
+ if (xsk->socket)
+ xsk_socket__delete(xsk->socket);
+ munmap(xsk->umem, UMEM_SIZE);
+}
+
+static void ip_csum(struct iphdr *iph)
+{
+ __u32 sum = 0;
+ __u16 *p;
+ int i;
+
+ iph->check = 0;
+ p = (void *)iph;
+ for (i = 0; i < sizeof(*iph) / sizeof(*p); i++)
+ sum += p[i];
+
+ while (sum >> 16)
+ sum = (sum & 0xffff) + (sum >> 16);
+
+ iph->check = ~sum;
+}
+
+static int generate_packet(struct xsk *xsk, __u16 dst_port)
+{
+ struct xdp_desc *tx_desc;
+ struct udphdr *udph;
+ struct ethhdr *eth;
+ struct iphdr *iph;
+ void *data;
+ __u32 idx;
+ int ret;
+
+ ret = xsk_ring_prod__reserve(&xsk->tx, 1, &idx);
+ if (!ASSERT_EQ(ret, 1, "xsk_ring_prod__reserve"))
+ return -1;
+
+ tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx);
+ tx_desc->addr = idx % (UMEM_NUM / 2) * UMEM_FRAME_SIZE;
+ printf("%p: tx_desc[%u]->addr=%llx\n", xsk, idx, tx_desc->addr);
+ data = xsk_umem__get_data(xsk->umem_area, tx_desc->addr);
+
+ eth = data;
+ iph = (void *)(eth + 1);
+ udph = (void *)(iph + 1);
+
+ memcpy(eth->h_dest, "\x00\x00\x00\x00\x00\x02", ETH_ALEN);
+ memcpy(eth->h_source, "\x00\x00\x00\x00\x00\x01", ETH_ALEN);
+ eth->h_proto = htons(ETH_P_IP);
+
+ iph->version = 0x4;
+ iph->ihl = 0x5;
+ iph->tos = 0x9;
+ iph->tot_len = htons(sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES);
+ iph->id = 0;
+ iph->frag_off = 0;
+ iph->ttl = 0;
+ iph->protocol = IPPROTO_UDP;
+ ASSERT_EQ(inet_pton(FAMILY, TX_ADDR, &iph->saddr), 1, "inet_pton(TX_ADDR)");
+ ASSERT_EQ(inet_pton(FAMILY, RX_ADDR, &iph->daddr), 1, "inet_pton(RX_ADDR)");
+ ip_csum(iph);
+
+ udph->source = htons(AF_XDP_SOURCE_PORT);
+ udph->dest = htons(dst_port);
+ udph->len = htons(sizeof(*udph) + UDP_PAYLOAD_BYTES);
+ udph->check = 0;
+
+ memset(udph + 1, 0xAA, UDP_PAYLOAD_BYTES);
+
+ tx_desc->len = sizeof(*eth) + sizeof(*iph) + sizeof(*udph) + UDP_PAYLOAD_BYTES;
+ xsk_ring_prod__submit(&xsk->tx, 1);
+
+ ret = sendto(xsk_socket__fd(xsk->socket), NULL, 0, MSG_DONTWAIT, NULL, 0);
+ if (!ASSERT_GE(ret, 0, "sendto"))
+ return ret;
+
+ return 0;
+}
+
+static void complete_tx(struct xsk *xsk)
+{
+ __u32 idx;
+ __u64 addr;
+
+ if (ASSERT_EQ(xsk_ring_cons__peek(&xsk->comp, 1, &idx), 1, "xsk_ring_cons__peek")) {
+ addr = *xsk_ring_cons__comp_addr(&xsk->comp, idx);
+
+ printf("%p: refill idx=%u addr=%llx\n", xsk, idx, addr);
+ *xsk_ring_prod__fill_addr(&xsk->fill, idx) = addr;
+ xsk_ring_prod__submit(&xsk->fill, 1);
+ }
+}
+
+static void refill_rx(struct xsk *xsk, __u64 addr)
+{
+ __u32 idx;
+
+ if (ASSERT_EQ(xsk_ring_prod__reserve(&xsk->fill, 1, &idx), 1, "xsk_ring_prod__reserve")) {
+ printf("%p: complete idx=%u addr=%llx\n", xsk, idx, addr);
+ *xsk_ring_prod__fill_addr(&xsk->fill, idx) = addr;
+ xsk_ring_prod__submit(&xsk->fill, 1);
+ }
+}
+
+static int verify_xsk_metadata(struct xsk *xsk)
+{
+ const struct xdp_desc *rx_desc;
+ struct pollfd fds = {};
+ struct xdp_meta *meta;
+ struct ethhdr *eth;
+ struct iphdr *iph;
+ __u64 comp_addr;
+ void *data;
+ __u64 addr;
+ __u32 idx;
+ int ret;
+
+ ret = recvfrom(xsk_socket__fd(xsk->socket), NULL, 0, MSG_DONTWAIT, NULL, NULL);
+ if (!ASSERT_EQ(ret, 0, "recvfrom"))
+ return -1;
+
+ fds.fd = xsk_socket__fd(xsk->socket);
+ fds.events = POLLIN;
+
+ ret = poll(&fds, 1, 1000);
+ if (!ASSERT_GT(ret, 0, "poll"))
+ return -1;
+
+ ret = xsk_ring_cons__peek(&xsk->rx, 1, &idx);
+ if (!ASSERT_EQ(ret, 1, "xsk_ring_cons__peek"))
+ return -2;
+
+ rx_desc = xsk_ring_cons__rx_desc(&xsk->rx, idx);
+ comp_addr = xsk_umem__extract_addr(rx_desc->addr);
+ addr = xsk_umem__add_offset_to_addr(rx_desc->addr);
+ printf("%p: rx_desc[%u]->addr=%llx addr=%llx comp_addr=%llx\n",
+ xsk, idx, rx_desc->addr, addr, comp_addr);
+ data = xsk_umem__get_data(xsk->umem_area, addr);
+
+ /* Make sure we got the packet offset correctly. */
+
+ eth = data;
+ ASSERT_EQ(eth->h_proto, htons(ETH_P_IP), "eth->h_proto");
+ iph = (void *)(eth + 1);
+ ASSERT_EQ((int)iph->version, 4, "iph->version");
+
+ /* custom metadata */
+
+ meta = data - sizeof(struct xdp_meta);
+
+ if (!ASSERT_NEQ(meta->rx_timestamp, 0, "rx_timestamp"))
+ return -1;
+
+ if (!ASSERT_NEQ(meta->rx_hash, 0, "rx_hash"))
+ return -1;
+
+ xsk_ring_cons__release(&xsk->rx, 1);
+ refill_rx(xsk, comp_addr);
+
+ return 0;
+}
+
+void test_xdp_metadata(void)
+{
+ struct xdp_metadata *bpf_obj = NULL;
+ struct nstoken *tok = NULL;
+ __u32 queue_id = QUEUE_ID;
+ struct bpf_program *prog;
+ struct xsk tx_xsk = {};
+ struct xsk rx_xsk = {};
+ int rx_ifindex;
+ int sock_fd;
+ int ret;
+
+ /* Setup new networking namespace, with a veth pair. */
+
+ SYS("ip netns add xdp_metadata");
+ tok = open_netns("xdp_metadata");
+ SYS("ip link add numtxqueues 1 numrxqueues 1 " TX_NAME
+ " type veth peer " RX_NAME " numtxqueues 1 numrxqueues 1");
+ SYS("ip link set dev " TX_NAME " address 00:00:00:00:00:01");
+ SYS("ip link set dev " RX_NAME " address 00:00:00:00:00:02");
+ SYS("ip link set dev " TX_NAME " up");
+ SYS("ip link set dev " RX_NAME " up");
+ SYS("ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
+ SYS("ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
+
+ rx_ifindex = if_nametoindex(RX_NAME);
+
+ /* Setup separate AF_XDP for TX and RX interfaces. */
+
+ ret = open_xsk(TX_NAME, &tx_xsk);
+ if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
+ goto out;
+
+ ret = open_xsk(RX_NAME, &rx_xsk);
+ if (!ASSERT_OK(ret, "open_xsk(RX_NAME)"))
+ goto out;
+
+ /* Attach BPF program to RX interface. */
+
+ bpf_obj = xdp_metadata__open();
+ if (!ASSERT_OK_PTR(bpf_obj, "open skeleton"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(bpf_obj->obj, "rx");
+ bpf_program__set_ifindex(prog, rx_ifindex);
+ bpf_program__set_flags(prog, BPF_F_XDP_HAS_METADATA);
+
+ if (!ASSERT_OK(xdp_metadata__load(bpf_obj), "load skeleton"))
+ goto out;
+
+ ret = bpf_xdp_attach(rx_ifindex,
+ bpf_program__fd(bpf_obj->progs.rx),
+ XDP_FLAGS, NULL);
+ if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
+ goto out;
+
+ sock_fd = xsk_socket__fd(rx_xsk.socket);
+ ret = bpf_map_update_elem(bpf_map__fd(bpf_obj->maps.xsk), &queue_id, &sock_fd, 0);
+ if (!ASSERT_GE(ret, 0, "bpf_map_update_elem"))
+ goto out;
+
+ /* Send packet destined to RX AF_XDP socket. */
+ if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
+ "generate AF_XDP_CONSUMER_PORT"))
+ goto out;
+
+ /* Verify AF_XDP RX packet has proper metadata. */
+ if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk), 0,
+ "verify_xsk_metadata"))
+ goto out;
+
+ complete_tx(&tx_xsk);
+
+out:
+ close_xsk(&rx_xsk);
+ close_xsk(&tx_xsk);
+ if (bpf_obj)
+ xdp_metadata__destroy(bpf_obj);
+ system("ip netns del xdp_metadata");
+ if (tok)
+ close_netns(tok);
+}
diff --git a/tools/testing/selftests/bpf/progs/xdp_metadata.c b/tools/testing/selftests/bpf/progs/xdp_metadata.c
new file mode 100644
index 000000000000..1b19a8d86efe
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/xdp_metadata.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <vmlinux.h>
+
+#ifndef ETH_P_IP
+#define ETH_P_IP 0x0800
+#endif
+
+#include "xdp_metadata.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+struct {
+ __uint(type, BPF_MAP_TYPE_XSKMAP);
+ __uint(max_entries, 4);
+ __type(key, __u32);
+ __type(value, __u32);
+} xsk SEC(".maps");
+
+extern bool bpf_xdp_metadata_rx_timestamp_supported(const struct xdp_md *ctx) __ksym;
+extern __u64 bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx) __ksym;
+extern bool bpf_xdp_metadata_rx_hash_supported(const struct xdp_md *ctx) __ksym;
+extern __u32 bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx) __ksym;
+
+SEC("xdp")
+int rx(struct xdp_md *ctx)
+{
+ void *data, *data_meta;
+ struct xdp_meta *meta;
+ int ret;
+
+ /* Reserve enough for all custom metadata. */
+
+ ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
+ if (ret != 0)
+ return XDP_DROP;
+
+ data = (void *)(long)ctx->data;
+ data_meta = (void *)(long)ctx->data_meta;
+
+ if (data_meta + sizeof(struct xdp_meta) > data)
+ return XDP_DROP;
+
+ meta = data_meta;
+
+ /* Export metadata. */
+
+ if (bpf_xdp_metadata_rx_timestamp_supported(ctx))
+ meta->rx_timestamp = bpf_xdp_metadata_rx_timestamp(ctx);
+
+ if (bpf_xdp_metadata_rx_hash_supported(ctx))
+ meta->rx_hash = bpf_xdp_metadata_rx_hash(ctx);
+
+ return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/xdp_metadata.h b/tools/testing/selftests/bpf/xdp_metadata.h
new file mode 100644
index 000000000000..c4892d122b7f
--- /dev/null
+++ b/tools/testing/selftests/bpf/xdp_metadata.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#pragma once
+
+struct xdp_meta {
+ __u64 rx_timestamp;
+ __u32 rx_hash;
+};
--
2.38.1.584.g0f3c55d4c2-goog