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freebsd-skq/sys/kern/uipc_socket.c
rwatson 4b81ce6dd2 Push acquisition of the accept mutex out of sofree() into the caller 
(sorele()/sotryfree()):

- This permits the caller to acquire the accept mutex before the socket
  mutex, avoiding sofree() having to drop the socket mutex and re-order,
  which could lead to races permitting more than one thread to enter
  sofree() after a socket is ready to be free'd.

- This also covers clearing of the so_pcb weak socket reference from
  the protocol to the socket, preventing races in clearing and
  evaluation of the reference such that sofree() might be called more
  than once on the same socket.

This appears to close a race I was able to easily trigger by repeatedly
opening and resetting TCP connections to a host, in which the
tcp_close() code called as a result of the RST raced with the close()
of the accepted socket in the user process resulting in simultaneous
attempts to de-allocate the same socket.  The new locking increases
the overhead for operations that may potentially free the socket, so we
will want to revise the synchronization strategy here as we normalize
the reference counting model for sockets.  The use of the accept mutex
in freeing of sockets that are not listen sockets is primarily
motivated by the potential need to remove the socket from the
incomplete connection queue on its parent (listen) socket, so cleaning
up the reference model here may allow us to substantially weaken the
synchronization requirements.

RELENG_5_3 candidate.

MFC after:	3 days
Reviewed by:	dwhite
Discussed with:	gnn, dwhite, green
Reported by:	Marc UBM Bocklet <ubm at u-boot-man dot de>
Reported by:	Vlad <marchenko at gmail dot com>
2004-10-18 22:19:43 +00:00

2263 lines
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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) {
ACCEPT_LOCK();
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);
}
/*
* Attempt to free a socket. This should really be sotryfree().
*
* We free the socket if the protocol is no longer interested in the socket,
* there's no file descriptor reference, and the refcount is 0. While the
* calling macro sotryfree() tests the refcount, sofree() has to test it
* again as it's possible to race with an accept()ing thread if the socket is
* in an listen queue of a listen socket, as being in the listen queue
* doesn't elevate the reference count. sofree() acquires the accept mutex
* early for this test in order to avoid that race.
*/
void
sofree(so)
struct socket *so;
{
struct socket *head;
ACCEPT_LOCK_ASSERT();
SOCK_LOCK_ASSERT(so);
if (so->so_pcb != NULL || (so->so_state & SS_NOFDREF) == 0 ||
so->so_count != 0) {
SOCK_UNLOCK(so);
ACCEPT_UNLOCK();
return;
}
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) {
SOCK_UNLOCK(so);
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));
SOCK_UNLOCK(so);
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:
ACCEPT_LOCK();
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;
SOCKBUF_LOCK(&so->so_snd);
SOCKBUF_LOCK(&so->so_rcv);
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)) {
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;
}
}
SOCKBUF_UNLOCK(&so->so_rcv);
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;
so = kn->kn_fp->f_data;
SOCKBUF_LOCK_ASSERT(&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;
return (1);
} else if (so->so_error) /* temporary udp error */
return (1);
else if (kn->kn_sfflags & NOTE_LOWAT)
return (kn->kn_data >= kn->kn_sdata);
else
return (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat);
}
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;
so = kn->kn_fp->f_data;
SOCKBUF_LOCK_ASSERT(&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;
return (1);
} else if (so->so_error) /* temporary udp error */
return (1);
else if (((so->so_state & SS_ISCONNECTED) == 0) &&
(so->so_proto->pr_flags & PR_CONNREQUIRED))
return (0);
else if (kn->kn_sfflags & NOTE_LOWAT)
return (kn->kn_data >= kn->kn_sdata);
else
return (kn->kn_data >= so->so_snd.sb_lowat);
}
/*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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