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 | |
22 | static const char param_dev_tap_name[] = "xmacvtap0" ; |
23 | static const char param_dev_dummy_name[] = "xdummy0" ; |
24 | static unsigned char param_hwaddr_src[] = { 0x00, 0xfe, 0x98, 0x14, 0x22, 0x42 }; |
25 | static 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 | |
33 | static 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 | |
44 | static struct rtattr *rtattr_begin(struct nlmsghdr *nh, unsigned short type) |
45 | { |
46 | return rtattr_add(nh, type, len: 0); |
47 | } |
48 | |
49 | static 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 | |
56 | static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short type, |
57 | const char *s) |
58 | { |
59 | struct rtattr *rta = rtattr_add(nh, type, strlen(s)); |
60 | |
61 | memcpy(RTA_DATA(rta), s, strlen(s)); |
62 | return rta; |
63 | } |
64 | |
65 | static struct rtattr *rtattr_add_strsz(struct nlmsghdr *nh, unsigned short type, |
66 | const char *s) |
67 | { |
68 | struct rtattr *rta = rtattr_add(nh, type, strlen(s) + 1); |
69 | |
70 | strcpy(RTA_DATA(rta), q: s); |
71 | return rta; |
72 | } |
73 | |
74 | static struct rtattr *rtattr_add_any(struct nlmsghdr *nh, unsigned short type, |
75 | const void *arr, size_t len) |
76 | { |
77 | struct rtattr *rta = rtattr_add(nh, type, len); |
78 | |
79 | memcpy(RTA_DATA(rta), arr, len); |
80 | return rta; |
81 | } |
82 | |
83 | static int dev_create(const char *dev, const char *link_type, |
84 | int (*fill_rtattr)(struct nlmsghdr *nh), |
85 | int (*fill_info_data)(struct nlmsghdr *nh)) |
86 | { |
87 | struct { |
88 | struct nlmsghdr nh; |
89 | struct ifinfomsg info; |
90 | unsigned char data[MAX_RTNL_PAYLOAD]; |
91 | } req; |
92 | struct rtattr *link_info, *info_data; |
93 | int ret, rtnl; |
94 | |
95 | rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); |
96 | if (rtnl < 0) { |
97 | fprintf(stderr, "%s: socket %s\n" , __func__, strerror(errno)); |
98 | return 1; |
99 | } |
100 | |
101 | memset(&req, 0, sizeof(req)); |
102 | req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.info)); |
103 | req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE; |
104 | req.nh.nlmsg_type = RTM_NEWLINK; |
105 | |
106 | req.info.ifi_family = AF_UNSPEC; |
107 | req.info.ifi_type = 1; |
108 | req.info.ifi_index = 0; |
109 | req.info.ifi_flags = IFF_BROADCAST | IFF_UP; |
110 | req.info.ifi_change = 0xffffffff; |
111 | |
112 | rtattr_add_str(nh: &req.nh, type: IFLA_IFNAME, s: dev); |
113 | |
114 | if (fill_rtattr) { |
115 | ret = fill_rtattr(&req.nh); |
116 | if (ret) |
117 | return ret; |
118 | } |
119 | |
120 | link_info = rtattr_begin(nh: &req.nh, IFLA_LINKINFO); |
121 | |
122 | rtattr_add_strsz(nh: &req.nh, type: IFLA_INFO_KIND, s: link_type); |
123 | |
124 | if (fill_info_data) { |
125 | info_data = rtattr_begin(nh: &req.nh, type: IFLA_INFO_DATA); |
126 | ret = fill_info_data(&req.nh); |
127 | if (ret) |
128 | return ret; |
129 | rtattr_end(nh: &req.nh, attr: info_data); |
130 | } |
131 | |
132 | rtattr_end(nh: &req.nh, attr: link_info); |
133 | |
134 | ret = send(rtnl, &req, req.nh.nlmsg_len, 0); |
135 | if (ret < 0) |
136 | fprintf(stderr, "%s: send %s\n" , __func__, strerror(errno)); |
137 | ret = (unsigned int)ret != req.nh.nlmsg_len; |
138 | |
139 | close(rtnl); |
140 | return ret; |
141 | } |
142 | |
143 | static int dev_delete(const char *dev) |
144 | { |
145 | struct { |
146 | struct nlmsghdr nh; |
147 | struct ifinfomsg info; |
148 | unsigned char data[MAX_RTNL_PAYLOAD]; |
149 | } req; |
150 | int ret, rtnl; |
151 | |
152 | rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); |
153 | if (rtnl < 0) { |
154 | fprintf(stderr, "%s: socket %s\n" , __func__, strerror(errno)); |
155 | return 1; |
156 | } |
157 | |
158 | memset(&req, 0, sizeof(req)); |
159 | req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.info)); |
160 | req.nh.nlmsg_flags = NLM_F_REQUEST; |
161 | req.nh.nlmsg_type = RTM_DELLINK; |
162 | |
163 | req.info.ifi_family = AF_UNSPEC; |
164 | |
165 | rtattr_add_str(nh: &req.nh, type: IFLA_IFNAME, s: dev); |
166 | |
167 | ret = send(rtnl, &req, req.nh.nlmsg_len, 0); |
168 | if (ret < 0) |
169 | fprintf(stderr, "%s: send %s\n" , __func__, strerror(errno)); |
170 | |
171 | ret = (unsigned int)ret != req.nh.nlmsg_len; |
172 | |
173 | close(rtnl); |
174 | return ret; |
175 | } |
176 | |
177 | static int macvtap_fill_rtattr(struct nlmsghdr *nh) |
178 | { |
179 | int ifindex; |
180 | |
181 | ifindex = if_nametoindex(param_dev_dummy_name); |
182 | if (ifindex == 0) { |
183 | fprintf(stderr, "%s: ifindex %s\n" , __func__, strerror(errno)); |
184 | return -errno; |
185 | } |
186 | |
187 | rtattr_add_any(nh, type: IFLA_LINK, arr: &ifindex, len: sizeof(ifindex)); |
188 | rtattr_add_any(nh, type: IFLA_ADDRESS, arr: param_hwaddr_src, ETH_ALEN); |
189 | |
190 | return 0; |
191 | } |
192 | |
193 | static int opentap(const char *devname) |
194 | { |
195 | int ifindex; |
196 | char buf[256]; |
197 | int fd; |
198 | struct ifreq ifr; |
199 | |
200 | ifindex = if_nametoindex(devname); |
201 | if (ifindex == 0) { |
202 | fprintf(stderr, "%s: ifindex %s\n" , __func__, strerror(errno)); |
203 | return -errno; |
204 | } |
205 | |
206 | sprintf(buf, fmt: "/dev/tap%d" , ifindex); |
207 | fd = open(buf, O_RDWR | O_NONBLOCK); |
208 | if (fd < 0) { |
209 | fprintf(stderr, "%s: open %s\n" , __func__, strerror(errno)); |
210 | return -errno; |
211 | } |
212 | |
213 | memset(&ifr, 0, sizeof(ifr)); |
214 | strcpy(p: ifr.ifr_name, q: devname); |
215 | ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR | IFF_MULTI_QUEUE; |
216 | if (ioctl(fd, TUNSETIFF, &ifr, sizeof(ifr)) < 0) |
217 | return -errno; |
218 | return fd; |
219 | } |
220 | |
221 | size_t build_eth(uint8_t *buf, uint16_t proto) |
222 | { |
223 | struct ethhdr *eth = (struct ethhdr *)buf; |
224 | |
225 | eth->h_proto = htons(proto); |
226 | memcpy(eth->h_source, param_hwaddr_src, ETH_ALEN); |
227 | memcpy(eth->h_dest, param_hwaddr_dest, ETH_ALEN); |
228 | |
229 | return ETH_HLEN; |
230 | } |
231 | |
232 | static uint32_t add_csum(const uint8_t *buf, int len) |
233 | { |
234 | uint32_t sum = 0; |
235 | uint16_t *sbuf = (uint16_t *)buf; |
236 | |
237 | while (len > 1) { |
238 | sum += *sbuf++; |
239 | len -= 2; |
240 | } |
241 | |
242 | if (len) |
243 | sum += *(uint8_t *)sbuf; |
244 | |
245 | return sum; |
246 | } |
247 | |
248 | static uint16_t finish_ip_csum(uint32_t sum) |
249 | { |
250 | uint16_t lo = sum & 0xffff; |
251 | uint16_t hi = sum >> 16; |
252 | |
253 | return ~(lo + hi); |
254 | |
255 | } |
256 | |
257 | static uint16_t build_ip_csum(const uint8_t *buf, int len, |
258 | uint32_t sum) |
259 | { |
260 | sum += add_csum(buf, len); |
261 | return finish_ip_csum(sum); |
262 | } |
263 | |
264 | static int (uint8_t *buf, int payload_len) |
265 | { |
266 | struct iphdr *iph = (struct iphdr *)buf; |
267 | |
268 | iph->ihl = 5; |
269 | iph->version = 4; |
270 | iph->ttl = 8; |
271 | iph->tot_len = |
272 | htons(sizeof(*iph) + sizeof(struct udphdr) + payload_len); |
273 | iph->id = htons(1337); |
274 | iph->protocol = IPPROTO_UDP; |
275 | iph->saddr = htonl((172 << 24) | (17 << 16) | 2); |
276 | iph->daddr = htonl((172 << 24) | (17 << 16) | 1); |
277 | iph->check = build_ip_csum(buf, len: iph->ihl << 2, sum: 0); |
278 | |
279 | return iph->ihl << 2; |
280 | } |
281 | |
282 | static int build_udp_packet(uint8_t *buf, int payload_len, bool csum_off) |
283 | { |
284 | const int ip4alen = sizeof(uint32_t); |
285 | struct udphdr *udph = (struct udphdr *)buf; |
286 | int len = sizeof(*udph) + payload_len; |
287 | uint32_t sum = 0; |
288 | |
289 | udph->source = htons(22); |
290 | udph->dest = htons(58822); |
291 | udph->len = htons(len); |
292 | |
293 | memset(buf + sizeof(struct udphdr), PKT_DATA, payload_len); |
294 | |
295 | sum = add_csum(buf: buf - 2 * ip4alen, len: 2 * ip4alen); |
296 | sum += htons(IPPROTO_UDP) + udph->len; |
297 | |
298 | if (!csum_off) |
299 | sum += add_csum(buf, len); |
300 | |
301 | udph->check = finish_ip_csum(sum); |
302 | |
303 | return sizeof(*udph) + payload_len; |
304 | } |
305 | |
306 | size_t build_test_packet_valid_udp_gso(uint8_t *buf, size_t payload_len) |
307 | { |
308 | uint8_t *cur = buf; |
309 | struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf; |
310 | |
311 | vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr); |
312 | vh->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; |
313 | vh->csum_start = ETH_HLEN + sizeof(struct iphdr); |
314 | vh->csum_offset = __builtin_offsetof(struct udphdr, check); |
315 | vh->gso_type = VIRTIO_NET_HDR_GSO_UDP; |
316 | vh->gso_size = ETH_DATA_LEN - sizeof(struct iphdr); |
317 | cur += sizeof(*vh); |
318 | |
319 | cur += build_eth(buf: cur, ETH_P_IP); |
320 | cur += build_ipv4_header(buf: cur, payload_len); |
321 | cur += build_udp_packet(buf: cur, payload_len, csum_off: true); |
322 | |
323 | return cur - buf; |
324 | } |
325 | |
326 | size_t build_test_packet_valid_udp_csum(uint8_t *buf, size_t payload_len) |
327 | { |
328 | uint8_t *cur = buf; |
329 | struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf; |
330 | |
331 | vh->flags = VIRTIO_NET_HDR_F_DATA_VALID; |
332 | vh->gso_type = VIRTIO_NET_HDR_GSO_NONE; |
333 | cur += sizeof(*vh); |
334 | |
335 | cur += build_eth(buf: cur, ETH_P_IP); |
336 | cur += build_ipv4_header(buf: cur, payload_len); |
337 | cur += build_udp_packet(buf: cur, payload_len, csum_off: false); |
338 | |
339 | return cur - buf; |
340 | } |
341 | |
342 | size_t build_test_packet_crash_tap_invalid_eth_proto(uint8_t *buf, |
343 | size_t payload_len) |
344 | { |
345 | uint8_t *cur = buf; |
346 | struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf; |
347 | |
348 | vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr); |
349 | vh->flags = 0; |
350 | vh->gso_type = VIRTIO_NET_HDR_GSO_UDP; |
351 | vh->gso_size = ETH_DATA_LEN - sizeof(struct iphdr); |
352 | cur += sizeof(*vh); |
353 | |
354 | cur += build_eth(buf: cur, proto: 0); |
355 | cur += sizeof(struct iphdr) + sizeof(struct udphdr); |
356 | cur += build_ipv4_header(buf: cur, payload_len); |
357 | cur += build_udp_packet(buf: cur, payload_len, csum_off: true); |
358 | cur += payload_len; |
359 | |
360 | return cur - buf; |
361 | } |
362 | |
363 | FIXTURE(tap) |
364 | { |
365 | int fd; |
366 | }; |
367 | |
368 | FIXTURE_SETUP(tap) |
369 | { |
370 | int ret; |
371 | |
372 | ret = dev_create(dev: param_dev_dummy_name, link_type: "dummy" , NULL, NULL); |
373 | EXPECT_EQ(ret, 0); |
374 | |
375 | ret = dev_create(dev: param_dev_tap_name, link_type: "macvtap" , fill_rtattr: macvtap_fill_rtattr, |
376 | NULL); |
377 | EXPECT_EQ(ret, 0); |
378 | |
379 | self->fd = opentap(devname: param_dev_tap_name); |
380 | ASSERT_GE(self->fd, 0); |
381 | } |
382 | |
383 | FIXTURE_TEARDOWN(tap) |
384 | { |
385 | int ret; |
386 | |
387 | if (self->fd != -1) |
388 | close(self->fd); |
389 | |
390 | ret = dev_delete(dev: param_dev_tap_name); |
391 | EXPECT_EQ(ret, 0); |
392 | |
393 | ret = dev_delete(dev: param_dev_dummy_name); |
394 | EXPECT_EQ(ret, 0); |
395 | } |
396 | |
397 | TEST_F(tap, test_packet_valid_udp_gso) |
398 | { |
399 | uint8_t pkt[TEST_PACKET_SZ]; |
400 | size_t off; |
401 | int ret; |
402 | |
403 | memset(pkt, 0, sizeof(pkt)); |
404 | off = build_test_packet_valid_udp_gso(buf: pkt, payload_len: 1021); |
405 | ret = write(self->fd, pkt, off); |
406 | ASSERT_EQ(ret, off); |
407 | } |
408 | |
409 | TEST_F(tap, test_packet_valid_udp_csum) |
410 | { |
411 | uint8_t pkt[TEST_PACKET_SZ]; |
412 | size_t off; |
413 | int ret; |
414 | |
415 | memset(pkt, 0, sizeof(pkt)); |
416 | off = build_test_packet_valid_udp_csum(buf: pkt, payload_len: 1024); |
417 | ret = write(self->fd, pkt, off); |
418 | ASSERT_EQ(ret, off); |
419 | } |
420 | |
421 | TEST_F(tap, test_packet_crash_tap_invalid_eth_proto) |
422 | { |
423 | uint8_t pkt[TEST_PACKET_SZ]; |
424 | size_t off; |
425 | int ret; |
426 | |
427 | memset(pkt, 0, sizeof(pkt)); |
428 | off = build_test_packet_crash_tap_invalid_eth_proto(buf: pkt, payload_len: 1024); |
429 | ret = write(self->fd, pkt, off); |
430 | ASSERT_EQ(ret, -1); |
431 | ASSERT_EQ(errno, EINVAL); |
432 | } |
433 | |
434 | TEST_HARNESS_MAIN |
435 | |