Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 920 insertions, 0 deletions

diff --git a/net/ipv4/ipvs/ip_vs_conn.c b/net/ipv4/ipvs/ip_vs_conn.c
new file mode 100644
index 000000000000..fd6feb5499fe
--- /dev/null
+++ b/net/ipv4/ipvs/ip_vs_conn.c
@@ -0,0 +1,920 @@
+/*
+ * IPVS         An implementation of the IP virtual server support for the
+ *              LINUX operating system.  IPVS is now implemented as a module
+ *              over the Netfilter framework. IPVS can be used to build a
+ *              high-performance and highly available server based on a
+ *              cluster of servers.
+ *
+ * Version:     $Id: ip_vs_conn.c,v 1.31 2003/04/18 09:03:16 wensong Exp $
+ *
+ * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
+ *              Peter Kese <peter.kese@ijs.si>
+ *              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.
+ *
+ * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
+ * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
+ * and others. Many code here is taken from IP MASQ code of kernel 2.2.
+ *
+ * Changes:
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>              /* for proc_net_* */
+#include <linux/seq_file.h>
+#include <linux/jhash.h>
+#include <linux/random.h>
+
+#include <net/ip_vs.h>
+
+
+/*
+ *  Connection hash table: for input and output packets lookups of IPVS
+ */
+static struct list_head *ip_vs_conn_tab;
+
+/*  SLAB cache for IPVS connections */
+static kmem_cache_t *ip_vs_conn_cachep;
+
+/*  counter for current IPVS connections */
+static atomic_t ip_vs_conn_count = ATOMIC_INIT(0);
+
+/*  counter for no client port connections */
+static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
+
+/* random value for IPVS connection hash */
+static unsigned int ip_vs_conn_rnd;
+
+/*
+ *  Fine locking granularity for big connection hash table
+ */
+#define CT_LOCKARRAY_BITS  4
+#define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
+#define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
+
+struct ip_vs_aligned_lock
+{
+        rwlock_t        l;
+} __attribute__((__aligned__(SMP_CACHE_BYTES)));
+
+/* lock array for conn table */
+static struct ip_vs_aligned_lock
+__ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
+
+static inline void ct_read_lock(unsigned key)
+{
+        read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_read_unlock(unsigned key)
+{
+        read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_write_lock(unsigned key)
+{
+        write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_write_unlock(unsigned key)
+{
+        write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_read_lock_bh(unsigned key)
+{
+        read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_read_unlock_bh(unsigned key)
+{
+        read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_write_lock_bh(unsigned key)
+{
+        write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+static inline void ct_write_unlock_bh(unsigned key)
+{
+        write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
+}
+
+
+/*
+ *      Returns hash value for IPVS connection entry
+ */
+static unsigned int ip_vs_conn_hashkey(unsigned proto, __u32 addr, __u16 port)
+{
+        return jhash_3words(addr, port, proto, ip_vs_conn_rnd)
+                & IP_VS_CONN_TAB_MASK;
+}
+
+
+/*
+ *      Hashes ip_vs_conn in ip_vs_conn_tab by proto,addr,port.
+ *      returns bool success.
+ */
+static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
+{
+        unsigned hash;
+        int ret;
+
+        /* Hash by protocol, client address and port */
+        hash = ip_vs_conn_hashkey(cp->protocol, cp->caddr, cp->cport);
+
+        ct_write_lock(hash);
+
+        if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
+                list_add(&cp->c_list, &ip_vs_conn_tab[hash]);
+                cp->flags |= IP_VS_CONN_F_HASHED;
+                atomic_inc(&cp->refcnt);
+                ret = 1;
+        } else {
+                IP_VS_ERR("ip_vs_conn_hash(): request for already hashed, "
+                          "called from %p\n", __builtin_return_address(0));
+                ret = 0;
+        }
+
+        ct_write_unlock(hash);
+
+        return ret;
+}
+
+
+/*
+ *      UNhashes ip_vs_conn from ip_vs_conn_tab.
+ *      returns bool success.
+ */
+static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
+{
+        unsigned hash;
+        int ret;
+
+        /* unhash it and decrease its reference counter */
+        hash = ip_vs_conn_hashkey(cp->protocol, cp->caddr, cp->cport);
+
+        ct_write_lock(hash);
+
+        if (cp->flags & IP_VS_CONN_F_HASHED) {
+                list_del(&cp->c_list);
+                cp->flags &= ~IP_VS_CONN_F_HASHED;
+                atomic_dec(&cp->refcnt);
+                ret = 1;
+        } else
+                ret = 0;
+
+        ct_write_unlock(hash);
+
+        return ret;
+}
+
+
+/*
+ *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
+ *  Called for pkts coming from OUTside-to-INside.
+ *      s_addr, s_port: pkt source address (foreign host)
+ *      d_addr, d_port: pkt dest address (load balancer)
+ */
+static inline struct ip_vs_conn *__ip_vs_conn_in_get
+(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port)
+{
+        unsigned hash;
+        struct ip_vs_conn *cp;
+
+        hash = ip_vs_conn_hashkey(protocol, s_addr, s_port);
+
+        ct_read_lock(hash);
+
+        list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
+                if (s_addr==cp->caddr && s_port==cp->cport &&
+                    d_port==cp->vport && d_addr==cp->vaddr &&
+                    protocol==cp->protocol) {
+                        /* HIT */
+                        atomic_inc(&cp->refcnt);
+                        ct_read_unlock(hash);
+                        return cp;
+                }
+        }
+
+        ct_read_unlock(hash);
+
+        return NULL;
+}
+
+struct ip_vs_conn *ip_vs_conn_in_get
+(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port)
+{
+        struct ip_vs_conn *cp;
+
+        cp = __ip_vs_conn_in_get(protocol, s_addr, s_port, d_addr, d_port);
+        if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt))
+                cp = __ip_vs_conn_in_get(protocol, s_addr, 0, d_addr, d_port);
+
+        IP_VS_DBG(7, "lookup/in %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n",
+                  ip_vs_proto_name(protocol),
+                  NIPQUAD(s_addr), ntohs(s_port),
+                  NIPQUAD(d_addr), ntohs(d_port),
+                  cp?"hit":"not hit");
+
+        return cp;
+}
+
+
+/*
+ *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
+ *  Called for pkts coming from inside-to-OUTside.
+ *      s_addr, s_port: pkt source address (inside host)
+ *      d_addr, d_port: pkt dest address (foreign host)
+ */
+struct ip_vs_conn *ip_vs_conn_out_get
+(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port)
+{
+        unsigned hash;
+        struct ip_vs_conn *cp, *ret=NULL;
+
+        /*
+         *      Check for "full" addressed entries
+         */
+        hash = ip_vs_conn_hashkey(protocol, d_addr, d_port);
+
+        ct_read_lock(hash);
+
+        list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
+                if (d_addr == cp->caddr && d_port == cp->cport &&
+                    s_port == cp->dport && s_addr == cp->daddr &&
+                    protocol == cp->protocol) {
+                        /* HIT */
+                        atomic_inc(&cp->refcnt);
+                        ret = cp;
+                        break;
+                }
+        }
+
+        ct_read_unlock(hash);
+
+        IP_VS_DBG(7, "lookup/out %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n",
+                  ip_vs_proto_name(protocol),
+                  NIPQUAD(s_addr), ntohs(s_port),
+                  NIPQUAD(d_addr), ntohs(d_port),
+                  ret?"hit":"not hit");
+
+        return ret;
+}
+
+
+/*
+ *      Put back the conn and restart its timer with its timeout
+ */
+void ip_vs_conn_put(struct ip_vs_conn *cp)
+{
+        /* reset it expire in its timeout */
+        mod_timer(&cp->timer, jiffies+cp->timeout);
+
+        __ip_vs_conn_put(cp);
+}
+
+
+/*
+ *      Fill a no_client_port connection with a client port number
+ */
+void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __u16 cport)
+{
+        if (ip_vs_conn_unhash(cp)) {
+                spin_lock(&cp->lock);
+                if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
+                        atomic_dec(&ip_vs_conn_no_cport_cnt);
+                        cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
+                        cp->cport = cport;
+                }
+                spin_unlock(&cp->lock);
+
+                /* hash on new dport */
+                ip_vs_conn_hash(cp);
+        }
+}
+
+
+/*
+ *      Bind a connection entry with the corresponding packet_xmit.
+ *      Called by ip_vs_conn_new.
+ */
+static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
+{
+        switch (IP_VS_FWD_METHOD(cp)) {
+        case IP_VS_CONN_F_MASQ:
+                cp->packet_xmit = ip_vs_nat_xmit;
+                break;
+
+        case IP_VS_CONN_F_TUNNEL:
+                cp->packet_xmit = ip_vs_tunnel_xmit;
+                break;
+
+        case IP_VS_CONN_F_DROUTE:
+                cp->packet_xmit = ip_vs_dr_xmit;
+                break;
+
+        case IP_VS_CONN_F_LOCALNODE:
+                cp->packet_xmit = ip_vs_null_xmit;
+                break;
+
+        case IP_VS_CONN_F_BYPASS:
+                cp->packet_xmit = ip_vs_bypass_xmit;
+                break;
+        }
+}
+
+
+static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
+{
+        return atomic_read(&dest->activeconns)
+                + atomic_read(&dest->inactconns);
+}
+
+/*
+ *      Bind a connection entry with a virtual service destination
+ *      Called just after a new connection entry is created.
+ */
+static inline void
+ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
+{
+        /* if dest is NULL, then return directly */
+        if (!dest)
+                return;
+
+        /* Increase the refcnt counter of the dest */
+        atomic_inc(&dest->refcnt);
+
+        /* Bind with the destination and its corresponding transmitter */
+        cp->flags |= atomic_read(&dest->conn_flags);
+        cp->dest = dest;
+
+        IP_VS_DBG(9, "Bind-dest %s c:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d "
+                  "d:%u.%u.%u.%u:%d fwd:%c s:%u flg:%X cnt:%d destcnt:%d\n",
+                  ip_vs_proto_name(cp->protocol),
+                  NIPQUAD(cp->caddr), ntohs(cp->cport),
+                  NIPQUAD(cp->vaddr), ntohs(cp->vport),
+                  NIPQUAD(cp->daddr), ntohs(cp->dport),
+                  ip_vs_fwd_tag(cp), cp->state,
+                  cp->flags, atomic_read(&cp->refcnt),
+                  atomic_read(&dest->refcnt));
+
+        /* Update the connection counters */
+        if (cp->cport || (cp->flags & IP_VS_CONN_F_NO_CPORT)) {
+                /* It is a normal connection, so increase the inactive
+                   connection counter because it is in TCP SYNRECV
+                   state (inactive) or other protocol inacive state */
+                atomic_inc(&dest->inactconns);
+        } else {
+                /* It is a persistent connection/template, so increase
+                   the peristent connection counter */
+                atomic_inc(&dest->persistconns);
+        }
+
+        if (dest->u_threshold != 0 &&
+            ip_vs_dest_totalconns(dest) >= dest->u_threshold)
+                dest->flags |= IP_VS_DEST_F_OVERLOAD;
+}
+
+
+/*
+ *      Unbind a connection entry with its VS destination
+ *      Called by the ip_vs_conn_expire function.
+ */
+static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
+{
+        struct ip_vs_dest *dest = cp->dest;
+
+        if (!dest)
+                return;
+
+        IP_VS_DBG(9, "Unbind-dest %s c:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d "
+                  "d:%u.%u.%u.%u:%d fwd:%c s:%u flg:%X cnt:%d destcnt:%d\n",
+                  ip_vs_proto_name(cp->protocol),
+                  NIPQUAD(cp->caddr), ntohs(cp->cport),
+                  NIPQUAD(cp->vaddr), ntohs(cp->vport),
+                  NIPQUAD(cp->daddr), ntohs(cp->dport),
+                  ip_vs_fwd_tag(cp), cp->state,
+                  cp->flags, atomic_read(&cp->refcnt),
+                  atomic_read(&dest->refcnt));
+
+        /* Update the connection counters */
+        if (cp->cport || (cp->flags & IP_VS_CONN_F_NO_CPORT)) {
+                /* It is a normal connection, so decrease the inactconns
+                   or activeconns counter */
+                if (cp->flags & IP_VS_CONN_F_INACTIVE) {
+                        atomic_dec(&dest->inactconns);
+                } else {
+                        atomic_dec(&dest->activeconns);
+                }
+        } else {
+                /* It is a persistent connection/template, so decrease
+                   the peristent connection counter */
+                atomic_dec(&dest->persistconns);
+        }
+
+        if (dest->l_threshold != 0) {
+                if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
+                        dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
+        } else if (dest->u_threshold != 0) {
+                if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
+                        dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
+        } else {
+                if (dest->flags & IP_VS_DEST_F_OVERLOAD)
+                        dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
+        }
+
+        /*
+         * Simply decrease the refcnt of the dest, because the
+         * dest will be either in service's destination list
+         * or in the trash.
+         */
+        atomic_dec(&dest->refcnt);
+}
+
+
+/*
+ *      Checking if the destination of a connection template is available.
+ *      If available, return 1, otherwise invalidate this connection
+ *      template and return 0.
+ */
+int ip_vs_check_template(struct ip_vs_conn *ct)
+{
+        struct ip_vs_dest *dest = ct->dest;
+
+        /*
+         * Checking the dest server status.
+         */
+        if ((dest == NULL) ||
+            !(dest->flags & IP_VS_DEST_F_AVAILABLE) || 
+            (sysctl_ip_vs_expire_quiescent_template && 
+             (atomic_read(&dest->weight) == 0))) {
+                IP_VS_DBG(9, "check_template: dest not available for "
+                          "protocol %s s:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d "
+                          "-> d:%u.%u.%u.%u:%d\n",
+                          ip_vs_proto_name(ct->protocol),
+                          NIPQUAD(ct->caddr), ntohs(ct->cport),
+                          NIPQUAD(ct->vaddr), ntohs(ct->vport),
+                          NIPQUAD(ct->daddr), ntohs(ct->dport));
+
+                /*
+                 * Invalidate the connection template
+                 */
+                if (ct->cport) {
+                        if (ip_vs_conn_unhash(ct)) {
+                                ct->dport = 65535;
+                                ct->vport = 65535;
+                                ct->cport = 0;
+                                ip_vs_conn_hash(ct);
+                        }
+                }
+
+                /*
+                 * Simply decrease the refcnt of the template,
+                 * don't restart its timer.
+                 */
+                atomic_dec(&ct->refcnt);
+                return 0;
+        }
+        return 1;
+}
+
+static void ip_vs_conn_expire(unsigned long data)
+{
+        struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
+
+        cp->timeout = 60*HZ;
+
+        /*
+         *      hey, I'm using it
+         */
+        atomic_inc(&cp->refcnt);
+
+        /*
+         *      do I control anybody?
+         */
+        if (atomic_read(&cp->n_control))
+                goto expire_later;
+
+        /*
+         *      unhash it if it is hashed in the conn table
+         */
+        if (!ip_vs_conn_unhash(cp))
+                goto expire_later;
+
+        /*
+         *      refcnt==1 implies I'm the only one referrer
+         */
+        if (likely(atomic_read(&cp->refcnt) == 1)) {
+                /* delete the timer if it is activated by other users */
+                if (timer_pending(&cp->timer))
+                        del_timer(&cp->timer);
+
+                /* does anybody control me? */
+                if (cp->control)
+                        ip_vs_control_del(cp);
+
+                if (unlikely(cp->app != NULL))
+                        ip_vs_unbind_app(cp);
+                ip_vs_unbind_dest(cp);
+                if (cp->flags & IP_VS_CONN_F_NO_CPORT)
+                        atomic_dec(&ip_vs_conn_no_cport_cnt);
+                atomic_dec(&ip_vs_conn_count);
+
+                kmem_cache_free(ip_vs_conn_cachep, cp);
+                return;
+        }
+
+        /* hash it back to the table */
+        ip_vs_conn_hash(cp);
+
+  expire_later:
+        IP_VS_DBG(7, "delayed: refcnt-1=%d conn.n_control=%d\n",
+                  atomic_read(&cp->refcnt)-1,
+                  atomic_read(&cp->n_control));
+
+        ip_vs_conn_put(cp);
+}
+
+
+void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
+{
+        if (del_timer(&cp->timer))
+                mod_timer(&cp->timer, jiffies);
+        __ip_vs_conn_put(cp);
+}
+
+
+/*
+ *      Create a new connection entry and hash it into the ip_vs_conn_tab
+ */
+struct ip_vs_conn *
+ip_vs_conn_new(int proto, __u32 caddr, __u16 cport, __u32 vaddr, __u16 vport,
+               __u32 daddr, __u16 dport, unsigned flags,
+               struct ip_vs_dest *dest)
+{
+        struct ip_vs_conn *cp;
+        struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
+
+        cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
+        if (cp == NULL) {
+                IP_VS_ERR_RL("ip_vs_conn_new: no memory available.\n");
+                return NULL;
+        }
+
+        memset(cp, 0, sizeof(*cp));
+        INIT_LIST_HEAD(&cp->c_list);
+        init_timer(&cp->timer);
+        cp->timer.data     = (unsigned long)cp;
+        cp->timer.function = ip_vs_conn_expire;
+        cp->protocol       = proto;
+        cp->caddr          = caddr;
+        cp->cport          = cport;
+        cp->vaddr          = vaddr;
+        cp->vport          = vport;
+        cp->daddr          = daddr;
+        cp->dport          = dport;
+        cp->flags          = flags;
+        spin_lock_init(&cp->lock);
+
+        /*
+         * Set the entry is referenced by the current thread before hashing
+         * it in the table, so that other thread run ip_vs_random_dropentry
+         * but cannot drop this entry.
+         */
+        atomic_set(&cp->refcnt, 1);
+
+        atomic_set(&cp->n_control, 0);
+        atomic_set(&cp->in_pkts, 0);
+
+        atomic_inc(&ip_vs_conn_count);
+        if (flags & IP_VS_CONN_F_NO_CPORT)
+                atomic_inc(&ip_vs_conn_no_cport_cnt);
+
+        /* Bind the connection with a destination server */
+        ip_vs_bind_dest(cp, dest);
+
+        /* Set its state and timeout */
+        cp->state = 0;
+        cp->timeout = 3*HZ;
+
+        /* Bind its packet transmitter */
+        ip_vs_bind_xmit(cp);
+
+        if (unlikely(pp && atomic_read(&pp->appcnt)))
+                ip_vs_bind_app(cp, pp);
+
+        /* Hash it in the ip_vs_conn_tab finally */
+        ip_vs_conn_hash(cp);
+
+        return cp;
+}
+
+
+/*
+ *      /proc/net/ip_vs_conn entries
+ */
+#ifdef CONFIG_PROC_FS
+
+static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
+{
+        int idx;
+        struct ip_vs_conn *cp;
+        
+        for(idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
+                ct_read_lock_bh(idx);
+                list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
+                        if (pos-- == 0) {
+                                seq->private = &ip_vs_conn_tab[idx];
+                                return cp;
+                        }
+                }
+                ct_read_unlock_bh(idx);
+        }
+
+        return NULL;
+}
+
+static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        seq->private = NULL;
+        return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
+}
+
+static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        struct ip_vs_conn *cp = v;
+        struct list_head *e, *l = seq->private;
+        int idx;
+
+        ++*pos;
+        if (v == SEQ_START_TOKEN) 
+                return ip_vs_conn_array(seq, 0);
+
+        /* more on same hash chain? */
+        if ((e = cp->c_list.next) != l)
+                return list_entry(e, struct ip_vs_conn, c_list);
+
+        idx = l - ip_vs_conn_tab;
+        ct_read_unlock_bh(idx);
+
+        while (++idx < IP_VS_CONN_TAB_SIZE) {
+                ct_read_lock_bh(idx);
+                list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
+                        seq->private = &ip_vs_conn_tab[idx];
+                        return cp;
+                }       
+                ct_read_unlock_bh(idx);
+        }
+        seq->private = NULL;
+        return NULL;
+}
+
+static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
+{
+        struct list_head *l = seq->private;
+
+        if (l)
+                ct_read_unlock_bh(l - ip_vs_conn_tab);
+}
+
+static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
+{
+
+        if (v == SEQ_START_TOKEN)
+                seq_puts(seq,
+   "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires\n");
+        else {
+                const struct ip_vs_conn *cp = v;
+
+                seq_printf(seq,
+                        "%-3s %08X %04X %08X %04X %08X %04X %-11s %7lu\n",
+                                ip_vs_proto_name(cp->protocol),
+                                ntohl(cp->caddr), ntohs(cp->cport),
+                                ntohl(cp->vaddr), ntohs(cp->vport),
+                                ntohl(cp->daddr), ntohs(cp->dport),
+                                ip_vs_state_name(cp->protocol, cp->state),
+                                (cp->timer.expires-jiffies)/HZ);
+        }
+        return 0;
+}
+
+static struct seq_operations ip_vs_conn_seq_ops = {
+        .start = ip_vs_conn_seq_start,
+        .next  = ip_vs_conn_seq_next,
+        .stop  = ip_vs_conn_seq_stop,
+        .show  = ip_vs_conn_seq_show,
+};
+
+static int ip_vs_conn_open(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &ip_vs_conn_seq_ops);
+}
+
+static struct file_operations ip_vs_conn_fops = {
+        .owner   = THIS_MODULE,
+        .open    = ip_vs_conn_open,
+        .read    = seq_read,
+        .llseek  = seq_lseek,
+        .release = seq_release,
+};
+#endif
+
+
+/*
+ *      Randomly drop connection entries before running out of memory
+ */
+static inline int todrop_entry(struct ip_vs_conn *cp)
+{
+        /*
+         * The drop rate array needs tuning for real environments.
+         * Called from timer bh only => no locking
+         */
+        static char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
+        static char todrop_counter[9] = {0};
+        int i;
+
+        /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
+           This will leave enough time for normal connection to get
+           through. */
+        if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
+                return 0;
+
+        /* Don't drop the entry if its number of incoming packets is not
+           located in [0, 8] */
+        i = atomic_read(&cp->in_pkts);
+        if (i > 8 || i < 0) return 0;
+
+        if (!todrop_rate[i]) return 0;
+        if (--todrop_counter[i] > 0) return 0;
+
+        todrop_counter[i] = todrop_rate[i];
+        return 1;
+}
+
+
+void ip_vs_random_dropentry(void)
+{
+        int idx;
+        struct ip_vs_conn *cp;
+        struct ip_vs_conn *ct;
+
+        /*
+         * Randomly scan 1/32 of the whole table every second
+         */
+        for (idx = 0; idx < (IP_VS_CONN_TAB_SIZE>>5); idx++) {
+                unsigned hash = net_random() & IP_VS_CONN_TAB_MASK;
+
+                /*
+                 *  Lock is actually needed in this loop.
+                 */
+                ct_write_lock(hash);
+
+                list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
+                        if (!cp->cport && !(cp->flags & IP_VS_CONN_F_NO_CPORT))
+                                /* connection template */
+                                continue;
+
+                        if (cp->protocol == IPPROTO_TCP) {
+                                switch(cp->state) {
+                                case IP_VS_TCP_S_SYN_RECV:
+                                case IP_VS_TCP_S_SYNACK:
+                                        break;
+
+                                case IP_VS_TCP_S_ESTABLISHED:
+                                        if (todrop_entry(cp))
+                                                break;
+                                        continue;
+
+                                default:
+                                        continue;
+                                }
+                        } else {
+                                if (!todrop_entry(cp))
+                                        continue;
+                        }
+
+                        /*
+                         * Drop the entry, and drop its ct if not referenced
+                         */
+                        atomic_inc(&cp->refcnt);
+                        ct_write_unlock(hash);
+
+                        if ((ct = cp->control))
+                                atomic_inc(&ct->refcnt);
+                        IP_VS_DBG(4, "del connection\n");
+                        ip_vs_conn_expire_now(cp);
+                        if (ct) {
+                                IP_VS_DBG(4, "del conn template\n");
+                                ip_vs_conn_expire_now(ct);
+                        }
+                        ct_write_lock(hash);
+                }
+                ct_write_unlock(hash);
+        }
+}
+
+
+/*
+ *      Flush all the connection entries in the ip_vs_conn_tab
+ */
+static void ip_vs_conn_flush(void)
+{
+        int idx;
+        struct ip_vs_conn *cp;
+        struct ip_vs_conn *ct;
+
+  flush_again:
+        for (idx=0; idx<IP_VS_CONN_TAB_SIZE; idx++) {
+                /*
+                 *  Lock is actually needed in this loop.
+                 */
+                ct_write_lock_bh(idx);
+
+                list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
+                        atomic_inc(&cp->refcnt);
+                        ct_write_unlock(idx);
+
+                        if ((ct = cp->control))
+                                atomic_inc(&ct->refcnt);
+                        IP_VS_DBG(4, "del connection\n");
+                        ip_vs_conn_expire_now(cp);
+                        if (ct) {
+                                IP_VS_DBG(4, "del conn template\n");
+                                ip_vs_conn_expire_now(ct);
+                        }
+                        ct_write_lock(idx);
+                }
+                ct_write_unlock_bh(idx);
+        }
+
+        /* the counter may be not NULL, because maybe some conn entries
+           are run by slow timer handler or unhashed but still referred */
+        if (atomic_read(&ip_vs_conn_count) != 0) {
+                schedule();
+                goto flush_again;
+        }
+}
+
+
+int ip_vs_conn_init(void)
+{
+        int idx;
+
+        /*
+         * Allocate the connection hash table and initialize its list heads
+         */
+        ip_vs_conn_tab = vmalloc(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head));
+        if (!ip_vs_conn_tab)
+                return -ENOMEM;
+
+        /* Allocate ip_vs_conn slab cache */
+        ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
+                                              sizeof(struct ip_vs_conn), 0,
+                                              SLAB_HWCACHE_ALIGN, NULL, NULL);
+        if (!ip_vs_conn_cachep) {
+                vfree(ip_vs_conn_tab);
+                return -ENOMEM;
+        }
+
+        IP_VS_INFO("Connection hash table configured "
+                   "(size=%d, memory=%ldKbytes)\n",
+                   IP_VS_CONN_TAB_SIZE,
+                   (long)(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head))/1024);
+        IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
+                  sizeof(struct ip_vs_conn));
+
+        for (idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
+                INIT_LIST_HEAD(&ip_vs_conn_tab[idx]);
+        }
+
+        for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
+                rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
+        }
+
+        proc_net_fops_create("ip_vs_conn", 0, &ip_vs_conn_fops);
+
+        /* calculate the random value for connection hash */
+        get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
+
+        return 0;
+}
+
+
+void ip_vs_conn_cleanup(void)
+{
+        /* flush all the connection entries first */
+        ip_vs_conn_flush();
+
+        /* Release the empty cache */
+        kmem_cache_destroy(ip_vs_conn_cachep);
+        proc_net_remove("ip_vs_conn");
+        vfree(ip_vs_conn_tab);
+}