diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/lwt_redirect.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/lwt_redirect.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/lwt_redirect.c b/tools/testing/selftests/bpf/prog_tests/lwt_redirect.c new file mode 100644 index 000000000000..835a1d756c16 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/lwt_redirect.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause + +/* + * Test suite of lwt_xmit BPF programs that redirect packets + * The file tests focus not only if these programs work as expected normally, + * but also if they can handle abnormal situations gracefully. + * + * WARNING + * ------- + * This test suite may crash the kernel, thus should be run in a VM. + * + * Setup: + * --------- + * All tests are performed in a single netns. Two lwt encap routes are setup for + * each subtest: + * + * ip route add 10.0.0.0/24 encap bpf xmit <obj> sec "<ingress_sec>" dev link_err + * ip route add 20.0.0.0/24 encap bpf xmit <obj> sec "<egress_sec>" dev link_err + * + * Here <obj> is statically defined to test_lwt_redirect.bpf.o, and each section + * of this object holds a program entry to test. The BPF object is built from + * progs/test_lwt_redirect.c. We didn't use generated BPF skeleton since the + * attachment for lwt programs are not supported by libbpf yet. + * + * For testing, ping commands are run in the test netns: + * + * ping 10.0.0.<ifindex> -c 1 -w 1 -s 100 + * ping 20.0.0.<ifindex> -c 1 -w 1 -s 100 + * + * Scenarios: + * -------------------------------- + * 1. Redirect to a running tap/tun device + * 2. Redirect to a down tap/tun device + * 3. Redirect to a vlan device with lower layer down + * + * Case 1, ping packets should be received by packet socket on target device + * when redirected to ingress, and by tun/tap fd when redirected to egress. + * + * Case 2,3 are considered successful as long as they do not crash the kernel + * as a regression. + * + * Case 1,2 use tap device to test redirect to device that requires MAC + * header, and tun device to test the case with no MAC header added. + */ +#include <sys/socket.h> +#include <net/if.h> +#include <linux/if_ether.h> +#include <linux/if_packet.h> +#include <linux/if_tun.h> +#include <linux/icmp.h> +#include <arpa/inet.h> +#include <unistd.h> +#include <errno.h> +#include <stdbool.h> +#include <stdlib.h> + +#define NETNS "ns_lwt_redirect" +#include "lwt_helpers.h" +#include "test_progs.h" +#include "network_helpers.h" + +#define BPF_OBJECT "test_lwt_redirect.bpf.o" +#define INGRESS_SEC(need_mac) ((need_mac) ? "redir_ingress" : "redir_ingress_nomac") +#define EGRESS_SEC(need_mac) ((need_mac) ? "redir_egress" : "redir_egress_nomac") +#define LOCAL_SRC "10.0.0.1" +#define CIDR_TO_INGRESS "10.0.0.0/24" +#define CIDR_TO_EGRESS "20.0.0.0/24" + +/* ping to redirect toward given dev, with last byte of dest IP being the target + * device index. + * + * Note: ping command inside BPF-CI is busybox version, so it does not have certain + * function, such like -m option to set packet mark. + */ +static void ping_dev(const char *dev, bool is_ingress) +{ + int link_index = if_nametoindex(dev); + char ip[256]; + + if (!ASSERT_GE(link_index, 0, "if_nametoindex")) + return; + + if (is_ingress) + snprintf(ip, sizeof(ip), "10.0.0.%d", link_index); + else + snprintf(ip, sizeof(ip), "20.0.0.%d", link_index); + + /* We won't get a reply. Don't fail here */ + SYS_NOFAIL("ping %s -c1 -W1 -s %d", + ip, ICMP_PAYLOAD_SIZE); +} + +static int new_packet_sock(const char *ifname) +{ + int err = 0; + int ignore_outgoing = 1; + int ifindex = -1; + int s = -1; + + s = socket(AF_PACKET, SOCK_RAW, 0); + if (!ASSERT_GE(s, 0, "socket(AF_PACKET)")) + return -1; + + ifindex = if_nametoindex(ifname); + if (!ASSERT_GE(ifindex, 0, "if_nametoindex")) { + close(s); + return -1; + } + + struct sockaddr_ll addr = { + .sll_family = AF_PACKET, + .sll_protocol = htons(ETH_P_IP), + .sll_ifindex = ifindex, + }; + + err = bind(s, (struct sockaddr *)&addr, sizeof(addr)); + if (!ASSERT_OK(err, "bind(AF_PACKET)")) { + close(s); + return -1; + } + + /* Use packet socket to capture only the ingress, so we can distinguish + * the case where a regression that actually redirects the packet to + * the egress. + */ + err = setsockopt(s, SOL_PACKET, PACKET_IGNORE_OUTGOING, + &ignore_outgoing, sizeof(ignore_outgoing)); + if (!ASSERT_OK(err, "setsockopt(PACKET_IGNORE_OUTGOING)")) { + close(s); + return -1; + } + + err = fcntl(s, F_SETFL, O_NONBLOCK); + if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) { + close(s); + return -1; + } + + return s; +} + +static int expect_icmp(char *buf, ssize_t len) +{ + struct ethhdr *eth = (struct ethhdr *)buf; + + if (len < (ssize_t)sizeof(*eth)) + return -1; + + if (eth->h_proto == htons(ETH_P_IP)) + return __expect_icmp_ipv4((char *)(eth + 1), len - sizeof(*eth)); + + return -1; +} + +static int expect_icmp_nomac(char *buf, ssize_t len) +{ + return __expect_icmp_ipv4(buf, len); +} + +static void send_and_capture_test_packets(const char *test_name, int tap_fd, + const char *target_dev, bool need_mac) +{ + int psock = -1; + struct timeval timeo = { + .tv_sec = 0, + .tv_usec = 250000, + }; + int ret = -1; + + filter_t filter = need_mac ? expect_icmp : expect_icmp_nomac; + + ping_dev(target_dev, false); + + ret = wait_for_packet(tap_fd, filter, &timeo); + if (!ASSERT_EQ(ret, 1, "wait_for_epacket")) { + log_err("%s egress test fails", test_name); + goto out; + } + + psock = new_packet_sock(target_dev); + ping_dev(target_dev, true); + + ret = wait_for_packet(psock, filter, &timeo); + if (!ASSERT_EQ(ret, 1, "wait_for_ipacket")) { + log_err("%s ingress test fails", test_name); + goto out; + } + +out: + if (psock >= 0) + close(psock); +} + +static int setup_redirect_target(const char *target_dev, bool need_mac) +{ + int target_index = -1; + int tap_fd = -1; + + tap_fd = open_tuntap(target_dev, need_mac); + if (!ASSERT_GE(tap_fd, 0, "open_tuntap")) + goto fail; + + target_index = if_nametoindex(target_dev); + if (!ASSERT_GE(target_index, 0, "if_nametoindex")) + goto fail; + + SYS(fail, "sysctl -w net.ipv6.conf.all.disable_ipv6=1"); + SYS(fail, "ip link add link_err type dummy"); + SYS(fail, "ip link set lo up"); + SYS(fail, "ip addr add dev lo " LOCAL_SRC "/32"); + SYS(fail, "ip link set link_err up"); + SYS(fail, "ip link set %s up", target_dev); + + SYS(fail, "ip route add %s dev link_err encap bpf xmit obj %s sec %s", + CIDR_TO_INGRESS, BPF_OBJECT, INGRESS_SEC(need_mac)); + + SYS(fail, "ip route add %s dev link_err encap bpf xmit obj %s sec %s", + CIDR_TO_EGRESS, BPF_OBJECT, EGRESS_SEC(need_mac)); + + return tap_fd; + +fail: + if (tap_fd >= 0) + close(tap_fd); + return -1; +} + +static void test_lwt_redirect_normal(void) +{ + const char *target_dev = "tap0"; + int tap_fd = -1; + bool need_mac = true; + + tap_fd = setup_redirect_target(target_dev, need_mac); + if (!ASSERT_GE(tap_fd, 0, "setup_redirect_target")) + return; + + send_and_capture_test_packets(__func__, tap_fd, target_dev, need_mac); + close(tap_fd); +} + +static void test_lwt_redirect_normal_nomac(void) +{ + const char *target_dev = "tun0"; + int tap_fd = -1; + bool need_mac = false; + + tap_fd = setup_redirect_target(target_dev, need_mac); + if (!ASSERT_GE(tap_fd, 0, "setup_redirect_target")) + return; + + send_and_capture_test_packets(__func__, tap_fd, target_dev, need_mac); + close(tap_fd); +} + +/* This test aims to prevent regression of future. As long as the kernel does + * not panic, it is considered as success. + */ +static void __test_lwt_redirect_dev_down(bool need_mac) +{ + const char *target_dev = "tap0"; + int tap_fd = -1; + + tap_fd = setup_redirect_target(target_dev, need_mac); + if (!ASSERT_GE(tap_fd, 0, "setup_redirect_target")) + return; + + SYS(out, "ip link set %s down", target_dev); + ping_dev(target_dev, true); + ping_dev(target_dev, false); + +out: + close(tap_fd); +} + +static void test_lwt_redirect_dev_down(void) +{ + __test_lwt_redirect_dev_down(true); +} + +static void test_lwt_redirect_dev_down_nomac(void) +{ + __test_lwt_redirect_dev_down(false); +} + +/* This test aims to prevent regression of future. As long as the kernel does + * not panic, it is considered as success. + */ +static void test_lwt_redirect_dev_carrier_down(void) +{ + const char *lower_dev = "tap0"; + const char *vlan_dev = "vlan100"; + int tap_fd = -1; + + tap_fd = setup_redirect_target(lower_dev, true); + if (!ASSERT_GE(tap_fd, 0, "setup_redirect_target")) + return; + + SYS(out, "ip link add vlan100 link %s type vlan id 100", lower_dev); + SYS(out, "ip link set %s up", vlan_dev); + SYS(out, "ip link set %s down", lower_dev); + ping_dev(vlan_dev, true); + ping_dev(vlan_dev, false); + +out: + close(tap_fd); +} + +static void *test_lwt_redirect_run(void *arg) +{ + netns_delete(); + RUN_TEST(lwt_redirect_normal); + RUN_TEST(lwt_redirect_normal_nomac); + RUN_TEST(lwt_redirect_dev_down); + RUN_TEST(lwt_redirect_dev_down_nomac); + RUN_TEST(lwt_redirect_dev_carrier_down); + return NULL; +} + +void test_lwt_redirect(void) +{ + pthread_t test_thread; + int err; + + /* Run the tests in their own thread to isolate the namespace changes + * so they do not affect the environment of other tests. + * (specifically needed because of unshare(CLONE_NEWNS) in open_netns()) + */ + err = pthread_create(&test_thread, NULL, &test_lwt_redirect_run, NULL); + if (ASSERT_OK(err, "pthread_create")) + ASSERT_OK(pthread_join(test_thread, NULL), "pthread_join"); +} |