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mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
freebsd/lib/libc/net/name6.c
Daniel Eischen d201fe46e3 Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions.  If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
	__sys_foo - actual system call
	_foo - weak definition to __sys_foo
	foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo.  In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde).  All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes.  <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h  namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE.  We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by:	-arch
2001-01-24 13:01:12 +00:00

1786 lines
41 KiB
C

/* $FreeBSD$ */
/* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project.
* All rights reserved.
*
* 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.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND 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 PROJECT 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.
*/
/*
* ++Copyright++ 1985, 1988, 1993
* -
* Copyright (c) 1985, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND 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.
* -
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
* -
* --Copyright--
*/
/*
* Atsushi Onoe <onoe@sm.sony.co.jp>
*/
/*
* TODO for thread safe
* use mutex for _hostconf, _hostconf_init.
* rewrite resolvers to be thread safe
*/
#include "namespace.h"
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/queue.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <nsswitch.h>
#include <unistd.h>
#include "un-namespace.h"
#ifndef _PATH_HOSTS
#define _PATH_HOSTS "/etc/hosts"
#endif
#ifndef MAXALIASES
#define MAXALIASES 10
#endif
#ifndef MAXADDRS
#define MAXADDRS 20
#endif
#ifndef MAXDNAME
#define MAXDNAME 1025
#endif
#ifdef INET6
#define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \
sizeof(struct in_addr))
#else
#define ADDRLEN(af) sizeof(struct in_addr)
#endif
#define MAPADDR(ab, ina) \
do { \
memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \
memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \
memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \
} while (0)
#define MAPADDRENABLED(flags) \
(((flags) & AI_V4MAPPED) || \
(((flags) & AI_V4MAPPED_CFG) && _mapped_addr_enabled()))
union inx_addr {
struct in_addr in_addr;
#ifdef INET6
struct in6_addr in6_addr;
#endif
struct {
u_char mau_zero[10];
u_char mau_one[2];
struct in_addr mau_inaddr;
} map_addr_un;
#define map_zero map_addr_un.mau_zero
#define map_one map_addr_un.mau_one
#define map_inaddr map_addr_un.mau_inaddr
};
static struct hostent *_hpcopy(struct hostent *hp, int *errp);
static struct hostent *_hpaddr(int af, const char *name, void *addr, int *errp);
static struct hostent *_hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp);
#ifdef INET6
static struct hostent *_hpmapv6(struct hostent *hp, int *errp);
#endif
static struct hostent *_hpsort(struct hostent *hp);
static struct hostent *_ghbyname(const char *name, int af, int flags, int *errp);
static char *_hgetword(char **pp);
static int _mapped_addr_enabled(void);
static FILE *_files_open(int *errp);
static int _files_ghbyname(void *, void *, va_list);
static int _files_ghbyaddr(void *, void *, va_list);
static void _files_shent(int stayopen);
static void _files_ehent(void);
#ifdef YP
static int _nis_ghbyname(void *, void *, va_list);
static int _nis_ghbyaddr(void *, void *, va_list);
#endif
static int _dns_ghbyname(void *, void *, va_list);
static int _dns_ghbyaddr(void *, void *, va_list);
static void _dns_shent(int stayopen);
static void _dns_ehent(void);
#ifdef ICMPNL
static int _icmp_ghbyaddr(void *, void *, va_list);
#endif /* ICMPNL */
/* Host lookup order if nsswitch.conf is broken or nonexistant */
static const ns_src default_src[] = {
{ NSSRC_FILES, NS_SUCCESS },
{ NSSRC_DNS, NS_SUCCESS },
#ifdef ICMPNL
#define NSSRC_ICMP "icmp"
{ NSSRC_ICMP, NS_SUCCESS },
#endif
{ 0 }
};
/*
* Check if kernel supports mapped address.
* implementation dependent
*/
#ifdef __KAME__
#include <sys/sysctl.h>
#endif /* __KAME__ */
static int
_mapped_addr_enabled(void)
{
/* implementation dependent check */
#if defined(__KAME__) && defined(IPV6CTL_MAPPED_ADDR)
int mib[4];
size_t len;
int val;
mib[0] = CTL_NET;
mib[1] = PF_INET6;
mib[2] = IPPROTO_IPV6;
mib[3] = IPV6CTL_MAPPED_ADDR;
len = sizeof(val);
if (sysctl(mib, 4, &val, &len, 0, 0) == 0 && val != 0)
return 1;
#endif /* __KAME__ && IPV6CTL_MAPPED_ADDR */
return 0;
}
/*
* Functions defined in RFC2553
* getipnodebyname, getipnodebyaddr, freehostent
*/
static struct hostent *
_ghbyname(const char *name, int af, int flags, int *errp)
{
struct hostent *hp;
int rval;
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_ghbyname, NULL)
{ NSSRC_DNS, _dns_ghbyname, NULL },
NS_NIS_CB(_nis_ghbyname, NULL)
{ 0 }
};
if (flags & AI_ADDRCONFIG) {
int s;
/*
* TODO:
* Note that implementation dependent test for address
* configuration should be done everytime called
* (or apropriate interval),
* because addresses will be dynamically assigned or deleted.
*/
if (af == AF_UNSPEC) {
if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
af = AF_INET;
else {
_close(s);
if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0)
af = AF_INET6;
else
_close(s);
}
}
if (af != AF_UNSPEC) {
if ((s = _socket(af, SOCK_DGRAM, 0)) < 0)
return NULL;
_close(s);
}
}
rval = nsdispatch(&hp, dtab, NSDB_HOSTS, "ghbyname", default_src,
name, af, errp);
return (rval == NS_SUCCESS) ? hp : NULL;
}
/* getipnodebyname() internal routine for multiple query(PF_UNSPEC) support. */
struct hostent *
_getipnodebyname_multi(const char *name, int af, int flags, int *errp)
{
struct hostent *hp;
union inx_addr addrbuf;
/* XXX: PF_UNSPEC is only supposed to be passed from getaddrinfo() */
if (af != AF_INET
#ifdef INET6
&& af != AF_INET6
#endif
&& af != PF_UNSPEC
)
{
*errp = NO_RECOVERY;
return NULL;
}
#ifdef INET6
/* special case for literal address */
if (inet_pton(AF_INET6, name, &addrbuf) == 1) {
if (af != AF_INET6) {
*errp = HOST_NOT_FOUND;
return NULL;
}
return _hpaddr(af, name, &addrbuf, errp);
}
#endif
if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) {
if (af != AF_INET) {
if (MAPADDRENABLED(flags)) {
MAPADDR(&addrbuf, &addrbuf.in_addr);
} else {
*errp = HOST_NOT_FOUND;
return NULL;
}
}
return _hpaddr(af, name, &addrbuf, errp);
}
*errp = HOST_NOT_FOUND;
hp = _ghbyname(name, af, flags, errp);
#ifdef INET6
if (af == AF_INET6
&& ((flags & AI_ALL) || hp == NULL)
&& (MAPADDRENABLED(flags))) {
struct hostent *hp2 = _ghbyname(name, AF_INET, flags, errp);
if (hp == NULL)
hp = _hpmapv6(hp2, errp);
else {
if (hp2 && strcmp(hp->h_name, hp2->h_name) != 0) {
freehostent(hp2);
hp2 = NULL;
}
hp = _hpmerge(hp, hp2, errp);
}
}
#endif
return _hpsort(hp);
}
struct hostent *
getipnodebyname(const char *name, int af, int flags, int *errp)
{
if (af != AF_INET
#ifdef INET6
&& af != AF_INET6
#endif
)
{
*errp = NO_RECOVERY;
return NULL;
}
return(_getipnodebyname_multi(name, af ,flags, errp));
}
struct hostent *
getipnodebyaddr(const void *src, size_t len, int af, int *errp)
{
struct hostent *hp;
int rval;
#ifdef INET6
struct in6_addr addrbuf;
#else
struct in_addr addrbuf;
#endif
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_ghbyaddr, NULL)
{ NSSRC_DNS, _dns_ghbyaddr, NULL },
NS_NIS_CB(_nis_ghbyaddr, NULL)
#ifdef ICMPNL
{ NSSRC_ICMP, _icmp_ghbyaddr, NULL },
#endif
{ 0 }
};
*errp = HOST_NOT_FOUND;
switch (af) {
case AF_INET:
if (len != sizeof(struct in_addr)) {
*errp = NO_RECOVERY;
return NULL;
}
if ((long)src & ~(sizeof(struct in_addr) - 1)) {
memcpy(&addrbuf, src, len);
src = &addrbuf;
}
if (((struct in_addr *)src)->s_addr == 0)
return NULL;
break;
#ifdef INET6
case AF_INET6:
if (len != sizeof(struct in6_addr)) {
*errp = NO_RECOVERY;
return NULL;
}
if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/
memcpy(&addrbuf, src, len);
src = &addrbuf;
}
if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src))
return NULL;
if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src)
|| IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) {
src = (char *)src +
(sizeof(struct in6_addr) - sizeof(struct in_addr));
af = AF_INET;
len = sizeof(struct in_addr);
}
break;
#endif
default:
*errp = NO_RECOVERY;
return NULL;
}
rval = nsdispatch(&hp, dtab, NSDB_HOSTS, "ghbyaddr", default_src,
src, len, af, errp);
return (rval == NS_SUCCESS) ? hp : NULL;
}
void
freehostent(struct hostent *ptr)
{
free(ptr);
}
#if 0
/* XXX: should be deprecated */
struct hostent *
getnodebyname(const char *name, int af, int flags)
{
return getipnodebyname(name, af, flags, &h_errno);
}
#ifdef __warn_references
__warn_references(getnodebyname,
"warning: getnodebyname() deprecated, "
"should use getaddrinfo() or getipnodebyname()");
#endif
struct hostent *
getnodebyaddr(const void *src, size_t len, int af)
{
return getipnodebyaddr(src, len, af, &h_errno);
}
#ifdef __warn_references
__warn_references(getnodebyaddr,
"warning: getnodebyaddr() deprecated, "
"should use getnameinfo() or getipnodebyaddr()");
#endif
#endif
/*
* Private utility functions
*/
/*
* _hpcopy: allocate and copy hostent structure
*/
static struct hostent *
_hpcopy(struct hostent *hp, int *errp)
{
struct hostent *nhp;
char *cp, **pp;
int size, addrsize;
int nalias = 0, naddr = 0;
int al_off;
int i;
if (hp == NULL)
return hp;
/* count size to be allocated */
size = sizeof(struct hostent);
if (hp->h_name != NULL)
size += strlen(hp->h_name) + 1;
if ((pp = hp->h_aliases) != NULL) {
for (i = 0; *pp != NULL; i++, pp++) {
if (**pp != '\0') {
size += strlen(*pp) + 1;
nalias++;
}
}
}
/* adjust alignment */
size = ALIGN(size);
al_off = size;
size += sizeof(char *) * (nalias + 1);
addrsize = ALIGN(hp->h_length);
if ((pp = hp->h_addr_list) != NULL) {
while (*pp++ != NULL)
naddr++;
}
size += addrsize * naddr;
size += sizeof(char *) * (naddr + 1);
/* copy */
if ((nhp = (struct hostent *)malloc(size)) == NULL) {
*errp = TRY_AGAIN;
return NULL;
}
cp = (char *)&nhp[1];
if (hp->h_name != NULL) {
nhp->h_name = cp;
strcpy(cp, hp->h_name);
cp += strlen(cp) + 1;
} else
nhp->h_name = NULL;
nhp->h_aliases = (char **)((char *)nhp + al_off);
if ((pp = hp->h_aliases) != NULL) {
for (i = 0; *pp != NULL; pp++) {
if (**pp != '\0') {
nhp->h_aliases[i++] = cp;
strcpy(cp, *pp);
cp += strlen(cp) + 1;
}
}
}
nhp->h_aliases[nalias] = NULL;
cp = (char *)&nhp->h_aliases[nalias + 1];
nhp->h_addrtype = hp->h_addrtype;
nhp->h_length = hp->h_length;
nhp->h_addr_list = (char **)cp;
if ((pp = hp->h_addr_list) != NULL) {
cp = (char *)&nhp->h_addr_list[naddr + 1];
for (i = 0; *pp != NULL; pp++) {
nhp->h_addr_list[i++] = cp;
memcpy(cp, *pp, hp->h_length);
cp += addrsize;
}
}
nhp->h_addr_list[naddr] = NULL;
return nhp;
}
/*
* _hpaddr: construct hostent structure with one address
*/
static struct hostent *
_hpaddr(int af, const char *name, void *addr, int *errp)
{
struct hostent *hp, hpbuf;
char *addrs[2];
hp = &hpbuf;
hp->h_name = (char *)name;
hp->h_aliases = NULL;
hp->h_addrtype = af;
hp->h_length = ADDRLEN(af);
hp->h_addr_list = addrs;
addrs[0] = (char *)addr;
addrs[1] = NULL;
return _hpcopy(hp, errp);
}
/*
* _hpmerge: merge 2 hostent structure, arguments will be freed
*/
static struct hostent *
_hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp)
{
int i, j;
int naddr, nalias;
char **pp;
struct hostent *hp, hpbuf;
char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1];
union inx_addr addrbuf[MAXADDRS];
if (hp1 == NULL)
return hp2;
if (hp2 == NULL)
return hp1;
#define HP(i) (i == 1 ? hp1 : hp2)
hp = &hpbuf;
hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name);
hp->h_aliases = aliases;
nalias = 0;
for (i = 1; i <= 2; i++) {
if ((pp = HP(i)->h_aliases) == NULL)
continue;
for (; nalias < MAXALIASES && *pp != NULL; pp++) {
/* check duplicates */
for (j = 0; j < nalias; j++)
if (strcasecmp(*pp, aliases[j]) == 0)
break;
if (j == nalias)
aliases[nalias++] = *pp;
}
}
aliases[nalias] = NULL;
#ifdef INET6
if (hp1->h_length != hp2->h_length) {
hp->h_addrtype = AF_INET6;
hp->h_length = sizeof(struct in6_addr);
} else {
#endif
hp->h_addrtype = hp1->h_addrtype;
hp->h_length = hp1->h_length;
#ifdef INET6
}
#endif
hp->h_addr_list = addrs;
naddr = 0;
for (i = 1; i <= 2; i++) {
if ((pp = HP(i)->h_addr_list) == NULL)
continue;
if (HP(i)->h_length == hp->h_length) {
while (naddr < MAXADDRS && *pp != NULL)
addrs[naddr++] = *pp++;
} else {
/* copy IPv4 addr as mapped IPv6 addr */
while (naddr < MAXADDRS && *pp != NULL) {
MAPADDR(&addrbuf[naddr], *pp++);
addrs[naddr] = (char *)&addrbuf[naddr];
naddr++;
}
}
}
addrs[naddr] = NULL;
hp = _hpcopy(hp, errp);
freehostent(hp1);
freehostent(hp2);
return hp;
}
/*
* _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses
*/
#ifdef INET6
static struct hostent *
_hpmapv6(struct hostent *hp, int *errp)
{
struct hostent *hp6;
if (hp == NULL)
return NULL;
if (hp->h_addrtype == AF_INET6)
return hp;
/* make dummy hostent to convert IPv6 address */
if ((hp6 = (struct hostent *)malloc(sizeof(struct hostent))) == NULL) {
*errp = TRY_AGAIN;
return NULL;
}
hp6->h_name = NULL;
hp6->h_aliases = NULL;
hp6->h_addrtype = AF_INET6;
hp6->h_length = sizeof(struct in6_addr);
hp6->h_addr_list = NULL;
return _hpmerge(hp6, hp, errp);
}
#endif
/*
* _hpsort: sort address by sortlist
*/
static struct hostent *
_hpsort(struct hostent *hp)
{
int i, j, n;
u_char *ap, *sp, *mp, **pp;
char t;
char order[MAXADDRS];
int nsort = _res.nsort;
if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0)
return hp;
for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) {
for (j = 0; j < nsort; j++) {
#ifdef INET6
if (_res_ext.sort_list[j].af != hp->h_addrtype)
continue;
sp = (u_char *)&_res_ext.sort_list[j].addr;
mp = (u_char *)&_res_ext.sort_list[j].mask;
#else
sp = (u_char *)&_res.sort_list[j].addr;
mp = (u_char *)&_res.sort_list[j].mask;
#endif
for (n = 0; n < hp->h_length; n++) {
if ((ap[n] & mp[n]) != sp[n])
break;
}
if (n == hp->h_length)
break;
}
order[i] = j;
}
n = i;
pp = (u_char **)hp->h_addr_list;
for (i = 0; i < n - 1; i++) {
for (j = i + 1; j < n; j++) {
if (order[i] > order[j]) {
ap = pp[i];
pp[i] = pp[j];
pp[j] = ap;
t = order[i];
order[i] = order[j];
order[j] = t;
}
}
}
return hp;
}
static char *
_hgetword(char **pp)
{
char c, *p, *ret;
const char *sp;
static const char sep[] = "# \t\n";
ret = NULL;
for (p = *pp; (c = *p) != '\0'; p++) {
for (sp = sep; *sp != '\0'; sp++) {
if (c == *sp)
break;
}
if (c == '#')
p[1] = '\0'; /* ignore rest of line */
if (ret == NULL) {
if (*sp == '\0')
ret = p;
} else {
if (*sp != '\0') {
*p++ = '\0';
break;
}
}
}
*pp = p;
if (ret == NULL || *ret == '\0')
return NULL;
return ret;
}
/*
* FILES (/etc/hosts)
*/
static FILE *
_files_open(int *errp)
{
FILE *fp;
fp = fopen(_PATH_HOSTS, "r");
if (fp == NULL)
*errp = NO_RECOVERY;
return fp;
}
static int
_files_ghbyname(void *rval, void *cb_data, va_list ap)
{
const char *name;
int af;
int *errp;
int match, nalias;
char *p, *line, *addrstr, *cname;
FILE *fp;
struct hostent *rethp, *hp, hpbuf;
char *aliases[MAXALIASES + 1], *addrs[2];
union inx_addr addrbuf;
char buf[BUFSIZ];
int af0;
name = va_arg(ap, const char *);
af = va_arg(ap, int);
errp = va_arg(ap, int *);
*(struct hostent **)rval = NULL;
if ((fp = _files_open(errp)) == NULL)
return NS_UNAVAIL;
rethp = hp = NULL;
af0 = af;
while (fgets(buf, sizeof(buf), fp)) {
line = buf;
if ((addrstr = _hgetword(&line)) == NULL
|| (cname = _hgetword(&line)) == NULL)
continue;
match = (strcasecmp(cname, name) == 0);
nalias = 0;
while ((p = _hgetword(&line)) != NULL) {
if (!match)
match = (strcasecmp(p, name) == 0);
if (nalias < MAXALIASES)
aliases[nalias++] = p;
}
if (!match)
continue;
switch (af0) {
case AF_INET:
if (inet_aton(addrstr, (struct in_addr *)&addrbuf)
!= 1) {
*errp = NO_DATA; /* name found */
continue;
}
af = af0;
break;
#ifdef INET6
case AF_INET6:
if (inet_pton(af, addrstr, &addrbuf) != 1) {
*errp = NO_DATA; /* name found */
continue;
}
af = af0;
break;
#endif
case AF_UNSPEC:
if (inet_aton(addrstr, (struct in_addr *)&addrbuf)
== 1) {
af = AF_INET;
break;
}
#ifdef INET6
if (inet_pton(AF_INET6, addrstr, &addrbuf) == 1) {
af = AF_INET6;
break;
}
#endif
*errp = NO_DATA; /* name found */
continue;
/* NOTREACHED */
}
hp = &hpbuf;
hp->h_name = cname;
hp->h_aliases = aliases;
aliases[nalias] = NULL;
hp->h_addrtype = af;
hp->h_length = ADDRLEN(af);
hp->h_addr_list = addrs;
addrs[0] = (char *)&addrbuf;
addrs[1] = NULL;
hp = _hpcopy(hp, errp);
rethp = _hpmerge(rethp, hp, errp);
}
fclose(fp);
*(struct hostent **)rval = rethp;
return (rethp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
}
static int
_files_ghbyaddr(void *rval, void *cb_data, va_list ap)
{
const void *addr;
int addrlen;
int af;
int *errp;
int nalias;
char *p, *line;
FILE *fp;
struct hostent *hp, hpbuf;
char *aliases[MAXALIASES + 1], *addrs[2];
union inx_addr addrbuf;
char buf[BUFSIZ];
addr = va_arg(ap, const void *);
addrlen = va_arg(ap, int);
af = va_arg(ap, int);
errp = va_arg(ap, int *);
*(struct hostent**)rval = NULL;
if ((fp = _files_open(errp)) == NULL)
return NS_UNAVAIL;
hp = NULL;
while (fgets(buf, sizeof(buf), fp)) {
line = buf;
if ((p = _hgetword(&line)) == NULL
|| (af == AF_INET
? inet_aton(p, (struct in_addr *)&addrbuf)
: inet_pton(af, p, &addrbuf)) != 1
|| memcmp(addr, &addrbuf, addrlen) != 0
|| (p = _hgetword(&line)) == NULL)
continue;
hp = &hpbuf;
hp->h_name = p;
hp->h_aliases = aliases;
nalias = 0;
while ((p = _hgetword(&line)) != NULL) {
if (nalias < MAXALIASES)
aliases[nalias++] = p;
}
aliases[nalias] = NULL;
hp->h_addrtype = af;
hp->h_length = addrlen;
hp->h_addr_list = addrs;
addrs[0] = (char *)&addrbuf;
addrs[1] = NULL;
hp = _hpcopy(hp, errp);
break;
}
fclose(fp);
*(struct hostent **)rval = hp;
return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
}
#ifdef YP
/*
* NIS
*
* XXX actually a hack, these are INET4 specific.
*/
static int
_nis_ghbyname(void *rval, void *cb_data, va_list ap)
{
const char *name;
int af;
int *errp;
struct hostent *hp = NULL;
name = va_arg(ap, const char *);
af = va_arg(ap, int);
errp = va_arg(ap, int *);
if (af == AF_UNSPEC)
af = AF_INET;
if (af == AF_INET) {
hp = _gethostbynisname(name, af);
if (hp != NULL)
hp = _hpcopy(hp, errp);
}
*(struct hostent **)rval = hp;
return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
}
static int
_nis_ghbyaddr(void *rval, void *cb_data, va_list ap)
{
const void *addr;
int addrlen;
int af;
int *errp;
struct hostent *hp = NULL;
addr = va_arg(ap, const void *);
addrlen = va_arg(ap, int);
af = va_arg(ap, int);
if (af == AF_INET) {
hp = _gethostbynisaddr(addr, addrlen, af);
if (hp != NULL)
hp = _hpcopy(hp, errp);
}
*(struct hostent **)rval = hp;
return (hp != NULL) ? NS_SUCCESS : NS_NOTFOUND;
}
#endif
struct __res_type_list {
SLIST_ENTRY(__res_type_list) rtl_entry;
int rtl_type;
};
#if PACKETSZ > 1024
#define MAXPACKET PACKETSZ
#else
#define MAXPACKET 1024
#endif
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
static struct hostent *getanswer __P((const querybuf *, int, const char *,
int, struct hostent *, int *));
/*
* we don't need to take care about sorting, nor IPv4 mapped address here.
*/
static struct hostent *
getanswer(answer, anslen, qname, qtype, template, errp)
const querybuf *answer;
int anslen;
const char *qname;
int qtype;
struct hostent *template;
int *errp;
{
register const HEADER *hp;
register const u_char *cp;
register int n;
const u_char *eom, *erdata;
char *bp, **ap, **hap;
int type, class, buflen, ancount, qdcount;
int haveanswer, had_error;
char tbuf[MAXDNAME];
const char *tname;
int (*name_ok) __P((const char *));
static char *h_addr_ptrs[MAXADDRS + 1];
static char *host_aliases[MAXALIASES];
static char hostbuf[8*1024];
#define BOUNDED_INCR(x) \
do { \
cp += x; \
if (cp > eom) { \
*errp = NO_RECOVERY; \
return (NULL); \
} \
} while (0)
#define BOUNDS_CHECK(ptr, count) \
do { \
if ((ptr) + (count) > eom) { \
*errp = NO_RECOVERY; \
return (NULL); \
} \
} while (0)
/* XXX do {} while (0) cannot be put here */
#define DNS_ASSERT(x) \
{ \
if (!(x)) { \
cp += n; \
continue; \
} \
}
/* XXX do {} while (0) cannot be put here */
#define DNS_FATAL(x) \
{ \
if (!(x)) { \
had_error++; \
continue; \
} \
}
tname = qname;
template->h_name = NULL;
eom = answer->buf + anslen;
switch (qtype) {
case T_A:
case T_AAAA:
name_ok = res_hnok;
break;
case T_PTR:
name_ok = res_dnok;
break;
default:
return (NULL); /* XXX should be abort(); */
}
/*
* find first satisfactory answer
*/
hp = &answer->hdr;
ancount = ntohs(hp->ancount);
qdcount = ntohs(hp->qdcount);
bp = hostbuf;
buflen = sizeof hostbuf;
cp = answer->buf;
BOUNDED_INCR(HFIXEDSZ);
if (qdcount != 1) {
*errp = NO_RECOVERY;
return (NULL);
}
n = dn_expand(answer->buf, eom, cp, bp, buflen);
if ((n < 0) || !(*name_ok)(bp)) {
*errp = NO_RECOVERY;
return (NULL);
}
BOUNDED_INCR(n + QFIXEDSZ);
if (qtype == T_A || qtype == T_AAAA) {
/* res_send() has already verified that the query name is the
* same as the one we sent; this just gets the expanded name
* (i.e., with the succeeding search-domain tacked on).
*/
n = strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
*errp = NO_RECOVERY;
return (NULL);
}
template->h_name = bp;
bp += n;
buflen -= n;
/* The qname can be abbreviated, but h_name is now absolute. */
qname = template->h_name;
}
ap = host_aliases;
*ap = NULL;
template->h_aliases = host_aliases;
hap = h_addr_ptrs;
*hap = NULL;
template->h_addr_list = h_addr_ptrs;
haveanswer = 0;
had_error = 0;
while (ancount-- > 0 && cp < eom && !had_error) {
n = dn_expand(answer->buf, eom, cp, bp, buflen);
DNS_FATAL(n >= 0);
DNS_FATAL((*name_ok)(bp));
cp += n; /* name */
BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
type = _getshort(cp);
cp += INT16SZ; /* type */
class = _getshort(cp);
cp += INT16SZ + INT32SZ; /* class, TTL */
n = _getshort(cp);
cp += INT16SZ; /* len */
BOUNDS_CHECK(cp, n);
erdata = cp + n;
DNS_ASSERT(class == C_IN);
if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
if (ap >= &host_aliases[MAXALIASES-1])
continue;
n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
DNS_FATAL(n >= 0);
DNS_FATAL((*name_ok)(tbuf));
cp += n;
if (cp != erdata) {
*errp = NO_RECOVERY;
return (NULL);
}
/* Store alias. */
*ap++ = bp;
n = strlen(bp) + 1; /* for the \0 */
DNS_FATAL(n < MAXHOSTNAMELEN);
bp += n;
buflen -= n;
/* Get canonical name. */
n = strlen(tbuf) + 1; /* for the \0 */
DNS_FATAL(n <= buflen);
DNS_FATAL(n < MAXHOSTNAMELEN);
strcpy(bp, tbuf);
template->h_name = bp;
bp += n;
buflen -= n;
continue;
}
if (qtype == T_PTR && type == T_CNAME) {
n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
if (n < 0 || !res_dnok(tbuf)) {
had_error++;
continue;
}
cp += n;
if (cp != erdata) {
*errp = NO_RECOVERY;
return (NULL);
}
/* Get canonical name. */
n = strlen(tbuf) + 1; /* for the \0 */
if (n > buflen || n >= MAXHOSTNAMELEN) {
had_error++;
continue;
}
strcpy(bp, tbuf);
tname = bp;
bp += n;
buflen -= n;
continue;
}
DNS_ASSERT(type == qtype);
switch (type) {
case T_PTR:
DNS_ASSERT(strcasecmp(tname, bp) == 0);
n = dn_expand(answer->buf, eom, cp, bp, buflen);
DNS_FATAL(n >= 0);
DNS_FATAL(res_hnok(bp));
#if MULTI_PTRS_ARE_ALIASES
cp += n;
if (cp != erdata) {
*errp = NO_RECOVERY;
return (NULL);
}
if (!haveanswer)
template->h_name = bp;
else if (ap < &host_aliases[MAXALIASES-1])
*ap++ = bp;
else
n = -1;
if (n != -1) {
n = strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
had_error++;
break;
}
bp += n;
buflen -= n;
}
break;
#else
template->h_name = bp;
*errp = NETDB_SUCCESS;
return (template);
#endif
case T_A:
case T_AAAA:
DNS_ASSERT(strcasecmp(template->h_name, bp) == 0);
DNS_ASSERT(n == template->h_length);
if (!haveanswer) {
register int nn;
template->h_name = bp;
nn = strlen(bp) + 1; /* for the \0 */
bp += nn;
buflen -= nn;
}
bp = (char *)ALIGN(bp);
DNS_FATAL(bp + n < &hostbuf[sizeof hostbuf]);
DNS_ASSERT(hap < &h_addr_ptrs[MAXADDRS-1]);
#ifdef FILTER_V4MAPPED
if (type == T_AAAA) {
struct in6_addr in6;
memcpy(&in6, cp, sizeof(in6));
DNS_ASSERT(IN6_IS_ADDR_V4MAPPED(&in6) == 0);
}
#endif
bcopy(cp, *hap++ = bp, n);
bp += n;
buflen -= n;
cp += n;
if (cp != erdata) {
*errp = NO_RECOVERY;
return (NULL);
}
break;
default:
abort();
}
if (!had_error)
haveanswer++;
}
if (haveanswer) {
*ap = NULL;
*hap = NULL;
if (!template->h_name) {
n = strlen(qname) + 1; /* for the \0 */
if (n > buflen || n >= MAXHOSTNAMELEN)
goto no_recovery;
strcpy(bp, qname);
template->h_name = bp;
bp += n;
buflen -= n;
}
*errp = NETDB_SUCCESS;
return (template);
}
no_recovery:
*errp = NO_RECOVERY;
return (NULL);
#undef BOUNDED_INCR
#undef BOUNDS_CHECK
#undef DNS_ASSERT
#undef DNS_FATAL
}
/* res_search() variant with multiple query support. */
static struct hostent *
_res_search_multi(name, rtl, errp)
const char *name; /* domain name */
struct __res_type_list *rtl; /* list of query types */
int *errp;
{
const char *cp, * const *domain;
struct hostent *hp0 = NULL, *hp;
struct hostent hpbuf;
u_int dots;
int trailing_dot, ret, saved_herrno;
int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
struct __res_type_list *rtl0 = rtl;
querybuf buf;
if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
*errp = NETDB_INTERNAL;
return (NULL);
}
dots = 0;
for (cp = name; *cp; cp++)
dots += (*cp == '.');
trailing_dot = 0;
if (cp > name && *--cp == '.')
trailing_dot++;
/* If there aren't any dots, it could be a user-level alias */
if (!dots && (cp = hostalias(name)) != NULL) {
for(rtl = rtl0; rtl != NULL;
rtl = SLIST_NEXT(rtl, rtl_entry)) {
ret = res_query(cp, C_IN, rtl->rtl_type, buf.buf,
sizeof(buf.buf));
if (ret > 0) {
hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
? AF_INET6 : AF_INET;
hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
hp = getanswer(&buf, ret, name, rtl->rtl_type,
&hpbuf, errp);
if (!hp)
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
}
}
return (hp0);
}
/*
* If there are dots in the name already, let's just give it a try
* 'as is'. The threshold can be set with the "ndots" option.
*/
saved_herrno = -1;
if (dots >= _res.ndots) {
for(rtl = rtl0; rtl != NULL;
rtl = SLIST_NEXT(rtl, rtl_entry)) {
ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type,
buf.buf, sizeof(buf.buf));
if (ret > 0) {
hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
? AF_INET6 : AF_INET;
hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
hp = getanswer(&buf, ret, name, rtl->rtl_type,
&hpbuf, errp);
if (!hp)
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
}
}
if (hp0 != NULL)
return (hp0);
saved_herrno = *errp;
tried_as_is++;
}
/*
* We do at least one level of search if
* - there is no dot and RES_DEFNAME is set, or
* - there is at least one dot, there is no trailing dot,
* and RES_DNSRCH is set.
*/
if ((!dots && (_res.options & RES_DEFNAMES)) ||
(dots && !trailing_dot && (_res.options & RES_DNSRCH))) {
int done = 0;
for (domain = (const char * const *)_res.dnsrch;
*domain && !done;
domain++) {
for(rtl = rtl0; rtl != NULL;
rtl = SLIST_NEXT(rtl, rtl_entry)) {
ret = res_querydomain(name, *domain, C_IN,
rtl->rtl_type,
buf.buf, sizeof(buf.buf));
if (ret > 0) {
hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
? AF_INET6 : AF_INET;
hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
hp = getanswer(&buf, ret, name,
rtl->rtl_type, &hpbuf, errp);
if (!hp)
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
}
}
if (hp0 != NULL)
return (hp0);
/*
* If no server present, give up.
* If name isn't found in this domain,
* keep trying higher domains in the search list
* (if that's enabled).
* On a NO_DATA error, keep trying, otherwise
* a wildcard entry of another type could keep us
* from finding this entry higher in the domain.
* If we get some other error (negative answer or
* server failure), then stop searching up,
* but try the input name below in case it's
* fully-qualified.
*/
if (errno == ECONNREFUSED) {
*errp = TRY_AGAIN;
return (NULL);
}
switch (*errp) {
case NO_DATA:
got_nodata++;
/* FALLTHROUGH */
case HOST_NOT_FOUND:
/* keep trying */
break;
case TRY_AGAIN:
if (buf.hdr.rcode == SERVFAIL) {
/* try next search element, if any */
got_servfail++;
break;
}
/* FALLTHROUGH */
default:
/* anything else implies that we're done */
done++;
}
/* if we got here for some reason other than DNSRCH,
* we only wanted one iteration of the loop, so stop.
*/
if (!(_res.options & RES_DNSRCH))
done++;
}
}
/*
* If we have not already tried the name "as is", do that now.
* note that we do this regardless of how many dots were in the
* name or whether it ends with a dot unless NOTLDQUERY is set.
*/
if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {
for(rtl = rtl0; rtl != NULL;
rtl = SLIST_NEXT(rtl, rtl_entry)) {
ret = res_querydomain(name, NULL, C_IN, rtl->rtl_type,
buf.buf, sizeof(buf.buf));
if (ret > 0) {
hpbuf.h_addrtype = (rtl->rtl_type == T_AAAA)
? AF_INET6 : AF_INET;
hpbuf.h_length = ADDRLEN(hpbuf.h_addrtype);
hp = getanswer(&buf, ret, name, rtl->rtl_type,
&hpbuf, errp);
if (!hp)
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
}
}
if (hp0 != NULL)
return (hp0);
}
/* if we got here, we didn't satisfy the search.
* if we did an initial full query, return that query's h_errno
* (note that we wouldn't be here if that query had succeeded).
* else if we ever got a nodata, send that back as the reason.
* else send back meaningless h_errno, that being the one from
* the last DNSRCH we did.
*/
if (saved_herrno != -1)
*errp = saved_herrno;
else if (got_nodata)
*errp = NO_DATA;
else if (got_servfail)
*errp = TRY_AGAIN;
return (NULL);
}
static int
_dns_ghbyname(void *rval, void *cb_data, va_list ap)
{
const char *name;
int af;
int *errp;
struct __res_type_list *rtl, rtl4;
#ifdef INET6
struct __res_type_list rtl6;
#endif
name = va_arg(ap, const char *);
af = va_arg(ap, int);
errp = va_arg(ap, int *);
#ifdef INET6
switch (af) {
case AF_UNSPEC:
SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
SLIST_NEXT(&rtl6, rtl_entry) = &rtl4; rtl6.rtl_type = T_AAAA;
rtl = &rtl6;
break;
case AF_INET6:
SLIST_NEXT(&rtl6, rtl_entry) = NULL; rtl6.rtl_type = T_AAAA;
rtl = &rtl6;
break;
case AF_INET:
SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
rtl = &rtl4;
break;
}
#else
SLIST_NEXT(&rtl4, rtl_entry) = NULL; rtl4.rtl_type = T_A;
rtl = &rtl4;
#endif
*(struct hostent **)rval = _res_search_multi(name, rtl, errp);
return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
}
static int
_dns_ghbyaddr(void *rval, void *cb_data, va_list ap)
{
const void *addr;
int addrlen;
int af;
int *errp;
int n;
struct hostent *hp;
u_char c, *cp;
char *bp;
struct hostent hbuf;
int na;
#ifdef INET6
static const char hex[] = "0123456789abcdef";
#endif
querybuf buf;
char qbuf[MAXDNAME+1];
char *hlist[2];
addr = va_arg(ap, const void *);
addrlen = va_arg(ap, int);
af = va_arg(ap, int);
errp = va_arg(ap, int *);
*(struct hostent **)rval = NULL;
#ifdef INET6
/* XXX */
if (af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr))
return NS_NOTFOUND;
#endif
if ((_res.options & RES_INIT) == 0) {
if (res_init() < 0) {
*errp = h_errno;
return NS_UNAVAIL;
}
}
memset(&hbuf, 0, sizeof(hbuf));
hbuf.h_name = NULL;
hbuf.h_addrtype = af;
hbuf.h_length = addrlen;
na = 0;
/* XXX assumes that MAXDNAME is big enough */
n = 0;
bp = qbuf;
cp = (u_char *)addr+addrlen-1;
switch (af) {
#ifdef INET6
case AF_INET6:
for (; n < addrlen; n++, cp--) {
c = *cp;
*bp++ = hex[c & 0xf];
*bp++ = '.';
*bp++ = hex[c >> 4];
*bp++ = '.';
}
strcpy(bp, "ip6.int");
break;
#endif
default:
for (; n < addrlen; n++, cp--) {
c = *cp;
if (c >= 100)
*bp++ = '0' + c / 100;
if (c >= 10)
*bp++ = '0' + (c % 100) / 10;
*bp++ = '0' + c % 10;
*bp++ = '.';
}
strcpy(bp, "in-addr.arpa");
break;
}
n = res_query(qbuf, C_IN, T_PTR, buf.buf, sizeof buf.buf);
if (n < 0) {
*errp = h_errno;
return NS_UNAVAIL;
}
hp = getanswer(&buf, n, qbuf, T_PTR, &hbuf, errp);
if (!hp)
return NS_NOTFOUND;
hbuf.h_addrtype = af;
hbuf.h_length = addrlen;
hbuf.h_addr_list = hlist;
hlist[0] = (char *)addr;
hlist[1] = NULL;
*(struct hostent **)rval = _hpcopy(&hbuf, errp);
return NS_SUCCESS;
}
static void
_dns_shent(int stayopen)
{
if ((_res.options & RES_INIT) == 0) {
if (res_init() < 0)
return;
}
if (stayopen)
_res.options |= RES_STAYOPEN | RES_USEVC;
}
static void
_dns_ehent(void)
{
_res.options &= ~(RES_STAYOPEN | RES_USEVC);
res_close();
}
#ifdef ICMPNL
/*
* experimental:
* draft-ietf-ipngwg-icmp-namelookups-02.txt
* ifindex is assumed to be encoded in addr.
*/
#include <sys/uio.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
struct _icmp_host_cache {
struct _icmp_host_cache *hc_next;
int hc_ifindex;
struct in6_addr hc_addr;
char *hc_name;
};
static char *
_icmp_fqdn_query(const struct in6_addr *addr, int ifindex)
{
int s;
struct icmp6_filter filter;
struct msghdr msg;
struct cmsghdr *cmsg;
struct in6_pktinfo *pkt;
char cbuf[256];
char buf[1024];
int cc;
struct icmp6_fqdn_query *fq;
struct icmp6_fqdn_reply *fr;
struct _icmp_host_cache *hc;
struct sockaddr_in6 sin6;
struct iovec iov;
fd_set s_fds, fds;
struct timeval tout;
int len;
char *name;
static int pid;
static struct _icmp_host_cache *hc_head;
for (hc = hc_head; hc; hc = hc->hc_next) {
if (hc->hc_ifindex == ifindex
&& IN6_ARE_ADDR_EQUAL(&hc->hc_addr, addr))
return hc->hc_name;
}
if (pid == 0)
pid = getpid();
ICMP6_FILTER_SETBLOCKALL(&filter);
ICMP6_FILTER_SETPASS(ICMP6_FQDN_REPLY, &filter);
FD_ZERO(&s_fds);
tout.tv_sec = 0;
tout.tv_usec = 200000; /*XXX: 200ms*/
fq = (struct icmp6_fqdn_query *)buf;
fq->icmp6_fqdn_type = ICMP6_FQDN_QUERY;
fq->icmp6_fqdn_code = 0;
fq->icmp6_fqdn_cksum = 0;
fq->icmp6_fqdn_id = (u_short)pid;
fq->icmp6_fqdn_unused = 0;
fq->icmp6_fqdn_cookie[0] = 0;
fq->icmp6_fqdn_cookie[1] = 0;
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = *addr;
memset(&msg, 0, sizeof(msg));
msg.msg_name = (caddr_t)&sin6;
msg.msg_namelen = sizeof(sin6);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = NULL;
msg.msg_controllen = 0;
iov.iov_base = (caddr_t)buf;
iov.iov_len = sizeof(struct icmp6_fqdn_query);
if (ifindex) {
msg.msg_control = cbuf;
msg.msg_controllen = sizeof(cbuf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
cmsg->cmsg_level = IPPROTO_IPV6;
cmsg->cmsg_type = IPV6_PKTINFO;
pkt = (struct in6_pktinfo *)&cmsg[1];
memset(&pkt->ipi6_addr, 0, sizeof(struct in6_addr));
pkt->ipi6_ifindex = ifindex;
cmsg = CMSG_NXTHDR(&msg, cmsg);
msg.msg_controllen = (char *)cmsg - cbuf;
}
if ((s = _socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0)
return NULL;
(void)_setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER,
(char *)&filter, sizeof(filter));
cc = _sendmsg(s, &msg, 0);
if (cc < 0) {
_close(s);
return NULL;
}
FD_SET(s, &s_fds);
for (;;) {
fds = s_fds;
if (_select(s + 1, &fds, NULL, NULL, &tout) <= 0) {
_close(s);
return NULL;
}
len = sizeof(sin6);
cc = _recvfrom(s, buf, sizeof(buf), 0,
(struct sockaddr *)&sin6, &len);
if (cc <= 0) {
_close(s);
return NULL;
}
if (cc < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr))
continue;
if (!IN6_ARE_ADDR_EQUAL(addr, &sin6.sin6_addr))
continue;
fr = (struct icmp6_fqdn_reply *)(buf + sizeof(struct ip6_hdr));
if (fr->icmp6_fqdn_type == ICMP6_FQDN_REPLY)
break;
}
_close(s);
if (fr->icmp6_fqdn_cookie[1] != 0) {
/* rfc1788 type */
name = buf + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 4;
len = (buf + cc) - name;
} else {
len = fr->icmp6_fqdn_namelen;
name = fr->icmp6_fqdn_name;
}
if (len <= 0)
return NULL;
name[len] = 0;
if ((hc = (struct _icmp_host_cache *)malloc(sizeof(*hc))) == NULL)
return NULL;
/* XXX: limit number of cached entries */
hc->hc_ifindex = ifindex;
hc->hc_addr = *addr;
hc->hc_name = strdup(name);
hc->hc_next = hc_head;
hc_head = hc;
return hc->hc_name;
}
static struct hostent *
_icmp_ghbyaddr(const void *addr, int addrlen, int af, int *errp)
{
char *hname;
int ifindex;
struct in6_addr addr6;
if (af != AF_INET6) {
/*
* Note: rfc1788 defines Who Are You for IPv4,
* but no one implements it.
*/
return NULL;
}
memcpy(&addr6, addr, addrlen);
ifindex = (addr6.s6_addr[2] << 8) | addr6.s6_addr[3];
addr6.s6_addr[2] = addr6.s6_addr[3] = 0;
if (!IN6_IS_ADDR_LINKLOCAL(&addr6))
return NULL; /*XXX*/
if ((hname = _icmp_fqdn_query(&addr6, ifindex)) == NULL)
return NULL;
return _hpaddr(af, hname, &addr6, errp);
}
#endif /* ICMPNL */