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/res_init.cpp b/res_init.cpp
new file mode 100644
index 0000000..f21ebad
--- /dev/null
+++ b/res_init.cpp
@@ -0,0 +1,443 @@
+/* $NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $ */
+
+/*
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 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.
+ */
+
+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * 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 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 <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
+#include "resolv_netid.h"
+#include "resolv_private.h"
+
+#include "res_private.h"
+
+/* Options. Should all be left alone. */
+#ifndef DEBUG
+#define DEBUG
+#endif
+
+static void res_setoptions(res_state, const char*, const char*);
+
+/*
+ * Resolver state default settings.
+ */
+
+/*
+ * Set up default settings. If the configuration file exist, the values
+ * there will have precedence. Otherwise, the server address is set to
+ * INADDR_ANY and the default domain name comes from the gethostname().
+ *
+ * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
+ * rather than INADDR_ANY ("0.0.0.0") as the default name server address
+ * since it was noted that INADDR_ANY actually meant ``the first interface
+ * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
+ * it had to be "up" in order for you to reach your own name server. It
+ * was later decided that since the recommended practice is to always
+ * install local static routes through 127.0.0.1 for all your network
+ * interfaces, that we could solve this problem without a code change.
+ *
+ * The configuration file should always be used, since it is the only way
+ * to specify a default domain. If you are running a server on your local
+ * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
+ * in the configuration file.
+ *
+ * Return 0 if completes successfully, -1 on error
+ */
+int res_ninit(res_state statp) {
+ extern int __res_vinit(res_state, int);
+
+ return (__res_vinit(statp, 0));
+}
+
+/* This function has to be reachable by res_data.c but not publicly. */
+int __res_vinit(res_state statp, int preinit) {
+ char *cp, **pp;
+ char buf[BUFSIZ];
+ int nserv = 0; /* number of nameserver records read from file */
+ int havesearch = 0;
+ int dots;
+ union res_sockaddr_union u[2];
+
+ if ((statp->options & RES_INIT) != 0U) res_ndestroy(statp);
+
+ if (!preinit) {
+ statp->netid = NETID_UNSET;
+ statp->retrans = RES_TIMEOUT;
+ statp->retry = RES_DFLRETRY;
+ statp->options = RES_DEFAULT;
+ statp->id = res_randomid();
+ statp->_mark = MARK_UNSET;
+ }
+
+ memset(u, 0, sizeof(u));
+ u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
+ u[nserv].sin.sin_family = AF_INET;
+ u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
+ nserv++;
+ statp->nscount = 0;
+ statp->ndots = 1;
+ statp->pfcode = 0;
+ statp->_vcsock = -1;
+ statp->_flags = 0;
+ statp->qhook = NULL;
+ statp->rhook = NULL;
+ statp->_u._ext.nscount = 0;
+ statp->_u._ext.ext = (struct __res_state_ext*) malloc(sizeof(*statp->_u._ext.ext));
+ if (statp->_u._ext.ext != NULL) {
+ memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
+ statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
+ strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
+ strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
+ }
+ statp->nsort = 0;
+ res_setservers(statp, u, nserv);
+
+ if (statp->defdname[0] == 0 && gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
+ (cp = strchr(buf, '.')) != NULL)
+ strcpy(statp->defdname, cp + 1);
+
+ /* find components of local domain that might be searched */
+ if (havesearch == 0) {
+ pp = statp->dnsrch;
+ *pp++ = statp->defdname;
+ *pp = NULL;
+
+ dots = 0;
+ for (cp = statp->defdname; *cp; cp++) dots += (*cp == '.');
+
+ cp = statp->defdname;
+ while (pp < statp->dnsrch + MAXDFLSRCH) {
+ if (dots < LOCALDOMAINPARTS) break;
+ cp = strchr(cp, '.') + 1; /* we know there is one */
+ *pp++ = cp;
+ dots--;
+ }
+ *pp = NULL;
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG) {
+ printf(";; res_init()... default dnsrch list:\n");
+ for (pp = statp->dnsrch; *pp; pp++) printf(";;\t%s\n", *pp);
+ printf(";;\t..END..\n");
+ }
+#endif
+ }
+
+ if ((cp = getenv("RES_OPTIONS")) != NULL) res_setoptions(statp, cp, "env");
+ if (nserv > 0) {
+ statp->nscount = nserv;
+ statp->options |= RES_INIT;
+ }
+ return (0);
+}
+
+static void res_setoptions(res_state statp, const char* options, const char* source) {
+ const char* cp = options;
+ int i;
+ struct __res_state_ext* ext = statp->_u._ext.ext;
+
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG)
+ printf(";; res_setoptions(\"%s\", \"%s\")...\n", options, source);
+#endif
+ while (*cp) {
+ /* skip leading and inner runs of spaces */
+ while (*cp == ' ' || *cp == '\t') cp++;
+ /* search for and process individual options */
+ if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
+ i = atoi(cp + sizeof("ndots:") - 1);
+ if (i <= RES_MAXNDOTS)
+ statp->ndots = i;
+ else
+ statp->ndots = RES_MAXNDOTS;
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG) printf(";;\tndots=%d\n", statp->ndots);
+#endif
+ } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
+ i = atoi(cp + sizeof("timeout:") - 1);
+ if (i <= RES_MAXRETRANS)
+ statp->retrans = i;
+ else
+ statp->retrans = RES_MAXRETRANS;
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG) printf(";;\ttimeout=%d\n", statp->retrans);
+#endif
+ } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)) {
+ i = atoi(cp + sizeof("attempts:") - 1);
+ if (i <= RES_MAXRETRY)
+ statp->retry = i;
+ else
+ statp->retry = RES_MAXRETRY;
+#ifdef DEBUG
+ if (statp->options & RES_DEBUG) printf(";;\tattempts=%d\n", statp->retry);
+#endif
+ } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
+#ifdef DEBUG
+ if (!(statp->options & RES_DEBUG)) {
+ printf(";; res_setoptions(\"%s\", \"%s\")..\n", options, source);
+ statp->options |= RES_DEBUG;
+ }
+ printf(";;\tdebug\n");
+#endif
+ } else if (!strncmp(cp, "no_tld_query", sizeof("no_tld_query") - 1) ||
+ !strncmp(cp, "no-tld-query", sizeof("no-tld-query") - 1)) {
+ statp->options |= RES_NOTLDQUERY;
+ } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
+ statp->options |= RES_USE_INET6;
+ } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
+ statp->options |= RES_ROTATE;
+ } else if (!strncmp(cp, "no-check-names", sizeof("no-check-names") - 1)) {
+ statp->options |= RES_NOCHECKNAME;
+ }
+#ifdef RES_USE_EDNS0
+ else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
+ statp->options |= RES_USE_EDNS0;
+ }
+#endif
+ else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
+ statp->options |= RES_USE_DNAME;
+ } else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
+ if (ext == NULL) goto skip;
+ cp += sizeof("nibble:") - 1;
+ i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
+ strncpy(ext->nsuffix, cp, (size_t) i);
+ ext->nsuffix[i] = '\0';
+ } else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
+ if (ext == NULL) goto skip;
+ cp += sizeof("nibble2:") - 1;
+ i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
+ strncpy(ext->nsuffix2, cp, (size_t) i);
+ ext->nsuffix2[i] = '\0';
+ } else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
+ cp += sizeof("v6revmode:") - 1;
+ /* "nibble" and "bitstring" used to be valid */
+ if (!strncmp(cp, "single", sizeof("single") - 1)) {
+ statp->options |= RES_NO_NIBBLE2;
+ } else if (!strncmp(cp, "both", sizeof("both") - 1)) {
+ statp->options &= ~RES_NO_NIBBLE2;
+ }
+ } else {
+ /* XXX - print a warning here? */
+ }
+ skip:
+ /* skip to next run of spaces */
+ while (*cp && *cp != ' ' && *cp != '\t') cp++;
+ }
+}
+
+/*
+ * This routine is for closing the socket if a virtual circuit is used and
+ * the program wants to close it. This provides support for endhostent()
+ * which expects to close the socket.
+ *
+ * This routine is not expected to be user visible.
+ */
+void res_nclose(res_state statp) {
+ int ns;
+
+ if (statp->_vcsock >= 0) {
+ (void) close(statp->_vcsock);
+ statp->_vcsock = -1;
+ statp->_flags &= ~(RES_F_VC | RES_F_CONN);
+ }
+ for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
+ if (statp->_u._ext.nssocks[ns] != -1) {
+ (void) close(statp->_u._ext.nssocks[ns]);
+ statp->_u._ext.nssocks[ns] = -1;
+ }
+ }
+}
+
+void res_ndestroy(res_state statp) {
+ res_nclose(statp);
+ if (statp->_u._ext.ext != NULL) free(statp->_u._ext.ext);
+ statp->options &= ~RES_INIT;
+ statp->_u._ext.ext = NULL;
+}
+
+const char* res_get_nibblesuffix(res_state statp) {
+ if (statp->_u._ext.ext) return (statp->_u._ext.ext->nsuffix);
+ return ("ip6.arpa");
+}
+
+const char* res_get_nibblesuffix2(res_state statp) {
+ if (statp->_u._ext.ext) return (statp->_u._ext.ext->nsuffix2);
+ return ("ip6.int");
+}
+
+void res_setservers(res_state statp, const union res_sockaddr_union* set, int cnt) {
+ int i, nserv;
+ size_t size;
+
+ /* close open servers */
+ res_nclose(statp);
+
+ /* cause rtt times to be forgotten */
+ statp->_u._ext.nscount = 0;
+
+ nserv = 0;
+ for (i = 0; i < cnt && nserv < MAXNS; i++) {
+ switch (set->sin.sin_family) {
+ case AF_INET:
+ size = sizeof(set->sin);
+ if (statp->_u._ext.ext)
+ memcpy(&statp->_u._ext.ext->nsaddrs[nserv], &set->sin, size);
+ if (size <= sizeof(statp->nsaddr_list[nserv]))
+ memcpy(&statp->nsaddr_list[nserv], &set->sin, size);
+ else
+ statp->nsaddr_list[nserv].sin_family = 0;
+ nserv++;
+ break;
+
+#ifdef HAS_INET6_STRUCTS
+ case AF_INET6:
+ size = sizeof(set->sin6);
+ if (statp->_u._ext.ext)
+ memcpy(&statp->_u._ext.ext->nsaddrs[nserv], &set->sin6, size);
+ if (size <= sizeof(statp->nsaddr_list[nserv]))
+ memcpy(&statp->nsaddr_list[nserv], &set->sin6, size);
+ else
+ statp->nsaddr_list[nserv].sin_family = 0;
+ nserv++;
+ break;
+#endif
+
+ default:
+ break;
+ }
+ set++;
+ }
+ statp->nscount = nserv;
+}
+
+int res_getservers(res_state statp, union res_sockaddr_union* set, int cnt) {
+ int i;
+ size_t size;
+ uint16_t family;
+
+ for (i = 0; i < statp->nscount && i < cnt; i++) {
+ if (statp->_u._ext.ext)
+ family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
+ else
+ family = statp->nsaddr_list[i].sin_family;
+
+ switch (family) {
+ case AF_INET:
+ size = sizeof(set->sin);
+ if (statp->_u._ext.ext)
+ memcpy(&set->sin, &statp->_u._ext.ext->nsaddrs[i], size);
+ else
+ memcpy(&set->sin, &statp->nsaddr_list[i], size);
+ break;
+
+#ifdef HAS_INET6_STRUCTS
+ case AF_INET6:
+ size = sizeof(set->sin6);
+ if (statp->_u._ext.ext)
+ memcpy(&set->sin6, &statp->_u._ext.ext->nsaddrs[i], size);
+ else
+ memcpy(&set->sin6, &statp->nsaddr_list[i], size);
+ break;
+#endif
+
+ default:
+ set->sin.sin_family = 0;
+ break;
+ }
+ set++;
+ }
+ return (statp->nscount);
+}
+
+void res_setnetcontext(res_state statp, const struct android_net_context* netcontext) {
+ if (statp != NULL) {
+ statp->netid = netcontext->dns_netid;
+ statp->_mark = netcontext->dns_mark;
+ statp->qhook = netcontext->qhook;
+ if (netcontext->flags & NET_CONTEXT_FLAG_USE_EDNS) {
+ statp->options |= RES_USE_EDNS0 | RES_USE_DNSSEC;
+ }
+ }
+}