Inform unwind about DNS servers it finds in leases.

ok florian@

6 files changed, 178 insertions, 11 deletions

diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index a2cff25f53f..1e78194af2e 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhclient.c,v 1.652 2019/11/06 12:14:19 krw Exp $	*/
+/*	$OpenBSD: dhclient.c,v 1.653 2019/11/19 14:35:07 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -154,6 +154,7 @@ void write_lease_db(struct client_lease_tq *);
 void write_option_db(struct client_lease *, struct client_lease *);
 char *lease_as_string(char *, struct client_lease *);
 struct proposal *lease_as_proposal(struct client_lease *);
+struct unwind_info *lease_as_unwind_info(struct client_lease *);
 void append_statement(char *, size_t, char *, char *);
 time_t lease_expiry(struct client_lease *);
 time_t lease_renewal(struct client_lease *);
@@ -348,6 +349,11 @@ rtm_dispatch(struct interface_info *ifi, struct rt_msghdr *rtm)
 
 	switch (rtm->rtm_type) {
 	case RTM_PROPOSAL:
+		if (rtm->rtm_priority == RTP_PROPOSAL_SOLICIT) {
+			if (quit == 0 && ifi->active != NULL)
+				tell_unwind(ifi->unwind_info, RTF_UP, ifi->flags);
+			return;
+		}
 		if (rtm->rtm_index != ifi->index ||
 		    rtm->rtm_priority != RTP_PROPOSAL_DHCLIENT)
 			return;
@@ -379,10 +385,14 @@ rtm_dispatch(struct interface_info *ifi, struct rt_msghdr *rtm)
 		if ((rtm->rtm_flags & RTF_UP) == 0)
 			fatalx("down");
 
- 		if ((ifm->ifm_xflags & IFXF_AUTOCONF4) == 0)
- 			ifi->flags &= ~IFI_AUTOCONF;
-		else if ((ifi->flags & IFI_AUTOCONF) == 0) {
-			/* Get new lease when AUTOCONF4 gets set. */
+ 		if ((ifm->ifm_xflags & IFXF_AUTOCONF4) == 0 &&
+		    (ifi->flags & IFI_AUTOCONF) != 0) {
+			/* Tell unwind when IFI_AUTOCONF is cleared. */
+			tell_unwind(ifi->unwind_info, 0, ifi->flags);
+			ifi->flags &= ~IFI_AUTOCONF;
+		} else if ((ifm->ifm_xflags & IFXF_AUTOCONF4) != 0 &&
+		    (ifi->flags & IFI_AUTOCONF) == 0) {
+			/* Get new lease when IFI_AUTOCONF is set. */
 			ifi->flags |= IFI_AUTOCONF;
 			quit = RESTART;
 			break;
@@ -926,6 +936,8 @@ dhcpnak(struct interface_info *ifi, const char *src)
 	ifi->active = NULL;
 	free(ifi->configured);
 	ifi->configured = NULL;
+	free(ifi->unwind_info);
+	ifi->unwind_info = NULL;
 
 	/* Stop sending DHCPREQUEST packets. */
 	cancel_timeout(ifi);
@@ -939,6 +951,7 @@ bind_lease(struct interface_info *ifi)
 {
 	struct client_lease	*lease, *pl, *ll;
 	struct proposal		*effective_proposal = NULL;
+	struct unwind_info	*unwind_info;
 	char			*msg = NULL;
 	time_t			 cur_time, renewal;
 	int			 rslt, seen;
@@ -968,6 +981,27 @@ bind_lease(struct interface_info *ifi)
 	ifi->active = ifi->offer;
 	ifi->offer = NULL;
 
+	/*
+	 * Supply unwind with updated info.
+	 */
+	unwind_info = lease_as_unwind_info(ifi->active);
+	if (ifi->unwind_info == NULL && unwind_info != NULL) {
+		ifi->unwind_info = unwind_info;
+		tell_unwind(ifi->unwind_info, RTF_UP, ifi->flags);
+	} else if (ifi->unwind_info != NULL && unwind_info == NULL) {
+		tell_unwind(ifi->unwind_info, 0, ifi->flags);
+		free(ifi->unwind_info);
+		ifi->unwind_info = NULL;
+	} else if (ifi->unwind_info != NULL && unwind_info != NULL) {
+		if (memcmp(ifi->unwind_info, unwind_info,
+		    sizeof(*ifi->unwind_info)) != 0) {
+			tell_unwind(ifi->unwind_info, 0, ifi->flags);
+			free(ifi->unwind_info);
+			ifi->unwind_info = unwind_info;
+			tell_unwind(ifi->unwind_info, RTF_UP, ifi->flags);
+		}
+	}
+
 	effective_proposal = lease_as_proposal(lease);
 	if (ifi->configured != NULL) {
 		if (memcmp(ifi->configured, effective_proposal,
@@ -1880,6 +1914,37 @@ append_statement(char *string, size_t sz, char *s1, char *s2)
 	strlcat(string, ";\n", sz);
 }
 
+struct unwind_info *
+lease_as_unwind_info(struct client_lease *lease)
+{
+	struct unwind_info	*unwind_info;
+	struct option_data	*opt;
+	unsigned int		 servers;
+
+	unwind_info = calloc(1, sizeof(*unwind_info));
+	if (unwind_info == NULL)
+		fatal("unwind_info");
+
+	opt = &lease->options[DHO_DOMAIN_NAME_SERVERS];
+	if (opt->len != 0) {
+		servers = opt->len / sizeof(in_addr_t);
+		if (servers > MAXNS)
+			servers = MAXNS;
+		if (servers > 0) {
+			unwind_info->count = servers;
+			memcpy(unwind_info->ns, opt->data, servers *
+			    sizeof(in_addr_t));
+		}
+	}
+
+	if (unwind_info->count == 0) {
+		free(unwind_info);
+		unwind_info = NULL;
+	}
+
+	return unwind_info;
+}
+
 struct proposal *
 lease_as_proposal(struct client_lease *lease)
 {
@@ -2697,6 +2762,8 @@ release_lease(struct interface_info *ifi)
 	make_release(ifi, ifi->active);
 	send_release(ifi);
 
+	tell_unwind(ifi->unwind_info, 0, ifi->flags);
+
 	revoke_proposal(ifi->configured);
 	imsg_flush(unpriv_ibuf);
 
@@ -2713,6 +2780,8 @@ release_lease(struct interface_info *ifi)
 	ifi->active = NULL;
 	free(ifi->configured);
 	ifi->configured = NULL;
+	free(ifi->unwind_info);
+	ifi->unwind_info = NULL;
 
 	log_warnx("%s: %s RELEASED to %s", log_procname, ifabuf, destbuf);
 }
diff --git a/sbin/dhclient/dhcpd.h b/sbin/dhclient/dhcpd.h
index 8ea427236c7..3328e17b63a 100644
--- a/sbin/dhclient/dhcpd.h
+++ b/sbin/dhclient/dhcpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcpd.h,v 1.282 2019/07/30 12:48:27 krw Exp $	*/
+/*	$OpenBSD: dhcpd.h,v 1.283 2019/11/19 14:35:08 krw Exp $	*/
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -149,6 +149,7 @@ struct interface_info {
 	struct client_lease	*offer;
 	char			*offer_src;
 	struct proposal		*configured;
+	struct unwind_info	*unwind_info;
 	struct client_lease_tq	 lease_db;
 };
 
@@ -248,3 +249,5 @@ void		 write_resolv_conf(void);
 
 void		 propose(struct proposal *);
 void		 revoke_proposal(struct proposal *);
+
+void		 tell_unwind(struct unwind_info *, int, int);
diff --git a/sbin/dhclient/dispatch.c b/sbin/dhclient/dispatch.c
index 0b43f190519..93c024989ee 100644
--- a/sbin/dhclient/dispatch.c
+++ b/sbin/dhclient/dispatch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dispatch.c,v 1.165 2019/05/10 01:29:31 guenther Exp $	*/
+/*	$OpenBSD: dispatch.c,v 1.166 2019/11/19 14:35:08 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -58,6 +58,7 @@
 #include <imsg.h>
 #include <limits.h>
 #include <poll.h>
+#include <resolv.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdint.h>
@@ -93,6 +94,8 @@ dispatch(struct interface_info *ifi, int routefd)
 			time(&ifi->startup_time);
 			free(ifi->configured);
 			ifi->configured = NULL;
+			free(ifi->unwind_info);
+			ifi->unwind_info = NULL;
 			ifi->state = S_PREBOOT;
 			state_preboot(ifi);
 		}
diff --git a/sbin/dhclient/kroute.c b/sbin/dhclient/kroute.c
index fab02e06613..b77ec287b9b 100644
--- a/sbin/dhclient/kroute.c
+++ b/sbin/dhclient/kroute.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kroute.c,v 1.169 2019/11/06 11:34:37 krw Exp $	*/
+/*	$OpenBSD: kroute.c,v 1.170 2019/11/19 14:35:08 krw Exp $	*/
 
 /*
  * Copyright 2012 Kenneth R Westerback <krw@openbsd.org>
@@ -1007,3 +1007,72 @@ priv_revoke_proposal(char *name, int ioctlfd, struct imsg_revoke *imsg,
 
 	delete_address(name, ioctlfd, proposal->ifa);
 }
+
+/*
+ * [priv_]tell_unwind sends out inforation unwind may be intereted in.
+ */
+void
+tell_unwind(struct unwind_info *unwind_info, int rtm_flags, int ifi_flags)
+{
+	struct	imsg_tell_unwind	 imsg;
+	int				 rslt;
+
+	if (unwind_info == NULL ||
+	    (ifi_flags & IFI_AUTOCONF) == 0 ||
+	    (ifi_flags & IFI_IN_CHARGE) == 0)
+		return;
+
+	memset(&imsg, 0, sizeof(imsg));
+
+	imsg.rtm_flags = rtm_flags;
+	memcpy(&imsg.unwind_info, unwind_info, sizeof(imsg.unwind_info));
+
+	rslt = imsg_compose(unpriv_ibuf, IMSG_TELL_UNWIND, 0, 0, -1, &imsg,
+	    sizeof(imsg));
+	if (rslt == -1)
+		log_warn("%s: imsg_compose(IMSG_TELL_UNWIND)", log_procname);
+}
+
+void
+priv_tell_unwind(int index, int routefd, int rdomain, struct imsg_tell_unwind *imsg)
+{
+	struct rt_msghdr		 rtm;
+	struct sockaddr_rtdns		 rtdns;
+	struct iovec			 iov[3];
+	long				 pad = 0;
+	int				 iovcnt = 0, padlen;
+
+	memset(&rtm, 0, sizeof(rtm));
+
+	rtm.rtm_version = RTM_VERSION;
+	rtm.rtm_type = RTM_PROPOSAL;
+	rtm.rtm_msglen = sizeof(rtm);
+	rtm.rtm_tableid = rdomain;
+	rtm.rtm_index = index;
+	rtm.rtm_seq = arc4random();
+	rtm.rtm_priority = RTP_PROPOSAL_DHCLIENT;
+	rtm.rtm_addrs = RTA_DNS;
+	rtm.rtm_flags = imsg->rtm_flags;
+
+	iov[iovcnt].iov_base = &rtm;
+	iov[iovcnt++].iov_len = sizeof(rtm);
+
+	memset(&rtdns, 0, sizeof(rtdns));
+	rtdns.sr_family = AF_INET;
+	rtdns.sr_len = 2 + imsg->unwind_info.count * sizeof(in_addr_t);
+	memcpy(rtdns.sr_dns, imsg->unwind_info.ns, imsg->unwind_info.count *
+	    sizeof(in_addr_t));
+
+	iov[iovcnt].iov_base = &rtdns;
+	iov[iovcnt++].iov_len = sizeof(rtdns);
+	rtm.rtm_msglen += sizeof(rtdns);
+	padlen = ROUNDUP(sizeof(rtdns)) - sizeof(rtdns);
+	if (padlen > 0) {
+		iov[iovcnt].iov_base = &pad;
+		iov[iovcnt++].iov_len = padlen;
+		rtm.rtm_msglen += padlen;
+	}
+
+	if (writev(routefd, iov, iovcnt) == -1)
+		log_warn("failed to tell unwind");
+}
diff --git a/sbin/dhclient/privsep.c b/sbin/dhclient/privsep.c
index 9d22916e0e3..1a2d7250b70 100644
--- a/sbin/dhclient/privsep.c
+++ b/sbin/dhclient/privsep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: privsep.c,v 1.75 2019/02/12 16:50:44 krw Exp $ */
+/*	$OpenBSD: privsep.c,v 1.76 2019/11/19 14:35:08 krw Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -27,6 +27,7 @@
 
 #include <errno.h>
 #include <imsg.h>
+#include <resolv.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdint.h>
@@ -94,6 +95,15 @@ dispatch_imsg(char *name, int rdomain, int ioctlfd, int routefd,
 				    resolv_conf, &lastidx);
 			break;
 
+		case IMSG_TELL_UNWIND:
+			if (imsg.hdr.len != IMSG_HEADER_SIZE +
+			    sizeof(struct imsg_tell_unwind))
+				log_warnx("%s: bad IMSG_TELL_UNWIND",
+				    log_procname);
+			else
+				priv_tell_unwind(index, routefd, rdomain, imsg.data);
+			break;
+
 		default:
 			log_warnx("%s: received unknown message, code %u",
 			    log_procname, imsg.hdr.type);
diff --git a/sbin/dhclient/privsep.h b/sbin/dhclient/privsep.h
index 0ef4032f620..b2e0a74d5ee 100644
--- a/sbin/dhclient/privsep.h
+++ b/sbin/dhclient/privsep.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: privsep.h,v 1.59 2019/02/12 16:50:44 krw Exp $ */
+/*	$OpenBSD: privsep.h,v 1.60 2019/11/19 14:35:08 krw Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -20,7 +20,8 @@ enum imsg_code {
 	IMSG_NONE,
 	IMSG_REVOKE,
 	IMSG_WRITE_RESOLV_CONF,
-	IMSG_PROPOSE
+	IMSG_PROPOSE,
+	IMSG_TELL_UNWIND
 };
 
 #define	RTLEN	128
@@ -39,6 +40,11 @@ struct proposal {
 	int		inits;
 };
 
+struct unwind_info {
+	in_addr_t	ns[MAXNS];
+	unsigned int	count;
+};
+
 struct imsg_propose {
 	struct proposal		proposal;
 };
@@ -47,9 +53,16 @@ struct imsg_revoke {
 	struct proposal		proposal;
 };
 
+struct imsg_tell_unwind {
+	struct unwind_info	unwind_info;
+	uint8_t			rtm_flags;
+};
+
 void	dispatch_imsg(char *, int, int, int, struct imsgbuf *);
 
 void	priv_write_resolv_conf(int, int, int, char *, int *);
 void	priv_propose(char *, int, struct imsg_propose *, char **, int, int, int);
 
 void	priv_revoke_proposal(char *, int, struct imsg_revoke *, char **);
+
+void	priv_tell_unwind(int, int, int, struct imsg_tell_unwind *);