[dpdk-dev] [RFC 04/24] vhost: move socket_fd and un sockaddr into trans_af_unix.c

[Stefan Hajnoczi]

The socket file descriptor and AF_UNIX sockaddr are specific to the
AF_UNIX transport, so move them into trans_af_unix.c.

In order to do this we need to begin defining the vhost_transport_ops
interface that will allow librte_vhost to support multiple transports.
This patch adds socket_init() and socket_cleanup() to
vhost_transport_ops.

Signed-off-by: Stefan Hajnoczi <stefanha at redhat.com>
---
 lib/librte_vhost/vhost.h         | 31 +++++++++++++++++-----
 lib/librte_vhost/socket.c        | 10 ++------
 lib/librte_vhost/trans_af_unix.c | 55 ++++++++++++++++++++++++++++++++--------
 3 files changed, 72 insertions(+), 24 deletions(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index e5279a572..3aefe6597 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -12,8 +12,6 @@
 #include <unistd.h>
 #include <linux/vhost.h>
 #include <linux/virtio_net.h>
-#include <sys/socket.h>
-#include <sys/un.h> /* TODO remove when trans_af_unix.c refactoring is done */
 #include <linux/if.h>
 #include <pthread.h>
 
@@ -205,6 +203,7 @@ struct guest_page {
 };
 
 struct virtio_net;
+struct vhost_user_socket;
 
 /**
  * A structure containing function pointers for transport-specific operations.
@@ -213,6 +212,30 @@ struct vhost_transport_ops {
 	/** Size of struct vhost_user_socket-derived per-socket state */
 	size_t socket_size;
 
+	/**
+	 * Initialize a vhost-user socket that is being created by
+	 * rte_vhost_driver_register().  This function checks that the flags
+	 * are valid but does not establish a vhost-user connection.
+	 *
+	 * @param vsocket
+	 *  new socket
+	 * @param flags
+	 *  flags argument from rte_vhost_driver_register()
+	 * @return
+	 *  0 on success, -1 on failure
+	 */
+	int (*socket_init)(struct vhost_user_socket *vsocket, uint64_t flags);
+
+	/**
+	 * Free resources associated with a socket, including any established
+	 * connections.  This function calls vhost_destroy_device() to destroy
+	 * established connections for this socket.
+	 *
+	 * @param vsocket
+	 *  vhost socket
+	 */
+	void (*socket_cleanup)(struct vhost_user_socket *vsocket);
+
 	/**
 	 * Notify the guest that used descriptors have been added to the vring.
 	 * The VRING_AVAIL_F_NO_INTERRUPT flag has already been checked so this
@@ -286,8 +309,6 @@ struct vhost_user_socket {
 	struct vhost_user_connection_list conn_list;
 	pthread_mutex_t conn_mutex;
 	char *path;
-	int socket_fd;
-	struct sockaddr_un un;
 	bool is_server;
 	bool reconnect;
 	bool dequeue_zero_copy;
@@ -325,14 +346,12 @@ struct vhost_user {
 
 extern struct vhost_user vhost_user;
 
-int create_unix_socket(struct vhost_user_socket *vsocket);
 int vhost_user_start_server(struct vhost_user_socket *vsocket);
 int vhost_user_start_client(struct vhost_user_socket *vsocket);
 
 extern pthread_t reconn_tid;
 
 int vhost_user_reconnect_init(void);
-bool vhost_user_remove_reconnect(struct vhost_user_socket *vsocket);
 
 #define VHOST_LOG_PAGE	4096
 
diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index fffffc663..78f847ccc 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -191,7 +191,7 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 	} else {
 		vsocket->is_server = true;
 	}
-	ret = create_unix_socket(vsocket);
+	ret = trans_ops->socket_init(vsocket, flags);
 	if (ret < 0) {
 		goto out_mutex;
 	}
@@ -231,13 +231,7 @@ rte_vhost_driver_unregister(const char *path)
 		struct vhost_user_socket *vsocket = vhost_user.vsockets[i];
 
 		if (!strcmp(vsocket->path, path)) {
-			if (vsocket->is_server) {
-				fdset_del(&vhost_user.fdset, vsocket->socket_fd);
-				close(vsocket->socket_fd);
-				unlink(path);
-			} else if (vsocket->reconnect) {
-				vhost_user_remove_reconnect(vsocket);
-			}
+			vsocket->trans_ops->socket_cleanup(vsocket);
 
 			pthread_mutex_lock(&vsocket->conn_mutex);
 			for (conn = TAILQ_FIRST(&vsocket->conn_list);
diff --git a/lib/librte_vhost/trans_af_unix.c b/lib/librte_vhost/trans_af_unix.c
index 5e3c5ab2a..cc8d7ccdc 100644
--- a/lib/librte_vhost/trans_af_unix.c
+++ b/lib/librte_vhost/trans_af_unix.c
@@ -33,6 +33,8 @@
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <sys/socket.h>
+#include <sys/un.h>
 #include <fcntl.h>
 
 #include <rte_log.h>
@@ -44,8 +46,11 @@
 
 struct af_unix_socket {
 	struct vhost_user_socket socket; /* must be the first field! */
+	int socket_fd;
+	struct sockaddr_un un;
 };
 
+static int create_unix_socket(struct vhost_user_socket *vsocket);
 static void vhost_user_read_cb(int connfd, void *dat, int *remove);
 
 /* return bytes# of read on success or negative val on failure. */
@@ -240,11 +245,13 @@ vhost_user_read_cb(int connfd, void *dat, int *remove)
 	}
 }
 
-int
+static int
 create_unix_socket(struct vhost_user_socket *vsocket)
 {
+	struct af_unix_socket *s =
+		container_of(vsocket, struct af_unix_socket, socket);
 	int fd;
-	struct sockaddr_un *un = &vsocket->un;
+	struct sockaddr_un *un = &s->un;
 
 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if (fd < 0)
@@ -265,18 +272,20 @@ create_unix_socket(struct vhost_user_socket *vsocket)
 	strncpy(un->sun_path, vsocket->path, sizeof(un->sun_path));
 	un->sun_path[sizeof(un->sun_path) - 1] = '\0';
 
-	vsocket->socket_fd = fd;
+	s->socket_fd = fd;
 	return 0;
 }
 
 int
 vhost_user_start_server(struct vhost_user_socket *vsocket)
 {
+	struct af_unix_socket *s =
+		container_of(vsocket, struct af_unix_socket, socket);
 	int ret;
-	int fd = vsocket->socket_fd;
+	int fd = s->socket_fd;
 	const char *path = vsocket->path;
 
-	ret = bind(fd, (struct sockaddr *)&vsocket->un, sizeof(vsocket->un));
+	ret = bind(fd, (struct sockaddr *)&s->un, sizeof(s->un));
 	if (ret < 0) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"failed to bind to %s: %s; remove it and try again\n",
@@ -427,13 +436,15 @@ vhost_user_reconnect_init(void)
 int
 vhost_user_start_client(struct vhost_user_socket *vsocket)
 {
+	struct af_unix_socket *s =
+		container_of(vsocket, struct af_unix_socket, socket);
 	int ret;
-	int fd = vsocket->socket_fd;
+	int fd = s->socket_fd;
 	const char *path = vsocket->path;
 	struct vhost_user_reconnect *reconn;
 
-	ret = vhost_user_connect_nonblock(fd, (struct sockaddr *)&vsocket->un,
-					  sizeof(vsocket->un));
+	ret = vhost_user_connect_nonblock(fd, (struct sockaddr *)&s->un,
+					  sizeof(s->un));
 	if (ret == 0) {
 		vhost_user_add_connection(fd, vsocket);
 		return 0;
@@ -456,7 +467,7 @@ vhost_user_start_client(struct vhost_user_socket *vsocket)
 		close(fd);
 		return -1;
 	}
-	reconn->un = vsocket->un;
+	reconn->un = s->un;
 	reconn->fd = fd;
 	reconn->vsocket = vsocket;
 	pthread_mutex_lock(&reconn_list.mutex);
@@ -466,7 +477,7 @@ vhost_user_start_client(struct vhost_user_socket *vsocket)
 	return 0;
 }
 
-bool
+static bool
 vhost_user_remove_reconnect(struct vhost_user_socket *vsocket)
 {
 	int found = false;
@@ -490,6 +501,28 @@ vhost_user_remove_reconnect(struct vhost_user_socket *vsocket)
 	return found;
 }
 
+static int
+af_unix_socket_init(struct vhost_user_socket *vsocket,
+		    uint64_t flags __rte_unused)
+{
+	return create_unix_socket(vsocket);
+}
+
+static void
+af_unix_socket_cleanup(struct vhost_user_socket *vsocket)
+{
+	struct af_unix_socket *s =
+		container_of(vsocket, struct af_unix_socket, socket);
+
+	if (vsocket->is_server) {
+		fdset_del(&vhost_user.fdset, s->socket_fd);
+		close(s->socket_fd);
+		unlink(vsocket->path);
+	} else if (vsocket->reconnect) {
+		vhost_user_remove_reconnect(vsocket);
+	}
+}
+
 static int
 af_unix_vring_call(struct virtio_net *dev __rte_unused,
 		   struct vhost_virtqueue *vq)
@@ -501,5 +534,7 @@ af_unix_vring_call(struct virtio_net *dev __rte_unused,
 
 const struct vhost_transport_ops af_unix_trans_ops = {
 	.socket_size = sizeof(struct af_unix_socket),
+	.socket_init = af_unix_socket_init,
+	.socket_cleanup = af_unix_socket_cleanup,
 	.vring_call = af_unix_vring_call,
 };
-- 
2.14.3