1#include <stdio.h>
 2#include <linux/bpf.h>
 3#include <unistd.h>
 4#include <linux/filter.h>
 5#include <linux/seccomp.h>
 6#include <sys/prctl.h>
 7#include "libbpf.h"
 8#include "bpf_load.h"
 
 
 
 
 
 
 
 
 9
10/* install fake seccomp program to enable seccomp code path inside the kernel,
11 * so that our kprobe attached to seccomp_phase1() can be triggered
12 */
13static void install_accept_all_seccomp(void)
14{
15	struct sock_filter filter[] = {
16		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
17	};
18	struct sock_fprog prog = {
19		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
20		.filter = filter,
21	};
22	if (prctl(PR_SET_SECCOMP, 2, &prog))
23		perror("prctl");
24}
25
26int main(int ac, char **argv)
27{
28	FILE *f;
 
 
 
 
29	char filename[256];
 
 
 
 
30
31	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
32
33	if (load_bpf_file(filename)) {
34		printf("%s", bpf_log_buf);
35		return 1;
36	}
37
38	install_accept_all_seccomp();
39
40	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
41	(void) f;
42
43	read_trace_pipe();
44
 
 
 
45	return 0;
46}

  1// SPDX-License-Identifier: GPL-2.0
  2#include <stdio.h>
  3#include <stdlib.h>
  4#include <unistd.h>
  5#include <linux/filter.h>
  6#include <linux/seccomp.h>
  7#include <sys/prctl.h>
  8#include <bpf/bpf.h>
  9#include <bpf/libbpf.h>
 10#include <sys/resource.h>
 11#include "trace_helpers.h"
 12
 13#ifdef __mips__
 14#define	MAX_ENTRIES  6000 /* MIPS n64 syscalls start at 5000 */
 15#else
 16#define	MAX_ENTRIES  1024
 17#endif
 18
 19/* install fake seccomp program to enable seccomp code path inside the kernel,
 20 * so that our kprobe attached to seccomp_phase1() can be triggered
 21 */
 22static void install_accept_all_seccomp(void)
 23{
 24	struct sock_filter filter[] = {
 25		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
 26	};
 27	struct sock_fprog prog = {
 28		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
 29		.filter = filter,
 30	};
 31	if (prctl(PR_SET_SECCOMP, 2, &prog))
 32		perror("prctl");
 33}
 34
 35int main(int ac, char **argv)
 36{
 37	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 38	struct bpf_link *link = NULL;
 39	struct bpf_program *prog;
 40	struct bpf_object *obj;
 41	int key, fd, progs_fd;
 42	char filename[256];
 43	const char *title;
 44	FILE *f;
 45
 46	setrlimit(RLIMIT_MEMLOCK, &r);
 47
 48	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 49	obj = bpf_object__open_file(filename, NULL);
 50	if (libbpf_get_error(obj)) {
 51		fprintf(stderr, "ERROR: opening BPF object file failed\n");
 52		return 0;
 53	}
 54
 55	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
 56	if (!prog) {
 57		printf("finding a prog in obj file failed\n");
 58		goto cleanup;
 59	}
 60
 61	/* load BPF program */
 62	if (bpf_object__load(obj)) {
 63		fprintf(stderr, "ERROR: loading BPF object file failed\n");
 64		goto cleanup;
 65	}
 66
 67	link = bpf_program__attach(prog);
 68	if (libbpf_get_error(link)) {
 69		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
 70		link = NULL;
 71		goto cleanup;
 72	}
 73
 74	progs_fd = bpf_object__find_map_fd_by_name(obj, "progs");
 75	if (progs_fd < 0) {
 76		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
 77		goto cleanup;
 78	}
 79
 80	bpf_object__for_each_program(prog, obj) {
 81		title = bpf_program__title(prog, false);
 82		/* register only syscalls to PROG_ARRAY */
 83		if (sscanf(title, "kprobe/%d", &key) != 1)
 84			continue;
 85
 86		fd = bpf_program__fd(prog);
 87		bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY);
 
 88	}
 89
 90	install_accept_all_seccomp();
 91
 92	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
 93	(void) f;
 94
 95	read_trace_pipe();
 96
 97cleanup:
 98	bpf_link__destroy(link);
 99	bpf_object__close(obj);
100	return 0;
101}