/*
- * ++Copyright++ 1985, 1989, 1993
- * -
* Copyright (c) 1985, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 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
* 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--
+ */
+
+/*
+ * 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
-static char rcsid[] = "$Id$";
+static const char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
+static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixie Exp $";
#endif /* LIBC_SCCS and not lint */
- /* change this to "0"
- * if you talk to a lot
- * of multi-homed SunOS
- * ("broken") name servers.
- */
-#define CHECK_SRVR_ADDR 1 /* XXX - should be in options.h */
-
/*
* 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 <stdio.h>
-#include <netdb.h>
#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
#include <resolv.h>
-#if defined(BSD) && (BSD >= 199306)
-# include <stdlib.h>
-# include <string.h>
-# include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <kernel-features.h>
+#include <libc-internal.h>
+
+#if PACKETSZ > 65536
+#define MAXPACKET PACKETSZ
#else
-# include "../conf/portability.h"
+#define MAXPACKET 65536
#endif
-#if defined(USE_OPTIONS_H)
-# include <../conf/options.h>
-#endif
+/* From ev_streams.c. */
-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? */
-
-#ifndef FD_SET
-/* XXX - should be in portability.h */
-#define NFDBITS 32
-#define FD_SETSIZE 32
-#define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
-#define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
-#define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
-#define FD_ZERO(p) bzero((char *)(p), sizeof(*(p)))
-#endif
+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;
+}
-/* XXX - this should be done in portability.h */
-#if (defined(BSD) && (BSD >= 199103)) || defined(linux)
-# define CAN_RECONNECT 1
-#else
-# define CAN_RECONNECT 0
-#endif
+/* From ev_timers.c. */
-#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 void
- Aerror(file, string, error, address)
- FILE *file;
- char *string;
- int error;
- struct sockaddr_in address;
- {
- int save = errno;
+#define BILLION 1000000000
- if (_res.options & RES_DEBUG) {
- fprintf(file, "res_send: %s ([%s].%u): %s\n",
- string,
- inet_ntoa(address.sin_addr),
- ntohs(address.sin_port),
- strerror(error));
- }
- __set_errno (save);
- }
- static void
- Perror(file, string, error)
- FILE *file;
- char *string;
- int error;
- {
- int save = errno;
+static inline void
+evConsTime(struct timespec *res, time_t sec, long nsec) {
+ res->tv_sec = sec;
+ res->tv_nsec = nsec;
+}
- if (_res.options & RES_DEBUG) {
- fprintf(file, "res_send: %s: %s\n",
- string, strerror(error));
+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;
}
- __set_errno (save);
- }
-#endif
+}
-static res_send_qhook Qhook = NULL;
-static res_send_rhook Rhook = NULL;
+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--;
+ }
+}
-void
-res_send_setqhook(hook)
- res_send_qhook hook;
-{
+static int
+evCmpTime(struct timespec a, struct timespec b) {
+ long x = a.tv_sec - b.tv_sec;
- Qhook = hook;
+ if (x == 0L)
+ x = a.tv_nsec - b.tv_nsec;
+ return (x < 0L ? (-1) : x > 0L ? (1) : (0));
}
-void
-res_send_setrhook(hook)
- res_send_rhook hook;
-{
+static void
+evNowTime(struct timespec *res) {
+ struct timeval now;
- Rhook = hook;
+ 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[]
* paul vixie, 29may94
*/
int
-res_isourserver(inp)
- const struct sockaddr_in *inp;
+res_ourserver_p(const res_state statp, const struct sockaddr_in6 *inp)
{
- struct sockaddr_in ina;
- register int ns, ret;
+ 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;
- ina = *inp;
- ret = 0;
- for (ns = 0; ns < _res.nscount; ns++) {
- register const struct sockaddr_in *srv = &_res.nsaddr_list[ns];
+ for (ns = 0; ns < statp->nscount; ns++) {
+ const struct sockaddr_in *srv =
+ (struct sockaddr_in *) get_nsaddr (statp, ns);
- if (srv->sin_family == ina.sin_family &&
- srv->sin_port == ina.sin_port &&
+ if ((srv->sin_family == AF_INET) &&
+ (srv->sin_port == port) &&
(srv->sin_addr.s_addr == INADDR_ANY ||
- srv->sin_addr.s_addr == ina.sin_addr.s_addr)) {
- ret++;
- break;
- }
+ 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 (ret);
+ 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 + HFIXESDZ <= eom
+ * buf + HFIXEDSZ <= eom
* returns:
* -1 : format error
* 0 : not found
* paul vixie, 29may94
*/
int
-res_nameinquery(name, type, class, buf, eom)
- const char *name;
- register int type, class;
- const u_char *buf, *eom;
+res_nameinquery(const char *name, int type, int class,
+ const u_char *buf, const u_char *eom)
{
- register const u_char *cp = buf + HFIXEDSZ;
+ const u_char *cp = buf + HFIXEDSZ;
int qdcount = ntohs(((HEADER*)buf)->qdcount);
while (qdcount-- > 0) {
char tname[MAXDNAME+1];
- register int n, ttype, tclass;
+ int n, ttype, tclass;
n = dn_expand(buf, eom, cp, tname, sizeof tname);
if (n < 0)
cp += n;
if (cp + 2 * INT16SZ > eom)
return (-1);
- ttype = _getshort(cp); cp += INT16SZ;
- tclass = _getshort(cp); cp += INT16SZ;
- if (ttype == type &&
- tclass == class &&
- strcasecmp(tname, name) == 0)
+ 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)
* paul vixie, 29may94
*/
int
-res_queriesmatch(buf1, eom1, buf2, eom2)
- const u_char *buf1, *eom1;
- const u_char *buf2, *eom2;
+res_queriesmatch(const u_char *buf1, const u_char *eom1,
+ const u_char *buf2, const u_char *eom2)
{
- register const u_char *cp = buf1 + HFIXEDSZ;
- int qdcount = ntohs(((HEADER*)buf1)->qdcount);
-
if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2)
return (-1);
- if (qdcount != ntohs(((HEADER*)buf2)->qdcount))
+ /*
+ * 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];
- register int n, ttype, tclass;
+ int n, ttype, tclass;
n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
if (n < 0)
cp += n;
if (cp + 2 * INT16SZ > eom1)
return (-1);
- ttype = _getshort(cp); cp += INT16SZ;
- tclass = _getshort(cp); cp += INT16SZ;
+ 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
-res_send(buf, buflen, ans, anssiz)
- const u_char *buf;
- int buflen;
- u_char *ans;
- int anssiz;
+__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)
{
- HEADER *hp = (HEADER *) buf;
- HEADER *anhp = (HEADER *) ans;
- int gotsomewhere, connreset, terrno, try, v_circuit, resplen, ns;
- register int n;
- u_int badns; /* XXX NSMAX can't exceed #/bits in this var */
+ int gotsomewhere, terrno, try, v_circuit, resplen, ns, n;
- if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
- /* errno should have been set by res_init() in this case. */
+ if (statp->nscount == 0) {
+ __set_errno (ESRCH);
return (-1);
}
- if (anssiz < HFIXEDSZ) {
+
+ if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) {
__set_errno (EINVAL);
return (-1);
}
- DprintQ((_res.options & RES_DEBUG) || (_res.pfcode & RES_PRF_QUERY),
+
+#ifdef USE_HOOKS
+ if (__glibc_unlikely (statp->qhook || statp->rhook)) {
+ if (anssiz < MAXPACKET && ansp) {
+ u_char *buf = malloc (MAXPACKET);
+ if (buf == NULL)
+ return (-1);
+ memcpy (buf, ans, HFIXEDSZ);
+ *ansp = buf;
+ ans = buf;
+ anssiz = MAXPACKET;
+ }
+ }
+#endif
+
+ DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY),
(stdout, ";; res_send()\n"), buf, buflen);
- v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
+ v_circuit = ((statp->options & RES_USEVC)
+ || buflen > PACKETSZ
+ || buflen2 > PACKETSZ);
gotsomewhere = 0;
- connreset = 0;
terrno = ETIMEDOUT;
- badns = 0;
/*
- * Send request, RETRY times, or until successful
+ * If the ns_addr_list in the resolver context has changed, then
+ * invalidate our cached copy and the associated timing data.
*/
- for (try = 0; try < _res.retry; try++) {
- for (ns = 0; ns < _res.nscount; ns++) {
- struct sockaddr_in *nsap = &_res.nsaddr_list[ns];
- same_ns:
- if (badns & (1 << ns)) {
- res_close();
- goto next_ns;
+ 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;
}
+ }
- if (Qhook) {
+ /*
+ * 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 (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) &&
+ (statp->options & RES_BLAST) == 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];
+#endif
+#if defined USE_HOOKS || defined DEBUG
+ struct sockaddr *nsap = get_nsaddr (statp, ns);
+#endif
+
+ same_ns:
+#ifdef USE_HOOKS
+ if (__glibc_unlikely (statp->qhook != NULL)) {
int done = 0, loops = 0;
do {
res_sendhookact act;
- act = (*Qhook)(&nsap, &buf, &buflen,
- ans, anssiz, &resplen);
+ struct sockaddr_in *nsap4;
+ nsap4 = (struct sockaddr_in *) nsap;
+ act = (*statp->qhook)(&nsap4, &buf, &buflen,
+ ans, anssiz, &resplen);
+ nsap = (struct sockaddr_in6 *) nsap4;
switch (act) {
case res_goahead:
done = 1;
break;
case res_nextns:
- res_close();
+ __res_iclose(statp, false);
goto next_ns;
case res_done:
return (resplen);
}
} while (!done);
}
+#endif
- Dprint(_res.options & RES_DEBUG,
+ Dprint(statp->options & RES_DEBUG,
(stdout, ";; Querying server (# %d) address = %s\n",
- ns + 1, inet_ntoa(nsap->sin_addr)));
+ ns + 1, inet_ntop(nsap->sa_family,
+ (nsap->sa_family == AF_INET6
+ ? &((struct sockaddr_in6 *) nsap)->sin6_addr
+ : &((struct sockaddr_in *) nsap)->sin_addr),
+ tmpbuf, sizeof (tmpbuf))));
- if (v_circuit) {
- int truncated;
- struct iovec iov[2];
- u_short len;
- u_char *cp;
-
- /*
- * Use virtual circuit;
- * at most one attempt per server.
- */
- try = _res.retry;
- truncated = 0;
- if ((s < 0) || (!vc)) {
- if (s >= 0)
- res_close();
-
- s = socket(PF_INET, SOCK_STREAM, 0);
- if (s < 0) {
- terrno = errno;
- Perror(stderr, "socket(vc)", errno);
- return (-1);
- }
- __set_errno (0);
- if (connect(s, (struct sockaddr *)nsap,
- sizeof(struct sockaddr)) < 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);
- iov[0].iov_base = (caddr_t)&len;
- iov[0].iov_len = INT16SZ;
- iov[1].iov_base = (caddr_t)buf;
- iov[1].iov_len = buflen;
- if (writev(s, iov, 2) != (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 = _getshort(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();
+ 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;
- }
- if (truncated) {
- /*
- * Flush rest of answer
- * so connection stays in synch.
- */
- anhp->tc = 1;
- len = resplen - anssiz;
- while (len != 0) {
- char junk[PACKETSZ];
-
- n = ((size_t) 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 timeval timeout;
- fd_set dsmask;
- struct sockaddr_in from;
- socklen_t fromlen;
-
- if ((s < 0) || vc) {
- if (vc)
- res_close();
- s = socket(PF_INET, SOCK_DGRAM, 0);
- if (s < 0) {
-#if !CAN_RECONNECT
- bad_dg_sock:
-#endif
- terrno = errno;
- Perror(stderr, "socket(dg)", errno);
- return (-1);
- }
- connected = 0;
- }
- /*
- * 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.
- */
- if (_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, (struct sockaddr *)nsap,
- sizeof(struct sockaddr)
- ) < 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) {
-#if CAN_RECONNECT
- 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(PF_INET, 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
- connected = 0;
- __set_errno (0);
- }
- if (sendto(s, (char*)buf, buflen, 0,
- (struct sockaddr *)nsap,
- sizeof(struct sockaddr))
- != buflen) {
- Aerror(stderr, "sendto", errno, *nsap);
- badns |= (1 << ns);
- res_close();
- goto next_ns;
- }
- }
-
- /*
- * 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;
- wait:
- if (s < 0 || s >= FD_SETSIZE) {
- Perror(stderr, "s out-of-bounds", EMFILE);
- res_close();
- goto next_ns;
- }
- FD_ZERO(&dsmask);
- FD_SET(s, &dsmask);
- n = select(s+1, &dsmask, (fd_set *)NULL,
- (fd_set *)NULL, &timeout);
- if (n < 0) {
- if (errno == EINTR)
- goto wait;
- Perror(stderr, "select", errno);
- res_close();
- goto next_ns;
- }
- if (n == 0) {
- /*
- * timeout
- */
- Dprint(_res.options & RES_DEBUG,
- (stdout, ";; timeout\n"));
- gotsomewhere = 1;
- res_close();
+ /* 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;
- }
- __set_errno (0);
- fromlen = sizeof(struct sockaddr_in);
- 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;
- }
-#if CHECK_SRVR_ADDR
- if (!(_res.options & RES_INSECURE1) &&
- !res_isourserver(&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();
+ if (v_circuit)
+ // XXX Check whether both requests failed or
+ // XXX whether one has been answered successfully
goto same_ns;
- }
- } /*if vc/dg*/
- Dprint((_res.options & RES_DEBUG) ||
- ((_res.pfcode & RES_PRF_REPLY) &&
- (_res.pfcode & RES_PRF_HEAD1)),
+ }
+
+ resplen = n;
+
+ Dprint((statp->options & RES_DEBUG) ||
+ ((statp->pfcode & RES_PRF_REPLY) &&
+ (statp->pfcode & RES_PRF_HEAD1)),
(stdout, ";; got answer:\n"));
- DprintQ((_res.options & RES_DEBUG) ||
- (_res.pfcode & RES_PRF_REPLY),
- (stdout, ""),
- ans, (resplen>anssiz)?anssiz:resplen);
+
+ 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 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 ((v_circuit && (statp->options & RES_USEVC) == 0) ||
+ (statp->options & RES_STAYOPEN) == 0) {
+ __res_iclose(statp, false);
}
- if (Rhook) {
+#ifdef USE_HOOKS
+ if (__glibc_unlikely (statp->rhook)) {
int done = 0, loops = 0;
do {
res_sendhookact act;
- act = (*Rhook)(nsap, buf, buflen,
- ans, anssiz, &resplen);
+ act = (*statp->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();
+ __res_iclose(statp, false);
goto next_ns;
case res_modified:
/* give the hook another try */
} while (!done);
}
+#endif
return (resplen);
- next_ns: ;
+ next_ns: ;
} /*foreach ns*/
} /*foreach retry*/
- res_close();
- if (!v_circuit)
+ __res_iclose(statp, false);
+ if (!v_circuit) {
if (!gotsomewhere)
- __set_errno (ECONNREFUSED); /* no nameservers found */
+ __set_errno (ECONNREFUSED); /* no nameservers found */
else
- __set_errno (ETIMEDOUT); /* no answer obtained */
- else
+ __set_errno (ETIMEDOUT); /* no answer obtained */
+ } else
__set_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()
+int
+res_nsend(res_state statp,
+ const u_char *buf, int buflen, u_char *ans, int anssiz)
{
- if (s >= 0) {
- (void) close(s);
- s = -1;
- connected = 0;
- vc = 0;
+ 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];
+}
+
+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;
+ u_char *ans = *ansp;
+ int orig_anssizp = *anssizp;
+ // XXX REMOVE
+ // int anssiz = *anssizp;
+ HEADER *anhp = (HEADER *) ans;
+ 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.
+ */
+#if __GNUC_PREREQ (4, 7)
+ DIAG_PUSH_NEEDS_COMMENT;
+ DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
+#endif
+ int resplen;
+#if __GNUC_PREREQ (4, 7)
+ DIAG_POP_NEEDS_COMMENT;
+#endif
+ struct iovec iov[4];
+ u_short len;
+ u_short len2;
+ u_char *cp;
+
+ if (resplen2 != NULL)
+ *resplen2 = 0;
+ 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, 0);
+ if (statp->_vcsock < 0) {
+ *terrno = errno;
+ Perror(statp, stderr, "socket(vc)", errno);
+ 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);
+ __res_iclose(statp, false);
+ return (0);
+ }
+ 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);
+ __res_iclose(statp, false);
+ return (0);
+ }
+ /*
+ * Receive length & response
+ */
+ int recvresp1 = 0;
+ 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);
+ __res_iclose(statp, false);
+ /*
+ * 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;
+ goto same_ns;
+ }
+ return (0);
+ }
+ int rlen = ntohs (rlen16);
+
+ int *thisanssizp;
+ u_char **thisansp;
+ int *thisresplenp;
+ if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) {
+ thisanssizp = anssizp;
+ thisansp = anscp ?: ansp;
+ assert (anscp != NULL || ansp2 == NULL);
+ thisresplenp = &resplen;
+ } else {
+ if (*anssizp != MAXPACKET) {
+ /* No buffer allocated for the first
+ reply. We can try to use the rest
+ of the user-provided buffer. */
+#if __GNUC_PREREQ (4, 7)
+ DIAG_PUSH_NEEDS_COMMENT;
+ DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
+#endif
+#if _STRING_ARCH_unaligned
+ *anssizp2 = orig_anssizp - resplen;
+ *ansp2 = *ansp + resplen;
+#else
+ int aligned_resplen
+ = ((resplen + __alignof__ (HEADER) - 1)
+ & ~(__alignof__ (HEADER) - 1));
+ *anssizp2 = orig_anssizp - aligned_resplen;
+ *ansp2 = *ansp + aligned_resplen;
+#endif
+#if __GNUC_PREREQ (4, 7)
+ DIAG_POP_NEEDS_COMMENT;
+#endif
+ } else {
+ /* The first reply did not fit into the
+ user-provided buffer. Maybe the second
+ answer will. */
+ *anssizp2 = orig_anssizp;
+ *ansp2 = *ansp;
+ }
+
+ thisanssizp = anssizp2;
+ thisansp = ansp2;
+ thisresplenp = resplen2;
+ }
+ anhp = (HEADER *) *thisansp;
+
+ *thisresplenp = rlen;
+ if (rlen > *thisanssizp) {
+ /* Yes, we test ANSCP here. If we have two buffers
+ both will be allocatable. */
+ if (__glibc_likely (anscp != NULL)) {
+ u_char *newp = malloc (MAXPACKET);
+ if (newp == NULL) {
+ *terrno = ENOMEM;
+ __res_iclose(statp, false);
+ return (0);
+ }
+ *thisanssizp = MAXPACKET;
+ *thisansp = newp;
+ if (thisansp == ansp2)
+ *ansp2_malloced = 1;
+ anhp = (HEADER *) newp;
+ 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;
+ __res_iclose(statp, false);
+ return (0);
+ }
+
+ 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);
+ __res_iclose(statp, false);
+ return (0);
+ }
+ 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;
}
-#ifdef ultrix
-/* ultrix 4.0 had some icky packaging in its libc.a. alias for it here.
- * there is more gunk of this kind over in res_debug.c.
- */
+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, 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, 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.
+ */
+ if (connect(EXT(statp).nssocks[ns], nsap, slen) < 0) {
+ Aerror(statp, stderr, "connect(dg)", errno, nsap);
+ __res_iclose(statp, false);
+ return (0);
+ }
+ }
-void
-_res_close()
+ return 1;
+}
+
+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)
{
- res_close();
+ const HEADER *hp = (HEADER *) buf;
+ const HEADER *hp2 = (HEADER *) buf2;
+ u_char *ans = *ansp;
+ int orig_anssizp = *anssizp;
+ 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)
+ return retval;
+ retry:
+ evNowTime(&now);
+ evConsTime(&timeout, seconds, 0);
+ evAddTime(&finish, &now, &timeout);
+ int need_recompute = 0;
+ int nwritten = 0;
+ int recvresp1 = 0;
+ int recvresp2 = buf2 == NULL;
+ pfd[0].fd = EXT(statp).nssocks[ns];
+ pfd[0].events = POLLOUT;
+ if (resplen2 != NULL)
+ *resplen2 = 0;
+ wait:
+ if (need_recompute) {
+ recompute_resend:
+ evNowTime(&now);
+ if (evCmpTime(finish, now) <= 0) {
+ poll_err_out:
+ Perror(statp, stderr, "poll", errno);
+ err_out:
+ __res_iclose(statp, false);
+ return (0);
+ }
+ 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;
+ 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);
+ goto err_out;
+ }
+ }
+ 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);
+ goto err_out;
+ }
+ 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) {
+ thisanssizp = anssizp;
+ thisansp = anscp ?: ansp;
+ assert (anscp != NULL || ansp2 == NULL);
+ thisresplenp = &resplen;
+ } else {
+ if (*anssizp != MAXPACKET) {
+ /* No buffer allocated for the first
+ reply. We can try to use the rest
+ of the user-provided buffer. */
+#if _STRING_ARCH_unaligned
+ *anssizp2 = orig_anssizp - resplen;
+ *ansp2 = *ansp + resplen;
+#else
+ int aligned_resplen
+ = ((resplen + __alignof__ (HEADER) - 1)
+ & ~(__alignof__ (HEADER) - 1));
+ *anssizp2 = orig_anssizp - aligned_resplen;
+ *ansp2 = *ansp + aligned_resplen;
+#endif
+ } else {
+ /* The first reply did not fit into the
+ user-provided buffer. Maybe the second
+ answer will. */
+ *anssizp2 = orig_anssizp;
+ *ansp2 = *ansp;
+ }
+
+ thisanssizp = anssizp2;
+ thisansp = ansp2;
+ thisresplenp = resplen2;
+ }
+
+ if (*thisanssizp < MAXPACKET
+ /* Yes, we test ANSCP here. If we have two buffers
+ both will be allocatable. */
+ && anscp
+#ifdef FIONREAD
+ && (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0
+ || *thisanssizp < *thisresplenp)
+#endif
+ ) {
+ u_char *newp = malloc (MAXPACKET);
+ if (newp != NULL) {
+ *anssizp = MAXPACKET;
+ *thisansp = ans = newp;
+ if (thisansp == ansp2)
+ *ansp2_malloced = 1;
+ }
+ }
+ 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);
+ goto err_out;
+ }
+ *gotsomewhere = 1;
+ if (__glibc_unlikely (*thisresplenp < HFIXEDSZ)) {
+ /*
+ * Undersized message.
+ */
+ Dprint(statp->options & RES_DEBUG,
+ (stdout, ";; undersized: %d\n",
+ *thisresplenp));
+ *terrno = EMSGSIZE;
+ goto err_out;
+ }
+ 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;
+ }
+#ifdef RES_USE_EDNS0
+ if (anhp->rcode == FORMERR
+ && (statp->options & RES_USE_EDNS0) != 0U) {
+ /*
+ * Do not retry if the server does 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"),
+ *thisansp,
+ (*thisresplenp > *thisanssizp)
+ ? *thisanssizp : *thisresplenp);
+ /* record the error */
+ statp->_flags |= RES_F_EDNS0ERR;
+ goto err_out;
+ }
+#endif
+ 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;
+ }
+
+ __res_iclose(statp, false);
+ /* don't retry if called from dig */
+ if (!statp->pfcode)
+ return (0);
+ }
+ 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...
+ 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)
+ return retval;
+ pfd[0].fd = EXT(statp).nssocks[ns];
+ }
+ }
+ goto wait;
+ }
+ /*
+ * All is well, or the error is fatal. Signal that the
+ * next nameserver ought not be tried.
+ */
+ return (resplen);
+ } else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
+ /* Something went wrong. We can stop trying. */
+ goto err_out;
+ }
+ else {
+ /* poll should not have returned > 0 in this case. */
+ abort ();
+ }
}
-#undef res_send
-int
-res_send(buf, buflen, ans, anssiz)
- const u_char *buf;
- int buflen;
- u_char *ans;
- int anssiz;
+#ifdef DEBUG
+static void
+Aerror(const res_state statp, FILE *file, const char *string, int error,
+ const struct sockaddr *address)
{
- return (__res_send(buf, buflen, ans, anssiz));
+ 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));
}
-#endif /* Ultrix 4.0 hackery */
projects / thirdparty / glibc.git / blobdiff