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netfilter: bridge: split ipv6 code into separated file

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Resolve compilation breakage when CONFIG_IPV6 is not set by moving the IPv6
code into a separated br_netfilter_ipv6.c file.

Fixes: efb6de9b4b ("netfilter: bridge: forward IPv6 fragmented packets")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2015-06-16 14:07:03 +02:00
parent c4e70a87d9
commit 230ac490f7
4 changed files with 315 additions and 239 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
include/net/netfilter/br_netfilter.h
View File

@ -1,6 +1,66 @@
#ifndef _BR_NETFILTER_H_
#define _BR_NETFILTER_H_
#include "../../../net/bridge/br_private.h"
static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
{
skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
if (likely(skb->nf_bridge))
atomic_set(&(skb->nf_bridge->use), 1);
return skb->nf_bridge;
}
void nf_bridge_update_protocol(struct sk_buff *skb);
static inline struct nf_bridge_info *
nf_bridge_info_get(const struct sk_buff *skb)
{
return skb->nf_bridge;
}
unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb);
static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
{
unsigned int len = nf_bridge_encap_header_len(skb);
skb_push(skb, len);
skb->network_header -= len;
}
int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb);
static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
{
struct net_bridge_port *port;
port = br_port_get_rcu(dev);
return port ? &port->br->fake_rtable : NULL;
}
struct net_device *setup_pre_routing(struct sk_buff *skb);
void br_netfilter_enable(void);
#if IS_ENABLED(CONFIG_IPV6)
int br_validate_ipv6(struct sk_buff *skb);
unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct nf_hook_state *state);
#else
static inline int br_validate_ipv6(struct sk_buff *skb)
{
return -1;
}
static inline unsigned int
br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, struct sk_buff *skb,
const struct nf_hook_state *state)
{
return NF_DROP;
}
#endif
#endif /* _BR_NETFILTER_H_ */

1
net/bridge/Makefile
View File

@ -13,6 +13,7 @@ bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o
bridge-$(subst m,y,$(CONFIG_BRIDGE_NETFILTER)) += br_nf_core.o
br_netfilter-y := br_netfilter_hooks.o
br_netfilter-$(subst m,y,$(CONFIG_IPV6)) += br_netfilter_ipv6.o
obj-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o
bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o

248
net/bridge/br_netfilter_hooks.c
View File

@ -123,11 +123,6 @@ struct brnf_frag_data {
static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage);
#endif
static struct nf_bridge_info *nf_bridge_info_get(const struct sk_buff *skb)
{
return skb->nf_bridge;
}
static void nf_bridge_info_free(struct sk_buff *skb)
{
if (skb->nf_bridge) {
@ -136,14 +131,6 @@ static void nf_bridge_info_free(struct sk_buff *skb)
}
}
static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
{
struct net_bridge_port *port;
port = br_port_get_rcu(dev);
return port ? &port->br->fake_rtable : NULL;
}
static inline struct net_device *bridge_parent(const struct net_device *dev)
{
struct net_bridge_port *port;
@ -152,15 +139,6 @@ static inline struct net_device *bridge_parent(const struct net_device *dev)
return port ? port->br->dev : NULL;
}
static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
{
skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
if (likely(skb->nf_bridge))
atomic_set(&(skb->nf_bridge->use), 1);
return skb->nf_bridge;
}
static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
{
struct nf_bridge_info *nf_bridge = skb->nf_bridge;
@ -178,7 +156,7 @@ static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
return nf_bridge;
}
static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
{
switch (skb->protocol) {
case __cpu_to_be16(ETH_P_8021Q):
@ -190,14 +168,6 @@ static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
}
}
static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
{
unsigned int len = nf_bridge_encap_header_len(skb);
skb_push(skb, len);
skb->network_header -= len;
}
static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
{
unsigned int len = nf_bridge_encap_header_len(skb);
@ -267,112 +237,7 @@ drop:
return -1;
}
/* We only check the length. A bridge shouldn't do any hop-by-hop stuff
* anyway
*/
static int check_hbh_len(struct sk_buff *skb)
{
unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
u32 pkt_len;
const unsigned char *nh = skb_network_header(skb);
int off = raw - nh;
int len = (raw[1] + 1) << 3;
if ((raw + len) - skb->data > skb_headlen(skb))
goto bad;
off += 2;
len -= 2;
while (len > 0) {
int optlen = nh[off + 1] + 2;
switch (nh[off]) {
case IPV6_TLV_PAD1:
optlen = 1;
break;
case IPV6_TLV_PADN:
break;
case IPV6_TLV_JUMBO:
if (nh[off + 1] != 4 || (off & 3) != 2)
goto bad;
pkt_len = ntohl(*(__be32 *)(nh + off + 2));
if (pkt_len <= IPV6_MAXPLEN ||
ipv6_hdr(skb)->payload_len)
goto bad;
if (pkt_len > skb->len - sizeof(struct ipv6hdr))
goto bad;
if (pskb_trim_rcsum(skb,
pkt_len + sizeof(struct ipv6hdr)))
goto bad;
nh = skb_network_header(skb);
break;
default:
if (optlen > len)
goto bad;
break;
}
off += optlen;
len -= optlen;
}
if (len == 0)
return 0;
bad:
return -1;
}
/* Equivalent to br_validate_ipv4 for IPv6 */
static int br_validate_ipv6(struct sk_buff *skb)
{
const struct ipv6hdr *hdr;
struct net_device *dev = skb->dev;
struct inet6_dev *idev = in6_dev_get(skb->dev);
u32 pkt_len;
u8 ip6h_len = sizeof(struct ipv6hdr);
if (!pskb_may_pull(skb, ip6h_len))
goto inhdr_error;
if (skb->len < ip6h_len)
goto drop;
hdr = ipv6_hdr(skb);
if (hdr->version != 6)
goto inhdr_error;
pkt_len = ntohs(hdr->payload_len);
if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
if (pkt_len + ip6h_len > skb->len) {
IP6_INC_STATS_BH(dev_net(dev), idev,
IPSTATS_MIB_INTRUNCATEDPKTS);
goto drop;
}
if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
IP6_INC_STATS_BH(dev_net(dev), idev,
IPSTATS_MIB_INDISCARDS);
goto drop;
}
}
if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
goto drop;
memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
/* No IP options in IPv6 header; however it should be
* checked if some next headers need special treatment
*/
return 0;
inhdr_error:
IP6_INC_STATS_BH(dev_net(dev), idev, IPSTATS_MIB_INHDRERRORS);
drop:
return -1;
}
static void nf_bridge_update_protocol(struct sk_buff *skb)
void nf_bridge_update_protocol(struct sk_buff *skb)
{
switch (skb->nf_bridge->orig_proto) {
case BRNF_PROTO_8021Q:
@ -391,7 +256,7 @@ static void nf_bridge_update_protocol(struct sk_buff *skb)
* don't, we use the neighbour framework to find out. In both cases, we make
* sure that br_handle_frame_finish() is called afterwards.
*/
static int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
{
struct neighbour *neigh;
struct dst_entry *dst;
@ -431,77 +296,11 @@ free_skb:
return 0;
}
static bool daddr_was_changed(const struct sk_buff *skb,
const struct nf_bridge_info *nf_bridge)
static inline bool
br_nf_ipv4_daddr_was_changed(const struct sk_buff *skb,
const struct nf_bridge_info *nf_bridge)
{
switch (skb->protocol) {
case htons(ETH_P_IP):
return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr;
case htons(ETH_P_IPV6):
return memcmp(&nf_bridge->ipv6_daddr, &ipv6_hdr(skb)->daddr,
sizeof(ipv6_hdr(skb)->daddr)) != 0;
default:
return false;
}
}
/* PF_BRIDGE/PRE_ROUTING: Undo the changes made for ip6tables
* PREROUTING and continue the bridge PRE_ROUTING hook. See comment
* for br_nf_pre_routing_finish(), same logic is used here but
* equivalent IPv6 function ip6_route_input() called indirectly.
*/
static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb)
{
struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
struct rtable *rt;
struct net_device *dev = skb->dev;
const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
if (nf_bridge->pkt_otherhost) {
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
if (daddr_was_changed(skb, nf_bridge)) {
skb_dst_drop(skb);
v6ops->route_input(skb);
if (skb_dst(skb)->error) {
kfree_skb(skb);
return 0;
}
if (skb_dst(skb)->dev == dev) {
skb->dev = nf_bridge->physindev;
nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
sk, skb, skb->dev, NULL,
br_nf_pre_routing_finish_bridge,
1);
return 0;
}
ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
skb->pkt_type = PACKET_HOST;
} else {
rt = bridge_parent_rtable(nf_bridge->physindev);
if (!rt) {
kfree_skb(skb);
return 0;
}
skb_dst_set_noref(skb, &rt->dst);
}
skb->dev = nf_bridge->physindev;
nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb,
skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr;
}
/* This requires some explaining. If DNAT has taken place,
@ -558,7 +357,7 @@ static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb)
nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
if (daddr_was_changed(skb, nf_bridge)) {
if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) {
if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
struct in_device *in_dev = __in_dev_get_rcu(dev);
@ -636,7 +435,7 @@ static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct
}
/* Some common code for IPv4/IPv6 */
static struct net_device *setup_pre_routing(struct sk_buff *skb)
struct net_device *setup_pre_routing(struct sk_buff *skb)
{
struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
@ -659,35 +458,6 @@ static struct net_device *setup_pre_routing(struct sk_buff *skb)
return skb->dev;
}
/* Replicate the checks that IPv6 does on packet reception and pass the packet
* to ip6tables.
*/
static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
struct nf_bridge_info *nf_bridge;
if (br_validate_ipv6(skb))
return NF_DROP;
nf_bridge_put(skb->nf_bridge);
if (!nf_bridge_alloc(skb))
return NF_DROP;
if (!setup_pre_routing(skb))
return NF_DROP;
nf_bridge = nf_bridge_info_get(skb);
nf_bridge->ipv6_daddr = ipv6_hdr(skb)->daddr;
skb->protocol = htons(ETH_P_IPV6);
NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->sk, skb,
skb->dev, NULL,
br_nf_pre_routing_finish_ipv6);
return NF_STOLEN;
}
/* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
* Replicate the checks that IPv4 does on packet reception.
* Set skb->dev to the bridge device (i.e. parent of the

245
net/bridge/br_netfilter_ipv6.c Normal file
View File

@ -0,0 +1,245 @@
/*
* Handle firewalling
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
* Bart De Schuymer <bdschuym@pandora.be>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Lennert dedicates this file to Kerstin Wurdinger.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/ip.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/if_pppox.h>
#include <linux/ppp_defs.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter_arp.h>
#include <linux/in_route.h>
#include <linux/inetdevice.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/route.h>
#include <net/netfilter/br_netfilter.h>
#include <asm/uaccess.h>
#include "br_private.h"
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
/* We only check the length. A bridge shouldn't do any hop-by-hop stuff
* anyway
*/
static int br_nf_check_hbh_len(struct sk_buff *skb)
{
unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
u32 pkt_len;
const unsigned char *nh = skb_network_header(skb);
int off = raw - nh;
int len = (raw[1] + 1) << 3;
if ((raw + len) - skb->data > skb_headlen(skb))
goto bad;
off += 2;
len -= 2;
while (len > 0) {
int optlen = nh[off + 1] + 2;
switch (nh[off]) {
case IPV6_TLV_PAD1:
optlen = 1;
break;
case IPV6_TLV_PADN:
break;
case IPV6_TLV_JUMBO:
if (nh[off + 1] != 4 || (off & 3) != 2)
goto bad;
pkt_len = ntohl(*(__be32 *)(nh + off + 2));
if (pkt_len <= IPV6_MAXPLEN ||
ipv6_hdr(skb)->payload_len)
goto bad;
if (pkt_len > skb->len - sizeof(struct ipv6hdr))
goto bad;
if (pskb_trim_rcsum(skb,
pkt_len + sizeof(struct ipv6hdr)))
goto bad;
nh = skb_network_header(skb);
break;
default:
if (optlen > len)
goto bad;
break;
}
off += optlen;
len -= optlen;
}
if (len == 0)
return 0;
bad:
return -1;
}
int br_validate_ipv6(struct sk_buff *skb)
{
const struct ipv6hdr *hdr;
struct net_device *dev = skb->dev;
struct inet6_dev *idev = in6_dev_get(skb->dev);
u32 pkt_len;
u8 ip6h_len = sizeof(struct ipv6hdr);
if (!pskb_may_pull(skb, ip6h_len))
goto inhdr_error;
if (skb->len < ip6h_len)
goto drop;
hdr = ipv6_hdr(skb);
if (hdr->version != 6)
goto inhdr_error;
pkt_len = ntohs(hdr->payload_len);
if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
if (pkt_len + ip6h_len > skb->len) {
IP6_INC_STATS_BH(dev_net(dev), idev,
IPSTATS_MIB_INTRUNCATEDPKTS);
goto drop;
}
if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
IP6_INC_STATS_BH(dev_net(dev), idev,
IPSTATS_MIB_INDISCARDS);
goto drop;
}
}
if (hdr->nexthdr == NEXTHDR_HOP && br_nf_check_hbh_len(skb))
goto drop;
memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
/* No IP options in IPv6 header; however it should be
* checked if some next headers need special treatment
*/
return 0;
inhdr_error:
IP6_INC_STATS_BH(dev_net(dev), idev, IPSTATS_MIB_INHDRERRORS);
drop:
return -1;
}
static inline bool
br_nf_ipv6_daddr_was_changed(const struct sk_buff *skb,
const struct nf_bridge_info *nf_bridge)
{
return memcmp(&nf_bridge->ipv6_daddr, &ipv6_hdr(skb)->daddr,
sizeof(ipv6_hdr(skb)->daddr)) != 0;
}
/* PF_BRIDGE/PRE_ROUTING: Undo the changes made for ip6tables
* PREROUTING and continue the bridge PRE_ROUTING hook. See comment
* for br_nf_pre_routing_finish(), same logic is used here but
* equivalent IPv6 function ip6_route_input() called indirectly.
*/
static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb)
{
struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
struct rtable *rt;
struct net_device *dev = skb->dev;
const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
if (nf_bridge->pkt_otherhost) {
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
if (br_nf_ipv6_daddr_was_changed(skb, nf_bridge)) {
skb_dst_drop(skb);
v6ops->route_input(skb);
if (skb_dst(skb)->error) {
kfree_skb(skb);
return 0;
}
if (skb_dst(skb)->dev == dev) {
skb->dev = nf_bridge->physindev;
nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
sk, skb, skb->dev, NULL,
br_nf_pre_routing_finish_bridge,
1);
return 0;
}
ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
skb->pkt_type = PACKET_HOST;
} else {
rt = bridge_parent_rtable(nf_bridge->physindev);
if (!rt) {
kfree_skb(skb);
return 0;
}
skb_dst_set_noref(skb, &rt->dst);
}
skb->dev = nf_bridge->physindev;
nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb,
skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
}
/* Replicate the checks that IPv6 does on packet reception and pass the packet
* to ip6tables.
*/
unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
struct nf_bridge_info *nf_bridge;
if (br_validate_ipv6(skb))
return NF_DROP;
nf_bridge_put(skb->nf_bridge);
if (!nf_bridge_alloc(skb))
return NF_DROP;
if (!setup_pre_routing(skb))
return NF_DROP;
nf_bridge = nf_bridge_info_get(skb);
nf_bridge->ipv6_daddr = ipv6_hdr(skb)->daddr;
skb->protocol = htons(ETH_P_IPV6);
NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->sk, skb,
skb->dev, NULL,
br_nf_pre_routing_finish_ipv6);
return NF_STOLEN;
}