8e20fa5ae9
malloc(9) flags within sys. Exceptions: - sys/contrib not touched - sys/mbuf.h edited manually
583 lines
14 KiB
C
583 lines
14 KiB
C
/*-
|
|
* 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 "opt_ipfw.h"
|
|
#include "opt_inet.h"
|
|
#include "opt_inet6.h"
|
|
#ifndef INET
|
|
#error IPFIREWALL requires INET.
|
|
#endif /* INET */
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/module.h>
|
|
#include <sys/kernel.h>
|
|
#include <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/ethernet.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>
|
|
#ifdef INET6
|
|
#include <netinet/ip6.h>
|
|
#include <netinet6/ip6_var.h>
|
|
#endif
|
|
|
|
#include <netgraph/ng_ipfw.h>
|
|
|
|
#include <netpfil/ipfw/ip_fw_private.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
|
|
|
|
static VNET_DEFINE(int, fwlink_enable) = 0;
|
|
#define V_fwlink_enable VNET(fwlink_enable)
|
|
|
|
int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
|
|
|
|
/* Forward declarations. */
|
|
static int ipfw_divert(struct mbuf **, int, struct ipfw_rule_ref *, int);
|
|
static int ipfw_check_packet(void *, struct mbuf **, struct ifnet *, int,
|
|
struct inpcb *);
|
|
static int ipfw_check_frame(void *, struct mbuf **, struct ifnet *, int,
|
|
struct inpcb *);
|
|
|
|
#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 */
|
|
|
|
SYSCTL_DECL(_net_link_ether);
|
|
SYSCTL_VNET_PROC(_net_link_ether, OID_AUTO, ipfw,
|
|
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fwlink_enable), 0,
|
|
ipfw_chg_hook, "I", "Pass ether pkts through firewall");
|
|
|
|
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.
|
|
*/
|
|
static int
|
|
ipfw_check_packet(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;
|
|
|
|
/* 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)
|
|
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 && args.next_hop6 == NULL)
|
|
break; /* pass */
|
|
#if (!defined(INET6) && !defined(INET))
|
|
ret = EACCES;
|
|
#else
|
|
{
|
|
struct m_tag *fwd_tag;
|
|
size_t len;
|
|
|
|
KASSERT(args.next_hop == NULL || args.next_hop6 == NULL,
|
|
("%s: both next_hop=%p and next_hop6=%p not NULL", __func__,
|
|
args.next_hop, args.next_hop6));
|
|
#ifdef INET6
|
|
if (args.next_hop6 != NULL)
|
|
len = sizeof(struct sockaddr_in6);
|
|
#endif
|
|
#ifdef INET
|
|
if (args.next_hop != NULL)
|
|
len = sizeof(struct sockaddr_in);
|
|
#endif
|
|
|
|
/* 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, len,
|
|
M_NOWAIT);
|
|
if (fwd_tag == NULL) {
|
|
ret = EACCES;
|
|
break; /* i.e. drop */
|
|
}
|
|
}
|
|
#ifdef INET6
|
|
if (args.next_hop6 != NULL) {
|
|
bcopy(args.next_hop6, (fwd_tag+1), len);
|
|
if (in6_localip(&args.next_hop6->sin6_addr))
|
|
(*m0)->m_flags |= M_FASTFWD_OURS;
|
|
(*m0)->m_flags |= M_IP6_NEXTHOP;
|
|
}
|
|
#endif
|
|
#ifdef INET
|
|
if (args.next_hop != NULL) {
|
|
bcopy(args.next_hop, (fwd_tag+1), len);
|
|
if (in_localip(args.next_hop->sin_addr))
|
|
(*m0)->m_flags |= M_FASTFWD_OURS;
|
|
(*m0)->m_flags |= M_IP_NEXTHOP;
|
|
}
|
|
#endif
|
|
m_tag_prepend(*m0, fwd_tag);
|
|
}
|
|
#endif /* INET || INET6 */
|
|
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;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* ipfw processing for ethernet packets (in and out).
|
|
* Inteface is NULL from ether_demux, and ifp from
|
|
* ether_output_frame.
|
|
*/
|
|
static int
|
|
ipfw_check_frame(void *arg, struct mbuf **m0, struct ifnet *dst, int dir,
|
|
struct inpcb *inp)
|
|
{
|
|
struct ether_header *eh;
|
|
struct ether_header save_eh;
|
|
struct mbuf *m;
|
|
int i, ret;
|
|
struct ip_fw_args args;
|
|
struct m_tag *mtag;
|
|
|
|
/* fetch start point from rule, if any */
|
|
mtag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
|
|
if (mtag == NULL) {
|
|
args.rule.slot = 0;
|
|
} else {
|
|
/* dummynet packet, already partially processed */
|
|
struct ipfw_rule_ref *r;
|
|
|
|
/* XXX can we free it after use ? */
|
|
mtag->m_tag_id = PACKET_TAG_NONE;
|
|
r = (struct ipfw_rule_ref *)(mtag + 1);
|
|
if (r->info & IPFW_ONEPASS)
|
|
return (0);
|
|
args.rule = *r;
|
|
}
|
|
|
|
/* I need some amt of data to be contiguous */
|
|
m = *m0;
|
|
i = min(m->m_pkthdr.len, max_protohdr);
|
|
if (m->m_len < i) {
|
|
m = m_pullup(m, i);
|
|
if (m == NULL) {
|
|
*m0 = m;
|
|
return (0);
|
|
}
|
|
}
|
|
eh = mtod(m, struct ether_header *);
|
|
save_eh = *eh; /* save copy for restore below */
|
|
m_adj(m, ETHER_HDR_LEN); /* strip ethernet header */
|
|
|
|
args.m = m; /* the packet we are looking at */
|
|
args.oif = dst; /* destination, if any */
|
|
args.next_hop = NULL; /* we do not support forward yet */
|
|
args.next_hop6 = NULL; /* we do not support forward yet */
|
|
args.eh = &save_eh; /* MAC header for bridged/MAC packets */
|
|
args.inp = NULL; /* used by ipfw uid/gid/jail rules */
|
|
i = ipfw_chk(&args);
|
|
m = args.m;
|
|
if (m != NULL) {
|
|
/*
|
|
* Restore Ethernet header, as needed, in case the
|
|
* mbuf chain was replaced by ipfw.
|
|
*/
|
|
M_PREPEND(m, ETHER_HDR_LEN, M_NOWAIT);
|
|
if (m == NULL) {
|
|
*m0 = NULL;
|
|
return (0);
|
|
}
|
|
if (eh != mtod(m, struct ether_header *))
|
|
bcopy(&save_eh, mtod(m, struct ether_header *),
|
|
ETHER_HDR_LEN);
|
|
}
|
|
*m0 = m;
|
|
|
|
ret = 0;
|
|
/* Check result of ipfw_chk() */
|
|
switch (i) {
|
|
case IP_FW_PASS:
|
|
break;
|
|
|
|
case IP_FW_DENY:
|
|
ret = EACCES;
|
|
break; /* i.e. drop */
|
|
|
|
case IP_FW_DUMMYNET:
|
|
ret = EACCES;
|
|
int dir;
|
|
|
|
if (ip_dn_io_ptr == NULL)
|
|
break; /* i.e. drop */
|
|
|
|
*m0 = NULL;
|
|
dir = PROTO_LAYER2 | (dst ? DIR_OUT : DIR_IN);
|
|
ip_dn_io_ptr(&m, dir, &args);
|
|
return 0;
|
|
|
|
default:
|
|
KASSERT(0, ("%s: unknown retval", __func__));
|
|
}
|
|
|
|
if (ret != 0) {
|
|
if (*m0)
|
|
FREE_PKT(*m0);
|
|
*m0 = NULL;
|
|
}
|
|
|
|
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 = mtod(*m0, struct 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_NOWAIT);
|
|
/* 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'.
|
|
*/
|
|
if (!tee) switch (ip->ip_v) {
|
|
case IPVERSION:
|
|
if (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) {
|
|
int hlen;
|
|
struct mbuf *reass;
|
|
|
|
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;
|
|
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;
|
|
}
|
|
break;
|
|
#ifdef INET6
|
|
case IPV6_VERSION >> 4:
|
|
{
|
|
struct ip6_hdr *const ip6 = mtod(clone, struct ip6_hdr *);
|
|
|
|
if (ip6->ip6_nxt == IPPROTO_FRAGMENT) {
|
|
int nxt, off;
|
|
|
|
off = sizeof(struct ip6_hdr);
|
|
nxt = frag6_input(&clone, &off, 0);
|
|
if (nxt == IPPROTO_DONE)
|
|
return (0);
|
|
}
|
|
break;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/* 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;
|
|
void *hook_func;
|
|
|
|
pfh = pfil_head_get(PFIL_TYPE_AF, pf);
|
|
if (pfh == NULL)
|
|
return ENOENT;
|
|
|
|
hook_func = (pf == AF_LINK) ? ipfw_check_frame : ipfw_check_packet;
|
|
|
|
(void) (onoff ? pfil_add_hook : pfil_remove_hook)
|
|
(hook_func, 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
|
|
if (arg == 0) /* detach */
|
|
ipfw_hook(0, AF_LINK);
|
|
else if (V_fwlink_enable && ipfw_hook(1, AF_LINK) != 0) {
|
|
error = ENOENT;
|
|
printf("ipfw_link_hook() error\n");
|
|
}
|
|
return error;
|
|
}
|
|
|
|
int
|
|
ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int *enable;
|
|
int newval;
|
|
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 if (arg1 == &VNET_NAME(fwlink_enable)) {
|
|
enable = &V_fwlink_enable;
|
|
af = AF_LINK;
|
|
}
|
|
else
|
|
return (EINVAL);
|
|
|
|
newval = *enable;
|
|
|
|
/* Handle sysctl change */
|
|
error = sysctl_handle_int(oidp, &newval, 0, req);
|
|
|
|
if (error)
|
|
return (error);
|
|
|
|
/* Formalize new value */
|
|
newval = (newval) ? 1 : 0;
|
|
|
|
if (*enable == newval)
|
|
return (0);
|
|
|
|
error = ipfw_hook(newval, af);
|
|
if (error)
|
|
return (error);
|
|
*enable = newval;
|
|
|
|
return (0);
|
|
}
|
|
/* end of file */
|