/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #include #include #include #include #include "bpf_helpers.h" #define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F struct bpf_map_def SEC("maps") progs = { .type = BPF_MAP_TYPE_PROG_ARRAY, .key_size = sizeof(u32), .value_size = sizeof(u32), .max_entries = 1024, }; SEC("kprobe/__seccomp_filter") int bpf_prog1(struct pt_regs *ctx) { int sc_nr = (int)PT_REGS_PARM1(ctx); /* dispatch into next BPF program depending on syscall number */ bpf_tail_call(ctx, &progs, sc_nr); /* fall through -> unknown syscall */ if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) { char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n"; bpf_trace_printk(fmt, sizeof(fmt), sc_nr); } return 0; } /* we jump here when syscall number == __NR_write */ PROG(__NR_write)(struct pt_regs *ctx) { struct seccomp_data sd; bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx)); if (sd.args[2] == 512) { char fmt[] = "write(fd=%d, buf=%p, size=%d)\n"; bpf_trace_printk(fmt, sizeof(fmt), sd.args[0], sd.args[1], sd.args[2]); } return 0; } PROG(__NR_read)(struct pt_regs *ctx) { struct seccomp_data sd; bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx)); if (sd.args[2] > 128 && sd.args[2] <= 1024) { char fmt[] = "read(fd=%d, buf=%p, size=%d)\n"; bpf_trace_printk(fmt, sizeof(fmt), sd.args[0], sd.args[1], sd.args[2]); } return 0; } PROG(__NR_mmap)(struct pt_regs *ctx) { char fmt[] = "mmap\n"; bpf_trace_printk(fmt, sizeof(fmt)); return 0; } char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE; 8c56ea410efb537e5b4d10365e14b140f110314c'>treecommitdiff
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