File: [cvs.NetBSD.org] / src / sys / kern / uipc_socket2.c (download)
Revision 1.120, Thu Jul 31 03:39:35 2014 UTC (9 years, 8 months ago) by rtr
Branch: MAIN
CVS Tags: tls-maxphys-base, tls-earlyentropy-base, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7
Changes since 1.119: +3 -3
lines
split PRU_DISCONNECT, PRU_SHUTDOWN and PRU_ABORT function out of
pr_generic() usrreq switches and put into separate functions
xxx_disconnect(struct socket *)
xxx_shutdown(struct socket *)
xxx_abort(struct socket *)
- always KASSERT(solocked(so)) even if not implemented
- replace calls to pr_generic() with req =
PRU_{DISCONNECT,SHUTDOWN,ABORT}
with calls to pr_{disconnect,shutdown,abort}() respectively
rename existing internal functions used to implement above functionality
to permit use of the names for xxx_{disconnect,shutdown,abort}().
- {l2cap,sco,rfcomm}_disconnect() ->
{l2cap,sco,rfcomm}_disconnect_pcb()
- {unp,rip,tcp}_disconnect() -> {unp,rip,tcp}_disconnect1()
- unp_shutdown() -> unp_shutdown1()
patch reviewed by rmind
|
/* $NetBSD: uipc_socket2.c,v 1.120 2014/07/31 03:39:35 rtr Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1982, 1986, 1988, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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_socket2.c 8.2 (Berkeley) 2/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uipc_socket2.c,v 1.120 2014/07/31 03:39:35 rtr Exp $");
#include "opt_mbuftrace.h"
#include "opt_sb_max.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/buf.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/kauth.h>
#include <sys/pool.h>
#include <sys/uidinfo.h>
/*
* Primitive routines for operating on sockets and socket buffers.
*
* Connection life-cycle:
*
* Normal sequence from the active (originating) side:
*
* - 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 during processing of disconnect():
*
* - soisdisconnecting() is called 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_q0 (0) for partial connections (i.e. connections in progress)
* - so_q (1) for connections already made and awaiting user acceptance.
*
* As a protocol is preparing incoming connections, it creates a socket
* structure queued on so_q0 by calling sonewconn(). When the connection
* is established, soisconnected() is called, and transfers the
* socket structure to so_q, making it available to accept().
*
* If a socket is closed with sockets on either so_q0 or so_q, these
* sockets are dropped.
*
* Locking rules and assumptions:
*
* o socket::so_lock can change on the fly. The low level routines used
* to lock sockets are aware of this. When so_lock is acquired, the
* routine locking must check to see if so_lock still points to the
* lock that was acquired. If so_lock has changed in the meantime, the
* now irrelevant lock that was acquired must be dropped and the lock
* operation retried. Although not proven here, this is completely safe
* on a multiprocessor system, even with relaxed memory ordering, given
* the next two rules:
*
* o In order to mutate so_lock, the lock pointed to by the current value
* of so_lock must be held: i.e., the socket must be held locked by the
* changing thread. The thread must issue membar_exit() to prevent
* memory accesses being reordered, and can set so_lock to the desired
* value. If the lock pointed to by the new value of so_lock is not
* held by the changing thread, the socket must then be considered
* unlocked.
*
* o If so_lock is mutated, and the previous lock referred to by so_lock
* could still be visible to other threads in the system (e.g. via file
* descriptor or protocol-internal reference), then the old lock must
* remain valid until the socket and/or protocol control block has been
* torn down.
*
* o If a socket has a non-NULL so_head value (i.e. is in the process of
* connecting), then locking the socket must also lock the socket pointed
* to by so_head: their lock pointers must match.
*
* o If a socket has connections in progress (so_q, so_q0 not empty) then
* locking the socket must also lock the sockets attached to both queues.
* Again, their lock pointers must match.
*
* o Beyond the initial lock assignment in socreate(), assigning locks to
* sockets is the responsibility of the individual protocols / protocol
* domains.
*/
static pool_cache_t socket_cache;
u_long sb_max = SB_MAX;/* maximum socket buffer size */
static u_long sb_max_adj; /* adjusted sb_max */
void
soisconnecting(struct socket *so)
{
KASSERT(solocked(so));
so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISCONNECTING;
}
void
soisconnected(struct socket *so)
{
struct socket *head;
head = so->so_head;
KASSERT(solocked(so));
KASSERT(head == NULL || solocked2(so, head));
so->so_state &= ~(SS_ISCONNECTING | SS_ISDISCONNECTING);
so->so_state |= SS_ISCONNECTED;
if (head && so->so_onq == &head->so_q0) {
if ((so->so_options & SO_ACCEPTFILTER) == 0) {
/*
* Re-enqueue and wake up any waiters, e.g.
* processes blocking on accept().
*/
soqremque(so, 0);
soqinsque(head, so, 1);
sorwakeup(head);
cv_broadcast(&head->so_cv);
} else {
so->so_upcall =
head->so_accf->so_accept_filter->accf_callback;
so->so_upcallarg = head->so_accf->so_accept_filter_arg;
so->so_rcv.sb_flags |= SB_UPCALL;
so->so_options &= ~SO_ACCEPTFILTER;
(*so->so_upcall)(so, so->so_upcallarg,
POLLIN|POLLRDNORM, M_DONTWAIT);
}
} else {
cv_broadcast(&so->so_cv);
sorwakeup(so);
sowwakeup(so);
}
}
void
soisdisconnecting(struct socket *so)
{
KASSERT(solocked(so));
so->so_state &= ~SS_ISCONNECTING;
so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
cv_broadcast(&so->so_cv);
sowwakeup(so);
sorwakeup(so);
}
void
soisdisconnected(struct socket *so)
{
KASSERT(solocked(so));
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
cv_broadcast(&so->so_cv);
sowwakeup(so);
sorwakeup(so);
}
void
soinit2(void)
{
socket_cache = pool_cache_init(sizeof(struct socket), 0, 0, 0,
"socket", NULL, IPL_SOFTNET, NULL, NULL, NULL);
}
/*
* sonewconn: accept a new connection.
*
* When an attempt at a new connection is noted on a socket which accepts
* connections, sonewconn(9) is called. If the connection is possible
* (subject to space constraints, etc) then we allocate a new structure,
* properly linked into the data structure of the original socket.
*
* => If 'soready' is true, then socket will become ready for accept() i.e.
* inserted into the so_q queue, SS_ISCONNECTED set and waiters awoken.
* => May be called from soft-interrupt context.
* => Listening socket should be locked.
* => Returns the new socket locked.
*/
struct socket *
sonewconn(struct socket *head, bool soready)
{
struct socket *so;
int soqueue, error;
KASSERT(solocked(head));
if (head->so_qlen + head->so_q0len > 3 * head->so_qlimit / 2) {
/* Listen queue overflow. */
return NULL;
}
if ((head->so_options & SO_ACCEPTFILTER) != 0) {
soready = false;
}
soqueue = soready ? 1 : 0;
if ((so = soget(false)) == NULL) {
return NULL;
}
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_proto = head->so_proto;
so->so_timeo = head->so_timeo;
so->so_pgid = head->so_pgid;
so->so_send = head->so_send;
so->so_receive = head->so_receive;
so->so_uidinfo = head->so_uidinfo;
so->so_cpid = head->so_cpid;
/*
* Share the lock with the listening-socket, it may get unshared
* once the connection is complete.
*/
mutex_obj_hold(head->so_lock);
so->so_lock = head->so_lock;
/*
* Reserve the space for socket buffers.
*/
#ifdef MBUFTRACE
so->so_mowner = head->so_mowner;
so->so_rcv.sb_mowner = head->so_rcv.sb_mowner;
so->so_snd.sb_mowner = head->so_snd.sb_mowner;
#endif
if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
goto out;
}
so->so_snd.sb_lowat = head->so_snd.sb_lowat;
so->so_rcv.sb_lowat = head->so_rcv.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 | SB_ASYNC);
so->so_snd.sb_flags |= head->so_snd.sb_flags & (SB_AUTOSIZE | SB_ASYNC);
/*
* Finally, perform the protocol attach. Note: a new socket
* lock may be assigned at this point (if so, it will be held).
*/
error = (*so->so_proto->pr_usrreqs->pr_attach)(so, 0);
if (error) {
out:
KASSERT(solocked(so));
KASSERT(so->so_accf == NULL);
soput(so);
/* Note: the listening socket shall stay locked. */
KASSERT(solocked(head));
return NULL;
}
KASSERT(solocked2(head, so));
/*
* Insert into the queue. If ready, update the connection status
* and wake up any waiters, e.g. processes blocking on accept().
*/
soqinsque(head, so, soqueue);
if (soready) {
so->so_state |= SS_ISCONNECTED;
sorwakeup(head);
cv_broadcast(&head->so_cv);
}
return so;
}
struct socket *
soget(bool waitok)
{
struct socket *so;
so = pool_cache_get(socket_cache, (waitok ? PR_WAITOK : PR_NOWAIT));
if (__predict_false(so == NULL))
return (NULL);
memset(so, 0, sizeof(*so));
TAILQ_INIT(&so->so_q0);
TAILQ_INIT(&so->so_q);
cv_init(&so->so_cv, "socket");
cv_init(&so->so_rcv.sb_cv, "netio");
cv_init(&so->so_snd.sb_cv, "netio");
selinit(&so->so_rcv.sb_sel);
selinit(&so->so_snd.sb_sel);
so->so_rcv.sb_so = so;
so->so_snd.sb_so = so;
return so;
}
void
soput(struct socket *so)
{
KASSERT(!cv_has_waiters(&so->so_cv));
KASSERT(!cv_has_waiters(&so->so_rcv.sb_cv));
KASSERT(!cv_has_waiters(&so->so_snd.sb_cv));
seldestroy(&so->so_rcv.sb_sel);
seldestroy(&so->so_snd.sb_sel);
mutex_obj_free(so->so_lock);
cv_destroy(&so->so_cv);
cv_destroy(&so->so_rcv.sb_cv);
cv_destroy(&so->so_snd.sb_cv);
pool_cache_put(socket_cache, so);
}
/*
* soqinsque: insert socket of a new connection into the specified
* accept queue of the listening socket (head).
*
* q = 0: queue of partial connections
* q = 1: queue of incoming connections
*/
void
soqinsque(struct socket *head, struct socket *so, int q)
{
KASSERT(q == 0 || q == 1);
KASSERT(solocked2(head, so));
KASSERT(so->so_onq == NULL);
KASSERT(so->so_head == NULL);
so->so_head = head;
if (q == 0) {
head->so_q0len++;
so->so_onq = &head->so_q0;
} else {
head->so_qlen++;
so->so_onq = &head->so_q;
}
TAILQ_INSERT_TAIL(so->so_onq, so, so_qe);
}
/*
* soqremque: remove socket from the specified queue.
*
* => Returns true if socket was removed from the specified queue.
* => False if socket was not removed (because it was in other queue).
*/
bool
soqremque(struct socket *so, int q)
{
struct socket *head = so->so_head;
KASSERT(q == 0 || q == 1);
KASSERT(solocked(so));
KASSERT(so->so_onq != NULL);
KASSERT(head != NULL);
if (q == 0) {
if (so->so_onq != &head->so_q0)
return false;
head->so_q0len--;
} else {
if (so->so_onq != &head->so_q)
return false;
head->so_qlen--;
}
KASSERT(solocked2(so, head));
TAILQ_REMOVE(so->so_onq, so, so_qe);
so->so_onq = NULL;
so->so_head = NULL;
return true;
}
/*
* socantsendmore: indicates that no more data will be sent on the
* socket; it would normally be applied to a socket when the user
* informs the system that no more data is to be sent, by the protocol
* code (in case pr_shutdown()).
*/
void
socantsendmore(struct socket *so)
{
KASSERT(solocked(so));
so->so_state |= SS_CANTSENDMORE;
sowwakeup(so);
}
/*
* socantrcvmore(): indicates that no more data will be received and
* will normally be applied to the socket by a protocol when it detects
* that the peer will send no more data. Data queued for reading in
* the socket may yet be read.
*/
void
socantrcvmore(struct socket *so)
{
KASSERT(solocked(so));
so->so_state |= SS_CANTRCVMORE;
sorwakeup(so);
}
/*
* Wait for data to arrive at/drain from a socket buffer.
*/
int
sbwait(struct sockbuf *sb)
{
struct socket *so;
kmutex_t *lock;
int error;
so = sb->sb_so;
KASSERT(solocked(so));
sb->sb_flags |= SB_NOTIFY;
lock = so->so_lock;
if ((sb->sb_flags & SB_NOINTR) != 0)
error = cv_timedwait(&sb->sb_cv, lock, sb->sb_timeo);
else
error = cv_timedwait_sig(&sb->sb_cv, lock, sb->sb_timeo);
if (__predict_false(lock != so->so_lock))
solockretry(so, lock);
return error;
}
/*
* Wakeup processes waiting on a socket buffer.
* Do asynchronous notification via SIGIO
* if the socket buffer has the SB_ASYNC flag set.
*/
void
sowakeup(struct socket *so, struct sockbuf *sb, int code)
{
int band;
KASSERT(solocked(so));
KASSERT(sb->sb_so == so);
if (code == POLL_IN)
band = POLLIN|POLLRDNORM;
else
band = POLLOUT|POLLWRNORM;
sb->sb_flags &= ~SB_NOTIFY;
selnotify(&sb->sb_sel, band, NOTE_SUBMIT);
cv_broadcast(&sb->sb_cv);
if (sb->sb_flags & SB_ASYNC)
fownsignal(so->so_pgid, SIGIO, code, band, so);
if (sb->sb_flags & SB_UPCALL)
(*so->so_upcall)(so, so->so_upcallarg, band, M_DONTWAIT);
}
/*
* Reset a socket's lock pointer. Wake all threads waiting on the
* socket's condition variables so that they can restart their waits
* using the new lock. The existing lock must be held.
*/
void
solockreset(struct socket *so, kmutex_t *lock)
{
KASSERT(solocked(so));
so->so_lock = lock;
cv_broadcast(&so->so_snd.sb_cv);
cv_broadcast(&so->so_rcv.sb_cv);
cv_broadcast(&so->so_cv);
}
/*
* Socket buffer (struct sockbuf) utility routines.
*
* Each socket contains two socket buffers: one for sending data and
* one for receiving data. Each buffer contains a queue of mbufs,
* information about the number of mbufs and amount of data in the
* queue, and other fields allowing poll() statements and notification
* on data availability to be implemented.
*
* Data stored in a socket buffer is maintained as a list of records.
* Each record is a list of mbufs chained together with the m_next
* field. Records are chained together with the m_nextpkt field. The upper
* level routine soreceive() expects the following conventions to be
* observed when placing information in the receive buffer:
*
* 1. If the protocol requires each message be preceded by the sender's
* name, then a record containing that name must be present before
* any associated data (mbuf's must be of type MT_SONAME).
* 2. If the protocol supports the exchange of ``access rights'' (really
* just additional data associated with the message), and there are
* ``rights'' to be received, then a record containing this data
* should be present (mbuf's must be of type MT_CONTROL).
* 3. If a name or rights record exists, then it must be followed by
* a data record, perhaps of zero length.
*
* Before using a new socket structure it is first necessary to reserve
* buffer space to the socket, by calling sbreserve(). This should commit
* some of the available buffer space in the system buffer pool for the
* socket (currently, it does nothing but enforce limits). The space
* should be released by calling sbrelease() when the socket is destroyed.
*/
int
sb_max_set(u_long new_sbmax)
{
int s;
if (new_sbmax < (16 * 1024))
return (EINVAL);
s = splsoftnet();
sb_max = new_sbmax;
sb_max_adj = (u_quad_t)new_sbmax * MCLBYTES / (MSIZE + MCLBYTES);
splx(s);
return (0);
}
int
soreserve(struct socket *so, u_long sndcc, u_long rcvcc)
{
KASSERT(so->so_pcb == NULL || solocked(so));
/*
* there's at least one application (a configure script of screen)
* which expects a fifo is writable even if it has "some" bytes
* in its buffer.
* so we want to make sure (hiwat - lowat) >= (some bytes).
*
* PIPE_BUF here is an arbitrary value chosen as (some bytes) above.
* we expect it's large enough for such applications.
*/
u_long lowat = MAX(sock_loan_thresh, MCLBYTES);
u_long hiwat = lowat + PIPE_BUF;
if (sndcc < hiwat)
sndcc = hiwat;
if (sbreserve(&so->so_snd, sndcc, so) == 0)
goto bad;
if (sbreserve(&so->so_rcv, rcvcc, so) == 0)
goto bad2;
if (so->so_rcv.sb_lowat == 0)
so->so_rcv.sb_lowat = 1;
if (so->so_snd.sb_lowat == 0)
so->so_snd.sb_lowat = lowat;
if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
return (0);
bad2:
sbrelease(&so->so_snd, so);
bad:
return (ENOBUFS);
}
/*
* Allot mbufs to a sockbuf.
* Attempt to scale mbmax so that mbcnt doesn't become limiting
* if buffering efficiency is near the normal case.
*/
int
sbreserve(struct sockbuf *sb, u_long cc, struct socket *so)
{
struct lwp *l = curlwp; /* XXX */
rlim_t maxcc;
struct uidinfo *uidinfo;
KASSERT(so->so_pcb == NULL || solocked(so));
KASSERT(sb->sb_so == so);
KASSERT(sb_max_adj != 0);
if (cc == 0 || cc > sb_max_adj)
return (0);
maxcc = l->l_proc->p_rlimit[RLIMIT_SBSIZE].rlim_cur;
uidinfo = so->so_uidinfo;
if (!chgsbsize(uidinfo, &sb->sb_hiwat, cc, maxcc))
return 0;
sb->sb_mbmax = min(cc * 2, sb_max);
if (sb->sb_lowat > sb->sb_hiwat)
sb->sb_lowat = sb->sb_hiwat;
return (1);
}
/*
* Free mbufs held by a socket, and reserved mbuf space. We do not assert
* that the socket is held locked here: see sorflush().
*/
void
sbrelease(struct sockbuf *sb, struct socket *so)
{
KASSERT(sb->sb_so == so);
sbflush(sb);
(void)chgsbsize(so->so_uidinfo, &sb->sb_hiwat, 0, RLIM_INFINITY);
sb->sb_mbmax = 0;
}
/*
* Routines to add and remove
* data from an mbuf queue.
*
* The routines sbappend() or sbappendrecord() are normally called to
* append new mbufs to a socket buffer, after checking that adequate
* space is available, comparing the function sbspace() with the amount
* of data to be added. sbappendrecord() differs from sbappend() in
* that data supplied is treated as the beginning of a new record.
* To place a sender's address, optional access rights, and data in a
* socket receive buffer, sbappendaddr() should be used. To place
* access rights and data in a socket receive buffer, sbappendrights()
* should be used. In either case, the new data begins a new record.
* Note that unlike sbappend() and sbappendrecord(), these routines check
* for the caller that there will be enough space to store the data.
* Each fails if there is not enough space, or if it cannot find mbufs
* to store additional information in.
*
* Reliable protocols may use the socket send buffer to hold data
* awaiting acknowledgement. Data is normally copied from a socket
* send buffer in a protocol with m_copy for output to a peer,
* and then removing the data from the socket buffer with sbdrop()
* or sbdroprecord() when the data is acknowledged by the peer.
*/
#ifdef SOCKBUF_DEBUG
void
sblastrecordchk(struct sockbuf *sb, const char *where)
{
struct mbuf *m = sb->sb_mb;
KASSERT(solocked(sb->sb_so));
while (m && m->m_nextpkt)
m = m->m_nextpkt;
if (m != sb->sb_lastrecord) {
printf("sblastrecordchk: sb_mb %p sb_lastrecord %p last %p\n",
sb->sb_mb, sb->sb_lastrecord, m);
printf("packet chain:\n");
for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
printf("\t%p\n", m);
panic("sblastrecordchk from %s", where);
}
}
void
sblastmbufchk(struct sockbuf *sb, const char *where)
{
struct mbuf *m = sb->sb_mb;
struct mbuf *n;
KASSERT(solocked(sb->sb_so));
while (m && m->m_nextpkt)
m = m->m_nextpkt;
while (m && m->m_next)
m = m->m_next;
if (m != sb->sb_mbtail) {
printf("sblastmbufchk: sb_mb %p sb_mbtail %p last %p\n",
sb->sb_mb, sb->sb_mbtail, m);
printf("packet tree:\n");
for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
printf("\t");
for (n = m; n != NULL; n = n->m_next)
printf("%p ", n);
printf("\n");
}
panic("sblastmbufchk from %s", where);
}
}
#endif /* SOCKBUF_DEBUG */
/*
* Link a chain of records onto a socket buffer
*/
#define SBLINKRECORDCHAIN(sb, m0, mlast) \
do { \
if ((sb)->sb_lastrecord != NULL) \
(sb)->sb_lastrecord->m_nextpkt = (m0); \
else \
(sb)->sb_mb = (m0); \
(sb)->sb_lastrecord = (mlast); \
} while (/*CONSTCOND*/0)
#define SBLINKRECORD(sb, m0) \
SBLINKRECORDCHAIN(sb, m0, m0)
/*
* Append mbuf chain m to the last record in the
* socket buffer sb. The additional space associated
* the mbuf chain is recorded in sb. Empty mbufs are
* discarded and mbufs are compacted where possible.
*/
void
sbappend(struct sockbuf *sb, struct mbuf *m)
{
struct mbuf *n;
KASSERT(solocked(sb->sb_so));
if (m == NULL)
return;
#ifdef MBUFTRACE
m_claimm(m, sb->sb_mowner);
#endif
SBLASTRECORDCHK(sb, "sbappend 1");
if ((n = sb->sb_lastrecord) != NULL) {
/*
* XXX Would like to simply use sb_mbtail here, but
* XXX I need to verify that I won't miss an EOR that
* XXX way.
*/
do {
if (n->m_flags & M_EOR) {
sbappendrecord(sb, m); /* XXXXXX!!!! */
return;
}
} while (n->m_next && (n = n->m_next));
} else {
/*
* If this is the first record in the socket buffer, it's
* also the last record.
*/
sb->sb_lastrecord = m;
}
sbcompress(sb, m, n);
SBLASTRECORDCHK(sb, "sbappend 2");
}
/*
* This version of sbappend() should only be used when the caller
* absolutely knows that there will never be more than one record
* in the socket buffer, that is, a stream protocol (such as TCP).
*/
void
sbappendstream(struct sockbuf *sb, struct mbuf *m)
{
KASSERT(solocked(sb->sb_so));
KDASSERT(m->m_nextpkt == NULL);
KASSERT(sb->sb_mb == sb->sb_lastrecord);
SBLASTMBUFCHK(sb, __func__);
#ifdef MBUFTRACE
m_claimm(m, sb->sb_mowner);
#endif
sbcompress(sb, m, sb->sb_mbtail);
sb->sb_lastrecord = sb->sb_mb;
SBLASTRECORDCHK(sb, __func__);
}
#ifdef SOCKBUF_DEBUG
void
sbcheck(struct sockbuf *sb)
{
struct mbuf *m, *m2;
u_long len, mbcnt;
KASSERT(solocked(sb->sb_so));
len = 0;
mbcnt = 0;
for (m = sb->sb_mb; m; m = m->m_nextpkt) {
for (m2 = m; m2 != NULL; m2 = m2->m_next) {
len += m2->m_len;
mbcnt += MSIZE;
if (m2->m_flags & M_EXT)
mbcnt += m2->m_ext.ext_size;
if (m2->m_nextpkt != NULL)
panic("sbcheck nextpkt");
}
}
if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
printf("cc %lu != %lu || mbcnt %lu != %lu\n", len, sb->sb_cc,
mbcnt, sb->sb_mbcnt);
panic("sbcheck");
}
}
#endif
/*
* As above, except the mbuf chain
* begins a new record.
*/
void
sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
{
struct mbuf *m;
KASSERT(solocked(sb->sb_so));
if (m0 == NULL)
return;
#ifdef MBUFTRACE
m_claimm(m0, sb->sb_mowner);
#endif
/*
* Put the first mbuf on the queue.
* Note this permits zero length records.
*/
sballoc(sb, m0);
SBLASTRECORDCHK(sb, "sbappendrecord 1");
SBLINKRECORD(sb, m0);
m = m0->m_next;
m0->m_next = 0;
if (m && (m0->m_flags & M_EOR)) {
m0->m_flags &= ~M_EOR;
m->m_flags |= M_EOR;
}
sbcompress(sb, m, m0);
SBLASTRECORDCHK(sb, "sbappendrecord 2");
}
/*
* As above except that OOB data
* is inserted at the beginning of the sockbuf,
* but after any other OOB data.
*/
void
sbinsertoob(struct sockbuf *sb, struct mbuf *m0)
{
struct mbuf *m, **mp;
KASSERT(solocked(sb->sb_so));
if (m0 == NULL)
return;
SBLASTRECORDCHK(sb, "sbinsertoob 1");
for (mp = &sb->sb_mb; (m = *mp) != NULL; mp = &((*mp)->m_nextpkt)) {
again:
switch (m->m_type) {
case MT_OOBDATA:
continue; /* WANT next train */
case MT_CONTROL:
if ((m = m->m_next) != NULL)
goto again; /* inspect THIS train further */
}
break;
}
/*
* Put the first mbuf on the queue.
* Note this permits zero length records.
*/
sballoc(sb, m0);
m0->m_nextpkt = *mp;
if (*mp == NULL) {
/* m0 is actually the new tail */
sb->sb_lastrecord = m0;
}
*mp = m0;
m = m0->m_next;
m0->m_next = 0;
if (m && (m0->m_flags & M_EOR)) {
m0->m_flags &= ~M_EOR;
m->m_flags |= M_EOR;
}
sbcompress(sb, m, m0);
SBLASTRECORDCHK(sb, "sbinsertoob 2");
}
/*
* Append address and data, and optionally, control (ancillary) data
* to the receive queue of a socket. If present,
* m0 must include a packet header with total length.
* Returns 0 if no space in sockbuf or insufficient mbufs.
*/
int
sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, struct mbuf *m0,
struct mbuf *control)
{
struct mbuf *m, *n, *nlast;
int space, len;
KASSERT(solocked(sb->sb_so));
space = asa->sa_len;
if (m0 != NULL) {
if ((m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr");
space += m0->m_pkthdr.len;
#ifdef MBUFTRACE
m_claimm(m0, sb->sb_mowner);
#endif
}
for (n = control; n; n = n->m_next) {
space += n->m_len;
MCLAIM(n, sb->sb_mowner);
if (n->m_next == NULL) /* keep pointer to last control buf */
break;
}
if (space > sbspace(sb))
return (0);
m = m_get(M_DONTWAIT, MT_SONAME);
if (m == NULL)
return (0);
MCLAIM(m, sb->sb_mowner);
/*
* XXX avoid 'comparison always true' warning which isn't easily
* avoided.
*/
len = asa->sa_len;
if (len > MLEN) {
MEXTMALLOC(m, asa->sa_len, M_NOWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
return (0);
}
}
m->m_len = asa->sa_len;
memcpy(mtod(m, void *), asa, asa->sa_len);
if (n)
n->m_next = m0; /* concatenate data to control */
else
control = m0;
m->m_next = control;
SBLASTRECORDCHK(sb, "sbappendaddr 1");
for (n = m; n->m_next != NULL; n = n->m_next)
sballoc(sb, n);
sballoc(sb, n);
nlast = n;
SBLINKRECORD(sb, m);
sb->sb_mbtail = nlast;
SBLASTMBUFCHK(sb, "sbappendaddr");
SBLASTRECORDCHK(sb, "sbappendaddr 2");
return (1);
}
/*
* Helper for sbappendchainaddr: prepend a struct sockaddr* to
* an mbuf chain.
*/
static inline struct mbuf *
m_prepend_sockaddr(struct sockbuf *sb, struct mbuf *m0,
const struct sockaddr *asa)
{
struct mbuf *m;
const int salen = asa->sa_len;
KASSERT(solocked(sb->sb_so));
/* only the first in each chain need be a pkthdr */
m = m_gethdr(M_DONTWAIT, MT_SONAME);
if (m == NULL)
return NULL;
MCLAIM(m, sb->sb_mowner);
#ifdef notyet
if (salen > MHLEN) {
MEXTMALLOC(m, salen, M_NOWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
return NULL;
}
}
#else
KASSERT(salen <= MHLEN);
#endif
m->m_len = salen;
memcpy(mtod(m, void *), asa, salen);
m->m_next = m0;
m->m_pkthdr.len = salen + m0->m_pkthdr.len;
return m;
}
int
sbappendaddrchain(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, int sbprio)
{
struct mbuf *m, *n, *n0, *nlast;
int error;
KASSERT(solocked(sb->sb_so));
/*
* XXX sbprio reserved for encoding priority of this* request:
* SB_PRIO_NONE --> honour normal sb limits
* SB_PRIO_ONESHOT_OVERFLOW --> if socket has any space,
* take whole chain. Intended for large requests
* that should be delivered atomically (all, or none).
* SB_PRIO_OVERDRAFT -- allow a small (2*MLEN) overflow
* over normal socket limits, for messages indicating
* buffer overflow in earlier normal/lower-priority messages
* SB_PRIO_BESTEFFORT --> ignore limits entirely.
* Intended for kernel-generated messages only.
* Up to generator to avoid total mbuf resource exhaustion.
*/
(void)sbprio;
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddrchain");
#ifdef notyet
space = sbspace(sb);
/*
* Enforce SB_PRIO_* limits as described above.
*/
#endif
n0 = NULL;
nlast = NULL;
for (m = m0; m; m = m->m_nextpkt) {
struct mbuf *np;
#ifdef MBUFTRACE
m_claimm(m, sb->sb_mowner);
#endif
/* Prepend sockaddr to this record (m) of input chain m0 */
n = m_prepend_sockaddr(sb, m, asa);
if (n == NULL) {
error = ENOBUFS;
goto bad;
}
/* Append record (asa+m) to end of new chain n0 */
if (n0 == NULL) {
n0 = n;
} else {
nlast->m_nextpkt = n;
}
/* Keep track of last record on new chain */
nlast = n;
for (np = n; np; np = np->m_next)
sballoc(sb, np);
}
SBLASTRECORDCHK(sb, "sbappendaddrchain 1");
/* Drop the entire chain of (asa+m) records onto the socket */
SBLINKRECORDCHAIN(sb, n0, nlast);
SBLASTRECORDCHK(sb, "sbappendaddrchain 2");
for (m = nlast; m->m_next; m = m->m_next)
;
sb->sb_mbtail = m;
SBLASTMBUFCHK(sb, "sbappendaddrchain");
return (1);
bad:
/*
* On error, free the prepended addreseses. For consistency
* with sbappendaddr(), leave it to our caller to free
* the input record chain passed to us as m0.
*/
while ((n = n0) != NULL) {
struct mbuf *np;
/* Undo the sballoc() of this record */
for (np = n; np; np = np->m_next)
sbfree(sb, np);
n0 = n->m_nextpkt; /* iterate at next prepended address */
MFREE(n, np); /* free prepended address (not data) */
}
return error;
}
int
sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control)
{
struct mbuf *m, *mlast, *n;
int space;
KASSERT(solocked(sb->sb_so));
space = 0;
if (control == NULL)
panic("sbappendcontrol");
for (m = control; ; m = m->m_next) {
space += m->m_len;
MCLAIM(m, sb->sb_mowner);
if (m->m_next == NULL)
break;
}
n = m; /* save pointer to last control buffer */
for (m = m0; m; m = m->m_next) {
MCLAIM(m, sb->sb_mowner);
space += m->m_len;
}
if (space > sbspace(sb))
return (0);
n->m_next = m0; /* concatenate data to control */
SBLASTRECORDCHK(sb, "sbappendcontrol 1");
for (m = control; m->m_next != NULL; m = m->m_next)
sballoc(sb, m);
sballoc(sb, m);
mlast = m;
SBLINKRECORD(sb, control);
sb->sb_mbtail = mlast;
SBLASTMBUFCHK(sb, "sbappendcontrol");
SBLASTRECORDCHK(sb, "sbappendcontrol 2");
return (1);
}
/*
* Compress mbuf chain m into the socket
* buffer sb following mbuf n. If n
* is null, the buffer is presumed empty.
*/
void
sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
{
int eor;
struct mbuf *o;
KASSERT(solocked(sb->sb_so));
eor = 0;
while (m) {
eor |= m->m_flags & M_EOR;
if (m->m_len == 0 &&
(eor == 0 ||
(((o = m->m_next) || (o = n)) &&
o->m_type == m->m_type))) {
if (sb->sb_lastrecord == m)
sb->sb_lastrecord = m->m_next;
m = m_free(m);
continue;
}
if (n && (n->m_flags & M_EOR) == 0 &&
/* M_TRAILINGSPACE() checks buffer writeability */
m->m_len <= MCLBYTES / 4 && /* XXX Don't copy too much */
m->m_len <= M_TRAILINGSPACE(n) &&
n->m_type == m->m_type) {
memcpy(mtod(n, char *) + n->m_len, mtod(m, void *),
(unsigned)m->m_len);
n->m_len += m->m_len;
sb->sb_cc += m->m_len;
m = m_free(m);
continue;
}
if (n)
n->m_next = m;
else
sb->sb_mb = m;
sb->sb_mbtail = m;
sballoc(sb, m);
n = m;
m->m_flags &= ~M_EOR;
m = m->m_next;
n->m_next = 0;
}
if (eor) {
if (n)
n->m_flags |= eor;
else
printf("semi-panic: sbcompress\n");
}
SBLASTMBUFCHK(sb, __func__);
}
/*
* Free all mbufs in a sockbuf.
* Check that all resources are reclaimed.
*/
void
sbflush(struct sockbuf *sb)
{
KASSERT(solocked(sb->sb_so));
KASSERT((sb->sb_flags & SB_LOCK) == 0);
while (sb->sb_mbcnt)
sbdrop(sb, (int)sb->sb_cc);
KASSERT(sb->sb_cc == 0);
KASSERT(sb->sb_mb == NULL);
KASSERT(sb->sb_mbtail == NULL);
KASSERT(sb->sb_lastrecord == NULL);
}
/*
* Drop data from (the front of) a sockbuf.
*/
void
sbdrop(struct sockbuf *sb, int len)
{
struct mbuf *m, *mn, *next;
KASSERT(solocked(sb->sb_so));
next = (m = sb->sb_mb) ? m->m_nextpkt : NULL;
while (len > 0) {
if (m == NULL) {
if (next == NULL)
panic("sbdrop(%p,%d): cc=%lu",
sb, len, sb->sb_cc);
m = next;
next = m->m_nextpkt;
continue;
}
if (m->m_len > len) {
m->m_len -= len;
m->m_data += len;
sb->sb_cc -= len;
break;
}
len -= m->m_len;
sbfree(sb, m);
MFREE(m, mn);
m = mn;
}
while (m && m->m_len == 0) {
sbfree(sb, m);
MFREE(m, mn);
m = mn;
}
if (m) {
sb->sb_mb = m;
m->m_nextpkt = next;
} else
sb->sb_mb = next;
/*
* First part is an inline SB_EMPTY_FIXUP(). Second part
* makes sure sb_lastrecord is up-to-date if we dropped
* part of the last record.
*/
m = sb->sb_mb;
if (m == NULL) {
sb->sb_mbtail = NULL;
sb->sb_lastrecord = NULL;
} else if (m->m_nextpkt == NULL)
sb->sb_lastrecord = m;
}
/*
* Drop a record off the front of a sockbuf
* and move the next record to the front.
*/
void
sbdroprecord(struct sockbuf *sb)
{
struct mbuf *m, *mn;
KASSERT(solocked(sb->sb_so));
m = sb->sb_mb;
if (m) {
sb->sb_mb = m->m_nextpkt;
do {
sbfree(sb, m);
MFREE(m, mn);
} while ((m = mn) != NULL);
}
SB_EMPTY_FIXUP(sb);
}
/*
* Create a "control" mbuf containing the specified data
* with the specified type for presentation on a socket buffer.
*/
struct mbuf *
sbcreatecontrol1(void **p, int size, int type, int level, int flags)
{
struct cmsghdr *cp;
struct mbuf *m;
int space = CMSG_SPACE(size);
if ((flags & M_DONTWAIT) && space > MCLBYTES) {
printf("%s: message too large %d\n", __func__, space);
return NULL;
}
if ((m = m_get(flags, MT_CONTROL)) == NULL)
return NULL;
if (space > MLEN) {
if (space > MCLBYTES)
MEXTMALLOC(m, space, M_WAITOK);
else
MCLGET(m, flags);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
return NULL;
}
}
cp = mtod(m, struct cmsghdr *);
*p = CMSG_DATA(cp);
m->m_len = space;
cp->cmsg_len = CMSG_LEN(size);
cp->cmsg_level = level;
cp->cmsg_type = type;
return m;
}
struct mbuf *
sbcreatecontrol(void *p, int size, int type, int level)
{
struct mbuf *m;
void *v;
m = sbcreatecontrol1(&v, size, type, level, M_DONTWAIT);
if (m == NULL)
return NULL;
memcpy(v, p, size);
return m;
}
void
solockretry(struct socket *so, kmutex_t *lock)
{
while (lock != so->so_lock) {
mutex_exit(lock);
lock = so->so_lock;
mutex_enter(lock);
}
}
bool
solocked(struct socket *so)
{
return mutex_owned(so->so_lock);
}
bool
solocked2(struct socket *so1, struct socket *so2)
{
kmutex_t *lock;
lock = so1->so_lock;
if (lock != so2->so_lock)
return false;
return mutex_owned(lock);
}
/*
* sosetlock: assign a default lock to a new socket.
*/
void
sosetlock(struct socket *so)
{
if (so->so_lock == NULL) {
kmutex_t *lock = softnet_lock;
so->so_lock = lock;
mutex_obj_hold(lock);
mutex_enter(lock);
}
KASSERT(solocked(so));
}
/*
* Set lock on sockbuf sb; sleep if lock is already held.
* Unless SB_NOINTR is set on sockbuf, sleep is interruptible.
* Returns error without lock if sleep is interrupted.
*/
int
sblock(struct sockbuf *sb, int wf)
{
struct socket *so;
kmutex_t *lock;
int error;
KASSERT(solocked(sb->sb_so));
for (;;) {
if (__predict_true((sb->sb_flags & SB_LOCK) == 0)) {
sb->sb_flags |= SB_LOCK;
return 0;
}
if (wf != M_WAITOK)
return EWOULDBLOCK;
so = sb->sb_so;
lock = so->so_lock;
if ((sb->sb_flags & SB_NOINTR) != 0) {
cv_wait(&so->so_cv, lock);
error = 0;
} else
error = cv_wait_sig(&so->so_cv, lock);
if (__predict_false(lock != so->so_lock))
solockretry(so, lock);
if (error != 0)
return error;
}
}
void
sbunlock(struct sockbuf *sb)
{
struct socket *so;
so = sb->sb_so;
KASSERT(solocked(so));
KASSERT((sb->sb_flags & SB_LOCK) != 0);
sb->sb_flags &= ~SB_LOCK;
cv_broadcast(&so->so_cv);
}
int
sowait(struct socket *so, bool catch, int timo)
{
kmutex_t *lock;
int error;
KASSERT(solocked(so));
KASSERT(catch || timo != 0);
lock = so->so_lock;
if (catch)
error = cv_timedwait_sig(&so->so_cv, lock, timo);
else
error = cv_timedwait(&so->so_cv, lock, timo);
if (__predict_false(lock != so->so_lock))
solockretry(so, lock);
return error;
}
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