diff options
Diffstat (limited to 'resolv/res_send.c')
| -rw-r--r-- | resolv/res_send.c | 1502 |
1 files changed, 0 insertions, 1502 deletions
diff --git a/resolv/res_send.c b/resolv/res_send.c deleted file mode 100644 index b7b8ecdfc4..0000000000 --- a/resolv/res_send.c +++ /dev/null @@ -1,1502 +0,0 @@ -/* Copyright (C) 2016-2017 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 - <http://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. - */ - -/* - * Send query to name server and wait for reply. - */ - -#include <assert.h> -#include <sys/types.h> -#include <sys/param.h> -#include <sys/time.h> -#include <sys/socket.h> -#include <sys/uio.h> -#include <sys/poll.h> - -#include <netinet/in.h> -#include <arpa/nameser.h> -#include <arpa/inet.h> -#include <sys/ioctl.h> - -#include <errno.h> -#include <fcntl.h> -#include <netdb.h> -#include <resolv/resolv-internal.h> -#include <signal.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <kernel-features.h> -#include <libc-diag.h> - -#if PACKETSZ > 65536 -#define MAXPACKET PACKETSZ -#else -#define MAXPACKET 65536 -#endif - -/* From ev_streams.c. */ - -static inline void -__attribute ((always_inline)) -evConsIovec(void *buf, size_t cnt, struct iovec *vec) { - memset(vec, 0xf5, sizeof (*vec)); - vec->iov_base = buf; - vec->iov_len = cnt; -} - -/* From ev_timers.c. */ - -#define BILLION 1000000000 - -static inline void -evConsTime(struct timespec *res, time_t sec, long nsec) { - res->tv_sec = sec; - res->tv_nsec = nsec; -} - -static inline void -evAddTime(struct timespec *res, const struct timespec *addend1, - const struct timespec *addend2) { - res->tv_sec = addend1->tv_sec + addend2->tv_sec; - res->tv_nsec = addend1->tv_nsec + addend2->tv_nsec; - if (res->tv_nsec >= BILLION) { - res->tv_sec++; - res->tv_nsec -= BILLION; - } -} - -static inline void -evSubTime(struct timespec *res, const struct timespec *minuend, - const struct timespec *subtrahend) { - res->tv_sec = minuend->tv_sec - subtrahend->tv_sec; - if (minuend->tv_nsec >= subtrahend->tv_nsec) - res->tv_nsec = minuend->tv_nsec - subtrahend->tv_nsec; - else { - res->tv_nsec = (BILLION - - subtrahend->tv_nsec + minuend->tv_nsec); - res->tv_sec--; - } -} - -static int -evCmpTime(struct timespec a, struct timespec b) { - long x = a.tv_sec - b.tv_sec; - - if (x == 0L) - x = a.tv_nsec - b.tv_nsec; - return (x < 0L ? (-1) : x > 0L ? (1) : (0)); -} - -static void -evNowTime(struct timespec *res) { - struct timeval now; - - if (gettimeofday(&now, NULL) < 0) - evConsTime(res, 0, 0); - else - TIMEVAL_TO_TIMESPEC (&now, res); -} - - -/* Options. Leave them on. */ -/* #undef DEBUG */ -#include "res_debug.h" - -#define EXT(res) ((res)->_u._ext) - -/* Forward. */ - -static struct sockaddr *get_nsaddr (res_state, int); -static int send_vc(res_state, const u_char *, int, - const u_char *, int, - u_char **, int *, int *, int, u_char **, - u_char **, int *, int *, int *); -static int send_dg(res_state, const u_char *, int, - const u_char *, int, - u_char **, int *, int *, int, - int *, int *, u_char **, - u_char **, int *, int *, int *); -#ifdef DEBUG -static void Aerror(const res_state, FILE *, const char *, int, - const struct sockaddr *); -static void Perror(const res_state, FILE *, const char *, int); -#endif -static int sock_eq(struct sockaddr_in6 *, struct sockaddr_in6 *); - -/* Public. */ - -/* int - * res_isourserver(ina) - * looks up "ina" in _res.ns_addr_list[] - * returns: - * 0 : not found - * >0 : found - * author: - * paul vixie, 29may94 - */ -int -res_ourserver_p(const res_state statp, const struct sockaddr_in6 *inp) -{ - int ns; - - if (inp->sin6_family == AF_INET) { - struct sockaddr_in *in4p = (struct sockaddr_in *) inp; - in_port_t port = in4p->sin_port; - in_addr_t addr = in4p->sin_addr.s_addr; - - for (ns = 0; ns < statp->nscount; ns++) { - const struct sockaddr_in *srv = - (struct sockaddr_in *) get_nsaddr (statp, ns); - - if ((srv->sin_family == AF_INET) && - (srv->sin_port == port) && - (srv->sin_addr.s_addr == INADDR_ANY || - srv->sin_addr.s_addr == addr)) - return (1); - } - } else if (inp->sin6_family == AF_INET6) { - for (ns = 0; ns < statp->nscount; ns++) { - const struct sockaddr_in6 *srv - = (struct sockaddr_in6 *) get_nsaddr (statp, ns); - if ((srv->sin6_family == AF_INET6) && - (srv->sin6_port == inp->sin6_port) && - !(memcmp(&srv->sin6_addr, &in6addr_any, - sizeof (struct in6_addr)) && - memcmp(&srv->sin6_addr, &inp->sin6_addr, - sizeof (struct in6_addr)))) - return (1); - } - } - return (0); -} - -/* int - * res_nameinquery(name, type, class, buf, eom) - * look for (name,type,class) 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 class, - const u_char *buf, const u_char *eom) -{ - const u_char *cp = buf + HFIXEDSZ; - int qdcount = ntohs(((HEADER*)buf)->qdcount); - - while (qdcount-- > 0) { - char tname[MAXDNAME+1]; - int n, ttype, tclass; - - n = dn_expand(buf, eom, cp, tname, sizeof tname); - if (n < 0) - return (-1); - cp += n; - if (cp + 2 * INT16SZ > eom) - return (-1); - NS_GET16(ttype, cp); - NS_GET16(tclass, cp); - if (ttype == type && tclass == class && - ns_samename(tname, name) == 1) - return (1); - } - return (0); -} -libresolv_hidden_def (res_nameinquery) - -/* 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) -{ - if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2) - 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 u_char *cp = buf1 + HFIXEDSZ; - - while (qdcount-- > 0) { - char tname[MAXDNAME+1]; - int n, ttype, tclass; - - n = dn_expand(buf1, eom1, cp, tname, sizeof tname); - if (n < 0) - return (-1); - cp += n; - if (cp + 2 * INT16SZ > eom1) - return (-1); - NS_GET16(ttype, cp); - NS_GET16(tclass, cp); - if (!res_nameinquery(tname, ttype, tclass, buf2, eom2)) - return (0); - } - return (1); -} -libresolv_hidden_def (res_queriesmatch) - -int -__libc_res_nsend(res_state statp, const u_char *buf, int buflen, - const u_char *buf2, int buflen2, - u_char *ans, int anssiz, u_char **ansp, u_char **ansp2, - int *nansp2, int *resplen2, int *ansp2_malloced) -{ - int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; - - if (statp->nscount == 0) { - __set_errno (ESRCH); - return (-1); - } - - if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) { - __set_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 - || buflen2 > PACKETSZ); - gotsomewhere = 0; - terrno = ETIMEDOUT; - - /* - * 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; - - if (EXT(statp).nscount != statp->nscount) - needclose++; - else - for (ns = 0; ns < statp->nscount; ns++) { - if (statp->nsaddr_list[ns].sin_family != 0 - && !sock_eq((struct sockaddr_in6 *) - &statp->nsaddr_list[ns], - EXT(statp).nsaddrs[ns])) - { - needclose++; - break; - } - } - if (needclose) { - __res_iclose(statp, false); - EXT(statp).nscount = 0; - } - } - - /* - * Maybe initialize our private copy of the ns_addr_list. - */ - if (EXT(statp).nscount == 0) { - for (ns = 0; ns < statp->nscount; ns++) { - EXT(statp).nssocks[ns] = -1; - if (statp->nsaddr_list[ns].sin_family == 0) - continue; - if (EXT(statp).nsaddrs[ns] == NULL) - EXT(statp).nsaddrs[ns] = - malloc(sizeof (struct sockaddr_in6)); - if (EXT(statp).nsaddrs[ns] != NULL) - memset (mempcpy(EXT(statp).nsaddrs[ns], - &statp->nsaddr_list[ns], - sizeof (struct sockaddr_in)), - '\0', - sizeof (struct sockaddr_in6) - - sizeof (struct sockaddr_in)); - } - EXT(statp).nscount = statp->nscount; - } - - /* - * Some resolvers want to even out the load on their nameservers. - * Note that RES_BLAST overrides RES_ROTATE. - */ - if (__glibc_unlikely ((statp->options & RES_ROTATE) != 0)) { - struct sockaddr_in ina; - struct sockaddr_in6 *inp; - int lastns = statp->nscount - 1; - int fd; - - inp = EXT(statp).nsaddrs[0]; - ina = statp->nsaddr_list[0]; - fd = EXT(statp).nssocks[0]; - for (ns = 0; ns < lastns; ns++) { - EXT(statp).nsaddrs[ns] = EXT(statp).nsaddrs[ns + 1]; - statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1]; - EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1]; - } - EXT(statp).nsaddrs[lastns] = inp; - statp->nsaddr_list[lastns] = ina; - EXT(statp).nssocks[lastns] = fd; - } - - /* - * Send request, RETRY times, or until successful. - */ - for (try = 0; try < statp->retry; try++) { - for (ns = 0; ns < statp->nscount; ns++) - { -#ifdef DEBUG - char tmpbuf[40]; - struct sockaddr *nsap = get_nsaddr (statp, ns); -#endif - - same_ns: - Dprint(statp->options & RES_DEBUG, - (stdout, ";; Querying server (# %d) address = %s\n", - ns + 1, inet_ntop(nsap->sa_family, - (nsap->sa_family == AF_INET6 - ? (void *) &((struct sockaddr_in6 *) nsap)->sin6_addr - : (void *) &((struct sockaddr_in *) nsap)->sin_addr), - tmpbuf, sizeof (tmpbuf)))); - - if (__glibc_unlikely (v_circuit)) { - /* Use VC; at most one attempt per server. */ - try = statp->retry; - n = send_vc(statp, buf, buflen, buf2, buflen2, - &ans, &anssiz, &terrno, - ns, ansp, ansp2, nansp2, resplen2, - ansp2_malloced); - if (n < 0) - return (-1); - if (n == 0 && (buf2 == NULL || *resplen2 == 0)) - goto next_ns; - } else { - /* Use datagrams. */ - n = send_dg(statp, buf, buflen, buf2, buflen2, - &ans, &anssiz, &terrno, - ns, &v_circuit, &gotsomewhere, ansp, - ansp2, nansp2, resplen2, ansp2_malloced); - if (n < 0) - return (-1); - if (n == 0 && (buf2 == NULL || *resplen2 == 0)) - goto next_ns; - if (v_circuit) - // XXX Check whether both requests failed or - // XXX whether one has been answered successfully - 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 (buf2 != NULL) { - DprintQ((statp->options & RES_DEBUG) || - (statp->pfcode & RES_PRF_REPLY), - (stdout, "%s", ""), - *ansp2, (*resplen2 > *nansp2) ? *nansp2 : *resplen2); - } - - /* - * 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) == 0) || - (statp->options & RES_STAYOPEN) == 0) { - __res_iclose(statp, false); - } - return (resplen); - next_ns: ; - } /*foreach ns*/ - } /*foreach retry*/ - __res_iclose(statp, false); - if (!v_circuit) { - if (!gotsomewhere) - __set_errno (ECONNREFUSED); /* no nameservers found */ - else - __set_errno (ETIMEDOUT); /* no answer obtained */ - } else - __set_errno (terrno); - return (-1); -} - -int -res_nsend(res_state statp, - const u_char *buf, int buflen, u_char *ans, int anssiz) -{ - return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz, - NULL, NULL, NULL, NULL, NULL); -} -libresolv_hidden_def (res_nsend) - -/* Private */ - -static struct sockaddr * -get_nsaddr (res_state statp, int n) -{ - - if (statp->nsaddr_list[n].sin_family == 0 && EXT(statp).nsaddrs[n] != NULL) - /* EXT(statp).nsaddrs[n] holds an address that is larger than - struct sockaddr, and user code did not update - statp->nsaddr_list[n]. */ - return (struct sockaddr *) EXT(statp).nsaddrs[n]; - else - /* User code updated statp->nsaddr_list[n], or statp->nsaddr_list[n] - has the same content as EXT(statp).nsaddrs[n]. */ - return (struct sockaddr *) (void *) &statp->nsaddr_list[n]; -} - -/* Close the resolver structure, assign zero to *RESPLEN2 if RESPLEN2 - is not NULL, and return zero. */ -static int -__attribute__ ((warn_unused_result)) -close_and_return_error (res_state statp, int *resplen2) -{ - __res_iclose(statp, false); - if (resplen2 != NULL) - *resplen2 = 0; - return 0; -} - -/* The send_vc function is responsible for sending a DNS query over TCP - to the nameserver numbered NS from the res_state STATP i.e. - EXT(statp).nssocks[ns]. The function supports sending both IPv4 and - IPv6 queries at the same serially on the same socket. - - Please note that for TCP there is no way to disable sending both - queries, unlike UDP, which honours RES_SNGLKUP and RES_SNGLKUPREOP - and sends the queries serially and waits for the result after each - sent query. This implementation should be corrected to honour these - options. - - Please also note that for TCP we send both queries over the same - socket one after another. This technically violates best practice - since the server is allowed to read the first query, respond, and - then close the socket (to service another client). If the server - does this, then the remaining second query in the socket data buffer - will cause the server to send the client an RST which will arrive - asynchronously and the client's OS will likely tear down the socket - receive buffer resulting in a potentially short read and lost - response data. This will force the client to retry the query again, - and this process may repeat until all servers and connection resets - are exhausted and then the query will fail. It's not known if this - happens with any frequency in real DNS server implementations. This - implementation should be corrected to use two sockets by default for - parallel queries. - - The query stored in BUF of BUFLEN length is sent first followed by - the query stored in BUF2 of BUFLEN2 length. Queries are sent - serially on the same socket. - - Answers to the query are stored firstly in *ANSP up to a max of - *ANSSIZP bytes. If more than *ANSSIZP bytes are needed and ANSCP - is non-NULL (to indicate that modifying the answer buffer is allowed) - then malloc is used to allocate a new response buffer and ANSCP and - ANSP will both point to the new buffer. If more than *ANSSIZP bytes - are needed but ANSCP is NULL, then as much of the response as - possible is read into the buffer, but the results will be truncated. - When truncation happens because of a small answer buffer the DNS - packets header field TC will bet set to 1, indicating a truncated - message and the rest of the socket data will be read and discarded. - - Answers to the query are stored secondly in *ANSP2 up to a max of - *ANSSIZP2 bytes, with the actual response length stored in - *RESPLEN2. If more than *ANSSIZP bytes are needed and ANSP2 - is non-NULL (required for a second query) then malloc is used to - allocate a new response buffer, *ANSSIZP2 is set to the new buffer - size and *ANSP2_MALLOCED is set to 1. - - The ANSP2_MALLOCED argument will eventually be removed as the - change in buffer pointer can be used to detect the buffer has - changed and that the caller should use free on the new buffer. - - Note that the answers may arrive in any order from the server and - therefore the first and second answer buffers may not correspond to - the first and second queries. - - It is not supported to call this function with a non-NULL ANSP2 - but a NULL ANSCP. Put another way, you can call send_vc with a - single unmodifiable buffer or two modifiable buffers, but no other - combination is supported. - - It is the caller's responsibility to free the malloc allocated - buffers by detecting that the pointers have changed from their - original values i.e. *ANSCP or *ANSP2 has changed. - - If errors are encountered then *TERRNO is set to an appropriate - errno value and a zero result is returned for a recoverable error, - and a less-than zero result is returned for a non-recoverable error. - - If no errors are encountered then *TERRNO is left unmodified and - a the length of the first response in bytes is returned. */ -static int -send_vc(res_state statp, - const u_char *buf, int buflen, const u_char *buf2, int buflen2, - u_char **ansp, int *anssizp, - int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2, - int *resplen2, int *ansp2_malloced) -{ - const HEADER *hp = (HEADER *) buf; - const HEADER *hp2 = (HEADER *) buf2; - HEADER *anhp = (HEADER *) *ansp; - struct sockaddr *nsap = get_nsaddr (statp, ns); - int truncating, connreset, n; - /* On some architectures compiler might emit a warning indicating - 'resplen' may be used uninitialized. However if buf2 == NULL - then this code won't be executed; if buf2 != NULL, then first - time round the loop recvresp1 and recvresp2 will be 0 so this - code won't be executed but "thisresplenp = &resplen;" followed - by "*thisresplenp = rlen;" will be executed so that subsequent - times round the loop resplen has been initialized. So this is - a false-positive. - */ - DIAG_PUSH_NEEDS_COMMENT; - DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized"); - int resplen; - DIAG_POP_NEEDS_COMMENT; - struct iovec iov[4]; - u_short len; - u_short len2; - u_char *cp; - - connreset = 0; - same_ns: - truncating = 0; - - /* Are we still talking to whom we want to talk to? */ - if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) { - struct sockaddr_in6 peer; - socklen_t size = sizeof peer; - - if (getpeername(statp->_vcsock, - (struct sockaddr *)&peer, &size) < 0 || - !sock_eq(&peer, (struct sockaddr_in6 *) nsap)) { - __res_iclose(statp, false); - statp->_flags &= ~RES_F_VC; - } - } - - if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) { - if (statp->_vcsock >= 0) - __res_iclose(statp, false); - - statp->_vcsock = socket - (nsap->sa_family, SOCK_STREAM | SOCK_CLOEXEC, 0); - if (statp->_vcsock < 0) { - *terrno = errno; - Perror(statp, stderr, "socket(vc)", errno); - if (resplen2 != NULL) - *resplen2 = 0; - return (-1); - } - __set_errno (0); - if (connect(statp->_vcsock, nsap, - nsap->sa_family == AF_INET - ? sizeof (struct sockaddr_in) - : sizeof (struct sockaddr_in6)) < 0) { - *terrno = errno; - Aerror(statp, stderr, "connect/vc", errno, nsap); - return close_and_return_error (statp, resplen2); - } - statp->_flags |= RES_F_VC; - } - - /* - * Send length & message - */ - len = htons ((u_short) buflen); - evConsIovec(&len, INT16SZ, &iov[0]); - evConsIovec((void*)buf, buflen, &iov[1]); - int niov = 2; - ssize_t explen = INT16SZ + buflen; - if (buf2 != NULL) { - len2 = htons ((u_short) buflen2); - evConsIovec(&len2, INT16SZ, &iov[2]); - evConsIovec((void*)buf2, buflen2, &iov[3]); - niov = 4; - explen += INT16SZ + buflen2; - } - if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, niov)) != explen) { - *terrno = errno; - Perror(statp, stderr, "write failed", errno); - return close_and_return_error (statp, resplen2); - } - /* - * Receive length & response - */ - int recvresp1 = 0; - /* Skip the second response if there is no second query. - To do that we mark the second response as received. */ - int recvresp2 = buf2 == NULL; - uint16_t rlen16; - read_len: - cp = (u_char *)&rlen16; - len = sizeof(rlen16); - while ((n = TEMP_FAILURE_RETRY (read(statp->_vcsock, cp, - (int)len))) > 0) { - cp += n; - if ((len -= n) <= 0) - break; - } - if (n <= 0) { - *terrno = errno; - Perror(statp, stderr, "read failed", errno); - /* - * 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) - { - __res_iclose (statp, false); - connreset = 1; - goto same_ns; - } - return close_and_return_error (statp, resplen2); - } - int rlen = ntohs (rlen16); - - int *thisanssizp; - u_char **thisansp; - int *thisresplenp; - if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { - /* We have not received any responses - yet or we only have one response to - receive. */ - thisanssizp = anssizp; - thisansp = anscp ?: ansp; - assert (anscp != NULL || ansp2 == NULL); - thisresplenp = &resplen; - } else { - thisanssizp = anssizp2; - thisansp = ansp2; - thisresplenp = resplen2; - } - anhp = (HEADER *) *thisansp; - - *thisresplenp = rlen; - /* Is the answer buffer too small? */ - if (*thisanssizp < rlen) { - /* If the current buffer is not the the static - user-supplied buffer then we can reallocate - it. */ - if (thisansp != NULL && thisansp != ansp) { - /* Always allocate MAXPACKET, callers expect - this specific size. */ - u_char *newp = malloc (MAXPACKET); - if (newp == NULL) - { - *terrno = ENOMEM; - return close_and_return_error (statp, resplen2); - } - *thisanssizp = MAXPACKET; - *thisansp = newp; - if (thisansp == ansp2) - *ansp2_malloced = 1; - anhp = (HEADER *) newp; - /* A uint16_t can't be larger than MAXPACKET - thus it's safe to allocate MAXPACKET but - read RLEN bytes instead. */ - len = rlen; - } else { - Dprint(statp->options & RES_DEBUG, - (stdout, ";; response truncated\n") - ); - truncating = 1; - len = *thisanssizp; - } - } else - len = rlen; - - if (__glibc_unlikely (len < HFIXEDSZ)) { - /* - * Undersized message. - */ - Dprint(statp->options & RES_DEBUG, - (stdout, ";; undersized: %d\n", len)); - *terrno = EMSGSIZE; - return close_and_return_error (statp, resplen2); - } - - cp = *thisansp; - while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){ - cp += n; - len -= n; - } - if (__glibc_unlikely (n <= 0)) { - *terrno = errno; - Perror(statp, stderr, "read(vc)", errno); - return close_and_return_error (statp, resplen2); - } - if (__glibc_unlikely (truncating)) { - /* - * Flush rest of answer so connection stays in synch. - */ - anhp->tc = 1; - len = rlen - *thisanssizp; - 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 application 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 ((recvresp1 || hp->id != anhp->id) - && (recvresp2 || hp2->id != anhp->id)) { - DprintQ((statp->options & RES_DEBUG) || - (statp->pfcode & RES_PRF_REPLY), - (stdout, ";; old answer (unexpected):\n"), - *thisansp, - (rlen > *thisanssizp) ? *thisanssizp: rlen); - goto read_len; - } - - /* Mark which reply we received. */ - if (recvresp1 == 0 && hp->id == anhp->id) - recvresp1 = 1; - else - recvresp2 = 1; - /* Repeat waiting if we have a second answer to arrive. */ - if ((recvresp1 & recvresp2) == 0) - goto read_len; - - /* - * All is well, or the error is fatal. Signal that the - * next nameserver ought not be tried. - */ - return resplen; -} - -static int -reopen (res_state statp, int *terrno, int ns) -{ - if (EXT(statp).nssocks[ns] == -1) { - struct sockaddr *nsap = get_nsaddr (statp, ns); - socklen_t slen; - - /* only try IPv6 if IPv6 NS and if not failed before */ - if (nsap->sa_family == AF_INET6 && !statp->ipv6_unavail) { - EXT(statp).nssocks[ns] = socket - (PF_INET6, - SOCK_DGRAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0); - if (EXT(statp).nssocks[ns] < 0) - statp->ipv6_unavail = errno == EAFNOSUPPORT; - slen = sizeof (struct sockaddr_in6); - } else if (nsap->sa_family == AF_INET) { - EXT(statp).nssocks[ns] = socket - (PF_INET, - SOCK_DGRAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0); - slen = sizeof (struct sockaddr_in); - } - if (EXT(statp).nssocks[ns] < 0) { - *terrno = errno; - Perror(statp, stderr, "socket(dg)", errno); - return (-1); - } - - /* - * 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. - */ - /* With GCC 5.3 when compiling with -Os the compiler - emits a warning that slen may be used uninitialized, - but that is never true. Both slen and - EXT(statp).nssocks[ns] are initialized together or - the function return -1 before control flow reaches - the call to connect with slen. */ - DIAG_PUSH_NEEDS_COMMENT; - DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized"); - if (connect(EXT(statp).nssocks[ns], nsap, slen) < 0) { - DIAG_POP_NEEDS_COMMENT; - Aerror(statp, stderr, "connect(dg)", errno, nsap); - __res_iclose(statp, false); - return (0); - } - } - - return 1; -} - -/* The send_dg function is responsible for sending a DNS query over UDP - to the nameserver numbered NS from the res_state STATP i.e. - EXT(statp).nssocks[ns]. The function supports IPv4 and IPv6 queries - along with the ability to send the query in parallel for both stacks - (default) or serially (RES_SINGLKUP). It also supports serial lookup - with a close and reopen of the socket used to talk to the server - (RES_SNGLKUPREOP) to work around broken name servers. - - The query stored in BUF of BUFLEN length is sent first followed by - the query stored in BUF2 of BUFLEN2 length. Queries are sent - in parallel (default) or serially (RES_SINGLKUP or RES_SNGLKUPREOP). - - Answers to the query are stored firstly in *ANSP up to a max of - *ANSSIZP bytes. If more than *ANSSIZP bytes are needed and ANSCP - is non-NULL (to indicate that modifying the answer buffer is allowed) - then malloc is used to allocate a new response buffer and ANSCP and - ANSP will both point to the new buffer. If more than *ANSSIZP bytes - are needed but ANSCP is NULL, then as much of the response as - possible is read into the buffer, but the results will be truncated. - When truncation happens because of a small answer buffer the DNS - packets header field TC will bet set to 1, indicating a truncated - message, while the rest of the UDP packet is discarded. - - Answers to the query are stored secondly in *ANSP2 up to a max of - *ANSSIZP2 bytes, with the actual response length stored in - *RESPLEN2. If more than *ANSSIZP bytes are needed and ANSP2 - is non-NULL (required for a second query) then malloc is used to - allocate a new response buffer, *ANSSIZP2 is set to the new buffer - size and *ANSP2_MALLOCED is set to 1. - - The ANSP2_MALLOCED argument will eventually be removed as the - change in buffer pointer can be used to detect the buffer has - changed and that the caller should use free on the new buffer. - - Note that the answers may arrive in any order from the server and - therefore the first and second answer buffers may not correspond to - the first and second queries. - - It is not supported to call this function with a non-NULL ANSP2 - but a NULL ANSCP. Put another way, you can call send_vc with a - single unmodifiable buffer or two modifiable buffers, but no other - combination is supported. - - It is the caller's responsibility to free the malloc allocated - buffers by detecting that the pointers have changed from their - original values i.e. *ANSCP or *ANSP2 has changed. - - If an answer is truncated because of UDP datagram DNS limits then - *V_CIRCUIT is set to 1 and the return value non-zero to indicate to - the caller to retry with TCP. The value *GOTSOMEWHERE is set to 1 - if any progress was made reading a response from the nameserver and - is used by the caller to distinguish between ECONNREFUSED and - ETIMEDOUT (the latter if *GOTSOMEWHERE is 1). - - If errors are encountered then *TERRNO is set to an appropriate - errno value and a zero result is returned for a recoverable error, - and a less-than zero result is returned for a non-recoverable error. - - If no errors are encountered then *TERRNO is left unmodified and - a the length of the first response in bytes is returned. */ -static int -send_dg(res_state statp, - const u_char *buf, int buflen, const u_char *buf2, int buflen2, - u_char **ansp, int *anssizp, - int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp, - u_char **ansp2, int *anssizp2, int *resplen2, int *ansp2_malloced) -{ - const HEADER *hp = (HEADER *) buf; - const HEADER *hp2 = (HEADER *) buf2; - struct timespec now, timeout, finish; - struct pollfd pfd[1]; - int ptimeout; - struct sockaddr_in6 from; - int resplen = 0; - int n; - - /* - * Compute time for the total operation. - */ - int seconds = (statp->retrans << ns); - if (ns > 0) - seconds /= statp->nscount; - if (seconds <= 0) - seconds = 1; - bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0; - bool single_request = (((statp->options & RES_SNGLKUP) != 0) - | single_request_reopen); - int save_gotsomewhere = *gotsomewhere; - - int retval; - retry_reopen: - retval = reopen (statp, terrno, ns); - if (retval <= 0) - { - if (resplen2 != NULL) - *resplen2 = 0; - return retval; - } - retry: - evNowTime(&now); - evConsTime(&timeout, seconds, 0); - evAddTime(&finish, &now, &timeout); - int need_recompute = 0; - int nwritten = 0; - int recvresp1 = 0; - /* Skip the second response if there is no second query. - To do that we mark the second response as received. */ - int recvresp2 = buf2 == NULL; - pfd[0].fd = EXT(statp).nssocks[ns]; - pfd[0].events = POLLOUT; - wait: - if (need_recompute) { - recompute_resend: - evNowTime(&now); - if (evCmpTime(finish, now) <= 0) { - poll_err_out: - Perror(statp, stderr, "poll", errno); - return close_and_return_error (statp, resplen2); - } - evSubTime(&timeout, &finish, &now); - need_recompute = 0; - } - /* Convert struct timespec in milliseconds. */ - ptimeout = timeout.tv_sec * 1000 + timeout.tv_nsec / 1000000; - - n = 0; - if (nwritten == 0) - n = __poll (pfd, 1, 0); - if (__glibc_unlikely (n == 0)) { - n = __poll (pfd, 1, ptimeout); - need_recompute = 1; - } - if (n == 0) { - Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n")); - if (resplen > 1 && (recvresp1 || (buf2 != NULL && recvresp2))) - { - /* There are quite a few broken name servers out - there which don't handle two outstanding - requests from the same source. There are also - broken firewall settings. If we time out after - having received one answer switch to the mode - where we send the second request only once we - have received the first answer. */ - if (!single_request) - { - statp->options |= RES_SNGLKUP; - single_request = true; - *gotsomewhere = save_gotsomewhere; - goto retry; - } - else if (!single_request_reopen) - { - statp->options |= RES_SNGLKUPREOP; - single_request_reopen = true; - *gotsomewhere = save_gotsomewhere; - __res_iclose (statp, false); - goto retry_reopen; - } - - *resplen2 = 1; - return resplen; - } - - *gotsomewhere = 1; - if (resplen2 != NULL) - *resplen2 = 0; - return 0; - } - if (n < 0) { - if (errno == EINTR) - goto recompute_resend; - - goto poll_err_out; - } - __set_errno (0); - if (pfd[0].revents & POLLOUT) { -#ifndef __ASSUME_SENDMMSG - static int have_sendmmsg; -#else -# define have_sendmmsg 1 -#endif - if (have_sendmmsg >= 0 && nwritten == 0 && buf2 != NULL - && !single_request) - { - struct iovec iov[2]; - struct mmsghdr reqs[2]; - reqs[0].msg_hdr.msg_name = NULL; - reqs[0].msg_hdr.msg_namelen = 0; - reqs[0].msg_hdr.msg_iov = &iov[0]; - reqs[0].msg_hdr.msg_iovlen = 1; - iov[0].iov_base = (void *) buf; - iov[0].iov_len = buflen; - reqs[0].msg_hdr.msg_control = NULL; - reqs[0].msg_hdr.msg_controllen = 0; - - reqs[1].msg_hdr.msg_name = NULL; - reqs[1].msg_hdr.msg_namelen = 0; - reqs[1].msg_hdr.msg_iov = &iov[1]; - reqs[1].msg_hdr.msg_iovlen = 1; - iov[1].iov_base = (void *) buf2; - iov[1].iov_len = buflen2; - reqs[1].msg_hdr.msg_control = NULL; - reqs[1].msg_hdr.msg_controllen = 0; - - int ndg = __sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL); - if (__glibc_likely (ndg == 2)) - { - if (reqs[0].msg_len != buflen - || reqs[1].msg_len != buflen2) - goto fail_sendmmsg; - - pfd[0].events = POLLIN; - nwritten += 2; - } - else if (ndg == 1 && reqs[0].msg_len == buflen) - goto just_one; - else if (ndg < 0 && (errno == EINTR || errno == EAGAIN)) - goto recompute_resend; - else - { -#ifndef __ASSUME_SENDMMSG - if (__glibc_unlikely (have_sendmmsg == 0)) - { - if (ndg < 0 && errno == ENOSYS) - { - have_sendmmsg = -1; - goto try_send; - } - have_sendmmsg = 1; - } -#endif - - fail_sendmmsg: - Perror(statp, stderr, "sendmmsg", errno); - return close_and_return_error (statp, resplen2); - } - } - else - { - ssize_t sr; -#ifndef __ASSUME_SENDMMSG - try_send: -#endif - if (nwritten != 0) - sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL); - else - sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL); - - if (sr != (nwritten != 0 ? buflen2 : buflen)) { - if (errno == EINTR || errno == EAGAIN) - goto recompute_resend; - Perror(statp, stderr, "send", errno); - return close_and_return_error (statp, resplen2); - } - just_one: - if (nwritten != 0 || buf2 == NULL || single_request) - pfd[0].events = POLLIN; - else - pfd[0].events = POLLIN | POLLOUT; - ++nwritten; - } - goto wait; - } else if (pfd[0].revents & POLLIN) { - int *thisanssizp; - u_char **thisansp; - int *thisresplenp; - - if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { - /* We have not received any responses - yet or we only have one response to - receive. */ - thisanssizp = anssizp; - thisansp = anscp ?: ansp; - assert (anscp != NULL || ansp2 == NULL); - thisresplenp = &resplen; - } else { - thisanssizp = anssizp2; - thisansp = ansp2; - thisresplenp = resplen2; - } - - if (*thisanssizp < MAXPACKET - /* If the current buffer is not the the static - user-supplied buffer then we can reallocate - it. */ - && (thisansp != NULL && thisansp != ansp) -#ifdef FIONREAD - /* Is the size too small? */ - && (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0 - || *thisanssizp < *thisresplenp) -#endif - ) { - /* Always allocate MAXPACKET, callers expect - this specific size. */ - u_char *newp = malloc (MAXPACKET); - if (newp != NULL) { - *thisanssizp = MAXPACKET; - *thisansp = newp; - if (thisansp == ansp2) - *ansp2_malloced = 1; - } - } - /* We could end up with truncation if anscp was NULL - (not allowed to change caller's buffer) and the - response buffer size is too small. This isn't a - reliable way to detect truncation because the ioctl - may be an inaccurate report of the UDP message size. - Therefore we use this only to issue debug output. - To do truncation accurately with UDP we need - MSG_TRUNC which is only available on Linux. We - can abstract out the Linux-specific feature in the - future to detect truncation. */ - if (__glibc_unlikely (*thisanssizp < *thisresplenp)) { - Dprint(statp->options & RES_DEBUG, - (stdout, ";; response may be truncated (UDP)\n") - ); - } - - HEADER *anhp = (HEADER *) *thisansp; - socklen_t fromlen = sizeof(struct sockaddr_in6); - assert (sizeof(from) <= fromlen); - *thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp, - *thisanssizp, 0, - (struct sockaddr *)&from, &fromlen); - if (__glibc_unlikely (*thisresplenp <= 0)) { - if (errno == EINTR || errno == EAGAIN) { - need_recompute = 1; - goto wait; - } - Perror(statp, stderr, "recvfrom", errno); - return close_and_return_error (statp, resplen2); - } - *gotsomewhere = 1; - if (__glibc_unlikely (*thisresplenp < HFIXEDSZ)) { - /* - * Undersized message. - */ - Dprint(statp->options & RES_DEBUG, - (stdout, ";; undersized: %d\n", - *thisresplenp)); - *terrno = EMSGSIZE; - return close_and_return_error (statp, resplen2); - } - if ((recvresp1 || hp->id != anhp->id) - && (recvresp2 || hp2->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"), - *thisansp, - (*thisresplenp > *thisanssizp) - ? *thisanssizp : *thisresplenp); - goto wait; - } - if (!(statp->options & RES_INSECURE1) && - !res_ourserver_p(statp, &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"), - *thisansp, - (*thisresplenp > *thisanssizp) - ? *thisanssizp : *thisresplenp); - goto wait; - } - if (!(statp->options & RES_INSECURE2) - && (recvresp1 || !res_queriesmatch(buf, buf + buflen, - *thisansp, - *thisansp - + *thisanssizp)) - && (recvresp2 || !res_queriesmatch(buf2, buf2 + buflen2, - *thisansp, - *thisansp - + *thisanssizp))) { - /* - * 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"), - *thisansp, - (*thisresplenp > *thisanssizp) - ? *thisanssizp : *thisresplenp); - goto wait; - } - if (anhp->rcode == SERVFAIL || - anhp->rcode == NOTIMP || - anhp->rcode == REFUSED) { - DprintQ(statp->options & RES_DEBUG, - (stdout, "server rejected query:\n"), - *thisansp, - (*thisresplenp > *thisanssizp) - ? *thisanssizp : *thisresplenp); - - next_ns: - if (recvresp1 || (buf2 != NULL && recvresp2)) { - *resplen2 = 0; - return resplen; - } - if (buf2 != NULL) - { - /* No data from the first reply. */ - resplen = 0; - /* We are waiting for a possible second reply. */ - if (hp->id == anhp->id) - recvresp1 = 1; - else - recvresp2 = 1; - - goto wait; - } - - /* don't retry if called from dig */ - if (!statp->pfcode) - return close_and_return_error (statp, resplen2); - __res_iclose(statp, false); - } - if (anhp->rcode == NOERROR && anhp->ancount == 0 - && anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) { - DprintQ(statp->options & RES_DEBUG, - (stdout, "referred query:\n"), - *thisansp, - (*thisresplenp > *thisanssizp) - ? *thisanssizp : *thisresplenp); - goto next_ns; - } - 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_iclose(statp, false); - // XXX if we have received one reply we could - // XXX use it and not repeat it over TCP... - if (resplen2 != NULL) - *resplen2 = 0; - return (1); - } - /* Mark which reply we received. */ - if (recvresp1 == 0 && hp->id == anhp->id) - recvresp1 = 1; - else - recvresp2 = 1; - /* Repeat waiting if we have a second answer to arrive. */ - if ((recvresp1 & recvresp2) == 0) { - if (single_request) { - pfd[0].events = POLLOUT; - if (single_request_reopen) { - __res_iclose (statp, false); - retval = reopen (statp, terrno, ns); - if (retval <= 0) - { - if (resplen2 != NULL) - *resplen2 = 0; - return retval; - } - pfd[0].fd = EXT(statp).nssocks[ns]; - } - } - goto wait; - } - /* All is well. We have received both responses (if - two responses were requested). */ - return (resplen); - } else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) - /* Something went wrong. We can stop trying. */ - return close_and_return_error (statp, resplen2); - else { - /* poll should not have returned > 0 in this case. */ - abort (); - } -} - -#ifdef DEBUG -static void -Aerror(const res_state statp, FILE *file, const char *string, int error, - const struct sockaddr *address) -{ - int save = errno; - - if ((statp->options & RES_DEBUG) != 0) { - char tmp[sizeof "xxxx.xxxx.xxxx.255.255.255.255"]; - - fprintf(file, "res_send: %s ([%s].%u): %s\n", - string, - (address->sa_family == AF_INET - ? inet_ntop(address->sa_family, - &((const struct sockaddr_in *) address)->sin_addr, - tmp, sizeof tmp) - : inet_ntop(address->sa_family, - &((const struct sockaddr_in6 *) address)->sin6_addr, - tmp, sizeof tmp)), - (address->sa_family == AF_INET - ? ntohs(((struct sockaddr_in *) address)->sin_port) - : address->sa_family == AF_INET6 - ? ntohs(((struct sockaddr_in6 *) address)->sin6_port) - : 0), - strerror(error)); - } - __set_errno (save); -} - -static void -Perror(const res_state statp, FILE *file, const char *string, int error) { - int save = errno; - - if ((statp->options & RES_DEBUG) != 0) - fprintf(file, "res_send: %s: %s\n", - string, strerror(error)); - __set_errno (save); -} -#endif - -static int -sock_eq(struct sockaddr_in6 *a1, struct sockaddr_in6 *a2) { - if (a1->sin6_family == a2->sin6_family) { - if (a1->sin6_family == AF_INET) - return ((((struct sockaddr_in *)a1)->sin_port == - ((struct sockaddr_in *)a2)->sin_port) && - (((struct sockaddr_in *)a1)->sin_addr.s_addr == - ((struct sockaddr_in *)a2)->sin_addr.s_addr)); - else - return ((a1->sin6_port == a2->sin6_port) && - !memcmp(&a1->sin6_addr, &a2->sin6_addr, - sizeof (struct in6_addr))); - } - if (a1->sin6_family == AF_INET) { - struct sockaddr_in6 *sap = a1; - a1 = a2; - a2 = sap; - } /* assumes that AF_INET and AF_INET6 are the only possibilities */ - return ((a1->sin6_port == ((struct sockaddr_in *)a2)->sin_port) && - IN6_IS_ADDR_V4MAPPED(&a1->sin6_addr) && - (a1->sin6_addr.s6_addr32[3] == - ((struct sockaddr_in *)a2)->sin_addr.s_addr)); -} |