[unix-history] / usr / src / sys / netinet / tcp_usrreq.c

/*	tcp_usrreq.c	1.70	82/11/03	*/

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mbuf.h"
#include "../h/socket.h"
#include "../h/socketvar.h"
#include "../h/protosw.h"

#include "../net/if.h"
#include "../net/route.h"
#include "../netinet/in.h"
#include "../netinet/in_pcb.h"
#include "../netinet/in_systm.h"
#include "../netinet/ip.h"
#include "../netinet/ip_var.h"
#include "../netinet/tcp.h"
#include "../netinet/tcp_fsm.h"
#include "../netinet/tcp_seq.h"
#include "../netinet/tcp_timer.h"
#include "../netinet/tcp_var.h"
#include "../netinet/tcpip.h"
#include "../netinet/tcp_debug.h"
#include <errno.h>

/*
 * TCP protocol interface to socket abstraction.
 */
extern	char *tcpstates[];
struct	tcpcb *tcp_newtcpcb();

/*
 * 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
 * (called from the software clock routine), then timertype tells which timer.
 */
/*ARGSUSED*/
tcp_usrreq(so, req, m, nam, opt)
	struct socket *so;
	int req;
	struct mbuf *m, *nam;
	struct socketopt *opt;
{
	register struct inpcb *inp = sotoinpcb(so);
	register struct tcpcb *tp;
	int s = splnet();
	int error = 0;
	int ostate;

	/*
	 * When a TCP is attached to a socket, then there will be
	 * a (struct inpcb) pointed at by the socket, and this
	 * structure will point at a subsidary (struct tcpcb).
	 */
	if (inp == 0 && req != PRU_ATTACH) {
		splx(s);
		return (EINVAL);		/* XXX */
	}
	if (inp) {
		tp = intotcpcb(inp);
		/* WHAT IF TP IS 0? */
#ifdef KPROF
		tcp_acounts[tp->t_state][req]++;
#endif
		ostate = tp->t_state;
	} else
		ostate = 0;
	switch (req) {

	/*
	 * TCP attaches to socket via PRU_ATTACH, reserving space,
	 * and an internet control block.
	 */
	case PRU_ATTACH:
		if (inp) {
			error = EISCONN;
			break;
		}
		error = tcp_attach(so);
		if (error)
			break;
		if ((so->so_options & SO_DONTLINGER) == 0)
			so->so_linger = TCP_LINGERTIME;
		tp = sototcpcb(so);
		break;

	/*
	 * 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.
	 */
	case PRU_DETACH:
		if (tp->t_state > TCPS_LISTEN)
			tcp_disconnect(tp);
		else {
			tcp_close(tp);
			tp = 0;
		}
		break;

	/*
	 * Give the socket an address.
	 */
	case PRU_BIND:
		error = in_pcbbind(inp, nam);
		if (error)
			break;
		break;

	/*
	 * Prepare to accept connections.
	 */
	case PRU_LISTEN:
		if (inp->inp_lport == 0)
			error = in_pcbbind(inp, (struct mbuf *)0);
		if (error == 0)
			tp->t_state = TCPS_LISTEN;
		break;

	/*
	 * 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.
	 */
	case PRU_CONNECT:
		if (inp->inp_lport == 0) {
			error = in_pcbbind(inp, (struct mbuf *)0);
			if (error)
				break;
		}
		error = in_pcbconnect(inp, nam);
		if (error)
			break;
		tp->t_template = tcp_template(tp);
		if (tp->t_template == 0) {
			in_pcbdisconnect(inp);
			error = ENOBUFS;
			break;
		}
		soisconnecting(so);
		tp->t_state = TCPS_SYN_SENT;
		tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
		tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2;
		tcp_sendseqinit(tp);
		error = tcp_output(tp);
		break;

	/*
	 * 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.
	 */
	case PRU_DISCONNECT:
		tcp_disconnect(tp);
		break;

	/*
	 * Accept a connection.  Essentially all the work is
	 * done at higher levels; just return the address
	 * of the peer, storing through addr.
	 */
	case PRU_ACCEPT: {
		struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *);

		nam->m_len = sizeof (struct sockaddr_in);
		sin->sin_family = AF_INET;
		sin->sin_port = inp->inp_fport;
		sin->sin_addr = inp->inp_faddr;
		break;
		}

	/*
	 * Mark the connection as being incapable of further output.
	 */
	case PRU_SHUTDOWN:
		socantsendmore(so);
		tcp_usrclosed(tp);
		error = tcp_output(tp);
		break;

	/*
	 * After a receive, possibly send window update to peer.
	 */
	case PRU_RCVD:
		(void) tcp_output(tp);
		break;

	/*
	 * Do a send by putting data in output queue and updating urgent
	 * marker if URG set.  Possibly send more data.
	 */
	case PRU_SEND:
		sbappend(&so->so_snd, m);
#ifdef notdef
		if (tp->t_flags & TF_PUSH)
			tp->snd_end = tp->snd_una + so->so_snd.sb_cc;
#endif
		error = tcp_output(tp);
		break;

	/*
	 * Abort the TCP.
	 */
	case PRU_ABORT:
		tcp_drop(tp, ECONNABORTED);
		break;

/* SOME AS YET UNIMPLEMENTED HOOKS */
	case PRU_CONTROL:
		error = EOPNOTSUPP;
		break;

	case PRU_SENSE:
		error = EOPNOTSUPP;
		break;
/* END UNIMPLEMENTED HOOKS */

	case PRU_RCVOOB:
		if (so->so_oobmark == 0 &&
		    (so->so_state & SS_RCVATMARK) == 0) {
			error = EINVAL;
			break;
		}
		if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
			error = EWOULDBLOCK;
			break;
		}
		m->m_len = 1;
		*mtod(m, caddr_t) = tp->t_iobc;
		break;

	case PRU_SENDOOB:
		if (sbspace(&so->so_snd) < -512) {
			error = ENOBUFS;
			break;
		}
		tp->snd_up = tp->snd_una + so->so_snd.sb_cc + 1;
		sbappend(&so->so_snd, m);
		tp->t_force = 1;
		error = tcp_output(tp);
		tp->t_force = 0;
		break;

	case PRU_SOCKADDR:
		in_setsockaddr(inp, nam);
		break;

	/*
	 * TCP slow timer went off; going through this
	 * routine for tracing's sake.
	 */
	case PRU_SLOWTIMO:
		tcp_timers(tp, (int)nam);
		req |= (int)nam << 8;		/* for debug's sake */
		break;

	default:
		panic("tcp_usrreq");
	}
	if (tp && (so->so_options & SO_DEBUG))
		tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req);
	splx(s);
	return (error);
}

int	tcp_sendspace = 1024*2;
int	tcp_recvspace = 1024*2;
/*
 * Attach TCP protocol to socket, allocating
 * internet protocol control block, tcp control block,
 * bufer space, and entering LISTEN state if to accept connections.
 */
tcp_attach(so)
	struct socket *so;
{
	register struct tcpcb *tp;
	struct inpcb *inp;
	int error;

	error = soreserve(so, tcp_sendspace, tcp_recvspace);
	if (error)
		goto bad;
	error = in_pcballoc(so, &tcb);
	if (error)
		goto bad;
	inp = sotoinpcb(so);
	tp = tcp_newtcpcb(inp);
	if (tp == 0) {
		error = ENOBUFS;
		goto bad2;
	}
	tp->t_state = TCPS_CLOSED;
	return (0);
bad2:
	in_pcbdetach(inp);
bad:
	return (error);
}

/*
 * Initiate (or continue) disconnect.
 * If embryonic state, just send reset (once).
 * If not in ``let data drain'' option, just drop.
 * Otherwise (hard), mark socket disconnecting and drop
 * current input data; switch states based on user close, and
 * send segment to peer (with FIN).
 */
tcp_disconnect(tp)
	struct tcpcb *tp;
{
	struct socket *so = tp->t_inpcb->inp_socket;

	if (tp->t_state < TCPS_ESTABLISHED)
		tcp_close(tp);
	else if (so->so_linger == 0)
		tcp_drop(tp, 0);
	else {
		soisdisconnecting(so);
		sbflush(&so->so_rcv);
		tcp_usrclosed(tp);
		(void) tcp_output(tp);
	}
}

/*
 * User issued close, and wish to trail through shutdown states:
 * if never received SYN, just forget it.  If got a SYN from peer,
 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
 * If already got a FIN from peer, then almost done; go to LAST_ACK
 * state.  In all other cases, have already sent FIN to peer (e.g.
 * after PRU_SHUTDOWN), and just have to play tedious game waiting
 * for peer to send FIN or not respond to keep-alives, etc.
 * We can let the user exit from the close as soon as the FIN is acked.
 */
tcp_usrclosed(tp)
	struct tcpcb *tp;
{

	switch (tp->t_state) {

	case TCPS_LISTEN:
	case TCPS_SYN_SENT:
		tp->t_state = TCPS_CLOSED;
		tcp_close(tp);
		break;

	case TCPS_SYN_RECEIVED:
	case TCPS_ESTABLISHED:
		tp->t_state = TCPS_FIN_WAIT_1;
		break;

	case TCPS_CLOSE_WAIT:
		tp->t_state = TCPS_LAST_ACK;
		break;
	}
	if (tp->t_state >= TCPS_FIN_WAIT_2)
		soisdisconnected(tp->t_inpcb->inp_socket);
}
Commit	Line	Data
59965020	1	/* tcp_usrreq.c 1.70 82/11/03 */
72f24d7d	2
4eb5d593	3	#include "../h/param.h"
72f24d7d	4	#include "../h/systm.h"
dad64fdf BJ	5	#include "../h/mbuf.h"
dad64fdf BJ	6	#include "../h/socket.h"
eee3ab16 BJ	7	#include "../h/socketvar.h"
eee3ab16 BJ	8	#include "../h/protosw.h"
6e7edb25 BJ	9
6e7edb25 BJ	10	#include "../net/if.h"
c124e997	11	#include "../net/route.h"
6e7edb25	12	#include "../netinet/in.h"
839fe741 BJ	13	#include "../netinet/in_pcb.h"
839fe741 BJ	14	#include "../netinet/in_systm.h"
839fe741 BJ	15	#include "../netinet/ip.h"
	16	#include "../netinet/ip_var.h"
	17	#include "../netinet/tcp.h"
	18	#include "../netinet/tcp_fsm.h"
	19	#include "../netinet/tcp_seq.h"
	20	#include "../netinet/tcp_timer.h"
	21	#include "../netinet/tcp_var.h"
	22	#include "../netinet/tcpip.h"
	23	#include "../netinet/tcp_debug.h"
8a2f82db	24	#include <errno.h>
eee3ab16	25
290e0b0a BJ	26	/*
	27	* TCP protocol interface to socket abstraction.
	28	*/
	29	extern char *tcpstates[];
4ad99bae	30	struct tcpcb *tcp_newtcpcb();
290e0b0a	31
9c5022e3	32	/*
290e0b0a	33	* Process a TCP user request for TCP tb. If this is a send request
9c5022e3 BJ	34	* then m is the mbuf chain of send data. If this is a timer expiration
	35	* (called from the software clock routine), then timertype tells which timer.
	36	*/
a8d3bf7f	37	/ARGSUSED/
8075bb0e	38	tcp_usrreq(so, req, m, nam, opt)
eee3ab16 BJ	39	struct socket *so;
eee3ab16 BJ	40	int req;
8075bb0e BJ	41	struct mbuf m, nam;
8075bb0e BJ	42	struct socketopt *opt;
4eb5d593	43	{
53a5409e	44	register struct inpcb *inp = sotoinpcb(so);
cdad2eb1	45	register struct tcpcb *tp;
72f24d7d	46	int s = splnet();
eee3ab16	47	int error = 0;
17b82ed4	48	int ostate;
72f24d7d	49
53a5409e	50	/*
290e0b0a BJ	51	* When a TCP is attached to a socket, then there will be
	52	* a (struct inpcb) pointed at by the socket, and this
	53	* structure will point at a subsidary (struct tcpcb).
53a5409e	54	*/
0974b45c	55	if (inp == 0 && req != PRU_ATTACH) {
a6503abf	56	splx(s);
290e0b0a	57	return (EINVAL); /* XXX */
a6503abf BJ	58	}
a6503abf BJ	59	if (inp) {
cdad2eb1	60	tp = intotcpcb(inp);
8075bb0e	61	/* WHAT IF TP IS 0? */
9c5022e3	62	#ifdef KPROF
a6503abf	63	tcp_acounts[tp->t_state][req]++;
9c5022e3	64	#endif
17b82ed4	65	ostate = tp->t_state;
ebf42a75 BJ	66	} else
ebf42a75 BJ	67	ostate = 0;
eee3ab16	68	switch (req) {
4eb5d593	69
290e0b0a BJ	70	/*
290e0b0a BJ	71	* TCP attaches to socket via PRU_ATTACH, reserving space,
8075bb0e	72	* and an internet control block.
290e0b0a	73	*/
eee3ab16	74	case PRU_ATTACH:
4ad99bae	75	if (inp) {
eee3ab16	76	error = EISCONN;
cdad2eb1	77	break;
53a5409e	78	}
a1edc12b	79	error = tcp_attach(so);
a6503abf	80	if (error)
4ad99bae	81	break;
8e65fd66 BJ	82	if ((so->so_options & SO_DONTLINGER) == 0)
8e65fd66 BJ	83	so->so_linger = TCP_LINGERTIME;
290e0b0a	84	tp = sototcpcb(so);
72f24d7d	85	break;
4eb5d593	86
290e0b0a BJ	87	/*
	88	* PRU_DETACH detaches the TCP protocol from the socket.
	89	* If the protocol state is non-embryonic, then can't
	90	* do this directly: have to initiate a PRU_DISCONNECT,
	91	* which may finish later; embryonic TCB's can just
	92	* be discarded here.
	93	*/
eee3ab16	94	case PRU_DETACH:
290e0b0a BJ	95	if (tp->t_state > TCPS_LISTEN)
	96	tcp_disconnect(tp);
	97	else {
	98	tcp_close(tp);
	99	tp = 0;
	100	}
eee3ab16 BJ	101	break;
eee3ab16 BJ	102
8075bb0e BJ	103	/*
	104	* Give the socket an address.
	105	*/
	106	case PRU_BIND:
	107	error = in_pcbbind(inp, nam);
	108	if (error)
	109	break;
	110	break;
	111
	112	/*
	113	* Prepare to accept connections.
	114	*/
	115	case PRU_LISTEN:
	116	if (inp->inp_lport == 0)
	117	error = in_pcbbind(inp, (struct mbuf *)0);
	118	if (error == 0)
	119	tp->t_state = TCPS_LISTEN;
	120	break;
	121
290e0b0a BJ	122	/*
	123	* Initiate connection to peer.
	124	* Create a template for use in transmissions on this connection.
	125	* Enter SYN_SENT state, and mark socket as connecting.
	126	* Start keep-alive timer, and seed output sequence space.
	127	* Send initial segment on connection.
	128	*/
eee3ab16	129	case PRU_CONNECT:
8075bb0e BJ	130	if (inp->inp_lport == 0) {
	131	error = in_pcbbind(inp, (struct mbuf *)0);
	132	if (error)
	133	break;
	134	}
	135	error = in_pcbconnect(inp, nam);
4ad99bae	136	if (error)
53a5409e	137	break;
b454c3ea	138	tp->t_template = tcp_template(tp);
290e0b0a BJ	139	if (tp->t_template == 0) {
	140	in_pcbdisconnect(inp);
	141	error = ENOBUFS;
	142	break;
	143	}
53a5409e	144	soisconnecting(so);
a6503abf	145	tp->t_state = TCPS_SYN_SENT;
4aed14e3 BJ	146	tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
	147	tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2;
	148	tcp_sendseqinit(tp);
8a2f82db	149	error = tcp_output(tp);
72f24d7d	150	break;
4eb5d593	151
290e0b0a BJ	152	/*
	153	* Initiate disconnect from peer.
	154	* If connection never passed embryonic stage, just drop;
	155	* else if don't need to let data drain, then can just drop anyways,
	156	* else have to begin TCP shutdown process: mark socket disconnecting,
	157	* drain unread data, state switch to reflect user close, and
	158	* send segment (e.g. FIN) to peer. Socket will be really disconnected
	159	* when peer sends FIN and acks ours.
	160	*
	161	* SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
	162	*/
	163	case PRU_DISCONNECT:
	164	tcp_disconnect(tp);
4aed14e3 BJ	165	break;
4aed14e3 BJ	166
290e0b0a BJ	167	/*
	168	* Accept a connection. Essentially all the work is
	169	* done at higher levels; just return the address
	170	* of the peer, storing through addr.
	171	*/
1acff8ec	172	case PRU_ACCEPT: {
8075bb0e	173	struct sockaddr_in sin = mtod(nam, struct sockaddr_in );
1acff8ec	174
8075bb0e BJ	175	nam->m_len = sizeof (struct sockaddr_in);
	176	sin->sin_family = AF_INET;
	177	sin->sin_port = inp->inp_fport;
	178	sin->sin_addr = inp->inp_faddr;
eee3ab16	179	break;
8075bb0e	180	}
eee3ab16	181
290e0b0a BJ	182	/*
	183	* Mark the connection as being incapable of further output.
	184	*/
eee3ab16	185	case PRU_SHUTDOWN:
0974b45c	186	socantsendmore(so);
4aed14e3	187	tcp_usrclosed(tp);
8a2f82db	188	error = tcp_output(tp);
72f24d7d BJ	189	break;
72f24d7d BJ	190
290e0b0a BJ	191	/*
	192	* After a receive, possibly send window update to peer.
	193	*/
eee3ab16	194	case PRU_RCVD:
f1b2fa5b	195	(void) tcp_output(tp);
72f24d7d BJ	196	break;
72f24d7d BJ	197
290e0b0a BJ	198	/*
	199	* Do a send by putting data in output queue and updating urgent
	200	* marker if URG set. Possibly send more data.
	201	*/
eee3ab16	202	case PRU_SEND:
a6503abf	203	sbappend(&so->so_snd, m);
8a2f82db	204	#ifdef notdef
0974b45c	205	if (tp->t_flags & TF_PUSH)
a6503abf	206	tp->snd_end = tp->snd_una + so->so_snd.sb_cc;
8a2f82db SL	207	#endif
8a2f82db SL	208	error = tcp_output(tp);
72f24d7d BJ	209	break;
72f24d7d BJ	210
290e0b0a BJ	211	/*
	212	* Abort the TCP.
	213	*/
eee3ab16	214	case PRU_ABORT:
a6503abf	215	tcp_drop(tp, ECONNABORTED);
72f24d7d BJ	216	break;
72f24d7d BJ	217
290e0b0a	218	/* SOME AS YET UNIMPLEMENTED HOOKS */
eee3ab16	219	case PRU_CONTROL:
53a5409e	220	error = EOPNOTSUPP;
eee3ab16 BJ	221	break;
eee3ab16 BJ	222
f1b2fa5b BJ	223	case PRU_SENSE:
	224	error = EOPNOTSUPP;
	225	break;
0244dbc7	226	/* END UNIMPLEMENTED HOOKS */
f1b2fa5b BJ	227
f1b2fa5b BJ	228	case PRU_RCVOOB:
8b5a83bb BJ	229	if (so->so_oobmark == 0 &&
8b5a83bb BJ	230	(so->so_state & SS_RCVATMARK) == 0) {
0244dbc7 BJ	231	error = EINVAL;
	232	break;
	233	}
b2db9217	234	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
8b5a83bb	235	error = EWOULDBLOCK;
b2db9217	236	break;
8b5a83bb	237	}
283ea225	238	m->m_len = 1;
b2db9217	239	*mtod(m, caddr_t) = tp->t_iobc;
f1b2fa5b BJ	240	break;
	241
	242	case PRU_SENDOOB:
8b5a83bb BJ	243	if (sbspace(&so->so_snd) < -512) {
	244	error = ENOBUFS;
	245	break;
	246	}
0244dbc7 BJ	247	tp->snd_up = tp->snd_una + so->so_snd.sb_cc + 1;
0244dbc7 BJ	248	sbappend(&so->so_snd, m);
b2db9217	249	tp->t_force = 1;
8a2f82db	250	error = tcp_output(tp);
b2db9217	251	tp->t_force = 0;
f1b2fa5b BJ	252	break;
f1b2fa5b BJ	253
126472ab	254	case PRU_SOCKADDR:
8075bb0e	255	in_setsockaddr(inp, nam);
126472ab SL	256	break;
126472ab SL	257
290e0b0a BJ	258	/*
	259	* TCP slow timer went off; going through this
	260	* routine for tracing's sake.
	261	*/
eee3ab16	262	case PRU_SLOWTIMO:
8075bb0e BJ	263	tcp_timers(tp, (int)nam);
8075bb0e BJ	264	req \|= (int)nam << 8; /* for debug's sake */
eee3ab16 BJ	265	break;
eee3ab16 BJ	266
9c5022e3 BJ	267	default:
9c5022e3 BJ	268	panic("tcp_usrreq");
72f24d7d	269	}
17b82ed4 BJ	270	if (tp && (so->so_options & SO_DEBUG))
17b82ed4 BJ	271	tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req);
72f24d7d	272	splx(s);
53a5409e	273	return (error);
4eb5d593	274	}
4aed14e3	275
306f91c9	276	int tcp_sendspace = 1024*2;
1bc20e72	277	int tcp_recvspace = 1024*2;
290e0b0a BJ	278	/*
	279	* Attach TCP protocol to socket, allocating
	280	* internet protocol control block, tcp control block,
	281	* bufer space, and entering LISTEN state if to accept connections.
	282	*/
8075bb0e	283	tcp_attach(so)
290e0b0a	284	struct socket *so;
290e0b0a BJ	285	{
	286	register struct tcpcb *tp;
	287	struct inpcb *inp;
	288	int error;
	289
59965020	290	error = soreserve(so, tcp_sendspace, tcp_recvspace);
ebf42a75 BJ	291	if (error)
	292	goto bad;
	293	error = in_pcballoc(so, &tcb);
290e0b0a	294	if (error)
8075bb0e BJ	295	goto bad;
8075bb0e BJ	296	inp = sotoinpcb(so);
290e0b0a	297	tp = tcp_newtcpcb(inp);
ebf42a75 BJ	298	if (tp == 0) {
	299	error = ENOBUFS;
	300	goto bad2;
	301	}
8075bb0e	302	tp->t_state = TCPS_CLOSED;
290e0b0a	303	return (0);
ebf42a75 BJ	304	bad2:
	305	in_pcbdetach(inp);
	306	bad:
	307	return (error);
290e0b0a BJ	308	}
	309
	310	/*
	311	* Initiate (or continue) disconnect.
	312	* If embryonic state, just send reset (once).
	313	* If not in ``let data drain'' option, just drop.
	314	* Otherwise (hard), mark socket disconnecting and drop
	315	* current input data; switch states based on user close, and
	316	* send segment to peer (with FIN).
	317	*/
	318	tcp_disconnect(tp)
	319	struct tcpcb *tp;
	320	{
	321	struct socket *so = tp->t_inpcb->inp_socket;
	322
	323	if (tp->t_state < TCPS_ESTABLISHED)
	324	tcp_close(tp);
8e65fd66	325	else if (so->so_linger == 0)
290e0b0a BJ	326	tcp_drop(tp, 0);
	327	else {
	328	soisdisconnecting(so);
	329	sbflush(&so->so_rcv);
	330	tcp_usrclosed(tp);
	331	(void) tcp_output(tp);
	332	}
	333	}
	334
	335	/*
	336	* User issued close, and wish to trail through shutdown states:
	337	* if never received SYN, just forget it. If got a SYN from peer,
	338	* but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
	339	* If already got a FIN from peer, then almost done; go to LAST_ACK
	340	* state. In all other cases, have already sent FIN to peer (e.g.
	341	* after PRU_SHUTDOWN), and just have to play tedious game waiting
	342	* for peer to send FIN or not respond to keep-alives, etc.
085a0b90	343	* We can let the user exit from the close as soon as the FIN is acked.
290e0b0a	344	*/
4aed14e3 BJ	345	tcp_usrclosed(tp)
	346	struct tcpcb *tp;
	347	{
	348
4aed14e3 BJ	349	switch (tp->t_state) {
	350
	351	case TCPS_LISTEN:
	352	case TCPS_SYN_SENT:
	353	tp->t_state = TCPS_CLOSED;
	354	tcp_close(tp);
	355	break;
	356
	357	case TCPS_SYN_RECEIVED:
	358	case TCPS_ESTABLISHED:
	359	tp->t_state = TCPS_FIN_WAIT_1;
	360	break;
	361
	362	case TCPS_CLOSE_WAIT:
	363	tp->t_state = TCPS_LAST_ACK;
	364	break;
	365	}
085a0b90 BJ	366	if (tp->t_state >= TCPS_FIN_WAIT_2)
085a0b90 BJ	367	soisdisconnected(tp->t_inpcb->inp_socket);
4aed14e3	368	}