xref: /linux/include/net/ip_vs.h (revision 91a4855d6c03e770e42f17c798a36a3c46e63de2) !
1 /* SPDX-License-Identifier: GPL-2.0 */
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 #include <asm/types.h>                  /* for __uXX types */
12 
13 #include <linux/list.h>                 /* for struct list_head */
14 #include <linux/rculist_bl.h>           /* for struct hlist_bl_head */
15 #include <linux/spinlock.h>             /* for struct rwlock_t */
16 #include <linux/atomic.h>               /* for struct atomic_t */
17 #include <linux/refcount.h>             /* for struct refcount_t */
18 #include <linux/workqueue.h>
19 
20 #include <linux/compiler.h>
21 #include <linux/timer.h>
22 #include <linux/bug.h>
23 
24 #include <net/checksum.h>
25 #include <linux/netfilter.h>		/* for union nf_inet_addr */
26 #include <linux/ip.h>
27 #include <linux/ipv6.h>			/* for struct ipv6hdr */
28 #include <net/ipv6.h>
29 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
30 #include <net/netfilter/nf_conntrack.h>
31 #endif
32 #include <net/net_namespace.h>		/* Netw namespace */
33 #include <linux/sched/isolation.h>
34 #include <linux/siphash.h>
35 
36 #define IP_VS_HDR_INVERSE	1
37 #define IP_VS_HDR_ICMP		2
38 
39 /* conn_tab limits (as per Kconfig) */
40 #define IP_VS_CONN_TAB_MIN_BITS	8
41 #if BITS_PER_LONG > 32
42 #define IP_VS_CONN_TAB_MAX_BITS	27
43 #else
44 #define IP_VS_CONN_TAB_MAX_BITS	20
45 #endif
46 
47 /* svc_table limits */
48 #define IP_VS_SVC_TAB_MIN_BITS	4
49 #define IP_VS_SVC_TAB_MAX_BITS	20
50 
51 /* Generic access of ipvs struct */
52 static inline struct netns_ipvs *net_ipvs(struct net* net)
53 {
54 	return net->ipvs;
55 }
56 
57 /* Connections' size value needed by ip_vs_ctl.c */
58 extern int ip_vs_conn_tab_size;
59 
60 struct ip_vs_iphdr {
61 	int hdr_flags;	/* ipvs flags */
62 	__u32 off;	/* Where IP or IPv4 header starts */
63 	__u32 len;	/* IPv4 simply where L4 starts
64 			 * IPv6 where L4 Transport Header starts */
65 	__u16 fragoffs; /* IPv6 fragment offset, 0 if first frag (or not frag)*/
66 	__s16 protocol;
67 	__s32 flags;
68 	union nf_inet_addr saddr;
69 	union nf_inet_addr daddr;
70 };
71 
72 static inline void *frag_safe_skb_hp(const struct sk_buff *skb, int offset,
73 				      int len, void *buffer)
74 {
75 	return skb_header_pointer(skb, offset, len, buffer);
76 }
77 
78 /* This function handles filling *ip_vs_iphdr, both for IPv4 and IPv6.
79  * IPv6 requires some extra work, as finding proper header position,
80  * depend on the IPv6 extension headers.
81  */
82 static inline int
83 ip_vs_fill_iph_skb_off(int af, const struct sk_buff *skb, int offset,
84 		       int hdr_flags, struct ip_vs_iphdr *iphdr)
85 {
86 	iphdr->hdr_flags = hdr_flags;
87 	iphdr->off = offset;
88 
89 #ifdef CONFIG_IP_VS_IPV6
90 	if (af == AF_INET6) {
91 		struct ipv6hdr _iph;
92 		const struct ipv6hdr *iph = skb_header_pointer(
93 			skb, offset, sizeof(_iph), &_iph);
94 		if (!iph)
95 			return 0;
96 
97 		iphdr->saddr.in6 = iph->saddr;
98 		iphdr->daddr.in6 = iph->daddr;
99 		/* ipv6_find_hdr() updates len, flags */
100 		iphdr->len	 = offset;
101 		iphdr->flags	 = 0;
102 		iphdr->protocol  = ipv6_find_hdr(skb, &iphdr->len, -1,
103 						 &iphdr->fragoffs,
104 						 &iphdr->flags);
105 		if (iphdr->protocol < 0)
106 			return 0;
107 	} else
108 #endif
109 	{
110 		struct iphdr _iph;
111 		const struct iphdr *iph = skb_header_pointer(
112 			skb, offset, sizeof(_iph), &_iph);
113 		if (!iph)
114 			return 0;
115 
116 		iphdr->len	= offset + iph->ihl * 4;
117 		iphdr->fragoffs	= 0;
118 		iphdr->protocol	= iph->protocol;
119 		iphdr->saddr.ip	= iph->saddr;
120 		iphdr->daddr.ip	= iph->daddr;
121 	}
122 
123 	return 1;
124 }
125 
126 static inline int
127 ip_vs_fill_iph_skb_icmp(int af, const struct sk_buff *skb, int offset,
128 			bool inverse, struct ip_vs_iphdr *iphdr)
129 {
130 	int hdr_flags = IP_VS_HDR_ICMP;
131 
132 	if (inverse)
133 		hdr_flags |= IP_VS_HDR_INVERSE;
134 
135 	return ip_vs_fill_iph_skb_off(af, skb, offset, hdr_flags, iphdr);
136 }
137 
138 static inline int
139 ip_vs_fill_iph_skb(int af, const struct sk_buff *skb, bool inverse,
140 		   struct ip_vs_iphdr *iphdr)
141 {
142 	int hdr_flags = 0;
143 
144 	if (inverse)
145 		hdr_flags |= IP_VS_HDR_INVERSE;
146 
147 	return ip_vs_fill_iph_skb_off(af, skb, skb_network_offset(skb),
148 				      hdr_flags, iphdr);
149 }
150 
151 static inline bool
152 ip_vs_iph_inverse(const struct ip_vs_iphdr *iph)
153 {
154 	return !!(iph->hdr_flags & IP_VS_HDR_INVERSE);
155 }
156 
157 static inline bool
158 ip_vs_iph_icmp(const struct ip_vs_iphdr *iph)
159 {
160 	return !!(iph->hdr_flags & IP_VS_HDR_ICMP);
161 }
162 
163 static inline void ip_vs_addr_copy(int af, union nf_inet_addr *dst,
164 				   const union nf_inet_addr *src)
165 {
166 #ifdef CONFIG_IP_VS_IPV6
167 	if (af == AF_INET6)
168 		dst->in6 = src->in6;
169 	else
170 #endif
171 	dst->ip = src->ip;
172 }
173 
174 static inline void ip_vs_addr_set(int af, union nf_inet_addr *dst,
175 				  const union nf_inet_addr *src)
176 {
177 #ifdef CONFIG_IP_VS_IPV6
178 	if (af == AF_INET6) {
179 		dst->in6 = src->in6;
180 		return;
181 	}
182 #endif
183 	dst->ip = src->ip;
184 	dst->all[1] = 0;
185 	dst->all[2] = 0;
186 	dst->all[3] = 0;
187 }
188 
189 static inline int ip_vs_addr_equal(int af, const union nf_inet_addr *a,
190 				   const union nf_inet_addr *b)
191 {
192 #ifdef CONFIG_IP_VS_IPV6
193 	if (af == AF_INET6)
194 		return ipv6_addr_equal(&a->in6, &b->in6);
195 #endif
196 	return a->ip == b->ip;
197 }
198 
199 #ifdef CONFIG_IP_VS_DEBUG
200 #include <linux/net.h>
201 
202 int ip_vs_get_debug_level(void);
203 
204 static inline const char *ip_vs_dbg_addr(int af, char *buf, size_t buf_len,
205 					 const union nf_inet_addr *addr,
206 					 int *idx)
207 {
208 	int len;
209 #ifdef CONFIG_IP_VS_IPV6
210 	if (af == AF_INET6)
211 		len = snprintf(&buf[*idx], buf_len - *idx, "[%pI6c]",
212 			       &addr->in6) + 1;
213 	else
214 #endif
215 		len = snprintf(&buf[*idx], buf_len - *idx, "%pI4",
216 			       &addr->ip) + 1;
217 
218 	*idx += len;
219 	BUG_ON(*idx > buf_len + 1);
220 	return &buf[*idx - len];
221 }
222 
223 #define IP_VS_DBG_BUF(level, msg, ...)					\
224 	do {								\
225 		char ip_vs_dbg_buf[160];				\
226 		int ip_vs_dbg_idx = 0;					\
227 		if (level <= ip_vs_get_debug_level())			\
228 			printk(KERN_DEBUG pr_fmt(msg), ##__VA_ARGS__);	\
229 	} while (0)
230 #define IP_VS_ERR_BUF(msg...)						\
231 	do {								\
232 		char ip_vs_dbg_buf[160];				\
233 		int ip_vs_dbg_idx = 0;					\
234 		pr_err(msg);						\
235 	} while (0)
236 
237 /* Only use from within IP_VS_DBG_BUF() or IP_VS_ERR_BUF macros */
238 #define IP_VS_DBG_ADDR(af, addr)					\
239 	ip_vs_dbg_addr(af, ip_vs_dbg_buf,				\
240 		       sizeof(ip_vs_dbg_buf), addr,			\
241 		       &ip_vs_dbg_idx)
242 
243 #define IP_VS_DBG(level, msg, ...)					\
244 	do {								\
245 		if (level <= ip_vs_get_debug_level())			\
246 			printk(KERN_DEBUG pr_fmt(msg), ##__VA_ARGS__);	\
247 	} while (0)
248 #define IP_VS_DBG_RL(msg, ...)						\
249 	do {								\
250 		if (net_ratelimit())					\
251 			printk(KERN_DEBUG pr_fmt(msg), ##__VA_ARGS__);	\
252 	} while (0)
253 #define IP_VS_DBG_PKT(level, af, pp, skb, ofs, msg)			\
254 	do {								\
255 		if (level <= ip_vs_get_debug_level())			\
256 			pp->debug_packet(af, pp, skb, ofs, msg);	\
257 	} while (0)
258 #define IP_VS_DBG_RL_PKT(level, af, pp, skb, ofs, msg)			\
259 	do {								\
260 		if (level <= ip_vs_get_debug_level() &&			\
261 		    net_ratelimit())					\
262 			pp->debug_packet(af, pp, skb, ofs, msg);	\
263 	} while (0)
264 #else	/* NO DEBUGGING at ALL */
265 #define IP_VS_DBG_BUF(level, msg...)  do {} while (0)
266 #define IP_VS_ERR_BUF(msg...)  do {} while (0)
267 #define IP_VS_DBG(level, msg...)  do {} while (0)
268 #define IP_VS_DBG_RL(msg...)  do {} while (0)
269 #define IP_VS_DBG_PKT(level, af, pp, skb, ofs, msg)	do {} while (0)
270 #define IP_VS_DBG_RL_PKT(level, af, pp, skb, ofs, msg)	do {} while (0)
271 #endif
272 
273 #define IP_VS_BUG() BUG()
274 #define IP_VS_ERR_RL(msg, ...)						\
275 	do {								\
276 		if (net_ratelimit())					\
277 			pr_err(msg, ##__VA_ARGS__);			\
278 	} while (0)
279 
280 struct ip_vs_aligned_lock {
281 	spinlock_t	l;	/* Protect buckets */
282 } ____cacheline_aligned_in_smp;
283 
284 /* For arrays per family */
285 enum {
286 	IP_VS_AF_INET,
287 	IP_VS_AF_INET6,
288 	IP_VS_AF_MAX
289 };
290 
291 static inline int ip_vs_af_index(int af)
292 {
293 	return af == AF_INET6 ? IP_VS_AF_INET6 : IP_VS_AF_INET;
294 }
295 
296 /* work_flags */
297 enum {
298 	IP_VS_WORK_SVC_RESIZE,		/* Schedule svc_resize_work */
299 	IP_VS_WORK_SVC_NORESIZE,	/* Stopping svc_resize_work */
300 	IP_VS_WORK_CONN_RESIZE,		/* Schedule conn_resize_work */
301 };
302 
303 /* The port number of FTP service (in network order). */
304 #define FTPPORT  cpu_to_be16(21)
305 #define FTPDATA  cpu_to_be16(20)
306 
307 /* TCP State Values */
308 enum {
309 	IP_VS_TCP_S_NONE = 0,
310 	IP_VS_TCP_S_ESTABLISHED,
311 	IP_VS_TCP_S_SYN_SENT,
312 	IP_VS_TCP_S_SYN_RECV,
313 	IP_VS_TCP_S_FIN_WAIT,
314 	IP_VS_TCP_S_TIME_WAIT,
315 	IP_VS_TCP_S_CLOSE,
316 	IP_VS_TCP_S_CLOSE_WAIT,
317 	IP_VS_TCP_S_LAST_ACK,
318 	IP_VS_TCP_S_LISTEN,
319 	IP_VS_TCP_S_SYNACK,
320 	IP_VS_TCP_S_LAST
321 };
322 
323 /* UDP State Values */
324 enum {
325 	IP_VS_UDP_S_NORMAL,
326 	IP_VS_UDP_S_LAST,
327 };
328 
329 /* ICMP State Values */
330 enum {
331 	IP_VS_ICMP_S_NORMAL,
332 	IP_VS_ICMP_S_LAST,
333 };
334 
335 /* SCTP State Values */
336 enum ip_vs_sctp_states {
337 	IP_VS_SCTP_S_NONE,
338 	IP_VS_SCTP_S_INIT1,
339 	IP_VS_SCTP_S_INIT,
340 	IP_VS_SCTP_S_COOKIE_SENT,
341 	IP_VS_SCTP_S_COOKIE_REPLIED,
342 	IP_VS_SCTP_S_COOKIE_WAIT,
343 	IP_VS_SCTP_S_COOKIE,
344 	IP_VS_SCTP_S_COOKIE_ECHOED,
345 	IP_VS_SCTP_S_ESTABLISHED,
346 	IP_VS_SCTP_S_SHUTDOWN_SENT,
347 	IP_VS_SCTP_S_SHUTDOWN_RECEIVED,
348 	IP_VS_SCTP_S_SHUTDOWN_ACK_SENT,
349 	IP_VS_SCTP_S_REJECTED,
350 	IP_VS_SCTP_S_CLOSED,
351 	IP_VS_SCTP_S_LAST
352 };
353 
354 /* Connection templates use bits from state */
355 #define IP_VS_CTPL_S_NONE		0x0000
356 #define IP_VS_CTPL_S_ASSURED		0x0001
357 #define IP_VS_CTPL_S_LAST		0x0002
358 
359 /* Delta sequence info structure
360  * Each ip_vs_conn has 2 (output AND input seq. changes).
361  * Only used in the VS/NAT.
362  */
363 struct ip_vs_seq {
364 	__u32			init_seq;	/* Add delta from this seq */
365 	__u32			delta;		/* Delta in sequence numbers */
366 	__u32			previous_delta;	/* Delta in sequence numbers
367 						 * before last resized pkt */
368 };
369 
370 /* counters per cpu */
371 struct ip_vs_counters {
372 	u64_stats_t	conns;		/* connections scheduled */
373 	u64_stats_t	inpkts;		/* incoming packets */
374 	u64_stats_t	outpkts;	/* outgoing packets */
375 	u64_stats_t	inbytes;	/* incoming bytes */
376 	u64_stats_t	outbytes;	/* outgoing bytes */
377 };
378 /* Stats per cpu */
379 struct ip_vs_cpu_stats {
380 	struct ip_vs_counters   cnt;
381 	struct u64_stats_sync   syncp;
382 };
383 
384 /* Default nice for estimator kthreads */
385 #define IPVS_EST_NICE		0
386 
387 /* IPVS statistics objects */
388 struct ip_vs_estimator {
389 	struct hlist_node	list;
390 
391 	u64			last_inbytes;
392 	u64			last_outbytes;
393 	u64			last_conns;
394 	u64			last_inpkts;
395 	u64			last_outpkts;
396 
397 	u64			cps;
398 	u64			inpps;
399 	u64			outpps;
400 	u64			inbps;
401 	u64			outbps;
402 
403 	s32			ktid:16,	/* kthread ID, -1=temp list */
404 				ktrow:8,	/* row/tick ID for kthread */
405 				ktcid:8;	/* chain ID for kthread tick */
406 };
407 
408 /*
409  * IPVS statistics object, 64-bit kernel version of struct ip_vs_stats_user
410  */
411 struct ip_vs_kstats {
412 	u64			conns;		/* connections scheduled */
413 	u64			inpkts;		/* incoming packets */
414 	u64			outpkts;	/* outgoing packets */
415 	u64			inbytes;	/* incoming bytes */
416 	u64			outbytes;	/* outgoing bytes */
417 
418 	u64			cps;		/* current connection rate */
419 	u64			inpps;		/* current in packet rate */
420 	u64			outpps;		/* current out packet rate */
421 	u64			inbps;		/* current in byte rate */
422 	u64			outbps;		/* current out byte rate */
423 };
424 
425 struct ip_vs_stats {
426 	struct ip_vs_kstats	kstats;		/* kernel statistics */
427 	struct ip_vs_estimator	est;		/* estimator */
428 	struct ip_vs_cpu_stats __percpu	*cpustats;	/* per cpu counters */
429 	spinlock_t		lock;		/* spin lock */
430 	struct ip_vs_kstats	kstats0;	/* reset values */
431 };
432 
433 struct ip_vs_stats_rcu {
434 	struct ip_vs_stats	s;
435 	struct rcu_head		rcu_head;
436 };
437 
438 int ip_vs_stats_init_alloc(struct ip_vs_stats *s);
439 struct ip_vs_stats *ip_vs_stats_alloc(void);
440 void ip_vs_stats_release(struct ip_vs_stats *stats);
441 void ip_vs_stats_free(struct ip_vs_stats *stats);
442 
443 /* Process estimators in multiple timer ticks (20/50/100, see ktrow) */
444 #define IPVS_EST_NTICKS		50
445 /* Estimation uses a 2-second period containing ticks (in jiffies) */
446 #define IPVS_EST_TICK		((2 * HZ) / IPVS_EST_NTICKS)
447 
448 /* Limit of CPU load per kthread (8 for 12.5%), ratio of CPU capacity (1/C).
449  * Value of 4 and above ensures kthreads will take work without exceeding
450  * the CPU capacity under different circumstances.
451  */
452 #define IPVS_EST_LOAD_DIVISOR	8
453 
454 /* Kthreads should not have work that exceeds the CPU load above 50% */
455 #define IPVS_EST_CPU_KTHREADS	(IPVS_EST_LOAD_DIVISOR / 2)
456 
457 /* Desired number of chains per timer tick (chain load factor in 100us units),
458  * 48=4.8ms of 40ms tick (12% CPU usage):
459  * 2 sec * 1000 ms in sec * 10 (100us in ms) / 8 (12.5%) / 50
460  */
461 #define IPVS_EST_CHAIN_FACTOR	\
462 	ALIGN_DOWN(2 * 1000 * 10 / IPVS_EST_LOAD_DIVISOR / IPVS_EST_NTICKS, 8)
463 
464 /* Compiled number of chains per tick
465  * The defines should match cond_resched_rcu
466  */
467 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
468 #define IPVS_EST_TICK_CHAINS	IPVS_EST_CHAIN_FACTOR
469 #else
470 #define IPVS_EST_TICK_CHAINS	1
471 #endif
472 
473 #if IPVS_EST_NTICKS > 127
474 #error Too many timer ticks for ktrow
475 #endif
476 
477 /* Multiple chains processed in same tick */
478 struct ip_vs_est_tick_data {
479 	struct rcu_head		rcu_head;
480 	struct hlist_head	chains[IPVS_EST_TICK_CHAINS];
481 	DECLARE_BITMAP(present, IPVS_EST_TICK_CHAINS);
482 	DECLARE_BITMAP(full, IPVS_EST_TICK_CHAINS);
483 	int			chain_len[IPVS_EST_TICK_CHAINS];
484 };
485 
486 /* Context for estimation kthread */
487 struct ip_vs_est_kt_data {
488 	struct netns_ipvs	*ipvs;
489 	struct task_struct	*task;		/* task if running */
490 	struct ip_vs_est_tick_data __rcu *ticks[IPVS_EST_NTICKS];
491 	DECLARE_BITMAP(avail, IPVS_EST_NTICKS);	/* tick has space for ests */
492 	unsigned long		est_timer;	/* estimation timer (jiffies) */
493 	struct ip_vs_stats	*calc_stats;	/* Used for calculation */
494 	int			tick_len[IPVS_EST_NTICKS];	/* est count */
495 	int			id;		/* ktid per netns */
496 	int			chain_max;	/* max ests per tick chain */
497 	int			tick_max;	/* max ests per tick */
498 	int			est_count;	/* attached ests to kthread */
499 	int			est_max_count;	/* max ests per kthread */
500 	int			add_row;	/* row for new ests */
501 	int			est_row;	/* estimated row */
502 };
503 
504 /* IPVS resizable hash tables */
505 struct ip_vs_rht {
506 	struct hlist_bl_head		*buckets;
507 	struct ip_vs_rht __rcu		*new_tbl; /* New/Same table	*/
508 	seqcount_t			*seqc;	/* Protects moves	*/
509 	struct ip_vs_aligned_lock	*lock;	/* Protect seqc		*/
510 	int				mask;	/* Buckets mask		*/
511 	int				size;	/* Buckets		*/
512 	int				seqc_mask; /* seqc mask		*/
513 	int				lock_mask; /* lock mask		*/
514 	u32				table_id;
515 	int				u_thresh; /* upper threshold	*/
516 	int				l_thresh; /* lower threshold	*/
517 	int				lfactor;  /* Load Factor (shift)*/
518 	int				bits;	/* size = 1 << bits	*/
519 	siphash_key_t			hash_key;
520 	struct rcu_head			rcu_head;
521 };
522 
523 /**
524  * ip_vs_rht_for_each_table() - Walk the hash tables
525  * @table:	struct ip_vs_rht __rcu *table
526  * @t:		current table, used as cursor, struct ip_vs_rht *var
527  * @p:		previous table, temp struct ip_vs_rht *var
528  *
529  * Walk tables assuming others can not change the installed tables
530  */
531 #define ip_vs_rht_for_each_table(table, t, p)				\
532 	for (p = NULL, t = rcu_dereference_protected(table, 1);		\
533 	     t != p;							\
534 	     p = t, t = rcu_dereference_protected(t->new_tbl, 1))
535 
536 /**
537  * ip_vs_rht_for_each_table_rcu() - Walk the hash tables under RCU reader lock
538  * @table:	struct ip_vs_rht __rcu *table
539  * @t:		current table, used as cursor, struct ip_vs_rht *var
540  * @p:		previous table, temp struct ip_vs_rht *var
541  *
542  * We usually search in one table and also in second table on resizing
543  */
544 #define ip_vs_rht_for_each_table_rcu(table, t, p)			\
545 	for (p = NULL, t = rcu_dereference(table);			\
546 	     t != p;							\
547 	     p = t, t = rcu_dereference(t->new_tbl))
548 
549 /**
550  * ip_vs_rht_for_each_bucket() - Walk all table buckets
551  * @t:		current table, used as cursor, struct ip_vs_rht *var
552  * @bucket:	bucket index, used as cursor, u32 var
553  * @head:	bucket address, used as cursor, struct hlist_bl_head *var
554  */
555 #define ip_vs_rht_for_each_bucket(t, bucket, head)			\
556 	for (bucket = 0, head = (t)->buckets;				\
557 	     bucket < t->size; bucket++, head++)
558 
559 /**
560  * ip_vs_rht_for_bucket_retry() - Retry bucket if entries are moved
561  * @t:		current table, used as cursor, struct ip_vs_rht *var
562  * @bucket:	index of current bucket or hash key
563  * @sc:		temp seqcount_t *var
564  * @seq:	temp unsigned int var for sequence count
565  * @retry:	temp int var
566  */
567 #define ip_vs_rht_for_bucket_retry(t, bucket, sc, seq, retry)		\
568 	for (retry = 1, sc = &(t)->seqc[(bucket) & (t)->seqc_mask];	\
569 	     retry && ({ seq = read_seqcount_begin(sc); 1; });		\
570 	     retry = read_seqcount_retry(sc, seq))
571 
572 /**
573  * DECLARE_IP_VS_RHT_WALK_BUCKETS_RCU() - Declare variables
574  *
575  * Variables for ip_vs_rht_walk_buckets_rcu
576  */
577 #define DECLARE_IP_VS_RHT_WALK_BUCKETS_RCU()				\
578 	struct ip_vs_rht *_t, *_p;					\
579 	unsigned int _seq;						\
580 	seqcount_t *_sc;						\
581 	u32 _bucket;							\
582 	int _retry
583 /**
584  * ip_vs_rht_walk_buckets_rcu() - Walk all buckets under RCU read lock
585  * @table:	struct ip_vs_rht __rcu *table
586  * @head:	bucket address, used as cursor, struct hlist_bl_head *var
587  *
588  * Can be used while others add/delete/move entries
589  * Not suitable if duplicates are not desired
590  * Possible cases for reader that uses cond_resched_rcu() in the loop:
591  * - new table can not be installed, no need to repeat
592  * - new table can be installed => check and repeat if new table is
593  * installed, needed for !PREEMPT_RCU
594  */
595 #define ip_vs_rht_walk_buckets_rcu(table, head)				\
596 	ip_vs_rht_for_each_table_rcu(table, _t, _p)			\
597 		ip_vs_rht_for_each_bucket(_t, _bucket, head)		\
598 			ip_vs_rht_for_bucket_retry(_t, _bucket, _sc,	\
599 						   _seq, _retry)
600 
601 /**
602  * DECLARE_IP_VS_RHT_WALK_BUCKET_RCU() - Declare variables
603  *
604  * Variables for ip_vs_rht_walk_bucket_rcu
605  */
606 #define DECLARE_IP_VS_RHT_WALK_BUCKET_RCU()				\
607 	unsigned int _seq;						\
608 	seqcount_t *_sc;						\
609 	int _retry
610 /**
611  * ip_vs_rht_walk_bucket_rcu() - Walk bucket under RCU read lock
612  * @t:		current table, struct ip_vs_rht *var
613  * @bucket:	index of current bucket or hash key
614  * @head:	bucket address, used as cursor, struct hlist_bl_head *var
615  *
616  * Can be used while others add/delete/move entries
617  * Not suitable if duplicates are not desired
618  * Possible cases for reader that uses cond_resched_rcu() in the loop:
619  * - new table can not be installed, no need to repeat
620  * - new table can be installed => check and repeat if new table is
621  * installed, needed for !PREEMPT_RCU
622  */
623 #define ip_vs_rht_walk_bucket_rcu(t, bucket, head)			\
624 	if (({ head = (t)->buckets + ((bucket) & (t)->mask); 0; }))	\
625 		{}							\
626 	else								\
627 		ip_vs_rht_for_bucket_retry(t, (bucket), _sc, _seq, _retry)
628 
629 /**
630  * DECLARE_IP_VS_RHT_WALK_BUCKETS_SAFE_RCU() - Declare variables
631  *
632  * Variables for ip_vs_rht_walk_buckets_safe_rcu
633  */
634 #define DECLARE_IP_VS_RHT_WALK_BUCKETS_SAFE_RCU()			\
635 	struct ip_vs_rht *_t, *_p;					\
636 	u32 _bucket
637 /**
638  * ip_vs_rht_walk_buckets_safe_rcu() - Walk all buckets under RCU read lock
639  * @table:	struct ip_vs_rht __rcu *table
640  * @head:	bucket address, used as cursor, struct hlist_bl_head *var
641  *
642  * Can be used while others add/delete entries but moving is disabled
643  * Using cond_resched_rcu() should be safe if tables do not change
644  */
645 #define ip_vs_rht_walk_buckets_safe_rcu(table, head)			\
646 	ip_vs_rht_for_each_table_rcu(table, _t, _p)			\
647 		ip_vs_rht_for_each_bucket(_t, _bucket, head)
648 
649 /**
650  * DECLARE_IP_VS_RHT_WALK_BUCKETS() - Declare variables
651  *
652  * Variables for ip_vs_rht_walk_buckets
653  */
654 #define DECLARE_IP_VS_RHT_WALK_BUCKETS()				\
655 	struct ip_vs_rht *_t, *_p;					\
656 	u32 _bucket
657 
658 /**
659  * ip_vs_rht_walk_buckets() - Walk all buckets
660  * @table:	struct ip_vs_rht __rcu *table
661  * @head:	bucket address, used as cursor, struct hlist_bl_head *var
662  *
663  * Use if others can not add/delete/move entries
664  */
665 #define ip_vs_rht_walk_buckets(table, head)				\
666 	ip_vs_rht_for_each_table(table, _t, _p)				\
667 		ip_vs_rht_for_each_bucket(_t, _bucket, head)
668 
669 /* Entries can be in one of two tables, so we flip bit when new table is
670  * created and store it as highest bit in hash keys
671  */
672 #define IP_VS_RHT_TABLE_ID_MASK	BIT(31)
673 
674 /* Check if hash key is from this table */
675 static inline bool ip_vs_rht_same_table(struct ip_vs_rht *t, u32 hash_key)
676 {
677 	return !((t->table_id ^ hash_key) & IP_VS_RHT_TABLE_ID_MASK);
678 }
679 
680 /* Build per-table hash key from hash value */
681 static inline u32 ip_vs_rht_build_hash_key(struct ip_vs_rht *t, u32 hash)
682 {
683 	return t->table_id | (hash & ~IP_VS_RHT_TABLE_ID_MASK);
684 }
685 
686 void ip_vs_rht_free(struct ip_vs_rht *t);
687 void ip_vs_rht_rcu_free(struct rcu_head *head);
688 struct ip_vs_rht *ip_vs_rht_alloc(int buckets, int scounts, int locks);
689 int ip_vs_rht_desired_size(struct netns_ipvs *ipvs, struct ip_vs_rht *t, int n,
690 			   int lfactor, int min_bits, int max_bits);
691 void ip_vs_rht_set_thresholds(struct ip_vs_rht *t, int size, int lfactor,
692 			      int min_bits, int max_bits);
693 u32 ip_vs_rht_hash_linfo(struct ip_vs_rht *t, int af,
694 			 const union nf_inet_addr *addr, u32 v1, u32 v2);
695 
696 struct dst_entry;
697 struct iphdr;
698 struct ip_vs_conn;
699 struct ip_vs_app;
700 struct sk_buff;
701 struct ip_vs_proto_data;
702 
703 struct ip_vs_protocol {
704 	struct ip_vs_protocol	*next;
705 	char			*name;
706 	u16			protocol;
707 	u16			num_states;
708 	int			dont_defrag;
709 
710 	void (*init)(struct ip_vs_protocol *pp);
711 
712 	void (*exit)(struct ip_vs_protocol *pp);
713 
714 	int (*init_netns)(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd);
715 
716 	void (*exit_netns)(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd);
717 
718 	int (*conn_schedule)(struct netns_ipvs *ipvs,
719 			     int af, struct sk_buff *skb,
720 			     struct ip_vs_proto_data *pd,
721 			     int *verdict, struct ip_vs_conn **cpp,
722 			     struct ip_vs_iphdr *iph);
723 
724 	struct ip_vs_conn *
725 	(*conn_in_get)(struct netns_ipvs *ipvs,
726 		       int af,
727 		       const struct sk_buff *skb,
728 		       const struct ip_vs_iphdr *iph);
729 
730 	struct ip_vs_conn *
731 	(*conn_out_get)(struct netns_ipvs *ipvs,
732 			int af,
733 			const struct sk_buff *skb,
734 			const struct ip_vs_iphdr *iph);
735 
736 	int (*snat_handler)(struct sk_buff *skb, struct ip_vs_protocol *pp,
737 			    struct ip_vs_conn *cp, struct ip_vs_iphdr *iph);
738 
739 	int (*dnat_handler)(struct sk_buff *skb, struct ip_vs_protocol *pp,
740 			    struct ip_vs_conn *cp, struct ip_vs_iphdr *iph);
741 
742 	const char *(*state_name)(int state);
743 
744 	void (*state_transition)(struct ip_vs_conn *cp, int direction,
745 				 const struct sk_buff *skb,
746 				 struct ip_vs_proto_data *pd);
747 
748 	int (*register_app)(struct netns_ipvs *ipvs, struct ip_vs_app *inc);
749 
750 	void (*unregister_app)(struct netns_ipvs *ipvs, struct ip_vs_app *inc);
751 
752 	int (*app_conn_bind)(struct ip_vs_conn *cp);
753 
754 	void (*debug_packet)(int af, struct ip_vs_protocol *pp,
755 			     const struct sk_buff *skb,
756 			     int offset,
757 			     const char *msg);
758 
759 	void (*timeout_change)(struct ip_vs_proto_data *pd, int flags);
760 };
761 
762 /* protocol data per netns */
763 struct ip_vs_proto_data {
764 	struct ip_vs_proto_data	*next;
765 	struct ip_vs_protocol	*pp;
766 	int			*timeout_table;	/* protocol timeout table */
767 	atomic_t		appcnt;		/* counter of proto app incs. */
768 	struct tcp_states_t	*tcp_state_table;
769 };
770 
771 struct ip_vs_protocol   *ip_vs_proto_get(unsigned short proto);
772 struct ip_vs_proto_data *ip_vs_proto_data_get(struct netns_ipvs *ipvs,
773 					      unsigned short proto);
774 
775 struct ip_vs_conn_param {
776 	struct netns_ipvs		*ipvs;
777 	const union nf_inet_addr	*caddr;
778 	const union nf_inet_addr	*vaddr;
779 	__be16				cport;
780 	__be16				vport;
781 	__u16				protocol;
782 	u16				af;
783 
784 	const struct ip_vs_pe		*pe;
785 	char				*pe_data;
786 	__u8				pe_data_len;
787 };
788 
789 /* Hash node in conn_tab */
790 struct ip_vs_conn_hnode {
791 	struct hlist_bl_node	node;		/* node in conn_tab */
792 	u32			hash_key;	/* Key for the hash table */
793 	u8			dir;		/* 0=out->in, 1=in->out */
794 } __packed;
795 
796 /* IP_VS structure allocated for each dynamically scheduled connection */
797 struct ip_vs_conn {
798 	/* Cacheline for hash table nodes - rarely modified */
799 
800 	struct ip_vs_conn_hnode	hn0;		/* Original direction */
801 	u8			af;		/* address family */
802 	__be16                  cport;
803 	struct ip_vs_conn_hnode	hn1;		/* Reply direction */
804 	u8			daf;		/* Address family of the dest */
805 	__be16                  dport;
806 	struct ip_vs_dest       *dest;          /* real server */
807 	atomic_t                n_control;      /* Number of controlled ones */
808 	volatile __u32          flags;          /* status flags */
809 	/* 44/64 */
810 
811 	struct ip_vs_conn       *control;       /* Master control connection */
812 	const struct ip_vs_pe	*pe;
813 	char			*pe_data;
814 	__u8			pe_data_len;
815 	volatile __u16          state;          /* state info */
816 	volatile __u16          old_state;      /* old state, to be used for
817 						 * state transition triggered
818 						 * synchronization
819 						 */
820 	/* 2-byte hole */
821 	/* 64/96 */
822 
823 	union nf_inet_addr      caddr;          /* client address */
824 	union nf_inet_addr      vaddr;          /* virtual address */
825 	/* 96/128 */
826 
827 	union nf_inet_addr      daddr;          /* destination address */
828 	__u32			fwmark;		/* Fire wall mark from skb */
829 	__be16                  vport;
830 	__u16                   protocol;       /* Which protocol (TCP/UDP) */
831 
832 	/* Note: we can group the following members into a structure,
833 	 * in order to save more space, and the following members are
834 	 * only used in VS/NAT anyway
835 	 */
836 	struct ip_vs_app        *app;           /* bound ip_vs_app object */
837 	void                    *app_data;      /* Application private data */
838 	/* 128/168 */
839 	struct_group(sync_conn_opt,
840 		struct ip_vs_seq  in_seq;       /* incoming seq. struct */
841 		struct ip_vs_seq  out_seq;      /* outgoing seq. struct */
842 	);
843 	/* 152/192 */
844 
845 	struct timer_list	timer;		/* Expiration timer */
846 	volatile unsigned long	timeout;	/* timeout */
847 	spinlock_t              lock;           /* lock for state transition */
848 	refcount_t		refcnt;		/* reference count */
849 	atomic_t                in_pkts;        /* incoming packet counter */
850 	/* 64-bit: 4-byte gap */
851 
852 	/* 188/256 */
853 	unsigned long		sync_endtime;	/* jiffies + sent_retries */
854 	struct netns_ipvs	*ipvs;
855 
856 	/* Packet transmitter for different forwarding methods.  If it
857 	 * mangles the packet, it must return NF_DROP or better NF_STOLEN,
858 	 * otherwise this must be changed to a sk_buff **.
859 	 * NF_ACCEPT can be returned when destination is local.
860 	 */
861 	int (*packet_xmit)(struct sk_buff *skb, struct ip_vs_conn *cp,
862 			   struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
863 
864 	struct rcu_head		rcu_head;
865 };
866 
867 /* Extended internal versions of struct ip_vs_service_user and ip_vs_dest_user
868  * for IPv6 support.
869  *
870  * We need these to conveniently pass around service and destination
871  * options, but unfortunately, we also need to keep the old definitions to
872  * maintain userspace backwards compatibility for the setsockopt interface.
873  */
874 struct ip_vs_service_user_kern {
875 	/* virtual service addresses */
876 	u16			af;
877 	u16			protocol;
878 	union nf_inet_addr	addr;		/* virtual ip address */
879 	__be16			port;
880 	u32			fwmark;		/* firewall mark of service */
881 
882 	/* virtual service options */
883 	char			*sched_name;
884 	char			*pe_name;
885 	unsigned int		flags;		/* virtual service flags */
886 	unsigned int		timeout;	/* persistent timeout in sec */
887 	__be32			netmask;	/* persistent netmask or plen */
888 };
889 
890 
891 struct ip_vs_dest_user_kern {
892 	/* destination server address */
893 	union nf_inet_addr	addr;
894 	__be16			port;
895 
896 	/* real server options */
897 	unsigned int		conn_flags;	/* connection flags */
898 	int			weight;		/* destination weight */
899 
900 	/* thresholds for active connections */
901 	u32			u_threshold;	/* upper threshold */
902 	u32			l_threshold;	/* lower threshold */
903 
904 	/* Address family of addr */
905 	u16			af;
906 
907 	u16			tun_type;	/* tunnel type */
908 	__be16			tun_port;	/* tunnel port */
909 	u16			tun_flags;	/* tunnel flags */
910 };
911 
912 
913 /*
914  * The information about the virtual service offered to the net and the
915  * forwarding entries.
916  */
917 struct ip_vs_service {
918 	struct hlist_bl_node	s_list;   /* node in service table */
919 	u32			hash_key; /* Key for the hash table */
920 	u16			af;       /* address family */
921 	__u16			protocol; /* which protocol (TCP/UDP) */
922 
923 	union nf_inet_addr	addr;	  /* IP address for virtual service */
924 	__u32                   fwmark;   /* firewall mark of the service */
925 	atomic_t		refcnt;   /* reference counter */
926 	__be16			port;	  /* port number for the service */
927 	unsigned int		flags;	  /* service status flags */
928 	unsigned int		timeout;  /* persistent timeout in ticks */
929 	__be32			netmask;  /* grouping granularity, mask/plen */
930 	struct netns_ipvs	*ipvs;
931 
932 	struct list_head	destinations;  /* real server d-linked list */
933 	__u32			num_dests;     /* number of servers */
934 	struct ip_vs_stats      stats;         /* statistics for the service */
935 
936 	/* for scheduling */
937 	struct ip_vs_scheduler __rcu *scheduler; /* bound scheduler object */
938 	spinlock_t		sched_lock;    /* lock sched_data */
939 	void			*sched_data;   /* scheduler application data */
940 
941 	/* alternate persistence engine */
942 	struct ip_vs_pe __rcu	*pe;
943 	int			conntrack_afmask;
944 
945 	struct rcu_head		rcu_head;
946 };
947 
948 /* Information for cached dst */
949 struct ip_vs_dest_dst {
950 	struct dst_entry	*dst_cache;	/* destination cache entry */
951 	u32			dst_cookie;
952 	union nf_inet_addr	dst_saddr;
953 	struct rcu_head		rcu_head;
954 };
955 
956 /* The real server destination forwarding entry with ip address, port number,
957  * and so on.
958  */
959 struct ip_vs_dest {
960 	struct list_head	n_list;   /* for the dests in the service */
961 	struct hlist_node	d_list;   /* for table with all the dests */
962 
963 	u16			af;		/* address family */
964 	__be16			port;		/* port number of the server */
965 	union nf_inet_addr	addr;		/* IP address of the server */
966 	volatile unsigned int	flags;		/* dest status flags */
967 	atomic_t		conn_flags;	/* flags to copy to conn */
968 	atomic_t		weight;		/* server weight */
969 	atomic_t		last_weight;	/* server latest weight */
970 	__u16			tun_type;	/* tunnel type */
971 	__be16			tun_port;	/* tunnel port */
972 	__u16			tun_flags;	/* tunnel flags */
973 
974 	refcount_t		refcnt;		/* reference counter */
975 	struct ip_vs_stats      stats;          /* statistics */
976 	unsigned long		idle_start;	/* start time, jiffies */
977 
978 	/* connection counters and thresholds */
979 	atomic_t		activeconns;	/* active connections */
980 	atomic_t		inactconns;	/* inactive connections */
981 	atomic_t		persistconns;	/* persistent connections */
982 	__u32			u_threshold;	/* upper threshold */
983 	__u32			l_threshold;	/* lower threshold */
984 
985 	/* for destination cache */
986 	spinlock_t		dst_lock;	/* lock of dst_cache */
987 	struct ip_vs_dest_dst __rcu *dest_dst;	/* cached dst info */
988 
989 	/* for virtual service */
990 	struct ip_vs_service __rcu *svc;	/* service it belongs to */
991 	__u16			protocol;	/* which protocol (TCP/UDP) */
992 	__be16			vport;		/* virtual port number */
993 	union nf_inet_addr	vaddr;		/* virtual IP address */
994 	__u32			vfwmark;	/* firewall mark of service */
995 
996 	struct rcu_head		rcu_head;
997 	struct list_head	t_list;		/* in dest_trash */
998 	unsigned int		in_rs_table:1;	/* we are in rs_table */
999 };
1000 
1001 /* The scheduler object */
1002 struct ip_vs_scheduler {
1003 	struct list_head	n_list;		/* d-linked list head */
1004 	char			*name;		/* scheduler name */
1005 	atomic_t		refcnt;		/* reference counter */
1006 	struct module		*module;	/* THIS_MODULE/NULL */
1007 
1008 	/* scheduler initializing service */
1009 	int (*init_service)(struct ip_vs_service *svc);
1010 	/* scheduling service finish */
1011 	void (*done_service)(struct ip_vs_service *svc);
1012 	/* dest is linked */
1013 	int (*add_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);
1014 	/* dest is unlinked */
1015 	int (*del_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);
1016 	/* dest is updated */
1017 	int (*upd_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);
1018 
1019 	/* selecting a server from the given service */
1020 	struct ip_vs_dest* (*schedule)(struct ip_vs_service *svc,
1021 				       const struct sk_buff *skb,
1022 				       struct ip_vs_iphdr *iph);
1023 };
1024 
1025 /* The persistence engine object */
1026 struct ip_vs_pe {
1027 	struct list_head	n_list;		/* d-linked list head */
1028 	char			*name;		/* scheduler name */
1029 	atomic_t		refcnt;		/* reference counter */
1030 	struct module		*module;	/* THIS_MODULE/NULL */
1031 
1032 	/* get the connection template, if any */
1033 	int (*fill_param)(struct ip_vs_conn_param *p, struct sk_buff *skb);
1034 	bool (*ct_match)(const struct ip_vs_conn_param *p,
1035 			 struct ip_vs_conn *ct);
1036 	u32 (*hashkey_raw)(const struct ip_vs_conn_param *p,
1037 			   struct ip_vs_rht *t, bool inverse);
1038 	int (*show_pe_data)(const struct ip_vs_conn *cp, char *buf);
1039 	/* create connections for real-server outgoing packets */
1040 	struct ip_vs_conn* (*conn_out)(struct ip_vs_service *svc,
1041 				       struct ip_vs_dest *dest,
1042 				       struct sk_buff *skb,
1043 				       const struct ip_vs_iphdr *iph,
1044 				       __be16 dport, __be16 cport);
1045 };
1046 
1047 /* The application module object (a.k.a. app incarnation) */
1048 struct ip_vs_app {
1049 	struct list_head	a_list;		/* member in app list */
1050 	int			type;		/* IP_VS_APP_TYPE_xxx */
1051 	char			*name;		/* application module name */
1052 	__u16			protocol;
1053 	struct module		*module;	/* THIS_MODULE/NULL */
1054 	struct list_head	incs_list;	/* list of incarnations */
1055 
1056 	/* members for application incarnations */
1057 	struct list_head	p_list;		/* member in proto app list */
1058 	struct ip_vs_app	*app;		/* its real application */
1059 	__be16			port;		/* port number in net order */
1060 	atomic_t		usecnt;		/* usage counter */
1061 	struct rcu_head		rcu_head;
1062 
1063 	/* output hook: Process packet in inout direction, diff set for TCP.
1064 	 * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok,
1065 	 *	   2=Mangled but checksum was not updated
1066 	 */
1067 	int (*pkt_out)(struct ip_vs_app *, struct ip_vs_conn *,
1068 		       struct sk_buff *, int *diff, struct ip_vs_iphdr *ipvsh);
1069 
1070 	/* input hook: Process packet in outin direction, diff set for TCP.
1071 	 * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok,
1072 	 *	   2=Mangled but checksum was not updated
1073 	 */
1074 	int (*pkt_in)(struct ip_vs_app *, struct ip_vs_conn *,
1075 		      struct sk_buff *, int *diff, struct ip_vs_iphdr *ipvsh);
1076 
1077 	/* ip_vs_app initializer */
1078 	int (*init_conn)(struct ip_vs_app *, struct ip_vs_conn *);
1079 
1080 	/* ip_vs_app finish */
1081 	int (*done_conn)(struct ip_vs_app *, struct ip_vs_conn *);
1082 
1083 
1084 	/* not used now */
1085 	int (*bind_conn)(struct ip_vs_app *, struct ip_vs_conn *,
1086 			 struct ip_vs_protocol *);
1087 
1088 	void (*unbind_conn)(struct ip_vs_app *, struct ip_vs_conn *);
1089 
1090 	int *			timeout_table;
1091 	int *			timeouts;
1092 	int			timeouts_size;
1093 
1094 	int (*conn_schedule)(struct sk_buff *skb, struct ip_vs_app *app,
1095 			     int *verdict, struct ip_vs_conn **cpp);
1096 
1097 	struct ip_vs_conn *
1098 	(*conn_in_get)(const struct sk_buff *skb, struct ip_vs_app *app,
1099 		       const struct iphdr *iph, int inverse);
1100 
1101 	struct ip_vs_conn *
1102 	(*conn_out_get)(const struct sk_buff *skb, struct ip_vs_app *app,
1103 			const struct iphdr *iph, int inverse);
1104 
1105 	int (*state_transition)(struct ip_vs_conn *cp, int direction,
1106 				const struct sk_buff *skb,
1107 				struct ip_vs_app *app);
1108 
1109 	void (*timeout_change)(struct ip_vs_app *app, int flags);
1110 };
1111 
1112 struct ipvs_master_sync_state {
1113 	struct list_head	sync_queue;
1114 	struct ip_vs_sync_buff	*sync_buff;
1115 	unsigned long		sync_queue_len;
1116 	unsigned int		sync_queue_delay;
1117 	struct delayed_work	master_wakeup_work;
1118 	struct netns_ipvs	*ipvs;
1119 };
1120 
1121 struct ip_vs_sync_thread_data;
1122 
1123 /* How much time to keep dests in trash */
1124 #define IP_VS_DEST_TRASH_PERIOD		(120 * HZ)
1125 
1126 struct ipvs_sync_daemon_cfg {
1127 	union nf_inet_addr	mcast_group;
1128 	int			syncid;
1129 	u16			sync_maxlen;
1130 	u16			mcast_port;
1131 	u8			mcast_af;
1132 	u8			mcast_ttl;
1133 	/* multicast interface name */
1134 	char			mcast_ifn[IP_VS_IFNAME_MAXLEN];
1135 };
1136 
1137 /* IPVS in network namespace */
1138 struct netns_ipvs {
1139 	int			gen;		/* Generation */
1140 	int			enable;		/* enable like nf_hooks do */
1141 	/* Hash table: for real service lookups */
1142 	#define IP_VS_RTAB_BITS 4
1143 	#define IP_VS_RTAB_SIZE (1 << IP_VS_RTAB_BITS)
1144 	#define IP_VS_RTAB_MASK (IP_VS_RTAB_SIZE - 1)
1145 
1146 	struct hlist_head	rs_table[IP_VS_RTAB_SIZE];
1147 	/* ip_vs_app */
1148 	struct list_head	app_list;
1149 	/* ip_vs_proto */
1150 	#define IP_VS_PROTO_TAB_SIZE	32	/* must be power of 2 */
1151 	struct ip_vs_proto_data *proto_data_table[IP_VS_PROTO_TAB_SIZE];
1152 	/* ip_vs_proto_tcp */
1153 #ifdef CONFIG_IP_VS_PROTO_TCP
1154 	#define	TCP_APP_TAB_BITS	4
1155 	#define	TCP_APP_TAB_SIZE	(1 << TCP_APP_TAB_BITS)
1156 	#define	TCP_APP_TAB_MASK	(TCP_APP_TAB_SIZE - 1)
1157 	struct list_head	tcp_apps[TCP_APP_TAB_SIZE];
1158 #endif
1159 	/* ip_vs_proto_udp */
1160 #ifdef CONFIG_IP_VS_PROTO_UDP
1161 	#define	UDP_APP_TAB_BITS	4
1162 	#define	UDP_APP_TAB_SIZE	(1 << UDP_APP_TAB_BITS)
1163 	#define	UDP_APP_TAB_MASK	(UDP_APP_TAB_SIZE - 1)
1164 	struct list_head	udp_apps[UDP_APP_TAB_SIZE];
1165 #endif
1166 	/* ip_vs_proto_sctp */
1167 #ifdef CONFIG_IP_VS_PROTO_SCTP
1168 	#define SCTP_APP_TAB_BITS	4
1169 	#define SCTP_APP_TAB_SIZE	(1 << SCTP_APP_TAB_BITS)
1170 	#define SCTP_APP_TAB_MASK	(SCTP_APP_TAB_SIZE - 1)
1171 	/* Hash table for SCTP application incarnations	 */
1172 	struct list_head	sctp_apps[SCTP_APP_TAB_SIZE];
1173 #endif
1174 	/* ip_vs_conn */
1175 	atomic_t		conn_count;      /* connection counter */
1176 	atomic_t		no_cport_conns[IP_VS_AF_MAX];
1177 	struct delayed_work	conn_resize_work;/* resize conn_tab */
1178 
1179 	/* ip_vs_ctl */
1180 	struct ip_vs_stats_rcu	*tot_stats;      /* Statistics & est. */
1181 
1182 	/* Trash for destinations */
1183 	struct list_head	dest_trash;
1184 	spinlock_t		dest_trash_lock;
1185 	struct timer_list	dest_trash_timer; /* expiration timer */
1186 	struct mutex		service_mutex;    /* service reconfig */
1187 	struct rw_semaphore	svc_resize_sem;   /* svc_table resizing */
1188 	struct delayed_work	svc_resize_work;  /* resize svc_table */
1189 	atomic_t		svc_table_changes;/* ++ on new table */
1190 	/* Service counters */
1191 	atomic_t		num_services[IP_VS_AF_MAX];   /* Services */
1192 	atomic_t		fwm_services[IP_VS_AF_MAX];   /* Services */
1193 	atomic_t		nonfwm_services[IP_VS_AF_MAX];/* Services */
1194 	atomic_t		ftpsvc_counter[IP_VS_AF_MAX]; /* FTPPORT */
1195 	atomic_t		nullsvc_counter[IP_VS_AF_MAX];/* Zero port */
1196 	atomic_t		conn_out_counter[IP_VS_AF_MAX];/* out conn */
1197 
1198 #ifdef CONFIG_SYSCTL
1199 	/* delayed work for expiring no dest connections */
1200 	struct delayed_work	expire_nodest_conn_work;
1201 	/* 1/rate drop and drop-entry variables */
1202 	struct delayed_work	defense_work;   /* Work handler */
1203 	int			drop_rate;
1204 	int			drop_counter;
1205 	int			old_secure_tcp;
1206 	atomic_t		dropentry;
1207 	s8			dropentry_counters[8];
1208 	/* locks in ctl.c */
1209 	spinlock_t		dropentry_lock;  /* drop entry handling */
1210 	spinlock_t		droppacket_lock; /* drop packet handling */
1211 	spinlock_t		securetcp_lock;  /* state and timeout tables */
1212 
1213 	/* sys-ctl struct */
1214 	struct ctl_table_header	*sysctl_hdr;
1215 	struct ctl_table	*sysctl_tbl;
1216 #endif
1217 
1218 	/* sysctl variables */
1219 	int			sysctl_amemthresh;
1220 	int			sysctl_am_droprate;
1221 	int			sysctl_drop_entry;
1222 	int			sysctl_drop_packet;
1223 	int			sysctl_secure_tcp;
1224 #ifdef CONFIG_IP_VS_NFCT
1225 	int			sysctl_conntrack;
1226 #endif
1227 	int			sysctl_snat_reroute;
1228 	int			sysctl_sync_ver;
1229 	int			sysctl_sync_ports;
1230 	int			sysctl_sync_persist_mode;
1231 	unsigned long		sysctl_sync_qlen_max;
1232 	int			sysctl_sync_sock_size;
1233 	int			sysctl_cache_bypass;
1234 	int			sysctl_expire_nodest_conn;
1235 	int			sysctl_sloppy_tcp;
1236 	int			sysctl_sloppy_sctp;
1237 	int			sysctl_expire_quiescent_template;
1238 	int			sysctl_sync_threshold[2];
1239 	unsigned int		sysctl_sync_refresh_period;
1240 	int			sysctl_sync_retries;
1241 	int			sysctl_nat_icmp_send;
1242 	int			sysctl_pmtu_disc;
1243 	int			sysctl_backup_only;
1244 	int			sysctl_conn_reuse_mode;
1245 	int			sysctl_schedule_icmp;
1246 	int			sysctl_ignore_tunneled;
1247 	int			sysctl_run_estimation;
1248 #ifdef CONFIG_SYSCTL
1249 	cpumask_var_t		sysctl_est_cpulist;	/* kthread cpumask */
1250 	int			est_cpulist_valid;	/* cpulist set */
1251 	int			sysctl_est_nice;	/* kthread nice */
1252 	int			est_stopped;		/* stop tasks */
1253 #endif
1254 	int			sysctl_conn_lfactor;
1255 	int			sysctl_svc_lfactor;
1256 
1257 	/* ip_vs_lblc */
1258 	int			sysctl_lblc_expiration;
1259 	struct ctl_table_header	*lblc_ctl_header;
1260 	struct ctl_table	*lblc_ctl_table;
1261 	/* ip_vs_lblcr */
1262 	int			sysctl_lblcr_expiration;
1263 	struct ctl_table_header	*lblcr_ctl_header;
1264 	struct ctl_table	*lblcr_ctl_table;
1265 	unsigned long		work_flags;	/* IP_VS_WORK_* flags */
1266 	/* ip_vs_est */
1267 	struct delayed_work	est_reload_work;/* Reload kthread tasks */
1268 	struct mutex		est_mutex;	/* protect kthread tasks */
1269 	struct hlist_head	est_temp_list;	/* Ests during calc phase */
1270 	struct ip_vs_est_kt_data **est_kt_arr;	/* Array of kthread data ptrs */
1271 	unsigned long		est_max_threads;/* Hard limit of kthreads */
1272 	int			est_calc_phase;	/* Calculation phase */
1273 	int			est_chain_max;	/* Calculated chain_max */
1274 	int			est_kt_count;	/* Allocated ptrs */
1275 	int			est_add_ktid;	/* ktid where to add ests */
1276 	atomic_t		est_genid;	/* kthreads reload genid */
1277 	atomic_t		est_genid_done;	/* applied genid */
1278 	/* ip_vs_sync */
1279 	spinlock_t		sync_lock;
1280 	struct ipvs_master_sync_state *ms;
1281 	spinlock_t		sync_buff_lock;
1282 	struct ip_vs_sync_thread_data *master_tinfo;
1283 	struct ip_vs_sync_thread_data *backup_tinfo;
1284 	int			threads_mask;
1285 	volatile int		sync_state;
1286 	struct mutex		sync_mutex;
1287 	struct ipvs_sync_daemon_cfg	mcfg;	/* Master Configuration */
1288 	struct ipvs_sync_daemon_cfg	bcfg;	/* Backup Configuration */
1289 	/* net name space ptr */
1290 	struct net		*net;            /* Needed by timer routines */
1291 	/* Number of heterogeneous destinations, needed because heterogeneous
1292 	 * are not supported when synchronization is enabled.
1293 	 */
1294 	unsigned int		mixed_address_family_dests;
1295 	unsigned int		hooks_afmask;	/* &1=AF_INET, &2=AF_INET6 */
1296 
1297 	struct ip_vs_rht __rcu	*svc_table;	/* Services */
1298 	struct ip_vs_rht __rcu	*conn_tab;	/* Connections */
1299 	atomic_t		conn_tab_changes;/* ++ on new table */
1300 };
1301 
1302 #define DEFAULT_SYNC_THRESHOLD	3
1303 #define DEFAULT_SYNC_PERIOD	50
1304 #define DEFAULT_SYNC_VER	1
1305 #define DEFAULT_SLOPPY_TCP	0
1306 #define DEFAULT_SLOPPY_SCTP	0
1307 #define DEFAULT_SYNC_REFRESH_PERIOD	(0U * HZ)
1308 #define DEFAULT_SYNC_RETRIES		0
1309 #define IPVS_SYNC_WAKEUP_RATE	8
1310 #define IPVS_SYNC_QLEN_MAX	(IPVS_SYNC_WAKEUP_RATE * 4)
1311 #define IPVS_SYNC_SEND_DELAY	(HZ / 50)
1312 #define IPVS_SYNC_CHECK_PERIOD	HZ
1313 #define IPVS_SYNC_FLUSH_TIME	(HZ * 2)
1314 #define IPVS_SYNC_PORTS_MAX	(1 << 6)
1315 
1316 #ifdef CONFIG_SYSCTL
1317 
1318 static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
1319 {
1320 	return ipvs->sysctl_sync_threshold[0];
1321 }
1322 
1323 static inline int sysctl_sync_period(struct netns_ipvs *ipvs)
1324 {
1325 	return READ_ONCE(ipvs->sysctl_sync_threshold[1]);
1326 }
1327 
1328 static inline unsigned int sysctl_sync_refresh_period(struct netns_ipvs *ipvs)
1329 {
1330 	return READ_ONCE(ipvs->sysctl_sync_refresh_period);
1331 }
1332 
1333 static inline int sysctl_sync_retries(struct netns_ipvs *ipvs)
1334 {
1335 	return ipvs->sysctl_sync_retries;
1336 }
1337 
1338 static inline int sysctl_sync_ver(struct netns_ipvs *ipvs)
1339 {
1340 	return ipvs->sysctl_sync_ver;
1341 }
1342 
1343 static inline int sysctl_sloppy_tcp(struct netns_ipvs *ipvs)
1344 {
1345 	return ipvs->sysctl_sloppy_tcp;
1346 }
1347 
1348 static inline int sysctl_sloppy_sctp(struct netns_ipvs *ipvs)
1349 {
1350 	return ipvs->sysctl_sloppy_sctp;
1351 }
1352 
1353 static inline int sysctl_sync_ports(struct netns_ipvs *ipvs)
1354 {
1355 	return READ_ONCE(ipvs->sysctl_sync_ports);
1356 }
1357 
1358 static inline int sysctl_sync_persist_mode(struct netns_ipvs *ipvs)
1359 {
1360 	return ipvs->sysctl_sync_persist_mode;
1361 }
1362 
1363 static inline unsigned long sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
1364 {
1365 	return ipvs->sysctl_sync_qlen_max;
1366 }
1367 
1368 static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
1369 {
1370 	return ipvs->sysctl_sync_sock_size;
1371 }
1372 
1373 static inline int sysctl_pmtu_disc(struct netns_ipvs *ipvs)
1374 {
1375 	return ipvs->sysctl_pmtu_disc;
1376 }
1377 
1378 static inline int sysctl_backup_only(struct netns_ipvs *ipvs)
1379 {
1380 	return ipvs->sync_state & IP_VS_STATE_BACKUP &&
1381 	       ipvs->sysctl_backup_only;
1382 }
1383 
1384 static inline int sysctl_conn_reuse_mode(struct netns_ipvs *ipvs)
1385 {
1386 	return ipvs->sysctl_conn_reuse_mode;
1387 }
1388 
1389 static inline int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
1390 {
1391 	return ipvs->sysctl_expire_nodest_conn;
1392 }
1393 
1394 static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs)
1395 {
1396 	return ipvs->sysctl_schedule_icmp;
1397 }
1398 
1399 static inline int sysctl_ignore_tunneled(struct netns_ipvs *ipvs)
1400 {
1401 	return ipvs->sysctl_ignore_tunneled;
1402 }
1403 
1404 static inline int sysctl_cache_bypass(struct netns_ipvs *ipvs)
1405 {
1406 	return ipvs->sysctl_cache_bypass;
1407 }
1408 
1409 static inline int sysctl_run_estimation(struct netns_ipvs *ipvs)
1410 {
1411 	return ipvs->sysctl_run_estimation;
1412 }
1413 
1414 static inline const struct cpumask *sysctl_est_cpulist(struct netns_ipvs *ipvs)
1415 {
1416 	if (ipvs->est_cpulist_valid)
1417 		return ipvs->sysctl_est_cpulist;
1418 	else
1419 		return housekeeping_cpumask(HK_TYPE_KTHREAD);
1420 }
1421 
1422 static inline const struct cpumask *sysctl_est_preferred_cpulist(struct netns_ipvs *ipvs)
1423 {
1424 	if (ipvs->est_cpulist_valid)
1425 		return ipvs->sysctl_est_cpulist;
1426 	else
1427 		return NULL;
1428 }
1429 
1430 static inline int sysctl_est_nice(struct netns_ipvs *ipvs)
1431 {
1432 	return ipvs->sysctl_est_nice;
1433 }
1434 
1435 #else
1436 
1437 static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
1438 {
1439 	return DEFAULT_SYNC_THRESHOLD;
1440 }
1441 
1442 static inline int sysctl_sync_period(struct netns_ipvs *ipvs)
1443 {
1444 	return DEFAULT_SYNC_PERIOD;
1445 }
1446 
1447 static inline unsigned int sysctl_sync_refresh_period(struct netns_ipvs *ipvs)
1448 {
1449 	return DEFAULT_SYNC_REFRESH_PERIOD;
1450 }
1451 
1452 static inline int sysctl_sync_retries(struct netns_ipvs *ipvs)
1453 {
1454 	return DEFAULT_SYNC_RETRIES & 3;
1455 }
1456 
1457 static inline int sysctl_sync_ver(struct netns_ipvs *ipvs)
1458 {
1459 	return DEFAULT_SYNC_VER;
1460 }
1461 
1462 static inline int sysctl_sloppy_tcp(struct netns_ipvs *ipvs)
1463 {
1464 	return DEFAULT_SLOPPY_TCP;
1465 }
1466 
1467 static inline int sysctl_sloppy_sctp(struct netns_ipvs *ipvs)
1468 {
1469 	return DEFAULT_SLOPPY_SCTP;
1470 }
1471 
1472 static inline int sysctl_sync_ports(struct netns_ipvs *ipvs)
1473 {
1474 	return 1;
1475 }
1476 
1477 static inline int sysctl_sync_persist_mode(struct netns_ipvs *ipvs)
1478 {
1479 	return 0;
1480 }
1481 
1482 static inline unsigned long sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
1483 {
1484 	return IPVS_SYNC_QLEN_MAX;
1485 }
1486 
1487 static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
1488 {
1489 	return 0;
1490 }
1491 
1492 static inline int sysctl_pmtu_disc(struct netns_ipvs *ipvs)
1493 {
1494 	return 1;
1495 }
1496 
1497 static inline int sysctl_backup_only(struct netns_ipvs *ipvs)
1498 {
1499 	return 0;
1500 }
1501 
1502 static inline int sysctl_conn_reuse_mode(struct netns_ipvs *ipvs)
1503 {
1504 	return 1;
1505 }
1506 
1507 static inline int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
1508 {
1509 	return 0;
1510 }
1511 
1512 static inline int sysctl_schedule_icmp(struct netns_ipvs *ipvs)
1513 {
1514 	return 0;
1515 }
1516 
1517 static inline int sysctl_ignore_tunneled(struct netns_ipvs *ipvs)
1518 {
1519 	return 0;
1520 }
1521 
1522 static inline int sysctl_cache_bypass(struct netns_ipvs *ipvs)
1523 {
1524 	return 0;
1525 }
1526 
1527 static inline int sysctl_run_estimation(struct netns_ipvs *ipvs)
1528 {
1529 	return 1;
1530 }
1531 
1532 static inline const struct cpumask *sysctl_est_cpulist(struct netns_ipvs *ipvs)
1533 {
1534 	return housekeeping_cpumask(HK_TYPE_KTHREAD);
1535 }
1536 
1537 static inline const struct cpumask *sysctl_est_preferred_cpulist(struct netns_ipvs *ipvs)
1538 {
1539 	return NULL;
1540 }
1541 
1542 static inline int sysctl_est_nice(struct netns_ipvs *ipvs)
1543 {
1544 	return IPVS_EST_NICE;
1545 }
1546 
1547 #endif
1548 
1549 /* Get load factor to map conn_count/u_thresh to t->size */
1550 static inline int sysctl_conn_lfactor(struct netns_ipvs *ipvs)
1551 {
1552 	return READ_ONCE(ipvs->sysctl_conn_lfactor);
1553 }
1554 
1555 /* Get load factor to map num_services/u_thresh to t->size
1556  * Smaller value decreases u_thresh to reduce collisions but increases
1557  * the table size
1558  * Returns factor where:
1559  * - <0: u_thresh = size >> -factor, eg. lfactor -2 = 25% load
1560  * - >=0: u_thresh = size << factor, eg. lfactor 1 = 200% load
1561  */
1562 static inline int sysctl_svc_lfactor(struct netns_ipvs *ipvs)
1563 {
1564 	return READ_ONCE(ipvs->sysctl_svc_lfactor);
1565 }
1566 
1567 /* IPVS core functions
1568  * (from ip_vs_core.c)
1569  */
1570 const char *ip_vs_proto_name(unsigned int proto);
1571 void ip_vs_init_hash_table(struct list_head *table, int rows);
1572 struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
1573 				      struct ip_vs_dest *dest,
1574 				      struct sk_buff *skb,
1575 				      const struct ip_vs_iphdr *iph,
1576 				      __be16 dport,
1577 				      __be16 cport);
1578 #define IP_VS_INIT_HASH_TABLE(t) ip_vs_init_hash_table((t), ARRAY_SIZE((t)))
1579 
1580 #define IP_VS_APP_TYPE_FTP	1
1581 
1582 /* ip_vs_conn handling functions
1583  * (from ip_vs_conn.c)
1584  */
1585 enum {
1586 	IP_VS_DIR_INPUT = 0,
1587 	IP_VS_DIR_OUTPUT,
1588 	IP_VS_DIR_INPUT_ONLY,
1589 	IP_VS_DIR_LAST,
1590 };
1591 
1592 static inline void ip_vs_conn_fill_param(struct netns_ipvs *ipvs, int af, int protocol,
1593 					 const union nf_inet_addr *caddr,
1594 					 __be16 cport,
1595 					 const union nf_inet_addr *vaddr,
1596 					 __be16 vport,
1597 					 struct ip_vs_conn_param *p)
1598 {
1599 	p->ipvs = ipvs;
1600 	p->af = af;
1601 	p->protocol = protocol;
1602 	p->caddr = caddr;
1603 	p->cport = cport;
1604 	p->vaddr = vaddr;
1605 	p->vport = vport;
1606 	p->pe = NULL;
1607 	p->pe_data = NULL;
1608 }
1609 
1610 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p);
1611 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p);
1612 
1613 struct ip_vs_conn * ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
1614 					    const struct sk_buff *skb,
1615 					    const struct ip_vs_iphdr *iph);
1616 
1617 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p);
1618 
1619 struct ip_vs_conn * ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
1620 					     const struct sk_buff *skb,
1621 					     const struct ip_vs_iphdr *iph);
1622 
1623 /* Get reference to gain full access to conn.
1624  * By default, RCU read-side critical sections have access only to
1625  * conn fields and its PE data, see ip_vs_conn_rcu_free() for reference.
1626  */
1627 static inline bool __ip_vs_conn_get(struct ip_vs_conn *cp)
1628 {
1629 	return refcount_inc_not_zero(&cp->refcnt);
1630 }
1631 
1632 /* put back the conn without restarting its timer */
1633 static inline void __ip_vs_conn_put(struct ip_vs_conn *cp)
1634 {
1635 	smp_mb__before_atomic();
1636 	refcount_dec(&cp->refcnt);
1637 }
1638 void ip_vs_conn_put(struct ip_vs_conn *cp);
1639 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport);
1640 int ip_vs_conn_desired_size(struct netns_ipvs *ipvs, struct ip_vs_rht *t,
1641 			    int lfactor);
1642 struct ip_vs_rht *ip_vs_conn_tab_alloc(struct netns_ipvs *ipvs, int buckets,
1643 				       int lfactor);
1644 
1645 static inline struct ip_vs_conn *
1646 ip_vs_hn0_to_conn(struct ip_vs_conn_hnode *hn)
1647 {
1648 	return container_of(hn, struct ip_vs_conn, hn0);
1649 }
1650 
1651 static inline struct ip_vs_conn *
1652 ip_vs_hn_to_conn(struct ip_vs_conn_hnode *hn)
1653 {
1654 	return hn->dir ? container_of(hn, struct ip_vs_conn, hn1) :
1655 			 container_of(hn, struct ip_vs_conn, hn0);
1656 }
1657 
1658 struct ip_vs_conn *ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
1659 				  const union nf_inet_addr *daddr,
1660 				  __be16 dport, unsigned int flags,
1661 				  struct ip_vs_dest *dest, __u32 fwmark);
1662 void ip_vs_conn_expire_now(struct ip_vs_conn *cp);
1663 
1664 const char *ip_vs_state_name(const struct ip_vs_conn *cp);
1665 
1666 void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp);
1667 int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest);
1668 void ip_vs_random_dropentry(struct netns_ipvs *ipvs);
1669 int ip_vs_conn_init(void);
1670 void ip_vs_conn_cleanup(void);
1671 
1672 static inline void ip_vs_control_del(struct ip_vs_conn *cp)
1673 {
1674 	struct ip_vs_conn *ctl_cp = cp->control;
1675 	if (!ctl_cp) {
1676 		IP_VS_ERR_BUF("request control DEL for uncontrolled: "
1677 			      "%s:%d to %s:%d\n",
1678 			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
1679 			      ntohs(cp->cport),
1680 			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
1681 			      ntohs(cp->vport));
1682 
1683 		return;
1684 	}
1685 
1686 	IP_VS_DBG_BUF(7, "DELeting control for: "
1687 		      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
1688 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
1689 		      ntohs(cp->cport),
1690 		      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
1691 		      ntohs(ctl_cp->cport));
1692 
1693 	cp->control = NULL;
1694 	if (atomic_read(&ctl_cp->n_control) == 0) {
1695 		IP_VS_ERR_BUF("BUG control DEL with n=0 : "
1696 			      "%s:%d to %s:%d\n",
1697 			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
1698 			      ntohs(cp->cport),
1699 			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
1700 			      ntohs(cp->vport));
1701 
1702 		return;
1703 	}
1704 	atomic_dec(&ctl_cp->n_control);
1705 }
1706 
1707 static inline void
1708 ip_vs_control_add(struct ip_vs_conn *cp, struct ip_vs_conn *ctl_cp)
1709 {
1710 	if (cp->control) {
1711 		IP_VS_ERR_BUF("request control ADD for already controlled: "
1712 			      "%s:%d to %s:%d\n",
1713 			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
1714 			      ntohs(cp->cport),
1715 			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
1716 			      ntohs(cp->vport));
1717 
1718 		ip_vs_control_del(cp);
1719 	}
1720 
1721 	IP_VS_DBG_BUF(7, "ADDing control for: "
1722 		      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
1723 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
1724 		      ntohs(cp->cport),
1725 		      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
1726 		      ntohs(ctl_cp->cport));
1727 
1728 	cp->control = ctl_cp;
1729 	atomic_inc(&ctl_cp->n_control);
1730 }
1731 
1732 /* Mark our template as assured */
1733 static inline void
1734 ip_vs_control_assure_ct(struct ip_vs_conn *cp)
1735 {
1736 	struct ip_vs_conn *ct = cp->control;
1737 
1738 	if (ct && !(ct->state & IP_VS_CTPL_S_ASSURED) &&
1739 	    (ct->flags & IP_VS_CONN_F_TEMPLATE))
1740 		ct->state |= IP_VS_CTPL_S_ASSURED;
1741 }
1742 
1743 /* IPVS netns init & cleanup functions */
1744 int ip_vs_estimator_net_init(struct netns_ipvs *ipvs);
1745 int ip_vs_control_net_init(struct netns_ipvs *ipvs);
1746 int ip_vs_protocol_net_init(struct netns_ipvs *ipvs);
1747 int ip_vs_app_net_init(struct netns_ipvs *ipvs);
1748 int ip_vs_conn_net_init(struct netns_ipvs *ipvs);
1749 int ip_vs_sync_net_init(struct netns_ipvs *ipvs);
1750 void ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs);
1751 void ip_vs_app_net_cleanup(struct netns_ipvs *ipvs);
1752 void ip_vs_protocol_net_cleanup(struct netns_ipvs *ipvs);
1753 void ip_vs_control_net_cleanup(struct netns_ipvs *ipvs);
1754 void ip_vs_estimator_net_cleanup(struct netns_ipvs *ipvs);
1755 void ip_vs_sync_net_cleanup(struct netns_ipvs *ipvs);
1756 void ip_vs_service_nets_cleanup(struct list_head *net_list);
1757 
1758 /* IPVS application functions
1759  * (from ip_vs_app.c)
1760  */
1761 #define IP_VS_APP_MAX_PORTS  8
1762 struct ip_vs_app *register_ip_vs_app(struct netns_ipvs *ipvs, struct ip_vs_app *app);
1763 void unregister_ip_vs_app(struct netns_ipvs *ipvs, struct ip_vs_app *app);
1764 int ip_vs_bind_app(struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
1765 void ip_vs_unbind_app(struct ip_vs_conn *cp);
1766 int register_ip_vs_app_inc(struct netns_ipvs *ipvs, struct ip_vs_app *app, __u16 proto,
1767 			   __u16 port);
1768 int ip_vs_app_inc_get(struct ip_vs_app *inc);
1769 void ip_vs_app_inc_put(struct ip_vs_app *inc);
1770 
1771 int ip_vs_app_pkt_out(struct ip_vs_conn *, struct sk_buff *skb,
1772 		      struct ip_vs_iphdr *ipvsh);
1773 int ip_vs_app_pkt_in(struct ip_vs_conn *, struct sk_buff *skb,
1774 		     struct ip_vs_iphdr *ipvsh);
1775 
1776 int register_ip_vs_pe(struct ip_vs_pe *pe);
1777 int unregister_ip_vs_pe(struct ip_vs_pe *pe);
1778 struct ip_vs_pe *ip_vs_pe_getbyname(const char *name);
1779 struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name);
1780 
1781 /* Use a #define to avoid all of module.h just for these trivial ops */
1782 #define ip_vs_pe_get(pe)			\
1783 	if (pe && pe->module)			\
1784 		__module_get(pe->module);
1785 
1786 #define ip_vs_pe_put(pe)			\
1787 	if (pe && pe->module)			\
1788 		module_put(pe->module);
1789 
1790 /* IPVS protocol functions (from ip_vs_proto.c) */
1791 int ip_vs_protocol_init(void);
1792 void ip_vs_protocol_cleanup(void);
1793 void ip_vs_protocol_timeout_change(struct netns_ipvs *ipvs, int flags);
1794 int *ip_vs_create_timeout_table(int *table, int size);
1795 void ip_vs_tcpudp_debug_packet(int af, struct ip_vs_protocol *pp,
1796 			       const struct sk_buff *skb, int offset,
1797 			       const char *msg);
1798 
1799 extern struct ip_vs_protocol ip_vs_protocol_tcp;
1800 extern struct ip_vs_protocol ip_vs_protocol_udp;
1801 extern struct ip_vs_protocol ip_vs_protocol_icmp;
1802 extern struct ip_vs_protocol ip_vs_protocol_esp;
1803 extern struct ip_vs_protocol ip_vs_protocol_ah;
1804 extern struct ip_vs_protocol ip_vs_protocol_sctp;
1805 
1806 /* Registering/unregistering scheduler functions
1807  * (from ip_vs_sched.c)
1808  */
1809 int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
1810 int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
1811 int ip_vs_bind_scheduler(struct ip_vs_service *svc,
1812 			 struct ip_vs_scheduler *scheduler);
1813 void ip_vs_unbind_scheduler(struct ip_vs_service *svc,
1814 			    struct ip_vs_scheduler *sched);
1815 struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name);
1816 void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler);
1817 struct ip_vs_conn *
1818 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
1819 	       struct ip_vs_proto_data *pd, int *ignored,
1820 	       struct ip_vs_iphdr *iph);
1821 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
1822 		struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph);
1823 
1824 void ip_vs_scheduler_err(struct ip_vs_service *svc, const char *msg);
1825 
1826 /* IPVS control data and functions (from ip_vs_ctl.c) */
1827 extern struct ip_vs_stats ip_vs_stats;
1828 extern int sysctl_ip_vs_sync_ver;
1829 
1830 struct ip_vs_service *
1831 ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u32 fwmark, __u16 protocol,
1832 		  const union nf_inet_addr *vaddr, __be16 vport);
1833 
1834 bool ip_vs_has_real_service(struct netns_ipvs *ipvs, int af, __u16 protocol,
1835 			    const union nf_inet_addr *daddr, __be16 dport);
1836 
1837 struct ip_vs_dest *
1838 ip_vs_find_real_service(struct netns_ipvs *ipvs, int af, __u16 protocol,
1839 			const union nf_inet_addr *daddr, __be16 dport);
1840 struct ip_vs_dest *ip_vs_find_tunnel(struct netns_ipvs *ipvs, int af,
1841 				     const union nf_inet_addr *daddr,
1842 				     __be16 tun_port);
1843 
1844 int ip_vs_use_count_inc(void);
1845 void ip_vs_use_count_dec(void);
1846 int ip_vs_register_nl_ioctl(void);
1847 void ip_vs_unregister_nl_ioctl(void);
1848 int ip_vs_control_init(void);
1849 void ip_vs_control_cleanup(void);
1850 struct ip_vs_dest *
1851 ip_vs_find_dest(struct netns_ipvs *ipvs, int svc_af, int dest_af,
1852 		const union nf_inet_addr *daddr, __be16 dport,
1853 		const union nf_inet_addr *vaddr, __be16 vport,
1854 		__u16 protocol, __u32 fwmark, __u32 flags);
1855 void ip_vs_try_bind_dest(struct ip_vs_conn *cp);
1856 
1857 static inline void ip_vs_dest_hold(struct ip_vs_dest *dest)
1858 {
1859 	refcount_inc(&dest->refcnt);
1860 }
1861 
1862 static inline void ip_vs_dest_put(struct ip_vs_dest *dest)
1863 {
1864 	smp_mb__before_atomic();
1865 	refcount_dec(&dest->refcnt);
1866 }
1867 
1868 static inline void ip_vs_dest_put_and_free(struct ip_vs_dest *dest)
1869 {
1870 	if (refcount_dec_and_test(&dest->refcnt))
1871 		kfree(dest);
1872 }
1873 
1874 /* IPVS sync daemon data and function prototypes
1875  * (from ip_vs_sync.c)
1876  */
1877 int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *cfg,
1878 		      int state);
1879 int stop_sync_thread(struct netns_ipvs *ipvs, int state);
1880 void ip_vs_sync_conn(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts);
1881 
1882 /* IPVS rate estimator prototypes (from ip_vs_est.c) */
1883 int ip_vs_start_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats);
1884 void ip_vs_stop_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats);
1885 void ip_vs_zero_estimator(struct ip_vs_stats *stats);
1886 void ip_vs_read_estimator(struct ip_vs_kstats *dst, struct ip_vs_stats *stats);
1887 void ip_vs_est_reload_start(struct netns_ipvs *ipvs);
1888 int ip_vs_est_kthread_start(struct netns_ipvs *ipvs,
1889 			    struct ip_vs_est_kt_data *kd);
1890 void ip_vs_est_kthread_stop(struct ip_vs_est_kt_data *kd);
1891 
1892 static inline void ip_vs_est_stopped_recalc(struct netns_ipvs *ipvs)
1893 {
1894 #ifdef CONFIG_SYSCTL
1895 	/* Stop tasks while cpulist is empty or if disabled with flag */
1896 	ipvs->est_stopped = !sysctl_run_estimation(ipvs) ||
1897 			    (ipvs->est_cpulist_valid &&
1898 			     cpumask_empty(sysctl_est_cpulist(ipvs)));
1899 #endif
1900 }
1901 
1902 static inline bool ip_vs_est_stopped(struct netns_ipvs *ipvs)
1903 {
1904 #ifdef CONFIG_SYSCTL
1905 	return ipvs->est_stopped;
1906 #else
1907 	return false;
1908 #endif
1909 }
1910 
1911 static inline int ip_vs_est_max_threads(struct netns_ipvs *ipvs)
1912 {
1913 	unsigned int limit = IPVS_EST_CPU_KTHREADS *
1914 			     cpumask_weight(sysctl_est_cpulist(ipvs));
1915 
1916 	return max(1U, limit);
1917 }
1918 
1919 /* Various IPVS packet transmitters (from ip_vs_xmit.c) */
1920 int ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1921 		    struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1922 int ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1923 		      struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1924 int ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1925 		   struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1926 int ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1927 		      struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1928 int ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1929 		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1930 int ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
1931 		    struct ip_vs_protocol *pp, int offset,
1932 		    unsigned int hooknum, struct ip_vs_iphdr *iph);
1933 void ip_vs_dest_dst_rcu_free(struct rcu_head *head);
1934 
1935 #ifdef CONFIG_IP_VS_IPV6
1936 int ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1937 			 struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1938 int ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1939 		      struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1940 int ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1941 			 struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1942 int ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1943 		     struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
1944 int ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
1945 		       struct ip_vs_protocol *pp, int offset,
1946 		       unsigned int hooknum, struct ip_vs_iphdr *iph);
1947 #endif
1948 
1949 #ifdef CONFIG_SYSCTL
1950 /* This is a simple mechanism to ignore packets when
1951  * we are loaded. Just set ip_vs_drop_rate to 'n' and
1952  * we start to drop 1/rate of the packets
1953  */
1954 static inline int ip_vs_todrop(struct netns_ipvs *ipvs)
1955 {
1956 	if (!ipvs->drop_rate)
1957 		return 0;
1958 	if (--ipvs->drop_counter > 0)
1959 		return 0;
1960 	ipvs->drop_counter = ipvs->drop_rate;
1961 	return 1;
1962 }
1963 #else
1964 static inline int ip_vs_todrop(struct netns_ipvs *ipvs) { return 0; }
1965 #endif
1966 
1967 #ifdef CONFIG_SYSCTL
1968 /* Enqueue delayed work for expiring no dest connections
1969  * Only run when sysctl_expire_nodest=1
1970  */
1971 static inline void ip_vs_enqueue_expire_nodest_conns(struct netns_ipvs *ipvs)
1972 {
1973 	if (sysctl_expire_nodest_conn(ipvs))
1974 		queue_delayed_work(system_long_wq,
1975 				   &ipvs->expire_nodest_conn_work, 1);
1976 }
1977 
1978 void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs);
1979 #else
1980 static inline void ip_vs_enqueue_expire_nodest_conns(struct netns_ipvs *ipvs) {}
1981 #endif
1982 
1983 #define IP_VS_DFWD_METHOD(dest) (atomic_read(&(dest)->conn_flags) & \
1984 				 IP_VS_CONN_F_FWD_MASK)
1985 
1986 /* ip_vs_fwd_tag returns the forwarding tag of the connection */
1987 #define IP_VS_FWD_METHOD(cp)  (cp->flags & IP_VS_CONN_F_FWD_MASK)
1988 
1989 static inline char ip_vs_fwd_tag(struct ip_vs_conn *cp)
1990 {
1991 	char fwd;
1992 
1993 	switch (IP_VS_FWD_METHOD(cp)) {
1994 	case IP_VS_CONN_F_MASQ:
1995 		fwd = 'M'; break;
1996 	case IP_VS_CONN_F_LOCALNODE:
1997 		fwd = 'L'; break;
1998 	case IP_VS_CONN_F_TUNNEL:
1999 		fwd = 'T'; break;
2000 	case IP_VS_CONN_F_DROUTE:
2001 		fwd = 'R'; break;
2002 	case IP_VS_CONN_F_BYPASS:
2003 		fwd = 'B'; break;
2004 	default:
2005 		fwd = '?'; break;
2006 	}
2007 	return fwd;
2008 }
2009 
2010 /* Check if connection uses double hashing */
2011 static inline bool ip_vs_conn_use_hash2(struct ip_vs_conn *cp)
2012 {
2013 	return IP_VS_FWD_METHOD(cp) == IP_VS_CONN_F_MASQ &&
2014 	       !(cp->flags & IP_VS_CONN_F_TEMPLATE);
2015 }
2016 
2017 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
2018 		    struct ip_vs_conn *cp, int dir);
2019 
2020 #ifdef CONFIG_IP_VS_IPV6
2021 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
2022 		       struct ip_vs_conn *cp, int dir);
2023 #endif
2024 
2025 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset);
2026 
2027 static inline __wsum ip_vs_check_diff4(__be32 old, __be32 new, __wsum oldsum)
2028 {
2029 	__be32 diff[2] = { ~old, new };
2030 
2031 	return csum_partial(diff, sizeof(diff), oldsum);
2032 }
2033 
2034 #ifdef CONFIG_IP_VS_IPV6
2035 static inline __wsum ip_vs_check_diff16(const __be32 *old, const __be32 *new,
2036 					__wsum oldsum)
2037 {
2038 	__be32 diff[8] = { ~old[3], ~old[2], ~old[1], ~old[0],
2039 			    new[3],  new[2],  new[1],  new[0] };
2040 
2041 	return csum_partial(diff, sizeof(diff), oldsum);
2042 }
2043 #endif
2044 
2045 static inline __wsum ip_vs_check_diff2(__be16 old, __be16 new, __wsum oldsum)
2046 {
2047 	__be16 diff[2] = { ~old, new };
2048 
2049 	return csum_partial(diff, sizeof(diff), oldsum);
2050 }
2051 
2052 /* Forget current conntrack (unconfirmed) and attach notrack entry */
2053 static inline void ip_vs_notrack(struct sk_buff *skb)
2054 {
2055 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2056 	enum ip_conntrack_info ctinfo;
2057 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
2058 
2059 	if (ct) {
2060 		nf_conntrack_put(&ct->ct_general);
2061 		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
2062 	}
2063 #endif
2064 }
2065 
2066 #ifdef CONFIG_IP_VS_NFCT
2067 /* Netfilter connection tracking
2068  * (from ip_vs_nfct.c)
2069  */
2070 static inline int ip_vs_conntrack_enabled(struct netns_ipvs *ipvs)
2071 {
2072 #ifdef CONFIG_SYSCTL
2073 	return ipvs->sysctl_conntrack;
2074 #else
2075 	return 0;
2076 #endif
2077 }
2078 
2079 void ip_vs_update_conntrack(struct sk_buff *skb, struct ip_vs_conn *cp,
2080 			    int outin);
2081 int ip_vs_confirm_conntrack(struct sk_buff *skb);
2082 void ip_vs_nfct_expect_related(struct sk_buff *skb, struct nf_conn *ct,
2083 			       struct ip_vs_conn *cp, u_int8_t proto,
2084 			       const __be16 port, int from_rs);
2085 void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp);
2086 
2087 #else
2088 
2089 static inline int ip_vs_conntrack_enabled(struct netns_ipvs *ipvs)
2090 {
2091 	return 0;
2092 }
2093 
2094 static inline void ip_vs_update_conntrack(struct sk_buff *skb,
2095 					  struct ip_vs_conn *cp, int outin)
2096 {
2097 }
2098 
2099 static inline int ip_vs_confirm_conntrack(struct sk_buff *skb)
2100 {
2101 	return NF_ACCEPT;
2102 }
2103 
2104 static inline void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp)
2105 {
2106 }
2107 #endif /* CONFIG_IP_VS_NFCT */
2108 
2109 /* Using old conntrack that can not be redirected to another real server? */
2110 static inline bool ip_vs_conn_uses_old_conntrack(struct ip_vs_conn *cp,
2111 						 struct sk_buff *skb)
2112 {
2113 #ifdef CONFIG_IP_VS_NFCT
2114 	enum ip_conntrack_info ctinfo;
2115 	struct nf_conn *ct;
2116 
2117 	ct = nf_ct_get(skb, &ctinfo);
2118 	if (ct && nf_ct_is_confirmed(ct))
2119 		return true;
2120 #endif
2121 	return false;
2122 }
2123 
2124 static inline int ip_vs_register_conntrack(struct ip_vs_service *svc)
2125 {
2126 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
2127 	int afmask = (svc->af == AF_INET6) ? 2 : 1;
2128 	int ret = 0;
2129 
2130 	if (!(svc->conntrack_afmask & afmask)) {
2131 		ret = nf_ct_netns_get(svc->ipvs->net, svc->af);
2132 		if (ret >= 0)
2133 			svc->conntrack_afmask |= afmask;
2134 	}
2135 	return ret;
2136 #else
2137 	return 0;
2138 #endif
2139 }
2140 
2141 static inline void ip_vs_unregister_conntrack(struct ip_vs_service *svc)
2142 {
2143 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
2144 	int afmask = (svc->af == AF_INET6) ? 2 : 1;
2145 
2146 	if (svc->conntrack_afmask & afmask) {
2147 		nf_ct_netns_put(svc->ipvs->net, svc->af);
2148 		svc->conntrack_afmask &= ~afmask;
2149 	}
2150 #endif
2151 }
2152 
2153 int ip_vs_register_hooks(struct netns_ipvs *ipvs, unsigned int af);
2154 void ip_vs_unregister_hooks(struct netns_ipvs *ipvs, unsigned int af);
2155 
2156 static inline int
2157 ip_vs_dest_conn_overhead(struct ip_vs_dest *dest)
2158 {
2159 	/* We think the overhead of processing active connections is 256
2160 	 * times higher than that of inactive connections in average. (This
2161 	 * 256 times might not be accurate, we will change it later) We
2162 	 * use the following formula to estimate the overhead now:
2163 	 *		  dest->activeconns*256 + dest->inactconns
2164 	 */
2165 	return (atomic_read(&dest->activeconns) << 8) +
2166 		atomic_read(&dest->inactconns);
2167 }
2168 
2169 #ifdef CONFIG_IP_VS_PROTO_TCP
2170 INDIRECT_CALLABLE_DECLARE(int
2171 	tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
2172 			 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph));
2173 #endif
2174 
2175 #ifdef CONFIG_IP_VS_PROTO_UDP
2176 INDIRECT_CALLABLE_DECLARE(int
2177 	udp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
2178 			 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph));
2179 #endif
2180 #endif	/* _NET_IP_VS_H */
2181