Make sure to always do source address selection on

an unbound socket, regardless of any multicast options.
If an address is specified via a multicast option, then
let it override normal the source address selection.

This fixes a bug where source address selection was
not being performed when multicast options were present
but without an interface being specified.

Reviewed by:	bz
MFC after:	1 day

1 files changed, 9 insertions, 8 deletions

diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index d742887..28cc029 100644
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -874,9 +874,10 @@ in_pcbconnect_setup(struct inpcb *inp, struct sockaddr *nam,
 		}
 	}
 	if (laddr.s_addr == INADDR_ANY) {
+		error = in_pcbladdr(inp, &faddr, &laddr, cred);
 		/*
 		 * If the destination address is multicast and an outgoing
-		 * interface has been set as a multicast option, use the
+		 * interface has been set as a multicast option, prefer the
 		 * address of that interface as our source address.
 		 */
 		if (IN_MULTICAST(ntohl(faddr.s_addr)) &&
@@ -893,16 +894,16 @@ in_pcbconnect_setup(struct inpcb *inp, struct sockaddr *nam,
 						break;
 				if (ia == NULL) {
 					IN_IFADDR_RUNLOCK();
-					return (EADDRNOTAVAIL);
+					error = EADDRNOTAVAIL;
+				} else {
+					laddr = ia->ia_addr.sin_addr;
+					IN_IFADDR_RUNLOCK();
+					error = 0;
 				}
-				laddr = ia->ia_addr.sin_addr;
-				IN_IFADDR_RUNLOCK();
 			}
-		} else {
-			error = in_pcbladdr(inp, &faddr, &laddr, cred);
-			if (error) 
-				return (error);
 		}
+		if (error)
+			return (error);
 	}
 	oinp = in_pcblookup_hash(inp->inp_pcbinfo, faddr, fport, laddr, lport,
 	    0, NULL);