xdp_vlan.c

  1// SPDX-License-Identifier: GPL-2.0
  2
  3/*
  4 * Network topology:
  5 *  -----------        -----------
  6 *  |  NS1    |        |   NS2   |
  7 *  | veth0  -|--------|- veth0  |
  8 *  -----------        -----------
  9 *
 10 */
 11
 12#define _GNU_SOURCE
 13#include <net/if.h>
 14#include <uapi/linux/if_link.h>
 15
 16#include "network_helpers.h"
 17#include "test_progs.h"
 18#include "test_xdp_vlan.skel.h"
 19
 20
 21#define VETH_NAME	"veth0"
 22#define NS_MAX_SIZE	32
 23#define NS1_NAME	"ns-xdp-vlan-1-"
 24#define NS2_NAME	"ns-xdp-vlan-2-"
 25#define NS1_IP_ADDR	"100.64.10.1"
 26#define NS2_IP_ADDR	"100.64.10.2"
 27#define VLAN_ID		4011
 28
 29static int setup_network(char *ns1, char *ns2)
 30{
 31	if (!ASSERT_OK(append_tid(ns1, NS_MAX_SIZE), "create ns1 name"))
 32		goto fail;
 33	if (!ASSERT_OK(append_tid(ns2, NS_MAX_SIZE), "create ns2 name"))
 34		goto fail;
 35
 36	SYS(fail, "ip netns add %s", ns1);
 37	SYS(fail, "ip netns add %s", ns2);
 38	SYS(fail, "ip -n %s link add %s type veth peer name %s netns %s",
 39	    ns1, VETH_NAME, VETH_NAME, ns2);
 40
 41	/* NOTICE: XDP require VLAN header inside packet payload
 42	 *  - Thus, disable VLAN offloading driver features
 43	 */
 44	SYS(fail, "ip netns exec %s ethtool -K %s rxvlan off txvlan off", ns1, VETH_NAME);
 45	SYS(fail, "ip netns exec %s ethtool -K %s rxvlan off txvlan off", ns2, VETH_NAME);
 46
 47	/* NS1 configuration */
 48	SYS(fail, "ip -n %s addr add %s/24 dev %s", ns1, NS1_IP_ADDR, VETH_NAME);
 49	SYS(fail, "ip -n %s link set %s up", ns1, VETH_NAME);
 50
 51	/* NS2 configuration */
 52	SYS(fail, "ip -n %s link add link %s name %s.%d type vlan id %d",
 53	    ns2, VETH_NAME, VETH_NAME, VLAN_ID, VLAN_ID);
 54	SYS(fail, "ip -n %s addr add %s/24 dev %s.%d", ns2, NS2_IP_ADDR, VETH_NAME, VLAN_ID);
 55	SYS(fail, "ip -n %s link set %s up", ns2, VETH_NAME);
 56	SYS(fail, "ip -n %s link set %s.%d up", ns2, VETH_NAME, VLAN_ID);
 57
 58	/* At this point ping should fail because VLAN tags are only used by NS2 */
 59	return !SYS_NOFAIL("ip netns exec %s ping -W 1 -c1 %s", ns2, NS1_IP_ADDR);
 60
 61fail:
 62	return -1;
 63}
 64
 65static void cleanup_network(const char *ns1, const char *ns2)
 66{
 67	SYS_NOFAIL("ip netns del %s", ns1);
 68	SYS_NOFAIL("ip netns del %s", ns2);
 69}
 70
 71static void xdp_vlan(struct bpf_program *xdp, struct bpf_program *tc, u32 flags)
 72{
 73	LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_EGRESS);
 74	LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
 75	char ns1[NS_MAX_SIZE] = NS1_NAME;
 76	char ns2[NS_MAX_SIZE] = NS2_NAME;
 77	struct nstoken *nstoken = NULL;
 78	int interface;
 79	int ret;
 80
 81	if (!ASSERT_OK(setup_network(ns1, ns2), "setup network"))
 82		goto cleanup;
 83
 84	nstoken = open_netns(ns1);
 85	if (!ASSERT_OK_PTR(nstoken, "open NS1"))
 86		goto cleanup;
 87
 88	interface = if_nametoindex(VETH_NAME);
 89	if (!ASSERT_NEQ(interface, 0, "get interface index"))
 90		goto cleanup;
 91
 92	ret = bpf_xdp_attach(interface, bpf_program__fd(xdp), flags, NULL);
 93	if (!ASSERT_OK(ret, "attach xdp_vlan_change"))
 94		goto cleanup;
 95
 96	tc_hook.ifindex = interface;
 97	ret = bpf_tc_hook_create(&tc_hook);
 98	if (!ASSERT_OK(ret, "bpf_tc_hook_create"))
 99		goto detach_xdp;
100
101	/* Now we'll use BPF programs to pop/push the VLAN tags */
102	tc_opts.prog_fd = bpf_program__fd(tc);
103	ret = bpf_tc_attach(&tc_hook, &tc_opts);
104	if (!ASSERT_OK(ret, "bpf_tc_attach"))
105		goto detach_xdp;
106
107	close_netns(nstoken);
108	nstoken = NULL;
109
110	/* Now the namespaces can reach each-other, test with pings */
111	SYS(detach_tc, "ip netns exec %s ping -i 0.2 -W 2 -c 2 %s > /dev/null", ns1, NS2_IP_ADDR);
112	SYS(detach_tc, "ip netns exec %s ping -i 0.2 -W 2 -c 2 %s > /dev/null", ns2, NS1_IP_ADDR);
113
114
115detach_tc:
116	bpf_tc_detach(&tc_hook, &tc_opts);
117detach_xdp:
118	bpf_xdp_detach(interface, flags, NULL);
119cleanup:
120	close_netns(nstoken);
121	cleanup_network(ns1, ns2);
122}
123
124/* First test: Remove VLAN by setting VLAN ID 0, using "xdp_vlan_change"
125 * egress use TC to add back VLAN tag 4011
126 */
127void test_xdp_vlan_change(void)
128{
129	struct test_xdp_vlan *skel;
130
131	skel = test_xdp_vlan__open_and_load();
132	if (!ASSERT_OK_PTR(skel, "xdp_vlan__open_and_load"))
133		return;
134
135	if (test__start_subtest("0"))
136		xdp_vlan(skel->progs.xdp_vlan_change, skel->progs.tc_vlan_push, 0);
137
138	if (test__start_subtest("DRV_MODE"))
139		xdp_vlan(skel->progs.xdp_vlan_change, skel->progs.tc_vlan_push,
140			 XDP_FLAGS_DRV_MODE);
141
142	if (test__start_subtest("SKB_MODE"))
143		xdp_vlan(skel->progs.xdp_vlan_change, skel->progs.tc_vlan_push,
144			 XDP_FLAGS_SKB_MODE);
145
146	test_xdp_vlan__destroy(skel);
147}
148
149/* Second test: XDP prog fully remove vlan header
150 *
151 * Catch kernel bug for generic-XDP, that doesn't allow us to
152 * remove a VLAN header, because skb->protocol still contain VLAN
153 * ETH_P_8021Q indication, and this cause overwriting of our changes.
154 */
155void test_xdp_vlan_remove(void)
156{
157	struct test_xdp_vlan *skel;
158
159	skel = test_xdp_vlan__open_and_load();
160	if (!ASSERT_OK_PTR(skel, "xdp_vlan__open_and_load"))
161		return;
162
163	if (test__start_subtest("0"))
164		xdp_vlan(skel->progs.xdp_vlan_remove_outer2, skel->progs.tc_vlan_push, 0);
165
166	if (test__start_subtest("DRV_MODE"))
167		xdp_vlan(skel->progs.xdp_vlan_remove_outer2, skel->progs.tc_vlan_push,
168			 XDP_FLAGS_DRV_MODE);
169
170	if (test__start_subtest("SKB_MODE"))
171		xdp_vlan(skel->progs.xdp_vlan_remove_outer2, skel->progs.tc_vlan_push,
172			 XDP_FLAGS_SKB_MODE);
173
174	test_xdp_vlan__destroy(skel);
175}