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-rw-r--r--drivers/net/tun.c28
-rw-r--r--tools/testing/selftests/bpf/network_helpers.c28
-rw-r--r--tools/testing/selftests/bpf/network_helpers.h3
-rw-r--r--tools/testing/selftests/bpf/prog_tests/lwt_helpers.h29
-rw-r--r--tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c145
-rw-r--r--tools/testing/selftests/bpf/progs/test_xdp_meta.c53
6 files changed, 230 insertions, 56 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 1e645d5e225c..55b60cb68d00 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -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 @@ build:
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);
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 80844a5fb1fe..29541d486c5e 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -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;
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index ebec8a8d6f81..9235976d0c50 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -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.
diff --git a/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h b/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
index fb1eb8c67361..ccec0fcdabc1 100644
--- a/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
+++ b/tools/testing/selftests/bpf/prog_tests/lwt_helpers.h
@@ -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 */
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c b/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
index 937da9b7532a..b9d9f0a502ce 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c
@@ -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 @@ close:
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);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_meta.c b/tools/testing/selftests/bpf/progs/test_xdp_meta.c
index fe2d71ae0e71..fcf6ca14f2ea 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_meta.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_meta.c
@@ -4,37 +4,50 @@
#include <bpf/bpf_helpers.h>
-#define __round_mask(x, y) ((__typeof__(x))((y) - 1))
-#define round_up(x, y) ((((x) - 1) | __round_mask(x, y)) + 1)
+#define META_SIZE 32
+
#define ctx_ptr(ctx, mem) (void *)(unsigned long)ctx->mem
+/* Demonstrates how metadata can be passed from an XDP program to a TC program
+ * using bpf_xdp_adjust_meta.
+ * For the sake of testing the metadata support in drivers, the XDP program uses
+ * a fixed-size payload after the Ethernet header as metadata. The TC program
+ * copies the metadata it receives into a map so it can be checked from
+ * userspace.
+ */
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, __u32);
+ __uint(value_size, META_SIZE);
+} test_result SEC(".maps");
+
SEC("tc")
int ing_cls(struct __sk_buff *ctx)
{
- __u8 *data, *data_meta, *data_end;
- __u32 diff = 0;
+ __u8 *data, *data_meta;
+ __u32 key = 0;
data_meta = ctx_ptr(ctx, data_meta);
- data_end = ctx_ptr(ctx, data_end);
data = ctx_ptr(ctx, data);
- if (data + ETH_ALEN > data_end ||
- data_meta + round_up(ETH_ALEN, 4) > data)
+ if (data_meta + META_SIZE > data)
return TC_ACT_SHOT;
- diff |= ((__u32 *)data_meta)[0] ^ ((__u32 *)data)[0];
- diff |= ((__u16 *)data_meta)[2] ^ ((__u16 *)data)[2];
+ bpf_map_update_elem(&test_result, &key, data_meta, BPF_ANY);
- return diff ? TC_ACT_SHOT : TC_ACT_OK;
+ return TC_ACT_SHOT;
}
SEC("xdp")
int ing_xdp(struct xdp_md *ctx)
{
- __u8 *data, *data_meta, *data_end;
+ __u8 *data, *data_meta, *data_end, *payload;
+ struct ethhdr *eth;
int ret;
- ret = bpf_xdp_adjust_meta(ctx, -round_up(ETH_ALEN, 4));
+ ret = bpf_xdp_adjust_meta(ctx, -META_SIZE);
if (ret < 0)
return XDP_DROP;
@@ -42,11 +55,21 @@ int ing_xdp(struct xdp_md *ctx)
data_end = ctx_ptr(ctx, data_end);
data = ctx_ptr(ctx, data);
- if (data + ETH_ALEN > data_end ||
- data_meta + round_up(ETH_ALEN, 4) > data)
+ eth = (struct ethhdr *)data;
+ payload = data + sizeof(struct ethhdr);
+
+ if (payload + META_SIZE > data_end ||
+ data_meta + META_SIZE > data)
+ return XDP_DROP;
+
+ /* The Linux networking stack may send other packets on the test
+ * interface that interfere with the test. Just drop them.
+ * The test packets can be recognized by their ethertype of zero.
+ */
+ if (eth->h_proto != 0)
return XDP_DROP;
- __builtin_memcpy(data_meta, data, ETH_ALEN);
+ __builtin_memcpy(data_meta, payload, META_SIZE);
return XDP_PASS;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.