diff options
Diffstat (limited to 'usr.sbin/nslookup/send.c')
| -rw-r--r-- | usr.sbin/nslookup/send.c | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/usr.sbin/nslookup/send.c b/usr.sbin/nslookup/send.c new file mode 100644 index 0000000..e895bfa --- /dev/null +++ b/usr.sbin/nslookup/send.c @@ -0,0 +1,412 @@ +/* + * ++Copyright++ 1985, 1989 + * - + * Copyright (c) 1985, 1989 + * 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-- + */ + +#ifndef lint +static char sccsid[] = "@(#)send.c 5.18 (Berkeley) 3/2/91"; +static char rcsid[] = "$Id: send.c,v 4.9.1.5 1994/06/06 09:08:43 vixie Exp $"; +#endif /* not lint */ + +/* + ****************************************************************************** + * + * send.c -- + * + * Routine to send request packets to a name server. + * + * Based on "@(#)res_send.c 6.25 (Berkeley) 6/1/90". + * + ****************************************************************************** + */ + + +/* + * 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 <stdio.h> +#include <errno.h> +#include <arpa/nameser.h> +#include <arpa/inet.h> +#include <resolv.h> +#include "res.h" +#include "../../conf/portability.h" + +static int s = -1; /* socket used for communications */ + + +#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 + + + +unsigned short nsport = NAMESERVER_PORT; + + + +/* + ****************************************************************************** + * + * SendRequest -- + * + * Sends a request packet to a name server whose address + * is specified by the first argument and returns with + * the answer packet. + * + * Results: + * SUCCESS - the request was sent and an answer + * was received. + * TIME_OUT - the virtual circuit connection timed-out + * or a reply to a datagram wasn't received. + * + * + ****************************************************************************** + */ + +int +SendRequest(nsAddrPtr, buf, buflen, answer, anslen, trueLenPtr) + struct in_addr *nsAddrPtr; + char *buf; + int buflen; + char *answer; + u_int anslen; + int *trueLenPtr; +{ + register int n; + int try, v_circuit, resplen; + 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; + struct iovec iov[2]; + int terrno = ETIMEDOUT; + char junk[512]; + struct sockaddr_in sin; + + if (_res.options & RES_DEBUG2) { + printf("------------\nSendRequest(), len %d\n", buflen); + Print_query(buf, buf+buflen, 1); + } + sin.sin_family = AF_INET; + sin.sin_port = htons(nsport); + sin.sin_addr = *nsAddrPtr; + v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ; + id = hp->id; + /* + * Send request, RETRY times, or until successful + */ + for (try = 0; try < _res.retry; try++) { + 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; + if (_res.options & RES_DEBUG) + perror("socket (vc) failed"); + continue; + } + if (connect(s, (struct sockaddr *)&sin, + sizeof(struct sockaddr)) < 0) { + terrno = errno; + if (_res.options & RES_DEBUG) + perror("connect failed"); + (void) close(s); + s = -1; + continue; + } + } + /* + * Send length & message + */ + __putshort(buflen, (u_char *)&len); + iov[0].iov_base = (caddr_t)&len; + iov[0].iov_len = INT16SZ; + iov[1].iov_base = buf; + iov[1].iov_len = buflen; + if (writev(s, iov, 2) != INT16SZ + buflen) { + terrno = errno; + if (_res.options & RES_DEBUG) + perror("write failed"); + (void) close(s); + s = -1; + continue; + } + /* + * Receive length & response + */ + cp = answer; + len = INT16SZ; + while ((n = read(s, (char *)cp, (int)len)) > 0) { + cp += n; + if ((len -= n) <= 0) + break; + } + if (n <= 0) { + terrno = errno; + if (_res.options & RES_DEBUG) + perror("read failed"); + (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; + } + continue; + } + cp = answer; + if ((resplen = _getshort((u_char*)cp)) > anslen) { + if (_res.options & RES_DEBUG) + fprintf(stderr, "response truncated\n"); + 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; + if (_res.options & RES_DEBUG) + perror("read failed"); + (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; + if (_res.options & RES_DEBUG) + perror("socket (dg) failed"); + continue; + } + } +#if BSD >= 43 + if (connected == 0) { + if (connect(s, (struct sockaddr *)&sin, + sizeof(struct sockaddr)) < 0) { + if (_res.options & RES_DEBUG) + perror("connect"); + continue; + } + connected = 1; + } + if (send(s, buf, buflen, 0) != buflen) { + if (_res.options & RES_DEBUG) + perror("send"); + continue; + } +#else /* BSD */ + if (sendto(s, buf, buflen, 0, + (struct sockaddr *) &sin, + sizeof(sin)) != buflen) { + if (_res.options & RES_DEBUG) + perror("sendto"); + continue; + } +#endif + + /* + * Wait for reply + */ + timeout.tv_sec = (_res.retrans << try); + if (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) { + if (_res.options & RES_DEBUG) + perror("select"); + continue; + } + if (n == 0) { + /* + * timeout + */ + if (_res.options & RES_DEBUG) + printf("timeout (%d secs)\n", + timeout.tv_sec); +#if BSD >= 43 + gotsomewhere = 1; +#endif + continue; + } + if ((resplen = recv(s, answer, anslen, 0)) <= 0) { + if (_res.options & RES_DEBUG) + perror("recvfrom"); + continue; + } + gotsomewhere = 1; + if (id != anhp->id) { + /* + * response from old query, ignore it + */ + if (_res.options & RES_DEBUG2) { + printf("------------\nOld answer:\n"); + Print_query(answer, answer+resplen, 1); + } + goto wait; + } + if (!(_res.options & RES_IGNTC) && anhp->tc) { + /* + * get rest of answer; + * use TCP with same server. + */ + if (_res.options & RES_DEBUG) + printf("truncated answer\n"); + (void) close(s); + s = -1; + v_circuit = 1; + goto usevc; + } + } + if (_res.options & RES_DEBUG) { + if (_res.options & RES_DEBUG2) + printf("------------\nGot answer (%d bytes):\n", + resplen); + else + printf("------------\nGot answer:\n"); + Print_query(answer, answer+resplen, 1); + } + (void) close(s); + s = -1; + *trueLenPtr = resplen; + return (SUCCESS); + } + if (s >= 0) { + (void) close(s); + s = -1; + } + if (v_circuit == 0) + if (gotsomewhere == 0) + return NO_RESPONSE; /* no nameservers found */ + else + return TIME_OUT; /* no answer obtained */ + else + if (errno == ECONNREFUSED) + return NO_RESPONSE; + else + return ERROR; +} + +/* + * This routine is for closing the socket if a virtual circuit is used and + * the program wants to close it. + * + * Called from the interrupt handler. + */ +SendRequest_close() +{ + if (s != -1) { + (void) close(s); + s = -1; + } +} |
