1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <errno.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <sys/wait.h>
21 #include <unistd.h>
22
23 #include <cutils/klog.h>
24 #include <log/log.h>
25 #include <logwrap/logwrap.h>
26
fatal(const char * msg)27 void fatal(const char* msg) {
28 fprintf(stderr, "%s", msg);
29 ALOG(LOG_ERROR, "logwrapper", "%s", msg);
30 exit(-1);
31 }
32
usage()33 void usage() {
34 fatal("Usage: logwrapper [-a] [-d] [-k] BINARY [ARGS ...]\n"
35 "\n"
36 "Forks and executes BINARY ARGS, redirecting stdout and stderr to\n"
37 "the Android logging system. Tag is set to BINARY, priority is\n"
38 "always LOG_INFO.\n"
39 "\n"
40 "-a: Causes logwrapper to do abbreviated logging.\n"
41 " This logs up to the first 4K and last 4K of the command\n"
42 " being run, and logs the output when the command exits\n"
43 "-d: Causes logwrapper to SIGSEGV when BINARY terminates\n"
44 " fault address is set to the status of wait()\n"
45 "-k: Causes logwrapper to log to the kernel log instead of\n"
46 " the Android system log\n");
47 }
48
main(int argc,char * argv[])49 int main(int argc, char* argv[]) {
50 int seg_fault_on_exit = 0;
51 int log_target = LOG_ALOG;
52 bool abbreviated = false;
53 int ch;
54 int status = 0xAAAA;
55 int rc;
56
57 while ((ch = getopt(argc, argv, "adk")) != -1) {
58 switch (ch) {
59 case 'a':
60 abbreviated = true;
61 break;
62 case 'd':
63 seg_fault_on_exit = 1;
64 break;
65 case 'k':
66 log_target = LOG_KLOG;
67 klog_set_level(6);
68 break;
69 case '?':
70 default:
71 usage();
72 }
73 }
74 argc -= optind;
75 argv += optind;
76
77 if (argc < 1) {
78 usage();
79 }
80
81 rc = logwrap_fork_execvp(argc, &argv[0], &status, true, log_target, abbreviated, nullptr);
82 if (!rc) {
83 if (WIFEXITED(status))
84 rc = WEXITSTATUS(status);
85 else
86 rc = -ECHILD;
87 }
88
89 if (seg_fault_on_exit) {
90 uintptr_t fault_address = (uintptr_t)status;
91 *(int*)fault_address = 0; // causes SIGSEGV with fault_address = status
92 }
93
94 return rc;
95 }
96