#include <machine/rtems-bsd-config.h>
/*-
* Copyright (c) 2004 Andre Oppermann, Internet Business Solutions AG
* 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("$FreeBSD$");
#include <rtems/bsd/local/opt_ipfw.h>
#include <rtems/bsd/local/opt_inet.h>
#include <rtems/bsd/local/opt_inet6.h>
#ifndef INET
#error IPFIREWALL requires INET.
#endif /* INET */
#include <rtems/bsd/sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <rtems/bsd/sys/lock.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/pfil.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/ipfw/ip_fw_private.h>
#include <netgraph/ng_ipfw.h>
#include <machine/in_cksum.h>
static VNET_DEFINE(int, fw_enable) = 1;
#define V_fw_enable VNET(fw_enable)
#ifdef INET6
static VNET_DEFINE(int, fw6_enable) = 1;
#define V_fw6_enable VNET(fw6_enable)
#endif
int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
/* Forward declarations. */
static int ipfw_divert(struct mbuf **, int, struct ipfw_rule_ref *, int);
#ifdef SYSCTL_NODE
SYSBEGIN(f1)
SYSCTL_DECL(_net_inet_ip_fw);
SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, enable,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_enable), 0,
ipfw_chg_hook, "I", "Enable ipfw");
#ifdef INET6
SYSCTL_DECL(_net_inet6_ip6_fw);
SYSCTL_VNET_PROC(_net_inet6_ip6_fw, OID_AUTO, enable,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw6_enable), 0,
ipfw_chg_hook, "I", "Enable ipfw+6");
#endif /* INET6 */
SYSEND
#endif /* SYSCTL_NODE */
/*
* The pfilter hook to pass packets to ipfw_chk and then to
* dummynet, divert, netgraph or other modules.
* The packet may be consumed.
*/
int
ipfw_check_hook(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
struct inpcb *inp)
{
struct ip_fw_args args;
struct m_tag *tag;
int ipfw;
int ret;
/* all the processing now uses ip_len in net format */
if (mtod(*m0, struct ip *)->ip_v == 4)
SET_NET_IPLEN(mtod(*m0, struct ip *));
/* convert dir to IPFW values */
dir = (dir == PFIL_IN) ? DIR_IN : DIR_OUT;
bzero(&args, sizeof(args));
again:
/*
* extract and remove the tag if present. If we are left
* with onepass, optimize the outgoing path.
*/
tag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
if (tag != NULL) {
args.rule = *((struct ipfw_rule_ref *)(tag+1));
m_tag_delete(*m0, tag);
if (args.rule.info & IPFW_ONEPASS) {
if (mtod(*m0, struct ip *)->ip_v == 4)
SET_HOST_IPLEN(mtod(*m0, struct ip *));
return (0);
}
}
args.m = *m0;
args.oif = dir == DIR_OUT ? ifp : NULL;
args.inp = inp;
ipfw = ipfw_chk(&args);
*m0 = args.m;
KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
__func__));
/* breaking out of the switch means drop */
ret = 0; /* default return value for pass */
switch (ipfw) {
case IP_FW_PASS:
/* next_hop may be set by ipfw_chk */
if (args.next_hop == NULL)
break; /* pass */
#if !defined(IPFIREWALL_FORWARD) || (!defined(INET6) && !defined(INET))
ret = EACCES;
#else
{
struct m_tag *fwd_tag;
/* Incoming packets should not be tagged so we do not
* m_tag_find. Outgoing packets may be tagged, so we
* reuse the tag if present.
*/
fwd_tag = (dir == DIR_IN) ? NULL :
m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
if (fwd_tag != NULL) {
m_tag_unlink(*m0, fwd_tag);
} else {
fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
sizeof(struct sockaddr_in), M_NOWAIT);
if (fwd_tag == NULL) {
ret = EACCES;
break; /* i.e. drop */
}
}
bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
m_tag_prepend(*m0, fwd_tag);
if (in_localip(args.next_hop->sin_addr))
(*m0)->m_flags |= M_FASTFWD_OURS;
}
#endif /* IPFIREWALL_FORWARD */
break;
case IP_FW_DENY:
ret = EACCES;
break; /* i.e. drop */
case IP_FW_DUMMYNET:
ret = EACCES;
if (ip_dn_io_ptr == NULL)
break; /* i.e. drop */
if (mtod(*m0, struct ip *)->ip_v == 4)
ret = ip_dn_io_ptr(m0, dir, &args);
else if (mtod(*m0, struct ip *)->ip_v == 6)
ret = ip_dn_io_ptr(m0, dir | PROTO_IPV6, &args);
else
break; /* drop it */
/*
* XXX should read the return value.
* dummynet normally eats the packet and sets *m0=NULL
* unless the packet can be sent immediately. In this
* case args is updated and we should re-run the
* check without clearing args.
*/
if (*m0 != NULL)
goto again;
break;
case IP_FW_TEE:
case IP_FW_DIVERT:
if (ip_divert_ptr == NULL) {
ret = EACCES;
break; /* i.e. drop */
}
ret = ipfw_divert(m0, dir, &args.rule,
(ipfw == IP_FW_TEE) ? 1 : 0);
/* continue processing for the original packet (tee). */
if (*m0)
goto again;
break;
case IP_FW_NGTEE:
case IP_FW_NETGRAPH:
if (ng_ipfw_input_p == NULL) {
ret = EACCES;
break; /* i.e. drop */
}
ret = ng_ipfw_input_p(m0, dir, &args,
(ipfw == IP_FW_NGTEE) ? 1 : 0);
if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */
goto again; /* continue with packet */
break;
case IP_FW_NAT:
/* honor one-pass in case of successful nat */
if (V_fw_one_pass)
break; /* ret is already 0 */
goto again;
case IP_FW_REASS:
goto again; /* continue with packet */
default:
KASSERT(0, ("%s: unknown retval", __func__));
}
if (ret != 0) {
if (*m0)
FREE_PKT(*m0);
*m0 = NULL;
}
if (*m0 && mtod(*m0, struct ip *)->ip_v == 4)
SET_HOST_IPLEN(mtod(*m0, struct ip *));
return ret;
}
/* do the divert, return 1 on error 0 on success */
static int
ipfw_divert(struct mbuf **m0, int incoming, struct ipfw_rule_ref *rule,
int tee)
{
/*
* ipfw_chk() has already tagged the packet with the divert tag.
* If tee is set, copy packet and return original.
* If not tee, consume packet and send it to divert socket.
*/
struct mbuf *clone;
struct ip *ip;
struct m_tag *tag;
/* Cloning needed for tee? */
if (tee == 0) {
clone = *m0; /* use the original mbuf */
*m0 = NULL;
} else {
clone = m_dup(*m0, M_DONTWAIT);
/* If we cannot duplicate the mbuf, we sacrifice the divert
* chain and continue with the tee-ed packet.
*/
if (clone == NULL)
return 1;
}
/*
* Divert listeners can normally handle non-fragmented packets,
* but we can only reass in the non-tee case.
* This means that listeners on a tee rule may get fragments,
* and have to live with that.
* Note that we now have the 'reass' ipfw option so if we care
* we can do it before a 'tee'.
*/
ip = mtod(clone, struct ip *);
if (!tee && ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) {
int hlen;
struct mbuf *reass;
SET_HOST_IPLEN(ip); /* ip_reass wants host order */
reass = ip_reass(clone); /* Reassemble packet. */
if (reass == NULL)
return 0; /* not an error */
/* if reass = NULL then it was consumed by ip_reass */
/*
* IP header checksum fixup after reassembly and leave header
* in network byte order.
*/
ip = mtod(reass, struct ip *);
hlen = ip->ip_hl << 2;
SET_NET_IPLEN(ip);
ip->ip_sum = 0;
if (hlen == sizeof(struct ip))
ip->ip_sum = in_cksum_hdr(ip);
else
ip->ip_sum = in_cksum(reass, hlen);
clone = reass;
}
/* attach a tag to the packet with the reinject info */
tag = m_tag_alloc(MTAG_IPFW_RULE, 0,
sizeof(struct ipfw_rule_ref), M_NOWAIT);
if (tag == NULL) {
FREE_PKT(clone);
return 1;
}
*((struct ipfw_rule_ref *)(tag+1)) = *rule;
m_tag_prepend(clone, tag);
/* Do the dirty job... */
ip_divert_ptr(clone, incoming);
return 0;
}
/*
* attach or detach hooks for a given protocol family
*/
static int
ipfw_hook(int onoff, int pf)
{
struct pfil_head *pfh;
pfh = pfil_head_get(PFIL_TYPE_AF, pf);
if (pfh == NULL)
return ENOENT;
(void) (onoff ? pfil_add_hook : pfil_remove_hook)
(ipfw_check_hook, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh);
return 0;
}
int
ipfw_attach_hooks(int arg)
{
int error = 0;
if (arg == 0) /* detach */
ipfw_hook(0, AF_INET);
else if (V_fw_enable && ipfw_hook(1, AF_INET) != 0) {
error = ENOENT; /* see ip_fw_pfil.c::ipfw_hook() */
printf("ipfw_hook() error\n");
}
#ifdef INET6
if (arg == 0) /* detach */
ipfw_hook(0, AF_INET6);
else if (V_fw6_enable && ipfw_hook(1, AF_INET6) != 0) {
error = ENOENT;
printf("ipfw6_hook() error\n");
}
#endif
return error;
}
int
ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
{
int enable;
int oldenable;
int error;
int af;
if (arg1 == &VNET_NAME(fw_enable)) {
enable = V_fw_enable;
af = AF_INET;
}
#ifdef INET6
else if (arg1 == &VNET_NAME(fw6_enable)) {
enable = V_fw6_enable;
af = AF_INET6;
}
#endif
else
return (EINVAL);
oldenable = enable;
error = sysctl_handle_int(oidp, &enable, 0, req);
if (error)
return (error);
enable = (enable) ? 1 : 0;
if (enable == oldenable)
return (0);
error = ipfw_hook(enable, af);
if (error)
return (error);
if (af == AF_INET)
V_fw_enable = enable;
#ifdef INET6
else if (af == AF_INET6)
V_fw6_enable = enable;
#endif
return (0);
}
/* end of file */
