1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <stdbool.h>
4 #include <linux/bpf.h>
5 #include <linux/netdev.h>
6 #include <bpf/bpf_helpers.h>
7 #include <bpf/bpf_endian.h>
8 #include <bpf/bpf_tracing.h>
9 #include <linux/if_ether.h>
10 #include <linux/ip.h>
11 #include <linux/ipv6.h>
12 #include <linux/in.h>
13 #include <linux/in6.h>
14 #include <linux/udp.h>
15 #include <asm-generic/errno-base.h>
16 
17 #include "xdp_features.h"
18 
19 #define ipv6_addr_equal(a, b)	((a).s6_addr32[0] == (b).s6_addr32[0] &&	\
20 				 (a).s6_addr32[1] == (b).s6_addr32[1] &&	\
21 				 (a).s6_addr32[2] == (b).s6_addr32[2] &&	\
22 				 (a).s6_addr32[3] == (b).s6_addr32[3])
23 
24 struct net_device;
25 struct bpf_prog;
26 
27 struct xdp_cpumap_stats {
28 	unsigned int redirect;
29 	unsigned int pass;
30 	unsigned int drop;
31 };
32 
33 struct {
34 	__uint(type, BPF_MAP_TYPE_ARRAY);
35 	__type(key, __u32);
36 	__type(value, __u32);
37 	__uint(max_entries, 1);
38 } stats SEC(".maps");
39 
40 struct {
41 	__uint(type, BPF_MAP_TYPE_ARRAY);
42 	__type(key, __u32);
43 	__type(value, __u32);
44 	__uint(max_entries, 1);
45 } dut_stats SEC(".maps");
46 
47 struct {
48 	__uint(type, BPF_MAP_TYPE_CPUMAP);
49 	__uint(key_size, sizeof(__u32));
50 	__uint(value_size, sizeof(struct bpf_cpumap_val));
51 	__uint(max_entries, 1);
52 } cpu_map SEC(".maps");
53 
54 struct {
55 	__uint(type, BPF_MAP_TYPE_DEVMAP);
56 	__uint(key_size, sizeof(__u32));
57 	__uint(value_size, sizeof(struct bpf_devmap_val));
58 	__uint(max_entries, 1);
59 } dev_map SEC(".maps");
60 
61 const volatile struct in6_addr tester_addr;
62 const volatile struct in6_addr dut_addr;
63 
64 static __always_inline int
65 xdp_process_echo_packet(struct xdp_md *xdp, bool dut)
66 {
67 	void *data_end = (void *)(long)xdp->data_end;
68 	void *data = (void *)(long)xdp->data;
69 	struct ethhdr *eh = data;
70 	struct tlv_hdr *tlv;
71 	struct udphdr *uh;
72 	__be16 port;
73 	__u8 *cmd;
74 
75 	if (eh + 1 > (struct ethhdr *)data_end)
76 		return -EINVAL;
77 
78 	if (eh->h_proto == bpf_htons(ETH_P_IP)) {
79 		struct iphdr *ih = (struct iphdr *)(eh + 1);
80 		__be32 saddr = dut ? tester_addr.s6_addr32[3]
81 				   : dut_addr.s6_addr32[3];
82 		__be32 daddr = dut ? dut_addr.s6_addr32[3]
83 				   : tester_addr.s6_addr32[3];
84 
85 		ih = (struct iphdr *)(eh + 1);
86 		if (ih + 1 > (struct iphdr *)data_end)
87 			return -EINVAL;
88 
89 		if (saddr != ih->saddr)
90 			return -EINVAL;
91 
92 		if (daddr != ih->daddr)
93 			return -EINVAL;
94 
95 		if (ih->protocol != IPPROTO_UDP)
96 			return -EINVAL;
97 
98 		uh = (struct udphdr *)(ih + 1);
99 	} else if (eh->h_proto == bpf_htons(ETH_P_IPV6)) {
100 		struct in6_addr saddr = dut ? tester_addr : dut_addr;
101 		struct in6_addr daddr = dut ? dut_addr : tester_addr;
102 		struct ipv6hdr *ih6 = (struct ipv6hdr *)(eh + 1);
103 
104 		if (ih6 + 1 > (struct ipv6hdr *)data_end)
105 			return -EINVAL;
106 
107 		if (!ipv6_addr_equal(saddr, ih6->saddr))
108 			return -EINVAL;
109 
110 		if (!ipv6_addr_equal(daddr, ih6->daddr))
111 			return -EINVAL;
112 
113 		if (ih6->nexthdr != IPPROTO_UDP)
114 			return -EINVAL;
115 
116 		uh = (struct udphdr *)(ih6 + 1);
117 	} else {
118 		return -EINVAL;
119 	}
120 
121 	if (uh + 1 > (struct udphdr *)data_end)
122 		return -EINVAL;
123 
124 	port = dut ? uh->dest : uh->source;
125 	if (port != bpf_htons(DUT_ECHO_PORT))
126 		return -EINVAL;
127 
128 	tlv = (struct tlv_hdr *)(uh + 1);
129 	if (tlv + 1 > data_end)
130 		return -EINVAL;
131 
132 	return bpf_htons(tlv->type) == CMD_ECHO ? 0 : -EINVAL;
133 }
134 
135 static __always_inline int
136 xdp_update_stats(struct xdp_md *xdp, bool tx, bool dut)
137 {
138 	__u32 *val, key = 0;
139 
140 	if (xdp_process_echo_packet(xdp, tx))
141 		return -EINVAL;
142 
143 	if (dut)
144 		val = bpf_map_lookup_elem(&dut_stats, &key);
145 	else
146 		val = bpf_map_lookup_elem(&stats, &key);
147 
148 	if (val)
149 		__sync_add_and_fetch(val, 1);
150 
151 	return 0;
152 }
153 
154 /* Tester */
155 
156 SEC("xdp")
157 int xdp_tester_check_tx(struct xdp_md *xdp)
158 {
159 	xdp_update_stats(xdp, true, false);
160 
161 	return XDP_PASS;
162 }
163 
164 SEC("xdp")
165 int xdp_tester_check_rx(struct xdp_md *xdp)
166 {
167 	xdp_update_stats(xdp, false, false);
168 
169 	return XDP_PASS;
170 }
171 
172 /* DUT */
173 
174 SEC("xdp")
175 int xdp_do_pass(struct xdp_md *xdp)
176 {
177 	xdp_update_stats(xdp, true, true);
178 
179 	return XDP_PASS;
180 }
181 
182 SEC("xdp")
183 int xdp_do_drop(struct xdp_md *xdp)
184 {
185 	if (xdp_update_stats(xdp, true, true))
186 		return XDP_PASS;
187 
188 	return XDP_DROP;
189 }
190 
191 SEC("xdp")
192 int xdp_do_aborted(struct xdp_md *xdp)
193 {
194 	if (xdp_process_echo_packet(xdp, true))
195 		return XDP_PASS;
196 
197 	return XDP_ABORTED;
198 }
199 
200 SEC("xdp")
201 int xdp_do_tx(struct xdp_md *xdp)
202 {
203 	void *data = (void *)(long)xdp->data;
204 	struct ethhdr *eh = data;
205 	__u8 tmp_mac[ETH_ALEN];
206 
207 	if (xdp_update_stats(xdp, true, true))
208 		return XDP_PASS;
209 
210 	__builtin_memcpy(tmp_mac, eh->h_source, ETH_ALEN);
211 	__builtin_memcpy(eh->h_source, eh->h_dest, ETH_ALEN);
212 	__builtin_memcpy(eh->h_dest, tmp_mac, ETH_ALEN);
213 
214 	return XDP_TX;
215 }
216 
217 SEC("xdp")
218 int xdp_do_redirect(struct xdp_md *xdp)
219 {
220 	if (xdp_process_echo_packet(xdp, true))
221 		return XDP_PASS;
222 
223 	return bpf_redirect_map(&cpu_map, 0, 0);
224 }
225 
226 SEC("tp_btf/xdp_exception")
227 int BPF_PROG(xdp_exception, const struct net_device *dev,
228 	     const struct bpf_prog *xdp, __u32 act)
229 {
230 	__u32 *val, key = 0;
231 
232 	val = bpf_map_lookup_elem(&dut_stats, &key);
233 	if (val)
234 		__sync_add_and_fetch(val, 1);
235 
236 	return 0;
237 }
238 
239 SEC("tp_btf/xdp_cpumap_kthread")
240 int BPF_PROG(tp_xdp_cpumap_kthread, int map_id, unsigned int processed,
241 	     unsigned int drops, int sched, struct xdp_cpumap_stats *xdp_stats)
242 {
243 	__u32 *val, key = 0;
244 
245 	val = bpf_map_lookup_elem(&dut_stats, &key);
246 	if (val)
247 		__sync_add_and_fetch(val, 1);
248 
249 	return 0;
250 }
251 
252 SEC("xdp/cpumap")
253 int xdp_do_redirect_cpumap(struct xdp_md *xdp)
254 {
255 	void *data = (void *)(long)xdp->data;
256 	struct ethhdr *eh = data;
257 	__u8 tmp_mac[ETH_ALEN];
258 
259 	if (xdp_process_echo_packet(xdp, true))
260 		return XDP_PASS;
261 
262 	__builtin_memcpy(tmp_mac, eh->h_source, ETH_ALEN);
263 	__builtin_memcpy(eh->h_source, eh->h_dest, ETH_ALEN);
264 	__builtin_memcpy(eh->h_dest, tmp_mac, ETH_ALEN);
265 
266 	return bpf_redirect_map(&dev_map, 0, 0);
267 }
268 
269 char _license[] SEC("license") = "GPL";
270