[PATCH 15/24] resolv: Move ns_samename into its own file, and into libc

[Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>]

But only as an internal symbol, __libc_ns_samename.  The libresolv
ABI is preserved.  This is because the function is deprecated, and
it does not make sense to add new symbol versions for deprecated
functions.

Also reformat the implementation to GNU style.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
---
 include/arpa/nameser.h     |  3 ++-
 resolv/Makefile            |  1 +
 resolv/Versions            |  1 +
 resolv/ns_print.c          |  6 +++---
 resolv/ns_samedomain.c     | 28 +++-------------------------
 resolv/ns_samename.c       | 38 ++++++++++++++++++++++++++++++++++++++
 resolv/res_query.c         |  2 +-
 resolv/res_send.c          |  4 ++--
 resolv/resolv-deprecated.c |  6 ++++++
 9 files changed, 57 insertions(+), 32 deletions(-)
 create mode 100644 resolv/ns_samename.c

diff --git a/include/arpa/nameser.h b/include/arpa/nameser.h
index a529cc86d3..53f1dbc7c3 100644
--- a/include/arpa/nameser.h
+++ b/include/arpa/nameser.h
@@ -68,7 +68,6 @@ libresolv_hidden_proto (ns_parserr)
 libresolv_hidden_proto (ns_sprintrr)
 libresolv_hidden_proto (ns_sprintrrf)
 libresolv_hidden_proto (ns_samedomain)
-libresolv_hidden_proto (ns_samename)
 libresolv_hidden_proto (ns_format_ttl)
 
 extern __typeof (ns_makecanon) __libc_ns_makecanon;
@@ -87,6 +86,8 @@ extern __typeof (ns_name_uncompress) __ns_name_uncompress;
 libc_hidden_proto (__ns_name_uncompress)
 extern __typeof (ns_name_unpack) __ns_name_unpack;
 libc_hidden_proto (__ns_name_unpack)
+extern __typeof (ns_samename) __libc_ns_samename;
+libc_hidden_proto (__libc_ns_samename)
 
 # endif /* !_ISOMAC */
 #endif
diff --git a/resolv/Makefile b/resolv/Makefile
index d1ad5e4cba..744da951ae 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -43,6 +43,7 @@ routines := \
   ns_name_skip \
   ns_name_uncompress \
   ns_name_unpack \
+  ns_samename \
   nsap_addr \
   res-close \
   res-name-checking \
diff --git a/resolv/Versions b/resolv/Versions
index 93078de25c..2201d4224c 100644
--- a/resolv/Versions
+++ b/resolv/Versions
@@ -73,6 +73,7 @@ libc {
     __libc_dn_expand;
     __libc_dn_skipname;
     __libc_ns_makecanon;
+    __libc_ns_samename;
     __libc_res_dnok;
     __libc_res_hnok;
     __ns_name_compress;
diff --git a/resolv/ns_print.c b/resolv/ns_print.c
index 9a9602d74c..43f39edf61 100644
--- a/resolv/ns_print.c
+++ b/resolv/ns_print.c
@@ -103,9 +103,9 @@ ns_sprintrrf(const u_char *msg, size_t msglen,
 	/*
 	 * Owner.
 	 */
-	if (name_ctx != NULL && ns_samename(name_ctx, name) == 1) {
+	if (name_ctx != NULL && __libc_ns_samename (name_ctx, name) == 1)
 		T(addstr("\t\t\t", 3, &buf, &buflen));
-	} else {
+	else {
 		len = prune_origin(name, origin);
 		if (*name == '\0') {
 			goto root;
@@ -621,7 +621,7 @@ prune_origin(const char *name, const char *origin) {
 	const char *oname = name;
 
 	while (*name != '\0') {
-		if (origin != NULL && ns_samename(name, origin) == 1)
+		if (origin != NULL && __libc_ns_samename (name, origin) == 1)
 			return (name - oname - (name > oname));
 		while (*name != '\0') {
 			if (*name == '\\') {
diff --git a/resolv/ns_samedomain.c b/resolv/ns_samedomain.c
index cfff2516b0..46cb8f5fb2 100644
--- a/resolv/ns_samedomain.c
+++ b/resolv/ns_samedomain.c
@@ -139,31 +139,9 @@ libresolv_hidden_def (ns_samedomain)
  *	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));
+ns_subdomain (const char *a, const char *b)
+{
+  return __libc_ns_samename (a, b) != 1 && ns_samedomain (a, b);
 }
 
-/*%
- *	determine whether domain name "a" is the same as domain name "b"
- *
- * return:
- *\li	-1 on error
- *\li	0 if names differ
- *\li	1 if names are the same
- */
-
-int
-ns_samename(const char *a, const char *b) {
-	char ta[NS_MAXDNAME], tb[NS_MAXDNAME];
-
-	if (__libc_ns_makecanon(a, ta, sizeof ta) < 0 ||
-	    __libc_ns_makecanon(b, tb, sizeof tb) < 0)
-		return (-1);
-	if (strcasecmp(ta, tb) == 0)
-		return (1);
-	else
-		return (0);
-}
-libresolv_hidden_def (ns_samename)
-
 /*! \file */
diff --git a/resolv/ns_samename.c b/resolv/ns_samename.c
new file mode 100644
index 0000000000..61fe3cab43
--- /dev/null
+++ b/resolv/ns_samename.c
@@ -0,0 +1,38 @@
+/* Check if two domain names are equal after trailing dot normalization.
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * 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.
+ */
+
+#include <arpa/nameser.h>
+#include <string.h>
+
+/* Determines whether domain name A is the same as domain name B.
+   Returns -1 on error, 0 if names differ, 1 if names are the
+   same.  */
+int
+__libc_ns_samename (const char *a, const char *b)
+{
+  char ta[NS_MAXDNAME], tb[NS_MAXDNAME];
+
+  if (__libc_ns_makecanon (a, ta, sizeof ta) < 0 ||
+      __libc_ns_makecanon (b, tb, sizeof tb) < 0)
+    return -1;
+  if (__strcasecmp (ta, tb) == 0)
+    return 1;
+  else
+    return 0;
+}
+libc_hidden_def (__libc_ns_samename)
diff --git a/resolv/res_query.c b/resolv/res_query.c
index ebbe5a6a4e..5b51af8451 100644
--- a/resolv/res_query.c
+++ b/resolv/res_query.c
@@ -656,7 +656,7 @@ __res_context_hostalias (struct resolv_context *ctx,
 		if (!*cp1)
 			break;
 		*cp1 = '\0';
-		if (ns_samename(buf, name) == 1) {
+		if (__libc_ns_samename(buf, name) == 1) {
 			while (isspace(*++cp1))
 				;
 			if (!*cp1)
diff --git a/resolv/res_send.c b/resolv/res_send.c
index 915fc6d2c6..dfea9fc7fa 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -224,8 +224,8 @@ res_nameinquery(const char *name, int type, int class,
 			return (-1);
 		NS_GET16(ttype, cp);
 		NS_GET16(tclass, cp);
-		if (ttype == type && tclass == class &&
-		    ns_samename(tname, name) == 1)
+		if (ttype == type && tclass == class
+		    && __libc_ns_samename (tname, name) == 1)
 			return (1);
 	}
 	return (0);
diff --git a/resolv/resolv-deprecated.c b/resolv/resolv-deprecated.c
index cbd1078dc2..d8344f8f39 100644
--- a/resolv/resolv-deprecated.c
+++ b/resolv/resolv-deprecated.c
@@ -33,3 +33,9 @@ ns_makecanon (const char *src, char *dst, size_t dstsize)
 {
   return __libc_ns_makecanon (src, dst, dstsize);
 }
+
+int
+ns_samename (const char *a, const char *b)
+{
+  return __libc_ns_samename (a, b);
+}
-- 
2.31.1