Lock down a socket, milestone 1.

o Add a mutex (sb_mtx) to struct sockbuf. This protects the data in a
  socket buffer. The mutex in the receive buffer also protects the data
  in struct socket.

o Determine the lock strategy for each members in struct socket.

o Lock down the following members:

  - so_count
  - so_options
  - so_linger
  - so_state

o Remove *_locked() socket APIs.  Make the following socket APIs
  touching the members above now require a locked socket:

 - sodisconnect()
 - soisconnected()
 - soisconnecting()
 - soisdisconnected()
 - soisdisconnecting()
 - sofree()
 - soref()
 - sorele()
 - sorwakeup()
 - sotryfree()
 - sowakeup()
 - sowwakeup()

Reviewed by:	alfred

1 files changed, 12 insertions, 0 deletions

diff --git a/sys/netnatm/natm.c b/sys/netnatm/natm.c
index e0535b6..27a9bd4 100644
--- a/sys/netnatm/natm.c
+++ b/sys/netnatm/natm.c
@@ -134,6 +134,7 @@ natm_usr_detach(struct socket *so)
      */
     npcb_free(npcb, NPCB_DESTROY);	/* drain */
     so->so_pcb = NULL;
+    SOCK_LOCK(so);
     sotryfree(so);
  out:
     splx(s);
@@ -216,7 +217,9 @@ natm_usr_connect(struct socket *so, struct sockaddr *nam, d_thread_t *p)
     }
     splx(s2);
 
+    SOCK_LOCK(so);
     soisconnected(so);
+    SOCK_UNLOCK(so);
 
  out:
     splx(s);
@@ -259,7 +262,9 @@ natm_usr_disconnect(struct socket *so)
     splx(s2);
 
     npcb_free(npcb, NPCB_REMOVE);
+    SOCK_LOCK(so);
     soisdisconnected(so);
+    SOCK_UNLOCK(so);
 
  out:
     splx(s);
@@ -482,6 +487,7 @@ struct proc *p;
 
       npcb_free(npcb, NPCB_DESTROY);	/* drain */
       so->so_pcb = NULL;
+      SOCK_LOCK(so);
       sotryfree(so);
 
       break;
@@ -552,7 +558,9 @@ struct proc *p;
       }
       splx(s2);
 
+      SOCK_LOCK(so);
       soisconnected(so);
+      SOCK_UNLOCK(so);
 
       break;
 
@@ -579,7 +587,9 @@ struct proc *p;
       splx(s2);
 
       npcb_free(npcb, NPCB_REMOVE);
+      SOCK_LOCK(so);
       soisdisconnected(so);
+      SOCK_UNLOCK(so);
 
       break;
 
@@ -752,7 +762,9 @@ m->m_pkthdr.rcvif = NULL;	/* null it out to be safe */
     natm_sookbytes += m->m_pkthdr.len;
 #endif
     sbappendrecord(&so->so_rcv, m);
+    SOCK_LOCK(so);
     sorwakeup(so);
+    SOCK_UNLOCK(so);
   } else {
 #ifdef NATM_STAT
     natm_sodropcnt++;