1 // SPDX-License-Identifier: GPL-2.0
2
3 #define _GNU_SOURCE
4
5 #include <arpa/inet.h>
6 #include <errno.h>
7 #include <error.h>
8 #include <fcntl.h>
9 #include <limits.h>
10 #include <linux/filter.h>
11 #include <linux/bpf.h>
12 #include <linux/if_packet.h>
13 #include <linux/if_vlan.h>
14 #include <linux/virtio_net.h>
15 #include <net/if.h>
16 #include <net/ethernet.h>
17 #include <netinet/ip.h>
18 #include <netinet/udp.h>
19 #include <poll.h>
20 #include <sched.h>
21 #include <stdbool.h>
22 #include <stdint.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/mman.h>
27 #include <sys/socket.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <unistd.h>
31
32 #include "psock_lib.h"
33
34 static bool cfg_use_bind;
35 static bool cfg_use_csum_off;
36 static bool cfg_use_csum_off_bad;
37 static bool cfg_use_dgram;
38 static bool cfg_use_gso;
39 static bool cfg_use_qdisc_bypass;
40 static bool cfg_use_vlan;
41 static bool cfg_use_vnet;
42
43 static char *cfg_ifname = "lo";
44 static int cfg_mtu = 1500;
45 static int cfg_payload_len = DATA_LEN;
46 static int cfg_truncate_len = INT_MAX;
47 static uint16_t cfg_port = 8000;
48
49 /* test sending up to max mtu + 1 */
50 #define TEST_SZ (sizeof(struct virtio_net_hdr) + ETH_HLEN + ETH_MAX_MTU + 1)
51
52 static char tbuf[TEST_SZ], rbuf[TEST_SZ];
53
add_csum_hword(const uint16_t * start,int num_u16)54 static unsigned long add_csum_hword(const uint16_t *start, int num_u16)
55 {
56 unsigned long sum = 0;
57 int i;
58
59 for (i = 0; i < num_u16; i++)
60 sum += start[i];
61
62 return sum;
63 }
64
build_ip_csum(const uint16_t * start,int num_u16,unsigned long sum)65 static uint16_t build_ip_csum(const uint16_t *start, int num_u16,
66 unsigned long sum)
67 {
68 sum += add_csum_hword(start, num_u16);
69
70 while (sum >> 16)
71 sum = (sum & 0xffff) + (sum >> 16);
72
73 return ~sum;
74 }
75
build_vnet_header(void * header)76 static int build_vnet_header(void *header)
77 {
78 struct virtio_net_hdr *vh = header;
79
80 vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr);
81
82 if (cfg_use_csum_off) {
83 vh->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
84 vh->csum_start = ETH_HLEN + sizeof(struct iphdr);
85 vh->csum_offset = __builtin_offsetof(struct udphdr, check);
86
87 /* position check field exactly one byte beyond end of packet */
88 if (cfg_use_csum_off_bad)
89 vh->csum_start += sizeof(struct udphdr) + cfg_payload_len -
90 vh->csum_offset - 1;
91 }
92
93 if (cfg_use_gso) {
94 vh->gso_type = VIRTIO_NET_HDR_GSO_UDP;
95 vh->gso_size = cfg_mtu - sizeof(struct iphdr);
96 }
97
98 return sizeof(*vh);
99 }
100
build_eth_header(void * header)101 static int build_eth_header(void *header)
102 {
103 struct ethhdr *eth = header;
104
105 if (cfg_use_vlan) {
106 uint16_t *tag = header + ETH_HLEN;
107
108 eth->h_proto = htons(ETH_P_8021Q);
109 tag[1] = htons(ETH_P_IP);
110 return ETH_HLEN + 4;
111 }
112
113 eth->h_proto = htons(ETH_P_IP);
114 return ETH_HLEN;
115 }
116
build_ipv4_header(void * header,int payload_len)117 static int build_ipv4_header(void *header, int payload_len)
118 {
119 struct iphdr *iph = header;
120
121 iph->ihl = 5;
122 iph->version = 4;
123 iph->ttl = 8;
124 iph->tot_len = htons(sizeof(*iph) + sizeof(struct udphdr) + payload_len);
125 iph->id = htons(1337);
126 iph->protocol = IPPROTO_UDP;
127 iph->saddr = htonl((172 << 24) | (17 << 16) | 2);
128 iph->daddr = htonl((172 << 24) | (17 << 16) | 1);
129 iph->check = build_ip_csum((void *) iph, iph->ihl << 1, 0);
130
131 return iph->ihl << 2;
132 }
133
build_udp_header(void * header,int payload_len)134 static int build_udp_header(void *header, int payload_len)
135 {
136 const int alen = sizeof(uint32_t);
137 struct udphdr *udph = header;
138 int len = sizeof(*udph) + payload_len;
139
140 udph->source = htons(9);
141 udph->dest = htons(cfg_port);
142 udph->len = htons(len);
143
144 if (cfg_use_csum_off)
145 udph->check = build_ip_csum(header - (2 * alen), alen,
146 htons(IPPROTO_UDP) + udph->len);
147 else
148 udph->check = 0;
149
150 return sizeof(*udph);
151 }
152
build_packet(int payload_len)153 static int build_packet(int payload_len)
154 {
155 int off = 0;
156
157 off += build_vnet_header(tbuf);
158 off += build_eth_header(tbuf + off);
159 off += build_ipv4_header(tbuf + off, payload_len);
160 off += build_udp_header(tbuf + off, payload_len);
161
162 if (off + payload_len > sizeof(tbuf))
163 error(1, 0, "payload length exceeds max");
164
165 memset(tbuf + off, DATA_CHAR, payload_len);
166
167 return off + payload_len;
168 }
169
do_bind(int fd)170 static void do_bind(int fd)
171 {
172 struct sockaddr_ll laddr = {0};
173
174 laddr.sll_family = AF_PACKET;
175 laddr.sll_protocol = htons(ETH_P_IP);
176 laddr.sll_ifindex = if_nametoindex(cfg_ifname);
177 if (!laddr.sll_ifindex)
178 error(1, errno, "if_nametoindex");
179
180 if (bind(fd, (void *)&laddr, sizeof(laddr)))
181 error(1, errno, "bind");
182 }
183
do_send(int fd,char * buf,int len)184 static void do_send(int fd, char *buf, int len)
185 {
186 int ret;
187
188 if (!cfg_use_vnet) {
189 buf += sizeof(struct virtio_net_hdr);
190 len -= sizeof(struct virtio_net_hdr);
191 }
192 if (cfg_use_dgram) {
193 buf += ETH_HLEN;
194 len -= ETH_HLEN;
195 }
196
197 if (cfg_use_bind) {
198 ret = write(fd, buf, len);
199 } else {
200 struct sockaddr_ll laddr = {0};
201
202 laddr.sll_protocol = htons(ETH_P_IP);
203 laddr.sll_ifindex = if_nametoindex(cfg_ifname);
204 if (!laddr.sll_ifindex)
205 error(1, errno, "if_nametoindex");
206
207 ret = sendto(fd, buf, len, 0, (void *)&laddr, sizeof(laddr));
208 }
209
210 if (ret == -1)
211 error(1, errno, "write");
212 if (ret != len)
213 error(1, 0, "write: %u %u", ret, len);
214
215 fprintf(stderr, "tx: %u\n", ret);
216 }
217
do_tx(void)218 static int do_tx(void)
219 {
220 const int one = 1;
221 int fd, len;
222
223 fd = socket(PF_PACKET, cfg_use_dgram ? SOCK_DGRAM : SOCK_RAW, 0);
224 if (fd == -1)
225 error(1, errno, "socket t");
226
227 if (cfg_use_bind)
228 do_bind(fd);
229
230 if (cfg_use_qdisc_bypass &&
231 setsockopt(fd, SOL_PACKET, PACKET_QDISC_BYPASS, &one, sizeof(one)))
232 error(1, errno, "setsockopt qdisc bypass");
233
234 if (cfg_use_vnet &&
235 setsockopt(fd, SOL_PACKET, PACKET_VNET_HDR, &one, sizeof(one)))
236 error(1, errno, "setsockopt vnet");
237
238 len = build_packet(cfg_payload_len);
239
240 if (cfg_truncate_len < len)
241 len = cfg_truncate_len;
242
243 do_send(fd, tbuf, len);
244
245 if (close(fd))
246 error(1, errno, "close t");
247
248 return len;
249 }
250
setup_rx(void)251 static int setup_rx(void)
252 {
253 struct timeval tv = { .tv_usec = 100 * 1000 };
254 struct sockaddr_in raddr = {0};
255 int fd;
256
257 fd = socket(PF_INET, SOCK_DGRAM, 0);
258 if (fd == -1)
259 error(1, errno, "socket r");
260
261 if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)))
262 error(1, errno, "setsockopt rcv timeout");
263
264 raddr.sin_family = AF_INET;
265 raddr.sin_port = htons(cfg_port);
266 raddr.sin_addr.s_addr = htonl(INADDR_ANY);
267
268 if (bind(fd, (void *)&raddr, sizeof(raddr)))
269 error(1, errno, "bind r");
270
271 return fd;
272 }
273
do_rx(int fd,int expected_len,char * expected)274 static void do_rx(int fd, int expected_len, char *expected)
275 {
276 int ret;
277
278 ret = recv(fd, rbuf, sizeof(rbuf), 0);
279 if (ret == -1)
280 error(1, errno, "recv");
281 if (ret != expected_len)
282 error(1, 0, "recv: %u != %u", ret, expected_len);
283
284 if (memcmp(rbuf, expected, ret))
285 error(1, 0, "recv: data mismatch");
286
287 fprintf(stderr, "rx: %u\n", ret);
288 }
289
setup_sniffer(void)290 static int setup_sniffer(void)
291 {
292 struct timeval tv = { .tv_usec = 100 * 1000 };
293 int fd;
294
295 fd = socket(PF_PACKET, SOCK_RAW, 0);
296 if (fd == -1)
297 error(1, errno, "socket p");
298
299 if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)))
300 error(1, errno, "setsockopt rcv timeout");
301
302 pair_udp_setfilter(fd);
303 do_bind(fd);
304
305 return fd;
306 }
307
parse_opts(int argc,char ** argv)308 static void parse_opts(int argc, char **argv)
309 {
310 int c;
311
312 while ((c = getopt(argc, argv, "bcCdgl:qt:vV")) != -1) {
313 switch (c) {
314 case 'b':
315 cfg_use_bind = true;
316 break;
317 case 'c':
318 cfg_use_csum_off = true;
319 break;
320 case 'C':
321 cfg_use_csum_off_bad = true;
322 break;
323 case 'd':
324 cfg_use_dgram = true;
325 break;
326 case 'g':
327 cfg_use_gso = true;
328 break;
329 case 'l':
330 cfg_payload_len = strtoul(optarg, NULL, 0);
331 break;
332 case 'q':
333 cfg_use_qdisc_bypass = true;
334 break;
335 case 't':
336 cfg_truncate_len = strtoul(optarg, NULL, 0);
337 break;
338 case 'v':
339 cfg_use_vnet = true;
340 break;
341 case 'V':
342 cfg_use_vlan = true;
343 break;
344 default:
345 error(1, 0, "%s: parse error", argv[0]);
346 }
347 }
348
349 if (cfg_use_vlan && cfg_use_dgram)
350 error(1, 0, "option vlan (-V) conflicts with dgram (-d)");
351
352 if (cfg_use_csum_off && !cfg_use_vnet)
353 error(1, 0, "option csum offload (-c) requires vnet (-v)");
354
355 if (cfg_use_csum_off_bad && !cfg_use_csum_off)
356 error(1, 0, "option csum bad (-C) requires csum offload (-c)");
357
358 if (cfg_use_gso && !cfg_use_csum_off)
359 error(1, 0, "option gso (-g) requires csum offload (-c)");
360 }
361
run_test(void)362 static void run_test(void)
363 {
364 int fdr, fds, total_len;
365
366 fdr = setup_rx();
367 fds = setup_sniffer();
368
369 total_len = do_tx();
370
371 /* BPF filter accepts only this length, vlan changes MAC */
372 if (cfg_payload_len == DATA_LEN && !cfg_use_vlan)
373 do_rx(fds, total_len - sizeof(struct virtio_net_hdr),
374 tbuf + sizeof(struct virtio_net_hdr));
375
376 do_rx(fdr, cfg_payload_len, tbuf + total_len - cfg_payload_len);
377
378 if (close(fds))
379 error(1, errno, "close s");
380 if (close(fdr))
381 error(1, errno, "close r");
382 }
383
main(int argc,char ** argv)384 int main(int argc, char **argv)
385 {
386 parse_opts(argc, argv);
387
388 if (system("ip link set dev lo mtu 1500"))
389 error(1, errno, "ip link set mtu");
390 if (system("ip addr add dev lo 172.17.0.1/24"))
391 error(1, errno, "ip addr add");
392 if (system("sysctl -w net.ipv4.conf.lo.accept_local=1"))
393 error(1, errno, "sysctl lo.accept_local");
394
395 run_test();
396
397 fprintf(stderr, "OK\n\n");
398 return 0;
399 }
400