svn commit: r269340 - head/sys/netinet

[Steven Hartland]

Author: smh
Date: Thu Jul 31 16:43:56 2014
New Revision: 269340
URL: http://svnweb.freebsd.org/changeset/base/269340

Log:
  Ensure that IP's added to CARP always use the CARP MAC
  
  Previously there was a race condition between the address addition
  and associating it with the CARP which resulted in the interface
  MAC, instead of the CARP MAC, being used for a brief amount of time.
  
  This caused "is using my IP address" warnings as well as data being
  sent to the wrong machine due to incorrect ARP entries being recorded
  by other devices on the network.

Modified:
  head/sys/netinet/in.c

Modified: head/sys/netinet/in.c
==============================================================================
--- head/sys/netinet/in.c	Thu Jul 31 16:17:30 2014	(r269339)
+++ head/sys/netinet/in.c	Thu Jul 31 16:43:56 2014	(r269340)
@@ -407,6 +407,12 @@ in_aifaddr_ioctl(u_long cmd, caddr_t dat
 	if (ifp->if_flags & IFF_LOOPBACK)
                 ia->ia_dstaddr = ia->ia_addr;
 
+	if (vhid != 0) {
+		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
+		if (error)
+			return (error);
+	}
+
 	/* if_addrhead is already referenced by ifa_alloc() */
 	IF_ADDR_WLOCK(ifp);
 	TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
@@ -418,12 +424,6 @@ in_aifaddr_ioctl(u_long cmd, caddr_t dat
 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
 	IN_IFADDR_WUNLOCK();
 
-	if (vhid != 0) {
-		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
-		if (error)
-			goto fail1;
-	}
-
 	/*
 	 * Give the interface a chance to initialize
 	 * if this is its first address,
@@ -432,7 +432,7 @@ in_aifaddr_ioctl(u_long cmd, caddr_t dat
 	if (ifp->if_ioctl != NULL) {
 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
 		if (error)
-			goto fail2;
+			goto fail1;
 	}
 
 	/*
@@ -446,7 +446,7 @@ in_aifaddr_ioctl(u_long cmd, caddr_t dat
 
 		error = in_addprefix(ia, flags);
 		if (error)
-			goto fail2;
+			goto fail1;
 	}
 
 	/*
@@ -464,7 +464,7 @@ in_aifaddr_ioctl(u_long cmd, caddr_t dat
 			error = ifa_add_loopback_route((struct ifaddr *)ia,
 			    (struct sockaddr *)&ia->ia_addr);
 			if (error)
-				goto fail3;
+				goto fail2;
 		} else
 			ifa_free(&eia->ia_ifa);
 	}
@@ -484,15 +484,14 @@ in_aifaddr_ioctl(u_long cmd, caddr_t dat
 
 	return (error);
 
-fail3:
+fail2:
 	if (vhid == 0)
 		(void )in_scrubprefix(ia, LLE_STATIC);
 
-fail2:
+fail1:
 	if (ia->ia_ifa.ifa_carp)
 		(*carp_detach_p)(&ia->ia_ifa);
 
-fail1:
 	IF_ADDR_WLOCK(ifp);
 	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
 	IF_ADDR_WUNLOCK(ifp);