// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* 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>
|
*/
|
|
#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 <linux/netfilter_bridge.h>
|
#include <net/netlink.h>
|
#include <linux/netfilter/nfnetlink.h>
|
#include <linux/netfilter/nfnetlink_log.h>
|
#include <linux/netfilter/nf_conntrack_common.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 <linux/atomic.h>
|
#include <linux/refcount.h>
|
|
|
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
|
#include "../bridge/br_private.h"
|
#endif
|
|
#define NFULNL_COPY_DISABLED 0xff
|
#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;
|
refcount_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 */
|
u32 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 unsigned 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)
|
{
|
refcount_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 && !refcount_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 && refcount_dec_and_test(&inst->use))
|
call_rcu(&inst->rcu, nfulnl_instance_free_rcu);
|
}
|
|
static void nfulnl_timer(struct timer_list *t);
|
|
static struct nfulnl_instance *
|
instance_create(struct net *net, u_int16_t group_num,
|
u32 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 */
|
refcount_set(&inst->use, 2);
|
|
timer_setup(&inst->timer, nfulnl_timer, 0);
|
|
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 void
|
nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
|
{
|
spin_lock_bh(&inst->lock);
|
inst->flushtimeout = timeout;
|
spin_unlock_bh(&inst->lock);
|
}
|
|
static void
|
nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
|
{
|
spin_lock_bh(&inst->lock);
|
inst->qthreshold = qthresh;
|
spin_unlock_bh(&inst->lock);
|
}
|
|
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 = alloc_skb(n, GFP_ATOMIC | __GFP_NOWARN);
|
if (!skb) {
|
if (n > pkt_size) {
|
/* try to allocate only as much as we need for current
|
* packet */
|
|
skb = alloc_skb(pkt_size, 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);
|
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(struct timer_list *t)
|
{
|
struct nfulnl_instance *inst = from_timer(inst, t, timer);
|
|
spin_lock_bh(&inst->lock);
|
if (inst->skb)
|
__nfulnl_send(inst);
|
spin_unlock_bh(&inst->lock);
|
instance_put(inst);
|
}
|
|
static u32 nfulnl_get_bridge_size(const struct sk_buff *skb)
|
{
|
u32 size = 0;
|
|
if (!skb_mac_header_was_set(skb))
|
return 0;
|
|
if (skb_vlan_tag_present(skb)) {
|
size += nla_total_size(0); /* nested */
|
size += nla_total_size(sizeof(u16)); /* id */
|
size += nla_total_size(sizeof(u16)); /* tag */
|
}
|
|
if (skb->network_header > skb->mac_header)
|
size += nla_total_size(skb->network_header - skb->mac_header);
|
|
return size;
|
}
|
|
static int nfulnl_put_bridge(struct nfulnl_instance *inst, const struct sk_buff *skb)
|
{
|
if (!skb_mac_header_was_set(skb))
|
return 0;
|
|
if (skb_vlan_tag_present(skb)) {
|
struct nlattr *nest;
|
|
nest = nla_nest_start(inst->skb, NFULA_VLAN);
|
if (!nest)
|
goto nla_put_failure;
|
|
if (nla_put_be16(inst->skb, NFULA_VLAN_TCI, htons(skb->vlan_tci)) ||
|
nla_put_be16(inst->skb, NFULA_VLAN_PROTO, skb->vlan_proto))
|
goto nla_put_failure;
|
|
nla_nest_end(inst->skb, nest);
|
}
|
|
if (skb->mac_header < skb->network_header) {
|
int len = (int)(skb->network_header - skb->mac_header);
|
|
if (nla_put(inst->skb, NFULA_L2HDR, len, skb_mac_header(skb)))
|
goto nla_put_failure;
|
}
|
|
return 0;
|
|
nla_put_failure:
|
return -1;
|
}
|
|
/* 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,
|
const struct nfnl_ct_hook *nfnl_ct,
|
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
|
{
|
struct nfulnl_msg_packet_hdr pmsg;
|
struct nlmsghdr *nlh;
|
sk_buff_data_t old_tail = inst->skb->tail;
|
struct sock *sk;
|
const unsigned char *hwhdrp;
|
|
nlh = nfnl_msg_put(inst->skb, 0, 0,
|
nfnl_msg_type(NFNL_SUBSYS_ULOG, NFULNL_MSG_PACKET),
|
0, pf, NFNETLINK_V0, htons(inst->group_num));
|
if (!nlh)
|
return -1;
|
|
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_thresh 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 {
|
struct net_device *physindev;
|
|
/* 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;
|
|
physindev = nf_bridge_get_physindev(skb);
|
if (physindev &&
|
nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
|
htonl(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_thresh 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 {
|
struct net_device *physoutdev;
|
|
/* 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;
|
|
physoutdev = nf_bridge_get_physoutdev(skb);
|
if (physoutdev &&
|
nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
|
htonl(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_was_set(skb) &&
|
skb_mac_header_len(skb) != 0) {
|
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 (hooknum <= NF_INET_FORWARD && skb->tstamp) {
|
struct nfulnl_msg_packet_timestamp ts;
|
struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
|
ts.sec = cpu_to_be64(kts.tv_sec);
|
ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
|
|
if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
|
goto nla_put_failure;
|
}
|
|
/* UID */
|
sk = skb->sk;
|
if (sk && sk_fullsock(sk)) {
|
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 (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
|
NFULA_CT, NFULA_CT_INFO) < 0)
|
goto nla_put_failure;
|
|
if ((pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE) &&
|
nfulnl_put_bridge(inst, skb) < 0)
|
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 = 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;
|
}
|
|
static const 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(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)
|
{
|
size_t size;
|
unsigned int data_len;
|
struct nfulnl_instance *inst;
|
const struct nf_loginfo *li;
|
unsigned int qthreshold;
|
unsigned int plen = 0;
|
struct nfnl_log_net *log = nfnl_log_pernet(net);
|
const struct nfnl_ct_hook *nfnl_ct = NULL;
|
struct nf_conn *ct = NULL;
|
enum ip_conntrack_info ctinfo;
|
|
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;
|
|
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));
|
if (inst->flags & NFULNL_CFG_F_CONNTRACK) {
|
nfnl_ct = rcu_dereference(nfnl_ct_hook);
|
if (nfnl_ct != NULL) {
|
ct = nfnl_ct->get_ct(skb, &ctinfo);
|
if (ct != NULL)
|
size += nfnl_ct->build_size(ct);
|
}
|
}
|
if (pf == NFPROTO_NETDEV || pf == NFPROTO_BRIDGE)
|
size += nfulnl_get_bridge_size(skb);
|
|
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:
|
data_len = inst->copy_range;
|
if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
|
(li->u.ulog.copy_len < data_len))
|
data_len = li->u.ulog.copy_len;
|
|
if (data_len > skb->len)
|
data_len = skb->len;
|
|
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,
|
nfnl_ct, ct, ctinfo);
|
|
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;
|
}
|
|
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 net *net, struct sock *ctnl,
|
struct sk_buff *skb, const struct nlmsghdr *nlh,
|
const struct nlattr * const nfqa[],
|
struct netlink_ext_ack *extack)
|
{
|
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 net *net, struct sock *ctnl,
|
struct sk_buff *skb, const struct nlmsghdr *nlh,
|
const struct nlattr * const nfula[],
|
struct netlink_ext_ack *extack)
|
{
|
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 nfnl_log_net *log = nfnl_log_pernet(net);
|
int ret = 0;
|
u16 flags = 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;
|
}
|
|
/* Check if we support these flags in first place, dependencies should
|
* be there too not to break atomicity.
|
*/
|
if (nfula[NFULA_CFG_FLAGS]) {
|
flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
|
|
if ((flags & NFULNL_CFG_F_CONNTRACK) &&
|
!rcu_access_pointer(nfnl_ct_hook)) {
|
#ifdef CONFIG_MODULES
|
nfnl_unlock(NFNL_SUBSYS_ULOG);
|
request_module("ip_conntrack_netlink");
|
nfnl_lock(NFNL_SUBSYS_ULOG);
|
if (rcu_access_pointer(nfnl_ct_hook)) {
|
ret = -EAGAIN;
|
goto out_put;
|
}
|
#endif
|
ret = -EOPNOTSUPP;
|
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;
|
goto out_put;
|
}
|
} else if (!inst) {
|
ret = -ENODEV;
|
goto out;
|
}
|
|
if (nfula[NFULA_CFG_MODE]) {
|
struct nfulnl_msg_config_mode *params =
|
nla_data(nfula[NFULA_CFG_MODE]);
|
|
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]);
|
|
nfulnl_set_timeout(inst, ntohl(timeout));
|
}
|
|
if (nfula[NFULA_CFG_NLBUFSIZ]) {
|
__be32 nlbufsiz = nla_get_be32(nfula[NFULA_CFG_NLBUFSIZ]);
|
|
nfulnl_set_nlbufsiz(inst, ntohl(nlbufsiz));
|
}
|
|
if (nfula[NFULA_CFG_QTHRESH]) {
|
__be32 qthresh = nla_get_be32(nfula[NFULA_CFG_QTHRESH]);
|
|
nfulnl_set_qthresh(inst, ntohl(qthresh));
|
}
|
|
if (nfula[NFULA_CFG_FLAGS])
|
nfulnl_set_flags(inst, 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;
|
|
seq_printf(s, "%5u %6u %5u %1u %5u %6u %2u\n",
|
inst->group_num,
|
inst->peer_portid, inst->qlen,
|
inst->copy_mode, inst->copy_range,
|
inst->flushtimeout, refcount_read(&inst->use));
|
|
return 0;
|
}
|
|
static const struct seq_operations nful_seq_ops = {
|
.start = seq_start,
|
.next = seq_next,
|
.stop = seq_stop,
|
.show = seq_show,
|
};
|
#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);
|
#ifdef CONFIG_PROC_FS
|
struct proc_dir_entry *proc;
|
kuid_t root_uid;
|
kgid_t root_gid;
|
#endif
|
|
for (i = 0; i < INSTANCE_BUCKETS; i++)
|
INIT_HLIST_HEAD(&log->instance_table[i]);
|
spin_lock_init(&log->instances_lock);
|
|
#ifdef CONFIG_PROC_FS
|
proc = proc_create_net("nfnetlink_log", 0440, net->nf.proc_netfilter,
|
&nful_seq_ops, sizeof(struct iter_state));
|
if (!proc)
|
return -ENOMEM;
|
|
root_uid = make_kuid(net->user_ns, 0);
|
root_gid = make_kgid(net->user_ns, 0);
|
if (uid_valid(root_uid) && gid_valid(root_gid))
|
proc_set_user(proc, root_uid, root_gid);
|
#endif
|
return 0;
|
}
|
|
static void __net_exit nfnl_log_net_exit(struct net *net)
|
{
|
struct nfnl_log_net *log = nfnl_log_pernet(net);
|
unsigned int i;
|
|
#ifdef CONFIG_PROC_FS
|
remove_proc_entry("nfnetlink_log", net->nf.proc_netfilter);
|
#endif
|
nf_log_unset(net, &nfulnl_logger);
|
for (i = 0; i < INSTANCE_BUCKETS; i++)
|
WARN_ON_ONCE(!hlist_empty(&log->instance_table[i]));
|
}
|
|
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;
|
|
status = register_pernet_subsys(&nfnl_log_net_ops);
|
if (status < 0) {
|
pr_err("failed to register pernet ops\n");
|
goto out;
|
}
|
|
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;
|
}
|
|
return status;
|
|
cleanup_subsys:
|
nfnetlink_subsys_unregister(&nfulnl_subsys);
|
cleanup_netlink_notifier:
|
netlink_unregister_notifier(&nfulnl_rtnl_notifier);
|
unregister_pernet_subsys(&nfnl_log_net_ops);
|
out:
|
return status;
|
}
|
|
static void __exit nfnetlink_log_fini(void)
|
{
|
nfnetlink_subsys_unregister(&nfulnl_subsys);
|
netlink_unregister_notifier(&nfulnl_rtnl_notifier);
|
unregister_pernet_subsys(&nfnl_log_net_ops);
|
nf_log_unregister(&nfulnl_logger);
|
}
|
|
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_ALIAS_NF_LOGGER(3, 1); /* NFPROTO_ARP */
|
MODULE_ALIAS_NF_LOGGER(5, 1); /* NFPROTO_NETDEV */
|
|
module_init(nfnetlink_log_init);
|
module_exit(nfnetlink_log_fini);
|
