[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
David S. Miller
parent
608c8e4f7b
commit
0597f2680d
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@ -0,0 +1,85 @@
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#ifndef _NFNETLINK_LOG_H
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#define _NFNETLINK_LOG_H
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/* This file describes the netlink messages (i.e. 'protocol packets'),
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* and not any kind of function definitions. It is shared between kernel and
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* userspace. Don't put kernel specific stuff in here */
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#include <linux/netfilter/nfnetlink.h>
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enum nfulnl_msg_types {
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NFULNL_MSG_PACKET, /* packet from kernel to userspace */
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NFULNL_MSG_CONFIG, /* connect to a particular queue */
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NFULNL_MSG_MAX
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};
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struct nfulnl_msg_packet_hdr {
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u_int16_t hw_protocol; /* hw protocol (network order) */
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u_int8_t hook; /* netfilter hook */
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u_int8_t _pad;
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} __attribute__ ((packed));
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struct nfulnl_msg_packet_hw {
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u_int16_t hw_addrlen;
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u_int16_t _pad;
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u_int8_t hw_addr[8];
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} __attribute__ ((packed));
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struct nfulnl_msg_packet_timestamp {
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u_int64_t sec;
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u_int64_t usec;
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} __attribute__ ((packed));
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#define NFULNL_PREFIXLEN 30 /* just like old log target */
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enum nfulnl_attr_type {
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NFULA_UNSPEC,
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NFULA_PACKET_HDR,
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NFULA_MARK, /* u_int32_t nfmark */
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NFULA_TIMESTAMP, /* nfulnl_msg_packet_timestamp */
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NFULA_IFINDEX_INDEV, /* u_int32_t ifindex */
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NFULA_IFINDEX_OUTDEV, /* u_int32_t ifindex */
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NFULA_HWADDR, /* nfulnl_msg_packet_hw */
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NFULA_PAYLOAD, /* opaque data payload */
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NFULA_PREFIX, /* string prefix */
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NFULA_UID, /* user id of socket */
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__NFULA_MAX
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};
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#define NFULA_MAX (__NFULA_MAX - 1)
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enum nfulnl_msg_config_cmds {
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NFULNL_CFG_CMD_NONE,
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NFULNL_CFG_CMD_BIND,
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NFULNL_CFG_CMD_UNBIND,
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NFULNL_CFG_CMD_PF_BIND,
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NFULNL_CFG_CMD_PF_UNBIND,
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};
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struct nfulnl_msg_config_cmd {
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u_int8_t command; /* nfulnl_msg_config_cmds */
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} __attribute__ ((packed));
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struct nfulnl_msg_config_mode {
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u_int32_t copy_range;
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u_int8_t copy_mode;
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u_int8_t _pad;
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} __attribute__ ((packed));
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enum nfulnl_attr_config {
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NFULA_CFG_UNSPEC,
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NFULA_CFG_CMD, /* nfulnl_msg_config_cmd */
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NFULA_CFG_MODE, /* nfulnl_msg_config_mode */
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NFULA_CFG_NLBUFSIZ, /* u_int32_t buffer size */
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NFULA_CFG_TIMEOUT, /* u_int32_t in 1/100 s */
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NFULA_CFG_QTHRESH, /* u_int32_t */
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__NFULA_CFG_MAX
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};
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#define NFULA_CFG_MAX (__NFULA_CFG_MAX -1)
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#define NFULNL_COPY_NONE 0x00
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#define NFULNL_COPY_META 0x01
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#define NFULNL_COPY_PACKET 0x02
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#endif /* _NFNETLINK_LOG_H */
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@ -11,3 +11,14 @@ config NETFILTER_NETLINK_QUEUE
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If this option isenabled, the kernel will include support
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for queueing packets via NFNETLINK.
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config NETFILTER_NETLINK_LOG
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tristate "Netfilter LOG over NFNETLINK interface"
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depends on NETFILTER_NETLINK
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help
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If this option is enabled, the kernel will include support
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for logging packets via NFNETLINK.
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This obsoletes the existing ipt_ULOG and ebg_ulog mechanisms,
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and is also scheduled to replace the old syslog-based ipt_LOG
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and ip6t_LOG modules.
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@ -1,2 +1,3 @@
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obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
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obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
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obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o
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@ -0,0 +1,995 @@
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/*
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* This is a module which is used for logging packets to userspace via
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* nfetlink.
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*
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* (C) 2005 by Harald Welte <laforge@netfilter.org>
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*
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* Based on the old ipv4-only ipt_ULOG.c:
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* (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/init.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/netdevice.h>
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#include <linux/netfilter.h>
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#include <linux/netlink.h>
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_log.h>
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#include <linux/spinlock.h>
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#include <linux/sysctl.h>
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#include <linux/proc_fs.h>
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#include <linux/security.h>
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#include <linux/list.h>
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#include <linux/jhash.h>
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#include <linux/random.h>
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#include <net/sock.h>
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#include <asm/atomic.h>
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#define NFULNL_NLBUFSIZ_DEFAULT 4096
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#define NFULNL_TIMEOUT_DEFAULT 100 /* every second */
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#define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */
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#define PRINTR(x, args...) do { if (net_ratelimit()) \
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printk(x, ## args); } while (0);
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#if 0
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#define UDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \
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__FILE__, __LINE__, __FUNCTION__, \
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## args)
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#else
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#define UDEBUG(x, ...)
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#endif
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struct nfulnl_instance {
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struct hlist_node hlist; /* global list of instances */
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spinlock_t lock;
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atomic_t use; /* use count */
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unsigned int qlen; /* number of nlmsgs in skb */
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struct sk_buff *skb; /* pre-allocatd skb */
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struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */
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struct timer_list timer;
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int peer_pid; /* PID of the peer process */
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/* configurable parameters */
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unsigned int flushtimeout; /* timeout until queue flush */
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unsigned int nlbufsiz; /* netlink buffer allocation size */
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unsigned int qthreshold; /* threshold of the queue */
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u_int32_t copy_range;
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u_int16_t group_num; /* number of this queue */
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u_int8_t copy_mode;
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};
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static DEFINE_RWLOCK(instances_lock);
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#define INSTANCE_BUCKETS 16
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static struct hlist_head instance_table[INSTANCE_BUCKETS];
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static unsigned int hash_init;
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static inline u_int8_t instance_hashfn(u_int16_t group_num)
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{
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return ((group_num & 0xff) % INSTANCE_BUCKETS);
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}
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static struct nfulnl_instance *
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__instance_lookup(u_int16_t group_num)
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{
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struct hlist_head *head;
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struct hlist_node *pos;
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struct nfulnl_instance *inst;
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UDEBUG("entering (group_num=%u)\n", group_num);
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head = &instance_table[instance_hashfn(group_num)];
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hlist_for_each_entry(inst, pos, head, hlist) {
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if (inst->group_num == group_num)
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return inst;
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}
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return NULL;
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}
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static inline void
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instance_get(struct nfulnl_instance *inst)
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{
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atomic_inc(&inst->use);
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}
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static struct nfulnl_instance *
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instance_lookup_get(u_int16_t group_num)
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{
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struct nfulnl_instance *inst;
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read_lock_bh(&instances_lock);
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inst = __instance_lookup(group_num);
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if (inst)
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instance_get(inst);
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read_unlock_bh(&instances_lock);
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return inst;
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}
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static void
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instance_put(struct nfulnl_instance *inst)
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{
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if (inst && atomic_dec_and_test(&inst->use)) {
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UDEBUG("kfree(inst=%p)\n", inst);
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kfree(inst);
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}
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}
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static void nfulnl_timer(unsigned long data);
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static struct nfulnl_instance *
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instance_create(u_int16_t group_num, int pid)
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{
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struct nfulnl_instance *inst;
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UDEBUG("entering (group_num=%u, pid=%d)\n", group_num,
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pid);
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write_lock_bh(&instances_lock);
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if (__instance_lookup(group_num)) {
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inst = NULL;
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UDEBUG("aborting, instance already exists\n");
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goto out_unlock;
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}
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inst = kmalloc(sizeof(*inst), GFP_ATOMIC);
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if (!inst)
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goto out_unlock;
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memset(inst, 0, sizeof(*inst));
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INIT_HLIST_NODE(&inst->hlist);
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inst->lock = SPIN_LOCK_UNLOCKED;
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/* needs to be two, since we _put() after creation */
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atomic_set(&inst->use, 2);
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init_timer(&inst->timer);
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inst->timer.function = nfulnl_timer;
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inst->timer.data = (unsigned long)inst;
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/* don't start timer yet. (re)start it with every packet */
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inst->peer_pid = pid;
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inst->group_num = group_num;
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inst->qthreshold = NFULNL_QTHRESH_DEFAULT;
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inst->flushtimeout = NFULNL_TIMEOUT_DEFAULT;
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inst->nlbufsiz = NFULNL_NLBUFSIZ_DEFAULT;
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inst->copy_mode = NFULNL_COPY_PACKET;
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inst->copy_range = 0xffff;
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if (!try_module_get(THIS_MODULE))
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goto out_free;
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hlist_add_head(&inst->hlist,
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&instance_table[instance_hashfn(group_num)]);
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UDEBUG("newly added node: %p, next=%p\n", &inst->hlist,
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inst->hlist.next);
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write_unlock_bh(&instances_lock);
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return inst;
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out_free:
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instance_put(inst);
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out_unlock:
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write_unlock_bh(&instances_lock);
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return NULL;
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}
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static int __nfulnl_send(struct nfulnl_instance *inst);
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static void
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_instance_destroy2(struct nfulnl_instance *inst, int lock)
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{
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/* first pull it out of the global list */
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if (lock)
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write_lock_bh(&instances_lock);
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UDEBUG("removing instance %p (queuenum=%u) from hash\n",
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inst, inst->group_num);
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hlist_del(&inst->hlist);
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if (lock)
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write_unlock_bh(&instances_lock);
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/* then flush all pending packets from skb */
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spin_lock_bh(&inst->lock);
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if (inst->skb) {
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if (inst->qlen)
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__nfulnl_send(inst);
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if (inst->skb) {
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kfree_skb(inst->skb);
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inst->skb = NULL;
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}
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}
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spin_unlock_bh(&inst->lock);
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/* and finally put the refcount */
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instance_put(inst);
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module_put(THIS_MODULE);
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}
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static inline void
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__instance_destroy(struct nfulnl_instance *inst)
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{
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_instance_destroy2(inst, 0);
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}
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static inline void
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instance_destroy(struct nfulnl_instance *inst)
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{
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_instance_destroy2(inst, 1);
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}
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static int
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nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode,
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unsigned int range)
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{
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int status = 0;
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spin_lock_bh(&inst->lock);
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switch (mode) {
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case NFULNL_COPY_NONE:
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case NFULNL_COPY_META:
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inst->copy_mode = mode;
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inst->copy_range = 0;
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break;
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case NFULNL_COPY_PACKET:
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inst->copy_mode = mode;
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/* we're using struct nfattr which has 16bit nfa_len */
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if (range > 0xffff)
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inst->copy_range = 0xffff;
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else
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inst->copy_range = range;
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break;
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default:
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status = -EINVAL;
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break;
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}
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spin_unlock_bh(&inst->lock);
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return status;
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}
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static int
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nfulnl_set_nlbufsiz(struct nfulnl_instance *inst, u_int32_t nlbufsiz)
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{
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int status;
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spin_lock_bh(&inst->lock);
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if (nlbufsiz < NFULNL_NLBUFSIZ_DEFAULT)
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status = -ERANGE;
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else if (nlbufsiz > 131072)
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status = -ERANGE;
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else {
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inst->nlbufsiz = nlbufsiz;
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status = 0;
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}
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spin_unlock_bh(&inst->lock);
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return status;
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}
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static int
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nfulnl_set_timeout(struct nfulnl_instance *inst, u_int32_t timeout)
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{
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spin_lock_bh(&inst->lock);
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inst->flushtimeout = timeout;
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spin_unlock_bh(&inst->lock);
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return 0;
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}
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static int
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nfulnl_set_qthresh(struct nfulnl_instance *inst, u_int32_t qthresh)
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{
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spin_lock_bh(&inst->lock);
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inst->qthreshold = qthresh;
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spin_unlock_bh(&inst->lock);
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return 0;
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}
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static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size,
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unsigned int pkt_size)
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{
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struct sk_buff *skb;
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UDEBUG("entered (%u, %u)\n", inst_size, pkt_size);
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/* alloc skb which should be big enough for a whole multipart
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* message. WARNING: has to be <= 128k due to slab restrictions */
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skb = alloc_skb(inst_size, GFP_ATOMIC);
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if (!skb) {
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PRINTR("nfnetlink_log: can't alloc whole buffer (%u bytes)\n",
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inst_size);
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/* try to allocate only as much as we need for current
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* packet */
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skb = alloc_skb(pkt_size, GFP_ATOMIC);
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if (!skb)
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PRINTR("nfnetlink_log: can't even alloc %u bytes\n",
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pkt_size);
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}
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return skb;
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}
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static int
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__nfulnl_send(struct nfulnl_instance *inst)
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{
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int status;
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if (timer_pending(&inst->timer))
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del_timer(&inst->timer);
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if (inst->qlen > 1)
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inst->lastnlh->nlmsg_type = NLMSG_DONE;
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status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT);
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if (status < 0) {
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UDEBUG("netlink_unicast() failed\n");
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/* FIXME: statistics */
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}
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inst->qlen = 0;
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inst->skb = NULL;
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inst->lastnlh = NULL;
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return status;
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}
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static void nfulnl_timer(unsigned long data)
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{
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struct nfulnl_instance *inst = (struct nfulnl_instance *)data;
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UDEBUG("timer function called, flushing buffer\n");
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spin_lock_bh(&inst->lock);
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__nfulnl_send(inst);
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instance_put(inst);
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spin_unlock_bh(&inst->lock);
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}
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static inline int
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__build_packet_message(struct nfulnl_instance *inst,
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const struct sk_buff *skb,
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unsigned int data_len,
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unsigned int pf,
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unsigned int hooknum,
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const struct net_device *indev,
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const struct net_device *outdev,
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const struct nf_loginfo *li,
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const char *prefix)
|
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{
|
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unsigned char *old_tail;
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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);
|
||||
|
|
@ -1041,6 +1041,7 @@ cleanup:
|
|||
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);
|
||||
|
|
|
|||
Loading…
Reference in New Issue