incubator-nuttx/libs/libc/netdb/lib_gaistrerror.c

131 lines
4.1 KiB
C

/****************************************************************************
* libs/libc/netdb/lib_gaistrerror.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdio.h>
#include <netdb.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define STRERROR_UNKNOWN "Unknown error"
#define STRERROR_BUFSIZE sizeof(STRERROR_UNKNOWN " 10")
/****************************************************************************
* Private Types
****************************************************************************/
struct errno_strmap_s
{
uint8_t errnum;
FAR const char *str;
};
/****************************************************************************
* Private Data
****************************************************************************/
#ifdef CONFIG_LIBC_GAISTRERROR
/* This table maps all error numbers to descriptive strings.
* The only assumption that the code makes with regard to this
* this table is that it is ordered by error number.
*
* The size of this table is quite large. Its size can be
* reduced by eliminating some of the more obscure error
* strings.
*
* Only short names are currently supported.
*/
static const struct errno_strmap_s g_gaierrnomap[] =
{
{ EAI_AGAIN, "EAI_AGAIN" },
{ EAI_BADFLAGS, "EAI_BADFLAGS" },
{ EAI_FAIL, "EAI_FAIL" },
{ EAI_FAMILY, "EAI_FAMILY" },
{ EAI_MEMORY, "EAI_MEMORY" },
{ EAI_NONAME, "EAI_NONAME" },
{ EAI_SERVICE, "EAI_SERVICE" },
{ EAI_SOCKTYPE, "EAI_SOCKTYPE" },
{ EAI_SYSTEM, "EAI_SYSTEM" },
{ EAI_OVERFLOW, "EAI_OVERFLOW" },
};
#define NERRNO_STRS (sizeof(g_gaierrnomap) / sizeof(struct errno_strmap_s))
#endif /* CONFIG_LIBC_GAISTRERROR */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: gai_strerror
****************************************************************************/
FAR const char *gai_strerror(int errnum)
{
#ifdef CONFIG_LIBC_GAISTRERROR_ERRNUM
static char s_err[STRERROR_BUFSIZE];
#endif
#ifdef CONFIG_LIBC_GAISTRERROR
int ndxlow = 0;
int ndxhi = NERRNO_STRS - 1;
int ndxmid;
do
{
ndxmid = (ndxlow + ndxhi) >> 1;
if (errnum > g_gaierrnomap[ndxmid].errnum)
{
ndxlow = ndxmid + 1;
}
else if (errnum < g_gaierrnomap[ndxmid].errnum)
{
ndxhi = ndxmid - 1;
}
else
{
return g_gaierrnomap[ndxmid].str;
}
}
while (ndxlow <= ndxhi);
#endif
#ifdef CONFIG_LIBC_GAISTRERROR_ERRNUM
if (snprintf(s_err, sizeof(s_err), STRERROR_UNKNOWN " %d", errnum)
< sizeof(s_err))
{
return s_err;
}
#elif !defined(CONFIG_LIBC_GAISTRERROR)
UNUSED(errnum);
#endif
return STRERROR_UNKNOWN;
}