/*
 *	Fast path Classifier
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) "mfp" " classifier:%s:%d: " fmt, __func__, __LINE__

#include "fp_common.h"
#include "fp_database.h"
#include "fp_device.h"
#include "fp_core.h"

struct fpc_stats {
	u32 total;
	u32 slow;
	u32 fast;
};

static struct fpc_stats stats;

#if LINUX_VERSION_CODE <= KERNEL_VERSION(3, 3, 0)
static unsigned int udp_ct_timeout = UDP_DEFAULT_TIMEOUT;
static unsigned int udp_ct_timeout_stream = UDP_DEFAULT_TIMEOUT_STREAM;
static unsigned int tcp_ct_timeout = TCP_DEFAULT_TIMEOUT;
#endif
static int fp_acct_flag = 1;
static int fp_ip_log_en = 255;
static int fp_ip_log_pkt_num;
static unsigned char *fp_ip_log_buf;
static int fp_ip_log_index;
#define ONE_IP_LOG_LEN	96

//#define CONFIG_SET_HL_64

static inline int fp_ip_decrease_ttl(struct sk_buff *skb)
{
	if (ip_hdr(skb)->version == 4)
		return ip_decrease_ttl(ip_hdr(skb));
	else
		return --ipv6_hdr(skb)->hop_limit;
}

/* builds a tuple according to the parameters received) */
static inline void build_tuple(const struct sk_buff *skb,
				struct nf_conntrack_tuple *tuple)
{
	int proto;
	struct udphdr *udph;
	/* Fill l3 info */
	if (ip_hdr(skb)->version == 4) {
		tuple->src.l3num = AF_INET;
		tuple->src.u3.ip = ip_hdr(skb)->saddr;
		tuple->dst.u3.ip = ip_hdr(skb)->daddr;
		proto = ip_hdr(skb)->protocol;
	} else {
		tuple->src.l3num = AF_INET6;
		tuple->src.u3.in6 = ipv6_hdr(skb)->saddr;
		tuple->dst.u3.in6 = ipv6_hdr(skb)->daddr;
		proto = ipv6_hdr(skb)->nexthdr;
	}

	/* Fill l4 info*/
	udph = (struct udphdr *)skb_transport_header(skb);
	tuple->dst.protonum = proto;
	tuple->dst.u.all = udph->dest;
	tuple->src.u.all = udph->source;
	tuple->dst.dir = 0;
}

static inline void log_ip_pkt(const struct sk_buff *skb, unsigned char *buf)
{
	struct tcphdr *tcph;
	struct iphdr *piphdr;
	struct ipv6hdr *pipv6hdr;
	struct timespec64 ts;
	piphdr = ip_hdr(skb);

	ktime_get_real_ts64(&ts);
	memcpy(buf, &ts.tv_sec, 8);
	buf += 8;
	memcpy(buf, &ts.tv_nsec, 4);
	buf += 4;
	/* Fill l3 info */
	if (piphdr->version == 4) {
		*buf = 4;
		buf += 1;
		*buf = piphdr->protocol;
		buf += 1;
		memcpy(buf, &piphdr->id, 2);
		buf += 2;
		memcpy(buf, &piphdr->tot_len, 2);
		buf += 4;
		memcpy(buf, &piphdr->saddr, 4);
		buf += 16;
		memcpy(buf, &piphdr->daddr, 4);
		buf += 16;
	} else {
		pipv6hdr = ipv6_hdr(skb);
		*buf = 6;
		buf += 1;
		*buf = pipv6hdr->nexthdr;
		buf += 1;
		*buf = 0;
		*(buf+1) = 0;
		buf += 2;
		memcpy(buf, &pipv6hdr->payload_len, 2);
		buf += 4;
		memcpy(buf, &pipv6hdr->saddr, 16);
		buf += 16;
		memcpy(buf, &pipv6hdr->daddr, 16);
		buf += 16;
	}

	/* Fill l4 info*/
	tcph = (struct tcphdr *)skb_transport_header(skb);

	memcpy(buf, &tcph->source, 2);
	buf += 2;
	memcpy(buf, &tcph->dest, 2);
	buf += 2;

	memcpy(buf, &tcph->seq, 4);
	buf += 4;

	memcpy(buf, &tcph->ack_seq, 4);
	buf += 4;
	memcpy(buf, ((char *)&tcph->ack_seq)+4, 2);
	buf += 2;


}

/* checksum adjust (inline) */
static inline void fpc_checksum(unsigned char *chksum,
				  unsigned char *optr, unsigned long olen,
				  unsigned char *nptr, unsigned long nlen,
				  int proto)
{
	long x, old, neu;

	if (proto == IPPROTO_UDP && *(__sum16 *)chksum == 0)
		return;

	x = chksum[0] * 256 + chksum[1];
	x = ~x & 0xFFFF;
	while (olen) {
		old = optr[0] * 256 + optr[1];
		optr += 2;
		x -= old & 0xffff;
		if (x <= 0) {
			x--;
			x &= 0xffff;
		}
		olen -= 2;
	}

	while (nlen) {
		neu = nptr[0] * 256 + nptr[1];
		nptr += 2;
		x += neu & 0xffff;
		if (x & 0x10000) {
			x++;
			x &= 0xffff;
		}
		nlen -= 2;
	}
	x = ~x & 0xFFFF;
	chksum[0] = (unsigned char)(x / 256);
	chksum[1] = (unsigned char)(x & 0xff);
}

static inline int fp_hard_header(struct sk_buff *skb, struct fpdb_entry *e)
{
	struct hh_cache *hh = &e->hh;
	int hh_len = hh->hh_len;
	unsigned int hh_alen = 0;
	unsigned int headroom;

	if (!hh_len)
		return 0;

	headroom = skb_headroom(skb);
	if (likely(hh_len <= HH_DATA_MOD)) {
		hh_alen = HH_DATA_MOD;

		/* this is inlined by gcc */
		if (likely(headroom >= HH_DATA_MOD))
			memcpy(skb->data - HH_DATA_MOD, hh->hh_data,
				HH_DATA_MOD);
	} else {
		hh_alen = HH_DATA_ALIGN(hh_len);

		if (likely(headroom >= hh_alen))
			memcpy(skb->data - hh_alen, hh->hh_data,
				hh_alen);
	}

	if (WARN_ON_ONCE(headroom < hh_alen))
		return 1;

	skb_push(skb, hh_len);

	return 0;
}

/**
 * Refresh ct (reschedule timeout)
 *
 * @param skb
 * @param el
 * @param acct   do accounting
 */
static inline void fpc_refresh(struct sk_buff *skb, struct fpdb_entry *el, int acct)
{
	struct nf_conn *ct = el->ct;
	const struct nf_conntrack_l4proto *l4proto;
	enum ip_conntrack_info ctinfo = el->dir ? IP_CT_IS_REPLY : 0;
	unsigned long extra_jiffies = 0;
#if LINUX_VERSION_CODE > KERNEL_VERSION(3, 3, 0)
	unsigned int *timeouts;
#endif

	l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
	NF_CT_ASSERT(l4proto);

#if LINUX_VERSION_CODE > KERNEL_VERSION(3, 3, 0)
	if (l4proto->l4proto == IPPROTO_TCP) {
		timeouts = nf_tcp_pernet(nf_ct_net(ct))->timeouts;
		WARN_ON(ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED);
		extra_jiffies = timeouts[TCP_CONNTRACK_ESTABLISHED];
	} else if (l4proto->l4proto == IPPROTO_UDP) {
		timeouts = nf_udp_pernet(nf_ct_net(ct))->timeouts;
		if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
			extra_jiffies =	timeouts[UDP_CT_REPLIED];
		else
			extra_jiffies =	timeouts[UDP_CT_UNREPLIED];
	}
#else
	if (l4proto->l4proto == IPPROTO_TCP) {
		WARN_ON(ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED);
		extra_jiffies = tcp_ct_timeout;
	} else if (l4proto->l4proto == IPPROTO_UDP) {
		if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
			extra_jiffies =	udp_ct_timeout_stream;
		else
			extra_jiffies =	udp_ct_timeout;
	}
#endif
	__nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, acct);

	fpdb_trace(el, (l4proto->l4proto == IPPROTO_TCP) ? tcp_hdr(skb) : NULL);
}

/**
 * Modify skb as if it was forwarded by the ip stack:
 * L2: Add MAC Header, set skb->pkt_type = PACKET_HOST
 * L3: Decrement ttl, NAT, checksum
 * L4: Checksum
 *
 * @param skb    skb to modify
 * @param el     fpdb_entry related to this connection
 */
static inline int fpc_modify(struct sk_buff *skb,
			       struct fpdb_entry *el)
{
	int version = ip_hdr(skb)->version;
	int proto = (version == 4) ? ip_hdr(skb)->protocol : ipv6_hdr(skb)->nexthdr;
	struct udphdr *udph = udp_hdr(skb);
	struct tcphdr *tcph = tcp_hdr(skb);

	/**
	 *  skb->pkt_type can be either PACKET_HOST or PACKET_OTHERHOST
	 *  (see fpc_classify_start). We also know that this flow passed
	 *  through slowpath (otherwise fastpath connection would not
	 *  have been created in the first place). Therefore it is safe
	 *  to change the pkt_type since this is what the IP Stack would
	 *  have done.
	 *
	 *  Slowpath behavior:
	 *  PACKET_OTHERHOST is set by the receiving interface if the
	 *  dest MAC is different from it's MAC address. In this case
	 *  this means that the packet is not destined to us and is
	 *  dropped. The only exception is if the receiving interface is
	 *  behind a bridge. In this case, the dest MAC in packets sent
	 *  outside the LAN is the bridge MAC address, in which case the
	 *  bridging code sets the pkt_type to PACKET_HOST before
	 *  routing the packet. Packes withing the LAN sre bridged and
	 *  are not passed to the upper layers, and therefore doesn't go
	 *  through fastpath unless CONFIG_BRIDGE_NETFILTER is enabled -
	 *  which is the only case where fastpath "misbehaves" and sets
	 *  the pkt_type to PACKET_HOST for bridged packets - this might
	 *  need revision in the future.
	 */
	skb->pkt_type = PACKET_HOST;

	if (fp_hard_header(skb, el))
		return 1;

	fp_ip_decrease_ttl(skb);

	/* NAT (incase used by this connection) */
	if (NF_CT_NAT(el->ct)) {
		void *old, *new;
		unsigned int size;
		__sum16 *check;

		/* NAT L3 ip addresses manipulation */
		if (likely(version == 4)) {
			struct iphdr *iph = ip_hdr(skb);
			iph->saddr = el->out_tuple.dst.u3.ip;
			iph->daddr = el->out_tuple.src.u3.ip;
		#ifdef CONFIG_SET_HL_64
			iph->ttl = 64;
		#endif
			ip_send_check(iph); /*IPv4 checksum */
		} else {
			struct ipv6hdr *iph = ipv6_hdr(skb);
			iph->saddr = el->out_tuple.dst.u3.in6;
			iph->daddr = el->out_tuple.src.u3.in6;
		#ifdef CONFIG_SET_HL_64
			iph->hop_limit = 64;
		#endif
		}

		/* Adjust transport header checksum */
		check = (proto == IPPROTO_UDP) ? &udph->check : &tcph->check;
		size = (version == 4) ? 4 : 16;
		old = &el->in_tuple.src.u3.in6;
		new = &el->out_tuple.dst.u3.in6;
		fpc_checksum((u8 *)check, old, size, new, size, proto);
		old = &el->in_tuple.dst.u3.in6;
		new = &el->out_tuple.src.u3.in6;
		fpc_checksum((u8 *)check, old, size, new, size, proto);


		/* NAT L4 ports manipulation */
		size = sizeof(__be16);
		old = &el->in_tuple.dst.u.all;
		new = &el->out_tuple.src.u.all;
		if (*(__be16 *)old != *(__be16 *)new) {
			udph->dest = *(__be16 *)new;
			fpc_checksum((u8 *)check, old, size, new, size, proto);
		}
		old = &el->in_tuple.src.u.all;
		new = &el->out_tuple.dst.u.all;
		if (*(__be16 *)old != *(__be16 *)new) {
			udph->source = *(__be16 *)new;
			fpc_checksum((u8 *)check, old, size, new, size, proto);
		}
	}

	return 0;
}

static inline bool ipv4_is_fragmented(struct iphdr *iph)
{
	__be16 df = iph->frag_off & htons(IP_DF);
	return (iph->frag_off && !df);
}

static inline int parse_headers(struct sk_buff *skb)
{
	int ihl, proto;

	BUG_ON(!skb);
	skb_reset_network_header(skb);

	/* L3 Protocol parsing */
	if (likely(ip_hdr(skb)->version == 4)) {
		ihl = ip_hdr(skb)->ihl * 4;
		proto = ip_hdr(skb)->protocol;

		/*ipv4 sanity checks*/
		if (unlikely(ihl > sizeof(struct iphdr))) {
			pr_debug("ipv4 options in header\n");
			return 0;
		}
		/* check ttl */
		if (unlikely(ip_hdr(skb)->ttl == 1)) {
			pr_debug("ip->ttl==1\n");
			return 0;
		}
		/* check fragmantation */
		if (unlikely(ipv4_is_fragmented(ip_hdr(skb)))) {
			pr_debug("fragmented packet (frag_offs=%x)\n",
				ntohs(ip_hdr(skb)->frag_off));
			return 0;
		}
		/* ipv4 reassembled pkts */
		if (unlikely(skb->data_len)) {
			pr_debug("ipv4 reassembled pkts --> send to slowpath\n");
			return 0;
		}
	} else if (likely(ip_hdr(skb)->version == 6)) {
		ihl = sizeof(struct ipv6hdr); /* without extentions */
		proto = ipv6_hdr(skb)->nexthdr;

		/* ipv6 sanity checks */
		if (unlikely(ipv6_hdr(skb)->hop_limit == 1)) {
			pr_debug("ip->ttl==1 --> send to slowpath\n");
			return 0;
		}

		/* ipv6 reassembled pkts */
		if (unlikely(skb->data_len)) {
			pr_debug("ipv6 reassembled pkts --> send to slowpath\n");
			return 0;
		}
	} else {
		/* Not an IP packet (neither ipv4 nor ipv6) */
		pr_debug("not an IP packet\n");
		return 0;
	}

	/* L4 Protocol parsing */
	skb_set_transport_header(skb, ihl);

	if (proto == IPPROTO_TCP) {
		struct tcphdr *th = tcp_hdr(skb);

		if (tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_FIN)) {
			pr_debug("tcp rst or fin\n");
			return 0;
		}
	} else if (proto != IPPROTO_UDP) {
		pr_debug("not a TCP or UDP packet\n");
		return 0;
	}

	return 1;
}

#define NETIF_INVALID(x) (!(x) || !netif_device_present(x) || \
			   !netif_running(x) || !netif_carrier_ok(x))

/**
 * finish classification for this database entry.
 * If skb is not NULL, it is tracked & mangled.
 *
 * @param skb    skb to mangle & track, or NULL if not desired
 * @param el     fpdb_entry previously aquired by fpc_classify
 */
int fpc_classify_finish(struct sk_buff *skb, struct fpdb_entry *el)
{
	int ret = 0;

	if (skb) {
		fpc_refresh(skb, el, fp_acct_flag);
		if (fpc_modify(skb, el)) {
			ret = 1;
			goto exit;
		}

		/* update timestamp if fpdb used */
		el->tstamp = jiffies;
		if (!el->tstamp)
			el->tstamp = 1;
	}
exit:
	fpdb_put(el);
	return ret;
}

/**
 * Classifies an skb as fast or slow, without changing the skb.
 * Caller MUST call fpc_classify_finish to free the database entry.
 *
 * @param skb    skb to classify
 *
 * @return fpdb_entry for this skb
 */
struct fpdb_entry *fpc_classify_start(struct sk_buff *skb, struct nf_conntrack_tuple *tuple)
{
	struct fpdb_entry *el = NULL;
	struct net_device *src, *dst;
	int tmp_log_pkt_index;
	unsigned char *plog_pos;

	BUG_ON(!skb);
	BUG_ON(!skb->dev); /* eth_type_trans always sets skb->dev - we count on it here */

	src = skb->dev;
	stats.total++;

	if (unlikely(skb_headroom(skb) < ETH_HLEN)) {
		pr_debug("No room for MAC header in skb\n");
		goto slowpath;
	}

	/* source device sanity checks */
	if (unlikely(NETIF_INVALID(src))) {
		pr_debug("src (%s) state invalid (%lu)\n", src->name, src->state);
		goto slowpath;
	}

	memset(tuple, 0, sizeof(struct nf_conntrack_tuple));

	if (unlikely(!parse_headers(skb)))
		goto slowpath;

	/* Check fp_database for match */
	build_tuple(skb, tuple);
	if (1 == fp_ip_log_en) {
		tmp_log_pkt_index = fp_ip_log_index++;
		if (fp_ip_log_index > fp_ip_log_pkt_num - 50)
			fp_ip_log_index = 0;

		plog_pos = fp_ip_log_buf + tmp_log_pkt_index*ONE_IP_LOG_LEN;
		log_ip_pkt(skb, plog_pos);
	}
	el = fpdb_get(tuple);
	if (unlikely(!el))
		goto slowpath;

	if (unlikely(el->block)) {
		pr_debug("entry blocked, send to slowpath\n");
		goto slowpath;
	}

	if (unlikely(nf_ct_protonum(el->ct) == IPPROTO_TCP) &&
		     el->ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED) {
		pr_debug("tcp connection state not established\n");
		goto slowpath;
	}

	if (unlikely(el->in_dev->dev != src &&
		     el->in_dev->br != src)) {
		/**
		 * Since entry can be updated (due to route changes) this case
		 * is legal for a short period of time in which packets are
		 * received using the old entry and transmitted using the new
		 * one. Since we dont knwo if this is the case or not we will
		 * just forward this packets to slowpath to decide what to do.
		 */
		pr_debug("in_dev->dev=%s(%p) != src=%s(%p)\n",
			el->in_dev->dev->name, el->in_dev->dev, src->name, src);
		goto slowpath;
	}

	if (unlikely(!el->in_dev->forward || !el->out_dev->forward)) {
		pr_debug("forwarding disabled (%s forward=%d, %s forward=%d)\n",
				el->in_dev->dev->name, el->in_dev->forward,
				el->out_dev->dev->name, el->out_dev->forward);
		goto slowpath;
	}

	dst = el->out_dev->dev;
	if (unlikely(NETIF_INVALID(dst))) {
		pr_debug("dst (%s) state invalid (%lu)\n", dst->name, dst->state);
		goto slowpath;
	}

	if (unlikely(dst->mtu < skb->len)) {
		pr_info_once("mtu (%d) < len (%d)\n", dst->mtu, skb->len);
		goto slowpath;
	}

	if (unlikely(dst == src)) {
		/* src == dst entries should be blocked, it's a bug otherwise */
		/* here we don't need to dump entry. It will cause assert */
		/* because it takes a lot of time yhuang 20160622 */
		pr_err("Bug in classifier dst_dev==src_dev(%s), block=%d\n",
		src->name, (unsigned int)el->block);
		/* FP_ERR_DUMP_ENTRY(NULL, el); */
		/* BUG_ON(debug_level & DBG_WARN_AS_ERR); */
		goto slowpath;

	}

	if (unlikely(dst->header_ops && !el->hh.hh_len)) {
		pr_debug("hh_cache not valid, send to slowpath\n");
		goto slowpath;
	}

	if (unlikely(skb->pkt_type != PACKET_HOST &&
		     skb->pkt_type != PACKET_OTHERHOST)) {
		pr_debug("invalid skb->pkt_type(%d)\n", skb->pkt_type);
		goto slowpath;
	}

	pr_debug("Packet from %s to %s (pkt_p %p len %d) classified as fast path\n",
		 src->name, dst->name, skb->data, skb->len);
	stats.fast++;
	return el;

slowpath:
	if (el)
		fpdb_put(el);
	pr_debug("Packet from %s (pkt_p %p len %d) classified as slow path\n",
		 src->name, skb->data, skb->len);
	stats.slow++;
	return NULL;

}


/**
 * classify, mangle, track and hold the output device
 * Caller MUST release the device with fp_dev_put() once finished.
 *
 * @param skb    skb to classify and mangle
 *
 * @return destination fp_net_device or NULL if classified as
 *         slow path
 */
struct fp_net_device *fpc_classify(struct sk_buff *skb)
{
	struct fpdb_entry *el;
	struct fp_net_device *fdev;
	struct nf_conntrack_tuple tuple;

	el = fpc_classify_start(skb, &tuple);
	if (unlikely(!el))
		return NULL;
	fdev = fpdev_hold(el->out_dev);
	if (fpc_classify_finish(skb, el))
		return NULL;

	return fdev;
}

static ssize_t stats_show(struct fastpath_module *m, char *buf)
{
	int len;

	len = sprintf(buf, "Fast Path Classifier statistics:\n");

	len += sprintf(buf + len, "Total Classified %d ", stats.total);
	len += sprintf(buf + len, "(Fast %d, Slow %d)\n", stats.fast, stats.slow);

	return len;
}

static ssize_t stats_clear(struct fastpath_module *m, const char *buf,
			    size_t count)
{
	pr_debug("reset stats...\n");
	memset(&stats, 0, sizeof(stats));
	return count;
}

#if LINUX_VERSION_CODE <= KERNEL_VERSION(3, 3, 0)
static ssize_t udp_ct_timeout_set(struct fastpath_module *m, const char *buf,
				   size_t count)
{
	unsigned int sec;
	sscanf(buf, "%u", &sec);
	udp_ct_timeout = sec * HZ;
	return count;
}

static ssize_t udp_ct_timeout_get(struct fastpath_module *m, char *buf)
{
	unsigned int sec = udp_ct_timeout / HZ;
	return sprintf(buf, "%u\n", sec);
}

static ssize_t tcp_ct_timeout_set(struct fastpath_module *m, const char *buf,
				   size_t count)
{
	unsigned int sec;
	sscanf(buf, "%u", &sec);
	tcp_ct_timeout = sec * HZ;
	return count;
}

static ssize_t tcp_ct_timeout_get(struct fastpath_module *m, char *buf)
{
	unsigned int sec = tcp_ct_timeout / HZ;
	return sprintf(buf, "%u\n", sec);
}


static FP_ATTR(udp_ct_timeout, S_IRUGO|S_IWUSR, udp_ct_timeout_get, udp_ct_timeout_set);
static FP_ATTR(tcp_ct_timeout, S_IRUGO|S_IWUSR, tcp_ct_timeout_get, tcp_ct_timeout_set);
#endif

static ssize_t fp_acct_set(struct fastpath_module *m, const char *buf,
				   size_t count)
{
	int flag;
	sscanf(buf, "%d", &flag);
	fp_acct_flag = flag;
	return count;
}

static ssize_t fp_acct_get(struct fastpath_module *m, char *buf)
{
	int flag = fp_acct_flag;
	return sprintf(buf, "%d\n", flag);
}


static ssize_t fp_ip_log_set(struct fastpath_module *m, const char *buf,
				   size_t count)
{
	int flag;
	int old_flag;
	int num;
	int ret;
	struct file *filep;
	mm_segment_t old_fs;

	sscanf(buf, "%d", &flag);
	switch (flag) {
	case 0:
		fp_ip_log_en = flag;
		pr_err("fp_ip_log_set: disable ip_log:fp_ip_log_index=%d to 0\n",
			fp_ip_log_index);
		fp_ip_log_index = 0;
		break;
	case 1:
		fp_ip_log_index = 0;
		sscanf(buf, "%d,%d", &flag, &num);

		if (fp_ip_log_buf == NULL) {
			fp_ip_log_buf = kzalloc(ONE_IP_LOG_LEN*num, GFP_KERNEL);
			if (fp_ip_log_buf == NULL)
				pr_err("fp_ip_log_set: %d,%d,%d, but malloc failed\n",
				flag, num, fp_ip_log_index);
			else
				pr_err("fp_ip_log_set: %d,%d,%d, buf=%x, size=%d\n",
				flag, num, fp_ip_log_index,
				(unsigned int)fp_ip_log_buf,
				num*ONE_IP_LOG_LEN);
		} else {

			pr_err(" fp_ip_log_set: buffer has been allocated:%d\n",
				fp_ip_log_pkt_num);
		}
		fp_ip_log_pkt_num = num;
		fp_ip_log_en = flag;
		break;

	case 2:
		old_flag = fp_ip_log_en;
		pr_err("fp_ip_log_set: output buf to file(tmp/iplog.txt):\
			old_flag=%d index=%d\n",
			old_flag, fp_ip_log_index);
		fp_ip_log_en = 2;
/*Don't delete this part of code. It's for reference on data structure
		{
			char* pex_log_pos;
			unsigned int* ptime_h;
			unsigned int* ptime_l;
			unsigned short* pver;
			unsigned short* ppro;
			unsigned short* plen;
			unsigned int* psadd;
			unsigned int* pdadd;
			unsigned short* psport;
			unsigned short* pdport;
			unsigned int* pseq;
			unsigned int* pack_seq;
			int i;

			for (i = 0; i < 2; i++) {
				pex_log_pos = fp_ip_log_buf+i*ONE_IP_LOG_LEN;
				ptime_h = (unsigned int*)pex_log_pos;
				pex_log_pos +=4;
				ptime_l = (unsigned int*)pex_log_pos;
				pex_log_pos +=4;
				pver = (unsigned short*)pex_log_pos;
				pex_log_pos +=2;
				ppro = (unsigned short*)pex_log_pos;
				pex_log_pos +=2;
				plen = (unsigned short*)pex_log_pos;
				pex_log_pos +=4;
				psadd = (unsigned int*)pex_log_pos;
				pex_log_pos += 16;
				pdadd = (unsigned int*) pex_log_pos;
				pex_log_pos+=16;
				psport = (unsigned short*) pex_log_pos;
				pex_log_pos +=2;
				pdport = (unsigned short*) pex_log_pos;
				pex_log_pos+=2;
				pseq = (unsigned int*)pex_log_pos;
				pex_log_pos +=4;
				pack_seq =(unsigned int*)pex_log_pos;

				pr_err("Time:%x %x, ver*pro:%x, pid:%x, len:%x,
				sadd:%x, dadd:%x, sport:%x, dport:%x,
				seq;%x, ack_seq:%x\n",
				*ptime_h, *ptime_l, *pver, *ppro, *plen,
				*psadd, *pdadd, *psport, *pdport,
				*pseq, *pack_seq);
			}
		}
*/
		filep = filp_open("/tmp/iplog.bin", O_RDWR|O_CREAT, 0644);
		if (IS_ERR(filep)) {
			pr_err("fp_ip_log_set: fail to open IP log file\n");
		} else {
			old_fs = get_fs();
			set_fs(KERNEL_DS);
			filep->f_pos = 0;
			ret = filep->f_op->write(filep, fp_ip_log_buf,
				ONE_IP_LOG_LEN*fp_ip_log_pkt_num,
				&filep->f_pos);
			set_fs(old_fs);
			pr_err("fp_ip_log_set: write to /tmp/iplog.bin, ret=%d\n",
				ret);
		}
		filp_close(filep, NULL);
		fp_ip_log_en = old_flag;
		break;
	case 3:
		fp_ip_log_en = flag;
		if (fp_ip_log_buf != NULL) {
			kfree(fp_ip_log_buf);
			pr_err("fp_ip_log_set: free the buffer\n");
			fp_ip_log_buf = NULL;
		} else {
			pr_err("fp_ip_log_set: buffer is NULL\n");
		}
		break;
	default:
		fp_ip_log_en = flag;
		pr_err("fp_ip_log_set: not support this command:\
			%d, but the log will stop\n", flag);
		break;
	}
	return count;
}

static ssize_t fp_ip_log_get(struct fastpath_module *m, char *buf)
{
	int flag = fp_ip_log_en;
	int num = fp_ip_log_pkt_num;
	return sprintf(buf, "%d,%d buf=%x\n",
		flag,
		num,
		(unsigned int)fp_ip_log_buf);
}


static FP_ATTR(fp_acct_flag, S_IRUGO|S_IWUSR, fp_acct_get, fp_acct_set);
static FP_ATTR(fp_ip_log, S_IRUGO|S_IWUSR, fp_ip_log_get, fp_ip_log_set);
static FP_ATTR(stats, S_IRUGO|S_IWUSR, stats_show, stats_clear);

static struct attribute *fp_classifier_attrs[] = {
	&fp_attr_stats.attr,
#if LINUX_VERSION_CODE <= KERNEL_VERSION(3, 3, 0)
	&fp_attr_udp_ct_timeout.attr,
	&fp_attr_tcp_ct_timeout.attr,
#endif
	&fp_attr_fp_acct_flag.attr,
	&fp_attr_fp_ip_log.attr,
	NULL, /* need to NULL terminate the list of attributes */
};

static void fp_classifier_release(struct kobject *kobj)
{
	struct fastpath_module *module = to_fpmod(kobj);

	pr_debug("fp_classifier released\n");
	kfree(module);
}

static struct kobj_type ktype_classifier = {
	.sysfs_ops	= &fp_sysfs_ops,
	.default_attrs	= fp_classifier_attrs,
	.release	= fp_classifier_release,
};

static int fp_classifier_probe(struct fastpath_module *module)
{
	int ret;

	module->priv = NULL;
	snprintf(module->name, sizeof(module->name), "fp_classifier");

	kobject_init(&module->kobj, &ktype_classifier);
	ret = kobject_add(&module->kobj, module->fastpath->kobj, "%s", module->name);
	if (ret < 0) {
		pr_err("kobject_add failed (%d)\n", ret);
		kobject_put(&module->kobj);
		return ret;
	}
	kobject_uevent(&module->kobj, KOBJ_ADD);

	pr_debug("fp_classifier probed\n");
	return 0;
}

static int fp_classifier_remove(struct fastpath_module *module)
{
	kobject_put(&module->kobj);

	pr_debug("fp_classifier removed\n");
	return 0;
}

struct fastpath_module_ops fp_classifier_ops = {
	.probe = fp_classifier_probe,
	.remove = fp_classifier_remove,
};