1// SPDX-License-Identifier: GPL-2.0
  2#include <test_progs.h>
  3#include <network_helpers.h>
  4#include <net/if.h>
  5#include "empty_skb.skel.h"
  6
  7#define SYS(cmd) ({ \
  8	if (!ASSERT_OK(system(cmd), (cmd))) \
  9		goto out; \
 10})
 11
 12void test_empty_skb(void)
 13{
 14	LIBBPF_OPTS(bpf_test_run_opts, tattr);
 15	struct empty_skb *bpf_obj = NULL;
 16	struct nstoken *tok = NULL;
 17	struct bpf_program *prog;
 18	char eth_hlen_pp[15];
 19	char eth_hlen[14];
 20	int veth_ifindex;
 21	int ipip_ifindex;
 22	int err;
 23	int i;
 24
 25	struct {
 26		const char *msg;
 27		const void *data_in;
 28		__u32 data_size_in;
 29		int *ifindex;
 30		int err;
 31		int ret;
 32		bool success_on_tc;
 33	} tests[] = {
 34		/* Empty packets are always rejected. */
 35
 36		{
 37			/* BPF_PROG_RUN ETH_HLEN size check */
 38			.msg = "veth empty ingress packet",
 39			.data_in = NULL,
 40			.data_size_in = 0,
 41			.ifindex = &veth_ifindex,
 42			.err = -EINVAL,
 43		},
 44		{
 45			/* BPF_PROG_RUN ETH_HLEN size check */
 46			.msg = "ipip empty ingress packet",
 47			.data_in = NULL,
 48			.data_size_in = 0,
 49			.ifindex = &ipip_ifindex,
 50			.err = -EINVAL,
 51		},
 52
 53		/* ETH_HLEN-sized packets:
 54		 * - can not be redirected at LWT_XMIT
 55		 * - can be redirected at TC to non-tunneling dest
 56		 */
 57
 58		{
 59			/* __bpf_redirect_common */
 60			.msg = "veth ETH_HLEN packet ingress",
 61			.data_in = eth_hlen,
 62			.data_size_in = sizeof(eth_hlen),
 63			.ifindex = &veth_ifindex,
 64			.ret = -ERANGE,
 65			.success_on_tc = true,
 66		},
 67		{
 68			/* __bpf_redirect_no_mac
 69			 *
 70			 * lwt: skb->len=0 <= skb_network_offset=0
 71			 * tc: skb->len=14 <= skb_network_offset=14
 72			 */
 73			.msg = "ipip ETH_HLEN packet ingress",
 74			.data_in = eth_hlen,
 75			.data_size_in = sizeof(eth_hlen),
 76			.ifindex = &ipip_ifindex,
 77			.ret = -ERANGE,
 78		},
 79
 80		/* ETH_HLEN+1-sized packet should be redirected. */
 81
 82		{
 83			.msg = "veth ETH_HLEN+1 packet ingress",
 84			.data_in = eth_hlen_pp,
 85			.data_size_in = sizeof(eth_hlen_pp),
 86			.ifindex = &veth_ifindex,
 87		},
 88		{
 89			.msg = "ipip ETH_HLEN+1 packet ingress",
 90			.data_in = eth_hlen_pp,
 91			.data_size_in = sizeof(eth_hlen_pp),
 92			.ifindex = &ipip_ifindex,
 93		},
 94	};
 95
 96	SYS("ip netns add empty_skb");
 97	tok = open_netns("empty_skb");
 98	SYS("ip link add veth0 type veth peer veth1");
 99	SYS("ip link set dev veth0 up");
100	SYS("ip link set dev veth1 up");
101	SYS("ip addr add 10.0.0.1/8 dev veth0");
102	SYS("ip addr add 10.0.0.2/8 dev veth1");
103	veth_ifindex = if_nametoindex("veth0");
104
105	SYS("ip link add ipip0 type ipip local 10.0.0.1 remote 10.0.0.2");
106	SYS("ip link set ipip0 up");
107	SYS("ip addr add 192.168.1.1/16 dev ipip0");
108	ipip_ifindex = if_nametoindex("ipip0");
109
110	bpf_obj = empty_skb__open_and_load();
111	if (!ASSERT_OK_PTR(bpf_obj, "open skeleton"))
112		goto out;
113
114	for (i = 0; i < ARRAY_SIZE(tests); i++) {
115		bpf_object__for_each_program(prog, bpf_obj->obj) {
116			char buf[128];
117			bool at_tc = !strncmp(bpf_program__section_name(prog), "tc", 2);
118
119			tattr.data_in = tests[i].data_in;
120			tattr.data_size_in = tests[i].data_size_in;
121
122			tattr.data_size_out = 0;
123			bpf_obj->bss->ifindex = *tests[i].ifindex;
124			bpf_obj->bss->ret = 0;
125			err = bpf_prog_test_run_opts(bpf_program__fd(prog), &tattr);
126			sprintf(buf, "err: %s [%s]", tests[i].msg, bpf_program__name(prog));
127
128			if (at_tc && tests[i].success_on_tc)
129				ASSERT_GE(err, 0, buf);
130			else
131				ASSERT_EQ(err, tests[i].err, buf);
132			sprintf(buf, "ret: %s [%s]", tests[i].msg, bpf_program__name(prog));
133			if (at_tc && tests[i].success_on_tc)
134				ASSERT_GE(bpf_obj->bss->ret, 0, buf);
135			else
136				ASSERT_EQ(bpf_obj->bss->ret, tests[i].ret, buf);
137		}
138	}
139
140out:
141	if (bpf_obj)
142		empty_skb__destroy(bpf_obj);
143	if (tok)
144		close_netns(tok);
145	system("ip netns del empty_skb");
146}