linux/net/netfilter/ipvs/ip_vs_app.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ip_vs_app.c: Application module support for IPVS
 *
 * Authors:     Wensong Zhang <[email protected]>
 *
 * 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, <[email protected]>
 */

#define KMSG_COMPONENT …
#define pr_fmt(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 <linux/stat.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/mutex.h>

#include <net/ip_vs.h>

EXPORT_SYMBOL(…);
EXPORT_SYMBOL(…);
EXPORT_SYMBOL(…);

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)
{ … }


static inline void ip_vs_app_put(struct ip_vs_app *app)
{ … }

static void ip_vs_app_inc_destroy(struct ip_vs_app *inc)
{ … }

static void ip_vs_app_inc_rcu_free(struct rcu_head *head)
{ … }

/*
 *	Allocate/initialize app incarnation and register it in proto apps.
 */
static int
ip_vs_app_inc_new(struct netns_ipvs *ipvs, struct ip_vs_app *app, __u16 proto,
		  __u16 port)
{ … }


/*
 *	Release app incarnation
 */
static void
ip_vs_app_inc_release(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
{ … }


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


/*
 *	Put the app inc (only called from timer or net softirq)
 */
void ip_vs_app_inc_put(struct ip_vs_app *inc)
{ … }


/*
 *	Register an application incarnation in protocol applications
 */
int
register_ip_vs_app_inc(struct netns_ipvs *ipvs, struct ip_vs_app *app, __u16 proto,
		       __u16 port)
{ … }


/* Register application for netns */
struct ip_vs_app *register_ip_vs_app(struct netns_ipvs *ipvs, struct ip_vs_app *app)
{ … }


/*
 *	ip_vs_app unregistration routine
 *	We are sure there are no app incarnations attached to services
 *	Caller should use synchronize_rcu() or rcu_barrier()
 */
void unregister_ip_vs_app(struct netns_ipvs *ipvs, struct ip_vs_app *app)
{ … }


/*
 *	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)
{ … }


/*
 *	Unbind cp from application incarnation (called by cp destructor)
 */
void ip_vs_unbind_app(struct ip_vs_conn *cp)
{ … }


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


/*
 *	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)
{ … }


/*
 *	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 int flag, __u32 seq, int diff)
{ … }

static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff *skb,
				  struct ip_vs_app *app,
				  struct ip_vs_iphdr *ipvsh)
{ … }

/*
 *	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_iphdr *ipvsh)
{ … }


static inline int app_tcp_pkt_in(struct ip_vs_conn *cp, struct sk_buff *skb,
				 struct ip_vs_app *app,
				 struct ip_vs_iphdr *ipvsh)
{ … }

/*
 *	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_iphdr *ipvsh)
{ … }


#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)
{ … }

static void *ip_vs_app_seq_start(struct seq_file *seq, loff_t *pos)
{ … }

static void *ip_vs_app_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{ … }

static void ip_vs_app_seq_stop(struct seq_file *seq, void *v)
{ … }

static int ip_vs_app_seq_show(struct seq_file *seq, void *v)
{ … }

static const struct seq_operations ip_vs_app_seq_ops = …;
#endif

int __net_init ip_vs_app_net_init(struct netns_ipvs *ipvs)
{ … }

void __net_exit ip_vs_app_net_cleanup(struct netns_ipvs *ipvs)
{ … }