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freebsd/sys/kern/uipc_accf.c
Pedro F. Giffuni 8a36da99de sys/kern: adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:20:12 +00:00

309 lines
8.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000 Paycounter, Inc.
* Copyright (c) 2005 Robert N. M. Watson
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/protosw.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/queue.h>
static struct mtx accept_filter_mtx;
MTX_SYSINIT(accept_filter, &accept_filter_mtx, "accept_filter_mtx",
MTX_DEF);
#define ACCEPT_FILTER_LOCK() mtx_lock(&accept_filter_mtx)
#define ACCEPT_FILTER_UNLOCK() mtx_unlock(&accept_filter_mtx)
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_NODE(_net, OID_AUTO, accf, CTLFLAG_RW, 0, "Accept filters");
SYSCTL_INT(_net_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;
ACCEPT_FILTER_LOCK();
SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
if (strcmp(p->accf_name, filt->accf_name) == 0) {
if (p->accf_callback != NULL) {
ACCEPT_FILTER_UNLOCK();
return (EEXIST);
} else {
p->accf_callback = filt->accf_callback;
ACCEPT_FILTER_UNLOCK();
free(filt, M_ACCF);
return (0);
}
}
if (p == NULL)
SLIST_INSERT_HEAD(&accept_filtlsthd, filt, accf_next);
ACCEPT_FILTER_UNLOCK();
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;
ACCEPT_FILTER_LOCK();
SLIST_FOREACH(p, &accept_filtlsthd, accf_next)
if (strcmp(p->accf_name, name) == 0)
break;
ACCEPT_FILTER_UNLOCK();
return (p);
}
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 error;
switch (event) {
case MOD_LOAD:
p = malloc(sizeof(*p), M_ACCF, M_WAITOK);
bcopy(accfp, p, sizeof(*p));
error = accept_filt_add(p);
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) {
error = accept_filt_del(accfp->accf_name);
} else
error = EOPNOTSUPP;
break;
case MOD_SHUTDOWN:
error = 0;
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
int
accept_filt_getopt(struct socket *so, struct sockopt *sopt)
{
struct accept_filter_arg *afap;
int error;
error = 0;
afap = malloc(sizeof(*afap), M_TEMP, M_WAITOK | M_ZERO);
SOCK_LOCK(so);
if ((so->so_options & SO_ACCEPTCONN) == 0) {
error = EINVAL;
goto out;
}
if (so->sol_accept_filter == NULL) {
error = EINVAL;
goto out;
}
strcpy(afap->af_name, so->sol_accept_filter->accf_name);
if (so->sol_accept_filter_str != NULL)
strcpy(afap->af_arg, so->sol_accept_filter_str);
out:
SOCK_UNLOCK(so);
if (error == 0)
error = sooptcopyout(sopt, afap, sizeof(*afap));
free(afap, M_TEMP);
return (error);
}
int
accept_filt_setopt(struct socket *so, struct sockopt *sopt)
{
struct accept_filter_arg *afap;
struct accept_filter *afp;
char *accept_filter_str = NULL;
void *accept_filter_arg = NULL;
int error;
/*
* Handle the simple delete case first.
*/
if (sopt == NULL || sopt->sopt_val == NULL) {
struct socket *sp, *sp1;
int wakeup;
SOCK_LOCK(so);
if ((so->so_options & SO_ACCEPTCONN) == 0) {
SOCK_UNLOCK(so);
return (EINVAL);
}
if (so->sol_accept_filter == NULL) {
SOCK_UNLOCK(so);
return (0);
}
if (so->sol_accept_filter->accf_destroy != NULL)
so->sol_accept_filter->accf_destroy(so);
if (so->sol_accept_filter_str != NULL)
free(so->sol_accept_filter_str, M_ACCF);
so->sol_accept_filter = NULL;
so->sol_accept_filter_arg = NULL;
so->sol_accept_filter_str = NULL;
so->so_options &= ~SO_ACCEPTFILTER;
/*
* Move from incomplete queue to complete only those
* connections, that are blocked by us.
*/
wakeup = 0;
TAILQ_FOREACH_SAFE(sp, &so->sol_incomp, so_list, sp1) {
SOCK_LOCK(sp);
if (sp->so_options & SO_ACCEPTFILTER) {
TAILQ_REMOVE(&so->sol_incomp, sp, so_list);
TAILQ_INSERT_TAIL(&so->sol_comp, sp, so_list);
sp->so_qstate = SQ_COMP;
sp->so_options &= ~SO_ACCEPTFILTER;
so->sol_incqlen--;
so->sol_qlen++;
wakeup = 1;
}
SOCK_UNLOCK(sp);
}
if (wakeup)
solisten_wakeup(so); /* unlocks */
else
SOLISTEN_UNLOCK(so);
return (0);
}
/*
* Pre-allocate any memory we may need later to avoid blocking at
* untimely moments. This does not optimize for invalid arguments.
*/
afap = malloc(sizeof(*afap), M_TEMP, M_WAITOK);
error = sooptcopyin(sopt, afap, sizeof *afap, sizeof *afap);
afap->af_name[sizeof(afap->af_name)-1] = '\0';
afap->af_arg[sizeof(afap->af_arg)-1] = '\0';
if (error) {
free(afap, M_TEMP);
return (error);
}
afp = accept_filt_get(afap->af_name);
if (afp == NULL) {
free(afap, M_TEMP);
return (ENOENT);
}
if (afp->accf_create != NULL && afap->af_name[0] != '\0') {
size_t len = strlen(afap->af_name) + 1;
accept_filter_str = malloc(len, M_ACCF, M_WAITOK);
strcpy(accept_filter_str, afap->af_name);
}
/*
* Require a listen socket; don't try to replace an existing filter
* without first removing it.
*/
SOCK_LOCK(so);
if ((so->so_options & SO_ACCEPTCONN) == 0 ||
so->sol_accept_filter != NULL) {
error = EINVAL;
goto out;
}
/*
* Invoke the accf_create() method of the filter if required. The
* socket mutex is held over this call, so create methods for filters
* can't block.
*/
if (afp->accf_create != NULL) {
accept_filter_arg = afp->accf_create(so, afap->af_arg);
if (accept_filter_arg == NULL) {
error = EINVAL;
goto out;
}
}
so->sol_accept_filter = afp;
so->sol_accept_filter_arg = accept_filter_arg;
so->sol_accept_filter_str = accept_filter_str;
so->so_options |= SO_ACCEPTFILTER;
out:
SOCK_UNLOCK(so);
if (accept_filter_str != NULL)
free(accept_filter_str, M_ACCF);
free(afap, M_TEMP);
return (error);
}