src/libsystemd/sd-resolve/test-resolve.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2005-2008 Lennart Poettering
   7   Copyright 2014 Daniel Buch
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <arpa/inet.h>
  27 #include <stdio.h>
  28 #include <netinet/in.h>
  29 #include <arpa/nameser.h>
  30 #include <resolv.h>
  31 #include <assert.h>
  32 #include <signal.h>
  33 #include <errno.h>
  34
  35 #include "socket-util.h"
  36 #include "sd-resolve.h"
  37 #include "resolve-util.h"
  38 #include "macro.h"
  39
  40 int main(int argc, char *argv[]) {
  41         int r = 0;
  42         _cleanup_resolve_unref_ sd_resolve *resolve = NULL;
  43         _cleanup_resolve_addrinfo_free_ struct addrinfo *ai = NULL;
  44         _cleanup_free_ unsigned char *srv = NULL;
  45         _cleanup_free_ char *host = NULL, *serv = NULL;
  46         sd_resolve_query *q1 = NULL, *q2 = NULL, *q3 = NULL;
  47
  48         struct addrinfo hints = {
  49                 .ai_family = PF_UNSPEC,
  50                 .ai_socktype = SOCK_STREAM,
  51                 .ai_flags = AI_CANONNAME
  52         };
  53
  54         struct sockaddr_in sa = {
  55                 .sin_family = AF_INET,
  56                 .sin_port = htons(80)
  57         };
  58
  59         assert_se(sd_resolve_new(&resolve) >= 0);
  60
  61         /* Make a name -> address query */
  62         r = sd_resolve_getaddrinfo(resolve, &q1, argc >= 2 ? argv[1] : "www.heise.de", NULL, &hints);
  63         if (r < 0)
  64                 log_error("sd_resolve_getaddrinfo(): %s\n", strerror(-r));
  65
  66         /* Make an address -> name query */
  67         sa.sin_addr.s_addr = inet_addr(argc >= 3 ? argv[2] : "193.99.144.71"),
  68         r = sd_resolve_getnameinfo(resolve, &q2, (struct sockaddr*) &sa, sizeof(sa), 0, true, true);
  69         if (r < 0)
  70                 log_error("sd_resolve_getnameinfo(): %s\n", strerror(-r));
  71
  72         /* Make a res_query() call */
  73         r = sd_resolve_res_query(resolve, &q3, "_xmpp-client._tcp.gmail.com", C_IN, T_SRV);
  74         if (r < 0)
  75                 log_error("sd_resolve_res_query(): %s\n", strerror(-r));
  76
  77         /* Wait until the three queries are completed */
  78         while (sd_resolve_is_done(q1) == 0 ||
  79                sd_resolve_is_done(q2) == 0 ||
  80                sd_resolve_is_done(q3) == 0) {
  81
  82                 r = sd_resolve_wait(resolve, (uint64_t) -1);
  83                 if (r < 0) {
  84                         log_error("sd_resolve_wait(): %s\n", strerror(-r));
  85                         assert_not_reached("sd_resolve_wait() failed");
  86                 }
  87         }
  88
  89         /* Interpret the result of the name -> addr query */
  90         r = sd_resolve_getaddrinfo_done(q1, &ai);
  91         if (r != 0)
  92                 log_error("error: %s %i\n", gai_strerror(r), r);
  93         else {
  94                 struct addrinfo *i;
  95
  96                 for (i = ai; i; i = i->ai_next) {
  97                         _cleanup_free_ char *addr = NULL;
  98
  99                         assert_se(sockaddr_pretty(i->ai_addr, i->ai_addrlen, false, &addr) == 0);
 100
 101                         puts(addr);
 102                 }
 103
 104                 printf("canonical name: %s\n", strna(ai->ai_canonname));
 105         }
 106
 107         /* Interpret the result of the addr -> name query */
 108         r = sd_resolve_getnameinfo_done(q2, &host, &serv);
 109         if (r)
 110                 log_error("error: %s %i\n", gai_strerror(r), r);
 111         else
 112                 printf("Host: %s -- Serv: %s\n", host, serv);
 113
 114         /* Interpret the result of the SRV lookup */
 115         r = sd_resolve_res_done(q3, &srv);
 116         if (r < 0)
 117                 log_error("error: %s %i\n", strerror(-r), r);
 118         else if (r == 0)
 119                 log_error("No reply for SRV lookup\n");
 120         else {
 121                 int qdcount, ancount, len;
 122                 const unsigned char *pos = srv + sizeof(HEADER);
 123                 unsigned char *end = srv + r;
 124                 HEADER *head = (HEADER *)srv;
 125                 char name[256];
 126
 127                 qdcount = ntohs(head->qdcount);
 128                 ancount = ntohs(head->ancount);
 129
 130                 printf("%d answers for srv lookup:\n", ancount);
 131
 132                 /* Ignore the questions */
 133                 while (qdcount-- > 0 && (len = dn_expand(srv, end, pos, name, 255)) >= 0) {
 134                         assert(len >= 0);
 135                         pos += len + QFIXEDSZ;
 136                 }
 137
 138                 /* Parse the answers */
 139                 while (ancount-- > 0 && (len = dn_expand(srv, end, pos, name, 255)) >= 0) {
 140                         /* Ignore the initial string */
 141                         uint16_t pref, weight, port;
 142                         assert(len >= 0);
 143                         pos += len;
 144                         /* Ignore type, ttl, class and dlen */
 145                         pos += 10;
 146
 147                         GETSHORT(pref, pos);
 148                         GETSHORT(weight, pos);
 149                         GETSHORT(port, pos);
 150                         len = dn_expand(srv, end, pos, name, 255);
 151                         printf("\tpreference: %2d weight: %2d port: %d host: %s\n",
 152                                         pref, weight, port, name);
 153
 154                         pos += len;
 155                 }
 156         }
 157
 158         return 0;
 159 }