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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2005-2008 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <assert.h>
#include <signal.h>
#include <errno.h>
#include "sd-resolv.h"
#include "resolv-util.h"
#include "macro.h"
int main(int argc, char *argv[]) {
int r = 1, ret;
_cleanup_resolv_free_ sd_resolv_t *asyncns = NULL;
_cleanup_resolv_addrinfo_free_ struct addrinfo *ai = NULL;
_cleanup_resolv_answer_free_ unsigned char *srv = NULL;
sd_resolv_query_t *q1, *q2, *q3;
struct addrinfo hints = {};
struct sockaddr_in sa = {};
char host[NI_MAXHOST] = "", serv[NI_MAXSERV] = "";
signal(SIGCHLD, SIG_IGN);
asyncns = sd_resolv_new(2);
if (!asyncns)
log_oom();
/* Make a name -> address query */
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
q1 = sd_resolv_getaddrinfo(asyncns, argc >= 2 ? argv[1] : "www.heise.de", NULL, &hints);
if (!q1)
fprintf(stderr, "sd_resolv_getaddrinfo(): %s\n", strerror(errno));
/* Make an address -> name query */
sa.sin_family = AF_INET;
sa.sin_addr.s_addr = inet_addr(argc >= 3 ? argv[2] : "193.99.144.71");
sa.sin_port = htons(80);
q2 = sd_resolv_getnameinfo(asyncns, (struct sockaddr*) &sa, sizeof(sa), 0, 1, 1);
if (!q2)
fprintf(stderr, "sd_resolv_getnameinfo(): %s\n", strerror(errno));
/* Make a res_query() call */
q3 = sd_resolv_res_query(asyncns, "_xmpp-client._tcp.gmail.com", C_IN, T_SRV);
if (!q3)
fprintf(stderr, "sd_resolv_res_query(): %s\n", strerror(errno));
/* Wait until the three queries are completed */
while (!sd_resolv_isdone(asyncns, q1) ||
!sd_resolv_isdone(asyncns, q2) ||
!sd_resolv_isdone(asyncns, q3)) {
if (sd_resolv_wait(asyncns, 1) < 0)
fprintf(stderr, "sd_resolv_wait(): %s\n", strerror(errno));
}
/* Interpret the result of the name -> addr query */
ret = sd_resolv_getaddrinfo_done(asyncns, q1, &ai);
if (ret)
fprintf(stderr, "error: %s %i\n", gai_strerror(ret), ret);
else {
struct addrinfo *i;
for (i = ai; i; i = i->ai_next) {
char t[256];
const char *p = NULL;
if (i->ai_family == PF_INET)
p = inet_ntop(AF_INET, &((struct sockaddr_in*) i->ai_addr)->sin_addr, t, sizeof(t));
else if (i->ai_family == PF_INET6)
p = inet_ntop(AF_INET6, &((struct sockaddr_in6*) i->ai_addr)->sin6_addr, t, sizeof(t));
printf("%s\n", p);
}
}
/* Interpret the result of the addr -> name query */
ret = sd_resolv_getnameinfo_done(asyncns, q2, host, sizeof(host), serv, sizeof(serv));
if (ret)
fprintf(stderr, "error: %s %i\n", gai_strerror(ret), ret);
else
printf("%s -- %s\n", host, serv);
/* Interpret the result of the SRV lookup */
ret = sd_resolv_res_done(asyncns, q3, &srv);
if (ret < 0) {
fprintf(stderr, "error: %s %i\n", strerror(errno), ret);
} else if (ret == 0) {
fprintf(stderr, "No reply for SRV lookup\n");
} else {
int qdcount;
int ancount;
int len;
const unsigned char *pos = srv + sizeof(HEADER);
unsigned char *end = srv + ret;
HEADER *head = (HEADER *)srv;
char name[256];
qdcount = ntohs(head->qdcount);
ancount = ntohs(head->ancount);
printf("%d answers for srv lookup:\n", ancount);
/* Ignore the questions */
while (qdcount-- > 0 && (len = dn_expand(srv, end, pos, name, 255)) >= 0) {
assert(len >= 0);
pos += len + QFIXEDSZ;
}
/* Parse the answers */
while (ancount-- > 0 && (len = dn_expand(srv, end, pos, name, 255)) >= 0) {
/* Ignore the initial string */
uint16_t pref, weight, port;
assert(len >= 0);
pos += len;
/* Ignore type, ttl, class and dlen */
pos += 10;
GETSHORT(pref, pos);
GETSHORT(weight, pos);
GETSHORT(port, pos);
len = dn_expand(srv, end, pos, name, 255);
printf("\tpreference: %2d weight: %2d port: %d host: %s\n",
pref, weight, port, name);
pos += len;
}
}
r = 0;
return r;
}
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