Procotol control block locking for netatalk DDP.

5 files changed, 134 insertions, 35 deletions

diff --git a/sys/netatalk/ddp_input.c b/sys/netatalk/ddp_input.c
index 679f943..58d4ad8 100644
--- a/sys/netatalk/ddp_input.c
+++ b/sys/netatalk/ddp_input.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2004 Robert N. M. Watson
  * Copyright (c) 1990,1994 Regents of The University of Michigan.
  * All Rights Reserved.  See COPYRIGHT.
  *
@@ -24,11 +25,13 @@
 #include <netatalk/at_var.h>
 #include <netatalk/ddp.h>
 #include <netatalk/ddp_var.h>
+#include <netatalk/ddp_pcb.h>
 #include <netatalk/at_extern.h>
 
 static volatile int	ddp_forward = 1;
 static volatile int	ddp_firewall = 0;
 static struct ddpstat	ddpstat;
+
 static struct route	forwro;
 
 static void     ddp_input(struct mbuf *, struct ifnet *, struct elaphdr *, int);
@@ -360,17 +363,16 @@ ddp_input(m, ifp, elh, phase)
      * Search for ddp protocol control blocks that match these
      * addresses. 
      */
+    DDP_LIST_SLOCK();
     if ((ddp = ddp_search(&from, &to, aa)) == NULL) {
-	m_freem(m);
-	return;
+	goto out;
     }
 
 #ifdef MAC
     SOCK_LOCK(ddp->ddp_socket);
     if (mac_check_socket_deliver(ddp->ddp_socket, m) != 0) {
 	SOCK_UNLOCK(ddp->ddp_socket);
-	m_freem(m);
-	return;
+	goto out;
     }
     SOCK_UNLOCK(ddp->ddp_socket);
 #endif
@@ -384,13 +386,17 @@ ddp_input(m, ifp, elh, phase)
 	 * If the socket is full (or similar error) dump the packet.
 	 */
 	ddpstat.ddps_nosockspace++;
-	m_freem(m);
-	return;
+	goto out;
     }
     /*
      * And wake up whatever might be waiting for it
      */
     sorwakeup(ddp->ddp_socket);
+    m = NULL;
+out:
+    DDP_LIST_SUNLOCK();
+    if (m != NULL)
+	m_freem(m);
 }
 
 #if 0
diff --git a/sys/netatalk/ddp_pcb.c b/sys/netatalk/ddp_pcb.c
index e6dc5fb..8073d55 100644
--- a/sys/netatalk/ddp_pcb.c
+++ b/sys/netatalk/ddp_pcb.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2004 Robert N. M. Watson
  * Copyright (c) 1990,1994 Regents of The University of Michigan.
  * All Rights Reserved.  See COPYRIGHT.
  *
@@ -22,12 +23,18 @@
 #include <netatalk/ddp_pcb.h>
 #include <netatalk/at_extern.h>
 
+struct mtx		 ddp_list_mtx;
 static struct ddpcb	*ddp_ports[ ATPORT_LAST ];
-struct ddpcb	*ddpcb_list = NULL;
+struct ddpcb		*ddpcb_list = NULL;
 
 void
 at_sockaddr(struct ddpcb *ddp, struct sockaddr **addr)
 {
+
+    /*
+     * Prevent modification of ddp during copy of addr.
+     */
+    DDP_LOCK_ASSERT(ddp);
     *addr = sodupsockaddr((struct sockaddr *)&ddp->ddp_lsat, M_NOWAIT);
 }
 
@@ -38,6 +45,12 @@ at_pcbsetaddr(struct ddpcb *ddp, struct sockaddr *addr, struct thread *td)
     struct at_ifaddr	*aa;
     struct ddpcb	*ddpp;
 
+    /*
+     * We read and write both the ddp passed in, and also ddp_ports.
+     */
+    DDP_LIST_XLOCK_ASSERT();
+    DDP_LOCK_ASSERT(ddp);
+
     if (ddp->ddp_lsat.sat_port != ATADDR_ANYPORT) { /* shouldn't be bound */
 	return (EINVAL);
     }
@@ -134,6 +147,9 @@ at_pcbconnect(struct ddpcb *ddp, struct sockaddr *addr, struct thread *td)
     struct ifnet	*ifp;
     u_short		hintnet = 0, net;
 
+    DDP_LIST_XLOCK_ASSERT();
+    DDP_LOCK_ASSERT(ddp);
+
     if (sat->sat_family != AF_APPLETALK) {
 	return (EAFNOSUPPORT);
     }
@@ -222,6 +238,9 @@ at_pcbconnect(struct ddpcb *ddp, struct sockaddr *addr, struct thread *td)
 void 
 at_pcbdisconnect(struct ddpcb	*ddp)
 {
+
+    DDP_LOCK_ASSERT(ddp);
+
     ddp->ddp_fsat.sat_addr.s_net = ATADDR_ANYNET;
     ddp->ddp_fsat.sat_addr.s_node = ATADDR_ANYNODE;
     ddp->ddp_fsat.sat_port = ATADDR_ANYPORT;
@@ -232,9 +251,15 @@ at_pcballoc(struct socket *so)
 {
 	struct ddpcb	*ddp;
 
-	MALLOC(ddp, struct ddpcb *, sizeof *ddp, M_PCB, M_WAITOK | M_ZERO);
+	DDP_LIST_XLOCK_ASSERT();
+
+	MALLOC(ddp, struct ddpcb *, sizeof *ddp, M_PCB, M_NOWAIT | M_ZERO);
+	DDP_LOCK_INIT(ddp);
 	ddp->ddp_lsat.sat_port = ATADDR_ANYPORT;
 
+	ddp->ddp_socket = so;
+	so->so_pcb = (caddr_t)ddp;
+
 	ddp->ddp_next = ddpcb_list;
 	ddp->ddp_prev = NULL;
 	ddp->ddp_pprev = NULL;
@@ -243,15 +268,19 @@ at_pcballoc(struct socket *so)
 		ddpcb_list->ddp_prev = ddp;
 	}
 	ddpcb_list = ddp;
-
-	ddp->ddp_socket = so;
-	so->so_pcb = (caddr_t)ddp;
-	return (0);
+	return(0);
 }
 
 void
 at_pcbdetach(struct socket *so, struct ddpcb *ddp)
 {
+
+    /*
+     * We modify ddp, ddp_ports, and the global list.
+     */
+    DDP_LIST_XLOCK_ASSERT();
+    DDP_LOCK_ASSERT(ddp);
+
     soisdisconnected(so);
     SOCK_LOCK(so);
     so->so_pcb = NULL;
@@ -282,6 +311,8 @@ at_pcbdetach(struct socket *so, struct ddpcb *ddp)
     if (ddp->ddp_next) {
 	ddp->ddp_next->ddp_prev = ddp->ddp_prev;
     }
+    DDP_UNLOCK(ddp);
+    DDP_LOCK_DESTROY(ddp);
     FREE(ddp, M_PCB);
 }
 
@@ -297,6 +328,8 @@ ddp_search(struct sockaddr_at *from, struct sockaddr_at *to,
 {
     struct ddpcb	*ddp;
 
+    DDP_LIST_SLOCK_ASSERT();
+
     /*
      * Check for bad ports.
      */
@@ -309,11 +342,13 @@ ddp_search(struct sockaddr_at *from, struct sockaddr_at *to,
      * the interface?
      */
     for (ddp = ddp_ports[ to->sat_port - 1 ]; ddp; ddp = ddp->ddp_pnext) {
+	DDP_LOCK(ddp);
 	/* XXX should we handle 0.YY? */
 
 	/* XXXX.YY to socket on destination interface */
 	if (to->sat_addr.s_net == ddp->ddp_lsat.sat_addr.s_net &&
 		to->sat_addr.s_node == ddp->ddp_lsat.sat_addr.s_node) {
+	    DDP_UNLOCK(ddp);
 	    break;
 	}
 
@@ -321,6 +356,7 @@ ddp_search(struct sockaddr_at *from, struct sockaddr_at *to,
 	if (to->sat_addr.s_node == ATADDR_BCAST && (to->sat_addr.s_net == 0 ||
 		to->sat_addr.s_net == ddp->ddp_lsat.sat_addr.s_net) &&
 		ddp->ddp_lsat.sat_addr.s_net == AA_SAT(aa)->sat_addr.s_net) {
+	    DDP_UNLOCK(ddp);
 	    break;
 	}
 
@@ -331,8 +367,10 @@ ddp_search(struct sockaddr_at *from, struct sockaddr_at *to,
 		ntohs(aa->aa_firstnet) &&
 		ntohs(ddp->ddp_lsat.sat_addr.s_net) <=
 		ntohs(aa->aa_lastnet)) {
+	    DDP_UNLOCK(ddp);
 	    break;
 	}
+	DDP_UNLOCK(ddp);
     }
     return (ddp);
 }
diff --git a/sys/netatalk/ddp_pcb.h b/sys/netatalk/ddp_pcb.h
index 819d674..85ec0cc 100644
--- a/sys/netatalk/ddp_pcb.h
+++ b/sys/netatalk/ddp_pcb.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2004 Robert N. M. Watson
  * Copyright (c) 1990,1994 Regents of The University of Michigan.
  * All Rights Reserved.  See COPYRIGHT.
  *
@@ -17,4 +18,23 @@ int	at_pcbsetaddr(struct ddpcb *ddp, struct sockaddr *addr,
 	    struct thread *td);
 void	at_sockaddr(struct ddpcb *ddp, struct sockaddr **addr);
 
+/* Lock macros for per-pcb locks. */
+#define	DDP_LOCK_INIT(ddp)	mtx_init(&(ddp)->ddp_mtx, "ddp_mtx",	\
+				    NULL, MTX_DEF)
+#define	DDP_LOCK_DESTROY(ddp)	mtx_destroy(&(ddp)->ddp_mtx)
+#define	DDP_LOCK(ddp)		mtx_lock(&(ddp)->ddp_mtx)
+#define	DDP_UNLOCK(ddp)		mtx_unlock(&(ddp)->ddp_mtx)
+#define	DDP_LOCK_ASSERT(ddp)	mtx_assert(&(ddp)->ddp_mtx, MA_OWNED)
+
+/* Lock macros for global pcb list lock. */
+#define	DDP_LIST_LOCK_INIT()	mtx_init(&ddp_list_mtx, "ddp_list_mtx",	\
+				    NULL, MTX_DEF)
+#define	DDP_LIST_LOCK_DESTROY()	mtx_destroy(&ddp_list_mtx)
+#define	DDP_LIST_XLOCK()	mtx_lock(&ddp_list_mtx)
+#define	DDP_LIST_XUNLOCK()	mtx_unlock(&ddp_list_mtx)
+#define	DDP_LIST_XLOCK_ASSERT()	mtx_assert(&ddp_list_mtx, MA_OWNED)
+#define	DDP_LIST_SLOCK()	mtx_lock(&ddp_list_mtx)
+#define	DDP_LIST_SUNLOCK()	mtx_unlock(&ddp_list_mtx)
+#define	DDP_LIST_SLOCK_ASSERT()	mtx_assert(&ddp_list_mtx, MA_OWNED)
+
 #endif
diff --git a/sys/netatalk/ddp_usrreq.c b/sys/netatalk/ddp_usrreq.c
index e33da4a..1621f1f 100644
--- a/sys/netatalk/ddp_usrreq.c
+++ b/sys/netatalk/ddp_usrreq.c
@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2004 Robert N. M. Watson
  * Copyright (c) 1990,1994 Regents of The University of Michigan.
  * All Rights Reserved.  See COPYRIGHT.
  *
@@ -33,17 +34,22 @@ ddp_attach(struct socket *so, int proto, struct thread *td)
 	struct ddpcb	*ddp;
 	int		error = 0;
 	
-
 	ddp = sotoddpcb(so);
-	if (ddp != NULL) {
-	    return (EINVAL);
-	}
+	if (ddp != NULL)
+		return (EINVAL);
 
+	/*
+	 * Allocate socket buffer space first so that it's present
+	 * before first use.
+	 */
+	error = soreserve(so, ddp_sendspace, ddp_recvspace);
+	if (error)
+		return (error);
+
+	DDP_LIST_XLOCK();
 	error = at_pcballoc(so);
-	if (error) {
-	    return (error);
-	}
-	return (soreserve(so, ddp_sendspace, ddp_recvspace));
+	DDP_LIST_XUNLOCK();
+	return (error);
 }
 
 static int
@@ -52,10 +58,13 @@ ddp_detach(struct socket *so)
 	struct ddpcb	*ddp;
 	
 	ddp = sotoddpcb(so);
-	if (ddp == NULL) {
+	if (ddp == NULL)
 	    return (EINVAL);
-	}
+
+	DDP_LIST_XLOCK();
+	DDP_LOCK(ddp);
 	at_pcbdetach(so, ddp);
+	DDP_LIST_XUNLOCK();
 	return (0);
 }
 
@@ -69,7 +78,11 @@ ddp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 	if (ddp == NULL) {
 	    return (EINVAL);
 	}
+	DDP_LIST_XLOCK();
+	DDP_LOCK(ddp);
 	error = at_pcbsetaddr(ddp, nam, td);
+	DDP_UNLOCK(ddp);
+	DDP_LIST_XUNLOCK();
 	return (error);
 }
     
@@ -84,11 +97,17 @@ ddp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 	    return (EINVAL);
 	}
 
+	DDP_LIST_XLOCK();
+	DDP_LOCK(ddp);
 	if (ddp->ddp_fsat.sat_port != ATADDR_ANYPORT) {
+	    DDP_UNLOCK(ddp);
+	    DDP_LIST_XUNLOCK();
 	    return (EISCONN);
 	}
 
-	error = at_pcbconnect(ddp, nam, td);
+	error = at_pcbconnect( ddp, nam, td );
+	DDP_UNLOCK(ddp);
+	DDP_LIST_XUNLOCK();
 	if (error == 0)
 	    soisconnected(so);
 	return (error);
@@ -104,12 +123,15 @@ ddp_disconnect(struct socket *so)
 	if (ddp == NULL) {
 	    return (EINVAL);
 	}
+	DDP_LOCK(ddp);
 	if (ddp->ddp_fsat.sat_addr.s_node == ATADDR_ANYNODE) {
+	    DDP_UNLOCK(ddp);
 	    return (ENOTCONN);
 	}
 
 	at_pcbdisconnect(ddp);
 	ddp->ddp_fsat.sat_addr.s_node = ATADDR_ANYNODE;
+	DDP_UNLOCK(ddp);
 	soisdisconnected(so);
 	return (0);
 }
@@ -144,23 +166,28 @@ ddp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
     	}
 
 	if (addr != NULL) {
+		DDP_LIST_XLOCK();
+		DDP_LOCK(ddp);
 		if (ddp->ddp_fsat.sat_port != ATADDR_ANYPORT) {
-			return (EISCONN);
+			error = EISCONN;
+			goto out;
 		}
 
 		error = at_pcbconnect(ddp, addr, td);
-		if (error) {
-			return (error);
+		if (error == 0) {
+			error = ddp_output(m, so);
+			at_pcbdisconnect(ddp);
 		}
+out:
+		DDP_UNLOCK(ddp);
+		DDP_LIST_XUNLOCK();
 	} else {
-		if (ddp->ddp_fsat.sat_port == ATADDR_ANYPORT) {
-			return (ENOTCONN);
-		}
-	}
-
-	error = ddp_output(m, so);
-	if (addr != NULL) {
-	    at_pcbdisconnect(ddp);
+		DDP_LOCK(ddp);
+		if (ddp->ddp_fsat.sat_port == ATADDR_ANYPORT)
+			error = ENOTCONN;
+		else
+			error = ddp_output(m, so);
+		DDP_UNLOCK(ddp);
 	}
 	return (error);
 }
@@ -174,20 +201,23 @@ ddp_abort(struct socket *so)
 	if (ddp == NULL) {
 		return (EINVAL);
 	}
+	DDP_LIST_XLOCK();
+	DDP_LOCK(ddp);
 	at_pcbdetach(so, ddp);
+	DDP_LIST_XUNLOCK();
 	return (0);
 }
 
 void 
 ddp_init(void)
 {
-
 	atintrq1.ifq_maxlen = IFQ_MAXLEN;
 	atintrq2.ifq_maxlen = IFQ_MAXLEN;
 	aarpintrq.ifq_maxlen = IFQ_MAXLEN;
 	mtx_init(&atintrq1.ifq_mtx, "at1_inq", NULL, MTX_DEF);
 	mtx_init(&atintrq2.ifq_mtx, "at2_inq", NULL, MTX_DEF);
 	mtx_init(&aarpintrq.ifq_mtx, "aarp_inq", NULL, MTX_DEF);
+	DDP_LIST_LOCK_INIT();
 	netisr_register(NETISR_ATALK1, at1intr, &atintrq1, 0);
 	netisr_register(NETISR_ATALK2, at2intr, &atintrq2, 0);
 	netisr_register(NETISR_AARP, aarpintr, &aarpintrq, 0);
@@ -202,6 +232,7 @@ ddp_clean(void)
     for (ddp = ddpcb_list; ddp != NULL; ddp = ddp->ddp_next) {
 	at_pcbdetach(ddp->ddp_socket, ddp);
     }
+    DDP_LIST_LOCK_DESTROY();
 }
 #endif
 
@@ -220,7 +251,9 @@ at_setsockaddr(struct socket *so, struct sockaddr **nam)
 	if (ddp == NULL) {
 	    return (EINVAL);
 	}
+	DDP_LOCK(ddp);
 	at_sockaddr(ddp, nam);
+	DDP_UNLOCK(ddp);
 	return (0);
 }
 
diff --git a/sys/netatalk/ddp_var.h b/sys/netatalk/ddp_var.h
index 1e74381..6fb3aed 100644
--- a/sys/netatalk/ddp_var.h
+++ b/sys/netatalk/ddp_var.h
@@ -13,6 +13,7 @@ struct ddpcb {
     struct socket	*ddp_socket;
     struct ddpcb	*ddp_prev, *ddp_next;
     struct ddpcb	*ddp_pprev, *ddp_pnext;
+    struct mtx		 ddp_mtx;
 };
 
 #define sotoddpcb(so)	((struct ddpcb *)(so)->so_pcb)
@@ -34,5 +35,6 @@ struct ddpstat {
 extern int	ddp_cksum;
 extern struct ddpcb		*ddpcb_list;
 extern struct pr_usrreqs	ddp_usrreqs;
+extern struct mtx		 ddp_list_mtx;
 #endif
 #endif /* _NETATALK_DDP_VAR_H_ */