michael@0: /*	$NetBSD: ns_name.c,v 1.3 2004/11/07 02:19:49 christos Exp $	*/
michael@0: 
michael@0: /*
michael@0:  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
michael@0:  * Copyright (c) 1996,1999 by Internet Software Consortium.
michael@0:  *
michael@0:  * Permission to use, copy, modify, and distribute this software for any
michael@0:  * purpose with or without fee is hereby granted, provided that the above
michael@0:  * copyright notice and this permission notice appear in all copies.
michael@0:  *
michael@0:  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
michael@0:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
michael@0:  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
michael@0:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
michael@0:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
michael@0:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
michael@0:  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
michael@0:  */
michael@0: 
michael@0: /*
michael@0:  * This version of this file is derived from Android 2.3 "Gingerbread",
michael@0:  * which contains uncredited changes by Android/Google developers.  It has
michael@0:  * been modified in 2011 for use in the Android build of Mozilla Firefox by
michael@0:  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
michael@0:  * and Steve Workman <sjhworkman@gmail.com>).
michael@0:  * These changes are offered under the same license as the original NetBSD
michael@0:  * file, whose copyright and license are unchanged above.
michael@0:  */
michael@0: 
michael@0: #define ANDROID_CHANGES 1
michael@0: #define MOZILLA_NECKO_EXCLUDE_CODE 1
michael@0: 
michael@0: #include <sys/cdefs.h>
michael@0: #ifndef lint
michael@0: #ifdef notdef
michael@0: static const char rcsid[] = "Id: ns_name.c,v 1.3.2.4.4.2 2004/05/04 03:27:47 marka Exp";
michael@0: #else
michael@0: __RCSID("$NetBSD: ns_name.c,v 1.3 2004/11/07 02:19:49 christos Exp $");
michael@0: #endif
michael@0: #endif
michael@0: 
michael@0: #include <sys/types.h>
michael@0: 
michael@0: #include <netinet/in.h>
michael@0: #include "arpa_nameser.h"
michael@0: 
michael@0: #include <errno.h>
michael@0: #ifdef ANDROID_CHANGES
michael@0: #include "resolv_private.h"
michael@0: #else
michael@0: #include <resolv.h>
michael@0: #endif
michael@0: #include <string.h>
michael@0: #include <ctype.h>
michael@0: #include <stdlib.h>
michael@0: #include <limits.h>
michael@0: 
michael@0: #ifdef SPRINTF_CHAR
michael@0: # define SPRINTF(x) strlen(sprintf/**/x)
michael@0: #else
michael@0: # define SPRINTF(x) ((size_t)sprintf x)
michael@0: #endif
michael@0: 
michael@0: #define NS_TYPE_ELT			0x40 /* EDNS0 extended label type */
michael@0: #define DNS_LABELTYPE_BITSTRING		0x41
michael@0: 
michael@0: /* Data. */
michael@0: 
michael@0: static const char	digits[] = "0123456789";
michael@0: 
michael@0: static const char digitvalue[256] = {
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,	/*16*/
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/
michael@0: 	 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1, /*64*/
michael@0: 	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/
michael@0: 	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
michael@0: 	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/
michael@0: };
michael@0: 
michael@0: /* Forward. */
michael@0: 
michael@0: static int		special(int);
michael@0: static int		printable(int);
michael@0: static int		dn_find(const u_char *, const u_char *,
michael@0: 				const u_char * const *,
michael@0: 				const u_char * const *);
michael@0: static int		encode_bitsring(const char **, const char *,
michael@0: 					unsigned char **, unsigned char **,
michael@0: 					unsigned const char *);
michael@0: static int		labellen(const u_char *);
michael@0: static int		decode_bitstring(const unsigned char **,
michael@0: 					 char *, const char *);
michael@0: 
michael@0: /* Public. */
michael@0: 
michael@0: /*
michael@0:  * ns_name_ntop(src, dst, dstsiz)
michael@0:  *	Convert an encoded domain name to printable ascii as per RFC1035.
michael@0:  * return:
michael@0:  *	Number of bytes written to buffer, or -1 (with errno set)
michael@0:  * notes:
michael@0:  *	The root is returned as "."
michael@0:  *	All other domains are returned in non absolute form
michael@0:  */
michael@0: int
michael@0: ns_name_ntop(const u_char *src, char *dst, size_t dstsiz)
michael@0: {
michael@0: 	const u_char *cp;
michael@0: 	char *dn, *eom;
michael@0: 	u_char c;
michael@0: 	u_int n;
michael@0: 	int l;
michael@0: 
michael@0: 	cp = src;
michael@0: 	dn = dst;
michael@0: 	eom = dst + dstsiz;
michael@0: 
michael@0: 	while ((n = *cp++) != 0) {
michael@0: 		if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
michael@0: 			/* Some kind of compression pointer. */
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		if (dn != dst) {
michael@0: 			if (dn >= eom) {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			*dn++ = '.';
michael@0: 		}
michael@0: 		if ((l = labellen(cp - 1)) < 0) {
michael@0: 			errno = EMSGSIZE; /* XXX */
michael@0: 			return(-1);
michael@0: 		}
michael@0: 		if (dn + l >= eom) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) {
michael@0: 			int m;
michael@0: 
michael@0: 			if (n != DNS_LABELTYPE_BITSTRING) {
michael@0: 				/* XXX: labellen should reject this case */
michael@0: 				errno = EINVAL;
michael@0: 				return(-1);
michael@0: 			}
michael@0: 			if ((m = decode_bitstring(&cp, dn, eom)) < 0)
michael@0: 			{
michael@0: 				errno = EMSGSIZE;
michael@0: 				return(-1);
michael@0: 			}
michael@0: 			dn += m;
michael@0: 			continue;
michael@0: 		}
michael@0: 		for (; l > 0; l--) {
michael@0: 			c = *cp++;
michael@0: 			if (special(c)) {
michael@0: 				if (dn + 1 >= eom) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				*dn++ = '\\';
michael@0: 				*dn++ = (char)c;
michael@0: 			} else if (!printable(c)) {
michael@0: 				if (dn + 3 >= eom) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				*dn++ = '\\';
michael@0: 				*dn++ = digits[c / 100];
michael@0: 				*dn++ = digits[(c % 100) / 10];
michael@0: 				*dn++ = digits[c % 10];
michael@0: 			} else {
michael@0: 				if (dn >= eom) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				*dn++ = (char)c;
michael@0: 			}
michael@0: 		}
michael@0: 	}
michael@0: 	if (dn == dst) {
michael@0: 		if (dn >= eom) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		*dn++ = '.';
michael@0: 	}
michael@0: 	if (dn >= eom) {
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	*dn++ = '\0';
michael@0: 	return (dn - dst);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * ns_name_pton(src, dst, dstsiz)
michael@0:  *	Convert a ascii string into an encoded domain name as per RFC1035.
michael@0:  * return:
michael@0:  *	-1 if it fails
michael@0:  *	1 if string was fully qualified
michael@0:  *	0 is string was not fully qualified
michael@0:  * notes:
michael@0:  *	Enforces label and domain length limits.
michael@0:  */
michael@0: 
michael@0: int
michael@0: ns_name_pton(const char *src, u_char *dst, size_t dstsiz)
michael@0: {
michael@0: 	u_char *label, *bp, *eom;
michael@0: 	int c, n, escaped, e = 0;
michael@0: 	char *cp;
michael@0: 
michael@0: 	escaped = 0;
michael@0: 	bp = dst;
michael@0: 	eom = dst + dstsiz;
michael@0: 	label = bp++;
michael@0: 
michael@0: 	while ((c = *src++) != 0) {
michael@0: 		if (escaped) {
michael@0: 			if (c == '[') { /* start a bit string label */
michael@0: 				if ((cp = strchr(src, ']')) == NULL) {
michael@0: 					errno = EINVAL; /* ??? */
michael@0: 					return(-1);
michael@0: 				}
michael@0: 				if ((e = encode_bitsring(&src, cp + 2,
michael@0: 							 &label, &bp, eom))
michael@0: 				    != 0) {
michael@0: 					errno = e;
michael@0: 					return(-1);
michael@0: 				}
michael@0: 				escaped = 0;
michael@0: 				label = bp++;
michael@0: 				if ((c = *src++) == 0)
michael@0: 					goto done;
michael@0: 				else if (c != '.') {
michael@0: 					errno = EINVAL;
michael@0: 					return(-1);
michael@0: 				}
michael@0: 				continue;
michael@0: 			}
michael@0: 			else if ((cp = strchr(digits, c)) != NULL) {
michael@0: 				n = (cp - digits) * 100;
michael@0: 				if ((c = *src++) == 0 ||
michael@0: 				    (cp = strchr(digits, c)) == NULL) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				n += (cp - digits) * 10;
michael@0: 				if ((c = *src++) == 0 ||
michael@0: 				    (cp = strchr(digits, c)) == NULL) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				n += (cp - digits);
michael@0: 				if (n > 255) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				c = n;
michael@0: 			}
michael@0: 			escaped = 0;
michael@0: 		} else if (c == '\\') {
michael@0: 			escaped = 1;
michael@0: 			continue;
michael@0: 		} else if (c == '.') {
michael@0: 			c = (bp - label - 1);
michael@0: 			if ((c & NS_CMPRSFLGS) != 0) {	/* Label too big. */
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			if (label >= eom) {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			*label = c;
michael@0: 			/* Fully qualified ? */
michael@0: 			if (*src == '\0') {
michael@0: 				if (c != 0) {
michael@0: 					if (bp >= eom) {
michael@0: 						errno = EMSGSIZE;
michael@0: 						return (-1);
michael@0: 					}
michael@0: 					*bp++ = '\0';
michael@0: 				}
michael@0: 				if ((bp - dst) > MAXCDNAME) {
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 				return (1);
michael@0: 			}
michael@0: 			if (c == 0 || *src == '.') {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			label = bp++;
michael@0: 			continue;
michael@0: 		}
michael@0: 		if (bp >= eom) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		*bp++ = (u_char)c;
michael@0: 	}
michael@0: 	c = (bp - label - 1);
michael@0: 	if ((c & NS_CMPRSFLGS) != 0) {		/* Label too big. */
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0:   done:
michael@0: 	if (label >= eom) {
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	*label = c;
michael@0: 	if (c != 0) {
michael@0: 		if (bp >= eom) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		*bp++ = 0;
michael@0: 	}
michael@0: 	if ((bp - dst) > MAXCDNAME) {	/* src too big */
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	return (0);
michael@0: }
michael@0: 
michael@0: #ifndef MOZILLA_NECKO_EXCLUDE_CODE
michael@0: /*
michael@0:  * ns_name_ntol(src, dst, dstsiz)
michael@0:  *	Convert a network strings labels into all lowercase.
michael@0:  * return:
michael@0:  *	Number of bytes written to buffer, or -1 (with errno set)
michael@0:  * notes:
michael@0:  *	Enforces label and domain length limits.
michael@0:  */
michael@0: 
michael@0: int
michael@0: ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
michael@0: {
michael@0: 	const u_char *cp;
michael@0: 	u_char *dn, *eom;
michael@0: 	u_char c;
michael@0: 	u_int n;
michael@0: 	int l;
michael@0: 
michael@0: 	cp = src;
michael@0: 	dn = dst;
michael@0: 	eom = dst + dstsiz;
michael@0: 
michael@0: 	if (dn >= eom) {
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	while ((n = *cp++) != 0) {
michael@0: 		if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
michael@0: 			/* Some kind of compression pointer. */
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		*dn++ = n;
michael@0: 		if ((l = labellen(cp - 1)) < 0) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		if (dn + l >= eom) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		for (; l > 0; l--) {
michael@0: 			c = *cp++;
michael@0: 			if (isupper(c))
michael@0: 				*dn++ = tolower(c);
michael@0: 			else
michael@0: 				*dn++ = c;
michael@0: 		}
michael@0: 	}
michael@0: 	*dn++ = '\0';
michael@0: 	return (dn - dst);
michael@0: }
michael@0: #endif
michael@0: 
michael@0: /*
michael@0:  * ns_name_unpack(msg, eom, src, dst, dstsiz)
michael@0:  *	Unpack a domain name from a message, source may be compressed.
michael@0:  * return:
michael@0:  *	-1 if it fails, or consumed octets if it succeeds.
michael@0:  */
michael@0: int
michael@0: ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
michael@0: 	       u_char *dst, size_t dstsiz)
michael@0: {
michael@0: 	const u_char *srcp, *dstlim;
michael@0: 	u_char *dstp;
michael@0: 	int n, len, checked, l;
michael@0: 
michael@0: 	len = -1;
michael@0: 	checked = 0;
michael@0: 	dstp = dst;
michael@0: 	srcp = src;
michael@0: 	dstlim = dst + dstsiz;
michael@0: 	if (srcp < msg || srcp >= eom) {
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	/* Fetch next label in domain name. */
michael@0: 	while ((n = *srcp++) != 0) {
michael@0: 		/* Check for indirection. */
michael@0: 		switch (n & NS_CMPRSFLGS) {
michael@0: 		case 0:
michael@0: 		case NS_TYPE_ELT:
michael@0: 			/* Limit checks. */
michael@0: 			if ((l = labellen(srcp - 1)) < 0) {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return(-1);
michael@0: 			}
michael@0: 			if (dstp + l + 1 >= dstlim || srcp + l >= eom) {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			checked += l + 1;
michael@0: 			*dstp++ = n;
michael@0: 			memcpy(dstp, srcp, (size_t)l);
michael@0: 			dstp += l;
michael@0: 			srcp += l;
michael@0: 			break;
michael@0: 
michael@0: 		case NS_CMPRSFLGS:
michael@0: 			if (srcp >= eom) {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			if (len < 0)
michael@0: 				len = srcp - src + 1;
michael@0: 			srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
michael@0: 			if (srcp < msg || srcp >= eom) {  /* Out of range. */
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			checked += 2;
michael@0: 			/*
michael@0: 			 * Check for loops in the compressed name;
michael@0: 			 * if we've looked at the whole message,
michael@0: 			 * there must be a loop.
michael@0: 			 */
michael@0: 			if (checked >= eom - msg) {
michael@0: 				errno = EMSGSIZE;
michael@0: 				return (-1);
michael@0: 			}
michael@0: 			break;
michael@0: 
michael@0: 		default:
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);			/* flag error */
michael@0: 		}
michael@0: 	}
michael@0: 	*dstp = '\0';
michael@0: 	if (len < 0)
michael@0: 		len = srcp - src;
michael@0: 	return (len);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
michael@0:  *	Pack domain name 'domain' into 'comp_dn'.
michael@0:  * return:
michael@0:  *	Size of the compressed name, or -1.
michael@0:  * notes:
michael@0:  *	'dnptrs' is an array of pointers to previous compressed names.
michael@0:  *	dnptrs[0] is a pointer to the beginning of the message. The array
michael@0:  *	ends with NULL.
michael@0:  *	'lastdnptr' is a pointer to the end of the array pointed to
michael@0:  *	by 'dnptrs'.
michael@0:  * Side effects:
michael@0:  *	The list of pointers in dnptrs is updated for labels inserted into
michael@0:  *	the message as we compress the name.  If 'dnptr' is NULL, we don't
michael@0:  *	try to compress names. If 'lastdnptr' is NULL, we don't update the
michael@0:  *	list.
michael@0:  */
michael@0: int
michael@0: ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
michael@0: 	     const u_char **dnptrs, const u_char **lastdnptr)
michael@0: {
michael@0: 	u_char *dstp;
michael@0: 	const u_char **cpp, **lpp, *eob, *msg;
michael@0: 	const u_char *srcp;
michael@0: 	int n, l, first = 1;
michael@0: 
michael@0: 	srcp = src;
michael@0: 	dstp = dst;
michael@0: 	eob = dstp + dstsiz;
michael@0: 	lpp = cpp = NULL;
michael@0: 	if (dnptrs != NULL) {
michael@0: 		if ((msg = *dnptrs++) != NULL) {
michael@0: 			for (cpp = dnptrs; *cpp != NULL; cpp++)
michael@0: 				;
michael@0: 			lpp = cpp;	/* end of list to search */
michael@0: 		}
michael@0: 	} else
michael@0: 		msg = NULL;
michael@0: 
michael@0: 	/* make sure the domain we are about to add is legal */
michael@0: 	l = 0;
michael@0: 	do {
michael@0: 		int l0;
michael@0: 
michael@0: 		n = *srcp;
michael@0: 		if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		if ((l0 = labellen(srcp)) < 0) {
michael@0: 			errno = EINVAL;
michael@0: 			return(-1);
michael@0: 		}
michael@0: 		l += l0 + 1;
michael@0: 		if (l > MAXCDNAME) {
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		srcp += l0 + 1;
michael@0: 	} while (n != 0);
michael@0: 
michael@0: 	/* from here on we need to reset compression pointer array on error */
michael@0: 	srcp = src;
michael@0: 	do {
michael@0: 		/* Look to see if we can use pointers. */
michael@0: 		n = *srcp;
michael@0: 		if (n != 0 && msg != NULL) {
michael@0: 			l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
michael@0: 				    (const u_char * const *)lpp);
michael@0: 			if (l >= 0) {
michael@0: 				if (dstp + 1 >= eob) {
michael@0: 					goto cleanup;
michael@0: 				}
michael@0: 				*dstp++ = ((u_int32_t)l >> 8) | NS_CMPRSFLGS;
michael@0: 				*dstp++ = l % 256;
michael@0: 				return (dstp - dst);
michael@0: 			}
michael@0: 			/* Not found, save it. */
michael@0: 			if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
michael@0: 			    (dstp - msg) < 0x4000 && first) {
michael@0: 				*cpp++ = dstp;
michael@0: 				*cpp = NULL;
michael@0: 				first = 0;
michael@0: 			}
michael@0: 		}
michael@0: 		/* copy label to buffer */
michael@0: 		if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
michael@0: 			/* Should not happen. */
michael@0: 			goto cleanup;
michael@0: 		}
michael@0: 		n = labellen(srcp);
michael@0: 		if (dstp + 1 + n >= eob) {
michael@0: 			goto cleanup;
michael@0: 		}
michael@0: 		memcpy(dstp, srcp, (size_t)(n + 1));
michael@0: 		srcp += n + 1;
michael@0: 		dstp += n + 1;
michael@0: 	} while (n != 0);
michael@0: 
michael@0: 	if (dstp > eob) {
michael@0: cleanup:
michael@0: 		if (msg != NULL)
michael@0: 			*lpp = NULL;
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	return (dstp - dst);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * ns_name_uncompress(msg, eom, src, dst, dstsiz)
michael@0:  *	Expand compressed domain name to presentation format.
michael@0:  * return:
michael@0:  *	Number of bytes read out of `src', or -1 (with errno set).
michael@0:  * note:
michael@0:  *	Root domain returns as "." not "".
michael@0:  */
michael@0: int
michael@0: ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
michael@0: 		   char *dst, size_t dstsiz)
michael@0: {
michael@0: 	u_char tmp[NS_MAXCDNAME];
michael@0: 	int n;
michael@0: 
michael@0: 	if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
michael@0: 		return (-1);
michael@0: 	if (ns_name_ntop(tmp, dst, dstsiz) == -1)
michael@0: 		return (-1);
michael@0: 	return (n);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
michael@0:  *	Compress a domain name into wire format, using compression pointers.
michael@0:  * return:
michael@0:  *	Number of bytes consumed in `dst' or -1 (with errno set).
michael@0:  * notes:
michael@0:  *	'dnptrs' is an array of pointers to previous compressed names.
michael@0:  *	dnptrs[0] is a pointer to the beginning of the message.
michael@0:  *	The list ends with NULL.  'lastdnptr' is a pointer to the end of the
michael@0:  *	array pointed to by 'dnptrs'. Side effect is to update the list of
michael@0:  *	pointers for labels inserted into the message as we compress the name.
michael@0:  *	If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
michael@0:  *	is NULL, we don't update the list.
michael@0:  */
michael@0: int
michael@0: ns_name_compress(const char *src, u_char *dst, size_t dstsiz,
michael@0: 		 const u_char **dnptrs, const u_char **lastdnptr)
michael@0: {
michael@0: 	u_char tmp[NS_MAXCDNAME];
michael@0: 
michael@0: 	if (ns_name_pton(src, tmp, sizeof tmp) == -1)
michael@0: 		return (-1);
michael@0: 	return (ns_name_pack(tmp, dst, (int)dstsiz, dnptrs, lastdnptr));
michael@0: }
michael@0: 
michael@0: #ifndef MOZILLA_NECKO_EXCLUDE_CODE
michael@0: /*
michael@0:  * Reset dnptrs so that there are no active references to pointers at or
michael@0:  * after src.
michael@0:  */
michael@0: void
michael@0: ns_name_rollback(const u_char *src, const u_char **dnptrs,
michael@0: 		 const u_char **lastdnptr)
michael@0: {
michael@0: 	while (dnptrs < lastdnptr && *dnptrs != NULL) {
michael@0: 		if (*dnptrs >= src) {
michael@0: 			*dnptrs = NULL;
michael@0: 			break;
michael@0: 		}
michael@0: 		dnptrs++;
michael@0: 	}
michael@0: }
michael@0: #endif
michael@0: 
michael@0: /*
michael@0:  * ns_name_skip(ptrptr, eom)
michael@0:  *	Advance *ptrptr to skip over the compressed name it points at.
michael@0:  * return:
michael@0:  *	0 on success, -1 (with errno set) on failure.
michael@0:  */
michael@0: int
michael@0: ns_name_skip(const u_char **ptrptr, const u_char *eom)
michael@0: {
michael@0: 	const u_char *cp;
michael@0: 	u_int n;
michael@0: 	int l;
michael@0: 
michael@0: 	cp = *ptrptr;
michael@0: 	while (cp < eom && (n = *cp++) != 0) {
michael@0: 		/* Check for indirection. */
michael@0: 		switch (n & NS_CMPRSFLGS) {
michael@0: 		case 0:			/* normal case, n == len */
michael@0: 			cp += n;
michael@0: 			continue;
michael@0: 		case NS_TYPE_ELT: /* EDNS0 extended label */
michael@0: 			if ((l = labellen(cp - 1)) < 0) {
michael@0: 				errno = EMSGSIZE; /* XXX */
michael@0: 				return(-1);
michael@0: 			}
michael@0: 			cp += l;
michael@0: 			continue;
michael@0: 		case NS_CMPRSFLGS:	/* indirection */
michael@0: 			cp++;
michael@0: 			break;
michael@0: 		default:		/* illegal type */
michael@0: 			errno = EMSGSIZE;
michael@0: 			return (-1);
michael@0: 		}
michael@0: 		break;
michael@0: 	}
michael@0: 	if (cp > eom) {
michael@0: 		errno = EMSGSIZE;
michael@0: 		return (-1);
michael@0: 	}
michael@0: 	*ptrptr = cp;
michael@0: 	return (0);
michael@0: }
michael@0: 
michael@0: /* Private. */
michael@0: 
michael@0: /*
michael@0:  * special(ch)
michael@0:  *	Thinking in noninternationalized USASCII (per the DNS spec),
michael@0:  *	is this characted special ("in need of quoting") ?
michael@0:  * return:
michael@0:  *	boolean.
michael@0:  */
michael@0: static int
michael@0: special(int ch) {
michael@0: 	switch (ch) {
michael@0: 	case 0x22: /* '"' */
michael@0: 	case 0x2E: /* '.' */
michael@0: 	case 0x3B: /* ';' */
michael@0: 	case 0x5C: /* '\\' */
michael@0: 	case 0x28: /* '(' */
michael@0: 	case 0x29: /* ')' */
michael@0: 	/* Special modifiers in zone files. */
michael@0: 	case 0x40: /* '@' */
michael@0: 	case 0x24: /* '$' */
michael@0: 		return (1);
michael@0: 	default:
michael@0: 		return (0);
michael@0: 	}
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * printable(ch)
michael@0:  *	Thinking in noninternationalized USASCII (per the DNS spec),
michael@0:  *	is this character visible and not a space when printed ?
michael@0:  * return:
michael@0:  *	boolean.
michael@0:  */
michael@0: static int
michael@0: printable(int ch) {
michael@0: 	return (ch > 0x20 && ch < 0x7f);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  *	Thinking in noninternationalized USASCII (per the DNS spec),
michael@0:  *	convert this character to lower case if it's upper case.
michael@0:  */
michael@0: static int
michael@0: mklower(int ch) {
michael@0: 	if (ch >= 0x41 && ch <= 0x5A)
michael@0: 		return (ch + 0x20);
michael@0: 	return (ch);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * dn_find(domain, msg, dnptrs, lastdnptr)
michael@0:  *	Search for the counted-label name in an array of compressed names.
michael@0:  * return:
michael@0:  *	offset from msg if found, or -1.
michael@0:  * notes:
michael@0:  *	dnptrs is the pointer to the first name on the list,
michael@0:  *	not the pointer to the start of the message.
michael@0:  */
michael@0: static int
michael@0: dn_find(const u_char *domain, const u_char *msg,
michael@0: 	const u_char * const *dnptrs,
michael@0: 	const u_char * const *lastdnptr)
michael@0: {
michael@0: 	const u_char *dn, *cp, *sp;
michael@0: 	const u_char * const *cpp;
michael@0: 	u_int n;
michael@0: 
michael@0: 	for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
michael@0: 		sp = *cpp;
michael@0: 		/*
michael@0: 		 * terminate search on:
michael@0: 		 * root label
michael@0: 		 * compression pointer
michael@0: 		 * unusable offset
michael@0: 		 */
michael@0: 		while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 &&
michael@0: 		       (sp - msg) < 0x4000) {
michael@0: 			dn = domain;
michael@0: 			cp = sp;
michael@0: 			while ((n = *cp++) != 0) {
michael@0: 				/*
michael@0: 				 * check for indirection
michael@0: 				 */
michael@0: 				switch (n & NS_CMPRSFLGS) {
michael@0: 				case 0:		/* normal case, n == len */
michael@0: 					n = labellen(cp - 1); /* XXX */
michael@0: 
michael@0: 					if (n != *dn++)
michael@0: 						goto next;
michael@0: 
michael@0: 					for (; n > 0; n--)
michael@0: 						if (mklower(*dn++) !=
michael@0: 						    mklower(*cp++))
michael@0: 							goto next;
michael@0: 					/* Is next root for both ? */
michael@0: 					if (*dn == '\0' && *cp == '\0')
michael@0: 						return (sp - msg);
michael@0: 					if (*dn)
michael@0: 						continue;
michael@0: 					goto next;
michael@0: 				case NS_CMPRSFLGS:	/* indirection */
michael@0: 					cp = msg + (((n & 0x3f) << 8) | *cp);
michael@0: 					break;
michael@0: 
michael@0: 				default:	/* illegal type */
michael@0: 					errno = EMSGSIZE;
michael@0: 					return (-1);
michael@0: 				}
michael@0: 			}
michael@0:  next: ;
michael@0: 			sp += *sp + 1;
michael@0: 		}
michael@0: 	}
michael@0: 	errno = ENOENT;
michael@0: 	return (-1);
michael@0: }
michael@0: 
michael@0: static int
michael@0: decode_bitstring(const unsigned char **cpp, char *dn, const char *eom)
michael@0: {
michael@0: 	const unsigned char *cp = *cpp;
michael@0: 	char *beg = dn, tc;
michael@0: 	int b, blen, plen, i;
michael@0: 
michael@0: 	if ((blen = (*cp & 0xff)) == 0)
michael@0: 		blen = 256;
michael@0: 	plen = (blen + 3) / 4;
michael@0: 	plen += sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1);
michael@0: 	if (dn + plen >= eom)
michael@0: 		return(-1);
michael@0: 
michael@0: 	cp++;
michael@0: 	i = SPRINTF((dn, "\\[x"));
michael@0: 	if (i < 0)
michael@0: 		return (-1);
michael@0: 	dn += i;
michael@0: 	for (b = blen; b > 7; b -= 8, cp++) {
michael@0: 		i = SPRINTF((dn, "%02x", *cp & 0xff));
michael@0: 		if (i < 0)
michael@0: 			return (-1);
michael@0: 		dn += i;
michael@0: 	}
michael@0: 	if (b > 4) {
michael@0: 		tc = *cp++;
michael@0: 		i = SPRINTF((dn, "%02x", tc & (0xff << (8 - b))));
michael@0: 		if (i < 0)
michael@0: 			return (-1);
michael@0: 		dn += i;
michael@0: 	} else if (b > 0) {
michael@0: 		tc = *cp++;
michael@0: 		i = SPRINTF((dn, "%1x",
michael@0: 			       (((u_int32_t)tc >> 4) & 0x0f) & (0x0f << (4 - b))));
michael@0: 		if (i < 0)
michael@0: 			return (-1);
michael@0: 		dn += i;
michael@0: 	}
michael@0: 	i = SPRINTF((dn, "/%d]", blen));
michael@0: 	if (i < 0)
michael@0: 		return (-1);
michael@0: 	dn += i;
michael@0: 
michael@0: 	*cpp = cp;
michael@0: 	return(dn - beg);
michael@0: }
michael@0: 
michael@0: static int
michael@0: encode_bitsring(const char **bp, const char *end, unsigned char **labelp,
michael@0: 	        unsigned char ** dst, unsigned const char *eom)
michael@0: {
michael@0: 	int afterslash = 0;
michael@0: 	const char *cp = *bp;
michael@0: 	unsigned char *tp;
michael@0: 	char c;
michael@0: 	const char *beg_blen;
michael@0: 	char *end_blen = NULL;
michael@0: 	int value = 0, count = 0, tbcount = 0, blen = 0;
michael@0: 
michael@0: 	beg_blen = end_blen = NULL;
michael@0: 
michael@0: 	/* a bitstring must contain at least 2 characters */
michael@0: 	if (end - cp < 2)
michael@0: 		return(EINVAL);
michael@0: 
michael@0: 	/* XXX: currently, only hex strings are supported */
michael@0: 	if (*cp++ != 'x')
michael@0: 		return(EINVAL);
michael@0: 	if (!isxdigit((*cp) & 0xff)) /* reject '\[x/BLEN]' */
michael@0: 		return(EINVAL);
michael@0: 
michael@0: 	for (tp = *dst + 1; cp < end && tp < eom; cp++) {
michael@0: 		switch((c = *cp)) {
michael@0: 		case ']':	/* end of the bitstring */
michael@0: 			if (afterslash) {
michael@0: 				if (beg_blen == NULL)
michael@0: 					return(EINVAL);
michael@0: 				blen = (int)strtol(beg_blen, &end_blen, 10);
michael@0: 				if (*end_blen != ']')
michael@0: 					return(EINVAL);
michael@0: 			}
michael@0: 			if (count)
michael@0: 				*tp++ = ((value << 4) & 0xff);
michael@0: 			cp++;	/* skip ']' */
michael@0: 			goto done;
michael@0: 		case '/':
michael@0: 			afterslash = 1;
michael@0: 			break;
michael@0: 		default:
michael@0: 			if (afterslash) {
michael@0: 				if (!isdigit(c&0xff))
michael@0: 					return(EINVAL);
michael@0: 				if (beg_blen == NULL) {
michael@0: 
michael@0: 					if (c == '0') {
michael@0: 						/* blen never begings with 0 */
michael@0: 						return(EINVAL);
michael@0: 					}
michael@0: 					beg_blen = cp;
michael@0: 				}
michael@0: 			} else {
michael@0: 				if (!isxdigit(c&0xff))
michael@0: 					return(EINVAL);
michael@0: 				value <<= 4;
michael@0: 				value += digitvalue[(int)c];
michael@0: 				count += 4;
michael@0: 				tbcount += 4;
michael@0: 				if (tbcount > 256)
michael@0: 					return(EINVAL);
michael@0: 				if (count == 8) {
michael@0: 					*tp++ = value;
michael@0: 					count = 0;
michael@0: 				}
michael@0: 			}
michael@0: 			break;
michael@0: 		}
michael@0: 	}
michael@0:   done:
michael@0: 	if (cp >= end || tp >= eom)
michael@0: 		return(EMSGSIZE);
michael@0: 
michael@0: 	/*
michael@0: 	 * bit length validation:
michael@0: 	 * If a <length> is present, the number of digits in the <bit-data>
michael@0: 	 * MUST be just sufficient to contain the number of bits specified
michael@0: 	 * by the <length>. If there are insignificant bits in a final
michael@0: 	 * hexadecimal or octal digit, they MUST be zero.
michael@0: 	 * RFC 2673, Section 3.2.
michael@0: 	 */
michael@0: 	if (blen > 0) {
michael@0: 		int traillen;
michael@0: 
michael@0: 		if (((blen + 3) & ~3) != tbcount)
michael@0: 			return(EINVAL);
michael@0: 		traillen = tbcount - blen; /* between 0 and 3 */
michael@0: 		if (((value << (8 - traillen)) & 0xff) != 0)
michael@0: 			return(EINVAL);
michael@0: 	}
michael@0: 	else
michael@0: 		blen = tbcount;
michael@0: 	if (blen == 256)
michael@0: 		blen = 0;
michael@0: 
michael@0: 	/* encode the type and the significant bit fields */
michael@0: 	**labelp = DNS_LABELTYPE_BITSTRING;
michael@0: 	**dst = blen;
michael@0: 
michael@0: 	*bp = cp;
michael@0: 	*dst = tp;
michael@0: 
michael@0: 	return(0);
michael@0: }
michael@0: 
michael@0: static int
michael@0: labellen(const u_char *lp)
michael@0: {
michael@0: 	int bitlen;
michael@0: 	u_char l = *lp;
michael@0: 
michael@0: 	if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
michael@0: 		/* should be avoided by the caller */
michael@0: 		return(-1);
michael@0: 	}
michael@0: 
michael@0: 	if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) {
michael@0: 		if (l == DNS_LABELTYPE_BITSTRING) {
michael@0: 			if ((bitlen = *(lp + 1)) == 0)
michael@0: 				bitlen = 256;
michael@0: 			return((bitlen + 7 ) / 8 + 1);
michael@0: 		}
michael@0: 		return(-1);	/* unknwon ELT */
michael@0: 	}
michael@0: 	return(l);
michael@0: }