Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
NetBSD/dist/bind/lib/irs/dns_nw.c

563 lines
13 KiB
C
Raw Blame History

/* $NetBSD: dns_nw.c,v 1.1.1.1 1999/11/20 18:54:08 veego Exp $ */
/*
* Copyright (c) 1996-1999 by Internet Software Consortium.
*
* 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.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "Id: dns_nw.c,v 1.19 1999/10/15 19:49:10 vixie Exp";
#endif /* LIBC_SCCS and not lint */
/* Imports. */
#include "port_before.h"
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <isc/memcluster.h>
#include <irs.h>
#include "port_after.h"
#include "irs_p.h"
#include "dns_p.h"
#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintf/**/x)
#else
# define SPRINTF(x) sprintf x
#endif
/* Definitions. */
#define MAXALIASES 35
#if PACKETSZ > 1024
#define MAXPACKET PACKETSZ
#else
#define MAXPACKET 1024
#endif
struct pvt {
struct nwent net;
char * ali[MAXALIASES];
char buf[BUFSIZ+1];
struct __res_state * res;
void (*free_res)(void *);
};
typedef union {
long al;
char ac;
} align;
enum by_what { by_addr, by_name };
/* Forwards. */
static void nw_close(struct irs_nw *);
static struct nwent * nw_byname(struct irs_nw *, const char *, int);
static struct nwent * nw_byaddr(struct irs_nw *, void *, int, int);
static struct nwent * nw_next(struct irs_nw *);
static void nw_rewind(struct irs_nw *);
static void nw_minimize(struct irs_nw *);
static struct __res_state * nw_res_get(struct irs_nw *this);
static void nw_res_set(struct irs_nw *this,
struct __res_state *res,
void (*free_res)(void *));
static struct nwent * get1101byaddr(struct irs_nw *, u_char *, int);
static struct nwent * get1101byname(struct irs_nw *, const char *);
static struct nwent * get1101answer(struct irs_nw *,
u_char *ansbuf, int anslen,
enum by_what by_what,
int af, const char *name,
const u_char *addr, int addrlen);
static struct nwent * get1101mask(struct irs_nw *this, struct nwent *);
static int make1101inaddr(const u_char *, int, char *, int);
static void normalize_name(char *name);
static int init(struct irs_nw *this);
/* Exports. */
struct irs_nw *
irs_dns_nw(struct irs_acc *this) {
struct irs_nw *nw;
struct pvt *pvt;
if (!(pvt = memget(sizeof *pvt))) {
errno = ENOMEM;
return (NULL);
}
memset(pvt, 0, sizeof *pvt);
if (!(nw = memget(sizeof *nw))) {
memput(pvt, sizeof *pvt);
errno = ENOMEM;
return (NULL);
}
memset(nw, 0x5e, sizeof *nw);
nw->private = pvt;
nw->close = nw_close;
nw->byname = nw_byname;
nw->byaddr = nw_byaddr;
nw->next = nw_next;
nw->rewind = nw_rewind;
nw->minimize = nw_minimize;
nw->res_get = nw_res_get;
nw->res_set = nw_res_set;
return (nw);
}
/* Methods. */
static void
nw_close(struct irs_nw *this) {
struct pvt *pvt = (struct pvt *)this->private;
nw_minimize(this);
if (pvt->res && pvt->free_res)
(*pvt->free_res)(pvt->res);
memput(pvt, sizeof *pvt);
memput(this, sizeof *this);
}
static struct nwent *
nw_byname(struct irs_nw *this, const char *name, int af) {
struct pvt *pvt = (struct pvt *)this->private;
if (init(this) == -1)
return (NULL);
switch (af) {
case AF_INET:
return (get1101byname(this, name));
default:
(void)NULL;
}
RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
errno = EAFNOSUPPORT;
return (NULL);
}
static struct nwent *
nw_byaddr(struct irs_nw *this, void *net, int len, int af) {
struct pvt *pvt = (struct pvt *)this->private;
if (init(this) == -1)
return (NULL);
switch (af) {
case AF_INET:
return (get1101byaddr(this, net, len));
default:
(void)NULL;
}
RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
errno = EAFNOSUPPORT;
return (NULL);
}
static struct nwent *
nw_next(struct irs_nw *this) {
return (NULL);
}
static void
nw_rewind(struct irs_nw *this) {
/* NOOP */
}
static void
nw_minimize(struct irs_nw *this) {
struct pvt *pvt = (struct pvt *)this->private;
if (pvt->res)
res_nclose(pvt->res);
}
static struct __res_state *
nw_res_get(struct irs_nw *this) {
struct pvt *pvt = (struct pvt *)this->private;
if (!pvt->res) {
struct __res_state *res;
res = (struct __res_state *)malloc(sizeof *res);
if (!res) {
errno = ENOMEM;
return (NULL);
}
memset(res, 0, sizeof *res);
nw_res_set(this, res, free);
}
return (pvt->res);
}
static void
nw_res_set(struct irs_nw *this, struct __res_state *res,
void (*free_res)(void *)) {
struct pvt *pvt = (struct pvt *)this->private;
if (pvt->res && pvt->free_res) {
res_nclose(pvt->res);
(*pvt->free_res)(pvt->res);
}
pvt->res = res;
pvt->free_res = free_res;
}
/* Private. */
static struct nwent *
get1101byname(struct irs_nw *this, const char *name) {
struct pvt *pvt = (struct pvt *)this->private;
u_char ansbuf[MAXPACKET];
int anslen;
anslen = res_nsearch(pvt->res, name, C_IN, T_PTR,
ansbuf, sizeof ansbuf);
if (anslen < 0)
return (NULL);
return (get1101mask(this, get1101answer(this, ansbuf, anslen, by_name,
AF_INET, name, NULL, 0)));
}
static struct nwent *
get1101byaddr(struct irs_nw *this, u_char *net, int len) {
struct pvt *pvt = (struct pvt *)this->private;
char qbuf[sizeof "255.255.255.255.in-addr.arpa"];
u_char ansbuf[MAXPACKET];
int anslen;
if (len < 1 || len > 32) {
errno = EINVAL;
RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
return (NULL);
}
if (make1101inaddr(net, len, qbuf, sizeof qbuf) < 0)
return (NULL);
anslen = res_nquery(pvt->res, qbuf, C_IN, T_PTR,
ansbuf, sizeof ansbuf);
if (anslen < 0)
return (NULL);
return (get1101mask(this, get1101answer(this, ansbuf, anslen, by_addr,
AF_INET, NULL, net, len)));
}
static struct nwent *
get1101answer(struct irs_nw *this,
u_char *ansbuf, int anslen, enum by_what by_what,
int af, const char *name, const u_char *addr, int addrlen)
{
struct pvt *pvt = (struct pvt *)this->private;
int type, class, buflen, ancount, qdcount, haveanswer;
char *bp, **ap;
u_char *cp, *eom;
HEADER *hp;
/* Initialize, and parse header. */
eom = ansbuf + anslen;
if (ansbuf + HFIXEDSZ > eom) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
hp = (HEADER *)ansbuf;
cp = ansbuf + HFIXEDSZ;
qdcount = ntohs(hp->qdcount);
while (qdcount-- > 0) {
int n = dn_skipname(cp, eom);
cp += n + QFIXEDSZ;
if (n < 0 || cp > eom) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
}
ancount = ntohs(hp->ancount);
if (!ancount) {
if (hp->aa)
RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
else
RES_SET_H_ERRNO(pvt->res, TRY_AGAIN);
return (NULL);
}
/* Prepare a return structure. */
bp = pvt->buf;
buflen = sizeof pvt->buf;
pvt->net.n_name = NULL;
pvt->net.n_aliases = pvt->ali;
pvt->net.n_addrtype = af;
pvt->net.n_addr = NULL;
pvt->net.n_length = addrlen;
/* Save input key if given. */
switch (by_what) {
case by_name:
if (name != NULL) {
int n = strlen(name) + 1;
if (n > buflen) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
pvt->net.n_name = strcpy(bp, name);
bp += n;
buflen -= n;
}
break;
case by_addr:
if (addr != NULL && addrlen != 0) {
int n = addrlen / 8 + ((addrlen % 8) != 0);
if (INADDRSZ > buflen) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
memset(bp, 0, INADDRSZ);
memcpy(bp, addr, n);
pvt->net.n_addr = bp;
bp += INADDRSZ;
buflen -= INADDRSZ;
}
break;
default:
abort();
}
/* Parse the answer, collect aliases. */
ap = pvt->ali;
haveanswer = 0;
while (--ancount >= 0 && cp < eom) {
int n = dn_expand(ansbuf, eom, cp, bp, buflen);
cp += n; /* Owner */
if (n < 0 || !maybe_dnok(pvt->res, bp) ||
cp + 3 * INT16SZ + INT32SZ > eom) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
GETSHORT(type, cp); /* Type */
GETSHORT(class, cp); /* Class */
cp += INT32SZ; /* TTL */
GETSHORT(n, cp); /* RDLENGTH */
if (class == C_IN && type == T_PTR) {
int nn;
nn = dn_expand(ansbuf, eom, cp, bp, buflen);
if (nn < 0 || !maybe_hnok(pvt->res, bp) || nn != n) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
normalize_name(bp);
switch (by_what) {
case by_addr: {
if (pvt->net.n_name == NULL)
pvt->net.n_name = bp;
else if (ns_samename(pvt->net.n_name, bp) == 1)
break;
else
*ap++ = bp;
nn = strlen(bp) + 1;
bp += nn;
buflen -= nn;
haveanswer++;
break;
}
case by_name: {
u_int b1, b2, b3, b4;
if (pvt->net.n_addr != NULL ||
sscanf(bp, "%u.%u.%u.%u.in-addr.arpa",
&b1, &b2, &b3, &b4) != 4)
break;
if (buflen < INADDRSZ) {
RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
return (NULL);
}
pvt->net.n_addr = bp;
*bp++ = b4;
*bp++ = b3;
*bp++ = b2;
*bp++ = b1;
buflen -= INADDRSZ;
pvt->net.n_length = INADDRSZ * 8;
haveanswer++;
}
}
}
cp += n; /* RDATA */
}
if (!haveanswer) {
RES_SET_H_ERRNO(pvt->res, TRY_AGAIN);
return (NULL);
}
*ap = NULL;
return (&pvt->net);
}
static struct nwent *
get1101mask(struct irs_nw *this, struct nwent *nwent) {
struct pvt *pvt = (struct pvt *)this->private;
char qbuf[sizeof "255.255.255.255.in-addr.arpa"], owner[MAXDNAME];
int anslen, type, class, ancount, qdcount;
u_char ansbuf[MAXPACKET], *cp, *eom;
HEADER *hp;
if (!nwent)
return (NULL);
if (make1101inaddr(nwent->n_addr, nwent->n_length, qbuf, sizeof qbuf)
< 0) {
/* "First, do no harm." */
return (nwent);
}
/* Query for the A RR that would hold this network's mask. */
anslen = res_nquery(pvt->res, qbuf, C_IN, T_A, ansbuf, sizeof ansbuf);
if (anslen < HFIXEDSZ)
return (nwent);
/* Initialize, and parse header. */
hp = (HEADER *)ansbuf;
cp = ansbuf + HFIXEDSZ;
eom = ansbuf + anslen;
qdcount = ntohs(hp->qdcount);
while (qdcount-- > 0) {
int n = dn_skipname(cp, eom);
cp += n + QFIXEDSZ;
if (n < 0 || cp > eom)
return (nwent);
}
ancount = ntohs(hp->ancount);
/* Parse the answer, collect aliases. */
while (--ancount >= 0 && cp < eom) {
int n = dn_expand(ansbuf, eom, cp, owner, sizeof owner);
if (n < 0 || !maybe_dnok(pvt->res, owner))
break;
cp += n; /* Owner */
if (cp + 3 * INT16SZ + INT32SZ > eom)
break;
GETSHORT(type, cp); /* Type */
GETSHORT(class, cp); /* Class */
cp += INT32SZ; /* TTL */
GETSHORT(n, cp); /* RDLENGTH */
if (cp + n > eom)
break;
if (n == INADDRSZ && class == C_IN && type == T_A &&
ns_samename(qbuf, owner) == 1) {
/* This A RR indicates the actual netmask. */
int nn, mm;
nwent->n_length = 0;
for (nn = 0; nn < INADDRSZ; nn++)
for (mm = 7; mm >= 0; mm--)
if (cp[nn] & (1 << mm))
nwent->n_length++;
else
break;
}
cp += n; /* RDATA */
}
return (nwent);
}
static int
make1101inaddr(const u_char *net, int bits, char *name, int size) {
int n, m;
/* Zero fill any whole bytes left out of the prefix. */
for (n = (32 - bits) / 8; n > 0; n--) {
if (size < (int)(sizeof "0."))
goto emsgsize;
m = SPRINTF((name, "0."));
name += m;
size -= m;
}
/* Format the partial byte, if any, within the prefix. */
if ((n = bits % 8) != 0) {
if (size < (int)(sizeof "255."))
goto emsgsize;
m = SPRINTF((name, "%u.",
net[bits / 8] & ~((1 << (8 - n)) - 1)));
name += m;
size -= m;
}
/* Format the whole bytes within the prefix. */
for (n = bits / 8; n > 0; n--) {
if (size < (int)(sizeof "255."))
goto emsgsize;
m = SPRINTF((name, "%u.", net[n - 1]));
name += m;
size -= m;
}
/* Add the static text. */
if (size < (int)(sizeof "in-addr.arpa"))
goto emsgsize;
(void) SPRINTF((name, "in-addr.arpa"));
return (0);
emsgsize:
errno = EMSGSIZE;
return (-1);
}
static void
normalize_name(char *name) {
char *t;
/* Make lower case. */
for (t = name; *t; t++)
if (isascii(*t) && isupper(*t))
*t = tolower(*t);
/* Remove trailing dots. */
while (t > name && t[-1] == '.')
*--t = '\0';
}
static int
init(struct irs_nw *this) {
struct pvt *pvt = (struct pvt *)this->private;
if (!pvt->res && !nw_res_get(this))
return (-1);
if (((pvt->res->options & RES_INIT) == 0) &&
res_ninit(pvt->res) == -1)
return (-1);
return (0);
}
Reference in New Issue View Git Blame Copy Permalink