/* * 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);	if (!newcon->usr_data) {		sock_release(newsock);		return -ENOMEM;	} 	/* 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_kern(s->net, AF_TIPC, SOCK_SEQPACKET, 0, &sock);	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)

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