2 * ip_vs_proto_udp.c: UDP load balancing support for IPVS
4 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
5 * Julian Anastasov <ja@ssi.bg>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
12 * Changes: Hans Schillstrom <hans.schillstrom@ericsson.com>
13 * Network name space (netns) aware.
17 #define KMSG_COMPONENT "IPVS"
18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
22 #include <linux/kernel.h>
23 #include <linux/netfilter.h>
24 #include <linux/netfilter_ipv4.h>
25 #include <linux/udp.h>
27 #include <net/ip_vs.h>
29 #include <net/ip6_checksum.h>
32 udp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
33 struct ip_vs_proto_data *pd,
34 int *verdict, struct ip_vs_conn **cpp,
35 struct ip_vs_iphdr *iph)
37 struct ip_vs_service *svc;
38 struct udphdr _udph, *uh;
39 __be16 _ports[2], *ports = NULL;
41 if (likely(!ip_vs_iph_icmp(iph))) {
42 /* IPv6 fragments, only first fragment will hit this */
43 uh = skb_header_pointer(skb, iph->len, sizeof(_udph), &_udph);
47 ports = skb_header_pointer(
48 skb, iph->len, sizeof(_ports), &_ports);
57 if (likely(!ip_vs_iph_inverse(iph)))
58 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol,
59 &iph->daddr, ports[1]);
61 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol,
62 &iph->saddr, ports[0]);
67 if (ip_vs_todrop(ipvs)) {
69 * It seems that we are very loaded.
70 * We have to drop this packet :(
78 * Let the virtual server select a real server for the
79 * incoming connection, and create a connection entry.
81 *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph);
82 if (!*cpp && ignored <= 0) {
84 *verdict = ip_vs_leave(svc, skb, pd, iph);
98 udp_fast_csum_update(int af, struct udphdr *uhdr,
99 const union nf_inet_addr *oldip,
100 const union nf_inet_addr *newip,
101 __be16 oldport, __be16 newport)
103 #ifdef CONFIG_IP_VS_IPV6
106 csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
107 ip_vs_check_diff2(oldport, newport,
108 ~csum_unfold(uhdr->check))));
112 csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
113 ip_vs_check_diff2(oldport, newport,
114 ~csum_unfold(uhdr->check))));
116 uhdr->check = CSUM_MANGLED_0;
120 udp_partial_csum_update(int af, struct udphdr *uhdr,
121 const union nf_inet_addr *oldip,
122 const union nf_inet_addr *newip,
123 __be16 oldlen, __be16 newlen)
125 #ifdef CONFIG_IP_VS_IPV6
128 ~csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
129 ip_vs_check_diff2(oldlen, newlen,
130 csum_unfold(uhdr->check))));
134 ~csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
135 ip_vs_check_diff2(oldlen, newlen,
136 csum_unfold(uhdr->check))));
141 udp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
142 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
145 unsigned int udphoff = iph->len;
147 int payload_csum = 0;
149 #ifdef CONFIG_IP_VS_IPV6
150 if (cp->af == AF_INET6 && iph->fragoffs)
153 oldlen = skb->len - udphoff;
155 /* csum_check requires unshared skb */
156 if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
159 if (unlikely(cp->app != NULL)) {
162 /* Some checks before mangling */
163 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
167 * Call application helper if needed
169 if (!(ret = ip_vs_app_pkt_out(cp, skb)))
171 /* ret=2: csum update is needed after payload mangling */
173 oldlen = skb->len - udphoff;
178 udph = (void *)skb_network_header(skb) + udphoff;
179 udph->source = cp->vport;
182 * Adjust UDP checksums
184 if (skb->ip_summed == CHECKSUM_PARTIAL) {
185 udp_partial_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
187 htons(skb->len - udphoff));
188 } else if (!payload_csum && (udph->check != 0)) {
189 /* Only port and addr are changed, do fast csum update */
190 udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
191 cp->dport, cp->vport);
192 if (skb->ip_summed == CHECKSUM_COMPLETE)
193 skb->ip_summed = (cp->app && pp->csum_check) ?
194 CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
196 /* full checksum calculation */
198 skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
199 #ifdef CONFIG_IP_VS_IPV6
200 if (cp->af == AF_INET6)
201 udph->check = csum_ipv6_magic(&cp->vaddr.in6,
204 cp->protocol, skb->csum);
207 udph->check = csum_tcpudp_magic(cp->vaddr.ip,
212 if (udph->check == 0)
213 udph->check = CSUM_MANGLED_0;
214 skb->ip_summed = CHECKSUM_UNNECESSARY;
215 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
216 pp->name, udph->check,
217 (char*)&(udph->check) - (char*)udph);
224 udp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
225 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
228 unsigned int udphoff = iph->len;
230 int payload_csum = 0;
232 #ifdef CONFIG_IP_VS_IPV6
233 if (cp->af == AF_INET6 && iph->fragoffs)
236 oldlen = skb->len - udphoff;
238 /* csum_check requires unshared skb */
239 if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
242 if (unlikely(cp->app != NULL)) {
245 /* Some checks before mangling */
246 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
250 * Attempt ip_vs_app call.
251 * It will fix ip_vs_conn
253 if (!(ret = ip_vs_app_pkt_in(cp, skb)))
255 /* ret=2: csum update is needed after payload mangling */
257 oldlen = skb->len - udphoff;
262 udph = (void *)skb_network_header(skb) + udphoff;
263 udph->dest = cp->dport;
266 * Adjust UDP checksums
268 if (skb->ip_summed == CHECKSUM_PARTIAL) {
269 udp_partial_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
271 htons(skb->len - udphoff));
272 } else if (!payload_csum && (udph->check != 0)) {
273 /* Only port and addr are changed, do fast csum update */
274 udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
275 cp->vport, cp->dport);
276 if (skb->ip_summed == CHECKSUM_COMPLETE)
277 skb->ip_summed = (cp->app && pp->csum_check) ?
278 CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
280 /* full checksum calculation */
282 skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
283 #ifdef CONFIG_IP_VS_IPV6
284 if (cp->af == AF_INET6)
285 udph->check = csum_ipv6_magic(&cp->caddr.in6,
288 cp->protocol, skb->csum);
291 udph->check = csum_tcpudp_magic(cp->caddr.ip,
296 if (udph->check == 0)
297 udph->check = CSUM_MANGLED_0;
298 skb->ip_summed = CHECKSUM_UNNECESSARY;
305 udp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
307 struct udphdr _udph, *uh;
308 unsigned int udphoff;
310 #ifdef CONFIG_IP_VS_IPV6
312 udphoff = sizeof(struct ipv6hdr);
315 udphoff = ip_hdrlen(skb);
317 uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
321 if (uh->check != 0) {
322 switch (skb->ip_summed) {
324 skb->csum = skb_checksum(skb, udphoff,
325 skb->len - udphoff, 0);
326 case CHECKSUM_COMPLETE:
327 #ifdef CONFIG_IP_VS_IPV6
328 if (af == AF_INET6) {
329 if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
330 &ipv6_hdr(skb)->daddr,
332 ipv6_hdr(skb)->nexthdr,
334 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0,
335 "Failed checksum for");
340 if (csum_tcpudp_magic(ip_hdr(skb)->saddr,
343 ip_hdr(skb)->protocol,
345 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0,
346 "Failed checksum for");
351 /* No need to checksum. */
358 static inline __u16 udp_app_hashkey(__be16 port)
360 return (((__force u16)port >> UDP_APP_TAB_BITS) ^ (__force u16)port)
365 static int udp_register_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
369 __be16 port = inc->port;
371 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_UDP);
373 hash = udp_app_hashkey(port);
375 list_for_each_entry(i, &ipvs->udp_apps[hash], p_list) {
376 if (i->port == port) {
381 list_add_rcu(&inc->p_list, &ipvs->udp_apps[hash]);
382 atomic_inc(&pd->appcnt);
390 udp_unregister_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
392 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_UDP);
394 atomic_dec(&pd->appcnt);
395 list_del_rcu(&inc->p_list);
399 static int udp_app_conn_bind(struct ip_vs_conn *cp)
401 struct netns_ipvs *ipvs = cp->ipvs;
403 struct ip_vs_app *inc;
406 /* Default binding: bind app only for NAT */
407 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
410 /* Lookup application incarnations and bind the right one */
411 hash = udp_app_hashkey(cp->vport);
414 list_for_each_entry_rcu(inc, &ipvs->udp_apps[hash], p_list) {
415 if (inc->port == cp->vport) {
416 if (unlikely(!ip_vs_app_inc_get(inc)))
420 IP_VS_DBG_BUF(9, "%s(): Binding conn %s:%u->"
421 "%s:%u to app %s on port %u\n",
423 IP_VS_DBG_ADDR(cp->af, &cp->caddr),
425 IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
427 inc->name, ntohs(inc->port));
431 result = inc->init_conn(inc, cp);
442 static const int udp_timeouts[IP_VS_UDP_S_LAST+1] = {
443 [IP_VS_UDP_S_NORMAL] = 5*60*HZ,
444 [IP_VS_UDP_S_LAST] = 2*HZ,
447 static const char *const udp_state_name_table[IP_VS_UDP_S_LAST+1] = {
448 [IP_VS_UDP_S_NORMAL] = "UDP",
449 [IP_VS_UDP_S_LAST] = "BUG!",
452 static const char * udp_state_name(int state)
454 if (state >= IP_VS_UDP_S_LAST)
456 return udp_state_name_table[state] ? udp_state_name_table[state] : "?";
460 udp_state_transition(struct ip_vs_conn *cp, int direction,
461 const struct sk_buff *skb,
462 struct ip_vs_proto_data *pd)
465 pr_err("UDP no ns data\n");
469 cp->timeout = pd->timeout_table[IP_VS_UDP_S_NORMAL];
472 static int __udp_init(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
474 ip_vs_init_hash_table(ipvs->udp_apps, UDP_APP_TAB_SIZE);
475 pd->timeout_table = ip_vs_create_timeout_table((int *)udp_timeouts,
476 sizeof(udp_timeouts));
477 if (!pd->timeout_table)
482 static void __udp_exit(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
484 kfree(pd->timeout_table);
488 struct ip_vs_protocol ip_vs_protocol_udp = {
490 .protocol = IPPROTO_UDP,
491 .num_states = IP_VS_UDP_S_LAST,
495 .init_netns = __udp_init,
496 .exit_netns = __udp_exit,
497 .conn_schedule = udp_conn_schedule,
498 .conn_in_get = ip_vs_conn_in_get_proto,
499 .conn_out_get = ip_vs_conn_out_get_proto,
500 .snat_handler = udp_snat_handler,
501 .dnat_handler = udp_dnat_handler,
502 .csum_check = udp_csum_check,
503 .state_transition = udp_state_transition,
504 .state_name = udp_state_name,
505 .register_app = udp_register_app,
506 .unregister_app = udp_unregister_app,
507 .app_conn_bind = udp_app_conn_bind,
508 .debug_packet = ip_vs_tcpudp_debug_packet,
509 .timeout_change = NULL,