Index: dns.c
===================================================================
--- dns.c	(revision cd7b81d00d1c21d57d2116b0632deb5a69c27ccc)
+++ dns.c	(revision cd7b81d00d1c21d57d2116b0632deb5a69c27ccc)
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2009 Michael Shalayeff
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef lint
+static const char rcsid[] = "$ABSD: dns.c,v 1.2 2010/01/03 01:30:00 kmerz Exp $";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <sysexits.h>
+#include <login_cap.h>
+#include <event.h>
+#include <pwd.h>
+#include <netdb.h>
+
+#include "icb.h"
+#include "icbd.h"
+
+void dns_dispatch(int, short, void *);
+int dns_pipe;
+
+int
+icbd_dns_init(void)
+{
+	struct event	ev;
+	int		pipe[2];
+	struct passwd	*pw;
+
+	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1) {
+		syslog(LOG_ERR, "socketpair: %m");
+		exit(EX_OSERR);
+	}
+
+	switch (fork()) {
+	case -1:
+		syslog(LOG_ERR, "fork: %m");
+		exit(EX_OSERR);
+	case 0:
+		break;
+
+	default:
+		close(pipe[1]);
+		dns_pipe = pipe[0];
+		return (0);
+	}
+
+	setproctitle("dns resolver");
+	close(pipe[0]);
+
+	if ((pw = getpwnam(ICBD_USER)) == NULL) {
+		syslog(LOG_ERR, "No passwd entry for %s", ICBD_USER);
+		exit(EX_NOUSER);
+	}
+	if (setusercontext(NULL, pw, pw->pw_uid,
+	    LOGIN_SETALL & ~LOGIN_SETUSER) < 0) {
+		syslog(LOG_ERR, "%s:%m", pw->pw_name);
+		exit(EX_NOPERM);
+	}
+	if (setuid(pw->pw_uid) < 0) {
+		syslog(LOG_ERR, "%d:%m", pw->pw_uid);
+		exit(EX_NOPERM);
+	}
+	if (chdir("/") < 0) {
+		syslog(LOG_ERR, "chdir: %m");
+		exit(EX_UNAVAILABLE);
+	}
+
+	event_init();
+
+	event_set(&ev, pipe[1], EV_READ | EV_PERSIST, dns_dispatch, NULL);
+	if (event_add(&ev, NULL) < 0) {
+		syslog(LOG_ERR, "event_add: %m");
+		exit (EX_UNAVAILABLE);
+	}
+
+	return event_dispatch();
+}
+
+void
+dns_dispatch(int fd, short event, void *arg)
+{
+	char host[NI_MAXHOST];
+	struct sockaddr_storage ss;
+	struct sockaddr *sa = (struct sockaddr *)&ss;
+	int gerr, ss_len = sizeof ss;
+
+	arg = NULL;
+	if (event != EV_READ)
+		return;
+
+	if (verbose)
+		syslog(LOG_DEBUG, "dns_dispatch");
+
+	if (read(fd, &ss, ss_len) != ss_len) {
+		syslog(LOG_ERR, "dns read: %m");
+		exit(1);
+	}
+
+	if ((gerr = getnameinfo(sa, sa->sa_len,
+	    host, sizeof host, NULL, 0, NI_NOFQDN))) {
+		syslog(LOG_ERR, "getnameinfo: %s", gai_strerror(gerr));
+		write(fd, host, sizeof host);
+		return;
+	}
+
+	if (verbose)
+		syslog(LOG_DEBUG, "dns_dispatch: resolved %s", host);
+
+	if (write(fd, host, sizeof host) != sizeof host)
+		syslog(LOG_ERR, "dns write: %m");
+}
+
+int
+dns_rresolv(struct icb_session *is, struct sockaddr_storage *ss)
+{
+	/* one-shot event for the reply */
+	event_set(&is->ev, dns_pipe, EV_READ, icbd_dns, is);
+	if (event_add(&is->ev, NULL) < 0) {
+		syslog(LOG_ERR, "event_add: %m");
+		exit (EX_UNAVAILABLE);
+	}
+
+	inet_ntop(ss->ss_family, ss->ss_family == AF_INET ?
+	    (void *)&((struct sockaddr_in *)ss)->sin_addr :
+	    (void *)&((struct sockaddr_in6 *)ss)->sin6_addr,
+	    is->host, sizeof is->host);
+
+	if (verbose)
+		syslog(LOG_DEBUG, "resolving: %s", is->host);
+
+	if (write(dns_pipe, ss, sizeof *ss) != sizeof *ss) {
+		syslog(LOG_ERR, "write: %m");
+		exit (EX_OSERR);
+	}
+
+	return 0;
+}
