Minimal changes to bring the resolver into the C++ era
It took surprisingly few changes, considering the leap from C with some
K&R constructs to C++17; most of the diffs are adding explicit pointer
casts and renaming variables called 'class' or 'try'.
As a result of building as C++, some of the names are now mangled,
making clashes with bionic harder. However, some names remain C due to
the __BEGIN_DECLS / __END_DECLS macros, scheduled to be removed in a
later cleanup pass.
Test: atest netd_integration_test
Change-Id: I3aefb9078421ec42f98f97d917785b365545feba
diff --git a/resolv/res_data.cpp b/resolv/res_data.cpp
new file mode 100644
index 0000000..45c311a
--- /dev/null
+++ b/resolv/res_data.cpp
@@ -0,0 +1,186 @@
+/* $NetBSD: res_data.c,v 1.8 2004/06/09 18:07:03 christos Exp $ */
+
+/*
+ * 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 ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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 <sys/param.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+#include <netinet/in.h>
+
+#include <ctype.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "res_private.h" // res_ourserver_p()
+#include "resolv_private.h"
+
+__LIBC_HIDDEN__
+extern const char* const _res_opcodes[] = {
+ "QUERY", "IQUERY", "CQUERYM", "CQUERYU", /* experimental */
+ "NOTIFY", /* experimental */
+ "UPDATE", "6", "7", "8", "9", "10",
+ "11", "12", "13", "ZONEINIT", "ZONEREF",
+};
+
+extern struct __res_state _nres;
+
+#define res_need_init() ((_nres.options & RES_INIT) == 0U)
+
+int res_init(void) {
+ int rv;
+ extern int __res_vinit(res_state, int);
+
+ /*
+ * These three fields used to be statically initialized. This made
+ * it hard to use this code in a shared library. It is necessary,
+ * now that we're doing dynamic initialization here, that we preserve
+ * the old semantics: if an application modifies one of these three
+ * fields of _res before res_init() is called, res_init() will not
+ * alter them. Of course, if an application is setting them to
+ * _zero_ before calling res_init(), hoping to override what used
+ * to be the static default, we can't detect it and unexpected results
+ * will follow. Zero for any of these fields would make no sense,
+ * so one can safely assume that the applications were already getting
+ * unexpected results.
+ *
+ * _nres.options is tricky since some apps were known to diddle the bits
+ * before res_init() was first called. We can't replicate that semantic
+ * with dynamic initialization (they may have turned bits off that are
+ * set in RES_DEFAULT). Our solution is to declare such applications
+ * "broken". They could fool us by setting RES_INIT but none do (yet).
+ */
+ if (!_nres.retrans) _nres.retrans = RES_TIMEOUT;
+ if (!_nres.retry) _nres.retry = 4;
+ if (!(_nres.options & RES_INIT)) _nres.options = RES_DEFAULT;
+
+ /*
+ * This one used to initialize implicitly to zero, so unless the app
+ * has set it to something in particular, we can randomize it now.
+ */
+ if (!_nres.id) _nres.id = res_randomid();
+
+ rv = __res_vinit(&_nres, 1);
+ return rv;
+}
+
+void p_query(const u_char* msg) {
+ fp_query(msg, stdout);
+}
+
+void fp_query(const u_char* msg, FILE* file) {
+ fp_nquery(msg, PACKETSZ, file);
+}
+
+void fp_nquery(const u_char* msg, int len, FILE* file) {
+ if (res_need_init() && res_init() == -1) return;
+
+ res_pquery(&_nres, msg, len, file);
+}
+
+int res_mkquery(int op, // opcode of query
+ const char* dname, // domain name
+ int cl, int type, // class and type of query
+ const u_char* data, // resource record data
+ int datalen, // length of data
+ const u_char* newrr_in, // new rr for modify or append
+ u_char* buf, // buffer to put query
+ int buflen) // size of buffer
+{
+ if (res_need_init() && res_init() == -1) {
+ RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
+ return -1;
+ }
+ return res_nmkquery(&_nres, op, dname, cl, type, data, datalen, newrr_in, buf, buflen);
+}
+
+int res_query(const char* name, // domain name
+ int cl, int type, // class and type of query
+ u_char* answer, // buffer to put answer
+ int anslen) // size of answer buffer
+{
+ if (res_need_init() && res_init() == -1) {
+ RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
+ return -1;
+ }
+ return res_nquery(&_nres, name, cl, type, answer, anslen);
+}
+
+void res_send_setqhook(res_send_qhook hook) {
+ _nres.qhook = hook;
+}
+
+void res_send_setrhook(res_send_rhook hook) {
+ _nres.rhook = hook;
+}
+
+int res_isourserver(const struct sockaddr_in* inp) {
+ return res_ourserver_p(&_nres, (const struct sockaddr*) (const void*) inp);
+}
+
+int res_send(const u_char* buf, int buflen, u_char* ans, int anssiz) {
+ if (res_need_init() && res_init() == -1) {
+ /* errno should have been set by res_init() in this case. */
+ return -1;
+ }
+
+ return res_nsend(&_nres, buf, buflen, ans, anssiz);
+}
+
+void res_close(void) {
+ res_nclose(&_nres);
+}
+
+int res_search(const char* name, // domain name
+ int cl, int type, // class and type of query
+ u_char* answer, // buffer to put answer
+ int anslen) // size of answer
+{
+ if (res_need_init() && res_init() == -1) {
+ RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
+ return -1;
+ }
+
+ return res_nsearch(&_nres, name, cl, type, answer, anslen);
+}
+
+int res_querydomain(const char* name, const char* domain,
+ int cl, int type, // class and type of query
+ u_char* answer, // buffer to put answer
+ int anslen) // size of answer
+{
+ if (res_need_init() && res_init() == -1) {
+ RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
+ return -1;
+ }
+
+ return res_nquerydomain(&_nres, name, domain, cl, type, answer, anslen);
+}
+
+int res_opt(int a, u_char* b, int c, int d) {
+ return res_nopt(&_nres, a, b, c, d);
+}
+
+const char* hostalias(const char* /*name*/) {
+ return NULL;
+}