projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 5bacd780 AS |
1 | /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com |
| 2 | * | |
| 3 | * This program is free software; you can redistribute it and/or | |
| 4 | * modify it under the terms of version 2 of the GNU General Public | |
| 5 | * License as published by the Free Software Foundation. | |
| 6 | */ | |
| 7 | #include <linux/ptrace.h> | |
| 8 | #include <linux/version.h> | |
| 9 | #include <uapi/linux/bpf.h> | |
| 10 | #include <uapi/linux/seccomp.h> | |
| 11 | #include "bpf_helpers.h" | |
| 12 | ||
| 13 | #define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F | |
| 14 | ||
| 15 | struct bpf_map_def SEC("maps") progs = { | |
| 16 | .type = BPF_MAP_TYPE_PROG_ARRAY, | |
| 17 | .key_size = sizeof(u32), | |
| 18 | .value_size = sizeof(u32), | |
| 19 | .max_entries = 1024, | |
| 20 | }; | |
| 21 | ||
| 973d94d8 | 22 | SEC("kprobe/__seccomp_filter") |
| 5bacd780 AS |
23 | int bpf_prog1(struct pt_regs *ctx) |
| 24 | { | |
| 973d94d8 | 25 | int sc_nr = (int)PT_REGS_PARM1(ctx); |
| 5bacd780 AS |
26 | |
| 27 | /* dispatch into next BPF program depending on syscall number */ | |
| 973d94d8 | 28 | bpf_tail_call(ctx, &progs, sc_nr); |
| 5bacd780 AS |
29 | |
| 30 | /* fall through -> unknown syscall */ | |
| 973d94d8 | 31 | if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) { |
| 5bacd780 | 32 | char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n"; |
| 973d94d8 | 33 | bpf_trace_printk(fmt, sizeof(fmt), sc_nr); |
| 5bacd780 AS |
34 | } |
| 35 | return 0; | |
| 36 | } | |
| 37 | ||
| 38 | /* we jump here when syscall number == __NR_write */ | |
| 39 | PROG(__NR_write)(struct pt_regs *ctx) | |
| 40 | { | |
| 02413cab | 41 | struct seccomp_data sd; |
| 5bacd780 | 42 | |
| 973d94d8 | 43 | bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx)); |
| 5bacd780 AS |
44 | if (sd.args[2] == 512) { |
| 45 | char fmt[] = "write(fd=%d, buf=%p, size=%d)\n"; | |
| 46 | bpf_trace_printk(fmt, sizeof(fmt), | |
| 47 | sd.args[0], sd.args[1], sd.args[2]); | |
| 48 | } | |
| 49 | return 0; | |
| 50 | } | |
| 51 | ||
| 52 | PROG(__NR_read)(struct pt_regs *ctx) | |
| 53 | { | |
| 02413cab | 54 | struct seccomp_data sd; |
| 5bacd780 | 55 | |
| 973d94d8 | 56 | bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx)); |
| 5bacd780 AS |
57 | if (sd.args[2] > 128 && sd.args[2] <= 1024) { |
| 58 | char fmt[] = "read(fd=%d, buf=%p, size=%d)\n"; | |
| 59 | bpf_trace_printk(fmt, sizeof(fmt), | |
| 60 | sd.args[0], sd.args[1], sd.args[2]); | |
| 61 | } | |
| 62 | return 0; | |
| 63 | } | |
| 64 | ||
| 65 | PROG(__NR_mmap)(struct pt_regs *ctx) | |
| 66 | { | |
| 67 | char fmt[] = "mmap\n"; | |
| 68 | bpf_trace_printk(fmt, sizeof(fmt)); | |
| 69 | return 0; | |
| 70 | } | |
| 71 | ||
| 72 | char _license[] SEC("license") = "GPL"; | |
| 73 | u32 _version SEC("version") = LINUX_VERSION_CODE; |