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freebsd-dev/sys/netinet/ip_fw_pfil.c
Marko Zec f6dfe47a14 Permit buiding kernels with options VIMAGE, restricted to only a single 
active network stack instance.  Turning on options VIMAGE at compile
time yields the following changes relative to default kernel build:

1) V_ accessor macros for virtualized variables resolve to structure
fields via base pointers, instead of being resolved as fields in global
structs or plain global variables.  As an example, V_ifnet becomes:

    options VIMAGE:          ((struct vnet_net *) vnet_net)->_ifnet
    default build:           vnet_net_0._ifnet
    options VIMAGE_GLOBALS:  ifnet

2) INIT_VNET_* macros will declare and set up base pointers to be used
by V_ accessor macros, instead of resolving to whitespace:

    INIT_VNET_NET(ifp->if_vnet); becomes

    struct vnet_net *vnet_net = (ifp->if_vnet)->mod_data[VNET_MOD_NET];

3) Memory for vnet modules registered via vnet_mod_register() is now
allocated at run time in sys/kern/kern_vimage.c, instead of per vnet
module structs being declared as globals.  If required, vnet modules
can now request the framework to provide them with allocated bzeroed
memory by filling in the vmi_size field in their vmi_modinfo structures.

4) structs socket, ifnet, inpcbinfo, tcpcb and syncache_head are
extended to hold a pointer to the parent vnet.  options VIMAGE builds
will fill in those fields as required.

5) curvnet is introduced as a new global variable in options VIMAGE
builds, always pointing to the default and only struct vnet.

6) struct sysctl_oid has been extended with additional two fields to
store major and minor virtualization module identifiers, oid_v_subs and
oid_v_mod.  SYSCTL_V_* family of macros will fill in those fields
accordingly, and store the offset in the appropriate vnet container
struct in oid_arg1.
In sysctl handlers dealing with virtualized sysctls, the
SYSCTL_RESOLVE_V_ARG1() macro will compute the address of the target
variable and make it available in arg1 variable for further processing.

Unused fields in structs vnet_inet, vnet_inet6 and vnet_ipfw have
been deleted.

Reviewed by:	bz, rwatson
Approved by:	julian (mentor)
2009-04-30 13:36:26 +00:00

601 lines
13 KiB
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/*-
* 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("$FreeBSD$");
#if !defined(KLD_MODULE)
#include "opt_ipfw.h"
#include "opt_ipdn.h"
#include "opt_inet.h"
#ifndef INET
#error IPFIREWALL requires INET.
#endif /* INET */
#endif /* KLD_MODULE */
#include "opt_inet6.h"
#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/socketvar.h>
#include <sys/sysctl.h>
#include <sys/ucred.h>
#include <sys/vimage.h>
#include <net/if.h>
#include <net/route.h>
#include <net/pfil.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/ip_divert.h>
#include <netinet/ip_dummynet.h>
#include <netinet/vinet.h>
#include <netgraph/ng_ipfw.h>
#include <machine/in_cksum.h>
#ifdef VIMAGE_GLOBALS
int fw_enable = 1;
#ifdef INET6
int fw6_enable = 1;
#endif
#endif
int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
/* Dummynet hooks. */
ip_dn_ruledel_t *ip_dn_ruledel_ptr = NULL;
/* Divert hooks. */
ip_divert_packet_t *ip_divert_ptr = NULL;
/* ng_ipfw hooks. */
ng_ipfw_input_t *ng_ipfw_input_p = NULL;
/* Forward declarations. */
static int ipfw_divert(struct mbuf **, int, int);
#define DIV_DIR_IN 1
#define DIV_DIR_OUT 0
int
ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
struct inpcb *inp)
{
INIT_VNET_INET(curvnet);
struct ip_fw_args args;
struct ng_ipfw_tag *ng_tag;
struct m_tag *dn_tag;
int ipfw = 0;
int divert;
int tee;
#ifdef IPFIREWALL_FORWARD
struct m_tag *fwd_tag;
#endif
KASSERT(dir == PFIL_IN, ("ipfw_check_in wrong direction!"));
bzero(&args, sizeof(args));
ng_tag = (struct ng_ipfw_tag *)m_tag_locate(*m0, NGM_IPFW_COOKIE, 0,
NULL);
if (ng_tag != NULL) {
KASSERT(ng_tag->dir == NG_IPFW_IN,
("ng_ipfw tag with wrong direction"));
args.rule = ng_tag->rule;
m_tag_delete(*m0, (struct m_tag *)ng_tag);
}
again:
dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
if (dn_tag != NULL){
struct dn_pkt_tag *dt;
dt = (struct dn_pkt_tag *)(dn_tag+1);
args.rule = dt->rule;
m_tag_delete(*m0, dn_tag);
}
args.m = *m0;
args.inp = inp;
tee = 0;
if (V_fw_one_pass == 0 || args.rule == NULL) {
ipfw = ipfw_chk(&args);
*m0 = args.m;
} else
ipfw = IP_FW_PASS;
KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
__func__));
switch (ipfw) {
case IP_FW_PASS:
if (args.next_hop == NULL)
goto pass;
#ifdef IPFIREWALL_FORWARD
fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
sizeof(struct sockaddr_in), M_NOWAIT);
if (fwd_tag == NULL)
goto 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;
goto pass;
#endif
break; /* not reached */
case IP_FW_DENY:
goto drop;
break; /* not reached */
case IP_FW_DUMMYNET:
if (!DUMMYNET_LOADED)
goto drop;
if (mtod(*m0, struct ip *)->ip_v == 4)
ip_dn_io_ptr(m0, DN_TO_IP_IN, &args);
else if (mtod(*m0, struct ip *)->ip_v == 6)
ip_dn_io_ptr(m0, DN_TO_IP6_IN, &args);
if (*m0 != NULL)
goto again;
return 0; /* packet consumed */
case IP_FW_TEE:
tee = 1;
/* fall through */
case IP_FW_DIVERT:
divert = ipfw_divert(m0, DIV_DIR_IN, tee);
if (divert) {
*m0 = NULL;
return 0; /* packet consumed */
} else {
args.rule = NULL;
goto again; /* continue with packet */
}
case IP_FW_NGTEE:
if (!NG_IPFW_LOADED)
goto drop;
(void)ng_ipfw_input_p(m0, NG_IPFW_IN, &args, 1);
goto again; /* continue with packet */
case IP_FW_NETGRAPH:
if (!NG_IPFW_LOADED)
goto drop;
return ng_ipfw_input_p(m0, NG_IPFW_IN, &args, 0);
case IP_FW_NAT:
goto again; /* continue with packet */
case IP_FW_REASS:
goto again;
default:
KASSERT(0, ("%s: unknown retval", __func__));
}
drop:
if (*m0)
m_freem(*m0);
*m0 = NULL;
return (EACCES);
pass:
return 0; /* not filtered */
}
int
ipfw_check_out(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
struct inpcb *inp)
{
INIT_VNET_INET(curvnet);
struct ip_fw_args args;
struct ng_ipfw_tag *ng_tag;
struct m_tag *dn_tag;
int ipfw = 0;
int divert;
int tee;
#ifdef IPFIREWALL_FORWARD
struct m_tag *fwd_tag;
#endif
KASSERT(dir == PFIL_OUT, ("ipfw_check_out wrong direction!"));
bzero(&args, sizeof(args));
ng_tag = (struct ng_ipfw_tag *)m_tag_locate(*m0, NGM_IPFW_COOKIE, 0,
NULL);
if (ng_tag != NULL) {
KASSERT(ng_tag->dir == NG_IPFW_OUT,
("ng_ipfw tag with wrong direction"));
args.rule = ng_tag->rule;
m_tag_delete(*m0, (struct m_tag *)ng_tag);
}
again:
dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
if (dn_tag != NULL) {
struct dn_pkt_tag *dt;
dt = (struct dn_pkt_tag *)(dn_tag+1);
args.rule = dt->rule;
m_tag_delete(*m0, dn_tag);
}
args.m = *m0;
args.oif = ifp;
args.inp = inp;
tee = 0;
if (V_fw_one_pass == 0 || args.rule == NULL) {
ipfw = ipfw_chk(&args);
*m0 = args.m;
} else
ipfw = IP_FW_PASS;
KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
__func__));
switch (ipfw) {
case IP_FW_PASS:
if (args.next_hop == NULL)
goto pass;
#ifdef IPFIREWALL_FORWARD
/* Overwrite existing tag. */
fwd_tag = m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
if (fwd_tag == NULL) {
fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
sizeof(struct sockaddr_in), M_NOWAIT);
if (fwd_tag == NULL)
goto drop;
} else
m_tag_unlink(*m0, fwd_tag);
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;
goto pass;
#endif
break; /* not reached */
case IP_FW_DENY:
goto drop;
break; /* not reached */
case IP_FW_DUMMYNET:
if (!DUMMYNET_LOADED)
break;
if (mtod(*m0, struct ip *)->ip_v == 4)
ip_dn_io_ptr(m0, DN_TO_IP_OUT, &args);
else if (mtod(*m0, struct ip *)->ip_v == 6)
ip_dn_io_ptr(m0, DN_TO_IP6_OUT, &args);
if (*m0 != NULL)
goto again;
return 0; /* packet consumed */
break;
case IP_FW_TEE:
tee = 1;
/* fall through */
case IP_FW_DIVERT:
divert = ipfw_divert(m0, DIV_DIR_OUT, tee);
if (divert) {
*m0 = NULL;
return 0; /* packet consumed */
} else {
args.rule = NULL;
goto again; /* continue with packet */
}
case IP_FW_NGTEE:
if (!NG_IPFW_LOADED)
goto drop;
(void)ng_ipfw_input_p(m0, NG_IPFW_OUT, &args, 1);
goto again; /* continue with packet */
case IP_FW_NETGRAPH:
if (!NG_IPFW_LOADED)
goto drop;
return ng_ipfw_input_p(m0, NG_IPFW_OUT, &args, 0);
case IP_FW_NAT:
goto again; /* continue with packet */
case IP_FW_REASS:
goto again;
default:
KASSERT(0, ("%s: unknown retval", __func__));
}
drop:
if (*m0)
m_freem(*m0);
*m0 = NULL;
return (EACCES);
pass:
return 0; /* not filtered */
}
static int
ipfw_divert(struct mbuf **m, int incoming, 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, *reass;
struct ip *ip;
int hlen;
reass = NULL;
/* Is divert module loaded? */
if (ip_divert_ptr == NULL)
goto nodivert;
/* Cloning needed for tee? */
if (tee)
clone = m_dup(*m, M_DONTWAIT);
else
clone = *m;
/* In case m_dup was unable to allocate mbufs. */
if (clone == NULL)
goto teeout;
/*
* Divert listeners can only handle non-fragmented packets.
* However when tee is set we will *not* de-fragment the packets;
* Doing do would put the reassembly into double-jeopardy. On top
* of that someone doing a tee will probably want to get the packet
* in its original form.
*/
ip = mtod(clone, struct ip *);
if (!tee && ip->ip_off & (IP_MF | IP_OFFMASK)) {
/* Reassemble packet. */
reass = ip_reass(clone);
/*
* IP header checksum fixup after reassembly and leave header
* in network byte order.
*/
if (reass != NULL) {
ip = mtod(reass, struct ip *);
hlen = ip->ip_hl << 2;
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
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;
} else
clone = NULL;
} else {
/* Convert header to network byte order. */
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
}
/* Do the dirty job... */
if (clone && ip_divert_ptr != NULL)
ip_divert_ptr(clone, incoming);
teeout:
/*
* For tee we leave the divert tag attached to original packet.
* It will then continue rule evaluation after the tee rule.
*/
if (tee)
return 0;
/* Packet diverted and consumed */
return 1;
nodivert:
m_freem(*m);
return 1;
}
static int
ipfw_hook(void)
{
struct pfil_head *pfh_inet;
pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
if (pfh_inet == NULL)
return ENOENT;
(void)pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
pfh_inet);
(void)pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
pfh_inet);
return 0;
}
static int
ipfw_unhook(void)
{
struct pfil_head *pfh_inet;
pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
if (pfh_inet == NULL)
return ENOENT;
(void)pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
pfh_inet);
(void)pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
pfh_inet);
return 0;
}
#ifdef INET6
static int
ipfw6_hook(void)
{
struct pfil_head *pfh_inet6;
pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
if (pfh_inet6 == NULL)
return ENOENT;
(void)pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
pfh_inet6);
(void)pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
pfh_inet6);
return 0;
}
static int
ipfw6_unhook(void)
{
struct pfil_head *pfh_inet6;
pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
if (pfh_inet6 == NULL)
return ENOENT;
(void)pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
pfh_inet6);
(void)pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
pfh_inet6);
return 0;
}
#endif /* INET6 */
int
ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
{
INIT_VNET_IPFW(curvnet);
int enable = *(int *)arg1;
int error;
error = sysctl_handle_int(oidp, &enable, 0, req);
if (error)
return (error);
enable = (enable) ? 1 : 0;
if (enable == *(int *)arg1)
return (0);
if (arg1 == &V_fw_enable) {
if (enable)
error = ipfw_hook();
else
error = ipfw_unhook();
}
#ifdef INET6
if (arg1 == &V_fw6_enable) {
if (enable)
error = ipfw6_hook();
else
error = ipfw6_unhook();
}
#endif
if (error)
return (error);
*(int *)arg1 = enable;
return (0);
}
static int
ipfw_modevent(module_t mod, int type, void *unused)
{
int err = 0;
switch (type) {
case MOD_LOAD:
if ((err = ipfw_init()) != 0) {
printf("ipfw_init() error\n");
break;
}
if ((err = ipfw_hook()) != 0) {
printf("ipfw_hook() error\n");
break;
}
#ifdef INET6
if ((err = ipfw6_hook()) != 0) {
printf("ipfw_hook() error\n");
break;
}
#endif
break;
case MOD_UNLOAD:
if ((err = ipfw_unhook()) > 0)
break;
#ifdef INET6
if ((err = ipfw6_unhook()) > 0)
break;
#endif
ipfw_destroy();
break;
default:
return EOPNOTSUPP;
break;
}
return err;
}
static moduledata_t ipfwmod = {
"ipfw",
ipfw_modevent,
0
};
DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY - 256);
MODULE_VERSION(ipfw, 2);
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