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mirror of https://git.FreeBSD.org/src.git synced 2024-12-25 11:37:56 +00:00
freebsd/sys/kern/uipc_socket.c
Matthew Dillon b1e4abd246 Give struct socket structures a ref counting interface similar to
vnodes.  This will hopefully serve as a base from which we can
expand the MP code.  We currently do not attempt to obtain any
mutex or SX locks, but the door is open to add them when we nail
down exactly how that part of it is going to work.
2001-11-17 03:07:11 +00:00

1679 lines
40 KiB
C

/*
* Copyright (c) 1982, 1986, 1988, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)uipc_socket.c 8.3 (Berkeley) 4/15/94
* $FreeBSD$
*/
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/domain.h>
#include <sys/file.h> /* for struct knote */
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/event.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <sys/jail.h>
#include <vm/vm_zone.h>
#include <machine/limits.h>
#ifdef INET
static int do_setopt_accept_filter(struct socket *so, struct sockopt *sopt);
#endif
static void filt_sordetach(struct knote *kn);
static int filt_soread(struct knote *kn, long hint);
static void filt_sowdetach(struct knote *kn);
static int filt_sowrite(struct knote *kn, long hint);
static int filt_solisten(struct knote *kn, long hint);
static struct filterops solisten_filtops =
{ 1, NULL, filt_sordetach, filt_solisten };
static struct filterops soread_filtops =
{ 1, NULL, filt_sordetach, filt_soread };
static struct filterops sowrite_filtops =
{ 1, NULL, filt_sowdetach, filt_sowrite };
struct vm_zone *socket_zone;
so_gen_t so_gencnt; /* generation count for sockets */
MALLOC_DEFINE(M_SONAME, "soname", "socket name");
MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
SYSCTL_DECL(_kern_ipc);
static int somaxconn = SOMAXCONN;
SYSCTL_INT(_kern_ipc, KIPC_SOMAXCONN, somaxconn, CTLFLAG_RW,
&somaxconn, 0, "Maximum pending socket connection queue size");
static int numopensockets;
SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
&numopensockets, 0, "Number of open sockets");
/*
* 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.
*/
/*
* Get a socket structure from our zone, and initialize it.
* We don't implement `waitok' yet (see comments in uipc_domain.c).
* Note that it would probably be better to allocate socket
* and PCB at the same time, but I'm not convinced that all
* the protocols can be easily modified to do this.
*
* soalloc() returns a socket with a ref count of 0.
*/
struct socket *
soalloc(waitok)
int waitok;
{
struct socket *so;
so = zalloc(socket_zone);
if (so) {
/* XXX race condition for reentrant kernel */
bzero(so, sizeof *so);
so->so_gencnt = ++so_gencnt;
so->so_zone = socket_zone;
/* sx_init(&so->so_sxlock, "socket sxlock"); */
TAILQ_INIT(&so->so_aiojobq);
++numopensockets;
}
return so;
}
/*
* socreate returns a socket with a ref count of 1. The socket should be
* closed with soclose().
*/
int
socreate(dom, aso, type, proto, td)
int dom;
struct socket **aso;
register int type;
int proto;
struct thread *td;
{
register struct protosw *prp;
register struct socket *so;
register int error;
if (proto)
prp = pffindproto(dom, proto, type);
else
prp = pffindtype(dom, type);
if (prp == 0 || prp->pr_usrreqs->pru_attach == 0)
return (EPROTONOSUPPORT);
if (jailed(td->td_proc->p_ucred) && jail_socket_unixiproute_only &&
prp->pr_domain->dom_family != PF_LOCAL &&
prp->pr_domain->dom_family != PF_INET &&
prp->pr_domain->dom_family != PF_ROUTE) {
return (EPROTONOSUPPORT);
}
if (prp->pr_type != type)
return (EPROTOTYPE);
so = soalloc(td != 0);
if (so == 0)
return (ENOBUFS);
TAILQ_INIT(&so->so_incomp);
TAILQ_INIT(&so->so_comp);
so->so_type = type;
so->so_cred = crhold(td->td_proc->p_ucred);
so->so_proto = prp;
soref(so);
error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
if (error) {
so->so_state |= SS_NOFDREF;
sorele(so);
return (error);
}
*aso = so;
return (0);
}
int
sobind(so, nam, td)
struct socket *so;
struct sockaddr *nam;
struct thread *td;
{
int s = splnet();
int error;
error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
splx(s);
return (error);
}
static void
sodealloc(struct socket *so)
{
KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
so->so_gencnt = ++so_gencnt;
if (so->so_rcv.sb_hiwat)
(void)chgsbsize(so->so_cred->cr_uidinfo,
&so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
if (so->so_snd.sb_hiwat)
(void)chgsbsize(so->so_cred->cr_uidinfo,
&so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
#ifdef INET
if (so->so_accf != NULL) {
if (so->so_accf->so_accept_filter != NULL &&
so->so_accf->so_accept_filter->accf_destroy != NULL) {
so->so_accf->so_accept_filter->accf_destroy(so);
}
if (so->so_accf->so_accept_filter_str != NULL)
FREE(so->so_accf->so_accept_filter_str, M_ACCF);
FREE(so->so_accf, M_ACCF);
}
#endif
crfree(so->so_cred);
/* sx_destroy(&so->so_sxlock); */
zfree(so->so_zone, so);
--numopensockets;
}
int
solisten(so, backlog, td)
register struct socket *so;
int backlog;
struct thread *td;
{
int s, error;
s = splnet();
error = (*so->so_proto->pr_usrreqs->pru_listen)(so, td);
if (error) {
splx(s);
return (error);
}
if (TAILQ_EMPTY(&so->so_comp))
so->so_options |= SO_ACCEPTCONN;
if (backlog < 0 || backlog > somaxconn)
backlog = somaxconn;
so->so_qlimit = backlog;
splx(s);
return (0);
}
void
sofree(so)
register struct socket *so;
{
struct socket *head = so->so_head;
KASSERT(so->so_count == 0, ("socket %p so_count not 0", so));
if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
return;
if (head != NULL) {
if (so->so_state & SS_INCOMP) {
TAILQ_REMOVE(&head->so_incomp, so, so_list);
head->so_incqlen--;
} else if (so->so_state & SS_COMP) {
/*
* We must not decommission a socket that's
* on the accept(2) queue. If we do, then
* accept(2) may hang after select(2) indicated
* that the listening socket was ready.
*/
return;
} else {
panic("sofree: not queued");
}
head->so_qlen--;
so->so_state &= ~SS_INCOMP;
so->so_head = NULL;
}
sbrelease(&so->so_snd, so);
sorflush(so);
sodealloc(so);
}
/*
* Close a socket on last file table reference removal.
* Initiate disconnect if connected.
* Free socket when disconnect complete.
*
* This function will sorele() the socket. Note that soclose() may be
* called prior to the ref count reaching zero. The actual socket
* structure will not be freed until the ref count reaches zero.
*/
int
soclose(so)
register struct socket *so;
{
int s = splnet(); /* conservative */
int error = 0;
funsetown(so->so_sigio);
if (so->so_options & SO_ACCEPTCONN) {
struct socket *sp, *sonext;
sp = TAILQ_FIRST(&so->so_incomp);
for (; sp != NULL; sp = sonext) {
sonext = TAILQ_NEXT(sp, so_list);
(void) soabort(sp);
}
for (sp = TAILQ_FIRST(&so->so_comp); sp != NULL; sp = sonext) {
sonext = TAILQ_NEXT(sp, so_list);
/* Dequeue from so_comp since sofree() won't do it */
TAILQ_REMOVE(&so->so_comp, sp, so_list);
so->so_qlen--;
sp->so_state &= ~SS_COMP;
sp->so_head = NULL;
(void) soabort(sp);
}
}
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) {
error = tsleep((caddr_t)&so->so_timeo,
PSOCK | PCATCH, "soclos", so->so_linger * hz);
if (error)
break;
}
}
}
drop:
if (so->so_pcb) {
int error2 = (*so->so_proto->pr_usrreqs->pru_detach)(so);
if (error == 0)
error = error2;
}
discard:
if (so->so_state & SS_NOFDREF)
panic("soclose: NOFDREF");
so->so_state |= SS_NOFDREF;
sorele(so);
splx(s);
return (error);
}
/*
* Must be called at splnet...
*/
int
soabort(so)
struct socket *so;
{
int error;
error = (*so->so_proto->pr_usrreqs->pru_abort)(so);
if (error) {
sotryfree(so); /* note: does not decrement the ref count */
return error;
}
return (0);
}
int
soaccept(so, nam)
register struct socket *so;
struct sockaddr **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_usrreqs->pru_accept)(so, nam);
splx(s);
return (error);
}
int
soconnect(so, nam, td)
register struct socket *so;
struct sockaddr *nam;
struct thread *td;
{
int s;
int error;
if (so->so_options & SO_ACCEPTCONN)
return (EOPNOTSUPP);
s = splnet();
/*
* 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_usrreqs->pru_connect)(so, nam, td);
splx(s);
return (error);
}
int
soconnect2(so1, so2)
register struct socket *so1;
struct socket *so2;
{
int s = splnet();
int error;
error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
splx(s);
return (error);
}
int
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_usrreqs->pru_disconnect)(so);
bad:
splx(s);
return (error);
}
#define SBLOCKWAIT(f) (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
/*
* 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.
* The data to be sent is described by "uio" if nonzero,
* otherwise by the mbuf chain "top" (which must be null
* if uio is not). Data provided in mbuf chain must be small
* enough to send all at once.
*
* Returns nonzero on error, timeout or signal; callers
* must check for short counts if EINTR/ERESTART are returned.
* Data and control buffers are freed on return.
*/
int
sosend(so, addr, uio, top, control, flags, td)
register struct socket *so;
struct sockaddr *addr;
struct uio *uio;
struct mbuf *top;
struct mbuf *control;
int flags;
struct thread *td;
{
struct mbuf **mp;
register struct mbuf *m;
register long space, len, resid;
int clen = 0, error, s, dontroute, mlen;
int atomic = sosendallatonce(so) || top;
if (uio)
resid = uio->uio_resid;
else
resid = top->m_pkthdr.len;
/*
* In theory resid should be unsigned.
* However, space must be signed, as it might be less than 0
* if we over-committed, and we must use a signed comparison
* of space and resid. On the other hand, a negative resid
* causes us to loop sending 0-length segments to the protocol.
*
* Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
* type sockets since that's an error.
*/
if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
error = EINVAL;
goto out;
}
dontroute =
(flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
(so->so_proto->pr_flags & PR_ATOMIC);
if (td)
td->td_proc->p_stats->p_ru.ru_msgsnd++;
if (control)
clen = control->m_len;
#define snderr(errno) { error = errno; splx(s); goto release; }
restart:
error = sblock(&so->so_snd, SBLOCKWAIT(flags));
if (error)
goto out;
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) {
/*
* `sendto' and `sendmsg' is allowed on a connection-
* based socket if it supports implied connect.
* Return ENOTCONN if not connected and no address is
* supplied.
*/
if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
if ((so->so_state & SS_ISCONFIRMING) == 0 &&
!(resid == 0 && clen != 0))
snderr(ENOTCONN);
} else if (addr == 0)
snderr(so->so_proto->pr_flags & PR_CONNREQUIRED ?
ENOTCONN : EDESTADDRREQ);
}
space = sbspace(&so->so_snd);
if (flags & MSG_OOB)
space += 1024;
if ((atomic && resid > so->so_snd.sb_hiwat) ||
clen > so->so_snd.sb_hiwat)
snderr(EMSGSIZE);
if (space < resid + clen && uio &&
(atomic || space < so->so_snd.sb_lowat || space < clen)) {
if (so->so_state & SS_NBIO)
snderr(EWOULDBLOCK);
sbunlock(&so->so_snd);
error = sbwait(&so->so_snd);
splx(s);
if (error)
goto out;
goto restart;
}
splx(s);
mp = &top;
space -= clen;
do {
if (uio == NULL) {
/*
* Data is prepackaged in "top".
*/
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
} else do {
if (top == 0) {
MGETHDR(m, M_TRYWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
goto release;
}
mlen = MHLEN;
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = (struct ifnet *)0;
} else {
MGET(m, M_TRYWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
goto release;
}
mlen = MLEN;
}
if (resid >= MINCLSIZE) {
MCLGET(m, M_TRYWAIT);
if ((m->m_flags & M_EXT) == 0)
goto nopages;
mlen = MCLBYTES;
len = min(min(mlen, resid), space);
} else {
nopages:
len = min(min(mlen, resid), space);
/*
* For datagram protocols, leave room
* for protocol headers in first mbuf.
*/
if (atomic && top == 0 && len < mlen)
MH_ALIGN(m, len);
}
space -= len;
error = uiomove(mtod(m, caddr_t), (int)len, uio);
resid = uio->uio_resid;
m->m_len = len;
*mp = m;
top->m_pkthdr.len += len;
if (error)
goto release;
mp = &m->m_next;
if (resid <= 0) {
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
break;
}
} while (space > 0 && atomic);
if (dontroute)
so->so_options |= SO_DONTROUTE;
s = splnet(); /* XXX */
/*
* XXX all the SS_CANTSENDMORE checks previously
* done could be out of date. We could have recieved
* a reset packet in an interrupt or maybe we slept
* while doing page faults in uiomove() etc. We could
* probably recheck again inside the splnet() protection
* here, but there are probably other places that this
* also happens. We must rethink this.
*/
error = (*so->so_proto->pr_usrreqs->pru_send)(so,
(flags & MSG_OOB) ? PRUS_OOB :
/*
* If the user set MSG_EOF, the protocol
* understands this flag and nothing left to
* send then use PRU_SEND_EOF instead of PRU_SEND.
*/
((flags & MSG_EOF) &&
(so->so_proto->pr_flags & PR_IMPLOPCL) &&
(resid <= 0)) ?
PRUS_EOF :
/* If there is more to send set PRUS_MORETOCOME */
(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
top, addr, control, td);
splx(s);
if (dontroute)
so->so_options &= ~SO_DONTROUTE;
clen = 0;
control = 0;
top = 0;
mp = &top;
if (error)
goto release;
} while (resid && space > 0);
} while (resid);
release:
sbunlock(&so->so_snd);
out:
if (top)
m_freem(top);
if (control)
m_freem(control);
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 or mbufs containing ancillary data,
* 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.
*
* The caller may receive the data as a single mbuf chain by supplying
* an mbuf **mp0 for use in returning the chain. The uio is then used
* only for the count in uio_resid.
*/
int
soreceive(so, psa, uio, mp0, controlp, flagsp)
register struct socket *so;
struct sockaddr **psa;
struct uio *uio;
struct mbuf **mp0;
struct mbuf **controlp;
int *flagsp;
{
struct mbuf *m, **mp;
register int flags, len, error, s, offset;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
int moff, type = 0;
int orig_resid = uio->uio_resid;
mp = mp0;
if (psa)
*psa = 0;
if (controlp)
*controlp = 0;
if (flagsp)
flags = *flagsp &~ MSG_EOR;
else
flags = 0;
if (flags & MSG_OOB) {
m = m_get(M_TRYWAIT, MT_DATA);
if (m == NULL)
return (ENOBUFS);
error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
if (error)
goto bad;
do {
error = uiomove(mtod(m, caddr_t),
(int) min(uio->uio_resid, m->m_len), uio);
m = m_free(m);
} while (uio->uio_resid && error == 0 && m);
bad:
if (m)
m_freem(m);
return (error);
}
if (mp)
*mp = (struct mbuf *)0;
if (so->so_state & SS_ISCONFIRMING && uio->uio_resid)
(*pr->pr_usrreqs->pru_rcvd)(so, 0);
restart:
error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
if (error)
return (error);
s = splnet();
m = so->so_rcv.sb_mb;
/*
* If we have less data than requested, block awaiting more
* (subject to any timeout) if:
* 1. the current count is less than the low water mark, or
* 2. MSG_WAITALL is set, and it is possible to do the entire
* receive operation at once if we block (resid <= hiwat).
* 3. MSG_DONTWAIT is not set
* If MSG_WAITALL is set but resid is larger than the receive buffer,
* we have to do the receive in sections, and thus risk returning
* a short count if a timeout or signal occurs after we start.
*/
if (m == 0 || (((flags & MSG_DONTWAIT) == 0 &&
so->so_rcv.sb_cc < uio->uio_resid) &&
(so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
m->m_nextpkt == 0 && (pr->pr_flags & PR_ATOMIC) == 0)) {
KASSERT(m != 0 || !so->so_rcv.sb_cc,
("receive: m == %p so->so_rcv.sb_cc == %lu",
m, so->so_rcv.sb_cc));
if (so->so_error) {
if (m)
goto dontblock;
error = so->so_error;
if ((flags & MSG_PEEK) == 0)
so->so_error = 0;
goto release;
}
if (so->so_state & SS_CANTRCVMORE) {
if (m)
goto dontblock;
else
goto release;
}
for (; m; m = m->m_next)
if (m->m_type == MT_OOBDATA || (m->m_flags & M_EOR)) {
m = so->so_rcv.sb_mb;
goto dontblock;
}
if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
(so->so_proto->pr_flags & PR_CONNREQUIRED)) {
error = ENOTCONN;
goto release;
}
if (uio->uio_resid == 0)
goto release;
if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT)) {
error = EWOULDBLOCK;
goto release;
}
sbunlock(&so->so_rcv);
error = sbwait(&so->so_rcv);
splx(s);
if (error)
return (error);
goto restart;
}
dontblock:
if (uio->uio_td)
uio->uio_td->td_proc->p_stats->p_ru.ru_msgrcv++;
nextrecord = m->m_nextpkt;
if (pr->pr_flags & PR_ADDR) {
KASSERT(m->m_type == MT_SONAME,
("m->m_type == %d", m->m_type));
orig_resid = 0;
if (psa)
*psa = dup_sockaddr(mtod(m, struct sockaddr *),
mp0 == 0);
if (flags & MSG_PEEK) {
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
MFREE(m, so->so_rcv.sb_mb);
m = so->so_rcv.sb_mb;
}
}
while (m && m->m_type == MT_CONTROL && error == 0) {
if (flags & MSG_PEEK) {
if (controlp)
*controlp = m_copy(m, 0, m->m_len);
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
so->so_rcv.sb_mb = m->m_next;
m->m_next = NULL;
if (pr->pr_domain->dom_externalize)
error =
(*pr->pr_domain->dom_externalize)(m, controlp);
else if (controlp)
*controlp = m;
else
m_freem(m);
m = so->so_rcv.sb_mb;
}
if (controlp) {
orig_resid = 0;
do
controlp = &(*controlp)->m_next;
while (*controlp != NULL);
}
}
if (m) {
if ((flags & MSG_PEEK) == 0)
m->m_nextpkt = nextrecord;
type = m->m_type;
if (type == MT_OOBDATA)
flags |= MSG_OOB;
}
moff = 0;
offset = 0;
while (m && uio->uio_resid > 0 && error == 0) {
if (m->m_type == MT_OOBDATA) {
if (type != MT_OOBDATA)
break;
} else if (type == MT_OOBDATA)
break;
else
KASSERT(m->m_type == MT_DATA || m->m_type == MT_HEADER,
("m->m_type == %d", m->m_type));
so->so_state &= ~SS_RCVATMARK;
len = uio->uio_resid;
if (so->so_oobmark && len > so->so_oobmark - offset)
len = so->so_oobmark - offset;
if (len > m->m_len - moff)
len = m->m_len - moff;
/*
* If mp is set, just pass back the mbufs.
* Otherwise copy them out via the uio, then free.
* Sockbuf must be consistent here (points to current mbuf,
* it points to next record) when we drop priority;
* we must note any additions to the sockbuf when we
* block interrupts again.
*/
if (mp == 0) {
splx(s);
error = uiomove(mtod(m, caddr_t) + moff, (int)len, uio);
s = splnet();
if (error)
goto release;
} else
uio->uio_resid -= len;
if (len == m->m_len - moff) {
if (m->m_flags & M_EOR)
flags |= MSG_EOR;
if (flags & MSG_PEEK) {
m = m->m_next;
moff = 0;
} else {
nextrecord = m->m_nextpkt;
sbfree(&so->so_rcv, m);
if (mp) {
*mp = m;
mp = &m->m_next;
so->so_rcv.sb_mb = m = m->m_next;
*mp = (struct mbuf *)0;
} else {
MFREE(m, so->so_rcv.sb_mb);
m = so->so_rcv.sb_mb;
}
if (m)
m->m_nextpkt = nextrecord;
}
} else {
if (flags & MSG_PEEK)
moff += len;
else {
if (mp)
*mp = m_copym(m, 0, len, M_TRYWAIT);
m->m_data += len;
m->m_len -= len;
so->so_rcv.sb_cc -= len;
}
}
if (so->so_oobmark) {
if ((flags & MSG_PEEK) == 0) {
so->so_oobmark -= len;
if (so->so_oobmark == 0) {
so->so_state |= SS_RCVATMARK;
break;
}
} else {
offset += len;
if (offset == so->so_oobmark)
break;
}
}
if (flags & MSG_EOR)
break;
/*
* If the MSG_WAITALL flag is set (for non-atomic socket),
* we must not quit until "uio->uio_resid == 0" or an error
* termination. If a signal/timeout occurs, return
* with a short count but without error.
* Keep sockbuf locked against other readers.
*/
while (flags & MSG_WAITALL && m == 0 && uio->uio_resid > 0 &&
!sosendallatonce(so) && !nextrecord) {
if (so->so_error || so->so_state & SS_CANTRCVMORE)
break;
/*
* Notify the protocol that some data has been
* drained before blocking.
*/
if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
(*pr->pr_usrreqs->pru_rcvd)(so, flags);
error = sbwait(&so->so_rcv);
if (error) {
sbunlock(&so->so_rcv);
splx(s);
return (0);
}
m = so->so_rcv.sb_mb;
if (m)
nextrecord = m->m_nextpkt;
}
}
if (m && pr->pr_flags & PR_ATOMIC) {
flags |= MSG_TRUNC;
if ((flags & MSG_PEEK) == 0)
(void) sbdroprecord(&so->so_rcv);
}
if ((flags & MSG_PEEK) == 0) {
if (m == 0)
so->so_rcv.sb_mb = nextrecord;
if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
(*pr->pr_usrreqs->pru_rcvd)(so, flags);
}
if (orig_resid == uio->uio_resid && orig_resid &&
(flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
sbunlock(&so->so_rcv);
splx(s);
goto restart;
}
if (flagsp)
*flagsp |= flags;
release:
sbunlock(&so->so_rcv);
splx(s);
return (error);
}
int
soshutdown(so, how)
register struct socket *so;
register int how;
{
register struct protosw *pr = so->so_proto;
if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
return (EINVAL);
if (how != SHUT_WR)
sorflush(so);
if (how != SHUT_RD)
return ((*pr->pr_usrreqs->pru_shutdown)(so));
return (0);
}
void
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;
sb->sb_flags |= SB_NOINTR;
(void) sblock(sb, M_WAITOK);
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, so);
}
#ifdef INET
static int
do_setopt_accept_filter(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
struct accept_filter_arg *afap = NULL;
struct accept_filter *afp;
struct so_accf *af = so->so_accf;
int error = 0;
/* do not set/remove accept filters on non listen sockets */
if ((so->so_options & SO_ACCEPTCONN) == 0) {
error = EINVAL;
goto out;
}
/* removing the filter */
if (sopt == NULL) {
if (af != NULL) {
if (af->so_accept_filter != NULL &&
af->so_accept_filter->accf_destroy != NULL) {
af->so_accept_filter->accf_destroy(so);
}
if (af->so_accept_filter_str != NULL) {
FREE(af->so_accept_filter_str, M_ACCF);
}
FREE(af, M_ACCF);
so->so_accf = NULL;
}
so->so_options &= ~SO_ACCEPTFILTER;
return (0);
}
/* adding a filter */
/* must remove previous filter first */
if (af != NULL) {
error = EINVAL;
goto out;
}
/* don't put large objects on the kernel stack */
MALLOC(afap, struct accept_filter_arg *, sizeof(*afap), M_TEMP, M_WAITOK);
error = sooptcopyin(sopt, afap, sizeof *afap, sizeof *afap);
afap->af_name[sizeof(afap->af_name)-1] = '\0';
afap->af_arg[sizeof(afap->af_arg)-1] = '\0';
if (error)
goto out;
afp = accept_filt_get(afap->af_name);
if (afp == NULL) {
error = ENOENT;
goto out;
}
MALLOC(af, struct so_accf *, sizeof(*af), M_ACCF, M_WAITOK | M_ZERO);
if (afp->accf_create != NULL) {
if (afap->af_name[0] != '\0') {
int len = strlen(afap->af_name) + 1;
MALLOC(af->so_accept_filter_str, char *, len, M_ACCF, M_WAITOK);
strcpy(af->so_accept_filter_str, afap->af_name);
}
af->so_accept_filter_arg = afp->accf_create(so, afap->af_arg);
if (af->so_accept_filter_arg == NULL) {
FREE(af->so_accept_filter_str, M_ACCF);
FREE(af, M_ACCF);
so->so_accf = NULL;
error = EINVAL;
goto out;
}
}
af->so_accept_filter = afp;
so->so_accf = af;
so->so_options |= SO_ACCEPTFILTER;
out:
if (afap != NULL)
FREE(afap, M_TEMP);
return (error);
}
#endif /* INET */
/*
* Perhaps this routine, and sooptcopyout(), below, ought to come in
* an additional variant to handle the case where the option value needs
* to be some kind of integer, but not a specific size.
* In addition to their use here, these functions are also called by the
* protocol-level pr_ctloutput() routines.
*/
int
sooptcopyin(sopt, buf, len, minlen)
struct sockopt *sopt;
void *buf;
size_t len;
size_t minlen;
{
size_t valsize;
/*
* If the user gives us more than we wanted, we ignore it,
* but if we don't get the minimum length the caller
* wants, we return EINVAL. On success, sopt->sopt_valsize
* is set to however much we actually retrieved.
*/
if ((valsize = sopt->sopt_valsize) < minlen)
return EINVAL;
if (valsize > len)
sopt->sopt_valsize = valsize = len;
if (sopt->sopt_td != 0)
return (copyin(sopt->sopt_val, buf, valsize));
bcopy(sopt->sopt_val, buf, valsize);
return 0;
}
int
sosetopt(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
int error, optval;
struct linger l;
struct timeval tv;
u_long val;
error = 0;
if (sopt->sopt_level != SOL_SOCKET) {
if (so->so_proto && so->so_proto->pr_ctloutput)
return ((*so->so_proto->pr_ctloutput)
(so, sopt));
error = ENOPROTOOPT;
} else {
switch (sopt->sopt_name) {
#ifdef INET
case SO_ACCEPTFILTER:
error = do_setopt_accept_filter(so, sopt);
if (error)
goto bad;
break;
#endif
case SO_LINGER:
error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
if (error)
goto bad;
so->so_linger = l.l_linger;
if (l.l_onoff)
so->so_options |= SO_LINGER;
else
so->so_options &= ~SO_LINGER;
break;
case SO_DEBUG:
case SO_KEEPALIVE:
case SO_DONTROUTE:
case SO_USELOOPBACK:
case SO_BROADCAST:
case SO_REUSEADDR:
case SO_REUSEPORT:
case SO_OOBINLINE:
case SO_TIMESTAMP:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
goto bad;
if (optval)
so->so_options |= sopt->sopt_name;
else
so->so_options &= ~sopt->sopt_name;
break;
case SO_SNDBUF:
case SO_RCVBUF:
case SO_SNDLOWAT:
case SO_RCVLOWAT:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
goto bad;
/*
* Values < 1 make no sense for any of these
* options, so disallow them.
*/
if (optval < 1) {
error = EINVAL;
goto bad;
}
switch (sopt->sopt_name) {
case SO_SNDBUF:
case SO_RCVBUF:
if (sbreserve(sopt->sopt_name == SO_SNDBUF ?
&so->so_snd : &so->so_rcv, (u_long)optval,
so, curthread) == 0) {
error = ENOBUFS;
goto bad;
}
break;
/*
* Make sure the low-water is never greater than
* the high-water.
*/
case SO_SNDLOWAT:
so->so_snd.sb_lowat =
(optval > so->so_snd.sb_hiwat) ?
so->so_snd.sb_hiwat : optval;
break;
case SO_RCVLOWAT:
so->so_rcv.sb_lowat =
(optval > so->so_rcv.sb_hiwat) ?
so->so_rcv.sb_hiwat : optval;
break;
}
break;
case SO_SNDTIMEO:
case SO_RCVTIMEO:
error = sooptcopyin(sopt, &tv, sizeof tv,
sizeof tv);
if (error)
goto bad;
/* assert(hz > 0); */
if (tv.tv_sec < 0 || tv.tv_sec > SHRT_MAX / hz ||
tv.tv_usec < 0 || tv.tv_usec >= 1000000) {
error = EDOM;
goto bad;
}
/* assert(tick > 0); */
/* assert(ULONG_MAX - SHRT_MAX >= 1000000); */
val = (u_long)(tv.tv_sec * hz) + tv.tv_usec / tick;
if (val > SHRT_MAX) {
error = EDOM;
goto bad;
}
switch (sopt->sopt_name) {
case SO_SNDTIMEO:
so->so_snd.sb_timeo = val;
break;
case SO_RCVTIMEO:
so->so_rcv.sb_timeo = val;
break;
}
break;
default:
error = ENOPROTOOPT;
break;
}
if (error == 0 && so->so_proto && so->so_proto->pr_ctloutput) {
(void) ((*so->so_proto->pr_ctloutput)
(so, sopt));
}
}
bad:
return (error);
}
/* Helper routine for getsockopt */
int
sooptcopyout(sopt, buf, len)
struct sockopt *sopt;
void *buf;
size_t len;
{
int error;
size_t valsize;
error = 0;
/*
* Documented get behavior is that we always return a value,
* possibly truncated to fit in the user's buffer.
* Traditional behavior is that we always tell the user
* precisely how much we copied, rather than something useful
* like the total amount we had available for her.
* Note that this interface is not idempotent; the entire answer must
* generated ahead of time.
*/
valsize = min(len, sopt->sopt_valsize);
sopt->sopt_valsize = valsize;
if (sopt->sopt_val != 0) {
if (sopt->sopt_td != 0)
error = copyout(buf, sopt->sopt_val, valsize);
else
bcopy(buf, sopt->sopt_val, valsize);
}
return error;
}
int
sogetopt(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
int error, optval;
struct linger l;
struct timeval tv;
#ifdef INET
struct accept_filter_arg *afap;
#endif
error = 0;
if (sopt->sopt_level != SOL_SOCKET) {
if (so->so_proto && so->so_proto->pr_ctloutput) {
return ((*so->so_proto->pr_ctloutput)
(so, sopt));
} else
return (ENOPROTOOPT);
} else {
switch (sopt->sopt_name) {
#ifdef INET
case SO_ACCEPTFILTER:
if ((so->so_options & SO_ACCEPTCONN) == 0)
return (EINVAL);
MALLOC(afap, struct accept_filter_arg *, sizeof(*afap),
M_TEMP, M_WAITOK | M_ZERO);
if ((so->so_options & SO_ACCEPTFILTER) != 0) {
strcpy(afap->af_name, so->so_accf->so_accept_filter->accf_name);
if (so->so_accf->so_accept_filter_str != NULL)
strcpy(afap->af_arg, so->so_accf->so_accept_filter_str);
}
error = sooptcopyout(sopt, afap, sizeof(*afap));
FREE(afap, M_TEMP);
break;
#endif
case SO_LINGER:
l.l_onoff = so->so_options & SO_LINGER;
l.l_linger = so->so_linger;
error = sooptcopyout(sopt, &l, sizeof l);
break;
case SO_USELOOPBACK:
case SO_DONTROUTE:
case SO_DEBUG:
case SO_KEEPALIVE:
case SO_REUSEADDR:
case SO_REUSEPORT:
case SO_BROADCAST:
case SO_OOBINLINE:
case SO_TIMESTAMP:
optval = so->so_options & sopt->sopt_name;
integer:
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case SO_TYPE:
optval = so->so_type;
goto integer;
case SO_ERROR:
optval = so->so_error;
so->so_error = 0;
goto integer;
case SO_SNDBUF:
optval = so->so_snd.sb_hiwat;
goto integer;
case SO_RCVBUF:
optval = so->so_rcv.sb_hiwat;
goto integer;
case SO_SNDLOWAT:
optval = so->so_snd.sb_lowat;
goto integer;
case SO_RCVLOWAT:
optval = so->so_rcv.sb_lowat;
goto integer;
case SO_SNDTIMEO:
case SO_RCVTIMEO:
optval = (sopt->sopt_name == SO_SNDTIMEO ?
so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
tv.tv_sec = optval / hz;
tv.tv_usec = (optval % hz) * tick;
error = sooptcopyout(sopt, &tv, sizeof tv);
break;
default:
error = ENOPROTOOPT;
break;
}
return (error);
}
}
/* XXX; prepare mbuf for (__FreeBSD__ < 3) routines. */
int
soopt_getm(struct sockopt *sopt, struct mbuf **mp)
{
struct mbuf *m, *m_prev;
int sopt_size = sopt->sopt_valsize;
MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_DATA);
if (m == 0)
return ENOBUFS;
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
return ENOBUFS;
}
m->m_len = min(MCLBYTES, sopt_size);
} else {
m->m_len = min(MLEN, sopt_size);
}
sopt_size -= m->m_len;
*mp = m;
m_prev = m;
while (sopt_size) {
MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_DATA);
if (m == 0) {
m_freem(*mp);
return ENOBUFS;
}
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_freem(*mp);
return ENOBUFS;
}
m->m_len = min(MCLBYTES, sopt_size);
} else {
m->m_len = min(MLEN, sopt_size);
}
sopt_size -= m->m_len;
m_prev->m_next = m;
m_prev = m;
}
return 0;
}
/* XXX; copyin sopt data into mbuf chain for (__FreeBSD__ < 3) routines. */
int
soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
{
struct mbuf *m0 = m;
if (sopt->sopt_val == NULL)
return 0;
while (m != NULL && sopt->sopt_valsize >= m->m_len) {
if (sopt->sopt_td != NULL) {
int error;
error = copyin(sopt->sopt_val, mtod(m, char *),
m->m_len);
if (error != 0) {
m_freem(m0);
return(error);
}
} else
bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
sopt->sopt_valsize -= m->m_len;
(caddr_t)sopt->sopt_val += m->m_len;
m = m->m_next;
}
if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
panic("ip6_sooptmcopyin");
return 0;
}
/* XXX; copyout mbuf chain data into soopt for (__FreeBSD__ < 3) routines. */
int
soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
{
struct mbuf *m0 = m;
size_t valsize = 0;
if (sopt->sopt_val == NULL)
return 0;
while (m != NULL && sopt->sopt_valsize >= m->m_len) {
if (sopt->sopt_td != NULL) {
int error;
error = copyout(mtod(m, char *), sopt->sopt_val,
m->m_len);
if (error != 0) {
m_freem(m0);
return(error);
}
} else
bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
sopt->sopt_valsize -= m->m_len;
(caddr_t)sopt->sopt_val += m->m_len;
valsize += m->m_len;
m = m->m_next;
}
if (m != NULL) {
/* enough soopt buffer should be given from user-land */
m_freem(m0);
return(EINVAL);
}
sopt->sopt_valsize = valsize;
return 0;
}
void
sohasoutofband(so)
register struct socket *so;
{
if (so->so_sigio != NULL)
pgsigio(so->so_sigio, SIGURG, 0);
selwakeup(&so->so_rcv.sb_sel);
}
int
sopoll(struct socket *so, int events, struct ucred *cred, struct thread *td)
{
int revents = 0;
int s = splnet();
if (events & (POLLIN | POLLRDNORM))
if (soreadable(so))
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (sowriteable(so))
revents |= events & (POLLOUT | POLLWRNORM);
if (events & (POLLPRI | POLLRDBAND))
if (so->so_oobmark || (so->so_state & SS_RCVATMARK))
revents |= events & (POLLPRI | POLLRDBAND);
if (revents == 0) {
if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
selrecord(td, &so->so_rcv.sb_sel);
so->so_rcv.sb_flags |= SB_SEL;
}
if (events & (POLLOUT | POLLWRNORM)) {
selrecord(td, &so->so_snd.sb_sel);
so->so_snd.sb_flags |= SB_SEL;
}
}
splx(s);
return (revents);
}
int
sokqfilter(struct file *fp, struct knote *kn)
{
struct socket *so = (struct socket *)kn->kn_fp->f_data;
struct sockbuf *sb;
int s;
switch (kn->kn_filter) {
case EVFILT_READ:
if (so->so_options & SO_ACCEPTCONN)
kn->kn_fop = &solisten_filtops;
else
kn->kn_fop = &soread_filtops;
sb = &so->so_rcv;
break;
case EVFILT_WRITE:
kn->kn_fop = &sowrite_filtops;
sb = &so->so_snd;
break;
default:
return (1);
}
s = splnet();
SLIST_INSERT_HEAD(&sb->sb_sel.si_note, kn, kn_selnext);
sb->sb_flags |= SB_KNOTE;
splx(s);
return (0);
}
static void
filt_sordetach(struct knote *kn)
{
struct socket *so = (struct socket *)kn->kn_fp->f_data;
int s = splnet();
SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext);
if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note))
so->so_rcv.sb_flags &= ~SB_KNOTE;
splx(s);
}
/*ARGSUSED*/
static int
filt_soread(struct knote *kn, long hint)
{
struct socket *so = (struct socket *)kn->kn_fp->f_data;
kn->kn_data = so->so_rcv.sb_cc;
if (so->so_state & SS_CANTRCVMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
}
if (so->so_error) /* temporary udp error */
return (1);
if (kn->kn_sfflags & NOTE_LOWAT)
return (kn->kn_data >= kn->kn_sdata);
return (kn->kn_data >= so->so_rcv.sb_lowat);
}
static void
filt_sowdetach(struct knote *kn)
{
struct socket *so = (struct socket *)kn->kn_fp->f_data;
int s = splnet();
SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext);
if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note))
so->so_snd.sb_flags &= ~SB_KNOTE;
splx(s);
}
/*ARGSUSED*/
static int
filt_sowrite(struct knote *kn, long hint)
{
struct socket *so = (struct socket *)kn->kn_fp->f_data;
kn->kn_data = sbspace(&so->so_snd);
if (so->so_state & SS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
}
if (so->so_error) /* temporary udp error */
return (1);
if (((so->so_state & SS_ISCONNECTED) == 0) &&
(so->so_proto->pr_flags & PR_CONNREQUIRED))
return (0);
if (kn->kn_sfflags & NOTE_LOWAT)
return (kn->kn_data >= kn->kn_sdata);
return (kn->kn_data >= so->so_snd.sb_lowat);
}
/*ARGSUSED*/
static int
filt_solisten(struct knote *kn, long hint)
{
struct socket *so = (struct socket *)kn->kn_fp->f_data;
kn->kn_data = so->so_qlen - so->so_incqlen;
return (! TAILQ_EMPTY(&so->so_comp));
}
int
socheckuid(struct socket *so, uid_t uid)
{
if (so == NULL)
return (EPERM);
if (so->so_cred->cr_uid == uid)
return (0);
return (EPERM);
}