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Diffstat (limited to 'net/ipv4/ipvs/ip_vs_proto_udp.c')
-rw-r--r--net/ipv4/ipvs/ip_vs_proto_udp.c427
1 files changed, 427 insertions, 0 deletions
diff --git a/net/ipv4/ipvs/ip_vs_proto_udp.c b/net/ipv4/ipvs/ip_vs_proto_udp.c
new file mode 100644
index 00000000000..8ae5f2e0aef
--- /dev/null
+++ b/net/ipv4/ipvs/ip_vs_proto_udp.c
@@ -0,0 +1,427 @@
+/*
+ * ip_vs_proto_udp.c: UDP load balancing support for IPVS
+ *
+ * Version: $Id: ip_vs_proto_udp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
+ *
+ * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
+ * Julian Anastasov <ja@ssi.bg>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Changes:
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/netfilter_ipv4.h>
+
+#include <net/ip_vs.h>
+
+
+static struct ip_vs_conn *
+udp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
+ const struct iphdr *iph, unsigned int proto_off, int inverse)
+{
+ struct ip_vs_conn *cp;
+ __u16 _ports[2], *pptr;
+
+ pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
+ if (pptr == NULL)
+ return NULL;
+
+ if (likely(!inverse)) {
+ cp = ip_vs_conn_in_get(iph->protocol,
+ iph->saddr, pptr[0],
+ iph->daddr, pptr[1]);
+ } else {
+ cp = ip_vs_conn_in_get(iph->protocol,
+ iph->daddr, pptr[1],
+ iph->saddr, pptr[0]);
+ }
+
+ return cp;
+}
+
+
+static struct ip_vs_conn *
+udp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
+ const struct iphdr *iph, unsigned int proto_off, int inverse)
+{
+ struct ip_vs_conn *cp;
+ __u16 _ports[2], *pptr;
+
+ pptr = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+ sizeof(_ports), _ports);
+ if (pptr == NULL)
+ return NULL;
+
+ if (likely(!inverse)) {
+ cp = ip_vs_conn_out_get(iph->protocol,
+ iph->saddr, pptr[0],
+ iph->daddr, pptr[1]);
+ } else {
+ cp = ip_vs_conn_out_get(iph->protocol,
+ iph->daddr, pptr[1],
+ iph->saddr, pptr[0]);
+ }
+
+ return cp;
+}
+
+
+static int
+udp_conn_schedule(struct sk_buff *skb, struct ip_vs_protocol *pp,
+ int *verdict, struct ip_vs_conn **cpp)
+{
+ struct ip_vs_service *svc;
+ struct udphdr _udph, *uh;
+
+ uh = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+ sizeof(_udph), &_udph);
+ if (uh == NULL) {
+ *verdict = NF_DROP;
+ return 0;
+ }
+
+ if ((svc = ip_vs_service_get(skb->nfmark, skb->nh.iph->protocol,
+ skb->nh.iph->daddr, uh->dest))) {
+ if (ip_vs_todrop()) {
+ /*
+ * It seems that we are very loaded.
+ * We have to drop this packet :(
+ */
+ ip_vs_service_put(svc);
+ *verdict = NF_DROP;
+ return 0;
+ }
+
+ /*
+ * Let the virtual server select a real server for the
+ * incoming connection, and create a connection entry.
+ */
+ *cpp = ip_vs_schedule(svc, skb);
+ if (!*cpp) {
+ *verdict = ip_vs_leave(svc, skb, pp);
+ return 0;
+ }
+ ip_vs_service_put(svc);
+ }
+ return 1;
+}
+
+
+static inline void
+udp_fast_csum_update(struct udphdr *uhdr, u32 oldip, u32 newip,
+ u16 oldport, u16 newport)
+{
+ uhdr->check =
+ ip_vs_check_diff(~oldip, newip,
+ ip_vs_check_diff(oldport ^ 0xFFFF,
+ newport, uhdr->check));
+ if (!uhdr->check)
+ uhdr->check = 0xFFFF;
+}
+
+static int
+udp_snat_handler(struct sk_buff **pskb,
+ struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
+{
+ struct udphdr *udph;
+ unsigned int udphoff = (*pskb)->nh.iph->ihl * 4;
+
+ /* csum_check requires unshared skb */
+ if (!ip_vs_make_skb_writable(pskb, udphoff+sizeof(*udph)))
+ return 0;
+
+ if (unlikely(cp->app != NULL)) {
+ /* Some checks before mangling */
+ if (pp->csum_check && !pp->csum_check(*pskb, pp))
+ return 0;
+
+ /*
+ * Call application helper if needed
+ */
+ if (!ip_vs_app_pkt_out(cp, pskb))
+ return 0;
+ }
+
+ udph = (void *)(*pskb)->nh.iph + udphoff;
+ udph->source = cp->vport;
+
+ /*
+ * Adjust UDP checksums
+ */
+ if (!cp->app && (udph->check != 0)) {
+ /* Only port and addr are changed, do fast csum update */
+ udp_fast_csum_update(udph, cp->daddr, cp->vaddr,
+ cp->dport, cp->vport);
+ if ((*pskb)->ip_summed == CHECKSUM_HW)
+ (*pskb)->ip_summed = CHECKSUM_NONE;
+ } else {
+ /* full checksum calculation */
+ udph->check = 0;
+ (*pskb)->csum = skb_checksum(*pskb, udphoff,
+ (*pskb)->len - udphoff, 0);
+ udph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
+ (*pskb)->len - udphoff,
+ cp->protocol,
+ (*pskb)->csum);
+ if (udph->check == 0)
+ udph->check = 0xFFFF;
+ IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
+ pp->name, udph->check,
+ (char*)&(udph->check) - (char*)udph);
+ }
+ return 1;
+}
+
+
+static int
+udp_dnat_handler(struct sk_buff **pskb,
+ struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
+{
+ struct udphdr *udph;
+ unsigned int udphoff = (*pskb)->nh.iph->ihl * 4;
+
+ /* csum_check requires unshared skb */
+ if (!ip_vs_make_skb_writable(pskb, udphoff+sizeof(*udph)))
+ return 0;
+
+ if (unlikely(cp->app != NULL)) {
+ /* Some checks before mangling */
+ if (pp->csum_check && !pp->csum_check(*pskb, pp))
+ return 0;
+
+ /*
+ * Attempt ip_vs_app call.
+ * It will fix ip_vs_conn
+ */
+ if (!ip_vs_app_pkt_in(cp, pskb))
+ return 0;
+ }
+
+ udph = (void *)(*pskb)->nh.iph + udphoff;
+ udph->dest = cp->dport;
+
+ /*
+ * Adjust UDP checksums
+ */
+ if (!cp->app && (udph->check != 0)) {
+ /* Only port and addr are changed, do fast csum update */
+ udp_fast_csum_update(udph, cp->vaddr, cp->daddr,
+ cp->vport, cp->dport);
+ if ((*pskb)->ip_summed == CHECKSUM_HW)
+ (*pskb)->ip_summed = CHECKSUM_NONE;
+ } else {
+ /* full checksum calculation */
+ udph->check = 0;
+ (*pskb)->csum = skb_checksum(*pskb, udphoff,
+ (*pskb)->len - udphoff, 0);
+ udph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
+ (*pskb)->len - udphoff,
+ cp->protocol,
+ (*pskb)->csum);
+ if (udph->check == 0)
+ udph->check = 0xFFFF;
+ (*pskb)->ip_summed = CHECKSUM_UNNECESSARY;
+ }
+ return 1;
+}
+
+
+static int
+udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
+{
+ struct udphdr _udph, *uh;
+ unsigned int udphoff = skb->nh.iph->ihl*4;
+
+ uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
+ if (uh == NULL)
+ return 0;
+
+ if (uh->check != 0) {
+ switch (skb->ip_summed) {
+ case CHECKSUM_NONE:
+ skb->csum = skb_checksum(skb, udphoff,
+ skb->len - udphoff, 0);
+ case CHECKSUM_HW:
+ if (csum_tcpudp_magic(skb->nh.iph->saddr,
+ skb->nh.iph->daddr,
+ skb->len - udphoff,
+ skb->nh.iph->protocol,
+ skb->csum)) {
+ IP_VS_DBG_RL_PKT(0, pp, skb, 0,
+ "Failed checksum for");
+ return 0;
+ }
+ break;
+ default:
+ /* CHECKSUM_UNNECESSARY */
+ break;
+ }
+ }
+ return 1;
+}
+
+
+/*
+ * Note: the caller guarantees that only one of register_app,
+ * unregister_app or app_conn_bind is called each time.
+ */
+
+#define UDP_APP_TAB_BITS 4
+#define UDP_APP_TAB_SIZE (1 << UDP_APP_TAB_BITS)
+#define UDP_APP_TAB_MASK (UDP_APP_TAB_SIZE - 1)
+
+static struct list_head udp_apps[UDP_APP_TAB_SIZE];
+static DEFINE_SPINLOCK(udp_app_lock);
+
+static inline __u16 udp_app_hashkey(__u16 port)
+{
+ return ((port >> UDP_APP_TAB_BITS) ^ port) & UDP_APP_TAB_MASK;
+}
+
+
+static int udp_register_app(struct ip_vs_app *inc)
+{
+ struct ip_vs_app *i;
+ __u16 hash, port = inc->port;
+ int ret = 0;
+
+ hash = udp_app_hashkey(port);
+
+
+ spin_lock_bh(&udp_app_lock);
+ list_for_each_entry(i, &udp_apps[hash], p_list) {
+ if (i->port == port) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
+ list_add(&inc->p_list, &udp_apps[hash]);
+ atomic_inc(&ip_vs_protocol_udp.appcnt);
+
+ out:
+ spin_unlock_bh(&udp_app_lock);
+ return ret;
+}
+
+
+static void
+udp_unregister_app(struct ip_vs_app *inc)
+{
+ spin_lock_bh(&udp_app_lock);
+ atomic_dec(&ip_vs_protocol_udp.appcnt);
+ list_del(&inc->p_list);
+ spin_unlock_bh(&udp_app_lock);
+}
+
+
+static int udp_app_conn_bind(struct ip_vs_conn *cp)
+{
+ int hash;
+ struct ip_vs_app *inc;
+ int result = 0;
+
+ /* Default binding: bind app only for NAT */
+ if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
+ return 0;
+
+ /* Lookup application incarnations and bind the right one */
+ hash = udp_app_hashkey(cp->vport);
+
+ spin_lock(&udp_app_lock);
+ list_for_each_entry(inc, &udp_apps[hash], p_list) {
+ if (inc->port == cp->vport) {
+ if (unlikely(!ip_vs_app_inc_get(inc)))
+ break;
+ spin_unlock(&udp_app_lock);
+
+ IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
+ "%u.%u.%u.%u:%u to app %s on port %u\n",
+ __FUNCTION__,
+ NIPQUAD(cp->caddr), ntohs(cp->cport),
+ NIPQUAD(cp->vaddr), ntohs(cp->vport),
+ inc->name, ntohs(inc->port));
+ cp->app = inc;
+ if (inc->init_conn)
+ result = inc->init_conn(inc, cp);
+ goto out;
+ }
+ }
+ spin_unlock(&udp_app_lock);
+
+ out:
+ return result;
+}
+
+
+static int udp_timeouts[IP_VS_UDP_S_LAST+1] = {
+ [IP_VS_UDP_S_NORMAL] = 5*60*HZ,
+ [IP_VS_UDP_S_LAST] = 2*HZ,
+};
+
+static char * udp_state_name_table[IP_VS_UDP_S_LAST+1] = {
+ [IP_VS_UDP_S_NORMAL] = "UDP",
+ [IP_VS_UDP_S_LAST] = "BUG!",
+};
+
+
+static int
+udp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
+{
+ return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_UDP_S_LAST,
+ udp_state_name_table, sname, to);
+}
+
+static const char * udp_state_name(int state)
+{
+ if (state >= IP_VS_UDP_S_LAST)
+ return "ERR!";
+ return udp_state_name_table[state] ? udp_state_name_table[state] : "?";
+}
+
+static int
+udp_state_transition(struct ip_vs_conn *cp, int direction,
+ const struct sk_buff *skb,
+ struct ip_vs_protocol *pp)
+{
+ cp->timeout = pp->timeout_table[IP_VS_UDP_S_NORMAL];
+ return 1;
+}
+
+static void udp_init(struct ip_vs_protocol *pp)
+{
+ IP_VS_INIT_HASH_TABLE(udp_apps);
+ pp->timeout_table = udp_timeouts;
+}
+
+static void udp_exit(struct ip_vs_protocol *pp)
+{
+}
+
+
+struct ip_vs_protocol ip_vs_protocol_udp = {
+ .name = "UDP",
+ .protocol = IPPROTO_UDP,
+ .dont_defrag = 0,
+ .init = udp_init,
+ .exit = udp_exit,
+ .conn_schedule = udp_conn_schedule,
+ .conn_in_get = udp_conn_in_get,
+ .conn_out_get = udp_conn_out_get,
+ .snat_handler = udp_snat_handler,
+ .dnat_handler = udp_dnat_handler,
+ .csum_check = udp_csum_check,
+ .state_transition = udp_state_transition,
+ .state_name = udp_state_name,
+ .register_app = udp_register_app,
+ .unregister_app = udp_unregister_app,
+ .app_conn_bind = udp_app_conn_bind,
+ .debug_packet = ip_vs_tcpudp_debug_packet,
+ .timeout_change = NULL,
+ .set_state_timeout = udp_set_state_timeout,
+};