From 943bb929afd9720bb6b8583b8e1cb40ef2e777c3 Mon Sep 17 00:00:00 2001
From: Robert Watson <rwatson@FreeBSD.org>
Date: Mon, 12 Jul 2004 04:45:46 +0000
Subject: [PATCH] Introduce a global mtx 'ngsocketlist_mtx' to protect the
 global ng_socket list during insert/delete.

---
 sys/netgraph/ng_socket.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/netgraph/ng_socket.c b/sys/netgraph/ng_socket.c
index 9a140b631ffd..52308f412c2c 100644
--- a/sys/netgraph/ng_socket.c
+++ b/sys/netgraph/ng_socket.c
@@ -55,6 +55,7 @@
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
+#include <sys/mutex.h>
 #include <sys/protosw.h>
 #include <sys/queue.h>
 #include <sys/signalvar.h>
@@ -154,6 +155,9 @@ SYSCTL_INT(_net_graph, OID_AUTO, recvspace, CTLFLAG_RW,
 /* List of all sockets */
 static LIST_HEAD(, ngpcb) ngsocklist;
 
+static struct mtx	ngsocketlist_mtx;
+MTX_SYSINIT(ngsocketlist, &ngsocketlist_mtx, "ng_socketlist", MTX_DEF);
+
 #define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
 
 /* If getting unexplained errors returned, set this to "kdb_enter("X"); */
@@ -525,7 +529,9 @@ ng_attach_common(struct socket *so, int type)
 	pcbp->ng_socket = so;
 
 	/* Add the socket to linked list */
+	mtx_lock(&ngsocketlist_mtx);
 	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
+	mtx_unlock(&ngsocketlist_mtx);
 	return (0);
 }
 
@@ -558,7 +564,9 @@ ng_detach_common(struct ngpcb *pcbp, int which)
 	}
 	pcbp->ng_socket->so_pcb = NULL;
 	pcbp->ng_socket = NULL;
+	mtx_lock(&ngsocketlist_mtx);
 	LIST_REMOVE(pcbp, socks);
+	mtx_unlock(&ngsocketlist_mtx);
 	FREE(pcbp, M_PCB);
 }