resolv: Move res_queriesmatch to its own file and into libc

And reformat it to GNU style.

The treatment of this function matches res_nameinquery, for the
reasons stated there.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 129 insertions, 0 deletions

diff --git a/resolv/res_queriesmatch.c b/resolv/res_queriesmatch.c
new file mode 100644
index 0000000000..4b56d33193
--- /dev/null
+++ b/resolv/res_queriesmatch.c
@@ -0,0 +1,129 @@
+/* Check if two DNS packets contain the same query.
+   Copyright (C) 2016-2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/*
+ * Copyright (c) 1985, 1989, 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.
+ */
+
+#include <resolv.h>
+
+/* Author: paul vixie, 29may94.  */
+int
+__libc_res_queriesmatch (const unsigned char *buf1, const unsigned char *eom1,
+                         const unsigned char *buf2, const unsigned char *eom2)
+{
+  if (eom1 - buf1 < HFIXEDSZ || eom2 - buf2 < HFIXEDSZ)
+    return -1;
+
+  /* Only header section present in replies to dynamic update
+     packets.  */
+  if ((((HEADER *) buf1)->opcode == ns_o_update) &&
+      (((HEADER *) buf2)->opcode == ns_o_update))
+    return 1;
+
+  /* Note that we initially do not convert QDCOUNT to the host byte
+     order.  We can compare it with the second buffer's QDCOUNT
+     value without doing this.  */
+  int qdcount = ((HEADER *) buf1)->qdcount;
+  if (qdcount != ((HEADER *) buf2)->qdcount)
+    return 0;
+
+  qdcount = htons (qdcount);
+  const unsigned char *cp = buf1 + HFIXEDSZ;
+
+  while (qdcount-- > 0)
+    {
+      char tname[MAXDNAME+1];
+      int n, ttype, tclass;
+
+      n = __libc_dn_expand (buf1, eom1, cp, tname, sizeof tname);
+      if (n < 0)
+        return -1;
+      cp += n;
+      if (eom1 - cp < 4)
+        return -1;
+      NS_GET16 (ttype, cp);
+      NS_GET16 (tclass, cp);
+      if (!__libc_res_nameinquery (tname, ttype, tclass, buf2, eom2))
+        return 0;
+    }
+  return 1;
+}
+libc_hidden_def (__libc_res_queriesmatch)