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freebsd/lib/libc/net/gethostnamadr.c

728 lines
17 KiB
C

/*-
* Copyright (c) 1994, Garrett Wollman
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include "reentrant.h"
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <nsswitch.h>
#include <arpa/nameser.h> /* XXX hack for _res */
#include <resolv.h> /* XXX hack for _res */
#include "un-namespace.h"
#include "netdb_private.h"
#ifdef NS_CACHING
#include "nscache.h"
#endif
static int gethostbyname_internal(const char *, int, struct hostent *, char *,
size_t, struct hostent **, int *, res_state);
/* Host lookup order if nsswitch.conf is broken or nonexistant */
static const ns_src default_src[] = {
{ NSSRC_FILES, NS_SUCCESS },
{ NSSRC_DNS, NS_SUCCESS },
{ 0 }
};
#ifdef NS_CACHING
static int host_id_func(char *, size_t *, va_list, void *);
static int host_marshal_func(char *, size_t *, void *, va_list, void *);
static int host_unmarshal_func(char *, size_t, void *, va_list, void *);
#endif
NETDB_THREAD_ALLOC(hostent)
NETDB_THREAD_ALLOC(hostent_data)
NETDB_THREAD_ALLOC(hostdata)
static void
hostent_free(void *ptr)
{
free(ptr);
}
static void
hostent_data_free(void *ptr)
{
struct hostent_data *hed = ptr;
if (hed == NULL)
return;
hed->stayopen = 0;
_endhosthtent(hed);
free(hed);
}
static void
hostdata_free(void *ptr)
{
free(ptr);
}
int
__copy_hostent(struct hostent *he, struct hostent *hptr, char *buf,
size_t buflen)
{
char *cp;
char **ptr;
int i, n;
int nptr, len;
/* Find out the amount of space required to store the answer. */
nptr = 2; /* NULL ptrs */
len = (char *)ALIGN(buf) - buf;
for (i = 0; he->h_addr_list[i]; i++, nptr++) {
len += he->h_length;
}
for (i = 0; he->h_aliases[i]; i++, nptr++) {
len += strlen(he->h_aliases[i]) + 1;
}
len += strlen(he->h_name) + 1;
len += nptr * sizeof(char*);
if (len > buflen) {
errno = ERANGE;
return (-1);
}
/* copy address size and type */
hptr->h_addrtype = he->h_addrtype;
n = hptr->h_length = he->h_length;
ptr = (char **)ALIGN(buf);
cp = (char *)ALIGN(buf) + nptr * sizeof(char *);
/* copy address list */
hptr->h_addr_list = ptr;
for (i = 0; he->h_addr_list[i]; i++ , ptr++) {
memcpy(cp, he->h_addr_list[i], n);
hptr->h_addr_list[i] = cp;
cp += n;
}
hptr->h_addr_list[i] = NULL;
ptr++;
/* copy official name */
n = strlen(he->h_name) + 1;
strcpy(cp, he->h_name);
hptr->h_name = cp;
cp += n;
/* copy aliases */
hptr->h_aliases = ptr;
for (i = 0 ; he->h_aliases[i]; i++) {
n = strlen(he->h_aliases[i]) + 1;
strcpy(cp, he->h_aliases[i]);
hptr->h_aliases[i] = cp;
cp += n;
}
hptr->h_aliases[i] = NULL;
return (0);
}
#ifdef NS_CACHING
static int
host_id_func(char *buffer, size_t *buffer_size, va_list ap, void *cache_mdata)
{
res_state statp;
u_long res_options;
const int op_id = 1;
char *str;
void *addr;
socklen_t len;
int type;
size_t desired_size, size;
enum nss_lookup_type lookup_type;
char *p;
int res = NS_UNAVAIL;
statp = __res_state();
res_options = statp->options & (RES_RECURSE | RES_DEFNAMES |
RES_DNSRCH | RES_NOALIASES | RES_USE_INET6);
lookup_type = (enum nss_lookup_type)cache_mdata;
switch (lookup_type) {
case nss_lt_name:
str = va_arg(ap, char *);
type = va_arg(ap, int);
size = strlen(str);
desired_size = sizeof(res_options) + sizeof(int) +
sizeof(enum nss_lookup_type) + sizeof(int) + size + 1;
if (desired_size > *buffer_size) {
res = NS_RETURN;
goto fin;
}
p = buffer;
memcpy(p, &res_options, sizeof(res_options));
p += sizeof(res_options);
memcpy(p, &op_id, sizeof(int));
p += sizeof(int);
memcpy(p, &lookup_type, sizeof(enum nss_lookup_type));
p += sizeof(int);
memcpy(p, &type, sizeof(int));
p += sizeof(int);
memcpy(p, str, size + 1);
res = NS_SUCCESS;
break;
case nss_lt_id:
addr = va_arg(ap, void *);
len = va_arg(ap, socklen_t);
type = va_arg(ap, int);
desired_size = sizeof(res_options) + sizeof(int) +
sizeof(enum nss_lookup_type) + sizeof(int) +
sizeof(socklen_t) + len;
if (desired_size > *buffer_size) {
res = NS_RETURN;
goto fin;
}
p = buffer;
memcpy(p, &res_options, sizeof(res_options));
p += sizeof(res_options);
memcpy(p, &op_id, sizeof(int));
p += sizeof(int);
memcpy(p, &lookup_type, sizeof(enum nss_lookup_type));
p += sizeof(int);
memcpy(p, &type, sizeof(int));
p += sizeof(int);
memcpy(p, &len, sizeof(socklen_t));
p += sizeof(socklen_t);
memcpy(p, addr, len);
res = NS_SUCCESS;
break;
default:
/* should be unreachable */
return (NS_UNAVAIL);
}
fin:
*buffer_size = desired_size;
return (res);
}
static int
host_marshal_func(char *buffer, size_t *buffer_size, void *retval, va_list ap,
void *cache_mdata)
{
char *str;
void *addr;
socklen_t len;
int type;
struct hostent *ht;
struct hostent new_ht;
size_t desired_size, aliases_size, addr_size, size;
char *p, **iter;
switch ((enum nss_lookup_type)cache_mdata) {
case nss_lt_name:
str = va_arg(ap, char *);
type = va_arg(ap, int);
break;
case nss_lt_id:
addr = va_arg(ap, void *);
len = va_arg(ap, socklen_t);
type = va_arg(ap, int);
break;
default:
/* should be unreachable */
return (NS_UNAVAIL);
}
ht = va_arg(ap, struct hostent *);
desired_size = _ALIGNBYTES + sizeof(struct hostent) + sizeof(char *);
if (ht->h_name != NULL)
desired_size += strlen(ht->h_name) + 1;
if (ht->h_aliases != NULL) {
aliases_size = 0;
for (iter = ht->h_aliases; *iter; ++iter) {
desired_size += strlen(*iter) + 1;
++aliases_size;
}
desired_size += _ALIGNBYTES +
(aliases_size + 1) * sizeof(char *);
}
if (ht->h_addr_list != NULL) {
addr_size = 0;
for (iter = ht->h_addr_list; *iter; ++iter)
++addr_size;
desired_size += addr_size * _ALIGN(ht->h_length);
desired_size += _ALIGNBYTES + (addr_size + 1) * sizeof(char *);
}
if (desired_size > *buffer_size) {
/* this assignment is here for future use */
*buffer_size = desired_size;
return (NS_RETURN);
}
memcpy(&new_ht, ht, sizeof(struct hostent));
memset(buffer, 0, desired_size);
*buffer_size = desired_size;
p = buffer + sizeof(struct hostent) + sizeof(char *);
memcpy(buffer + sizeof(struct hostent), &p, sizeof(char *));
p = (char *)_ALIGN(p);
if (new_ht.h_name != NULL) {
size = strlen(new_ht.h_name);
memcpy(p, new_ht.h_name, size);
new_ht.h_name = p;
p += size + 1;
}
if (new_ht.h_aliases != NULL) {
p = (char *)_ALIGN(p);
memcpy(p, new_ht.h_aliases, sizeof(char *) * aliases_size);
new_ht.h_aliases = (char **)p;
p += sizeof(char *) * (aliases_size + 1);
for (iter = new_ht.h_aliases; *iter; ++iter) {
size = strlen(*iter);
memcpy(p, *iter, size);
*iter = p;
p += size + 1;
}
}
if (new_ht.h_addr_list != NULL) {
p = (char *)_ALIGN(p);
memcpy(p, new_ht.h_addr_list, sizeof(char *) * addr_size);
new_ht.h_addr_list = (char **)p;
p += sizeof(char *) * (addr_size + 1);
size = _ALIGN(new_ht.h_length);
for (iter = new_ht.h_addr_list; *iter; ++iter) {
memcpy(p, *iter, size);
*iter = p;
p += size + 1;
}
}
memcpy(buffer, &new_ht, sizeof(struct hostent));
return (NS_SUCCESS);
}
static int
host_unmarshal_func(char *buffer, size_t buffer_size, void *retval, va_list ap,
void *cache_mdata)
{
char *str;
void *addr;
socklen_t len;
int type;
struct hostent *ht;
char *p;
char **iter;
char *orig_buf;
size_t orig_buf_size;
switch ((enum nss_lookup_type)cache_mdata) {
case nss_lt_name:
str = va_arg(ap, char *);
type = va_arg(ap, int);
break;
case nss_lt_id:
addr = va_arg(ap, void *);
len = va_arg(ap, socklen_t);
type = va_arg(ap, int);
break;
default:
/* should be unreachable */
return (NS_UNAVAIL);
}
ht = va_arg(ap, struct hostent *);
orig_buf = va_arg(ap, char *);
orig_buf_size = va_arg(ap, size_t);
if (orig_buf_size <
buffer_size - sizeof(struct hostent) - sizeof(char *)) {
errno = ERANGE;
return (NS_RETURN);
}
memcpy(ht, buffer, sizeof(struct hostent));
memcpy(&p, buffer + sizeof(struct hostent), sizeof(char *));
orig_buf = (char *)_ALIGN(orig_buf);
memcpy(orig_buf, buffer + sizeof(struct hostent) + sizeof(char *) +
_ALIGN(p) - (size_t)p,
buffer_size - sizeof(struct hostent) - sizeof(char *) -
_ALIGN(p) + (size_t)p);
p = (char *)_ALIGN(p);
NS_APPLY_OFFSET(ht->h_name, orig_buf, p, char *);
if (ht->h_aliases != NULL) {
NS_APPLY_OFFSET(ht->h_aliases, orig_buf, p, char **);
for (iter = ht->h_aliases; *iter; ++iter)
NS_APPLY_OFFSET(*iter, orig_buf, p, char *);
}
if (ht->h_addr_list != NULL) {
NS_APPLY_OFFSET(ht->h_addr_list, orig_buf, p, char **);
for (iter = ht->h_addr_list; *iter; ++iter)
NS_APPLY_OFFSET(*iter, orig_buf, p, char *);
}
*((struct hostent **)retval) = ht;
return (NS_SUCCESS);
}
#endif /* NS_CACHING */
static int
fakeaddr(const char *name, int af, struct hostent *hp, char *buf,
size_t buflen, res_state statp)
{
struct hostent_data *hed;
struct hostent he;
if ((hed = __hostent_data_init()) == NULL) {
errno = ENOMEM;
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
return (-1);
}
if ((af != AF_INET ||
inet_aton(name, (struct in_addr *)hed->host_addr) != 1) &&
inet_pton(af, name, hed->host_addr) != 1) {
RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
return (-1);
}
strncpy(hed->hostbuf, name, MAXDNAME);
hed->hostbuf[MAXDNAME] = '\0';
if (af == AF_INET && (statp->options & RES_USE_INET6) != 0U) {
_map_v4v6_address((char *)hed->host_addr,
(char *)hed->host_addr);
af = AF_INET6;
}
he.h_addrtype = af;
switch(af) {
case AF_INET:
he.h_length = NS_INADDRSZ;
break;
case AF_INET6:
he.h_length = NS_IN6ADDRSZ;
break;
default:
errno = EAFNOSUPPORT;
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
return (-1);
}
he.h_name = hed->hostbuf;
he.h_aliases = hed->host_aliases;
hed->host_aliases[0] = NULL;
hed->h_addr_ptrs[0] = (char *)hed->host_addr;
hed->h_addr_ptrs[1] = NULL;
he.h_addr_list = hed->h_addr_ptrs;
if (__copy_hostent(&he, hp, buf, buflen) != 0) {
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
return (-1);
}
RES_SET_H_ERRNO(statp, NETDB_SUCCESS);
return (0);
}
int
gethostbyname_r(const char *name, struct hostent *he, char *buffer,
size_t buflen, struct hostent **result, int *h_errnop)
{
res_state statp;
statp = __res_state();
if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) {
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
return (-1);
}
if (statp->options & RES_USE_INET6) {
if (fakeaddr(name, AF_INET, he, buffer, buflen, statp) == 0) {
*result = he;
return (0);
}
if (gethostbyname_internal(name, AF_INET6, he, buffer, buflen,
result, h_errnop, statp) == 0)
return (0);
}
return (gethostbyname_internal(name, AF_INET, he, buffer, buflen,
result, h_errnop, statp));
}
int
gethostbyname2_r(const char *name, int af, struct hostent *he, char *buffer,
size_t buflen, struct hostent **result, int *h_errnop)
{
res_state statp;
statp = __res_state();
if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) {
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
return (-1);
}
return (gethostbyname_internal(name, af, he, buffer, buflen, result,
h_errnop, statp));
}
int
gethostbyname_internal(const char *name, int af, struct hostent *hp, char *buf,
size_t buflen, struct hostent **result, int *h_errnop, res_state statp)
{
const char *cp;
int rval, ret_errno = 0;
char abuf[MAXDNAME];
#ifdef NS_CACHING
static const nss_cache_info cache_info =
NS_COMMON_CACHE_INFO_INITIALIZER(
hosts, (void *)nss_lt_name,
host_id_func, host_marshal_func, host_unmarshal_func);
#endif
static const ns_dtab dtab[] = {
NS_FILES_CB(_ht_gethostbyname, NULL)
{ NSSRC_DNS, _dns_gethostbyname, NULL },
NS_NIS_CB(_nis_gethostbyname, NULL) /* force -DHESIOD */
#ifdef NS_CACHING
NS_CACHE_CB(&cache_info)
#endif
{ 0 }
};
switch (af) {
case AF_INET:
case AF_INET6:
break;
default:
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
*h_errnop = statp->res_h_errno;
errno = EAFNOSUPPORT;
return (-1);
}
/*
* if there aren't any dots, it could be a user-level alias.
* this is also done in res_query() since we are not the only
* function that looks up host names.
*/
if (!strchr(name, '.') &&
(cp = res_hostalias(statp, name, abuf, sizeof abuf)))
name = cp;
if (fakeaddr(name, af, hp, buf, buflen, statp) == 0) {
*result = hp;
return (0);
}
rval = _nsdispatch((void *)result, dtab, NSDB_HOSTS,
"gethostbyname2_r", default_src, name, af, hp, buf, buflen,
&ret_errno, h_errnop);
if (rval != NS_SUCCESS) {
errno = ret_errno;
return ((ret_errno != 0) ? ret_errno : -1);
}
return (0);
}
int
gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *hp,
char *buf, size_t buflen, struct hostent **result, int *h_errnop)
{
const u_char *uaddr = (const u_char *)addr;
const struct in6_addr *addr6;
socklen_t size;
int rval, ret_errno = 0;
res_state statp;
#ifdef NS_CACHING
static const nss_cache_info cache_info =
NS_COMMON_CACHE_INFO_INITIALIZER(
hosts, (void *)nss_lt_id,
host_id_func, host_marshal_func, host_unmarshal_func);
#endif
static const ns_dtab dtab[] = {
NS_FILES_CB(_ht_gethostbyaddr, NULL)
{ NSSRC_DNS, _dns_gethostbyaddr, NULL },
NS_NIS_CB(_nis_gethostbyaddr, NULL) /* force -DHESIOD */
#ifdef NS_CACHING
NS_CACHE_CB(&cache_info)
#endif
{ 0 }
};
statp = __res_state();
if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) {
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
*h_errnop = statp->res_h_errno;
return (-1);
}
if (af == AF_INET6 && len == NS_IN6ADDRSZ) {
addr6 = (const struct in6_addr *)addr;
if (IN6_IS_ADDR_LINKLOCAL(addr6)) {
RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
*h_errnop = statp->res_h_errno;
return (-1);
}
if (IN6_IS_ADDR_V4MAPPED(addr6) ||
IN6_IS_ADDR_V4COMPAT(addr6)) {
/* Unmap. */
uaddr += NS_IN6ADDRSZ - NS_INADDRSZ;
af = AF_INET;
len = NS_INADDRSZ;
}
}
switch (af) {
case AF_INET:
size = NS_INADDRSZ;
break;
case AF_INET6:
size = NS_IN6ADDRSZ;
break;
default:
errno = EAFNOSUPPORT;
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
*h_errnop = statp->res_h_errno;
return (-1);
}
if (size != len) {
errno = EINVAL;
RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
*h_errnop = statp->res_h_errno;
return (-1);
}
rval = _nsdispatch((void *)result, dtab, NSDB_HOSTS,
"gethostbyaddr_r", default_src, uaddr, len, af, hp, buf, buflen,
&ret_errno, h_errnop);
if (rval != NS_SUCCESS) {
errno = ret_errno;
return ((ret_errno != 0) ? ret_errno : -1);
}
return (0);
}
struct hostent *
gethostbyname(const char *name)
{
struct hostdata *hd;
struct hostent *rval;
int ret_h_errno;
if ((hd = __hostdata_init()) == NULL)
return (NULL);
if (gethostbyname_r(name, &hd->host, hd->data, sizeof(hd->data), &rval,
&ret_h_errno) != 0)
return (NULL);
return (rval);
}
struct hostent *
gethostbyname2(const char *name, int af)
{
struct hostdata *hd;
struct hostent *rval;
int ret_h_errno;
if ((hd = __hostdata_init()) == NULL)
return (NULL);
if (gethostbyname2_r(name, af, &hd->host, hd->data, sizeof(hd->data),
&rval, &ret_h_errno) != 0)
return (NULL);
return (rval);
}
struct hostent *
gethostbyaddr(const void *addr, socklen_t len, int af)
{
struct hostdata *hd;
struct hostent *rval;
int ret_h_errno;
if ((hd = __hostdata_init()) == NULL)
return (NULL);
if (gethostbyaddr_r(addr, len, af, &hd->host, hd->data,
sizeof(hd->data), &rval, &ret_h_errno) != 0)
return (NULL);
return (rval);
}
void
sethostent(int stayopen)
{
struct hostent_data *hed;
if ((hed = __hostent_data_init()) == NULL)
return;
_sethosthtent(stayopen, hed);
_sethostdnsent(stayopen);
}
void
endhostent(void)
{
struct hostent_data *hed;
if ((hed = __hostent_data_init()) == NULL)
return;
_endhosthtent(hed);
_endhostdnsent();
}