static int query_domain(st_netfd_t nfd, const char *name, struct in_addr *addr,
st_utime_t timeout)
{
querybuf_t qbuf;
u_char *buf = qbuf.buf;
HEADER *hp = &qbuf.hdr;
int blen = sizeof(qbuf);
int i, len, id;
for (i = 0; i < _res.nscount; i++) {
len = res_mkquery(QUERY, name, C_IN, T_A, NULL, 0, NULL, buf, blen);
if (len <= 0) {
h_errno = NO_RECOVERY;
return -1;
}
id = hp->id;
if (st_sendto(nfd, buf, len, (struct sockaddr *)&(_res.nsaddr_list[i]),
sizeof(struct sockaddr), timeout) != len) {
h_errno = NETDB_INTERNAL;
/* EINTR means interrupt by other thread, NOT by a caught signal */
if (errno == EINTR)
return -1;
continue;
}
/* Wait for reply */
do {
len = st_recvfrom(nfd, buf, blen, NULL, NULL, timeout);
if (len <= 0)
break;
} while (id != hp->id);
if (len < HFIXEDSZ) {
h_errno = NETDB_INTERNAL;
if (len >= 0)
errno = EMSGSIZE;
else if (errno == EINTR) /* see the comment above */
return -1;
continue;
}
hp->ancount = ntohs(hp->ancount);
hp->qdcount = ntohs(hp->qdcount);
if ((hp->rcode != NOERROR) || (hp->ancount == 0)) {
switch (hp->rcode) {
case NXDOMAIN:
h_errno = HOST_NOT_FOUND;
break;
case SERVFAIL:
h_errno = TRY_AGAIN;
break;
case NOERROR:
h_errno = NO_DATA;
break;
case FORMERR:
case NOTIMP:
case REFUSED:
default:
h_errno = NO_RECOVERY;
}
continue;
}
if (parse_answer(&qbuf, len, addr) == 0)
return 0;
}
return -1;
}
static int query_domain(st_netfd_t nfd, const char *name, struct in_addr *addr,
st_utime_t timeout)
{
// name="www.baidu.com";
#if 0
char *name=malloc(128);
memset(name,0,128);
strcpy(name,hostname);
LOGD("hostname [%s] name[%s]",hostname,name);
#endif
querybuf_t qbuf;
u_char *buf = qbuf.buf;
HEADER *hp = &qbuf.hdr;
int blen = sizeof(qbuf);
int i, len, id;
for (i = 0; i < _res.nscount; i++) {
len = res_mkquery(QUERY, name, C_IN, T_A, NULL, 0, NULL, buf, blen);
if (len <= 0) {
h_errno = NO_RECOVERY;
return -1;
}
id = hp->id;
if (st_sendto(nfd, buf, len, (struct sockaddr *)&(_res.nsaddr_list[i]),
sizeof(struct sockaddr), timeout) != len) {
h_errno = NETDB_INTERNAL;
/* EINTR means interrupt by other thread, NOT by a caught signal */
if (errno == EINTR)
return -1;
continue;
}
len = st_recvfrom(nfd, buf, blen, NULL, NULL, timeout);
LOGD(" st_recvfrom len[%d]",len);
return 0;
/* Wait for reply */
do {
len = st_recvfrom(nfd, buf, blen, NULL, NULL, timeout);
if (len <= 0) /*一直接收不到应答消息啊*/
{
LOGD(" st_recvfrom len[%d]",len);
break;
}
} while (id != hp->id);
if (len < HFIXEDSZ) {
h_errno = NETDB_INTERNAL;
if (len >= 0)
errno = EMSGSIZE;
else if (errno == EINTR) /* see the comment above */
return -1;
continue;
}
hp->ancount = ntohs(hp->ancount);
hp->qdcount = ntohs(hp->qdcount);
if ((hp->rcode != NOERROR) || (hp->ancount == 0)) {
switch (hp->rcode) {
case NXDOMAIN:
h_errno = HOST_NOT_FOUND;
break;
case SERVFAIL:
h_errno = TRY_AGAIN;
break;
case NOERROR: /*走这里*/
h_errno = NO_DATA;
break;
case FORMERR:
case NOTIMP:
case REFUSED:
default: /*走这里*/
h_errno = NO_RECOVERY;
}
continue;
}
if (parse_answer(&qbuf, len, addr) == 0)
{ LOGD("after parse_answer");
//free(name);//add by me for malloc
return 0;//走这里
}
}
///free(name);//add by me 20150923
return -1;
}
