[PATCH bpf-next v2 8/8] selftests/bpf: Simple program to dump XDP RX metadata

Stanislav Fomichev
2022-11-21T18:26:40Z

To be used for verification of driver implementations. Note that
the skb path is gone from the series, but I'm still keeping the
implementation for any possible future work.

$ xdp_hw_metadata <ifname>

On the other machine:

$ echo -n xdp | nc -u -q1 <target> 9091 # for AF_XDP
$ echo -n skb | nc -u -q1 <target> 9092 # for skb

Sample output:

# xdp
xsk_ring_cons__peek: 1
0x19f9090: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
rx_timestamp_supported: 1
rx_timestamp: 1667850075063948829
0x19f9090: complete idx=8 addr=8000

# skb
found skb hwtstamp = 1668314052.854274681

Decoding:
# xdp
rx_timestamp=1667850075.063948829

$ date -d @1667850075
Mon Nov 7 11:41:15 AM PST 2022
$ date
Mon Nov 7 11:42:05 AM PST 2022

# skb
$ date -d @1668314052
Sat Nov 12 08:34:12 PM PST 2022
$ date
Sat Nov 12 08:37:06 PM PST 2022

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/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 6 +-
.../selftests/bpf/progs/xdp_hw_metadata.c | 93 ++++
tools/testing/selftests/bpf/xdp_hw_metadata.c | 405 ++++++++++++++++++
4 files changed, 504 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
create mode 100644 tools/testing/selftests/bpf/xdp_hw_metadata.c

diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 07d2d0a8c5cb..01e3baeefd4f 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -46,3 +46,4 @@ test_cpp
xskxceiver
xdp_redirect_multi
xdp_synproxy
+xdp_hw_metadata
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 4eed22fa3681..189b39b0e5d0 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -83,7 +83,7 @@ TEST_PROGS_EXTENDED := with_addr.sh \
TEST_GEN_PROGS_EXTENDED = test_sock_addr test_skb_cgroup_id_user \
flow_dissector_load test_flow_dissector test_tcp_check_syncookie_user \
test_lirc_mode2_user xdping test_cpp runqslower bench bpf_testmod.ko \
- xskxceiver xdp_redirect_multi xdp_synproxy veristat
+ xskxceiver xdp_redirect_multi xdp_synproxy veristat xdp_hw_metadata

TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read $(OUTPUT)/sign-file
TEST_GEN_FILES += liburandom_read.so
@@ -241,6 +241,9 @@ $(OUTPUT)/test_maps: $(TESTING_HELPERS)
$(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS)
$(OUTPUT)/xsk.o: $(BPFOBJ)
$(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o
+$(OUTPUT)/xdp_hw_metadata: $(OUTPUT)/xsk.o $(OUTPUT)/xdp_hw_metadata.skel.h
+$(OUTPUT)/xdp_hw_metadata: $(OUTPUT)/network_helpers.o
+$(OUTPUT)/xdp_hw_metadata: LDFLAGS += -static

BPFTOOL ?= $(DEFAULT_BPFTOOL)
$(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \
@@ -383,6 +386,7 @@ linked_maps.skel.h-deps := linked_maps1.bpf.o linked_maps2.bpf.o
test_subskeleton.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o test_subskeleton.bpf.o
test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o
test_usdt.skel.h-deps := test_usdt.bpf.o test_usdt_multispec.bpf.o
+xdp_hw_metadata.skel.h-deps := xdp_hw_metadata.bpf.o

LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))

diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
new file mode 100644
index 000000000000..0ae409094883
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/udp.h>
+#include <stdbool.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#include "xdp_metadata.h"
+
+struct {
+ __uint(type, BPF_MAP_TYPE_XSKMAP);
+ __uint(max_entries, 256);
+ __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, *data_end;
+ struct ipv6hdr *ip6h = NULL;
+ struct ethhdr *eth = NULL;
+ struct udphdr *udp = NULL;
+ struct iphdr *iph = NULL;
+ struct xdp_meta *meta;
+ int ret;
+
+ data = (void *)(long)ctx->data;
+ data_end = (void *)(long)ctx->data_end;
+ eth = data;
+ if (eth + 1 < data_end) {
+ if (eth->h_proto == bpf_htons(ETH_P_IP)) {
+ iph = (void *)(eth + 1);
+ if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
+ udp = (void *)(iph + 1);
+ }
+ if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
+ ip6h = (void *)(eth + 1);
+ if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
+ udp = (void *)(ip6h + 1);
+ }
+ if (udp && udp + 1 > data_end)
+ udp = NULL;
+ }
+
+ if (!udp)
+ return XDP_PASS;
+
+ if (udp->dest != bpf_htons(9091))
+ return XDP_PASS;
+
+ bpf_printk("forwarding UDP:9091 to AF_XDP");
+
+ ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
+ if (ret != 0) {
+ bpf_printk("bpf_xdp_adjust_meta returned %d", ret);
+ return XDP_PASS;
+ }
+
+ data = (void *)(long)ctx->data;
+ data_meta = (void *)(long)ctx->data_meta;
+ meta = data_meta;
+
+ if (meta + 1 > data) {
+ bpf_printk("bpf_xdp_adjust_meta doesn't appear to work");
+ return XDP_PASS;
+ }
+
+ if (bpf_xdp_metadata_rx_timestamp_supported(ctx)) {
+ meta->rx_timestamp = bpf_xdp_metadata_rx_timestamp(ctx);
+ bpf_printk("populated rx_timestamp with %u", meta->rx_timestamp);
+ }
+
+ if (bpf_xdp_metadata_rx_hash_supported(ctx)) {
+ meta->rx_hash = bpf_xdp_metadata_rx_hash(ctx);
+ bpf_printk("populated rx_hash with %u", meta->rx_hash);
+ }
+
+ return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
new file mode 100644
index 000000000000..7823a35a1ef7
--- /dev/null
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Reference program for verifying XDP metadata on real HW. Functional test
+ * only, doesn't test the performance.
+ *
+ * RX:
+ * - UDP 9091 packets are diverted into AF_XDP
+ * - Metadata verified:
+ * - rx_timestamp
+ * - rx_hash
+ *
+ * TX:
+ * - TBD
+ */
+
+#include <test_progs.h>
+#include <network_helpers.h>
+#include "xdp_hw_metadata.skel.h"
+#include "xsk.h"
+
+#include <error.h>
+#include <linux/errqueue.h>
+#include <linux/if_link.h>
+#include <linux/net_tstamp.h>
+#include <linux/udp.h>
+#include <linux/sockios.h>
+#include <sys/mman.h>
+#include <net/if.h>
+#include <poll.h>
+
+#include "xdp_metadata.h"
+
+#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 | XDP_FLAGS_REPLACE)
+
+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;
+};
+
+struct xdp_hw_metadata *bpf_obj;
+struct xsk *rx_xsk;
+const char *ifname;
+int ifindex;
+int rxq;
+
+void test__fail(void) { /* for network_helpers.c */ }
+
+static int open_xsk(const char *ifname, struct xsk *xsk, __u32 queue_id)
+{
+ 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 (xsk->umem_area == MAP_FAILED)
+ return -ENOMEM;
+
+ ret = xsk_umem__create(&xsk->umem,
+ xsk->umem_area, UMEM_SIZE,
+ &xsk->fill,
+ &xsk->comp,
+ &umem_config);
+ if (ret)
+ return ret;
+
+ ret = xsk_socket__create(&xsk->socket, ifname, queue_id,
+ xsk->umem,
+ &xsk->rx,
+ &xsk->tx,
+ &socket_config);
+ if (ret)
+ 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);
+ 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 refill_rx(struct xsk *xsk, __u64 addr)
+{
+ __u32 idx;
+
+ if (xsk_ring_prod__reserve(&xsk->fill, 1, &idx) == 1) {
+ 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 void verify_xdp_metadata(void *data)
+{
+ struct xdp_meta *meta;
+
+ meta = data - sizeof(*meta);
+
+ printf("rx_timestamp: %llu\n", meta->rx_timestamp);
+ printf("rx_hash: %u\n", meta->rx_hash);
+}
+
+static void verify_skb_metadata(int fd)
+{
+ char cmsg_buf[1024];
+ char packet_buf[128];
+
+ struct scm_timestamping *ts;
+ struct iovec packet_iov;
+ struct cmsghdr *cmsg;
+ struct msghdr hdr;
+
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.msg_iov = &packet_iov;
+ hdr.msg_iovlen = 1;
+ packet_iov.iov_base = packet_buf;
+ packet_iov.iov_len = sizeof(packet_buf);
+
+ hdr.msg_control = cmsg_buf;
+ hdr.msg_controllen = sizeof(cmsg_buf);
+
+ if (recvmsg(fd, &hdr, 0) < 0)
+ error(-1, errno, "recvmsg");
+
+ for (cmsg = CMSG_FIRSTHDR(&hdr); cmsg != NULL;
+ cmsg = CMSG_NXTHDR(&hdr, cmsg)) {
+
+ if (cmsg->cmsg_level != SOL_SOCKET)
+ continue;
+
+ switch (cmsg->cmsg_type) {
+ case SCM_TIMESTAMPING:
+ ts = (struct scm_timestamping *)CMSG_DATA(cmsg);
+ if (ts->ts[2].tv_sec || ts->ts[2].tv_nsec) {
+ printf("found skb hwtstamp = %lu.%lu\n",
+ ts->ts[2].tv_sec, ts->ts[2].tv_nsec);
+ return;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ printf("skb hwtstamp is not found!\n");
+}
+
+static int verify_metadata(struct xsk *rx_xsk, int rxq, int server_fd)
+{
+ const struct xdp_desc *rx_desc;
+ struct pollfd fds[rxq + 1];
+ __u64 comp_addr;
+ __u64 addr;
+ __u32 idx;
+ int ret;
+ int i;
+
+ for (i = 0; i < rxq; i++) {
+ fds[i].fd = xsk_socket__fd(rx_xsk[i].socket);
+ fds[i].events = POLLIN;
+ fds[i].revents = 0;
+ }
+
+ fds[rxq].fd = server_fd;
+ fds[rxq].events = POLLIN;
+ fds[rxq].revents = 0;
+
+ while (true) {
+ errno = 0;
+ ret = poll(fds, rxq + 1, 1000);
+ printf("poll: %d (%d)\n", ret, errno);
+ if (ret < 0)
+ break;
+ if (ret == 0)
+ continue;
+
+ if (fds[rxq].revents)
+ verify_skb_metadata(server_fd);
+
+ for (i = 0; i < rxq; i++) {
+ if (fds[i].revents == 0)
+ continue;
+
+ struct xsk *xsk = &rx_xsk[i];
+
+ ret = xsk_ring_cons__peek(&xsk->rx, 1, &idx);
+ printf("xsk_ring_cons__peek: %d\n", ret);
+ if (ret != 1)
+ continue;
+
+ 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);
+ verify_xdp_metadata(xsk_umem__get_data(xsk->umem_area, addr));
+ xsk_ring_cons__release(&xsk->rx, 1);
+ refill_rx(xsk, comp_addr);
+ }
+ }
+
+ return 0;
+}
+
+struct ethtool_channels {
+ __u32 cmd;
+ __u32 max_rx;
+ __u32 max_tx;
+ __u32 max_other;
+ __u32 max_combined;
+ __u32 rx_count;
+ __u32 tx_count;
+ __u32 other_count;
+ __u32 combined_count;
+};
+
+#define ETHTOOL_GCHANNELS 0x0000003c /* Get no of channels */
+
+static int rxq_num(const char *ifname)
+{
+ struct ethtool_channels ch = {
+ .cmd = ETHTOOL_GCHANNELS,
+ };
+
+ struct ifreq ifr = {
+ .ifr_data = (void *)&ch,
+ };
+ strcpy(ifr.ifr_name, ifname);
+ int fd, ret;
+
+ fd = socket(AF_UNIX, SOCK_DGRAM, 0);
+ if (fd < 0)
+ error(-1, errno, "socket");
+
+ ret = ioctl(fd, SIOCETHTOOL, &ifr);
+ if (ret < 0)
+ error(-1, errno, "socket");
+
+ close(fd);
+
+ return ch.rx_count;
+}
+
+static void cleanup(void)
+{
+ LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
+ int ret;
+ int i;
+
+ if (bpf_obj) {
+ opts.old_prog_fd = bpf_program__fd(bpf_obj->progs.rx);
+ if (opts.old_prog_fd >= 0) {
+ printf("detaching bpf program....\n");
+ ret = bpf_xdp_detach(ifindex, XDP_FLAGS, &opts);
+ if (ret)
+ printf("failed to detach XDP program: %d\n", ret);
+ }
+ }
+
+ for (i = 0; i < rxq; i++)
+ close_xsk(&rx_xsk[i]);
+
+ if (bpf_obj)
+ xdp_hw_metadata__destroy(bpf_obj);
+}
+
+static void handle_signal(int sig)
+{
+ /* interrupting poll() is all we need */
+}
+
+static void timestamping_enable(int fd, int val)
+{
+ int ret;
+
+ ret = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val));
+ if (ret < 0)
+ error(-1, errno, "setsockopt(SO_TIMESTAMPING)");
+}
+
+int main(int argc, char *argv[])
+{
+ int server_fd = -1;
+ int ret;
+ int i;
+
+ struct bpf_program *prog;
+
+ if (argc != 2) {
+ fprintf(stderr, "pass device name\n");
+ return -1;
+ }
+
+ ifname = argv[1];
+ ifindex = if_nametoindex(ifname);
+ rxq = rxq_num(ifname);
+
+ printf("rxq: %d\n", rxq);
+
+ rx_xsk = malloc(sizeof(struct xsk) * rxq);
+ if (!rx_xsk)
+ error(-1, ENOMEM, "malloc");
+
+ for (i = 0; i < rxq; i++) {
+ printf("open_xsk(%s, %p, %d)\n", ifname, &rx_xsk[i], i);
+ ret = open_xsk(ifname, &rx_xsk[i], i);
+ if (ret)
+ error(-1, -ret, "open_xsk");
+
+ printf("xsk_socket__fd() -> %d\n", xsk_socket__fd(rx_xsk[i].socket));
+ }
+
+ printf("open bpf program...\n");
+ bpf_obj = xdp_hw_metadata__open();
+ if (libbpf_get_error(bpf_obj))
+ error(-1, libbpf_get_error(bpf_obj), "xdp_hw_metadata__open");
+
+ prog = bpf_object__find_program_by_name(bpf_obj->obj, "rx");
+ bpf_program__set_ifindex(prog, ifindex);
+ bpf_program__set_flags(prog, BPF_F_XDP_HAS_METADATA);
+
+ printf("load bpf program...\n");
+ ret = xdp_hw_metadata__load(bpf_obj);
+ if (ret)
+ error(-1, -ret, "xdp_hw_metadata__load");
+
+ printf("prepare skb endpoint...\n");
+ server_fd = start_server(AF_INET6, SOCK_DGRAM, NULL, 9092, 1000);
+ if (server_fd < 0)
+ error(-1, errno, "start_server");
+ timestamping_enable(server_fd,
+ SOF_TIMESTAMPING_SOFTWARE |
+ SOF_TIMESTAMPING_RAW_HARDWARE);
+
+ printf("prepare xsk map...\n");
+ for (i = 0; i < rxq; i++) {
+ int sock_fd = xsk_socket__fd(rx_xsk[i].socket);
+ __u32 queue_id = i;
+
+ printf("map[%d] = %d\n", queue_id, sock_fd);
+ ret = bpf_map_update_elem(bpf_map__fd(bpf_obj->maps.xsk), &queue_id, &sock_fd, 0);
+ if (ret)
+ error(-1, -ret, "bpf_map_update_elem");
+ }
+
+ printf("attach bpf program...\n");
+ ret = bpf_xdp_attach(ifindex,
+ bpf_program__fd(bpf_obj->progs.rx),
+ XDP_FLAGS, NULL);
+ if (ret)
+ error(-1, -ret, "bpf_xdp_attach");
+
+ signal(SIGINT, handle_signal);
+ ret = verify_metadata(rx_xsk, rxq, server_fd);
+ close(server_fd);
+ cleanup();
+ if (ret)
+ error(-1, -ret, "verify_metadata");
+}
--
2.38.1.584.g0f3c55d4c2-goog