/* $NetBSD: getnetnamadr.c,v 1.42 2012/03/13 21:13:41 christos Exp $ */
/* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
* Dep. Matematica Universidade de Coimbra, Portugal, Europe
*
* 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.
*/
/*
* Copyright (c) 1983, 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. 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)getnetbyaddr.c 8.1 (Berkeley) 6/4/93";
static char sccsid_[] = "from getnetnamadr.c 1.4 (Coimbra) 93/06/03";
static char rcsid[] = "Id: getnetnamadr.c,v 8.8 1997/06/01 20:34:37 vixie Exp ";
#else
__RCSID("$NetBSD: getnetnamadr.c,v 1.42 2012/03/13 21:13:41 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#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 <assert.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <nsswitch.h>
#include <resolv.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#ifdef __weak_alias
__weak_alias(getnetbyaddr,_getnetbyaddr)
__weak_alias(getnetbyname,_getnetbyname)
#endif
extern int _net_stayopen;
#define BYADDR 0
#define BYNAME 1
#define MAXALIASES 35
#define MAXPACKET (64*1024)
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
typedef union {
long al;
char ac;
} align;
#ifdef YP
static char *__ypdomain;
static char *__ypcurrent;
static int __ypcurrentlen;
#endif
static struct netent net_entry;
static char *net_aliases[MAXALIASES];
static int parse_reversed_addr(const char *, in_addr_t *);
static struct netent *getnetanswer(querybuf *, int, int);
static int _files_getnetbyaddr(void *, void *, va_list);
static int _files_getnetbyname(void *, void *, va_list);
static int _dns_getnetbyaddr(void *, void *, va_list);
static int _dns_getnetbyname(void *, void *, va_list);
#ifdef YP
static int _yp_getnetbyaddr(void *, void *, va_list);
static int _yp_getnetbyname(void *, void *, va_list);
static struct netent *_ypnetent(char *);
#endif
/*
* parse_reversed_addr --
* parse str, which should be of the form 'd.c.b.a.IN-ADDR.ARPA'
* (a PTR as per RFC 1101) and convert into an in_addr_t of the
* address 'a.b.c.d'.
* returns 0 on success (storing in *result), or -1 on error.
*/
static int
parse_reversed_addr(const char *str, in_addr_t *result)
{
unsigned long octet[4];
const char *sp;
char *ep;
int octidx;
sp = str;
/* find the four octets 'd.b.c.a.' */
for (octidx = 0; octidx < 4; octidx++) {
/* ensure it's a number */
if (!isdigit((unsigned char)*sp))
return -1;
octet[octidx] = strtoul(sp, &ep, 10);
/* with a trailing '.' */
if (*ep != '.')
return -1;
/* and is 0 <= octet <= 255 */
if (octet[octidx] > 255)
return -1;
sp = ep + 1;
}
/* ensure trailer is correct */
if (strcasecmp(sp, "IN-ADDR.ARPA") != 0)
return -1;
*result = 0;
/* build result from octets in reverse */
for (octidx = 3; octidx >= 0; octidx--) {
*result <<= 8;
*result |= (in_addr_t)(octet[octidx] & 0xff);
}
return 0;
}
static struct netent *
getnetanswer(querybuf *answer, int anslen, int net_i)
{
static char n_name[MAXDNAME];
static char netbuf[PACKETSZ];
HEADER *hp;
u_char *cp;
int n;
u_char *eom;
int type, class, ancount, qdcount, haveanswer;
char *in, *bp, **ap, *ep;
assert(answer != NULL);
/*
* find first satisfactory answer
*
* answer --> +------------+ ( MESSAGE )
* | Header |
* +------------+
* | Question | the question for the name server
* +------------+
* | Answer | RRs answering the question
* +------------+
* | Authority | RRs pointing toward an authority
* | Additional | RRs holding additional information
* +------------+
*/
eom = answer->buf + anslen;
hp = &answer->hdr;
ancount = ntohs(hp->ancount); /* #/records in the answer section */
qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
bp = netbuf;
ep = netbuf + sizeof(netbuf);
cp = answer->buf + HFIXEDSZ;
if (!qdcount) {
if (hp->aa)
h_errno = HOST_NOT_FOUND;
else
h_errno = TRY_AGAIN;
return NULL;
}
while (qdcount-- > 0) {
n = __dn_skipname(cp, eom);
if (n < 0 || (cp + n + QFIXEDSZ) > eom) {
h_errno = NO_RECOVERY;
return(NULL);
}
cp += n + QFIXEDSZ;
}
ap = net_aliases;
*ap = NULL;
net_entry.n_aliases = net_aliases;
haveanswer = 0;
n_name[0] = '\0';
while (--ancount >= 0 && cp < eom) {
n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
if ((n < 0) || !res_dnok(bp))
break;
cp += n;
(void)strlcpy(n_name, bp, sizeof(n_name));
GETSHORT(type, cp);
GETSHORT(class, cp);
cp += INT32SZ; /* TTL */
GETSHORT(n, cp);
if (class == C_IN && type == T_PTR) {
n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
if ((n < 0) || !res_hnok(bp)) {
cp += n;
return NULL;
}
cp += n;
*ap++ = bp;
bp += strlen(bp) + 1;
net_entry.n_addrtype =
(class == C_IN) ? AF_INET : AF_UNSPEC;
haveanswer++;
}
}
if (haveanswer) {
*ap = NULL;
switch (net_i) {
case BYADDR:
net_entry.n_name = *net_entry.n_aliases;
net_entry.n_net = 0L;
break;
case BYNAME:
ap = net_entry.n_aliases;
next_alias:
in = *ap++;
if (in == NULL) {
h_errno = HOST_NOT_FOUND;
return NULL;
}
net_entry.n_name = n_name;
if (parse_reversed_addr(in, &net_entry.n_net) == -1)
goto next_alias;
break;
}
net_entry.n_aliases++;
return &net_entry;
}
h_errno = TRY_AGAIN;
return NULL;
}
/*ARGSUSED*/
static int
_files_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
{
struct netent **retval = va_arg(ap, struct netent **);
uint32_t net = va_arg(ap, uint32_t);
int type = va_arg(ap, int);
struct netent *np;
setnetent(_net_stayopen);
while ((np = getnetent()) != NULL)
if (np->n_addrtype == type && np->n_net == net)
break;
if (!_net_stayopen)
endnetent();
if (np != NULL) {
*retval = np;
return NS_SUCCESS;
} else {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
}
/*ARGSUSED*/
static int
_dns_getnetbyaddr(void *cbrv, void *cbdata, va_list ap)
{
struct netent **retval = va_arg(ap, struct netent **);
uint32_t net = va_arg(ap, uint32_t);
int type = va_arg(ap, int);
unsigned int netbr[4];
int nn, anslen;
querybuf *buf;
char qbuf[MAXDNAME];
uint32_t net2;
struct netent *np;
res_state res;
if (type != AF_INET)
return NS_UNAVAIL;
for (nn = 4, net2 = net; net2; net2 >>= 8)
netbr[--nn] = (unsigned int)(net2 & 0xff);
switch (nn) {
default:
return NS_UNAVAIL;
case 3: /* Class A */
snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]);
break;
case 2: /* Class B */
snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa",
netbr[3], netbr[2]);
break;
case 1: /* Class C */
snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa",
netbr[3], netbr[2], netbr[1]);
break;
case 0: /* Class D - E */
snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
netbr[3], netbr[2], netbr[1], netbr[0]);
break;
}
buf = malloc(sizeof(*buf));
if (buf == NULL) {
h_errno = NETDB_INTERNAL;
return NS_NOTFOUND;
}
res = __res_get_state();
if (res == NULL) {
free(buf);
return NS_NOTFOUND;
}
anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf,
(int)sizeof(buf->buf));
if (anslen < 0) {
free(buf);
#ifdef DEBUG
if (res->options & RES_DEBUG)
printf("res_query failed\n");
#endif
__res_put_state(res);
return NS_NOTFOUND;
}
__res_put_state(res);
np = getnetanswer(buf, anslen, BYADDR);
free(buf);
if (np) {
/* maybe net should be unsigned? */
uint32_t u_net = net;
/* Strip trailing zeros */
while ((u_net & 0xff) == 0 && u_net != 0)
u_net >>= 8;
np->n_net = u_net;
}
if (np != NULL) {
*retval = np;
return NS_SUCCESS;
} else {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
}
struct netent *
getnetbyaddr(uint32_t net, int net_type)
{
int rv;
struct netent *retval;
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_getnetbyaddr, NULL)
{ NSSRC_DNS, _dns_getnetbyaddr, NULL }, /* force -DHESIOD */
NS_NIS_CB(_yp_getnetbyaddr, NULL)
NS_NULL_CB
};
retval = NULL;
h_errno = NETDB_INTERNAL;
rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyaddr",
__nsdefaultsrc, &retval, net, net_type);
if (rv == NS_SUCCESS) {
h_errno = NETDB_SUCCESS;
return retval;
}
return NULL;
}
/*ARGSUSED*/
static int
_files_getnetbyname(void *cbrv, void *cbdata, va_list ap)
{
struct netent **retval = va_arg(ap, struct netent **);
const char *name = va_arg(ap, const char *);
struct netent *np;
char **cp;
setnetent(_net_stayopen);
while ((np = getnetent()) != NULL) {
if (strcasecmp(np->n_name, name) == 0)
break;
for (cp = np->n_aliases; *cp != 0; cp++)
if (strcasecmp(*cp, name) == 0)
goto found;
}
found:
if (!_net_stayopen)
endnetent();
if (np != NULL) {
*retval = np;
return NS_SUCCESS;
} else {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
}
/*ARGSUSED*/
static int
_dns_getnetbyname(void *cbrv, void *cbdata, va_list ap)
{
struct netent **retval = va_arg(ap, struct netent **);
const char *name = va_arg(ap, const char *);
int anslen;
querybuf *buf;
char qbuf[MAXDNAME];
struct netent *np;
res_state res;
strlcpy(&qbuf[0], name, sizeof(qbuf));
buf = malloc(sizeof(*buf));
if (buf == NULL) {
h_errno = NETDB_INTERNAL;
return NS_NOTFOUND;
}
res = __res_get_state();
if (res == NULL) {
free(buf);
return NS_NOTFOUND;
}
anslen = res_nsearch(res, qbuf, C_IN, T_PTR, buf->buf,
(int)sizeof(buf->buf));
if (anslen < 0) {
free(buf);
#ifdef DEBUG
if (res->options & RES_DEBUG)
printf("res_search failed\n");
#endif
__res_put_state(res);
return NS_NOTFOUND;
}
__res_put_state(res);
np = getnetanswer(buf, anslen, BYNAME);
free(buf);
if (np != NULL) {
*retval = np;
return NS_SUCCESS;
} else {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
}
struct netent *
getnetbyname(const char *name)
{
int rv;
struct netent *retval;
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_getnetbyname, NULL)
{ NSSRC_DNS, _dns_getnetbyname, NULL }, /* force -DHESIOD */
NS_NIS_CB(_yp_getnetbyname, NULL)
NS_NULL_CB
};
assert(name != NULL);
retval = NULL;
h_errno = NETDB_INTERNAL;
rv = nsdispatch(NULL, dtab, NSDB_NETWORKS, "getnetbyname",
__nsdefaultsrc, &retval, name);
if (rv == NS_SUCCESS) {
h_errno = NETDB_SUCCESS;
return retval;
}
return NULL;
}
#ifdef YP
/*ARGSUSED*/
static int
_yp_getnetbyaddr(void *cbrv, void *cb_data, va_list ap)
{
struct netent **retval = va_arg(ap, struct netent **);
uint32_t net = va_arg(ap, uint32_t);
int type = va_arg(ap, int);
struct netent *np;
char qbuf[MAXDNAME];
unsigned int netbr[4];
uint32_t net2;
int r;
if (type != AF_INET)
return NS_UNAVAIL;
if (!__ypdomain) {
if (_yp_check(&__ypdomain) == 0)
return NS_UNAVAIL;
}
np = NULL;
if (__ypcurrent)
free(__ypcurrent);
__ypcurrent = NULL;
for (r = 4, net2 = net; net2; net2 >>= 8)
netbr[--r] = (unsigned int)(net2 & 0xff);
switch (r) {
default:
return NS_UNAVAIL;
case 3: /* Class A */
snprintf(qbuf, sizeof(qbuf), "%u", netbr[3]);
break;
case 2: /* Class B */
snprintf(qbuf, sizeof(qbuf), "%u.%u", netbr[2], netbr[3]);
break;
case 1: /* Class C */
snprintf(qbuf, sizeof(qbuf), "%u.%u.%u", netbr[1], netbr[2],
netbr[3]);
break;
case 0: /* Class D - E */
snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u", netbr[0], netbr[1],
netbr[2], netbr[3]);
break;
}
r = yp_match(__ypdomain, "networks.byaddr", qbuf, (int)strlen(qbuf),
&__ypcurrent, &__ypcurrentlen);
if (r == 0)
np = _ypnetent(__ypcurrent);
if (np != NULL) {
*retval = np;
return NS_SUCCESS;
} else {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
}
/*ARGSUSED*/
static int
_yp_getnetbyname(void *cbrv, void *cbdata, va_list ap)
{
struct netent **retval = va_arg(ap, struct netent **);
const char *name = va_arg(ap, const char *);
struct netent *np;
int r;
if (!__ypdomain) {
if (_yp_check(&__ypdomain) == 0)
return NS_UNAVAIL;
}
np = NULL;
if (__ypcurrent)
free(__ypcurrent);
__ypcurrent = NULL;
r = yp_match(__ypdomain, "networks.byname", name, (int)strlen(name),
&__ypcurrent, &__ypcurrentlen);
if (r == 0)
np = _ypnetent(__ypcurrent);
if (np != NULL) {
*retval = np;
return NS_SUCCESS;
} else {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
}
static struct netent *
_ypnetent(char *line)
{
char *cp, *p, **q;
assert(line != NULL);
net_entry.n_name = line;
cp = strpbrk(line, " \t");
if (cp == NULL)
return NULL;
*cp++ = '\0';
while (*cp == ' ' || *cp == '\t')
cp++;
p = strpbrk(cp, " \t");
if (p != NULL)
*p++ = '\0';
net_entry.n_net = inet_network(cp);
#if (defined(__sparc__) && defined(_LP64)) || \
defined(__alpha__) || \
(defined(__i386__) && defined(_LP64)) || \
(defined(__sh__) && defined(_LP64))
net_entry.__n_pad0 = 0;
#endif
net_entry.n_addrtype = AF_INET;
q = net_entry.n_aliases = net_aliases;
if (p != NULL) {
cp = p;
while (cp && *cp) {
if (*cp == ' ' || *cp == '\t') {
cp++;
continue;
}
if (q < &net_aliases[MAXALIASES - 1])
*q++ = cp;
cp = strpbrk(cp, " \t");
if (cp != NULL)
*cp++ = '\0';
}
}
*q = NULL;
return &net_entry;
}
#endif
↑ V547 Expression 'class == ns_c_in' is always true.