release/src/router/nginx/src/os/unix/ngx_errno.c

   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 #ifndef NGX_SYS_NERR
  12 #define NGX_SYS_NERR  128
  13 #endif
  14
  15 /*
  16  * The strerror() messages are copied because:
  17  *
  18  * 1) strerror() and strerror_r() functions are not Async-Signal-Safe,
  19  *    therefore, they cannot be used in signal handlers;
  20  *
  21  * 2) a direct sys_errlist[] array may be used instead of these functions,
  22  *    but Linux linker warns about its usage:
  23  *
  24  * warning: `sys_errlist' is deprecated; use `strerror' or `strerror_r' instead
  25  * warning: `sys_nerr' is deprecated; use `strerror' or `strerror_r' instead
  26  *
  27  *    causing false bug reports.
  28  */
  29
  30
  31 static ngx_str_t  *ngx_sys_errlist;
  32 static ngx_str_t   ngx_unknown_error = ngx_string("Unknown error");
  33
  34
  35 u_char *
  36 ngx_strerror(ngx_err_t err, u_char *errstr, size_t size)
  37 {
  38     ngx_str_t  *msg;
  39
  40     msg = ((ngx_uint_t) err < NGX_SYS_NERR) ? &ngx_sys_errlist[err]:
  41                                               &ngx_unknown_error;
  42     size = ngx_min(size, msg->len);
  43
  44     return ngx_cpymem(errstr, msg->data, size);
  45 }
  46
  47
  48 ngx_int_t
  49 ngx_strerror_init(void)
  50 {
  51     char       *msg;
  52     u_char     *p;
  53     size_t      len;
  54     ngx_err_t   err;
  55
  56     /*
  57      * ngx_strerror() is not ready to work at this stage, therefore,
  58      * malloc() is used and possible errors are logged using strerror().
  59      */
  60
  61     len = NGX_SYS_NERR * sizeof(ngx_str_t);
  62
  63     ngx_sys_errlist = malloc(len);
  64     if (ngx_sys_errlist == NULL) {
  65         goto failed;
  66     }
  67
  68     for (err = 0; err < NGX_SYS_NERR; err++) {
  69         msg = strerror(err);
  70         len = ngx_strlen(msg);
  71
  72         p = malloc(len);
  73         if (p == NULL) {
  74             goto failed;
  75         }
  76
  77         ngx_memcpy(p, msg, len);
  78         ngx_sys_errlist[err].len = len;
  79         ngx_sys_errlist[err].data = p;
  80     }
  81
  82     return NGX_OK;
  83
  84 failed:
  85
  86     err = errno;
  87     ngx_log_stderr(0, "malloc(%uz) failed (%d: %s)", len, err, strerror(err));
  88
  89     return NGX_ERROR;
  90 }