integrate changes from bind 4.9 (most of them); continue to use address

[unix-history] / usr / src / lib / libc / net / res_send.c

diff --git a/usr/src/lib/libc/net/res_send.c b/usr/src/lib/libc/net/res_send.c
index 0980e93..4d9db11 100644 (file)
--- a/usr/src/lib/libc/net/res_send.c
+++ b/usr/src/lib/libc/net/res_send.c
@@ -1,89 +1,138 @@
-
-/*
- * Copyright (c) 1985 Regents of the University of California.
- * All rights reserved.  The Berkeley software License Agreement
- * specifies the terms and conditions for redistribution.
+/*-
+ * Copyright (c) 1985, 1989 Regents of the University of California.
+ * All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ * -
+ * Portions Copyright (c) 1993 by Digital Equipment Corporation.
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies, and that
+ * the name of Digital Equipment Corporation not be used in advertising or
+ * publicity pertaining to distribution of the document or software without
+ * specific, written prior permission.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
+ * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ * -
+ * --Copyright--

  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)

-static char sccsid[] = "@(#)res_send.c 6.5 (Berkeley) %G%";
-#endif LIBC_SCCS and not lint
+static char sccsid[] = "@(#)res_send.c 6.28 (Berkeley) %G%";
+static char rcsid[] = "$Id: res_send.c,v 4.9.1.1 1993/05/02 22:43:03 vixie Rel $";
+#endif /* LIBC_SCCS and not lint */

 
 /*
  * Send query to name server and wait for reply.
  */
 
 
 /*
  * Send query to name server and wait for reply.
  */
 

-#include <sys/types.h>
+#include <sys/param.h>

 #include <sys/time.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 #include <sys/socket.h>

+#include <sys/uio.h>

 #include <netinet/in.h>
 #include <netinet/in.h>

+#include <arpa/nameser.h>
+#include <arpa/inet.h>

 #include <stdio.h>
 #include <errno.h>
 #include <stdio.h>
 #include <errno.h>

-#include <arpa/nameser.h>
-#include <arpa/resolv.h>
+#include <resolv.h>
+#include <unistd.h>
+#include <string.h>

 
 

-extern int errno;
+static int s = -1;     /* socket used for communications */
+static struct sockaddr no_addr;

 
 

-#define KEEPOPEN (RES_USEVC|RES_STAYOPEN)
+#ifndef FD_SET
+#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

 
 res_send(buf, buflen, answer, anslen)
 
 res_send(buf, buflen, answer, anslen)

-       char *buf;
+       const char *buf;

        int buflen;
        char *answer;
        int anslen;
 {
        register int n;
        int buflen;
        char *answer;
        int anslen;
 {
        register int n;

-       int retry, v_circuit, resplen, ns;
-       static int s = -1;
-       int gotsomewhere = 0;
+       int try, v_circuit, resplen, ns;
+       int gotsomewhere = 0, connected = 0;
+       int connreset = 0;

        u_short id, len;
        char *cp;
        u_short id, len;
        char *cp;

-       int dsmask;
+       fd_set dsmask;

        struct timeval timeout;
        HEADER *hp = (HEADER *) buf;
        HEADER *anhp = (HEADER *) answer;
        struct timeval timeout;
        HEADER *hp = (HEADER *) buf;
        HEADER *anhp = (HEADER *) answer;

+       u_int badns;            /* XXX NSMAX can't exceed #/bits per this */
+       struct iovec iov[2];
+       int terrno = ETIMEDOUT;
+       char junk[512];

 
 #ifdef DEBUG
 
 #ifdef DEBUG

-       if (_res.options & RES_DEBUG) {
-               printf("res_send()\n");
-               p_query(buf);
+       if ((_res.options & RES_DEBUG) || (_res.pfcode & RES_PRF_QUERY)) {
+               printf(";; res_send()\n");
+               __p_query(buf);

        }
        }

-#endif DEBUG
+#endif

        if (!(_res.options & RES_INIT))
                if (res_init() == -1) {
                        return(-1);
                }
        v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
        id = hp->id;
        if (!(_res.options & RES_INIT))
                if (res_init() == -1) {
                        return(-1);
                }
        v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
        id = hp->id;

+       badns = 0;

        /*
         * Send request, RETRY times, or until successful
         */
        /*
         * Send request, RETRY times, or until successful
         */

-       for (retry = _res.retry; --retry >= 0; ) {
-          for (ns = 0; ns < _res.nscount; ns++) {
+       for (try = 0; try < _res.retry; try++) {
+           for (ns = 0; ns < _res.nscount; ns++) {
+               if (badns & (1<<ns))
+                       continue;

 #ifdef DEBUG
                if (_res.options & RES_DEBUG)
 #ifdef DEBUG
                if (_res.options & RES_DEBUG)

-                       printf("Querying server (# %d) address = %s\n", ns+1,
-                             inet_ntoa(_res.nsaddr_list[ns].sin_addr.s_addr)); 
-#endif DEBUG
+                       printf(";; Querying server (# %d) address = %s\n",
+                              ns+1,
+                              inet_ntoa(_res.nsaddr_list[ns].sin_addr));
+#endif
+       usevc:

                if (v_circuit) {
                if (v_circuit) {

+                       int truncated = 0;
+

                        /*
                        /*

-                        * Use virtual circuit.
+                        * Use virtual circuit;
+                        * at most one attempt per server.

                         */
                         */

+                       try = _res.retry;

                        if (s < 0) {
                                s = socket(AF_INET, SOCK_STREAM, 0);
                                if (s < 0) {
                        if (s < 0) {
                                s = socket(AF_INET, SOCK_STREAM, 0);
                                if (s < 0) {

+                                       terrno = errno;

 #ifdef DEBUG
                                        if (_res.options & RES_DEBUG)
 #ifdef DEBUG
                                        if (_res.options & RES_DEBUG)

-                                           printf("socket failed %d\n",errno);
-#endif DEBUG
+                                           perror("socket (vc) failed");
+#endif

                                        continue;
                                }
                                        continue;
                                }

-                               if (connect(s, &(_res.nsaddr_list[ns]), 
-                                  sizeof(struct sockaddr)) < 0) {
+                               if (connect(s,
+                                   (struct sockaddr *)&(_res.nsaddr_list[ns]),
+                                   sizeof(struct sockaddr)) < 0) {
+                                       terrno = errno;

 #ifdef DEBUG
                                        if (_res.options & RES_DEBUG)
 #ifdef DEBUG
                                        if (_res.options & RES_DEBUG)

-                                           printf("connect failed %d\n",errno);
-#endif DEBUG
+                                           perror("connect failed");
+#endif

                                        (void) close(s);
                                        s = -1;
                                        continue;
                                        (void) close(s);
                                        s = -1;
                                        continue;


@@ -92,13 +141,17 @@ res_send(buf, buflen, answer, anslen)
                        /*
                         * Send length & message
                         */
                        /*
                         * Send length & message
                         */

-                       len = htons(buflen);
-                       if (write(s, &len, sizeof(len)) != sizeof(len) ||
-                                   write(s, buf, buflen) != buflen) {
+                       len = htons((u_short)buflen);
+                       iov[0].iov_base = (caddr_t)&len;
+                       iov[0].iov_len = sizeof(len);
+                       iov[1].iov_base = (char *)buf;
+                       iov[1].iov_len = buflen;
+                       if (writev(s, iov, 2) != sizeof(len) + buflen) {
+                               terrno = errno;

 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("write failed %d\n", errno);
-#endif DEBUG
+                                       perror("write failed");
+#endif

                                (void) close(s);
                                s = -1;
                                continue;
                                (void) close(s);
                                s = -1;
                                continue;


@@ -108,75 +161,173 @@ res_send(buf, buflen, answer, anslen)
                         */
                        cp = answer;
                        len = sizeof(short);
                         */
                        cp = answer;
                        len = sizeof(short);

-                       while (len > 0 && (n = read(s, cp, len)) > 0) {
+                       while (len != 0 &&
+                           (n = read(s, (char *)cp, (int)len)) > 0) {

                                cp += n;
                                len -= n;
                        }
                        if (n <= 0) {
                                cp += n;
                                len -= n;
                        }
                        if (n <= 0) {

+                               terrno = errno;

 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("read failed %d\n", errno);
-#endif DEBUG
+                                       perror("read failed");
+#endif

                                (void) close(s);
                                s = -1;
                                (void) close(s);
                                s = -1;

+                               /*
+                                * 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;
+                                       ns--;
+                               }

                                continue;
                        }
                        cp = answer;
                                continue;
                        }
                        cp = answer;

-                       resplen = len = ntohs(*(short *)cp);
-                       while (len > 0 && (n = read(s, cp, len)) > 0) {
+                       if ((resplen = ntohs(*(u_short *)cp)) > anslen) {
+#ifdef DEBUG
+                               if (_res.options & RES_DEBUG)
+                                       fprintf(stderr,
+                                               ";; response truncated\n");
+#endif
+                               len = anslen;
+                               truncated = 1;
+                       } else
+                               len = resplen;
+                       while (len != 0 &&
+                          (n = read(s, (char *)cp, (int)len)) > 0) {

                                cp += n;
                                len -= n;
                        }
                        if (n <= 0) {
                                cp += n;
                                len -= n;
                        }
                        if (n <= 0) {

+                               terrno = errno;

 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("read failed %d\n", errno);
-#endif DEBUG
+                                       perror("read failed");
+#endif

                                (void) close(s);
                                s = -1;
                                continue;
                        }
                                (void) close(s);
                                s = -1;
                                continue;
                        }

+                       if (truncated) {
+                               /*
+                                * Flush rest of answer
+                                * so connection stays in synch.
+                                */
+                               anhp->tc = 1;
+                               len = resplen - anslen;
+                               while (len != 0) {
+                                       n = (len > sizeof(junk) ?
+                                           sizeof(junk) : len);
+                                       if ((n = read(s, junk, n)) > 0)
+                                               len -= n;
+                                       else
+                                               break;
+                               }
+                       }

                } else {
                        /*
                         * Use datagrams.
                         */
                } else {
                        /*
                         * Use datagrams.
                         */

-                       if (s < 0)
+                       if (s < 0) {

                                s = socket(AF_INET, SOCK_DGRAM, 0);
                                s = socket(AF_INET, SOCK_DGRAM, 0);

-#if    BSD >= 43
-                       if (connect(s, &_res.nsaddr_list[ns],
-                           sizeof(struct sockaddr)) < 0 ||
-                           send(s, buf, buflen, 0) != buflen) {
-#ifdef DEBUG
-                               if (_res.options & RES_DEBUG) 
-                                       printf("connect/send errno = %d\n",
-                                           errno);
-#endif DEBUG
-                               continue;
+                               if (s < 0) {
+                                       terrno = errno;
+#ifdef DEBUG
+                                       if (_res.options & RES_DEBUG)
+                                           perror("socket (dg) failed");
+#endif
+                                       continue;
+                               }

                        }
                        }

-#else BSD
-                       if (sendto(s, buf, buflen, 0, &_res.nsaddr_list[ns],
-                           sizeof(struct sockaddr)) != buflen) {
+                       /*
+                        * I'm tired of answering this question, so:
+                        * 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)) {
+                               /*
+                                * Don't use connect if we might
+                                * still receive a response
+                                * from another server.
+                                */
+                               if (connected == 0) {
+                                       if (connect(s,
+                                           (struct sockaddr *)
+                                           &_res.nsaddr_list[ns],
+                                           sizeof(struct sockaddr)) < 0) {

 #ifdef DEBUG
 #ifdef DEBUG

-                               if (_res.options & RES_DEBUG) 
-                                       printf("sendto errno = %d\n", errno);
-#endif DEBUG
-                               continue;
+                                               if (_res.options & RES_DEBUG)
+                                                       perror("connect");
+#endif
+                                               continue;
+                                       }
+                                       connected = 1;
+                               }
+                               if (send(s, buf, buflen, 0) != buflen) {
+#ifdef DEBUG
+                                       if (_res.options & RES_DEBUG)
+                                               perror("send");
+#endif
+                                       continue;
+                               }
+                       } else {
+                               /*
+                                * Disconnect if we want to listen
+                                * for responses from more than one server.
+                                */
+                               if (connected) {
+                                       (void) connect(s, &no_addr,
+                                           sizeof(no_addr));
+                                       connected = 0;
+                               }
+                               if (sendto(s, buf, buflen, 0,
+                                   (struct sockaddr *)&_res.nsaddr_list[ns],
+                                   sizeof(struct sockaddr)) != buflen) {
+#ifdef DEBUG
+                                       if (_res.options & RES_DEBUG)
+                                               perror("sendto");
+#endif
+                                       continue;
+                               }

                        }
                        }

-#endif BSD
+

                        /*
                        /*

-                        * Wait for reply 
+                        * Wait for reply

                         */
                         */

-                       timeout.tv_sec = 
-                               ((_res.retrans * _res.retry) / _res.nscount);
+                       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:
                        timeout.tv_usec = 0;
 wait:

-                       dsmask = 1 << s;
-                       n = select(s+1, &dsmask, 0, 0, &timeout);
+                       FD_ZERO(&dsmask);
+                       FD_SET(s, &dsmask);
+                       n = select(s+1, &dsmask, (fd_set *)NULL,
+                               (fd_set *)NULL, &timeout);

                        if (n < 0) {
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
                        if (n < 0) {
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("select errno = %d\n", errno);
-#endif DEBUG
+                                       perror("select");
+#endif

                                continue;
                        }
                        if (n == 0) {
                                continue;
                        }
                        if (n == 0) {


@@ -185,16 +336,16 @@ wait:
                                 */
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
                                 */
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("timeout\n");
-#endif DEBUG
+                                       printf(";; timeout\n");
+#endif

                                gotsomewhere = 1;
                                continue;
                        }
                        if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
                                gotsomewhere = 1;
                                continue;
                        }
                        if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("recvfrom, errno=%d\n", errno);
-#endif DEBUG
+                                       perror("recvfrom");
+#endif

                                continue;
                        }
                        gotsomewhere = 1;
                                continue;
                        }
                        gotsomewhere = 1;


@@ -203,52 +354,89 @@ wait:
                                 * response from old query, ignore it
                                 */
 #ifdef DEBUG
                                 * response from old query, ignore it
                                 */
 #ifdef DEBUG

-                               if (_res.options & RES_DEBUG) {
-                                       printf("old answer:\n");
-                                       p_query(answer);
+                               if ((_res.options & RES_DEBUG) ||
+                                   (_res.pfcode & RES_PRF_REPLY)) {
+                                       printf(";; old answer:\n");
+                                       __p_query(answer);

                                }
                                }

-#endif DEBUG
+#endif

                                goto wait;
                        }
                                goto wait;
                        }

+                       if (anhp->rcode == SERVFAIL || anhp->rcode == NOTIMP ||
+                           anhp->rcode == REFUSED) {
+#ifdef DEBUG
+                               if (_res.options & RES_DEBUG) {
+                                       printf("server rejected query:\n");
+                                       __p_query(answer);
+                               }
+#endif
+                               badns |= (1<<ns);
+                               continue;
+                       }

                        if (!(_res.options & RES_IGNTC) && anhp->tc) {
                                /*
                        if (!(_res.options & RES_IGNTC) && anhp->tc) {
                                /*

-                                * get rest of answer
+                                * get rest of answer;
+                                * use TCP with same server.

                                 */
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)
                                 */
 #ifdef DEBUG
                                if (_res.options & RES_DEBUG)

-                                       printf("truncated answer\n");
-#endif DEBUG
+                                       printf(";; truncated answer\n");
+#endif

                                (void) close(s);
                                s = -1;
                                (void) close(s);
                                s = -1;

-                               retry = _res.retry;

                                v_circuit = 1;
                                v_circuit = 1;

-                               continue;
+                               goto usevc;

                        }
                }
 #ifdef DEBUG
                        }
                }
 #ifdef DEBUG

-               if (_res.options & RES_DEBUG) {
-                       printf("got answer:\n");
-                       p_query(answer);
-               }
-#endif DEBUG
+               if (_res.options & RES_DEBUG)
+                       printf(";; got answer:\n");
+               if ((_res.options & RES_DEBUG) ||
+                   (_res.pfcode & RES_PRF_REPLY))
+                       __p_query(answer);
+#endif

                /*
                /*

-                * We are going to 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 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 ((_res.options & KEEPOPEN) == KEEPOPEN && ns == 0) {
-                       return (resplen);
-               } else {
+               if ((v_circuit &&
+                   ((_res.options & RES_USEVC) == 0 || ns != 0)) ||
+                   (_res.options & RES_STAYOPEN) == 0) {

                        (void) close(s);
                        s = -1;
                        (void) close(s);
                        s = -1;

-                       return (resplen);

                }
                }

+               return (resplen);

           }
        }
           }
        }

-       (void) close(s);
-       if (v_circuit == 0 && gotsomewhere == 0)
-               errno = ECONNREFUSED;
+       if (s >= 0) {
+               (void) close(s);
+               s = -1;
+       }
+       if (v_circuit == 0)
+               if (gotsomewhere == 0)
+                       errno = ECONNREFUSED;   /* no nameservers found */
+               else
+                       errno = ETIMEDOUT;      /* no answer obtained */

        else
        else

-               errno = ETIMEDOUT;
+               errno = terrno;

        return (-1);
 }
        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.
+ */
+_res_close()
+{
+       if (s != -1) {
+               (void) close(s);
+               s = -1;
+       }
+}