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freebsd/sys/kern/uipc_accf.c
Alfred Perlstein 34b94e8b82 Accept filter maintainance
Update copyrights.

Introduce a new sysctl node:
  net.inet.accf

Although acceptfilters need refcounting to be properly (safely) unloaded
as a temporary hack allow them to be unloaded if the sysctl
net.inet.accf.unloadable is set, this is really for developers who want
to work on thier own filters.

A near complete re-write of the accf_http filter:
  1) Parse check if the request is HTTP/1.0 or HTTP/1.1 if not dump
     to the application.
     Because of the performance implications of this there is a sysctl
     'net.inet.accf.http.parsehttpversion' that when set to non-zero
     parses the HTTP version.
     The default is to parse the version.
  2) Check if a socket has filled and dump to the listener
  3) optimize the way that mbuf boundries are handled using some voodoo
  4) even though you'd expect accept filters to only be used on TCP
     connections that don't use m_nextpkt I've fixed the accept filter
     for socket connections that use this.

This rewrite of accf_http should allow someone to use them and maintain
full HTTP compliance as long as net.inet.accf.http.parsehttpversion is
set.
2000-09-06 18:49:13 +00:00

152 lines
4.1 KiB
C

/*
* Copyright (c) 2000 Paycounter, Inc.
* Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org>
* 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#define ACCEPT_FILTER_MOD
#include "opt_param.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/domain.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/queue.h>
static SLIST_HEAD(, accept_filter) accept_filtlsthd =
SLIST_HEAD_INITIALIZER(&accept_filtlsthd);
MALLOC_DEFINE(M_ACCF, "accf", "accept filter data");
static int unloadable = 0;
SYSCTL_DECL(_net_inet); /* XXX: some header should do this for me */
SYSCTL_NODE(_net_inet, OID_AUTO, accf, CTLFLAG_RW, 0, "Accept filters");
SYSCTL_INT(_net_inet_accf, OID_AUTO, unloadable, CTLFLAG_RW, &unloadable, 0,
"Allow unload of accept filters (not recommended)");
/*
* must be passed a malloc'd structure so we don't explode if the kld
* is unloaded, we leak the struct on deallocation to deal with this,
* but if a filter is loaded with the same name as a leaked one we re-use
* the entry.
*/
int
accept_filt_add(struct accept_filter *filt)
{
struct accept_filter *p;
SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
if (strcmp(p->accf_name, filt->accf_name) == 0) {
if (p->accf_callback != NULL) {
return (EEXIST);
} else {
p->accf_callback = filt->accf_callback;
FREE(filt, M_ACCF);
return (0);
}
}
if (p == NULL)
SLIST_INSERT_HEAD(&accept_filtlsthd, filt, accf_next);
return (0);
}
int
accept_filt_del(char *name)
{
struct accept_filter *p;
p = accept_filt_get(name);
if (p == NULL)
return (ENOENT);
p->accf_callback = NULL;
return (0);
}
struct accept_filter *
accept_filt_get(char *name)
{
struct accept_filter *p;
SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
if (strcmp(p->accf_name, name) == 0)
return (p);
return (NULL);
}
int
accept_filt_generic_mod_event(module_t mod, int event, void *data)
{
struct accept_filter *p;
struct accept_filter *accfp = (struct accept_filter *) data;
int s, error;
switch (event) {
case MOD_LOAD:
MALLOC(p, struct accept_filter *, sizeof(*p), M_ACCF, M_WAITOK);
bcopy(accfp, p, sizeof(*p));
s = splnet();
error = accept_filt_add(p);
splx(s);
break;
case MOD_UNLOAD:
/*
* Do not support unloading yet. we don't keep track of refcounts
* and unloading an accept filter callback and then having it called
* is a bad thing. A simple fix would be to track the refcount
* in the struct accept_filter.
*/
if (unloadable != 0) {
s = splnet();
error = accept_filt_del(accfp->accf_name);
splx(s);
} else
error = EOPNOTSUPP;
break;
case MOD_SHUTDOWN:
error = 0;
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}