[unix-history] / usr / src / sys / kern / uipc_socket2.c

/*	uipc_socket2.c	4.17	81/12/22	*/

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/file.h"
#include "../h/inode.h"
#include "../h/buf.h"
#include "../h/mbuf.h"
#include "../h/protosw.h"
#include "../h/socket.h"
#include "../h/socketvar.h"
#include "../net/in.h"
#include "../net/in_systm.h"

/*
 * Primitive routines for operating on sockets and socket buffers
 */

/*
 * Procedures to manipulate state flags of socket
 * and do appropriate wakeups.  Normal sequence is that
 * soisconnecting() is called during processing of connect() call,
 * resulting in an eventual call to soisconnected() if/when the
 * connection is established.  When the connection is torn down
 * soisdisconnecting() is called during processing of disconnect() call,
 * and soisdisconnected() is called when the connection to the peer
 * is totally severed.  The semantics of these routines are such that
 * connectionless protocols can call soisconnected() and soisdisconnected()
 * only, bypassing the in-progress calls when setting up a ``connection''
 * takes no time.
 *
 * When higher level protocols are implemented in
 * the kernel, the wakeups done here will sometimes
 * be implemented as software-interrupt process scheduling.
 */

soisconnecting(so)
	struct socket *so;
{

	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
	so->so_state |= SS_ISCONNECTING;
	wakeup((caddr_t)&so->so_timeo);
}

soisconnected(so)
	struct socket *so;
{

	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING);
	so->so_state |= SS_ISCONNECTED;
	wakeup((caddr_t)&so->so_timeo);
}

soisdisconnecting(so)
	struct socket *so;
{

	so->so_state &= ~SS_ISCONNECTING;
	so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
	wakeup((caddr_t)&so->so_timeo);
	sowwakeup(so);
	sorwakeup(so);
}

soisdisconnected(so)
	struct socket *so;
{

	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
	so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE);
	wakeup((caddr_t)&so->so_timeo);
	sowwakeup(so);
	sorwakeup(so);
}

/*
 * Socantsendmore indicates that no more data will be sent on the
 * socket; it would normally be applied to a socket when the user
 * informs the system that no more data is to be sent, by the protocol
 * code (in case PRU_SHUTDOWN).  Socantrcvmore indicates that no more data
 * will be received, and will normally be applied to the socket by a
 * protocol when it detects that the peer will send no more data.
 * Data queued for reading in the socket may yet be read.
 */

socantsendmore(so)
	struct socket *so;
{

	so->so_state |= SS_CANTSENDMORE;
	sowwakeup(so);
}

socantrcvmore(so)
	struct socket *so;
{

	so->so_state |= SS_CANTRCVMORE;
	sorwakeup(so);
}

/*
 * Socket select/wakeup routines.
 */

/*
 * Interface routine to select() system
 * call for sockets.
 */
soselect(so, flag)
	register struct socket *so;
	int flag;
{

	if (flag & FREAD) {
		if (soreadable(so))
			return (1);
		sbselqueue(&so->so_rcv);
	}
	if (flag & FWRITE) {
		if (sowriteable(so))
			return (1);
		sbselqueue(&so->so_snd);
	}
	return (0);
}

/*
 * Queue a process for a select on a socket buffer.
 */
sbselqueue(sb)
	struct sockbuf *sb;
{
	register struct proc *p;

	if ((p = sb->sb_sel) && p->p_wchan == (caddr_t)&selwait)
		sb->sb_flags |= SB_COLL;
	else
		sb->sb_sel = u.u_procp;
}

/*
 * Wait for data to arrive at/drain from a socket buffer.
 */
sbwait(sb)
	struct sockbuf *sb;
{

	sb->sb_flags |= SB_WAIT;
	sleep((caddr_t)&sb->sb_cc, PZERO+1);
}

/*
 * Wakeup processes waiting on a socket buffer.
 */
sbwakeup(sb)
	struct sockbuf *sb;
{

	if (sb->sb_sel) {
		selwakeup(sb->sb_sel, sb->sb_flags & SB_COLL);
		sb->sb_sel = 0;
		sb->sb_flags &= ~SB_COLL;
	}
	if (sb->sb_flags & SB_WAIT) {
		sb->sb_flags &= ~SB_WAIT;
		wakeup((caddr_t)&sb->sb_cc);
	}
}

/*
 * Socket buffer (struct sockbuf) utility routines.
 *
 * Each socket contains two socket buffers: one for sending data and
 * one for receiving data.  Each buffer contains a queue of mbufs,
 * information about the number of mbufs and amount of data in the
 * queue, and other fields allowing select() statements and notification
 * on data availability to be implemented.
 *
 * Before using a new socket structure it is first necessary to reserve
 * buffer space to the socket, by calling sbreserve.  This commits
 * some of the available buffer space in the system buffer pool for the
 * socket.  The space should be released by calling sbrelease when the
 * socket is destroyed.
 *
 * The routine sbappend() is normally called to append new mbufs
 * to a socket buffer, after checking that adequate space is available
 * comparing the function spspace() with the amount of data to be added.
 * Data is normally removed from a socket buffer in a protocol by
 * first calling m_copy on the socket buffer mbuf chain and sending this
 * to a peer, and then removing the data from the socket buffer with
 * sbdrop when the data is acknowledged by the peer (or immediately
 * in the case of unreliable protocols.)
 *
 * Protocols which do not require connections place both source address
 * and data information in socket buffer queues.  The source addresses
 * are stored in single mbufs after each data item, and are easily found
 * as the data items are all marked with end of record markers.  The
 * sbappendaddr() routine stores a datum and associated address in
 * a socket buffer.  Note that, unlike sbappend(), this routine checks
 * for the caller that there will be enough space to store the data.
 * It fails if there is not enough space, or if it cannot find
 * a mbuf to store the address in.
 *
 * The higher-level routines sosend and soreceive (in socket.c)
 * also add data to, and remove data from socket buffers repectively.
 */

/*
 * Allot mbufs to a sockbuf.
 */
sbreserve(sb, cc)
	struct sockbuf *sb;
{

	if (m_reserve((cc*2)/MSIZE) == 0)
		return (0);
	sb->sb_hiwat = cc;
	sb->sb_mbmax = cc*2;
	return (1);
}

/*
 * Free mbufs held by a socket, and reserved mbuf space.
 */
sbrelease(sb)
	struct sockbuf *sb;
{

	sbflush(sb);
	m_release(sb->sb_mbmax/MSIZE);
	sb->sb_hiwat = sb->sb_mbmax = 0;
}

/*
 * Routines to add (at the end) and remove (from the beginning)
 * data from a mbuf queue.
 */

/*
 * Append mbuf queue m to sockbuf sb.
 */
sbappend(sb, m)
	register struct mbuf *m;
	register struct sockbuf *sb;
{
	register struct mbuf **np, *n;

	np = &sb->sb_mb;
	n = 0;
	while (*np) {
		n = *np;
		np = &n->m_next;
	}
	while (m) {
		if (m->m_len == 0 && (int)m->m_act == 0) {
			m = m_free(m);
			continue;
		}
		if (n && n->m_off <= MMAXOFF && m->m_off <= MMAXOFF &&
		   (int)n->m_act == 0 && (int)m->m_act == 0 &&
		   (n->m_off + n->m_len + m->m_len) <= MMAXOFF) {
			bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
			    (unsigned)m->m_len);
			n->m_len += m->m_len;
			sb->sb_cc += m->m_len;
			m = m_free(m);
			continue;
		}
		sballoc(sb, m);
		*np = m;
		n = m;
		np = &n->m_next;
		m = m->m_next;
	}
}

/*
 * Append data and address.
 * Return 0 if no space in sockbuf or if
 * can't get mbuf to stuff address in.
 */
sbappendaddr(sb, asa, m0)
	struct sockbuf *sb;
	struct sockaddr *asa;
	struct mbuf *m0;
{
	struct sockaddr *msa;
	register struct mbuf *m;
	register int len = sizeof (struct sockaddr);

	m = m0;
	if (m == 0)
		panic("sbappendaddr");
	for (;;) {
		len += m->m_len;
		if (m->m_next == 0) {
			m->m_act = (struct mbuf *)1;
			break;
		}
		m = m->m_next;
	}
	if (len > sbspace(sb))
		return (0);
	m = m_get(0);
	if (m == 0)
		return (0);
	m->m_off = MMINOFF;
	m->m_len = sizeof (struct sockaddr);
	msa = mtod(m, struct sockaddr *);
	*msa = *asa;
	m->m_act = (struct mbuf *)1;
	sbappend(sb, m);
	sbappend(sb, m0);
	return (1);
}

/*
 * Free all mbufs on a sockbuf mbuf chain.
 * Check that resource allocations return to 0.
 */
sbflush(sb)
	struct sockbuf *sb;
{

	if (sb->sb_flags & SB_LOCK)
		panic("sbflush");
	if (sb->sb_cc)
		sbdrop(sb, sb->sb_cc);
	if (sb->sb_cc || sb->sb_mbcnt || sb->sb_mb)
		panic("sbflush 2");
}

/*
 * Drop data from (the front of) a sockbuf chain.
 */
sbdrop(sb, len)
	register struct sockbuf *sb;
	register int len;
{
	register struct mbuf *m = sb->sb_mb, *mn;

	while (len > 0) {
		if (m == 0)
			panic("sbdrop");
		if (m->m_len > len) {
			m->m_len -= len;
			m->m_off += len;
			sb->sb_cc -= len;
			break;
		}
		len -= m->m_len;
		sbfree(sb, m);
		MFREE(m, mn);
		m = mn;
	}
	sb->sb_mb = m;
}

/*
printm(m)
	struct mbuf *m;
{

	printf("<");
	while (m) {
		printf("%d,", m->m_len);
		m = m->m_next;
	}
	printf(">");
	printf("\n");
}
*/
Commit	Line	Data
c64d826c	1	/* uipc_socket2.c 4.17 81/12/22 */
681ebb17 BJ	2
	3	#include "../h/param.h"
	4	#include "../h/systm.h"
	5	#include "../h/dir.h"
	6	#include "../h/user.h"
	7	#include "../h/proc.h"
	8	#include "../h/file.h"
	9	#include "../h/inode.h"
	10	#include "../h/buf.h"
	11	#include "../h/mbuf.h"
681ebb17 BJ	12	#include "../h/protosw.h"
	13	#include "../h/socket.h"
	14	#include "../h/socketvar.h"
c5ff2e32 BJ	15	#include "../net/in.h"
c5ff2e32 BJ	16	#include "../net/in_systm.h"
681ebb17 BJ	17
	18	/*
	19	* Primitive routines for operating on sockets and socket buffers
	20	*/
	21
	22	/*
	23	* Procedures to manipulate state flags of socket
4c078bb2 BJ	24	* and do appropriate wakeups. Normal sequence is that
	25	* soisconnecting() is called during processing of connect() call,
	26	* resulting in an eventual call to soisconnected() if/when the
	27	* connection is established. When the connection is torn down
	28	* soisdisconnecting() is called during processing of disconnect() call,
	29	* and soisdisconnected() is called when the connection to the peer
	30	* is totally severed. The semantics of these routines are such that
	31	* connectionless protocols can call soisconnected() and soisdisconnected()
	32	* only, bypassing the in-progress calls when setting up a ``connection''
	33	* takes no time.
	34	*
	35	* When higher level protocols are implemented in
	36	* the kernel, the wakeups done here will sometimes
	37	* be implemented as software-interrupt process scheduling.
681ebb17	38	*/
4c078bb2	39
681ebb17 BJ	40	soisconnecting(so)
	41	struct socket *so;
	42	{
	43
	44	so->so_state &= ~(SS_ISCONNECTED\|SS_ISDISCONNECTING);
	45	so->so_state \|= SS_ISCONNECTING;
	46	wakeup((caddr_t)&so->so_timeo);
	47	}
	48
	49	soisconnected(so)
	50	struct socket *so;
	51	{
	52
	53	so->so_state &= ~(SS_ISCONNECTING\|SS_ISDISCONNECTING);
	54	so->so_state \|= SS_ISCONNECTED;
	55	wakeup((caddr_t)&so->so_timeo);
	56	}
	57
	58	soisdisconnecting(so)
	59	struct socket *so;
	60	{
	61
72857acf	62	so->so_state &= ~SS_ISCONNECTING;
681ebb17 BJ	63	so->so_state \|= (SS_ISDISCONNECTING\|SS_CANTRCVMORE\|SS_CANTSENDMORE);
681ebb17 BJ	64	wakeup((caddr_t)&so->so_timeo);
4c078bb2	65	sowwakeup(so);
b454c3ea	66	sorwakeup(so);
681ebb17 BJ	67	}
	68
	69	soisdisconnected(so)
	70	struct socket *so;
	71	{
	72
	73	so->so_state &= ~(SS_ISCONNECTING\|SS_ISCONNECTED\|SS_ISDISCONNECTING);
	74	so->so_state \|= (SS_CANTRCVMORE\|SS_CANTSENDMORE);
	75	wakeup((caddr_t)&so->so_timeo);
	76	sowwakeup(so);
	77	sorwakeup(so);
	78	}
	79
4c078bb2 BJ	80	/*
	81	* Socantsendmore indicates that no more data will be sent on the
	82	* socket; it would normally be applied to a socket when the user
	83	* informs the system that no more data is to be sent, by the protocol
	84	* code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
	85	* will be received, and will normally be applied to the socket by a
	86	* protocol when it detects that the peer will send no more data.
	87	* Data queued for reading in the socket may yet be read.
	88	*/
	89
ae921915 BJ	90	socantsendmore(so)
	91	struct socket *so;
	92	{
	93
	94	so->so_state \|= SS_CANTSENDMORE;
	95	sowwakeup(so);
	96	}
	97
	98	socantrcvmore(so)
	99	struct socket *so;
	100	{
	101
	102	so->so_state \|= SS_CANTRCVMORE;
	103	sorwakeup(so);
	104	}
	105
681ebb17	106	/*
4c078bb2 BJ	107	* Socket select/wakeup routines.
	108	*/
	109
	110	/*
	111	* Interface routine to select() system
	112	* call for sockets.
681ebb17 BJ	113	*/
	114	soselect(so, flag)
	115	register struct socket *so;
	116	int flag;
	117	{
	118
	119	if (flag & FREAD) {
	120	if (soreadable(so))
	121	return (1);
	122	sbselqueue(&so->so_rcv);
	123	}
	124	if (flag & FWRITE) {
	125	if (sowriteable(so))
	126	return (1);
	127	sbselqueue(&so->so_snd);
	128	}
	129	return (0);
	130	}
	131
	132	/*
	133	* Queue a process for a select on a socket buffer.
	134	*/
	135	sbselqueue(sb)
	136	struct sockbuf *sb;
	137	{
	138	register struct proc *p;
	139
ae921915	140	if ((p = sb->sb_sel) && p->p_wchan == (caddr_t)&selwait)
681ebb17 BJ	141	sb->sb_flags \|= SB_COLL;
	142	else
	143	sb->sb_sel = u.u_procp;
	144	}
	145
ae921915 BJ	146	/*
	147	* Wait for data to arrive at/drain from a socket buffer.
	148	*/
	149	sbwait(sb)
	150	struct sockbuf *sb;
	151	{
	152
	153	sb->sb_flags \|= SB_WAIT;
	154	sleep((caddr_t)&sb->sb_cc, PZERO+1);
	155	}
	156
681ebb17 BJ	157	/*
	158	* Wakeup processes waiting on a socket buffer.
	159	*/
	160	sbwakeup(sb)
	161	struct sockbuf *sb;
	162	{
	163
	164	if (sb->sb_sel) {
	165	selwakeup(sb->sb_sel, sb->sb_flags & SB_COLL);
	166	sb->sb_sel = 0;
	167	sb->sb_flags &= ~SB_COLL;
	168	}
	169	if (sb->sb_flags & SB_WAIT) {
	170	sb->sb_flags &= ~SB_WAIT;
388ca8bd	171	wakeup((caddr_t)&sb->sb_cc);
681ebb17 BJ	172	}
	173	}
	174
4c078bb2 BJ	175	/*
	176	* Socket buffer (struct sockbuf) utility routines.
	177	*
	178	* Each socket contains two socket buffers: one for sending data and
	179	* one for receiving data. Each buffer contains a queue of mbufs,
	180	* information about the number of mbufs and amount of data in the
	181	* queue, and other fields allowing select() statements and notification
	182	* on data availability to be implemented.
	183	*
	184	* Before using a new socket structure it is first necessary to reserve
	185	* buffer space to the socket, by calling sbreserve. This commits
	186	* some of the available buffer space in the system buffer pool for the
	187	* socket. The space should be released by calling sbrelease when the
	188	* socket is destroyed.
	189	*
	190	* The routine sbappend() is normally called to append new mbufs
	191	* to a socket buffer, after checking that adequate space is available
	192	* comparing the function spspace() with the amount of data to be added.
	193	* Data is normally removed from a socket buffer in a protocol by
	194	* first calling m_copy on the socket buffer mbuf chain and sending this
	195	* to a peer, and then removing the data from the socket buffer with
	196	* sbdrop when the data is acknowledged by the peer (or immediately
b454c3ea	197	* in the case of unreliable protocols.)
4c078bb2 BJ	198	*
	199	* Protocols which do not require connections place both source address
	200	* and data information in socket buffer queues. The source addresses
	201	* are stored in single mbufs after each data item, and are easily found
	202	* as the data items are all marked with end of record markers. The
	203	* sbappendaddr() routine stores a datum and associated address in
	204	* a socket buffer. Note that, unlike sbappend(), this routine checks
	205	* for the caller that there will be enough space to store the data.
	206	* It fails if there is not enough space, or if it cannot find
	207	* a mbuf to store the address in.
	208	*
	209	* The higher-level routines sosend and soreceive (in socket.c)
b454c3ea	210	* also add data to, and remove data from socket buffers repectively.
4c078bb2 BJ	211	*/
4c078bb2 BJ	212
681ebb17 BJ	213	/*
	214	* Allot mbufs to a sockbuf.
	215	*/
	216	sbreserve(sb, cc)
	217	struct sockbuf *sb;
	218	{
	219
196d84fd	220	if (m_reserve((cc*2)/MSIZE) == 0)
681ebb17	221	return (0);
d028a086	222	sb->sb_hiwat = cc;
76a6e254	223	sb->sb_mbmax = cc*2;
ae921915	224	return (1);
681ebb17 BJ	225	}
	226
	227	/*
	228	* Free mbufs held by a socket, and reserved mbuf space.
	229	*/
	230	sbrelease(sb)
	231	struct sockbuf *sb;
	232	{
	233
	234	sbflush(sb);
d5a69809	235	m_release(sb->sb_mbmax/MSIZE);
d028a086	236	sb->sb_hiwat = sb->sb_mbmax = 0;
681ebb17 BJ	237	}
	238
	239	/*
	240	* Routines to add (at the end) and remove (from the beginning)
	241	* data from a mbuf queue.
	242	*/
	243
	244	/*
	245	* Append mbuf queue m to sockbuf sb.
	246	*/
	247	sbappend(sb, m)
	248	register struct mbuf *m;
	249	register struct sockbuf *sb;
	250	{
	251	register struct mbuf *np, n;
	252
	253	np = &sb->sb_mb;
388ca8bd BJ	254	n = 0;
	255	while (*np) {
	256	n = *np;
681ebb17	257	np = &n->m_next;
388ca8bd	258	}
681ebb17	259	while (m) {
a73ab5ae	260	if (m->m_len == 0 && (int)m->m_act == 0) {
c64d826c	261	m = m_free(m);
a73ab5ae BJ	262	continue;
a73ab5ae BJ	263	}
681ebb17 BJ	264	if (n && n->m_off <= MMAXOFF && m->m_off <= MMAXOFF &&
681ebb17 BJ	265	(int)n->m_act == 0 && (int)m->m_act == 0 &&
76a6e254 BJ	266	(n->m_off + n->m_len + m->m_len) <= MMAXOFF) {
76a6e254 BJ	267	bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
ae921915	268	(unsigned)m->m_len);
681ebb17 BJ	269	n->m_len += m->m_len;
	270	sb->sb_cc += m->m_len;
	271	m = m_free(m);
	272	continue;
	273	}
	274	sballoc(sb, m);
	275	*np = m;
	276	n = m;
	277	np = &n->m_next;
	278	m = m->m_next;
	279	}
	280	}
	281
4c078bb2 BJ	282	/*
	283	* Append data and address.
	284	* Return 0 if no space in sockbuf or if
	285	* can't get mbuf to stuff address in.
	286	*/
2b4b57cd BJ	287	sbappendaddr(sb, asa, m0)
	288	struct sockbuf *sb;
	289	struct sockaddr *asa;
	290	struct mbuf *m0;
	291	{
	292	struct sockaddr *msa;
	293	register struct mbuf *m;
	294	register int len = sizeof (struct sockaddr);
	295
76a6e254 BJ	296	m = m0;
	297	if (m == 0)
	298	panic("sbappendaddr");
	299	for (;;) {
2b4b57cd	300	len += m->m_len;
76a6e254 BJ	301	if (m->m_next == 0) {
	302	m->m_act = (struct mbuf *)1;
	303	break;
	304	}
	305	m = m->m_next;
	306	}
509e40dd	307	if (len > sbspace(sb))
2b4b57cd BJ	308	return (0);
2b4b57cd BJ	309	m = m_get(0);
509e40dd	310	if (m == 0)
2b4b57cd BJ	311	return (0);
	312	m->m_off = MMINOFF;
	313	m->m_len = sizeof (struct sockaddr);
	314	msa = mtod(m, struct sockaddr *);
	315	msa = asa;
	316	m->m_act = (struct mbuf *)1;
	317	sbappend(sb, m);
2b4b57cd BJ	318	sbappend(sb, m0);
	319	return (1);
	320	}
	321
681ebb17 BJ	322	/*
	323	* Free all mbufs on a sockbuf mbuf chain.
	324	* Check that resource allocations return to 0.
	325	*/
	326	sbflush(sb)
	327	struct sockbuf *sb;
	328	{
	329
	330	if (sb->sb_flags & SB_LOCK)
	331	panic("sbflush");
a73ab5ae BJ	332	if (sb->sb_cc)
a73ab5ae BJ	333	sbdrop(sb, sb->sb_cc);
681ebb17 BJ	334	if (sb->sb_cc \|\| sb->sb_mbcnt \|\| sb->sb_mb)
	335	panic("sbflush 2");
	336	}
	337
	338	/*
	339	* Drop data from (the front of) a sockbuf chain.
	340	*/
	341	sbdrop(sb, len)
	342	register struct sockbuf *sb;
	343	register int len;
	344	{
	345	register struct mbuf m = sb->sb_mb, mn;
	346
	347	while (len > 0) {
	348	if (m == 0)
	349	panic("sbdrop");
b9f0d37f	350	if (m->m_len > len) {
681ebb17 BJ	351	m->m_len -= len;
	352	m->m_off += len;
	353	sb->sb_cc -= len;
	354	break;
	355	}
b9f0d37f BJ	356	len -= m->m_len;
	357	sbfree(sb, m);
	358	MFREE(m, mn);
	359	m = mn;
681ebb17 BJ	360	}
	361	sb->sb_mb = m;
	362	}
a73ab5ae BJ	363
	364	/*
	365	printm(m)
	366	struct mbuf *m;
	367	{
	368
	369	printf("<");
	370	while (m) {
	371	printf("%d,", m->m_len);
	372	m = m->m_next;
	373	}
	374	printf(">");
	375	printf("\n");
	376	}
	377	*/