Commit 93b1e055 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 

Martin KaFai Lau says:

====================
pull-request: bpf-next 2025-03-06

We've added 6 non-merge commits during the last 13 day(s) which contain
a total of 6 files changed, 230 insertions(+), 56 deletions(-).

The main changes are:

1) Add XDP metadata support for tun driver, from Marcus Wichelmann.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Fix file descriptor assertion in open_tuntap helper
  selftests/bpf: Add test for XDP metadata support in tun driver
  selftests/bpf: Refactor xdp_context_functional test and bpf program
  selftests/bpf: Move open_tuntap to network helpers
  net: tun: Enable transfer of XDP metadata to skb
  net: tun: Enable XDP metadata support
====================

Link: https://patch.msgid.link/20250307055335.441298-1-martin.lau@linux.dev


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 7ae495a5 72aad21d

drivers/net/tun.c

+23 −5
Original line number Diff line number Diff line
@@ -1535,7 +1535,8 @@ static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile, 


static struct sk_buff *__tun_build_skb(struct tun_file *tfile,

				       struct page_frag *alloc_frag, char *buf,

				       int buflen, int len, int pad)

				       int buflen, int len, int pad,

				       int metasize)

{

	struct sk_buff *skb = build_skb(buf, buflen);
@@ -1544,6 +1545,8 @@ static struct sk_buff *__tun_build_skb(struct tun_file *tfile, 


	skb_reserve(skb, pad);

	skb_put(skb, len);

	if (metasize)

		skb_metadata_set(skb, metasize);

	skb_set_owner_w(skb, tfile->socket.sk);



	get_page(alloc_frag->page);
@@ -1603,6 +1606,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, 
	char *buf;

	size_t copied;

	int pad = TUN_RX_PAD;

	int metasize = 0;

	int err = 0;



	rcu_read_lock();
@@ -1630,7 +1634,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, 
	if (hdr->gso_type || !xdp_prog) {

		*skb_xdp = 1;

		return __tun_build_skb(tfile, alloc_frag, buf, buflen, len,

				       pad);

				       pad, metasize);

	}



	*skb_xdp = 0;
@@ -1644,7 +1648,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, 
		u32 act;



		xdp_init_buff(&xdp, buflen, &tfile->xdp_rxq);

		xdp_prepare_buff(&xdp, buf, pad, len, false);

		xdp_prepare_buff(&xdp, buf, pad, len, true);



		act = bpf_prog_run_xdp(xdp_prog, &xdp);

		if (act == XDP_REDIRECT || act == XDP_TX) {
@@ -1665,12 +1669,18 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, 


		pad = xdp.data - xdp.data_hard_start;

		len = xdp.data_end - xdp.data;



		/* It is known that the xdp_buff was prepared with metadata

		 * support, so the metasize will never be negative.

		 */

		metasize = xdp.data - xdp.data_meta;

	}

	bpf_net_ctx_clear(bpf_net_ctx);

	rcu_read_unlock();

	local_bh_enable();



	return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad);

	return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad,

			       metasize);



out:

	bpf_net_ctx_clear(bpf_net_ctx);
@@ -2353,6 +2363,7 @@ static int tun_xdp_one(struct tun_struct *tun, 
	struct sk_buff_head *queue;

	u32 rxhash = 0, act;

	int buflen = hdr->buflen;

	int metasize = 0;

	int ret = 0;

	bool skb_xdp = false;

	struct page *page;
@@ -2368,7 +2379,6 @@ static int tun_xdp_one(struct tun_struct *tun, 
		}



		xdp_init_buff(xdp, buflen, &tfile->xdp_rxq);

		xdp_set_data_meta_invalid(xdp);



		act = bpf_prog_run_xdp(xdp_prog, xdp);

		ret = tun_xdp_act(tun, xdp_prog, xdp, act);
@@ -2408,6 +2418,14 @@ static int tun_xdp_one(struct tun_struct *tun, 
	skb_reserve(skb, xdp->data - xdp->data_hard_start);

	skb_put(skb, xdp->data_end - xdp->data);



	/* The externally provided xdp_buff may have no metadata support, which

	 * is marked by xdp->data_meta being xdp->data + 1. This will lead to a

	 * metasize of -1 and is the reason why the condition checks for > 0.

	 */

	metasize = xdp->data - xdp->data_meta;

	if (metasize > 0)

		skb_metadata_set(skb, metasize);



	if (tun_vnet_hdr_to_skb(tun->flags, skb, gso)) {

		atomic_long_inc(&tun->rx_frame_errors);

		kfree_skb(skb);

tools/testing/selftests/bpf/network_helpers.c

+28 −0
Original line number Diff line number Diff line
@@ -548,6 +548,34 @@ void close_netns(struct nstoken *token) 
	free(token);

}



int open_tuntap(const char *dev_name, bool need_mac)

{

	int err = 0;

	struct ifreq ifr;

	int fd = open("/dev/net/tun", O_RDWR);



	if (!ASSERT_GE(fd, 0, "open(/dev/net/tun)"))

		return -1;



	ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);

	strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);

	ifr.ifr_name[IFNAMSIZ - 1] = '\0';



	err = ioctl(fd, TUNSETIFF, &ifr);

	if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {

		close(fd);

		return -1;

	}



	err = fcntl(fd, F_SETFL, O_NONBLOCK);

	if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) {

		close(fd);

		return -1;

	}



	return fd;

}



int get_socket_local_port(int sock_fd)

{

	struct sockaddr_storage addr;

tools/testing/selftests/bpf/network_helpers.h

+3 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
typedef __u16 __sum16;

#include <linux/if_ether.h>

#include <linux/if_packet.h>

#include <linux/if_tun.h>

#include <linux/ip.h>

#include <linux/ipv6.h>

#include <linux/ethtool.h>
@@ -85,6 +86,8 @@ int get_socket_local_port(int sock_fd); 
int get_hw_ring_size(char *ifname, struct ethtool_ringparam *ring_param);

int set_hw_ring_size(char *ifname, struct ethtool_ringparam *ring_param);



int open_tuntap(const char *dev_name, bool need_mac);



struct nstoken;

/**

 * open_netns() - Switch to specified network namespace by name.

tools/testing/selftests/bpf/prog_tests/lwt_helpers.h

+0 −29
Original line number Diff line number Diff line
@@ -5,7 +5,6 @@ 


#include <time.h>

#include <net/if.h>

#include <linux/if_tun.h>

#include <linux/icmp.h>



#include "test_progs.h"
@@ -37,34 +36,6 @@ static inline int netns_delete(void) 
	return system("ip netns del " NETNS ">/dev/null 2>&1");

}



static int open_tuntap(const char *dev_name, bool need_mac)

{

	int err = 0;

	struct ifreq ifr;

	int fd = open("/dev/net/tun", O_RDWR);



	if (!ASSERT_GT(fd, 0, "open(/dev/net/tun)"))

		return -1;



	ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);

	strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);

	ifr.ifr_name[IFNAMSIZ - 1] = '\0';



	err = ioctl(fd, TUNSETIFF, &ifr);

	if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {

		close(fd);

		return -1;

	}



	err = fcntl(fd, F_SETFL, O_NONBLOCK);

	if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) {

		close(fd);

		return -1;

	}



	return fd;

}



#define ICMP_PAYLOAD_SIZE     100



/* Match an ICMP packet with payload len ICMP_PAYLOAD_SIZE */

tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c

+138 −7
Original line number Diff line number Diff line
@@ -4,12 +4,20 @@ 
#include "test_xdp_context_test_run.skel.h"

#include "test_xdp_meta.skel.h"



#define TX_ADDR "10.0.0.1"

#define RX_ADDR "10.0.0.2"

#define RX_NAME "veth0"

#define TX_NAME "veth1"

#define TX_NETNS "xdp_context_tx"

#define RX_NETNS "xdp_context_rx"

#define TAP_NAME "tap0"

#define TAP_NETNS "xdp_context_tuntap"



#define TEST_PAYLOAD_LEN 32

static const __u8 test_payload[TEST_PAYLOAD_LEN] = {

	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,

};



void test_xdp_context_error(int prog_fd, struct bpf_test_run_opts opts,

			    __u32 data_meta, __u32 data, __u32 data_end,
@@ -112,7 +120,59 @@ void test_xdp_context_test_run(void) 
	test_xdp_context_test_run__destroy(skel);

}



void test_xdp_context_functional(void)

static int send_test_packet(int ifindex)

{

	int n, sock = -1;

	__u8 packet[sizeof(struct ethhdr) + TEST_PAYLOAD_LEN];



	/* The ethernet header is not relevant for this test and doesn't need to

	 * be meaningful.

	 */

	struct ethhdr eth = { 0 };



	memcpy(packet, &eth, sizeof(eth));

	memcpy(packet + sizeof(eth), test_payload, TEST_PAYLOAD_LEN);



	sock = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW);

	if (!ASSERT_GE(sock, 0, "socket"))

		goto err;



	struct sockaddr_ll saddr = {

		.sll_family = PF_PACKET,

		.sll_ifindex = ifindex,

		.sll_halen = ETH_ALEN

	};

	n = sendto(sock, packet, sizeof(packet), 0, (struct sockaddr *)&saddr,

		   sizeof(saddr));

	if (!ASSERT_EQ(n, sizeof(packet), "sendto"))

		goto err;



	close(sock);

	return 0;



err:

	if (sock >= 0)

		close(sock);

	return -1;

}



static void assert_test_result(struct test_xdp_meta *skel)

{

	int err;

	__u32 map_key = 0;

	__u8 map_value[TEST_PAYLOAD_LEN];



	err = bpf_map__lookup_elem(skel->maps.test_result, &map_key,

				   sizeof(map_key), &map_value,

				   TEST_PAYLOAD_LEN, BPF_ANY);

	if (!ASSERT_OK(err, "lookup test_result"))

		return;



	ASSERT_MEMEQ(&map_value, &test_payload, TEST_PAYLOAD_LEN,

		     "test_result map contains test payload");

}



void test_xdp_context_veth(void)

{

	LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);

	LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
@@ -120,7 +180,7 @@ void test_xdp_context_functional(void) 
	struct bpf_program *tc_prog, *xdp_prog;

	struct test_xdp_meta *skel = NULL;

	struct nstoken *nstoken = NULL;

	int rx_ifindex;

	int rx_ifindex, tx_ifindex;

	int ret;



	tx_ns = netns_new(TX_NETNS, false);
@@ -138,7 +198,6 @@ void test_xdp_context_functional(void) 
	if (!ASSERT_OK_PTR(nstoken, "setns rx_ns"))

		goto close;



	SYS(close, "ip addr add " RX_ADDR "/24 dev " RX_NAME);

	SYS(close, "ip link set dev " RX_NAME " up");



	skel = test_xdp_meta__open_and_load();
@@ -179,9 +238,17 @@ void test_xdp_context_functional(void) 
	if (!ASSERT_OK_PTR(nstoken, "setns tx_ns"))

		goto close;



	SYS(close, "ip addr add " TX_ADDR "/24 dev " TX_NAME);

	SYS(close, "ip link set dev " TX_NAME " up");

	ASSERT_OK(SYS_NOFAIL("ping -c 1 " RX_ADDR), "ping");



	tx_ifindex = if_nametoindex(TX_NAME);

	if (!ASSERT_GE(tx_ifindex, 0, "if_nametoindex tx"))

		goto close;



	ret = send_test_packet(tx_ifindex);

	if (!ASSERT_OK(ret, "send_test_packet"))

		goto close;



	assert_test_result(skel);



close:

	close_netns(nstoken);
@@ -190,3 +257,67 @@ void test_xdp_context_functional(void) 
	netns_free(tx_ns);

}



void test_xdp_context_tuntap(void)

{

	LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);

	LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);

	struct netns_obj *ns = NULL;

	struct test_xdp_meta *skel = NULL;

	__u8 packet[sizeof(struct ethhdr) + TEST_PAYLOAD_LEN];

	int tap_fd = -1;

	int tap_ifindex;

	int ret;



	ns = netns_new(TAP_NETNS, true);

	if (!ASSERT_OK_PTR(ns, "create and open ns"))

		return;



	tap_fd = open_tuntap(TAP_NAME, true);

	if (!ASSERT_GE(tap_fd, 0, "open_tuntap"))

		goto close;



	SYS(close, "ip link set dev " TAP_NAME " up");



	skel = test_xdp_meta__open_and_load();

	if (!ASSERT_OK_PTR(skel, "open and load skeleton"))

		goto close;



	tap_ifindex = if_nametoindex(TAP_NAME);

	if (!ASSERT_GE(tap_ifindex, 0, "if_nametoindex"))

		goto close;



	tc_hook.ifindex = tap_ifindex;

	ret = bpf_tc_hook_create(&tc_hook);

	if (!ASSERT_OK(ret, "bpf_tc_hook_create"))

		goto close;



	tc_opts.prog_fd = bpf_program__fd(skel->progs.ing_cls);

	ret = bpf_tc_attach(&tc_hook, &tc_opts);

	if (!ASSERT_OK(ret, "bpf_tc_attach"))

		goto close;



	ret = bpf_xdp_attach(tap_ifindex, bpf_program__fd(skel->progs.ing_xdp),

			     0, NULL);

	if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))

		goto close;



	/* The ethernet header is not relevant for this test and doesn't need to

	 * be meaningful.

	 */

	struct ethhdr eth = { 0 };



	memcpy(packet, &eth, sizeof(eth));

	memcpy(packet + sizeof(eth), test_payload, TEST_PAYLOAD_LEN);



	ret = write(tap_fd, packet, sizeof(packet));

	if (!ASSERT_EQ(ret, sizeof(packet), "write packet"))

		goto close;



	assert_test_result(skel);



close:

	if (tap_fd >= 0)

		close(tap_fd);

	test_xdp_meta__destroy(skel);

	netns_free(ns);

}