syncache_socket(): fix abort path by calling pru_abort directly

On syncache_socket() abort path, the inp's {fport,lport,faddr,laddr}
is either incomplete or half destroyed, which causes tcp_soport()
mapping the socket to a wrong CPU.  However, in syncache code, inp
is only accessed or created by its owner CPU, i.e. we are already on
the inp's owner CPU during the socket aborting.

Add soabort_oncpu(), which calls pru_abort directly.  Use it on
syncache_socket() abort path.

sys/kern/uipc_msg.c

@@ -92,6 +92,18 @@ so_pru_aborta(struct socket *so)
 	lwkt_sendmsg(port, &msg->nm_netmsg.nm_lmsg);
 }
 
+/*
+ * Abort a socket and free it.  Called from soabort_oncpu() only.
+ * Caller must make sure that the current CPU is inpcb's owner CPU.
+ *
+ * The SS_ABORTING flag must already be set.
+ */
+void
+so_pru_abort_oncpu(struct socket *so)
+{
+	so->so_proto->pr_usrreqs->pru_abort(so);
+}
+
 int
 so_pru_accept(struct socket *so, struct sockaddr **nam)
 {

sys/kern/uipc_socket.c

@@ -407,6 +407,15 @@ soaborta(struct socket *so)
 	}
 }
 
+void
+soabort_oncpu(struct socket *so)
+{
+	if ((so->so_state & SS_ABORTING) == 0) {
+		so->so_state |= SS_ABORTING;
+		so_pru_abort_oncpu(so);
+	}
+}
+
 int
 soaccept(struct socket *so, struct sockaddr **nam)
 {

sys/netinet/tcp_syncache.c

@@ -800,7 +800,7 @@ syncache_socket(struct syncache *sc, struct socket *lso, struct mbuf *m)
 
 abort:
 	if (so != NULL)
-		soaborta(so);
+		soabort_oncpu(so);
 	return (NULL);
 }
 

sys/sys/socketops.h

@@ -75,6 +75,7 @@ so_pru_soreceive(struct socket *so, struct sockaddr **paddr, struct uio *uio,
 
 void so_pru_abort (struct socket *so);
 void so_pru_aborta (struct socket *so);
+void so_pru_abort_oncpu (struct socket *so);
 int so_pru_accept (struct socket *so, struct sockaddr **nam);
 int so_pru_attach (struct socket *so, int proto, struct pru_attach_info *ai);
 int so_pru_bind (struct socket *so, struct sockaddr *nam, struct thread *td);

sys/sys/socketvar.h

@@ -357,6 +357,7 @@ int	_ssb_lock (struct signalsockbuf *sb);
 
 void	soabort (struct socket *so);
 void	soaborta (struct socket *so);
+void	soabort_oncpu (struct socket *so);
 int	soaccept (struct socket *so, struct sockaddr **nam);
 struct	socket *soalloc (int waitok);
 int	sobind (struct socket *so, struct sockaddr *nam, struct thread *td);