dbb4756491
of a socket. This avoids lock order reversal caused by locking a process in pgsigio(). sowakeup() and the callers of it (sowwakeup, soisconnected, etc.) now require sigio_lock to be locked. Provide sowwakeup_locked(), soisconnected_locked(), and so on in case where we have to modify a socket and wake up a process atomically.
71 lines
2.1 KiB
C
71 lines
2.1 KiB
C
/*-
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* Copyright (c) 2000 Alfred Perlstein <alfred@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#define ACCEPT_FILTER_MOD
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#include <sys/param.h>
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#include <sys/sysctl.h>
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#include <sys/kernel.h>
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#include <sys/socketvar.h>
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/* accept filter that holds a socket until data arrives */
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static void sohasdata(struct socket *so, void *arg, int waitflag);
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static struct accept_filter accf_data_filter = {
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"dataready",
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sohasdata,
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NULL,
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NULL
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};
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static moduledata_t accf_data_mod = {
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"accf_data",
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accept_filt_generic_mod_event,
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&accf_data_filter
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};
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DECLARE_MODULE(accf_data, accf_data_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
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static void
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sohasdata(struct socket *so, void *arg, int waitflag)
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{
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SIGIO_SLOCK();
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if (!soreadable(so)) {
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SIGIO_SUNLOCK();
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return;
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}
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so->so_upcall = NULL;
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so->so_rcv.sb_flags &= ~SB_UPCALL;
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soisconnected_locked(so);
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SIGIO_SUNLOCK();
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return;
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}
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