+++ /dev/null
-/**
- * BPF Simulator
- *
- * Copyright (c) 2012 Red Hat <pmoore@redhat.com>
- * Author: Paul Moore <paul@paul-moore.com>
- */
-
-/*
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License as
- * published by the Free Software Foundation.
- *
- * This library is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
- * for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, see <http://www.gnu.org/licenses>.
- */
-
-#include <elf.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <inttypes.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <linux/audit.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-
-#include "bpf.h"
-#include "util.h"
-
-#define BPF_PRG_MAX_LEN 4096
-
-/**
- * BPF simulator machine state
- */
-struct sim_state {
- uint32_t acc;
- uint32_t temp[BPF_SCRATCH_SIZE];
-};
-
-struct bpf_program {
- size_t i_cnt;
- bpf_instr_raw *i;
-};
-
-static unsigned int opt_verbose = 0;
-
-/**
- * Print the usage information to stderr and exit
- * @param program the name of the current program being invoked
- *
- * Print the usage information and exit with EINVAL.
- *
- */
-static void exit_usage(const char *program)
-{
- fprintf(stderr,
- "usage: %s -f <bpf_file> [-v] [-h]"
- " -a <arch> -s <syscall_num> [-0 <a0>] ... [-5 <a5>]\n",
- program);
- exit(EINVAL);
-}
-
-/**
- * Handle a simulator fault
- * @param rc the error or return code
- *
- * Print a "FAULT" to stderr to indicate a simulator fault, and an errno value
- * if the simulator is running in verbose mode, then exit with EFAULT.
- *
- */
-static void exit_fault(unsigned int rc)
-{
- if (opt_verbose)
- fprintf(stderr, "FAULT: errno = %d\n", rc);
- else
- fprintf(stderr, "FAULT\n");
- exit(EFAULT);
-}
-
-/**
- * Handle a BPF program error
- * @param rc the error or return code
- * @param line the line number
- *
- * Print an "ERROR" to stderr to indicate a program error, and an errno value
- * if the simulator is running in verbose mode, then exit with ENOEXEC.
- *
- */
-static void exit_error(unsigned int rc, unsigned int line)
-{
- if (opt_verbose)
- fprintf(stderr, "ERROR: errno = %d, line = %d\n", rc, line);
- else
- fprintf(stderr, "ERROR\n");
- exit(ENOEXEC);
-}
-
-/**
- * Handle a simulator return/action
- * @param action the return value
- * @param line the line number
- *
- * Display the action to stdout and exit with 0.
- *
- */
-static void end_action(uint32_t action, unsigned int line)
-{
- uint32_t act = action & SECCOMP_RET_ACTION;
- uint32_t data = action & SECCOMP_RET_DATA;
-
- switch (act) {
- case SECCOMP_RET_KILL:
- fprintf(stdout, "KILL\n");
- break;
- case SECCOMP_RET_TRAP:
- fprintf(stdout, "TRAP\n");
- break;
- case SECCOMP_RET_ERRNO:
- fprintf(stdout, "ERRNO(%u)\n", data);
- break;
- case SECCOMP_RET_TRACE:
- fprintf(stdout, "TRACE(%u)\n", data);
- break;
- case SECCOMP_RET_ALLOW:
- fprintf(stdout, "ALLOW\n");
- break;
- default:
- exit_error(EDOM, line);
- }
-
- exit(0);
-}
-
-/**
- * Execute a BPF program
- * @param prg the loaded BPF program
- * @param sys_data the syscall record being tested
- *
- * Simulate the BPF program with the given syscall record.
- *
- */
-static void bpf_execute(const struct bpf_program *prg,
- const struct seccomp_data *sys_data)
-{
- unsigned int ip, ip_c;
- struct sim_state state;
- bpf_instr_raw *bpf;
- unsigned char *sys_data_b = (unsigned char *)sys_data;
- uint16_t code;
- uint8_t jt;
- uint8_t jf;
- uint32_t k;
-
- /* initialize the machine state */
- ip_c = 0;
- ip = 0;
- memset(&state, 0, sizeof(state));
-
- while (ip < prg->i_cnt) {
- /* get the instruction and bump the ip */
- ip_c = ip;
- bpf = &prg->i[ip++];
-
- code = ttoh16(arch, bpf->code);
- jt = bpf->jt;
- jf = bpf->jf;
- k = ttoh32(arch, bpf->k);
-
- switch (code) {
- case BPF_LD+BPF_W+BPF_ABS:
- if (k < BPF_SYSCALL_MAX) {
- uint32_t val = *((uint32_t *)&sys_data_b[k]);
- state.acc = ttoh32(arch, val);
- } else
- exit_error(ERANGE, ip_c);
- break;
- case BPF_ALU+BPF_OR+BPF_K:
- state.acc |= k;
- break;
- case BPF_ALU+BPF_AND+BPF_K:
- state.acc &= k;
- break;
- case BPF_JMP+BPF_JA:
- ip += k;
- break;
- case BPF_JMP+BPF_JEQ+BPF_K:
- if (state.acc == k)
- ip += jt;
- else
- ip += jf;
- break;
- case BPF_JMP+BPF_JGT+BPF_K:
- if (state.acc > k)
- ip += jt;
- else
- ip += jf;
- break;
- case BPF_JMP+BPF_JGE+BPF_K:
- if (state.acc >= k)
- ip += jt;
- else
- ip += jf;
- break;
- case BPF_RET+BPF_K:
- end_action(k, ip_c);
- break;
- default:
- /* since we don't support the full bpf language just
- * yet, this could be either a fault or an error, we'll
- * treat it as a fault until we provide full support */
- exit_fault(EOPNOTSUPP);
- }
- }
-
- /* if we've reached here there is a problem with the program */
- exit_error(ERANGE, ip_c);
-}
-
-/**
- * main
- */
-int main(int argc, char *argv[])
-{
- int opt;
- int iter;
- char *opt_file = NULL;
- FILE *file;
- size_t file_read_len;
- struct seccomp_data sys_data;
- struct bpf_program bpf_prg;
-
- /* initialize the syscall record */
- memset(&sys_data, 0, sizeof(sys_data));
-
- /* parse the command line */
- while ((opt = getopt(argc, argv, "a:f:hs:v0:1:2:3:4:5:")) > 0) {
- switch (opt) {
- case 'a':
- if (strcmp(optarg, "x86") == 0)
- arch = AUDIT_ARCH_I386;
- else if (strcmp(optarg, "x86_64") == 0)
- arch = AUDIT_ARCH_X86_64;
- else if (strcmp(optarg, "x32") == 0)
- arch = AUDIT_ARCH_X86_64;
- else if (strcmp(optarg, "arm") == 0)
- arch = AUDIT_ARCH_ARM;
- else if (strcmp(optarg, "aarch64") == 0)
- arch = AUDIT_ARCH_AARCH64;
- else if (strcmp(optarg, "mips") == 0)
- arch = AUDIT_ARCH_MIPS;
- else if (strcmp(optarg, "mipsel") == 0)
- arch = AUDIT_ARCH_MIPSEL;
- else if (strcmp(optarg, "mips64") == 0)
- arch = AUDIT_ARCH_MIPS64;
- else if (strcmp(optarg, "mipsel64") == 0)
- arch = AUDIT_ARCH_MIPSEL64;
- else if (strcmp(optarg, "mips64n32") == 0)
- arch = AUDIT_ARCH_MIPS64N32;
- else if (strcmp(optarg, "mipsel64n32") == 0)
- arch = AUDIT_ARCH_MIPSEL64N32;
- else if (strcmp(optarg, "ppc") == 0)
- arch = AUDIT_ARCH_PPC;
- else if (strcmp(optarg, "ppc64") == 0)
- arch = AUDIT_ARCH_PPC64;
- else if (strcmp(optarg, "ppc64le") == 0)
- arch = AUDIT_ARCH_PPC64LE;
- else if (strcmp(optarg, "s390") == 0)
- arch = AUDIT_ARCH_S390;
- else if (strcmp(optarg, "s390x") == 0)
- arch = AUDIT_ARCH_S390X;
- else
- exit_fault(EINVAL);
- break;
- case 'f':
- opt_file = strdup(optarg);
- if (opt_file == NULL)
- exit_fault(ENOMEM);
- break;
- case 's':
- sys_data.nr = strtol(optarg, NULL, 0);
- break;
- case 'v':
- opt_verbose = 1;
- break;
- case '0':
- sys_data.args[0] = strtoull(optarg, NULL, 0);
- break;
- case '1':
- sys_data.args[1] = strtoull(optarg, NULL, 0);
- break;
- case '2':
- sys_data.args[2] = strtoull(optarg, NULL, 0);
- break;
- case '3':
- sys_data.args[3] = strtoull(optarg, NULL, 0);
- break;
- case '4':
- sys_data.args[4] = strtoull(optarg, NULL, 0);
- break;
- case '5':
- sys_data.args[5] = strtoull(optarg, NULL, 0);
- break;
- case 'h':
- default:
- /* usage information */
- exit_usage(argv[0]);
- }
- }
-
- /* adjust the endianess of sys_data to match the target */
- sys_data.nr = htot32(arch, sys_data.nr);
- sys_data.arch = htot32(arch, arch);
- sys_data.instruction_pointer = htot64(arch,
- sys_data.instruction_pointer);
- for (iter = 0; iter < BPF_SYS_ARG_MAX; iter++)
- sys_data.args[iter] = htot64(arch, sys_data.args[iter]);
-
- /* allocate space for the bpf program */
- /* XXX - we should make this dynamic */
- bpf_prg.i_cnt = 0;
- bpf_prg.i = calloc(BPF_PRG_MAX_LEN, sizeof(*bpf_prg.i));
- if (bpf_prg.i == NULL)
- exit_fault(ENOMEM);
-
- /* load the bpf program */
- file = fopen(opt_file, "r");
- if (file == NULL)
- exit_fault(errno);
- do {
- file_read_len = fread(&(bpf_prg.i[bpf_prg.i_cnt]),
- sizeof(*bpf_prg.i), 1, file);
- if (file_read_len == 1)
- bpf_prg.i_cnt++;
-
- /* check the size */
- if (bpf_prg.i_cnt == BPF_PRG_MAX_LEN)
- exit_fault(E2BIG);
- } while (file_read_len > 0);
- fclose(file);
-
- /* execute the bpf program */
- bpf_execute(&bpf_prg, &sys_data);
-
- /* we should never reach here */
- exit_fault(EFAULT);
- return 0;
-}
projects / linux-seccomp.git / blobdiff