1/* $OpenBSD: strerror_r.c,v 1.6 2005/08/08 08:05:37 espie Exp $ */
2/* Public Domain <marc@snafu.org> */
3
4// G++ automatically defines _GNU_SOURCE, which then means that <string.h>
5// gives us the GNU variant.
6#undef _GNU_SOURCE
7
8#include <string.h>
9
10#include <errno.h>
11#include <limits.h>
12#include <signal.h>
13#include <stdio.h>
14
15#include "private/ErrnoRestorer.h"
16#include "private/libc_logging.h"
17
18struct Pair {
19  int code;
20  const char* msg;
21};
22
23static const char* __code_string_lookup(const Pair* strings, int code) {
24  for (size_t i = 0; strings[i].msg != NULL; ++i) {
25    if (strings[i].code == code) {
26      return strings[i].msg;
27    }
28  }
29  return NULL;
30}
31
32static const Pair _sys_error_strings[] = {
33#define  __BIONIC_ERRDEF(x,y,z)  { x, z },
34#include <sys/_errdefs.h>
35  { 0, NULL }
36};
37
38extern "C" __LIBC_HIDDEN__ const char* __strerror_lookup(int error_number) {
39  return __code_string_lookup(_sys_error_strings, error_number);
40}
41
42static const Pair _sys_signal_strings[] = {
43#define  __BIONIC_SIGDEF(signal_number, signal_description)  { signal_number, signal_description },
44#include <sys/_sigdefs.h>
45  { 0, NULL }
46};
47
48extern "C" __LIBC_HIDDEN__ const char* __strsignal_lookup(int signal_number) {
49  return __code_string_lookup(_sys_signal_strings, signal_number);
50}
51
52int strerror_r(int error_number, char* buf, size_t buf_len) {
53  ErrnoRestorer errno_restorer;
54  size_t length;
55
56  const char* error_name = __strerror_lookup(error_number);
57  if (error_name != NULL) {
58    length = strlcpy(buf, error_name, buf_len);
59  } else {
60    length = __libc_format_buffer(buf, buf_len, "Unknown error %d", error_number);
61  }
62  if (length >= buf_len) {
63    errno_restorer.override(ERANGE);
64    return -1;
65  }
66
67  return 0;
68}
69
70extern "C" char* __gnu_strerror_r(int error_number, char* buf, size_t buf_len) {
71  ErrnoRestorer errno_restorer; // The glibc strerror_r doesn't set errno if it truncates...
72  strerror_r(error_number, buf, buf_len);
73  return buf; // ...and just returns whatever fit.
74}
75
76extern "C" __LIBC_HIDDEN__ const char* __strsignal(int signal_number, char* buf, size_t buf_len) {
77  const char* signal_name = __strsignal_lookup(signal_number);
78  if (signal_name != NULL) {
79    return signal_name;
80  }
81
82  const char* prefix = "Unknown";
83  if (signal_number >= SIGRTMIN && signal_number <= SIGRTMAX) {
84    prefix = "Real-time";
85    signal_number -= SIGRTMIN;
86  }
87  size_t length = snprintf(buf, buf_len, "%s signal %d", prefix, signal_number);
88  if (length >= buf_len) {
89    return NULL;
90  }
91  return buf;
92}
93