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-rw-r--r--net/tipc/server.c634
1 files changed, 634 insertions, 0 deletions
diff --git a/net/tipc/server.c b/net/tipc/server.c
new file mode 100644
index 000000000..77ff03ed1
--- /dev/null
+++ b/net/tipc/server.c
@@ -0,0 +1,634 @@
+/*
+ * net/tipc/server.c: TIPC server infrastructure
+ *
+ * Copyright (c) 2012-2013, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "server.h"
+#include "core.h"
+#include "socket.h"
+#include <net/sock.h>
+#include <linux/module.h>
+
+/* Number of messages to send before rescheduling */
+#define MAX_SEND_MSG_COUNT 25
+#define MAX_RECV_MSG_COUNT 25
+#define CF_CONNECTED 1
+#define CF_SERVER 2
+
+#define sock2con(x) ((struct tipc_conn *)(x)->sk_user_data)
+
+/**
+ * struct tipc_conn - TIPC connection structure
+ * @kref: reference counter to connection object
+ * @conid: connection identifier
+ * @sock: socket handler associated with connection
+ * @flags: indicates connection state
+ * @server: pointer to connected server
+ * @rwork: receive work item
+ * @usr_data: user-specified field
+ * @rx_action: what to do when connection socket is active
+ * @outqueue: pointer to first outbound message in queue
+ * @outqueue_lock: control access to the outqueue
+ * @outqueue: list of connection objects for its server
+ * @swork: send work item
+ */
+struct tipc_conn {
+ struct kref kref;
+ int conid;
+ struct socket *sock;
+ unsigned long flags;
+ struct tipc_server *server;
+ struct work_struct rwork;
+ int (*rx_action) (struct tipc_conn *con);
+ void *usr_data;
+ struct list_head outqueue;
+ spinlock_t outqueue_lock;
+ struct work_struct swork;
+};
+
+/* An entry waiting to be sent */
+struct outqueue_entry {
+ struct list_head list;
+ struct kvec iov;
+ struct sockaddr_tipc dest;
+};
+
+static void tipc_recv_work(struct work_struct *work);
+static void tipc_send_work(struct work_struct *work);
+static void tipc_clean_outqueues(struct tipc_conn *con);
+
+static void tipc_conn_kref_release(struct kref *kref)
+{
+ struct tipc_conn *con = container_of(kref, struct tipc_conn, kref);
+ struct sockaddr_tipc *saddr = con->server->saddr;
+ struct socket *sock = con->sock;
+ struct sock *sk;
+
+ if (sock) {
+ sk = sock->sk;
+ if (test_bit(CF_SERVER, &con->flags)) {
+ __module_get(sock->ops->owner);
+ __module_get(sk->sk_prot_creator->owner);
+ }
+ saddr->scope = -TIPC_NODE_SCOPE;
+ kernel_bind(sock, (struct sockaddr *)saddr, sizeof(*saddr));
+ sock_release(sock);
+ con->sock = NULL;
+ }
+
+ tipc_clean_outqueues(con);
+ kfree(con);
+}
+
+static void conn_put(struct tipc_conn *con)
+{
+ kref_put(&con->kref, tipc_conn_kref_release);
+}
+
+static void conn_get(struct tipc_conn *con)
+{
+ kref_get(&con->kref);
+}
+
+static struct tipc_conn *tipc_conn_lookup(struct tipc_server *s, int conid)
+{
+ struct tipc_conn *con;
+
+ spin_lock_bh(&s->idr_lock);
+ con = idr_find(&s->conn_idr, conid);
+ if (con)
+ conn_get(con);
+ spin_unlock_bh(&s->idr_lock);
+ return con;
+}
+
+static void sock_data_ready(struct sock *sk)
+{
+ struct tipc_conn *con;
+
+ read_lock(&sk->sk_callback_lock);
+ con = sock2con(sk);
+ if (con && test_bit(CF_CONNECTED, &con->flags)) {
+ conn_get(con);
+ if (!queue_work(con->server->rcv_wq, &con->rwork))
+ conn_put(con);
+ }
+ read_unlock(&sk->sk_callback_lock);
+}
+
+static void sock_write_space(struct sock *sk)
+{
+ struct tipc_conn *con;
+
+ read_lock(&sk->sk_callback_lock);
+ con = sock2con(sk);
+ if (con && test_bit(CF_CONNECTED, &con->flags)) {
+ conn_get(con);
+ if (!queue_work(con->server->send_wq, &con->swork))
+ conn_put(con);
+ }
+ read_unlock(&sk->sk_callback_lock);
+}
+
+static void tipc_register_callbacks(struct socket *sock, struct tipc_conn *con)
+{
+ struct sock *sk = sock->sk;
+
+ write_lock_bh(&sk->sk_callback_lock);
+
+ sk->sk_data_ready = sock_data_ready;
+ sk->sk_write_space = sock_write_space;
+ sk->sk_user_data = con;
+
+ con->sock = sock;
+
+ write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void tipc_unregister_callbacks(struct tipc_conn *con)
+{
+ struct sock *sk = con->sock->sk;
+
+ write_lock_bh(&sk->sk_callback_lock);
+ sk->sk_user_data = NULL;
+ write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void tipc_close_conn(struct tipc_conn *con)
+{
+ struct tipc_server *s = con->server;
+
+ if (test_and_clear_bit(CF_CONNECTED, &con->flags)) {
+ if (con->conid)
+ s->tipc_conn_shutdown(con->conid, con->usr_data);
+
+ spin_lock_bh(&s->idr_lock);
+ idr_remove(&s->conn_idr, con->conid);
+ s->idr_in_use--;
+ spin_unlock_bh(&s->idr_lock);
+
+ tipc_unregister_callbacks(con);
+
+ /* We shouldn't flush pending works as we may be in the
+ * thread. In fact the races with pending rx/tx work structs
+ * are harmless for us here as we have already deleted this
+ * connection from server connection list and set
+ * sk->sk_user_data to 0 before releasing connection object.
+ */
+ kernel_sock_shutdown(con->sock, SHUT_RDWR);
+
+ conn_put(con);
+ }
+}
+
+static struct tipc_conn *tipc_alloc_conn(struct tipc_server *s)
+{
+ struct tipc_conn *con;
+ int ret;
+
+ con = kzalloc(sizeof(struct tipc_conn), GFP_ATOMIC);
+ if (!con)
+ return ERR_PTR(-ENOMEM);
+
+ kref_init(&con->kref);
+ INIT_LIST_HEAD(&con->outqueue);
+ spin_lock_init(&con->outqueue_lock);
+ INIT_WORK(&con->swork, tipc_send_work);
+ INIT_WORK(&con->rwork, tipc_recv_work);
+
+ spin_lock_bh(&s->idr_lock);
+ ret = idr_alloc(&s->conn_idr, con, 0, 0, GFP_ATOMIC);
+ if (ret < 0) {
+ kfree(con);
+ spin_unlock_bh(&s->idr_lock);
+ return ERR_PTR(-ENOMEM);
+ }
+ con->conid = ret;
+ s->idr_in_use++;
+ spin_unlock_bh(&s->idr_lock);
+
+ set_bit(CF_CONNECTED, &con->flags);
+ con->server = s;
+
+ return con;
+}
+
+static int tipc_receive_from_sock(struct tipc_conn *con)
+{
+ struct msghdr msg = {};
+ struct tipc_server *s = con->server;
+ struct sockaddr_tipc addr;
+ struct kvec iov;
+ void *buf;
+ int ret;
+
+ buf = kmem_cache_alloc(s->rcvbuf_cache, GFP_ATOMIC);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out_close;
+ }
+
+ iov.iov_base = buf;
+ iov.iov_len = s->max_rcvbuf_size;
+ msg.msg_name = &addr;
+ ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
+ MSG_DONTWAIT);
+ if (ret <= 0) {
+ kmem_cache_free(s->rcvbuf_cache, buf);
+ goto out_close;
+ }
+
+ s->tipc_conn_recvmsg(sock_net(con->sock->sk), con->conid, &addr,
+ con->usr_data, buf, ret);
+
+ kmem_cache_free(s->rcvbuf_cache, buf);
+
+ return 0;
+
+out_close:
+ if (ret != -EWOULDBLOCK)
+ tipc_close_conn(con);
+ else if (ret == 0)
+ /* Don't return success if we really got EOF */
+ ret = -EAGAIN;
+
+ return ret;
+}
+
+static int tipc_accept_from_sock(struct tipc_conn *con)
+{
+ struct tipc_server *s = con->server;
+ struct socket *sock = con->sock;
+ struct socket *newsock;
+ struct tipc_conn *newcon;
+ int ret;
+
+ ret = kernel_accept(sock, &newsock, O_NONBLOCK);
+ if (ret < 0)
+ return ret;
+
+ newcon = tipc_alloc_conn(con->server);
+ if (IS_ERR(newcon)) {
+ ret = PTR_ERR(newcon);
+ sock_release(newsock);
+ return ret;
+ }
+
+ newcon->rx_action = tipc_receive_from_sock;
+ tipc_register_callbacks(newsock, newcon);
+
+ /* Notify that new connection is incoming */
+ newcon->usr_data = s->tipc_conn_new(newcon->conid);
+
+ /* Wake up receive process in case of 'SYN+' message */
+ newsock->sk->sk_data_ready(newsock->sk);
+ return ret;
+}
+
+static struct socket *tipc_create_listen_sock(struct tipc_conn *con)
+{
+ struct tipc_server *s = con->server;
+ struct socket *sock = NULL;
+ int ret;
+
+ ret = __sock_create(s->net, AF_TIPC, SOCK_SEQPACKET, 0, &sock, 1);
+ if (ret < 0)
+ return NULL;
+ ret = kernel_setsockopt(sock, SOL_TIPC, TIPC_IMPORTANCE,
+ (char *)&s->imp, sizeof(s->imp));
+ if (ret < 0)
+ goto create_err;
+ ret = kernel_bind(sock, (struct sockaddr *)s->saddr, sizeof(*s->saddr));
+ if (ret < 0)
+ goto create_err;
+
+ switch (s->type) {
+ case SOCK_STREAM:
+ case SOCK_SEQPACKET:
+ con->rx_action = tipc_accept_from_sock;
+
+ ret = kernel_listen(sock, 0);
+ if (ret < 0)
+ goto create_err;
+ break;
+ case SOCK_DGRAM:
+ case SOCK_RDM:
+ con->rx_action = tipc_receive_from_sock;
+ break;
+ default:
+ pr_err("Unknown socket type %d\n", s->type);
+ goto create_err;
+ }
+
+ /* As server's listening socket owner and creator is the same module,
+ * we have to decrease TIPC module reference count to guarantee that
+ * it remains zero after the server socket is created, otherwise,
+ * executing "rmmod" command is unable to make TIPC module deleted
+ * after TIPC module is inserted successfully.
+ *
+ * However, the reference count is ever increased twice in
+ * sock_create_kern(): one is to increase the reference count of owner
+ * of TIPC socket's proto_ops struct; another is to increment the
+ * reference count of owner of TIPC proto struct. Therefore, we must
+ * decrement the module reference count twice to ensure that it keeps
+ * zero after server's listening socket is created. Of course, we
+ * must bump the module reference count twice as well before the socket
+ * is closed.
+ */
+ module_put(sock->ops->owner);
+ module_put(sock->sk->sk_prot_creator->owner);
+ set_bit(CF_SERVER, &con->flags);
+
+ return sock;
+
+create_err:
+ kernel_sock_shutdown(sock, SHUT_RDWR);
+ sock_release(sock);
+ return NULL;
+}
+
+static int tipc_open_listening_sock(struct tipc_server *s)
+{
+ struct socket *sock;
+ struct tipc_conn *con;
+
+ con = tipc_alloc_conn(s);
+ if (IS_ERR(con))
+ return PTR_ERR(con);
+
+ sock = tipc_create_listen_sock(con);
+ if (!sock) {
+ idr_remove(&s->conn_idr, con->conid);
+ s->idr_in_use--;
+ kfree(con);
+ return -EINVAL;
+ }
+
+ tipc_register_callbacks(sock, con);
+ return 0;
+}
+
+static struct outqueue_entry *tipc_alloc_entry(void *data, int len)
+{
+ struct outqueue_entry *entry;
+ void *buf;
+
+ entry = kmalloc(sizeof(struct outqueue_entry), GFP_ATOMIC);
+ if (!entry)
+ return NULL;
+
+ buf = kmalloc(len, GFP_ATOMIC);
+ if (!buf) {
+ kfree(entry);
+ return NULL;
+ }
+
+ memcpy(buf, data, len);
+ entry->iov.iov_base = buf;
+ entry->iov.iov_len = len;
+
+ return entry;
+}
+
+static void tipc_free_entry(struct outqueue_entry *e)
+{
+ kfree(e->iov.iov_base);
+ kfree(e);
+}
+
+static void tipc_clean_outqueues(struct tipc_conn *con)
+{
+ struct outqueue_entry *e, *safe;
+
+ spin_lock_bh(&con->outqueue_lock);
+ list_for_each_entry_safe(e, safe, &con->outqueue, list) {
+ list_del(&e->list);
+ tipc_free_entry(e);
+ }
+ spin_unlock_bh(&con->outqueue_lock);
+}
+
+int tipc_conn_sendmsg(struct tipc_server *s, int conid,
+ struct sockaddr_tipc *addr, void *data, size_t len)
+{
+ struct outqueue_entry *e;
+ struct tipc_conn *con;
+
+ con = tipc_conn_lookup(s, conid);
+ if (!con)
+ return -EINVAL;
+
+ e = tipc_alloc_entry(data, len);
+ if (!e) {
+ conn_put(con);
+ return -ENOMEM;
+ }
+
+ if (addr)
+ memcpy(&e->dest, addr, sizeof(struct sockaddr_tipc));
+
+ spin_lock_bh(&con->outqueue_lock);
+ list_add_tail(&e->list, &con->outqueue);
+ spin_unlock_bh(&con->outqueue_lock);
+
+ if (test_bit(CF_CONNECTED, &con->flags)) {
+ if (!queue_work(s->send_wq, &con->swork))
+ conn_put(con);
+ } else {
+ conn_put(con);
+ }
+ return 0;
+}
+
+void tipc_conn_terminate(struct tipc_server *s, int conid)
+{
+ struct tipc_conn *con;
+
+ con = tipc_conn_lookup(s, conid);
+ if (con) {
+ tipc_close_conn(con);
+ conn_put(con);
+ }
+}
+
+static void tipc_send_to_sock(struct tipc_conn *con)
+{
+ int count = 0;
+ struct tipc_server *s = con->server;
+ struct outqueue_entry *e;
+ struct msghdr msg;
+ int ret;
+
+ spin_lock_bh(&con->outqueue_lock);
+ while (1) {
+ e = list_entry(con->outqueue.next, struct outqueue_entry,
+ list);
+ if ((struct list_head *) e == &con->outqueue)
+ break;
+ spin_unlock_bh(&con->outqueue_lock);
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_flags = MSG_DONTWAIT;
+
+ if (s->type == SOCK_DGRAM || s->type == SOCK_RDM) {
+ msg.msg_name = &e->dest;
+ msg.msg_namelen = sizeof(struct sockaddr_tipc);
+ }
+ ret = kernel_sendmsg(con->sock, &msg, &e->iov, 1,
+ e->iov.iov_len);
+ if (ret == -EWOULDBLOCK || ret == 0) {
+ cond_resched();
+ goto out;
+ } else if (ret < 0) {
+ goto send_err;
+ }
+
+ /* Don't starve users filling buffers */
+ if (++count >= MAX_SEND_MSG_COUNT) {
+ cond_resched();
+ count = 0;
+ }
+
+ spin_lock_bh(&con->outqueue_lock);
+ list_del(&e->list);
+ tipc_free_entry(e);
+ }
+ spin_unlock_bh(&con->outqueue_lock);
+out:
+ return;
+
+send_err:
+ tipc_close_conn(con);
+}
+
+static void tipc_recv_work(struct work_struct *work)
+{
+ struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
+ int count = 0;
+
+ while (test_bit(CF_CONNECTED, &con->flags)) {
+ if (con->rx_action(con))
+ break;
+
+ /* Don't flood Rx machine */
+ if (++count >= MAX_RECV_MSG_COUNT) {
+ cond_resched();
+ count = 0;
+ }
+ }
+ conn_put(con);
+}
+
+static void tipc_send_work(struct work_struct *work)
+{
+ struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
+
+ if (test_bit(CF_CONNECTED, &con->flags))
+ tipc_send_to_sock(con);
+
+ conn_put(con);
+}
+
+static void tipc_work_stop(struct tipc_server *s)
+{
+ destroy_workqueue(s->rcv_wq);
+ destroy_workqueue(s->send_wq);
+}
+
+static int tipc_work_start(struct tipc_server *s)
+{
+ s->rcv_wq = alloc_workqueue("tipc_rcv", WQ_UNBOUND, 1);
+ if (!s->rcv_wq) {
+ pr_err("can't start tipc receive workqueue\n");
+ return -ENOMEM;
+ }
+
+ s->send_wq = alloc_workqueue("tipc_send", WQ_UNBOUND, 1);
+ if (!s->send_wq) {
+ pr_err("can't start tipc send workqueue\n");
+ destroy_workqueue(s->rcv_wq);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int tipc_server_start(struct tipc_server *s)
+{
+ int ret;
+
+ spin_lock_init(&s->idr_lock);
+ idr_init(&s->conn_idr);
+ s->idr_in_use = 0;
+
+ s->rcvbuf_cache = kmem_cache_create(s->name, s->max_rcvbuf_size,
+ 0, SLAB_HWCACHE_ALIGN, NULL);
+ if (!s->rcvbuf_cache)
+ return -ENOMEM;
+
+ ret = tipc_work_start(s);
+ if (ret < 0) {
+ kmem_cache_destroy(s->rcvbuf_cache);
+ return ret;
+ }
+ ret = tipc_open_listening_sock(s);
+ if (ret < 0) {
+ tipc_work_stop(s);
+ kmem_cache_destroy(s->rcvbuf_cache);
+ return ret;
+ }
+ return ret;
+}
+
+void tipc_server_stop(struct tipc_server *s)
+{
+ struct tipc_conn *con;
+ int total = 0;
+ int id;
+
+ spin_lock_bh(&s->idr_lock);
+ for (id = 0; total < s->idr_in_use; id++) {
+ con = idr_find(&s->conn_idr, id);
+ if (con) {
+ total++;
+ spin_unlock_bh(&s->idr_lock);
+ tipc_close_conn(con);
+ spin_lock_bh(&s->idr_lock);
+ }
+ }
+ spin_unlock_bh(&s->idr_lock);
+
+ tipc_work_stop(s);
+ kmem_cache_destroy(s->rcvbuf_cache);
+ idr_destroy(&s->conn_idr);
+}