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authorJon Maloy <jon.maloy@ericsson.com>2018-02-15 12:40:50 +0300
committerDavid S. Miller <davem@davemloft.net>2018-02-16 23:26:34 +0300
commit0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 (patch)
treeb410be206ad34d2f4bc7f32bb9236d4d46141eb4
parent5c45ab24ac77ea32eae7d3576cf37c3ddb259f80 (diff)
downloadlinux-0ef897be12b8b4cf297b6016e79ec97ec90f2cf6.tar.xz
tipc: separate topology server listener socket from subcsriber sockets
We move the listener socket to struct tipc_server and give it its own work item. This makes it easier to follow the code, and entails some simplifications in the reception code in subscriber sockets. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/tipc/server.c328
1 files changed, 147 insertions, 181 deletions
diff --git a/net/tipc/server.c b/net/tipc/server.c
index 0abbdd698662..0e351e81690e 100644
--- a/net/tipc/server.c
+++ b/net/tipc/server.c
@@ -64,7 +64,6 @@
* @tipc_conn_new: callback will be called when new connection is incoming
* @tipc_conn_release: callback will be called before releasing the connection
* @tipc_conn_recvmsg: callback will be called when message arrives
- * @saddr: TIPC server address
* @name: server name
* @imp: message importance
* @type: socket type
@@ -74,10 +73,11 @@ struct tipc_server {
spinlock_t idr_lock; /* for idr list */
int idr_in_use;
struct net *net;
+ struct work_struct awork;
struct workqueue_struct *rcv_wq;
struct workqueue_struct *send_wq;
int max_rcvbuf_size;
- struct sockaddr_tipc *saddr;
+ struct socket *listener;
char name[TIPC_SERVER_NAME_LEN];
};
@@ -106,7 +106,6 @@ struct tipc_conn {
struct list_head sub_list;
spinlock_t sub_lock; /* for subscription list */
struct work_struct rwork;
- int (*rx_action) (struct tipc_conn *con);
struct list_head outqueue;
spinlock_t outqueue_lock;
struct work_struct swork;
@@ -121,12 +120,6 @@ struct outqueue_entry {
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 struct tipc_conn *sock2con(struct sock *sk)
-{
- return sk->sk_user_data;
-}
static bool connected(struct tipc_conn *con)
{
@@ -137,21 +130,21 @@ 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 socket *sock = con->sock;
+ struct outqueue_entry *e, *safe;
- if (sock) {
- if (test_bit(CF_SERVER, &con->flags)) {
- __module_get(sock->ops->owner);
- __module_get(sock->sk->sk_prot_creator->owner);
- }
- 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);
+ if (con->sock)
+ sock_release(con->sock);
+
+ spin_lock_bh(&con->outqueue_lock);
+ list_for_each_entry_safe(e, safe, &con->outqueue, list) {
+ list_del(&e->list);
+ kfree(e);
+ }
+ spin_unlock_bh(&con->outqueue_lock);
kfree(con);
}
@@ -178,14 +171,14 @@ static struct tipc_conn *tipc_conn_lookup(struct tipc_server *s, int conid)
}
/* sock_data_ready - interrupt callback indicating the socket has data to read
- * The queued job is launched in tipc_recv_from_sock()
+ * The queued work is launched into tipc_recv_work()->tipc_recv_from_sock()
*/
static void sock_data_ready(struct sock *sk)
{
struct tipc_conn *con;
read_lock_bh(&sk->sk_callback_lock);
- con = sock2con(sk);
+ con = sk->sk_user_data;
if (connected(con)) {
conn_get(con);
if (!queue_work(con->server->rcv_wq, &con->rwork))
@@ -195,15 +188,15 @@ static void sock_data_ready(struct sock *sk)
}
/* sock_write_space - interrupt callback after a sendmsg EAGAIN
- * Indicates that there now is more is space in the send buffer
- * The queued job is launched in tipc_send_to_sock()
+ * Indicates that there now is more space in the send buffer
+ * The queued work is launched into tipc_send_work()->tipc_send_to_sock()
*/
static void sock_write_space(struct sock *sk)
{
struct tipc_conn *con;
read_lock_bh(&sk->sk_callback_lock);
- con = sock2con(sk);
+ con = sk->sk_user_data;
if (connected(con)) {
conn_get(con);
if (!queue_work(con->server->send_wq, &con->swork))
@@ -212,23 +205,8 @@ static void sock_write_space(struct sock *sk)
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);
-}
-
/* tipc_con_delete_sub - delete a specific or all subscriptions
- * for a given subscriber
+ * for a given subscriber
*/
static void tipc_con_delete_sub(struct tipc_conn *con, struct tipc_subscr *s)
{
@@ -268,6 +246,7 @@ static void tipc_close_conn(struct tipc_conn *con)
/* Don't flush pending works, -just let them expire */
kernel_sock_shutdown(con->sock, SHUT_RDWR);
+
conn_put(con);
}
@@ -357,117 +336,8 @@ static int tipc_receive_from_sock(struct tipc_conn *con)
return ret;
}
-static int tipc_accept_from_sock(struct tipc_conn *con)
-{
- 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);
-
- /* 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 imp = TIPC_CRITICAL_IMPORTANCE;
- 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 *)&imp, sizeof(imp));
- if (ret < 0)
- goto create_err;
- ret = kernel_bind(sock, (struct sockaddr *)s->saddr, sizeof(*s->saddr));
- if (ret < 0)
- goto create_err;
-
- con->rx_action = tipc_accept_from_sock;
- ret = kernel_listen(sock, 0);
- if (ret < 0)
- 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 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);
- kfree(e);
- }
- spin_unlock_bh(&con->outqueue_lock);
-}
-
-/* tipc_conn_queue_evt - interrupt level call from a subscription instance
- * The queued job is launched in tipc_send_to_sock()
+/* tipc_conn_queue_evt() - interrupt level call from a subscription instance
+ * The queued work is launched into tipc_send_work()->tipc_send_to_sock()
*/
void tipc_conn_queue_evt(struct net *net, int conid,
u32 event, struct tipc_event *evt)
@@ -588,9 +458,9 @@ static void tipc_send_to_sock(struct tipc_conn *con)
1, sizeof(*evt));
if (ret == -EWOULDBLOCK || ret == 0) {
cond_resched();
- goto out;
+ return;
} else if (ret < 0) {
- goto err;
+ return tipc_close_conn(con);
}
} else {
tipc_send_kern_top_evt(srv->net, evt);
@@ -606,10 +476,6 @@ static void tipc_send_to_sock(struct tipc_conn *con)
kfree(e);
}
spin_unlock_bh(&con->outqueue_lock);
-out:
- return;
-err:
- tipc_close_conn(con);
}
static void tipc_recv_work(struct work_struct *work)
@@ -618,7 +484,7 @@ static void tipc_recv_work(struct work_struct *work)
int count = 0;
while (connected(con)) {
- if (con->rx_action(con))
+ if (tipc_receive_from_sock(con))
break;
/* Don't flood Rx machine */
@@ -640,10 +506,113 @@ static void tipc_send_work(struct work_struct *work)
conn_put(con);
}
-static void tipc_work_stop(struct tipc_server *s)
+static void tipc_accept_from_sock(struct work_struct *work)
{
- destroy_workqueue(s->rcv_wq);
- destroy_workqueue(s->send_wq);
+ struct tipc_server *srv = container_of(work, struct tipc_server, awork);
+ struct socket *lsock = srv->listener;
+ struct socket *newsock;
+ struct tipc_conn *con;
+ struct sock *newsk;
+ int ret;
+
+ while (1) {
+ ret = kernel_accept(lsock, &newsock, O_NONBLOCK);
+ if (ret < 0)
+ return;
+ con = tipc_alloc_conn(srv);
+ if (IS_ERR(con)) {
+ ret = PTR_ERR(con);
+ sock_release(newsock);
+ return;
+ }
+ /* Register callbacks */
+ newsk = newsock->sk;
+ write_lock_bh(&newsk->sk_callback_lock);
+ newsk->sk_data_ready = sock_data_ready;
+ newsk->sk_write_space = sock_write_space;
+ newsk->sk_user_data = con;
+ con->sock = newsock;
+ write_unlock_bh(&newsk->sk_callback_lock);
+
+ /* Wake up receive process in case of 'SYN+' message */
+ newsk->sk_data_ready(newsk);
+ }
+}
+
+/* listener_sock_data_ready - interrupt callback indicating new connection
+ * The queued job is launched into tipc_accept_from_sock()
+ */
+static void listener_sock_data_ready(struct sock *sk)
+{
+ struct tipc_server *srv;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ srv = sk->sk_user_data;
+ if (srv->listener)
+ queue_work(srv->rcv_wq, &srv->awork);
+ read_unlock_bh(&sk->sk_callback_lock);
+}
+
+static int tipc_create_listener_sock(struct tipc_server *srv)
+{
+ int imp = TIPC_CRITICAL_IMPORTANCE;
+ struct socket *lsock = NULL;
+ struct sockaddr_tipc saddr;
+ struct sock *sk;
+ int rc;
+
+ rc = sock_create_kern(srv->net, AF_TIPC, SOCK_SEQPACKET, 0, &lsock);
+ if (rc < 0)
+ return rc;
+
+ srv->listener = lsock;
+ sk = lsock->sk;
+ write_lock_bh(&sk->sk_callback_lock);
+ sk->sk_data_ready = listener_sock_data_ready;
+ sk->sk_user_data = srv;
+ write_unlock_bh(&sk->sk_callback_lock);
+
+ rc = kernel_setsockopt(lsock, SOL_TIPC, TIPC_IMPORTANCE,
+ (char *)&imp, sizeof(imp));
+ if (rc < 0)
+ goto err;
+
+ saddr.family = AF_TIPC;
+ saddr.addrtype = TIPC_ADDR_NAMESEQ;
+ saddr.addr.nameseq.type = TIPC_TOP_SRV;
+ saddr.addr.nameseq.lower = TIPC_TOP_SRV;
+ saddr.addr.nameseq.upper = TIPC_TOP_SRV;
+ saddr.scope = TIPC_NODE_SCOPE;
+
+ rc = kernel_bind(lsock, (struct sockaddr *)&saddr, sizeof(saddr));
+ if (rc < 0)
+ goto err;
+ rc = kernel_listen(lsock, 0);
+ if (rc < 0)
+ goto 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(lsock->ops->owner);
+ module_put(sk->sk_prot_creator->owner);
+
+ return 0;
+err:
+ sock_release(lsock);
+ return -EINVAL;
}
static int tipc_work_start(struct tipc_server *s)
@@ -664,32 +633,26 @@ static int tipc_work_start(struct tipc_server *s)
return 0;
}
+static void tipc_work_stop(struct tipc_server *s)
+{
+ destroy_workqueue(s->rcv_wq);
+ destroy_workqueue(s->send_wq);
+}
+
int tipc_topsrv_start(struct net *net)
{
struct tipc_net *tn = tipc_net(net);
const char name[] = "topology_server";
- struct sockaddr_tipc *saddr;
struct tipc_server *srv;
int ret;
- saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
- if (!saddr)
- return -ENOMEM;
- saddr->family = AF_TIPC;
- saddr->addrtype = TIPC_ADDR_NAMESEQ;
- saddr->addr.nameseq.type = TIPC_TOP_SRV;
- saddr->addr.nameseq.lower = TIPC_TOP_SRV;
- saddr->addr.nameseq.upper = TIPC_TOP_SRV;
- saddr->scope = TIPC_NODE_SCOPE;
-
srv = kzalloc(sizeof(*srv), GFP_ATOMIC);
- if (!srv) {
- kfree(saddr);
+ if (!srv)
return -ENOMEM;
- }
- srv->net = net;
- srv->saddr = saddr;
- srv->max_rcvbuf_size = sizeof(struct tipc_subscr);
+
+ srv->net = net;
+ srv->max_rcvbuf_size = sizeof(struct tipc_subscr);
+ INIT_WORK(&srv->awork, tipc_accept_from_sock);
strncpy(srv->name, name, strlen(name) + 1);
tn->topsrv = srv;
@@ -703,7 +666,7 @@ int tipc_topsrv_start(struct net *net)
if (ret < 0)
return ret;
- ret = tipc_open_listening_sock(srv);
+ ret = tipc_create_listener_sock(srv);
if (ret < 0)
tipc_work_stop(srv);
@@ -713,6 +676,7 @@ int tipc_topsrv_start(struct net *net)
void tipc_topsrv_stop(struct net *net)
{
struct tipc_server *srv = tipc_topsrv(net);
+ struct socket *lsock = srv->listener;
struct tipc_conn *con;
int id;
@@ -725,10 +689,12 @@ void tipc_topsrv_stop(struct net *net)
spin_lock_bh(&srv->idr_lock);
}
}
+ __module_get(lsock->ops->owner);
+ __module_get(lsock->sk->sk_prot_creator->owner);
+ sock_release(lsock);
+ srv->listener = NULL;
spin_unlock_bh(&srv->idr_lock);
-
tipc_work_stop(srv);
idr_destroy(&srv->conn_idr);
- kfree(srv->saddr);
kfree(srv);
}