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alistair23-linux/net/netfilter/nfnetlink_log.c
David S. Miller 958d03b016 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 
Pablo Neira Ayuso says:

====================
netfilter/ipvs updates for net-next

The following patchset contains Netfilter updates for your net-next
tree, this includes the NAT redirection support for nf_tables, the
cgroup support for nft meta and conntrack zone support for the connlimit
match. Coming after those, a bunch of sparse warning fixes, missing
netns bits and cleanups. More specifically, they are:

1) Prepare IPv4 and IPv6 NAT redirect code to use it from nf_tables,
   patches from Arturo Borrero.

2) Introduce the nf_tables redir expression, from Arturo Borrero.

3) Remove an unnecessary assignment in ip_vs_xmit/__ip_vs_get_out_rt().
   Patch from Alex Gartrell.

4) Add nft_log_dereference() macro to the nf_log infrastructure, patch
   from Marcelo Leitner.

5) Add some extra validation when registering logger families, also
   from Marcelo.

6) Some spelling cleanups from stephen hemminger.

7) Fix sparse warning in nf_logger_find_get().

8) Add cgroup support to nf_tables meta, patch from Ana Rey.

9) A Kconfig fix for the new redir expression and fix sparse warnings in
   the new redir expression.

10) Fix several sparse warnings in the netfilter tree, from
    Florian Westphal.

11) Reduce verbosity when OOM in nfnetlink_log. User can basically do
    nothing when this situation occurs.

12) Add conntrack zone support to xt_connlimit, again from Florian.

13) Add netnamespace support to the h323 conntrack helper, contributed
    by Vasily Averin.

14) Remove unnecessary nul-pointer checks before free_percpu() and
    module_put(), from Markus Elfring.

15) Use pr_fmt in nfnetlink_log, again patch from Marcelo Leitner.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-24 16:00:58 -05:00

1114 lines
27 KiB
C
Raw Blame History

/*
* This is a module which is used for logging packets to userspace via
* nfetlink.
*
* (C) 2005 by Harald Welte <laforge@netfilter.org>
* (C) 2006-2012 Patrick McHardy <kaber@trash.net>
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <net/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/slab.h>
#include <net/sock.h>
#include <net/netfilter/nf_log.h>
#include <net/netns/generic.h>
#include <net/netfilter/nfnetlink_log.h>
#include <linux/atomic.h>
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
#include "../bridge/br_private.h"
#endif
#define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE
#define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
#define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
/* max packet size is limited by 16-bit struct nfattr nfa_len field */
#define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN)
#define PRINTR(x, args...) do { if (net_ratelimit()) \
printk(x, ## args); } while (0);
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 timer_list timer;
struct net *net;
struct user_namespace *peer_user_ns; /* User namespace of the peer process */
int peer_portid; /* PORTID 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_int32_t seq; /* instance-local sequential counter */
u_int16_t group_num; /* number of this queue */
u_int16_t flags;
u_int8_t copy_mode;
struct rcu_head rcu;
};
#define INSTANCE_BUCKETS 16
static int nfnl_log_net_id __read_mostly;
struct nfnl_log_net {
spinlock_t instances_lock;
struct hlist_head instance_table[INSTANCE_BUCKETS];
atomic_t global_seq;
};
static struct nfnl_log_net *nfnl_log_pernet(struct net *net)
{
return net_generic(net, nfnl_log_net_id);
}
static inline u_int8_t instance_hashfn(u_int16_t group_num)
{
return ((group_num & 0xff) % INSTANCE_BUCKETS);
}
static struct nfulnl_instance *
__instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
{
struct hlist_head *head;
struct nfulnl_instance *inst;
head = &log->instance_table[instance_hashfn(group_num)];
hlist_for_each_entry_rcu(inst, 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(struct nfnl_log_net *log, u_int16_t group_num)
{
struct nfulnl_instance *inst;
rcu_read_lock_bh();
inst = __instance_lookup(log, group_num);
if (inst && !atomic_inc_not_zero(&inst->use))
inst = NULL;
rcu_read_unlock_bh();
return inst;
}
static void nfulnl_instance_free_rcu(struct rcu_head *head)
{
struct nfulnl_instance *inst =
container_of(head, struct nfulnl_instance, rcu);
put_net(inst->net);
kfree(inst);
module_put(THIS_MODULE);
}
static void
instance_put(struct nfulnl_instance *inst)
{
if (inst && atomic_dec_and_test(&inst->use))
call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
}
static void nfulnl_timer(unsigned long data);
static struct nfulnl_instance *
instance_create(struct net *net, u_int16_t group_num,
int portid, struct user_namespace *user_ns)
{
struct nfulnl_instance *inst;
struct nfnl_log_net *log = nfnl_log_pernet(net);
int err;
spin_lock_bh(&log->instances_lock);
if (__instance_lookup(log, group_num)) {
err = -EEXIST;
goto out_unlock;
}
inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
if (!inst) {
err = -ENOMEM;
goto out_unlock;
}
if (!try_module_get(THIS_MODULE)) {
kfree(inst);
err = -EAGAIN;
goto out_unlock;
}
INIT_HLIST_NODE(&inst->hlist);
spin_lock_init(&inst->lock);
/* needs to be two, since we _put() after creation */
atomic_set(&inst->use, 2);
setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
inst->net = get_net(net);
inst->peer_user_ns = user_ns;
inst->peer_portid = portid;
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 = NFULNL_COPY_RANGE_MAX;
hlist_add_head_rcu(&inst->hlist,
&log->instance_table[instance_hashfn(group_num)]);
spin_unlock_bh(&log->instances_lock);
return inst;
out_unlock:
spin_unlock_bh(&log->instances_lock);
return ERR_PTR(err);
}
static void __nfulnl_flush(struct nfulnl_instance *inst);
/* called with BH disabled */
static void
__instance_destroy(struct nfulnl_instance *inst)
{
/* first pull it out of the global list */
hlist_del_rcu(&inst->hlist);
/* then flush all pending packets from skb */
spin_lock(&inst->lock);
/* lockless readers wont be able to use us */
inst->copy_mode = NFULNL_COPY_DISABLED;
if (inst->skb)
__nfulnl_flush(inst);
spin_unlock(&inst->lock);
/* and finally put the refcount */
instance_put(inst);
}
static inline void
instance_destroy(struct nfnl_log_net *log,
struct nfulnl_instance *inst)
{
spin_lock_bh(&log->instances_lock);
__instance_destroy(inst);
spin_unlock_bh(&log->instances_lock);
}
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;
if (range == 0)
range = NFULNL_COPY_RANGE_MAX;
inst->copy_range = min_t(unsigned int,
range, NFULNL_COPY_RANGE_MAX);
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 int
nfulnl_set_flags(struct nfulnl_instance *inst, u_int16_t flags)
{
spin_lock_bh(&inst->lock);
inst->flags = flags;
spin_unlock_bh(&inst->lock);
return 0;
}
static struct sk_buff *
nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
unsigned int pkt_size)
{
struct sk_buff *skb;
unsigned int n;
/* alloc skb which should be big enough for a whole multipart
* message. WARNING: has to be <= 128k due to slab restrictions */
n = max(inst_size, pkt_size);
skb = nfnetlink_alloc_skb(net, n, peer_portid, GFP_ATOMIC);
if (!skb) {
if (n > pkt_size) {
/* try to allocate only as much as we need for current
* packet */
skb = nfnetlink_alloc_skb(net, pkt_size,
peer_portid, GFP_ATOMIC);
}
}
return skb;
}
static void
__nfulnl_send(struct nfulnl_instance *inst)
{
if (inst->qlen > 1) {
struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
NLMSG_DONE,
sizeof(struct nfgenmsg),
0);
if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
inst->skb->len, skb_tailroom(inst->skb))) {
kfree_skb(inst->skb);
goto out;
}
}
nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
MSG_DONTWAIT);
out:
inst->qlen = 0;
inst->skb = NULL;
}
static void
__nfulnl_flush(struct nfulnl_instance *inst)
{
/* timer holds a reference */
if (del_timer(&inst->timer))
instance_put(inst);
if (inst->skb)
__nfulnl_send(inst);
}
static void
nfulnl_timer(unsigned long data)
{
struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
spin_lock_bh(&inst->lock);
if (inst->skb)
__nfulnl_send(inst);
spin_unlock_bh(&inst->lock);
instance_put(inst);
}
/* This is an inline function, we don't really care about a long
* list of arguments */
static inline int
__build_packet_message(struct nfnl_log_net *log,
struct nfulnl_instance *inst,
const struct sk_buff *skb,
unsigned int data_len,
u_int8_t pf,
unsigned int hooknum,
const struct net_device *indev,
const struct net_device *outdev,
const char *prefix, unsigned int plen)
{
struct nfulnl_msg_packet_hdr pmsg;
struct nlmsghdr *nlh;
struct nfgenmsg *nfmsg;
sk_buff_data_t old_tail = inst->skb->tail;
struct sock *sk;
const unsigned char *hwhdrp;
nlh = nlmsg_put(inst->skb, 0, 0,
NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
sizeof(struct nfgenmsg), 0);
if (!nlh)
return -1;
nfmsg = nlmsg_data(nlh);
nfmsg->nfgen_family = pf;
nfmsg->version = NFNETLINK_V0;
nfmsg->res_id = htons(inst->group_num);
memset(&pmsg, 0, sizeof(pmsg));
pmsg.hw_protocol = skb->protocol;
pmsg.hook = hooknum;
if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
goto nla_put_failure;
if (prefix &&
nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
goto nla_put_failure;
if (indev) {
#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
htonl(indev->ifindex)))
goto nla_put_failure;
#else
if (pf == PF_BRIDGE) {
/* Case 1: outdev is physical input device, we need to
* look for bridge group (when called from
* netfilter_bridge) */
if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
htonl(indev->ifindex)) ||
/* this is the bridge group "brX" */
/* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
goto nla_put_failure;
} else {
/* Case 2: indev is bridge group, we need to look for
* physical device (when called from ipv4) */
if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
htonl(indev->ifindex)))
goto nla_put_failure;
if (skb->nf_bridge && skb->nf_bridge->physindev &&
nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
htonl(skb->nf_bridge->physindev->ifindex)))
goto nla_put_failure;
}
#endif
}
if (outdev) {
#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
htonl(outdev->ifindex)))
goto nla_put_failure;
#else
if (pf == PF_BRIDGE) {
/* Case 1: outdev is physical output device, we need to
* look for bridge group (when called from
* netfilter_bridge) */
if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
htonl(outdev->ifindex)) ||
/* this is the bridge group "brX" */
/* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
goto nla_put_failure;
} else {
/* Case 2: indev is a bridge group, we need to look
* for physical device (when called from ipv4) */
if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
htonl(outdev->ifindex)))
goto nla_put_failure;
if (skb->nf_bridge && skb->nf_bridge->physoutdev &&
nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
htonl(skb->nf_bridge->physoutdev->ifindex)))
goto nla_put_failure;
}
#endif
}
if (skb->mark &&
nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
goto nla_put_failure;
if (indev && skb->dev &&
skb->mac_header != skb->network_header) {
struct nfulnl_msg_packet_hw phw;
int len;
memset(&phw, 0, sizeof(phw));
len = dev_parse_header(skb, phw.hw_addr);
if (len > 0) {
phw.hw_addrlen = htons(len);
if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
goto nla_put_failure;
}
}
if (indev && skb_mac_header_was_set(skb)) {
if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
nla_put_be16(inst->skb, NFULA_HWLEN,
htons(skb->dev->hard_header_len)))
goto nla_put_failure;
hwhdrp = skb_mac_header(skb);
if (skb->dev->type == ARPHRD_SIT)
hwhdrp -= ETH_HLEN;
if (hwhdrp >= skb->head &&
nla_put(inst->skb, NFULA_HWHEADER,
skb->dev->hard_header_len, hwhdrp))
goto nla_put_failure;
}
if (skb->tstamp.tv64) {
struct nfulnl_msg_packet_timestamp ts;
struct timeval tv = ktime_to_timeval(skb->tstamp);
ts.sec = cpu_to_be64(tv.tv_sec);
ts.usec = cpu_to_be64(tv.tv_usec);
if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
goto nla_put_failure;
}
/* UID */
sk = skb->sk;
if (sk && sk->sk_state != TCP_TIME_WAIT) {
read_lock_bh(&sk->sk_callback_lock);
if (sk->sk_socket && sk->sk_socket->file) {
struct file *file = sk->sk_socket->file;
const struct cred *cred = file->f_cred;
struct user_namespace *user_ns = inst->peer_user_ns;
__be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
__be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
read_unlock_bh(&sk->sk_callback_lock);
if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
nla_put_be32(inst->skb, NFULA_GID, gid))
goto nla_put_failure;
} else
read_unlock_bh(&sk->sk_callback_lock);
}
/* local sequence number */
if ((inst->flags & NFULNL_CFG_F_SEQ) &&
nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
goto nla_put_failure;
/* global sequence number */
if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
htonl(atomic_inc_return(&log->global_seq))))
goto nla_put_failure;
if (data_len) {
struct nlattr *nla;
int size = nla_attr_size(data_len);
if (skb_tailroom(inst->skb) < nla_total_size(data_len))
goto nla_put_failure;
nla = (struct nlattr *)skb_put(inst->skb, nla_total_size(data_len));
nla->nla_type = NFULA_PAYLOAD;
nla->nla_len = size;
if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
BUG();
}
nlh->nlmsg_len = inst->skb->tail - old_tail;
return 0;
nla_put_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 */
void
nfulnl_log_packet(struct net *net,
u_int8_t 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 plen;
struct nfnl_log_net *log = nfnl_log_pernet(net);
if (li_user && li_user->type == NF_LOG_TYPE_ULOG)
li = li_user;
else
li = &default_loginfo;
inst = instance_lookup_get(log, li->u.ulog.group);
if (!inst)
return;
plen = 0;
if (prefix)
plen = strlen(prefix) + 1;
/* 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_total_size(sizeof(struct nfgenmsg))
+ nla_total_size(sizeof(struct nfulnl_msg_packet_hdr))
+ nla_total_size(sizeof(u_int32_t)) /* ifindex */
+ nla_total_size(sizeof(u_int32_t)) /* ifindex */
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ nla_total_size(sizeof(u_int32_t)) /* ifindex */
+ nla_total_size(sizeof(u_int32_t)) /* ifindex */
#endif
+ nla_total_size(sizeof(u_int32_t)) /* mark */
+ nla_total_size(sizeof(u_int32_t)) /* uid */
+ nla_total_size(sizeof(u_int32_t)) /* gid */
+ nla_total_size(plen) /* prefix */
+ nla_total_size(sizeof(struct nfulnl_msg_packet_hw))
+ nla_total_size(sizeof(struct nfulnl_msg_packet_timestamp))
+ nla_total_size(sizeof(struct nfgenmsg)); /* NLMSG_DONE */
if (in && skb_mac_header_was_set(skb)) {
size += nla_total_size(skb->dev->hard_header_len)
+ nla_total_size(sizeof(u_int16_t)) /* hwtype */
+ nla_total_size(sizeof(u_int16_t)); /* hwlen */
}
spin_lock_bh(&inst->lock);
if (inst->flags & NFULNL_CFG_F_SEQ)
size += nla_total_size(sizeof(u_int32_t));
if (inst->flags & NFULNL_CFG_F_SEQ_GLOBAL)
size += nla_total_size(sizeof(u_int32_t));
qthreshold = inst->qthreshold;
/* per-rule qthreshold overrides per-instance */
if (li->u.ulog.qthreshold)
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 > skb->len)
data_len = skb->len;
else
data_len = inst->copy_range;
size += nla_total_size(data_len);
break;
case NFULNL_COPY_DISABLED:
default:
goto unlock_and_release;
}
if (inst->skb && 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. */
__nfulnl_flush(inst);
}
if (!inst->skb) {
inst->skb = nfulnl_alloc_skb(net, inst->peer_portid,
inst->nlbufsiz, size);
if (!inst->skb)
goto alloc_failure;
}
inst->qlen++;
__build_packet_message(log, inst, skb, data_len, pf,
hooknum, in, out, prefix, plen);
if (inst->qlen >= qthreshold)
__nfulnl_flush(inst);
/* timer_pending always called within inst->lock, so there
* is no chance of a race here */
else if (!timer_pending(&inst->timer)) {
instance_get(inst);
inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
add_timer(&inst->timer);
}
unlock_and_release:
spin_unlock_bh(&inst->lock);
instance_put(inst);
return;
alloc_failure:
/* FIXME: statistics */
goto unlock_and_release;
}
EXPORT_SYMBOL_GPL(nfulnl_log_packet);
static int
nfulnl_rcv_nl_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct netlink_notify *n = ptr;
struct nfnl_log_net *log = nfnl_log_pernet(n->net);
if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
int i;
/* destroy all instances for this portid */
spin_lock_bh(&log->instances_lock);
for (i = 0; i < INSTANCE_BUCKETS; i++) {
struct hlist_node *t2;
struct nfulnl_instance *inst;
struct hlist_head *head = &log->instance_table[i];
hlist_for_each_entry_safe(inst, t2, head, hlist) {
if (n->portid == inst->peer_portid)
__instance_destroy(inst);
}
}
spin_unlock_bh(&log->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,
const struct nlmsghdr *nlh,
const struct nlattr * const nfqa[])
{
return -ENOTSUPP;
}
static struct nf_logger nfulnl_logger __read_mostly = {
.name = "nfnetlink_log",
.type = NF_LOG_TYPE_ULOG,
.logfn = &nfulnl_log_packet,
.me = THIS_MODULE,
};
static const struct nla_policy nfula_cfg_policy[NFULA_CFG_MAX+1] = {
[NFULA_CFG_CMD] = { .len = sizeof(struct nfulnl_msg_config_cmd) },
[NFULA_CFG_MODE] = { .len = sizeof(struct nfulnl_msg_config_mode) },
[NFULA_CFG_TIMEOUT] = { .type = NLA_U32 },
[NFULA_CFG_QTHRESH] = { .type = NLA_U32 },
[NFULA_CFG_NLBUFSIZ] = { .type = NLA_U32 },
[NFULA_CFG_FLAGS] = { .type = NLA_U16 },
};
static int
nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const nfula[])
{
struct nfgenmsg *nfmsg = nlmsg_data(nlh);
u_int16_t group_num = ntohs(nfmsg->res_id);
struct nfulnl_instance *inst;
struct nfulnl_msg_config_cmd *cmd = NULL;
struct net *net = sock_net(ctnl);
struct nfnl_log_net *log = nfnl_log_pernet(net);
int ret = 0;
if (nfula[NFULA_CFG_CMD]) {
u_int8_t pf = nfmsg->nfgen_family;
cmd = nla_data(nfula[NFULA_CFG_CMD]);
/* Commands without queue context */
switch (cmd->command) {
case NFULNL_CFG_CMD_PF_BIND:
return nf_log_bind_pf(net, pf, &nfulnl_logger);
case NFULNL_CFG_CMD_PF_UNBIND:
nf_log_unbind_pf(net, pf);
return 0;
}
}
inst = instance_lookup_get(log, group_num);
if (inst && inst->peer_portid != NETLINK_CB(skb).portid) {
ret = -EPERM;
goto out_put;
}
if (cmd != NULL) {
switch (cmd->command) {
case NFULNL_CFG_CMD_BIND:
if (inst) {
ret = -EBUSY;
goto out_put;
}
inst = instance_create(net, group_num,
NETLINK_CB(skb).portid,
sk_user_ns(NETLINK_CB(skb).sk));
if (IS_ERR(inst)) {
ret = PTR_ERR(inst);
goto out;
}
break;
case NFULNL_CFG_CMD_UNBIND:
if (!inst) {
ret = -ENODEV;
goto out;
}
instance_destroy(log, inst);
goto out_put;
default:
ret = -ENOTSUPP;
break;
}
}
if (nfula[NFULA_CFG_MODE]) {
struct nfulnl_msg_config_mode *params;
params = nla_data(nfula[NFULA_CFG_MODE]);
if (!inst) {
ret = -ENODEV;
goto out;
}
nfulnl_set_mode(inst, params->copy_mode,
ntohl(params->copy_range));
}
if (nfula[NFULA_CFG_TIMEOUT]) {
__be32 timeout = nla_get_be32(nfula[NFULA_CFG_TIMEOUT]);
if (!inst) {
ret = -ENODEV;
goto out;
}
nfulnl_set_timeout(inst, ntohl(timeout));
}
if (nfula[NFULA_CFG_NLBUFSIZ]) {
__be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
if (!inst) {
ret = -ENODEV;
goto out;
}
nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
}
if (nfula[NFULA_CFG_QTHRESH]) {
__be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
if (!inst) {
ret = -ENODEV;
goto out;
}
nfulnl_set_qthresh(inst, ntohl(qthresh));
}
if (nfula[NFULA_CFG_FLAGS]) {
__be16 flags = nla_get_be16(nfula[NFULA_CFG_FLAGS]);
if (!inst) {
ret = -ENODEV;
goto out;
}
nfulnl_set_flags(inst, ntohs(flags));
}
out_put:
instance_put(inst);
out:
return ret;
}
static const struct nfnl_callback nfulnl_cb[NFULNL_MSG_MAX] = {
[NFULNL_MSG_PACKET] = { .call = nfulnl_recv_unsupp,
.attr_count = NFULA_MAX, },
[NFULNL_MSG_CONFIG] = { .call = nfulnl_recv_config,
.attr_count = NFULA_CFG_MAX,
.policy = nfula_cfg_policy },
};
static const struct nfnetlink_subsystem nfulnl_subsys = {
.name = "log",
.subsys_id = NFNL_SUBSYS_ULOG,
.cb_count = NFULNL_MSG_MAX,
.cb = nfulnl_cb,
};
#ifdef CONFIG_PROC_FS
struct iter_state {
struct seq_net_private p;
unsigned int bucket;
};
static struct hlist_node *get_first(struct net *net, struct iter_state *st)
{
struct nfnl_log_net *log;
if (!st)
return NULL;
log = nfnl_log_pernet(net);
for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
struct hlist_head *head = &log->instance_table[st->bucket];
if (!hlist_empty(head))
return rcu_dereference_bh(hlist_first_rcu(head));
}
return NULL;
}
static struct hlist_node *get_next(struct net *net, struct iter_state *st,
struct hlist_node *h)
{
h = rcu_dereference_bh(hlist_next_rcu(h));
while (!h) {
struct nfnl_log_net *log;
struct hlist_head *head;
if (++st->bucket >= INSTANCE_BUCKETS)
return NULL;
log = nfnl_log_pernet(net);
head = &log->instance_table[st->bucket];
h = rcu_dereference_bh(hlist_first_rcu(head));
}
return h;
}
static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
loff_t pos)
{
struct hlist_node *head;
head = get_first(net, st);
if (head)
while (pos && (head = get_next(net, st, head)))
pos--;
return pos ? NULL : head;
}
static void *seq_start(struct seq_file *s, loff_t *pos)
__acquires(rcu_bh)
{
rcu_read_lock_bh();
return get_idx(seq_file_net(s), s->private, *pos);
}
static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
{
(*pos)++;
return get_next(seq_file_net(s), s->private, v);
}
static void seq_stop(struct seq_file *s, void *v)
__releases(rcu_bh)
{
rcu_read_unlock_bh();
}
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_portid, inst->qlen,
inst->copy_mode, inst->copy_range,
inst->flushtimeout, atomic_read(&inst->use));
}
static const 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)
{
return seq_open_net(inode, file, &nful_seq_ops,
sizeof(struct iter_state));
}
static const struct file_operations nful_file_ops = {
.owner = THIS_MODULE,
.open = nful_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
#endif /* PROC_FS */
static int __net_init nfnl_log_net_init(struct net *net)
{
unsigned int i;
struct nfnl_log_net *log = nfnl_log_pernet(net);
for (i = 0; i < INSTANCE_BUCKETS; i++)
INIT_HLIST_HEAD(&log->instance_table[i]);
spin_lock_init(&log->instances_lock);
#ifdef CONFIG_PROC_FS
if (!proc_create("nfnetlink_log", 0440,
net->nf.proc_netfilter, &nful_file_ops))
return -ENOMEM;
#endif
return 0;
}
static void __net_exit nfnl_log_net_exit(struct net *net)
{
#ifdef CONFIG_PROC_FS
remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
#endif
nf_log_unset(net, &nfulnl_logger);
}
static struct pernet_operations nfnl_log_net_ops = {
.init = nfnl_log_net_init,
.exit = nfnl_log_net_exit,
.id = &nfnl_log_net_id,
.size = sizeof(struct nfnl_log_net),
};
static int __init nfnetlink_log_init(void)
{
int status = -ENOMEM;
netlink_register_notifier(&nfulnl_rtnl_notifier);
status = nfnetlink_subsys_register(&nfulnl_subsys);
if (status < 0) {
pr_err("failed to create netlink socket\n");
goto cleanup_netlink_notifier;
}
status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger);
if (status < 0) {
pr_err("failed to register logger\n");
goto cleanup_subsys;
}
status = register_pernet_subsys(&nfnl_log_net_ops);
if (status < 0) {
pr_err("failed to register pernet ops\n");
goto cleanup_logger;
}
return status;
cleanup_logger:
nf_log_unregister(&nfulnl_logger);
cleanup_subsys:
nfnetlink_subsys_unregister(&nfulnl_subsys);
cleanup_netlink_notifier:
netlink_unregister_notifier(&nfulnl_rtnl_notifier);
return status;
}
static void __exit nfnetlink_log_fini(void)
{
unregister_pernet_subsys(&nfnl_log_net_ops);
nf_log_unregister(&nfulnl_logger);
nfnetlink_subsys_unregister(&nfulnl_subsys);
netlink_unregister_notifier(&nfulnl_rtnl_notifier);
}
MODULE_DESCRIPTION("netfilter userspace logging");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_ULOG);
MODULE_ALIAS_NF_LOGGER(AF_INET, 1);
MODULE_ALIAS_NF_LOGGER(AF_INET6, 1);
MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 1);
module_init(nfnetlink_log_init);
module_exit(nfnetlink_log_fini);
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