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freebsd-dev/sys/kern/uipc_socket.c
Maxim Konovalov ab77175063 o "avaliable" -> "available". 
PR:		208141
Submitted by:	Tyler Littlefield
2016-03-21 08:03:50 +00:00

3721 lines
94 KiB
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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_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/hhook.h>
#include <sys/kernel.h>
#include <sys/khelp.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/taskqueue.h>
#include <sys/uio.h>
#include <sys/jail.h>
#include <sys/syslog.h>
#include <netinet/in.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 int inline hhook_run_socket(struct socket *so, void *hctx, int32_t h_id);
fo_kqfilter_t soo_kqfilter;
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,
};
so_gen_t so_gencnt; /* generation count for sockets */
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)));
VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
#define V_socket_hhh VNET(socket_hhh)
/*
* Limit on the number of connections in the listen queue waiting
* for accept(2).
* NB: The orginal sysctl somaxconn is still available but hidden
* to prevent confusion about the actual purpose of this number.
*/
static u_int somaxconn = SOMAXCONN;
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);
/*
* The purpose of the UINT_MAX / 3 limit, is so that the formula
* 3 * so_qlimit / 2
* below, will not overflow.
*/
if (val < 1 || val > UINT_MAX / 3)
return (EINVAL);
somaxconn = val;
return (0);
}
SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue, CTLTYPE_UINT | CTLFLAG_RW,
0, sizeof(int), sysctl_somaxconn, "I",
"Maximum listen socket pending connection accept queue size");
SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP,
0, sizeof(int), sysctl_somaxconn, "I",
"Maximum listen socket pending connection accept queue size (compat)");
static int numopensockets;
SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
&numopensockets, 0, "Number of open 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");
/*
* Initialize the socket subsystem and set up the socket
* memory allocator.
*/
static uma_zone_t socket_zone;
int maxsockets;
static void
socket_zone_change(void *tag)
{
maxsockets = uma_zone_set_max(socket_zone, maxsockets);
}
static void
socket_hhook_register(int subtype)
{
if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
&V_socket_hhh[subtype],
HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
printf("%s: WARNING: unable to register hook\n", __func__);
}
static void
socket_hhook_deregister(int subtype)
{
if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
printf("%s: WARNING: unable to deregister hook\n", __func__);
}
static void
socket_init(void *tag)
{
socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
maxsockets = uma_zone_set_max(socket_zone, maxsockets);
uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
EVENTHANDLER_PRI_FIRST);
}
SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
static void
socket_vnet_init(const void *unused __unused)
{
int i;
/* We expect a contiguous range */
for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
socket_hhook_register(i);
}
VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
socket_vnet_init, NULL);
static void
socket_vnet_uninit(const void *unused __unused)
{
int i;
for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
socket_hhook_deregister(i);
}
VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
socket_vnet_uninit, NULL);
/*
* 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, maxfiles);
}
SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
/*
* 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 &&
newmaxsockets <= maxfiles) {
maxsockets = newmaxsockets;
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 available");
/*
* 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
if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
uma_zfree(socket_zone, so);
return (NULL);
}
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_snd.sb_aiojobq);
TAILQ_INIT(&so->so_rcv.sb_aiojobq);
TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
#ifdef VIMAGE
VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
__func__, __LINE__, so));
so->so_vnet = vnet;
#endif
/* We shouldn't need the so_global_mtx */
if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
/* Do we need more comprehensive error returns? */
uma_zfree(socket_zone, so);
return (NULL);
}
mtx_lock(&so_global_mtx);
so->so_gencnt = ++so_gencnt;
++numopensockets;
#ifdef VIMAGE
vnet->vnet_sockcnt++;
#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);
/* remove accept filter if one is present. */
if (so->so_accf != NULL)
do_setopt_accept_filter(so, NULL);
#ifdef MAC
mac_socket_destroy(so);
#endif
hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
crfree(so->so_cred);
khelp_destroy_osd(&so->osd);
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) {
/* No support for domain. */
if (pffinddomain(dom) == NULL)
return (EAFNOSUPPORT);
/* No support for socket type. */
if (proto == 0 && type != 0)
return (EPROTOTYPE);
return (EPROTONOSUPPORT);
}
if (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_INET6) ||
(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 SS_ISCONFIRMING, or SS_ISCONNECTED.
*
* Note: the ref count on the socket is 0 on return.
*/
struct socket *
sonewconn(struct socket *head, int connstatus)
{
static struct timeval lastover;
static struct timeval overinterval = { 60, 0 };
static int overcount;
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
overcount++;
if (ratecheck(&lastover, &overinterval)) {
log(LOG_DEBUG, "%s: pcb %p: Listen queue overflow: "
"%i already in queue awaiting acceptance "
"(%d occurrences)\n",
__func__, head->so_pcb, head->so_qlen, overcount);
overcount = 0;
}
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) {
log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
"limit reached or out of memory\n",
__func__, head->so_pcb);
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)) {
sodealloc(so);
log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
__func__, head->so_pcb);
return (NULL);
}
if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
sodealloc(so);
log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
__func__, head->so_pcb);
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();
/*
* The accept socket may be tearing down but we just
* won a race on the ACCEPT_LOCK.
* However, if sctp_peeloff() is called on a 1-to-many
* style socket, the SO_ACCEPTCONN doesn't need to be set.
*/
if (!(head->so_options & SO_ACCEPTCONN) &&
((head->so_proto->pr_protocol != IPPROTO_SCTP) ||
(head->so_type != SOCK_SEQPACKET))) {
SOCK_LOCK(so);
so->so_head = NULL;
sofree(so); /* NB: returns ACCEPT_UNLOCK'ed. */
return (NULL);
}
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);
}
int
sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
CURVNET_SET(so->so_vnet);
error = (*so->so_proto->pr_usrreqs->pru_bindat)(fd, 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_incomp 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);
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);
ACCEPT_LOCK();
if (so->so_options & SO_ACCEPTCONN) {
struct socket *sp;
/*
* Prevent new additions to the accept queues due
* to ACCEPT_LOCK races while we are draining them.
*/
so->so_options &= ~SO_ACCEPTCONN;
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();
}
KASSERT((TAILQ_EMPTY(&so->so_comp)),
("%s: so_comp populated", __func__));
KASSERT((TAILQ_EMPTY(&so->so_incomp)),
("%s: so_incomp populated", __func__));
}
SOCK_LOCK(so);
KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
so->so_state |= SS_NOFDREF;
sorele(so); /* NB: Returns with ACCEPT_UNLOCK(). */
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)
{
return (soconnectat(AT_FDCWD, so, nam, td));
}
int
soconnectat(int fd, 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;
if (fd == AT_FDCWD) {
error = (*so->so_proto->pr_usrreqs->pru_connect)(so,
nam, td);
} else {
error = (*so->so_proto->pr_usrreqs->pru_connectat)(fd,
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);
}
#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;
ssize_t resid;
int clen = 0, error, dontroute;
KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
("sosend_dgram: !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 {
/*
* 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;
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;
ssize_t 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 {
/*
* Copy the data from userland into a mbuf
* chain. If resid is 0, which can happen
* only if we have control to send, then
* a single empty mbuf is returned. This
* is a workaround to prevent protocol send
* methods to panic.
*/
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;
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_WAITOK, MT_DATA);
error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
if (error)
goto bad;
do {
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, error, offset;
ssize_t len;
struct protosw *pr = so->so_proto;
struct mbuf *nextrecord;
int moff, type = 0;
ssize_t 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_DONTWAIT is not set
*/
if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
sbavail(&so->so_rcv) < uio->uio_resid) &&
sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
KASSERT(m != NULL || !sbavail(&so->so_rcv),
("receive: m == %p sbavail == %u",
m, sbavail(&so->so_rcv)));
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, flags);
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 && !(m->m_flags & M_NOTAVAIL) && 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 || m->m_type == MT_CONTROL) {
if (type != m->m_type)
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);
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) {
m->m_nextpkt = 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) {
if (flags & MSG_DONTWAIT) {
*mp = m_copym(m, 0, len,
M_NOWAIT);
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;
}
} else {
SOCKBUF_UNLOCK(&so->so_rcv);
*mp = m_copym(m, 0, len,
M_WAITOK);
SOCKBUF_LOCK(&so->so_rcv);
}
}
sbcut_locked(&so->so_rcv, 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.
* XXXAO: (MSG_WAITALL | MSG_PEEK) isn't properly handled.
*/
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 (sbavail(sb) > 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 (sbavail(sb) > 0)
goto deliver;
else
goto out;
}
/* Socket buffer is empty and we shall not block. */
if (sbavail(sb) == 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 (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
((so->so_state & SS_NBIO) ||
(flags & (MSG_DONTWAIT|MSG_NBIO)) ||
sbavail(sb) >= sb->sb_lowat ||
sbavail(sb) >= uio->uio_resid ||
sbavail(sb) >= sb->sb_hiwat) ) {
goto deliver;
}
/* On MSG_WAITALL we must wait until all data or error arrives. */
if ((flags & MSG_WAITALL) &&
(sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
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(sbavail(sb) > 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, sbavail(sb));
if (mp0 != NULL) {
/* Dequeue as many mbufs as possible. */
if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
if (*mp0 == NULL)
*mp0 = sb->sb_mb;
else
m_cat(*mp0, sb->sb_mb);
for (m = sb->sb_mb;
m != NULL && m->m_len <= len;
m = m->m_next) {
KASSERT(!(m->m_flags & M_NOTAVAIL),
("%s: m %p not available", __func__, m));
len -= m->m_len;
uio->uio_resid -= m->m_len;
sbfree(sb, m);
n = m;
}
n->m_next = NULL;
sb->sb_mb = m;
sb->sb_lastrecord = sb->sb_mb;
if (sb->sb_mb == NULL)
SB_EMPTY_FIXUP(sb);
}
/* 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_NOWAIT);
if (m == NULL)
len = 0; /* Don't flush data from sockbuf. */
else
uio->uio_resid -= len;
if (*mp0 != NULL)
m_cat(*mp0, 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, error;
ssize_t len;
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(sbavail(&so->so_rcv) == 0,
("soreceive_dgram: sb_mb NULL but sbavail %u",
sbavail(&so->so_rcv)));
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). In some cases there can be only MT_CONTROL mbufs without
* MT_DATA mbufs.
*/
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, flags);
} else if (controlp != NULL)
*controlp = cm;
else
m_freem(cm);
if (controlp != NULL) {
while (*controlp != NULL)
controlp = &(*controlp)->m_next;
}
cm = cmn;
}
}
KASSERT(m == NULL || 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);
if ((so->so_state &
(SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0)
return (ENOTCONN);
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);
wakeup(&so->so_timeo);
CURVNET_RESTORE();
return (error);
}
wakeup(&so->so_timeo);
CURVNET_RESTORE();
return (0);
}
void
sorflush(struct socket *so)
{
struct sockbuf *sb = &so->so_rcv;
struct protosw *pr = so->so_proto;
struct socket aso;
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(&aso, sizeof(aso));
aso.so_pcb = so->so_pcb;
bcopy(&sb->sb_startzero, &aso.so_rcv.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 copied socket. Don't call
* any unsafe routines (that rely on locks being initialized) on aso.
*/
if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
(*pr->pr_domain->dom_dispose)(&aso);
sbrelease_internal(&aso.so_rcv, so);
}
/*
* Wrapper for Socket established helper hook.
* Parameters: socket, context of the hook point, hook id.
*/
static int inline
hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
{
struct socket_hhook_data hhook_data = {
.so = so,
.hctx = hctx,
.m = NULL,
.status = 0
};
CURVNET_SET(so->so_vnet);
HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
CURVNET_RESTORE();
/* Ugly but needed, since hhooks return void for now */
return (hhook_data.status);
}
/*
* 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;
sbintime_t 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->pr_ctloutput != NULL) {
error = (*so->so_proto->pr_ctloutput)(so, sopt);
CURVNET_RESTORE();
return (error);
}
error = ENOPROTOOPT;
} else {
switch (sopt->sopt_name) {
case SO_ACCEPTFILTER:
error = do_setopt_accept_filter(so, sopt);
if (error)
goto bad;
break;
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 (error)
goto bad;
if (optval < 0 || optval >= rt_numfibs) {
error = EINVAL;
goto bad;
}
if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
(so->so_proto->pr_domain->dom_family == PF_INET6) ||
(so->so_proto->pr_domain->dom_family == PF_ROUTE)))
so->so_fibnum = optval;
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;
if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
tv.tv_usec >= 1000000) {
error = EDOM;
goto bad;
}
if (tv.tv_sec > INT32_MAX)
val = SBT_MAX;
else
val = tvtosbt(tv);
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:
if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
error = hhook_run_socket(so, sopt,
HHOOK_SOCKET_OPT);
else
error = ENOPROTOOPT;
break;
}
if (error == 0 && 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->pr_ctloutput != NULL)
error = (*so->so_proto->pr_ctloutput)(so, sopt);
else
error = ENOPROTOOPT;
CURVNET_RESTORE();
return (error);
} else {
switch (sopt->sopt_name) {
case SO_ACCEPTFILTER:
error = do_getopt_accept_filter(so, sopt);
break;
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_PROTOCOL:
optval = so->so_proto->pr_protocol;
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:
tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
#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:
if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
error = hhook_run_socket(so, sopt,
HHOOK_SOCKET_OPT);
else
error = ENOPROTOOPT;
break;
}
}
#ifdef MAC
bad:
#endif
CURVNET_RESTORE();
return (error);
}
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_WAITOK : M_NOWAIT, MT_DATA);
if (m == NULL)
return ENOBUFS;
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
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_WAITOK : M_NOWAIT, MT_DATA);
if (m == NULL) {
m_freem(*mp);
return ENOBUFS;
}
if (sopt_size > MLEN) {
MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
M_NOWAIT);
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);
}
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);
}
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_bindat_notsupp(int fd, 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_connectat_notsupp(int fd, 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;
}
int
pru_ready_notsupp(struct socket *so, struct mbuf *m, int count)
{
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 = sbavail(&so->so_rcv) - 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);
if (kn->kn_sfflags & NOTE_LOWAT) {
if (kn->kn_data >= kn->kn_sdata)
return 1;
} else {
if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
return 1;
}
/* This hook returning non-zero indicates an event, not error */
return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
}
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);
hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
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);
}
/*
* 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_NOWAIT);
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;
socantrcvmore_locked(so);
SOCKBUF_LOCK(&so->so_snd);
socantsendmore_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;
socantrcvmore_locked(so);
SOCKBUF_LOCK(&so->so_snd);
sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
socantsendmore_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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