[NETFILTER]: Add new "nfnetlink_log" userspace packet logging facility

This is a generic (layer3 independent) version of what ipt_ULOG is already
doing for IPv4 today.  ipt_ULOG, ebt_ulog and finally also ip[6]t_LOG will
be deprecated by this mechanism in the long term.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harald Welte 2005-08-09 19:58:39 -07:00 committed by David S. Miller
parent 608c8e4f7b
commit 0597f2680d
5 changed files with 1093 additions and 0 deletions

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@ -0,0 +1,85 @@
#ifndef _NFNETLINK_LOG_H
#define _NFNETLINK_LOG_H
/* This file describes the netlink messages (i.e. 'protocol packets'),
* and not any kind of function definitions. It is shared between kernel and
* userspace. Don't put kernel specific stuff in here */
#include <linux/netfilter/nfnetlink.h>
enum nfulnl_msg_types {
NFULNL_MSG_PACKET, /* packet from kernel to userspace */
NFULNL_MSG_CONFIG, /* connect to a particular queue */
NFULNL_MSG_MAX
};
struct nfulnl_msg_packet_hdr {
u_int16_t hw_protocol; /* hw protocol (network order) */
u_int8_t hook; /* netfilter hook */
u_int8_t _pad;
} __attribute__ ((packed));
struct nfulnl_msg_packet_hw {
u_int16_t hw_addrlen;
u_int16_t _pad;
u_int8_t hw_addr[8];
} __attribute__ ((packed));
struct nfulnl_msg_packet_timestamp {
u_int64_t sec;
u_int64_t usec;
} __attribute__ ((packed));
#define NFULNL_PREFIXLEN 30 /* just like old log target */
enum nfulnl_attr_type {
NFULA_UNSPEC,
NFULA_PACKET_HDR,
NFULA_MARK, /* u_int32_t nfmark */
NFULA_TIMESTAMP, /* nfulnl_msg_packet_timestamp */
NFULA_IFINDEX_INDEV, /* u_int32_t ifindex */
NFULA_IFINDEX_OUTDEV, /* u_int32_t ifindex */
NFULA_HWADDR, /* nfulnl_msg_packet_hw */
NFULA_PAYLOAD, /* opaque data payload */
NFULA_PREFIX, /* string prefix */
NFULA_UID, /* user id of socket */
__NFULA_MAX
};
#define NFULA_MAX (__NFULA_MAX - 1)
enum nfulnl_msg_config_cmds {
NFULNL_CFG_CMD_NONE,
NFULNL_CFG_CMD_BIND,
NFULNL_CFG_CMD_UNBIND,
NFULNL_CFG_CMD_PF_BIND,
NFULNL_CFG_CMD_PF_UNBIND,
};
struct nfulnl_msg_config_cmd {
u_int8_t command; /* nfulnl_msg_config_cmds */
} __attribute__ ((packed));
struct nfulnl_msg_config_mode {
u_int32_t copy_range;
u_int8_t copy_mode;
u_int8_t _pad;
} __attribute__ ((packed));
enum nfulnl_attr_config {
NFULA_CFG_UNSPEC,
NFULA_CFG_CMD, /* nfulnl_msg_config_cmd */
NFULA_CFG_MODE, /* nfulnl_msg_config_mode */
NFULA_CFG_NLBUFSIZ, /* u_int32_t buffer size */
NFULA_CFG_TIMEOUT, /* u_int32_t in 1/100 s */
NFULA_CFG_QTHRESH, /* u_int32_t */
__NFULA_CFG_MAX
};
#define NFULA_CFG_MAX (__NFULA_CFG_MAX -1)
#define NFULNL_COPY_NONE 0x00
#define NFULNL_COPY_META 0x01
#define NFULNL_COPY_PACKET 0x02
#endif /* _NFNETLINK_LOG_H */

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@ -11,3 +11,14 @@ config NETFILTER_NETLINK_QUEUE
If this option isenabled, the kernel will include support
for queueing packets via NFNETLINK.
config NETFILTER_NETLINK_LOG
tristate "Netfilter LOG over NFNETLINK interface"
depends on NETFILTER_NETLINK
help
If this option is enabled, the kernel will include support
for logging packets via NFNETLINK.
This obsoletes the existing ipt_ULOG and ebg_ulog mechanisms,
and is also scheduled to replace the old syslog-based ipt_LOG
and ip6t_LOG modules.

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@ -1,2 +1,3 @@
obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o

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@ -0,0 +1,995 @@
/*
* This is a module which is used for logging packets to userspace via
* nfetlink.
*
* (C) 2005 by Harald Welte <laforge@netfilter.org>
*
* Based on the old ipv4-only ipt_ULOG.c:
* (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/netlink.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_log.h>
#include <linux/spinlock.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/security.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <net/sock.h>
#include <asm/atomic.h>
#define NFULNL_NLBUFSIZ_DEFAULT 4096
#define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
#define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
#define PRINTR(x, args...) do { if (net_ratelimit()) \
printk(x, ## args); } while (0);
#if 0
#define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
__FILE__, __LINE__, __FUNCTION__, \
## args)
#else
#define UDEBUG(x, ...)
#endif
struct nfulnl_instance {
struct hlist_node hlist; /* global list of instances */
spinlock_t lock;
atomic_t use; /* use count */
unsigned int qlen; /* number of nlmsgs in skb */
struct sk_buff *skb; /* pre-allocatd skb */
struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
struct timer_list timer;
int peer_pid; /* PID of the peer process */
/* configurable parameters */
unsigned int flushtimeout; /* timeout until queue flush */
unsigned int nlbufsiz; /* netlink buffer allocation size */
unsigned int qthreshold; /* threshold of the queue */
u_int32_t copy_range;
u_int16_t group_num; /* number of this queue */
u_int8_t copy_mode;
};
static DEFINE_RWLOCK(instances_lock);
#define INSTANCE_BUCKETS 16
static struct hlist_head instance_table[INSTANCE_BUCKETS];
static unsigned int hash_init;
static inline u_int8_t instance_hashfn(u_int16_t group_num)
{
return ((group_num & 0xff) % INSTANCE_BUCKETS);
}
static struct nfulnl_instance *
__instance_lookup(u_int16_t group_num)
{
struct hlist_head *head;
struct hlist_node *pos;
struct nfulnl_instance *inst;
UDEBUG("entering (group_num=%u)\n", group_num);
head = &instance_table[instance_hashfn(group_num)];
hlist_for_each_entry(inst, pos, head, hlist) {
if (inst->group_num == group_num)
return inst;
}
return NULL;
}
static inline void
instance_get(struct nfulnl_instance *inst)
{
atomic_inc(&inst->use);
}
static struct nfulnl_instance *
instance_lookup_get(u_int16_t group_num)
{
struct nfulnl_instance *inst;
read_lock_bh(&instances_lock);
inst = __instance_lookup(group_num);
if (inst)
instance_get(inst);
read_unlock_bh(&instances_lock);
return inst;
}
static void
instance_put(struct nfulnl_instance *inst)
{
if (inst && atomic_dec_and_test(&inst->use)) {
UDEBUG("kfree(inst=%p)\n", inst);
kfree(inst);
}
}
static void nfulnl_timer(unsigned long data);
static struct nfulnl_instance *
instance_create(u_int16_t group_num, int pid)
{
struct nfulnl_instance *inst;
UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
pid);
write_lock_bh(&instances_lock);
if (__instance_lookup(group_num)) {
inst = NULL;
UDEBUG("aborting, instance already exists\n");
goto out_unlock;
}
inst = kmalloc(sizeof(*inst), GFP_ATOMIC);
if (!inst)
goto out_unlock;
memset(inst, 0, sizeof(*inst));
INIT_HLIST_NODE(&inst->hlist);
inst->lock = SPIN_LOCK_UNLOCKED;
/* needs to be two, since we _put() after creation */
atomic_set(&inst->use, 2);
init_timer(&inst->timer);
inst->timer.function = nfulnl_timer;
inst->timer.data = (unsigned long)inst;
/* don't start timer yet. (re)start it with every packet */
inst->peer_pid = pid;
inst->group_num = group_num;
inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
inst->copy_mode = NFULNL_COPY_PACKET;
inst->copy_range = 0xffff;
if (!try_module_get(THIS_MODULE))
goto out_free;
hlist_add_head(&inst->hlist,
&instance_table[instance_hashfn(group_num)]);
UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
inst->hlist.next);
write_unlock_bh(&instances_lock);
return inst;
out_free:
instance_put(inst);
out_unlock:
write_unlock_bh(&instances_lock);
return NULL;
}
static int __nfulnl_send(struct nfulnl_instance *inst);
static void
_instance_destroy2(struct nfulnl_instance *inst, int lock)
{
/* first pull it out of the global list */
if (lock)
write_lock_bh(&instances_lock);
UDEBUG("removing instance %p (queuenum=%u) from hash\n",
inst, inst->group_num);
hlist_del(&inst->hlist);
if (lock)
write_unlock_bh(&instances_lock);
/* then flush all pending packets from skb */
spin_lock_bh(&inst->lock);
if (inst->skb) {
if (inst->qlen)
__nfulnl_send(inst);
if (inst->skb) {
kfree_skb(inst->skb);
inst->skb = NULL;
}
}
spin_unlock_bh(&inst->lock);
/* and finally put the refcount */
instance_put(inst);
module_put(THIS_MODULE);
}
static inline void
__instance_destroy(struct nfulnl_instance *inst)
{
_instance_destroy2(inst, 0);
}
static inline void
instance_destroy(struct nfulnl_instance *inst)
{
_instance_destroy2(inst, 1);
}
static int
nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
unsigned int range)
{
int status = 0;
spin_lock_bh(&inst->lock);
switch (mode) {
case NFULNL_COPY_NONE:
case NFULNL_COPY_META:
inst->copy_mode = mode;
inst->copy_range = 0;
break;
case NFULNL_COPY_PACKET:
inst->copy_mode = mode;
/* we're using struct nfattr which has 16bit nfa_len */
if (range > 0xffff)
inst->copy_range = 0xffff;
else
inst->copy_range = range;
break;
default:
status = -EINVAL;
break;
}
spin_unlock_bh(&inst->lock);
return status;
}
static int
nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
{
int status;
spin_lock_bh(&inst->lock);
if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
status = -ERANGE;
else if (nlbufsiz > 131072)
status = -ERANGE;
else {
inst->nlbufsiz = nlbufsiz;
status = 0;
}
spin_unlock_bh(&inst->lock);
return status;
}
static int
nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
{
spin_lock_bh(&inst->lock);
inst->flushtimeout = timeout;
spin_unlock_bh(&inst->lock);
return 0;
}
static int
nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
{
spin_lock_bh(&inst->lock);
inst->qthreshold = qthresh;
spin_unlock_bh(&inst->lock);
return 0;
}
static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
unsigned int pkt_size)
{
struct sk_buff *skb;
UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
/* alloc skb which should be big enough for a whole multipart
* message. WARNING: has to be <= 128k due to slab restrictions */
skb = alloc_skb(inst_size, GFP_ATOMIC);
if (!skb) {
PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
inst_size);
/* try to allocate only as much as we need for current
* packet */
skb = alloc_skb(pkt_size, GFP_ATOMIC);
if (!skb)
PRINTR("nfnetlink_log: can't even alloc %u bytes\n",
pkt_size);
}
return skb;
}
static int
__nfulnl_send(struct nfulnl_instance *inst)
{
int status;
if (timer_pending(&inst->timer))
del_timer(&inst->timer);
if (inst->qlen > 1)
inst->lastnlh->nlmsg_type = NLMSG_DONE;
status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
if (status < 0) {
UDEBUG("netlink_unicast() failed\n");
/* FIXME: statistics */
}
inst->qlen = 0;
inst->skb = NULL;
inst->lastnlh = NULL;
return status;
}
static void nfulnl_timer(unsigned long data)
{
struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
UDEBUG("timer function called, flushing buffer\n");
spin_lock_bh(&inst->lock);
__nfulnl_send(inst);
instance_put(inst);
spin_unlock_bh(&inst->lock);
}
static inline int
__build_packet_message(struct nfulnl_instance *inst,
const struct sk_buff *skb,
unsigned int data_len,
unsigned int pf,
unsigned int hooknum,
const struct net_device *indev,
const struct net_device *outdev,
const struct nf_loginfo *li,
const char *prefix)
{
unsigned char *old_tail;
struct nfulnl_msg_packet_hdr pmsg;
struct nlmsghdr *nlh;
struct nfgenmsg *nfmsg;
u_int32_t tmp_uint;
UDEBUG("entered\n");
old_tail = inst->skb->tail;
nlh = NLMSG_PUT(inst->skb, 0, 0,
NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
sizeof(struct nfgenmsg));
nfmsg = NLMSG_DATA(nlh);
nfmsg->nfgen_family = pf;
nfmsg->version = NFNETLINK_V0;
nfmsg->res_id = htons(inst->group_num);
pmsg.hw_protocol = htons(skb->protocol);
pmsg.hook = hooknum;
NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
if (prefix) {
int slen = strlen(prefix);
if (slen > NFULNL_PREFIXLEN)
slen = NFULNL_PREFIXLEN;
NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
}
if (indev) {
tmp_uint = htonl(indev->ifindex);
NFA_PUT(inst->skb, NFULA_IFINDEX_INDEV, sizeof(tmp_uint),
&tmp_uint);
}
if (outdev) {
tmp_uint = htonl(outdev->ifindex);
NFA_PUT(inst->skb, NFULA_IFINDEX_OUTDEV, sizeof(tmp_uint),
&tmp_uint);
}
if (skb->nfmark) {
tmp_uint = htonl(skb->nfmark);
NFA_PUT(inst->skb, NFULA_MARK, sizeof(tmp_uint), &tmp_uint);
}
if (indev && skb->dev && skb->dev->hard_header_parse) {
struct nfulnl_msg_packet_hw phw;
phw.hw_addrlen =
skb->dev->hard_header_parse((struct sk_buff *)skb,
phw.hw_addr);
phw.hw_addrlen = htons(phw.hw_addrlen);
NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
}
if (skb->stamp.tv_sec) {
struct nfulnl_msg_packet_timestamp ts;
ts.sec = cpu_to_be64(skb->stamp.tv_sec);
ts.usec = cpu_to_be64(skb->stamp.tv_usec);
NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
}
/* UID */
if (skb->sk) {
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
u_int32_t uid = htonl(skb->sk->sk_socket->file->f_uid);
/* need to unlock here since NFA_PUT may goto */
read_unlock_bh(&skb->sk->sk_callback_lock);
NFA_PUT(inst->skb, NFULA_UID, sizeof(uid), &uid);
} else
read_unlock_bh(&skb->sk->sk_callback_lock);
}
if (data_len) {
struct nfattr *nfa;
int size = NFA_LENGTH(data_len);
if (skb_tailroom(inst->skb) < (int)NFA_SPACE(data_len)) {
printk(KERN_WARNING "nfnetlink_log: no tailroom!\n");
goto nlmsg_failure;
}
nfa = (struct nfattr *)skb_put(inst->skb, NFA_ALIGN(size));
nfa->nfa_type = NFULA_PAYLOAD;
nfa->nfa_len = size;
if (skb_copy_bits(skb, 0, NFA_DATA(nfa), data_len))
BUG();
}
nlh->nlmsg_len = inst->skb->tail - old_tail;
return 0;
nlmsg_failure:
UDEBUG("nlmsg_failure\n");
nfattr_failure:
PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
return -1;
}
#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
static struct nf_loginfo default_loginfo = {
.type = NF_LOG_TYPE_ULOG,
.u = {
.ulog = {
.copy_len = 0xffff,
.group = 0,
.qthreshold = 1,
},
},
};
/* log handler for internal netfilter logging api */
static void
nfulnl_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_user,
const char *prefix)
{
unsigned int size, data_len;
struct nfulnl_instance *inst;
const struct nf_loginfo *li;
unsigned int qthreshold;
unsigned int nlbufsiz;
if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
li = li_user;
else
li = &default_loginfo;
inst = instance_lookup_get(li->u.ulog.group);
if (!inst)
inst = instance_lookup_get(0);
if (!inst) {
PRINTR("nfnetlink_log: trying to log packet, "
"but no instance for group %u\n", li->u.ulog.group);
return;
}
/* all macros expand to constant values at compile time */
/* FIXME: do we want to make the size calculation conditional based on
* what is actually present? way more branches and checks, but more
* memory efficient... */
size = NLMSG_SPACE(sizeof(struct nfgenmsg))
+ NFA_SPACE(sizeof(struct nfulnl_msg_packet_hdr))
+ NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
+ NFA_SPACE(sizeof(u_int32_t)) /* ifindex */
+ NFA_SPACE(sizeof(u_int32_t)) /* mark */
+ NFA_SPACE(sizeof(u_int32_t)) /* uid */
+ NFA_SPACE(NFULNL_PREFIXLEN) /* prefix */
+ NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
+ NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
UDEBUG("initial size=%u\n", size);
spin_lock_bh(&inst->lock);
qthreshold = inst->qthreshold;
/* per-rule qthreshold overrides per-instance */
if (qthreshold > li->u.ulog.qthreshold)
qthreshold = li->u.ulog.qthreshold;
switch (inst->copy_mode) {
case NFULNL_COPY_META:
case NFULNL_COPY_NONE:
data_len = 0;
break;
case NFULNL_COPY_PACKET:
if (inst->copy_range == 0
|| inst->copy_range > skb->len)
data_len = skb->len;
else
data_len = inst->copy_range;
size += NFA_SPACE(data_len);
UDEBUG("copy_packet, therefore size now %u\n", size);
break;
default:
spin_unlock_bh(&inst->lock);
instance_put(inst);
return;
}
if (size > inst->nlbufsiz)
nlbufsiz = size;
else
nlbufsiz = inst->nlbufsiz;
if (!inst->skb) {
if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
inst->nlbufsiz, size);
goto alloc_failure;
}
} else if (inst->qlen >= qthreshold ||
size > skb_tailroom(inst->skb)) {
/* either the queue len is too high or we don't have
* enough room in the skb left. flush to userspace. */
UDEBUG("flushing old skb\n");
__nfulnl_send(inst);
if (!(inst->skb = nfulnl_alloc_skb(nlbufsiz, size))) {
UDEBUG("error in nfulnl_alloc_skb(%u, %u)\n",
inst->nlbufsiz, size);
goto alloc_failure;
}
}
UDEBUG("qlen %d, qthreshold %d\n", inst->qlen, qthreshold);
inst->qlen++;
__build_packet_message(inst, skb, data_len, pf,
hooknum, in, out, li, prefix);
/* timer_pending always called within inst->lock, so there
* is no chance of a race here */
if (!timer_pending(&inst->timer)) {
instance_get(inst);
inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
add_timer(&inst->timer);
}
spin_unlock_bh(&inst->lock);
return;
alloc_failure:
spin_unlock_bh(&inst->lock);
instance_put(inst);
UDEBUG("error allocating skb\n");
/* FIXME: statistics */
}
static int
nfulnl_rcv_nl_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct netlink_notify *n = ptr;
if (event == NETLINK_URELEASE &&
n->protocol == NETLINK_NETFILTER && n->pid) {
int i;
/* destroy all instances for this pid */
write_lock_bh(&instances_lock);
for (i = 0; i < INSTANCE_BUCKETS; i++) {
struct hlist_node *tmp, *t2;
struct nfulnl_instance *inst;
struct hlist_head *head = &instance_table[i];
hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) {
UDEBUG("node = %p\n", inst);
if (n->pid == inst->peer_pid)
__instance_destroy(inst);
}
}
write_unlock_bh(&instances_lock);
}
return NOTIFY_DONE;
}
static struct notifier_block nfulnl_rtnl_notifier = {
.notifier_call = nfulnl_rcv_nl_event,
};
static int
nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
{
return -ENOTSUPP;
}
static struct nf_logger nfulnl_logger = {
.name = "nfnetlink_log",
.logfn = &nfulnl_log_packet,
.me = THIS_MODULE,
};
static const int nfula_min[NFULA_MAX] = {
[NFULA_PACKET_HDR-1] = sizeof(struct nfulnl_msg_packet_hdr),
[NFULA_MARK-1] = sizeof(u_int32_t),
[NFULA_TIMESTAMP-1] = sizeof(struct nfulnl_msg_packet_timestamp),
[NFULA_IFINDEX_INDEV-1] = sizeof(u_int32_t),
[NFULA_IFINDEX_OUTDEV-1]= sizeof(u_int32_t),
[NFULA_HWADDR-1] = sizeof(struct nfulnl_msg_packet_hw),
[NFULA_PAYLOAD-1] = 0,
[NFULA_PREFIX-1] = 0,
[NFULA_UID-1] = sizeof(u_int32_t),
};
static const int nfula_cfg_min[NFULA_CFG_MAX] = {
[NFULA_CFG_CMD-1] = sizeof(struct nfulnl_msg_config_cmd),
[NFULA_CFG_MODE-1] = sizeof(struct nfulnl_msg_config_mode),
[NFULA_CFG_TIMEOUT-1] = sizeof(u_int32_t),
[NFULA_CFG_QTHRESH-1] = sizeof(u_int32_t),
[NFULA_CFG_NLBUFSIZ-1] = sizeof(u_int32_t),
};
static int
nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
struct nlmsghdr *nlh, struct nfattr *nfula[], int *errp)
{
struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
u_int16_t group_num = ntohs(nfmsg->res_id);
struct nfulnl_instance *inst;
int ret = 0;
UDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
if (nfattr_bad_size(nfula, NFULA_CFG_MAX, nfula_cfg_min)) {
UDEBUG("bad attribute size\n");
return -EINVAL;
}
inst = instance_lookup_get(group_num);
if (nfula[NFULA_CFG_CMD-1]) {
u_int8_t pf = nfmsg->nfgen_family;
struct nfulnl_msg_config_cmd *cmd;
cmd = NFA_DATA(nfula[NFULA_CFG_CMD-1]);
UDEBUG("found CFG_CMD for\n");
switch (cmd->command) {
case NFULNL_CFG_CMD_BIND:
if (inst) {
ret = -EBUSY;
goto out_put;
}
inst = instance_create(group_num,
NETLINK_CB(skb).pid);
if (!inst) {
ret = -EINVAL;
goto out_put;
}
break;
case NFULNL_CFG_CMD_UNBIND:
if (!inst) {
ret = -ENODEV;
goto out_put;
}
if (inst->peer_pid != NETLINK_CB(skb).pid) {
ret = -EPERM;
goto out_put;
}
instance_destroy(inst);
break;
case NFULNL_CFG_CMD_PF_BIND:
UDEBUG("registering log handler for pf=%u\n", pf);
ret = nf_log_register(pf, &nfulnl_logger);
break;
case NFULNL_CFG_CMD_PF_UNBIND:
UDEBUG("unregistering log handler for pf=%u\n", pf);
/* This is a bug and a feature. We cannot unregister
* other handlers, like nfnetlink_inst can */
nf_log_unregister_pf(pf);
break;
default:
ret = -EINVAL;
break;
}
} else {
if (!inst) {
UDEBUG("no config command, and no instance for "
"group=%u pid=%u =>ENOENT\n",
group_num, NETLINK_CB(skb).pid);
ret = -ENOENT;
goto out_put;
}
if (inst->peer_pid != NETLINK_CB(skb).pid) {
UDEBUG("no config command, and wrong pid\n");
ret = -EPERM;
goto out_put;
}
}
if (nfula[NFULA_CFG_MODE-1]) {
struct nfulnl_msg_config_mode *params;
params = NFA_DATA(nfula[NFULA_CFG_MODE-1]);
nfulnl_set_mode(inst, params->copy_mode,
ntohs(params->copy_range));
}
if (nfula[NFULA_CFG_TIMEOUT-1]) {
u_int32_t timeout =
*(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_TIMEOUT-1]);
nfulnl_set_timeout(inst, ntohl(timeout));
}
if (nfula[NFULA_CFG_NLBUFSIZ-1]) {
u_int32_t nlbufsiz =
*(u_int32_t *)NFA_DATA(nfula[NFULA_CFG_NLBUFSIZ-1]);
nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
}
if (nfula[NFULA_CFG_QTHRESH-1]) {
u_int32_t qthresh =
*(u_int16_t *)NFA_DATA(nfula[NFULA_CFG_QTHRESH-1]);
nfulnl_set_qthresh(inst, ntohl(qthresh));
}
out_put:
instance_put(inst);
return ret;
}
static struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
[NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
.cap_required = CAP_NET_ADMIN },
[NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
.cap_required = CAP_NET_ADMIN },
};
static struct nfnetlink_subsystem nfulnl_subsys = {
.name = "log",
.subsys_id = NFNL_SUBSYS_ULOG,
.cb_count = NFULNL_MSG_MAX,
.attr_count = NFULA_MAX,
.cb = nfulnl_cb,
};
#ifdef CONFIG_PROC_FS
struct iter_state {
unsigned int bucket;
};
static struct hlist_node *get_first(struct seq_file *seq)
{
struct iter_state *st = seq->private;
if (!st)
return NULL;
for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
if (!hlist_empty(&instance_table[st->bucket]))
return instance_table[st->bucket].first;
}
return NULL;
}
static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
{
struct iter_state *st = seq->private;
h = h->next;
while (!h) {
if (++st->bucket >= INSTANCE_BUCKETS)
return NULL;
h = instance_table[st->bucket].first;
}
return h;
}
static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
{
struct hlist_node *head;
head = get_first(seq);
if (head)
while (pos && (head = get_next(seq, head)))
pos--;
return pos ? NULL : head;
}
static void *seq_start(struct seq_file *seq, loff_t *pos)
{
read_lock_bh(&instances_lock);
return get_idx(seq, *pos);
}
static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
{
(*pos)++;
return get_next(s, v);
}
static void seq_stop(struct seq_file *s, void *v)
{
read_unlock_bh(&instances_lock);
}
static int seq_show(struct seq_file *s, void *v)
{
const struct nfulnl_instance *inst = v;
return seq_printf(s, "%5d %6d %5d %1d %5d %6d %2d\n",
inst->group_num,
inst->peer_pid, inst->qlen,
inst->copy_mode, inst->copy_range,
inst->flushtimeout, atomic_read(&inst->use));
}
static struct seq_operations nful_seq_ops = {
.start = seq_start,
.next = seq_next,
.stop = seq_stop,
.show = seq_show,
};
static int nful_open(struct inode *inode, struct file *file)
{
struct seq_file *seq;
struct iter_state *is;
int ret;
is = kmalloc(sizeof(*is), GFP_KERNEL);
if (!is)
return -ENOMEM;
memset(is, 0, sizeof(*is));
ret = seq_open(file, &nful_seq_ops);
if (ret < 0)
goto out_free;
seq = file->private_data;
seq->private = is;
return ret;
out_free:
kfree(is);
return ret;
}
static struct file_operations nful_file_ops = {
.owner = THIS_MODULE,
.open = nful_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
#endif /* PROC_FS */
static int
init_or_cleanup(int init)
{
int i, status = -ENOMEM;
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc_nful;
#endif
if (!init)
goto cleanup;
for (i = 0; i < INSTANCE_BUCKETS; i++)
INIT_HLIST_HEAD(&instance_table[i]);
/* it's not really all that important to have a random value, so
* we can do this from the init function, even if there hasn't
* been that much entropy yet */
get_random_bytes(&hash_init, sizeof(hash_init));
netlink_register_notifier(&nfulnl_rtnl_notifier);
status = nfnetlink_subsys_register(&nfulnl_subsys);
if (status < 0) {
printk(KERN_ERR "log: failed to create netlink socket\n");
goto cleanup_netlink_notifier;
}
#ifdef CONFIG_PROC_FS
proc_nful = create_proc_entry("nfnetlink_log", 0440,
proc_net_netfilter);
if (!proc_nful)
goto cleanup_subsys;
proc_nful->proc_fops = &nful_file_ops;
#endif
return status;
cleanup:
nf_log_unregister_logger(&nfulnl_logger);
#ifdef CONFIG_PROC_FS
remove_proc_entry("nfnetlink_log", proc_net_netfilter);
cleanup_subsys:
#endif
nfnetlink_subsys_unregister(&nfulnl_subsys);
cleanup_netlink_notifier:
netlink_unregister_notifier(&nfulnl_rtnl_notifier);
return status;
}
static int __init init(void)
{
return init_or_cleanup(1);
}
static void __exit fini(void)
{
init_or_cleanup(0);
}
MODULE_DESCRIPTION("netfilter userspace logging");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_LICENSE("GPL");
module_init(init);
module_exit(fini);

View File

@ -1041,6 +1041,7 @@ init_or_cleanup(int init)
nf_unregister_queue_handlers(nfqnl_enqueue_packet);
unregister_netdevice_notifier(&nfqnl_dev_notifier);
#ifdef CONFIG_PROC_FS
remove_proc_entry("nfnetlink_queue", proc_net_netfilter);
cleanup_subsys:
#endif
nfnetlink_subsys_unregister(&nfqnl_subsys);