1 /*
2 * Copyright (c) 2023-2024 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 #include <darwintest.h>
30
31 #include <sys/ioctl.h>
32 #include <sys/sysctl.h>
33 #include <sys/uio.h>
34
35 #include <net/if.h>
36 #include <net/if_arp.h>
37 #include <net/if_fake_var.h>
38 #include <net/bpf.h>
39 #include <net/ethernet.h>
40
41 #include <netinet/ip.h>
42
43 #include <stdlib.h>
44 #include <string.h>
45 #include <strings.h>
46
47 #include "net_test_lib.h"
48 #include "bpflib.h"
49 #include "in_cksum.h"
50
51 T_GLOBAL_META(
52 T_META_NAMESPACE("xnu.net"),
53 T_META_ASROOT(true),
54 T_META_RADAR_COMPONENT_NAME("xnu"),
55 T_META_RADAR_COMPONENT_VERSION("networking"),
56 T_META_CHECK_LEAKS(false));
57
58 #define MAXBUF 32
59 static void
HexDump(void * data,size_t len)60 HexDump(void *data, size_t len)
61 {
62 size_t i, j, k;
63 unsigned char *ptr = (unsigned char *)data;
64 unsigned char buf[3 * MAXBUF + 1];
65
66 for (i = 0; i < len; i += MAXBUF) {
67 for (j = i, k = 0; j < i + MAXBUF && j < len; j++) {
68 unsigned char msnbl = ptr[j] >> 4;
69 unsigned char lsnbl = ptr[j] & 0x0f;
70
71 buf[k++] = msnbl < 10 ? msnbl + '0' : msnbl + 'a' - 10;
72 buf[k++] = lsnbl < 10 ? lsnbl + '0' : lsnbl + 'a' - 10;
73 if ((j % 2) == 1) {
74 buf[k++] = ' ';
75 }
76 if ((j % MAXBUF) == MAXBUF - 1) {
77 buf[k++] = ' ';
78 }
79 }
80 buf[k] = 0;
81 T_LOG("%5zd: %s\n", i, buf);
82 }
83 }
84
85 static char ifname1[IF_NAMESIZE];
86 static char ifname2[IF_NAMESIZE];
87 static int default_fake_max_mtu = 0;
88
89 static void
cleanup(void)90 cleanup(void)
91 {
92 if (ifname1[0] != '\0') {
93 (void)ifnet_destroy(ifname1, false);
94 T_LOG("ifnet_destroy %s", ifname1);
95 }
96 if (ifname2[0] != '\0') {
97 (void)ifnet_destroy(ifname2, false);
98 T_LOG("ifnet_destroy %s", ifname2);
99 }
100
101 if (default_fake_max_mtu != 0) {
102 T_LOG("sysctl net.link.fake.max_mtu=%d", default_fake_max_mtu);
103 (void) sysctlbyname("net.link.fake.max_mtu", NULL, NULL, &default_fake_max_mtu, sizeof(int));
104 }
105 }
106
107 static void
init(int mtu)108 init(int mtu)
109 {
110 T_ATEND(cleanup);
111
112 if (mtu > 0) {
113 size_t oldlen = sizeof(int);
114 T_ASSERT_POSIX_SUCCESS(sysctlbyname("net.link.fake.max_mtu", &default_fake_max_mtu, &oldlen, &mtu, sizeof(int)),
115 "sysctl net.link.fake.max_mtu %d -> %d", default_fake_max_mtu, mtu);
116 }
117 }
118
119 static int
setup_feth_pair(int mtu)120 setup_feth_pair(int mtu)
121 {
122 int error = 0;
123
124 strlcpy(ifname1, FETH_NAME, sizeof(ifname1));
125 error = ifnet_create_2(ifname1, sizeof(ifname1));
126 if (error != 0) {
127 ifname1[0] = '\0';
128 goto done;
129 }
130 T_LOG("created %s", ifname1);
131
132 strlcpy(ifname2, FETH_NAME, sizeof(ifname2));
133 error = ifnet_create_2(ifname2, sizeof(ifname2));
134 if (error != 0) {
135 ifname2[0] = '\0';
136 goto done;
137 }
138 T_LOG("created %s", ifname2);
139
140 ifnet_attach_ip(ifname1);
141
142 fake_set_peer(ifname1, ifname2);
143 if (mtu != 0) {
144 ifnet_set_mtu(ifname1, mtu);
145 ifnet_set_mtu(ifname2, mtu);
146 }
147 done:
148 return error;
149 }
150
151 static int
create_bpf_on_interface(const char * ifname,int * out_fd,int * out_bdlen,u_int write_size_max)152 create_bpf_on_interface(const char *ifname, int *out_fd, int *out_bdlen, u_int write_size_max)
153 {
154 int bpf_fd = -1;
155 int error = 0;
156 int bdlen = 0;
157 u_int value;
158
159 bpf_fd = bpf_new();
160 if (bpf_fd < 0) {
161 error = errno;
162 T_LOG("bpf_new");
163 goto done;
164 }
165 T_ASSERT_POSIX_SUCCESS(bpf_set_blen(bpf_fd, 128 * 1024), NULL);
166
167 T_ASSERT_POSIX_SUCCESS(bpf_get_blen(bpf_fd, &bdlen), NULL);
168
169 T_ASSERT_POSIX_SUCCESS(bpf_set_immediate(bpf_fd, 1), NULL);
170
171 T_ASSERT_POSIX_SUCCESS(bpf_setif(bpf_fd, ifname), "bpf set if %s",
172 ifname1);
173
174 T_ASSERT_POSIX_SUCCESS(bpf_set_see_sent(bpf_fd, 1), NULL);
175
176 T_ASSERT_POSIX_SUCCESS(bpf_set_header_complete(bpf_fd, 1), NULL);
177
178 #ifdef BIOCSWRITEMAX
179 T_ASSERT_POSIX_SUCCESS(bpf_set_write_size_max(bpf_fd, write_size_max), NULL);
180
181 T_ASSERT_POSIX_SUCCESS(bpf_get_write_size_max(bpf_fd, &value), NULL);
182
183 T_LOG("write_size_max %u %s value %u", write_size_max, write_size_max != value ? "!=" : "==", value);
184 #else
185 if (write_size_max > 0) {
186 T_SKIP("BIOCSWRITEMAX not supported");
187 }
188 #endif
189
190 #ifdef BIOCSBATCHWRITE
191 T_ASSERT_POSIX_SUCCESS(bpf_set_batch_write(bpf_fd, 1), NULL);
192
193 T_ASSERT_POSIX_SUCCESS(bpf_get_batch_write(bpf_fd, &value), NULL);
194
195 T_LOG("batch_write %u %s 1", value, value != 1 ? "!=" : "==");
196 #else
197 T_SKIP("BIOCSBATCHWRITE not supported");
198 #endif
199
200 struct timeval five_seconds = { .tv_sec = 5, .tv_usec = 0 };
201 T_ASSERT_POSIX_SUCCESS(bpf_set_timeout(bpf_fd, &five_seconds), NULL);
202
203 done:
204 *out_bdlen = bdlen;
205 *out_fd = bpf_fd;
206 return error;
207 }
208
209 static void
make_bootp_packet(struct iovec * iov,u_int ip_len,int id)210 make_bootp_packet(struct iovec *iov, u_int ip_len, int id)
211 {
212 u_int payload_len;
213
214 if (ip_len == 0) {
215 payload_len = (u_int)sizeof(dhcp_min_payload);
216 } else {
217 T_ASSERT_GE((size_t)ip_len, sizeof(struct ip) + sizeof(struct udphdr) + sizeof(dhcp_min_payload),
218 "ip_len");
219 payload_len = ip_len - (sizeof(struct ip) + sizeof(struct udphdr));
220 }
221
222 struct ether_addr src_eaddr = { 0 };
223 ifnet_get_lladdr(ifname1, &src_eaddr);
224
225 struct in_addr src_ip = { .s_addr = INADDR_ANY };
226 uint16_t src_port = 68;
227
228 struct ether_addr dst_eaddr = { 0 };
229 memset(dst_eaddr.octet, 255, ETHER_ADDR_LEN);
230
231 struct in_addr dst_ip = { .s_addr = INADDR_BROADCAST };
232
233 uint16_t dst_port = 67;
234
235 void *payload = calloc(1, payload_len);
236
237 make_dhcp_payload((dhcp_min_payload_t)payload, &src_eaddr);
238
239 struct bootp *dhcp = (struct bootp *)payload;
240 dhcp->bp_xid = (uint32_t)id;
241
242 u_int pkt_size = ETHER_HDR_LEN + IP_MAXPACKET;
243 unsigned char *pkt = calloc(1, pkt_size);
244
245 u_int frame_length = ethernet_udp4_frame_populate((void *)pkt,
246 pkt_size,
247 &src_eaddr,
248 src_ip,
249 src_port,
250 &dst_eaddr,
251 dst_ip,
252 dst_port,
253 payload,
254 payload_len);
255
256 T_ASSERT_EQ(sizeof(struct bpf_hdr), BPF_WORDALIGN(sizeof(struct bpf_hdr)), "bpfhdr.bh_hdrlen == BPF_WORDALIGN(sizeof(struct bpf_hdr))");
257
258 struct bpf_hdr bpfhdr = { 0 };
259 bpfhdr.bh_caplen = frame_length;
260 bpfhdr.bh_datalen = frame_length;
261 bpfhdr.bh_hdrlen = sizeof(struct bpf_hdr);
262
263 iov->iov_len = BPF_WORDALIGN(bpfhdr.bh_hdrlen + frame_length);
264 iov->iov_base = calloc(1, iov->iov_len);
265
266 T_LOG("iov_len %lu bh_hdrlen %u frame_length %u ip_len %u payload_len %u",
267 iov->iov_len, bpfhdr.bh_hdrlen, frame_length, ip_len, payload_len);
268
269 bcopy(&bpfhdr, iov->iov_base, bpfhdr.bh_hdrlen);
270 bcopy(pkt, (char *)iov->iov_base + bpfhdr.bh_hdrlen, frame_length);
271
272 free(pkt);
273 free(payload);
274 }
275
276 static void
do_bpf_write_batch(int count,const char * ifname,u_int ip_len,bool expect_success,u_int write_size_max)277 do_bpf_write_batch(int count, const char *ifname, u_int ip_len, bool expect_success, u_int write_size_max)
278 {
279 int bpf_fd = -1;
280 int bdlen = 0;
281 struct iovec *iovs = NULL;
282 int i;
283
284 T_ASSERT_POSIX_ZERO(create_bpf_on_interface(ifname, &bpf_fd, &bdlen, write_size_max), NULL);
285 T_LOG("bpf bdlen %d", bdlen);
286
287 /*
288 * Allocate an iovec for each packet that contains the BPF header + the data
289 */
290 iovs = calloc((size_t)count, sizeof(struct iovec));
291
292 ssize_t total_len = 0;
293 for (i = 0; i < count; i++) {
294 make_bootp_packet(&iovs[i], ip_len, i + 1);
295 total_len += iovs[i].iov_len;
296
297 struct bpf_hdr *h0 = (struct bpf_hdr *)iovs[i].iov_base;;
298
299 T_LOG("tv_sec %u tv_usec %u caplen %u datalen %u hdrlen %u",
300 h0->bh_tstamp.tv_sec, h0->bh_tstamp.tv_usec,
301 h0->bh_caplen, h0->bh_datalen, h0->bh_hdrlen);
302
303 HexDump(iovs[i].iov_base, MIN((size_t)iovs[i].iov_len, 512));
304
305 T_ASSERT_EQ((int)(iovs[i].iov_len % BPF_ALIGNMENT), 0, "iovs[i].iov_len %% BPF_ALIGNMENT == 0");
306 }
307 T_LOG("total_len %ld", total_len);
308
309 ssize_t nwritten;
310 nwritten = writev(bpf_fd, iovs, count);
311
312 T_LOG("bpf write returned %ld", nwritten);
313
314 if (expect_success) {
315 T_ASSERT_POSIX_SUCCESS(nwritten, "write bpf");
316 } else {
317 T_ASSERT_POSIX_FAILURE(nwritten, EMSGSIZE, "write bpf");
318 goto done;
319 }
320
321 T_LOG("bpf written %ld bytes over %lu", nwritten, total_len);
322
323 T_ASSERT_GE((size_t)nwritten, iovs[0].iov_len, "nwritten %lu >= iovs[0].iov_len %lu", nwritten, iovs[0].iov_len);
324
325 /*
326 * Give 100 ms for the packets to be captured
327 */
328 usleep(100000);
329
330 /*
331 * Read the batch and verify the content matches what we just sent.
332 */
333 unsigned char *buffer = calloc(1, (size_t)bdlen);
334 T_ASSERT_NOTNULL(buffer, "malloc()");
335
336 ssize_t nread = read(bpf_fd, buffer, (size_t)bdlen);
337
338 T_ASSERT_POSIX_SUCCESS(nread, "read bpf");
339
340 T_LOG("bpf read %ld bytes", nread);
341
342 /*
343 * We need at least the BPF header
344 */
345 T_ASSERT_GT((size_t)nread, sizeof(sizeof(struct bpf_hdr)), NULL);
346
347 unsigned char *bp = buffer;
348 unsigned char *ep = buffer + nread;
349
350 for (i = 0; i < count && bp < ep; i++) {
351 struct bpf_hdr *hp = (struct bpf_hdr *)(void *)bp;
352
353 T_LOG("tv_sec %u tv_usec %u caplen %u datalen %u hdrlen %u",
354 hp->bh_tstamp.tv_sec, hp->bh_tstamp.tv_usec,
355 hp->bh_caplen, hp->bh_datalen, hp->bh_hdrlen);
356
357 HexDump(bp, MIN((size_t)BPF_WORDALIGN(hp->bh_hdrlen + hp->bh_caplen), 512));
358
359 /*
360 * Note: The following will fail if there is parasitic traffic and that should not happen over feth
361 */
362 unsigned char *p0 = iovs[i].iov_base;
363 struct bpf_hdr *h0 = (struct bpf_hdr *)iovs[i].iov_base;;
364
365 T_ASSERT_EQ(h0->bh_caplen, hp->bh_caplen, "h0->bh_caplen %d == hp->bh_caplen %d", h0->bh_caplen, hp->bh_caplen);
366 T_ASSERT_EQ(h0->bh_datalen, hp->bh_datalen, "h0->bh_datalen %d == hp->bh_datalen %d", h0->bh_datalen, hp->bh_datalen);
367
368 T_ASSERT_EQ_INT(bcmp(h0->bh_hdrlen + p0, hp->bh_hdrlen + bp, hp->bh_caplen), 0, "bpf read same bytes as written iov %d", i);
369
370 bp += BPF_WORDALIGN(hp->bh_hdrlen + hp->bh_caplen);
371 }
372
373 if (buffer != NULL) {
374 free(buffer);
375 }
376 done:
377 if (bpf_fd != -1) {
378 close(bpf_fd);
379 }
380 }
381
382 static void
test_bpf_write_batch(int count,u_int data_len,int mtu,bool expect_success,u_int write_size_max)383 test_bpf_write_batch(int count, u_int data_len, int mtu, bool expect_success, u_int write_size_max)
384 {
385 init(mtu);
386
387 T_ASSERT_POSIX_ZERO(setup_feth_pair(mtu), NULL);
388
389 do_bpf_write_batch(count, ifname1, data_len, expect_success, write_size_max);
390 }
391
392 T_DECL(bpf_write_batch_dhcp, "BPF write DHCP feth MTU 1500")
393 {
394 test_bpf_write_batch(1, 0, 1500, true, 0);
395 }
396
397 T_DECL(bpf_write_batch_dhcp_x2, "BPF write DHCP feth MTU 1500 x 2")
398 {
399 test_bpf_write_batch(2, 0, 1500, true, 0);
400 }
401
402 T_DECL(bpf_write_batch_dhcp_x3, "BPF write DHCP feth MTU 1500 x 3")
403 {
404 test_bpf_write_batch(3, 0, 1500, true, 0);
405 }
406
407 T_DECL(bpf_write_batch_1020, "BPF write 1020 feth MTU 1500 x 2")
408 {
409 test_bpf_write_batch(2, 1020, 1500, true, 0);
410 }
411
412 T_DECL(bpf_write_batch_1021, "BPF write 1021 feth MTU 1500 x 2")
413 {
414 test_bpf_write_batch(2, 1021, 1500, true, 0);
415 }
416
417 T_DECL(bpf_write_batch_1022, "BPF write 1022 feth MTU 1500 x 2")
418 {
419 test_bpf_write_batch(2, 1022, 1500, true, 0);
420 }
421
422 T_DECL(bpf_write_batch_1023, "BPF write 1023 feth MTU 1500 x2 ")
423 {
424 test_bpf_write_batch(2, 1023, 1500, true, 0);
425 }
426