1
2 /*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10
11
12 /*
13 * The strerror() messages are copied because:
14 *
15 * 1) strerror() and strerror_r() functions are not Async-Signal-Safe,
16 * therefore, they cannot be used in signal handlers;
17 *
18 * 2) a direct sys_errlist[] array may be used instead of these functions,
19 * but Linux linker warns about its usage:
20 *
21 * warning: `sys_errlist' is deprecated; use `strerror' or `strerror_r' instead
22 * warning: `sys_nerr' is deprecated; use `strerror' or `strerror_r' instead
23 *
24 * causing false bug reports.
25 */
26
27
28 static ngx_str_t *ngx_sys_errlist;
29 static ngx_str_t ngx_unknown_error = ngx_string("Unknown error");
30
31
32 u_char *
ngx_strerror(ngx_err_t err,u_char * errstr,size_t size)33 ngx_strerror(ngx_err_t err, u_char *errstr, size_t size)
34 {
35 ngx_str_t *msg;
36
37 msg = ((ngx_uint_t) err < NGX_SYS_NERR) ? &ngx_sys_errlist[err]:
38 &ngx_unknown_error;
39 size = ngx_min(size, msg->len);
40
41 return ngx_cpymem(errstr, msg->data, size);
42 }
43
44
45 ngx_int_t
ngx_strerror_init(void)46 ngx_strerror_init(void)
47 {
48 char *msg;
49 u_char *p;
50 size_t len;
51 ngx_err_t err;
52
53 /*
54 * ngx_strerror() is not ready to work at this stage, therefore,
55 * malloc() is used and possible errors are logged using strerror().
56 */
57
58 len = NGX_SYS_NERR * sizeof(ngx_str_t);
59
60 ngx_sys_errlist = malloc(len);
61 if (ngx_sys_errlist == NULL) {
62 goto failed;
63 }
64
65 for (err = 0; err < NGX_SYS_NERR; err++) {
66 msg = strerror(err);
67 len = ngx_strlen(msg);
68
69 p = malloc(len);
70 if (p == NULL) {
71 goto failed;
72 }
73
74 ngx_memcpy(p, msg, len);
75 ngx_sys_errlist[err].len = len;
76 ngx_sys_errlist[err].data = p;
77 }
78
79 return NGX_OK;
80
81 failed:
82
83 err = errno;
84 ngx_log_stderr(0, "malloc(%uz) failed (%d: %s)", len, err, strerror(err));
85
86 return NGX_ERROR;
87 }
88