| /* |
| * 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 "addr.h" |
| #include "msg.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 tipc_server *s = con->server; |
| struct sockaddr_tipc *saddr = s->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; |
| } |
| spin_lock_bh(&s->idr_lock); |
| idr_remove(&s->conn_idr, con->conid); |
| s->idr_in_use--; |
| spin_unlock_bh(&s->idr_lock); |
| 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) { |
| if (!test_bit(CF_CONNECTED, &con->flags) || |
| !kref_get_unless_zero(&con->kref)) |
| con = NULL; |
| } |
| spin_unlock_bh(&s->idr_lock); |
| return con; |
| } |
| |
| static void sock_data_ready(struct sock *sk) |
| { |
| struct tipc_conn *con; |
| |
| read_lock_bh(&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_bh(&sk->sk_callback_lock); |
| } |
| |
| static void sock_write_space(struct sock *sk) |
| { |
| struct tipc_conn *con; |
| |
| read_lock_bh(&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_bh(&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_close_conn(struct tipc_conn *con) |
| { |
| struct tipc_server *s = con->server; |
| struct sock *sk = con->sock->sk; |
| bool disconnect = false; |
| |
| write_lock_bh(&sk->sk_callback_lock); |
| disconnect = test_and_clear_bit(CF_CONNECTED, &con->flags); |
| if (disconnect) { |
| sk->sk_user_data = NULL; |
| if (con->conid) |
| s->tipc_conn_release(con->conid, con->usr_data); |
| } |
| write_unlock_bh(&sk->sk_callback_lock); |
| |
| /* Handle concurrent calls from sending and receiving threads */ |
| if (!disconnect) |
| return; |
| |
| /* Don't flush pending works, -just let them expire */ |
| 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 tipc_server *s = con->server; |
| struct sock *sk = con->sock->sk; |
| struct sockaddr_tipc addr; |
| struct msghdr msg = {}; |
| 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; |
| iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, iov.iov_len); |
| ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT); |
| if (ret <= 0) { |
| kmem_cache_free(s->rcvbuf_cache, buf); |
| goto out_close; |
| } |
| |
| read_lock_bh(&sk->sk_callback_lock); |
| if (test_bit(CF_CONNECTED, &con->flags)) |
| ret = s->tipc_conn_recvmsg(sock_net(con->sock->sk), con->conid, |
| &addr, con->usr_data, buf, ret); |
| read_unlock_bh(&sk->sk_callback_lock); |
| kmem_cache_free(s->rcvbuf_cache, buf); |
| if (ret < 0) |
| tipc_conn_terminate(s, con->conid); |
| return ret; |
| |
| 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); |
| conn_put(newcon); |
| 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 = kmemdup(data, len, GFP_ATOMIC); |
| if (!buf) { |
| kfree(entry); |
| return NULL; |
| } |
| |
| 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; |
| |
| if (!test_bit(CF_CONNECTED, &con->flags)) { |
| conn_put(con); |
| return 0; |
| } |
| |
| 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 (!queue_work(s->send_wq, &con->swork)) |
| 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); |
| } |
| } |
| |
| bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type, u32 lower, |
| u32 upper, u32 filter, int *conid) |
| { |
| struct tipc_subscriber *scbr; |
| struct tipc_subscr sub; |
| struct tipc_server *s; |
| struct tipc_conn *con; |
| |
| sub.seq.type = type; |
| sub.seq.lower = lower; |
| sub.seq.upper = upper; |
| sub.timeout = TIPC_WAIT_FOREVER; |
| sub.filter = filter; |
| *(u32 *)&sub.usr_handle = port; |
| |
| con = tipc_alloc_conn(tipc_topsrv(net)); |
| if (IS_ERR(con)) |
| return false; |
| |
| *conid = con->conid; |
| s = con->server; |
| scbr = s->tipc_conn_new(*conid); |
| if (!scbr) { |
| conn_put(con); |
| return false; |
| } |
| |
| con->usr_data = scbr; |
| con->sock = NULL; |
| s->tipc_conn_recvmsg(net, *conid, NULL, scbr, &sub, sizeof(sub)); |
| return true; |
| } |
| |
| void tipc_topsrv_kern_unsubscr(struct net *net, int conid) |
| { |
| struct tipc_conn *con; |
| struct tipc_server *srv; |
| |
| con = tipc_conn_lookup(tipc_topsrv(net), conid); |
| if (!con) |
| return; |
| |
| test_and_clear_bit(CF_CONNECTED, &con->flags); |
| srv = con->server; |
| if (con->conid) |
| srv->tipc_conn_release(con->conid, con->usr_data); |
| conn_put(con); |
| conn_put(con); |
| } |
| |
| static void tipc_send_kern_top_evt(struct net *net, struct tipc_event *evt) |
| { |
| u32 port = *(u32 *)&evt->s.usr_handle; |
| u32 self = tipc_own_addr(net); |
| struct sk_buff_head evtq; |
| struct sk_buff *skb; |
| |
| skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt), |
| self, self, port, port, 0); |
| if (!skb) |
| return; |
| msg_set_dest_droppable(buf_msg(skb), true); |
| memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt)); |
| skb_queue_head_init(&evtq); |
| __skb_queue_tail(&evtq, skb); |
| tipc_sk_rcv(net, &evtq); |
| } |
| |
| static void tipc_send_to_sock(struct tipc_conn *con) |
| { |
| struct tipc_server *s = con->server; |
| struct outqueue_entry *e; |
| struct tipc_event *evt; |
| struct msghdr msg; |
| int count = 0; |
| int ret; |
| |
| spin_lock_bh(&con->outqueue_lock); |
| while (test_bit(CF_CONNECTED, &con->flags)) { |
| e = list_entry(con->outqueue.next, struct outqueue_entry, list); |
| if ((struct list_head *) e == &con->outqueue) |
| break; |
| |
| spin_unlock_bh(&con->outqueue_lock); |
| |
| if (con->sock) { |
| 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; |
| } |
| } else { |
| evt = e->iov.iov_base; |
| tipc_send_kern_top_evt(s->net, evt); |
| } |
| /* 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_ordered_workqueue("tipc_rcv", 0); |
| if (!s->rcv_wq) { |
| pr_err("can't start tipc receive workqueue\n"); |
| return -ENOMEM; |
| } |
| |
| s->send_wq = alloc_ordered_workqueue("tipc_send", 0); |
| 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 id; |
| |
| spin_lock_bh(&s->idr_lock); |
| for (id = 0; s->idr_in_use; id++) { |
| con = idr_find(&s->conn_idr, id); |
| if (con) { |
| 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); |
| } |