diff options
Diffstat (limited to 'newlib/libc/sys/linux/net/res_send.c')
| -rw-r--r-- | newlib/libc/sys/linux/net/res_send.c | 954 |
1 files changed, 954 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/net/res_send.c b/newlib/libc/sys/linux/net/res_send.c new file mode 100644 index 000000000..153d2f5d9 --- /dev/null +++ b/newlib/libc/sys/linux/net/res_send.c @@ -0,0 +1,954 @@ +/* + * 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. + */ + +/* + * Portions Copyright (c) 1996 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. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93"; +static char orig_rcsid[] = "From: Id: res_send.c,v 8.20 1998/04/06 23:27:51 halley Exp $"; +#endif /* LIBC_SCCS and not lint */ +#include <sys/cdefs.h> +#include <sys/types.h> +#include <machine/endian.h> + +/* + * Send query to name server and wait for reply. + */ + +#include <sys/types.h> +#include <sys/event.h> +#include <sys/poll.h> +#include <sys/param.h> +#include <sys/time.h> +#include <sys/socket.h> +#include <sys/uio.h> + +#include <netinet/in.h> +#include <arpa/nameser.h> +#include <arpa/inet.h> + +#include <errno.h> +#include <netdb.h> +#include <resolv.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "res_config.h" + +static int s = -1; /* socket used for communications */ +static int connected = 0; /* is the socket connected */ +static int vc = 0; /* is the socket a virtual circuit? */ +static int af = 0; /* address family of socket */ +static res_send_qhook Qhook = NULL; +static res_send_rhook Rhook = NULL; + + +#define CAN_RECONNECT 1 + +#ifndef DEBUG +# define Dprint(cond, args) /*empty*/ +# define DprintQ(cond, args, query, size) /*empty*/ +# define Aerror(file, string, error, address) /*empty*/ +# define Perror(file, string, error) /*empty*/ +#else +# define Dprint(cond, args) if (cond) {fprintf args;} else {} +# define DprintQ(cond, args, query, size) if (cond) {\ + fprintf args;\ + __fp_nquery(query, size, stdout);\ + } else {} +static char abuf[NI_MAXHOST]; +static char pbuf[NI_MAXSERV]; +static void Aerror(FILE *, char *, int, struct sockaddr *); +static void Perror(FILE *, char *, int); + + static void + Aerror(file, string, error, address) + FILE *file; + char *string; + int error; + struct sockaddr *address; + { + int save = errno; + + if (_res.options & RES_DEBUG) { + if (getnameinfo(address, 0, abuf, sizeof(abuf), + pbuf, sizeof(pbuf), + NI_NUMERICHOST|NI_NUMERICSERV|NI_WITHSCOPEID) != 0) { + strncpy(abuf, "?", sizeof(abuf)); + strncpy(pbuf, "?", sizeof(pbuf)); + } + fprintf(file, "res_send: %s ([%s].%s): %s\n", + string, abuf, pbuf, strerror(error)); + } + errno = save; + } + static void + Perror(file, string, error) + FILE *file; + char *string; + int error; + { + int save = errno; + + if (_res.options & RES_DEBUG) { + fprintf(file, "res_send: %s: %s\n", + string, strerror(error)); + } + errno = save; + } +#endif + +void +res_send_setqhook(hook) + res_send_qhook hook; +{ + + Qhook = hook; +} + +void +res_send_setrhook(hook) + res_send_rhook hook; +{ + + Rhook = hook; +} + +static struct sockaddr * get_nsaddr(size_t); + +/* + * pick appropriate nsaddr_list for use. see res_init() for initialization. + */ +static struct sockaddr * +get_nsaddr(n) + size_t n; +{ + + if (!_res.nsaddr_list[n].sin_family) { + /* + * - _res_ext.nsaddr_list[n] holds an address that is larger + * than struct sockaddr, and + * - user code did not update _res.nsaddr_list[n]. + */ + return (struct sockaddr *)&_res_ext.nsaddr_list[n]; + } else { + /* + * - user code updated _res.nsaddr_list[n], or + * - _res.nsaddr_list[n] has the same content as + * _res_ext.nsaddr_list[n]. + */ + return (struct sockaddr *)&_res.nsaddr_list[n]; + } +} + +/* int + * res_isourserver(ina) + * looks up "ina" in _res.ns_addr_list[] + * returns: + * 0 : not found + * >0 : found + * author: + * paul vixie, 29may94 + */ +int +res_isourserver(inp) + const struct sockaddr_in *inp; +{ + const struct sockaddr_in6 *in6p = (const struct sockaddr_in6 *)inp; + const struct sockaddr_in6 *srv6; + const struct sockaddr_in *srv; + int ns, ret; + + ret = 0; + switch (inp->sin_family) { + case AF_INET6: + for (ns = 0; ns < _res.nscount; ns++) { + srv6 = (struct sockaddr_in6 *)get_nsaddr(ns); + if (srv6->sin6_family == in6p->sin6_family && + srv6->sin6_port == in6p->sin6_port && + srv6->sin6_scope_id == in6p->sin6_scope_id && + (IN6_IS_ADDR_UNSPECIFIED(&srv6->sin6_addr) || + IN6_ARE_ADDR_EQUAL(&srv6->sin6_addr, + &in6p->sin6_addr))) { + ret++; + break; + } + } + break; + case AF_INET: + for (ns = 0; ns < _res.nscount; ns++) { + srv = (struct sockaddr_in *)get_nsaddr(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)) { + ret++; + break; + } + } + break; + } + return (ret); +} + +/* 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(name, type, class, buf, eom) + const char *name; + int type, class; + const u_char *buf, *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); + ttype = ns_get16(cp); cp += INT16SZ; + tclass = ns_get16(cp); cp += INT16SZ; + if (ttype == type && + tclass == class && + strcasecmp(tname, name) == 0) + 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(buf1, eom1, buf2, eom2) + const u_char *buf1, *eom1; + const u_char *buf2, *eom2; +{ + const u_char *cp = buf1 + HFIXEDSZ; + int qdcount = ntohs(((HEADER*)buf1)->qdcount); + + 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); + + if (qdcount != ntohs(((HEADER*)buf2)->qdcount)) + return (0); + 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); + ttype = ns_get16(cp); cp += INT16SZ; + tclass = ns_get16(cp); cp += INT16SZ; + if (!res_nameinquery(tname, ttype, tclass, buf2, eom2)) + return (0); + } + return (1); +} + +int +res_send(buf, buflen, ans, anssiz) + const u_char *buf; + int buflen; + u_char *ans; + int anssiz; +{ + HEADER *hp = (HEADER *) buf; + HEADER *anhp = (HEADER *) ans; + int gotsomewhere, connreset, terrno, try, v_circuit, resplen, ns, n; + int kq; + u_int badns; /* XXX NSMAX can't exceed #/bits in this variable */ + + if ((_res.options & RES_INIT) == 0 && res_init() == -1) { + /* errno should have been set by res_init() in this case. */ + return (-1); + } + if (anssiz < HFIXEDSZ) { + errno = EINVAL; + return (-1); + } + DprintQ((_res.options & RES_DEBUG) || (_res.pfcode & RES_PRF_QUERY), + (stdout, ";; res_send()\n"), buf, buflen); + v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ; + gotsomewhere = 0; + connreset = 0; + terrno = ETIMEDOUT; + badns = 0; + + /* + * Send request, RETRY times, or until successful + */ + for (try = 0; try < _res.retry; try++) { + for (ns = 0; ns < _res.nscount; ns++) { + struct sockaddr *nsap = get_nsaddr(ns); + socklen_t salen; + + if (nsap->sa_family == AF_INET6) + salen = sizeof(struct sockaddr_in6); + else if (nsap->sa_family == AF_INET) + salen = sizeof(struct sockaddr_in); + else + salen = 0; /*unknown, die on connect*/ + + same_ns: + if (badns & (1 << ns)) { + res_close(); + goto next_ns; + } + + if (Qhook) { + int done = 0, loops = 0; + + do { + res_sendhookact act; + + act = (*Qhook)((struct sockaddr_in **)&nsap, + &buf, &buflen, + ans, anssiz, &resplen); + switch (act) { + case res_goahead: + done = 1; + break; + case res_nextns: + res_close(); + goto next_ns; + case res_done: + close(kq); + return (resplen); + case res_modified: + /* give the hook another try */ + if (++loops < 42) /*doug adams*/ + break; + /*FALLTHROUGH*/ + case res_error: + /*FALLTHROUGH*/ + default: + close(kq); + return (-1); + } + } while (!done); + } + + Dprint((_res.options & RES_DEBUG) && + getnameinfo(nsap, salen, abuf, sizeof(abuf), + NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID) == 0, + (stdout, ";; Querying server (# %d) address = %s\n", + ns + 1, abuf)); + + if (v_circuit) { + int truncated; + u_short len; + u_char *cp; + ssize_t rc; + + /* + * Use virtual circuit; + * at most one attempt per server. + */ + try = _res.retry; + truncated = 0; + if (s < 0 || !vc || hp->opcode == ns_o_update || + af != nsap->sa_family) { + if (s >= 0) + res_close(); + + af = nsap->sa_family; + s = socket(af, SOCK_STREAM, 0); + if (s < 0) { + terrno = errno; + Perror(stderr, "socket(vc)", errno); + badns |= (1 << ns); + res_close(); + goto next_ns; + } + errno = 0; + if (connect(s, nsap, salen) < 0) { + terrno = errno; + Aerror(stderr, "connect/vc", + errno, nsap); + badns |= (1 << ns); + res_close(); + goto next_ns; + } + vc = 1; + } + /* + * Send length & message + */ + putshort((u_short)buflen, (u_char*)&len); +#if !defined(_ELIX_LEVEL) || _ELIX_LEVEL >= 2 + { + struct iovec iov[2]; + iov[0].iov_base = (caddr_t)&len; + iov[0].iov_len = INT16SZ; + iov[1].iov_base = (caddr_t)buf; + iov[1].iov_len = buflen; + rc = writev(s, iov, 2); + } +#else /* EL/IX level 1 */ + { + char *tmpbuf; + tmpbuf = malloc (INT16SZ + buflen); + memcpy (tmpbuf, &len, INT16SZ); + memcpy (tmpbuf + INT16SZ, buf, buflen); + rc = write (s, tmpbuf, INT16SZ + buflen); + } +#endif /* EL/IX level 1 */ + if (rc != (INT16SZ + buflen)) { + terrno = errno; + Perror(stderr, "write failed", errno); + badns |= (1 << ns); + res_close(); + goto next_ns; + } + /* + * Receive length & response + */ + read_len: + cp = ans; + len = INT16SZ; + while ((n = read(s, (char *)cp, (int)len)) > 0) { + cp += n; + if ((len -= n) <= 0) + break; + } + if (n <= 0) { + terrno = errno; + Perror(stderr, "read failed", errno); + res_close(); + /* + * 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_close(); + goto same_ns; + } + res_close(); + goto next_ns; + } + resplen = ns_get16(ans); + if (resplen > anssiz) { + Dprint(_res.options & RES_DEBUG, + (stdout, ";; response truncated\n") + ); + truncated = 1; + len = anssiz; + } else + len = resplen; + if (len < HFIXEDSZ) { + /* + * Undersized message. + */ + Dprint(_res.options & RES_DEBUG, + (stdout, ";; undersized: %d\n", len)); + terrno = EMSGSIZE; + badns |= (1 << ns); + res_close(); + goto next_ns; + } + cp = ans; + while (len != 0 && + (n = read(s, (char *)cp, (int)len)) > 0) { + cp += n; + len -= n; + } + if (n <= 0) { + terrno = errno; + Perror(stderr, "read(vc)", errno); + res_close(); + goto next_ns; + } + if (truncated) { + /* + * Flush rest of answer + * so connection stays in synch. + */ + anhp->tc = 1; + len = resplen - anssiz; + while (len != 0) { + char junk[PACKETSZ]; + + n = (len > sizeof(junk) + ? sizeof(junk) + : len); + if ((n = read(s, junk, n)) > 0) + len -= n; + else + break; + } + } + /* + * 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. Anyway drop the packet and + * wait for the correct one. + */ + if (hp->id != anhp->id) { + DprintQ((_res.options & RES_DEBUG) || + (_res.pfcode & RES_PRF_REPLY), + (stdout, ";; old answer (unexpected):\n"), + ans, (resplen>anssiz)?anssiz:resplen); + goto read_len; + } + } else { + /* + * Use datagrams. + */ + struct pollfd pfd[1]; + int ptimeout; + struct timespec ts; + struct timeval timeout, ctv; + struct sockaddr_storage from; + int fromlen; + + if (s < 0 || vc || af != nsap->sa_family) { + if (vc) + res_close(); + af = nsap->sa_family; + s = socket(af, SOCK_DGRAM, 0); + if (s < 0) { +#ifndef CAN_RECONNECT + bad_dg_sock: +#endif + terrno = errno; + Perror(stderr, "socket(dg)", errno); + badns |= (1 << ns); + res_close(); + goto next_ns; + } + connected = 0; + } +#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 we have sent queries to at least two servers, + * however, we don't want to remain connected, + * as we wish to receive answers from the first + * server to respond. + * + * When the option "insecure1" is specified, we'd + * rather expect to see responses from an "unknown" + * address. In order to let the kernel accept such + * responses, do not connect the socket here. + * XXX: or do we need an explicit option to disable + * connecting? + */ + if (!(_res.options & RES_INSECURE1) && + (_res.nscount == 1 || (try == 0 && ns == 0))) { + /* + * Connect only if we are sure we won't + * receive a response from another server. + */ + if (!connected) { + if (connect(s, nsap, salen) < 0) { + Aerror(stderr, + "connect(dg)", + errno, nsap); + badns |= (1 << ns); + res_close(); + goto next_ns; + } + connected = 1; + } + + if (send(s, (char*)buf, buflen, 0) != buflen) { + Perror(stderr, "send", errno); + badns |= (1 << ns); + res_close(); + goto next_ns; + } + } else { + /* + * Disconnect if we want to listen + * for responses from more than one server. + */ + if (connected) { +#ifdef CAN_RECONNECT + /* XXX: any errornous address */ + struct sockaddr_in no_addr; + + no_addr.sin_family = AF_INET; + no_addr.sin_addr.s_addr = INADDR_ANY; + no_addr.sin_port = 0; + (void) connect(s, + (struct sockaddr *) + &no_addr, + sizeof no_addr); +#else + int s1 = socket(af, SOCK_DGRAM,0); + if (s1 < 0) + goto bad_dg_sock; + (void)_dup2(s1, s); + (void)close(s1); + Dprint(_res.options & RES_DEBUG, + (stdout, ";; new DG socket\n")) +#endif /* CAN_RECONNECT */ + connected = 0; + errno = 0; + } +#endif /* !CANNOT_CONNECT_DGRAM */ + if (sendto(s, (char*)buf, buflen, 0, + nsap, salen) != buflen) { + Aerror(stderr, "sendto", errno, nsap); + badns |= (1 << ns); + res_close(); + goto next_ns; + } +#ifndef CANNOT_CONNECT_DGRAM + } +#endif /* !CANNOT_CONNECT_DGRAM */ + + /* + * Wait for reply + */ + + timeout.tv_sec = (_res.retrans << try); + if (try > 0) + timeout.tv_sec /= _res.nscount; + if ((long) timeout.tv_sec <= 0) + timeout.tv_sec = 1; + timeout.tv_usec = 0; + TIMEVAL_TO_TIMESPEC(&timeout, &ts); + (void) gettimeofday(&ctv, NULL); + timeradd(&timeout, &ctv, &timeout); + + /* Convert struct timespec in milliseconds. */ + ptimeout = timeout.tv_sec * 1000 + timeout.tv_usec / 1000; + wait: + pfd[0].fd = s; + pfd[0].events = POLLIN; + n = poll (pfd, 1, ptimeout); + + if (s < 0) { + Perror(stderr, "s out-of-bounds", EMFILE); + res_close(); + goto next_ns; + } + + if (n < 0) { + if (errno == EINTR) { + (void) gettimeofday(&ctv, NULL); + if (timercmp(&ctv, &timeout, <)) { + timersub(&timeout, &ctv, &ctv); + TIMEVAL_TO_TIMESPEC(&ctv, &ts); + goto wait; + } + } + Perror(stderr, "poll", errno); + res_close(); + goto next_ns; + } + + if (n == 0) { + /* + * timeout + */ + Dprint(_res.options & RES_DEBUG, + (stdout, ";; timeout\n")); + gotsomewhere = 1; + res_close(); + goto next_ns; + } + errno = 0; + fromlen = sizeof(from); + resplen = recvfrom(s, (char*)ans, anssiz, 0, + (struct sockaddr *)&from, &fromlen); + if (resplen <= 0) { + Perror(stderr, "recvfrom", errno); + res_close(); + goto next_ns; + } + gotsomewhere = 1; + if (resplen < HFIXEDSZ) { + /* + * Undersized message. + */ + Dprint(_res.options & RES_DEBUG, + (stdout, ";; undersized: %d\n", + resplen)); + terrno = EMSGSIZE; + badns |= (1 << ns); + res_close(); + goto next_ns; + } + if (hp->id != anhp->id) { + /* + * response from old query, ignore it. + * XXX - potential security hazard could + * be detected here. + */ + DprintQ((_res.options & RES_DEBUG) || + (_res.pfcode & RES_PRF_REPLY), + (stdout, ";; old answer:\n"), + ans, (resplen>anssiz)?anssiz:resplen); + goto wait; + } +#ifdef CHECK_SRVR_ADDR + if (!(_res.options & RES_INSECURE1) && + !res_isourserver((struct sockaddr_in *)&from)) { + /* + * response from wrong server? ignore it. + * XXX - potential security hazard could + * be detected here. + */ + DprintQ((_res.options & RES_DEBUG) || + (_res.pfcode & RES_PRF_REPLY), + (stdout, ";; not our server:\n"), + ans, (resplen>anssiz)?anssiz:resplen); + goto wait; + } +#endif + if (!(_res.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((_res.options & RES_DEBUG) || + (_res.pfcode & RES_PRF_REPLY), + (stdout, ";; wrong query name:\n"), + ans, (resplen>anssiz)?anssiz:resplen); + goto wait; + } + if (anhp->rcode == SERVFAIL || + anhp->rcode == NOTIMP || + anhp->rcode == REFUSED) { + DprintQ(_res.options & RES_DEBUG, + (stdout, "server rejected query:\n"), + ans, (resplen>anssiz)?anssiz:resplen); + badns |= (1 << ns); + res_close(); + /* don't retry if called from dig */ + if (!_res.pfcode) + goto next_ns; + } + if (!(_res.options & RES_IGNTC) && anhp->tc) { + /* + * get rest of answer; + * use TCP with same server. + */ + Dprint(_res.options & RES_DEBUG, + (stdout, ";; truncated answer\n")); + v_circuit = 1; + res_close(); + goto same_ns; + } + } /*if vc/dg*/ + Dprint((_res.options & RES_DEBUG) || + ((_res.pfcode & RES_PRF_REPLY) && + (_res.pfcode & RES_PRF_HEAD1)), + (stdout, ";; got answer:\n")); +#if 0 + DprintQ((_res.options & RES_DEBUG) || + (_res.pfcode & RES_PRF_REPLY), + (stdout, ""), + ans, (resplen>anssiz)?anssiz:resplen); +#endif + /* + * If using virtual circuits, we assume that the first server + * is preferred over the rest (i.e. it is on the local + * machine) and only keep that one open. + * 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 && (!(_res.options & RES_USEVC) || ns != 0)) || + !(_res.options & RES_STAYOPEN)) { + res_close(); + } + if (Rhook) { + int done = 0, loops = 0; + + do { + res_sendhookact act; + + act = (*Rhook)((struct sockaddr_in *)nsap, + buf, buflen, + ans, anssiz, &resplen); + switch (act) { + case res_goahead: + case res_done: + done = 1; + break; + case res_nextns: + res_close(); + goto next_ns; + case res_modified: + /* give the hook another try */ + if (++loops < 42) /*doug adams*/ + break; + /*FALLTHROUGH*/ + case res_error: + /*FALLTHROUGH*/ + default: + close(kq); + return (-1); + } + } while (!done); + + } + close(kq); + return (resplen); + next_ns: ; + } /*foreach ns*/ + } /*foreach retry*/ + res_close(); + close(kq); + if (!v_circuit) { + if (!gotsomewhere) + errno = ECONNREFUSED; /* no nameservers found */ + else + errno = ETIMEDOUT; /* no answer obtained */ + } else + errno = terrno; + return (-1); +} + +/* + * 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_close() +{ + if (s >= 0) { + (void)close(s); + s = -1; + connected = 0; + vc = 0; + af = 0; + } +} + +/* + * Weak aliases for applications that use certain private entry points, + * and fail to include <resolv.h>. + */ +#undef res_close +__weak_reference(__res_close, _res_close); +#undef res_send +__weak_reference(__res_send, res_send); |