Linux-2.6.12-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!
diff --git a/net/ipv4/ipvs/ip_vs_sync.c b/net/ipv4/ipvs/ip_vs_sync.c
new file mode 100644
index 0000000..25c4795
--- /dev/null
+++ b/net/ipv4/ipvs/ip_vs_sync.c
@@ -0,0 +1,892 @@
+/*
+ * 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_sync.c,v 1.13 2003/06/08 09:31:19 wensong Exp $
+ *
+ * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
+ *
+ * ip_vs_sync: sync connection info from master load balancer to backups
+ * through multicast
+ *
+ * Changes:
+ * Alexandre Cassen : Added master & backup support at a time.
+ * Alexandre Cassen : Added SyncID support for incoming sync
+ * messages filtering.
+ * Justin Ossevoort : Fix endian problem on sync message size.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/net.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/igmp.h> /* for ip_mc_join_group */
+
+#include <net/ip.h>
+#include <net/sock.h>
+#include <asm/uaccess.h> /* for get_fs and set_fs */
+
+#include <net/ip_vs.h>
+
+#define IP_VS_SYNC_GROUP 0xe0000051 /* multicast addr - 224.0.0.81 */
+#define IP_VS_SYNC_PORT 8848 /* multicast port */
+
+
+/*
+ * IPVS sync connection entry
+ */
+struct ip_vs_sync_conn {
+ __u8 reserved;
+
+ /* Protocol, addresses and port numbers */
+ __u8 protocol; /* Which protocol (TCP/UDP) */
+ __u16 cport;
+ __u16 vport;
+ __u16 dport;
+ __u32 caddr; /* client address */
+ __u32 vaddr; /* virtual address */
+ __u32 daddr; /* destination address */
+
+ /* Flags and state transition */
+ __u16 flags; /* status flags */
+ __u16 state; /* state info */
+
+ /* The sequence options start here */
+};
+
+struct ip_vs_sync_conn_options {
+ struct ip_vs_seq in_seq; /* incoming seq. struct */
+ struct ip_vs_seq out_seq; /* outgoing seq. struct */
+};
+
+#define IP_VS_SYNC_CONN_TIMEOUT (3*60*HZ)
+#define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn))
+#define FULL_CONN_SIZE \
+(sizeof(struct ip_vs_sync_conn) + sizeof(struct ip_vs_sync_conn_options))
+
+
+/*
+ The master mulitcasts messages to the backup load balancers in the
+ following format.
+
+ 0 1 2 3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Count Conns | SyncID | Size |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | |
+ | IPVS Sync Connection (1) |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | . |
+ | . |
+ | . |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | |
+ | IPVS Sync Connection (n) |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+#define SYNC_MESG_HEADER_LEN 4
+
+struct ip_vs_sync_mesg {
+ __u8 nr_conns;
+ __u8 syncid;
+ __u16 size;
+
+ /* ip_vs_sync_conn entries start here */
+};
+
+/* the maximum length of sync (sending/receiving) message */
+static int sync_send_mesg_maxlen;
+static int sync_recv_mesg_maxlen;
+
+struct ip_vs_sync_buff {
+ struct list_head list;
+ unsigned long firstuse;
+
+ /* pointers for the message data */
+ struct ip_vs_sync_mesg *mesg;
+ unsigned char *head;
+ unsigned char *end;
+};
+
+
+/* the sync_buff list head and the lock */
+static LIST_HEAD(ip_vs_sync_queue);
+static DEFINE_SPINLOCK(ip_vs_sync_lock);
+
+/* current sync_buff for accepting new conn entries */
+static struct ip_vs_sync_buff *curr_sb = NULL;
+static DEFINE_SPINLOCK(curr_sb_lock);
+
+/* ipvs sync daemon state */
+volatile int ip_vs_sync_state = IP_VS_STATE_NONE;
+volatile int ip_vs_master_syncid = 0;
+volatile int ip_vs_backup_syncid = 0;
+
+/* multicast interface name */
+char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
+char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
+
+/* multicast addr */
+static struct sockaddr_in mcast_addr;
+
+
+static inline void sb_queue_tail(struct ip_vs_sync_buff *sb)
+{
+ spin_lock(&ip_vs_sync_lock);
+ list_add_tail(&sb->list, &ip_vs_sync_queue);
+ spin_unlock(&ip_vs_sync_lock);
+}
+
+static inline struct ip_vs_sync_buff * sb_dequeue(void)
+{
+ struct ip_vs_sync_buff *sb;
+
+ spin_lock_bh(&ip_vs_sync_lock);
+ if (list_empty(&ip_vs_sync_queue)) {
+ sb = NULL;
+ } else {
+ sb = list_entry(ip_vs_sync_queue.next,
+ struct ip_vs_sync_buff,
+ list);
+ list_del(&sb->list);
+ }
+ spin_unlock_bh(&ip_vs_sync_lock);
+
+ return sb;
+}
+
+static inline struct ip_vs_sync_buff * ip_vs_sync_buff_create(void)
+{
+ struct ip_vs_sync_buff *sb;
+
+ if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
+ return NULL;
+
+ if (!(sb->mesg=kmalloc(sync_send_mesg_maxlen, GFP_ATOMIC))) {
+ kfree(sb);
+ return NULL;
+ }
+ sb->mesg->nr_conns = 0;
+ sb->mesg->syncid = ip_vs_master_syncid;
+ sb->mesg->size = 4;
+ sb->head = (unsigned char *)sb->mesg + 4;
+ sb->end = (unsigned char *)sb->mesg + sync_send_mesg_maxlen;
+ sb->firstuse = jiffies;
+ return sb;
+}
+
+static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
+{
+ kfree(sb->mesg);
+ kfree(sb);
+}
+
+/*
+ * Get the current sync buffer if it has been created for more
+ * than the specified time or the specified time is zero.
+ */
+static inline struct ip_vs_sync_buff *
+get_curr_sync_buff(unsigned long time)
+{
+ struct ip_vs_sync_buff *sb;
+
+ spin_lock_bh(&curr_sb_lock);
+ if (curr_sb && (time == 0 ||
+ time_before(jiffies - curr_sb->firstuse, time))) {
+ sb = curr_sb;
+ curr_sb = NULL;
+ } else
+ sb = NULL;
+ spin_unlock_bh(&curr_sb_lock);
+ return sb;
+}
+
+
+/*
+ * Add an ip_vs_conn information into the current sync_buff.
+ * Called by ip_vs_in.
+ */
+void ip_vs_sync_conn(struct ip_vs_conn *cp)
+{
+ struct ip_vs_sync_mesg *m;
+ struct ip_vs_sync_conn *s;
+ int len;
+
+ spin_lock(&curr_sb_lock);
+ if (!curr_sb) {
+ if (!(curr_sb=ip_vs_sync_buff_create())) {
+ spin_unlock(&curr_sb_lock);
+ IP_VS_ERR("ip_vs_sync_buff_create failed.\n");
+ return;
+ }
+ }
+
+ len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
+ SIMPLE_CONN_SIZE;
+ m = curr_sb->mesg;
+ s = (struct ip_vs_sync_conn *)curr_sb->head;
+
+ /* copy members */
+ s->protocol = cp->protocol;
+ s->cport = cp->cport;
+ s->vport = cp->vport;
+ s->dport = cp->dport;
+ s->caddr = cp->caddr;
+ s->vaddr = cp->vaddr;
+ s->daddr = cp->daddr;
+ s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
+ s->state = htons(cp->state);
+ if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
+ struct ip_vs_sync_conn_options *opt =
+ (struct ip_vs_sync_conn_options *)&s[1];
+ memcpy(opt, &cp->in_seq, sizeof(*opt));
+ }
+
+ m->nr_conns++;
+ m->size += len;
+ curr_sb->head += len;
+
+ /* check if there is a space for next one */
+ if (curr_sb->head+FULL_CONN_SIZE > curr_sb->end) {
+ sb_queue_tail(curr_sb);
+ curr_sb = NULL;
+ }
+ spin_unlock(&curr_sb_lock);
+
+ /* synchronize its controller if it has */
+ if (cp->control)
+ ip_vs_sync_conn(cp->control);
+}
+
+
+/*
+ * Process received multicast message and create the corresponding
+ * ip_vs_conn entries.
+ */
+static void ip_vs_process_message(const char *buffer, const size_t buflen)
+{
+ struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer;
+ struct ip_vs_sync_conn *s;
+ struct ip_vs_sync_conn_options *opt;
+ struct ip_vs_conn *cp;
+ char *p;
+ int i;
+
+ /* Convert size back to host byte order */
+ m->size = ntohs(m->size);
+
+ if (buflen != m->size) {
+ IP_VS_ERR("bogus message\n");
+ return;
+ }
+
+ /* SyncID sanity check */
+ if (ip_vs_backup_syncid != 0 && m->syncid != ip_vs_backup_syncid) {
+ IP_VS_DBG(7, "Ignoring incoming msg with syncid = %d\n",
+ m->syncid);
+ return;
+ }
+
+ p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
+ for (i=0; i<m->nr_conns; i++) {
+ s = (struct ip_vs_sync_conn *)p;
+ cp = ip_vs_conn_in_get(s->protocol,
+ s->caddr, s->cport,
+ s->vaddr, s->vport);
+ if (!cp) {
+ cp = ip_vs_conn_new(s->protocol,
+ s->caddr, s->cport,
+ s->vaddr, s->vport,
+ s->daddr, s->dport,
+ ntohs(s->flags), NULL);
+ if (!cp) {
+ IP_VS_ERR("ip_vs_conn_new failed\n");
+ return;
+ }
+ cp->state = ntohs(s->state);
+ } else if (!cp->dest) {
+ /* it is an entry created by the synchronization */
+ cp->state = ntohs(s->state);
+ cp->flags = ntohs(s->flags) | IP_VS_CONN_F_HASHED;
+ } /* Note that we don't touch its state and flags
+ if it is a normal entry. */
+
+ if (ntohs(s->flags) & IP_VS_CONN_F_SEQ_MASK) {
+ opt = (struct ip_vs_sync_conn_options *)&s[1];
+ memcpy(&cp->in_seq, opt, sizeof(*opt));
+ p += FULL_CONN_SIZE;
+ } else
+ p += SIMPLE_CONN_SIZE;
+
+ atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]);
+ cp->timeout = IP_VS_SYNC_CONN_TIMEOUT;
+ ip_vs_conn_put(cp);
+
+ if (p > buffer+buflen) {
+ IP_VS_ERR("bogus message\n");
+ return;
+ }
+ }
+}
+
+
+/*
+ * Setup loopback of outgoing multicasts on a sending socket
+ */
+static void set_mcast_loop(struct sock *sk, u_char loop)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ /* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
+ lock_sock(sk);
+ inet->mc_loop = loop ? 1 : 0;
+ release_sock(sk);
+}
+
+/*
+ * Specify TTL for outgoing multicasts on a sending socket
+ */
+static void set_mcast_ttl(struct sock *sk, u_char ttl)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
+ lock_sock(sk);
+ inet->mc_ttl = ttl;
+ release_sock(sk);
+}
+
+/*
+ * Specifiy default interface for outgoing multicasts
+ */
+static int set_mcast_if(struct sock *sk, char *ifname)
+{
+ struct net_device *dev;
+ struct inet_sock *inet = inet_sk(sk);
+
+ if ((dev = __dev_get_by_name(ifname)) == NULL)
+ return -ENODEV;
+
+ if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
+ return -EINVAL;
+
+ lock_sock(sk);
+ inet->mc_index = dev->ifindex;
+ /* inet->mc_addr = 0; */
+ release_sock(sk);
+
+ return 0;
+}
+
+
+/*
+ * Set the maximum length of sync message according to the
+ * specified interface's MTU.
+ */
+static int set_sync_mesg_maxlen(int sync_state)
+{
+ struct net_device *dev;
+ int num;
+
+ if (sync_state == IP_VS_STATE_MASTER) {
+ if ((dev = __dev_get_by_name(ip_vs_master_mcast_ifn)) == NULL)
+ return -ENODEV;
+
+ num = (dev->mtu - sizeof(struct iphdr) -
+ sizeof(struct udphdr) -
+ SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE;
+ sync_send_mesg_maxlen =
+ SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num;
+ IP_VS_DBG(7, "setting the maximum length of sync sending "
+ "message %d.\n", sync_send_mesg_maxlen);
+ } else if (sync_state == IP_VS_STATE_BACKUP) {
+ if ((dev = __dev_get_by_name(ip_vs_backup_mcast_ifn)) == NULL)
+ return -ENODEV;
+
+ sync_recv_mesg_maxlen = dev->mtu -
+ sizeof(struct iphdr) - sizeof(struct udphdr);
+ IP_VS_DBG(7, "setting the maximum length of sync receiving "
+ "message %d.\n", sync_recv_mesg_maxlen);
+ }
+
+ return 0;
+}
+
+
+/*
+ * Join a multicast group.
+ * the group is specified by a class D multicast address 224.0.0.0/8
+ * in the in_addr structure passed in as a parameter.
+ */
+static int
+join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
+{
+ struct ip_mreqn mreq;
+ struct net_device *dev;
+ int ret;
+
+ memset(&mreq, 0, sizeof(mreq));
+ memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
+
+ if ((dev = __dev_get_by_name(ifname)) == NULL)
+ return -ENODEV;
+ if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
+ return -EINVAL;
+
+ mreq.imr_ifindex = dev->ifindex;
+
+ lock_sock(sk);
+ ret = ip_mc_join_group(sk, &mreq);
+ release_sock(sk);
+
+ return ret;
+}
+
+
+static int bind_mcastif_addr(struct socket *sock, char *ifname)
+{
+ struct net_device *dev;
+ u32 addr;
+ struct sockaddr_in sin;
+
+ if ((dev = __dev_get_by_name(ifname)) == NULL)
+ return -ENODEV;
+
+ addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
+ if (!addr)
+ IP_VS_ERR("You probably need to specify IP address on "
+ "multicast interface.\n");
+
+ IP_VS_DBG(7, "binding socket with (%s) %u.%u.%u.%u\n",
+ ifname, NIPQUAD(addr));
+
+ /* Now bind the socket with the address of multicast interface */
+ sin.sin_family = AF_INET;
+ sin.sin_addr.s_addr = addr;
+ sin.sin_port = 0;
+
+ return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
+}
+
+/*
+ * Set up sending multicast socket over UDP
+ */
+static struct socket * make_send_sock(void)
+{
+ struct socket *sock;
+
+ /* First create a socket */
+ if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
+ IP_VS_ERR("Error during creation of socket; terminating\n");
+ return NULL;
+ }
+
+ if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) {
+ IP_VS_ERR("Error setting outbound mcast interface\n");
+ goto error;
+ }
+
+ set_mcast_loop(sock->sk, 0);
+ set_mcast_ttl(sock->sk, 1);
+
+ if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) {
+ IP_VS_ERR("Error binding address of the mcast interface\n");
+ goto error;
+ }
+
+ if (sock->ops->connect(sock,
+ (struct sockaddr*)&mcast_addr,
+ sizeof(struct sockaddr), 0) < 0) {
+ IP_VS_ERR("Error connecting to the multicast addr\n");
+ goto error;
+ }
+
+ return sock;
+
+ error:
+ sock_release(sock);
+ return NULL;
+}
+
+
+/*
+ * Set up receiving multicast socket over UDP
+ */
+static struct socket * make_receive_sock(void)
+{
+ struct socket *sock;
+
+ /* First create a socket */
+ if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
+ IP_VS_ERR("Error during creation of socket; terminating\n");
+ return NULL;
+ }
+
+ /* it is equivalent to the REUSEADDR option in user-space */
+ sock->sk->sk_reuse = 1;
+
+ if (sock->ops->bind(sock,
+ (struct sockaddr*)&mcast_addr,
+ sizeof(struct sockaddr)) < 0) {
+ IP_VS_ERR("Error binding to the multicast addr\n");
+ goto error;
+ }
+
+ /* join the multicast group */
+ if (join_mcast_group(sock->sk,
+ (struct in_addr*)&mcast_addr.sin_addr,
+ ip_vs_backup_mcast_ifn) < 0) {
+ IP_VS_ERR("Error joining to the multicast group\n");
+ goto error;
+ }
+
+ return sock;
+
+ error:
+ sock_release(sock);
+ return NULL;
+}
+
+
+static int
+ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
+{
+ struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
+ struct kvec iov;
+ int len;
+
+ EnterFunction(7);
+ iov.iov_base = (void *)buffer;
+ iov.iov_len = length;
+
+ len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
+
+ LeaveFunction(7);
+ return len;
+}
+
+static void
+ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
+{
+ int msize;
+
+ msize = msg->size;
+
+ /* Put size in network byte order */
+ msg->size = htons(msg->size);
+
+ if (ip_vs_send_async(sock, (char *)msg, msize) != msize)
+ IP_VS_ERR("ip_vs_send_async error\n");
+}
+
+static int
+ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
+{
+ struct msghdr msg = {NULL,};
+ struct kvec iov;
+ int len;
+
+ EnterFunction(7);
+
+ /* Receive a packet */
+ iov.iov_base = buffer;
+ iov.iov_len = (size_t)buflen;
+
+ len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, 0);
+
+ if (len < 0)
+ return -1;
+
+ LeaveFunction(7);
+ return len;
+}
+
+
+static DECLARE_WAIT_QUEUE_HEAD(sync_wait);
+static pid_t sync_master_pid = 0;
+static pid_t sync_backup_pid = 0;
+
+static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait);
+static int stop_master_sync = 0;
+static int stop_backup_sync = 0;
+
+static void sync_master_loop(void)
+{
+ struct socket *sock;
+ struct ip_vs_sync_buff *sb;
+
+ /* create the sending multicast socket */
+ sock = make_send_sock();
+ if (!sock)
+ return;
+
+ IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, "
+ "syncid = %d\n",
+ ip_vs_master_mcast_ifn, ip_vs_master_syncid);
+
+ for (;;) {
+ while ((sb=sb_dequeue())) {
+ ip_vs_send_sync_msg(sock, sb->mesg);
+ ip_vs_sync_buff_release(sb);
+ }
+
+ /* check if entries stay in curr_sb for 2 seconds */
+ if ((sb = get_curr_sync_buff(2*HZ))) {
+ ip_vs_send_sync_msg(sock, sb->mesg);
+ ip_vs_sync_buff_release(sb);
+ }
+
+ if (stop_master_sync)
+ break;
+
+ ssleep(1);
+ }
+
+ /* clean up the sync_buff queue */
+ while ((sb=sb_dequeue())) {
+ ip_vs_sync_buff_release(sb);
+ }
+
+ /* clean up the current sync_buff */
+ if ((sb = get_curr_sync_buff(0))) {
+ ip_vs_sync_buff_release(sb);
+ }
+
+ /* release the sending multicast socket */
+ sock_release(sock);
+}
+
+
+static void sync_backup_loop(void)
+{
+ struct socket *sock;
+ char *buf;
+ int len;
+
+ if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) {
+ IP_VS_ERR("sync_backup_loop: kmalloc error\n");
+ return;
+ }
+
+ /* create the receiving multicast socket */
+ sock = make_receive_sock();
+ if (!sock)
+ goto out;
+
+ IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, "
+ "syncid = %d\n",
+ ip_vs_backup_mcast_ifn, ip_vs_backup_syncid);
+
+ for (;;) {
+ /* do you have data now? */
+ while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) {
+ if ((len =
+ ip_vs_receive(sock, buf,
+ sync_recv_mesg_maxlen)) <= 0) {
+ IP_VS_ERR("receiving message error\n");
+ break;
+ }
+ /* disable bottom half, because it accessed the data
+ shared by softirq while getting/creating conns */
+ local_bh_disable();
+ ip_vs_process_message(buf, len);
+ local_bh_enable();
+ }
+
+ if (stop_backup_sync)
+ break;
+
+ ssleep(1);
+ }
+
+ /* release the sending multicast socket */
+ sock_release(sock);
+
+ out:
+ kfree(buf);
+}
+
+
+static void set_sync_pid(int sync_state, pid_t sync_pid)
+{
+ if (sync_state == IP_VS_STATE_MASTER)
+ sync_master_pid = sync_pid;
+ else if (sync_state == IP_VS_STATE_BACKUP)
+ sync_backup_pid = sync_pid;
+}
+
+static void set_stop_sync(int sync_state, int set)
+{
+ if (sync_state == IP_VS_STATE_MASTER)
+ stop_master_sync = set;
+ else if (sync_state == IP_VS_STATE_BACKUP)
+ stop_backup_sync = set;
+ else {
+ stop_master_sync = set;
+ stop_backup_sync = set;
+ }
+}
+
+static int sync_thread(void *startup)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ mm_segment_t oldmm;
+ int state;
+ const char *name;
+
+ /* increase the module use count */
+ ip_vs_use_count_inc();
+
+ if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) {
+ state = IP_VS_STATE_MASTER;
+ name = "ipvs_syncmaster";
+ } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) {
+ state = IP_VS_STATE_BACKUP;
+ name = "ipvs_syncbackup";
+ } else {
+ IP_VS_BUG();
+ ip_vs_use_count_dec();
+ return -EINVAL;
+ }
+
+ daemonize(name);
+
+ oldmm = get_fs();
+ set_fs(KERNEL_DS);
+
+ /* Block all signals */
+ spin_lock_irq(¤t->sighand->siglock);
+ siginitsetinv(¤t->blocked, 0);
+ recalc_sigpending();
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ /* set the maximum length of sync message */
+ set_sync_mesg_maxlen(state);
+
+ /* set up multicast address */
+ mcast_addr.sin_family = AF_INET;
+ mcast_addr.sin_port = htons(IP_VS_SYNC_PORT);
+ mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP);
+
+ add_wait_queue(&sync_wait, &wait);
+
+ set_sync_pid(state, current->pid);
+ complete((struct completion *)startup);
+
+ /* processing master/backup loop here */
+ if (state == IP_VS_STATE_MASTER)
+ sync_master_loop();
+ else if (state == IP_VS_STATE_BACKUP)
+ sync_backup_loop();
+ else IP_VS_BUG();
+
+ remove_wait_queue(&sync_wait, &wait);
+
+ /* thread exits */
+ set_sync_pid(state, 0);
+ IP_VS_INFO("sync thread stopped!\n");
+
+ set_fs(oldmm);
+
+ /* decrease the module use count */
+ ip_vs_use_count_dec();
+
+ set_stop_sync(state, 0);
+ wake_up(&stop_sync_wait);
+
+ return 0;
+}
+
+
+static int fork_sync_thread(void *startup)
+{
+ pid_t pid;
+
+ /* fork the sync thread here, then the parent process of the
+ sync thread is the init process after this thread exits. */
+ repeat:
+ if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) {
+ IP_VS_ERR("could not create sync_thread due to %d... "
+ "retrying.\n", pid);
+ ssleep(1);
+ goto repeat;
+ }
+
+ return 0;
+}
+
+
+int start_sync_thread(int state, char *mcast_ifn, __u8 syncid)
+{
+ DECLARE_COMPLETION(startup);
+ pid_t pid;
+
+ if ((state == IP_VS_STATE_MASTER && sync_master_pid) ||
+ (state == IP_VS_STATE_BACKUP && sync_backup_pid))
+ return -EEXIST;
+
+ IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
+ IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n",
+ sizeof(struct ip_vs_sync_conn));
+
+ ip_vs_sync_state |= state;
+ if (state == IP_VS_STATE_MASTER) {
+ strcpy(ip_vs_master_mcast_ifn, mcast_ifn);
+ ip_vs_master_syncid = syncid;
+ } else {
+ strcpy(ip_vs_backup_mcast_ifn, mcast_ifn);
+ ip_vs_backup_syncid = syncid;
+ }
+
+ repeat:
+ if ((pid = kernel_thread(fork_sync_thread, &startup, 0)) < 0) {
+ IP_VS_ERR("could not create fork_sync_thread due to %d... "
+ "retrying.\n", pid);
+ ssleep(1);
+ goto repeat;
+ }
+
+ wait_for_completion(&startup);
+
+ return 0;
+}
+
+
+int stop_sync_thread(int state)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ if ((state == IP_VS_STATE_MASTER && !sync_master_pid) ||
+ (state == IP_VS_STATE_BACKUP && !sync_backup_pid))
+ return -ESRCH;
+
+ IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
+ IP_VS_INFO("stopping sync thread %d ...\n",
+ (state == IP_VS_STATE_MASTER) ? sync_master_pid : sync_backup_pid);
+
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ add_wait_queue(&stop_sync_wait, &wait);
+ set_stop_sync(state, 1);
+ ip_vs_sync_state -= state;
+ wake_up(&sync_wait);
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&stop_sync_wait, &wait);
+
+ /* Note: no need to reap the sync thread, because its parent
+ process is the init process */
+
+ if ((state == IP_VS_STATE_MASTER && stop_master_sync) ||
+ (state == IP_VS_STATE_BACKUP && stop_backup_sync))
+ IP_VS_BUG();
+
+ return 0;
+}