selftests/bpf: Add AF_INET packet generation to xdp_metadata

The easiest way to simulate stripped VLAN tag in veth is to send a packet
from VLAN interface, attached to veth. Unfortunately, this approach is
incompatible with AF_XDP on TX side, because VLAN interfaces do not have
such feature.

Check both packets sent via AF_XDP TX and regular socket.

AF_INET packet will also have a filled-in hash type (XDP_RSS_TYPE_L4),
unlike AF_XDP packet, so more values can be checked.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20231205210847.28460-18-larysa.zaremba@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
index 33cdf88efa6b9243e95c7894c9ec1590e54ceaac..e7f06cbdd84585bfa5e2521d9aabb7bb06a8f9be 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c
@@ -20,7 +20,7 @@
 
 #define UDP_PAYLOAD_BYTES 4
 
-#define AF_XDP_SOURCE_PORT 1234
+#define UDP_SOURCE_PORT 1234
 #define AF_XDP_CONSUMER_PORT 8080
 
 #define UMEM_NUM 16
@@ -33,6 +33,12 @@
 #define RX_ADDR "10.0.0.2"
 #define PREFIX_LEN "8"
 #define FAMILY AF_INET
+#define TX_NETNS_NAME "xdp_metadata_tx"
+#define RX_NETNS_NAME "xdp_metadata_rx"
+#define TX_MAC "00:00:00:00:00:01"
+#define RX_MAC "00:00:00:00:00:02"
+
+#define XDP_RSS_TYPE_L4 BIT(3)
 
 struct xsk {
        void *umem_area;
@@ -181,7 +187,7 @@ static int generate_packet(struct xsk *xsk, __u16 dst_port)
        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->source = htons(UDP_SOURCE_PORT);
        udph->dest = htons(dst_port);
        udph->len = htons(sizeof(*udph) + UDP_PAYLOAD_BYTES);
        udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
@@ -204,6 +210,30 @@ static int generate_packet(struct xsk *xsk, __u16 dst_port)
        return 0;
 }
 
+static int generate_packet_inet(void)
+{
+       char udp_payload[UDP_PAYLOAD_BYTES];
+       struct sockaddr_in rx_addr;
+       int sock_fd, err = 0;
+
+       /* Build a packet */
+       memset(udp_payload, 0xAA, UDP_PAYLOAD_BYTES);
+       rx_addr.sin_addr.s_addr = inet_addr(RX_ADDR);
+       rx_addr.sin_family = AF_INET;
+       rx_addr.sin_port = htons(AF_XDP_CONSUMER_PORT);
+
+       sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+       if (!ASSERT_GE(sock_fd, 0, "socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)"))
+               return sock_fd;
+
+       err = sendto(sock_fd, udp_payload, UDP_PAYLOAD_BYTES, MSG_DONTWAIT,
+                    (void *)&rx_addr, sizeof(rx_addr));
+       ASSERT_GE(err, 0, "sendto");
+
+       close(sock_fd);
+       return err;
+}
+
 static void complete_tx(struct xsk *xsk)
 {
        struct xsk_tx_metadata *meta;
@@ -236,7 +266,7 @@ static void refill_rx(struct xsk *xsk, __u64 addr)
        }
 }
 
-static int verify_xsk_metadata(struct xsk *xsk)
+static int verify_xsk_metadata(struct xsk *xsk, bool sent_from_af_xdp)
 {
        const struct xdp_desc *rx_desc;
        struct pollfd fds = {};
@@ -290,17 +320,36 @@ static int verify_xsk_metadata(struct xsk *xsk)
        if (!ASSERT_NEQ(meta->rx_hash, 0, "rx_hash"))
                return -1;
 
+       if (!sent_from_af_xdp) {
+               if (!ASSERT_NEQ(meta->rx_hash_type & XDP_RSS_TYPE_L4, 0, "rx_hash_type"))
+                       return -1;
+               goto done;
+       }
+
        ASSERT_EQ(meta->rx_hash_type, 0, "rx_hash_type");
 
        /* checksum offload */
        ASSERT_EQ(udph->check, htons(0x721c), "csum");
 
+done:
        xsk_ring_cons__release(&xsk->rx, 1);
        refill_rx(xsk, comp_addr);
 
        return 0;
 }
 
+static void switch_ns_to_rx(struct nstoken **tok)
+{
+       close_netns(*tok);
+       *tok = open_netns(RX_NETNS_NAME);
+}
+
+static void switch_ns_to_tx(struct nstoken **tok)
+{
+       close_netns(*tok);
+       *tok = open_netns(TX_NETNS_NAME);
+}
+
 void test_xdp_metadata(void)
 {
        struct xdp_metadata2 *bpf_obj2 = NULL;
@@ -318,27 +367,31 @@ void test_xdp_metadata(void)
        int sock_fd;
        int ret;
 
-       /* Setup new networking namespace, with a veth pair. */
+       /* Setup new networking namespaces, with a veth pair. */
+       SYS(out, "ip netns add " TX_NETNS_NAME);
+       SYS(out, "ip netns add " RX_NETNS_NAME);
 
-       SYS(out, "ip netns add xdp_metadata");
-       tok = open_netns("xdp_metadata");
+       tok = open_netns(TX_NETNS_NAME);
        SYS(out, "ip link add numtxqueues 1 numrxqueues 1 " TX_NAME
            " type veth peer " RX_NAME " numtxqueues 1 numrxqueues 1");
-       SYS(out, "ip link set dev " TX_NAME " address 00:00:00:00:00:01");
-       SYS(out, "ip link set dev " RX_NAME " address 00:00:00:00:00:02");
+       SYS(out, "ip link set " RX_NAME " netns " RX_NETNS_NAME);
+
+       SYS(out, "ip link set dev " TX_NAME " address " TX_MAC);
        SYS(out, "ip link set dev " TX_NAME " up");
-       SYS(out, "ip link set dev " RX_NAME " up");
        SYS(out, "ip addr add " TX_ADDR "/" PREFIX_LEN " dev " TX_NAME);
+
+       /* Avoid ARP calls */
+       SYS(out, "ip -4 neigh add " RX_ADDR " lladdr " RX_MAC " dev " TX_NAME);
+
+       switch_ns_to_rx(&tok);
+
+       SYS(out, "ip link set dev " RX_NAME " address " RX_MAC);
+       SYS(out, "ip link set dev " RX_NAME " up");
        SYS(out, "ip addr add " RX_ADDR "/" PREFIX_LEN " dev " RX_NAME);
 
        rx_ifindex = if_nametoindex(RX_NAME);
-       tx_ifindex = if_nametoindex(TX_NAME);
 
-       /* Setup separate AF_XDP for TX and RX interfaces. */
-
-       ret = open_xsk(tx_ifindex, &tx_xsk);
-       if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
-               goto out;
+       /* Setup separate AF_XDP for RX interface. */
 
        ret = open_xsk(rx_ifindex, &rx_xsk);
        if (!ASSERT_OK(ret, "open_xsk(RX_NAME)"))
@@ -379,18 +432,38 @@ void test_xdp_metadata(void)
        if (!ASSERT_GE(ret, 0, "bpf_map_update_elem"))
                goto out;
 
-       /* Send packet destined to RX AF_XDP socket. */
+       switch_ns_to_tx(&tok);
+
+       /* Setup separate AF_XDP for TX interface nad send packet to the RX socket. */
+       tx_ifindex = if_nametoindex(TX_NAME);
+       ret = open_xsk(tx_ifindex, &tx_xsk);
+       if (!ASSERT_OK(ret, "open_xsk(TX_NAME)"))
+               goto out;
+
        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,
+       switch_ns_to_rx(&tok);
+
+       /* Verify packet sent from AF_XDP has proper metadata. */
+       if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk, true), 0,
                       "verify_xsk_metadata"))
                goto out;
 
+       switch_ns_to_tx(&tok);
        complete_tx(&tx_xsk);
 
+       /* Now check metadata of packet, generated with network stack */
+       if (!ASSERT_GE(generate_packet_inet(), 0, "generate UDP packet"))
+               goto out;
+
+       switch_ns_to_rx(&tok);
+
+       if (!ASSERT_GE(verify_xsk_metadata(&rx_xsk, false), 0,
+                      "verify_xsk_metadata"))
+               goto out;
+
        /* Make sure freplace correctly picks up original bound device
         * and doesn't crash.
         */
@@ -408,11 +481,15 @@ void test_xdp_metadata(void)
        if (!ASSERT_OK(xdp_metadata2__attach(bpf_obj2), "attach freplace"))
                goto out;
 
+       switch_ns_to_tx(&tok);
+
        /* Send packet to trigger . */
        if (!ASSERT_GE(generate_packet(&tx_xsk, AF_XDP_CONSUMER_PORT), 0,
                       "generate freplace packet"))
                goto out;
 
+       switch_ns_to_rx(&tok);
+
        while (!retries--) {
                if (bpf_obj2->bss->called)
                        break;
@@ -427,5 +504,6 @@ out:
        xdp_metadata__destroy(bpf_obj);
        if (tok)
                close_netns(tok);
-       SYS_NOFAIL("ip netns del xdp_metadata");
+       SYS_NOFAIL("ip netns del " RX_NETNS_NAME);
+       SYS_NOFAIL("ip netns del " TX_NETNS_NAME);
 }