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