openadk/package/dsniff/patches/patch-dns_c

$Id$
--- dsniff-2.4.orig/dns.c	1970-01-01 00:00:00.000000000 +0100
+++ dsniff-2.4/dns.c	2007-01-23 00:20:48.000000000 +0100
@@ -0,0 +1,677 @@
+/*
+ * Copyright (c) 1985, 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.
+ */
+
+/*
+ * Portions 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.
+ */
+
+/*
+ * 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.
+ */
+
+/*
+ *
+ * DNS helper functions not implemented in uclibc
+ *
+ */
+
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <ctype.h>
+#include <resolv.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+static const char	digits[] = "0123456789";
+
+/* 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 *);
+
+
+/*
+ * 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;
+
+	cp = src;
+	dn = dst;
+	eom = dst + dstsiz;
+
+	while ((n = *cp++) != 0) {
+		if ((n & NS_CMPRSFLGS) != 0) {
+			/* Some kind of compression pointer. */
+			return (-1);
+		}
+		if (dn != dst) {
+			if (dn >= eom) {
+				return (-1);
+			}
+			*dn++ = '.';
+		}
+		if (dn + n >= eom) {
+			return (-1);
+		}
+		for ((void)NULL; n > 0; n--) {
+			c = *cp++;
+			if (special(c)) {
+				if (dn + 1 >= eom) {
+					return (-1);
+				}
+				*dn++ = '\\';
+				*dn++ = (char)c;
+			} else if (!printable(c)) {
+				if (dn + 3 >= eom) {
+					return (-1);
+				}
+				*dn++ = '\\';
+				*dn++ = digits[c / 100];
+				*dn++ = digits[(c % 100) / 10];
+				*dn++ = digits[c % 10];
+			} else {
+				if (dn >= eom) {
+					return (-1);
+				}
+				*dn++ = (char)c;
+			}
+		}
+	}
+	if (dn == dst) {
+		if (dn >= eom) {
+			return (-1);
+		}
+		*dn++ = '.';
+	}
+	if (dn >= eom) {
+		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;
+	char *cp;
+
+	escaped = 0;
+	bp = dst;
+	eom = dst + dstsiz;
+	label = bp++;
+
+	while ((c = *src++) != 0) {
+		if (escaped) {
+			if ((cp = strchr(digits, c)) != NULL) {
+				n = (cp - digits) * 100;
+				if ((c = *src++) == 0 ||
+				    (cp = strchr(digits, c)) == NULL) {
+					return (-1);
+				}
+				n += (cp - digits) * 10;
+				if ((c = *src++) == 0 ||
+				    (cp = strchr(digits, c)) == NULL) {
+					return (-1);
+				}
+				n += (cp - digits);
+				if (n > 255) {
+					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. */
+				return (-1);
+			}
+			if (label >= eom) {
+				return (-1);
+			}
+			*label = c;
+			/* Fully qualified ? */
+			if (*src == '\0') {
+				if (c != 0) {
+					if (bp >= eom) {
+						return (-1);
+					}
+					*bp++ = '\0';
+				}
+				if ((bp - dst) > MAXCDNAME) {
+					return (-1);
+				}
+				return (1);
+			}
+			if (c == 0 || *src == '.') {
+				return (-1);
+			}
+			label = bp++;
+			continue;
+		}
+		if (bp >= eom) {
+			return (-1);
+		}
+		*bp++ = (u_char)c;
+	}
+	c = (bp - label - 1);
+	if ((c & NS_CMPRSFLGS) != 0) {		/* Label too big. */
+		return (-1);
+	}
+	if (label >= eom) {
+		return (-1);
+	}
+	*label = c;
+	if (c != 0) {
+		if (bp >= eom) {
+			return (-1);
+		}
+		*bp++ = 0;
+	}
+	if ((bp - dst) > MAXCDNAME) {	/* src too big */
+		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;
+
+	cp = src;
+	dn = dst;
+	eom = dst + dstsiz;
+
+	while ((n = *cp++) != 0) {
+		if ((n & NS_CMPRSFLGS) != 0) {
+			/* Some kind of compression pointer. */
+			return (-1);
+		}
+		*dn++ = n;
+		if (dn + n >= eom) {
+			return (-1);
+		}
+		for ((void)NULL; n > 0; n--) {
+			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;
+
+	len = -1;
+	checked = 0;
+	dstp = dst;
+	srcp = src;
+	dstlim = dst + dstsiz;
+	if (srcp < msg || srcp >= eom) {
+		return (-1);
+	}
+	/* Fetch next label in domain name. */
+	while ((n = *srcp++) != 0) {
+		/* Check for indirection. */
+		switch (n & NS_CMPRSFLGS) {
+		case 0:
+			/* Limit checks. */
+			if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
+				return (-1);
+			}
+			checked += n + 1;
+			*dstp++ = n;
+			memcpy(dstp, srcp, n);
+			dstp += n;
+			srcp += n;
+			break;
+
+		case NS_CMPRSFLGS:
+			if (srcp >= eom) {
+				return (-1);
+			}
+			if (len < 0)
+				len = srcp - src + 1;
+			srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
+			if (srcp < msg || srcp >= eom) {  /* Out of range. */
+				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) {
+				return (-1);
+			}
+			break;
+
+		default:
+			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;
+	lpp = cpp = NULL;
+	if (dnptrs != NULL) {
+		if ((msg = *dnptrs++) != NULL) {
+			for (cpp = dnptrs; *cpp != NULL; cpp++)
+				(void)NULL;
+			lpp = cpp;	/* end of list to search */
+		}
+	} else
+		msg = NULL;
+
+	/* make sure the domain we are about to add is legal */
+	l = 0;
+	do {
+		n = *srcp;
+		if ((n & NS_CMPRSFLGS) != 0) {
+			return (-1);
+		}
+		l += n + 1;
+		if (l > MAXCDNAME) {
+			return (-1);
+		}
+		srcp += n + 1;
+	} while (n != 0);
+
+	/* from here on we need to reset compression pointer array on error */
+	srcp = src;
+	do {
+		/* Look to see if we can use pointers. */
+		n = *srcp;
+		if (n != 0 && msg != NULL) {
+			l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
+				    (const u_char * const *)lpp);
+			if (l >= 0) {
+				if (dstp + 1 >= eob) {
+					goto cleanup;
+				}
+				*dstp++ = (l >> 8) | NS_CMPRSFLGS;
+				*dstp++ = l % 256;
+				return (dstp - dst);
+			}
+			/* Not found, save it. */
+			if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
+			    (dstp - msg) < 0x4000 && first) {
+				*cpp++ = dstp;
+				*cpp = NULL;
+				first = 0;
+			}
+		}
+		/* copy label to buffer */
+		if (n & NS_CMPRSFLGS) {		/* Should not happen. */
+			goto cleanup;
+		}
+		if (dstp + 1 + n >= eob) {
+			goto cleanup;
+		}
+		memcpy(dstp, srcp, n + 1);
+		srcp += n + 1;
+		dstp += n + 1;
+	} while (n != 0);
+
+	if (dstp > eob) {
+cleanup:
+		if (msg != NULL)
+			*lpp = NULL;
+		return (-1);
+	} 
+	return (dstp - dst);
+}
+
+/*
+ * ns_name_uncompress(msg, eom, src, dst, dstsiz)
+ *	Expand compressed domain name to presentation format.
+ * return:
+ *	Number of bytes read out of `src', or -1 (with errno set).
+ * note:
+ *	Root domain returns as "." not "".
+ */
+int
+ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
+		   char *dst, size_t dstsiz)
+{
+	u_char tmp[NS_MAXCDNAME];
+	int n;
+	
+	if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
+		return (-1);
+	if (ns_name_ntop(tmp, dst, dstsiz) == -1)
+		return (-1);
+	return (n);
+}
+
+/*
+ * ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
+ *	Compress a domain name into wire format, using compression pointers.
+ * return:
+ *	Number of bytes consumed in `dst' or -1 (with errno set).
+ * notes:
+ *	'dnptrs' is an array of pointers to previous compressed names.
+ *	dnptrs[0] is a pointer to the beginning of the message.
+ *	The list ends with NULL.  'lastdnptr' is a pointer to the end of the
+ *	array pointed to by 'dnptrs'. Side effect is to update the list of
+ *	pointers 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_compress(const char *src, u_char *dst, size_t dstsiz,
+		 const u_char **dnptrs, const u_char **lastdnptr)
+{
+	u_char tmp[NS_MAXCDNAME];
+
+	if (ns_name_pton(src, tmp, sizeof tmp) == -1)
+		return (-1);
+	return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
+}
+
+/*
+ * special(ch)
+ *	Thinking in noninternationalized USASCII (per the DNS spec),
+ *	is this characted special ("in need of quoting") ?
+ * return:
+ *	boolean.
+ */
+static int
+special(int ch) {
+	switch (ch) {
+	case 0x22: /* '"' */
+	case 0x2E: /* '.' */
+	case 0x3B: /* ';' */
+	case 0x5C: /* '\\' */
+	/* Special modifiers in zone files. */
+	case 0x40: /* '@' */
+	case 0x24: /* '$' */
+		return (1);
+	default:
+		return (0);
+	}
+}
+
+/*
+ * printable(ch)
+ *	Thinking in noninternationalized USASCII (per the DNS spec),
+ *	is this character visible and not a space when printed ?
+ * return:
+ *	boolean.
+ */
+static int
+printable(int ch) {
+	return (ch > 0x20 && ch < 0x7f);
+}
+
+/*
+ *	Thinking in noninternationalized USASCII (per the DNS spec),
+ *	convert this character to lower case if it's upper case.
+ */
+static int
+mklower(int ch) {
+	if (ch >= 0x41 && ch <= 0x5A)
+		return (ch + 0x20);
+	return (ch);
+}
+
+/*
+ * dn_find(domain, msg, dnptrs, lastdnptr)
+ *	Search for the counted-label name in an array of compressed names.
+ * return:
+ *	offset from msg if found, or -1.
+ * notes:
+ *	dnptrs is the pointer to the first name on the list,
+ *	not the pointer to the start of the message.
+ */
+static int
+dn_find(const u_char *domain, const u_char *msg,
+	const u_char * const *dnptrs,
+	const u_char * const *lastdnptr)
+{
+	const u_char *dn, *cp, *sp;
+	const u_char * const *cpp;
+	u_int n;
+
+	for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
+		sp = *cpp;
+		/*
+		 * terminate search on:
+		 * root label
+		 * compression pointer
+		 * unusable offset
+		 */
+		while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 &&
+		       (sp - msg) < 0x4000) {
+			dn = domain;
+			cp = sp;
+			while ((n = *cp++) != 0) {
+				/*
+				 * check for indirection
+				 */
+				switch (n & NS_CMPRSFLGS) {
+				case 0:		/* normal case, n == len */
+					if (n != *dn++)
+						goto next;
+					for ((void)NULL; n > 0; n--)
+						if (mklower(*dn++) !=
+						    mklower(*cp++))
+							goto next;
+					/* Is next root for both ? */
+					if (*dn == '\0' && *cp == '\0')
+						return (sp - msg);
+					if (*dn)
+						continue;
+					goto next;
+
+				case NS_CMPRSFLGS:	/* indirection */
+					cp = msg + (((n & 0x3f) << 8) | *cp);
+					break;
+
+				default:	/* illegal type */
+					return (-1);
+				}
+			}
+ next:
+			sp += *sp + 1;
+		}
+	}
+	return (-1);
+}
+
+/*
+ * Expand compressed domain name 'comp_dn' to full domain name.
+ * 'msg' is a pointer to the begining of the message,
+ * 'eomorig' points to the first location after the message,
+ * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
+ * Return size of compressed name or -1 if there was an error.
+ */
+int
+dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
+	  char *dst, int dstsiz)
+{
+	int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
+
+	if (n > 0 && dst[0] == '.')
+		dst[0] = '\0';
+	return (n);
+}
+
+/*
+ * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
+ * Return the size of the compressed name or -1.
+ * 'length' is the size of the array pointed to by 'comp_dn'.
+ */
+int
+dn_comp(const char *src, u_char *dst, int dstsiz,
+	u_char **dnptrs, u_char **lastdnptr)
+{
+	return (ns_name_compress(src, dst, (size_t)dstsiz,
+				 (const u_char **)dnptrs,
+				 (const u_char **)lastdnptr));
+}
+