handle "tunnels" without a destination address

this is used for mgre, which has a local address but dynamically
addresses other endpoints based on routing information.

"tunneladdr" takes a single address (where "tunnel" takes two) and
sets the destination address in the ioctl to an AF_UNSPEC destination.

tunnel status is changed so it recognises this and only outputs the
local address if the destination is AF_UNSPEC. the tunnel status
is also changed so it can tell the difference between tunnels being
unsupported on the interface (ie, ENOTTY comes back) or if there's
just no address configured yet (EADDRNOTAVAIL), which allows the
other tunnel params like ttl and df to be shown.

tested with and without -DSMALL

1 files changed, 92 insertions, 22 deletions

diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
index 5b041e08021..993a1ed32c8 100644
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ifconfig.c,v 1.361 2018/02/23 05:17:39 akoshibe Exp $	*/
+/*	$OpenBSD: ifconfig.c,v 1.362 2018/02/27 22:32:26 dlg Exp $	*/
 /*	$NetBSD: ifconfig.c,v 1.40 1997/10/01 02:19:43 enami Exp $	*/
 
 /*
@@ -200,6 +200,7 @@ void	unsetifnwflag(const char *, int);
 void	setifnetmask(const char *, int);
 void	setifprefixlen(const char *, int);
 void	settunnel(const char *, const char *);
+void	settunneladdr(const char *, int);
 void	deletetunnel(const char *, int);
 void	settunnelinst(const char *, int);
 void	settunnelttl(const char *, int);
@@ -453,6 +454,7 @@ const struct	cmd {
 	{ "defer",	1,		0,		setpfsync_defer },
 	{ "-defer",	0,		0,		setpfsync_defer },
 	{ "tunnel",	NEXTARG2,	0,		NULL, settunnel },
+	{ "tunneladdr",	NEXTARG,	0,		settunneladdr },
 	{ "-tunnel",	0,		0,		deletetunnel },
 	/* deletetunnel is for backward compat, remove during 6.4-current */
 	{ "deletetunnel",  0,		0,		deletetunnel },
@@ -2736,42 +2738,76 @@ print_media_word(uint64_t ifmw, int print_type, int as_syntax)
 		printf(" instance %lld", IFM_INST(ifmw));
 }
 
-/* ARGSUSED */
 static void
-phys_status(int force)
+print_tunnel(const struct if_laddrreq *req)
 {
 	char psrcaddr[NI_MAXHOST];
 	char pdstaddr[NI_MAXHOST];
 	const char *ver = "";
 	const int niflag = NI_NUMERICHOST;
-	struct if_laddrreq req;
-	in_port_t dstport = 0;
+
+	if (req == NULL) {
+		printf("(unset)");
+		return;
+	}
 
 	psrcaddr[0] = pdstaddr[0] = '\0';
 
-	memset(&req, 0, sizeof(req));
-	(void) strlcpy(req.iflr_name, name, sizeof(req.iflr_name));
-	if (ioctl(s, SIOCGLIFPHYADDR, (caddr_t)&req) < 0)
-		return;
-	if (getnameinfo((struct sockaddr *)&req.addr, req.addr.ss_len,
+	if (getnameinfo((struct sockaddr *)&req->addr, req->addr.ss_len,
 	    psrcaddr, sizeof(psrcaddr), 0, 0, niflag) != 0)
 		strlcpy(psrcaddr, "<error>", sizeof(psrcaddr));
-	if (req.addr.ss_family == AF_INET6)
+	if (req->addr.ss_family == AF_INET6)
 		ver = "6";
 
-	if (req.dstaddr.ss_family == AF_INET)
-		dstport = ((struct sockaddr_in *)&req.dstaddr)->sin_port;
-	else if (req.dstaddr.ss_family == AF_INET6)
-		dstport = ((struct sockaddr_in6 *)&req.dstaddr)->sin6_port;
-	if (getnameinfo((struct sockaddr *)&req.dstaddr, req.dstaddr.ss_len,
-	    pdstaddr, sizeof(pdstaddr), 0, 0, niflag) != 0)
-		strlcpy(pdstaddr, "<error>", sizeof(pdstaddr));
+	printf("inet%s %s", ver, psrcaddr);
+
+	if (req->dstaddr.ss_family != AF_UNSPEC) {
+		in_port_t dstport = 0;
+		const struct sockaddr_in *sin;
+		const struct sockaddr_in6 *sin6;
+
+		if (getnameinfo((struct sockaddr *)&req->dstaddr,
+		    req->dstaddr.ss_len, pdstaddr, sizeof(pdstaddr),
+		    0, 0, niflag) != 0)
+			strlcpy(pdstaddr, "<error>", sizeof(pdstaddr));
+
+		printf(" -> %s", pdstaddr);
+
+		switch (req->dstaddr.ss_family) {
+		case AF_INET:
+			sin = (const struct sockaddr_in *)&req->dstaddr;
+			dstport = sin->sin_port;
+			break;
+		case AF_INET6:
+			sin6 = (const struct sockaddr_in6 *)&req->dstaddr;
+			dstport = sin6->sin6_port;
+			break;
+		}
 
-	printf("\ttunnel: inet%s %s -> %s", ver,
-	    psrcaddr, pdstaddr);
+		if (dstport)
+			printf(":%u", ntohs(dstport));
+	}
+}
+
+/* ARGSUSED */
+static void
+phys_status(int force)
+{
+	struct if_laddrreq req;
+	struct if_laddrreq *r = &req;
+
+	memset(&req, 0, sizeof(req));
+	(void) strlcpy(req.iflr_name, name, sizeof(req.iflr_name));
+	if (ioctl(s, SIOCGLIFPHYADDR, (caddr_t)&req) < 0) {
+		if (errno != EADDRNOTAVAIL)
+			return;
+
+		r = NULL;
+	}
+
+	printf("\ttunnel: ");
+	print_tunnel(r);
 
-	if (dstport)
-		printf(":%u", ntohs(dstport));
 	if (ioctl(s, SIOCGLIFPHYTTL, (caddr_t)&ifr) == 0) {
 		if (ifr.ifr_ttl == -1)
 			printf(" ttl copy");
@@ -3273,6 +3309,40 @@ settunnel(const char *src, const char *dst)
 	freeaddrinfo(dstres);
 }
 
+void
+settunneladdr(const char *addr, int ignored)
+{
+	struct addrinfo hints, *res;
+	struct if_laddrreq req;
+	ssize_t len;
+	int rv;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_protocol = 0;
+	hints.ai_flags = AI_PASSIVE;
+
+	rv = getaddrinfo(addr, NULL, &hints, &res);
+	if (rv != 0)
+		errx(1, "tunneladdr %s: %s", addr, gai_strerror(rv));
+
+	memset(&req, 0, sizeof(req));
+	len = strlcpy(req.iflr_name, name, sizeof(req.iflr_name));
+	if (len >= sizeof(req.iflr_name))
+		errx(1, "%s: Interface name too long", name);
+
+	memcpy(&req.addr, res->ai_addr, res->ai_addrlen);
+
+	req.dstaddr.ss_len = 2;
+	req.dstaddr.ss_family = AF_UNSPEC;
+
+	if (ioctl(s, SIOCSLIFPHYADDR, &req) < 0)
+		warn("tunneladdr %s", addr);
+
+	freeaddrinfo(res);
+}
+
 /* ARGSUSED */
 void
 deletetunnel(const char *ignored, int alsoignored)