Contributors: 8
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Bart De Schuymer |
756 |
74.93% |
1 |
4.17% |
| Jan Engelhardt |
96 |
9.51% |
13 |
54.17% |
| Joe Perches |
88 |
8.72% |
4 |
16.67% |
| David S. Miller |
39 |
3.87% |
2 |
8.33% |
| Tobin C Harding |
18 |
1.78% |
1 |
4.17% |
| Pablo Neira Ayuso |
7 |
0.69% |
1 |
4.17% |
| Andrew Morton |
4 |
0.40% |
1 |
4.17% |
| Thomas Gleixner |
1 |
0.10% |
1 |
4.17% |
| Total |
1009 |
|
24 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* ebt_stp
*
* Authors:
* Bart De Schuymer <bdschuym@pandora.be>
* Stephen Hemminger <shemminger@osdl.org>
*
* July, 2003
*/
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_stp.h>
#define BPDU_TYPE_CONFIG 0
struct stp_header {
u8 dsap;
u8 ssap;
u8 ctrl;
u8 pid;
u8 vers;
u8 type;
};
struct stp_config_pdu {
u8 flags;
u8 root[8];
u8 root_cost[4];
u8 sender[8];
u8 port[2];
u8 msg_age[2];
u8 max_age[2];
u8 hello_time[2];
u8 forward_delay[2];
};
#define NR16(p) (p[0] << 8 | p[1])
#define NR32(p) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3])
static bool ebt_filter_config(const struct ebt_stp_info *info,
const struct stp_config_pdu *stpc)
{
const struct ebt_stp_config_info *c;
u16 v16;
u32 v32;
c = &info->config;
if ((info->bitmask & EBT_STP_FLAGS) &&
NF_INVF(info, EBT_STP_FLAGS, c->flags != stpc->flags))
return false;
if (info->bitmask & EBT_STP_ROOTPRIO) {
v16 = NR16(stpc->root);
if (NF_INVF(info, EBT_STP_ROOTPRIO,
v16 < c->root_priol || v16 > c->root_priou))
return false;
}
if (info->bitmask & EBT_STP_ROOTADDR) {
if (NF_INVF(info, EBT_STP_ROOTADDR,
!ether_addr_equal_masked(&stpc->root[2],
c->root_addr,
c->root_addrmsk)))
return false;
}
if (info->bitmask & EBT_STP_ROOTCOST) {
v32 = NR32(stpc->root_cost);
if (NF_INVF(info, EBT_STP_ROOTCOST,
v32 < c->root_costl || v32 > c->root_costu))
return false;
}
if (info->bitmask & EBT_STP_SENDERPRIO) {
v16 = NR16(stpc->sender);
if (NF_INVF(info, EBT_STP_SENDERPRIO,
v16 < c->sender_priol || v16 > c->sender_priou))
return false;
}
if (info->bitmask & EBT_STP_SENDERADDR) {
if (NF_INVF(info, EBT_STP_SENDERADDR,
!ether_addr_equal_masked(&stpc->sender[2],
c->sender_addr,
c->sender_addrmsk)))
return false;
}
if (info->bitmask & EBT_STP_PORT) {
v16 = NR16(stpc->port);
if (NF_INVF(info, EBT_STP_PORT,
v16 < c->portl || v16 > c->portu))
return false;
}
if (info->bitmask & EBT_STP_MSGAGE) {
v16 = NR16(stpc->msg_age);
if (NF_INVF(info, EBT_STP_MSGAGE,
v16 < c->msg_agel || v16 > c->msg_ageu))
return false;
}
if (info->bitmask & EBT_STP_MAXAGE) {
v16 = NR16(stpc->max_age);
if (NF_INVF(info, EBT_STP_MAXAGE,
v16 < c->max_agel || v16 > c->max_ageu))
return false;
}
if (info->bitmask & EBT_STP_HELLOTIME) {
v16 = NR16(stpc->hello_time);
if (NF_INVF(info, EBT_STP_HELLOTIME,
v16 < c->hello_timel || v16 > c->hello_timeu))
return false;
}
if (info->bitmask & EBT_STP_FWDD) {
v16 = NR16(stpc->forward_delay);
if (NF_INVF(info, EBT_STP_FWDD,
v16 < c->forward_delayl || v16 > c->forward_delayu))
return false;
}
return true;
}
static bool
ebt_stp_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct ebt_stp_info *info = par->matchinfo;
const struct stp_header *sp;
struct stp_header _stph;
const u8 header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};
sp = skb_header_pointer(skb, 0, sizeof(_stph), &_stph);
if (sp == NULL)
return false;
/* The stp code only considers these */
if (memcmp(sp, header, sizeof(header)))
return false;
if ((info->bitmask & EBT_STP_TYPE) &&
NF_INVF(info, EBT_STP_TYPE, info->type != sp->type))
return false;
if (sp->type == BPDU_TYPE_CONFIG &&
info->bitmask & EBT_STP_CONFIG_MASK) {
const struct stp_config_pdu *st;
struct stp_config_pdu _stpc;
st = skb_header_pointer(skb, sizeof(_stph),
sizeof(_stpc), &_stpc);
if (st == NULL)
return false;
return ebt_filter_config(info, st);
}
return true;
}
static int ebt_stp_mt_check(const struct xt_mtchk_param *par)
{
const struct ebt_stp_info *info = par->matchinfo;
const struct ebt_entry *e = par->entryinfo;
if (info->bitmask & ~EBT_STP_MASK || info->invflags & ~EBT_STP_MASK ||
!(info->bitmask & EBT_STP_MASK))
return -EINVAL;
/* Make sure the match only receives stp frames */
if (!par->nft_compat &&
(!ether_addr_equal(e->destmac, eth_stp_addr) ||
!(e->bitmask & EBT_DESTMAC) ||
!is_broadcast_ether_addr(e->destmsk)))
return -EINVAL;
return 0;
}
static struct xt_match ebt_stp_mt_reg __read_mostly = {
.name = "stp",
.revision = 0,
.family = NFPROTO_BRIDGE,
.match = ebt_stp_mt,
.checkentry = ebt_stp_mt_check,
.matchsize = sizeof(struct ebt_stp_info),
.me = THIS_MODULE,
};
static int __init ebt_stp_init(void)
{
return xt_register_match(&ebt_stp_mt_reg);
}
static void __exit ebt_stp_fini(void)
{
xt_unregister_match(&ebt_stp_mt_reg);
}
module_init(ebt_stp_init);
module_exit(ebt_stp_fini);
MODULE_DESCRIPTION("Ebtables: Spanning Tree Protocol packet match");
MODULE_LICENSE("GPL");