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_send.cpp b/resolv/res_send.cpp
new file mode 100644
index 0000000..fad08ee
--- /dev/null
+++ b/resolv/res_send.cpp
@@ -0,0 +1,1273 @@
+/* $NetBSD: res_send.c,v 1.9 2006/01/24 17:41:25 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.
+ */
+
+/*
+ * Send query to name server and wait for reply.
+ */
+
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+#include <netinet/in.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <async_safe/log.h>
+
+#include "private/android_filesystem_config.h"
+#include "res_private.h"
+#include "resolv_cache.h"
+#include "resolv_netid.h"
+#include "resolv_private.h"
+#include "resolv_stats.h"
+
+/* Options. Leave them on. */
+#ifndef DEBUG
+#define DEBUG
+#endif
+
+#include "res_debug.h"
+
+#define EXT(res) ((res)->_u._ext)
+#define DBG 0
+
+/* Forward. */
+
+static int get_salen(const struct sockaddr*);
+static struct sockaddr* get_nsaddr(res_state, size_t);
+static int send_vc(res_state, struct __res_params* params, const u_char*, int, u_char*, int, int*,
+ int, time_t*, int*, int*);
+static int send_dg(res_state, struct __res_params* params, const u_char*, int, u_char*, int, int*,
+ int, int*, int*, time_t*, int*, int*);
+static void Aerror(const res_state, FILE*, const char*, int, const struct sockaddr*, int);
+static void Perror(const res_state, FILE*, const char*, int);
+static int sock_eq(struct sockaddr*, struct sockaddr*);
+void res_pquery(const res_state, const u_char*, int, FILE*);
+static int connect_with_timeout(int sock, const struct sockaddr* nsap, socklen_t salen,
+ const struct timespec timeout);
+static int retrying_poll(const int sock, short events, const struct timespec* finish);
+
+/* BIONIC-BEGIN: implement source port randomization */
+typedef union {
+ struct sockaddr sa;
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+} _sockaddr_union;
+
+// BEGIN: Code copied from ISC eventlib
+// TODO: move away from this code
+
+#define BILLION 1000000000
+
+static struct timespec evConsTime(time_t sec, long nsec) {
+ struct timespec x;
+
+ x.tv_sec = sec;
+ x.tv_nsec = nsec;
+ return (x);
+}
+
+static struct timespec evAddTime(struct timespec addend1, struct timespec addend2) {
+ struct timespec x;
+
+ x.tv_sec = addend1.tv_sec + addend2.tv_sec;
+ x.tv_nsec = addend1.tv_nsec + addend2.tv_nsec;
+ if (x.tv_nsec >= BILLION) {
+ x.tv_sec++;
+ x.tv_nsec -= BILLION;
+ }
+ return (x);
+}
+
+static struct timespec evSubTime(struct timespec minuend, struct timespec subtrahend) {
+ struct timespec x;
+
+ x.tv_sec = minuend.tv_sec - subtrahend.tv_sec;
+ if (minuend.tv_nsec >= subtrahend.tv_nsec)
+ x.tv_nsec = minuend.tv_nsec - subtrahend.tv_nsec;
+ else {
+ x.tv_nsec = BILLION - subtrahend.tv_nsec + minuend.tv_nsec;
+ x.tv_sec--;
+ }
+ return (x);
+}
+
+static int evCmpTime(struct timespec a, struct timespec b) {
+#define SGN(x) ((x) < 0 ? (-1) : (x) > 0 ? (1) : (0));
+ time_t s = a.tv_sec - b.tv_sec;
+ long n;
+
+ if (s != 0) return SGN(s);
+
+ n = a.tv_nsec - b.tv_nsec;
+ return SGN(n);
+}
+
+static struct timespec evNowTime(void) {
+ struct timespec tsnow;
+ clock_gettime(CLOCK_REALTIME, &tsnow);
+ return tsnow;
+}
+
+static struct iovec evConsIovec(void* buf, size_t cnt) {
+ struct iovec ret;
+
+ memset(&ret, 0xf5, sizeof ret);
+ ret.iov_base = buf;
+ ret.iov_len = cnt;
+ return ret;
+}
+
+// END: Code copied from ISC eventlib
+
+static int random_bind(int s, int family) {
+ _sockaddr_union u;
+ int j;
+ socklen_t slen;
+
+ /* clear all, this also sets the IP4/6 address to 'any' */
+ memset(&u, 0, sizeof u);
+
+ switch (family) {
+ case AF_INET:
+ u.sin.sin_family = family;
+ slen = sizeof u.sin;
+ break;
+ case AF_INET6:
+ u.sin6.sin6_family = family;
+ slen = sizeof u.sin6;
+ break;
+ default:
+ errno = EPROTO;
+ return -1;
+ }
+
+ /* first try to bind to a random source port a few times */
+ for (j = 0; j < 10; j++) {
+ /* find a random port between 1025 .. 65534 */
+ int port = 1025 + (res_randomid() % (65535 - 1025));
+ if (family == AF_INET)
+ u.sin.sin_port = htons(port);
+ else
+ u.sin6.sin6_port = htons(port);
+
+ if (!bind(s, &u.sa, slen)) return 0;
+ }
+
+ // nothing after 10 attempts, our network table is probably busy
+ // let the system decide which port is best
+ if (family == AF_INET)
+ u.sin.sin_port = 0;
+ else
+ u.sin6.sin6_port = 0;
+
+ return bind(s, &u.sa, slen);
+}
+/* BIONIC-END */
+
+static const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
+
+/* Public. */
+
+/* int
+ * res_isourserver(ina)
+ * looks up "ina" in _res.ns_addr_list[]
+ * returns:
+ * 0 : not found
+ * >0 : found
+ * author:
+ * paul vixie, 29may94
+ */
+__LIBC_HIDDEN__ int res_ourserver_p(const res_state statp, const struct sockaddr* sa) {
+ const struct sockaddr_in *inp, *srv;
+ const struct sockaddr_in6 *in6p, *srv6;
+ int ns;
+
+ switch (sa->sa_family) {
+ case AF_INET:
+ inp = (const struct sockaddr_in*) (const void*) sa;
+ for (ns = 0; ns < statp->nscount; ns++) {
+ srv = (struct sockaddr_in*) (void*) get_nsaddr(statp, (size_t) ns);
+ if (srv->sin_family == inp->sin_family && srv->sin_port == inp->sin_port &&
+ (srv->sin_addr.s_addr == INADDR_ANY ||
+ srv->sin_addr.s_addr == inp->sin_addr.s_addr))
+ return (1);
+ }
+ break;
+ case AF_INET6:
+ if (EXT(statp).ext == NULL) break;
+ in6p = (const struct sockaddr_in6*) (const void*) sa;
+ for (ns = 0; ns < statp->nscount; ns++) {
+ srv6 = (struct sockaddr_in6*) (void*) get_nsaddr(statp, (size_t) ns);
+ if (srv6->sin6_family == in6p->sin6_family && srv6->sin6_port == in6p->sin6_port &&
+#ifdef HAVE_SIN6_SCOPE_ID
+ (srv6->sin6_scope_id == 0 || srv6->sin6_scope_id == in6p->sin6_scope_id) &&
+#endif
+ (IN6_IS_ADDR_UNSPECIFIED(&srv6->sin6_addr) ||
+ IN6_ARE_ADDR_EQUAL(&srv6->sin6_addr, &in6p->sin6_addr)))
+ return (1);
+ }
+ break;
+ default:
+ break;
+ }
+ return (0);
+}
+
+/* int
+ * res_nameinquery(name, type, cl, buf, eom)
+ * look for (name, type, cl) in the query section of packet (buf, eom)
+ * requires:
+ * buf + HFIXEDSZ <= eom
+ * returns:
+ * -1 : format error
+ * 0 : not found
+ * >0 : found
+ * author:
+ * paul vixie, 29may94
+ */
+int res_nameinquery(const char* name, int type, int cl, const u_char* buf, const u_char* eom) {
+ const u_char* cp = buf + HFIXEDSZ;
+ int qdcount = ntohs(((const HEADER*) (const void*) buf)->qdcount);
+
+ while (qdcount-- > 0) {
+ char tname[MAXDNAME + 1];
+ int n = dn_expand(buf, eom, cp, tname, sizeof tname);
+ if (n < 0) return (-1);
+ cp += n;
+ if (cp + 2 * INT16SZ > eom) return (-1);
+ int ttype = ns_get16(cp);
+ cp += INT16SZ;
+ int tclass = ns_get16(cp);
+ cp += INT16SZ;
+ if (ttype == type && tclass == cl && ns_samename(tname, name) == 1) return (1);
+ }
+ return (0);
+}
+
+/* int
+ * res_queriesmatch(buf1, eom1, buf2, eom2)
+ * is there a 1:1 mapping of (name,type,class)
+ * in (buf1,eom1) and (buf2,eom2)?
+ * returns:
+ * -1 : format error
+ * 0 : not a 1:1 mapping
+ * >0 : is a 1:1 mapping
+ * author:
+ * paul vixie, 29may94
+ */
+int res_queriesmatch(const u_char* buf1, const u_char* eom1, const u_char* buf2,
+ const u_char* eom2) {
+ const u_char* cp = buf1 + HFIXEDSZ;
+ int qdcount = ntohs(((const HEADER*) (const void*) buf1)->qdcount);
+
+ if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2) return (-1);
+
+ /*
+ * Only header section present in replies to
+ * dynamic update packets.
+ */
+ if ((((const HEADER*) (const void*) buf1)->opcode == ns_o_update) &&
+ (((const HEADER*) (const void*) buf2)->opcode == ns_o_update))
+ return (1);
+
+ if (qdcount != ntohs(((const HEADER*) (const void*) buf2)->qdcount)) return (0);
+ while (qdcount-- > 0) {
+ char tname[MAXDNAME + 1];
+ int n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
+ if (n < 0) return (-1);
+ cp += n;
+ if (cp + 2 * INT16SZ > eom1) return (-1);
+ int ttype = ns_get16(cp);
+ cp += INT16SZ;
+ int tclass = ns_get16(cp);
+ cp += INT16SZ;
+ if (!res_nameinquery(tname, ttype, tclass, buf2, eom2)) return (0);
+ }
+ return (1);
+}
+
+int res_nsend(res_state statp, const u_char* buf, int buflen, u_char* ans, int anssiz) {
+ int gotsomewhere, terrno, v_circuit, resplen, n;
+ char abuf[NI_MAXHOST];
+ ResolvCacheStatus cache_status = RESOLV_CACHE_UNSUPPORTED;
+
+ if (anssiz < HFIXEDSZ) {
+ errno = EINVAL;
+ return (-1);
+ }
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY),
+ (stdout, ";; res_send()\n"), buf, buflen);
+ v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ;
+ gotsomewhere = 0;
+ terrno = ETIMEDOUT;
+
+ int anslen = 0;
+ cache_status = _resolv_cache_lookup(statp->netid, buf, buflen, ans, anssiz, &anslen);
+
+ if (cache_status == RESOLV_CACHE_FOUND) {
+ return anslen;
+ } else if (cache_status != RESOLV_CACHE_UNSUPPORTED) {
+ // had a cache miss for a known network, so populate the thread private
+ // data so the normal resolve path can do its thing
+ _resolv_populate_res_for_net(statp);
+ }
+ if (statp->nscount == 0) {
+ // We have no nameservers configured, so there's no point trying.
+ // Tell the cache the query failed, or any retries and anyone else asking the same
+ // question will block for PENDING_REQUEST_TIMEOUT seconds instead of failing fast.
+ _resolv_cache_query_failed(statp->netid, buf, buflen);
+ errno = ESRCH;
+ return (-1);
+ }
+
+ /*
+ * If the ns_addr_list in the resolver context has changed, then
+ * invalidate our cached copy and the associated timing data.
+ */
+ if (EXT(statp).nscount != 0) {
+ int needclose = 0;
+ struct sockaddr_storage peer;
+ socklen_t peerlen;
+
+ if (EXT(statp).nscount != statp->nscount) {
+ needclose++;
+ } else {
+ for (int ns = 0; ns < statp->nscount; ns++) {
+ if (statp->nsaddr_list[ns].sin_family &&
+ !sock_eq((struct sockaddr*) (void*) &statp->nsaddr_list[ns],
+ (struct sockaddr*) (void*) &EXT(statp).ext->nsaddrs[ns])) {
+ needclose++;
+ break;
+ }
+
+ if (EXT(statp).nssocks[ns] == -1) continue;
+ peerlen = sizeof(peer);
+ if (getpeername(EXT(statp).nssocks[ns], (struct sockaddr*) (void*) &peer,
+ &peerlen) < 0) {
+ needclose++;
+ break;
+ }
+ if (!sock_eq((struct sockaddr*) (void*) &peer, get_nsaddr(statp, (size_t) ns))) {
+ needclose++;
+ break;
+ }
+ }
+ }
+ if (needclose) {
+ res_nclose(statp);
+ EXT(statp).nscount = 0;
+ }
+ }
+
+ /*
+ * Maybe initialize our private copy of the ns_addr_list.
+ */
+ if (EXT(statp).nscount == 0) {
+ for (int ns = 0; ns < statp->nscount; ns++) {
+ EXT(statp).nstimes[ns] = RES_MAXTIME;
+ EXT(statp).nssocks[ns] = -1;
+ if (!statp->nsaddr_list[ns].sin_family) continue;
+ EXT(statp).ext->nsaddrs[ns].sin = statp->nsaddr_list[ns];
+ }
+ EXT(statp).nscount = statp->nscount;
+ }
+
+ /*
+ * Some resolvers want to even out the load on their nameservers.
+ * Note that RES_BLAST overrides RES_ROTATE.
+ */
+ if ((statp->options & RES_ROTATE) != 0U && (statp->options & RES_BLAST) == 0U) {
+ union res_sockaddr_union inu;
+ struct sockaddr_in ina;
+ int lastns = statp->nscount - 1;
+ int fd;
+ u_int16_t nstime;
+
+ if (EXT(statp).ext != NULL) inu = EXT(statp).ext->nsaddrs[0];
+ ina = statp->nsaddr_list[0];
+ fd = EXT(statp).nssocks[0];
+ nstime = EXT(statp).nstimes[0];
+ for (int ns = 0; ns < lastns; ns++) {
+ if (EXT(statp).ext != NULL)
+ EXT(statp).ext->nsaddrs[ns] = EXT(statp).ext->nsaddrs[ns + 1];
+ statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
+ EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
+ EXT(statp).nstimes[ns] = EXT(statp).nstimes[ns + 1];
+ }
+ if (EXT(statp).ext != NULL) EXT(statp).ext->nsaddrs[lastns] = inu;
+ statp->nsaddr_list[lastns] = ina;
+ EXT(statp).nssocks[lastns] = fd;
+ EXT(statp).nstimes[lastns] = nstime;
+ }
+
+ /*
+ * Send request, RETRY times, or until successful.
+ */
+ for (int attempt = 0; attempt < statp->retry; ++attempt) {
+ struct __res_stats stats[MAXNS];
+ struct __res_params params;
+ int revision_id = _resolv_cache_get_resolver_stats(statp->netid, ¶ms, stats);
+ bool usable_servers[MAXNS];
+ android_net_res_stats_get_usable_servers(¶ms, stats, statp->nscount, usable_servers);
+
+ for (int ns = 0; ns < statp->nscount; ns++) {
+ if (!usable_servers[ns]) continue;
+ struct sockaddr* nsap;
+ int nsaplen;
+ time_t now = 0;
+ int rcode = RCODE_INTERNAL_ERROR;
+ int delay = 0;
+ nsap = get_nsaddr(statp, (size_t) ns);
+ nsaplen = get_salen(nsap);
+ statp->_flags &= ~RES_F_LASTMASK;
+ statp->_flags |= (ns << RES_F_LASTSHIFT);
+
+ same_ns:
+ if (statp->qhook) {
+ int done = 0, loops = 0;
+
+ do {
+ res_sendhookact act;
+
+ act = (*statp->qhook)(&nsap, &buf, &buflen, ans, anssiz, &resplen);
+ switch (act) {
+ case res_goahead:
+ done = 1;
+ break;
+ case res_nextns:
+ res_nclose(statp);
+ goto next_ns;
+ case res_done:
+ if (cache_status == RESOLV_CACHE_NOTFOUND) {
+ _resolv_cache_add(statp->netid, buf, buflen, ans, resplen);
+ }
+ return (resplen);
+ case res_modified:
+ /* give the hook another try */
+ if (++loops < 42) /*doug adams*/
+ break;
+ /*FALLTHROUGH*/
+ case res_error:
+ /*FALLTHROUGH*/
+ default:
+ goto fail;
+ }
+ } while (!done);
+ }
+
+ Dprint(((statp->options & RES_DEBUG) &&
+ getnameinfo(nsap, (socklen_t) nsaplen, abuf, sizeof(abuf), NULL, 0, niflags) ==
+ 0),
+ (stdout, ";; Querying server (# %d) address = %s\n", ns + 1, abuf));
+
+ if (v_circuit) {
+ /* Use VC; at most one attempt per server. */
+ attempt = statp->retry;
+
+ n = send_vc(statp, ¶ms, buf, buflen, ans, anssiz, &terrno, ns, &now, &rcode,
+ &delay);
+
+ /*
+ * Only record stats the first time we try a query. This ensures that
+ * queries that deterministically fail (e.g., a name that always returns
+ * SERVFAIL or times out) do not unduly affect the stats.
+ */
+ if (attempt == 0) {
+ struct __res_sample sample;
+ _res_stats_set_sample(&sample, now, rcode, delay);
+ _resolv_cache_add_resolver_stats_sample(statp->netid, revision_id, ns, &sample,
+ params.max_samples);
+ }
+
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "used send_vc %d\n", n);
+ }
+
+ if (n < 0) goto fail;
+ if (n == 0) goto next_ns;
+ resplen = n;
+ } else {
+ /* Use datagrams. */
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "using send_dg\n");
+ }
+
+ n = send_dg(statp, ¶ms, buf, buflen, ans, anssiz, &terrno, ns, &v_circuit,
+ &gotsomewhere, &now, &rcode, &delay);
+
+ /* Only record stats the first time we try a query. See above. */
+ if (attempt == 0) {
+ struct __res_sample sample;
+ _res_stats_set_sample(&sample, now, rcode, delay);
+ _resolv_cache_add_resolver_stats_sample(statp->netid, revision_id, ns, &sample,
+ params.max_samples);
+ }
+
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "used send_dg %d\n", n);
+ }
+
+ if (n < 0) goto fail;
+ if (n == 0) goto next_ns;
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "time=%ld\n", time(NULL));
+ }
+ if (v_circuit) goto same_ns;
+ resplen = n;
+ }
+
+ Dprint((statp->options & RES_DEBUG) ||
+ ((statp->pfcode & RES_PRF_REPLY) && (statp->pfcode & RES_PRF_HEAD1)),
+ (stdout, ";; got answer:\n"));
+
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY),
+ (stdout, "%s", ""), ans, (resplen > anssiz) ? anssiz : resplen);
+
+ if (cache_status == RESOLV_CACHE_NOTFOUND) {
+ _resolv_cache_add(statp->netid, buf, buflen, ans, resplen);
+ }
+ /*
+ * If we have temporarily opened a virtual circuit,
+ * or if we haven't been asked to keep a socket open,
+ * close the socket.
+ */
+ if ((v_circuit && (statp->options & RES_USEVC) == 0U) ||
+ (statp->options & RES_STAYOPEN) == 0U) {
+ res_nclose(statp);
+ }
+ if (statp->rhook) {
+ int done = 0, loops = 0;
+
+ do {
+ res_sendhookact act;
+
+ act = (*statp->rhook)(nsap, buf, buflen, ans, anssiz, &resplen);
+ switch (act) {
+ case res_goahead:
+ case res_done:
+ done = 1;
+ break;
+ case res_nextns:
+ res_nclose(statp);
+ goto next_ns;
+ case res_modified:
+ /* give the hook another try */
+ if (++loops < 42) /*doug adams*/
+ break;
+ /*FALLTHROUGH*/
+ case res_error:
+ /*FALLTHROUGH*/
+ default:
+ goto fail;
+ }
+ } while (!done);
+ }
+ return (resplen);
+ next_ns:;
+ } // for each ns
+ } // for each retry
+ res_nclose(statp);
+ if (!v_circuit) {
+ if (!gotsomewhere)
+ errno = ECONNREFUSED; /* no nameservers found */
+ else
+ errno = ETIMEDOUT; /* no answer obtained */
+ } else
+ errno = terrno;
+
+ _resolv_cache_query_failed(statp->netid, buf, buflen);
+
+ return (-1);
+fail:
+
+ _resolv_cache_query_failed(statp->netid, buf, buflen);
+ res_nclose(statp);
+ return (-1);
+}
+
+/* Private */
+
+static int get_salen(const struct sockaddr* sa) {
+ if (sa->sa_family == AF_INET)
+ return (sizeof(struct sockaddr_in));
+ else if (sa->sa_family == AF_INET6)
+ return (sizeof(struct sockaddr_in6));
+ else
+ return (0); /* unknown, die on connect */
+}
+
+/*
+ * pick appropriate nsaddr_list for use. see res_init() for initialization.
+ */
+static struct sockaddr* get_nsaddr(res_state statp, size_t n) {
+ if (!statp->nsaddr_list[n].sin_family && EXT(statp).ext) {
+ /*
+ * - EXT(statp).ext->nsaddrs[n] holds an address that is larger
+ * than struct sockaddr, and
+ * - user code did not update statp->nsaddr_list[n].
+ */
+ return (struct sockaddr*) (void*) &EXT(statp).ext->nsaddrs[n];
+ } else {
+ /*
+ * - user code updated statp->nsaddr_list[n], or
+ * - statp->nsaddr_list[n] has the same content as
+ * EXT(statp).ext->nsaddrs[n].
+ */
+ return (struct sockaddr*) (void*) &statp->nsaddr_list[n];
+ }
+}
+
+static struct timespec get_timeout(const res_state statp, const struct __res_params* params,
+ const int ns) {
+ int msec;
+ if (params->base_timeout_msec != 0) {
+ // TODO: scale the timeout by retry attempt and maybe number of servers
+ msec = params->base_timeout_msec;
+ } else {
+ // Legacy algorithm which scales the timeout by nameserver number.
+ // For instance, with 4 nameservers: 5s, 2.5s, 5s, 10s
+ // This has no effect with 1 or 2 nameservers
+ msec = (statp->retrans * 1000) << ns;
+ if (ns > 0) {
+ msec /= statp->nscount;
+ }
+ if (msec < 1000) {
+ msec = 1000; // Use at least 100ms
+ }
+ }
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "using timeout of %d msec\n", msec);
+ }
+
+ struct timespec result;
+ result.tv_sec = msec / 1000;
+ result.tv_nsec = (msec % 1000) * 1000000;
+ return result;
+}
+
+static int send_vc(res_state statp, struct __res_params* params, const u_char* buf, int buflen,
+ u_char* ans, int anssiz, int* terrno, int ns, time_t* at, int* rcode,
+ int* delay) {
+ *at = time(NULL);
+ *rcode = RCODE_INTERNAL_ERROR;
+ *delay = 0;
+ const HEADER* hp = (const HEADER*) (const void*) buf;
+ HEADER* anhp = (HEADER*) (void*) ans;
+ struct sockaddr* nsap;
+ int nsaplen;
+ int truncating, connreset, resplen, n;
+ struct iovec iov[2];
+ u_short len;
+ u_char* cp;
+
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", "using send_vc\n");
+ }
+
+ nsap = get_nsaddr(statp, (size_t) ns);
+ nsaplen = get_salen(nsap);
+
+ connreset = 0;
+same_ns:
+ truncating = 0;
+
+ struct timespec now = evNowTime();
+
+ /* Are we still talking to whom we want to talk to? */
+ if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
+ struct sockaddr_storage peer;
+ socklen_t size = sizeof peer;
+ unsigned old_mark;
+ socklen_t mark_size = sizeof(old_mark);
+ if (getpeername(statp->_vcsock, (struct sockaddr*) (void*) &peer, &size) < 0 ||
+ !sock_eq((struct sockaddr*) (void*) &peer, nsap) ||
+ getsockopt(statp->_vcsock, SOL_SOCKET, SO_MARK, &old_mark, &mark_size) < 0 ||
+ old_mark != statp->_mark) {
+ res_nclose(statp);
+ statp->_flags &= ~RES_F_VC;
+ }
+ }
+
+ if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) {
+ if (statp->_vcsock >= 0) res_nclose(statp);
+
+ statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM | SOCK_CLOEXEC, 0);
+ if (statp->_vcsock < 0) {
+ switch (errno) {
+ case EPROTONOSUPPORT:
+ case EPFNOSUPPORT:
+ case EAFNOSUPPORT:
+ Perror(statp, stderr, "socket(vc)", errno);
+ return (0);
+ default:
+ *terrno = errno;
+ Perror(statp, stderr, "socket(vc)", errno);
+ return (-1);
+ }
+ }
+ fchown(statp->_vcsock, AID_DNS, -1);
+ if (statp->_mark != MARK_UNSET) {
+ if (setsockopt(statp->_vcsock, SOL_SOCKET, SO_MARK, &statp->_mark,
+ sizeof(statp->_mark)) < 0) {
+ *terrno = errno;
+ Perror(statp, stderr, "setsockopt", errno);
+ return -1;
+ }
+ }
+ errno = 0;
+ if (random_bind(statp->_vcsock, nsap->sa_family) < 0) {
+ *terrno = errno;
+ Aerror(statp, stderr, "bind/vc", errno, nsap, nsaplen);
+ res_nclose(statp);
+ return (0);
+ }
+ if (connect_with_timeout(statp->_vcsock, nsap, (socklen_t) nsaplen,
+ get_timeout(statp, params, ns)) < 0) {
+ *terrno = errno;
+ Aerror(statp, stderr, "connect/vc", errno, nsap, nsaplen);
+ res_nclose(statp);
+ /*
+ * The way connect_with_timeout() is implemented prevents us from reliably
+ * determining whether this was really a timeout or e.g. ECONNREFUSED. Since
+ * currently both cases are handled in the same way, there is no need to
+ * change this (yet). If we ever need to reliably distinguish between these
+ * cases, both connect_with_timeout() and retrying_poll() need to be
+ * modified, though.
+ */
+ *rcode = RCODE_TIMEOUT;
+ return (0);
+ }
+ statp->_flags |= RES_F_VC;
+ }
+
+ /*
+ * Send length & message
+ */
+ ns_put16((u_short) buflen, (u_char*) (void*) &len);
+ iov[0] = evConsIovec(&len, INT16SZ);
+ iov[1] = evConsIovec((void*) buf, (size_t) buflen);
+ if (writev(statp->_vcsock, iov, 2) != (INT16SZ + buflen)) {
+ *terrno = errno;
+ Perror(statp, stderr, "write failed", errno);
+ res_nclose(statp);
+ return (0);
+ }
+ /*
+ * Receive length & response
+ */
+read_len:
+ cp = ans;
+ len = INT16SZ;
+ while ((n = read(statp->_vcsock, (char*) cp, (size_t) len)) > 0) {
+ cp += n;
+ if ((len -= n) == 0) break;
+ }
+ if (n <= 0) {
+ *terrno = errno;
+ Perror(statp, stderr, "read failed", errno);
+ res_nclose(statp);
+ /*
+ * A long running process might get its TCP
+ * connection reset if the remote server was
+ * restarted. Requery the server instead of
+ * trying a new one. When there is only one
+ * server, this means that a query might work
+ * instead of failing. We only allow one reset
+ * per query to prevent looping.
+ */
+ if (*terrno == ECONNRESET && !connreset) {
+ connreset = 1;
+ res_nclose(statp);
+ goto same_ns;
+ }
+ res_nclose(statp);
+ return (0);
+ }
+ resplen = ns_get16(ans);
+ if (resplen > anssiz) {
+ Dprint(statp->options & RES_DEBUG, (stdout, ";; response truncated\n"));
+ truncating = 1;
+ len = anssiz;
+ } else
+ len = resplen;
+ if (len < HFIXEDSZ) {
+ /*
+ * Undersized message.
+ */
+ Dprint(statp->options & RES_DEBUG, (stdout, ";; undersized: %d\n", len));
+ *terrno = EMSGSIZE;
+ res_nclose(statp);
+ return (0);
+ }
+ cp = ans;
+ while (len != 0 && (n = read(statp->_vcsock, (char*) cp, (size_t) len)) > 0) {
+ cp += n;
+ len -= n;
+ }
+ if (n <= 0) {
+ *terrno = errno;
+ Perror(statp, stderr, "read(vc)", errno);
+ res_nclose(statp);
+ return (0);
+ }
+
+ if (truncating) {
+ /*
+ * Flush rest of answer so connection stays in synch.
+ */
+ anhp->tc = 1;
+ len = resplen - anssiz;
+ while (len != 0) {
+ char junk[PACKETSZ];
+
+ n = read(statp->_vcsock, junk, (len > sizeof junk) ? sizeof junk : len);
+ if (n > 0)
+ len -= n;
+ else
+ break;
+ }
+ }
+ /*
+ * If the calling applicating has bailed out of
+ * a previous call and failed to arrange to have
+ * the circuit closed or the server has got
+ * itself confused, then drop the packet and
+ * wait for the correct one.
+ */
+ if (hp->id != anhp->id) {
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY),
+ (stdout, ";; old answer (unexpected):\n"), ans,
+ (resplen > anssiz) ? anssiz : resplen);
+ goto read_len;
+ }
+
+ /*
+ * All is well, or the error is fatal. Signal that the
+ * next nameserver ought not be tried.
+ */
+ if (resplen > 0) {
+ struct timespec done = evNowTime();
+ *delay = _res_stats_calculate_rtt(&done, &now);
+ *rcode = anhp->rcode;
+ }
+ return (resplen);
+}
+
+/* return -1 on error (errno set), 0 on success */
+static int connect_with_timeout(int sock, const struct sockaddr* nsap, socklen_t salen,
+ const struct timespec timeout) {
+ int res, origflags;
+
+ origflags = fcntl(sock, F_GETFL, 0);
+ fcntl(sock, F_SETFL, origflags | O_NONBLOCK);
+
+ res = connect(sock, nsap, salen);
+ if (res < 0 && errno != EINPROGRESS) {
+ res = -1;
+ goto done;
+ }
+ if (res != 0) {
+ struct timespec now = evNowTime();
+ struct timespec finish = evAddTime(now, timeout);
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", " %d send_vc\n", sock);
+ }
+
+ res = retrying_poll(sock, POLLIN | POLLOUT, &finish);
+ if (res <= 0) {
+ res = -1;
+ }
+ }
+done:
+ fcntl(sock, F_SETFL, origflags);
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc",
+ " %d connect_with_const timeout returning %d\n", sock, res);
+ }
+ return res;
+}
+
+static int retrying_poll(const int sock, const short events, const struct timespec* finish) {
+ struct timespec now, timeout;
+
+retry:
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", " %d retrying_poll\n", sock);
+ }
+
+ now = evNowTime();
+ if (evCmpTime(*finish, now) > 0)
+ timeout = evSubTime(*finish, now);
+ else
+ timeout = evConsTime(0L, 0L);
+ struct pollfd fds = {.fd = sock, .events = events};
+ int n = ppoll(&fds, 1, &timeout, /*sigmask=*/NULL);
+ if (n == 0) {
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", " %d retrying_poll timeout\n", sock);
+ }
+ errno = ETIMEDOUT;
+ return 0;
+ }
+ if (n < 0) {
+ if (errno == EINTR) goto retry;
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", " %d retrying_poll got error %d\n",
+ sock, n);
+ }
+ return n;
+ }
+ if (fds.revents & (POLLIN | POLLOUT | POLLERR)) {
+ int error;
+ socklen_t len = sizeof(error);
+ if (getsockopt(sock, SOL_SOCKET, SO_ERROR, &error, &len) < 0 || error) {
+ errno = error;
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc",
+ " %d retrying_poll dot error2 %d\n", sock, errno);
+ }
+
+ return -1;
+ }
+ }
+ if (DBG) {
+ async_safe_format_log(ANDROID_LOG_DEBUG, "libc", " %d retrying_poll returning %d\n", sock,
+ n);
+ }
+
+ return n;
+}
+
+static int send_dg(res_state statp, struct __res_params* params, const u_char* buf, int buflen,
+ u_char* ans, int anssiz, int* terrno, int ns, int* v_circuit, int* gotsomewhere,
+ time_t* at, int* rcode, int* delay) {
+ *at = time(NULL);
+ *rcode = RCODE_INTERNAL_ERROR;
+ *delay = 0;
+ const HEADER* hp = (const HEADER*) (const void*) buf;
+ HEADER* anhp = (HEADER*) (void*) ans;
+ const struct sockaddr* nsap;
+ int nsaplen;
+ struct timespec now, timeout, finish, done;
+ struct sockaddr_storage from;
+ socklen_t fromlen;
+ int resplen, n, s;
+
+ nsap = get_nsaddr(statp, (size_t) ns);
+ nsaplen = get_salen(nsap);
+ if (EXT(statp).nssocks[ns] == -1) {
+ EXT(statp).nssocks[ns] = socket(nsap->sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+ if (EXT(statp).nssocks[ns] < 0) {
+ switch (errno) {
+ case EPROTONOSUPPORT:
+ case EPFNOSUPPORT:
+ case EAFNOSUPPORT:
+ Perror(statp, stderr, "socket(dg)", errno);
+ return (0);
+ default:
+ *terrno = errno;
+ Perror(statp, stderr, "socket(dg)", errno);
+ return (-1);
+ }
+ }
+
+ fchown(EXT(statp).nssocks[ns], AID_DNS, -1);
+ if (statp->_mark != MARK_UNSET) {
+ if (setsockopt(EXT(statp).nssocks[ns], SOL_SOCKET, SO_MARK, &(statp->_mark),
+ sizeof(statp->_mark)) < 0) {
+ res_nclose(statp);
+ return -1;
+ }
+ }
+#ifndef CANNOT_CONNECT_DGRAM
+ /*
+ * On a 4.3BSD+ machine (client and server,
+ * actually), sending to a nameserver datagram
+ * port with no nameserver will cause an
+ * ICMP port unreachable message to be returned.
+ * If our datagram socket is "connected" to the
+ * server, we get an ECONNREFUSED error on the next
+ * socket operation, and select returns if the
+ * error message is received. We can thus detect
+ * the absence of a nameserver without timing out.
+ */
+ if (random_bind(EXT(statp).nssocks[ns], nsap->sa_family) < 0) {
+ Aerror(statp, stderr, "bind(dg)", errno, nsap, nsaplen);
+ res_nclose(statp);
+ return (0);
+ }
+ if (connect(EXT(statp).nssocks[ns], nsap, (socklen_t) nsaplen) < 0) {
+ Aerror(statp, stderr, "connect(dg)", errno, nsap, nsaplen);
+ res_nclose(statp);
+ return (0);
+ }
+#endif /* !CANNOT_CONNECT_DGRAM */
+ Dprint(statp->options & RES_DEBUG, (stdout, ";; new DG socket\n"))
+ }
+ s = EXT(statp).nssocks[ns];
+#ifndef CANNOT_CONNECT_DGRAM
+ if (send(s, (const char*) buf, (size_t) buflen, 0) != buflen) {
+ Perror(statp, stderr, "send", errno);
+ res_nclose(statp);
+ return (0);
+ }
+#else /* !CANNOT_CONNECT_DGRAM */
+ if (sendto(s, (const char*) buf, buflen, 0, nsap, nsaplen) != buflen) {
+ Aerror(statp, stderr, "sendto", errno, nsap, nsaplen);
+ res_nclose(statp);
+ return (0);
+ }
+#endif /* !CANNOT_CONNECT_DGRAM */
+
+ /*
+ * Wait for reply.
+ */
+ timeout = get_timeout(statp, params, ns);
+ now = evNowTime();
+ finish = evAddTime(now, timeout);
+retry:
+ n = retrying_poll(s, POLLIN, &finish);
+
+ if (n == 0) {
+ *rcode = RCODE_TIMEOUT;
+ Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n"));
+ *gotsomewhere = 1;
+ return (0);
+ }
+ if (n < 0) {
+ Perror(statp, stderr, "poll", errno);
+ res_nclose(statp);
+ return (0);
+ }
+ errno = 0;
+ fromlen = sizeof(from);
+ resplen = recvfrom(s, (char*) ans, (size_t) anssiz, 0, (struct sockaddr*) (void*) &from,
+ &fromlen);
+ if (resplen <= 0) {
+ Perror(statp, stderr, "recvfrom", errno);
+ res_nclose(statp);
+ return (0);
+ }
+ *gotsomewhere = 1;
+ if (resplen < HFIXEDSZ) {
+ /*
+ * Undersized message.
+ */
+ Dprint(statp->options & RES_DEBUG, (stdout, ";; undersized: %d\n", resplen));
+ *terrno = EMSGSIZE;
+ res_nclose(statp);
+ return (0);
+ }
+ if (hp->id != anhp->id) {
+ /*
+ * response from old query, ignore it.
+ * XXX - potential security hazard could
+ * be detected here.
+ */
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY),
+ (stdout, ";; old answer:\n"), ans, (resplen > anssiz) ? anssiz : resplen);
+ goto retry;
+ }
+ if (!(statp->options & RES_INSECURE1) &&
+ !res_ourserver_p(statp, (struct sockaddr*) (void*) &from)) {
+ /*
+ * response from wrong server? ignore it.
+ * XXX - potential security hazard could
+ * be detected here.
+ */
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY),
+ (stdout, ";; not our server:\n"), ans, (resplen > anssiz) ? anssiz : resplen);
+ goto retry;
+ }
+#ifdef RES_USE_EDNS0
+ if (anhp->rcode == FORMERR && (statp->options & RES_USE_EDNS0) != 0U) {
+ /*
+ * Do not retry if the server do not understand EDNS0.
+ * The case has to be captured here, as FORMERR packet do not
+ * carry query section, hence res_queriesmatch() returns 0.
+ */
+ DprintQ(statp->options & RES_DEBUG, (stdout, "server rejected query with EDNS0:\n"), ans,
+ (resplen > anssiz) ? anssiz : resplen);
+ /* record the error */
+ statp->_flags |= RES_F_EDNS0ERR;
+ res_nclose(statp);
+ return (0);
+ }
+#endif
+ if (!(statp->options & RES_INSECURE2) &&
+ !res_queriesmatch(buf, buf + buflen, ans, ans + anssiz)) {
+ /*
+ * response contains wrong query? ignore it.
+ * XXX - potential security hazard could
+ * be detected here.
+ */
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_REPLY),
+ (stdout, ";; wrong query name:\n"), ans, (resplen > anssiz) ? anssiz : resplen);
+ goto retry;
+ ;
+ }
+ done = evNowTime();
+ *delay = _res_stats_calculate_rtt(&done, &now);
+ if (anhp->rcode == SERVFAIL || anhp->rcode == NOTIMP || anhp->rcode == REFUSED) {
+ DprintQ(statp->options & RES_DEBUG, (stdout, "server rejected query:\n"), ans,
+ (resplen > anssiz) ? anssiz : resplen);
+ res_nclose(statp);
+ /* don't retry if called from dig */
+ if (!statp->pfcode) {
+ *rcode = anhp->rcode;
+ return (0);
+ }
+ }
+ if (!(statp->options & RES_IGNTC) && anhp->tc) {
+ /*
+ * To get the rest of answer,
+ * use TCP with same server.
+ */
+ Dprint(statp->options & RES_DEBUG, (stdout, ";; truncated answer\n"));
+ *v_circuit = 1;
+ res_nclose(statp);
+ return (1);
+ }
+ /*
+ * All is well, or the error is fatal. Signal that the
+ * next nameserver ought not be tried.
+ */
+ if (resplen > 0) {
+ *rcode = anhp->rcode;
+ }
+ return (resplen);
+}
+
+static void Aerror(const res_state statp, FILE* file, const char* string, int error,
+ const struct sockaddr* address, int alen) {
+ int save = errno;
+ char hbuf[NI_MAXHOST];
+ char sbuf[NI_MAXSERV];
+
+ if ((statp->options & RES_DEBUG) != 0U) {
+ if (getnameinfo(address, (socklen_t) alen, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf),
+ niflags)) {
+ strncpy(hbuf, "?", sizeof(hbuf) - 1);
+ hbuf[sizeof(hbuf) - 1] = '\0';
+ strncpy(sbuf, "?", sizeof(sbuf) - 1);
+ sbuf[sizeof(sbuf) - 1] = '\0';
+ }
+ fprintf(file, "res_send: %s ([%s].%s): %s\n", string, hbuf, sbuf, strerror(error));
+ }
+ errno = save;
+}
+
+static void Perror(const res_state statp, FILE* file, const char* string, int error) {
+ int save = errno;
+
+ if ((statp->options & RES_DEBUG) != 0U)
+ fprintf(file, "res_send: %s: %s\n", string, strerror(error));
+ errno = save;
+}
+
+static int sock_eq(struct sockaddr* a, struct sockaddr* b) {
+ struct sockaddr_in *a4, *b4;
+ struct sockaddr_in6 *a6, *b6;
+
+ if (a->sa_family != b->sa_family) return 0;
+ switch (a->sa_family) {
+ case AF_INET:
+ a4 = (struct sockaddr_in*) (void*) a;
+ b4 = (struct sockaddr_in*) (void*) b;
+ return a4->sin_port == b4->sin_port && a4->sin_addr.s_addr == b4->sin_addr.s_addr;
+ case AF_INET6:
+ a6 = (struct sockaddr_in6*) (void*) a;
+ b6 = (struct sockaddr_in6*) (void*) b;
+ return a6->sin6_port == b6->sin6_port &&
+#ifdef HAVE_SIN6_SCOPE_ID
+ a6->sin6_scope_id == b6->sin6_scope_id &&
+#endif
+ IN6_ARE_ADDR_EQUAL(&a6->sin6_addr, &b6->sin6_addr);
+ default:
+ return 0;
+ }
+}