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3cd6db794c
freebsd/sys/kern/uipc_socket.c
Attilio Rao 6aba400a70 Fix a deficiency in the selinfo interface: 
If a selinfo object is recorded (via selrecord()) and then it is
quickly destroyed, with the waiters missing the opportunity to awake,
at the next iteration they will find the selinfo object destroyed,
causing a PF#.

That happens because the selinfo interface has no way to drain the
waiters before to destroy the registered selinfo object. Also this
race is quite rare to get in practice, because it would require a
selrecord(), a poll request by another thread and a quick destruction
of the selrecord()'ed selinfo object.

Fix this by adding the seldrain() routine which should be called
before to destroy the selinfo objects (in order to avoid such case),
and fix the present cases where it might have already been called.
Sometimes, the context is safe enough to prevent this type of race,
like it happens in device drivers which installs selinfo objects on
poll callbacks. There, the destruction of the selinfo object happens
at driver detach time, when all the filedescriptors should be already
closed, thus there cannot be a race.
For this case, mfi(4) device driver can be set as an example, as it
implements a full correct logic for preventing this from happening.

Sponsored by:	Sandvine Incorporated
Reported by:	rstone
Tested by:	pluknet
Reviewed by:	jhb, kib
Approved by:	re (bz)
MFC after:	3 weeks
2011-08-25 15:51:54 +00:00

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/*-
* Copyright (c) 1982, 1986, 1988, 1990, 1993
* The Regents of the University of California.
* Copyright (c) 2004 The FreeBSD Foundation
* Copyright (c) 2004-2008 Robert N. M. Watson
* 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
*/
/*
* Comments on the socket life cycle:
*
* soalloc() sets of socket layer state for a socket, called only by
* socreate() and sonewconn(). Socket layer private.
*
* sodealloc() tears down socket layer state for a socket, called only by
* sofree() and sonewconn(). Socket layer private.
*
* pru_attach() associates protocol layer state with an allocated socket;
* called only once, may fail, aborting socket allocation. This is called
* from socreate() and sonewconn(). Socket layer private.
*
* pru_detach() disassociates protocol layer state from an attached socket,
* and will be called exactly once for sockets in which pru_attach() has
* been successfully called. If pru_attach() returned an error,
* pru_detach() will not be called. Socket layer private.
*
* pru_abort() and pru_close() notify the protocol layer that the last
* consumer of a socket is starting to tear down the socket, and that the
* protocol should terminate the connection. Historically, pru_abort() also
* detached protocol state from the socket state, but this is no longer the
* case.
*
* socreate() creates a socket and attaches protocol state. This is a public
* interface that may be used by socket layer consumers to create new
* sockets.
*
* sonewconn() creates a socket and attaches protocol state. This is a
* public interface that may be used by protocols to create new sockets when
* a new connection is received and will be available for accept() on a
* listen socket.
*
* soclose() destroys a socket after possibly waiting for it to disconnect.
* This is a public interface that socket consumers should use to close and
* release a socket when done with it.
*
* soabort() destroys a socket without waiting for it to disconnect (used
* only for incoming connections that are already partially or fully
* connected). This is used internally by the socket layer when clearing
* listen socket queues (due to overflow or close on the listen socket), but
* is also a public interface protocols may use to abort connections in
* their incomplete listen queues should they no longer be required. Sockets
* placed in completed connection listen queues should not be aborted for
* reasons described in the comment above the soclose() implementation. This
* is not a general purpose close routine, and except in the specific
* circumstances described here, should not be used.
*
* sofree() will free a socket and its protocol state if all references on
* the socket have been released, and is the public interface to attempt to
* free a socket when a reference is removed. This is a socket layer private
* interface.
*
* NOTE: In addition to socreate() and soclose(), which provide a single
* socket reference to the consumer to be managed as required, there are two
* calls to explicitly manage socket references, soref(), and sorele().
* Currently, these are generally required only when transitioning a socket
* from a listen queue to a file descriptor, in order to prevent garbage
* collection of the socket at an untimely moment. For a number of reasons,
* these interfaces are not preferred, and should be avoided.
*
* NOTE: With regard to VNETs the general rule is that callers do not set
* curvnet. Exceptions to this rule include soabort(), sodisconnect(),
* sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
* and sorflush(), which are usually called from a pre-set VNET context.
* sopoll() currently does not need a VNET context to be set.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_zero.h"
#include "opt_compat.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/eventhandler.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 <net/route.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <sys/jail.h>
#include <net/vnet.h>
#include <security/mac/mac_framework.h>
#include <vm/uma.h>
#ifdef COMPAT_FREEBSD32
#include <sys/mount.h>
#include <sys/sysent.h>
#include <compat/freebsd32/freebsd32.h>
#endif
static int soreceive_rcvoob(struct socket *so, struct uio *uio,
int flags);
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 = {
.f_isfd = 1,
.f_detach = filt_sordetach,
.f_event = filt_solisten,
};
static struct filterops soread_filtops = {
.f_isfd = 1,
.f_detach = filt_sordetach,
.f_event = filt_soread,
};
static struct filterops sowrite_filtops = {
.f_isfd = 1,
.f_detach = filt_sowdetach,
.f_event = filt_sowrite,
};
uma_zone_t socket_zone;
so_gen_t so_gencnt; /* generation count for sockets */
int maxsockets;
MALLOC_DEFINE(M_SONAME, "soname", "socket name");
MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
#define VNET_SO_ASSERT(so) \
VNET_ASSERT(curvnet != NULL, \
("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
static int somaxconn = SOMAXCONN;
static int sysctl_somaxconn(SYSCTL_HANDLER_ARGS);
/* XXX: we dont have SYSCTL_USHORT */
SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn, CTLTYPE_UINT | CTLFLAG_RW,
0, sizeof(int), sysctl_somaxconn, "I", "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.
*/
static struct mtx so_global_mtx;
MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
/*
* General IPC sysctl name space, used by sockets and a variety of other IPC
* types.
*/
SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
/*
* Sysctl to get and set the maximum global sockets limit. Notify protocols
* of the change so that they can update their dependent limits as required.
*/
static int
sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
{
int error, newmaxsockets;
newmaxsockets = maxsockets;
error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
if (error == 0 && req->newptr) {
if (newmaxsockets > maxsockets) {
maxsockets = newmaxsockets;
if (maxsockets > ((maxfiles / 4) * 3)) {
maxfiles = (maxsockets * 5) / 4;
maxfilesperproc = (maxfiles * 9) / 10;
}
EVENTHANDLER_INVOKE(maxsockets_change);
} else
error = EINVAL;
}
return (error);
}
SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets, CTLTYPE_INT|CTLFLAG_RW,
&maxsockets, 0, sysctl_maxsockets, "IU",
"Maximum number of sockets avaliable");
/*
* Initialise maxsockets. This SYSINIT must be run after
* tunable_mbinit().
*/
static void
init_maxsockets(void *ignored)
{
TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters));
}
SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
/*
* 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.
*/
static struct socket *
soalloc(struct vnet *vnet)
{
struct socket *so;
so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
if (so == NULL)
return (NULL);
#ifdef MAC
if (mac_socket_init(so, M_NOWAIT) != 0) {
uma_zfree(socket_zone, so);
return (NULL);
}
#endif
SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
sx_init(&so->so_snd.sb_sx, "so_snd_sx");
sx_init(&so->so_rcv.sb_sx, "so_rcv_sx");
TAILQ_INIT(&so->so_aiojobq);
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
++numopensockets;
#ifdef VIMAGE
VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
__func__, __LINE__, so));
vnet->vnet_sockcnt++;
so->so_vnet = vnet;
#endif
mtx_unlock(&so_global_mtx);
return (so);
}
/*
* Free the storage associated with a socket at the socket layer, tear down
* locks, labels, etc. All protocol state is assumed already to have been
* torn down (and possibly never set up) by the caller.
*/
static void
sodealloc(struct socket *so)
{
KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
--numopensockets; /* Could be below, but faster here. */
#ifdef VIMAGE
VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
__func__, __LINE__, so));
so->so_vnet->vnet_sockcnt--;
#endif
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_socket_destroy(so);
#endif
crfree(so->so_cred);
sx_destroy(&so->so_snd.sb_sx);
sx_destroy(&so->so_rcv.sb_sx);
SOCKBUF_LOCK_DESTROY(&so->so_snd);
SOCKBUF_LOCK_DESTROY(&so->so_rcv);
uma_zfree(socket_zone, so);
}
/*
* socreate returns a socket with a ref count of 1. The socket should be
* closed with soclose().
*/
int
socreate(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 ||
prp->pr_usrreqs->pru_attach == pru_attach_notsupp)
return (EPROTONOSUPPORT);
if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
return (EPROTONOSUPPORT);
if (prp->pr_type != type)
return (EPROTOTYPE);
so = soalloc(CRED_TO_VNET(cred));
if (so == NULL)
return (ENOBUFS);
TAILQ_INIT(&so->so_incomp);
TAILQ_INIT(&so->so_comp);
so->so_type = type;
so->so_cred = crhold(cred);
if ((prp->pr_domain->dom_family == PF_INET) ||
(prp->pr_domain->dom_family == PF_ROUTE))
so->so_fibnum = td->td_proc->p_fibnum;
else
so->so_fibnum = 0;
so->so_proto = prp;
#ifdef MAC
mac_socket_create(cred, so);
#endif
knlist_init_mtx(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
knlist_init_mtx(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
so->so_count = 1;
/*
* Auto-sizing of socket buffers is managed by the protocols and
* the appropriate flags must be set in the pru_attach function.
*/
CURVNET_SET(so->so_vnet);
error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
CURVNET_RESTORE();
if (error) {
KASSERT(so->so_count == 1, ("socreate: so_count %d",
so->so_count));
so->so_count = 0;
sodealloc(so);
return (error);
}
*aso = so;
return (0);
}
#ifdef REGRESSION
static int regression_sonewconn_earlytest = 1;
SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
&regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
#endif
/*
* When an attempt at a new connection is noted on a socket which accepts
* connections, sonewconn is called. If the connection is possible (subject
* to space constraints, etc.) then we allocate a new structure, propoerly
* linked into the data structure of the original socket, and return this.
* Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
*
* Note: the ref count on the socket is 0 on return.
*/
struct socket *
sonewconn(struct socket *head, int connstatus)
{
struct socket *so;
int over;
ACCEPT_LOCK();
over = (head->so_qlen > 3 * head->so_qlimit / 2);
ACCEPT_UNLOCK();
#ifdef REGRESSION
if (regression_sonewconn_earlytest && over)
#else
if (over)
#endif
return (NULL);
VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
__func__, __LINE__, head));
so = soalloc(head->so_vnet);
if (so == NULL)
return (NULL);
if ((head->so_options & SO_ACCEPTFILTER) != 0)
connstatus = 0;
so->so_head = head;
so->so_type = head->so_type;
so->so_options = head->so_options &~ SO_ACCEPTCONN;
so->so_linger = head->so_linger;
so->so_state = head->so_state | SS_NOFDREF;
so->so_fibnum = head->so_fibnum;
so->so_proto = head->so_proto;
so->so_cred = crhold(head->so_cred);
#ifdef MAC
mac_socket_newconn(head, so);
#endif
knlist_init_mtx(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
knlist_init_mtx(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
VNET_SO_ASSERT(head);
if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat) ||
(*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
sodealloc(so);
return (NULL);
}
so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
so->so_snd.sb_lowat = head->so_snd.sb_lowat;
so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
so->so_snd.sb_timeo = head->so_snd.sb_timeo;
so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
so->so_state |= connstatus;
ACCEPT_LOCK();
if (connstatus) {
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
so->so_qstate |= SQ_COMP;
head->so_qlen++;
} else {
/*
* Keep removing sockets from the head until there's room for
* us to insert on the tail. In pre-locking revisions, this
* was a simple if(), but as we could be racing with other
* threads and soabort() requires dropping locks, we must
* loop waiting for the condition to be true.
*/
while (head->so_incqlen > head->so_qlimit) {
struct socket *sp;
sp = TAILQ_FIRST(&head->so_incomp);
TAILQ_REMOVE(&head->so_incomp, sp, so_list);
head->so_incqlen--;
sp->so_qstate &= ~SQ_INCOMP;
sp->so_head = NULL;
ACCEPT_UNLOCK();
soabort(sp);
ACCEPT_LOCK();
}
TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
so->so_qstate |= SQ_INCOMP;
head->so_incqlen++;
}
ACCEPT_UNLOCK();
if (connstatus) {
sorwakeup(head);
wakeup_one(&head->so_timeo);
}
return (so);
}
int
sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
CURVNET_RESTORE();
return error;
}
/*
* solisten() transitions a socket from a non-listening state to a listening
* state, but can also be used to update the listen queue depth on an
* existing listen socket. The protocol will call back into the sockets
* layer using solisten_proto_check() and solisten_proto() to check and set
* socket-layer listen state. Call backs are used so that the protocol can
* acquire both protocol and socket layer locks in whatever order is required
* by the protocol.
*
* Protocol implementors are advised to hold the socket lock across the
* socket-layer test and set to avoid races at the socket layer.
*/
int
solisten(struct socket *so, int backlog, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = (*so->so_proto->pr_usrreqs->pru_listen)(so, backlog, td);
CURVNET_RESTORE();
return error;
}
int
solisten_proto_check(struct socket *so)
{
SOCK_LOCK_ASSERT(so);
if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
SS_ISDISCONNECTING))
return (EINVAL);
return (0);
}
void
solisten_proto(struct socket *so, int backlog)
{
SOCK_LOCK_ASSERT(so);
if (backlog < 0 || backlog > somaxconn)
backlog = somaxconn;
so->so_qlimit = backlog;
so->so_options |= SO_ACCEPTCONN;
}
/*
* Evaluate the reference count and named references on a socket; if no
* references remain, free it. This should be called whenever a reference is
* released, such as in sorele(), but also when named reference flags are
* cleared in socket or protocol code.
*
* sofree() will free the socket if:
*
* - There are no outstanding file descriptor references or related consumers
* (so_count == 0).
*
* - The socket has been closed by user space, if ever open (SS_NOFDREF).
*
* - The protocol does not have an outstanding strong reference on the socket
* (SS_PROTOREF).
*
* - The socket is not in a completed connection queue, so a process has been
* notified that it is present. If it is removed, the user process may
* block in accept() despite select() saying the socket was ready.
*/
void
sofree(struct socket *so)
{
struct protosw *pr = so->so_proto;
struct socket *head;
ACCEPT_LOCK_ASSERT();
SOCK_LOCK_ASSERT(so);
if ((so->so_state & SS_NOFDREF) == 0 || so->so_count != 0 ||
(so->so_state & SS_PROTOREF) || (so->so_qstate & SQ_COMP)) {
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"));
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));
if (so->so_options & SO_ACCEPTCONN) {
KASSERT((TAILQ_EMPTY(&so->so_comp)), ("sofree: so_comp populated"));
KASSERT((TAILQ_EMPTY(&so->so_incomp)), ("sofree: so_comp populated"));
}
SOCK_UNLOCK(so);
ACCEPT_UNLOCK();
VNET_SO_ASSERT(so);
if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
(*pr->pr_domain->dom_dispose)(so->so_rcv.sb_mb);
if (pr->pr_usrreqs->pru_detach != NULL)
(*pr->pr_usrreqs->pru_detach)(so);
/*
* From this point on, we assume that no other references to this
* socket exist anywhere else in the stack. Therefore, no locks need
* to be acquired or held.
*
* We used to do a lot of socket buffer and socket locking here, as
* well as invoke sorflush() and perform wakeups. The direct call to
* dom_dispose() and sbrelease_internal() are an inlining of what was
* necessary from sorflush().
*
* Notice that the socket buffer and kqueue state are torn down
* before calling pru_detach. This means that protocols shold not
* assume they can perform socket wakeups, etc, in their detach code.
*/
sbdestroy(&so->so_snd, so);
sbdestroy(&so->so_rcv, so);
seldrain(&so->so_snd.sb_sel);
seldrain(&so->so_rcv.sb_sel);
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(struct socket *so)
{
int error = 0;
KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
CURVNET_SET(so->so_vnet);
funsetown(&so->so_sigio);
if (so->so_state & SS_ISCONNECTED) {
if ((so->so_state & SS_ISDISCONNECTING) == 0) {
error = sodisconnect(so);
if (error) {
if (error == ENOTCONN)
error = 0;
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_proto->pr_usrreqs->pru_close != NULL)
(*so->so_proto->pr_usrreqs->pru_close)(so);
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();
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();
soabort(sp);
ACCEPT_LOCK();
}
ACCEPT_UNLOCK();
}
ACCEPT_LOCK();
SOCK_LOCK(so);
KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
so->so_state |= SS_NOFDREF;
sorele(so);
CURVNET_RESTORE();
return (error);
}
/*
* soabort() is used to abruptly tear down a connection, such as when a
* resource limit is reached (listen queue depth exceeded), or if a listen
* socket is closed while there are sockets waiting to be accepted.
*
* This interface is tricky, because it is called on an unreferenced socket,
* and must be called only by a thread that has actually removed the socket
* from the listen queue it was on, or races with other threads are risked.
*
* This interface will call into the protocol code, so must not be called
* with any socket locks held. Protocols do call it while holding their own
* recursible protocol mutexes, but this is something that should be subject
* to review in the future.
*/
void
soabort(struct socket *so)
{
/*
* In as much as is possible, assert that no references to this
* socket are held. This is not quite the same as asserting that the
* current thread is responsible for arranging for no references, but
* is as close as we can get for now.
*/
KASSERT(so->so_count == 0, ("soabort: so_count"));
KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF"));
KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF"));
KASSERT((so->so_state & SQ_COMP) == 0, ("soabort: SQ_COMP"));
KASSERT((so->so_state & SQ_INCOMP) == 0, ("soabort: SQ_INCOMP"));
VNET_SO_ASSERT(so);
if (so->so_proto->pr_usrreqs->pru_abort != NULL)
(*so->so_proto->pr_usrreqs->pru_abort)(so);
ACCEPT_LOCK();
SOCK_LOCK(so);
sofree(so);
}
int
soaccept(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);
CURVNET_SET(so->so_vnet);
error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
CURVNET_RESTORE();
return (error);
}
int
soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
if (so->so_options & SO_ACCEPTCONN)
return (EOPNOTSUPP);
CURVNET_SET(so->so_vnet);
/*
* 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 {
/*
* Prevent accumulated error from previous connection from
* biting us.
*/
so->so_error = 0;
error = (*so->so_proto->pr_usrreqs->pru_connect)(so, nam, td);
}
CURVNET_RESTORE();
return (error);
}
int
soconnect2(struct socket *so1, struct socket *so2)
{
int error;
CURVNET_SET(so1->so_vnet);
error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
CURVNET_RESTORE();
return (error);
}
int
sodisconnect(struct socket *so)
{
int error;
if ((so->so_state & SS_ISCONNECTED) == 0)
return (ENOTCONN);
if (so->so_state & SS_ISDISCONNECTING)
return (EALREADY);
VNET_SO_ASSERT(so);
error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
return (error);
}
#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>
/*
* sosend_copyin() is only used if zero copy sockets are enabled. Otherwise
* sosend_dgram() and sosend_generic() use m_uiotombuf().
*
* sosend_copyin() accepts a uio and prepares an mbuf chain holding part or
* all of the data referenced by the uio. If desired, it uses zero-copy.
* *space will be updated to reflect data copied in.
*
* NB: If atomic I/O is requested, the caller must already have checked that
* space can hold resid bytes.
*
* NB: In the event of an error, the caller may need to free the partial
* chain pointed to by *mpp. The contents of both *uio and *space may be
* modified even in the case of an error.
*/
static int
sosend_copyin(struct uio *uio, struct mbuf **retmp, int atomic, long *space,
int flags)
{
struct mbuf *m, **mp, *top;
long len, resid;
int error;
#ifdef ZERO_COPY_SOCKETS
int cow_send;
#endif
*retmp = top = NULL;
mp = &top;
len = 0;
resid = uio->uio_resid;
error = 0;
do {
#ifdef ZERO_COPY_SOCKETS
cow_send = 0;
#endif /* ZERO_COPY_SOCKETS */
if (resid >= MINCLSIZE) {
#ifdef ZERO_COPY_SOCKETS
if (top == NULL) {
m = m_gethdr(M_WAITOK, MT_DATA);
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = NULL;
} else
m = m_get(M_WAITOK, MT_DATA);
if (so_zero_copy_send &&
resid>=PAGE_SIZE &&
*space>=PAGE_SIZE &&
uio->uio_iov->iov_len>=PAGE_SIZE) {
so_zerocp_stats.size_ok++;
so_zerocp_stats.align_ok++;
cow_send = socow_setup(m, uio);
len = cow_send;
}
if (!cow_send) {
m_clget(m, M_WAITOK);
len = min(min(MCLBYTES, resid), *space);
}
#else /* ZERO_COPY_SOCKETS */
if (top == NULL) {
m = m_getcl(M_WAIT, MT_DATA, M_PKTHDR);
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = NULL;
} else
m = m_getcl(M_WAIT, MT_DATA, 0);
len = min(min(MCLBYTES, resid), *space);
#endif /* ZERO_COPY_SOCKETS */
} else {
if (top == NULL) {
m = m_gethdr(M_WAIT, MT_DATA);
m->m_pkthdr.len = 0;
m->m_pkthdr.rcvif = NULL;
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_WAIT, MT_DATA);
len = min(min(MLEN, resid), *space);
}
}
if (m == NULL) {
error = ENOBUFS;
goto out;
}
*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)
goto out;
mp = &m->m_next;
if (resid <= 0) {
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
break;
}
} while (*space > 0 && atomic);
out:
*retmp = top;
return (error);
}
#endif /*ZERO_COPY_SOCKETS*/
#define SBLOCKWAIT(f) (((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
int
sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
long space, resid;
int clen = 0, error, dontroute;
#ifdef ZERO_COPY_SOCKETS
int atomic = sosendallatonce(so) || top;
#endif
KASSERT(so->so_type == SOCK_DGRAM, ("sodgram_send: !SOCK_DGRAM"));
KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
("sodgram_send: !PR_ATOMIC"));
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.
*/
if (resid < 0) {
error = EINVAL;
goto out;
}
dontroute =
(flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
if (td != NULL)
td->td_ru.ru_msgsnd++;
if (control != NULL)
clen = control->m_len;
SOCKBUF_LOCK(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EPIPE;
goto out;
}
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
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)) {
SOCKBUF_UNLOCK(&so->so_snd);
error = ENOTCONN;
goto out;
}
} else if (addr == NULL) {
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
error = ENOTCONN;
else
error = EDESTADDRREQ;
SOCKBUF_UNLOCK(&so->so_snd);
goto out;
}
}
/*
* Do we need MSG_OOB support in SOCK_DGRAM? Signs here may be a
* problem and need fixing.
*/
space = sbspace(&so->so_snd);
if (flags & MSG_OOB)
space += 1024;
space -= clen;
SOCKBUF_UNLOCK(&so->so_snd);
if (resid > space) {
error = EMSGSIZE;
goto out;
}
if (uio == NULL) {
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
} else {
#ifdef ZERO_COPY_SOCKETS
error = sosend_copyin(uio, &top, atomic, &space, flags);
if (error)
goto out;
#else
/*
* Copy the data from userland into a mbuf chain.
* If no data is to be copied in, a single empty mbuf
* is returned.
*/
top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
(M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
if (top == NULL) {
error = EFAULT; /* only possible error */
goto out;
}
space -= resid - uio->uio_resid;
#endif
resid = uio->uio_resid;
}
KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
/*
* XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
* than with.
*/
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.
*/
VNET_SO_ASSERT(so);
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;
out:
if (top != NULL)
m_freem(top);
if (control != NULL)
m_freem(control);
return (error);
}
/*
* Send on a socket. If send must go all at once and message is larger than
* send buffering, then hard error. Lock against other senders. If must go
* all at once and not enough room now, then inform user that this would
* block and do nothing. Otherwise, if nonblocking, send as much as
* possible. The data to be sent is described by "uio" if nonzero, otherwise
* by the mbuf chain "top" (which must be null if uio is not). Data provided
* in mbuf chain must be small enough to send all at once.
*
* Returns nonzero on error, timeout or signal; callers must check for short
* counts if EINTR/ERESTART are returned. Data and control buffers are freed
* on return.
*/
int
sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
long space, resid;
int clen = 0, error, dontroute;
int atomic = sosendallatonce(so) || top;
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_ru.ru_msgsnd++;
if (control != NULL)
clen = control->m_len;
error = sblock(&so->so_snd, SBLOCKWAIT(flags));
if (error)
goto out;
restart:
do {
SOCKBUF_LOCK(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EPIPE;
goto release;
}
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_snd);
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)) {
SOCKBUF_UNLOCK(&so->so_snd);
error = ENOTCONN;
goto release;
}
} else if (addr == NULL) {
SOCKBUF_UNLOCK(&so->so_snd);
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
error = ENOTCONN;
else
error = EDESTADDRREQ;
goto release;
}
}
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) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EMSGSIZE;
goto release;
}
if (space < resid + clen &&
(atomic || space < so->so_snd.sb_lowat || space < clen)) {
if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
SOCKBUF_UNLOCK(&so->so_snd);
error = EWOULDBLOCK;
goto release;
}
error = sbwait(&so->so_snd);
SOCKBUF_UNLOCK(&so->so_snd);
if (error)
goto release;
goto restart;
}
SOCKBUF_UNLOCK(&so->so_snd);
space -= clen;
do {
if (uio == NULL) {
resid = 0;
if (flags & MSG_EOR)
top->m_flags |= M_EOR;
} else {
#ifdef ZERO_COPY_SOCKETS
error = sosend_copyin(uio, &top, atomic,
&space, flags);
if (error != 0)
goto release;
#else
/*
* Copy the data from userland into a mbuf
* chain. If no data is to be copied in,
* a single empty mbuf is returned.
*/
top = m_uiotombuf(uio, M_WAITOK, space,
(atomic ? max_hdr : 0),
(atomic ? M_PKTHDR : 0) |
((flags & MSG_EOR) ? M_EOR : 0));
if (top == NULL) {
error = EFAULT; /* only possible error */
goto release;
}
space -= resid - uio->uio_resid;
#endif
resid = uio->uio_resid;
}
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.
*/
VNET_SO_ASSERT(so);
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;
if (error)
goto release;
} while (resid && space > 0);
} while (resid);
release:
sbunlock(&so->so_snd);
out:
if (top != NULL)
m_freem(top);
if (control != NULL)
m_freem(control);
return (error);
}
int
sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = so->so_proto->pr_usrreqs->pru_sosend(so, addr, uio, top,
control, flags, td);
CURVNET_RESTORE();
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.
*
* Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
* unable to return an mbuf chain to the caller.
*/
static int
soreceive_rcvoob(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"));
VNET_SO_ASSERT(so);
m = m_get(M_WAIT, MT_DATA);
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) {
int disposable;
if ((m->m_flags & M_EXT)
&& (m->m_ext.ext_type == EXT_DISPOSABLE))
disposable = 1;
else
disposable = 0;
error = uiomoveco(mtod(m, void *),
min(uio->uio_resid, m->m_len),
uio, 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 allow parallelism
* between network receive and copying to user space, as well as avoid
* sleeping with a mutex held, we release the socket buffer mutex during the
* user space copy. 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_generic(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 ((pr->pr_flags & PR_WANTRCVD) && (so->so_state & SS_ISCONFIRMING)
&& uio->uio_resid) {
VNET_SO_ASSERT(so);
(*pr->pr_usrreqs->pru_rcvd)(so, 0);
}
error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
if (error)
return (error);
restart:
SOCKBUF_LOCK(&so->so_rcv);
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;
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
if (m == NULL) {
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
} else
goto dontblock;
}
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)) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = ENOTCONN;
goto release;
}
if (uio->uio_resid == 0) {
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
if ((so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO))) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = EWOULDBLOCK;
goto release;
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
error = sbwait(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
if (error)
goto release;
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_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);
VNET_SO_ASSERT(so);
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;
}
if (m != NULL)
nextrecord = so->so_rcv.sb_mb->m_nextpkt;
else
nextrecord = so->so_rcv.sb_mb;
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 == %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) {
int disposable;
if ((m->m_flags & M_EXT)
&& (m->m_ext.ext_type == EXT_DISPOSABLE))
disposable = 1;
else
disposable = 0;
error = uiomoveco(mtod(m, char *) + moff,
(int)len, uio,
disposable);
} else
#endif /* ZERO_COPY_SOCKETS */
error = uiomove(mtod(m, char *) + moff, (int)len, uio);
SOCKBUF_LOCK(&so->so_rcv);
if (error) {
/*
* The MT_SONAME mbuf has already been removed
* from the record, so it is necessary to
* remove the data mbufs, if any, to preserve
* the invariant in the case of PR_ADDR that
* requires MT_SONAME mbufs at the head of
* each record.
*/
if (m && pr->pr_flags & PR_ATOMIC &&
((flags & MSG_PEEK) == 0))
(void)sbdroprecord_locked(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
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;
}
sockbuf_pushsync(&so->so_rcv, nextrecord);
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
}
} else {
if (flags & MSG_PEEK)
moff += len;
else {
if (mp != NULL) {
int copy_flag;
if (flags & MSG_DONTWAIT)
copy_flag = M_DONTWAIT;
else
copy_flag = M_WAIT;
if (copy_flag == M_WAIT)
SOCKBUF_UNLOCK(&so->so_rcv);
*mp = m_copym(m, 0, len, copy_flag);
if (copy_flag == M_WAIT)
SOCKBUF_LOCK(&so->so_rcv);
if (*mp == NULL) {
/*
* m_copym() couldn't
* allocate an mbuf. Adjust
* uio_resid back (it was
* adjusted down by len
* bytes, which we didn't end
* up "copying" over).
*/
uio->uio_resid += len;
break;
}
}
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) {
SOCKBUF_UNLOCK(&so->so_rcv);
VNET_SO_ASSERT(so);
(*pr->pr_usrreqs->pru_rcvd)(so, flags);
SOCKBUF_LOCK(&so->so_rcv);
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
/*
* We could receive some data while was notifying
* the protocol. Skip blocking in this case.
*/
if (so->so_rcv.sb_mb == NULL) {
error = sbwait(&so->so_rcv);
if (error) {
SOCKBUF_UNLOCK(&so->so_rcv);
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 soreceive() is being done from the socket callback,
* then don't need to generate ACK to peer to update window,
* since ACK will be generated on return to TCP.
*/
if (!(flags & MSG_SOCALLBCK) &&
(pr->pr_flags & PR_WANTRCVD)) {
SOCKBUF_UNLOCK(&so->so_rcv);
VNET_SO_ASSERT(so);
(*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) {
SOCKBUF_UNLOCK(&so->so_rcv);
goto restart;
}
SOCKBUF_UNLOCK(&so->so_rcv);
if (flagsp != NULL)
*flagsp |= flags;
release:
sbunlock(&so->so_rcv);
return (error);
}
/*
* Optimized version of soreceive() for stream (TCP) sockets.
*/
int
soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
int len = 0, error = 0, flags, oresid;
struct sockbuf *sb;
struct mbuf *m, *n = NULL;
/* We only do stream sockets. */
if (so->so_type != SOCK_STREAM)
return (EINVAL);
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
return (EINVAL);
if (flagsp != NULL)
flags = *flagsp &~ MSG_EOR;
else
flags = 0;
if (flags & MSG_OOB)
return (soreceive_rcvoob(so, uio, flags));
if (mp0 != NULL)
*mp0 = NULL;
sb = &so->so_rcv;
/* Prevent other readers from entering the socket. */
error = sblock(sb, SBLOCKWAIT(flags));
if (error)
goto out;
SOCKBUF_LOCK(sb);
/* Easy one, no space to copyout anything. */
if (uio->uio_resid == 0) {
error = EINVAL;
goto out;
}
oresid = uio->uio_resid;
/* We will never ever get anything unless we are or were connected. */
if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
error = ENOTCONN;
goto out;
}
restart:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
/* Abort if socket has reported problems. */
if (so->so_error) {
if (sb->sb_cc > 0)
goto deliver;
if (oresid > uio->uio_resid)
goto out;
error = so->so_error;
if (!(flags & MSG_PEEK))
so->so_error = 0;
goto out;
}
/* Door is closed. Deliver what is left, if any. */
if (sb->sb_state & SBS_CANTRCVMORE) {
if (sb->sb_cc > 0)
goto deliver;
else
goto out;
}
/* Socket buffer is empty and we shall not block. */
if (sb->sb_cc == 0 &&
((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
error = EAGAIN;
goto out;
}
/* Socket buffer got some data that we shall deliver now. */
if (sb->sb_cc > 0 && !(flags & MSG_WAITALL) &&
((sb->sb_flags & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO)) ||
sb->sb_cc >= sb->sb_lowat ||
sb->sb_cc >= uio->uio_resid ||
sb->sb_cc >= sb->sb_hiwat) ) {
goto deliver;
}
/* On MSG_WAITALL we must wait until all data or error arrives. */
if ((flags & MSG_WAITALL) &&
(sb->sb_cc >= uio->uio_resid || sb->sb_cc >= sb->sb_lowat))
goto deliver;
/*
* Wait and block until (more) data comes in.
* NB: Drops the sockbuf lock during wait.
*/
error = sbwait(sb);
if (error)
goto out;
goto restart;
deliver:
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
KASSERT(sb->sb_cc > 0, ("%s: sockbuf empty", __func__));
KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
/* Statistics. */
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv++;
/* Fill uio until full or current end of socket buffer is reached. */
len = min(uio->uio_resid, sb->sb_cc);
if (mp0 != NULL) {
/* Dequeue as many mbufs as possible. */
if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
for (*mp0 = m = sb->sb_mb;
m != NULL && m->m_len <= len;
m = m->m_next) {
len -= m->m_len;
uio->uio_resid -= m->m_len;
sbfree(sb, m);
n = m;
}
sb->sb_mb = m;
if (sb->sb_mb == NULL)
SB_EMPTY_FIXUP(sb);
n->m_next = NULL;
}
/* Copy the remainder. */
if (len > 0) {
KASSERT(sb->sb_mb != NULL,
("%s: len > 0 && sb->sb_mb empty", __func__));
m = m_copym(sb->sb_mb, 0, len, M_DONTWAIT);
if (m == NULL)
len = 0; /* Don't flush data from sockbuf. */
else
uio->uio_resid -= m->m_len;
if (*mp0 != NULL)
n->m_next = m;
else
*mp0 = m;
if (*mp0 == NULL) {
error = ENOBUFS;
goto out;
}
}
} else {
/* NB: Must unlock socket buffer as uiomove may sleep. */
SOCKBUF_UNLOCK(sb);
error = m_mbuftouio(uio, sb->sb_mb, len);
SOCKBUF_LOCK(sb);
if (error)
goto out;
}
SBLASTRECORDCHK(sb);
SBLASTMBUFCHK(sb);
/*
* Remove the delivered data from the socket buffer unless we
* were only peeking.
*/
if (!(flags & MSG_PEEK)) {
if (len > 0)
sbdrop_locked(sb, len);
/* Notify protocol that we drained some data. */
if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
(((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
!(flags & MSG_SOCALLBCK))) {
SOCKBUF_UNLOCK(sb);
VNET_SO_ASSERT(so);
(*so->so_proto->pr_usrreqs->pru_rcvd)(so, flags);
SOCKBUF_LOCK(sb);
}
}
/*
* For MSG_WAITALL we may have to loop again and wait for
* more data to come in.
*/
if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
goto restart;
out:
SOCKBUF_LOCK_ASSERT(sb);
SBLASTRECORDCHK(sb);
SBLASTMBUFCHK(sb);
SOCKBUF_UNLOCK(sb);
sbunlock(sb);
return (error);
}
/*
* Optimized version of soreceive() for simple datagram cases from userspace.
* Unlike in the stream case, we're able to drop a datagram if copyout()
* fails, and because we handle datagrams atomically, we don't need to use a
* sleep lock to prevent I/O interlacing.
*/
int
soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
struct mbuf *m, *m2;
int flags, len, error;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
if (psa != NULL)
*psa = NULL;
if (controlp != NULL)
*controlp = NULL;
if (flagsp != NULL)
flags = *flagsp &~ MSG_EOR;
else
flags = 0;
/*
* For any complicated cases, fall back to the full
* soreceive_generic().
*/
if (mp0 != NULL || (flags & MSG_PEEK) || (flags & MSG_OOB))
return (soreceive_generic(so, psa, uio, mp0, controlp,
flagsp));
/*
* Enforce restrictions on use.
*/
KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
("soreceive_dgram: wantrcvd"));
KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
("soreceive_dgram: SBS_RCVATMARK"));
KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
("soreceive_dgram: P_CONNREQUIRED"));
/*
* Loop blocking while waiting for a datagram.
*/
SOCKBUF_LOCK(&so->so_rcv);
while ((m = so->so_rcv.sb_mb) == NULL) {
KASSERT(so->so_rcv.sb_cc == 0,
("soreceive_dgram: sb_mb NULL but sb_cc %u",
so->so_rcv.sb_cc));
if (so->so_error) {
error = so->so_error;
so->so_error = 0;
SOCKBUF_UNLOCK(&so->so_rcv);
return (error);
}
if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
uio->uio_resid == 0) {
SOCKBUF_UNLOCK(&so->so_rcv);
return (0);
}
if ((so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO))) {
SOCKBUF_UNLOCK(&so->so_rcv);
return (EWOULDBLOCK);
}
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
error = sbwait(&so->so_rcv);
if (error) {
SOCKBUF_UNLOCK(&so->so_rcv);
return (error);
}
}
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
if (uio->uio_td)
uio->uio_td->td_ru.ru_msgrcv++;
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
nextrecord = m->m_nextpkt;
if (nextrecord == NULL) {
KASSERT(so->so_rcv.sb_lastrecord == m,
("soreceive_dgram: lastrecord != m"));
}
KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
("soreceive_dgram: m_nextpkt != nextrecord"));
/*
* Pull 'm' and its chain off the front of the packet queue.
*/
so->so_rcv.sb_mb = NULL;
sockbuf_pushsync(&so->so_rcv, nextrecord);
/*
* Walk 'm's chain and free that many bytes from the socket buffer.
*/
for (m2 = m; m2 != NULL; m2 = m2->m_next)
sbfree(&so->so_rcv, m2);
/*
* Do a few last checks before we let go of the lock.
*/
SBLASTRECORDCHK(&so->so_rcv);
SBLASTMBUFCHK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_rcv);
if (pr->pr_flags & PR_ADDR) {
KASSERT(m->m_type == MT_SONAME,
("m->m_type == %d", m->m_type));
if (psa != NULL)
*psa = sodupsockaddr(mtod(m, struct sockaddr *),
M_NOWAIT);
m = m_free(m);
}
if (m == NULL) {
/* XXXRW: Can this happen? */
return (0);
}
/*
* Packet to copyout() is now in 'm' and it is disconnected from the
* queue.
*
* Process one or more MT_CONTROL mbufs present before any data mbufs
* in the first mbuf chain on the socket buffer. We call into the
* protocol to perform externalization (or freeing if controlp ==
* NULL).
*/
if (m->m_type == MT_CONTROL) {
struct mbuf *cm = NULL, *cmn;
struct mbuf **cme = &cm;
do {
m2 = m->m_next;
m->m_next = NULL;
*cme = m;
cme = &(*cme)->m_next;
m = m2;
} while (m != NULL && m->m_type == MT_CONTROL);
while (cm != NULL) {
cmn = cm->m_next;
cm->m_next = NULL;
if (pr->pr_domain->dom_externalize != NULL) {
error = (*pr->pr_domain->dom_externalize)
(cm, controlp);
} else if (controlp != NULL)
*controlp = cm;
else
m_freem(cm);
if (controlp != NULL) {
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
cm = cmn;
}
}
KASSERT(m->m_type == MT_DATA, ("soreceive_dgram: !data"));
while (m != NULL && uio->uio_resid > 0) {
len = uio->uio_resid;
if (len > m->m_len)
len = m->m_len;
error = uiomove(mtod(m, char *), (int)len, uio);
if (error) {
m_freem(m);
return (error);
}
if (len == m->m_len)
m = m_free(m);
else {
m->m_data += len;
m->m_len -= len;
}
}
if (m != NULL)
flags |= MSG_TRUNC;
m_freem(m);
if (flagsp != NULL)
*flagsp |= flags;
return (0);
}
int
soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
int error;
CURVNET_SET(so->so_vnet);
error = (so->so_proto->pr_usrreqs->pru_soreceive(so, psa, uio, mp0,
controlp, flagsp));
CURVNET_RESTORE();
return (error);
}
int
soshutdown(struct socket *so, int how)
{
struct protosw *pr = so->so_proto;
int error;
if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
return (EINVAL);
CURVNET_SET(so->so_vnet);
if (pr->pr_usrreqs->pru_flush != NULL) {
(*pr->pr_usrreqs->pru_flush)(so, how);
}
if (how != SHUT_WR)
sorflush(so);
if (how != SHUT_RD) {
error = (*pr->pr_usrreqs->pru_shutdown)(so);
CURVNET_RESTORE();
return (error);
}
CURVNET_RESTORE();
return (0);
}
void
sorflush(struct socket *so)
{
struct sockbuf *sb = &so->so_rcv;
struct protosw *pr = so->so_proto;
struct sockbuf asb;
VNET_SO_ASSERT(so);
/*
* In order to avoid calling dom_dispose with the socket buffer mutex
* held, and in order to generally avoid holding the lock for a long
* time, we make a copy of the socket buffer and clear the original
* (except locks, state). The new socket buffer copy won't have
* initialized locks so we can only call routines that won't use or
* assert those locks.
*
* Dislodge threads currently blocked in receive and wait to acquire
* a lock against other simultaneous readers before clearing the
* socket buffer. Don't let our acquire be interrupted by a signal
* despite any existing socket disposition on interruptable waiting.
*/
socantrcvmore(so);
(void) sblock(sb, SBL_WAIT | SBL_NOINTR);
/*
* Invalidate/clear most of the sockbuf structure, but leave selinfo
* and mutex data unchanged.
*/
SOCKBUF_LOCK(sb);
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);
sbunlock(sb);
/*
* Dispose of special rights and flush the socket buffer. Don't call
* any unsafe routines (that rely on locks being initialized) on asb.
*/
if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
(*pr->pr_domain->dom_dispose)(asb.sb_mb);
sbrelease_internal(&asb, so);
}
/*
* 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(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(struct socket *so, struct sockopt *sopt)
{
int error, optval;
struct linger l;
struct timeval tv;
u_long val;
uint32_t val32;
#ifdef MAC
struct mac extmac;
#endif
CURVNET_SET(so->so_vnet);
error = 0;
if (sopt->sopt_level != SOL_SOCKET) {
if (so->so_proto && so->so_proto->pr_ctloutput) {
error = (*so->so_proto->pr_ctloutput)(so, sopt);
CURVNET_RESTORE();
return (error);
}
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:
case SO_NO_DDP:
case SO_NO_OFFLOAD:
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_SETFIB:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (optval < 0 || optval > rt_numfibs) {
error = EINVAL;
goto bad;
}
if (so->so_proto != NULL &&
((so->so_proto->pr_domain->dom_family == PF_INET) ||
(so->so_proto->pr_domain->dom_family == PF_ROUTE))) {
so->so_fibnum = optval;
/* Note: ignore error */
if (so->so_proto->pr_ctloutput)
(*so->so_proto->pr_ctloutput)(so, sopt);
} else {
so->so_fibnum = 0;
}
break;
case SO_USER_COOKIE:
error = sooptcopyin(sopt, &val32, sizeof val32,
sizeof val32);
if (error)
goto bad;
so->so_user_cookie = val32;
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;
}
(sopt->sopt_name == SO_SNDBUF ? &so->so_snd :
&so->so_rcv)->sb_flags &= ~SB_AUTOSIZE;
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:
#ifdef COMPAT_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
struct timeval32 tv32;
error = sooptcopyin(sopt, &tv32, sizeof tv32,
sizeof tv32);
CP(tv32, tv, tv_sec);
CP(tv32, tv, tv_usec);
} else
#endif
error = sooptcopyin(sopt, &tv, sizeof tv,
sizeof tv);
if (error)
goto bad;
/* assert(hz > 0); */
if (tv.tv_sec < 0 || tv.tv_sec > INT_MAX / hz ||
tv.tv_usec < 0 || tv.tv_usec >= 1000000) {
error = EDOM;
goto bad;
}
/* assert(tick > 0); */
/* assert(ULONG_MAX - INT_MAX >= 1000000); */
val = (u_long)(tv.tv_sec * hz) + tv.tv_usec / tick;
if (val > INT_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:
CURVNET_RESTORE();
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(struct socket *so, struct sockopt *sopt)
{
int error, optval;
struct linger l;
struct timeval tv;
#ifdef MAC
struct mac extmac;
#endif
CURVNET_SET(so->so_vnet);
error = 0;
if (sopt->sopt_level != SOL_SOCKET) {
if (so->so_proto && so->so_proto->pr_ctloutput)
error = (*so->so_proto->pr_ctloutput)(so, sopt);
else
error = ENOPROTOOPT;
CURVNET_RESTORE();
return (error);
} else {
switch (sopt->sopt_name) {
#ifdef INET
case SO_ACCEPTFILTER:
error = do_getopt_accept_filter(so, sopt);
break;
#endif
case SO_LINGER:
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_ACCEPTCONN:
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:
SOCK_LOCK(so);
optval = so->so_error;
so->so_error = 0;
SOCK_UNLOCK(so);
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;
#ifdef COMPAT_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
struct timeval32 tv32;
CP(tv, tv32, tv_sec);
CP(tv, tv32, tv_usec);
error = sooptcopyout(sopt, &tv32, sizeof tv32);
} else
#endif
error = sooptcopyout(sopt, &tv, sizeof tv);
break;
case SO_LABEL:
#ifdef MAC
error = sooptcopyin(sopt, &extmac, sizeof(extmac),
sizeof(extmac));
if (error)
goto bad;
error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
so, &extmac);
if (error)
goto bad;
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)
goto bad;
error = mac_getsockopt_peerlabel(
sopt->sopt_td->td_ucred, so, &extmac);
if (error)
goto bad;
error = sooptcopyout(sopt, &extmac, sizeof extmac);
#else
error = EOPNOTSUPP;
#endif
break;
case SO_LISTENQLIMIT:
optval = so->so_qlimit;
goto integer;
case SO_LISTENQLEN:
optval = so->so_qlen;
goto integer;
case SO_LISTENINCQLEN:
optval = so->so_incqlen;
goto integer;
default:
error = ENOPROTOOPT;
break;
}
}
#ifdef MAC
bad:
#endif
CURVNET_RESTORE();
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_WAIT : M_DONTWAIT, MT_DATA);
if (m == NULL)
return ENOBUFS;
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td ? M_WAIT : 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_WAIT : M_DONTWAIT, MT_DATA);
if (m == NULL) {
m_freem(*mp);
return ENOBUFS;
}
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td != NULL ? M_WAIT :
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);
}
/*
* sohasoutofband(): protocol notifies socket layer of the arrival of new
* out-of-band data, which will then notify socket consumers.
*/
void
sohasoutofband(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)
{
/*
* We do not need to set or assert curvnet as long as everyone uses
* sopoll_generic().
*/
return (so->so_proto->pr_usrreqs->pru_sopoll(so, events, active_cred,
td));
}
int
sopoll_generic(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 (soreadabledata(so))
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (sowriteable(so))
revents |= events & (POLLOUT | POLLWRNORM);
if (events & (POLLPRI | POLLRDBAND))
if (so->so_oobmark || (so->so_rcv.sb_state & SBS_RCVATMARK))
revents |= events & (POLLPRI | POLLRDBAND);
if ((events & POLLINIGNEOF) == 0) {
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
revents |= events & (POLLIN | POLLRDNORM);
if (so->so_snd.sb_state & SBS_CANTSENDMORE)
revents |= POLLHUP;
}
}
if (revents == 0) {
if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
selrecord(td, &so->so_rcv.sb_sel);
so->so_rcv.sb_flags |= SB_SEL;
}
if (events & (POLLOUT | POLLWRNORM)) {
selrecord(td, &so->so_snd.sb_sel);
so->so_snd.sb_flags |= SB_SEL;
}
}
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);
}
/*
* Some routines that return EOPNOTSUPP for entry points that are not
* supported by a protocol. Fill in as needed.
*/
int
pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
{
return EOPNOTSUPP;
}
int
pru_attach_notsupp(struct socket *so, int proto, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_connect2_notsupp(struct socket *so1, struct socket *so2)
{
return EOPNOTSUPP;
}
int
pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
struct ifnet *ifp, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_disconnect_notsupp(struct socket *so)
{
return EOPNOTSUPP;
}
int
pru_listen_notsupp(struct socket *so, int backlog, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
{
return EOPNOTSUPP;
}
int
pru_rcvd_notsupp(struct socket *so, int flags)
{
return EOPNOTSUPP;
}
int
pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
{
return EOPNOTSUPP;
}
int
pru_send_notsupp(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *addr, struct mbuf *control, struct thread *td)
{
return EOPNOTSUPP;
}
/*
* This isn't really a ``null'' operation, but it's the default one and
* doesn't do anything destructive.
*/
int
pru_sense_null(struct socket *so, struct stat *sb)
{
sb->st_blksize = so->so_snd.sb_hiwat;
return 0;
}
int
pru_shutdown_notsupp(struct socket *so)
{
return EOPNOTSUPP;
}
int
pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
{
return EOPNOTSUPP;
}
int
pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
return EOPNOTSUPP;
}
int
pru_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
struct thread *td)
{
return EOPNOTSUPP;
}
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 (EPERM);
return (0);
}
static int
sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
{
int error;
int val;
val = somaxconn;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error || !req->newptr )
return (error);
if (val < 1 || val > USHRT_MAX)
return (EINVAL);
somaxconn = val;
return (0);
}
/*
* These functions are used by protocols to notify the socket layer (and its
* consumers) of state changes in the sockets driven by protocol-side events.
*/
/*
* Procedures to manipulate state flags of socket and do appropriate wakeups.
*
* Normal sequence from the active (originating) side is that
* soisconnecting() is called during processing of connect() call, resulting
* in an eventual call to soisconnected() if/when the connection is
* established. When the connection is torn down soisdisconnecting() is
* called during processing of disconnect() call, and soisdisconnected() is
* called when the connection to the peer is totally severed. The semantics
* of these routines are such that connectionless protocols can call
* soisconnected() and soisdisconnected() only, bypassing the in-progress
* calls when setting up a ``connection'' takes no time.
*
* From the passive side, a socket is created with two queues of sockets:
* so_incomp for connections in progress and so_comp for connections already
* made and awaiting user acceptance. As a protocol is preparing incoming
* connections, it creates a socket structure queued on so_incomp by calling
* sonewconn(). When the connection is established, soisconnected() is
* called, and transfers the socket structure to so_comp, making it available
* to accept().
*
* If a socket is closed with sockets on either so_incomp or so_comp, these
* sockets are dropped.
*
* If higher-level protocols are implemented in the kernel, the wakeups done
* here will sometimes cause software-interrupt process scheduling.
*/
void
soisconnecting(struct socket *so)
{
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISCONNECTING;
SOCK_UNLOCK(so);
}
void
soisconnected(struct socket *so)
{
struct socket *head;
int ret;
restart:
ACCEPT_LOCK();
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
so->so_state |= SS_ISCONNECTED;
head = so->so_head;
if (head != NULL && (so->so_qstate & SQ_INCOMP)) {
if ((so->so_options & SO_ACCEPTFILTER) == 0) {
SOCK_UNLOCK(so);
TAILQ_REMOVE(&head->so_incomp, so, so_list);
head->so_incqlen--;
so->so_qstate &= ~SQ_INCOMP;
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
head->so_qlen++;
so->so_qstate |= SQ_COMP;
ACCEPT_UNLOCK();
sorwakeup(head);
wakeup_one(&head->so_timeo);
} else {
ACCEPT_UNLOCK();
soupcall_set(so, SO_RCV,
head->so_accf->so_accept_filter->accf_callback,
head->so_accf->so_accept_filter_arg);
so->so_options &= ~SO_ACCEPTFILTER;
ret = head->so_accf->so_accept_filter->accf_callback(so,
head->so_accf->so_accept_filter_arg, M_DONTWAIT);
if (ret == SU_ISCONNECTED)
soupcall_clear(so, SO_RCV);
SOCK_UNLOCK(so);
if (ret == SU_ISCONNECTED)
goto restart;
}
return;
}
SOCK_UNLOCK(so);
ACCEPT_UNLOCK();
wakeup(&so->so_timeo);
sorwakeup(so);
sowwakeup(so);
}
void
soisdisconnecting(struct socket *so)
{
/*
* Note: This code assumes that SOCK_LOCK(so) and
* SOCKBUF_LOCK(&so->so_rcv) are the same.
*/
SOCKBUF_LOCK(&so->so_rcv);
so->so_state &= ~SS_ISCONNECTING;
so->so_state |= SS_ISDISCONNECTING;
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sowwakeup_locked(so);
wakeup(&so->so_timeo);
}
void
soisdisconnected(struct socket *so)
{
/*
* Note: This code assumes that SOCK_LOCK(so) and
* SOCKBUF_LOCK(&so->so_rcv) are the same.
*/
SOCKBUF_LOCK(&so->so_rcv);
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISDISCONNECTED;
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sbdrop_locked(&so->so_snd, so->so_snd.sb_cc);
sowwakeup_locked(so);
wakeup(&so->so_timeo);
}
/*
* Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
*/
struct sockaddr *
sodupsockaddr(const struct sockaddr *sa, int mflags)
{
struct sockaddr *sa2;
sa2 = malloc(sa->sa_len, M_SONAME, mflags);
if (sa2)
bcopy(sa, sa2, sa->sa_len);
return sa2;
}
/*
* Register per-socket buffer upcalls.
*/
void
soupcall_set(struct socket *so, int which,
int (*func)(struct socket *, void *, int), void *arg)
{
struct sockbuf *sb;
switch (which) {
case SO_RCV:
sb = &so->so_rcv;
break;
case SO_SND:
sb = &so->so_snd;
break;
default:
panic("soupcall_set: bad which");
}
SOCKBUF_LOCK_ASSERT(sb);
#if 0
/* XXX: accf_http actually wants to do this on purpose. */
KASSERT(sb->sb_upcall == NULL, ("soupcall_set: overwriting upcall"));
#endif
sb->sb_upcall = func;
sb->sb_upcallarg = arg;
sb->sb_flags |= SB_UPCALL;
}
void
soupcall_clear(struct socket *so, int which)
{
struct sockbuf *sb;
switch (which) {
case SO_RCV:
sb = &so->so_rcv;
break;
case SO_SND:
sb = &so->so_snd;
break;
default:
panic("soupcall_clear: bad which");
}
SOCKBUF_LOCK_ASSERT(sb);
KASSERT(sb->sb_upcall != NULL, ("soupcall_clear: no upcall to clear"));
sb->sb_upcall = NULL;
sb->sb_upcallarg = NULL;
sb->sb_flags &= ~SB_UPCALL;
}
/*
* Create an external-format (``xsocket'') structure using the information in
* the kernel-format socket structure pointed to by so. This is done to
* reduce the spew of irrelevant information over this interface, to isolate
* user code from changes in the kernel structure, and potentially to provide
* information-hiding if we decide that some of this information should be
* hidden from users.
*/
void
sotoxsocket(struct socket *so, struct xsocket *xso)
{
xso->xso_len = sizeof *xso;
xso->xso_so = so;
xso->so_type = so->so_type;
xso->so_options = so->so_options;
xso->so_linger = so->so_linger;
xso->so_state = so->so_state;
xso->so_pcb = so->so_pcb;
xso->xso_protocol = so->so_proto->pr_protocol;
xso->xso_family = so->so_proto->pr_domain->dom_family;
xso->so_qlen = so->so_qlen;
xso->so_incqlen = so->so_incqlen;
xso->so_qlimit = so->so_qlimit;
xso->so_timeo = so->so_timeo;
xso->so_error = so->so_error;
xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
xso->so_oobmark = so->so_oobmark;
sbtoxsockbuf(&so->so_snd, &xso->so_snd);
sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
xso->so_uid = so->so_cred->cr_uid;
}
/*
* Socket accessor functions to provide external consumers with
* a safe interface to socket state
*
*/
void
so_listeners_apply_all(struct socket *so, void (*func)(struct socket *, void *), void *arg)
{
TAILQ_FOREACH(so, &so->so_comp, so_list)
func(so, arg);
}
struct sockbuf *
so_sockbuf_rcv(struct socket *so)
{
return (&so->so_rcv);
}
struct sockbuf *
so_sockbuf_snd(struct socket *so)
{
return (&so->so_snd);
}
int
so_state_get(const struct socket *so)
{
return (so->so_state);
}
void
so_state_set(struct socket *so, int val)
{
so->so_state = val;
}
int
so_options_get(const struct socket *so)
{
return (so->so_options);
}
void
so_options_set(struct socket *so, int val)
{
so->so_options = val;
}
int
so_error_get(const struct socket *so)
{
return (so->so_error);
}
void
so_error_set(struct socket *so, int val)
{
so->so_error = val;
}
int
so_linger_get(const struct socket *so)
{
return (so->so_linger);
}
void
so_linger_set(struct socket *so, int val)
{
so->so_linger = val;
}
struct protosw *
so_protosw_get(const struct socket *so)
{
return (so->so_proto);
}
void
so_protosw_set(struct socket *so, struct protosw *val)
{
so->so_proto = val;
}
void
so_sorwakeup(struct socket *so)
{
sorwakeup(so);
}
void
so_sowwakeup(struct socket *so)
{
sowwakeup(so);
}
void
so_sorwakeup_locked(struct socket *so)
{
sorwakeup_locked(so);
}
void
so_sowwakeup_locked(struct socket *so)
{
sowwakeup_locked(so);
}
void
so_lock(struct socket *so)
{
SOCK_LOCK(so);
}
void
so_unlock(struct socket *so)
{
SOCK_UNLOCK(so);
}
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