selftests/bpf: Add tests for XDP bonding
authorJussi Maki <joamaki@gmail.com>
Sat, 31 Jul 2021 05:57:38 +0000 (05:57 +0000)
committerDaniel Borkmann <daniel@iogearbox.net>
Mon, 9 Aug 2021 21:25:15 +0000 (23:25 +0200)
Add a test suite to test XDP bonding implementation over a pair of
veth devices.

Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210731055738.16820-8-joamaki@gmail.com
tools/testing/selftests/bpf/prog_tests/xdp_bonding.c [new file with mode: 0644]

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c b/tools/testing/selftests/bpf/prog_tests/xdp_bonding.c
new file mode 100644 (file)
index 0000000..6b186b4
--- /dev/null
@@ -0,0 +1,520 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/**
+ * Test XDP bonding support
+ *
+ * Sets up two bonded veth pairs between two fresh namespaces
+ * and verifies that XDP_TX program loaded on a bond device
+ * are correctly loaded onto the slave devices and XDP_TX'd
+ * packets are balanced using bonding.
+ */
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <net/if.h>
+#include <linux/if_link.h>
+#include "test_progs.h"
+#include "network_helpers.h"
+#include <linux/if_bonding.h>
+#include <linux/limits.h>
+#include <linux/udp.h>
+
+#include "xdp_dummy.skel.h"
+#include "xdp_redirect_multi_kern.skel.h"
+#include "xdp_tx.skel.h"
+
+#define BOND1_MAC {0x00, 0x11, 0x22, 0x33, 0x44, 0x55}
+#define BOND1_MAC_STR "00:11:22:33:44:55"
+#define BOND2_MAC {0x00, 0x22, 0x33, 0x44, 0x55, 0x66}
+#define BOND2_MAC_STR "00:22:33:44:55:66"
+#define NPACKETS 100
+
+static int root_netns_fd = -1;
+
+static void restore_root_netns(void)
+{
+       ASSERT_OK(setns(root_netns_fd, CLONE_NEWNET), "restore_root_netns");
+}
+
+static int setns_by_name(char *name)
+{
+       int nsfd, err;
+       char nspath[PATH_MAX];
+
+       snprintf(nspath, sizeof(nspath), "%s/%s", "/var/run/netns", name);
+       nsfd = open(nspath, O_RDONLY | O_CLOEXEC);
+       if (nsfd < 0)
+               return -1;
+
+       err = setns(nsfd, CLONE_NEWNET);
+       close(nsfd);
+       return err;
+}
+
+static int get_rx_packets(const char *iface)
+{
+       FILE *f;
+       char line[512];
+       int iface_len = strlen(iface);
+
+       f = fopen("/proc/net/dev", "r");
+       if (!f)
+               return -1;
+
+       while (fgets(line, sizeof(line), f)) {
+               char *p = line;
+
+               while (*p == ' ')
+                       p++; /* skip whitespace */
+               if (!strncmp(p, iface, iface_len)) {
+                       p += iface_len;
+                       if (*p++ != ':')
+                               continue;
+                       while (*p == ' ')
+                               p++; /* skip whitespace */
+                       while (*p && *p != ' ')
+                               p++; /* skip rx bytes */
+                       while (*p == ' ')
+                               p++; /* skip whitespace */
+                       fclose(f);
+                       return atoi(p);
+               }
+       }
+       fclose(f);
+       return -1;
+}
+
+#define MAX_BPF_LINKS 8
+
+struct skeletons {
+       struct xdp_dummy *xdp_dummy;
+       struct xdp_tx *xdp_tx;
+       struct xdp_redirect_multi_kern *xdp_redirect_multi_kern;
+
+       int nlinks;
+       struct bpf_link *links[MAX_BPF_LINKS];
+};
+
+static int xdp_attach(struct skeletons *skeletons, struct bpf_program *prog, char *iface)
+{
+       struct bpf_link *link;
+       int ifindex;
+
+       ifindex = if_nametoindex(iface);
+       if (!ASSERT_GT(ifindex, 0, "get ifindex"))
+               return -1;
+
+       if (!ASSERT_LE(skeletons->nlinks+1, MAX_BPF_LINKS, "too many XDP programs attached"))
+               return -1;
+
+       link = bpf_program__attach_xdp(prog, ifindex);
+       if (!ASSERT_OK_PTR(link, "attach xdp program"))
+               return -1;
+
+       skeletons->links[skeletons->nlinks++] = link;
+       return 0;
+}
+
+enum {
+       BOND_ONE_NO_ATTACH = 0,
+       BOND_BOTH_AND_ATTACH,
+};
+
+static const char * const mode_names[] = {
+       [BOND_MODE_ROUNDROBIN]   = "balance-rr",
+       [BOND_MODE_ACTIVEBACKUP] = "active-backup",
+       [BOND_MODE_XOR]          = "balance-xor",
+       [BOND_MODE_BROADCAST]    = "broadcast",
+       [BOND_MODE_8023AD]       = "802.3ad",
+       [BOND_MODE_TLB]          = "balance-tlb",
+       [BOND_MODE_ALB]          = "balance-alb",
+};
+
+static const char * const xmit_policy_names[] = {
+       [BOND_XMIT_POLICY_LAYER2]       = "layer2",
+       [BOND_XMIT_POLICY_LAYER34]      = "layer3+4",
+       [BOND_XMIT_POLICY_LAYER23]      = "layer2+3",
+       [BOND_XMIT_POLICY_ENCAP23]      = "encap2+3",
+       [BOND_XMIT_POLICY_ENCAP34]      = "encap3+4",
+};
+
+static int bonding_setup(struct skeletons *skeletons, int mode, int xmit_policy,
+                        int bond_both_attach)
+{
+#define SYS(fmt, ...)                                          \
+       ({                                                      \
+               char cmd[1024];                                 \
+               snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \
+               if (!ASSERT_OK(system(cmd), cmd))               \
+                       return -1;                              \
+       })
+
+       SYS("ip netns add ns_dst");
+       SYS("ip link add veth1_1 type veth peer name veth2_1 netns ns_dst");
+       SYS("ip link add veth1_2 type veth peer name veth2_2 netns ns_dst");
+
+       SYS("ip link add bond1 type bond mode %s xmit_hash_policy %s",
+           mode_names[mode], xmit_policy_names[xmit_policy]);
+       SYS("ip link set bond1 up address " BOND1_MAC_STR " addrgenmode none");
+       SYS("ip -netns ns_dst link add bond2 type bond mode %s xmit_hash_policy %s",
+           mode_names[mode], xmit_policy_names[xmit_policy]);
+       SYS("ip -netns ns_dst link set bond2 up address " BOND2_MAC_STR " addrgenmode none");
+
+       SYS("ip link set veth1_1 master bond1");
+       if (bond_both_attach == BOND_BOTH_AND_ATTACH) {
+               SYS("ip link set veth1_2 master bond1");
+       } else {
+               SYS("ip link set veth1_2 up addrgenmode none");
+
+               if (xdp_attach(skeletons, skeletons->xdp_dummy->progs.xdp_dummy_prog, "veth1_2"))
+                       return -1;
+       }
+
+       SYS("ip -netns ns_dst link set veth2_1 master bond2");
+
+       if (bond_both_attach == BOND_BOTH_AND_ATTACH)
+               SYS("ip -netns ns_dst link set veth2_2 master bond2");
+       else
+               SYS("ip -netns ns_dst link set veth2_2 up addrgenmode none");
+
+       /* Load a dummy program on sending side as with veth peer needs to have a
+        * XDP program loaded as well.
+        */
+       if (xdp_attach(skeletons, skeletons->xdp_dummy->progs.xdp_dummy_prog, "bond1"))
+               return -1;
+
+       if (bond_both_attach == BOND_BOTH_AND_ATTACH) {
+               if (!ASSERT_OK(setns_by_name("ns_dst"), "set netns to ns_dst"))
+                       return -1;
+
+               if (xdp_attach(skeletons, skeletons->xdp_tx->progs.xdp_tx, "bond2"))
+                       return -1;
+
+               restore_root_netns();
+       }
+
+       return 0;
+
+#undef SYS
+}
+
+static void bonding_cleanup(struct skeletons *skeletons)
+{
+       restore_root_netns();
+       while (skeletons->nlinks) {
+               skeletons->nlinks--;
+               bpf_link__destroy(skeletons->links[skeletons->nlinks]);
+       }
+       ASSERT_OK(system("ip link delete bond1"), "delete bond1");
+       ASSERT_OK(system("ip link delete veth1_1"), "delete veth1_1");
+       ASSERT_OK(system("ip link delete veth1_2"), "delete veth1_2");
+       ASSERT_OK(system("ip netns delete ns_dst"), "delete ns_dst");
+}
+
+static int send_udp_packets(int vary_dst_ip)
+{
+       struct ethhdr eh = {
+               .h_source = BOND1_MAC,
+               .h_dest = BOND2_MAC,
+               .h_proto = htons(ETH_P_IP),
+       };
+       uint8_t buf[128] = {};
+       struct iphdr *iph = (struct iphdr *)(buf + sizeof(eh));
+       struct udphdr *uh = (struct udphdr *)(buf + sizeof(eh) + sizeof(*iph));
+       int i, s = -1;
+       int ifindex;
+
+       s = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW);
+       if (!ASSERT_GE(s, 0, "socket"))
+               goto err;
+
+       ifindex = if_nametoindex("bond1");
+       if (!ASSERT_GT(ifindex, 0, "get bond1 ifindex"))
+               goto err;
+
+       memcpy(buf, &eh, sizeof(eh));
+       iph->ihl = 5;
+       iph->version = 4;
+       iph->tos = 16;
+       iph->id = 1;
+       iph->ttl = 64;
+       iph->protocol = IPPROTO_UDP;
+       iph->saddr = 1;
+       iph->daddr = 2;
+       iph->tot_len = htons(sizeof(buf) - ETH_HLEN);
+       iph->check = 0;
+
+       for (i = 1; i <= NPACKETS; i++) {
+               int n;
+               struct sockaddr_ll saddr_ll = {
+                       .sll_ifindex = ifindex,
+                       .sll_halen = ETH_ALEN,
+                       .sll_addr = BOND2_MAC,
+               };
+
+               /* vary the UDP destination port for even distribution with roundrobin/xor modes */
+               uh->dest++;
+
+               if (vary_dst_ip)
+                       iph->daddr++;
+
+               n = sendto(s, buf, sizeof(buf), 0, (struct sockaddr *)&saddr_ll, sizeof(saddr_ll));
+               if (!ASSERT_EQ(n, sizeof(buf), "sendto"))
+                       goto err;
+       }
+
+       return 0;
+
+err:
+       if (s >= 0)
+               close(s);
+       return -1;
+}
+
+static void test_xdp_bonding_with_mode(struct skeletons *skeletons, int mode, int xmit_policy)
+{
+       int bond1_rx;
+
+       if (bonding_setup(skeletons, mode, xmit_policy, BOND_BOTH_AND_ATTACH))
+               goto out;
+
+       if (send_udp_packets(xmit_policy != BOND_XMIT_POLICY_LAYER34))
+               goto out;
+
+       bond1_rx = get_rx_packets("bond1");
+       ASSERT_EQ(bond1_rx, NPACKETS, "expected more received packets");
+
+       switch (mode) {
+       case BOND_MODE_ROUNDROBIN:
+       case BOND_MODE_XOR: {
+               int veth1_rx = get_rx_packets("veth1_1");
+               int veth2_rx = get_rx_packets("veth1_2");
+               int diff = abs(veth1_rx - veth2_rx);
+
+               ASSERT_GE(veth1_rx + veth2_rx, NPACKETS, "expected more packets");
+
+               switch (xmit_policy) {
+               case BOND_XMIT_POLICY_LAYER2:
+                       ASSERT_GE(diff, NPACKETS,
+                                 "expected packets on only one of the interfaces");
+                       break;
+               case BOND_XMIT_POLICY_LAYER23:
+               case BOND_XMIT_POLICY_LAYER34:
+                       ASSERT_LT(diff, NPACKETS/2,
+                                 "expected even distribution of packets");
+                       break;
+               default:
+                       PRINT_FAIL("Unimplemented xmit_policy=%d\n", xmit_policy);
+                       break;
+               }
+               break;
+       }
+       case BOND_MODE_ACTIVEBACKUP: {
+               int veth1_rx = get_rx_packets("veth1_1");
+               int veth2_rx = get_rx_packets("veth1_2");
+               int diff = abs(veth1_rx - veth2_rx);
+
+               ASSERT_GE(diff, NPACKETS,
+                         "expected packets on only one of the interfaces");
+               break;
+       }
+       default:
+               PRINT_FAIL("Unimplemented xmit_policy=%d\n", xmit_policy);
+               break;
+       }
+
+out:
+       bonding_cleanup(skeletons);
+}
+
+/* Test the broadcast redirection using xdp_redirect_map_multi_prog and adding
+ * all the interfaces to it and checking that broadcasting won't send the packet
+ * to neither the ingress bond device (bond2) or its slave (veth2_1).
+ */
+static void test_xdp_bonding_redirect_multi(struct skeletons *skeletons)
+{
+       static const char * const ifaces[] = {"bond2", "veth2_1", "veth2_2"};
+       int veth1_1_rx, veth1_2_rx;
+       int err;
+
+       if (bonding_setup(skeletons, BOND_MODE_ROUNDROBIN, BOND_XMIT_POLICY_LAYER23,
+                         BOND_ONE_NO_ATTACH))
+               goto out;
+
+
+       if (!ASSERT_OK(setns_by_name("ns_dst"), "could not set netns to ns_dst"))
+               goto out;
+
+       /* populate the devmap with the relevant interfaces */
+       for (int i = 0; i < ARRAY_SIZE(ifaces); i++) {
+               int ifindex = if_nametoindex(ifaces[i]);
+               int map_fd = bpf_map__fd(skeletons->xdp_redirect_multi_kern->maps.map_all);
+
+               if (!ASSERT_GT(ifindex, 0, "could not get interface index"))
+                       goto out;
+
+               err = bpf_map_update_elem(map_fd, &ifindex, &ifindex, 0);
+               if (!ASSERT_OK(err, "add interface to map_all"))
+                       goto out;
+       }
+
+       if (xdp_attach(skeletons,
+                      skeletons->xdp_redirect_multi_kern->progs.xdp_redirect_map_multi_prog,
+                      "bond2"))
+               goto out;
+
+       restore_root_netns();
+
+       if (send_udp_packets(BOND_MODE_ROUNDROBIN))
+               goto out;
+
+       veth1_1_rx = get_rx_packets("veth1_1");
+       veth1_2_rx = get_rx_packets("veth1_2");
+
+       ASSERT_EQ(veth1_1_rx, 0, "expected no packets on veth1_1");
+       ASSERT_GE(veth1_2_rx, NPACKETS, "expected packets on veth1_2");
+
+out:
+       restore_root_netns();
+       bonding_cleanup(skeletons);
+}
+
+/* Test that XDP programs cannot be attached to both the bond master and slaves simultaneously */
+static void test_xdp_bonding_attach(struct skeletons *skeletons)
+{
+       struct bpf_link *link = NULL;
+       struct bpf_link *link2 = NULL;
+       int veth, bond;
+       int err;
+
+       if (!ASSERT_OK(system("ip link add veth type veth"), "add veth"))
+               goto out;
+       if (!ASSERT_OK(system("ip link add bond type bond"), "add bond"))
+               goto out;
+
+       veth = if_nametoindex("veth");
+       if (!ASSERT_GE(veth, 0, "if_nametoindex veth"))
+               goto out;
+       bond = if_nametoindex("bond");
+       if (!ASSERT_GE(bond, 0, "if_nametoindex bond"))
+               goto out;
+
+       /* enslaving with a XDP program loaded fails */
+       link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, veth);
+       if (!ASSERT_OK_PTR(link, "attach program to veth"))
+               goto out;
+
+       err = system("ip link set veth master bond");
+       if (!ASSERT_NEQ(err, 0, "attaching slave with xdp program expected to fail"))
+               goto out;
+
+       bpf_link__destroy(link);
+       link = NULL;
+
+       err = system("ip link set veth master bond");
+       if (!ASSERT_OK(err, "set veth master"))
+               goto out;
+
+       /* attaching to slave when master has no program is allowed */
+       link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, veth);
+       if (!ASSERT_OK_PTR(link, "attach program to slave when enslaved"))
+               goto out;
+
+       /* attaching to master not allowed when slave has program loaded */
+       link2 = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, bond);
+       if (!ASSERT_ERR_PTR(link2, "attach program to master when slave has program"))
+               goto out;
+
+       bpf_link__destroy(link);
+       link = NULL;
+
+       /* attaching XDP program to master allowed when slave has no program */
+       link = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, bond);
+       if (!ASSERT_OK_PTR(link, "attach program to master"))
+               goto out;
+
+       /* attaching to slave not allowed when master has program loaded */
+       link2 = bpf_program__attach_xdp(skeletons->xdp_dummy->progs.xdp_dummy_prog, bond);
+       ASSERT_ERR_PTR(link2, "attach program to slave when master has program");
+
+out:
+       bpf_link__destroy(link);
+       bpf_link__destroy(link2);
+
+       system("ip link del veth");
+       system("ip link del bond");
+}
+
+static int libbpf_debug_print(enum libbpf_print_level level,
+                             const char *format, va_list args)
+{
+       if (level != LIBBPF_WARN)
+               vprintf(format, args);
+       return 0;
+}
+
+struct bond_test_case {
+       char *name;
+       int mode;
+       int xmit_policy;
+};
+
+static struct bond_test_case bond_test_cases[] = {
+       { "xdp_bonding_roundrobin", BOND_MODE_ROUNDROBIN, BOND_XMIT_POLICY_LAYER23, },
+       { "xdp_bonding_activebackup", BOND_MODE_ACTIVEBACKUP, BOND_XMIT_POLICY_LAYER23 },
+
+       { "xdp_bonding_xor_layer2", BOND_MODE_XOR, BOND_XMIT_POLICY_LAYER2, },
+       { "xdp_bonding_xor_layer23", BOND_MODE_XOR, BOND_XMIT_POLICY_LAYER23, },
+       { "xdp_bonding_xor_layer34", BOND_MODE_XOR, BOND_XMIT_POLICY_LAYER34, },
+};
+
+void test_xdp_bonding(void)
+{
+       libbpf_print_fn_t old_print_fn;
+       struct skeletons skeletons = {};
+       int i;
+
+       old_print_fn = libbpf_set_print(libbpf_debug_print);
+
+       root_netns_fd = open("/proc/self/ns/net", O_RDONLY);
+       if (!ASSERT_GE(root_netns_fd, 0, "open /proc/self/ns/net"))
+               goto out;
+
+       skeletons.xdp_dummy = xdp_dummy__open_and_load();
+       if (!ASSERT_OK_PTR(skeletons.xdp_dummy, "xdp_dummy__open_and_load"))
+               goto out;
+
+       skeletons.xdp_tx = xdp_tx__open_and_load();
+       if (!ASSERT_OK_PTR(skeletons.xdp_tx, "xdp_tx__open_and_load"))
+               goto out;
+
+       skeletons.xdp_redirect_multi_kern = xdp_redirect_multi_kern__open_and_load();
+       if (!ASSERT_OK_PTR(skeletons.xdp_redirect_multi_kern,
+                          "xdp_redirect_multi_kern__open_and_load"))
+               goto out;
+
+       if (!test__start_subtest("xdp_bonding_attach"))
+               test_xdp_bonding_attach(&skeletons);
+
+       for (i = 0; i < ARRAY_SIZE(bond_test_cases); i++) {
+               struct bond_test_case *test_case = &bond_test_cases[i];
+
+               if (!test__start_subtest(test_case->name))
+                       test_xdp_bonding_with_mode(
+                               &skeletons,
+                               test_case->mode,
+                               test_case->xmit_policy);
+       }
+
+       if (!test__start_subtest("xdp_bonding_redirect_multi"))
+               test_xdp_bonding_redirect_multi(&skeletons);
+
+out:
+       xdp_dummy__destroy(skeletons.xdp_dummy);
+       xdp_tx__destroy(skeletons.xdp_tx);
+       xdp_redirect_multi_kern__destroy(skeletons.xdp_redirect_multi_kern);
+
+       libbpf_set_print(old_print_fn);
+       if (root_netns_fd >= 0)
+               close(root_netns_fd);
+}