BSD 4.4 Lite Lib Sources

1 files changed, 468 insertions, 0 deletions

diff --git a/lib/libc/net/res_send.c b/lib/libc/net/res_send.c
new file mode 100644
index 0000000..5c80cf4
--- /dev/null
+++ b/lib/libc/net/res_send.c
@@ -0,0 +1,468 @@
+/*-
+ * Copyright (c) 1985, 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * -
+ * Portions Copyright (c) 1993 by Digital Equipment Corporation.
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies, and that
+ * the name of Digital Equipment Corporation not be used in advertising or
+ * publicity pertaining to distribution of the document or software without
+ * specific, written prior permission.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
+ * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ * -
+ * --Copyright--
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)res_send.c	8.1 (Berkeley) 6/4/93";
+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.
+ */
+
+#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 <stdio.h>
+#include <errno.h>
+#include <resolv.h>
+#include <unistd.h>
+#include <string.h>
+
+static int s = -1;	/* socket used for communications */
+static struct sockaddr no_addr;
+
+#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)
+	const char *buf;
+	int buflen;
+	char *answer;
+	int anslen;
+{
+	register int n;
+	int try, v_circuit, resplen, ns;
+	int gotsomewhere = 0, connected = 0;
+	int connreset = 0;
+	u_short id, len;
+	char *cp;
+	fd_set dsmask;
+	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
+	if ((_res.options & RES_DEBUG) || (_res.pfcode & RES_PRF_QUERY)) {
+		printf(";; res_send()\n");
+		__p_query(buf);
+	}
+#endif
+	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
+	 */
+	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)
+			printf(";; Querying server (# %d) address = %s\n",
+			       ns+1,
+			       inet_ntoa(_res.nsaddr_list[ns].sin_addr));
+#endif
+	usevc:
+		if (v_circuit) {
+			int truncated = 0;
+
+			/*
+			 * 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) {
+					terrno = errno;
+#ifdef DEBUG
+					if (_res.options & RES_DEBUG)
+					    perror("socket (vc) failed");
+#endif
+					continue;
+				}
+				if (connect(s,
+				    (struct sockaddr *)&(_res.nsaddr_list[ns]),
+				    sizeof(struct sockaddr)) < 0) {
+					terrno = errno;
+#ifdef DEBUG
+					if (_res.options & RES_DEBUG)
+					    perror("connect failed");
+#endif
+					(void) close(s);
+					s = -1;
+					continue;
+				}
+			}
+			/*
+			 * Send length & message
+			 */
+			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)
+					perror("write failed");
+#endif
+				(void) close(s);
+				s = -1;
+				continue;
+			}
+			/*
+			 * Receive length & response
+			 */
+			cp = answer;
+			len = sizeof(short);
+			while (len != 0 &&
+			    (n = read(s, (char *)cp, (int)len)) > 0) {
+				cp += n;
+				len -= n;
+			}
+			if (n <= 0) {
+				terrno = errno;
+#ifdef DEBUG
+				if (_res.options & RES_DEBUG)
+					perror("read failed");
+#endif
+				(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;
+			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) {
+				terrno = errno;
+#ifdef DEBUG
+				if (_res.options & RES_DEBUG)
+					perror("read failed");
+#endif
+				(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.
+			 */
+			if (s < 0) {
+				s = socket(AF_INET, SOCK_DGRAM, 0);
+				if (s < 0) {
+					terrno = errno;
+#ifdef DEBUG
+					if (_res.options & RES_DEBUG)
+					    perror("socket (dg) failed");
+#endif
+					continue;
+				}
+			}
+			/*
+			 * 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
+						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;
+				}
+			}
+
+			/*
+			 * 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:
+			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)
+					perror("select");
+#endif
+				continue;
+			}
+			if (n == 0) {
+				/*
+				 * timeout
+				 */
+#ifdef DEBUG
+				if (_res.options & RES_DEBUG)
+					printf(";; timeout\n");
+#endif
+				gotsomewhere = 1;
+				continue;
+			}
+			if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
+#ifdef DEBUG
+				if (_res.options & RES_DEBUG)
+					perror("recvfrom");
+#endif
+				continue;
+			}
+			gotsomewhere = 1;
+			if (id != anhp->id) {
+				/*
+				 * response from old query, ignore it
+				 */
+#ifdef DEBUG
+				if ((_res.options & RES_DEBUG) ||
+				    (_res.pfcode & RES_PRF_REPLY)) {
+					printf(";; old answer:\n");
+					__p_query(answer);
+				}
+#endif
+				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) {
+				/*
+				 * get rest of answer;
+				 * use TCP with same server.
+				 */
+#ifdef DEBUG
+				if (_res.options & RES_DEBUG)
+					printf(";; truncated answer\n");
+#endif
+				(void) close(s);
+				s = -1;
+				v_circuit = 1;
+				goto usevc;
+			}
+		}
+#ifdef DEBUG
+		if (_res.options & RES_DEBUG)
+			printf(";; got answer:\n");
+		if ((_res.options & RES_DEBUG) ||
+		    (_res.pfcode & RES_PRF_REPLY))
+			__p_query(answer);
+#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) == 0 || ns != 0)) ||
+		    (_res.options & RES_STAYOPEN) == 0) {
+			(void) close(s);
+			s = -1;
+		}
+		return (resplen);
+	   }
+	}
+	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
+		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.
+ */
+_res_close()
+{
+	if (s != -1) {
+		(void) close(s);
+		s = -1;
+	}
+}