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/* $OpenBSD: ntp_dns.c,v 1.7 2015/01/13 02:28:56 bcook Exp $ */
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/*
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* Copyright (c) 2003-2008 Henning Brauer <henning@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
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* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
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* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/types.h>
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#include <sys/resource.h>
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#include <sys/time.h>
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#include <err.h>
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#include <errno.h>
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#include <poll.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "ntpd.h"
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volatile sig_atomic_t quit_dns = 0;
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struct imsgbuf *ibuf_dns;
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void sighdlr_dns(int);
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int dns_dispatch_imsg(void);
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void
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sighdlr_dns(int sig)
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{
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switch (sig) {
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case SIGTERM:
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case SIGINT:
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quit_dns = 1;
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break;
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}
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}
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pid_t
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ntp_dns(int pipe_ntp[2], struct ntpd_conf *nconf, struct passwd *pw)
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{
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pid_t pid;
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struct pollfd pfd[1];
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int nfds;
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switch (pid = fork()) {
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case -1:
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fatal("cannot fork");
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break;
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case 0:
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break;
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default:
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return (pid);
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}
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if (setpriority(PRIO_PROCESS, 0, 0) == -1)
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warn("could not set priority");
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/* in this case the parent didn't init logging and didn't daemonize */
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if (nconf->settime && !nconf->debug) {
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log_init(nconf->debug);
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if (setsid() == -1)
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fatal("setsid");
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}
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setproctitle("dns engine");
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close(pipe_ntp[0]);
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if (setgroups(1, &pw->pw_gid) ||
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setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
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setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
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fatal("can't drop privileges");
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signal(SIGTERM, sighdlr_dns);
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signal(SIGINT, sighdlr_dns);
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signal(SIGHUP, sighdlr_dns);
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if ((ibuf_dns = malloc(sizeof(struct imsgbuf))) == NULL)
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fatal(NULL);
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imsg_init(ibuf_dns, pipe_ntp[1]);
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while (quit_dns == 0) {
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pfd[0].fd = ibuf_dns->fd;
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pfd[0].events = POLLIN;
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if (ibuf_dns->w.queued)
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pfd[0].events |= POLLOUT;
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if ((nfds = poll(pfd, 1, INFTIM)) == -1)
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if (errno != EINTR) {
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log_warn("poll error");
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quit_dns = 1;
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}
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if (nfds > 0 && (pfd[0].revents & POLLOUT))
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if (msgbuf_write(&ibuf_dns->w) <= 0 &&
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errno != EAGAIN) {
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log_warn("pipe write error (to ntp engine)");
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quit_dns = 1;
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}
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if (nfds > 0 && pfd[0].revents & POLLIN) {
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nfds--;
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if (dns_dispatch_imsg() == -1)
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quit_dns = 1;
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}
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}
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msgbuf_clear(&ibuf_dns->w);
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free(ibuf_dns);
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_exit(0);
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}
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int
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dns_dispatch_imsg(void)
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{
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struct imsg imsg;
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int n, cnt;
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char *name;
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struct ntp_addr *h, *hn;
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struct ibuf *buf;
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if ((n = imsg_read(ibuf_dns)) == -1)
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return (-1);
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if (n == 0) { /* connection closed */
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log_warnx("dispatch_imsg in main: pipe closed");
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return (-1);
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}
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for (;;) {
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if ((n = imsg_get(ibuf_dns, &imsg)) == -1)
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return (-1);
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if (n == 0)
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break;
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switch (imsg.hdr.type) {
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case IMSG_HOST_DNS:
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name = imsg.data;
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if (imsg.hdr.len < 1 + IMSG_HEADER_SIZE)
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fatalx("invalid IMSG_HOST_DNS received");
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imsg.hdr.len -= 1 + IMSG_HEADER_SIZE;
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if (name[imsg.hdr.len] != '\0' ||
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strlen(name) != imsg.hdr.len)
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fatalx("invalid IMSG_HOST_DNS received");
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if ((cnt = host_dns(name, &hn)) == -1)
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break;
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buf = imsg_create(ibuf_dns, IMSG_HOST_DNS,
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imsg.hdr.peerid, 0,
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cnt * sizeof(struct sockaddr_storage));
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if (cnt > 0) {
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if (buf) {
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for (h = hn; h != NULL; h = h->next)
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if (imsg_add(buf, &h->ss,
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sizeof(h->ss)) == -1) {
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buf = NULL;
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break;
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}
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if (buf)
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imsg_close(ibuf_dns, buf);
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}
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host_dns_free(hn);
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hn = NULL;
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}
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break;
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default:
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break;
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}
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imsg_free(&imsg);
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}
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return (0);
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}
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