[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / ipvs / ip_vs_app.c

/*
 * ip_vs_app.c: Application module support for IPVS
 *
 * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
 *
 *              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.
 *
 * Most code here is taken from ip_masq_app.c in kernel 2.2. The difference
 * is that ip_vs_app module handles the reverse direction (incoming requests
 * and outgoing responses).
 *
 *		IP_MASQ_APP application masquerading module
 *
 * Author:	Juan Jose Ciarlante, <jjciarla@raiz.uncu.edu.ar>
 *
 */

#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <asm/system.h>
#include <linux/stat.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/mutex.h>

#include <net/ip_vs.h>

EXPORT_SYMBOL(register_ip_vs_app);
EXPORT_SYMBOL(unregister_ip_vs_app);
EXPORT_SYMBOL(register_ip_vs_app_inc);

static DEFINE_MUTEX(__ip_vs_app_mutex);

/*
 *	Get an ip_vs_app object
 */
static inline int ip_vs_app_get(struct ip_vs_app *app)
{
	return try_module_get(app->module);
}


static inline void ip_vs_app_put(struct ip_vs_app *app)
{
	module_put(app->module);
}


/*
 *	Allocate/initialize app incarnation and register it in proto apps.
 */
static int
ip_vs_app_inc_new(struct net *net, struct ip_vs_app *app, __u16 proto,
		  __u16 port)
{
	struct ip_vs_protocol *pp;
	struct ip_vs_app *inc;
	int ret;

	if (!(pp = ip_vs_proto_get(proto)))
		return -EPROTONOSUPPORT;

	if (!pp->unregister_app)
		return -EOPNOTSUPP;

	inc = kmemdup(app, sizeof(*inc), GFP_KERNEL);
	if (!inc)
		return -ENOMEM;
	INIT_LIST_HEAD(&inc->p_list);
	INIT_LIST_HEAD(&inc->incs_list);
	inc->app = app;
	inc->port = htons(port);
	atomic_set(&inc->usecnt, 0);

	if (app->timeouts) {
		inc->timeout_table =
			ip_vs_create_timeout_table(app->timeouts,
						   app->timeouts_size);
		if (!inc->timeout_table) {
			ret = -ENOMEM;
			goto out;
		}
	}

	ret = pp->register_app(net, inc);
	if (ret)
		goto out;

	list_add(&inc->a_list, &app->incs_list);
	IP_VS_DBG(9, "%s App %s:%u registered\n",
		  pp->name, inc->name, ntohs(inc->port));

	return 0;

  out:
	kfree(inc->timeout_table);
	kfree(inc);
	return ret;
}


/*
 *	Release app incarnation
 */
static void
ip_vs_app_inc_release(struct net *net, struct ip_vs_app *inc)
{
	struct ip_vs_protocol *pp;

	if (!(pp = ip_vs_proto_get(inc->protocol)))
		return;

	if (pp->unregister_app)
		pp->unregister_app(net, inc);

	IP_VS_DBG(9, "%s App %s:%u unregistered\n",
		  pp->name, inc->name, ntohs(inc->port));

	list_del(&inc->a_list);

	kfree(inc->timeout_table);
	kfree(inc);
}


/*
 *	Get reference to app inc (only called from softirq)
 *
 */
int ip_vs_app_inc_get(struct ip_vs_app *inc)
{
	int result;

	atomic_inc(&inc->usecnt);
	if (unlikely((result = ip_vs_app_get(inc->app)) != 1))
		atomic_dec(&inc->usecnt);
	return result;
}


/*
 *	Put the app inc (only called from timer or net softirq)
 */
void ip_vs_app_inc_put(struct ip_vs_app *inc)
{
	ip_vs_app_put(inc->app);
	atomic_dec(&inc->usecnt);
}


/*
 *	Register an application incarnation in protocol applications
 */
int
register_ip_vs_app_inc(struct net *net, struct ip_vs_app *app, __u16 proto,
		       __u16 port)
{
	int result;

	mutex_lock(&__ip_vs_app_mutex);

	result = ip_vs_app_inc_new(net, app, proto, port);

	mutex_unlock(&__ip_vs_app_mutex);

	return result;
}


/*
 *	ip_vs_app registration routine
 */
int register_ip_vs_app(struct net *net, struct ip_vs_app *app)
{
	struct netns_ipvs *ipvs = net_ipvs(net);
	/* increase the module use count */
	ip_vs_use_count_inc();

	mutex_lock(&__ip_vs_app_mutex);

	list_add(&app->a_list, &ipvs->app_list);

	mutex_unlock(&__ip_vs_app_mutex);

	return 0;
}


/*
 *	ip_vs_app unregistration routine
 *	We are sure there are no app incarnations attached to services
 */
void unregister_ip_vs_app(struct net *net, struct ip_vs_app *app)
{
	struct ip_vs_app *inc, *nxt;

	mutex_lock(&__ip_vs_app_mutex);

	list_for_each_entry_safe(inc, nxt, &app->incs_list, a_list) {
		ip_vs_app_inc_release(net, inc);
	}

	list_del(&app->a_list);

	mutex_unlock(&__ip_vs_app_mutex);

	/* decrease the module use count */
	ip_vs_use_count_dec();
}


/*
 *	Bind ip_vs_conn to its ip_vs_app (called by cp constructor)
 */
int ip_vs_bind_app(struct ip_vs_conn *cp,
		   struct ip_vs_protocol *pp)
{
	return pp->app_conn_bind(cp);
}


/*
 *	Unbind cp from application incarnation (called by cp destructor)
 */
void ip_vs_unbind_app(struct ip_vs_conn *cp)
{
	struct ip_vs_app *inc = cp->app;

	if (!inc)
		return;

	if (inc->unbind_conn)
		inc->unbind_conn(inc, cp);
	if (inc->done_conn)
		inc->done_conn(inc, cp);
	ip_vs_app_inc_put(inc);
	cp->app = NULL;
}


/*
 *	Fixes th->seq based on ip_vs_seq info.
 */
static inline void vs_fix_seq(const struct ip_vs_seq *vseq, struct tcphdr *th)
{
	__u32 seq = ntohl(th->seq);

	/*
	 *	Adjust seq with delta-offset for all packets after
	 *	the most recent resized pkt seq and with previous_delta offset
	 *	for all packets	before most recent resized pkt seq.
	 */
	if (vseq->delta || vseq->previous_delta) {
		if(after(seq, vseq->init_seq)) {
			th->seq = htonl(seq + vseq->delta);
			IP_VS_DBG(9, "%s(): added delta (%d) to seq\n",
				  __func__, vseq->delta);
		} else {
			th->seq = htonl(seq + vseq->previous_delta);
			IP_VS_DBG(9, "%s(): added previous_delta (%d) to seq\n",
				  __func__, vseq->previous_delta);
		}
	}
}


/*
 *	Fixes th->ack_seq based on ip_vs_seq info.
 */
static inline void
vs_fix_ack_seq(const struct ip_vs_seq *vseq, struct tcphdr *th)
{
	__u32 ack_seq = ntohl(th->ack_seq);

	/*
	 * Adjust ack_seq with delta-offset for
	 * the packets AFTER most recent resized pkt has caused a shift
	 * for packets before most recent resized pkt, use previous_delta
	 */
	if (vseq->delta || vseq->previous_delta) {
		/* since ack_seq is the number of octet that is expected
		   to receive next, so compare it with init_seq+delta */
		if(after(ack_seq, vseq->init_seq+vseq->delta)) {
			th->ack_seq = htonl(ack_seq - vseq->delta);
			IP_VS_DBG(9, "%s(): subtracted delta "
				  "(%d) from ack_seq\n", __func__, vseq->delta);

		} else {
			th->ack_seq = htonl(ack_seq - vseq->previous_delta);
			IP_VS_DBG(9, "%s(): subtracted "
				  "previous_delta (%d) from ack_seq\n",
				  __func__, vseq->previous_delta);
		}
	}
}


/*
 *	Updates ip_vs_seq if pkt has been resized
 *	Assumes already checked proto==IPPROTO_TCP and diff!=0.
 */
static inline void vs_seq_update(struct ip_vs_conn *cp, struct ip_vs_seq *vseq,
				 unsigned flag, __u32 seq, int diff)
{
	/* spinlock is to keep updating cp->flags atomic */
	spin_lock(&cp->lock);
	if (!(cp->flags & flag) || after(seq, vseq->init_seq)) {
		vseq->previous_delta = vseq->delta;
		vseq->delta += diff;
		vseq->init_seq = seq;
		cp->flags |= flag;
	}
	spin_unlock(&cp->lock);
}

static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb,
				  struct ip_vs_app *app)
{
	int diff;
	const unsigned int tcp_offset = ip_hdrlen(skb);
	struct tcphdr *th;
	__u32 seq;

	if (!skb_make_writable(skb, tcp_offset + sizeof(*th)))
		return 0;

	th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset);

	/*
	 *	Remember seq number in case this pkt gets resized
	 */
	seq = ntohl(th->seq);

	/*
	 *	Fix seq stuff if flagged as so.
	 */
	if (cp->flags & IP_VS_CONN_F_OUT_SEQ)
		vs_fix_seq(&cp->out_seq, th);
	if (cp->flags & IP_VS_CONN_F_IN_SEQ)
		vs_fix_ack_seq(&cp->in_seq, th);

	/*
	 *	Call private output hook function
	 */
	if (app->pkt_out == NULL)
		return 1;

	if (!app->pkt_out(app, cp, skb, &diff))
		return 0;

	/*
	 *	Update ip_vs seq stuff if len has changed.
	 */
	if (diff != 0)
		vs_seq_update(cp, &cp->out_seq,
			      IP_VS_CONN_F_OUT_SEQ, seq, diff);

	return 1;
}

/*
 *	Output pkt hook. Will call bound ip_vs_app specific function
 *	called by ipvs packet handler, assumes previously checked cp!=NULL
 *	returns false if it can't handle packet (oom)
 */
int ip_vs_app_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb)
{
	struct ip_vs_app *app;

	/*
	 *	check if application module is bound to
	 *	this ip_vs_conn.
	 */
	if ((app = cp->app) == NULL)
		return 1;

	/* TCP is complicated */
	if (cp->protocol == IPPROTO_TCP)
		return app_tcp_pkt_out(cp, skb, app);

	/*
	 *	Call private output hook function
	 */
	if (app->pkt_out == NULL)
		return 1;

	return app->pkt_out(app, cp, skb, NULL);
}


static inline int app_tcp_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb,
				 struct ip_vs_app *app)
{
	int diff;
	const unsigned int tcp_offset = ip_hdrlen(skb);
	struct tcphdr *th;
	__u32 seq;

	if (!skb_make_writable(skb, tcp_offset + sizeof(*th)))
		return 0;

	th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset);

	/*
	 *	Remember seq number in case this pkt gets resized
	 */
	seq = ntohl(th->seq);

	/*
	 *	Fix seq stuff if flagged as so.
	 */
	if (cp->flags & IP_VS_CONN_F_IN_SEQ)
		vs_fix_seq(&cp->in_seq, th);
	if (cp->flags & IP_VS_CONN_F_OUT_SEQ)
		vs_fix_ack_seq(&cp->out_seq, th);

	/*
	 *	Call private input hook function
	 */
	if (app->pkt_in == NULL)
		return 1;

	if (!app->pkt_in(app, cp, skb, &diff))
		return 0;

	/*
	 *	Update ip_vs seq stuff if len has changed.
	 */
	if (diff != 0)
		vs_seq_update(cp, &cp->in_seq,
			      IP_VS_CONN_F_IN_SEQ, seq, diff);

	return 1;
}

/*
 *	Input pkt hook. Will call bound ip_vs_app specific function
 *	called by ipvs packet handler, assumes previously checked cp!=NULL.
 *	returns false if can't handle packet (oom).
 */
int ip_vs_app_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb)
{
	struct ip_vs_app *app;

	/*
	 *	check if application module is bound to
	 *	this ip_vs_conn.
	 */
	if ((app = cp->app) == NULL)
		return 1;

	/* TCP is complicated */
	if (cp->protocol == IPPROTO_TCP)
		return app_tcp_pkt_in(cp, skb, app);

	/*
	 *	Call private input hook function
	 */
	if (app->pkt_in == NULL)
		return 1;

	return app->pkt_in(app, cp, skb, NULL);
}


#ifdef CONFIG_PROC_FS
/*
 *	/proc/net/ip_vs_app entry function
 */

static struct ip_vs_app *ip_vs_app_idx(struct netns_ipvs *ipvs, loff_t pos)
{
	struct ip_vs_app *app, *inc;

	list_for_each_entry(app, &ipvs->app_list, a_list) {
		list_for_each_entry(inc, &app->incs_list, a_list) {
			if (pos-- == 0)
				return inc;
		}
	}
	return NULL;

}

static void *ip_vs_app_seq_start(struct seq_file *seq, loff_t *pos)
{
	struct net *net = seq_file_net(seq);
	struct netns_ipvs *ipvs = net_ipvs(net);

	mutex_lock(&__ip_vs_app_mutex);

	return *pos ? ip_vs_app_idx(ipvs, *pos - 1) : SEQ_START_TOKEN;
}

static void *ip_vs_app_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct ip_vs_app *inc, *app;
	struct list_head *e;
	struct net *net = seq_file_net(seq);
	struct netns_ipvs *ipvs = net_ipvs(net);

	++*pos;
	if (v == SEQ_START_TOKEN)
		return ip_vs_app_idx(ipvs, 0);

	inc = v;
	app = inc->app;

	if ((e = inc->a_list.next) != &app->incs_list)
		return list_entry(e, struct ip_vs_app, a_list);

	/* go on to next application */
	for (e = app->a_list.next; e != &ipvs->app_list; e = e->next) {
		app = list_entry(e, struct ip_vs_app, a_list);
		list_for_each_entry(inc, &app->incs_list, a_list) {
			return inc;
		}
	}
	return NULL;
}

static void ip_vs_app_seq_stop(struct seq_file *seq, void *v)
{
	mutex_unlock(&__ip_vs_app_mutex);
}

static int ip_vs_app_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_puts(seq, "prot port    usecnt name\n");
	else {
		const struct ip_vs_app *inc = v;

		seq_printf(seq, "%-3s  %-7u %-6d %-17s\n",
			   ip_vs_proto_name(inc->protocol),
			   ntohs(inc->port),
			   atomic_read(&inc->usecnt),
			   inc->name);
	}
	return 0;
}

static const struct seq_operations ip_vs_app_seq_ops = {
	.start = ip_vs_app_seq_start,
	.next  = ip_vs_app_seq_next,
	.stop  = ip_vs_app_seq_stop,
	.show  = ip_vs_app_seq_show,
};

static int ip_vs_app_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &ip_vs_app_seq_ops,
			    sizeof(struct seq_net_private));
}

static const struct file_operations ip_vs_app_fops = {
	.owner	 = THIS_MODULE,
	.open	 = ip_vs_app_open,
	.read	 = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release_net,
};
#endif

int __net_init __ip_vs_app_init(struct net *net)
{
	struct netns_ipvs *ipvs = net_ipvs(net);

	INIT_LIST_HEAD(&ipvs->app_list);
	proc_net_fops_create(net, "ip_vs_app", 0, &ip_vs_app_fops);
	return 0;
}

void __net_exit __ip_vs_app_cleanup(struct net *net)
{
	proc_net_remove(net, "ip_vs_app");
}

int __init ip_vs_app_init(void)
{
	return 0;
}


void ip_vs_app_cleanup(void)
{
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ip_vs_app.c: Application module support for IPVS
	3	*
1da177e4 LT	4	* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*
	11	* Most code here is taken from ip_masq_app.c in kernel 2.2. The difference
	12	* is that ip_vs_app module handles the reverse direction (incoming requests
	13	* and outgoing responses).
	14	*
	15	* IP_MASQ_APP application masquerading module
	16	*
	17	* Author: Juan Jose Ciarlante, <jjciarla@raiz.uncu.edu.ar>
	18	*
	19	*/
	20
9aada7ac HE	21	#define KMSG_COMPONENT "IPVS"
	22	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	23
1da177e4 LT	24	#include <linux/module.h>
	25	#include <linux/kernel.h>
	26	#include <linux/skbuff.h>
	27	#include <linux/in.h>
	28	#include <linux/ip.h>
af1e1cf0	29	#include <linux/netfilter.h>
5a0e3ad6	30	#include <linux/slab.h>
457c4cbc	31	#include <net/net_namespace.h>
1da177e4	32	#include <net/protocol.h>
c752f073	33	#include <net/tcp.h>
1da177e4 LT	34	#include <asm/system.h>
	35	#include <linux/stat.h>
	36	#include <linux/proc_fs.h>
	37	#include <linux/seq_file.h>
57b47a53	38	#include <linux/mutex.h>
1da177e4 LT	39
	40	#include <net/ip_vs.h>
	41
	42	EXPORT_SYMBOL(register_ip_vs_app);
	43	EXPORT_SYMBOL(unregister_ip_vs_app);
	44	EXPORT_SYMBOL(register_ip_vs_app_inc);
	45
736561a0 SH	46	static DEFINE_MUTEX(__ip_vs_app_mutex);
736561a0 SH	47
1da177e4 LT	48	/*
	49	* Get an ip_vs_app object
	50	*/
	51	static inline int ip_vs_app_get(struct ip_vs_app *app)
	52	{
85b60680	53	return try_module_get(app->module);
1da177e4 LT	54	}
	55
	56
	57	static inline void ip_vs_app_put(struct ip_vs_app *app)
	58	{
85b60680	59	module_put(app->module);
1da177e4 LT	60	}
	61
	62
	63	/*
	64	* Allocate/initialize app incarnation and register it in proto apps.
	65	*/
	66	static int
ab8a5e84 HS	67	ip_vs_app_inc_new(struct net net, struct ip_vs_app app, __u16 proto,
ab8a5e84 HS	68	__u16 port)
1da177e4 LT	69	{
	70	struct ip_vs_protocol *pp;
	71	struct ip_vs_app *inc;
	72	int ret;
	73
	74	if (!(pp = ip_vs_proto_get(proto)))
	75	return -EPROTONOSUPPORT;
	76
	77	if (!pp->unregister_app)
	78	return -EOPNOTSUPP;
	79
8b2ed4bb	80	inc = kmemdup(app, sizeof(*inc), GFP_KERNEL);
1da177e4 LT	81	if (!inc)
1da177e4 LT	82	return -ENOMEM;
1da177e4 LT	83	INIT_LIST_HEAD(&inc->p_list);
	84	INIT_LIST_HEAD(&inc->incs_list);
	85	inc->app = app;
	86	inc->port = htons(port);
	87	atomic_set(&inc->usecnt, 0);
	88
	89	if (app->timeouts) {
	90	inc->timeout_table =
	91	ip_vs_create_timeout_table(app->timeouts,
	92	app->timeouts_size);
	93	if (!inc->timeout_table) {
	94	ret = -ENOMEM;
	95	goto out;
	96	}
	97	}
	98
ab8a5e84	99	ret = pp->register_app(net, inc);
1da177e4 LT	100	if (ret)
	101	goto out;
	102
	103	list_add(&inc->a_list, &app->incs_list);
26c15cfd JA	104	IP_VS_DBG(9, "%s App %s:%u registered\n",
26c15cfd JA	105	pp->name, inc->name, ntohs(inc->port));
1da177e4 LT	106
	107	return 0;
	108
	109	out:
a51482bd	110	kfree(inc->timeout_table);
1da177e4 LT	111	kfree(inc);
	112	return ret;
	113	}
	114
	115
	116	/*
	117	* Release app incarnation
	118	*/
	119	static void
ab8a5e84	120	ip_vs_app_inc_release(struct net net, struct ip_vs_app inc)
1da177e4 LT	121	{
	122	struct ip_vs_protocol *pp;
	123
	124	if (!(pp = ip_vs_proto_get(inc->protocol)))
	125	return;
	126
	127	if (pp->unregister_app)
ab8a5e84	128	pp->unregister_app(net, inc);
1da177e4 LT	129
1da177e4 LT	130	IP_VS_DBG(9, "%s App %s:%u unregistered\n",
26c15cfd	131	pp->name, inc->name, ntohs(inc->port));
1da177e4 LT	132
	133	list_del(&inc->a_list);
	134
a51482bd	135	kfree(inc->timeout_table);
1da177e4 LT	136	kfree(inc);
	137	}
	138
	139
	140	/*
	141	* Get reference to app inc (only called from softirq)
	142	*
	143	*/
	144	int ip_vs_app_inc_get(struct ip_vs_app *inc)
	145	{
	146	int result;
	147
	148	atomic_inc(&inc->usecnt);
	149	if (unlikely((result = ip_vs_app_get(inc->app)) != 1))
	150	atomic_dec(&inc->usecnt);
	151	return result;
	152	}
	153
	154
	155	/*
	156	* Put the app inc (only called from timer or net softirq)
	157	*/
	158	void ip_vs_app_inc_put(struct ip_vs_app *inc)
	159	{
	160	ip_vs_app_put(inc->app);
	161	atomic_dec(&inc->usecnt);
	162	}
	163
	164
	165	/*
	166	* Register an application incarnation in protocol applications
	167	*/
	168	int
ab8a5e84 HS	169	register_ip_vs_app_inc(struct net net, struct ip_vs_app app, __u16 proto,
ab8a5e84 HS	170	__u16 port)
1da177e4 LT	171	{
	172	int result;
	173
736561a0	174	mutex_lock(&__ip_vs_app_mutex);
1da177e4	175
ab8a5e84	176	result = ip_vs_app_inc_new(net, app, proto, port);
1da177e4	177
736561a0	178	mutex_unlock(&__ip_vs_app_mutex);
1da177e4 LT	179
	180	return result;
	181	}
	182
	183
	184	/*
	185	* ip_vs_app registration routine
	186	*/
ab8a5e84	187	int register_ip_vs_app(struct net net, struct ip_vs_app app)
1da177e4	188	{
ab8a5e84	189	struct netns_ipvs *ipvs = net_ipvs(net);
1da177e4 LT	190	/* increase the module use count */
	191	ip_vs_use_count_inc();
	192
736561a0	193	mutex_lock(&__ip_vs_app_mutex);
1da177e4	194
ab8a5e84	195	list_add(&app->a_list, &ipvs->app_list);
1da177e4	196
736561a0	197	mutex_unlock(&__ip_vs_app_mutex);
1da177e4 LT	198
	199	return 0;
	200	}
	201
	202
	203	/*
	204	* ip_vs_app unregistration routine
	205	* We are sure there are no app incarnations attached to services
	206	*/
ab8a5e84	207	void unregister_ip_vs_app(struct net net, struct ip_vs_app app)
1da177e4 LT	208	{
	209	struct ip_vs_app inc, nxt;
	210
736561a0	211	mutex_lock(&__ip_vs_app_mutex);
1da177e4 LT	212
1da177e4 LT	213	list_for_each_entry_safe(inc, nxt, &app->incs_list, a_list) {
ab8a5e84	214	ip_vs_app_inc_release(net, inc);
1da177e4 LT	215	}
	216
	217	list_del(&app->a_list);
	218
736561a0	219	mutex_unlock(&__ip_vs_app_mutex);
1da177e4 LT	220
	221	/* decrease the module use count */
	222	ip_vs_use_count_dec();
	223	}
	224
	225
1da177e4 LT	226	/*
	227	* Bind ip_vs_conn to its ip_vs_app (called by cp constructor)
	228	*/
ab8a5e84 HS	229	int ip_vs_bind_app(struct ip_vs_conn *cp,
ab8a5e84 HS	230	struct ip_vs_protocol *pp)
1da177e4 LT	231	{
	232	return pp->app_conn_bind(cp);
	233	}
	234
	235
	236	/*
	237	* Unbind cp from application incarnation (called by cp destructor)
	238	*/
	239	void ip_vs_unbind_app(struct ip_vs_conn *cp)
	240	{
	241	struct ip_vs_app *inc = cp->app;
	242
	243	if (!inc)
	244	return;
	245
	246	if (inc->unbind_conn)
	247	inc->unbind_conn(inc, cp);
	248	if (inc->done_conn)
	249	inc->done_conn(inc, cp);
	250	ip_vs_app_inc_put(inc);
	251	cp->app = NULL;
	252	}
	253
	254
	255	/*
	256	* Fixes th->seq based on ip_vs_seq info.
	257	*/
	258	static inline void vs_fix_seq(const struct ip_vs_seq vseq, struct tcphdr th)
	259	{
	260	__u32 seq = ntohl(th->seq);
	261
	262	/*
	263	* Adjust seq with delta-offset for all packets after
	264	* the most recent resized pkt seq and with previous_delta offset
	265	* for all packets before most recent resized pkt seq.
	266	*/
	267	if (vseq->delta \|\| vseq->previous_delta) {
	268	if(after(seq, vseq->init_seq)) {
	269	th->seq = htonl(seq + vseq->delta);
1e3e238e HE	270	IP_VS_DBG(9, "%s(): added delta (%d) to seq\n",
1e3e238e HE	271	__func__, vseq->delta);
1da177e4 LT	272	} else {
1da177e4 LT	273	th->seq = htonl(seq + vseq->previous_delta);
1e3e238e HE	274	IP_VS_DBG(9, "%s(): added previous_delta (%d) to seq\n",
1e3e238e HE	275	__func__, vseq->previous_delta);
1da177e4 LT	276	}
	277	}
	278	}
	279
	280
	281	/*
	282	* Fixes th->ack_seq based on ip_vs_seq info.
	283	*/
	284	static inline void
	285	vs_fix_ack_seq(const struct ip_vs_seq vseq, struct tcphdr th)
	286	{
	287	__u32 ack_seq = ntohl(th->ack_seq);
	288
	289	/*
	290	* Adjust ack_seq with delta-offset for
	291	* the packets AFTER most recent resized pkt has caused a shift
	292	* for packets before most recent resized pkt, use previous_delta
	293	*/
	294	if (vseq->delta \|\| vseq->previous_delta) {
	295	/* since ack_seq is the number of octet that is expected
	296	to receive next, so compare it with init_seq+delta */
	297	if(after(ack_seq, vseq->init_seq+vseq->delta)) {
	298	th->ack_seq = htonl(ack_seq - vseq->delta);
1e3e238e HE	299	IP_VS_DBG(9, "%s(): subtracted delta "
1e3e238e HE	300	"(%d) from ack_seq\n", __func__, vseq->delta);
1da177e4 LT	301
	302	} else {
	303	th->ack_seq = htonl(ack_seq - vseq->previous_delta);
1e3e238e	304	IP_VS_DBG(9, "%s(): subtracted "
1da177e4	305	"previous_delta (%d) from ack_seq\n",
1e3e238e	306	__func__, vseq->previous_delta);
1da177e4 LT	307	}
	308	}
	309	}
	310
	311
	312	/*
	313	* Updates ip_vs_seq if pkt has been resized
	314	* Assumes already checked proto==IPPROTO_TCP and diff!=0.
	315	*/
	316	static inline void vs_seq_update(struct ip_vs_conn cp, struct ip_vs_seq vseq,
	317	unsigned flag, __u32 seq, int diff)
	318	{
	319	/* spinlock is to keep updating cp->flags atomic */
	320	spin_lock(&cp->lock);
	321	if (!(cp->flags & flag) \|\| after(seq, vseq->init_seq)) {
	322	vseq->previous_delta = vseq->delta;
	323	vseq->delta += diff;
	324	vseq->init_seq = seq;
	325	cp->flags \|= flag;
	326	}
	327	spin_unlock(&cp->lock);
	328	}
	329
3db05fea	330	static inline int app_tcp_pkt_out(struct ip_vs_conn cp, struct sk_buff skb,
1da177e4 LT	331	struct ip_vs_app *app)
	332	{
	333	int diff;
3db05fea	334	const unsigned int tcp_offset = ip_hdrlen(skb);
1da177e4 LT	335	struct tcphdr *th;
	336	__u32 seq;
	337
3db05fea	338	if (!skb_make_writable(skb, tcp_offset + sizeof(*th)))
1da177e4 LT	339	return 0;
1da177e4 LT	340
3db05fea	341	th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset);
1da177e4 LT	342
	343	/*
	344	* Remember seq number in case this pkt gets resized
	345	*/
	346	seq = ntohl(th->seq);
	347
	348	/*
	349	* Fix seq stuff if flagged as so.
	350	*/
	351	if (cp->flags & IP_VS_CONN_F_OUT_SEQ)
	352	vs_fix_seq(&cp->out_seq, th);
	353	if (cp->flags & IP_VS_CONN_F_IN_SEQ)
	354	vs_fix_ack_seq(&cp->in_seq, th);
	355
	356	/*
	357	* Call private output hook function
	358	*/
	359	if (app->pkt_out == NULL)
	360	return 1;
	361
3db05fea	362	if (!app->pkt_out(app, cp, skb, &diff))
1da177e4 LT	363	return 0;
	364
	365	/*
	366	* Update ip_vs seq stuff if len has changed.
	367	*/
	368	if (diff != 0)
	369	vs_seq_update(cp, &cp->out_seq,
	370	IP_VS_CONN_F_OUT_SEQ, seq, diff);
	371
	372	return 1;
	373	}
	374
	375	/*
	376	* Output pkt hook. Will call bound ip_vs_app specific function
	377	* called by ipvs packet handler, assumes previously checked cp!=NULL
	378	* returns false if it can't handle packet (oom)
	379	*/
3db05fea	380	int ip_vs_app_pkt_out(struct ip_vs_conn cp, struct sk_buff skb)
1da177e4 LT	381	{
	382	struct ip_vs_app *app;
	383
	384	/*
	385	* check if application module is bound to
	386	* this ip_vs_conn.
	387	*/
	388	if ((app = cp->app) == NULL)
	389	return 1;
	390
	391	/* TCP is complicated */
	392	if (cp->protocol == IPPROTO_TCP)
3db05fea	393	return app_tcp_pkt_out(cp, skb, app);
1da177e4 LT	394
	395	/*
	396	* Call private output hook function
	397	*/
	398	if (app->pkt_out == NULL)
	399	return 1;
	400
3db05fea	401	return app->pkt_out(app, cp, skb, NULL);
1da177e4 LT	402	}
	403
	404
3db05fea	405	static inline int app_tcp_pkt_in(struct ip_vs_conn cp, struct sk_buff skb,
1da177e4 LT	406	struct ip_vs_app *app)
	407	{
	408	int diff;
3db05fea	409	const unsigned int tcp_offset = ip_hdrlen(skb);
1da177e4 LT	410	struct tcphdr *th;
	411	__u32 seq;
	412
3db05fea	413	if (!skb_make_writable(skb, tcp_offset + sizeof(*th)))
1da177e4 LT	414	return 0;
1da177e4 LT	415
3db05fea	416	th = (struct tcphdr *)(skb_network_header(skb) + tcp_offset);
1da177e4 LT	417
	418	/*
	419	* Remember seq number in case this pkt gets resized
	420	*/
	421	seq = ntohl(th->seq);
	422
	423	/*
	424	* Fix seq stuff if flagged as so.
	425	*/
	426	if (cp->flags & IP_VS_CONN_F_IN_SEQ)
	427	vs_fix_seq(&cp->in_seq, th);
	428	if (cp->flags & IP_VS_CONN_F_OUT_SEQ)
	429	vs_fix_ack_seq(&cp->out_seq, th);
	430
	431	/*
	432	* Call private input hook function
	433	*/
	434	if (app->pkt_in == NULL)
	435	return 1;
	436
3db05fea	437	if (!app->pkt_in(app, cp, skb, &diff))
1da177e4 LT	438	return 0;
	439
	440	/*
	441	* Update ip_vs seq stuff if len has changed.
	442	*/
	443	if (diff != 0)
	444	vs_seq_update(cp, &cp->in_seq,
	445	IP_VS_CONN_F_IN_SEQ, seq, diff);
	446
	447	return 1;
	448	}
	449
	450	/*
	451	* Input pkt hook. Will call bound ip_vs_app specific function
	452	* called by ipvs packet handler, assumes previously checked cp!=NULL.
	453	* returns false if can't handle packet (oom).
	454	*/
3db05fea	455	int ip_vs_app_pkt_in(struct ip_vs_conn cp, struct sk_buff skb)
1da177e4 LT	456	{
	457	struct ip_vs_app *app;
	458
	459	/*
	460	* check if application module is bound to
	461	* this ip_vs_conn.
	462	*/
	463	if ((app = cp->app) == NULL)
	464	return 1;
	465
	466	/* TCP is complicated */
	467	if (cp->protocol == IPPROTO_TCP)
3db05fea	468	return app_tcp_pkt_in(cp, skb, app);
1da177e4 LT	469
	470	/*
	471	* Call private input hook function
	472	*/
	473	if (app->pkt_in == NULL)
	474	return 1;
	475
3db05fea	476	return app->pkt_in(app, cp, skb, NULL);
1da177e4 LT	477	}
	478
	479
	480	#ifdef CONFIG_PROC_FS
	481	/*
	482	* /proc/net/ip_vs_app entry function
	483	*/
	484
ab8a5e84	485	static struct ip_vs_app ip_vs_app_idx(struct netns_ipvs ipvs, loff_t pos)
1da177e4 LT	486	{
	487	struct ip_vs_app app, inc;
	488
ab8a5e84	489	list_for_each_entry(app, &ipvs->app_list, a_list) {
1da177e4 LT	490	list_for_each_entry(inc, &app->incs_list, a_list) {
	491	if (pos-- == 0)
	492	return inc;
	493	}
	494	}
	495	return NULL;
	496
	497	}
	498
	499	static void ip_vs_app_seq_start(struct seq_file seq, loff_t *pos)
	500	{
ab8a5e84 HS	501	struct net *net = seq_file_net(seq);
	502	struct netns_ipvs *ipvs = net_ipvs(net);
	503
736561a0	504	mutex_lock(&__ip_vs_app_mutex);
1da177e4	505
ab8a5e84	506	return pos ? ip_vs_app_idx(ipvs, pos - 1) : SEQ_START_TOKEN;
1da177e4 LT	507	}
	508
	509	static void ip_vs_app_seq_next(struct seq_file seq, void v, loff_t pos)
	510	{
	511	struct ip_vs_app inc, app;
	512	struct list_head *e;
ab8a5e84 HS	513	struct net *net = seq_file_net(seq);
ab8a5e84 HS	514	struct netns_ipvs *ipvs = net_ipvs(net);
1da177e4 LT	515
	516	++*pos;
	517	if (v == SEQ_START_TOKEN)
ab8a5e84	518	return ip_vs_app_idx(ipvs, 0);
1da177e4 LT	519
	520	inc = v;
	521	app = inc->app;
	522
	523	if ((e = inc->a_list.next) != &app->incs_list)
	524	return list_entry(e, struct ip_vs_app, a_list);
	525
	526	/* go on to next application */
ab8a5e84	527	for (e = app->a_list.next; e != &ipvs->app_list; e = e->next) {
1da177e4 LT	528	app = list_entry(e, struct ip_vs_app, a_list);
	529	list_for_each_entry(inc, &app->incs_list, a_list) {
	530	return inc;
	531	}
	532	}
	533	return NULL;
	534	}
	535
	536	static void ip_vs_app_seq_stop(struct seq_file seq, void v)
	537	{
736561a0	538	mutex_unlock(&__ip_vs_app_mutex);
1da177e4 LT	539	}
	540
	541	static int ip_vs_app_seq_show(struct seq_file seq, void v)
	542	{
	543	if (v == SEQ_START_TOKEN)
	544	seq_puts(seq, "prot port usecnt name\n");
	545	else {
	546	const struct ip_vs_app *inc = v;
	547
	548	seq_printf(seq, "%-3s %-7u %-6d %-17s\n",
	549	ip_vs_proto_name(inc->protocol),
	550	ntohs(inc->port),
	551	atomic_read(&inc->usecnt),
	552	inc->name);
	553	}
	554	return 0;
	555	}
	556
56b3d975	557	static const struct seq_operations ip_vs_app_seq_ops = {
1da177e4 LT	558	.start = ip_vs_app_seq_start,
	559	.next = ip_vs_app_seq_next,
	560	.stop = ip_vs_app_seq_stop,
	561	.show = ip_vs_app_seq_show,
	562	};
	563
	564	static int ip_vs_app_open(struct inode inode, struct file file)
	565	{
ab8a5e84 HS	566	return seq_open_net(inode, file, &ip_vs_app_seq_ops,
ab8a5e84 HS	567	sizeof(struct seq_net_private));
1da177e4 LT	568	}
1da177e4 LT	569
9a32144e	570	static const struct file_operations ip_vs_app_fops = {
1da177e4 LT	571	.owner = THIS_MODULE,
	572	.open = ip_vs_app_open,
	573	.read = seq_read,
	574	.llseek = seq_lseek,
0f08190f	575	.release = seq_release_net,
1da177e4 LT	576	};
	577	#endif
	578
7a4f0761	579	int __net_init __ip_vs_app_init(struct net *net)
1da177e4	580	{
ab8a5e84 HS	581	struct netns_ipvs *ipvs = net_ipvs(net);
ab8a5e84 HS	582
ab8a5e84	583	INIT_LIST_HEAD(&ipvs->app_list);
61b1ab45	584	proc_net_fops_create(net, "ip_vs_app", 0, &ip_vs_app_fops);
1da177e4 LT	585	return 0;
	586	}
	587
7a4f0761	588	void __net_exit __ip_vs_app_cleanup(struct net *net)
61b1ab45 HS	589	{
	590	proc_net_remove(net, "ip_vs_app");
	591	}
	592
61b1ab45 HS	593	int __init ip_vs_app_init(void)
61b1ab45 HS	594	{
7a4f0761	595	return 0;
61b1ab45 HS	596	}
61b1ab45 HS	597
1da177e4 LT	598
	599	void ip_vs_app_cleanup(void)
	600	{
1da177e4	601	}