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authorMurray Stokely <murray@FreeBSD.org>2002-02-19 11:04:34 +0000
committerMurray Stokely <murray@FreeBSD.org>2002-02-19 11:04:34 +0000
commitce99b771f886a2c842db7aa803c9a5a5918f42c8 (patch)
tree229464d9b3244ab78e2784c9a0a1f78de317089a /contrib/isc-dhcp/minires/ns_samedomain.c
parent7657fb140fbd218ea326d55bd3c43c4077f03d9a (diff)
downloadsrc-ce99b771f886a2c842db7aa803c9a5a5918f42c8.tar.gz
src-ce99b771f886a2c842db7aa803c9a5a5918f42c8.zip
Import ISC DHCP 3.0.1 RC6 client.
Notes
Notes: svn path=/vendor/isc-dhcp/dist/; revision=90908
Diffstat (limited to 'contrib/isc-dhcp/minires/ns_samedomain.c')
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1 files changed, 210 insertions, 0 deletions
diff --git a/contrib/isc-dhcp/minires/ns_samedomain.c b/contrib/isc-dhcp/minires/ns_samedomain.c
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+/*
+ * Copyright (c) 1995,1999 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.
+ */
+
+#ifndef lint
+static const char rcsid[] = "$Id: ns_samedomain.c,v 1.3 2001/01/16 22:33:09 mellon Exp $";
+#endif
+
+#include <sys/types.h>
+#include <errno.h>
+#include <string.h>
+
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "minires/minires.h"
+#include "arpa/nameser.h"
+
+/*
+ * int
+ * ns_samedomain(a, b)
+ * Check whether a name belongs to a domain.
+ * Inputs:
+ * a - the domain whose ancestory is being verified
+ * b - the potential ancestor we're checking against
+ * Return:
+ * boolean - is a at or below b?
+ * Notes:
+ * Trailing dots are first removed from name and domain.
+ * Always compare complete subdomains, not only whether the
+ * domain name is the trailing string of the given name.
+ *
+ * "host.foobar.top" lies in "foobar.top" and in "top" and in ""
+ * but NOT in "bar.top"
+ */
+
+int
+ns_samedomain(const char *a, const char *b) {
+ size_t la, lb;
+ int diff, i, escaped;
+ const char *cp;
+
+ la = strlen(a);
+ lb = strlen(b);
+
+ /* Ignore a trailing label separator (i.e. an unescaped dot) in 'a'. */
+ if (la != 0 && a[la - 1] == '.') {
+ escaped = 0;
+ /* Note this loop doesn't get executed if la==1. */
+ for (i = la - 2; i >= 0; i--)
+ if (a[i] == '\\') {
+ if (escaped)
+ escaped = 0;
+ else
+ escaped = 1;
+ } else
+ break;
+ if (!escaped)
+ la--;
+ }
+
+ /* Ignore a trailing label separator (i.e. an unescaped dot) in 'b'. */
+ if (lb != 0 && b[lb - 1] == '.') {
+ escaped = 0;
+ /* note this loop doesn't get executed if lb==1 */
+ for (i = lb - 2; i >= 0; i--)
+ if (b[i] == '\\') {
+ if (escaped)
+ escaped = 0;
+ else
+ escaped = 1;
+ } else
+ break;
+ if (!escaped)
+ lb--;
+ }
+
+ /* lb == 0 means 'b' is the root domain, so 'a' must be in 'b'. */
+ if (lb == 0)
+ return (1);
+
+ /* 'b' longer than 'a' means 'a' can't be in 'b'. */
+ if (lb > la)
+ return (0);
+
+ /* 'a' and 'b' being equal at this point indicates sameness. */
+ if (lb == la)
+ return (strncasecmp(a, b, lb) == 0);
+
+ /* Ok, we know la > lb. */
+
+ diff = la - lb;
+
+ /*
+ * If 'a' is only 1 character longer than 'b', then it can't be
+ * a subdomain of 'b' (because of the need for the '.' label
+ * separator).
+ */
+ if (diff < 2)
+ return (0);
+
+ /*
+ * If the character before the last 'lb' characters of 'b'
+ * isn't '.', then it can't be a match (this lets us avoid
+ * having "foobar.com" match "bar.com").
+ */
+ if (a[diff - 1] != '.')
+ return (0);
+
+ /*
+ * We're not sure about that '.', however. It could be escaped
+ * and thus not a really a label separator.
+ */
+ escaped = 0;
+ for (i = diff - 2; i >= 0; i--)
+ if (a[i] == '\\') {
+ if (escaped)
+ escaped = 0;
+ else
+ escaped = 1;
+ } else
+ break;
+ if (escaped)
+ return (0);
+
+ /* Now compare aligned trailing substring. */
+ cp = a + diff;
+ return (strncasecmp(cp, b, lb) == 0);
+}
+
+/*
+ * int
+ * ns_subdomain(a, b)
+ * is "a" a subdomain of "b"?
+ */
+int
+ns_subdomain(const char *a, const char *b) {
+ return (ns_samename(a, b) != 1 && ns_samedomain(a, b));
+}
+
+/*
+ * int
+ * ns_makecanon(src, dst, dstsize)
+ * make a canonical copy of domain name "src"
+ * notes:
+ * foo -> foo.
+ * foo. -> foo.
+ * foo.. -> foo.
+ * foo\. -> foo\..
+ * foo\\. -> foo\\.
+ */
+
+isc_result_t
+ns_makecanon(const char *src, char *dst, size_t dstsize) {
+ size_t n = strlen(src);
+
+ if (n + sizeof "." > dstsize) {
+ ISC_R_NOSPACE;
+ }
+ strcpy(dst, src);
+ while (n > 0 && dst[n - 1] == '.') /* Ends in "." */
+ if (n > 1 && dst[n - 2] == '\\' && /* Ends in "\." */
+ (n < 2 || dst[n - 3] != '\\')) /* But not "\\." */
+ break;
+ else
+ dst[--n] = '\0';
+ dst[n++] = '.';
+ dst[n] = '\0';
+ return ISC_R_SUCCESS;
+}
+
+/*
+ * int
+ * ns_samename(a, b)
+ * determine whether domain name "a" is the same as domain name "b"
+ * return:
+ * -1 on error
+ * 0 if names differ
+ * 1 if names are the same
+ */
+
+int
+ns_samename(const char *a, const char *b) {
+ char ta[NS_MAXDNAME], tb[NS_MAXDNAME];
+ isc_result_t status;
+
+ status = ns_makecanon(a, ta, sizeof ta);
+ if (status != ISC_R_SUCCESS)
+ return status;
+ status = ns_makecanon(b, tb, sizeof tb);
+ if (status != ISC_R_SUCCESS)
+ return (-1);
+ if (strcasecmp(ta, tb) == 0)
+ return (1);
+ else
+ return (0);
+}