xref: /linux/include/net/ip_vs.h (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  *      IP Virtual Server
3  *      data structure and functionality definitions
4  */
5 
6 #ifndef _NET_IP_VS_H
7 #define _NET_IP_VS_H
8 
9 #include <linux/ip_vs.h>                /* definitions shared with userland */
10 
11 /* old ipvsadm versions still include this file directly */
12 #ifdef __KERNEL__
13 
14 #include <asm/types.h>                  /* for __uXX types */
15 
16 #include <linux/sysctl.h>               /* for ctl_path */
17 #include <linux/list.h>                 /* for struct list_head */
18 #include <linux/spinlock.h>             /* for struct rwlock_t */
19 #include <asm/atomic.h>                 /* for struct atomic_t */
20 #include <linux/compiler.h>
21 #include <linux/timer.h>
22 
23 #include <net/checksum.h>
24 #include <linux/netfilter.h>		/* for union nf_inet_addr */
25 #include <linux/ip.h>
26 #include <linux/ipv6.h>			/* for struct ipv6hdr */
27 #include <net/ipv6.h>			/* for ipv6_addr_copy */
28 
29 struct ip_vs_iphdr {
30 	int len;
31 	__u8 protocol;
32 	union nf_inet_addr saddr;
33 	union nf_inet_addr daddr;
34 };
35 
36 static inline void
37 ip_vs_fill_iphdr(int af, const void *nh, struct ip_vs_iphdr *iphdr)
38 {
39 #ifdef CONFIG_IP_VS_IPV6
40 	if (af == AF_INET6) {
41 		const struct ipv6hdr *iph = nh;
42 		iphdr->len = sizeof(struct ipv6hdr);
43 		iphdr->protocol = iph->nexthdr;
44 		ipv6_addr_copy(&iphdr->saddr.in6, &iph->saddr);
45 		ipv6_addr_copy(&iphdr->daddr.in6, &iph->daddr);
46 	} else
47 #endif
48 	{
49 		const struct iphdr *iph = nh;
50 		iphdr->len = iph->ihl * 4;
51 		iphdr->protocol = iph->protocol;
52 		iphdr->saddr.ip = iph->saddr;
53 		iphdr->daddr.ip = iph->daddr;
54 	}
55 }
56 
57 static inline void ip_vs_addr_copy(int af, union nf_inet_addr *dst,
58 				   const union nf_inet_addr *src)
59 {
60 #ifdef CONFIG_IP_VS_IPV6
61 	if (af == AF_INET6)
62 		ipv6_addr_copy(&dst->in6, &src->in6);
63 	else
64 #endif
65 	dst->ip = src->ip;
66 }
67 
68 static inline int ip_vs_addr_equal(int af, const union nf_inet_addr *a,
69 				   const union nf_inet_addr *b)
70 {
71 #ifdef CONFIG_IP_VS_IPV6
72 	if (af == AF_INET6)
73 		return ipv6_addr_equal(&a->in6, &b->in6);
74 #endif
75 	return a->ip == b->ip;
76 }
77 
78 #ifdef CONFIG_IP_VS_DEBUG
79 #include <linux/net.h>
80 
81 extern int ip_vs_get_debug_level(void);
82 
83 static inline const char *ip_vs_dbg_addr(int af, char *buf, size_t buf_len,
84 					 const union nf_inet_addr *addr,
85 					 int *idx)
86 {
87 	int len;
88 #ifdef CONFIG_IP_VS_IPV6
89 	if (af == AF_INET6)
90 		len = snprintf(&buf[*idx], buf_len - *idx, "[" NIP6_FMT "]",
91 			       NIP6(addr->in6)) + 1;
92 	else
93 #endif
94 		len = snprintf(&buf[*idx], buf_len - *idx, NIPQUAD_FMT,
95 			       NIPQUAD(addr->ip)) + 1;
96 
97 	*idx += len;
98 	BUG_ON(*idx > buf_len + 1);
99 	return &buf[*idx - len];
100 }
101 
102 #define IP_VS_DBG_BUF(level, msg...)			\
103     do {						\
104 	    char ip_vs_dbg_buf[160];			\
105 	    int ip_vs_dbg_idx = 0;			\
106 	    if (level <= ip_vs_get_debug_level())	\
107 		    printk(KERN_DEBUG "IPVS: " msg);	\
108     } while (0)
109 #define IP_VS_ERR_BUF(msg...)				\
110     do {						\
111 	    char ip_vs_dbg_buf[160];			\
112 	    int ip_vs_dbg_idx = 0;			\
113 	    printk(KERN_ERR "IPVS: " msg);		\
114     } while (0)
115 
116 /* Only use from within IP_VS_DBG_BUF() or IP_VS_ERR_BUF macros */
117 #define IP_VS_DBG_ADDR(af, addr)			\
118     ip_vs_dbg_addr(af, ip_vs_dbg_buf,			\
119 		   sizeof(ip_vs_dbg_buf), addr,		\
120 		   &ip_vs_dbg_idx)
121 
122 #define IP_VS_DBG(level, msg...)			\
123     do {						\
124 	    if (level <= ip_vs_get_debug_level())	\
125 		    printk(KERN_DEBUG "IPVS: " msg);	\
126     } while (0)
127 #define IP_VS_DBG_RL(msg...)				\
128     do {						\
129 	    if (net_ratelimit())			\
130 		    printk(KERN_DEBUG "IPVS: " msg);	\
131     } while (0)
132 #define IP_VS_DBG_PKT(level, pp, skb, ofs, msg)		\
133     do {						\
134 	    if (level <= ip_vs_get_debug_level())	\
135 		pp->debug_packet(pp, skb, ofs, msg);	\
136     } while (0)
137 #define IP_VS_DBG_RL_PKT(level, pp, skb, ofs, msg)	\
138     do {						\
139 	    if (level <= ip_vs_get_debug_level() &&	\
140 		net_ratelimit())			\
141 		pp->debug_packet(pp, skb, ofs, msg);	\
142     } while (0)
143 #else	/* NO DEBUGGING at ALL */
144 #define IP_VS_DBG_BUF(level, msg...)  do {} while (0)
145 #define IP_VS_ERR_BUF(msg...)  do {} while (0)
146 #define IP_VS_DBG(level, msg...)  do {} while (0)
147 #define IP_VS_DBG_RL(msg...)  do {} while (0)
148 #define IP_VS_DBG_PKT(level, pp, skb, ofs, msg)		do {} while (0)
149 #define IP_VS_DBG_RL_PKT(level, pp, skb, ofs, msg)	do {} while (0)
150 #endif
151 
152 #define IP_VS_BUG() BUG()
153 #define IP_VS_ERR(msg...) printk(KERN_ERR "IPVS: " msg)
154 #define IP_VS_INFO(msg...) printk(KERN_INFO "IPVS: " msg)
155 #define IP_VS_WARNING(msg...) \
156 	printk(KERN_WARNING "IPVS: " msg)
157 #define IP_VS_ERR_RL(msg...)				\
158     do {						\
159 	    if (net_ratelimit())			\
160 		    printk(KERN_ERR "IPVS: " msg);	\
161     } while (0)
162 
163 #ifdef CONFIG_IP_VS_DEBUG
164 #define EnterFunction(level)						\
165     do {								\
166 	    if (level <= ip_vs_get_debug_level())			\
167 		    printk(KERN_DEBUG "Enter: %s, %s line %i\n",	\
168 			   __func__, __FILE__, __LINE__);		\
169     } while (0)
170 #define LeaveFunction(level)                                            \
171     do {                                                                \
172 	    if (level <= ip_vs_get_debug_level())                       \
173 			printk(KERN_DEBUG "Leave: %s, %s line %i\n",    \
174 			       __func__, __FILE__, __LINE__);       \
175     } while (0)
176 #else
177 #define EnterFunction(level)   do {} while (0)
178 #define LeaveFunction(level)   do {} while (0)
179 #endif
180 
181 #define	IP_VS_WAIT_WHILE(expr)	while (expr) { cpu_relax(); }
182 
183 
184 /*
185  *      The port number of FTP service (in network order).
186  */
187 #define FTPPORT  __constant_htons(21)
188 #define FTPDATA  __constant_htons(20)
189 
190 /*
191  *      TCP State Values
192  */
193 enum {
194 	IP_VS_TCP_S_NONE = 0,
195 	IP_VS_TCP_S_ESTABLISHED,
196 	IP_VS_TCP_S_SYN_SENT,
197 	IP_VS_TCP_S_SYN_RECV,
198 	IP_VS_TCP_S_FIN_WAIT,
199 	IP_VS_TCP_S_TIME_WAIT,
200 	IP_VS_TCP_S_CLOSE,
201 	IP_VS_TCP_S_CLOSE_WAIT,
202 	IP_VS_TCP_S_LAST_ACK,
203 	IP_VS_TCP_S_LISTEN,
204 	IP_VS_TCP_S_SYNACK,
205 	IP_VS_TCP_S_LAST
206 };
207 
208 /*
209  *	UDP State Values
210  */
211 enum {
212 	IP_VS_UDP_S_NORMAL,
213 	IP_VS_UDP_S_LAST,
214 };
215 
216 /*
217  *	ICMP State Values
218  */
219 enum {
220 	IP_VS_ICMP_S_NORMAL,
221 	IP_VS_ICMP_S_LAST,
222 };
223 
224 /*
225  *	Delta sequence info structure
226  *	Each ip_vs_conn has 2 (output AND input seq. changes).
227  *      Only used in the VS/NAT.
228  */
229 struct ip_vs_seq {
230 	__u32			init_seq;	/* Add delta from this seq */
231 	__u32			delta;		/* Delta in sequence numbers */
232 	__u32			previous_delta;	/* Delta in sequence numbers
233 						   before last resized pkt */
234 };
235 
236 
237 /*
238  *	IPVS statistics objects
239  */
240 struct ip_vs_estimator {
241 	struct list_head	list;
242 
243 	u64			last_inbytes;
244 	u64			last_outbytes;
245 	u32			last_conns;
246 	u32			last_inpkts;
247 	u32			last_outpkts;
248 
249 	u32			cps;
250 	u32			inpps;
251 	u32			outpps;
252 	u32			inbps;
253 	u32			outbps;
254 };
255 
256 struct ip_vs_stats
257 {
258 	struct ip_vs_stats_user	ustats;         /* statistics */
259 	struct ip_vs_estimator	est;		/* estimator */
260 
261 	spinlock_t              lock;           /* spin lock */
262 };
263 
264 struct dst_entry;
265 struct iphdr;
266 struct ip_vs_conn;
267 struct ip_vs_app;
268 struct sk_buff;
269 
270 struct ip_vs_protocol {
271 	struct ip_vs_protocol	*next;
272 	char			*name;
273 	u16			protocol;
274 	u16			num_states;
275 	int			dont_defrag;
276 	atomic_t		appcnt;		/* counter of proto app incs */
277 	int			*timeout_table;	/* protocol timeout table */
278 
279 	void (*init)(struct ip_vs_protocol *pp);
280 
281 	void (*exit)(struct ip_vs_protocol *pp);
282 
283 	int (*conn_schedule)(int af, struct sk_buff *skb,
284 			     struct ip_vs_protocol *pp,
285 			     int *verdict, struct ip_vs_conn **cpp);
286 
287 	struct ip_vs_conn *
288 	(*conn_in_get)(int af,
289 		       const struct sk_buff *skb,
290 		       struct ip_vs_protocol *pp,
291 		       const struct ip_vs_iphdr *iph,
292 		       unsigned int proto_off,
293 		       int inverse);
294 
295 	struct ip_vs_conn *
296 	(*conn_out_get)(int af,
297 			const struct sk_buff *skb,
298 			struct ip_vs_protocol *pp,
299 			const struct ip_vs_iphdr *iph,
300 			unsigned int proto_off,
301 			int inverse);
302 
303 	int (*snat_handler)(struct sk_buff *skb,
304 			    struct ip_vs_protocol *pp, struct ip_vs_conn *cp);
305 
306 	int (*dnat_handler)(struct sk_buff *skb,
307 			    struct ip_vs_protocol *pp, struct ip_vs_conn *cp);
308 
309 	int (*csum_check)(int af, struct sk_buff *skb,
310 			  struct ip_vs_protocol *pp);
311 
312 	const char *(*state_name)(int state);
313 
314 	int (*state_transition)(struct ip_vs_conn *cp, int direction,
315 				const struct sk_buff *skb,
316 				struct ip_vs_protocol *pp);
317 
318 	int (*register_app)(struct ip_vs_app *inc);
319 
320 	void (*unregister_app)(struct ip_vs_app *inc);
321 
322 	int (*app_conn_bind)(struct ip_vs_conn *cp);
323 
324 	void (*debug_packet)(struct ip_vs_protocol *pp,
325 			     const struct sk_buff *skb,
326 			     int offset,
327 			     const char *msg);
328 
329 	void (*timeout_change)(struct ip_vs_protocol *pp, int flags);
330 
331 	int (*set_state_timeout)(struct ip_vs_protocol *pp, char *sname, int to);
332 };
333 
334 extern struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto);
335 
336 /*
337  *	IP_VS structure allocated for each dynamically scheduled connection
338  */
339 struct ip_vs_conn {
340 	struct list_head        c_list;         /* hashed list heads */
341 
342 	/* Protocol, addresses and port numbers */
343 	u16                      af;		/* address family */
344 	union nf_inet_addr       caddr;          /* client address */
345 	union nf_inet_addr       vaddr;          /* virtual address */
346 	union nf_inet_addr       daddr;          /* destination address */
347 	__be16                   cport;
348 	__be16                   vport;
349 	__be16                   dport;
350 	__u16                   protocol;       /* Which protocol (TCP/UDP) */
351 
352 	/* counter and timer */
353 	atomic_t		refcnt;		/* reference count */
354 	struct timer_list	timer;		/* Expiration timer */
355 	volatile unsigned long	timeout;	/* timeout */
356 
357 	/* Flags and state transition */
358 	spinlock_t              lock;           /* lock for state transition */
359 	volatile __u16          flags;          /* status flags */
360 	volatile __u16          state;          /* state info */
361 	volatile __u16          old_state;      /* old state, to be used for
362 						 * state transition triggerd
363 						 * synchronization
364 						 */
365 
366 	/* Control members */
367 	struct ip_vs_conn       *control;       /* Master control connection */
368 	atomic_t                n_control;      /* Number of controlled ones */
369 	struct ip_vs_dest       *dest;          /* real server */
370 	atomic_t                in_pkts;        /* incoming packet counter */
371 
372 	/* packet transmitter for different forwarding methods.  If it
373 	   mangles the packet, it must return NF_DROP or better NF_STOLEN,
374 	   otherwise this must be changed to a sk_buff **.
375 	 */
376 	int (*packet_xmit)(struct sk_buff *skb, struct ip_vs_conn *cp,
377 			   struct ip_vs_protocol *pp);
378 
379 	/* Note: we can group the following members into a structure,
380 	   in order to save more space, and the following members are
381 	   only used in VS/NAT anyway */
382 	struct ip_vs_app        *app;           /* bound ip_vs_app object */
383 	void                    *app_data;      /* Application private data */
384 	struct ip_vs_seq        in_seq;         /* incoming seq. struct */
385 	struct ip_vs_seq        out_seq;        /* outgoing seq. struct */
386 };
387 
388 
389 /*
390  *	Extended internal versions of struct ip_vs_service_user and
391  *	ip_vs_dest_user for IPv6 support.
392  *
393  *	We need these to conveniently pass around service and destination
394  *	options, but unfortunately, we also need to keep the old definitions to
395  *	maintain userspace backwards compatibility for the setsockopt interface.
396  */
397 struct ip_vs_service_user_kern {
398 	/* virtual service addresses */
399 	u16			af;
400 	u16			protocol;
401 	union nf_inet_addr	addr;		/* virtual ip address */
402 	u16			port;
403 	u32			fwmark;		/* firwall mark of service */
404 
405 	/* virtual service options */
406 	char			*sched_name;
407 	unsigned		flags;		/* virtual service flags */
408 	unsigned		timeout;	/* persistent timeout in sec */
409 	u32			netmask;	/* persistent netmask */
410 };
411 
412 
413 struct ip_vs_dest_user_kern {
414 	/* destination server address */
415 	union nf_inet_addr	addr;
416 	u16			port;
417 
418 	/* real server options */
419 	unsigned		conn_flags;	/* connection flags */
420 	int			weight;		/* destination weight */
421 
422 	/* thresholds for active connections */
423 	u32			u_threshold;	/* upper threshold */
424 	u32			l_threshold;	/* lower threshold */
425 };
426 
427 
428 /*
429  *	The information about the virtual service offered to the net
430  *	and the forwarding entries
431  */
432 struct ip_vs_service {
433 	struct list_head	s_list;   /* for normal service table */
434 	struct list_head	f_list;   /* for fwmark-based service table */
435 	atomic_t		refcnt;   /* reference counter */
436 	atomic_t		usecnt;   /* use counter */
437 
438 	u16			af;       /* address family */
439 	__u16			protocol; /* which protocol (TCP/UDP) */
440 	union nf_inet_addr	addr;	  /* IP address for virtual service */
441 	__be16			port;	  /* port number for the service */
442 	__u32                   fwmark;   /* firewall mark of the service */
443 	unsigned		flags;	  /* service status flags */
444 	unsigned		timeout;  /* persistent timeout in ticks */
445 	__be32			netmask;  /* grouping granularity */
446 
447 	struct list_head	destinations;  /* real server d-linked list */
448 	__u32			num_dests;     /* number of servers */
449 	struct ip_vs_stats      stats;         /* statistics for the service */
450 	struct ip_vs_app	*inc;	  /* bind conns to this app inc */
451 
452 	/* for scheduling */
453 	struct ip_vs_scheduler	*scheduler;    /* bound scheduler object */
454 	rwlock_t		sched_lock;    /* lock sched_data */
455 	void			*sched_data;   /* scheduler application data */
456 };
457 
458 
459 /*
460  *	The real server destination forwarding entry
461  *	with ip address, port number, and so on.
462  */
463 struct ip_vs_dest {
464 	struct list_head	n_list;   /* for the dests in the service */
465 	struct list_head	d_list;   /* for table with all the dests */
466 
467 	u16			af;		/* address family */
468 	union nf_inet_addr	addr;		/* IP address of the server */
469 	__be16			port;		/* port number of the server */
470 	volatile unsigned	flags;		/* dest status flags */
471 	atomic_t		conn_flags;	/* flags to copy to conn */
472 	atomic_t		weight;		/* server weight */
473 
474 	atomic_t		refcnt;		/* reference counter */
475 	struct ip_vs_stats      stats;          /* statistics */
476 
477 	/* connection counters and thresholds */
478 	atomic_t		activeconns;	/* active connections */
479 	atomic_t		inactconns;	/* inactive connections */
480 	atomic_t		persistconns;	/* persistent connections */
481 	__u32			u_threshold;	/* upper threshold */
482 	__u32			l_threshold;	/* lower threshold */
483 
484 	/* for destination cache */
485 	spinlock_t		dst_lock;	/* lock of dst_cache */
486 	struct dst_entry	*dst_cache;	/* destination cache entry */
487 	u32			dst_rtos;	/* RT_TOS(tos) for dst */
488 
489 	/* for virtual service */
490 	struct ip_vs_service	*svc;		/* service it belongs to */
491 	__u16			protocol;	/* which protocol (TCP/UDP) */
492 	union nf_inet_addr	vaddr;		/* virtual IP address */
493 	__be16			vport;		/* virtual port number */
494 	__u32			vfwmark;	/* firewall mark of service */
495 };
496 
497 
498 /*
499  *	The scheduler object
500  */
501 struct ip_vs_scheduler {
502 	struct list_head	n_list;		/* d-linked list head */
503 	char			*name;		/* scheduler name */
504 	atomic_t		refcnt;		/* reference counter */
505 	struct module		*module;	/* THIS_MODULE/NULL */
506 #ifdef CONFIG_IP_VS_IPV6
507 	int			supports_ipv6;	/* scheduler has IPv6 support */
508 #endif
509 
510 	/* scheduler initializing service */
511 	int (*init_service)(struct ip_vs_service *svc);
512 	/* scheduling service finish */
513 	int (*done_service)(struct ip_vs_service *svc);
514 	/* scheduler updating service */
515 	int (*update_service)(struct ip_vs_service *svc);
516 
517 	/* selecting a server from the given service */
518 	struct ip_vs_dest* (*schedule)(struct ip_vs_service *svc,
519 				       const struct sk_buff *skb);
520 };
521 
522 
523 /*
524  *	The application module object (a.k.a. app incarnation)
525  */
526 struct ip_vs_app
527 {
528 	struct list_head	a_list;		/* member in app list */
529 	int			type;		/* IP_VS_APP_TYPE_xxx */
530 	char			*name;		/* application module name */
531 	__u16			protocol;
532 	struct module		*module;	/* THIS_MODULE/NULL */
533 	struct list_head	incs_list;	/* list of incarnations */
534 
535 	/* members for application incarnations */
536 	struct list_head	p_list;		/* member in proto app list */
537 	struct ip_vs_app	*app;		/* its real application */
538 	__be16			port;		/* port number in net order */
539 	atomic_t		usecnt;		/* usage counter */
540 
541 	/* output hook: return false if can't linearize. diff set for TCP.  */
542 	int (*pkt_out)(struct ip_vs_app *, struct ip_vs_conn *,
543 		       struct sk_buff *, int *diff);
544 
545 	/* input hook: return false if can't linearize. diff set for TCP. */
546 	int (*pkt_in)(struct ip_vs_app *, struct ip_vs_conn *,
547 		      struct sk_buff *, int *diff);
548 
549 	/* ip_vs_app initializer */
550 	int (*init_conn)(struct ip_vs_app *, struct ip_vs_conn *);
551 
552 	/* ip_vs_app finish */
553 	int (*done_conn)(struct ip_vs_app *, struct ip_vs_conn *);
554 
555 
556 	/* not used now */
557 	int (*bind_conn)(struct ip_vs_app *, struct ip_vs_conn *,
558 			 struct ip_vs_protocol *);
559 
560 	void (*unbind_conn)(struct ip_vs_app *, struct ip_vs_conn *);
561 
562 	int *			timeout_table;
563 	int *			timeouts;
564 	int			timeouts_size;
565 
566 	int (*conn_schedule)(struct sk_buff *skb, struct ip_vs_app *app,
567 			     int *verdict, struct ip_vs_conn **cpp);
568 
569 	struct ip_vs_conn *
570 	(*conn_in_get)(const struct sk_buff *skb, struct ip_vs_app *app,
571 		       const struct iphdr *iph, unsigned int proto_off,
572 		       int inverse);
573 
574 	struct ip_vs_conn *
575 	(*conn_out_get)(const struct sk_buff *skb, struct ip_vs_app *app,
576 			const struct iphdr *iph, unsigned int proto_off,
577 			int inverse);
578 
579 	int (*state_transition)(struct ip_vs_conn *cp, int direction,
580 				const struct sk_buff *skb,
581 				struct ip_vs_app *app);
582 
583 	void (*timeout_change)(struct ip_vs_app *app, int flags);
584 };
585 
586 
587 /*
588  *      IPVS core functions
589  *      (from ip_vs_core.c)
590  */
591 extern const char *ip_vs_proto_name(unsigned proto);
592 extern void ip_vs_init_hash_table(struct list_head *table, int rows);
593 #define IP_VS_INIT_HASH_TABLE(t) ip_vs_init_hash_table((t), ARRAY_SIZE((t)))
594 
595 #define IP_VS_APP_TYPE_FTP	1
596 
597 /*
598  *     ip_vs_conn handling functions
599  *     (from ip_vs_conn.c)
600  */
601 
602 /*
603  *     IPVS connection entry hash table
604  */
605 #ifndef CONFIG_IP_VS_TAB_BITS
606 #define CONFIG_IP_VS_TAB_BITS   12
607 #endif
608 
609 #define IP_VS_CONN_TAB_BITS	CONFIG_IP_VS_TAB_BITS
610 #define IP_VS_CONN_TAB_SIZE     (1 << IP_VS_CONN_TAB_BITS)
611 #define IP_VS_CONN_TAB_MASK     (IP_VS_CONN_TAB_SIZE - 1)
612 
613 enum {
614 	IP_VS_DIR_INPUT = 0,
615 	IP_VS_DIR_OUTPUT,
616 	IP_VS_DIR_INPUT_ONLY,
617 	IP_VS_DIR_LAST,
618 };
619 
620 extern struct ip_vs_conn *ip_vs_conn_in_get
621 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
622  const union nf_inet_addr *d_addr, __be16 d_port);
623 
624 extern struct ip_vs_conn *ip_vs_ct_in_get
625 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
626  const union nf_inet_addr *d_addr, __be16 d_port);
627 
628 extern struct ip_vs_conn *ip_vs_conn_out_get
629 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
630  const union nf_inet_addr *d_addr, __be16 d_port);
631 
632 /* put back the conn without restarting its timer */
633 static inline void __ip_vs_conn_put(struct ip_vs_conn *cp)
634 {
635 	atomic_dec(&cp->refcnt);
636 }
637 extern void ip_vs_conn_put(struct ip_vs_conn *cp);
638 extern void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport);
639 
640 extern struct ip_vs_conn *
641 ip_vs_conn_new(int af, int proto, const union nf_inet_addr *caddr, __be16 cport,
642 	       const union nf_inet_addr *vaddr, __be16 vport,
643 	       const union nf_inet_addr *daddr, __be16 dport, unsigned flags,
644 	       struct ip_vs_dest *dest);
645 extern void ip_vs_conn_expire_now(struct ip_vs_conn *cp);
646 
647 extern const char * ip_vs_state_name(__u16 proto, int state);
648 
649 extern void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp);
650 extern int ip_vs_check_template(struct ip_vs_conn *ct);
651 extern void ip_vs_random_dropentry(void);
652 extern int ip_vs_conn_init(void);
653 extern void ip_vs_conn_cleanup(void);
654 
655 static inline void ip_vs_control_del(struct ip_vs_conn *cp)
656 {
657 	struct ip_vs_conn *ctl_cp = cp->control;
658 	if (!ctl_cp) {
659 		IP_VS_ERR_BUF("request control DEL for uncontrolled: "
660 			      "%s:%d to %s:%d\n",
661 			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
662 			      ntohs(cp->cport),
663 			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
664 			      ntohs(cp->vport));
665 
666 		return;
667 	}
668 
669 	IP_VS_DBG_BUF(7, "DELeting control for: "
670 		      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
671 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
672 		      ntohs(cp->cport),
673 		      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
674 		      ntohs(ctl_cp->cport));
675 
676 	cp->control = NULL;
677 	if (atomic_read(&ctl_cp->n_control) == 0) {
678 		IP_VS_ERR_BUF("BUG control DEL with n=0 : "
679 			      "%s:%d to %s:%d\n",
680 			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
681 			      ntohs(cp->cport),
682 			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
683 			      ntohs(cp->vport));
684 
685 		return;
686 	}
687 	atomic_dec(&ctl_cp->n_control);
688 }
689 
690 static inline void
691 ip_vs_control_add(struct ip_vs_conn *cp, struct ip_vs_conn *ctl_cp)
692 {
693 	if (cp->control) {
694 		IP_VS_ERR_BUF("request control ADD for already controlled: "
695 			      "%s:%d to %s:%d\n",
696 			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
697 			      ntohs(cp->cport),
698 			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
699 			      ntohs(cp->vport));
700 
701 		ip_vs_control_del(cp);
702 	}
703 
704 	IP_VS_DBG_BUF(7, "ADDing control for: "
705 		      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
706 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
707 		      ntohs(cp->cport),
708 		      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
709 		      ntohs(ctl_cp->cport));
710 
711 	cp->control = ctl_cp;
712 	atomic_inc(&ctl_cp->n_control);
713 }
714 
715 
716 /*
717  *      IPVS application functions
718  *      (from ip_vs_app.c)
719  */
720 #define IP_VS_APP_MAX_PORTS  8
721 extern int register_ip_vs_app(struct ip_vs_app *app);
722 extern void unregister_ip_vs_app(struct ip_vs_app *app);
723 extern int ip_vs_bind_app(struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
724 extern void ip_vs_unbind_app(struct ip_vs_conn *cp);
725 extern int
726 register_ip_vs_app_inc(struct ip_vs_app *app, __u16 proto, __u16 port);
727 extern int ip_vs_app_inc_get(struct ip_vs_app *inc);
728 extern void ip_vs_app_inc_put(struct ip_vs_app *inc);
729 
730 extern int ip_vs_app_pkt_out(struct ip_vs_conn *, struct sk_buff *skb);
731 extern int ip_vs_app_pkt_in(struct ip_vs_conn *, struct sk_buff *skb);
732 extern int ip_vs_skb_replace(struct sk_buff *skb, gfp_t pri,
733 			     char *o_buf, int o_len, char *n_buf, int n_len);
734 extern int ip_vs_app_init(void);
735 extern void ip_vs_app_cleanup(void);
736 
737 
738 /*
739  *	IPVS protocol functions (from ip_vs_proto.c)
740  */
741 extern int ip_vs_protocol_init(void);
742 extern void ip_vs_protocol_cleanup(void);
743 extern void ip_vs_protocol_timeout_change(int flags);
744 extern int *ip_vs_create_timeout_table(int *table, int size);
745 extern int
746 ip_vs_set_state_timeout(int *table, int num, char **names, char *name, int to);
747 extern void
748 ip_vs_tcpudp_debug_packet(struct ip_vs_protocol *pp, const struct sk_buff *skb,
749 			  int offset, const char *msg);
750 
751 extern struct ip_vs_protocol ip_vs_protocol_tcp;
752 extern struct ip_vs_protocol ip_vs_protocol_udp;
753 extern struct ip_vs_protocol ip_vs_protocol_icmp;
754 extern struct ip_vs_protocol ip_vs_protocol_esp;
755 extern struct ip_vs_protocol ip_vs_protocol_ah;
756 
757 
758 /*
759  *      Registering/unregistering scheduler functions
760  *      (from ip_vs_sched.c)
761  */
762 extern int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
763 extern int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
764 extern int ip_vs_bind_scheduler(struct ip_vs_service *svc,
765 				struct ip_vs_scheduler *scheduler);
766 extern int ip_vs_unbind_scheduler(struct ip_vs_service *svc);
767 extern struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name);
768 extern void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler);
769 extern struct ip_vs_conn *
770 ip_vs_schedule(struct ip_vs_service *svc, const struct sk_buff *skb);
771 extern int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
772 			struct ip_vs_protocol *pp);
773 
774 
775 /*
776  *      IPVS control data and functions (from ip_vs_ctl.c)
777  */
778 extern int sysctl_ip_vs_cache_bypass;
779 extern int sysctl_ip_vs_expire_nodest_conn;
780 extern int sysctl_ip_vs_expire_quiescent_template;
781 extern int sysctl_ip_vs_sync_threshold[2];
782 extern int sysctl_ip_vs_nat_icmp_send;
783 extern struct ip_vs_stats ip_vs_stats;
784 extern const struct ctl_path net_vs_ctl_path[];
785 
786 extern struct ip_vs_service *
787 ip_vs_service_get(int af, __u32 fwmark, __u16 protocol,
788 		  const union nf_inet_addr *vaddr, __be16 vport);
789 
790 static inline void ip_vs_service_put(struct ip_vs_service *svc)
791 {
792 	atomic_dec(&svc->usecnt);
793 }
794 
795 extern struct ip_vs_dest *
796 ip_vs_lookup_real_service(int af, __u16 protocol,
797 			  const union nf_inet_addr *daddr, __be16 dport);
798 
799 extern int ip_vs_use_count_inc(void);
800 extern void ip_vs_use_count_dec(void);
801 extern int ip_vs_control_init(void);
802 extern void ip_vs_control_cleanup(void);
803 extern struct ip_vs_dest *
804 ip_vs_find_dest(int af, const union nf_inet_addr *daddr, __be16 dport,
805 		const union nf_inet_addr *vaddr, __be16 vport, __u16 protocol);
806 extern struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp);
807 
808 
809 /*
810  *      IPVS sync daemon data and function prototypes
811  *      (from ip_vs_sync.c)
812  */
813 extern volatile int ip_vs_sync_state;
814 extern volatile int ip_vs_master_syncid;
815 extern volatile int ip_vs_backup_syncid;
816 extern char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
817 extern char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
818 extern int start_sync_thread(int state, char *mcast_ifn, __u8 syncid);
819 extern int stop_sync_thread(int state);
820 extern void ip_vs_sync_conn(struct ip_vs_conn *cp);
821 
822 
823 /*
824  *      IPVS rate estimator prototypes (from ip_vs_est.c)
825  */
826 extern int ip_vs_estimator_init(void);
827 extern void ip_vs_estimator_cleanup(void);
828 extern void ip_vs_new_estimator(struct ip_vs_stats *stats);
829 extern void ip_vs_kill_estimator(struct ip_vs_stats *stats);
830 extern void ip_vs_zero_estimator(struct ip_vs_stats *stats);
831 
832 /*
833  *	Various IPVS packet transmitters (from ip_vs_xmit.c)
834  */
835 extern int ip_vs_null_xmit
836 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
837 extern int ip_vs_bypass_xmit
838 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
839 extern int ip_vs_nat_xmit
840 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
841 extern int ip_vs_tunnel_xmit
842 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
843 extern int ip_vs_dr_xmit
844 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
845 extern int ip_vs_icmp_xmit
846 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, int offset);
847 extern void ip_vs_dst_reset(struct ip_vs_dest *dest);
848 
849 #ifdef CONFIG_IP_VS_IPV6
850 extern int ip_vs_bypass_xmit_v6
851 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
852 extern int ip_vs_nat_xmit_v6
853 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
854 extern int ip_vs_tunnel_xmit_v6
855 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
856 extern int ip_vs_dr_xmit_v6
857 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
858 extern int ip_vs_icmp_xmit_v6
859 (struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp,
860  int offset);
861 #endif
862 
863 /*
864  *	This is a simple mechanism to ignore packets when
865  *	we are loaded. Just set ip_vs_drop_rate to 'n' and
866  *	we start to drop 1/rate of the packets
867  */
868 extern int ip_vs_drop_rate;
869 extern int ip_vs_drop_counter;
870 
871 static __inline__ int ip_vs_todrop(void)
872 {
873 	if (!ip_vs_drop_rate) return 0;
874 	if (--ip_vs_drop_counter > 0) return 0;
875 	ip_vs_drop_counter = ip_vs_drop_rate;
876 	return 1;
877 }
878 
879 /*
880  *      ip_vs_fwd_tag returns the forwarding tag of the connection
881  */
882 #define IP_VS_FWD_METHOD(cp)  (cp->flags & IP_VS_CONN_F_FWD_MASK)
883 
884 static inline char ip_vs_fwd_tag(struct ip_vs_conn *cp)
885 {
886 	char fwd;
887 
888 	switch (IP_VS_FWD_METHOD(cp)) {
889 	case IP_VS_CONN_F_MASQ:
890 		fwd = 'M'; break;
891 	case IP_VS_CONN_F_LOCALNODE:
892 		fwd = 'L'; break;
893 	case IP_VS_CONN_F_TUNNEL:
894 		fwd = 'T'; break;
895 	case IP_VS_CONN_F_DROUTE:
896 		fwd = 'R'; break;
897 	case IP_VS_CONN_F_BYPASS:
898 		fwd = 'B'; break;
899 	default:
900 		fwd = '?'; break;
901 	}
902 	return fwd;
903 }
904 
905 extern void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
906 			   struct ip_vs_conn *cp, int dir);
907 
908 #ifdef CONFIG_IP_VS_IPV6
909 extern void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
910 			      struct ip_vs_conn *cp, int dir);
911 #endif
912 
913 extern __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset);
914 
915 static inline __wsum ip_vs_check_diff4(__be32 old, __be32 new, __wsum oldsum)
916 {
917 	__be32 diff[2] = { ~old, new };
918 
919 	return csum_partial((char *) diff, sizeof(diff), oldsum);
920 }
921 
922 #ifdef CONFIG_IP_VS_IPV6
923 static inline __wsum ip_vs_check_diff16(const __be32 *old, const __be32 *new,
924 					__wsum oldsum)
925 {
926 	__be32 diff[8] = { ~old[3], ~old[2], ~old[1], ~old[0],
927 			    new[3],  new[2],  new[1],  new[0] };
928 
929 	return csum_partial((char *) diff, sizeof(diff), oldsum);
930 }
931 #endif
932 
933 static inline __wsum ip_vs_check_diff2(__be16 old, __be16 new, __wsum oldsum)
934 {
935 	__be16 diff[2] = { ~old, new };
936 
937 	return csum_partial((char *) diff, sizeof(diff), oldsum);
938 }
939 
940 #endif /* __KERNEL__ */
941 
942 #endif	/* _NET_IP_VS_H */
943