delete debugging stuff.

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

#ifndef lint
static char sccsid[] = "@(#)res_send.c  4.2 (Berkeley) %G%";
#endif

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

#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <errno.h>
#include <nameser.h>
#include <resolv.h>

extern int errno;

sendquery(buf, buflen, answer, anslen)
       char *buf;
       int buflen;
       char *answer;
       int anslen;
{
       register int n;
       int s, retry, v_circuit, resplen;
       u_short id, len;
       char *cp;
       int dsmask;
       struct timeval timeout;
       HEADER *hp = (HEADER *) buf;
       HEADER *anhp = (HEADER *) answer;

       if (_res.options & RES_DEBUG) {
               printf("sendquery()\n");
               p_query(buf);
       }
       if (!(_res.options & RES_INIT)) {
               if (!res_init())
                       return (-1);
       }
       s = -1;
       v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
       id = hp->id;
       /*
        * Send request, RETRY times, or until successful
        */
       for (retry = _res.retry; --retry >= 0; ) {
               if (v_circuit) {
                       /*
                        * Use virtual circuit.
                        */
                       if (s < 0)
                               s = socket(AF_INET, SOCK_STREAM, 0);
                       if (connect(s, &_res.nsaddr, sizeof(_res.nsaddr)) < 0) {
                               if (_res.options & RES_DEBUG)
                                       printf("connect failed %d\n", errno);
                               (void) close(s);
                               s = -1;
                               continue;
                       }
                       /*
                        * Send length & message
                        */
                       len = htons(buflen);
                       if (write(s, &len, sizeof(len)) != sizeof(len) ||
                           write(s, buf, buflen) != buflen) {
                               if (_res.options & RES_DEBUG)
                                       printf("write failed %d\n", errno);
                               (void) close(s);
                               s = -1;
                               continue;
                       }
                       /*
                        * Receive length & response
                        */
                       cp = answer;
                       len = sizeof(short);
                       while (len > 0 && (n = read(s, cp, len)) > 0) {
                               cp += n;
                               len -= n;
                       }
                       if (n <= 0) {
                               if (_res.options & RES_DEBUG)
                                       printf("read failed %d\n", errno);
                               (void) close(s);
                               s = -1;
                               continue;
                       }
                       cp = answer;
                       resplen = len = ntohs(*(short *)cp);
                       while (len > 0 && (n = read(s, cp, len)) > 0) {
                               cp += n;
                               len -= n;
                       }
                       if (n <= 0) {
                               if (_res.options & RES_DEBUG)
                                       printf("read failed %d\n", errno);
                               (void) close(s);
                               s = -1;
                               continue;
                       }
               } else {
                       /*
                        * Use datagrams.
                        */
                       if (s < 0)
                               s = socket(AF_INET, SOCK_DGRAM, 0);
                       if (sendto(s, buf, buflen, 0, &_res.nsaddr,
                           sizeof(_res.nsaddr)) != buflen) {
                               if (_res.options & RES_DEBUG)
                                       printf("sendto errno = %d\n", errno);
                       }
                       /*
                        * Wait for reply 
                        */
                       timeout.tv_sec = _res.retrans;
                       timeout.tv_usec = 0;
                       dsmask = 1 << s;
                       n = select(s+1, &dsmask, 0, 0, &timeout);
                       if (n < 0) {
                               if (_res.options & RES_DEBUG)
                                       printf("select errno = %d\n", errno);
                               continue;
                       }
                       if (n == 0) {
                               /*
                                * timeout
                                */
                               if (_res.options & RES_DEBUG)
                                       printf("timeout\n");
                               continue;
                       }
                       if ((resplen = recvfrom(s, answer, anslen,
                           0, 0, 0)) <= 0) {
                               if (_res.options & RES_DEBUG)
                                       printf("recvfrom, errno=%d\n", errno);
                               continue;
                       }
                       if (id != anhp->id) {
                               /*
                                * response from old query, ignore it
                                */
                               if (_res.options & RES_DEBUG) {
                                       printf("old answer:\n");
                                       p_query(answer);
                               }
                               continue;
                       }
                       if (!(_res.options & RES_IGNTC) && anhp->tc) {
                               /*
                                * get rest of answer
                                */
                               if (_res.options & RES_DEBUG)
                                       printf("truncated answer\n");
                               (void) close(s);
                               s = -1;
                               retry = _res.retry;
                               v_circuit = 1;
                               continue;
                       }
               }
               if (_res.options & RES_DEBUG) {
                       printf("got answer:\n");
                       p_query(answer);
               }
               return (resplen);
       }
       return (-1);
}