freebsd-dev/sys/kern/uipc_domain.c
2022-08-26 10:35:35 -07:00

496 lines
11 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 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_domain.c 8.2 (Berkeley) 10/18/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/eventhandler.h>
#include <sys/epoch.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rmlock.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <machine/atomic.h>
#include <net/vnet.h>
/*
* System initialization
*
* Note: domain initialization takes place on a per domain basis
* as a result of traversing a SYSINIT linker set. Most likely,
* each domain would want to call DOMAIN_SET(9) itself, which
* would cause the domain to be added just after domaininit()
* is called during startup.
*
* See DOMAIN_SET(9) for details on its use.
*/
static void domaininit(void *);
SYSINIT(domain, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, domaininit, NULL);
static void domainfinalize(void *);
SYSINIT(domainfin, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST, domainfinalize,
NULL);
struct domain *domains; /* registered protocol domains */
int domain_init_status = 0;
static struct mtx dom_mtx; /* domain list lock */
MTX_SYSINIT(domain, &dom_mtx, "domain list", MTX_DEF);
static int
pr_accept_notsupp(struct socket *so, struct sockaddr **nam)
{
return (EOPNOTSUPP);
}
static int
pr_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
{
return (EOPNOTSUPP);
}
static int
pr_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_connect2_notsupp(struct socket *so1, struct socket *so2)
{
return (EOPNOTSUPP);
}
static int
pr_control_notsupp(struct socket *so, u_long cmd, void *data,
struct ifnet *ifp, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_disconnect_notsupp(struct socket *so)
{
return (EOPNOTSUPP);
}
static int
pr_listen_notsupp(struct socket *so, int backlog, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
{
return (EOPNOTSUPP);
}
static int
pr_rcvd_notsupp(struct socket *so, int flags)
{
return (EOPNOTSUPP);
}
static int
pr_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
{
return (EOPNOTSUPP);
}
static int
pr_send_notsupp(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *addr, struct mbuf *control, struct thread *td)
{
if (control != NULL)
m_freem(control);
if ((flags & PRUS_NOTREADY) == 0)
m_freem(m);
return (EOPNOTSUPP);
}
static int
pr_ready_notsupp(struct socket *so, struct mbuf *m, int count)
{
return (EOPNOTSUPP);
}
static int
pr_shutdown_notsupp(struct socket *so)
{
return (EOPNOTSUPP);
}
static int
pr_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
{
return (EOPNOTSUPP);
}
static int
pr_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
pr_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
return (EOPNOTSUPP);
}
static int
pr_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
struct thread *td)
{
return (EOPNOTSUPP);
}
static void
pr_init(struct protosw *pr)
{
KASSERT(pr->pr_attach != NULL,
("%s: protocol doesn't have pr_attach", __func__));
#define DEFAULT(foo, bar) if (pr->foo == NULL) pr->foo = bar
DEFAULT(pr_sosend, sosend_generic);
DEFAULT(pr_soreceive, soreceive_generic);
DEFAULT(pr_sopoll, sopoll_generic);
#define NOTSUPP(foo) if (pr->foo == NULL) pr->foo = foo ## _notsupp
NOTSUPP(pr_accept);
NOTSUPP(pr_aio_queue);
NOTSUPP(pr_bind);
NOTSUPP(pr_bindat);
NOTSUPP(pr_connect);
NOTSUPP(pr_connect2);
NOTSUPP(pr_connectat);
NOTSUPP(pr_control);
NOTSUPP(pr_disconnect);
NOTSUPP(pr_listen);
NOTSUPP(pr_peeraddr);
NOTSUPP(pr_rcvd);
NOTSUPP(pr_rcvoob);
NOTSUPP(pr_send);
NOTSUPP(pr_shutdown);
NOTSUPP(pr_sockaddr);
NOTSUPP(pr_sosend);
NOTSUPP(pr_soreceive);
NOTSUPP(pr_sopoll);
NOTSUPP(pr_ready);
}
/*
* Add a new protocol domain to the list of supported domains
* Note: you cant unload it again because a socket may be using it.
* XXX can't fail at this time.
*/
void
domain_init(struct domain *dp)
{
struct protosw *pr;
int flags;
MPASS(IS_DEFAULT_VNET(curvnet));
flags = atomic_load_acq_int(&dp->dom_flags);
if ((flags & DOMF_SUPPORTED) == 0)
return;
MPASS((flags & DOMF_INITED) == 0);
for (int i = 0; i < dp->dom_nprotosw; i++)
if ((pr = dp->dom_protosw[i]) != NULL) {
pr->pr_domain = dp;
pr_init(pr);
}
/*
* update global information about maximums
*/
max_hdr = max_linkhdr + max_protohdr;
max_datalen = MHLEN - max_hdr;
if (max_datalen < 1)
panic("%s: max_datalen < 1", __func__);
atomic_set_rel_int(&dp->dom_flags, DOMF_INITED);
}
/*
* Add a new protocol domain to the list of supported domains
* Note: you cant unload it again because a socket may be using it.
* XXX can't fail at this time.
*/
void
domain_add(struct domain *dp)
{
if (dp->dom_probe != NULL && (*dp->dom_probe)() != 0)
return;
atomic_set_rel_int(&dp->dom_flags, DOMF_SUPPORTED);
mtx_lock(&dom_mtx);
dp->dom_next = domains;
domains = dp;
KASSERT(domain_init_status >= 1,
("attempt to domain_add(%s) before domaininit()",
dp->dom_name));
#ifndef INVARIANTS
if (domain_init_status < 1)
printf("WARNING: attempt to domain_add(%s) before "
"domaininit()\n", dp->dom_name);
#endif
mtx_unlock(&dom_mtx);
}
void
domain_remove(struct domain *dp)
{
if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
return;
mtx_lock(&dom_mtx);
if (domains == dp) {
domains = dp->dom_next;
} else {
struct domain *curr;
for (curr = domains; curr != NULL; curr = curr->dom_next) {
if (curr->dom_next == dp) {
curr->dom_next = dp->dom_next;
break;
}
}
}
mtx_unlock(&dom_mtx);
}
/* ARGSUSED*/
static void
domaininit(void *dummy)
{
if (max_linkhdr < 16) /* XXX */
max_linkhdr = 16;
mtx_lock(&dom_mtx);
KASSERT(domain_init_status == 0, ("domaininit called too late!"));
domain_init_status = 1;
mtx_unlock(&dom_mtx);
}
/* ARGSUSED*/
static void
domainfinalize(void *dummy)
{
mtx_lock(&dom_mtx);
KASSERT(domain_init_status == 1, ("domainfinalize called too late!"));
domain_init_status = 2;
mtx_unlock(&dom_mtx);
}
struct domain *
pffinddomain(int family)
{
struct domain *dp;
for (dp = domains; dp != NULL; dp = dp->dom_next)
if (dp->dom_family == family)
return (dp);
return (NULL);
}
struct protosw *
pffindtype(int family, int type)
{
struct domain *dp;
struct protosw *pr;
dp = pffinddomain(family);
if (dp == NULL)
return (NULL);
for (int i = 0; i < dp->dom_nprotosw; i++)
if ((pr = dp->dom_protosw[i]) != NULL && pr->pr_type == type)
return (pr);
return (NULL);
}
struct protosw *
pffindproto(int family, int protocol, int type)
{
struct domain *dp;
struct protosw *pr;
struct protosw *maybe;
dp = pffinddomain(family);
if (dp == NULL)
return (NULL);
maybe = NULL;
for (int i = 0; i < dp->dom_nprotosw; i++) {
if ((pr = dp->dom_protosw[i]) == NULL)
continue;
if ((pr->pr_protocol == protocol) && (pr->pr_type == type))
return (pr);
/* XXX: raw catches all. Why? */
if (type == SOCK_RAW && pr->pr_type == SOCK_RAW &&
pr->pr_protocol == 0 && maybe == NULL)
maybe = pr;
}
return (maybe);
}
/*
* The caller must make sure that the new protocol is fully set up and ready to
* accept requests before it is registered.
*/
int
protosw_register(struct domain *dp, struct protosw *npr)
{
struct protosw **prp;
MPASS(dp);
MPASS(npr && npr->pr_type > 0 && npr->pr_protocol > 0);
prp = NULL;
/*
* Protect us against races when two protocol registrations for
* the same protocol happen at the same time.
*/
mtx_lock(&dom_mtx);
for (int i = 0; i < dp->dom_nprotosw; i++) {
if (dp->dom_protosw[i] == NULL) {
/* Remember the first free spacer. */
if (prp == NULL)
prp = &dp->dom_protosw[i];
} else {
/*
* The new protocol must not yet exist.
* XXXAO: Check only protocol?
* XXXGL: Maybe assert that it doesn't exist?
*/
if ((dp->dom_protosw[i]->pr_type == npr->pr_type) &&
(dp->dom_protosw[i]->pr_protocol ==
npr->pr_protocol)) {
mtx_unlock(&dom_mtx);
return (EEXIST);
}
}
}
/* If no free spacer is found we can't add the new protocol. */
if (prp == NULL) {
mtx_unlock(&dom_mtx);
return (ENOMEM);
}
npr->pr_domain = dp;
pr_init(npr);
*prp = npr;
mtx_unlock(&dom_mtx);
return (0);
}
/*
* The caller must make sure the protocol and its functions correctly shut down
* all sockets and release all locks and memory references.
*/
int
protosw_unregister(struct protosw *pr)
{
struct domain *dp;
struct protosw **prp;
dp = pr->pr_domain;
prp = NULL;
mtx_lock(&dom_mtx);
/* The protocol must exist and only once. */
for (int i = 0; i < dp->dom_nprotosw; i++) {
if (dp->dom_protosw[i] == pr) {
KASSERT(prp == NULL,
("%s: domain %p protocol %p registered twice\n",
__func__, dp, pr));
prp = &dp->dom_protosw[i];
}
}
/* Protocol does not exist. XXXGL: assert that it does? */
if (prp == NULL) {
mtx_unlock(&dom_mtx);
return (EPROTONOSUPPORT);
}
/* De-orbit the protocol and make the slot available again. */
*prp = NULL;
mtx_unlock(&dom_mtx);
return (0);
}