glibc/resolv/compat-gethnamaddr.c
Florian Weimer 640bbdf71c resolv: Move dn_expand to its own file and into libc
And reformat to GNU style.

This switches back to the dn_expand name for the ABI symbol and turns
__dn_expand into a compatibility symbol.  With the improved namespace
management in current glibc, it is no longer necessary to use a
private namespace symbol.  To avoid old code binding to a
GLIBC_PRIVATE symbol by accident, use __libc_dn_expand for the
internal symbol name.

The symbols dn_expand, __dnexpand were moved using
scripts/move-symbol-to-libc.py, followed by an adjustment to make
dn_expand the only GLIBC_2.34 symbol.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 07:56:21 +02:00

919 lines
22 KiB
C

/*
* ++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.
* 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--
*/
/* XXX This file is not used by any of the resolver functions implemented by
glibc (i.e. get*info and gethostby*). It cannot be removed however because
it exports symbols in the libresolv ABI. The file is not maintained any
more, nor are these functions. */
#include <shlib-compat.h>
#if SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_25)
# include <sys/types.h>
# include <sys/param.h>
# include <sys/socket.h>
# include <netinet/in.h>
# include <arpa/inet.h>
# include <arpa/nameser.h>
# include <stdio.h>
# include <netdb.h>
# include <resolv/resolv-internal.h>
# include <resolv/resolv_context.h>
# include <ctype.h>
# include <errno.h>
# include <stdlib.h>
# include <string.h>
# define MAXALIASES 35
# define MAXADDRS 35
static char *h_addr_ptrs[MAXADDRS + 1];
static struct hostent host;
static char *host_aliases[MAXALIASES];
static char hostbuf[8*1024];
static u_char host_addr[16]; /* IPv4 or IPv6 */
static FILE *hostf = NULL;
static int stayopen = 0;
static struct hostent *res_gethostbyname2_context (struct resolv_context *,
const char *name, int af);
static void map_v4v6_address (const char *src, char *dst) __THROW;
static void map_v4v6_hostent (struct hostent *hp, char **bp, int *len) __THROW;
extern void addrsort (char **, int) __THROW;
# if PACKETSZ > 65536
# define MAXPACKET PACKETSZ
# else
# define MAXPACKET 65536
# endif
/* As per RFC 1034 and 1035 a host name cannot exceed 255 octets in length. */
# ifdef MAXHOSTNAMELEN
# undef MAXHOSTNAMELEN
# endif
# define MAXHOSTNAMELEN 256
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
typedef union {
int32_t al;
char ac;
} align;
# ifndef h_errno
extern int h_errno;
# endif
# define BOUNDED_INCR(x) \
do { \
cp += x; \
if (cp > eom) { \
__set_h_errno (NO_RECOVERY); \
return (NULL); \
} \
} while (0)
# define BOUNDS_CHECK(ptr, count) \
do { \
if ((ptr) + (count) > eom) { \
__set_h_errno (NO_RECOVERY); \
return (NULL); \
} \
} while (0)
static struct hostent *
getanswer (const querybuf *answer, int anslen, const char *qname, int qtype)
{
const HEADER *hp;
const u_char *cp;
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) (const char *);
tname = qname;
host.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) {
__set_h_errno (NO_RECOVERY);
return (NULL);
}
n = __libc_dn_expand (answer->buf, eom, cp, bp, buflen);
if ((n < 0) || !(*name_ok)(bp)) {
__set_h_errno (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) {
__set_h_errno (NO_RECOVERY);
return (NULL);
}
host.h_name = bp;
bp += n;
buflen -= n;
/* The qname can be abbreviated, but h_name is now absolute. */
qname = host.h_name;
}
ap = host_aliases;
*ap = NULL;
host.h_aliases = host_aliases;
hap = h_addr_ptrs;
*hap = NULL;
host.h_addr_list = h_addr_ptrs;
haveanswer = 0;
had_error = 0;
while (ancount-- > 0 && cp < eom && !had_error) {
n = __libc_dn_expand (answer->buf, eom, cp, bp, buflen);
if ((n < 0) || !(*name_ok)(bp)) {
had_error++;
continue;
}
cp += n; /* name */
BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
type = ns_get16(cp);
cp += INT16SZ; /* type */
class = ns_get16(cp);
cp += INT16SZ + INT32SZ; /* class, TTL */
n = ns_get16(cp);
cp += INT16SZ; /* len */
BOUNDS_CHECK(cp, n);
erdata = cp + n;
if (class != C_IN) {
/* XXX - debug? syslog? */
cp += n;
continue; /* XXX - had_error++ ? */
}
if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
if (ap >= &host_aliases[MAXALIASES-1])
continue;
n = __libc_dn_expand (answer->buf, eom, cp,
tbuf, sizeof tbuf);
if ((n < 0) || !(*name_ok)(tbuf)) {
had_error++;
continue;
}
cp += n;
if (cp != erdata) {
__set_h_errno (NO_RECOVERY);
return (NULL);
}
/* Store alias. */
*ap++ = bp;
n = strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
had_error++;
continue;
}
bp += n;
buflen -= n;
/* Get canonical name. */
n = strlen(tbuf) + 1; /* for the \0 */
if (n > buflen || n >= MAXHOSTNAMELEN) {
had_error++;
continue;
}
strcpy(bp, tbuf);
host.h_name = bp;
bp += n;
buflen -= n;
continue;
}
if (qtype == T_PTR && type == T_CNAME) {
n = __libc_dn_expand (answer->buf, eom, cp,
tbuf, sizeof tbuf);
if (n < 0 || !res_dnok(tbuf)) {
had_error++;
continue;
}
cp += n;
if (cp != erdata) {
__set_h_errno (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;
}
if (type != qtype) {
/* Log a low priority message if we get an unexpected
* record, but skip it if we are using DNSSEC since it
* uses many different types in responses that do not
* match QTYPE.
*/
cp += n;
continue; /* XXX - had_error++ ? */
}
switch (type) {
case T_PTR:
if (strcasecmp(tname, bp) != 0) {
cp += n;
continue; /* XXX - had_error++ ? */
}
n = __libc_dn_expand (answer->buf, eom, cp,
bp, buflen);
if ((n < 0) || !res_hnok(bp)) {
had_error++;
break;
}
cp += n;
if (cp != erdata) {
__set_h_errno (NO_RECOVERY);
return (NULL);
}
if (!haveanswer)
host.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;
case T_A:
case T_AAAA:
if (strcasecmp(host.h_name, bp) != 0) {
cp += n;
continue; /* XXX - had_error++ ? */
}
if (n != host.h_length) {
cp += n;
continue;
}
if (!haveanswer) {
int nn;
host.h_name = bp;
nn = strlen(bp) + 1; /* for the \0 */
bp += nn;
buflen -= nn;
}
/* XXX: when incrementing bp, we have to decrement
* buflen by the same amount --okir */
buflen -= sizeof(align) - ((u_long)bp % sizeof(align));
bp += sizeof(align) - ((u_long)bp % sizeof(align));
if (bp + n >= &hostbuf[sizeof hostbuf]) {
had_error++;
continue;
}
if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
cp += n;
continue;
}
memmove(*hap++ = bp, cp, n);
bp += n;
buflen -= n;
cp += n;
if (cp != erdata) {
__set_h_errno (NO_RECOVERY);
return (NULL);
}
break;
default:
abort();
}
if (!had_error)
haveanswer++;
}
if (haveanswer) {
*ap = NULL;
*hap = NULL;
/*
* Note: we sort even if host can take only one address
* in its return structures - should give it the "best"
* address in that case, not some random one
*/
if (_res.nsort && haveanswer > 1 && qtype == T_A)
addrsort(h_addr_ptrs, haveanswer);
if (!host.h_name) {
n = strlen(qname) + 1; /* for the \0 */
if (n > buflen || n >= MAXHOSTNAMELEN)
goto no_recovery;
strcpy(bp, qname);
host.h_name = bp;
bp += n;
buflen -= n;
}
if (res_use_inet6 ())
map_v4v6_hostent(&host, &bp, &buflen);
__set_h_errno (NETDB_SUCCESS);
return (&host);
}
no_recovery:
__set_h_errno (NO_RECOVERY);
return (NULL);
}
extern struct hostent *res_gethostbyname2(const char *name, int af);
libresolv_hidden_proto (res_gethostbyname2)
struct hostent *
res_gethostbyname (const char *name)
{
struct resolv_context *ctx = __resolv_context_get ();
if (ctx == NULL)
{
__set_h_errno (NETDB_INTERNAL);
return NULL;
}
if (res_use_inet6 ())
{
struct hostent *hp = res_gethostbyname2_context (ctx, name, AF_INET6);
if (hp != NULL)
{
__resolv_context_put (ctx);
return hp;
}
}
struct hostent *hp = res_gethostbyname2_context (ctx, name, AF_INET);
__resolv_context_put (ctx);
return hp;
}
compat_symbol (libresolv, res_gethostbyname, res_gethostbyname, GLIBC_2_0);
static struct hostent *
res_gethostbyname2_context (struct resolv_context *ctx,
const char *name, int af)
{
union
{
querybuf *buf;
u_char *ptr;
} buf;
querybuf *origbuf;
const char *cp;
char *bp;
int n, size, type, len;
struct hostent *ret;
switch (af) {
case AF_INET:
size = INADDRSZ;
type = T_A;
break;
case AF_INET6:
size = IN6ADDRSZ;
type = T_AAAA;
break;
default:
__set_h_errno (NETDB_INTERNAL);
__set_errno (EAFNOSUPPORT);
return (NULL);
}
host.h_addrtype = af;
host.h_length = size;
/*
* 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.
*/
char abuf[MAXDNAME];
if (strchr (name, '.') != NULL
&& (cp = __res_context_hostalias (ctx, name, abuf, sizeof (abuf))))
name = cp;
/*
* disallow names consisting only of digits/dots, unless
* they end in a dot.
*/
if (isdigit(name[0]))
for (cp = name;; ++cp) {
if (!*cp) {
if (*--cp == '.')
break;
/*
* All-numeric, no dot at the end.
* Fake up a hostent as if we'd actually
* done a lookup.
*/
if (inet_pton(af, name, host_addr) <= 0) {
__set_h_errno (HOST_NOT_FOUND);
return (NULL);
}
strncpy(hostbuf, name, MAXDNAME);
hostbuf[MAXDNAME] = '\0';
bp = hostbuf + MAXDNAME;
len = sizeof hostbuf - MAXDNAME;
host.h_name = hostbuf;
host.h_aliases = host_aliases;
host_aliases[0] = NULL;
h_addr_ptrs[0] = (char *)host_addr;
h_addr_ptrs[1] = NULL;
host.h_addr_list = h_addr_ptrs;
if (res_use_inet6 ())
map_v4v6_hostent(&host, &bp, &len);
__set_h_errno (NETDB_SUCCESS);
return (&host);
}
if (!isdigit(*cp) && *cp != '.')
break;
}
if ((isxdigit(name[0]) && strchr(name, ':') != NULL) ||
name[0] == ':')
for (cp = name;; ++cp) {
if (!*cp) {
if (*--cp == '.')
break;
/*
* All-IPv6-legal, no dot at the end.
* Fake up a hostent as if we'd actually
* done a lookup.
*/
if (inet_pton(af, name, host_addr) <= 0) {
__set_h_errno (HOST_NOT_FOUND);
return (NULL);
}
strncpy(hostbuf, name, MAXDNAME);
hostbuf[MAXDNAME] = '\0';
bp = hostbuf + MAXDNAME;
len = sizeof hostbuf - MAXDNAME;
host.h_name = hostbuf;
host.h_aliases = host_aliases;
host_aliases[0] = NULL;
h_addr_ptrs[0] = (char *)host_addr;
h_addr_ptrs[1] = NULL;
host.h_addr_list = h_addr_ptrs;
__set_h_errno (NETDB_SUCCESS);
return (&host);
}
if (!isxdigit(*cp) && *cp != ':' && *cp != '.')
break;
}
buf.buf = origbuf = (querybuf *) alloca (1024);
if ((n = __res_context_search
(ctx, name, C_IN, type, buf.buf->buf, 1024,
&buf.ptr, NULL, NULL, NULL, NULL)) < 0) {
if (buf.buf != origbuf)
free (buf.buf);
if (errno == ECONNREFUSED)
return (_gethtbyname2(name, af));
return (NULL);
}
ret = getanswer(buf.buf, n, name, type);
if (buf.buf != origbuf)
free (buf.buf);
return ret;
}
struct hostent *
res_gethostbyname2 (const char *name, int af)
{
struct resolv_context *ctx = __resolv_context_get ();
if (ctx == NULL)
{
__set_h_errno (NETDB_INTERNAL);
return NULL;
}
struct hostent *hp = res_gethostbyname2_context (ctx, name, AF_INET);
__resolv_context_put (ctx);
return hp;
}
libresolv_hidden_def (res_gethostbyname2)
compat_symbol (libresolv, res_gethostbyname2, res_gethostbyname2, GLIBC_2_0);
static struct hostent *
res_gethostbyaddr_context (struct resolv_context *ctx,
const void *addr, socklen_t len, int af)
{
const u_char *uaddr = (const u_char *)addr;
static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
int n;
socklen_t size;
union
{
querybuf *buf;
u_char *ptr;
} buf;
querybuf *orig_buf;
struct hostent *hp;
char qbuf[MAXDNAME+1], *qp = NULL;
if (af == AF_INET6 && len == IN6ADDRSZ &&
(!memcmp(uaddr, mapped, sizeof mapped) ||
!memcmp(uaddr, tunnelled, sizeof tunnelled))) {
/* Unmap. */
addr += sizeof mapped;
uaddr += sizeof mapped;
af = AF_INET;
len = INADDRSZ;
}
switch (af) {
case AF_INET:
size = INADDRSZ;
break;
case AF_INET6:
size = IN6ADDRSZ;
break;
default:
__set_errno (EAFNOSUPPORT);
__set_h_errno (NETDB_INTERNAL);
return (NULL);
}
if (size != len) {
__set_errno (EINVAL);
__set_h_errno (NETDB_INTERNAL);
return (NULL);
}
switch (af) {
case AF_INET:
(void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa",
(uaddr[3] & 0xff),
(uaddr[2] & 0xff),
(uaddr[1] & 0xff),
(uaddr[0] & 0xff));
break;
case AF_INET6:
qp = qbuf;
for (n = IN6ADDRSZ - 1; n >= 0; n--) {
qp += sprintf(qp, "%x.%x.",
uaddr[n] & 0xf,
(uaddr[n] >> 4) & 0xf);
}
strcpy(qp, "ip6.arpa");
break;
default:
abort();
}
buf.buf = orig_buf = (querybuf *) alloca (1024);
n = __res_context_query (ctx, qbuf, C_IN, T_PTR, buf.buf->buf, 1024,
&buf.ptr, NULL, NULL, NULL, NULL);
if (n < 0) {
if (buf.buf != orig_buf)
free (buf.buf);
if (errno == ECONNREFUSED)
return (_gethtbyaddr(addr, len, af));
return (NULL);
}
hp = getanswer(buf.buf, n, qbuf, T_PTR);
if (buf.buf != orig_buf)
free (buf.buf);
if (!hp)
return (NULL); /* h_errno was set by getanswer() */
hp->h_addrtype = af;
hp->h_length = len;
memmove(host_addr, addr, len);
h_addr_ptrs[0] = (char *)host_addr;
h_addr_ptrs[1] = NULL;
if (af == AF_INET && res_use_inet6 ()) {
map_v4v6_address((char*)host_addr, (char*)host_addr);
hp->h_addrtype = AF_INET6;
hp->h_length = IN6ADDRSZ;
}
__set_h_errno (NETDB_SUCCESS);
return (hp);
}
struct hostent *
res_gethostbyaddr (const void *addr, socklen_t len, int af)
{
struct resolv_context *ctx = __resolv_context_get ();
if (ctx == NULL)
{
__set_h_errno (NETDB_INTERNAL);
return NULL;
}
struct hostent *hp = res_gethostbyaddr_context (ctx, addr, len, af);
__resolv_context_put (ctx);
return hp;
}
compat_symbol (libresolv, res_gethostbyaddr, res_gethostbyaddr, GLIBC_2_0);
void
_sethtent (int f)
{
if (!hostf)
hostf = fopen(_PATH_HOSTS, "rce" );
else
rewind(hostf);
stayopen = f;
}
libresolv_hidden_def (_sethtent)
compat_symbol (libresolv, _sethtent, _sethtent, GLIBC_2_0);
static void
_endhtent (void)
{
if (hostf && !stayopen) {
(void) fclose(hostf);
hostf = NULL;
}
}
struct hostent *
_gethtent (void)
{
char *p;
char *cp, **q;
int af, len;
if (!hostf && !(hostf = fopen(_PATH_HOSTS, "rce" ))) {
__set_h_errno (NETDB_INTERNAL);
return (NULL);
}
again:
if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
__set_h_errno (HOST_NOT_FOUND);
return (NULL);
}
if (*p == '#')
goto again;
if (!(cp = strpbrk(p, "#\n")))
goto again;
*cp = '\0';
if (!(cp = strpbrk(p, " \t")))
goto again;
*cp++ = '\0';
if (inet_pton(AF_INET6, p, host_addr) > 0) {
af = AF_INET6;
len = IN6ADDRSZ;
} else if (inet_pton(AF_INET, p, host_addr) > 0) {
if (res_use_inet6 ()) {
map_v4v6_address((char*)host_addr, (char*)host_addr);
af = AF_INET6;
len = IN6ADDRSZ;
} else {
af = AF_INET;
len = INADDRSZ;
}
} else {
goto again;
}
h_addr_ptrs[0] = (char *)host_addr;
h_addr_ptrs[1] = NULL;
host.h_addr_list = h_addr_ptrs;
host.h_length = len;
host.h_addrtype = af;
while (*cp == ' ' || *cp == '\t')
cp++;
host.h_name = cp;
q = host.h_aliases = host_aliases;
if ((cp = strpbrk(cp, " \t")))
*cp++ = '\0';
while (cp && *cp) {
if (*cp == ' ' || *cp == '\t') {
cp++;
continue;
}
if (q < &host_aliases[MAXALIASES - 1])
*q++ = cp;
if ((cp = strpbrk(cp, " \t")))
*cp++ = '\0';
}
*q = NULL;
__set_h_errno (NETDB_SUCCESS);
return (&host);
}
libresolv_hidden_def (_gethtent)
compat_symbol (libresolv, _gethtent, _gethtent, GLIBC_2_0);
struct hostent *
_gethtbyname (const char *name)
{
struct hostent *hp;
if (res_use_inet6 ()) {
hp = _gethtbyname2(name, AF_INET6);
if (hp)
return (hp);
}
return (_gethtbyname2(name, AF_INET));
}
compat_symbol (libresolv, _gethtbyname, _gethtbyname, GLIBC_2_0);
struct hostent *
_gethtbyname2 (const char *name, int af)
{
struct hostent *p;
char **cp;
_sethtent(0);
while ((p = _gethtent())) {
if (p->h_addrtype != af)
continue;
if (strcasecmp(p->h_name, name) == 0)
break;
for (cp = p->h_aliases; *cp != 0; cp++)
if (strcasecmp(*cp, name) == 0)
goto found;
}
found:
_endhtent();
return (p);
}
libresolv_hidden_def (_gethtbyname2)
compat_symbol (libresolv, _gethtbyname2, _gethtbyname2, GLIBC_2_0);
struct hostent *
_gethtbyaddr (const char *addr, size_t len, int af)
{
struct hostent *p;
_sethtent(0);
while ((p = _gethtent()))
if (p->h_addrtype == af && !memcmp(p->h_addr, addr, len))
break;
_endhtent();
return (p);
}
libresolv_hidden_def (_gethtbyaddr)
compat_symbol (libresolv, _gethtbyaddr, _gethtbyaddr, GLIBC_2_0);
static void
map_v4v6_address (const char *src, char *dst)
{
u_char *p = (u_char *)dst;
char tmp[INADDRSZ];
int i;
/* Stash a temporary copy so our caller can update in place. */
memcpy(tmp, src, INADDRSZ);
/* Mark this ipv6 addr as a mapped ipv4. */
for (i = 0; i < 10; i++)
*p++ = 0x00;
*p++ = 0xff;
*p++ = 0xff;
/* Retrieve the saved copy and we're done. */
memcpy((void*)p, tmp, INADDRSZ);
}
static void
map_v4v6_hostent (struct hostent *hp, char **bpp, int *lenp)
{
char **ap;
if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
return;
hp->h_addrtype = AF_INET6;
hp->h_length = IN6ADDRSZ;
for (ap = hp->h_addr_list; *ap; ap++) {
int i = sizeof(align) - ((u_long)*bpp % sizeof(align));
if (*lenp < (i + IN6ADDRSZ)) {
/* Out of memory. Truncate address list here. XXX */
*ap = NULL;
return;
}
*bpp += i;
*lenp -= i;
map_v4v6_address(*ap, *bpp);
*ap = *bpp;
*bpp += IN6ADDRSZ;
*lenp -= IN6ADDRSZ;
}
}
extern void
addrsort (char **ap, int num)
{
int i, j;
char **p;
short aval[MAXADDRS];
int needsort = 0;
p = ap;
for (i = 0; i < num; i++, p++) {
for (j = 0 ; (unsigned)j < _res.nsort; j++)
if (_res.sort_list[j].addr.s_addr ==
(((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask))
break;
aval[i] = j;
if (needsort == 0 && i > 0 && j < aval[i-1])
needsort = i;
}
if (!needsort)
return;
while (needsort < num) {
for (j = needsort - 1; j >= 0; j--) {
if (aval[j] > aval[j+1]) {
char *hp;
i = aval[j];
aval[j] = aval[j+1];
aval[j+1] = i;
hp = ap[j];
ap[j] = ap[j+1];
ap[j+1] = hp;
} else
break;
}
needsort++;
}
}
#endif /* SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25) */