2 * ip_vs_proto_udp.c: UDP load balancing support for IPVS
4 * Version: $Id: ip_vs_proto_udp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
6 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
7 * Julian Anastasov <ja@ssi.bg>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
20 #include <linux/kernel.h>
21 #include <linux/netfilter_ipv4.h>
22 #include <linux/udp.h>
24 #include <net/ip_vs.h>
27 static struct ip_vs_conn
*
28 udp_conn_in_get(const struct sk_buff
*skb
, struct ip_vs_protocol
*pp
,
29 const struct iphdr
*iph
, unsigned int proto_off
, int inverse
)
31 struct ip_vs_conn
*cp
;
32 __be16 _ports
[2], *pptr
;
34 pptr
= skb_header_pointer(skb
, proto_off
, sizeof(_ports
), _ports
);
38 if (likely(!inverse
)) {
39 cp
= ip_vs_conn_in_get(iph
->protocol
,
43 cp
= ip_vs_conn_in_get(iph
->protocol
,
52 static struct ip_vs_conn
*
53 udp_conn_out_get(const struct sk_buff
*skb
, struct ip_vs_protocol
*pp
,
54 const struct iphdr
*iph
, unsigned int proto_off
, int inverse
)
56 struct ip_vs_conn
*cp
;
57 __be16 _ports
[2], *pptr
;
59 pptr
= skb_header_pointer(skb
, skb
->nh
.iph
->ihl
*4,
60 sizeof(_ports
), _ports
);
64 if (likely(!inverse
)) {
65 cp
= ip_vs_conn_out_get(iph
->protocol
,
69 cp
= ip_vs_conn_out_get(iph
->protocol
,
79 udp_conn_schedule(struct sk_buff
*skb
, struct ip_vs_protocol
*pp
,
80 int *verdict
, struct ip_vs_conn
**cpp
)
82 struct ip_vs_service
*svc
;
83 struct udphdr _udph
, *uh
;
85 uh
= skb_header_pointer(skb
, skb
->nh
.iph
->ihl
*4,
86 sizeof(_udph
), &_udph
);
92 if ((svc
= ip_vs_service_get(skb
->mark
, skb
->nh
.iph
->protocol
,
93 skb
->nh
.iph
->daddr
, uh
->dest
))) {
96 * It seems that we are very loaded.
97 * We have to drop this packet :(
99 ip_vs_service_put(svc
);
105 * Let the virtual server select a real server for the
106 * incoming connection, and create a connection entry.
108 *cpp
= ip_vs_schedule(svc
, skb
);
110 *verdict
= ip_vs_leave(svc
, skb
, pp
);
113 ip_vs_service_put(svc
);
120 udp_fast_csum_update(struct udphdr
*uhdr
, __be32 oldip
, __be32 newip
,
121 __be16 oldport
, __be16 newport
)
124 ip_vs_check_diff(~oldip
, newip
,
125 ip_vs_check_diff(oldport
^ htons(0xFFFF),
126 newport
, uhdr
->check
));
128 uhdr
->check
= CSUM_MANGLED_0
;
132 udp_snat_handler(struct sk_buff
**pskb
,
133 struct ip_vs_protocol
*pp
, struct ip_vs_conn
*cp
)
136 unsigned int udphoff
= (*pskb
)->nh
.iph
->ihl
* 4;
138 /* csum_check requires unshared skb */
139 if (!ip_vs_make_skb_writable(pskb
, udphoff
+sizeof(*udph
)))
142 if (unlikely(cp
->app
!= NULL
)) {
143 /* Some checks before mangling */
144 if (pp
->csum_check
&& !pp
->csum_check(*pskb
, pp
))
148 * Call application helper if needed
150 if (!ip_vs_app_pkt_out(cp
, pskb
))
154 udph
= (void *)(*pskb
)->nh
.iph
+ udphoff
;
155 udph
->source
= cp
->vport
;
158 * Adjust UDP checksums
160 if (!cp
->app
&& (udph
->check
!= 0)) {
161 /* Only port and addr are changed, do fast csum update */
162 udp_fast_csum_update(udph
, cp
->daddr
, cp
->vaddr
,
163 cp
->dport
, cp
->vport
);
164 if ((*pskb
)->ip_summed
== CHECKSUM_COMPLETE
)
165 (*pskb
)->ip_summed
= CHECKSUM_NONE
;
167 /* full checksum calculation */
169 (*pskb
)->csum
= skb_checksum(*pskb
, udphoff
,
170 (*pskb
)->len
- udphoff
, 0);
171 udph
->check
= csum_tcpudp_magic(cp
->vaddr
, cp
->caddr
,
172 (*pskb
)->len
- udphoff
,
175 if (udph
->check
== 0)
176 udph
->check
= CSUM_MANGLED_0
;
177 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
178 pp
->name
, udph
->check
,
179 (char*)&(udph
->check
) - (char*)udph
);
186 udp_dnat_handler(struct sk_buff
**pskb
,
187 struct ip_vs_protocol
*pp
, struct ip_vs_conn
*cp
)
190 unsigned int udphoff
= (*pskb
)->nh
.iph
->ihl
* 4;
192 /* csum_check requires unshared skb */
193 if (!ip_vs_make_skb_writable(pskb
, udphoff
+sizeof(*udph
)))
196 if (unlikely(cp
->app
!= NULL
)) {
197 /* Some checks before mangling */
198 if (pp
->csum_check
&& !pp
->csum_check(*pskb
, pp
))
202 * Attempt ip_vs_app call.
203 * It will fix ip_vs_conn
205 if (!ip_vs_app_pkt_in(cp
, pskb
))
209 udph
= (void *)(*pskb
)->nh
.iph
+ udphoff
;
210 udph
->dest
= cp
->dport
;
213 * Adjust UDP checksums
215 if (!cp
->app
&& (udph
->check
!= 0)) {
216 /* Only port and addr are changed, do fast csum update */
217 udp_fast_csum_update(udph
, cp
->vaddr
, cp
->daddr
,
218 cp
->vport
, cp
->dport
);
219 if ((*pskb
)->ip_summed
== CHECKSUM_COMPLETE
)
220 (*pskb
)->ip_summed
= CHECKSUM_NONE
;
222 /* full checksum calculation */
224 (*pskb
)->csum
= skb_checksum(*pskb
, udphoff
,
225 (*pskb
)->len
- udphoff
, 0);
226 udph
->check
= csum_tcpudp_magic(cp
->caddr
, cp
->daddr
,
227 (*pskb
)->len
- udphoff
,
230 if (udph
->check
== 0)
231 udph
->check
= CSUM_MANGLED_0
;
232 (*pskb
)->ip_summed
= CHECKSUM_UNNECESSARY
;
239 udp_csum_check(struct sk_buff
*skb
, struct ip_vs_protocol
*pp
)
241 struct udphdr _udph
, *uh
;
242 unsigned int udphoff
= skb
->nh
.iph
->ihl
*4;
244 uh
= skb_header_pointer(skb
, udphoff
, sizeof(_udph
), &_udph
);
248 if (uh
->check
!= 0) {
249 switch (skb
->ip_summed
) {
251 skb
->csum
= skb_checksum(skb
, udphoff
,
252 skb
->len
- udphoff
, 0);
253 case CHECKSUM_COMPLETE
:
254 if (csum_tcpudp_magic(skb
->nh
.iph
->saddr
,
257 skb
->nh
.iph
->protocol
,
259 IP_VS_DBG_RL_PKT(0, pp
, skb
, 0,
260 "Failed checksum for");
265 /* No need to checksum. */
274 * Note: the caller guarantees that only one of register_app,
275 * unregister_app or app_conn_bind is called each time.
278 #define UDP_APP_TAB_BITS 4
279 #define UDP_APP_TAB_SIZE (1 << UDP_APP_TAB_BITS)
280 #define UDP_APP_TAB_MASK (UDP_APP_TAB_SIZE - 1)
282 static struct list_head udp_apps
[UDP_APP_TAB_SIZE
];
283 static DEFINE_SPINLOCK(udp_app_lock
);
285 static inline __u16
udp_app_hashkey(__be16 port
)
287 return (((__force u16
)port
>> UDP_APP_TAB_BITS
) ^ (__force u16
)port
)
292 static int udp_register_app(struct ip_vs_app
*inc
)
296 __be16 port
= inc
->port
;
299 hash
= udp_app_hashkey(port
);
302 spin_lock_bh(&udp_app_lock
);
303 list_for_each_entry(i
, &udp_apps
[hash
], p_list
) {
304 if (i
->port
== port
) {
309 list_add(&inc
->p_list
, &udp_apps
[hash
]);
310 atomic_inc(&ip_vs_protocol_udp
.appcnt
);
313 spin_unlock_bh(&udp_app_lock
);
319 udp_unregister_app(struct ip_vs_app
*inc
)
321 spin_lock_bh(&udp_app_lock
);
322 atomic_dec(&ip_vs_protocol_udp
.appcnt
);
323 list_del(&inc
->p_list
);
324 spin_unlock_bh(&udp_app_lock
);
328 static int udp_app_conn_bind(struct ip_vs_conn
*cp
)
331 struct ip_vs_app
*inc
;
334 /* Default binding: bind app only for NAT */
335 if (IP_VS_FWD_METHOD(cp
) != IP_VS_CONN_F_MASQ
)
338 /* Lookup application incarnations and bind the right one */
339 hash
= udp_app_hashkey(cp
->vport
);
341 spin_lock(&udp_app_lock
);
342 list_for_each_entry(inc
, &udp_apps
[hash
], p_list
) {
343 if (inc
->port
== cp
->vport
) {
344 if (unlikely(!ip_vs_app_inc_get(inc
)))
346 spin_unlock(&udp_app_lock
);
348 IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
349 "%u.%u.%u.%u:%u to app %s on port %u\n",
351 NIPQUAD(cp
->caddr
), ntohs(cp
->cport
),
352 NIPQUAD(cp
->vaddr
), ntohs(cp
->vport
),
353 inc
->name
, ntohs(inc
->port
));
356 result
= inc
->init_conn(inc
, cp
);
360 spin_unlock(&udp_app_lock
);
367 static int udp_timeouts
[IP_VS_UDP_S_LAST
+1] = {
368 [IP_VS_UDP_S_NORMAL
] = 5*60*HZ
,
369 [IP_VS_UDP_S_LAST
] = 2*HZ
,
372 static char * udp_state_name_table
[IP_VS_UDP_S_LAST
+1] = {
373 [IP_VS_UDP_S_NORMAL
] = "UDP",
374 [IP_VS_UDP_S_LAST
] = "BUG!",
379 udp_set_state_timeout(struct ip_vs_protocol
*pp
, char *sname
, int to
)
381 return ip_vs_set_state_timeout(pp
->timeout_table
, IP_VS_UDP_S_LAST
,
382 udp_state_name_table
, sname
, to
);
385 static const char * udp_state_name(int state
)
387 if (state
>= IP_VS_UDP_S_LAST
)
389 return udp_state_name_table
[state
] ? udp_state_name_table
[state
] : "?";
393 udp_state_transition(struct ip_vs_conn
*cp
, int direction
,
394 const struct sk_buff
*skb
,
395 struct ip_vs_protocol
*pp
)
397 cp
->timeout
= pp
->timeout_table
[IP_VS_UDP_S_NORMAL
];
401 static void udp_init(struct ip_vs_protocol
*pp
)
403 IP_VS_INIT_HASH_TABLE(udp_apps
);
404 pp
->timeout_table
= udp_timeouts
;
407 static void udp_exit(struct ip_vs_protocol
*pp
)
412 struct ip_vs_protocol ip_vs_protocol_udp
= {
414 .protocol
= IPPROTO_UDP
,
418 .conn_schedule
= udp_conn_schedule
,
419 .conn_in_get
= udp_conn_in_get
,
420 .conn_out_get
= udp_conn_out_get
,
421 .snat_handler
= udp_snat_handler
,
422 .dnat_handler
= udp_dnat_handler
,
423 .csum_check
= udp_csum_check
,
424 .state_transition
= udp_state_transition
,
425 .state_name
= udp_state_name
,
426 .register_app
= udp_register_app
,
427 .unregister_app
= udp_unregister_app
,
428 .app_conn_bind
= udp_app_conn_bind
,
429 .debug_packet
= ip_vs_tcpudp_debug_packet
,
430 .timeout_change
= NULL
,
431 .set_state_timeout
= udp_set_state_timeout
,