Commit 67139457 authored by Mohsin Bashir's avatar Mohsin Bashir Committed by Jakub Kicinski
Browse files

selftests: drv-net: Test XDP_TX support 



Add test to verify the XDP_TX functionality by generating traffic from a
remote node on a specific UDP port and redirecting it back to the sender.

./drivers/net/xdp.py
TAP version 13
1..5
ok 1 xdp.test_xdp_native_pass_sb
ok 2 xdp.test_xdp_native_pass_mb
ok 3 xdp.test_xdp_native_drop_sb
ok 4 xdp.test_xdp_native_drop_mb
ok 5 xdp.test_xdp_native_tx_mb
\# Totals: pass:5 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: default avatarMohsin Bashir <mohsin.bashr@gmail.com>
Link: https://patch.msgid.link/20250719083059.3209169-4-mohsin.bashr@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1cbcb1b2

tools/testing/selftests/drivers/net/xdp.py

+34 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ class XDPAction(Enum): 
    """Enum for XDP actions."""

    PASS = 0  # Pass the packet up to the stack

    DROP = 1  # Drop the packet

    TX = 2    # Route the packet to the remote host





class XDPStats(Enum):
@@ -34,6 +35,7 @@ class XDPStats(Enum): 
    RX = 0    # Count of valid packets received for testing

    PASS = 1  # Count of packets passed up to the stack

    DROP = 2  # Count of packets dropped

    TX = 3    # Count of incoming packets routed to the remote host





@dataclass
@@ -180,6 +182,8 @@ def _get_stats(xdp_map_id): 
            stats_formatted[XDPStats.PASS.value] = val

        elif stats_dump[key]["formatted"]["key"] == XDPStats.DROP.value:

            stats_formatted[XDPStats.DROP.value] = val

        elif stats_dump[key]["formatted"]["key"] == XDPStats.TX.value:

            stats_formatted[XDPStats.TX.value] = val



    return stats_formatted
@@ -278,6 +282,35 @@ def test_xdp_native_drop_mb(cfg): 
    _test_drop(cfg, bpf_info, 8000)





def test_xdp_native_tx_mb(cfg):

    """

    Tests the XDP_TX action for a multi-buff case.



    Args:

        cfg: Configuration object containing network settings.

    """

    cfg.require_cmd("socat", remote=True)



    bpf_info = BPFProgInfo("xdp_prog_frags", "xdp_native.bpf.o", "xdp.frags", 9000)

    prog_info = _load_xdp_prog(cfg, bpf_info)

    port = rand_port()



    _set_xdp_map("map_xdp_setup", TestConfig.MODE.value, XDPAction.TX.value)

    _set_xdp_map("map_xdp_setup", TestConfig.PORT.value, port)



    test_string = ''.join(random.choice(string.ascii_lowercase) for _ in range(8000))

    rx_udp = f"socat -{cfg.addr_ipver} -T 2 -u UDP-RECV:{port},reuseport STDOUT"

    tx_udp = f"echo {test_string} | socat -t 2 -u STDIN UDP:{cfg.baddr}:{port}"



    with bkg(rx_udp, host=cfg.remote, exit_wait=True) as rnc:

        cmd(tx_udp, host=cfg.remote, shell=True)



    stats = _get_stats(prog_info['maps']['map_xdp_stats'])



    ksft_eq(rnc.stdout.strip(), test_string, "UDP packet exchange failed")

    ksft_eq(stats[XDPStats.TX.value], 1, "TX stats mismatch")





def main():

    """

    Main function to execute the XDP tests.
@@ -294,6 +327,7 @@ def main(): 
                test_xdp_native_pass_mb,

                test_xdp_native_drop_sb,

                test_xdp_native_drop_mb,

                test_xdp_native_tx_mb,

            ],

            args=(cfg,))

    ksft_exit()

tools/testing/selftests/net/lib/xdp_native.bpf.c

+80 −0
Original line number Diff line number Diff line
@@ -18,12 +18,14 @@ enum { 
enum {

	XDP_MODE_PASS = 0,

	XDP_MODE_DROP = 1,

	XDP_MODE_TX = 2,

} xdp_map_modes;



enum {

	STATS_RX = 0,

	STATS_PASS = 1,

	STATS_DROP = 2,

	STATS_TX = 3,

} xdp_stats;



struct {
@@ -117,6 +119,82 @@ static int xdp_mode_drop_handler(struct xdp_md *ctx, __u16 port) 
	return XDP_DROP;

}



static void swap_machdr(void *data)

{

	struct ethhdr *eth = data;

	__u8 tmp_mac[ETH_ALEN];



	__builtin_memcpy(tmp_mac, eth->h_source, ETH_ALEN);

	__builtin_memcpy(eth->h_source, eth->h_dest, ETH_ALEN);

	__builtin_memcpy(eth->h_dest, tmp_mac, ETH_ALEN);

}



static int xdp_mode_tx_handler(struct xdp_md *ctx, __u16 port)

{

	void *data_end = (void *)(long)ctx->data_end;

	void *data = (void *)(long)ctx->data;

	struct udphdr *udph = NULL;

	struct ethhdr *eth = data;



	if (data + sizeof(*eth) > data_end)

		return XDP_PASS;



	if (eth->h_proto == bpf_htons(ETH_P_IP)) {

		struct iphdr *iph = data + sizeof(*eth);

		__be32 tmp_ip = iph->saddr;



		if (iph + 1 > (struct iphdr *)data_end ||

		    iph->protocol != IPPROTO_UDP)

			return XDP_PASS;



		udph = data + sizeof(*iph) + sizeof(*eth);



		if (udph + 1 > (struct udphdr *)data_end)

			return XDP_PASS;

		if (udph->dest != bpf_htons(port))

			return XDP_PASS;



		record_stats(ctx, STATS_RX);

		swap_machdr((void *)eth);



		iph->saddr = iph->daddr;

		iph->daddr = tmp_ip;



		record_stats(ctx, STATS_TX);



		return XDP_TX;



	} else if (eth->h_proto  == bpf_htons(ETH_P_IPV6)) {

		struct ipv6hdr *ipv6h = data + sizeof(*eth);

		struct in6_addr tmp_ipv6;



		if (ipv6h + 1 > (struct ipv6hdr *)data_end ||

		    ipv6h->nexthdr != IPPROTO_UDP)

			return XDP_PASS;



		udph = data + sizeof(*ipv6h) + sizeof(*eth);



		if (udph + 1 > (struct udphdr *)data_end)

			return XDP_PASS;

		if (udph->dest != bpf_htons(port))

			return XDP_PASS;



		record_stats(ctx, STATS_RX);

		swap_machdr((void *)eth);



		__builtin_memcpy(&tmp_ipv6, &ipv6h->saddr, sizeof(tmp_ipv6));

		__builtin_memcpy(&ipv6h->saddr, &ipv6h->daddr,

				 sizeof(tmp_ipv6));

		__builtin_memcpy(&ipv6h->daddr, &tmp_ipv6, sizeof(tmp_ipv6));



		record_stats(ctx, STATS_TX);



		return XDP_TX;

	}



	return XDP_PASS;

}



static int xdp_prog_common(struct xdp_md *ctx)

{

	__u32 key, *port;
@@ -137,6 +215,8 @@ static int xdp_prog_common(struct xdp_md *ctx) 
		return xdp_mode_pass(ctx, (__u16)(*port));

	case XDP_MODE_DROP:

		return xdp_mode_drop_handler(ctx, (__u16)(*port));

	case XDP_MODE_TX:

		return xdp_mode_tx_handler(ctx, (__u16)(*port));

	}



	/* Default action is to simple pass */