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

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

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

1432 lines
35 KiB
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/*
* Copyright (c) 1982, 1986, 1988, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include "opt_param.h"
#include <sys/param.h>
#include <sys/aio.h> /* for aio_swake proto */
#include <sys/domain.h>
#include <sys/event.h>
#include <sys/file.h> /* for maxfiles */
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
int maxsockets;
void (*aio_swake)(struct socket *, struct sockbuf *);
/*
* Primitive routines for operating on sockets and socket buffers
*/
u_long sb_max = SB_MAX;
static u_long sb_max_adj =
SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
static u_long sb_efficiency = 8; /* parameter for sbreserve() */
/*
* 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(so)
register struct socket *so;
{
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISCONNECTING;
SOCK_UNLOCK(so);
}
void
soisconnected(so)
struct socket *so;
{
struct socket *head;
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
so->so_state |= SS_ISCONNECTED;
SOCK_UNLOCK(so);
ACCEPT_LOCK();
head = so->so_head;
if (head != NULL && (so->so_qstate & SQ_INCOMP)) {
if ((so->so_options & SO_ACCEPTFILTER) == 0) {
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();
SOCK_LOCK(so);
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;
SOCK_UNLOCK(so);
so->so_upcall(so, so->so_upcallarg, M_TRYWAIT);
}
return;
}
ACCEPT_UNLOCK();
wakeup(&so->so_timeo);
sorwakeup(so);
sowwakeup(so);
}
void
soisdisconnecting(so)
register struct socket *so;
{
/*
* XXXRW: This code separately acquires SOCK_LOCK(so) and
* SOCKBUF_LOCK(&so->so_rcv) even though they are the same mutex to
* avoid introducing the assumption that they are the same.
*/
SOCK_LOCK(so);
so->so_state &= ~SS_ISCONNECTING;
so->so_state |= SS_ISDISCONNECTING;
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sowwakeup_locked(so);
wakeup(&so->so_timeo);
}
void
soisdisconnected(so)
register struct socket *so;
{
/*
* XXXRW: This code separately acquires SOCK_LOCK(so) and
* SOCKBUF_LOCK(&so->so_rcv) even though they are the same mutex to
* avoid introducing the assumption that they are the same.
*/
/* XXXRW: so_state locking? */
SOCK_LOCK(so);
so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
so->so_state |= SS_ISDISCONNECTED;
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
sorwakeup_locked(so);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sbdrop_locked(&so->so_snd, so->so_snd.sb_cc);
sowwakeup_locked(so);
wakeup(&so->so_timeo);
}
/*
* When an attempt at a new connection is noted on a socket
* which accepts connections, sonewconn is called. If the
* connection is possible (subject to space constraints, etc.)
* then we allocate a new structure, propoerly linked into the
* data structure of the original socket, and return this.
* Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
*
* note: the ref count on the socket is 0 on return
*/
struct socket *
sonewconn(head, connstatus)
register struct socket *head;
int connstatus;
{
register struct socket *so;
int over;
ACCEPT_LOCK();
over = (head->so_qlen > 3 * head->so_qlimit / 2);
ACCEPT_UNLOCK();
if (over)
return ((struct socket *)0);
so = soalloc(M_NOWAIT);
if (so == NULL)
return ((struct socket *)0);
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_proto = head->so_proto;
so->so_timeo = head->so_timeo;
so->so_cred = crhold(head->so_cred);
#ifdef MAC
SOCK_LOCK(head);
mac_create_socket_from_socket(head, so);
SOCK_UNLOCK(head);
#endif
knlist_init(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
knlist_init(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat) ||
(*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
sodealloc(so);
return ((struct socket *)0);
}
ACCEPT_LOCK();
if (connstatus) {
TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
so->so_qstate |= SQ_COMP;
head->so_qlen++;
} else {
/*
* XXXRW: 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(&so->so_incomp, sp, so_list);
head->so_incqlen--;
sp->so_qstate &= ~SQ_INCOMP;
sp->so_head = NULL;
ACCEPT_UNLOCK();
(void) 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) {
so->so_state |= connstatus;
sorwakeup(head);
wakeup_one(&head->so_timeo);
}
return (so);
}
/*
* 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 PRU_SHUTDOWN). 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
socantsendmore_locked(so)
struct socket *so;
{
SOCKBUF_LOCK_ASSERT(&so->so_snd);
so->so_snd.sb_state |= SBS_CANTSENDMORE;
sowwakeup_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
}
void
socantsendmore(so)
struct socket *so;
{
SOCKBUF_LOCK(&so->so_snd);
socantsendmore_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_snd), MA_NOTOWNED);
}
void
socantrcvmore_locked(so)
struct socket *so;
{
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
so->so_rcv.sb_state |= SBS_CANTRCVMORE;
sorwakeup_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
void
socantrcvmore(so)
struct socket *so;
{
SOCKBUF_LOCK(&so->so_rcv);
socantrcvmore_locked(so);
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
/*
* Wait for data to arrive at/drain from a socket buffer.
*/
int
sbwait(sb)
struct sockbuf *sb;
{
SOCKBUF_LOCK_ASSERT(sb);
sb->sb_flags |= SB_WAIT;
return (msleep(&sb->sb_cc, &sb->sb_mtx,
(sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait",
sb->sb_timeo));
}
/*
* Lock a sockbuf already known to be locked;
* return any error returned from sleep (EINTR).
*/
int
sb_lock(sb)
register struct sockbuf *sb;
{
int error;
SOCKBUF_LOCK_ASSERT(sb);
while (sb->sb_flags & SB_LOCK) {
sb->sb_flags |= SB_WANT;
error = msleep(&sb->sb_flags, &sb->sb_mtx,
(sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK|PCATCH,
"sblock", 0);
if (error)
return (error);
}
sb->sb_flags |= SB_LOCK;
return (0);
}
/*
* Wakeup processes waiting on a socket buffer. Do asynchronous
* notification via SIGIO if the socket has the SS_ASYNC flag set.
*
* Called with the socket buffer lock held; will release the lock by the end
* of the function. This allows the caller to acquire the socket buffer lock
* while testing for the need for various sorts of wakeup and hold it through
* to the point where it's no longer required. We currently hold the lock
* through calls out to other subsystems (with the exception of kqueue), and
* then release it to avoid lock order issues. It's not clear that's
* correct.
*/
void
sowakeup(so, sb)
register struct socket *so;
register struct sockbuf *sb;
{
SOCKBUF_LOCK_ASSERT(sb);
selwakeuppri(&sb->sb_sel, PSOCK);
sb->sb_flags &= ~SB_SEL;
if (sb->sb_flags & SB_WAIT) {
sb->sb_flags &= ~SB_WAIT;
wakeup(&sb->sb_cc);
}
KNOTE_LOCKED(&sb->sb_sel.si_note, 0);
SOCKBUF_UNLOCK(sb);
if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
pgsigio(&so->so_sigio, SIGIO, 0);
if (sb->sb_flags & SB_UPCALL)
(*so->so_upcall)(so, so->so_upcallarg, M_DONTWAIT);
if (sb->sb_flags & SB_AIO)
aio_swake(so, sb);
mtx_assert(SOCKBUF_MTX(sb), MA_NOTOWNED);
}
/*
* 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 select() 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_RIGHTS).
* 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
soreserve(so, sndcc, rcvcc)
register struct socket *so;
u_long sndcc, rcvcc;
{
struct thread *td = curthread;
SOCKBUF_LOCK(&so->so_snd);
SOCKBUF_LOCK(&so->so_rcv);
if (sbreserve_locked(&so->so_snd, sndcc, so, td) == 0)
goto bad;
if (sbreserve_locked(&so->so_rcv, rcvcc, so, td) == 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 = MCLBYTES;
if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_snd);
return (0);
bad2:
sbrelease_locked(&so->so_snd, so);
bad:
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_UNLOCK(&so->so_snd);
return (ENOBUFS);
}
static int
sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
{
int error = 0;
u_long old_sb_max = sb_max;
error = SYSCTL_OUT(req, arg1, sizeof(u_long));
if (error || !req->newptr)
return (error);
error = SYSCTL_IN(req, arg1, sizeof(u_long));
if (error)
return (error);
if (sb_max < MSIZE + MCLBYTES) {
sb_max = old_sb_max;
return (EINVAL);
}
sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
return (0);
}
/*
* 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_locked(sb, cc, so, td)
struct sockbuf *sb;
u_long cc;
struct socket *so;
struct thread *td;
{
rlim_t sbsize_limit;
SOCKBUF_LOCK_ASSERT(sb);
/*
* td will only be NULL when we're in an interrupt
* (e.g. in tcp_input())
*/
if (cc > sb_max_adj)
return (0);
if (td != NULL) {
PROC_LOCK(td->td_proc);
sbsize_limit = lim_cur(td->td_proc, RLIMIT_SBSIZE);
PROC_UNLOCK(td->td_proc);
} else
sbsize_limit = RLIM_INFINITY;
if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
sbsize_limit))
return (0);
sb->sb_mbmax = min(cc * sb_efficiency, sb_max);
if (sb->sb_lowat > sb->sb_hiwat)
sb->sb_lowat = sb->sb_hiwat;
return (1);
}
int
sbreserve(sb, cc, so, td)
struct sockbuf *sb;
u_long cc;
struct socket *so;
struct thread *td;
{
int error;
SOCKBUF_LOCK(sb);
error = sbreserve_locked(sb, cc, so, td);
SOCKBUF_UNLOCK(sb);
return (error);
}
/*
* Free mbufs held by a socket, and reserved mbuf space.
*/
void
sbrelease_locked(sb, so)
struct sockbuf *sb;
struct socket *so;
{
SOCKBUF_LOCK_ASSERT(sb);
sbflush_locked(sb);
(void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
RLIM_INFINITY);
sb->sb_mbmax = 0;
}
void
sbrelease(sb, so)
struct sockbuf *sb;
struct socket *so;
{
SOCKBUF_LOCK(sb);
sbrelease_locked(sb, so);
SOCKBUF_UNLOCK(sb);
}
/*
* 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 *file, int line)
{
struct mbuf *m = sb->sb_mb;
SOCKBUF_LOCK_ASSERT(sb);
while (m && m->m_nextpkt)
m = m->m_nextpkt;
if (m != sb->sb_lastrecord) {
printf("%s: sb_mb %p sb_lastrecord %p last %p\n",
__func__, 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("%s from %s:%u", __func__, file, line);
}
}
void
sblastmbufchk(struct sockbuf *sb, const char *file, int line)
{
struct mbuf *m = sb->sb_mb;
struct mbuf *n;
SOCKBUF_LOCK_ASSERT(sb);
while (m && m->m_nextpkt)
m = m->m_nextpkt;
while (m && m->m_next)
m = m->m_next;
if (m != sb->sb_mbtail) {
printf("%s: sb_mb %p sb_mbtail %p last %p\n",
__func__, 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("%s from %s:%u", __func__, file, line);
}
}
#endif /* SOCKBUF_DEBUG */
#define SBLINKRECORD(sb, m0) do { \
SOCKBUF_LOCK_ASSERT(sb); \
if ((sb)->sb_lastrecord != NULL) \
(sb)->sb_lastrecord->m_nextpkt = (m0); \
else \
(sb)->sb_mb = (m0); \
(sb)->sb_lastrecord = (m0); \
} while (/*CONSTCOND*/0)
/*
* 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_locked(sb, m)
struct sockbuf *sb;
struct mbuf *m;
{
register struct mbuf *n;
SOCKBUF_LOCK_ASSERT(sb);
if (m == 0)
return;
SBLASTRECORDCHK(sb);
n = sb->sb_mb;
if (n) {
while (n->m_nextpkt)
n = n->m_nextpkt;
do {
if (n->m_flags & M_EOR) {
sbappendrecord_locked(sb, m); /* XXXXXX!!!! */
return;
}
} while (n->m_next && (n = n->m_next));
} else {
/*
* 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.
*/
if ((n = sb->sb_lastrecord) != NULL) {
do {
if (n->m_flags & M_EOR) {
sbappendrecord_locked(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);
}
/*
* 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(sb, m)
struct sockbuf *sb;
struct mbuf *m;
{
SOCKBUF_LOCK(sb);
sbappend_locked(sb, m);
SOCKBUF_UNLOCK(sb);
}
/*
* 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_locked(struct sockbuf *sb, struct mbuf *m)
{
SOCKBUF_LOCK_ASSERT(sb);
KASSERT(m->m_nextpkt == NULL,("sbappendstream 0"));
KASSERT(sb->sb_mb == sb->sb_lastrecord,("sbappendstream 1"));
SBLASTMBUFCHK(sb);
sbcompress(sb, m, sb->sb_mbtail);
sb->sb_lastrecord = sb->sb_mb;
SBLASTRECORDCHK(sb);
}
/*
* 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)
{
SOCKBUF_LOCK(sb);
sbappendstream_locked(sb, m);
SOCKBUF_UNLOCK(sb);
}
#ifdef SOCKBUF_DEBUG
void
sbcheck(sb)
struct sockbuf *sb;
{
struct mbuf *m;
struct mbuf *n = 0;
u_long len = 0, mbcnt = 0;
SOCKBUF_LOCK_ASSERT(sb);
for (m = sb->sb_mb; m; m = n) {
n = m->m_nextpkt;
for (; m; m = m->m_next) {
len += m->m_len;
mbcnt += MSIZE;
if (m->m_flags & M_EXT) /*XXX*/ /* pretty sure this is bogus */
mbcnt += m->m_ext.ext_size;
}
}
if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
printf("cc %ld != %u || mbcnt %ld != %u\n", len, sb->sb_cc,
mbcnt, sb->sb_mbcnt);
panic("sbcheck");
}
}
#endif
/*
* As above, except the mbuf chain
* begins a new record.
*/
void
sbappendrecord_locked(sb, m0)
register struct sockbuf *sb;
register struct mbuf *m0;
{
register struct mbuf *m;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 == 0)
return;
m = sb->sb_mb;
if (m)
while (m->m_nextpkt)
m = m->m_nextpkt;
/*
* Put the first mbuf on the queue.
* Note this permits zero length records.
*/
sballoc(sb, m0);
SBLASTRECORDCHK(sb);
SBLINKRECORD(sb, m0);
if (m)
m->m_nextpkt = m0;
else
sb->sb_mb = 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);
}
/*
* As above, except the mbuf chain
* begins a new record.
*/
void
sbappendrecord(sb, m0)
register struct sockbuf *sb;
register struct mbuf *m0;
{
SOCKBUF_LOCK(sb);
sbappendrecord_locked(sb, m0);
SOCKBUF_UNLOCK(sb);
}
/*
* As above except that OOB data
* is inserted at the beginning of the sockbuf,
* but after any other OOB data.
*/
void
sbinsertoob_locked(sb, m0)
register struct sockbuf *sb;
register struct mbuf *m0;
{
register struct mbuf *m;
register struct mbuf **mp;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 == 0)
return;
for (mp = &sb->sb_mb; *mp ; mp = &((*mp)->m_nextpkt)) {
m = *mp;
again:
switch (m->m_type) {
case MT_OOBDATA:
continue; /* WANT next train */
case MT_CONTROL:
m = m->m_next;
if (m)
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;
*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);
}
/*
* As above except that OOB data
* is inserted at the beginning of the sockbuf,
* but after any other OOB data.
*/
void
sbinsertoob(sb, m0)
register struct sockbuf *sb;
register struct mbuf *m0;
{
SOCKBUF_LOCK(sb);
sbinsertoob_locked(sb, m0);
SOCKBUF_UNLOCK(sb);
}
/*
* 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_locked(sb, asa, m0, control)
struct sockbuf *sb;
const struct sockaddr *asa;
struct mbuf *m0, *control;
{
struct mbuf *m, *n, *nlast;
int space = asa->sa_len;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr_locked");
if (m0)
space += m0->m_pkthdr.len;
space += m_length(control, &n);
if (space > sbspace(sb))
return (0);
#if MSIZE <= 256
if (asa->sa_len > MLEN)
return (0);
#endif
MGET(m, M_DONTWAIT, MT_SONAME);
if (m == 0)
return (0);
m->m_len = asa->sa_len;
bcopy(asa, mtod(m, caddr_t), asa->sa_len);
if (n)
n->m_next = m0; /* concatenate data to control */
else
control = m0;
m->m_next = control;
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);
SBLASTRECORDCHK(sb);
return (1);
}
/*
* 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(sb, asa, m0, control)
struct sockbuf *sb;
const struct sockaddr *asa;
struct mbuf *m0, *control;
{
int retval;
SOCKBUF_LOCK(sb);
retval = sbappendaddr_locked(sb, asa, m0, control);
SOCKBUF_UNLOCK(sb);
return (retval);
}
int
sbappendcontrol_locked(sb, m0, control)
struct sockbuf *sb;
struct mbuf *control, *m0;
{
struct mbuf *m, *n, *mlast;
int space;
SOCKBUF_LOCK_ASSERT(sb);
if (control == 0)
panic("sbappendcontrol_locked");
space = m_length(control, &n) + m_length(m0, NULL);
if (space > sbspace(sb))
return (0);
n->m_next = m0; /* concatenate data to control */
SBLASTRECORDCHK(sb);
for (m = control; m->m_next; m = m->m_next)
sballoc(sb, m);
sballoc(sb, m);
mlast = m;
SBLINKRECORD(sb, control);
sb->sb_mbtail = mlast;
SBLASTMBUFCHK(sb);
SBLASTRECORDCHK(sb);
return (1);
}
int
sbappendcontrol(sb, m0, control)
struct sockbuf *sb;
struct mbuf *control, *m0;
{
int retval;
SOCKBUF_LOCK(sb);
retval = sbappendcontrol_locked(sb, m0, control);
SOCKBUF_UNLOCK(sb);
return (retval);
}
/*
* Compress mbuf chain m into the socket
* buffer sb following mbuf n. If n
* is null, the buffer is presumed empty.
*/
void
sbcompress(sb, m, n)
register struct sockbuf *sb;
register struct mbuf *m, *n;
{
register int eor = 0;
register struct mbuf *o;
SOCKBUF_LOCK_ASSERT(sb);
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_WRITABLE(n) &&
m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
m->m_len <= M_TRAILINGSPACE(n) &&
n->m_type == m->m_type) {
bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
(unsigned)m->m_len);
n->m_len += m->m_len;
sb->sb_cc += m->m_len;
if (m->m_type != MT_DATA && m->m_type != MT_HEADER &&
m->m_type != MT_OOBDATA)
/* XXX: Probably don't need.*/
sb->sb_ctl += 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);
}
/*
* Free all mbufs in a sockbuf.
* Check that all resources are reclaimed.
*/
void
sbflush_locked(sb)
register struct sockbuf *sb;
{
SOCKBUF_LOCK_ASSERT(sb);
if (sb->sb_flags & SB_LOCK)
panic("sbflush_locked: locked");
while (sb->sb_mbcnt) {
/*
* Don't call sbdrop(sb, 0) if the leading mbuf is non-empty:
* we would loop forever. Panic instead.
*/
if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len))
break;
sbdrop_locked(sb, (int)sb->sb_cc);
}
if (sb->sb_cc || sb->sb_mb || sb->sb_mbcnt)
panic("sbflush_locked: cc %u || mb %p || mbcnt %u", sb->sb_cc, (void *)sb->sb_mb, sb->sb_mbcnt);
}
void
sbflush(sb)
register struct sockbuf *sb;
{
SOCKBUF_LOCK(sb);
sbflush_locked(sb);
SOCKBUF_UNLOCK(sb);
}
/*
* Drop data from (the front of) a sockbuf.
*/
void
sbdrop_locked(sb, len)
register struct sockbuf *sb;
register int len;
{
register struct mbuf *m;
struct mbuf *next;
SOCKBUF_LOCK_ASSERT(sb);
next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
while (len > 0) {
if (m == 0) {
if (next == 0)
panic("sbdrop");
m = next;
next = m->m_nextpkt;
continue;
}
if (m->m_len > len) {
m->m_len -= len;
m->m_data += len;
sb->sb_cc -= len;
if (m->m_type != MT_DATA && m->m_type != MT_HEADER &&
m->m_type != MT_OOBDATA)
sb->sb_ctl -= len;
break;
}
len -= m->m_len;
sbfree(sb, m);
m = m_free(m);
}
while (m && m->m_len == 0) {
sbfree(sb, m);
m = m_free(m);
}
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 data from (the front of) a sockbuf.
*/
void
sbdrop(sb, len)
register struct sockbuf *sb;
register int len;
{
SOCKBUF_LOCK(sb);
sbdrop_locked(sb, len);
SOCKBUF_UNLOCK(sb);
}
/*
* Drop a record off the front of a sockbuf
* and move the next record to the front.
*/
void
sbdroprecord_locked(sb)
register struct sockbuf *sb;
{
register struct mbuf *m;
SOCKBUF_LOCK_ASSERT(sb);
m = sb->sb_mb;
if (m) {
sb->sb_mb = m->m_nextpkt;
do {
sbfree(sb, m);
m = m_free(m);
} while (m);
}
SB_EMPTY_FIXUP(sb);
}
/*
* Drop a record off the front of a sockbuf
* and move the next record to the front.
*/
void
sbdroprecord(sb)
register struct sockbuf *sb;
{
SOCKBUF_LOCK(sb);
sbdroprecord_locked(sb);
SOCKBUF_UNLOCK(sb);
}
/*
* Create a "control" mbuf containing the specified data
* with the specified type for presentation on a socket buffer.
*/
struct mbuf *
sbcreatecontrol(p, size, type, level)
caddr_t p;
register int size;
int type, level;
{
register struct cmsghdr *cp;
struct mbuf *m;
if (CMSG_SPACE((u_int)size) > MCLBYTES)
return ((struct mbuf *) NULL);
if (CMSG_SPACE((u_int)size > MLEN))
m = m_getcl(M_DONTWAIT, MT_CONTROL, 0);
else
m = m_get(M_DONTWAIT, MT_CONTROL);
if (m == NULL)
return ((struct mbuf *) NULL);
cp = mtod(m, struct cmsghdr *);
m->m_len = 0;
KASSERT(CMSG_SPACE((u_int)size) <= M_TRAILINGSPACE(m),
("sbcreatecontrol: short mbuf"));
if (p != NULL)
(void)memcpy(CMSG_DATA(cp), p, size);
m->m_len = CMSG_SPACE(size);
cp->cmsg_len = CMSG_LEN(size);
cp->cmsg_level = level;
cp->cmsg_type = type;
return (m);
}
/*
* 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_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_connect2_notsupp(struct socket *so1, struct socket *so2)
{
return EOPNOTSUPP;
}
int
pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
struct ifnet *ifp, struct thread *td)
{
return EOPNOTSUPP;
}
int
pru_listen_notsupp(struct socket *so, struct thread *td)
{
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;
}
/*
* 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;
}
/*
* For protocol types that don't keep cached copies of labels in their
* pcbs, provide a null sosetlabel that does a NOOP.
*/
void
pru_sosetlabel_null(struct socket *so)
{
}
/*
* 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;
}
/*
* 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;
}
/*
* This does the same for sockbufs. Note that the xsockbuf structure,
* since it is always embedded in a socket, does not include a self
* pointer nor a length. We make this entry point public in case
* some other mechanism needs it.
*/
void
sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
{
xsb->sb_cc = sb->sb_cc;
xsb->sb_hiwat = sb->sb_hiwat;
xsb->sb_mbcnt = sb->sb_mbcnt;
xsb->sb_mbmax = sb->sb_mbmax;
xsb->sb_lowat = sb->sb_lowat;
xsb->sb_flags = sb->sb_flags;
xsb->sb_timeo = sb->sb_timeo;
}
/*
* Here is the definition of some of the basic objects in the kern.ipc
* branch of the MIB.
*/
SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
/* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
static int dummy;
SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_ULONG|CTLFLAG_RW,
&sb_max, 0, sysctl_handle_sb_max, "LU", "Maximum socket buffer size");
SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RDTUN,
&maxsockets, 0, "Maximum number of sockets avaliable");
SYSCTL_ULONG(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
&sb_efficiency, 0, "");
/*
* Initialise maxsockets
*/
static void init_maxsockets(void *ignored)
{
TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters));
}
SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
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