/* $Id: ex-rdns.c,v 1.8 2007/01/07 22:46:47 mjt Exp $ parallel rDNS resolver example - read IP addresses from stdin, write domain names to stdout Copyright (C) 2005 Michael Tokarev This file is part of UDNS library, an async DNS stub resolver. This library 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. This library 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 this library, in file named COPYING.LGPL; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include #include #include #include "udns.h" static int curq; static const char *n2ip(const unsigned char *c) { static char b[sizeof("255.255.255.255")]; sprintf(b, "%u.%u.%u.%u", c[0], c[1], c[2], c[3]); return b; } static void dnscb(struct dns_ctx *ctx, struct dns_rr_ptr *rr, void *data) { const char *ip = n2ip((unsigned char *)&data); int i; --curq; if (rr) { printf("%s", ip); for(i = 0; i < rr->dnsptr_nrr; ++i) printf(" %s", rr->dnsptr_ptr[i]); putchar('\n'); free(rr); } else fprintf(stderr, "%s: %s\n", ip, dns_strerror(dns_status(ctx))); } int main(int argc, char **argv) { int c, t; time_t now; int maxq = 10; struct pollfd pfd; char linebuf[1024]; char *eol; int eof; if (dns_init(NULL, 1) < 0) { fprintf(stderr, "unable to initialize dns library\n"); return 1; } while((c = getopt(argc, argv, "m:r")) != EOF) switch(c) { case 'm': maxq = atoi(optarg); break; case 'r': dns_set_opt(0, DNS_OPT_FLAGS, dns_set_opt(0, DNS_OPT_FLAGS, -1) | DNS_NORD); break; default: return 1; } if (argc != optind) return 1; pfd.fd = dns_sock(0); pfd.events = POLLIN; now = time(NULL); c = optind; eof = 0; while(curq || !eof) { if (!eof && curq < maxq) { union { struct in_addr a; void *p; } pa; if (!fgets(linebuf, sizeof(linebuf), stdin)) { eof = 1; continue; } eol = strchr(linebuf, '\n'); if (eol) *eol = '\0'; if (!linebuf[0]) continue; if (dns_pton(AF_INET, linebuf, &pa.a) <= 0) fprintf(stderr, "%s: invalid address\n", linebuf); else if (dns_submit_a4ptr(0, &pa.a, dnscb, pa.p) == 0) fprintf(stderr, "%s: unable to submit query: %s\n", linebuf, dns_strerror(dns_status(0))); else ++curq; continue; } if (curq) { t = dns_timeouts(0, -1, now); t = poll(&pfd, 1, c * 1000); now = time(NULL); if (t) dns_ioevent(0, now); } } return 0; }