Acquire or assert the IPX PCB list lock or IPX PCB lock during various

protocol methods relating to IPX.  Conditionally acquire the PCB list
lock in the send operation only if the socket requires binding in order
to use the requested address.

Remove spl's generally no longer required during these accesses.

MFC after:	3 weeks

1 files changed, 72 insertions, 33 deletions

diff --git a/sys/netipx/ipx_usrreq.c b/sys/netipx/ipx_usrreq.c
index 508e0aa1861e..dd03614c94a2 100644
--- a/sys/netipx/ipx_usrreq.c
+++ b/sys/netipx/ipx_usrreq.c
@@ -129,6 +129,7 @@ ipx_input(m, ipxp)
 	struct sockaddr_ipx ipx_ipx;
 
 	KASSERT(ipxp != NULL, ("ipx_input: NULL ipxpcb"));
+	IPX_LOCK_ASSERT(ipxp);
 	/*
 	 * Construct sockaddr format source address.
 	 * Stuff source address and datagram in user buffer.
@@ -174,6 +175,9 @@ ipx_drop(ipxp, errno)
 {
 	struct socket *so = ipxp->ipxp_socket;
 
+	IPX_LIST_LOCK_ASSERT();
+	IPX_LOCK_ASSERT(ipxp);
+
 	/*
 	 * someday, in the IPX world
 	 * we will generate error protocol packets
@@ -202,6 +206,8 @@ ipx_output(ipxp, m0)
 	struct mbuf *m;
 	struct mbuf *mprev = NULL;
 
+	IPX_LOCK_ASSERT(ipxp);
+
 	/*
 	 * Calculate data length.
 	 */
@@ -417,12 +423,12 @@ static int
 ipx_usr_abort(so)
 	struct socket *so;
 {
-	int s;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
 
-	s = splnet();
+	IPX_LIST_LOCK();
+	IPX_LOCK(ipxp);
 	ipx_pcbdetach(ipxp);
-	splx(s);
+	IPX_LIST_UNLOCK();
 	soisdisconnected(so);
 	ACCEPT_LOCK();
 	SOCK_LOCK(so);
@@ -436,15 +442,14 @@ ipx_attach(so, proto, td)
 	int proto;
 	struct thread *td;
 {
-	int error;
-	int s;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
+	int error;
 
 	if (ipxp != NULL)
 		return (EINVAL);
-	s = splnet();
+	IPX_LIST_LOCK();
 	error = ipx_pcballoc(so, &ipxpcb_list, td);
-	splx(s);
+	IPX_LIST_UNLOCK();
 	if (error == 0)
 		error = soreserve(so, ipxsendspace, ipxrecvspace);
 	return (error);
@@ -457,8 +462,14 @@ ipx_bind(so, nam, td)
 	struct thread *td;
 {
 	struct ipxpcb *ipxp = sotoipxpcb(so);
+	int error;
 
-	return (ipx_pcbbind(ipxp, nam, td));
+	IPX_LIST_LOCK();
+	IPX_LOCK(ipxp);
+	error = ipx_pcbbind(ipxp, nam, td);
+	IPX_UNLOCK(ipxp);
+	IPX_LIST_UNLOCK();
+	return (error);
 }
 
 static int
@@ -467,17 +478,21 @@ ipx_connect(so, nam, td)
 	struct sockaddr *nam;
 	struct thread *td;
 {
-	int error;
-	int s;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
+	int error;
 
-	if (!ipx_nullhost(ipxp->ipxp_faddr))
-		return (EISCONN);
-	s = splnet();
+	IPX_LIST_LOCK();
+	IPX_LOCK(ipxp);
+	if (!ipx_nullhost(ipxp->ipxp_faddr)) {
+		error = EISCONN;
+		goto out;
+	}
 	error = ipx_pcbconnect(ipxp, nam, td);
-	splx(s);
 	if (error == 0)
 		soisconnected(so);
+out:
+	IPX_UNLOCK(ipxp);
+	IPX_LIST_UNLOCK();
 	return (error);
 }
 
@@ -485,14 +500,14 @@ static int
 ipx_detach(so)
 	struct socket *so;
 {
-	int s;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
 
 	if (ipxp == NULL)
 		return (ENOTCONN);
-	s = splnet();
+	IPX_LIST_LOCK();
+	IPX_LOCK(ipxp);
 	ipx_pcbdetach(ipxp);
-	splx(s);
+	IPX_LIST_UNLOCK();
 	return (0);
 }
 
@@ -500,15 +515,21 @@ static int
 ipx_disconnect(so)
 	struct socket *so;
 {
-	int s;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
+	int error;
 
-	if (ipx_nullhost(ipxp->ipxp_faddr))
-		return (ENOTCONN);
-	s = splnet();
+	IPX_LIST_LOCK();
+	IPX_LOCK(ipxp);
+	error = 0;
+	if (ipx_nullhost(ipxp->ipxp_faddr)) {
+		error = ENOTCONN;
+		goto out;
+	}
 	ipx_pcbdisconnect(ipxp);
-	splx(s);
 	soisdisconnected(so);
+out:
+	IPX_UNLOCK(ipxp);
+	IPX_LIST_UNLOCK();
 	return (0);
 }
 
@@ -535,25 +556,36 @@ ipx_send(so, flags, m, nam, control, td)
 	int error;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
 	struct ipx_addr laddr;
-	int s = 0;
 
+	/*
+	 * Attempt to only acquire the necessary locks: if the socket is
+	 * already connected, we don't need to hold the IPX list lock to be
+	 * used by ipx_pcbconnect() and ipx_pcbdisconnect(), just the IPX
+	 * pcb lock.
+	 */
 	if (nam != NULL) {
+		IPX_LIST_LOCK();
+		IPX_LOCK(ipxp);
 		laddr = ipxp->ipxp_laddr;
 		if (!ipx_nullhost(ipxp->ipxp_faddr)) {
+			IPX_UNLOCK(ipxp);
+			IPX_LIST_UNLOCK();
 			error = EISCONN;
 			goto send_release;
 		}
 		/*
 		 * Must block input while temporarily connected.
 		 */
-		s = splnet();
 		error = ipx_pcbconnect(ipxp, nam, td);
 		if (error) {
-			splx(s);
+			IPX_UNLOCK(ipxp);
+			IPX_LIST_UNLOCK();
 			goto send_release;
 		}
 	} else {
+		IPX_LOCK(ipxp);
 		if (ipx_nullhost(ipxp->ipxp_faddr)) {
+			IPX_UNLOCK(ipxp);
 			error = ENOTCONN;
 			goto send_release;
 		}
@@ -562,9 +594,11 @@ ipx_send(so, flags, m, nam, control, td)
 	m = NULL;
 	if (nam != NULL) {
 		ipx_pcbdisconnect(ipxp);
-		splx(s);
 		ipxp->ipxp_laddr = laddr;
-	}
+		IPX_UNLOCK(ipxp);
+		IPX_LIST_UNLOCK();
+	} else
+		IPX_UNLOCK(ipxp);
 
 send_release:
 	if (m != NULL)
@@ -598,21 +632,26 @@ ripx_attach(so, proto, td)
 	struct thread *td;
 {
 	int error = 0;
-	int s;
 	struct ipxpcb *ipxp = sotoipxpcb(so);
 
 	if (td != NULL && (error = suser(td)) != 0)
 		return (error);
-	s = splnet();
+	/*
+	 * We hold the IPX list lock for the duration as address parameters
+	 * of the IPX pcb are changed.  Since no one else holds a reference
+	 * to the ipxpcb yet, we don't need the ipxpcb lock here.
+	 */
+	IPX_LIST_LOCK();
 	error = ipx_pcballoc(so, &ipxrawpcb_list, td);
-	splx(s);
 	if (error)
-		return (error);
+		goto out;
+	ipxp = sotoipxpcb(so);
 	error = soreserve(so, ipxsendspace, ipxrecvspace);
 	if (error)
-		return (error);
-	ipxp = sotoipxpcb(so);
+		goto out;
 	ipxp->ipxp_faddr.x_host = ipx_broadhost;
 	ipxp->ipxp_flags = IPXP_RAWIN | IPXP_RAWOUT;
+out:
+	IPX_LIST_UNLOCK();
 	return (error);
 }