src/port/strerror.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * strerror.c
   4  *        Replacements for standard strerror() and strerror_r() functions
   5  *
   6  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        src/port/strerror.c
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "c.h"
  16
  17 /*
  18  * Within this file, "strerror" means the platform's function not pg_strerror,
  19  * and likewise for "strerror_r"
  20  */
  21 #undef strerror
  22 #undef strerror_r
  23
  24 static char *gnuish_strerror_r(int errnum, char *buf, size_t buflen);
  25 static char *get_errno_symbol(int errnum);
  26 #ifdef WIN32
  27 static char *win32_socket_strerror(int errnum, char *buf, size_t buflen);
  28 #endif
  29
  30
  31 /*
  32  * A slightly cleaned-up version of strerror()
  33  */
  34 char *
  35 pg_strerror(int errnum)
  36 {
  37         static char errorstr_buf[PG_STRERROR_R_BUFLEN];
  38
  39         return pg_strerror_r(errnum, errorstr_buf, sizeof(errorstr_buf));
  40 }
  41
  42 /*
  43  * A slightly cleaned-up version of strerror_r()
  44  */
  45 char *
  46 pg_strerror_r(int errnum, char *buf, size_t buflen)
  47 {
  48         char       *str;
  49
  50         /* If it's a Windows Winsock error, that needs special handling */
  51 #ifdef WIN32
  52         /* Winsock error code range, per WinError.h */
  53         if (errnum >= 10000 && errnum <= 11999)
  54                 return win32_socket_strerror(errnum, buf, buflen);
  55 #endif
  56
  57         /* Try the platform's strerror_r(), or maybe just strerror() */
  58         str = gnuish_strerror_r(errnum, buf, buflen);
  59
  60         /*
  61          * Some strerror()s return an empty string for out-of-range errno.  This
  62          * is ANSI C spec compliant, but not exactly useful.  Also, we may get
  63          * back strings of question marks if libc cannot transcode the message to
  64          * the codeset specified by LC_CTYPE.  If we get nothing useful, first try
  65          * get_errno_symbol(), and if that fails, print the numeric errno.
  66          */
  67         if (str == NULL || *str == '\0' || *str == '?')
  68                 str = get_errno_symbol(errnum);
  69
  70         if (str == NULL)
  71         {
  72                 snprintf(buf, buflen, _("operating system error %d"), errnum);
  73                 str = buf;
  74         }
  75
  76         return str;
  77 }
  78
  79 /*
  80  * Simple wrapper to emulate GNU strerror_r if what the platform provides is
  81  * POSIX.  Also, if platform lacks strerror_r altogether, fall back to plain
  82  * strerror; it might not be very thread-safe, but tough luck.
  83  */
  84 static char *
  85 gnuish_strerror_r(int errnum, char *buf, size_t buflen)
  86 {
  87 #ifdef HAVE_STRERROR_R
  88 #ifdef STRERROR_R_INT
  89         /* POSIX API */
  90         if (strerror_r(errnum, buf, buflen) == 0)
  91                 return buf;
  92         return NULL;                            /* let caller deal with failure */
  93 #else
  94         /* GNU API */
  95         return strerror_r(errnum, buf, buflen);
  96 #endif
  97 #else                                                   /* !HAVE_STRERROR_R */
  98         char       *sbuf = strerror(errnum);
  99
 100         if (sbuf == NULL)                       /* can this still happen anywhere? */
 101                 return NULL;
 102         /* To minimize thread-unsafety hazard, copy into caller's buffer */
 103         strlcpy(buf, sbuf, buflen);
 104         return buf;
 105 #endif
 106 }
 107
 108 /*
 109  * Returns a symbol (e.g. "ENOENT") for an errno code.
 110  * Returns NULL if the code is unrecognized.
 111  */
 112 static char *
 113 get_errno_symbol(int errnum)
 114 {
 115         switch (errnum)
 116         {
 117                 case E2BIG:
 118                         return "E2BIG";
 119                 case EACCES:
 120                         return "EACCES";
 121                 case EADDRINUSE:
 122                         return "EADDRINUSE";
 123                 case EADDRNOTAVAIL:
 124                         return "EADDRNOTAVAIL";
 125                 case EAFNOSUPPORT:
 126                         return "EAFNOSUPPORT";
 127 #ifdef EAGAIN
 128                 case EAGAIN:
 129                         return "EAGAIN";
 130 #endif
 131 #ifdef EALREADY
 132                 case EALREADY:
 133                         return "EALREADY";
 134 #endif
 135                 case EBADF:
 136                         return "EBADF";
 137 #ifdef EBADMSG
 138                 case EBADMSG:
 139                         return "EBADMSG";
 140 #endif
 141                 case EBUSY:
 142                         return "EBUSY";
 143                 case ECHILD:
 144                         return "ECHILD";
 145                 case ECONNABORTED:
 146                         return "ECONNABORTED";
 147                 case ECONNREFUSED:
 148                         return "ECONNREFUSED";
 149                 case ECONNRESET:
 150                         return "ECONNRESET";
 151                 case EDEADLK:
 152                         return "EDEADLK";
 153                 case EDOM:
 154                         return "EDOM";
 155                 case EEXIST:
 156                         return "EEXIST";
 157                 case EFAULT:
 158                         return "EFAULT";
 159                 case EFBIG:
 160                         return "EFBIG";
 161                 case EHOSTDOWN:
 162                         return "EHOSTDOWN";
 163                 case EHOSTUNREACH:
 164                         return "EHOSTUNREACH";
 165                 case EIDRM:
 166                         return "EIDRM";
 167                 case EINPROGRESS:
 168                         return "EINPROGRESS";
 169                 case EINTR:
 170                         return "EINTR";
 171                 case EINVAL:
 172                         return "EINVAL";
 173                 case EIO:
 174                         return "EIO";
 175                 case EISCONN:
 176                         return "EISCONN";
 177                 case EISDIR:
 178                         return "EISDIR";
 179 #ifdef ELOOP
 180                 case ELOOP:
 181                         return "ELOOP";
 182 #endif
 183                 case EMFILE:
 184                         return "EMFILE";
 185                 case EMLINK:
 186                         return "EMLINK";
 187                 case EMSGSIZE:
 188                         return "EMSGSIZE";
 189                 case ENAMETOOLONG:
 190                         return "ENAMETOOLONG";
 191                 case ENETDOWN:
 192                         return "ENETDOWN";
 193                 case ENETRESET:
 194                         return "ENETRESET";
 195                 case ENETUNREACH:
 196                         return "ENETUNREACH";
 197                 case ENFILE:
 198                         return "ENFILE";
 199                 case ENOBUFS:
 200                         return "ENOBUFS";
 201                 case ENODEV:
 202                         return "ENODEV";
 203                 case ENOENT:
 204                         return "ENOENT";
 205                 case ENOEXEC:
 206                         return "ENOEXEC";
 207                 case ENOMEM:
 208                         return "ENOMEM";
 209                 case ENOSPC:
 210                         return "ENOSPC";
 211                 case ENOSYS:
 212                         return "ENOSYS";
 213                 case ENOTCONN:
 214                         return "ENOTCONN";
 215                 case ENOTDIR:
 216                         return "ENOTDIR";
 217 #if defined(ENOTEMPTY) && (ENOTEMPTY != EEXIST) /* same code on AIX */
 218                 case ENOTEMPTY:
 219                         return "ENOTEMPTY";
 220 #endif
 221                 case ENOTSOCK:
 222                         return "ENOTSOCK";
 223 #ifdef ENOTSUP
 224                 case ENOTSUP:
 225                         return "ENOTSUP";
 226 #endif
 227                 case ENOTTY:
 228                         return "ENOTTY";
 229                 case ENXIO:
 230                         return "ENXIO";
 231 #if defined(EOPNOTSUPP) && (!defined(ENOTSUP) || (EOPNOTSUPP != ENOTSUP))
 232                 case EOPNOTSUPP:
 233                         return "EOPNOTSUPP";
 234 #endif
 235 #ifdef EOVERFLOW
 236                 case EOVERFLOW:
 237                         return "EOVERFLOW";
 238 #endif
 239                 case EPERM:
 240                         return "EPERM";
 241                 case EPIPE:
 242                         return "EPIPE";
 243                 case EPROTONOSUPPORT:
 244                         return "EPROTONOSUPPORT";
 245                 case ERANGE:
 246                         return "ERANGE";
 247 #ifdef EROFS
 248                 case EROFS:
 249                         return "EROFS";
 250 #endif
 251                 case ESRCH:
 252                         return "ESRCH";
 253                 case ETIMEDOUT:
 254                         return "ETIMEDOUT";
 255 #ifdef ETXTBSY
 256                 case ETXTBSY:
 257                         return "ETXTBSY";
 258 #endif
 259 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
 260                 case EWOULDBLOCK:
 261                         return "EWOULDBLOCK";
 262 #endif
 263                 case EXDEV:
 264                         return "EXDEV";
 265         }
 266
 267         return NULL;
 268 }
 269
 270
 271 #ifdef WIN32
 272
 273 /*
 274  * Windows' strerror() doesn't know the Winsock codes, so handle them this way
 275  */
 276 static char *
 277 win32_socket_strerror(int errnum, char *buf, size_t buflen)
 278 {
 279         static HANDLE handleDLL = INVALID_HANDLE_VALUE;
 280
 281         if (handleDLL == INVALID_HANDLE_VALUE)
 282         {
 283                 handleDLL = LoadLibraryEx("netmsg.dll", NULL,
 284                                                                   DONT_RESOLVE_DLL_REFERENCES | LOAD_LIBRARY_AS_DATAFILE);
 285                 if (handleDLL == NULL)
 286                 {
 287                         snprintf(buf, buflen,
 288                                          "winsock error %d (could not load netmsg.dll to translate: error code %lu)",
 289                                          errnum, GetLastError());
 290                         return buf;
 291                 }
 292         }
 293
 294         ZeroMemory(buf, buflen);
 295         if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS |
 296                                           FORMAT_MESSAGE_FROM_SYSTEM |
 297                                           FORMAT_MESSAGE_FROM_HMODULE,
 298                                           handleDLL,
 299                                           errnum,
 300                                           MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
 301                                           buf,
 302                                           buflen - 1,
 303                                           NULL) == 0)
 304         {
 305                 /* Failed to get id */
 306                 snprintf(buf, buflen, "unrecognized winsock error %d", errnum);
 307         }
 308
 309         return buf;
 310 }
 311
 312 #endif                                                  /* WIN32 */