4.3BSD-UWisc/src/sys/sys/uipc_socket.c
/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
* @(#)uipc_socket.c 7.1 (Berkeley) 6/5/86
*/
#ifndef lint
static char rcs_id[] = {"$Header: uipc_socket.c,v 3.1 86/10/22 13:45:14 tadl Exp $"};
#endif not lint
/*
* RCS Info
* $Locker: $
*/
#include "param.h"
#include "systm.h"
#include "user.h"
#include "proc.h"
#include "file.h"
#include "buf.h"
#include "mbuf.h"
#include "un.h"
#include "domain.h"
#include "protosw.h"
#include "socket.h"
#include "socketvar.h"
#include "stat.h"
#include "ioctl.h"
#include "uio.h"
#include "../net/route.h"
#include "../netinet/in.h"
#include "../net/if.h"
/*
* Socket operation routines.
* These routines are called by the routines in
* sys_socket.c or from a system process, and
* implement the semantics of socket operations by
* switching out to the protocol specific routines.
*
* TODO:
* test socketpair
* clean up async
* out-of-band is a kludge
*/
/*ARGSUSED*/
socreate(dom, aso, type, proto)
struct socket **aso;
register int type;
int proto;
{
register struct protosw *prp;
register struct socket *so;
register struct mbuf *m;
register int error;
if (proto)
prp = pffindproto(dom, proto, type);
else
prp = pffindtype(dom, type);
if (prp == 0)
return (EPROTONOSUPPORT);
if (prp->pr_type != type)
return (EPROTOTYPE);
m = m_getclr(M_WAIT, MT_SOCKET);
if (m == 0)
return (ENOBUFS);
so = mtod(m, struct socket *);
so->so_options = 0;
so->so_state = 0;
so->so_type = type;
if (u.u_uid == 0)
so->so_state = SS_PRIV;
so->so_proto = prp;
error =
(*prp->pr_usrreq)(so, PRU_ATTACH,
(struct mbuf *)0, (struct mbuf *)proto, (struct mbuf *)0);
if (error) {
so->so_state |= SS_NOFDREF;
sofree(so);
return (error);
}
*aso = so;
return (0);
}
sobind(so, nam)
struct socket *so;
struct mbuf *nam;
{
int s = splnet();
int error;
error =
(*so->so_proto->pr_usrreq)(so, PRU_BIND,
(struct mbuf *)0, nam, (struct mbuf *)0);
splx(s);
return (error);
}
solisten(so, backlog)
register struct socket *so;
int backlog;
{
int s = splnet(), error;
error =
(*so->so_proto->pr_usrreq)(so, PRU_LISTEN,
(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
if (error) {
splx(s);
return (error);
}
if (so->so_q == 0) {
so->so_q = so;
so->so_q0 = so;
so->so_options |= SO_ACCEPTCONN;
}
if (backlog < 0)
backlog = 0;
so->so_qlimit = MIN(backlog, SOMAXCONN);
splx(s);
return (0);
}
sofree(so)
register struct socket *so;
{
if (so->so_head) {
if (!soqremque(so, 0) && !soqremque(so, 1))
panic("sofree dq");
so->so_head = 0;
}
if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
return;
sbrelease(&so->so_snd);
sorflush(so);
(void) m_free(dtom(so));
}
/*
* Close a socket on last file table reference removal.
* Initiate disconnect if connected.
* Free socket when disconnect complete.
*/
soclose(so)
register struct socket *so;
{
int s = splnet(); /* conservative */
int error;
if (so->so_options & SO_ACCEPTCONN) {
while (so->so_q0 != so)
(void) soabort(so->so_q0);
while (so->so_q != so)
(void) soabort(so->so_q);
}
if (so->so_pcb == 0)
goto discard;
if (so->so_state & SS_ISCONNECTED) {
if ((so->so_state & SS_ISDISCONNECTING) == 0) {
error = sodisconnect(so);
if (error)
goto drop;
}
if (so->so_options & SO_LINGER) {
if ((so->so_state & SS_ISDISCONNECTING) &&
(so->so_state & SS_NBIO))
goto drop;
while (so->so_state & SS_ISCONNECTED)
sleep((caddr_t)&so->so_timeo, PZERO+1);
}
}
drop:
if (so->so_pcb) {
int error2 =
(*so->so_proto->pr_usrreq)(so, PRU_DETACH,
(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
if (error == 0)
error = error2;
}
discard:
if (so->so_state & SS_NOFDREF)
panic("soclose: NOFDREF");
so->so_state |= SS_NOFDREF;
sofree(so);
splx(s);
return (error);
}
/*
* Must be called at splnet...
*/
soabort(so)
struct socket *so;
{
return (
(*so->so_proto->pr_usrreq)(so, PRU_ABORT,
(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0));
}
soaccept(so, nam)
register struct socket *so;
struct mbuf *nam;
{
int s = splnet();
int error;
if ((so->so_state & SS_NOFDREF) == 0)
panic("soaccept: !NOFDREF");
so->so_state &= ~SS_NOFDREF;
error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT,
(struct mbuf *)0, nam, (struct mbuf *)0);
splx(s);
return (error);
}
soconnect(so, nam)
register struct socket *so;
struct mbuf *nam;
{
int s = splnet();
int error;
/*
* If protocol is connection-based, can only connect once.
* Otherwise, if connected, try to disconnect first.
* This allows user to disconnect by connecting to, e.g.,
* a null address.
*/
if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
(error = sodisconnect(so))))
error = EISCONN;
else
error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,
(struct mbuf *)0, nam, (struct mbuf *)0);
splx(s);
return (error);
}
soconnect2(so1, so2)
register struct socket *so1;
struct socket *so2;
{
int s = splnet();
int error;
error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2,
(struct mbuf *)0, (struct mbuf *)so2, (struct mbuf *)0);
splx(s);
return (error);
}
sodisconnect(so)
register struct socket *so;
{
int s = splnet();
int error;
if ((so->so_state & SS_ISCONNECTED) == 0) {
error = ENOTCONN;
goto bad;
}
if (so->so_state & SS_ISDISCONNECTING) {
error = EALREADY;
goto bad;
}
error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
bad:
splx(s);
return (error);
}
/*
* Send on a socket.
* If send must go all at once and message is larger than
* send buffering, then hard error.
* Lock against other senders.
* If must go all at once and not enough room now, then
* inform user that this would block and do nothing.
* Otherwise, if nonblocking, send as much as possible.
*/
sosend(so, nam, uio, flags, rights)
register struct socket *so;
struct mbuf *nam;
register struct uio *uio;
int flags;
struct mbuf *rights;
{
struct mbuf *top = 0;
register struct mbuf *m, **mp;
register int space;
int len, rlen = 0, error = 0, s, dontroute, first = 1;
if (sosendallatonce(so) && uio->uio_resid > so->so_snd.sb_hiwat)
return (EMSGSIZE);
dontroute =
(flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
(so->so_proto->pr_flags & PR_ATOMIC);
u.u_ru.ru_msgsnd++;
if (rights)
rlen = rights->m_len;
#define snderr(errno) { error = errno; splx(s); goto release; }
restart:
sblock(&so->so_snd);
do {
s = splnet();
if (so->so_state & SS_CANTSENDMORE)
snderr(EPIPE);
if (so->so_error) {
error = so->so_error;
so->so_error = 0; /* ??? */
splx(s);
goto release;
}
if ((so->so_state & SS_ISCONNECTED) == 0) {
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
snderr(ENOTCONN);
if (nam == 0)
snderr(EDESTADDRREQ);
}
if (flags & MSG_OOB)
space = 1024;
else {
space = sbspace(&so->so_snd);
if (space <= rlen ||
(sosendallatonce(so) &&
space < uio->uio_resid + rlen) ||
(uio->uio_resid >= CLBYTES && space < CLBYTES &&
so->so_snd.sb_cc >= CLBYTES &&
(so->so_state & SS_NBIO) == 0)) {
if (so->so_state & SS_NBIO) {
if (first)
error = EWOULDBLOCK;
splx(s);
goto release;
}
sbunlock(&so->so_snd);
sbwait(&so->so_snd);
splx(s);
goto restart;
}
}
splx(s);
mp = ⊤
space -= rlen;
while (space > 0) {
MGET(m, M_WAIT, MT_DATA);
if (uio->uio_resid >= CLBYTES / 2 && space >= CLBYTES) {
MCLGET(m);
if (m->m_len != CLBYTES)
goto nopages;
len = MIN(CLBYTES, uio->uio_resid);
space -= CLBYTES;
} else {
nopages:
len = MIN(MIN(MLEN, uio->uio_resid), space);
space -= len;
}
error = uiomove(mtod(m, caddr_t), len, UIO_WRITE, uio);
m->m_len = len;
*mp = m;
if (error)
goto release;
mp = &m->m_next;
if (uio->uio_resid <= 0)
break;
}
if (dontroute)
so->so_options |= SO_DONTROUTE;
s = splnet(); /* XXX */
error = (*so->so_proto->pr_usrreq)(so,
(flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
top, (caddr_t)nam, rights);
splx(s);
if (dontroute)
so->so_options &= ~SO_DONTROUTE;
rights = 0;
rlen = 0;
top = 0;
first = 0;
if (error)
break;
} while (uio->uio_resid);
release:
sbunlock(&so->so_snd);
if (top)
m_freem(top);
if (error == EPIPE)
psignal(u.u_procp, SIGPIPE);
return (error);
}
/*
* Implement receive operations on a socket.
* We depend on the way that records are added to the sockbuf
* by sbappend*. In particular, each record (mbufs linked through m_next)
* must begin with an address if the protocol so specifies,
* followed by an optional mbuf containing access rights if supported
* by the protocol, and then zero or more mbufs of data.
* In order to avoid blocking network interrupts for the entire time here,
* we splx() while doing the actual copy to user space.
* Although the sockbuf is locked, new data may still be appended,
* and thus we must maintain consistency of the sockbuf during that time.
*/
soreceive(so, aname, uio, flags, rightsp)
register struct socket *so;
struct mbuf **aname;
register struct uio *uio;
int flags;
struct mbuf **rightsp;
{
register struct mbuf *m;
register int len, error = 0, s, tomark;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
int moff;
if (rightsp)
*rightsp = 0;
if (aname)
*aname = 0;
if (flags & MSG_OOB) {
m = m_get(M_WAIT, MT_DATA);
error = (*pr->pr_usrreq)(so, PRU_RCVOOB,
m, (struct mbuf *)(flags & MSG_PEEK), (struct mbuf *)0);
if (error)
goto bad;
do {
len = uio->uio_resid;
if (len > m->m_len)
len = m->m_len;
error =
uiomove(mtod(m, caddr_t), (int)len, UIO_READ, uio);
m = m_free(m);
} while (uio->uio_resid && error == 0 && m);
bad:
if (m)
m_freem(m);
return (error);
}
restart:
sblock(&so->so_rcv);
s = splnet();
#define rcverr(errno) { error = errno; splx(s); goto release; }
if (so->so_rcv.sb_cc == 0) {
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
splx(s);
goto release;
}
if (so->so_state & SS_CANTRCVMORE) {
splx(s);
goto release;
}
if ((so->so_state & SS_ISCONNECTED) == 0 &&
(so->so_proto->pr_flags & PR_CONNREQUIRED))
rcverr(ENOTCONN);
if (uio->uio_resid == 0)
goto release;
if (so->so_state & SS_NBIO)
rcverr(EWOULDBLOCK);
sbunlock(&so->so_rcv);
sbwait(&so->so_rcv);
splx(s);
goto restart;
}
u.u_ru.ru_msgrcv++;
m = so->so_rcv.sb_mb;
if (m == 0)
panic("receive 1");
nextrecord = m->m_act;
if (pr->pr_flags & PR_ADDR) {
if (m->m_type != MT_SONAME)
panic("receive 1a");
if (flags & MSG_PEEK) {
if (aname)
*aname = m_copy(m, 0, m->m_len);
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
if (aname) {
*aname = m;
m = m->m_next;
(*aname)->m_next = 0;
so->so_rcv.sb_mb = m;
} else {
MFREE(m, so->so_rcv.sb_mb);
m = so->so_rcv.sb_mb;
}
if (m)
m->m_act = nextrecord;
}
}
if (m && m->m_type == MT_RIGHTS) {
if ((pr->pr_flags & PR_RIGHTS) == 0)
panic("receive 2");
if (flags & MSG_PEEK) {
if (rightsp)
*rightsp = m_copy(m, 0, m->m_len);
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
if (rightsp) {
*rightsp = m;
so->so_rcv.sb_mb = m->m_next;
m->m_next = 0;
m = so->so_rcv.sb_mb;
} else {
MFREE(m, so->so_rcv.sb_mb);
m = so->so_rcv.sb_mb;
}
if (m)
m->m_act = nextrecord;
}
}
moff = 0;
tomark = so->so_oobmark;
while (m && uio->uio_resid > 0 && error == 0) {
if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
panic("receive 3");
len = uio->uio_resid;
so->so_state &= ~SS_RCVATMARK;
if (tomark && len > tomark)
len = tomark;
if (len > m->m_len - moff)
len = m->m_len - moff;
splx(s);
error =
uiomove(mtod(m, caddr_t) + moff, (int)len, UIO_READ, uio);
s = splnet();
if (len == m->m_len - moff) {
if (flags & MSG_PEEK) {
m = m->m_next;
moff = 0;
} else {
nextrecord = m->m_act;
sbfree(&so->so_rcv, m);
MFREE(m, so->so_rcv.sb_mb);
m = so->so_rcv.sb_mb;
if (m)
m->m_act = nextrecord;
}
} else {
if (flags & MSG_PEEK)
moff += len;
else {
m->m_off += len;
m->m_len -= len;
so->so_rcv.sb_cc -= len;
}
}
if ((flags & MSG_PEEK) == 0 && so->so_oobmark) {
so->so_oobmark -= len;
if (so->so_oobmark == 0) {
so->so_state |= SS_RCVATMARK;
break;
}
}
if (tomark) {
tomark -= len;
if (tomark == 0)
break;
}
}
if ((flags & MSG_PEEK) == 0) {
if (m == 0)
so->so_rcv.sb_mb = nextrecord;
else if (pr->pr_flags & PR_ATOMIC)
(void) sbdroprecord(&so->so_rcv);
if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
(*pr->pr_usrreq)(so, PRU_RCVD, (struct mbuf *)0,
(struct mbuf *)0, (struct mbuf *)0);
if (error == 0 && rightsp && *rightsp &&
pr->pr_domain->dom_externalize)
error = (*pr->pr_domain->dom_externalize)(*rightsp);
}
release:
sbunlock(&so->so_rcv);
splx(s);
return (error);
}
soshutdown(so, how)
register struct socket *so;
register int how;
{
register struct protosw *pr = so->so_proto;
how++;
if (how & FREAD)
sorflush(so);
if (how & FWRITE)
return ((*pr->pr_usrreq)(so, PRU_SHUTDOWN,
(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0));
return (0);
}
sorflush(so)
register struct socket *so;
{
register struct sockbuf *sb = &so->so_rcv;
register struct protosw *pr = so->so_proto;
register int s;
struct sockbuf asb;
sblock(sb);
s = splimp();
socantrcvmore(so);
sbunlock(sb);
asb = *sb;
bzero((caddr_t)sb, sizeof (*sb));
splx(s);
if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
(*pr->pr_domain->dom_dispose)(asb.sb_mb);
sbrelease(&asb);
}
sosetopt(so, level, optname, m0)
register struct socket *so;
int level, optname;
struct mbuf *m0;
{
int error = 0;
register struct mbuf *m = m0;
if (level != SOL_SOCKET) {
if (so->so_proto && so->so_proto->pr_ctloutput)
return ((*so->so_proto->pr_ctloutput)
(PRCO_SETOPT, so, level, optname, &m0));
error = ENOPROTOOPT;
} else {
switch (optname) {
case SO_LINGER:
if (m == NULL || m->m_len != sizeof (struct linger)) {
error = EINVAL;
goto bad;
}
so->so_linger = mtod(m, struct linger *)->l_linger;
/* fall thru... */
case SO_DEBUG:
case SO_KEEPALIVE:
case SO_DONTROUTE:
case SO_USELOOPBACK:
case SO_BROADCAST:
case SO_REUSEADDR:
case SO_OOBINLINE:
if (m == NULL || m->m_len < sizeof (int)) {
error = EINVAL;
goto bad;
}
if (*mtod(m, int *))
so->so_options |= optname;
else
so->so_options &= ~optname;
break;
case SO_SNDBUF:
case SO_RCVBUF:
case SO_SNDLOWAT:
case SO_RCVLOWAT:
case SO_SNDTIMEO:
case SO_RCVTIMEO:
if (m == NULL || m->m_len < sizeof (int)) {
error = EINVAL;
goto bad;
}
switch (optname) {
case SO_SNDBUF:
case SO_RCVBUF:
if (sbreserve(optname == SO_SNDBUF ? &so->so_snd :
&so->so_rcv, *mtod(m, int *)) == 0) {
error = ENOBUFS;
goto bad;
}
break;
case SO_SNDLOWAT:
so->so_snd.sb_lowat = *mtod(m, int *);
break;
case SO_RCVLOWAT:
so->so_rcv.sb_lowat = *mtod(m, int *);
break;
case SO_SNDTIMEO:
so->so_snd.sb_timeo = *mtod(m, int *);
break;
case SO_RCVTIMEO:
so->so_rcv.sb_timeo = *mtod(m, int *);
break;
}
break;
default:
error = ENOPROTOOPT;
break;
}
}
bad:
if (m)
(void) m_free(m);
return (error);
}
sogetopt(so, level, optname, mp)
register struct socket *so;
int level, optname;
struct mbuf **mp;
{
register struct mbuf *m;
if (level != SOL_SOCKET) {
if (so->so_proto && so->so_proto->pr_ctloutput) {
return ((*so->so_proto->pr_ctloutput)
(PRCO_GETOPT, so, level, optname, mp));
} else
return (ENOPROTOOPT);
} else {
m = m_get(M_WAIT, MT_SOOPTS);
m->m_len = sizeof (int);
switch (optname) {
case SO_LINGER:
m->m_len = sizeof (struct linger);
mtod(m, struct linger *)->l_onoff =
so->so_options & SO_LINGER;
mtod(m, struct linger *)->l_linger = so->so_linger;
break;
case SO_USELOOPBACK:
case SO_DONTROUTE:
case SO_DEBUG:
case SO_KEEPALIVE:
case SO_REUSEADDR:
case SO_BROADCAST:
case SO_OOBINLINE:
*mtod(m, int *) = so->so_options & optname;
break;
case SO_TYPE:
*mtod(m, int *) = so->so_type;
break;
case SO_ERROR:
*mtod(m, int *) = so->so_error;
so->so_error = 0;
break;
case SO_SNDBUF:
*mtod(m, int *) = so->so_snd.sb_hiwat;
break;
case SO_RCVBUF:
*mtod(m, int *) = so->so_rcv.sb_hiwat;
break;
case SO_SNDLOWAT:
*mtod(m, int *) = so->so_snd.sb_lowat;
break;
case SO_RCVLOWAT:
*mtod(m, int *) = so->so_rcv.sb_lowat;
break;
case SO_SNDTIMEO:
*mtod(m, int *) = so->so_snd.sb_timeo;
break;
case SO_RCVTIMEO:
*mtod(m, int *) = so->so_rcv.sb_timeo;
break;
default:
(void)m_free(m);
return (ENOPROTOOPT);
}
*mp = m;
return (0);
}
}
sohasoutofband(so)
register struct socket *so;
{
struct proc *p;
if (so->so_pgrp < 0)
gsignal(-so->so_pgrp, SIGURG);
else if (so->so_pgrp > 0 && (p = pfind(so->so_pgrp)) != 0)
psignal(p, SIGURG);
if (so->so_rcv.sb_sel) {
selwakeup(so->so_rcv.sb_sel, so->so_rcv.sb_flags & SB_COLL);
so->so_rcv.sb_sel = 0;
so->so_rcv.sb_flags &= ~SB_COLL;
}
}