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authorJulius Volz <juliusv@google.com>2008-09-19 12:32:57 +0200
committerSimon Horman <horms@verge.net.au>2008-10-07 08:38:24 +1100
commitcb7f6a7b716e801097b564dec3ccb58d330aef56 (patch)
tree92fa8fa5381e04576c43eab88874ab54ea670767 /net/netfilter/ipvs/ip_vs_proto_tcp.c
parent8d5803bf6fbe5264000afc8c34bff08e8ecc023b (diff)
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IPVS: Move IPVS to net/netfilter/ipvs
Since IPVS now has partial IPv6 support, this patch moves IPVS from net/ipv4/ipvs to net/netfilter/ipvs. It's a result of: $ git mv net/ipv4/ipvs net/netfilter and adapting the relevant Kconfigs/Makefiles to the new path. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'net/netfilter/ipvs/ip_vs_proto_tcp.c')
-rw-r--r--net/netfilter/ipvs/ip_vs_proto_tcp.c732
1 files changed, 732 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c
new file mode 100644
index 00000000000..dd4566ea2bf
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c
@@ -0,0 +1,732 @@
+/*
+ * ip_vs_proto_tcp.c: TCP load balancing support for IPVS
+ *
+ * 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/ip.h>
+#include <linux/tcp.h> /* for tcphdr */
+#include <net/ip.h>
+#include <net/tcp.h> /* for csum_tcpudp_magic */
+#include <net/ip6_checksum.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+
+#include <net/ip_vs.h>
+
+
+static struct ip_vs_conn *
+tcp_conn_in_get(int af, const struct sk_buff *skb, struct ip_vs_protocol *pp,
+ const struct ip_vs_iphdr *iph, unsigned int proto_off,
+ int inverse)
+{
+ __be16 _ports[2], *pptr;
+
+ pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
+ if (pptr == NULL)
+ return NULL;
+
+ if (likely(!inverse)) {
+ return ip_vs_conn_in_get(af, iph->protocol,
+ &iph->saddr, pptr[0],
+ &iph->daddr, pptr[1]);
+ } else {
+ return ip_vs_conn_in_get(af, iph->protocol,
+ &iph->daddr, pptr[1],
+ &iph->saddr, pptr[0]);
+ }
+}
+
+static struct ip_vs_conn *
+tcp_conn_out_get(int af, const struct sk_buff *skb, struct ip_vs_protocol *pp,
+ const struct ip_vs_iphdr *iph, unsigned int proto_off,
+ int inverse)
+{
+ __be16 _ports[2], *pptr;
+
+ pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
+ if (pptr == NULL)
+ return NULL;
+
+ if (likely(!inverse)) {
+ return ip_vs_conn_out_get(af, iph->protocol,
+ &iph->saddr, pptr[0],
+ &iph->daddr, pptr[1]);
+ } else {
+ return ip_vs_conn_out_get(af, iph->protocol,
+ &iph->daddr, pptr[1],
+ &iph->saddr, pptr[0]);
+ }
+}
+
+
+static int
+tcp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
+ int *verdict, struct ip_vs_conn **cpp)
+{
+ struct ip_vs_service *svc;
+ struct tcphdr _tcph, *th;
+ struct ip_vs_iphdr iph;
+
+ ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
+
+ th = skb_header_pointer(skb, iph.len, sizeof(_tcph), &_tcph);
+ if (th == NULL) {
+ *verdict = NF_DROP;
+ return 0;
+ }
+
+ if (th->syn &&
+ (svc = ip_vs_service_get(af, skb->mark, iph.protocol, &iph.daddr,
+ th->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
+tcp_fast_csum_update(int af, struct tcphdr *tcph,
+ const union nf_inet_addr *oldip,
+ const union nf_inet_addr *newip,
+ __be16 oldport, __be16 newport)
+{
+#ifdef CONFIG_IP_VS_IPV6
+ if (af == AF_INET6)
+ tcph->check =
+ csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
+ ip_vs_check_diff2(oldport, newport,
+ ~csum_unfold(tcph->check))));
+ else
+#endif
+ tcph->check =
+ csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
+ ip_vs_check_diff2(oldport, newport,
+ ~csum_unfold(tcph->check))));
+}
+
+
+static inline void
+tcp_partial_csum_update(int af, struct tcphdr *tcph,
+ const union nf_inet_addr *oldip,
+ const union nf_inet_addr *newip,
+ __be16 oldlen, __be16 newlen)
+{
+#ifdef CONFIG_IP_VS_IPV6
+ if (af == AF_INET6)
+ tcph->check =
+ csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
+ ip_vs_check_diff2(oldlen, newlen,
+ ~csum_unfold(tcph->check))));
+ else
+#endif
+ tcph->check =
+ csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
+ ip_vs_check_diff2(oldlen, newlen,
+ ~csum_unfold(tcph->check))));
+}
+
+
+static int
+tcp_snat_handler(struct sk_buff *skb,
+ struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
+{
+ struct tcphdr *tcph;
+ unsigned int tcphoff;
+ int oldlen;
+
+#ifdef CONFIG_IP_VS_IPV6
+ if (cp->af == AF_INET6)
+ tcphoff = sizeof(struct ipv6hdr);
+ else
+#endif
+ tcphoff = ip_hdrlen(skb);
+ oldlen = skb->len - tcphoff;
+
+ /* csum_check requires unshared skb */
+ if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
+ return 0;
+
+ if (unlikely(cp->app != NULL)) {
+ /* Some checks before mangling */
+ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+ return 0;
+
+ /* Call application helper if needed */
+ if (!ip_vs_app_pkt_out(cp, skb))
+ return 0;
+ }
+
+ tcph = (void *)skb_network_header(skb) + tcphoff;
+ tcph->source = cp->vport;
+
+ /* Adjust TCP checksums */
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
+ htonl(oldlen),
+ htonl(skb->len - tcphoff));
+ } else if (!cp->app) {
+ /* Only port and addr are changed, do fast csum update */
+ tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
+ cp->dport, cp->vport);
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->ip_summed = CHECKSUM_NONE;
+ } else {
+ /* full checksum calculation */
+ tcph->check = 0;
+ skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
+#ifdef CONFIG_IP_VS_IPV6
+ if (cp->af == AF_INET6)
+ tcph->check = csum_ipv6_magic(&cp->vaddr.in6,
+ &cp->caddr.in6,
+ skb->len - tcphoff,
+ cp->protocol, skb->csum);
+ else
+#endif
+ tcph->check = csum_tcpudp_magic(cp->vaddr.ip,
+ cp->caddr.ip,
+ skb->len - tcphoff,
+ cp->protocol,
+ skb->csum);
+
+ IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
+ pp->name, tcph->check,
+ (char*)&(tcph->check) - (char*)tcph);
+ }
+ return 1;
+}
+
+
+static int
+tcp_dnat_handler(struct sk_buff *skb,
+ struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
+{
+ struct tcphdr *tcph;
+ unsigned int tcphoff;
+ int oldlen;
+
+#ifdef CONFIG_IP_VS_IPV6
+ if (cp->af == AF_INET6)
+ tcphoff = sizeof(struct ipv6hdr);
+ else
+#endif
+ tcphoff = ip_hdrlen(skb);
+ oldlen = skb->len - tcphoff;
+
+ /* csum_check requires unshared skb */
+ if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
+ return 0;
+
+ if (unlikely(cp->app != NULL)) {
+ /* Some checks before mangling */
+ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+ return 0;
+
+ /*
+ * Attempt ip_vs_app call.
+ * It will fix ip_vs_conn and iph ack_seq stuff
+ */
+ if (!ip_vs_app_pkt_in(cp, skb))
+ return 0;
+ }
+
+ tcph = (void *)skb_network_header(skb) + tcphoff;
+ tcph->dest = cp->dport;
+
+ /*
+ * Adjust TCP checksums
+ */
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
+ htonl(oldlen),
+ htonl(skb->len - tcphoff));
+ } else if (!cp->app) {
+ /* Only port and addr are changed, do fast csum update */
+ tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr,
+ cp->vport, cp->dport);
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->ip_summed = CHECKSUM_NONE;
+ } else {
+ /* full checksum calculation */
+ tcph->check = 0;
+ skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
+#ifdef CONFIG_IP_VS_IPV6
+ if (cp->af == AF_INET6)
+ tcph->check = csum_ipv6_magic(&cp->caddr.in6,
+ &cp->daddr.in6,
+ skb->len - tcphoff,
+ cp->protocol, skb->csum);
+ else
+#endif
+ tcph->check = csum_tcpudp_magic(cp->caddr.ip,
+ cp->daddr.ip,
+ skb->len - tcphoff,
+ cp->protocol,
+ skb->csum);
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ }
+ return 1;
+}
+
+
+static int
+tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
+{
+ unsigned int tcphoff;
+
+#ifdef CONFIG_IP_VS_IPV6
+ if (af == AF_INET6)
+ tcphoff = sizeof(struct ipv6hdr);
+ else
+#endif
+ tcphoff = ip_hdrlen(skb);
+
+ switch (skb->ip_summed) {
+ case CHECKSUM_NONE:
+ skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
+ case CHECKSUM_COMPLETE:
+#ifdef CONFIG_IP_VS_IPV6
+ if (af == AF_INET6) {
+ if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr,
+ skb->len - tcphoff,
+ ipv6_hdr(skb)->nexthdr,
+ skb->csum)) {
+ IP_VS_DBG_RL_PKT(0, pp, skb, 0,
+ "Failed checksum for");
+ return 0;
+ }
+ } else
+#endif
+ if (csum_tcpudp_magic(ip_hdr(skb)->saddr,
+ ip_hdr(skb)->daddr,
+ skb->len - tcphoff,
+ ip_hdr(skb)->protocol,
+ skb->csum)) {
+ IP_VS_DBG_RL_PKT(0, pp, skb, 0,
+ "Failed checksum for");
+ return 0;
+ }
+ break;
+ default:
+ /* No need to checksum. */
+ break;
+ }
+
+ return 1;
+}
+
+
+#define TCP_DIR_INPUT 0
+#define TCP_DIR_OUTPUT 4
+#define TCP_DIR_INPUT_ONLY 8
+
+static const int tcp_state_off[IP_VS_DIR_LAST] = {
+ [IP_VS_DIR_INPUT] = TCP_DIR_INPUT,
+ [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT,
+ [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY,
+};
+
+/*
+ * Timeout table[state]
+ */
+static int tcp_timeouts[IP_VS_TCP_S_LAST+1] = {
+ [IP_VS_TCP_S_NONE] = 2*HZ,
+ [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ,
+ [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ,
+ [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ,
+ [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ,
+ [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ,
+ [IP_VS_TCP_S_CLOSE] = 10*HZ,
+ [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ,
+ [IP_VS_TCP_S_LAST_ACK] = 30*HZ,
+ [IP_VS_TCP_S_LISTEN] = 2*60*HZ,
+ [IP_VS_TCP_S_SYNACK] = 120*HZ,
+ [IP_VS_TCP_S_LAST] = 2*HZ,
+};
+
+static char * tcp_state_name_table[IP_VS_TCP_S_LAST+1] = {
+ [IP_VS_TCP_S_NONE] = "NONE",
+ [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED",
+ [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT",
+ [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV",
+ [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT",
+ [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT",
+ [IP_VS_TCP_S_CLOSE] = "CLOSE",
+ [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT",
+ [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK",
+ [IP_VS_TCP_S_LISTEN] = "LISTEN",
+ [IP_VS_TCP_S_SYNACK] = "SYNACK",
+ [IP_VS_TCP_S_LAST] = "BUG!",
+};
+
+#define sNO IP_VS_TCP_S_NONE
+#define sES IP_VS_TCP_S_ESTABLISHED
+#define sSS IP_VS_TCP_S_SYN_SENT
+#define sSR IP_VS_TCP_S_SYN_RECV
+#define sFW IP_VS_TCP_S_FIN_WAIT
+#define sTW IP_VS_TCP_S_TIME_WAIT
+#define sCL IP_VS_TCP_S_CLOSE
+#define sCW IP_VS_TCP_S_CLOSE_WAIT
+#define sLA IP_VS_TCP_S_LAST_ACK
+#define sLI IP_VS_TCP_S_LISTEN
+#define sSA IP_VS_TCP_S_SYNACK
+
+struct tcp_states_t {
+ int next_state[IP_VS_TCP_S_LAST];
+};
+
+static const char * tcp_state_name(int state)
+{
+ if (state >= IP_VS_TCP_S_LAST)
+ return "ERR!";
+ return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?";
+}
+
+static struct tcp_states_t tcp_states [] = {
+/* INPUT */
+/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
+/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
+/*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }},
+/*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
+/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }},
+
+/* OUTPUT */
+/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
+/*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }},
+/*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
+/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
+/*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
+
+/* INPUT-ONLY */
+/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
+/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
+/*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
+/*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
+/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
+};
+
+static struct tcp_states_t tcp_states_dos [] = {
+/* INPUT */
+/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
+/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }},
+/*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }},
+/*ack*/ {{sCL, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }},
+/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
+
+/* OUTPUT */
+/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
+/*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }},
+/*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
+/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
+/*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
+
+/* INPUT-ONLY */
+/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
+/*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }},
+/*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
+/*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
+/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
+};
+
+static struct tcp_states_t *tcp_state_table = tcp_states;
+
+
+static void tcp_timeout_change(struct ip_vs_protocol *pp, int flags)
+{
+ int on = (flags & 1); /* secure_tcp */
+
+ /*
+ ** FIXME: change secure_tcp to independent sysctl var
+ ** or make it per-service or per-app because it is valid
+ ** for most if not for all of the applications. Something
+ ** like "capabilities" (flags) for each object.
+ */
+ tcp_state_table = (on? tcp_states_dos : tcp_states);
+}
+
+static int
+tcp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
+{
+ return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_TCP_S_LAST,
+ tcp_state_name_table, sname, to);
+}
+
+static inline int tcp_state_idx(struct tcphdr *th)
+{
+ if (th->rst)
+ return 3;
+ if (th->syn)
+ return 0;
+ if (th->fin)
+ return 1;
+ if (th->ack)
+ return 2;
+ return -1;
+}
+
+static inline void
+set_tcp_state(struct ip_vs_protocol *pp, struct ip_vs_conn *cp,
+ int direction, struct tcphdr *th)
+{
+ int state_idx;
+ int new_state = IP_VS_TCP_S_CLOSE;
+ int state_off = tcp_state_off[direction];
+
+ /*
+ * Update state offset to INPUT_ONLY if necessary
+ * or delete NO_OUTPUT flag if output packet detected
+ */
+ if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
+ if (state_off == TCP_DIR_OUTPUT)
+ cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
+ else
+ state_off = TCP_DIR_INPUT_ONLY;
+ }
+
+ if ((state_idx = tcp_state_idx(th)) < 0) {
+ IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx);
+ goto tcp_state_out;
+ }
+
+ new_state = tcp_state_table[state_off+state_idx].next_state[cp->state];
+
+ tcp_state_out:
+ if (new_state != cp->state) {
+ struct ip_vs_dest *dest = cp->dest;
+
+ IP_VS_DBG_BUF(8, "%s %s [%c%c%c%c] %s:%d->"
+ "%s:%d state: %s->%s conn->refcnt:%d\n",
+ pp->name,
+ ((state_off == TCP_DIR_OUTPUT) ?
+ "output " : "input "),
+ th->syn ? 'S' : '.',
+ th->fin ? 'F' : '.',
+ th->ack ? 'A' : '.',
+ th->rst ? 'R' : '.',
+ IP_VS_DBG_ADDR(cp->af, &cp->daddr),
+ ntohs(cp->dport),
+ IP_VS_DBG_ADDR(cp->af, &cp->caddr),
+ ntohs(cp->cport),
+ tcp_state_name(cp->state),
+ tcp_state_name(new_state),
+ atomic_read(&cp->refcnt));
+
+ if (dest) {
+ if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
+ (new_state != IP_VS_TCP_S_ESTABLISHED)) {
+ atomic_dec(&dest->activeconns);
+ atomic_inc(&dest->inactconns);
+ cp->flags |= IP_VS_CONN_F_INACTIVE;
+ } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
+ (new_state == IP_VS_TCP_S_ESTABLISHED)) {
+ atomic_inc(&dest->activeconns);
+ atomic_dec(&dest->inactconns);
+ cp->flags &= ~IP_VS_CONN_F_INACTIVE;
+ }
+ }
+ }
+
+ cp->timeout = pp->timeout_table[cp->state = new_state];
+}
+
+
+/*
+ * Handle state transitions
+ */
+static int
+tcp_state_transition(struct ip_vs_conn *cp, int direction,
+ const struct sk_buff *skb,
+ struct ip_vs_protocol *pp)
+{
+ struct tcphdr _tcph, *th;
+
+#ifdef CONFIG_IP_VS_IPV6
+ int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
+#else
+ int ihl = ip_hdrlen(skb);
+#endif
+
+ th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph);
+ if (th == NULL)
+ return 0;
+
+ spin_lock(&cp->lock);
+ set_tcp_state(pp, cp, direction, th);
+ spin_unlock(&cp->lock);
+
+ return 1;
+}
+
+
+/*
+ * Hash table for TCP application incarnations
+ */
+#define TCP_APP_TAB_BITS 4
+#define TCP_APP_TAB_SIZE (1 << TCP_APP_TAB_BITS)
+#define TCP_APP_TAB_MASK (TCP_APP_TAB_SIZE - 1)
+
+static struct list_head tcp_apps[TCP_APP_TAB_SIZE];
+static DEFINE_SPINLOCK(tcp_app_lock);
+
+static inline __u16 tcp_app_hashkey(__be16 port)
+{
+ return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port)
+ & TCP_APP_TAB_MASK;
+}
+
+
+static int tcp_register_app(struct ip_vs_app *inc)
+{
+ struct ip_vs_app *i;
+ __u16 hash;
+ __be16 port = inc->port;
+ int ret = 0;
+
+ hash = tcp_app_hashkey(port);
+
+ spin_lock_bh(&tcp_app_lock);
+ list_for_each_entry(i, &tcp_apps[hash], p_list) {
+ if (i->port == port) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
+ list_add(&inc->p_list, &tcp_apps[hash]);
+ atomic_inc(&ip_vs_protocol_tcp.appcnt);
+
+ out:
+ spin_unlock_bh(&tcp_app_lock);
+ return ret;
+}
+
+
+static void
+tcp_unregister_app(struct ip_vs_app *inc)
+{
+ spin_lock_bh(&tcp_app_lock);
+ atomic_dec(&ip_vs_protocol_tcp.appcnt);
+ list_del(&inc->p_list);
+ spin_unlock_bh(&tcp_app_lock);
+}
+
+
+static int
+tcp_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 = tcp_app_hashkey(cp->vport);
+
+ spin_lock(&tcp_app_lock);
+ list_for_each_entry(inc, &tcp_apps[hash], p_list) {
+ if (inc->port == cp->vport) {
+ if (unlikely(!ip_vs_app_inc_get(inc)))
+ break;
+ spin_unlock(&tcp_app_lock);
+
+ IP_VS_DBG_BUF(9, "%s: Binding conn %s:%u->"
+ "%s:%u to app %s on port %u\n",
+ __func__,
+ IP_VS_DBG_ADDR(cp->af, &cp->caddr),
+ ntohs(cp->cport),
+ IP_VS_DBG_ADDR(cp->af, &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(&tcp_app_lock);
+
+ out:
+ return result;
+}
+
+
+/*
+ * Set LISTEN timeout. (ip_vs_conn_put will setup timer)
+ */
+void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp)
+{
+ spin_lock(&cp->lock);
+ cp->state = IP_VS_TCP_S_LISTEN;
+ cp->timeout = ip_vs_protocol_tcp.timeout_table[IP_VS_TCP_S_LISTEN];
+ spin_unlock(&cp->lock);
+}
+
+
+static void ip_vs_tcp_init(struct ip_vs_protocol *pp)
+{
+ IP_VS_INIT_HASH_TABLE(tcp_apps);
+ pp->timeout_table = tcp_timeouts;
+}
+
+
+static void ip_vs_tcp_exit(struct ip_vs_protocol *pp)
+{
+}
+
+
+struct ip_vs_protocol ip_vs_protocol_tcp = {
+ .name = "TCP",
+ .protocol = IPPROTO_TCP,
+ .num_states = IP_VS_TCP_S_LAST,
+ .dont_defrag = 0,
+ .appcnt = ATOMIC_INIT(0),
+ .init = ip_vs_tcp_init,
+ .exit = ip_vs_tcp_exit,
+ .register_app = tcp_register_app,
+ .unregister_app = tcp_unregister_app,
+ .conn_schedule = tcp_conn_schedule,
+ .conn_in_get = tcp_conn_in_get,
+ .conn_out_get = tcp_conn_out_get,
+ .snat_handler = tcp_snat_handler,
+ .dnat_handler = tcp_dnat_handler,
+ .csum_check = tcp_csum_check,
+ .state_name = tcp_state_name,
+ .state_transition = tcp_state_transition,
+ .app_conn_bind = tcp_app_conn_bind,
+ .debug_packet = ip_vs_tcpudp_debug_packet,
+ .timeout_change = tcp_timeout_change,
+ .set_state_timeout = tcp_set_state_timeout,
+};