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

/*	uipc_socket2.c	4.22	82/03/19	*/

#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);
	sorwakeup(so);
	sowwakeup(so);
}

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, rw)
	register struct socket *so;
	int rw;
{
	int s = splnet();

	switch (rw) {

	case FREAD:
		if (soreadable(so)) {
			splx(s);
			return (1);
		}
		sbselqueue(&so->so_rcv);
		break;

	case FWRITE:
		if (sowriteable(so)) {
			splx(s);
			return (1);
		}
		sbselqueue(&so->so_snd);
		break;
	}
	splx(s);
	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 *n;

	n = sb->sb_mb;
	if (n)
		while (n->m_next)
			n = 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);
		if (n == 0)
			sb->sb_mb = m;
		else
			n->m_next = m;
		n = m;
		m = m->m_next;
		n->m_next = 0;
	}
}

/*
 * 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(M_DONTWAIT);
	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;
}
Commit	Line	Data
4b11abe3	1	/* uipc_socket2.c 4.22 82/03/19 */
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);
f957a49a BJ	56	sorwakeup(so);
f957a49a BJ	57	sowwakeup(so);
681ebb17 BJ	58	}
	59
	60	soisdisconnecting(so)
	61	struct socket *so;
	62	{
	63
72857acf	64	so->so_state &= ~SS_ISCONNECTING;
681ebb17 BJ	65	so->so_state \|= (SS_ISDISCONNECTING\|SS_CANTRCVMORE\|SS_CANTSENDMORE);
681ebb17 BJ	66	wakeup((caddr_t)&so->so_timeo);
4c078bb2	67	sowwakeup(so);
b454c3ea	68	sorwakeup(so);
681ebb17 BJ	69	}
	70
	71	soisdisconnected(so)
	72	struct socket *so;
	73	{
	74
	75	so->so_state &= ~(SS_ISCONNECTING\|SS_ISCONNECTED\|SS_ISDISCONNECTING);
	76	so->so_state \|= (SS_CANTRCVMORE\|SS_CANTSENDMORE);
	77	wakeup((caddr_t)&so->so_timeo);
	78	sowwakeup(so);
	79	sorwakeup(so);
	80	}
	81
4c078bb2 BJ	82	/*
	83	* Socantsendmore indicates that no more data will be sent on the
	84	* socket; it would normally be applied to a socket when the user
	85	* informs the system that no more data is to be sent, by the protocol
	86	* code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
	87	* will be received, and will normally be applied to the socket by a
	88	* protocol when it detects that the peer will send no more data.
	89	* Data queued for reading in the socket may yet be read.
	90	*/
	91
ae921915 BJ	92	socantsendmore(so)
	93	struct socket *so;
	94	{
	95
	96	so->so_state \|= SS_CANTSENDMORE;
	97	sowwakeup(so);
	98	}
	99
	100	socantrcvmore(so)
	101	struct socket *so;
	102	{
	103
	104	so->so_state \|= SS_CANTRCVMORE;
	105	sorwakeup(so);
	106	}
	107
681ebb17	108	/*
4c078bb2 BJ	109	* Socket select/wakeup routines.
	110	*/
	111
	112	/*
	113	* Interface routine to select() system
	114	* call for sockets.
681ebb17	115	*/
477b2112	116	soselect(so, rw)
681ebb17	117	register struct socket *so;
477b2112	118	int rw;
681ebb17	119	{
f957a49a	120	int s = splnet();
681ebb17	121
477b2112 BJ	122	switch (rw) {
	123
	124	case FREAD:
f957a49a BJ	125	if (soreadable(so)) {
f957a49a BJ	126	splx(s);
681ebb17	127	return (1);
f957a49a	128	}
681ebb17	129	sbselqueue(&so->so_rcv);
477b2112 BJ	130	break;
	131
	132	case FWRITE:
f957a49a BJ	133	if (sowriteable(so)) {
f957a49a BJ	134	splx(s);
681ebb17	135	return (1);
f957a49a	136	}
681ebb17	137	sbselqueue(&so->so_snd);
477b2112	138	break;
681ebb17	139	}
f957a49a	140	splx(s);
681ebb17 BJ	141	return (0);
	142	}
	143
	144	/*
	145	* Queue a process for a select on a socket buffer.
	146	*/
	147	sbselqueue(sb)
	148	struct sockbuf *sb;
	149	{
	150	register struct proc *p;
	151
ae921915	152	if ((p = sb->sb_sel) && p->p_wchan == (caddr_t)&selwait)
681ebb17 BJ	153	sb->sb_flags \|= SB_COLL;
	154	else
	155	sb->sb_sel = u.u_procp;
	156	}
	157
ae921915 BJ	158	/*
	159	* Wait for data to arrive at/drain from a socket buffer.
	160	*/
	161	sbwait(sb)
	162	struct sockbuf *sb;
	163	{
	164
	165	sb->sb_flags \|= SB_WAIT;
	166	sleep((caddr_t)&sb->sb_cc, PZERO+1);
	167	}
	168
681ebb17 BJ	169	/*
	170	* Wakeup processes waiting on a socket buffer.
	171	*/
	172	sbwakeup(sb)
	173	struct sockbuf *sb;
	174	{
	175
	176	if (sb->sb_sel) {
	177	selwakeup(sb->sb_sel, sb->sb_flags & SB_COLL);
	178	sb->sb_sel = 0;
	179	sb->sb_flags &= ~SB_COLL;
	180	}
	181	if (sb->sb_flags & SB_WAIT) {
	182	sb->sb_flags &= ~SB_WAIT;
388ca8bd	183	wakeup((caddr_t)&sb->sb_cc);
681ebb17 BJ	184	}
	185	}
	186
4c078bb2 BJ	187	/*
	188	* Socket buffer (struct sockbuf) utility routines.
	189	*
	190	* Each socket contains two socket buffers: one for sending data and
	191	* one for receiving data. Each buffer contains a queue of mbufs,
	192	* information about the number of mbufs and amount of data in the
	193	* queue, and other fields allowing select() statements and notification
	194	* on data availability to be implemented.
	195	*
	196	* Before using a new socket structure it is first necessary to reserve
	197	* buffer space to the socket, by calling sbreserve. This commits
	198	* some of the available buffer space in the system buffer pool for the
	199	* socket. The space should be released by calling sbrelease when the
	200	* socket is destroyed.
	201	*
	202	* The routine sbappend() is normally called to append new mbufs
	203	* to a socket buffer, after checking that adequate space is available
	204	* comparing the function spspace() with the amount of data to be added.
	205	* Data is normally removed from a socket buffer in a protocol by
	206	* first calling m_copy on the socket buffer mbuf chain and sending this
	207	* to a peer, and then removing the data from the socket buffer with
	208	* sbdrop when the data is acknowledged by the peer (or immediately
b454c3ea	209	* in the case of unreliable protocols.)
4c078bb2 BJ	210	*
	211	* Protocols which do not require connections place both source address
	212	* and data information in socket buffer queues. The source addresses
	213	* are stored in single mbufs after each data item, and are easily found
	214	* as the data items are all marked with end of record markers. The
	215	* sbappendaddr() routine stores a datum and associated address in
	216	* a socket buffer. Note that, unlike sbappend(), this routine checks
	217	* for the caller that there will be enough space to store the data.
	218	* It fails if there is not enough space, or if it cannot find
	219	* a mbuf to store the address in.
	220	*
	221	* The higher-level routines sosend and soreceive (in socket.c)
b454c3ea	222	* also add data to, and remove data from socket buffers repectively.
4c078bb2 BJ	223	*/
4c078bb2 BJ	224
681ebb17 BJ	225	/*
	226	* Allot mbufs to a sockbuf.
	227	*/
	228	sbreserve(sb, cc)
	229	struct sockbuf *sb;
	230	{
	231
196d84fd	232	if (m_reserve((cc*2)/MSIZE) == 0)
681ebb17	233	return (0);
d028a086	234	sb->sb_hiwat = cc;
76a6e254	235	sb->sb_mbmax = cc*2;
ae921915	236	return (1);
681ebb17 BJ	237	}
	238
	239	/*
	240	* Free mbufs held by a socket, and reserved mbuf space.
	241	*/
	242	sbrelease(sb)
	243	struct sockbuf *sb;
	244	{
	245
	246	sbflush(sb);
d5a69809	247	m_release(sb->sb_mbmax/MSIZE);
d028a086	248	sb->sb_hiwat = sb->sb_mbmax = 0;
681ebb17 BJ	249	}
	250
	251	/*
	252	* Routines to add (at the end) and remove (from the beginning)
	253	* data from a mbuf queue.
	254	*/
	255
	256	/*
	257	* Append mbuf queue m to sockbuf sb.
	258	*/
	259	sbappend(sb, m)
	260	register struct mbuf *m;
	261	register struct sockbuf *sb;
	262	{
e495e1cc	263	register struct mbuf *n;
681ebb17	264
e495e1cc BJ	265	n = sb->sb_mb;
	266	if (n)
	267	while (n->m_next)
	268	n = n->m_next;
681ebb17	269	while (m) {
a73ab5ae	270	if (m->m_len == 0 && (int)m->m_act == 0) {
c64d826c	271	m = m_free(m);
a73ab5ae BJ	272	continue;
a73ab5ae BJ	273	}
681ebb17 BJ	274	if (n && n->m_off <= MMAXOFF && m->m_off <= MMAXOFF &&
681ebb17 BJ	275	(int)n->m_act == 0 && (int)m->m_act == 0 &&
76a6e254 BJ	276	(n->m_off + n->m_len + m->m_len) <= MMAXOFF) {
76a6e254 BJ	277	bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
ae921915	278	(unsigned)m->m_len);
681ebb17 BJ	279	n->m_len += m->m_len;
	280	sb->sb_cc += m->m_len;
	281	m = m_free(m);
	282	continue;
	283	}
	284	sballoc(sb, m);
e495e1cc BJ	285	if (n == 0)
	286	sb->sb_mb = m;
	287	else
	288	n->m_next = m;
681ebb17	289	n = m;
681ebb17	290	m = m->m_next;
e495e1cc	291	n->m_next = 0;
681ebb17 BJ	292	}
	293	}
	294
4c078bb2 BJ	295	/*
	296	* Append data and address.
	297	* Return 0 if no space in sockbuf or if
	298	* can't get mbuf to stuff address in.
	299	*/
2b4b57cd BJ	300	sbappendaddr(sb, asa, m0)
	301	struct sockbuf *sb;
	302	struct sockaddr *asa;
	303	struct mbuf *m0;
	304	{
	305	struct sockaddr *msa;
	306	register struct mbuf *m;
	307	register int len = sizeof (struct sockaddr);
	308
76a6e254 BJ	309	m = m0;
	310	if (m == 0)
	311	panic("sbappendaddr");
	312	for (;;) {
2b4b57cd	313	len += m->m_len;
76a6e254 BJ	314	if (m->m_next == 0) {
	315	m->m_act = (struct mbuf *)1;
	316	break;
	317	}
	318	m = m->m_next;
	319	}
509e40dd	320	if (len > sbspace(sb))
2b4b57cd	321	return (0);
99308d84	322	m = m_get(M_DONTWAIT);
509e40dd	323	if (m == 0)
2b4b57cd BJ	324	return (0);
	325	m->m_off = MMINOFF;
	326	m->m_len = sizeof (struct sockaddr);
	327	msa = mtod(m, struct sockaddr *);
	328	msa = asa;
	329	m->m_act = (struct mbuf *)1;
	330	sbappend(sb, m);
2b4b57cd BJ	331	sbappend(sb, m0);
	332	return (1);
	333	}
	334
681ebb17 BJ	335	/*
	336	* Free all mbufs on a sockbuf mbuf chain.
	337	* Check that resource allocations return to 0.
	338	*/
	339	sbflush(sb)
	340	struct sockbuf *sb;
	341	{
	342
	343	if (sb->sb_flags & SB_LOCK)
	344	panic("sbflush");
a73ab5ae BJ	345	if (sb->sb_cc)
a73ab5ae BJ	346	sbdrop(sb, sb->sb_cc);
681ebb17 BJ	347	if (sb->sb_cc \|\| sb->sb_mbcnt \|\| sb->sb_mb)
	348	panic("sbflush 2");
	349	}
	350
	351	/*
	352	* Drop data from (the front of) a sockbuf chain.
	353	*/
	354	sbdrop(sb, len)
	355	register struct sockbuf *sb;
	356	register int len;
	357	{
	358	register struct mbuf m = sb->sb_mb, mn;
	359
	360	while (len > 0) {
	361	if (m == 0)
	362	panic("sbdrop");
b9f0d37f	363	if (m->m_len > len) {
681ebb17 BJ	364	m->m_len -= len;
	365	m->m_off += len;
	366	sb->sb_cc -= len;
	367	break;
	368	}
b9f0d37f BJ	369	len -= m->m_len;
	370	sbfree(sb, m);
	371	MFREE(m, mn);
	372	m = mn;
681ebb17 BJ	373	}
	374	sb->sb_mb = m;
	375	}