1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912
|
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Facebook */
#include <vmlinux.h>
#include <string.h>
#include <stdbool.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
#include "errno.h"
char _license[] SEC("license") = "GPL";
int pid, err, val;
struct ringbuf_sample {
int pid;
int seq;
long value;
char comm[16];
};
struct {
__uint(type, BPF_MAP_TYPE_RINGBUF);
__uint(max_entries, 4096);
} ringbuf SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, __u32);
__type(value, __u32);
} array_map SEC(".maps");
SEC("?tp/syscalls/sys_enter_nanosleep")
int test_read_write(void *ctx)
{
char write_data[64] = "hello there, world!!";
char read_data[64] = {};
struct bpf_dynptr ptr;
int i;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr);
/* Write data into the dynptr */
err = bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0);
/* Read the data that was written into the dynptr */
err = err ?: bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
/* Ensure the data we read matches the data we wrote */
for (i = 0; i < sizeof(read_data); i++) {
if (read_data[i] != write_data[i]) {
err = 1;
break;
}
}
bpf_ringbuf_discard_dynptr(&ptr, 0);
return 0;
}
SEC("?tp/syscalls/sys_enter_nanosleep")
int test_dynptr_data(void *ctx)
{
__u32 key = 0, val = 235, *map_val;
struct bpf_dynptr ptr;
__u32 map_val_size;
void *data;
map_val_size = sizeof(*map_val);
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
bpf_map_update_elem(&array_map, &key, &val, 0);
map_val = bpf_map_lookup_elem(&array_map, &key);
if (!map_val) {
err = 1;
return 0;
}
bpf_dynptr_from_mem(map_val, map_val_size, 0, &ptr);
/* Try getting a data slice that is out of range */
data = bpf_dynptr_data(&ptr, map_val_size + 1, 1);
if (data) {
err = 2;
return 0;
}
/* Try getting more bytes than available */
data = bpf_dynptr_data(&ptr, 0, map_val_size + 1);
if (data) {
err = 3;
return 0;
}
data = bpf_dynptr_data(&ptr, 0, sizeof(__u32));
if (!data) {
err = 4;
return 0;
}
*(__u32 *)data = 999;
err = bpf_probe_read_kernel(&val, sizeof(val), data);
if (err)
return 0;
if (val != *(int *)data)
err = 5;
return 0;
}
static int ringbuf_callback(__u32 index, void *data)
{
struct ringbuf_sample *sample;
struct bpf_dynptr *ptr = (struct bpf_dynptr *)data;
sample = bpf_dynptr_data(ptr, 0, sizeof(*sample));
if (!sample)
err = 2;
else
sample->pid += index;
return 0;
}
SEC("?tp/syscalls/sys_enter_nanosleep")
int test_ringbuf(void *ctx)
{
struct bpf_dynptr ptr;
struct ringbuf_sample *sample;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
val = 100;
/* check that you can reserve a dynamic size reservation */
err = bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr);
sample = err ? NULL : bpf_dynptr_data(&ptr, 0, sizeof(*sample));
if (!sample) {
err = 1;
goto done;
}
sample->pid = 10;
/* Can pass dynptr to callback functions */
bpf_loop(10, ringbuf_callback, &ptr, 0);
if (sample->pid != 55)
err = 2;
done:
bpf_ringbuf_discard_dynptr(&ptr, 0);
return 0;
}
SEC("?cgroup_skb/egress")
int test_skb_readonly(struct __sk_buff *skb)
{
__u8 write_data[2] = {1, 2};
struct bpf_dynptr ptr;
int ret;
if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
err = 1;
return 1;
}
/* since cgroup skbs are read only, writes should fail */
ret = bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0);
if (ret != -EINVAL) {
err = 2;
return 1;
}
return 1;
}
SEC("?cgroup_skb/egress")
int test_dynptr_skb_data(struct __sk_buff *skb)
{
struct bpf_dynptr ptr;
__u64 *data;
if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
err = 1;
return 1;
}
/* This should return NULL. Must use bpf_dynptr_slice API */
data = bpf_dynptr_data(&ptr, 0, 1);
if (data) {
err = 2;
return 1;
}
return 1;
}
SEC("tp/syscalls/sys_enter_nanosleep")
int test_adjust(void *ctx)
{
struct bpf_dynptr ptr;
__u32 bytes = 64;
__u32 off = 10;
__u32 trim = 15;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
err = bpf_ringbuf_reserve_dynptr(&ringbuf, bytes, 0, &ptr);
if (err) {
err = 1;
goto done;
}
if (bpf_dynptr_size(&ptr) != bytes) {
err = 2;
goto done;
}
/* Advance the dynptr by off */
err = bpf_dynptr_adjust(&ptr, off, bpf_dynptr_size(&ptr));
if (err) {
err = 3;
goto done;
}
if (bpf_dynptr_size(&ptr) != bytes - off) {
err = 4;
goto done;
}
/* Trim the dynptr */
err = bpf_dynptr_adjust(&ptr, off, 15);
if (err) {
err = 5;
goto done;
}
/* Check that the size was adjusted correctly */
if (bpf_dynptr_size(&ptr) != trim - off) {
err = 6;
goto done;
}
done:
bpf_ringbuf_discard_dynptr(&ptr, 0);
return 0;
}
SEC("tp/syscalls/sys_enter_nanosleep")
int test_adjust_err(void *ctx)
{
char write_data[45] = "hello there, world!!";
struct bpf_dynptr ptr;
__u32 size = 64;
__u32 off = 20;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
if (bpf_ringbuf_reserve_dynptr(&ringbuf, size, 0, &ptr)) {
err = 1;
goto done;
}
/* Check that start can't be greater than end */
if (bpf_dynptr_adjust(&ptr, 5, 1) != -EINVAL) {
err = 2;
goto done;
}
/* Check that start can't be greater than size */
if (bpf_dynptr_adjust(&ptr, size + 1, size + 1) != -ERANGE) {
err = 3;
goto done;
}
/* Check that end can't be greater than size */
if (bpf_dynptr_adjust(&ptr, 0, size + 1) != -ERANGE) {
err = 4;
goto done;
}
if (bpf_dynptr_adjust(&ptr, off, size)) {
err = 5;
goto done;
}
/* Check that you can't write more bytes than available into the dynptr
* after you've adjusted it
*/
if (bpf_dynptr_write(&ptr, 0, &write_data, sizeof(write_data), 0) != -E2BIG) {
err = 6;
goto done;
}
/* Check that even after adjusting, submitting/discarding
* a ringbuf dynptr works
*/
bpf_ringbuf_submit_dynptr(&ptr, 0);
return 0;
done:
bpf_ringbuf_discard_dynptr(&ptr, 0);
return 0;
}
SEC("tp/syscalls/sys_enter_nanosleep")
int test_zero_size_dynptr(void *ctx)
{
char write_data = 'x', read_data;
struct bpf_dynptr ptr;
__u32 size = 64;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
if (bpf_ringbuf_reserve_dynptr(&ringbuf, size, 0, &ptr)) {
err = 1;
goto done;
}
/* After this, the dynptr has a size of 0 */
if (bpf_dynptr_adjust(&ptr, size, size)) {
err = 2;
goto done;
}
/* Test that reading + writing non-zero bytes is not ok */
if (bpf_dynptr_read(&read_data, sizeof(read_data), &ptr, 0, 0) != -E2BIG) {
err = 3;
goto done;
}
if (bpf_dynptr_write(&ptr, 0, &write_data, sizeof(write_data), 0) != -E2BIG) {
err = 4;
goto done;
}
/* Test that reading + writing 0 bytes from a 0-size dynptr is ok */
if (bpf_dynptr_read(&read_data, 0, &ptr, 0, 0)) {
err = 5;
goto done;
}
if (bpf_dynptr_write(&ptr, 0, &write_data, 0, 0)) {
err = 6;
goto done;
}
err = 0;
done:
bpf_ringbuf_discard_dynptr(&ptr, 0);
return 0;
}
SEC("tp/syscalls/sys_enter_nanosleep")
int test_dynptr_is_null(void *ctx)
{
struct bpf_dynptr ptr1;
struct bpf_dynptr ptr2;
__u64 size = 4;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
/* Pass in invalid flags, get back an invalid dynptr */
if (bpf_ringbuf_reserve_dynptr(&ringbuf, size, 123, &ptr1) != -EINVAL) {
err = 1;
goto exit_early;
}
/* Test that the invalid dynptr is null */
if (!bpf_dynptr_is_null(&ptr1)) {
err = 2;
goto exit_early;
}
/* Get a valid dynptr */
if (bpf_ringbuf_reserve_dynptr(&ringbuf, size, 0, &ptr2)) {
err = 3;
goto exit;
}
/* Test that the valid dynptr is not null */
if (bpf_dynptr_is_null(&ptr2)) {
err = 4;
goto exit;
}
exit:
bpf_ringbuf_discard_dynptr(&ptr2, 0);
exit_early:
bpf_ringbuf_discard_dynptr(&ptr1, 0);
return 0;
}
SEC("cgroup_skb/egress")
int test_dynptr_is_rdonly(struct __sk_buff *skb)
{
struct bpf_dynptr ptr1;
struct bpf_dynptr ptr2;
struct bpf_dynptr ptr3;
/* Pass in invalid flags, get back an invalid dynptr */
if (bpf_dynptr_from_skb(skb, 123, &ptr1) != -EINVAL) {
err = 1;
return 0;
}
/* Test that an invalid dynptr is_rdonly returns false */
if (bpf_dynptr_is_rdonly(&ptr1)) {
err = 2;
return 0;
}
/* Get a read-only dynptr */
if (bpf_dynptr_from_skb(skb, 0, &ptr2)) {
err = 3;
return 0;
}
/* Test that the dynptr is read-only */
if (!bpf_dynptr_is_rdonly(&ptr2)) {
err = 4;
return 0;
}
/* Get a read-writeable dynptr */
if (bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &ptr3)) {
err = 5;
goto done;
}
/* Test that the dynptr is read-only */
if (bpf_dynptr_is_rdonly(&ptr3)) {
err = 6;
goto done;
}
done:
bpf_ringbuf_discard_dynptr(&ptr3, 0);
return 0;
}
SEC("cgroup_skb/egress")
int test_dynptr_clone(struct __sk_buff *skb)
{
struct bpf_dynptr ptr1;
struct bpf_dynptr ptr2;
__u32 off = 2, size;
/* Get a dynptr */
if (bpf_dynptr_from_skb(skb, 0, &ptr1)) {
err = 1;
return 0;
}
if (bpf_dynptr_adjust(&ptr1, off, bpf_dynptr_size(&ptr1))) {
err = 2;
return 0;
}
/* Clone the dynptr */
if (bpf_dynptr_clone(&ptr1, &ptr2)) {
err = 3;
return 0;
}
size = bpf_dynptr_size(&ptr1);
/* Check that the clone has the same size and rd-only */
if (bpf_dynptr_size(&ptr2) != size) {
err = 4;
return 0;
}
if (bpf_dynptr_is_rdonly(&ptr2) != bpf_dynptr_is_rdonly(&ptr1)) {
err = 5;
return 0;
}
/* Advance and trim the original dynptr */
bpf_dynptr_adjust(&ptr1, 5, 5);
/* Check that only original dynptr was affected, and the clone wasn't */
if (bpf_dynptr_size(&ptr2) != size) {
err = 6;
return 0;
}
return 0;
}
SEC("?cgroup_skb/egress")
int test_dynptr_skb_no_buff(struct __sk_buff *skb)
{
struct bpf_dynptr ptr;
__u64 *data;
if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
err = 1;
return 1;
}
/* This may return NULL. SKB may require a buffer */
data = bpf_dynptr_slice(&ptr, 0, NULL, 1);
return !!data;
}
SEC("?cgroup_skb/egress")
int test_dynptr_skb_strcmp(struct __sk_buff *skb)
{
struct bpf_dynptr ptr;
char *data;
if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
err = 1;
return 1;
}
/* This may return NULL. SKB may require a buffer */
data = bpf_dynptr_slice(&ptr, 0, NULL, 10);
if (data) {
bpf_strncmp(data, 10, "foo");
return 1;
}
return 1;
}
SEC("tp_btf/kfree_skb")
int BPF_PROG(test_dynptr_skb_tp_btf, void *skb, void *location)
{
__u8 write_data[2] = {1, 2};
struct bpf_dynptr ptr;
int ret;
if (bpf_dynptr_from_skb(skb, 0, &ptr)) {
err = 1;
return 1;
}
/* since tp_btf skbs are read only, writes should fail */
ret = bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0);
if (ret != -EINVAL) {
err = 2;
return 1;
}
return 1;
}
static inline int bpf_memcmp(const char *a, const char *b, u32 size)
{
int i;
bpf_for(i, 0, size) {
if (a[i] != b[i])
return a[i] < b[i] ? -1 : 1;
}
return 0;
}
SEC("?tp/syscalls/sys_enter_nanosleep")
int test_dynptr_copy(void *ctx)
{
char data[] = "hello there, world!!";
char buf[32] = {'\0'};
__u32 sz = sizeof(data);
struct bpf_dynptr src, dst;
bpf_ringbuf_reserve_dynptr(&ringbuf, sz, 0, &src);
bpf_ringbuf_reserve_dynptr(&ringbuf, sz, 0, &dst);
/* Test basic case of copying contiguous memory backed dynptrs */
err = bpf_dynptr_write(&src, 0, data, sz, 0);
err = err ?: bpf_dynptr_copy(&dst, 0, &src, 0, sz);
err = err ?: bpf_dynptr_read(buf, sz, &dst, 0, 0);
err = err ?: bpf_memcmp(data, buf, sz);
/* Test that offsets are handled correctly */
err = err ?: bpf_dynptr_copy(&dst, 3, &src, 5, sz - 5);
err = err ?: bpf_dynptr_read(buf, sz - 5, &dst, 3, 0);
err = err ?: bpf_memcmp(data + 5, buf, sz - 5);
bpf_ringbuf_discard_dynptr(&src, 0);
bpf_ringbuf_discard_dynptr(&dst, 0);
return 0;
}
SEC("xdp")
int test_dynptr_copy_xdp(struct xdp_md *xdp)
{
struct bpf_dynptr ptr_buf, ptr_xdp;
char data[] = "qwertyuiopasdfghjkl";
char buf[32] = {'\0'};
__u32 len = sizeof(data);
int i, chunks = 200;
/* ptr_xdp is backed by non-contiguous memory */
bpf_dynptr_from_xdp(xdp, 0, &ptr_xdp);
bpf_ringbuf_reserve_dynptr(&ringbuf, len * chunks, 0, &ptr_buf);
/* Destination dynptr is backed by non-contiguous memory */
bpf_for(i, 0, chunks) {
err = bpf_dynptr_write(&ptr_buf, i * len, data, len, 0);
if (err)
goto out;
}
err = bpf_dynptr_copy(&ptr_xdp, 0, &ptr_buf, 0, len * chunks);
if (err)
goto out;
bpf_for(i, 0, chunks) {
__builtin_memset(buf, 0, sizeof(buf));
err = bpf_dynptr_read(&buf, len, &ptr_xdp, i * len, 0);
if (err)
goto out;
if (bpf_memcmp(data, buf, len) != 0)
goto out;
}
/* Source dynptr is backed by non-contiguous memory */
__builtin_memset(buf, 0, sizeof(buf));
bpf_for(i, 0, chunks) {
err = bpf_dynptr_write(&ptr_buf, i * len, buf, len, 0);
if (err)
goto out;
}
err = bpf_dynptr_copy(&ptr_buf, 0, &ptr_xdp, 0, len * chunks);
if (err)
goto out;
bpf_for(i, 0, chunks) {
__builtin_memset(buf, 0, sizeof(buf));
err = bpf_dynptr_read(&buf, len, &ptr_buf, i * len, 0);
if (err)
goto out;
if (bpf_memcmp(data, buf, len) != 0)
goto out;
}
/* Both source and destination dynptrs are backed by non-contiguous memory */
err = bpf_dynptr_copy(&ptr_xdp, 2, &ptr_xdp, len, len * (chunks - 1));
if (err)
goto out;
bpf_for(i, 0, chunks - 1) {
__builtin_memset(buf, 0, sizeof(buf));
err = bpf_dynptr_read(&buf, len, &ptr_xdp, 2 + i * len, 0);
if (err)
goto out;
if (bpf_memcmp(data, buf, len) != 0)
goto out;
}
if (bpf_dynptr_copy(&ptr_xdp, 2000, &ptr_xdp, 0, len * chunks) != -E2BIG)
err = 1;
out:
bpf_ringbuf_discard_dynptr(&ptr_buf, 0);
return XDP_DROP;
}
void *user_ptr;
/* Contains the copy of the data pointed by user_ptr.
* Size 384 to make it not fit into a single kernel chunk when copying
* but less than the maximum bpf stack size (512).
*/
char expected_str[384];
__u32 test_len[7] = {0/* placeholder */, 0, 1, 2, 255, 256, 257};
typedef int (*bpf_read_dynptr_fn_t)(struct bpf_dynptr *dptr, u32 off,
u32 size, const void *unsafe_ptr);
/* Returns the offset just before the end of the maximum sized xdp fragment.
* Any write larger than 32 bytes will be split between 2 fragments.
*/
__u32 xdp_near_frag_end_offset(void)
{
const __u32 headroom = 256;
const __u32 max_frag_size = __PAGE_SIZE - headroom - sizeof(struct skb_shared_info);
/* 32 bytes before the approximate end of the fragment */
return max_frag_size - 32;
}
/* Use __always_inline on test_dynptr_probe[_str][_xdp]() and callbacks
* of type bpf_read_dynptr_fn_t to prevent compiler from generating
* indirect calls that make program fail to load with "unknown opcode" error.
*/
static __always_inline void test_dynptr_probe(void *ptr, bpf_read_dynptr_fn_t bpf_read_dynptr_fn)
{
char buf[sizeof(expected_str)];
struct bpf_dynptr ptr_buf;
int i;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return;
err = bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(buf), 0, &ptr_buf);
bpf_for(i, 0, ARRAY_SIZE(test_len)) {
__u32 len = test_len[i];
err = err ?: bpf_read_dynptr_fn(&ptr_buf, 0, test_len[i], ptr);
if (len > sizeof(buf))
break;
err = err ?: bpf_dynptr_read(&buf, len, &ptr_buf, 0, 0);
if (err || bpf_memcmp(expected_str, buf, len))
err = 1;
/* Reset buffer and dynptr */
__builtin_memset(buf, 0, sizeof(buf));
err = err ?: bpf_dynptr_write(&ptr_buf, 0, buf, len, 0);
}
bpf_ringbuf_discard_dynptr(&ptr_buf, 0);
}
static __always_inline void test_dynptr_probe_str(void *ptr,
bpf_read_dynptr_fn_t bpf_read_dynptr_fn)
{
char buf[sizeof(expected_str)];
struct bpf_dynptr ptr_buf;
__u32 cnt, i;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return;
bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(buf), 0, &ptr_buf);
bpf_for(i, 0, ARRAY_SIZE(test_len)) {
__u32 len = test_len[i];
cnt = bpf_read_dynptr_fn(&ptr_buf, 0, len, ptr);
if (cnt != len)
err = 1;
if (len > sizeof(buf))
continue;
err = err ?: bpf_dynptr_read(&buf, len, &ptr_buf, 0, 0);
if (!len)
continue;
if (err || bpf_memcmp(expected_str, buf, len - 1) || buf[len - 1] != '\0')
err = 1;
}
bpf_ringbuf_discard_dynptr(&ptr_buf, 0);
}
static __always_inline void test_dynptr_probe_xdp(struct xdp_md *xdp, void *ptr,
bpf_read_dynptr_fn_t bpf_read_dynptr_fn)
{
struct bpf_dynptr ptr_xdp;
char buf[sizeof(expected_str)];
__u32 off, i;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return;
off = xdp_near_frag_end_offset();
err = bpf_dynptr_from_xdp(xdp, 0, &ptr_xdp);
bpf_for(i, 0, ARRAY_SIZE(test_len)) {
__u32 len = test_len[i];
err = err ?: bpf_read_dynptr_fn(&ptr_xdp, off, len, ptr);
if (len > sizeof(buf))
continue;
err = err ?: bpf_dynptr_read(&buf, len, &ptr_xdp, off, 0);
if (err || bpf_memcmp(expected_str, buf, len))
err = 1;
/* Reset buffer and dynptr */
__builtin_memset(buf, 0, sizeof(buf));
err = err ?: bpf_dynptr_write(&ptr_xdp, off, buf, len, 0);
}
}
static __always_inline void test_dynptr_probe_str_xdp(struct xdp_md *xdp, void *ptr,
bpf_read_dynptr_fn_t bpf_read_dynptr_fn)
{
struct bpf_dynptr ptr_xdp;
char buf[sizeof(expected_str)];
__u32 cnt, off, i;
if (bpf_get_current_pid_tgid() >> 32 != pid)
return;
off = xdp_near_frag_end_offset();
err = bpf_dynptr_from_xdp(xdp, 0, &ptr_xdp);
if (err)
return;
bpf_for(i, 0, ARRAY_SIZE(test_len)) {
__u32 len = test_len[i];
cnt = bpf_read_dynptr_fn(&ptr_xdp, off, len, ptr);
if (cnt != len)
err = 1;
if (len > sizeof(buf))
continue;
err = err ?: bpf_dynptr_read(&buf, len, &ptr_xdp, off, 0);
if (!len)
continue;
if (err || bpf_memcmp(expected_str, buf, len - 1) || buf[len - 1] != '\0')
err = 1;
__builtin_memset(buf, 0, sizeof(buf));
err = err ?: bpf_dynptr_write(&ptr_xdp, off, buf, len, 0);
}
}
SEC("xdp")
int test_probe_read_user_dynptr(struct xdp_md *xdp)
{
test_dynptr_probe(user_ptr, bpf_probe_read_user_dynptr);
if (!err)
test_dynptr_probe_xdp(xdp, user_ptr, bpf_probe_read_user_dynptr);
return XDP_PASS;
}
SEC("xdp")
int test_probe_read_kernel_dynptr(struct xdp_md *xdp)
{
test_dynptr_probe(expected_str, bpf_probe_read_kernel_dynptr);
if (!err)
test_dynptr_probe_xdp(xdp, expected_str, bpf_probe_read_kernel_dynptr);
return XDP_PASS;
}
SEC("xdp")
int test_probe_read_user_str_dynptr(struct xdp_md *xdp)
{
test_dynptr_probe_str(user_ptr, bpf_probe_read_user_str_dynptr);
if (!err)
test_dynptr_probe_str_xdp(xdp, user_ptr, bpf_probe_read_user_str_dynptr);
return XDP_PASS;
}
SEC("xdp")
int test_probe_read_kernel_str_dynptr(struct xdp_md *xdp)
{
test_dynptr_probe_str(expected_str, bpf_probe_read_kernel_str_dynptr);
if (!err)
test_dynptr_probe_str_xdp(xdp, expected_str, bpf_probe_read_kernel_str_dynptr);
return XDP_PASS;
}
SEC("fentry.s/" SYS_PREFIX "sys_nanosleep")
int test_copy_from_user_dynptr(void *ctx)
{
test_dynptr_probe(user_ptr, bpf_copy_from_user_dynptr);
return 0;
}
SEC("fentry.s/" SYS_PREFIX "sys_nanosleep")
int test_copy_from_user_str_dynptr(void *ctx)
{
test_dynptr_probe_str(user_ptr, bpf_copy_from_user_str_dynptr);
return 0;
}
static int bpf_copy_data_from_user_task(struct bpf_dynptr *dptr, u32 off,
u32 size, const void *unsafe_ptr)
{
struct task_struct *task = bpf_get_current_task_btf();
return bpf_copy_from_user_task_dynptr(dptr, off, size, unsafe_ptr, task);
}
static int bpf_copy_data_from_user_task_str(struct bpf_dynptr *dptr, u32 off,
u32 size, const void *unsafe_ptr)
{
struct task_struct *task = bpf_get_current_task_btf();
return bpf_copy_from_user_task_str_dynptr(dptr, off, size, unsafe_ptr, task);
}
SEC("fentry.s/" SYS_PREFIX "sys_nanosleep")
int test_copy_from_user_task_dynptr(void *ctx)
{
test_dynptr_probe(user_ptr, bpf_copy_data_from_user_task);
return 0;
}
SEC("fentry.s/" SYS_PREFIX "sys_nanosleep")
int test_copy_from_user_task_str_dynptr(void *ctx)
{
test_dynptr_probe_str(user_ptr, bpf_copy_data_from_user_task_str);
return 0;
}
|