freebsd-skq/sys/net/raw_usrreq.c
Alexander V. Chernikov 4a01b854ca SO_RERROR indicates that receive buffer overflows should be handled as errors.
Historically receive buffer overflows have been ignored and programs
could not tell if they missed messages or messages had been truncated
because of overflows. Since programs historically do not expect to get
receive overflow errors, this behavior is not the default.

This is really really important for programs that use route(4) to keep in sync
with the system. If we loose a message then we need to reload the full system
state, otherwise the behaviour from that point is undefined and can lead
to chasing bogus bug reports.
2021-02-08 21:42:20 +00:00

279 lines
6.3 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1980, 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.
*
* @(#)raw_usrreq.c 8.1 (Berkeley) 6/10/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <net/if.h>
#include <net/vnet.h>
#include <net/raw_cb.h>
MTX_SYSINIT(rawcb_mtx, &rawcb_mtx, "rawcb", MTX_DEF);
/*
* Initialize raw connection block q.
*/
void
raw_init(void)
{
LIST_INIT(&V_rawcb_list);
}
/*
* Raw protocol input routine. Find the socket associated with the packet(s)
* and move them over. If nothing exists for this packet, drop it.
*/
/*
* Raw protocol interface.
*/
void
raw_input(struct mbuf *m0, struct sockproto *proto, struct sockaddr *src)
{
return (raw_input_ext(m0, proto, src, NULL));
}
void
raw_input_ext(struct mbuf *m0, struct sockproto *proto, struct sockaddr *src,
raw_input_cb_fn cb)
{
struct rawcb *rp;
struct mbuf *m = m0;
struct socket *last;
last = NULL;
mtx_lock(&rawcb_mtx);
LIST_FOREACH(rp, &V_rawcb_list, list) {
if (rp->rcb_proto.sp_family != proto->sp_family)
continue;
if (rp->rcb_proto.sp_protocol &&
rp->rcb_proto.sp_protocol != proto->sp_protocol)
continue;
if (cb != NULL && (*cb)(m, proto, src, rp) != 0)
continue;
if (last) {
struct mbuf *n;
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
if (n) {
if (sbappendaddr(&last->so_rcv, src,
n, (struct mbuf *)0) == 0) {
soroverflow(last);
m_freem(n);
} else
sorwakeup(last);
}
}
last = rp->rcb_socket;
}
if (last) {
if (sbappendaddr(&last->so_rcv, src,
m, (struct mbuf *)0) == 0) {
soroverflow(last);
m_freem(m);
} else
sorwakeup(last);
} else
m_freem(m);
mtx_unlock(&rawcb_mtx);
}
/*ARGSUSED*/
void
raw_ctlinput(int cmd, struct sockaddr *arg, void *dummy)
{
if (cmd < 0 || cmd >= PRC_NCMDS)
return;
/* INCOMPLETE */
}
static void
raw_uabort(struct socket *so)
{
KASSERT(sotorawcb(so) != NULL, ("raw_uabort: rp == NULL"));
soisdisconnected(so);
}
static void
raw_uclose(struct socket *so)
{
KASSERT(sotorawcb(so) != NULL, ("raw_uabort: rp == NULL"));
soisdisconnected(so);
}
/* pru_accept is EOPNOTSUPP */
static int
raw_uattach(struct socket *so, int proto, struct thread *td)
{
int error;
/*
* Implementors of raw sockets will already have allocated the PCB,
* so it must be non-NULL here.
*/
KASSERT(sotorawcb(so) != NULL, ("raw_uattach: so_pcb == NULL"));
if (td != NULL) {
error = priv_check(td, PRIV_NET_RAW);
if (error)
return (error);
}
return (raw_attach(so, proto));
}
static int
raw_ubind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (EINVAL);
}
static int
raw_uconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
return (EINVAL);
}
/* pru_connect2 is EOPNOTSUPP */
/* pru_control is EOPNOTSUPP */
static void
raw_udetach(struct socket *so)
{
struct rawcb *rp = sotorawcb(so);
KASSERT(rp != NULL, ("raw_udetach: rp == NULL"));
raw_detach(rp);
}
static int
raw_udisconnect(struct socket *so)
{
KASSERT(sotorawcb(so) != NULL, ("raw_udisconnect: rp == NULL"));
return (ENOTCONN);
}
/* pru_listen is EOPNOTSUPP */
static int
raw_upeeraddr(struct socket *so, struct sockaddr **nam)
{
KASSERT(sotorawcb(so) != NULL, ("raw_upeeraddr: rp == NULL"));
return (ENOTCONN);
}
/* pru_rcvd is EOPNOTSUPP */
/* pru_rcvoob is EOPNOTSUPP */
static int
raw_usend(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
struct mbuf *control, struct thread *td)
{
KASSERT(sotorawcb(so) != NULL, ("raw_usend: rp == NULL"));
if ((flags & PRUS_OOB) || (control && control->m_len)) {
if (m != NULL)
m_freem(m);
if (control != NULL)
m_freem(control);
return (EOPNOTSUPP);
}
/*
* For historical (bad?) reasons, we effectively ignore the address
* argument to sendto(2). Perhaps we should return an error instead?
*/
return ((*so->so_proto->pr_output)(m, so));
}
/* pru_sense is null */
static int
raw_ushutdown(struct socket *so)
{
KASSERT(sotorawcb(so) != NULL, ("raw_ushutdown: rp == NULL"));
socantsendmore(so);
return (0);
}
static int
raw_usockaddr(struct socket *so, struct sockaddr **nam)
{
KASSERT(sotorawcb(so) != NULL, ("raw_usockaddr: rp == NULL"));
return (EINVAL);
}
struct pr_usrreqs raw_usrreqs = {
.pru_abort = raw_uabort,
.pru_attach = raw_uattach,
.pru_bind = raw_ubind,
.pru_connect = raw_uconnect,
.pru_detach = raw_udetach,
.pru_disconnect = raw_udisconnect,
.pru_peeraddr = raw_upeeraddr,
.pru_send = raw_usend,
.pru_shutdown = raw_ushutdown,
.pru_sockaddr = raw_usockaddr,
.pru_close = raw_uclose,
};