freebsd-skq/sys/netinet/ipfw/ip_fw_pfil.c
Robert Watson eddfbb763d Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00

600 lines
13 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("$FreeBSD$");
#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 <netgraph/ng_ipfw.h>
#include <machine/in_cksum.h>
VNET_DEFINE(int, fw_enable) = 1;
#ifdef INET6
VNET_DEFINE(int, fw6_enable) = 1;
#endif
int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
/* 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)
{
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;
args.rule_id = ng_tag->rule_id;
args.chain_id = ng_tag->chain_id;
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;
args.rule_id = dt->rule_id;
args.chain_id = dt->chain_id;
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 (ip_dn_io_ptr == NULL)
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)
{
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;
args.rule_id = ng_tag->rule_id;
args.chain_id = ng_tag->chain_id;
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;
args.rule_id = dt->rule_id;
args.chain_id = dt->chain_id;
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 (ip_dn_io_ptr == NULL)
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)
{
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);