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1// SPDX-License-Identifier: GPL-2.0
2
3#define _GNU_SOURCE
4
5#include <errno.h>
6#include <fcntl.h>
7#include <stdio.h>
8#include <stdlib.h>
9#include <string.h>
10#include <unistd.h>
11#include <net/if.h>
12#include <linux/if_tun.h>
13#include <linux/netlink.h>
14#include <linux/rtnetlink.h>
15#include <sys/ioctl.h>
16#include <sys/socket.h>
17#include <linux/virtio_net.h>
18#include <netinet/ip.h>
19#include <netinet/udp.h>
20#include "kselftest_harness.h"
21
22static const char param_dev_tap_name[] = "xmacvtap0";
23static const char param_dev_dummy_name[] = "xdummy0";
24static unsigned char param_hwaddr_src[] = { 0x00, 0xfe, 0x98, 0x14, 0x22, 0x42 };
25static unsigned char param_hwaddr_dest[] = {
26 0x00, 0xfe, 0x98, 0x94, 0xd2, 0x43
27};
28
29#define MAX_RTNL_PAYLOAD (2048)
30#define PKT_DATA 0xCB
31#define TEST_PACKET_SZ (sizeof(struct virtio_net_hdr) + ETH_HLEN + ETH_MAX_MTU)
32
33static struct rtattr *rtattr_add(struct nlmsghdr *nh, unsigned short type,
34 unsigned short len)
35{
36 struct rtattr *rta =
37 (struct rtattr *)((uint8_t *)nh + RTA_ALIGN(nh->nlmsg_len));
38 rta->rta_type = type;
39 rta->rta_len = RTA_LENGTH(len);
40 nh->nlmsg_len = RTA_ALIGN(nh->nlmsg_len) + RTA_ALIGN(rta->rta_len);
41 return rta;
42}
43
44static struct rtattr *rtattr_begin(struct nlmsghdr *nh, unsigned short type)
45{
46 return rtattr_add(nh, type, 0);
47}
48
49static void rtattr_end(struct nlmsghdr *nh, struct rtattr *attr)
50{
51 uint8_t *end = (uint8_t *)nh + nh->nlmsg_len;
52
53 attr->rta_len = end - (uint8_t *)attr;
54}
55
56static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short type,
57 const char *s)
58{
59 unsigned int strsz = strlen(s) + 1;
60 struct rtattr *rta;
61
62 rta = rtattr_add(nh, type, strsz);
63
64 memcpy(RTA_DATA(rta), s, strsz);
65 return rta;
66}
67
68static struct rtattr *rtattr_add_any(struct nlmsghdr *nh, unsigned short type,
69 const void *arr, size_t len)
70{
71 struct rtattr *rta = rtattr_add(nh, type, len);
72
73 memcpy(RTA_DATA(rta), arr, len);
74 return rta;
75}
76
77static int dev_create(const char *dev, const char *link_type,
78 int (*fill_rtattr)(struct nlmsghdr *nh),
79 int (*fill_info_data)(struct nlmsghdr *nh))
80{
81 struct {
82 struct nlmsghdr nh;
83 struct ifinfomsg info;
84 unsigned char data[MAX_RTNL_PAYLOAD];
85 } req;
86 struct rtattr *link_info, *info_data;
87 int ret, rtnl;
88
89 rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
90 if (rtnl < 0) {
91 fprintf(stderr, "%s: socket %s\n", __func__, strerror(errno));
92 return 1;
93 }
94
95 memset(&req, 0, sizeof(req));
96 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.info));
97 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE;
98 req.nh.nlmsg_type = RTM_NEWLINK;
99
100 req.info.ifi_family = AF_UNSPEC;
101 req.info.ifi_type = 1;
102 req.info.ifi_index = 0;
103 req.info.ifi_flags = IFF_BROADCAST | IFF_UP;
104 req.info.ifi_change = 0xffffffff;
105
106 rtattr_add_str(&req.nh, IFLA_IFNAME, dev);
107
108 if (fill_rtattr) {
109 ret = fill_rtattr(&req.nh);
110 if (ret)
111 return ret;
112 }
113
114 link_info = rtattr_begin(&req.nh, IFLA_LINKINFO);
115
116 rtattr_add_str(&req.nh, IFLA_INFO_KIND, link_type);
117
118 if (fill_info_data) {
119 info_data = rtattr_begin(&req.nh, IFLA_INFO_DATA);
120 ret = fill_info_data(&req.nh);
121 if (ret)
122 return ret;
123 rtattr_end(&req.nh, info_data);
124 }
125
126 rtattr_end(&req.nh, link_info);
127
128 ret = send(rtnl, &req, req.nh.nlmsg_len, 0);
129 if (ret < 0)
130 fprintf(stderr, "%s: send %s\n", __func__, strerror(errno));
131 ret = (unsigned int)ret != req.nh.nlmsg_len;
132
133 close(rtnl);
134 return ret;
135}
136
137static int dev_delete(const char *dev)
138{
139 struct {
140 struct nlmsghdr nh;
141 struct ifinfomsg info;
142 unsigned char data[MAX_RTNL_PAYLOAD];
143 } req;
144 int ret, rtnl;
145
146 rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
147 if (rtnl < 0) {
148 fprintf(stderr, "%s: socket %s\n", __func__, strerror(errno));
149 return 1;
150 }
151
152 memset(&req, 0, sizeof(req));
153 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.info));
154 req.nh.nlmsg_flags = NLM_F_REQUEST;
155 req.nh.nlmsg_type = RTM_DELLINK;
156
157 req.info.ifi_family = AF_UNSPEC;
158
159 rtattr_add_str(&req.nh, IFLA_IFNAME, dev);
160
161 ret = send(rtnl, &req, req.nh.nlmsg_len, 0);
162 if (ret < 0)
163 fprintf(stderr, "%s: send %s\n", __func__, strerror(errno));
164
165 ret = (unsigned int)ret != req.nh.nlmsg_len;
166
167 close(rtnl);
168 return ret;
169}
170
171static int macvtap_fill_rtattr(struct nlmsghdr *nh)
172{
173 int ifindex;
174
175 ifindex = if_nametoindex(param_dev_dummy_name);
176 if (ifindex == 0) {
177 fprintf(stderr, "%s: ifindex %s\n", __func__, strerror(errno));
178 return -errno;
179 }
180
181 rtattr_add_any(nh, IFLA_LINK, &ifindex, sizeof(ifindex));
182 rtattr_add_any(nh, IFLA_ADDRESS, param_hwaddr_src, ETH_ALEN);
183
184 return 0;
185}
186
187static int opentap(const char *devname)
188{
189 int ifindex;
190 char buf[256];
191 int fd;
192 struct ifreq ifr;
193
194 ifindex = if_nametoindex(devname);
195 if (ifindex == 0) {
196 fprintf(stderr, "%s: ifindex %s\n", __func__, strerror(errno));
197 return -errno;
198 }
199
200 sprintf(buf, "/dev/tap%d", ifindex);
201 fd = open(buf, O_RDWR | O_NONBLOCK);
202 if (fd < 0) {
203 fprintf(stderr, "%s: open %s\n", __func__, strerror(errno));
204 return -errno;
205 }
206
207 memset(&ifr, 0, sizeof(ifr));
208 strcpy(ifr.ifr_name, devname);
209 ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR | IFF_MULTI_QUEUE;
210 if (ioctl(fd, TUNSETIFF, &ifr, sizeof(ifr)) < 0)
211 return -errno;
212 return fd;
213}
214
215size_t build_eth(uint8_t *buf, uint16_t proto)
216{
217 struct ethhdr *eth = (struct ethhdr *)buf;
218
219 eth->h_proto = htons(proto);
220 memcpy(eth->h_source, param_hwaddr_src, ETH_ALEN);
221 memcpy(eth->h_dest, param_hwaddr_dest, ETH_ALEN);
222
223 return ETH_HLEN;
224}
225
226static uint32_t add_csum(const uint8_t *buf, int len)
227{
228 uint32_t sum = 0;
229 uint16_t *sbuf = (uint16_t *)buf;
230
231 while (len > 1) {
232 sum += *sbuf++;
233 len -= 2;
234 }
235
236 if (len)
237 sum += *(uint8_t *)sbuf;
238
239 return sum;
240}
241
242static uint16_t finish_ip_csum(uint32_t sum)
243{
244 uint16_t lo = sum & 0xffff;
245 uint16_t hi = sum >> 16;
246
247 return ~(lo + hi);
248
249}
250
251static uint16_t build_ip_csum(const uint8_t *buf, int len,
252 uint32_t sum)
253{
254 sum += add_csum(buf, len);
255 return finish_ip_csum(sum);
256}
257
258static int build_ipv4_header(uint8_t *buf, int payload_len)
259{
260 struct iphdr *iph = (struct iphdr *)buf;
261
262 iph->ihl = 5;
263 iph->version = 4;
264 iph->ttl = 8;
265 iph->tot_len =
266 htons(sizeof(*iph) + sizeof(struct udphdr) + payload_len);
267 iph->id = htons(1337);
268 iph->protocol = IPPROTO_UDP;
269 iph->saddr = htonl((172 << 24) | (17 << 16) | 2);
270 iph->daddr = htonl((172 << 24) | (17 << 16) | 1);
271 iph->check = build_ip_csum(buf, iph->ihl << 2, 0);
272
273 return iph->ihl << 2;
274}
275
276static int build_udp_packet(uint8_t *buf, int payload_len, bool csum_off)
277{
278 const int ip4alen = sizeof(uint32_t);
279 struct udphdr *udph = (struct udphdr *)buf;
280 int len = sizeof(*udph) + payload_len;
281 uint32_t sum = 0;
282
283 udph->source = htons(22);
284 udph->dest = htons(58822);
285 udph->len = htons(len);
286
287 memset(buf + sizeof(struct udphdr), PKT_DATA, payload_len);
288
289 sum = add_csum(buf - 2 * ip4alen, 2 * ip4alen);
290 sum += htons(IPPROTO_UDP) + udph->len;
291
292 if (!csum_off)
293 sum += add_csum(buf, len);
294
295 udph->check = finish_ip_csum(sum);
296
297 return sizeof(*udph) + payload_len;
298}
299
300size_t build_test_packet_valid_udp_gso(uint8_t *buf, size_t payload_len)
301{
302 uint8_t *cur = buf;
303 struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf;
304
305 vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr);
306 vh->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
307 vh->csum_start = ETH_HLEN + sizeof(struct iphdr);
308 vh->csum_offset = __builtin_offsetof(struct udphdr, check);
309 vh->gso_type = VIRTIO_NET_HDR_GSO_UDP;
310 vh->gso_size = ETH_DATA_LEN - sizeof(struct iphdr);
311 cur += sizeof(*vh);
312
313 cur += build_eth(cur, ETH_P_IP);
314 cur += build_ipv4_header(cur, payload_len);
315 cur += build_udp_packet(cur, payload_len, true);
316
317 return cur - buf;
318}
319
320size_t build_test_packet_valid_udp_csum(uint8_t *buf, size_t payload_len)
321{
322 uint8_t *cur = buf;
323 struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf;
324
325 vh->flags = VIRTIO_NET_HDR_F_DATA_VALID;
326 vh->gso_type = VIRTIO_NET_HDR_GSO_NONE;
327 cur += sizeof(*vh);
328
329 cur += build_eth(cur, ETH_P_IP);
330 cur += build_ipv4_header(cur, payload_len);
331 cur += build_udp_packet(cur, payload_len, false);
332
333 return cur - buf;
334}
335
336size_t build_test_packet_crash_tap_invalid_eth_proto(uint8_t *buf,
337 size_t payload_len)
338{
339 uint8_t *cur = buf;
340 struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf;
341
342 vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr);
343 vh->flags = 0;
344 vh->gso_type = VIRTIO_NET_HDR_GSO_UDP;
345 vh->gso_size = ETH_DATA_LEN - sizeof(struct iphdr);
346 cur += sizeof(*vh);
347
348 cur += build_eth(cur, 0);
349 cur += sizeof(struct iphdr) + sizeof(struct udphdr);
350 cur += build_ipv4_header(cur, payload_len);
351 cur += build_udp_packet(cur, payload_len, true);
352 cur += payload_len;
353
354 return cur - buf;
355}
356
357FIXTURE(tap)
358{
359 int fd;
360};
361
362FIXTURE_SETUP(tap)
363{
364 int ret;
365
366 ret = dev_create(param_dev_dummy_name, "dummy", NULL, NULL);
367 EXPECT_EQ(ret, 0);
368
369 ret = dev_create(param_dev_tap_name, "macvtap", macvtap_fill_rtattr,
370 NULL);
371 EXPECT_EQ(ret, 0);
372
373 self->fd = opentap(param_dev_tap_name);
374 ASSERT_GE(self->fd, 0);
375}
376
377FIXTURE_TEARDOWN(tap)
378{
379 int ret;
380
381 if (self->fd != -1)
382 close(self->fd);
383
384 ret = dev_delete(param_dev_tap_name);
385 EXPECT_EQ(ret, 0);
386
387 ret = dev_delete(param_dev_dummy_name);
388 EXPECT_EQ(ret, 0);
389}
390
391TEST_F(tap, test_packet_valid_udp_gso)
392{
393 uint8_t pkt[TEST_PACKET_SZ];
394 size_t off;
395 int ret;
396
397 memset(pkt, 0, sizeof(pkt));
398 off = build_test_packet_valid_udp_gso(pkt, 1021);
399 ret = write(self->fd, pkt, off);
400 ASSERT_EQ(ret, off);
401}
402
403TEST_F(tap, test_packet_valid_udp_csum)
404{
405 uint8_t pkt[TEST_PACKET_SZ];
406 size_t off;
407 int ret;
408
409 memset(pkt, 0, sizeof(pkt));
410 off = build_test_packet_valid_udp_csum(pkt, 1024);
411 ret = write(self->fd, pkt, off);
412 ASSERT_EQ(ret, off);
413}
414
415TEST_F(tap, test_packet_crash_tap_invalid_eth_proto)
416{
417 uint8_t pkt[TEST_PACKET_SZ];
418 size_t off;
419 int ret;
420
421 memset(pkt, 0, sizeof(pkt));
422 off = build_test_packet_crash_tap_invalid_eth_proto(pkt, 1024);
423 ret = write(self->fd, pkt, off);
424 ASSERT_EQ(ret, -1);
425 ASSERT_EQ(errno, EINVAL);
426}
427
428TEST_HARNESS_MAIN