| /* |
| * 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. |
| * |
| * 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/inetdevice.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 <linux/udp.h> |
| |
| #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) */ |
| __be16 cport; |
| __be16 vport; |
| __be16 dport; |
| __be32 caddr; /* client address */ |
| __be32 vaddr; /* virtual address */ |
| __be32 daddr; /* destination address */ |
| |
| /* Flags and state transition */ |
| __be16 flags; /* status flags */ |
| __be16 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 */ |
| }; |
| |
| struct ip_vs_sync_thread_data { |
| struct completion *startup; |
| int state; |
| }; |
| |
| #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; |
| struct ip_vs_protocol *pp; |
| struct ip_vs_dest *dest; |
| char *p; |
| int i; |
| |
| if (buflen < sizeof(struct ip_vs_sync_mesg)) { |
| IP_VS_ERR_RL("sync message header too short\n"); |
| return; |
| } |
| |
| /* Convert size back to host byte order */ |
| m->size = ntohs(m->size); |
| |
| if (buflen != m->size) { |
| IP_VS_ERR_RL("bogus sync message size\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++) { |
| unsigned flags, state; |
| |
| if (p + SIMPLE_CONN_SIZE > buffer+buflen) { |
| IP_VS_ERR_RL("bogus conn in sync message\n"); |
| return; |
| } |
| s = (struct ip_vs_sync_conn *) p; |
| flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC; |
| flags &= ~IP_VS_CONN_F_HASHED; |
| if (flags & IP_VS_CONN_F_SEQ_MASK) { |
| opt = (struct ip_vs_sync_conn_options *)&s[1]; |
| p += FULL_CONN_SIZE; |
| if (p > buffer+buflen) { |
| IP_VS_ERR_RL("bogus conn options in sync message\n"); |
| return; |
| } |
| } else { |
| opt = NULL; |
| p += SIMPLE_CONN_SIZE; |
| } |
| |
| state = ntohs(s->state); |
| if (!(flags & IP_VS_CONN_F_TEMPLATE)) { |
| pp = ip_vs_proto_get(s->protocol); |
| if (!pp) { |
| IP_VS_ERR_RL("Unsupported protocol %u in sync msg\n", |
| s->protocol); |
| continue; |
| } |
| if (state >= pp->num_states) { |
| IP_VS_DBG(2, "Invalid %s state %u in sync msg\n", |
| pp->name, state); |
| continue; |
| } |
| } else { |
| /* protocol in templates is not used for state/timeout */ |
| pp = NULL; |
| if (state > 0) { |
| IP_VS_DBG(2, "Invalid template state %u in sync msg\n", |
| state); |
| state = 0; |
| } |
| } |
| |
| if (!(flags & IP_VS_CONN_F_TEMPLATE)) |
| cp = ip_vs_conn_in_get(s->protocol, |
| s->caddr, s->cport, |
| s->vaddr, s->vport); |
| else |
| cp = ip_vs_ct_in_get(s->protocol, |
| s->caddr, s->cport, |
| s->vaddr, s->vport); |
| if (!cp) { |
| /* |
| * Find the appropriate destination for the connection. |
| * If it is not found the connection will remain unbound |
| * but still handled. |
| */ |
| dest = ip_vs_find_dest(s->daddr, s->dport, |
| s->vaddr, s->vport, |
| s->protocol); |
| /* Set the approprite ativity flag */ |
| if (s->protocol == IPPROTO_TCP) { |
| if (state != IP_VS_TCP_S_ESTABLISHED) |
| flags |= IP_VS_CONN_F_INACTIVE; |
| else |
| flags &= ~IP_VS_CONN_F_INACTIVE; |
| } |
| cp = ip_vs_conn_new(s->protocol, |
| s->caddr, s->cport, |
| s->vaddr, s->vport, |
| s->daddr, s->dport, |
| flags, dest); |
| if (dest) |
| atomic_dec(&dest->refcnt); |
| if (!cp) { |
| IP_VS_ERR("ip_vs_conn_new failed\n"); |
| return; |
| } |
| } else if (!cp->dest) { |
| dest = ip_vs_try_bind_dest(cp); |
| if (dest) |
| atomic_dec(&dest->refcnt); |
| } else if ((cp->dest) && (cp->protocol == IPPROTO_TCP) && |
| (cp->state != state)) { |
| /* update active/inactive flag for the connection */ |
| dest = cp->dest; |
| if (!(cp->flags & IP_VS_CONN_F_INACTIVE) && |
| (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) && |
| (state == IP_VS_TCP_S_ESTABLISHED)) { |
| atomic_inc(&dest->activeconns); |
| atomic_dec(&dest->inactconns); |
| cp->flags &= ~IP_VS_CONN_F_INACTIVE; |
| } |
| } |
| |
| if (opt) |
| memcpy(&cp->in_seq, opt, sizeof(*opt)); |
| atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]); |
| cp->state = state; |
| cp->old_state = cp->state; |
| /* |
| * We can not recover the right timeout for templates |
| * in all cases, we can not find the right fwmark |
| * virtual service. If needed, we can do it for |
| * non-fwmark persistent services. |
| */ |
| if (!(flags & IP_VS_CONN_F_TEMPLATE) && pp->timeout_table) |
| cp->timeout = pp->timeout_table[state]; |
| else |
| cp->timeout = (3*60*HZ); |
| ip_vs_conn_put(cp); |
| } |
| } |
| |
| |
| /* |
| * 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(&init_net, 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(&init_net, 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(&init_net, 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(&init_net, 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; |
| __be32 addr; |
| struct sockaddr_in sin; |
| |
| if ((dev = __dev_get_by_name(&init_net, 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; |
| |
| msleep_interruptible(1000); |
| } |
| |
| /* 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; |
| |
| msleep_interruptible(1000); |
| } |
| |
| /* 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; |
| struct ip_vs_sync_thread_data *tinfo = startup; |
| |
| /* 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, task_pid_nr(current)); |
| complete(tinfo->startup); |
| |
| /* |
| * once we call the completion queue above, we should |
| * null out that reference, since its allocated on the |
| * stack of the creating kernel thread |
| */ |
| tinfo->startup = NULL; |
| |
| /* 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 */ |
| |
| /* |
| * If we weren't explicitly stopped, then we |
| * exited in error, and should undo our state |
| */ |
| if ((!stop_master_sync) && (!stop_backup_sync)) |
| ip_vs_sync_state -= tinfo->state; |
| |
| 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); |
| |
| /* |
| * we need to free the structure that was allocated |
| * for us in start_sync_thread |
| */ |
| kfree(tinfo); |
| 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); |
| msleep_interruptible(1000); |
| goto repeat; |
| } |
| |
| return 0; |
| } |
| |
| |
| int start_sync_thread(int state, char *mcast_ifn, __u8 syncid) |
| { |
| DECLARE_COMPLETION_ONSTACK(startup); |
| pid_t pid; |
| struct ip_vs_sync_thread_data *tinfo; |
| |
| if ((state == IP_VS_STATE_MASTER && sync_master_pid) || |
| (state == IP_VS_STATE_BACKUP && sync_backup_pid)) |
| return -EEXIST; |
| |
| /* |
| * Note that tinfo will be freed in sync_thread on exit |
| */ |
| tinfo = kmalloc(sizeof(struct ip_vs_sync_thread_data), GFP_KERNEL); |
| if (!tinfo) |
| return -ENOMEM; |
| |
| IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current)); |
| 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) { |
| strlcpy(ip_vs_master_mcast_ifn, mcast_ifn, |
| sizeof(ip_vs_master_mcast_ifn)); |
| ip_vs_master_syncid = syncid; |
| } else { |
| strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn, |
| sizeof(ip_vs_backup_mcast_ifn)); |
| ip_vs_backup_syncid = syncid; |
| } |
| |
| tinfo->state = state; |
| tinfo->startup = &startup; |
| |
| repeat: |
| if ((pid = kernel_thread(fork_sync_thread, tinfo, 0)) < 0) { |
| IP_VS_ERR("could not create fork_sync_thread due to %d... " |
| "retrying.\n", pid); |
| msleep_interruptible(1000); |
| 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", __func__, task_pid_nr(current)); |
| 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; |
| } |