ns_name.c

bind 9.3结合mysql数据库

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * 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 ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

#ifndef lint
static const char rcsid[] = "$Id: ns_name.c,v 1.3.2.4.4.2 2004/05/04 03:27:47 marka Exp $";
#endif

#include "port_before.h"

#include <sys/types.h>

#include <netinet/in.h>
#include <arpa/nameser.h>

#include <errno.h>
#include <resolv.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <limits.h>

#include "port_after.h"

#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintf/**/x)
#else
# define SPRINTF(x) ((size_t)sprintf x)
#endif

#define NS_TYPE_ELT			0x40 /* EDNS0 extended label type */
#define DNS_LABELTYPE_BITSTRING		0x41

/* Data. */

static const char	digits[] = "0123456789";

static const char digitvalue[256] = {
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,	/*16*/
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/
	 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1, /*64*/
	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/
	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/
};

/* Forward. */

static int		special(int);
static int		printable(int);
static int		dn_find(const u_char *, const u_char *,
				const u_char * const *,
				const u_char * const *);
static int		encode_bitsring(const char **, const char *,
					unsigned char **, unsigned char **,
					unsigned const char *);
static int		labellen(const u_char *);
static int		decode_bitstring(const unsigned char **,
					 char *, const char *);

/* Public. */

/*
 * ns_name_ntop(src, dst, dstsiz)
 *	Convert an encoded domain name to printable ascii as per RFC1035.
 * return:
 *	Number of bytes written to buffer, or -1 (with errno set)
 * notes:
 *	The root is returned as "."
 *	All other domains are returned in non absolute form
 */
int
ns_name_ntop(const u_char *src, char *dst, size_t dstsiz)
{
	const u_char *cp;
	char *dn, *eom;
	u_char c;
	u_int n;
	int l;

	cp = src;
	dn = dst;
	eom = dst + dstsiz;

	while ((n = *cp++) != 0) {
		if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
			/* Some kind of compression pointer. */
			errno = EMSGSIZE;
			return (-1);
		}
		if (dn != dst) {
			if (dn >= eom) {
				errno = EMSGSIZE;
				return (-1);
			}
			*dn++ = '.';
		}
		if ((l = labellen(cp - 1)) < 0) {
			errno = EMSGSIZE; /* XXX */
			return(-1);
		}
		if (dn + l >= eom) {
			errno = EMSGSIZE;
			return (-1);
		}
		if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) {
			int m;

			if (n != DNS_LABELTYPE_BITSTRING) {
				/* XXX: labellen should reject this case */
				errno = EINVAL;
				return(-1);
			}
			if ((m = decode_bitstring(&cp, dn, eom)) < 0)
			{
				errno = EMSGSIZE;
				return(-1);
			}
			dn += m; 
			continue;
		}
		for ((void)NULL; l > 0; l--) {
			c = *cp++;
			if (special(c)) {
				if (dn + 1 >= eom) {
					errno = EMSGSIZE;
					return (-1);
				}
				*dn++ = '\\';
				*dn++ = (char)c;
			} else if (!printable(c)) {
				if (dn + 3 >= eom) {
					errno = EMSGSIZE;
					return (-1);
				}
				*dn++ = '\\';
				*dn++ = digits[c / 100];
				*dn++ = digits[(c % 100) / 10];
				*dn++ = digits[c % 10];
			} else {
				if (dn >= eom) {
					errno = EMSGSIZE;
					return (-1);
				}
				*dn++ = (char)c;
			}
		}
	}
	if (dn == dst) {
		if (dn >= eom) {
			errno = EMSGSIZE;
			return (-1);
		}
		*dn++ = '.';
	}
	if (dn >= eom) {
		errno = EMSGSIZE;
		return (-1);
	}
	*dn++ = '\0';
	return (dn - dst);
}

/*
 * ns_name_pton(src, dst, dstsiz)
 *	Convert a ascii string into an encoded domain name as per RFC1035.
 * return:
 *	-1 if it fails
 *	1 if string was fully qualified
 *	0 is string was not fully qualified
 * notes:
 *	Enforces label and domain length limits.
 */

int
ns_name_pton(const char *src, u_char *dst, size_t dstsiz)
{
	u_char *label, *bp, *eom;
	int c, n, escaped, e = 0;
	char *cp;

	escaped = 0;
	bp = dst;
	eom = dst + dstsiz;
	label = bp++;

	while ((c = *src++) != 0) {
		if (escaped) {
			if (c == '[') { /* start a bit string label */
				if ((cp = strchr(src, ']')) == NULL) {
					errno = EINVAL; /* ??? */
					return(-1);
				}
				if ((e = encode_bitsring(&src, cp + 2,
							 &label, &bp, eom))
				    != 0) {
					errno = e;
					return(-1);
				}
				escaped = 0;
				label = bp++;
				if ((c = *src++) == 0)
					goto done;
				else if (c != '.') {
					errno = EINVAL;
					return(-1);
				}
				continue;
			}
			else if ((cp = strchr(digits, c)) != NULL) {
				n = (cp - digits) * 100;
				if ((c = *src++) == 0 ||
				    (cp = strchr(digits, c)) == NULL) {
					errno = EMSGSIZE;
					return (-1);
				}
				n += (cp - digits) * 10;
				if ((c = *src++) == 0 ||
				    (cp = strchr(digits, c)) == NULL) {
					errno = EMSGSIZE;
					return (-1);
				}
				n += (cp - digits);
				if (n > 255) {
					errno = EMSGSIZE;
					return (-1);
				}
				c = n;
			}
			escaped = 0;
		} else if (c == '\\') {
			escaped = 1;
			continue;
		} else if (c == '.') {
			c = (bp - label - 1);
			if ((c & NS_CMPRSFLGS) != 0) {	/* Label too big. */
				errno = EMSGSIZE;
				return (-1);
			}
			if (label >= eom) {
				errno = EMSGSIZE;
				return (-1);
			}
			*label = c;
			/* Fully qualified ? */
			if (*src == '\0') {
				if (c != 0) {
					if (bp >= eom) {
						errno = EMSGSIZE;
						return (-1);
					}
					*bp++ = '\0';
				}
				if ((bp - dst) > MAXCDNAME) {
					errno = EMSGSIZE;
					return (-1);
				}
				return (1);
			}
			if (c == 0 || *src == '.') {
				errno = EMSGSIZE;
				return (-1);
			}
			label = bp++;
			continue;
		}
		if (bp >= eom) {
			errno = EMSGSIZE;
			return (-1);
		}
		*bp++ = (u_char)c;
	}
	c = (bp - label - 1);
	if ((c & NS_CMPRSFLGS) != 0) {		/* Label too big. */
		errno = EMSGSIZE;
		return (-1);
	}
  done:
	if (label >= eom) {
		errno = EMSGSIZE;
		return (-1);
	}
	*label = c;
	if (c != 0) {
		if (bp >= eom) {
			errno = EMSGSIZE;
			return (-1);
		}
		*bp++ = 0;
	}
	if ((bp - dst) > MAXCDNAME) {	/* src too big */
		errno = EMSGSIZE;
		return (-1);
	}
	return (0);
}

/*
 * ns_name_ntol(src, dst, dstsiz)
 *	Convert a network strings labels into all lowercase.
 * return:
 *	Number of bytes written to buffer, or -1 (with errno set)
 * notes:
 *	Enforces label and domain length limits.
 */

int
ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
{
	const u_char *cp;
	u_char *dn, *eom;
	u_char c;
	u_int n;
	int l;

	cp = src;
	dn = dst;
	eom = dst + dstsiz;

	if (dn >= eom) {
		errno = EMSGSIZE;
		return (-1);
	}
	while ((n = *cp++) != 0) {
		if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
			/* Some kind of compression pointer. */
			errno = EMSGSIZE;
			return (-1);
		}
		*dn++ = n;
		if ((l = labellen(cp - 1)) < 0) {
			errno = EMSGSIZE;
			return (-1);
		}
		if (dn + l >= eom) {
			errno = EMSGSIZE;
			return (-1);
		}
		for ((void)NULL; l > 0; l--) {
			c = *cp++;
			if (isupper(c))
				*dn++ = tolower(c);
			else
				*dn++ = c;
		}
	}
	*dn++ = '\0';
	return (dn - dst);
}

/*
 * ns_name_unpack(msg, eom, src, dst, dstsiz)
 *	Unpack a domain name from a message, source may be compressed.
 * return:
 *	-1 if it fails, or consumed octets if it succeeds.
 */
int
ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
	       u_char *dst, size_t dstsiz)
{
	const u_char *srcp, *dstlim;
	u_char *dstp;
	int n, len, checked, l;

	len = -1;
	checked = 0;
	dstp = dst;
	srcp = src;
	dstlim = dst + dstsiz;
	if (srcp < msg || srcp >= eom) {
		errno = EMSGSIZE;
		return (-1);
	}
	/* Fetch next label in domain name. */
	while ((n = *srcp++) != 0) {
		/* Check for indirection. */
		switch (n & NS_CMPRSFLGS) {
		case 0:
		case NS_TYPE_ELT:
			/* Limit checks. */
			if ((l = labellen(srcp - 1)) < 0) {
				errno = EMSGSIZE;
				return(-1);
			}
			if (dstp + l + 1 >= dstlim || srcp + l >= eom) {
				errno = EMSGSIZE;
				return (-1);
			}
			checked += l + 1;
			*dstp++ = n;
			memcpy(dstp, srcp, l);
			dstp += l;
			srcp += l;
			break;

		case NS_CMPRSFLGS:
			if (srcp >= eom) {
				errno = EMSGSIZE;
				return (-1);
			}
			if (len < 0)
				len = srcp - src + 1;
			srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
			if (srcp < msg || srcp >= eom) {  /* Out of range. */
				errno = EMSGSIZE;
				return (-1);
			}
			checked += 2;
			/*
			 * Check for loops in the compressed name;
			 * if we've looked at the whole message,
			 * there must be a loop.
			 */
			if (checked >= eom - msg) {
				errno = EMSGSIZE;
				return (-1);
			}
			break;

		default:
			errno = EMSGSIZE;
			return (-1);			/* flag error */
		}
	}
	*dstp = '\0';
	if (len < 0)
		len = srcp - src;
	return (len);
}

/*
 * ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
 *	Pack domain name 'domain' into 'comp_dn'.
 * return:
 *	Size of the compressed name, or -1.
 * notes:
 *	'dnptrs' is an array of pointers to previous compressed names.
 *	dnptrs[0] is a pointer to the beginning of the message. The array
 *	ends with NULL.
 *	'lastdnptr' is a pointer to the end of the array pointed to
 *	by 'dnptrs'.
 * Side effects:
 *	The list of pointers in dnptrs is updated for labels inserted into
 *	the message as we compress the name.  If 'dnptr' is NULL, we don't
 *	try to compress names. If 'lastdnptr' is NULL, we don't update the
 *	list.
 */
int
ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
	     const u_char **dnptrs, const u_char **lastdnptr)
{
	u_char *dstp;
	const u_char **cpp, **lpp, *eob, *msg;
	const u_char *srcp;
	int n, l, first = 1;

	srcp = src;
	dstp = dst;
	eob = dstp + dstsiz;