2005-04-17 00:20:36 +02:00
|
|
|
/*
|
|
|
|
* netfilter module for userspace bridged Ethernet frames logging daemons
|
|
|
|
*
|
|
|
|
* Authors:
|
|
|
|
* Bart De Schuymer <bdschuym@pandora.be>
|
2005-12-14 08:14:08 +01:00
|
|
|
* Harald Welte <laforge@netfilter.org>
|
2005-04-17 00:20:36 +02:00
|
|
|
*
|
|
|
|
* November, 2004
|
|
|
|
*
|
|
|
|
* Based on ipt_ULOG.c, which is
|
|
|
|
* (C) 2000-2002 by Harald Welte <laforge@netfilter.org>
|
|
|
|
*
|
|
|
|
* This module accepts two parameters:
|
|
|
|
*
|
|
|
|
* nlbufsiz:
|
|
|
|
* The parameter specifies how big the buffer for each netlink multicast
|
|
|
|
* group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
|
|
|
|
* get accumulated in the kernel until they are sent to userspace. It is
|
|
|
|
* NOT possible to allocate more than 128kB, and it is strongly discouraged,
|
|
|
|
* because atomically allocating 128kB inside the network rx softirq is not
|
|
|
|
* reliable. Please also keep in mind that this buffer size is allocated for
|
|
|
|
* each nlgroup you are using, so the total kernel memory usage increases
|
|
|
|
* by that factor.
|
|
|
|
*
|
|
|
|
* flushtimeout:
|
|
|
|
* Specify, after how many hundredths of a second the queue should be
|
|
|
|
* flushed even if it is not full yet.
|
|
|
|
*
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/config.h>
|
|
|
|
#include <linux/spinlock.h>
|
|
|
|
#include <linux/socket.h>
|
|
|
|
#include <linux/skbuff.h>
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/timer.h>
|
|
|
|
#include <linux/netlink.h>
|
|
|
|
#include <linux/netdevice.h>
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/netfilter_bridge/ebtables.h>
|
|
|
|
#include <linux/netfilter_bridge/ebt_ulog.h>
|
|
|
|
#include <net/sock.h>
|
|
|
|
#include "../br_private.h"
|
|
|
|
|
|
|
|
#define PRINTR(format, args...) do { if (net_ratelimit()) \
|
|
|
|
printk(format , ## args); } while (0)
|
|
|
|
|
|
|
|
static unsigned int nlbufsiz = 4096;
|
|
|
|
module_param(nlbufsiz, uint, 0600);
|
|
|
|
MODULE_PARM_DESC(nlbufsiz, "netlink buffer size (number of bytes) "
|
|
|
|
"(defaults to 4096)");
|
|
|
|
|
|
|
|
static unsigned int flushtimeout = 10;
|
|
|
|
module_param(flushtimeout, uint, 0600);
|
|
|
|
MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths ofa second) "
|
|
|
|
"(defaults to 10)");
|
|
|
|
|
|
|
|
typedef struct {
|
|
|
|
unsigned int qlen; /* number of nlmsgs' in the skb */
|
|
|
|
struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
|
|
|
|
struct sk_buff *skb; /* the pre-allocated skb */
|
|
|
|
struct timer_list timer; /* the timer function */
|
|
|
|
spinlock_t lock; /* the per-queue lock */
|
|
|
|
} ebt_ulog_buff_t;
|
|
|
|
|
|
|
|
static ebt_ulog_buff_t ulog_buffers[EBT_ULOG_MAXNLGROUPS];
|
|
|
|
static struct sock *ebtulognl;
|
|
|
|
|
|
|
|
/* send one ulog_buff_t to userspace */
|
|
|
|
static void ulog_send(unsigned int nlgroup)
|
|
|
|
{
|
|
|
|
ebt_ulog_buff_t *ub = &ulog_buffers[nlgroup];
|
|
|
|
|
|
|
|
if (timer_pending(&ub->timer))
|
|
|
|
del_timer(&ub->timer);
|
|
|
|
|
|
|
|
/* last nlmsg needs NLMSG_DONE */
|
|
|
|
if (ub->qlen > 1)
|
|
|
|
ub->lastnlh->nlmsg_type = NLMSG_DONE;
|
|
|
|
|
2005-08-15 04:29:52 +02:00
|
|
|
NETLINK_CB(ub->skb).dst_group = nlgroup + 1;
|
|
|
|
netlink_broadcast(ebtulognl, ub->skb, 0, nlgroup + 1, GFP_ATOMIC);
|
2005-04-17 00:20:36 +02:00
|
|
|
|
|
|
|
ub->qlen = 0;
|
|
|
|
ub->skb = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* timer function to flush queue in flushtimeout time */
|
|
|
|
static void ulog_timer(unsigned long data)
|
|
|
|
{
|
|
|
|
spin_lock_bh(&ulog_buffers[data].lock);
|
|
|
|
if (ulog_buffers[data].skb)
|
|
|
|
ulog_send(data);
|
|
|
|
spin_unlock_bh(&ulog_buffers[data].lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct sk_buff *ulog_alloc_skb(unsigned int size)
|
|
|
|
{
|
|
|
|
struct sk_buff *skb;
|
|
|
|
|
|
|
|
skb = alloc_skb(nlbufsiz, GFP_ATOMIC);
|
|
|
|
if (!skb) {
|
|
|
|
PRINTR(KERN_ERR "ebt_ulog: can't alloc whole buffer "
|
|
|
|
"of size %ub!\n", nlbufsiz);
|
|
|
|
if (size < nlbufsiz) {
|
|
|
|
/* try to allocate only as much as we need for
|
|
|
|
* current packet */
|
|
|
|
skb = alloc_skb(size, GFP_ATOMIC);
|
|
|
|
if (!skb)
|
|
|
|
PRINTR(KERN_ERR "ebt_ulog: can't even allocate "
|
|
|
|
"buffer of size %ub\n", size);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return skb;
|
|
|
|
}
|
|
|
|
|
2005-12-14 08:14:08 +01:00
|
|
|
static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
|
2005-04-17 00:20:36 +02:00
|
|
|
const struct net_device *in, const struct net_device *out,
|
2005-12-14 08:14:08 +01:00
|
|
|
const struct ebt_ulog_info *uloginfo, const char *prefix)
|
2005-04-17 00:20:36 +02:00
|
|
|
{
|
|
|
|
ebt_ulog_packet_msg_t *pm;
|
|
|
|
size_t size, copy_len;
|
|
|
|
struct nlmsghdr *nlh;
|
|
|
|
unsigned int group = uloginfo->nlgroup;
|
|
|
|
ebt_ulog_buff_t *ub = &ulog_buffers[group];
|
|
|
|
spinlock_t *lock = &ub->lock;
|
|
|
|
|
|
|
|
if ((uloginfo->cprange == 0) ||
|
|
|
|
(uloginfo->cprange > skb->len + ETH_HLEN))
|
|
|
|
copy_len = skb->len + ETH_HLEN;
|
|
|
|
else
|
|
|
|
copy_len = uloginfo->cprange;
|
|
|
|
|
|
|
|
size = NLMSG_SPACE(sizeof(*pm) + copy_len);
|
|
|
|
if (size > nlbufsiz) {
|
|
|
|
PRINTR("ebt_ulog: Size %Zd needed, but nlbufsiz=%d\n",
|
|
|
|
size, nlbufsiz);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_lock_bh(lock);
|
|
|
|
|
|
|
|
if (!ub->skb) {
|
|
|
|
if (!(ub->skb = ulog_alloc_skb(size)))
|
|
|
|
goto alloc_failure;
|
|
|
|
} else if (size > skb_tailroom(ub->skb)) {
|
|
|
|
ulog_send(group);
|
|
|
|
|
|
|
|
if (!(ub->skb = ulog_alloc_skb(size)))
|
|
|
|
goto alloc_failure;
|
|
|
|
}
|
|
|
|
|
|
|
|
nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, 0,
|
|
|
|
size - NLMSG_ALIGN(sizeof(*nlh)));
|
|
|
|
ub->qlen++;
|
|
|
|
|
|
|
|
pm = NLMSG_DATA(nlh);
|
|
|
|
|
|
|
|
/* Fill in the ulog data */
|
|
|
|
pm->version = EBT_ULOG_VERSION;
|
|
|
|
do_gettimeofday(&pm->stamp);
|
|
|
|
if (ub->qlen == 1)
|
2005-08-15 02:24:31 +02:00
|
|
|
skb_set_timestamp(ub->skb, &pm->stamp);
|
2005-04-17 00:20:36 +02:00
|
|
|
pm->data_len = copy_len;
|
|
|
|
pm->mark = skb->nfmark;
|
|
|
|
pm->hook = hooknr;
|
|
|
|
if (uloginfo->prefix != NULL)
|
|
|
|
strcpy(pm->prefix, uloginfo->prefix);
|
|
|
|
else
|
|
|
|
*(pm->prefix) = '\0';
|
|
|
|
|
|
|
|
if (in) {
|
|
|
|
strcpy(pm->physindev, in->name);
|
|
|
|
/* If in isn't a bridge, then physindev==indev */
|
|
|
|
if (in->br_port)
|
|
|
|
strcpy(pm->indev, in->br_port->br->dev->name);
|
|
|
|
else
|
|
|
|
strcpy(pm->indev, in->name);
|
|
|
|
} else
|
|
|
|
pm->indev[0] = pm->physindev[0] = '\0';
|
|
|
|
|
|
|
|
if (out) {
|
|
|
|
/* If out exists, then out is a bridge port */
|
|
|
|
strcpy(pm->physoutdev, out->name);
|
|
|
|
strcpy(pm->outdev, out->br_port->br->dev->name);
|
|
|
|
} else
|
|
|
|
pm->outdev[0] = pm->physoutdev[0] = '\0';
|
|
|
|
|
|
|
|
if (skb_copy_bits(skb, -ETH_HLEN, pm->data, copy_len) < 0)
|
|
|
|
BUG();
|
|
|
|
|
|
|
|
if (ub->qlen > 1)
|
|
|
|
ub->lastnlh->nlmsg_flags |= NLM_F_MULTI;
|
|
|
|
|
|
|
|
ub->lastnlh = nlh;
|
|
|
|
|
|
|
|
if (ub->qlen >= uloginfo->qthreshold)
|
|
|
|
ulog_send(group);
|
|
|
|
else if (!timer_pending(&ub->timer)) {
|
|
|
|
ub->timer.expires = jiffies + flushtimeout * HZ / 100;
|
|
|
|
add_timer(&ub->timer);
|
|
|
|
}
|
|
|
|
|
|
|
|
unlock:
|
|
|
|
spin_unlock_bh(lock);
|
|
|
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
nlmsg_failure:
|
|
|
|
printk(KERN_CRIT "ebt_ulog: error during NLMSG_PUT. This should "
|
|
|
|
"not happen, please report to author.\n");
|
|
|
|
goto unlock;
|
|
|
|
alloc_failure:
|
|
|
|
goto unlock;
|
|
|
|
}
|
|
|
|
|
2005-12-14 08:14:08 +01:00
|
|
|
/* this function is registered with the netfilter core */
|
|
|
|
static void ebt_log_packet(unsigned int pf, unsigned int hooknum,
|
|
|
|
const struct sk_buff *skb, const struct net_device *in,
|
|
|
|
const struct net_device *out, const struct nf_loginfo *li,
|
|
|
|
const char *prefix)
|
|
|
|
{
|
|
|
|
struct ebt_ulog_info loginfo;
|
|
|
|
|
|
|
|
if (!li || li->type != NF_LOG_TYPE_ULOG) {
|
|
|
|
loginfo.nlgroup = EBT_ULOG_DEFAULT_NLGROUP;
|
|
|
|
loginfo.cprange = 0;
|
|
|
|
loginfo.qthreshold = EBT_ULOG_DEFAULT_QTHRESHOLD;
|
|
|
|
loginfo.prefix[0] = '\0';
|
|
|
|
} else {
|
|
|
|
loginfo.nlgroup = li->u.ulog.group;
|
|
|
|
loginfo.cprange = li->u.ulog.copy_len;
|
|
|
|
loginfo.qthreshold = li->u.ulog.qthreshold;
|
|
|
|
strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
|
|
|
|
}
|
|
|
|
|
|
|
|
ebt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void ebt_ulog(const struct sk_buff *skb, unsigned int hooknr,
|
|
|
|
const struct net_device *in, const struct net_device *out,
|
|
|
|
const void *data, unsigned int datalen)
|
|
|
|
{
|
|
|
|
struct ebt_ulog_info *uloginfo = (struct ebt_ulog_info *)data;
|
|
|
|
|
|
|
|
ebt_ulog_packet(hooknr, skb, in, out, uloginfo, NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
static int ebt_ulog_check(const char *tablename, unsigned int hookmask,
|
|
|
|
const struct ebt_entry *e, void *data, unsigned int datalen)
|
|
|
|
{
|
|
|
|
struct ebt_ulog_info *uloginfo = (struct ebt_ulog_info *)data;
|
|
|
|
|
|
|
|
if (datalen != EBT_ALIGN(sizeof(struct ebt_ulog_info)) ||
|
|
|
|
uloginfo->nlgroup > 31)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
uloginfo->prefix[EBT_ULOG_PREFIX_LEN - 1] = '\0';
|
|
|
|
|
|
|
|
if (uloginfo->qthreshold > EBT_ULOG_MAX_QLEN)
|
|
|
|
uloginfo->qthreshold = EBT_ULOG_MAX_QLEN;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct ebt_watcher ulog = {
|
|
|
|
.name = EBT_ULOG_WATCHER,
|
|
|
|
.watcher = ebt_ulog,
|
|
|
|
.check = ebt_ulog_check,
|
|
|
|
.me = THIS_MODULE,
|
|
|
|
};
|
|
|
|
|
2005-12-14 08:14:08 +01:00
|
|
|
static struct nf_logger ebt_ulog_logger = {
|
|
|
|
.name = EBT_ULOG_WATCHER,
|
|
|
|
.logfn = &ebt_log_packet,
|
|
|
|
.me = THIS_MODULE,
|
|
|
|
};
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
static int __init init(void)
|
|
|
|
{
|
|
|
|
int i, ret = 0;
|
|
|
|
|
|
|
|
if (nlbufsiz >= 128*1024) {
|
|
|
|
printk(KERN_NOTICE "ebt_ulog: Netlink buffer has to be <= 128kB,"
|
|
|
|
" please try a smaller nlbufsiz parameter.\n");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* initialize ulog_buffers */
|
|
|
|
for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
|
|
|
|
init_timer(&ulog_buffers[i].timer);
|
|
|
|
ulog_buffers[i].timer.function = ulog_timer;
|
|
|
|
ulog_buffers[i].timer.data = i;
|
|
|
|
spin_lock_init(&ulog_buffers[i].lock);
|
|
|
|
}
|
|
|
|
|
2005-08-15 21:33:26 +02:00
|
|
|
ebtulognl = netlink_kernel_create(NETLINK_NFLOG, EBT_ULOG_MAXNLGROUPS,
|
|
|
|
NULL, THIS_MODULE);
|
2005-04-17 00:20:36 +02:00
|
|
|
if (!ebtulognl)
|
|
|
|
ret = -ENOMEM;
|
|
|
|
else if ((ret = ebt_register_watcher(&ulog)))
|
|
|
|
sock_release(ebtulognl->sk_socket);
|
|
|
|
|
2005-12-14 08:14:08 +01:00
|
|
|
if (nf_log_register(PF_BRIDGE, &ebt_ulog_logger) < 0) {
|
|
|
|
printk(KERN_WARNING "ebt_ulog: not logging via ulog "
|
|
|
|
"since somebody else already registered for PF_BRIDGE\n");
|
|
|
|
/* we cannot make module load fail here, since otherwise
|
|
|
|
* ebtables userspace would abort */
|
|
|
|
}
|
|
|
|
|
2005-04-17 00:20:36 +02:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit fini(void)
|
|
|
|
{
|
|
|
|
ebt_ulog_buff_t *ub;
|
|
|
|
int i;
|
|
|
|
|
2005-12-14 08:14:08 +01:00
|
|
|
nf_log_unregister_logger(&ebt_ulog_logger);
|
2005-04-17 00:20:36 +02:00
|
|
|
ebt_unregister_watcher(&ulog);
|
|
|
|
for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
|
|
|
|
ub = &ulog_buffers[i];
|
|
|
|
if (timer_pending(&ub->timer))
|
|
|
|
del_timer(&ub->timer);
|
|
|
|
spin_lock_bh(&ub->lock);
|
|
|
|
if (ub->skb) {
|
|
|
|
kfree_skb(ub->skb);
|
|
|
|
ub->skb = NULL;
|
|
|
|
}
|
|
|
|
spin_unlock_bh(&ub->lock);
|
|
|
|
}
|
|
|
|
sock_release(ebtulognl->sk_socket);
|
|
|
|
}
|
|
|
|
|
|
|
|
module_init(init);
|
|
|
|
module_exit(fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
|
|
|
|
MODULE_DESCRIPTION("ebtables userspace logging module for bridged Ethernet"
|
|
|
|
" frames");
|