Replace in_pcbladdr() with a more generic inner subroutine for

in_pcbconnect() called in_pcbconnect_setup(). This version performs
all of the functions of in_pcbconnect() except for the final
committing of changes to the PCB. In the case of an EADDRINUSE error
it can also provide to the caller the PCB of the duplicate connection,
avoiding an extra in_pcblookup_hash() lookup in tcp_connect().

This change will allow the "temporary connect" hack in udp_output()
to be removed and is part of the preparation for adding the
IP_SENDSRCADDR control message.

Discussed on:	-net
Approved by:	re

1 files changed, 121 insertions, 84 deletions

diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index 5ea538a..e7992d5 100644
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -404,32 +404,110 @@ in_pcbbind_setup(inp, nam, laddrp, lportp, td)
 }
 
 /*
- *   Transform old in_pcbconnect() into an inner subroutine for new
- *   in_pcbconnect(): Do some validity-checking on the remote
- *   address (in mbuf 'nam') and then determine local host address
- *   (i.e., which interface) to use to access that remote host.
- *
- *   This preserves definition of in_pcbconnect(), while supporting a
- *   slightly different version for T/TCP.  (This is more than
- *   a bit of a kludge, but cleaning up the internal interfaces would
- *   have forced minor changes in every protocol).
+ * Connect from a socket to a specified address.
+ * Both address and port must be specified in argument sin.
+ * If don't have a local address for this socket yet,
+ * then pick one.
  */
+int
+in_pcbconnect(inp, nam, td)
+	register struct inpcb *inp;
+	struct sockaddr *nam;
+	struct thread *td;
+{
+	u_short lport, fport;
+	in_addr_t laddr, faddr;
+	int anonport, error;
+
+	lport = inp->inp_lport;
+	laddr = inp->inp_laddr.s_addr;
+	anonport = (lport == 0);
+	error = in_pcbconnect_setup(inp, nam, &laddr, &lport, &faddr, &fport,
+	    NULL, td);
+	if (error)
+		return (error);
+
+	/* Do the initial binding of the local address if required. */
+	if (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0) {
+		inp->inp_lport = lport;
+		inp->inp_laddr.s_addr = laddr;
+		if (in_pcbinshash(inp) != 0) {
+			inp->inp_laddr.s_addr = INADDR_ANY;
+			inp->inp_lport = 0;
+			return (EAGAIN);
+		}
+	}
+
+	/* Commit the remaining changes. */
+	inp->inp_lport = lport;
+	inp->inp_laddr.s_addr = laddr;
+	inp->inp_faddr.s_addr = faddr;
+	inp->inp_fport = fport;
+	in_pcbrehash(inp);
+	if (anonport)
+		inp->inp_flags |= INP_ANONPORT;
+	return (0);
+}
 
+/*
+ * Set up for a connect from a socket to the specified address.
+ * On entry, *laddrp and *lportp should contain the current local
+ * address and port for the PCB; these are updated to the values
+ * that should be placed in inp_laddr and inp_lport to complete
+ * the connect.
+ *
+ * On success, *faddrp and *fportp will be set to the remote address
+ * and port. These are not updated in the error case.
+ *
+ * If the operation fails because the connection already exists,
+ * *oinpp will be set to the PCB of that connection so that the
+ * caller can decide to override it. In all other cases, *oinpp
+ * is set to NULL.
+ */
 int
-in_pcbladdr(inp, nam, plocal_sin)
+in_pcbconnect_setup(inp, nam, laddrp, lportp, faddrp, fportp, oinpp, td)
 	register struct inpcb *inp;
 	struct sockaddr *nam;
-	struct sockaddr_in **plocal_sin;
+	in_addr_t *laddrp;
+	u_short *lportp;
+	in_addr_t *faddrp;
+	u_short *fportp;
+	struct inpcb **oinpp;
+	struct thread *td;
 {
+	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
 	struct in_ifaddr *ia;
-	register struct sockaddr_in *sin = (struct sockaddr_in *)nam;
+	struct sockaddr_in sa;
+	struct ucred *cred;
+	struct inpcb *oinp;
+	struct in_addr laddr, faddr;
+	u_short lport, fport;
+	int error;
 
+	if (oinpp != NULL)
+		*oinpp = NULL;
 	if (nam->sa_len != sizeof (*sin))
 		return (EINVAL);
 	if (sin->sin_family != AF_INET)
 		return (EAFNOSUPPORT);
 	if (sin->sin_port == 0)
 		return (EADDRNOTAVAIL);
+	laddr.s_addr = *laddrp;
+	lport = *lportp;
+	faddr = sin->sin_addr;
+	fport = sin->sin_port;
+	cred = inp->inp_socket->so_cred;
+	if (laddr.s_addr == INADDR_ANY && jailed(cred)) {
+		bzero(&sa, sizeof(sa));
+		sa.sin_addr.s_addr = htonl(prison_getip(cred));
+		sa.sin_len = sizeof(sa);
+		sa.sin_family = AF_INET;
+		error = in_pcbbind_setup(inp, (struct sockaddr *)&sa,
+		    &laddr.s_addr, &lport, td);
+		if (error)
+			return (error);
+	}
+
 	if (!TAILQ_EMPTY(&in_ifaddrhead)) {
 		/*
 		 * If the destination address is INADDR_ANY,
@@ -438,13 +516,15 @@ in_pcbladdr(inp, nam, plocal_sin)
 		 * and the primary interface supports broadcast,
 		 * choose the broadcast address for that interface.
 		 */
-		if (sin->sin_addr.s_addr == INADDR_ANY)
-		    sin->sin_addr = IA_SIN(TAILQ_FIRST(&in_ifaddrhead))->sin_addr;
-		else if (sin->sin_addr.s_addr == (u_long)INADDR_BROADCAST &&
-		  (TAILQ_FIRST(&in_ifaddrhead)->ia_ifp->if_flags & IFF_BROADCAST))
-		    sin->sin_addr = satosin(&TAILQ_FIRST(&in_ifaddrhead)->ia_broadaddr)->sin_addr;
+		if (faddr.s_addr == INADDR_ANY)
+			faddr = IA_SIN(TAILQ_FIRST(&in_ifaddrhead))->sin_addr;
+		else if (faddr.s_addr == (u_long)INADDR_BROADCAST &&
+		    (TAILQ_FIRST(&in_ifaddrhead)->ia_ifp->if_flags &
+		    IFF_BROADCAST))
+			faddr = satosin(&TAILQ_FIRST(
+			    &in_ifaddrhead)->ia_broadaddr)->sin_addr;
 	}
-	if (inp->inp_laddr.s_addr == INADDR_ANY) {
+	if (laddr.s_addr == INADDR_ANY) {
 		register struct route *ro;
 
 		ia = (struct in_ifaddr *)0;
@@ -457,8 +537,7 @@ in_pcbladdr(inp, nam, plocal_sin)
 		ro = &inp->inp_route;
 		if (ro->ro_rt &&
 		    (ro->ro_dst.sa_family != AF_INET ||
-		     satosin(&ro->ro_dst)->sin_addr.s_addr !=
-		     sin->sin_addr.s_addr ||
+		     satosin(&ro->ro_dst)->sin_addr.s_addr != faddr.s_addr ||
 		     inp->inp_socket->so_options & SO_DONTROUTE)) {
 			RTFREE(ro->ro_rt);
 			ro->ro_rt = (struct rtentry *)0;
@@ -470,8 +549,7 @@ in_pcbladdr(inp, nam, plocal_sin)
 			bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
 			ro->ro_dst.sa_family = AF_INET;
 			ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
-			((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
-				sin->sin_addr;
+			((struct sockaddr_in *)&ro->ro_dst)->sin_addr = faddr;
 			rtalloc(ro);
 		}
 		/*
@@ -483,13 +561,14 @@ in_pcbladdr(inp, nam, plocal_sin)
 		if (ro->ro_rt && !(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK))
 			ia = ifatoia(ro->ro_rt->rt_ifa);
 		if (ia == 0) {
-			u_short fport = sin->sin_port;
+			bzero(&sa, sizeof(sa));
+			sa.sin_addr = faddr;
+			sa.sin_len = sizeof(sa);
+			sa.sin_family = AF_INET;
 
-			sin->sin_port = 0;
-			ia = ifatoia(ifa_ifwithdstaddr(sintosa(sin)));
+			ia = ifatoia(ifa_ifwithdstaddr(sintosa(&sa)));
 			if (ia == 0)
-				ia = ifatoia(ifa_ifwithnet(sintosa(sin)));
-			sin->sin_port = fport;
+				ia = ifatoia(ifa_ifwithnet(sintosa(&sa)));
 			if (ia == 0)
 				ia = TAILQ_FIRST(&in_ifaddrhead);
 			if (ia == 0)
@@ -500,7 +579,7 @@ in_pcbladdr(inp, nam, plocal_sin)
 		 * interface has been set as a multicast option, use the
 		 * address of that interface as our source address.
 		 */
-		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)) &&
+		if (IN_MULTICAST(ntohl(faddr.s_addr)) &&
 		    inp->inp_moptions != NULL) {
 			struct ip_moptions *imo;
 			struct ifnet *ifp;
@@ -515,67 +594,25 @@ in_pcbladdr(inp, nam, plocal_sin)
 					return (EADDRNOTAVAIL);
 			}
 		}
-	/*
-	 * Don't do pcblookup call here; return interface in plocal_sin
-	 * and exit to caller, that will do the lookup.
-	 */
-		*plocal_sin = &ia->ia_addr;
-
-	}
-	return(0);
-}
-
-/*
- * Outer subroutine:
- * Connect from a socket to a specified address.
- * Both address and port must be specified in argument sin.
- * If don't have a local address for this socket yet,
- * then pick one.
- */
-int
-in_pcbconnect(inp, nam, td)
-	register struct inpcb *inp;
-	struct sockaddr *nam;
-	struct thread *td;
-{
-	struct sockaddr_in *ifaddr;
-	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
-	struct sockaddr_in sa;
-	struct ucred *cred;
-	int error;
-
-	cred = inp->inp_socket->so_cred;
-	if (inp->inp_laddr.s_addr == INADDR_ANY && jailed(cred)) {
-		bzero(&sa, sizeof (sa));
-		sa.sin_addr.s_addr = htonl(prison_getip(cred));
-		sa.sin_len=sizeof (sa);
-		sa.sin_family = AF_INET;
-		error = in_pcbbind(inp, (struct sockaddr *)&sa, td);
-		if (error)
-			return (error);
+		laddr = ia->ia_addr.sin_addr;
 	}
-	/*
-	 *   Call inner routine, to assign local interface address.
-	 */
-	if ((error = in_pcbladdr(inp, nam, &ifaddr)) != 0)
-		return(error);
 
-	if (in_pcblookup_hash(inp->inp_pcbinfo, sin->sin_addr, sin->sin_port,
-	    inp->inp_laddr.s_addr ? inp->inp_laddr : ifaddr->sin_addr,
-	    inp->inp_lport, 0, NULL) != NULL) {
+	oinp = in_pcblookup_hash(inp->inp_pcbinfo, faddr, fport, laddr, lport,
+	    0, NULL);
+	if (oinp != NULL) {
+		if (oinpp != NULL)
+			*oinpp = oinp;
 		return (EADDRINUSE);
 	}
-	if (inp->inp_laddr.s_addr == INADDR_ANY) {
-		if (inp->inp_lport == 0) {
-			error = in_pcbbind(inp, (struct sockaddr *)0, td);
-			if (error)
-				return (error);
-		}
-		inp->inp_laddr = ifaddr->sin_addr;
+	if (lport == 0) {
+		error = in_pcbbind_setup(inp, NULL, &laddr.s_addr, &lport, td);
+		if (error)
+			return (error);
 	}
-	inp->inp_faddr = sin->sin_addr;
-	inp->inp_fport = sin->sin_port;
-	in_pcbrehash(inp);
+	*laddrp = laddr.s_addr;
+	*lportp = lport;
+	*faddrp = faddr.s_addr;
+	*fportp = fport;
 	return (0);
 }