Modify the kernel to use the new pr_usrreqs interface rather than the old

pr_usrreq mechanism which was poorly designed and error-prone.  This
commit renames pr_usrreq to pr_ousrreq so that old code which depended on it
would break in an obvious manner.  This commit also implements the new
interface for TCP, although the old function is left as an example
(#ifdef'ed out).  This commit ALSO fixes a longstanding bug in the
TCP timer processing (introduced by davidg on 1995/04/12) which caused
timer processing on a TCB to always stop after a single timer had
expired (because it misinterpreted the return value from tcp_usrreq()
to indicate that the TCB had been deleted).  Finally, some code
related to polling has been deleted from if.c because it is not
relevant t -current and doesn't look at all like my current code.

1 files changed, 428 insertions, 1 deletions

diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c
index bf6c89c..c7c62b2 100644
--- a/sys/netinet/tcp_usrreq.c
+++ b/sys/netinet/tcp_usrreq.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
- *	$Id: tcp_usrreq.c,v 1.21 1995/12/06 23:37:42 bde Exp $
+ *	$Id: tcp_usrreq.c,v 1.22 1996/03/11 15:13:37 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -77,6 +77,8 @@ static struct tcpcb *
 		tcp_disconnect __P((struct tcpcb *));
 static struct tcpcb *
 		tcp_usrclosed __P((struct tcpcb *));
+
+#ifdef notdef
 /*
  * Process a TCP user request for TCP tb.  If this is a send request
  * then m is the mbuf chain of send data.  If this is a timer expiration
@@ -391,6 +393,431 @@ tcp_usrreq(so, req, m, nam, control)
 	splx(s);
 	return (error);
 }
+#endif
+
+#ifdef TCPDEBUG
+#define	TCPDEBUG0	int ostate
+#define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
+#define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) && \
+				tcp_trace(TA_USER, ostate, tp, 0, req)
+#else
+#define	TCPDEBUG0
+#define	TCPDEBUG1()
+#define	TCPDEBUG2(req)
+#endif
+
+/*
+ * TCP attaches to socket via pru_attach(), reserving space,
+ * and an internet control block.
+ */
+static int
+tcp_usr_attach(struct socket *so, int proto)
+{
+	int s = splnet();
+	int error;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp = 0;
+	TCPDEBUG0;
+
+	TCPDEBUG1();
+	if (inp) {
+		error = EISCONN;
+		goto out;
+	}
+
+	error = tcp_attach(so);
+	if (error)
+		goto out;
+
+	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
+		so->so_linger = TCP_LINGERTIME * hz;
+	tp = sototcpcb(so);
+out:
+	TCPDEBUG2(PRU_ATTACH);
+	splx(s);
+	return error;
+}
+
+/*
+ * pru_detach() detaches the TCP protocol from the socket.
+ * If the protocol state is non-embryonic, then can't
+ * do this directly: have to initiate a pru_disconnect(),
+ * which may finish later; embryonic TCB's can just
+ * be discarded here.
+ */
+static int
+tcp_usr_detach(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	TCPDEBUG0;
+
+	if (inp == 0) {
+		splx(s);
+		return EINVAL;	/* XXX */
+	}
+	tp = intotcpcb(inp);
+	TCPDEBUG1();
+	if (tp->t_state > TCPS_LISTEN)
+		tp = tcp_disconnect(tp);
+	else
+		tp = tcp_close(tp);
+
+	TCPDEBUG2(PRU_DETACH);
+	splx(s);
+	return error;
+}
+
+#define	COMMON_START()	TCPDEBUG0; \
+			do { \
+				     if (inp == 0) { \
+					     splx(s); \
+					     return EINVAL; \
+				     } \
+				     tp = intotcpcb(inp); \
+				     TCPDEBUG1(); \
+		     } while(0)
+			     
+#define COMMON_END(req)	out: TCPDEBUG2(req); splx(s); return error; goto out
+
+
+/*
+ * Give the socket an address.
+ */
+static int
+tcp_usr_bind(struct socket *so, struct mbuf *nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	struct sockaddr_in *sinp;
+
+	COMMON_START();
+
+	/*
+	 * Must check for multicast addresses and disallow binding
+	 * to them.
+	 */
+	sinp = mtod(nam, struct sockaddr_in *);
+	if (sinp->sin_family == AF_INET &&
+	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}
+	error = in_pcbbind(inp, nam);
+	if (error)
+		goto out;
+	COMMON_END(PRU_BIND);
+
+}
+
+/*
+ * Prepare to accept connections.
+ */
+static int
+tcp_usr_listen(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	if (inp->inp_lport == 0)
+		error = in_pcbbind(inp, NULL);
+	if (error == 0)
+		tp->t_state = TCPS_LISTEN;
+	COMMON_END(PRU_LISTEN);
+}
+
+/*
+ * Initiate connection to peer.
+ * Create a template for use in transmissions on this connection.
+ * Enter SYN_SENT state, and mark socket as connecting.
+ * Start keep-alive timer, and seed output sequence space.
+ * Send initial segment on connection.
+ */
+static int
+tcp_usr_connect(struct socket *so, struct mbuf *nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	struct sockaddr_in *sinp;
+
+	COMMON_START();
+
+	/*
+	 * Must disallow TCP ``connections'' to multicast addresses.
+	 */
+	sinp = mtod(nam, struct sockaddr_in *);
+	if (sinp->sin_family == AF_INET
+	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}
+
+	if ((error = tcp_connect(tp, nam)) != 0)
+		goto out;
+	error = tcp_output(tp);
+	COMMON_END(PRU_CONNECT);
+}
+
+/*
+ * Initiate disconnect from peer.
+ * If connection never passed embryonic stage, just drop;
+ * else if don't need to let data drain, then can just drop anyways,
+ * else have to begin TCP shutdown process: mark socket disconnecting,
+ * drain unread data, state switch to reflect user close, and
+ * send segment (e.g. FIN) to peer.  Socket will be really disconnected
+ * when peer sends FIN and acks ours.
+ *
+ * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
+ */
+static int
+tcp_usr_disconnect(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	tp = tcp_disconnect(tp);
+	COMMON_END(PRU_DISCONNECT);
+}
+
+/*
+ * Accept a connection.  Essentially all the work is
+ * done at higher levels; just return the address
+ * of the peer, storing through addr.
+ */
+static int
+tcp_usr_accept(struct socket *so, struct mbuf *nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	in_setpeeraddr(inp, nam);
+	COMMON_END(PRU_ACCEPT);
+}
+
+/*
+ * Mark the connection as being incapable of further output.
+ */
+static int
+tcp_usr_shutdown(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	socantsendmore(so);
+	tp = tcp_usrclosed(tp);
+	if (tp)
+		error = tcp_output(tp);
+	COMMON_END(PRU_SHUTDOWN);
+}
+
+/*
+ * After a receive, possibly send window update to peer.
+ */
+static int
+tcp_usr_rcvd(struct socket *so, int flags)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	tcp_output(tp);
+	COMMON_END(PRU_RCVD);
+}
+
+/*
+ * Do a send by putting data in output queue and updating urgent
+ * marker if URG set.  Possibly send more data.
+ */
+static int
+tcp_usr_send(struct socket *so, int flags, struct mbuf *m, struct mbuf *nam,
+	     struct mbuf *control)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	if (control && control->m_len) {
+		m_freem(control); /* XXX shouldn't caller do this??? */
+		if (m)
+			m_freem(m);
+		return EINVAL;
+	}
+
+	if(!(flags & PRUS_OOB)) {
+		sbappend(&so->so_snd, m);
+		if (nam && tp->t_state < TCPS_SYN_SENT) {
+			/*
+			 * Do implied connect if not yet connected,
+			 * initialize window to default value, and
+			 * initialize maxseg/maxopd using peer's cached
+			 * MSS.
+			 */
+			error = tcp_connect(tp, nam);
+			if (error)
+				goto out;
+			tp->snd_wnd = TTCP_CLIENT_SND_WND;
+			tcp_mss(tp, -1);
+		}
+
+		if (flags & PRUS_EOF) {
+			/*
+			 * Close the send side of the connection after
+			 * the data is sent.
+			 */
+			socantsendmore(so);
+			tp = tcp_usrclosed(tp);
+		}
+		if (tp != NULL)
+			error = tcp_output(tp);
+	} else {
+		if (sbspace(&so->so_snd) < -512) {
+			m_freem(m);
+			error = ENOBUFS;
+			goto out;
+		}
+		/*
+		 * According to RFC961 (Assigned Protocols),
+		 * the urgent pointer points to the last octet
+		 * of urgent data.  We continue, however,
+		 * to consider it to indicate the first octet
+		 * of data past the urgent section.
+		 * Otherwise, snd_up should be one lower.
+		 */
+		sbappend(&so->so_snd, m);
+		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
+		tp->t_force = 1;
+		error = tcp_output(tp);
+		tp->t_force = 0;
+	}
+	COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB : 
+		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
+}
+
+/*
+ * Abort the TCP.
+ */
+static int
+tcp_usr_abort(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	tp = tcp_drop(tp, ECONNABORTED);
+	COMMON_END(PRU_ABORT);
+}
+
+/*
+ * Fill in st_bklsize for fstat() operations on a socket.
+ */
+static int
+tcp_usr_sense(struct socket *so, struct stat *sb)
+{
+	int s = splnet();
+
+	sb->st_blksize = so->so_snd.sb_hiwat;
+	splx(s);
+	return 0;
+}
+
+/*
+ * Receive out-of-band data.
+ */
+static int
+tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	if ((so->so_oobmark == 0 &&
+	     (so->so_state & SS_RCVATMARK) == 0) ||
+	    so->so_options & SO_OOBINLINE ||
+	    tp->t_oobflags & TCPOOB_HADDATA) {
+		error = EINVAL;
+		goto out;
+	}
+	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
+		error = EWOULDBLOCK;
+		goto out;
+	}
+	m->m_len = 1;
+	*mtod(m, caddr_t) = tp->t_iobc;
+	if ((flags & MSG_PEEK) == 0)
+		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
+	COMMON_END(PRU_RCVOOB);
+}
+
+static int
+tcp_usr_sockaddr(struct socket *so, struct mbuf *nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	in_setsockaddr(inp, nam);
+	COMMON_END(PRU_SOCKADDR);
+}
+
+static int
+tcp_usr_peeraddr(struct socket *so, struct mbuf *nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	in_setpeeraddr(inp, nam);
+	COMMON_END(PRU_PEERADDR);
+}
+
+/*
+ * XXX - this should just be a call to in_control, but we need to get
+ * the types worked out.
+ */
+static int
+tcp_usr_control(struct socket *so, int cmd, caddr_t arg, struct ifnet *ifp)
+{
+	return in_control(so, cmd, arg, ifp);
+}
+
+/* xxx - should be const */
+struct pr_usrreqs tcp_usrreqs = {
+	tcp_usr_abort, tcp_usr_accept, tcp_usr_attach, tcp_usr_bind,
+	tcp_usr_connect, pru_connect2_notsupp, tcp_usr_control, tcp_usr_detach,
+	tcp_usr_disconnect, tcp_usr_listen, tcp_usr_peeraddr, tcp_usr_rcvd,
+	tcp_usr_rcvoob, tcp_usr_send, tcp_usr_sense, tcp_usr_shutdown,
+	tcp_usr_sockaddr
+};
 
 /*
  * Common subroutine to open a TCP connection to remote host specified