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freebsd-nq/sys/kern/uipc_socket.c
John-Mark Gurney ad3b9257c2 Add locking to the kqueue subsystem. This also makes the kqueue subsystem 
a more complete subsystem, and removes the knowlege of how things are
implemented from the drivers.  Include locking around filter ops, so a
module like aio will know when not to be unloaded if there are outstanding
knotes using it's filter ops.

Currently, it uses the MTX_DUPOK even though it is not always safe to
aquire duplicate locks.  Witness currently doesn't support the ability
to discover if a dup lock is ok (in some cases).

Reviewed by:	green, rwatson (both earlier versions)
2004-08-15 06:24:42 +00:00

2267 lines
58 KiB
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/*
* Copyright (c) 2004 The FreeBSD Foundation
* Copyright (c) 2004 Robert Watson
* 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.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_mac.h"
#include "opt_zero.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mac.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/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/uma.h>
static int soreceive_rcvoob(struct socket *so, struct uio *uio,
int flags);
#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 };
uma_zone_t 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");
#ifdef ZERO_COPY_SOCKETS
/* These aren't static because they're used in other files. */
int so_zero_copy_send = 1;
int so_zero_copy_receive = 1;
SYSCTL_NODE(_kern_ipc, OID_AUTO, zero_copy, CTLFLAG_RD, 0,
"Zero copy controls");
SYSCTL_INT(_kern_ipc_zero_copy, OID_AUTO, receive, CTLFLAG_RW,
&so_zero_copy_receive, 0, "Enable zero copy receive");
SYSCTL_INT(_kern_ipc_zero_copy, OID_AUTO, send, CTLFLAG_RW,
&so_zero_copy_send, 0, "Enable zero copy send");
#endif /* ZERO_COPY_SOCKETS */
/*
* accept_mtx locks down per-socket fields relating to accept queues. See
* socketvar.h for an annotation of the protected fields of struct socket.
*/
struct mtx accept_mtx;
MTX_SYSINIT(accept_mtx, &accept_mtx, "accept", MTX_DEF);
/*
* so_global_mtx protects so_gencnt, numopensockets, and the per-socket
* so_gencnt field.
*
* XXXRW: These variables might be better manipulated using atomic operations
* for improved efficiency.
*/
static struct mtx so_global_mtx;
MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
/*
* 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.
* 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(int mflags)
{
struct socket *so;
#ifdef MAC
int error;
#endif
so = uma_zalloc(socket_zone, mflags | M_ZERO);
if (so != NULL) {
#ifdef MAC
error = mac_init_socket(so, mflags);
if (error != 0) {
uma_zfree(socket_zone, so);
so = NULL;
return so;
}
#endif
SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
/* sx_init(&so->so_sxlock, "socket sxlock"); */
TAILQ_INIT(&so->so_aiojobq);
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
++numopensockets;
mtx_unlock(&so_global_mtx);
}
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, cred, td)
int dom;
struct socket **aso;
int type;
int proto;
struct ucred *cred;
struct thread *td;
{
struct protosw *prp;
struct socket *so;
int error;
if (proto)
prp = pffindproto(dom, proto, type);
else
prp = pffindtype(dom, type);
if (prp == NULL || prp->pr_usrreqs->pru_attach == NULL)
return (EPROTONOSUPPORT);
if (jailed(cred) && 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(M_WAITOK);
if (so == NULL)
return (ENOBUFS);
TAILQ_INIT(&so->so_incomp);
TAILQ_INIT(&so->so_comp);
so->so_type = type;
so->so_cred = crhold(cred);
so->so_proto = prp;
#ifdef MAC
mac_create_socket(cred, so);
#endif
SOCK_LOCK(so);
knlist_init(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
knlist_init(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
soref(so);
SOCK_UNLOCK(so);
error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
if (error) {
SOCK_LOCK(so);
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;
{
return ((*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td));
}
void
sodealloc(struct socket *so)
{
KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
mtx_unlock(&so_global_mtx);
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
/* remove acccept filter if one is present. */
if (so->so_accf != NULL)
do_setopt_accept_filter(so, NULL);
#endif
#ifdef MAC
mac_destroy_socket(so);
#endif
crfree(so->so_cred);
SOCKBUF_LOCK_DESTROY(&so->so_snd);
SOCKBUF_LOCK_DESTROY(&so->so_rcv);
/* sx_destroy(&so->so_sxlock); */
uma_zfree(socket_zone, so);
/*
* XXXRW: Seems like a shame to grab the mutex again down here, but
* we don't want to decrement the socket count until after we free
* the socket, and we can't increment the gencnt on the socket after
* we free, it so...
*/
mtx_lock(&so_global_mtx);
--numopensockets;
mtx_unlock(&so_global_mtx);
}
int
solisten(so, backlog, td)
struct socket *so;
int backlog;
struct thread *td;
{
int error;
/*
* XXXRW: Ordering issue here -- perhaps we need to set
* SO_ACCEPTCONN before the call to pru_listen()?
* XXXRW: General atomic test-and-set concerns here also.
*/
if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
SS_ISDISCONNECTING))
return (EINVAL);
error = (*so->so_proto->pr_usrreqs->pru_listen)(so, td);
if (error)
return (error);
ACCEPT_LOCK();
if (TAILQ_EMPTY(&so->so_comp)) {
SOCK_LOCK(so);
so->so_options |= SO_ACCEPTCONN;
SOCK_UNLOCK(so);
}
if (backlog < 0 || backlog > somaxconn)
backlog = somaxconn;
so->so_qlimit = backlog;
ACCEPT_UNLOCK();
return (0);
}
void
sofree(so)
struct socket *so;
{
struct socket *head;
KASSERT(so->so_count == 0, ("socket %p so_count not 0", so));
SOCK_LOCK_ASSERT(so);
if (so->so_pcb != NULL || (so->so_state & SS_NOFDREF) == 0) {
SOCK_UNLOCK(so);
return;
}
SOCK_UNLOCK(so);
ACCEPT_LOCK();
head = so->so_head;
if (head != NULL) {
KASSERT((so->so_qstate & SQ_COMP) != 0 ||
(so->so_qstate & SQ_INCOMP) != 0,
("sofree: so_head != NULL, but neither SQ_COMP nor "
"SQ_INCOMP"));
KASSERT((so->so_qstate & SQ_COMP) == 0 ||
(so->so_qstate & SQ_INCOMP) == 0,
("sofree: so->so_qstate is SQ_COMP and also SQ_INCOMP"));
/*
* accept(2) is responsible draining the completed
* connection queue and freeing those sockets, so
* we just return here if this socket is currently
* on the completed connection queue. Otherwise,
* accept(2) may hang after select(2) has indicating
* that a listening socket was ready. If it's an
* incomplete connection, we remove it from the queue
* and free it; otherwise, it won't be released until
* the listening socket is closed.
*/
if ((so->so_qstate & SQ_COMP) != 0) {
ACCEPT_UNLOCK();
return;
}
TAILQ_REMOVE(&head->so_incomp, so, so_list);
head->so_incqlen--;
so->so_qstate &= ~SQ_INCOMP;
so->so_head = NULL;
}
KASSERT((so->so_qstate & SQ_COMP) == 0 &&
(so->so_qstate & SQ_INCOMP) == 0,
("sofree: so_head == NULL, but still SQ_COMP(%d) or SQ_INCOMP(%d)",
so->so_qstate & SQ_COMP, so->so_qstate & SQ_INCOMP));
ACCEPT_UNLOCK();
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_flags |= SB_NOINTR;
(void)sblock(&so->so_snd, M_WAITOK);
/*
* socantsendmore_locked() drops the socket buffer mutex so that it
* can safely perform wakeups. Re-acquire the mutex before
* continuing.
*/
socantsendmore_locked(so);
SOCKBUF_LOCK(&so->so_snd);
sbunlock(&so->so_snd);
sbrelease_locked(&so->so_snd, so);
SOCKBUF_UNLOCK(&so->so_snd);
sorflush(so);
knlist_destroy(&so->so_rcv.sb_sel.si_note);
knlist_destroy(&so->so_snd.sb_sel.si_note);
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)
struct socket *so;
{
int error = 0;
KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
funsetown(&so->so_sigio);
if (so->so_options & SO_ACCEPTCONN) {
struct socket *sp;
ACCEPT_LOCK();
while ((sp = TAILQ_FIRST(&so->so_incomp)) != NULL) {
TAILQ_REMOVE(&so->so_incomp, sp, so_list);
so->so_incqlen--;
sp->so_qstate &= ~SQ_INCOMP;
sp->so_head = NULL;
ACCEPT_UNLOCK();
(void) soabort(sp);
ACCEPT_LOCK();
}
while ((sp = TAILQ_FIRST(&so->so_comp)) != NULL) {
TAILQ_REMOVE(&so->so_comp, sp, so_list);
so->so_qlen--;
sp->so_qstate &= ~SQ_COMP;
sp->so_head = NULL;
ACCEPT_UNLOCK();
(void) soabort(sp);
ACCEPT_LOCK();
}
ACCEPT_UNLOCK();
}
if (so->so_pcb == NULL)
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(&so->so_timeo,
PSOCK | PCATCH, "soclos", so->so_linger * hz);
if (error)
break;
}
}
}
drop:
if (so->so_pcb != NULL) {
int error2 = (*so->so_proto->pr_usrreqs->pru_detach)(so);
if (error == 0)
error = error2;
}
discard:
SOCK_LOCK(so);
KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
so->so_state |= SS_NOFDREF;
sorele(so);
return (error);
}
/*
* soabort() must not be called with any socket locks held, as it calls
* into the protocol, which will call back into the socket code causing
* it to acquire additional socket locks that may cause recursion or lock
* order reversals.
*/
int
soabort(so)
struct socket *so;
{
int error;
error = (*so->so_proto->pr_usrreqs->pru_abort)(so);
if (error) {
SOCK_LOCK(so);
sotryfree(so); /* note: does not decrement the ref count */
return error;
}
return (0);
}
int
soaccept(so, nam)
struct socket *so;
struct sockaddr **nam;
{
int error;
SOCK_LOCK(so);
KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF"));
so->so_state &= ~SS_NOFDREF;
SOCK_UNLOCK(so);
error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
return (error);
}
int
soconnect(so, nam, td)
struct socket *so;
struct sockaddr *nam;
struct thread *td;
{
int error;
if (so->so_options & SO_ACCEPTCONN)
return (EOPNOTSUPP);
/*
* 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);
return (error);
}
int
soconnect2(so1, so2)
struct socket *so1;
struct socket *so2;
{
return ((*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2));
}
int
sodisconnect(so)
struct socket *so;
{
int error;
if ((so->so_state & SS_ISCONNECTED) == 0)
return (ENOTCONN);
if (so->so_state & SS_ISDISCONNECTING)
return (EALREADY);
error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
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.
*/
#ifdef ZERO_COPY_SOCKETS
struct so_zerocopy_stats{
int size_ok;
int align_ok;
int found_ifp;
};
struct so_zerocopy_stats so_zerocp_stats = {0,0,0};
#include <netinet/in.h>
#include <net/route.h>
#include <netinet/in_pcb.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#endif /*ZERO_COPY_SOCKETS*/
int
sosend(so, addr, uio, top, control, flags, td)
struct socket *so;
struct sockaddr *addr;
struct uio *uio;
struct mbuf *top;
struct mbuf *control;
int flags;
struct thread *td;
{
struct mbuf **mp;
struct mbuf *m;
long space, len = 0, resid;
int clen = 0, error, dontroute;
int atomic = sosendallatonce(so) || top;
#ifdef ZERO_COPY_SOCKETS
int cow_send;
#endif /* ZERO_COPY_SOCKETS */
if (uio != NULL)
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 != NULL)
td->td_proc->p_stats->p_ru.ru_msgsnd++;
if (control != NULL)
clen = control->m_len;
#define snderr(errno) { error = (errno); goto release; }
SOCKBUF_LOCK(&so->so_snd);
restart:
SOCKBUF_LOCK_ASSERT(&so->so_snd);
error = sblock(&so->so_snd, SBLOCKWAIT(flags));
if (error)
goto out_locked;
do {
SOCKBUF_LOCK_ASSERT(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE)
snderr(EPIPE);
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
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 == NULL)
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 &&
(atomic || space < so->so_snd.sb_lowat || space < clen)) {
if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO))
snderr(EWOULDBLOCK);
sbunlock(&so->so_snd);
error = sbwait(&so->so_snd);
if (error)
goto out_locked;
goto restart;
}
SOCKBUF_UNLOCK(&so->so_snd);
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 {
#ifdef ZERO_COPY_SOCKETS
cow_send = 0;
#endif /* ZERO_COPY_SOCKETS */
if (resid >= MINCLSIZE) {
#ifdef ZERO_COPY_SOCKETS
if (top == NULL) {
MGETHDR(m, M_TRYWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
SOCKBUF_LOCK(&so->so_snd);
goto release;
}
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = (struct ifnet *)0;
} else {
MGET(m, M_TRYWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
SOCKBUF_LOCK(&so->so_snd);
goto release;
}
}
if (so_zero_copy_send &&
resid>=PAGE_SIZE &&
space>=PAGE_SIZE &&
uio->uio_iov->iov_len>=PAGE_SIZE) {
so_zerocp_stats.size_ok++;
if (!((vm_offset_t)
uio->uio_iov->iov_base & PAGE_MASK)){
so_zerocp_stats.align_ok++;
cow_send = socow_setup(m, uio);
}
}
if (!cow_send) {
MCLGET(m, M_TRYWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
m = NULL;
} else {
len = min(min(MCLBYTES, resid), space);
}
} else
len = PAGE_SIZE;
#else /* ZERO_COPY_SOCKETS */
if (top == NULL) {
m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR);
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = (struct ifnet *)0;
} else
m = m_getcl(M_TRYWAIT, MT_DATA, 0);
len = min(min(MCLBYTES, resid), space);
#endif /* ZERO_COPY_SOCKETS */
} else {
if (top == NULL) {
m = m_gethdr(M_TRYWAIT, MT_DATA);
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = (struct ifnet *)0;
len = min(min(MHLEN, resid), space);
/*
* For datagram protocols, leave room
* for protocol headers in first mbuf.
*/
if (atomic && m && len < MHLEN)
MH_ALIGN(m, len);
} else {
m = m_get(M_TRYWAIT, MT_DATA);
len = min(min(MLEN, resid), space);
}
}
if (m == NULL) {
error = ENOBUFS;
SOCKBUF_LOCK(&so->so_snd);
goto release;
}
space -= len;
#ifdef ZERO_COPY_SOCKETS
if (cow_send)
error = 0;
else
#endif /* ZERO_COPY_SOCKETS */
error = uiomove(mtod(m, void *), (int)len, uio);
resid = uio->uio_resid;
m->m_len = len;
*mp = m;
top->m_pkthdr.len += len;
if (error) {
SOCKBUF_LOCK(&so->so_snd);
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) {
SOCK_LOCK(so);
so->so_options |= SO_DONTROUTE;
SOCK_UNLOCK(so);
}
/*
* XXX all the SBS_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 locking 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);
if (dontroute) {
SOCK_LOCK(so);
so->so_options &= ~SO_DONTROUTE;
SOCK_UNLOCK(so);
}
clen = 0;
control = NULL;
top = NULL;
mp = &top;
if (error) {
SOCKBUF_LOCK(&so->so_snd);
goto release;
}
} while (resid && space > 0);
SOCKBUF_LOCK(&so->so_snd);
} while (resid);
release:
SOCKBUF_LOCK_ASSERT(&so->so_snd);
sbunlock(&so->so_snd);
out_locked:
SOCKBUF_LOCK_ASSERT(&so->so_snd);
SOCKBUF_UNLOCK(&so->so_snd);
out:
if (top != NULL)
m_freem(top);
if (control != NULL)
m_freem(control);
return (error);
}
/*
* The part of soreceive() that implements reading non-inline out-of-band
* data from a socket. For more complete comments, see soreceive(), from
* which this code originated.
*
* XXXRW: Note that soreceive_rcvoob(), unlike the remainder of soreiceve(),
* is unable to return an mbuf chain to the caller.
*/
static int
soreceive_rcvoob(so, uio, flags)
struct socket *so;
struct uio *uio;
int flags;
{
struct protosw *pr = so->so_proto;
struct mbuf *m;
int error;
KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
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 {
#ifdef ZERO_COPY_SOCKETS
if (so_zero_copy_receive) {
vm_page_t pg;
int disposable;
if ((m->m_flags & M_EXT)
&& (m->m_ext.ext_type == EXT_DISPOSABLE))
disposable = 1;
else
disposable = 0;
pg = PHYS_TO_VM_PAGE(vtophys(mtod(m, caddr_t)));
if (uio->uio_offset == -1)
uio->uio_offset =IDX_TO_OFF(pg->pindex);
error = uiomoveco(mtod(m, void *),
min(uio->uio_resid, m->m_len),
uio, pg->object,
disposable);
} else
#endif /* ZERO_COPY_SOCKETS */
error = uiomove(mtod(m, void *),
(int) min(uio->uio_resid, m->m_len), uio);
m = m_free(m);
} while (uio->uio_resid && error == 0 && m);
bad:
if (m != NULL)
m_freem(m);
return (error);
}
/*
* Following replacement or removal of the first mbuf on the first mbuf chain
* of a socket buffer, push necessary state changes back into the socket
* buffer so that other consumers see the values consistently. 'nextrecord'
* is the callers locally stored value of the original value of
* sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
* NOTE: 'nextrecord' may be NULL.
*/
static __inline void
sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
{
SOCKBUF_LOCK_ASSERT(sb);
/*
* First, update for the new value of nextrecord. If necessary, make
* it the first record.
*/
if (sb->sb_mb != NULL)
sb->sb_mb->m_nextpkt = nextrecord;
else
sb->sb_mb = nextrecord;
/*
* Now update any dependent socket buffer fields to reflect the new
* state. This is an expanded inline of SB_EMPTY_FIXUP(), with the
* addition of a second clause that takes care of the case where
* sb_mb has been updated, but remains the last record.
*/
if (sb->sb_mb == NULL) {
sb->sb_mbtail = NULL;
sb->sb_lastrecord = NULL;
} else if (sb->sb_mb->m_nextpkt == NULL)
sb->sb_lastrecord = sb->sb_mb;
}
/*
* 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)
struct socket *so;
struct sockaddr **psa;
struct uio *uio;
struct mbuf **mp0;
struct mbuf **controlp;
int *flagsp;
{
struct mbuf *m, **mp;
int flags, len, error, offset;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
int moff, type = 0;
int orig_resid = uio->uio_resid;
mp = mp0;
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
*controlp = NULL;
if (flagsp != NULL)
flags = *flagsp &~ MSG_EOR;
else
flags = 0;
if (flags & MSG_OOB)
return (soreceive_rcvoob(so, uio, flags));
if (mp != NULL)
*mp = NULL;
if (so->so_state & SS_ISCONFIRMING && uio->uio_resid)
(*pr->pr_usrreqs->pru_rcvd)(so, 0);
SOCKBUF_LOCK(&so->so_rcv);
restart:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
if (error)
goto out;
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 == NULL || (((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 == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
KASSERT(m != NULL || !so->so_rcv.sb_cc,
("receive: m == %p so->so_rcv.sb_cc == %u",
m, so->so_rcv.sb_cc));
if (so->so_error) {
if (m != NULL)
goto dontblock;
error = so->so_error;
if ((flags & MSG_PEEK) == 0)
so->so_error = 0;
goto release;
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
if (m)
goto dontblock;
else
goto release;
}
for (; m != NULL; 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|MSG_NBIO))) {
error = EWOULDBLOCK;
goto release;
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
sbunlock(&so->so_rcv);
error = sbwait(&so->so_rcv);
if (error)
goto out;
goto restart;
}
dontblock:
/*
* From this point onward, we maintain 'nextrecord' as a cache of the
* pointer to the next record in the socket buffer. We must keep the
* various socket buffer pointers and local stack versions of the
* pointers in sync, pushing out modifications before dropping the
* socket buffer mutex, and re-reading them when picking it up.
*
* Otherwise, we will race with the network stack appending new data
* or records onto the socket buffer by using inconsistent/stale
* versions of the field, possibly resulting in socket buffer
* corruption.
*
* By holding the high-level sblock(), we prevent simultaneous
* readers from pulling off the front of the socket buffer.
*/
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (uio->uio_td)
uio->uio_td->td_proc->p_stats->p_ru.ru_msgrcv++;
KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
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 != NULL)
*psa = sodupsockaddr(mtod(m, struct sockaddr *),
M_NOWAIT);
if (flags & MSG_PEEK) {
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
so->so_rcv.sb_mb = m_free(m);
m = so->so_rcv.sb_mb;
sockbuf_pushsync(&so->so_rcv, nextrecord);
}
}
/*
* Process one or more MT_CONTROL mbufs present before any data mbufs
* in the first mbuf chain on the socket buffer. If MSG_PEEK, we
* just copy the data; if !MSG_PEEK, we call into the protocol to
* perform externalization (or freeing if controlp == NULL).
*/
if (m != NULL && m->m_type == MT_CONTROL) {
struct mbuf *cm = NULL, *cmn;
struct mbuf **cme = &cm;
do {
if (flags & MSG_PEEK) {
if (controlp != NULL) {
*controlp = m_copy(m, 0, m->m_len);
controlp = &(*controlp)->m_next;
}
m = m->m_next;
} else {
sbfree(&so->so_rcv, m);
so->so_rcv.sb_mb = m->m_next;
m->m_next = NULL;
*cme = m;
cme = &(*cme)->m_next;
m = so->so_rcv.sb_mb;
}
} while (m != NULL && m->m_type == MT_CONTROL);
if ((flags & MSG_PEEK) == 0)
sockbuf_pushsync(&so->so_rcv, nextrecord);
while (cm != NULL) {
cmn = cm->m_next;
cm->m_next = NULL;
if (pr->pr_domain->dom_externalize != NULL) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = (*pr->pr_domain->dom_externalize)
(cm, controlp);
SOCKBUF_LOCK(&so->so_rcv);
} else if (controlp != NULL)
*controlp = cm;
else
m_freem(cm);
if (controlp != NULL) {
orig_resid = 0;
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
cm = cmn;
}
nextrecord = so->so_rcv.sb_mb->m_nextpkt;
orig_resid = 0;
}
if (m != NULL) {
if ((flags & MSG_PEEK) == 0) {
KASSERT(m->m_nextpkt == nextrecord,
("soreceive: post-control, nextrecord !sync"));
if (nextrecord == NULL) {
KASSERT(so->so_rcv.sb_mb == m,
("soreceive: post-control, sb_mb!=m"));
KASSERT(so->so_rcv.sb_lastrecord == m,
("soreceive: post-control, lastrecord!=m"));
}
}
type = m->m_type;
if (type == MT_OOBDATA)
flags |= MSG_OOB;
} else {
if ((flags & MSG_PEEK) == 0) {
KASSERT(so->so_rcv.sb_mb == nextrecord,
("soreceive: sb_mb != nextrecord"));
if (so->so_rcv.sb_mb == NULL) {
KASSERT(so->so_rcv.sb_lastrecord == NULL,
("soreceive: sb_lastercord != NULL"));
}
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
/*
* Now continue to read any data mbufs off of the head of the socket
* buffer until the read request is satisfied. Note that 'type' is
* used to store the type of any mbuf reads that have happened so far
* such that soreceive() can stop reading if the type changes, which
* causes soreceive() to return only one of regular data and inline
* out-of-band data in a single socket receive operation.
*/
moff = 0;
offset = 0;
while (m != NULL && uio->uio_resid > 0 && error == 0) {
/*
* If the type of mbuf has changed since the last mbuf
* examined ('type'), end the receive operation.
*/
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
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_rcv.sb_state &= ~SBS_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 == NULL) {
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
#ifdef ZERO_COPY_SOCKETS
if (so_zero_copy_receive) {
vm_page_t pg;
int disposable;
if ((m->m_flags & M_EXT)
&& (m->m_ext.ext_type == EXT_DISPOSABLE))
disposable = 1;
else
disposable = 0;
pg = PHYS_TO_VM_PAGE(vtophys(mtod(m, caddr_t) +
moff));
if (uio->uio_offset == -1)
uio->uio_offset =IDX_TO_OFF(pg->pindex);
error = uiomoveco(mtod(m, char *) + moff,
(int)len, uio,pg->object,
disposable);
} else
#endif /* ZERO_COPY_SOCKETS */
error = uiomove(mtod(m, char *) + moff, (int)len, uio);
SOCKBUF_LOCK(&so->so_rcv);
if (error)
goto release;
} else
uio->uio_resid -= len;
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
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 != NULL) {
*mp = m;
mp = &m->m_next;
so->so_rcv.sb_mb = m = m->m_next;
*mp = NULL;
} else {
so->so_rcv.sb_mb = m_free(m);
m = so->so_rcv.sb_mb;
}
if (m != NULL) {
m->m_nextpkt = nextrecord;
if (nextrecord == NULL)
so->so_rcv.sb_lastrecord = m;
} else {
so->so_rcv.sb_mb = nextrecord;
SB_EMPTY_FIXUP(&so->so_rcv);
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
}
} else {
if (flags & MSG_PEEK)
moff += len;
else {
if (mp != NULL) {
SOCKBUF_UNLOCK(&so->so_rcv);
*mp = m_copym(m, 0, len, M_TRYWAIT);
SOCKBUF_LOCK(&so->so_rcv);
}
m->m_data += len;
m->m_len -= len;
so->so_rcv.sb_cc -= len;
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_oobmark) {
if ((flags & MSG_PEEK) == 0) {
so->so_oobmark -= len;
if (so->so_oobmark == 0) {
so->so_rcv.sb_state |= SBS_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 == NULL && uio->uio_resid > 0 &&
!sosendallatonce(so) && nextrecord == NULL) {
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_error || so->so_rcv.sb_state & SBS_CANTRCVMORE)
break;
/*
* Notify the protocol that some data has been
* drained before blocking.
*/
if (pr->pr_flags & PR_WANTRCVD && so->so_pcb != NULL) {
SOCKBUF_UNLOCK(&so->so_rcv);
(*pr->pr_usrreqs->pru_rcvd)(so, flags);
SOCKBUF_LOCK(&so->so_rcv);
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
error = sbwait(&so->so_rcv);
if (error)
goto release;
m = so->so_rcv.sb_mb;
if (m != NULL)
nextrecord = m->m_nextpkt;
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (m != NULL && pr->pr_flags & PR_ATOMIC) {
flags |= MSG_TRUNC;
if ((flags & MSG_PEEK) == 0)
(void) sbdroprecord_locked(&so->so_rcv);
}
if ((flags & MSG_PEEK) == 0) {
if (m == NULL) {
/*
* First part is an inline SB_EMPTY_FIXUP(). Second
* part makes sure sb_lastrecord is up-to-date if
* there is still data in the socket buffer.
*/
so->so_rcv.sb_mb = nextrecord;
if (so->so_rcv.sb_mb == NULL) {
so->so_rcv.sb_mbtail = NULL;
so->so_rcv.sb_lastrecord = NULL;
} else if (nextrecord->m_nextpkt == NULL)
so->so_rcv.sb_lastrecord = nextrecord;
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
if (pr->pr_flags & PR_WANTRCVD && so->so_pcb) {
SOCKBUF_UNLOCK(&so->so_rcv);
(*pr->pr_usrreqs->pru_rcvd)(so, flags);
SOCKBUF_LOCK(&so->so_rcv);
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (orig_resid == uio->uio_resid && orig_resid &&
(flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
sbunlock(&so->so_rcv);
goto restart;
}
if (flagsp != NULL)
*flagsp |= flags;
release:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
sbunlock(&so->so_rcv);
out:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
return (error);
}
int
soshutdown(so, how)
struct socket *so;
int how;
{
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)
struct socket *so;
{
struct sockbuf *sb = &so->so_rcv;
struct protosw *pr = so->so_proto;
struct sockbuf asb;
/*
* XXXRW: This is quite ugly. The existing code made a copy of the
* socket buffer, then zero'd the original to clear the buffer
* fields. However, with mutexes in the socket buffer, this causes
* problems. We only clear the zeroable bits of the original;
* however, we have to initialize and destroy the mutex in the copy
* so that dom_dispose() and sbrelease() can lock t as needed.
*/
SOCKBUF_LOCK(sb);
sb->sb_flags |= SB_NOINTR;
(void) sblock(sb, M_WAITOK);
/*
* socantrcvmore_locked() drops the socket buffer mutex so that it
* can safely perform wakeups. Re-acquire the mutex before
* continuing.
*/
socantrcvmore_locked(so);
SOCKBUF_LOCK(sb);
sbunlock(sb);
/*
* Invalidate/clear most of the sockbuf structure, but leave
* selinfo and mutex data unchanged.
*/
bzero(&asb, offsetof(struct sockbuf, sb_startzero));
bcopy(&sb->sb_startzero, &asb.sb_startzero,
sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
bzero(&sb->sb_startzero,
sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
SOCKBUF_UNLOCK(sb);
SOCKBUF_LOCK_INIT(&asb, "so_rcv");
if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
(*pr->pr_domain->dom_dispose)(asb.sb_mb);
sbrelease(&asb, so);
SOCKBUF_LOCK_DESTROY(&asb);
}
#ifdef INET
static int
do_setopt_accept_filter(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
struct accept_filter_arg *afap;
struct accept_filter *afp;
struct so_accf *newaf;
int error = 0;
newaf = NULL;
afap = NULL;
/*
* XXXRW: Configuring accept filters should be an atomic test-and-set
* operation to prevent races during setup and attach. There may be
* more general issues of racing and ordering here that are not yet
* addressed by locking.
*/
/* do not set/remove accept filters on non listen sockets */
SOCK_LOCK(so);
if ((so->so_options & SO_ACCEPTCONN) == 0) {
SOCK_UNLOCK(so);
return (EINVAL);
}
/* removing the filter */
if (sopt == NULL) {
if (so->so_accf != NULL) {
struct so_accf *af = so->so_accf;
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;
SOCK_UNLOCK(so);
return (0);
}
SOCK_UNLOCK(so);
/*-
* Adding a filter.
*
* Do memory allocation, copyin, and filter lookup now while we're
* not holding any locks. Avoids sleeping with a mutex, as well as
* introducing a lock order between accept filter locks and socket
* locks here.
*/
MALLOC(afap, struct accept_filter_arg *, sizeof(*afap), M_TEMP,
M_WAITOK);
/* don't put large objects on the kernel stack */
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) {
FREE(afap, M_TEMP);
return (error);
}
afp = accept_filt_get(afap->af_name);
if (afp == NULL) {
FREE(afap, M_TEMP);
return (ENOENT);
}
/*
* Allocate the new accept filter instance storage. We may have to
* free it again later if we fail to attach it. If attached
* properly, 'newaf' is NULLed to avoid a free() while in use.
*/
MALLOC(newaf, struct so_accf *, sizeof(*newaf), M_ACCF, M_WAITOK |
M_ZERO);
if (afp->accf_create != NULL && afap->af_name[0] != '\0') {
int len = strlen(afap->af_name) + 1;
MALLOC(newaf->so_accept_filter_str, char *, len, M_ACCF,
M_WAITOK);
strcpy(newaf->so_accept_filter_str, afap->af_name);
}
SOCK_LOCK(so);
/* must remove previous filter first */
if (so->so_accf != NULL) {
error = EINVAL;
goto out;
}
/*
* Invoke the accf_create() method of the filter if required.
* XXXRW: the socket mutex is held over this call, so the create
* method cannot block. This may be something we have to change, but
* it would require addressing possible races.
*/
if (afp->accf_create != NULL) {
newaf->so_accept_filter_arg =
afp->accf_create(so, afap->af_arg);
if (newaf->so_accept_filter_arg == NULL) {
error = EINVAL;
goto out;
}
}
newaf->so_accept_filter = afp;
so->so_accf = newaf;
so->so_options |= SO_ACCEPTFILTER;
newaf = NULL;
out:
SOCK_UNLOCK(so);
if (newaf != NULL) {
if (newaf->so_accept_filter_str != NULL)
FREE(newaf->so_accept_filter_str, M_ACCF);
FREE(newaf, M_ACCF);
}
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 != NULL)
return (copyin(sopt->sopt_val, buf, valsize));
bcopy(sopt->sopt_val, buf, valsize);
return 0;
}
/*
* Kernel version of setsockopt(2)/
* XXX: optlen is size_t, not socklen_t
*/
int
so_setsockopt(struct socket *so, int level, int optname, void *optval,
size_t optlen)
{
struct sockopt sopt;
sopt.sopt_level = level;
sopt.sopt_name = optname;
sopt.sopt_dir = SOPT_SET;
sopt.sopt_val = optval;
sopt.sopt_valsize = optlen;
sopt.sopt_td = NULL;
return (sosetopt(so, &sopt));
}
int
sosetopt(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
int error, optval;
struct linger l;
struct timeval tv;
u_long val;
#ifdef MAC
struct mac extmac;
#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));
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;
SOCK_LOCK(so);
so->so_linger = l.l_linger;
if (l.l_onoff)
so->so_options |= SO_LINGER;
else
so->so_options &= ~SO_LINGER;
SOCK_UNLOCK(so);
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:
case SO_BINTIME:
case SO_NOSIGPIPE:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
goto bad;
SOCK_LOCK(so);
if (optval)
so->so_options |= sopt->sopt_name;
else
so->so_options &= ~sopt->sopt_name;
SOCK_UNLOCK(so);
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:
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_lowat =
(optval > so->so_snd.sb_hiwat) ?
so->so_snd.sb_hiwat : optval;
SOCKBUF_UNLOCK(&so->so_snd);
break;
case SO_RCVLOWAT:
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_lowat =
(optval > so->so_rcv.sb_hiwat) ?
so->so_rcv.sb_hiwat : optval;
SOCKBUF_UNLOCK(&so->so_rcv);
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;
}
if (val == 0 && tv.tv_usec != 0)
val = 1;
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;
case SO_LABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof extmac,
sizeof extmac);
if (error)
goto bad;
error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
so, &extmac);
#else
error = EOPNOTSUPP;
#endif
break;
default:
error = ENOPROTOOPT;
break;
}
if (error == 0 && so->so_proto != NULL &&
so->so_proto->pr_ctloutput != NULL) {
(void) ((*so->so_proto->pr_ctloutput)
(so, sopt));
}
}
bad:
return (error);
}
/* Helper routine for getsockopt */
int
sooptcopyout(struct sockopt *sopt, const 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 != NULL) {
if (sopt->sopt_td != NULL)
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
#ifdef MAC
struct mac extmac;
#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:
/* Unlocked read. */
if ((so->so_options & SO_ACCEPTCONN) == 0)
return (EINVAL);
MALLOC(afap, struct accept_filter_arg *, sizeof(*afap),
M_TEMP, M_WAITOK | M_ZERO);
SOCK_LOCK(so);
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);
}
SOCK_UNLOCK(so);
error = sooptcopyout(sopt, afap, sizeof(*afap));
FREE(afap, M_TEMP);
break;
#endif
case SO_LINGER:
/*
* XXXRW: We grab the lock here to get a consistent
* snapshot of both fields. This may not really
* be necessary.
*/
SOCK_LOCK(so);
l.l_onoff = so->so_options & SO_LINGER;
l.l_linger = so->so_linger;
SOCK_UNLOCK(so);
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:
case SO_BINTIME:
case SO_NOSIGPIPE:
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;
case SO_LABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof(extmac),
sizeof(extmac));
if (error)
return (error);
error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
so, &extmac);
if (error)
return (error);
error = sooptcopyout(sopt, &extmac, sizeof extmac);
#else
error = EOPNOTSUPP;
#endif
break;
case SO_PEERLABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof(extmac),
sizeof(extmac));
if (error)
return (error);
error = mac_getsockopt_peerlabel(
sopt->sopt_td->td_ucred, so, &extmac);
if (error)
return (error);
error = sooptcopyout(sopt, &extmac, sizeof extmac);
#else
error = EOPNOTSUPP;
#endif
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 == NULL)
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 == NULL) {
m_freem(*mp);
return ENOBUFS;
}
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td != NULL ? M_TRYWAIT :
M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_freem(m);
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;
sopt->sopt_val = (char *)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;
sopt->sopt_val = (char *)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)
struct socket *so;
{
if (so->so_sigio != NULL)
pgsigio(&so->so_sigio, SIGURG, 0);
selwakeuppri(&so->so_rcv.sb_sel, PSOCK);
}
int
sopoll(struct socket *so, int events, struct ucred *active_cred,
struct thread *td)
{
int revents = 0;
if (events & (POLLIN | POLLRDNORM))
if (soreadable(so))
revents |= events & (POLLIN | POLLRDNORM);
if (events & POLLINIGNEOF)
if (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat ||
!TAILQ_EMPTY(&so->so_comp) || so->so_error)
revents |= POLLINIGNEOF;
if (events & (POLLOUT | POLLWRNORM))
if (sowriteable(so))
revents |= events & (POLLOUT | POLLWRNORM);
if (events & (POLLPRI | POLLRDBAND))
if (so->so_oobmark || (so->so_rcv.sb_state & SBS_RCVATMARK))
revents |= events & (POLLPRI | POLLRDBAND);
if (revents == 0) {
if (events &
(POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM |
POLLRDBAND)) {
SOCKBUF_LOCK(&so->so_rcv);
selrecord(td, &so->so_rcv.sb_sel);
so->so_rcv.sb_flags |= SB_SEL;
SOCKBUF_UNLOCK(&so->so_rcv);
}
if (events & (POLLOUT | POLLWRNORM)) {
SOCKBUF_LOCK(&so->so_snd);
selrecord(td, &so->so_snd.sb_sel);
so->so_snd.sb_flags |= SB_SEL;
SOCKBUF_UNLOCK(&so->so_snd);
}
}
return (revents);
}
int
soo_kqfilter(struct file *fp, struct knote *kn)
{
struct socket *so = kn->kn_fp->f_data;
struct sockbuf *sb;
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 (EINVAL);
}
SOCKBUF_LOCK(sb);
knlist_add(&sb->sb_sel.si_note, kn, 1);
sb->sb_flags |= SB_KNOTE;
SOCKBUF_UNLOCK(sb);
return (0);
}
static void
filt_sordetach(struct knote *kn)
{
struct socket *so = kn->kn_fp->f_data;
SOCKBUF_LOCK(&so->so_rcv);
knlist_remove(&so->so_rcv.sb_sel.si_note, kn, 1);
if (knlist_empty(&so->so_rcv.sb_sel.si_note))
so->so_rcv.sb_flags &= ~SB_KNOTE;
SOCKBUF_UNLOCK(&so->so_rcv);
}
/*ARGSUSED*/
static int
filt_soread(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data;
int need_lock, result;
/*
* XXXRW: Conditional locking because filt_soread() can be called
* either from KNOTE() in the socket context where the socket buffer
* lock is already held, or from kqueue() itself.
*/
need_lock = !SOCKBUF_OWNED(&so->so_rcv);
if (need_lock)
SOCKBUF_LOCK(&so->so_rcv);
kn->kn_data = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
result = 1;
} else if (so->so_error) /* temporary udp error */
result = 1;
else if (kn->kn_sfflags & NOTE_LOWAT)
result = (kn->kn_data >= kn->kn_sdata);
else
result = (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat);
if (need_lock)
SOCKBUF_UNLOCK(&so->so_rcv);
return (result);
}
static void
filt_sowdetach(struct knote *kn)
{
struct socket *so = kn->kn_fp->f_data;
SOCKBUF_LOCK(&so->so_snd);
knlist_remove(&so->so_snd.sb_sel.si_note, kn, 1);
if (knlist_empty(&so->so_snd.sb_sel.si_note))
so->so_snd.sb_flags &= ~SB_KNOTE;
SOCKBUF_UNLOCK(&so->so_snd);
}
/*ARGSUSED*/
static int
filt_sowrite(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data;
int need_lock, result;
/*
* XXXRW: Conditional locking because filt_soread() can be called
* either from KNOTE() in the socket context where the socket buffer
* lock is already held, or from kqueue() itself.
*/
need_lock = !SOCKBUF_OWNED(&so->so_snd);
if (need_lock)
SOCKBUF_LOCK(&so->so_snd);
kn->kn_data = sbspace(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
result = 1;
} else if (so->so_error) /* temporary udp error */
result = 1;
else if (((so->so_state & SS_ISCONNECTED) == 0) &&
(so->so_proto->pr_flags & PR_CONNREQUIRED))
result = 0;
else if (kn->kn_sfflags & NOTE_LOWAT)
result = (kn->kn_data >= kn->kn_sdata);
else
result = (kn->kn_data >= so->so_snd.sb_lowat);
if (need_lock)
SOCKBUF_UNLOCK(&so->so_snd);
return (result);
}
/*ARGSUSED*/
static int
filt_solisten(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data;
kn->kn_data = so->so_qlen;
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);
}
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