Add SO_BINDANY socket option from BSD/OS.

The option allows a socket to be bound to addresses which are not
local to the machine.  In order to receive packets for these addresses
SO_BINDANY needs to be combined with matching outgoing pf(4) divert
rules, see pf.conf(5).

ok beck@

4 files changed, 18 insertions, 6 deletions

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 45728e18533..7422689fa11 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uipc_socket.c,v 1.68 2008/05/02 06:49:32 ckuethe Exp $	*/
+/*	$OpenBSD: uipc_socket.c,v 1.69 2008/05/09 02:52:15 markus Exp $	*/
 /*	$NetBSD: uipc_socket.c,v 1.21 1996/02/04 02:17:52 christos Exp $	*/
 
 /*
@@ -981,6 +981,13 @@ sosetopt(struct socket *so, int level, int optname, struct mbuf *m0)
 		error = ENOPROTOOPT;
 	} else {
 		switch (optname) {
+		case SO_BINDANY:
+			if ((error = suser(curproc, 0)) != 0)	/* XXX */
+				goto bad;
+			break;
+		}
+
+		switch (optname) {
 
 		case SO_LINGER:
 			if (m == NULL || m->m_len != sizeof (struct linger) ||
@@ -992,6 +999,7 @@ sosetopt(struct socket *so, int level, int optname, struct mbuf *m0)
 			so->so_linger = mtod(m, struct linger *)->l_linger;
 			/* FALLTHROUGH */
 
+		case SO_BINDANY:
 		case SO_DEBUG:
 		case SO_KEEPALIVE:
 		case SO_DONTROUTE:
@@ -1127,6 +1135,7 @@ sogetopt(struct socket *so, int level, int optname, struct mbuf **mp)
 			mtod(m, struct linger *)->l_linger = so->so_linger;
 			break;
 
+		case SO_BINDANY:
 		case SO_USELOOPBACK:
 		case SO_DONTROUTE:
 		case SO_DEBUG:
diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index e3e8d58bdfa..58702c81a36 100644
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in_pcb.c,v 1.95 2008/05/09 02:44:54 markus Exp $	*/
+/*	$OpenBSD: in_pcb.c,v 1.96 2008/05/09 02:52:15 markus Exp $	*/
 /*	$NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $	*/
 
 /*
@@ -284,7 +284,8 @@ in_pcbbind(v, nam)
 				reuseport = SO_REUSEADDR|SO_REUSEPORT;
 		} else if (sin->sin_addr.s_addr != INADDR_ANY) {
 			sin->sin_port = 0;		/* yech... */
-			if (in_iawithaddr(sin->sin_addr, NULL) == 0)
+			if (!(so->so_options & SO_BINDANY) &&
+			    in_iawithaddr(sin->sin_addr, NULL) == 0)
 				return (EADDRNOTAVAIL);
 		}
 		if (lport) {
diff --git a/sys/netinet/raw_ip.c b/sys/netinet/raw_ip.c
index 3b621e57678..1b45549be3c 100644
--- a/sys/netinet/raw_ip.c
+++ b/sys/netinet/raw_ip.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: raw_ip.c,v 1.42 2008/05/09 02:44:54 markus Exp $	*/
+/*	$OpenBSD: raw_ip.c,v 1.43 2008/05/09 02:52:15 markus Exp $	*/
 /*	$NetBSD: raw_ip.c,v 1.25 1996/02/18 18:58:33 christos Exp $	*/
 
 /*
@@ -408,7 +408,8 @@ rip_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
 		    ((addr->sin_family != AF_INET) &&
 		     (addr->sin_family != AF_IMPLINK)) ||
 		    (addr->sin_addr.s_addr &&
-		     ifa_ifwithaddr(sintosa(addr)) == 0)) {
+		     (!(so->so_options & SO_BINDANY) &&
+		     in_iawithaddr(addr->sin_addr, NULL) == 0))) {
 			error = EADDRNOTAVAIL;
 			break;
 		}
diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index a5bb2afeacb..b960fbf86b6 100644
--- a/sys/sys/socket.h
+++ b/sys/sys/socket.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: socket.h,v 1.57 2008/05/02 06:49:32 ckuethe Exp $	*/
+/*	$OpenBSD: socket.h,v 1.58 2008/05/09 02:52:15 markus Exp $	*/
 /*	$NetBSD: socket.h,v 1.14 1996/02/09 18:25:36 christos Exp $	*/
 
 /*
@@ -68,6 +68,7 @@
 #define	SO_REUSEPORT	0x0200		/* allow local address & port reuse */
 #define SO_JUMBO	0x0400		/* try to use jumbograms */
 #define SO_TIMESTAMP	0x0800		/* timestamp received dgram traffic */
+#define	SO_BINDANY	0x1000		/* allow bind to any address */
 
 /*
  * Additional options, not kept in so_options.