/
host.c
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/
host.c
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/*
* Copyright (c) 2016 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup libc
* @{
*/
/** @file Internet host specification
*
* Either a host name or an address.
*/
#include <errno.h>
#include <inet/addr.h>
#include <inet/dnsr.h>
#include <inet/host.h>
#include <inet/hostname.h>
#include <stdio.h>
#include <stdlib.h>
#include <str.h>
/** Parse host string.
*
* @param str Host string
* @param rhost Place to store pointer to new host structure
* @param endptr Place to store pointer to next character in string or @c NULL
*
* @return EOK on success. EINVAL if @a str does not start with a valid
* host specification or if @a endptr is @c NULL and @a str contains
* extra characters at the end. ENOMEM if out of memory
*/
errno_t inet_host_parse(const char *str, inet_host_t **rhost,
char **endptr)
{
inet_host_t *host;
inet_addr_t addr;
char *name;
char *aend;
errno_t rc;
host = calloc(1, sizeof(inet_host_t));
if (host == NULL)
return ENOMEM;
/* Try address */
rc = inet_addr_parse(str, &addr, &aend);
if (rc == EOK) {
host->hform = inet_host_addr;
host->host.addr = addr;
goto have_host;
}
/* Try <hostname> */
rc = inet_hostname_parse(str, &name, &aend);
if (rc == EOK) {
host->hform = inet_host_name;
host->host.name = name;
goto have_host;
}
free(host);
return EINVAL;
have_host:
if (*aend != '\0' && endptr == NULL) {
/* Extra characters */
free(host);
return EINVAL;
}
*rhost = host;
if (endptr != NULL)
*endptr = (char *)aend;
return EOK;
}
/** Convert host structure to string representation.
*
* @param host Host structure
* @param rstr Place to store pointer to new string
* @return EOK on success, ENOMEM if out of memory
*/
errno_t inet_host_format(inet_host_t *host, char **rstr)
{
errno_t rc;
char *str = NULL;
switch (host->hform) {
case inet_host_addr:
rc = inet_addr_format(&host->host.addr, &str);
if (rc != EOK) {
assert(rc == ENOMEM);
return ENOMEM;
}
break;
case inet_host_name:
str = str_dup(host->host.name);
if (str == NULL)
return ENOMEM;
break;
}
*rstr = str;
return EOK;
}
/** Destroy host structure.
*
* @param host Host structure or @c NULL
*/
void inet_host_destroy(inet_host_t *host)
{
if (host == NULL)
return;
switch (host->hform) {
case inet_host_addr:
break;
case inet_host_name:
free(host->host.name);
break;
}
free(host);
}
/** Look up first address corresponding to host.
*
* If host contains a host name, name resolution is performed.
*
* @param host Host structure
* @param version Desired IP version (ip_any to get any version)
* @param addr Place to store address
*
* @reutrn EOK on success, ENOENT on resolurion failure
*/
errno_t inet_host_lookup_one(inet_host_t *host, ip_ver_t version, inet_addr_t *addr)
{
dnsr_hostinfo_t *hinfo = NULL;
errno_t rc;
switch (host->hform) {
case inet_host_addr:
*addr = host->host.addr;
break;
case inet_host_name:
rc = dnsr_name2host(host->host.name, &hinfo, version);
if (rc != EOK) {
dnsr_hostinfo_destroy(hinfo);
return ENOENT;
}
*addr = hinfo->addr;
dnsr_hostinfo_destroy(hinfo);
break;
}
return EOK;
}
/** Look up first address corresponding to host string.
*
* If host contains a host name, name resolution is performed.
*
* @param str Host string
* @param version Desired IP version (ip_any to get any version)
* @param addr Place to store address
* @param endptr Place to store pointer to next character in string or @c NULL
* @param errmsg Place to store pointer to error message (no need to free it)
* or @c NULL
*
* @return EOK on success. EINVAL if @a str has incorrect format or if
* @a endptr is @c NULL and @a str contains extra characters at
* the end. ENOENT if host was not found during resolution,
* ENOMEM if out of memory
*/
errno_t inet_host_plookup_one(const char *str, ip_ver_t version, inet_addr_t *addr,
char **endptr, const char **errmsg)
{
inet_host_t *host = NULL;
char *eptr;
errno_t rc;
rc = inet_host_parse(str, &host, endptr != NULL ? &eptr : NULL);
if (rc != EOK) {
switch (rc) {
case EINVAL:
if (errmsg != NULL)
*errmsg = "Invalid format";
goto error;
case ENOMEM:
if (errmsg != NULL)
*errmsg = "Out of memory";
goto error;
default:
assert(false);
}
}
rc = inet_host_lookup_one(host, version, addr);
if (rc != EOK) {
/* XXX Distinguish between 'not found' and other error */
rc = ENOENT;
if (errmsg != NULL)
*errmsg = "Name resolution failed";
goto error;
}
inet_host_destroy(host);
if (endptr != NULL)
*endptr = eptr;
return EOK;
error:
inet_host_destroy(host);
return rc;
}
/** @}
*/