906 lines
20 KiB
C
Executable file
906 lines
20 KiB
C
Executable file
/*
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* Copyright (c) 1985, 1989 Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)res_send.c 6.27 (Berkeley) 2/24/91";
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#endif /* LIBC_SCCS and not lint */
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/*
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* Send query to name server and wait for reply.
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*/
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#if !_MINIX
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#include <sys/param.h>
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#include <sys/time.h>
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#include <sys/socket.h>
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#include <sys/uio.h>
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#include <netinet/in.h>
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#include <arpa/nameser.h>
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#include <stdio.h>
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#include <errno.h>
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#include <resolv.h>
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#include <unistd.h>
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#include <string.h>
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#else /* _MINIX */
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#include <sys/types.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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#include <assert.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <net/hton.h>
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#include <net/netlib.h>
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#include <net/gen/in.h>
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#include <net/gen/inet.h>
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#include <net/gen/netdb.h>
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#include <net/gen/nameser.h>
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#include <net/gen/resolv.h>
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#include <net/gen/tcp.h>
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#include <net/gen/tcp_io.h>
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#include <net/gen/udp.h>
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#include <net/gen/udp_hdr.h>
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#include <net/gen/udp_io.h>
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typedef u16_t u_short;
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static int tcp_connect _ARGS(( ipaddr_t host, Tcpport_t port, int *terrno ));
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static int tcpip_writeall _ARGS(( int fd, const char *buf, size_t siz ));
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static int udp_connect _ARGS(( void ));
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static int udp_sendto _ARGS(( int fd, const char *buf, unsigned buflen,
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ipaddr_t addr, Udpport_t port ));
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static int udp_receive _ARGS(( int fd, char *buf, unsigned buflen,
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time_t timeout ));
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static void alarm_handler _ARGS(( int sig ));
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#endif /* !_MINIX */
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static int s = -1; /* socket used for communications */
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#if !_MINIX
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static struct sockaddr no_addr;
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#ifndef FD_SET
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#define NFDBITS 32
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#define FD_SETSIZE 32
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#define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
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#define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
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#define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
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#define FD_ZERO(p) bzero((char *)(p), sizeof(*(p)))
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#endif /* FD_SET */
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#endif /* _MINIX */
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res_send(buf, buflen, answer, anslen)
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const char *buf;
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int buflen;
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char *answer;
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int anslen;
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{
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register int n;
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int try, v_circuit, resplen, ns;
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int gotsomewhere = 0, connected = 0;
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int connreset = 0;
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#if !_MINIX
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u_short id, len;
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#else /* _MINIX */
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u16_t id, len;
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#endif /* !_MINIX */
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char *cp;
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#if !_MINIX
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fd_set dsmask;
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struct timeval timeout;
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HEADER *hp = (HEADER *) buf;
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HEADER *anhp = (HEADER *) answer;
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struct iovec iov[2];
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#else /* _MINIX */
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time_t timeout;
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dns_hdr_t *hp = (dns_hdr_t *) buf;
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dns_hdr_t *anhp = (dns_hdr_t *) answer;
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#endif /* !_MINIX */
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int terrno = ETIMEDOUT;
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char junk[512];
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#ifdef DEBUG
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if (_res.options & RES_DEBUG) {
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printf("res_send()\n");
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__p_query(buf);
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}
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#endif /* DEBUG */
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if (!(_res.options & RES_INIT))
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if (res_init() == -1) {
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return(-1);
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}
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v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
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#if !_MINIX
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id = hp->id;
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#else /* _MINIX */
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id = hp->dh_id;
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#endif /* !_MINIX */
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/*
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* Send request, RETRY times, or until successful
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*/
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for (try = 0; try < _res.retry; try++) {
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for (ns = 0; ns < _res.nscount; ns++) {
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#ifdef DEBUG
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#if !_MINIX
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if (_res.options & RES_DEBUG)
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printf("Querying server (# %d) address = %s\n", ns+1,
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inet_ntoa(_res.nsaddr_list[ns].sin_addr));
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#else /* _MINIX */
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if (_res.options & RES_DEBUG)
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printf("Querying server (# %d) address = %s\n", ns+1,
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inet_ntoa(_res.nsaddr_list[ns]));
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#endif /* !_MINIX */
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#endif /* DEBUG */
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usevc:
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if (v_circuit) {
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#if !_MINIX
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int truncated = 0;
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/*
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* Use virtual circuit;
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* at most one attempt per server.
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*/
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try = _res.retry;
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if (s < 0) {
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s = socket(AF_INET, SOCK_STREAM, 0);
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if (s < 0) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("socket (vc) failed");
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#endif /* DEBUG */
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continue;
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}
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if (connect(s,
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(struct sockaddr *)&(_res.nsaddr_list[ns]),
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sizeof(struct sockaddr)) < 0) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("connect failed");
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#endif /* DEBUG */
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(void) close(s);
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s = -1;
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continue;
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}
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}
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/*
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* Send length & message
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*/
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len = htons((u_short)buflen);
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iov[0].iov_base = (caddr_t)&len;
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iov[0].iov_len = sizeof(len);
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iov[1].iov_base = (char *)buf;
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iov[1].iov_len = buflen;
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if (writev(s, iov, 2) != sizeof(len) + buflen) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("write failed");
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#endif /* DEBUG */
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(void) close(s);
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s = -1;
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continue;
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}
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/*
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* Receive length & response
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*/
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cp = answer;
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len = sizeof(short);
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while (len != 0 &&
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(n = read(s, (char *)cp, (int)len)) > 0) {
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cp += n;
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len -= n;
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}
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if (n <= 0) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("read failed");
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#endif /* DEBUG */
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(void) close(s);
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s = -1;
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/*
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* A long running process might get its TCP
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* connection reset if the remote server was
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* restarted. Requery the server instead of
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* trying a new one. When there is only one
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* server, this means that a query might work
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* instead of failing. We only allow one reset
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* per query to prevent looping.
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*/
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if (terrno == ECONNRESET && !connreset) {
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connreset = 1;
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ns--;
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}
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continue;
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}
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cp = answer;
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if ((resplen = ntohs(*(u_short *)cp)) > anslen) {
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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fprintf(stderr, "response truncated\n");
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#endif /* DEBUG */
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len = anslen;
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truncated = 1;
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} else
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len = resplen;
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while (len != 0 &&
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(n = read(s, (char *)cp, (int)len)) > 0) {
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cp += n;
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len -= n;
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}
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if (n <= 0) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("read failed");
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#endif /* DEBUG */
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(void) close(s);
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s = -1;
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continue;
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}
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if (truncated) {
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/*
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* Flush rest of answer
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* so connection stays in synch.
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*/
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anhp->tc = 1;
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len = resplen - anslen;
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while (len != 0) {
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n = (len > sizeof(junk) ?
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sizeof(junk) : len);
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if ((n = read(s, junk, n)) > 0)
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len -= n;
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else
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break;
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}
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}
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#else /* _MINIX */
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int truncated = 0;
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int nbytes;
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/*
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* Use virtual circuit;
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* at most one attempt per server.
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*/
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try = _res.retry;
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if (s < 0)
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{
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s= tcp_connect(_res.nsaddr_list[ns],
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_res.nsport_list[ns], &terrno);
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if (s == -1)
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continue;
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}
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/*
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* Send length & message
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*/
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len = htons((u_short)buflen);
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nbytes= tcpip_writeall(s, (char *)&len,
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sizeof(len));
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if (nbytes != sizeof(len))
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{
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terrno= errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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fprintf(stderr, "write failed: %s\n",
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strerror(terrno));
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#endif /* DEBUG */
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close(s);
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s= -1;
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continue;
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}
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nbytes= tcpip_writeall(s, buf, buflen);
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if (nbytes != buflen)
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{
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terrno= errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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fprintf(stderr, "write failed: %s\n",
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strerror(terrno));
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#endif /* DEBUG */
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close(s);
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s= -1;
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continue;
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}
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/*
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* Receive length & response
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*/
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cp = answer;
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len = sizeof(short);
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while (len != 0)
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{
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n = read(s, (char *)cp, (int)len);
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if (n <= 0)
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break;
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cp += n;
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assert(len >= n);
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len -= n;
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}
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if (len) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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fprintf(stderr, "read failed: %s\n",
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strerror(terrno));
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#endif /* DEBUG */
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close(s);
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s= -1;
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/*
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* A long running process might get its TCP
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* connection reset if the remote server was
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* restarted. Requery the server instead of
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* trying a new one. When there is only one
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* server, this means that a query might work
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* instead of failing. We only allow one reset
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* per query to prevent looping.
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*/
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if (terrno == ECONNRESET && !connreset) {
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connreset = 1;
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ns--;
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}
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continue;
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}
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cp = answer;
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if ((resplen = ntohs(*(u_short *)cp)) > anslen) {
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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fprintf(stderr, "response truncated\n");
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#endif /* DEBUG */
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len = anslen;
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truncated = 1;
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} else
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len = resplen;
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while (len != 0)
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{
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n= read(s, (char *)cp, (int)len);
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if (n <= 0)
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break;
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cp += n;
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assert(len >= n);
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len -= n;
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}
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if (len) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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fprintf(stderr, "read failed: %s\n",
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strerror(terrno));
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#endif /* DEBUG */
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close(s);
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s= -1;
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continue;
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}
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if (truncated) {
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/*
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* Flush rest of answer
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* so connection stays in synch.
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*/
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anhp->dh_flag1 |= DHF_TC;
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len = resplen - anslen;
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while (len != 0) {
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n = (len > sizeof(junk) ?
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sizeof(junk) : len);
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n = read(s, junk, n);
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if (n <= 0)
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{
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assert(len >= n);
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len -= n;
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}
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else
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break;
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}
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}
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#endif /* _MINIX */
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} else {
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#if !_MINIX
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/*
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* Use datagrams.
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*/
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if (s < 0) {
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s = socket(AF_INET, SOCK_DGRAM, 0);
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if (s < 0) {
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terrno = errno;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("socket (dg) failed");
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#endif /* DEBUG */
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continue;
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}
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}
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#if BSD >= 43
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/*
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* I'm tired of answering this question, so:
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* On a 4.3BSD+ machine (client and server,
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* actually), sending to a nameserver datagram
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* port with no nameserver will cause an
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* ICMP port unreachable message to be returned.
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* If our datagram socket is "connected" to the
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* server, we get an ECONNREFUSED error on the next
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* socket operation, and select returns if the
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* error message is received. We can thus detect
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* the absence of a nameserver without timing out.
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* If we have sent queries to at least two servers,
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* however, we don't want to remain connected,
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* as we wish to receive answers from the first
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* server to respond.
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*/
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if (_res.nscount == 1 || (try == 0 && ns == 0)) {
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/*
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* Don't use connect if we might
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* still receive a response
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* from another server.
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*/
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if (connected == 0) {
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if (connect(s, (struct sockaddr *)&_res.nsaddr_list[ns],
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sizeof(struct sockaddr)) < 0) {
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("connect");
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#endif /* DEBUG */
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continue;
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}
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connected = 1;
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}
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if (send(s, buf, buflen, 0) != buflen) {
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("send");
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#endif /* DEBUG */
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continue;
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}
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} else {
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/*
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* Disconnect if we want to listen
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* for responses from more than one server.
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*/
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if (connected) {
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(void) connect(s, &no_addr,
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sizeof(no_addr));
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connected = 0;
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}
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#endif /* BSD */
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if (sendto(s, buf, buflen, 0,
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(struct sockaddr *)&_res.nsaddr_list[ns],
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sizeof(struct sockaddr)) != buflen) {
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("sendto");
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#endif /* DEBUG */
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continue;
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}
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#if BSD >= 43
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}
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#endif /* BSD */
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/*
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* Wait for reply
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*/
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timeout.tv_sec = (_res.retrans << try);
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if (try > 0)
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timeout.tv_sec /= _res.nscount;
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if (timeout.tv_sec <= 0)
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timeout.tv_sec = 1;
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timeout.tv_usec = 0;
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wait:
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FD_ZERO(&dsmask);
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FD_SET(s, &dsmask);
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n = select(s+1, &dsmask, (fd_set *)NULL,
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(fd_set *)NULL, &timeout);
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if (n < 0) {
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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perror("select");
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#endif /* DEBUG */
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continue;
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}
|
|
if (n == 0) {
|
|
/*
|
|
* timeout
|
|
*/
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
printf("timeout\n");
|
|
#endif /* DEBUG */
|
|
#if BSD >= 43
|
|
gotsomewhere = 1;
|
|
#endif
|
|
continue;
|
|
}
|
|
if ((resplen = recv(s, answer, anslen, 0)) <= 0) {
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
perror("recvfrom");
|
|
#endif /* DEBUG */
|
|
continue;
|
|
}
|
|
gotsomewhere = 1;
|
|
if (id != anhp->id) {
|
|
/*
|
|
* response from old query, ignore it
|
|
*/
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG) {
|
|
printf("old answer:\n");
|
|
__p_query(answer);
|
|
}
|
|
#endif /* DEBUG */
|
|
goto wait;
|
|
}
|
|
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 /* DEBUG */
|
|
(void) close(s);
|
|
s = -1;
|
|
v_circuit = 1;
|
|
goto usevc;
|
|
}
|
|
#else /* _MINIX */
|
|
/*
|
|
* Use datagrams.
|
|
*/
|
|
if (s < 0) {
|
|
s = udp_connect();
|
|
if (s < 0) {
|
|
terrno = errno;
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
perror("udp_connect failed");
|
|
#endif /* DEBUG */
|
|
continue;
|
|
}
|
|
}
|
|
if (udp_sendto(s, buf, buflen, _res.nsaddr_list[ns],
|
|
_res.nsport_list[ns]) != buflen) {
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
perror("sendto");
|
|
#endif /* DEBUG */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Wait for reply
|
|
*/
|
|
timeout= (_res.retrans << try);
|
|
if (try > 0)
|
|
timeout /= _res.nscount;
|
|
if (timeout <= 0)
|
|
timeout= 1;
|
|
wait:
|
|
if ((resplen= udp_receive(s, answer, anslen, timeout))
|
|
== -1)
|
|
{
|
|
if (errno == EINTR)
|
|
{
|
|
/*
|
|
* timeout
|
|
*/
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
printf("timeout\n");
|
|
#endif /* DEBUG */
|
|
gotsomewhere = 1;
|
|
}
|
|
else
|
|
{
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
perror("udp_receive");
|
|
#endif /* DEBUG */
|
|
}
|
|
continue;
|
|
}
|
|
gotsomewhere = 1;
|
|
if (id != anhp->dh_id) {
|
|
/*
|
|
* response from old query, ignore it
|
|
*/
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG) {
|
|
printf("old answer:\n");
|
|
__p_query(answer);
|
|
}
|
|
#endif /* DEBUG */
|
|
goto wait;
|
|
}
|
|
if (!(_res.options & RES_IGNTC) &&
|
|
(anhp->dh_flag1 & DHF_TC)) {
|
|
/*
|
|
* get rest of answer;
|
|
* use TCP with same server.
|
|
*/
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
printf("truncated answer\n");
|
|
#endif /* DEBUG */
|
|
(void) close(s);
|
|
s = -1;
|
|
v_circuit = 1;
|
|
goto usevc;
|
|
}
|
|
#endif /* !_MINIX */
|
|
}
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG) {
|
|
printf("got answer:\n");
|
|
__p_query(answer);
|
|
}
|
|
#endif /* DEBUG */
|
|
/*
|
|
* 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.
|
|
*/
|
|
void
|
|
_res_close()
|
|
{
|
|
if (s != -1) {
|
|
(void) close(s);
|
|
s = -1;
|
|
}
|
|
}
|
|
|
|
#if _MINIX
|
|
static int tcp_connect(host, port, terrno)
|
|
ipaddr_t host;
|
|
tcpport_t port;
|
|
int *terrno;
|
|
{
|
|
char *dev_name;
|
|
int fd;
|
|
int error;
|
|
nwio_tcpconf_t tcpconf;
|
|
nwio_tcpcl_t clopt;
|
|
|
|
dev_name= getenv("TCP_DEVICE");
|
|
if (!dev_name)
|
|
dev_name= TCP_DEVICE;
|
|
fd= open(dev_name, O_RDWR);
|
|
if (fd == -1)
|
|
{
|
|
*terrno= errno;
|
|
return -1;
|
|
}
|
|
tcpconf.nwtc_flags= NWTC_EXCL | NWTC_LP_SEL | NWTC_SET_RA | NWTC_SET_RP;
|
|
tcpconf.nwtc_remaddr= host;
|
|
tcpconf.nwtc_remport= port;
|
|
error= ioctl(fd, NWIOSTCPCONF, &tcpconf);
|
|
if (error == -1)
|
|
{
|
|
*terrno= errno;
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
clopt.nwtcl_flags= 0;
|
|
error= ioctl(fd, NWIOTCPCONN, &clopt);
|
|
if (error == -1)
|
|
{
|
|
*terrno= errno;
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
*terrno= 0;
|
|
return fd;
|
|
}
|
|
|
|
static int tcpip_writeall(fd, buf, siz)
|
|
int fd;
|
|
const char *buf;
|
|
size_t siz;
|
|
{
|
|
size_t siz_org;
|
|
int nbytes;
|
|
|
|
siz_org= siz;
|
|
|
|
while (siz)
|
|
{
|
|
nbytes= write(fd, buf, siz);
|
|
if (nbytes <= 0)
|
|
return siz_org-siz;
|
|
assert(siz >= nbytes);
|
|
buf += nbytes;
|
|
siz -= nbytes;
|
|
}
|
|
return siz_org;
|
|
}
|
|
|
|
|
|
static int udp_connect()
|
|
{
|
|
nwio_udpopt_t udpopt;
|
|
char *dev_name;
|
|
int fd, r, terrno;
|
|
|
|
dev_name= getenv("UDP_DEVICE");
|
|
if (!dev_name)
|
|
dev_name= UDP_DEVICE;
|
|
fd= open(dev_name, O_RDWR);
|
|
if (fd == -1)
|
|
return -1;
|
|
|
|
udpopt.nwuo_flags= NWUO_COPY | NWUO_LP_SEL | NWUO_EN_LOC |
|
|
NWUO_EN_BROAD | NWUO_RP_ANY | NWUO_RA_ANY | NWUO_RWDATALL |
|
|
NWUO_DI_IPOPT;
|
|
r= ioctl(fd, NWIOSUDPOPT, &udpopt);
|
|
if (r == -1)
|
|
{
|
|
terrno= errno;
|
|
close(fd);
|
|
errno= terrno;
|
|
return -1;
|
|
}
|
|
return fd;
|
|
}
|
|
|
|
static int udp_sendto(fd, buf, buflen, addr, port)
|
|
int fd;
|
|
const char *buf;
|
|
unsigned buflen;
|
|
ipaddr_t addr;
|
|
udpport_t port;
|
|
{
|
|
char *newbuf;
|
|
udp_io_hdr_t *udp_io_hdr;
|
|
int r, terrno;
|
|
|
|
newbuf= malloc(sizeof(*udp_io_hdr) + buflen);
|
|
if (newbuf == NULL)
|
|
{
|
|
errno= ENOMEM;
|
|
return -1;
|
|
}
|
|
udp_io_hdr= (udp_io_hdr_t *)newbuf;
|
|
udp_io_hdr->uih_dst_addr= addr;
|
|
udp_io_hdr->uih_dst_port= port;
|
|
udp_io_hdr->uih_ip_opt_len= 0;
|
|
udp_io_hdr->uih_data_len= buflen;
|
|
|
|
memcpy(newbuf + sizeof(*udp_io_hdr), buf, buflen);
|
|
r= write(fd, newbuf, sizeof(*udp_io_hdr) + buflen);
|
|
terrno= errno;
|
|
free(newbuf);
|
|
if (r >= sizeof(*udp_io_hdr))
|
|
r -= sizeof(*udp_io_hdr);
|
|
errno= terrno;
|
|
return r;
|
|
}
|
|
|
|
static void alarm_handler(sig)
|
|
int sig;
|
|
{
|
|
signal(SIGALRM, alarm_handler);
|
|
alarm(1);
|
|
}
|
|
|
|
static int udp_receive(fd, buf, buflen, timeout)
|
|
int fd;
|
|
char *buf;
|
|
unsigned buflen;
|
|
time_t timeout;
|
|
{
|
|
char *newbuf;
|
|
udp_io_hdr_t *udp_io_hdr;
|
|
int r, terrno;
|
|
void (*u_handler) _ARGS(( int sig ));
|
|
time_t u_timeout;
|
|
|
|
newbuf= malloc(sizeof(*udp_io_hdr) + buflen);
|
|
if (newbuf == NULL)
|
|
{
|
|
errno= ENOMEM;
|
|
return -1;
|
|
}
|
|
|
|
u_handler= signal(SIGALRM, alarm_handler);
|
|
u_timeout= alarm(timeout);
|
|
|
|
r= read(fd, newbuf, sizeof(*udp_io_hdr) + buflen);
|
|
terrno= errno;
|
|
|
|
if (r < 0 || r <= sizeof(*udp_io_hdr))
|
|
{
|
|
if (r > 0)
|
|
r= 0;
|
|
free(newbuf);
|
|
|
|
|
|
alarm(0);
|
|
signal(SIGALRM, u_handler);
|
|
alarm(u_timeout);
|
|
|
|
errno= terrno;
|
|
return r;
|
|
}
|
|
|
|
memcpy(buf, newbuf + sizeof(*udp_io_hdr), r - sizeof(*udp_io_hdr));
|
|
free(newbuf);
|
|
|
|
alarm(0);
|
|
signal(SIGALRM, u_handler);
|
|
alarm(u_timeout);
|
|
|
|
return r-sizeof(*udp_io_hdr);
|
|
}
|
|
|
|
#endif
|