12025cf9eSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2ae0078fcSDexuan Cui /*
3ae0078fcSDexuan Cui  * Hyper-V transport for vsock
4ae0078fcSDexuan Cui  *
5ae0078fcSDexuan Cui  * Hyper-V Sockets supplies a byte-stream based communication mechanism
6ae0078fcSDexuan Cui  * between the host and the VM. This driver implements the necessary
7ae0078fcSDexuan Cui  * support in the VM by introducing the new vsock transport.
8ae0078fcSDexuan Cui  *
9ae0078fcSDexuan Cui  * Copyright (c) 2017, Microsoft Corporation.
10ae0078fcSDexuan Cui  */
11ae0078fcSDexuan Cui #include <linux/module.h>
12ae0078fcSDexuan Cui #include <linux/vmalloc.h>
13ae0078fcSDexuan Cui #include <linux/hyperv.h>
14ae0078fcSDexuan Cui #include <net/sock.h>
15ae0078fcSDexuan Cui #include <net/af_vsock.h>
16ae0078fcSDexuan Cui 
17ae0078fcSDexuan Cui /* The host side's design of the feature requires 6 exact 4KB pages for
18ae0078fcSDexuan Cui  * recv/send rings respectively -- this is suboptimal considering memory
19ae0078fcSDexuan Cui  * consumption, however unluckily we have to live with it, before the
20ae0078fcSDexuan Cui  * host comes up with a better design in the future.
21ae0078fcSDexuan Cui  */
22ae0078fcSDexuan Cui #define PAGE_SIZE_4K		4096
23ae0078fcSDexuan Cui #define RINGBUFFER_HVS_RCV_SIZE (PAGE_SIZE_4K * 6)
24ae0078fcSDexuan Cui #define RINGBUFFER_HVS_SND_SIZE (PAGE_SIZE_4K * 6)
25ae0078fcSDexuan Cui 
26ae0078fcSDexuan Cui /* The MTU is 16KB per the host side's design */
27ae0078fcSDexuan Cui #define HVS_MTU_SIZE		(1024 * 16)
28ae0078fcSDexuan Cui 
29a9eeb998SSunil Muthuswamy /* How long to wait for graceful shutdown of a connection */
30a9eeb998SSunil Muthuswamy #define HVS_CLOSE_TIMEOUT (8 * HZ)
31a9eeb998SSunil Muthuswamy 
32ae0078fcSDexuan Cui struct vmpipe_proto_header {
33ae0078fcSDexuan Cui 	u32 pkt_type;
34ae0078fcSDexuan Cui 	u32 data_size;
35ae0078fcSDexuan Cui };
36ae0078fcSDexuan Cui 
37ae0078fcSDexuan Cui /* For recv, we use the VMBus in-place packet iterator APIs to directly copy
38ae0078fcSDexuan Cui  * data from the ringbuffer into the userspace buffer.
39ae0078fcSDexuan Cui  */
40ae0078fcSDexuan Cui struct hvs_recv_buf {
41ae0078fcSDexuan Cui 	/* The header before the payload data */
42ae0078fcSDexuan Cui 	struct vmpipe_proto_header hdr;
43ae0078fcSDexuan Cui 
44ae0078fcSDexuan Cui 	/* The payload */
45ae0078fcSDexuan Cui 	u8 data[HVS_MTU_SIZE];
46ae0078fcSDexuan Cui };
47ae0078fcSDexuan Cui 
48ae0078fcSDexuan Cui /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use
49ae0078fcSDexuan Cui  * a small size, i.e. HVS_SEND_BUF_SIZE, to minimize the dynamically-allocated
50ae0078fcSDexuan Cui  * buffer, because tests show there is no significant performance difference.
51ae0078fcSDexuan Cui  *
52ae0078fcSDexuan Cui  * Note: the buffer can be eliminated in the future when we add new VMBus
53ae0078fcSDexuan Cui  * ringbuffer APIs that allow us to directly copy data from userspace buffer
54ae0078fcSDexuan Cui  * to VMBus ringbuffer.
55ae0078fcSDexuan Cui  */
56ae0078fcSDexuan Cui #define HVS_SEND_BUF_SIZE (PAGE_SIZE_4K - sizeof(struct vmpipe_proto_header))
57ae0078fcSDexuan Cui 
58ae0078fcSDexuan Cui struct hvs_send_buf {
59ae0078fcSDexuan Cui 	/* The header before the payload data */
60ae0078fcSDexuan Cui 	struct vmpipe_proto_header hdr;
61ae0078fcSDexuan Cui 
62ae0078fcSDexuan Cui 	/* The payload */
63ae0078fcSDexuan Cui 	u8 data[HVS_SEND_BUF_SIZE];
64ae0078fcSDexuan Cui };
65ae0078fcSDexuan Cui 
66ae0078fcSDexuan Cui #define HVS_HEADER_LEN	(sizeof(struct vmpacket_descriptor) + \
67ae0078fcSDexuan Cui 			 sizeof(struct vmpipe_proto_header))
68ae0078fcSDexuan Cui 
69ae0078fcSDexuan Cui /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and
70ae0078fcSDexuan Cui  * __hv_pkt_iter_next().
71ae0078fcSDexuan Cui  */
72ae0078fcSDexuan Cui #define VMBUS_PKT_TRAILER_SIZE	(sizeof(u64))
73ae0078fcSDexuan Cui 
74ae0078fcSDexuan Cui #define HVS_PKT_LEN(payload_len)	(HVS_HEADER_LEN + \
75ae0078fcSDexuan Cui 					 ALIGN((payload_len), 8) + \
76ae0078fcSDexuan Cui 					 VMBUS_PKT_TRAILER_SIZE)
77ae0078fcSDexuan Cui 
78ae0078fcSDexuan Cui union hvs_service_id {
79ae0078fcSDexuan Cui 	uuid_le	srv_id;
80ae0078fcSDexuan Cui 
81ae0078fcSDexuan Cui 	struct {
82ae0078fcSDexuan Cui 		unsigned int svm_port;
83ae0078fcSDexuan Cui 		unsigned char b[sizeof(uuid_le) - sizeof(unsigned int)];
84ae0078fcSDexuan Cui 	};
85ae0078fcSDexuan Cui };
86ae0078fcSDexuan Cui 
87ae0078fcSDexuan Cui /* Per-socket state (accessed via vsk->trans) */
88ae0078fcSDexuan Cui struct hvsock {
89ae0078fcSDexuan Cui 	struct vsock_sock *vsk;
90ae0078fcSDexuan Cui 
91ae0078fcSDexuan Cui 	uuid_le vm_srv_id;
92ae0078fcSDexuan Cui 	uuid_le host_srv_id;
93ae0078fcSDexuan Cui 
94ae0078fcSDexuan Cui 	struct vmbus_channel *chan;
95ae0078fcSDexuan Cui 	struct vmpacket_descriptor *recv_desc;
96ae0078fcSDexuan Cui 
97ae0078fcSDexuan Cui 	/* The length of the payload not delivered to userland yet */
98ae0078fcSDexuan Cui 	u32 recv_data_len;
99ae0078fcSDexuan Cui 	/* The offset of the payload */
100ae0078fcSDexuan Cui 	u32 recv_data_off;
101ae0078fcSDexuan Cui 
102ae0078fcSDexuan Cui 	/* Have we sent the zero-length packet (FIN)? */
103ae0078fcSDexuan Cui 	bool fin_sent;
104ae0078fcSDexuan Cui };
105ae0078fcSDexuan Cui 
106ae0078fcSDexuan Cui /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is
107ae0078fcSDexuan Cui  * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here:
108ae0078fcSDexuan Cui  * when we write apps to connect to the host, we can only use VMADDR_CID_ANY
109ae0078fcSDexuan Cui  * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we
110ae0078fcSDexuan Cui  * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY
111ae0078fcSDexuan Cui  * as the local cid.
112ae0078fcSDexuan Cui  *
113ae0078fcSDexuan Cui  * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV:
114ae0078fcSDexuan Cui  * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-
115ae0078fcSDexuan Cui  * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with
116ae0078fcSDexuan Cui  * the below sockaddr:
117ae0078fcSDexuan Cui  *
118ae0078fcSDexuan Cui  * struct SOCKADDR_HV
119ae0078fcSDexuan Cui  * {
120ae0078fcSDexuan Cui  *    ADDRESS_FAMILY Family;
121ae0078fcSDexuan Cui  *    USHORT Reserved;
122ae0078fcSDexuan Cui  *    GUID VmId;
123ae0078fcSDexuan Cui  *    GUID ServiceId;
124ae0078fcSDexuan Cui  * };
125ae0078fcSDexuan Cui  * Note: VmID is not used by Linux VM and actually it isn't transmitted via
126ae0078fcSDexuan Cui  * VMBus, because here it's obvious the host and the VM can easily identify
127ae0078fcSDexuan Cui  * each other. Though the VmID is useful on the host, especially in the case
128ae0078fcSDexuan Cui  * of Windows container, Linux VM doesn't need it at all.
129ae0078fcSDexuan Cui  *
130ae0078fcSDexuan Cui  * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit
131ae0078fcSDexuan Cui  * the available GUID space of SOCKADDR_HV so that we can create a mapping
132ae0078fcSDexuan Cui  * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing
133ae0078fcSDexuan Cui  * Hyper-V Sockets apps on the host and in Linux VM is:
134ae0078fcSDexuan Cui  *
135ae0078fcSDexuan Cui  ****************************************************************************
136ae0078fcSDexuan Cui  * The only valid Service GUIDs, from the perspectives of both the host and *
137ae0078fcSDexuan Cui  * Linux VM, that can be connected by the other end, must conform to this   *
138ae0078fcSDexuan Cui  * format: <port>-facb-11e6-bd58-64006a7986d3, and the "port" must be in    *
139ae0078fcSDexuan Cui  * this range [0, 0x7FFFFFFF].                                              *
140ae0078fcSDexuan Cui  ****************************************************************************
141ae0078fcSDexuan Cui  *
142ae0078fcSDexuan Cui  * When we write apps on the host to connect(), the GUID ServiceID is used.
143ae0078fcSDexuan Cui  * When we write apps in Linux VM to connect(), we only need to specify the
144ae0078fcSDexuan Cui  * port and the driver will form the GUID and use that to request the host.
145ae0078fcSDexuan Cui  *
146ae0078fcSDexuan Cui  * From the perspective of Linux VM:
147ae0078fcSDexuan Cui  * 1. the local ephemeral port (i.e. the local auto-bound port when we call
148ae0078fcSDexuan Cui  * connect() without explicit bind()) is generated by __vsock_bind_stream(),
149ae0078fcSDexuan Cui  * and the range is [1024, 0xFFFFFFFF).
150ae0078fcSDexuan Cui  * 2. the remote ephemeral port (i.e. the auto-generated remote port for
151ae0078fcSDexuan Cui  * a connect request initiated by the host's connect()) is generated by
152ae0078fcSDexuan Cui  * hvs_remote_addr_init() and the range is [0x80000000, 0xFFFFFFFF).
153ae0078fcSDexuan Cui  */
154ae0078fcSDexuan Cui 
155ae0078fcSDexuan Cui #define MAX_LISTEN_PORT			((u32)0x7FFFFFFF)
156ae0078fcSDexuan Cui #define MAX_VM_LISTEN_PORT		MAX_LISTEN_PORT
157ae0078fcSDexuan Cui #define MAX_HOST_LISTEN_PORT		MAX_LISTEN_PORT
158ae0078fcSDexuan Cui #define MIN_HOST_EPHEMERAL_PORT		(MAX_HOST_LISTEN_PORT + 1)
159ae0078fcSDexuan Cui 
160ae0078fcSDexuan Cui /* 00000000-facb-11e6-bd58-64006a7986d3 */
161ae0078fcSDexuan Cui static const uuid_le srv_id_template =
162ae0078fcSDexuan Cui 	UUID_LE(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58,
163ae0078fcSDexuan Cui 		0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3);
164ae0078fcSDexuan Cui 
165ae0078fcSDexuan Cui static bool is_valid_srv_id(const uuid_le *id)
166ae0078fcSDexuan Cui {
167ae0078fcSDexuan Cui 	return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(uuid_le) - 4);
168ae0078fcSDexuan Cui }
169ae0078fcSDexuan Cui 
170ae0078fcSDexuan Cui static unsigned int get_port_by_srv_id(const uuid_le *svr_id)
171ae0078fcSDexuan Cui {
172ae0078fcSDexuan Cui 	return *((unsigned int *)svr_id);
173ae0078fcSDexuan Cui }
174ae0078fcSDexuan Cui 
175ae0078fcSDexuan Cui static void hvs_addr_init(struct sockaddr_vm *addr, const uuid_le *svr_id)
176ae0078fcSDexuan Cui {
177ae0078fcSDexuan Cui 	unsigned int port = get_port_by_srv_id(svr_id);
178ae0078fcSDexuan Cui 
179ae0078fcSDexuan Cui 	vsock_addr_init(addr, VMADDR_CID_ANY, port);
180ae0078fcSDexuan Cui }
181ae0078fcSDexuan Cui 
182ae0078fcSDexuan Cui static void hvs_remote_addr_init(struct sockaddr_vm *remote,
183ae0078fcSDexuan Cui 				 struct sockaddr_vm *local)
184ae0078fcSDexuan Cui {
185ae0078fcSDexuan Cui 	static u32 host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT;
186ae0078fcSDexuan Cui 	struct sock *sk;
187ae0078fcSDexuan Cui 
188ae0078fcSDexuan Cui 	vsock_addr_init(remote, VMADDR_CID_ANY, VMADDR_PORT_ANY);
189ae0078fcSDexuan Cui 
190ae0078fcSDexuan Cui 	while (1) {
191ae0078fcSDexuan Cui 		/* Wrap around ? */
192ae0078fcSDexuan Cui 		if (host_ephemeral_port < MIN_HOST_EPHEMERAL_PORT ||
193ae0078fcSDexuan Cui 		    host_ephemeral_port == VMADDR_PORT_ANY)
194ae0078fcSDexuan Cui 			host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT;
195ae0078fcSDexuan Cui 
196ae0078fcSDexuan Cui 		remote->svm_port = host_ephemeral_port++;
197ae0078fcSDexuan Cui 
198ae0078fcSDexuan Cui 		sk = vsock_find_connected_socket(remote, local);
199ae0078fcSDexuan Cui 		if (!sk) {
200ae0078fcSDexuan Cui 			/* Found an available ephemeral port */
201ae0078fcSDexuan Cui 			return;
202ae0078fcSDexuan Cui 		}
203ae0078fcSDexuan Cui 
204ae0078fcSDexuan Cui 		/* Release refcnt got in vsock_find_connected_socket */
205ae0078fcSDexuan Cui 		sock_put(sk);
206ae0078fcSDexuan Cui 	}
207ae0078fcSDexuan Cui }
208ae0078fcSDexuan Cui 
209ae0078fcSDexuan Cui static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan)
210ae0078fcSDexuan Cui {
211ae0078fcSDexuan Cui 	set_channel_pending_send_size(chan,
212ae0078fcSDexuan Cui 				      HVS_PKT_LEN(HVS_SEND_BUF_SIZE));
213ae0078fcSDexuan Cui 
214ae0078fcSDexuan Cui 	/* See hvs_stream_has_space(): we must make sure the host has seen
215ae0078fcSDexuan Cui 	 * the new pending send size, before we can re-check the writable
216ae0078fcSDexuan Cui 	 * bytes.
217ae0078fcSDexuan Cui 	 */
218ae0078fcSDexuan Cui 	virt_mb();
219ae0078fcSDexuan Cui }
220ae0078fcSDexuan Cui 
221ae0078fcSDexuan Cui static void hvs_clear_channel_pending_send_size(struct vmbus_channel *chan)
222ae0078fcSDexuan Cui {
223ae0078fcSDexuan Cui 	set_channel_pending_send_size(chan, 0);
224ae0078fcSDexuan Cui 
225ae0078fcSDexuan Cui 	/* Ditto */
226ae0078fcSDexuan Cui 	virt_mb();
227ae0078fcSDexuan Cui }
228ae0078fcSDexuan Cui 
229ae0078fcSDexuan Cui static bool hvs_channel_readable(struct vmbus_channel *chan)
230ae0078fcSDexuan Cui {
231ae0078fcSDexuan Cui 	u32 readable = hv_get_bytes_to_read(&chan->inbound);
232ae0078fcSDexuan Cui 
233ae0078fcSDexuan Cui 	/* 0-size payload means FIN */
234ae0078fcSDexuan Cui 	return readable >= HVS_PKT_LEN(0);
235ae0078fcSDexuan Cui }
236ae0078fcSDexuan Cui 
237ae0078fcSDexuan Cui static int hvs_channel_readable_payload(struct vmbus_channel *chan)
238ae0078fcSDexuan Cui {
239ae0078fcSDexuan Cui 	u32 readable = hv_get_bytes_to_read(&chan->inbound);
240ae0078fcSDexuan Cui 
241ae0078fcSDexuan Cui 	if (readable > HVS_PKT_LEN(0)) {
242ae0078fcSDexuan Cui 		/* At least we have 1 byte to read. We don't need to return
243ae0078fcSDexuan Cui 		 * the exact readable bytes: see vsock_stream_recvmsg() ->
244ae0078fcSDexuan Cui 		 * vsock_stream_has_data().
245ae0078fcSDexuan Cui 		 */
246ae0078fcSDexuan Cui 		return 1;
247ae0078fcSDexuan Cui 	}
248ae0078fcSDexuan Cui 
249ae0078fcSDexuan Cui 	if (readable == HVS_PKT_LEN(0)) {
250ae0078fcSDexuan Cui 		/* 0-size payload means FIN */
251ae0078fcSDexuan Cui 		return 0;
252ae0078fcSDexuan Cui 	}
253ae0078fcSDexuan Cui 
254ae0078fcSDexuan Cui 	/* No payload or FIN */
255ae0078fcSDexuan Cui 	return -1;
256ae0078fcSDexuan Cui }
257ae0078fcSDexuan Cui 
258ae0078fcSDexuan Cui static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan)
259ae0078fcSDexuan Cui {
260ae0078fcSDexuan Cui 	u32 writeable = hv_get_bytes_to_write(&chan->outbound);
261ae0078fcSDexuan Cui 	size_t ret;
262ae0078fcSDexuan Cui 
263ae0078fcSDexuan Cui 	/* The ringbuffer mustn't be 100% full, and we should reserve a
264ae0078fcSDexuan Cui 	 * zero-length-payload packet for the FIN: see hv_ringbuffer_write()
265ae0078fcSDexuan Cui 	 * and hvs_shutdown().
266ae0078fcSDexuan Cui 	 */
267ae0078fcSDexuan Cui 	if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0))
268ae0078fcSDexuan Cui 		return 0;
269ae0078fcSDexuan Cui 
270ae0078fcSDexuan Cui 	ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0);
271ae0078fcSDexuan Cui 
272ae0078fcSDexuan Cui 	return round_down(ret, 8);
273ae0078fcSDexuan Cui }
274ae0078fcSDexuan Cui 
275ae0078fcSDexuan Cui static int hvs_send_data(struct vmbus_channel *chan,
276ae0078fcSDexuan Cui 			 struct hvs_send_buf *send_buf, size_t to_write)
277ae0078fcSDexuan Cui {
278ae0078fcSDexuan Cui 	send_buf->hdr.pkt_type = 1;
279ae0078fcSDexuan Cui 	send_buf->hdr.data_size = to_write;
280ae0078fcSDexuan Cui 	return vmbus_sendpacket(chan, &send_buf->hdr,
281ae0078fcSDexuan Cui 				sizeof(send_buf->hdr) + to_write,
282ae0078fcSDexuan Cui 				0, VM_PKT_DATA_INBAND, 0);
283ae0078fcSDexuan Cui }
284ae0078fcSDexuan Cui 
285ae0078fcSDexuan Cui static void hvs_channel_cb(void *ctx)
286ae0078fcSDexuan Cui {
287ae0078fcSDexuan Cui 	struct sock *sk = (struct sock *)ctx;
288ae0078fcSDexuan Cui 	struct vsock_sock *vsk = vsock_sk(sk);
289ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
290ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
291ae0078fcSDexuan Cui 
292ae0078fcSDexuan Cui 	if (hvs_channel_readable(chan))
293ae0078fcSDexuan Cui 		sk->sk_data_ready(sk);
294ae0078fcSDexuan Cui 
295ae0078fcSDexuan Cui 	/* See hvs_stream_has_space(): when we reach here, the writable bytes
296ae0078fcSDexuan Cui 	 * may be already less than HVS_PKT_LEN(HVS_SEND_BUF_SIZE).
297ae0078fcSDexuan Cui 	 */
298ae0078fcSDexuan Cui 	if (hv_get_bytes_to_write(&chan->outbound) > 0)
299ae0078fcSDexuan Cui 		sk->sk_write_space(sk);
300ae0078fcSDexuan Cui }
301ae0078fcSDexuan Cui 
302a9eeb998SSunil Muthuswamy static void hvs_do_close_lock_held(struct vsock_sock *vsk,
303a9eeb998SSunil Muthuswamy 				   bool cancel_timeout)
304a9eeb998SSunil Muthuswamy {
305a9eeb998SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
306a9eeb998SSunil Muthuswamy 
307a9eeb998SSunil Muthuswamy 	sock_set_flag(sk, SOCK_DONE);
308a9eeb998SSunil Muthuswamy 	vsk->peer_shutdown = SHUTDOWN_MASK;
309a9eeb998SSunil Muthuswamy 	if (vsock_stream_has_data(vsk) <= 0)
310a9eeb998SSunil Muthuswamy 		sk->sk_state = TCP_CLOSING;
311a9eeb998SSunil Muthuswamy 	sk->sk_state_change(sk);
312a9eeb998SSunil Muthuswamy 	if (vsk->close_work_scheduled &&
313a9eeb998SSunil Muthuswamy 	    (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
314a9eeb998SSunil Muthuswamy 		vsk->close_work_scheduled = false;
315a9eeb998SSunil Muthuswamy 		vsock_remove_sock(vsk);
316a9eeb998SSunil Muthuswamy 
317a9eeb998SSunil Muthuswamy 		/* Release the reference taken while scheduling the timeout */
318a9eeb998SSunil Muthuswamy 		sock_put(sk);
319a9eeb998SSunil Muthuswamy 	}
320a9eeb998SSunil Muthuswamy }
321a9eeb998SSunil Muthuswamy 
322ae0078fcSDexuan Cui static void hvs_close_connection(struct vmbus_channel *chan)
323ae0078fcSDexuan Cui {
324ae0078fcSDexuan Cui 	struct sock *sk = get_per_channel_state(chan);
325ae0078fcSDexuan Cui 
326b4562ca7SDexuan Cui 	lock_sock(sk);
327a9eeb998SSunil Muthuswamy 	hvs_do_close_lock_held(vsock_sk(sk), true);
328b4562ca7SDexuan Cui 	release_sock(sk);
329ae0078fcSDexuan Cui }
330ae0078fcSDexuan Cui 
331ae0078fcSDexuan Cui static void hvs_open_connection(struct vmbus_channel *chan)
332ae0078fcSDexuan Cui {
333ae0078fcSDexuan Cui 	uuid_le *if_instance, *if_type;
334ae0078fcSDexuan Cui 	unsigned char conn_from_host;
335ae0078fcSDexuan Cui 
336ae0078fcSDexuan Cui 	struct sockaddr_vm addr;
337ae0078fcSDexuan Cui 	struct sock *sk, *new = NULL;
338ae0078fcSDexuan Cui 	struct vsock_sock *vnew;
339ae0078fcSDexuan Cui 	struct hvsock *hvs, *hvs_new;
340ae0078fcSDexuan Cui 	int ret;
341ae0078fcSDexuan Cui 
342ae0078fcSDexuan Cui 	if_type = &chan->offermsg.offer.if_type;
343ae0078fcSDexuan Cui 	if_instance = &chan->offermsg.offer.if_instance;
344ae0078fcSDexuan Cui 	conn_from_host = chan->offermsg.offer.u.pipe.user_def[0];
345ae0078fcSDexuan Cui 
346ae0078fcSDexuan Cui 	/* The host or the VM should only listen on a port in
347ae0078fcSDexuan Cui 	 * [0, MAX_LISTEN_PORT]
348ae0078fcSDexuan Cui 	 */
349ae0078fcSDexuan Cui 	if (!is_valid_srv_id(if_type) ||
350ae0078fcSDexuan Cui 	    get_port_by_srv_id(if_type) > MAX_LISTEN_PORT)
351ae0078fcSDexuan Cui 		return;
352ae0078fcSDexuan Cui 
353ae0078fcSDexuan Cui 	hvs_addr_init(&addr, conn_from_host ? if_type : if_instance);
354ae0078fcSDexuan Cui 	sk = vsock_find_bound_socket(&addr);
355ae0078fcSDexuan Cui 	if (!sk)
356ae0078fcSDexuan Cui 		return;
357ae0078fcSDexuan Cui 
358b4562ca7SDexuan Cui 	lock_sock(sk);
3593b4477d2SStefan Hajnoczi 	if ((conn_from_host && sk->sk_state != TCP_LISTEN) ||
3603b4477d2SStefan Hajnoczi 	    (!conn_from_host && sk->sk_state != TCP_SYN_SENT))
361ae0078fcSDexuan Cui 		goto out;
362ae0078fcSDexuan Cui 
363ae0078fcSDexuan Cui 	if (conn_from_host) {
364ae0078fcSDexuan Cui 		if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog)
365ae0078fcSDexuan Cui 			goto out;
366ae0078fcSDexuan Cui 
367ae0078fcSDexuan Cui 		new = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
368ae0078fcSDexuan Cui 				     sk->sk_type, 0);
369ae0078fcSDexuan Cui 		if (!new)
370ae0078fcSDexuan Cui 			goto out;
371ae0078fcSDexuan Cui 
3723b4477d2SStefan Hajnoczi 		new->sk_state = TCP_SYN_SENT;
373ae0078fcSDexuan Cui 		vnew = vsock_sk(new);
374ae0078fcSDexuan Cui 		hvs_new = vnew->trans;
375ae0078fcSDexuan Cui 		hvs_new->chan = chan;
376ae0078fcSDexuan Cui 	} else {
377ae0078fcSDexuan Cui 		hvs = vsock_sk(sk)->trans;
378ae0078fcSDexuan Cui 		hvs->chan = chan;
379ae0078fcSDexuan Cui 	}
380ae0078fcSDexuan Cui 
381ae0078fcSDexuan Cui 	set_channel_read_mode(chan, HV_CALL_DIRECT);
382ae0078fcSDexuan Cui 	ret = vmbus_open(chan, RINGBUFFER_HVS_SND_SIZE,
383ae0078fcSDexuan Cui 			 RINGBUFFER_HVS_RCV_SIZE, NULL, 0,
384ae0078fcSDexuan Cui 			 hvs_channel_cb, conn_from_host ? new : sk);
385ae0078fcSDexuan Cui 	if (ret != 0) {
386ae0078fcSDexuan Cui 		if (conn_from_host) {
387ae0078fcSDexuan Cui 			hvs_new->chan = NULL;
388ae0078fcSDexuan Cui 			sock_put(new);
389ae0078fcSDexuan Cui 		} else {
390ae0078fcSDexuan Cui 			hvs->chan = NULL;
391ae0078fcSDexuan Cui 		}
392ae0078fcSDexuan Cui 		goto out;
393ae0078fcSDexuan Cui 	}
394ae0078fcSDexuan Cui 
395ae0078fcSDexuan Cui 	set_per_channel_state(chan, conn_from_host ? new : sk);
396ae0078fcSDexuan Cui 	vmbus_set_chn_rescind_callback(chan, hvs_close_connection);
397ae0078fcSDexuan Cui 
398ae0078fcSDexuan Cui 	if (conn_from_host) {
3993b4477d2SStefan Hajnoczi 		new->sk_state = TCP_ESTABLISHED;
400ae0078fcSDexuan Cui 		sk->sk_ack_backlog++;
401ae0078fcSDexuan Cui 
402ae0078fcSDexuan Cui 		hvs_addr_init(&vnew->local_addr, if_type);
403ae0078fcSDexuan Cui 		hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);
404ae0078fcSDexuan Cui 
405ae0078fcSDexuan Cui 		hvs_new->vm_srv_id = *if_type;
406ae0078fcSDexuan Cui 		hvs_new->host_srv_id = *if_instance;
407ae0078fcSDexuan Cui 
408ae0078fcSDexuan Cui 		vsock_insert_connected(vnew);
409ae0078fcSDexuan Cui 
410ae0078fcSDexuan Cui 		vsock_enqueue_accept(sk, new);
411ae0078fcSDexuan Cui 	} else {
4123b4477d2SStefan Hajnoczi 		sk->sk_state = TCP_ESTABLISHED;
413ae0078fcSDexuan Cui 		sk->sk_socket->state = SS_CONNECTED;
414ae0078fcSDexuan Cui 
415ae0078fcSDexuan Cui 		vsock_insert_connected(vsock_sk(sk));
416ae0078fcSDexuan Cui 	}
417ae0078fcSDexuan Cui 
418ae0078fcSDexuan Cui 	sk->sk_state_change(sk);
419ae0078fcSDexuan Cui 
420ae0078fcSDexuan Cui out:
421ae0078fcSDexuan Cui 	/* Release refcnt obtained when we called vsock_find_bound_socket() */
422ae0078fcSDexuan Cui 	sock_put(sk);
423b4562ca7SDexuan Cui 
424b4562ca7SDexuan Cui 	release_sock(sk);
425ae0078fcSDexuan Cui }
426ae0078fcSDexuan Cui 
427ae0078fcSDexuan Cui static u32 hvs_get_local_cid(void)
428ae0078fcSDexuan Cui {
429ae0078fcSDexuan Cui 	return VMADDR_CID_ANY;
430ae0078fcSDexuan Cui }
431ae0078fcSDexuan Cui 
432ae0078fcSDexuan Cui static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk)
433ae0078fcSDexuan Cui {
434ae0078fcSDexuan Cui 	struct hvsock *hvs;
435ae0078fcSDexuan Cui 
436ae0078fcSDexuan Cui 	hvs = kzalloc(sizeof(*hvs), GFP_KERNEL);
437ae0078fcSDexuan Cui 	if (!hvs)
438ae0078fcSDexuan Cui 		return -ENOMEM;
439ae0078fcSDexuan Cui 
440ae0078fcSDexuan Cui 	vsk->trans = hvs;
441ae0078fcSDexuan Cui 	hvs->vsk = vsk;
442ae0078fcSDexuan Cui 
443ae0078fcSDexuan Cui 	return 0;
444ae0078fcSDexuan Cui }
445ae0078fcSDexuan Cui 
446ae0078fcSDexuan Cui static int hvs_connect(struct vsock_sock *vsk)
447ae0078fcSDexuan Cui {
448ae0078fcSDexuan Cui 	union hvs_service_id vm, host;
449ae0078fcSDexuan Cui 	struct hvsock *h = vsk->trans;
450ae0078fcSDexuan Cui 
451ae0078fcSDexuan Cui 	vm.srv_id = srv_id_template;
452ae0078fcSDexuan Cui 	vm.svm_port = vsk->local_addr.svm_port;
453ae0078fcSDexuan Cui 	h->vm_srv_id = vm.srv_id;
454ae0078fcSDexuan Cui 
455ae0078fcSDexuan Cui 	host.srv_id = srv_id_template;
456ae0078fcSDexuan Cui 	host.svm_port = vsk->remote_addr.svm_port;
457ae0078fcSDexuan Cui 	h->host_srv_id = host.srv_id;
458ae0078fcSDexuan Cui 
459ae0078fcSDexuan Cui 	return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id);
460ae0078fcSDexuan Cui }
461ae0078fcSDexuan Cui 
462a9eeb998SSunil Muthuswamy static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode)
463a9eeb998SSunil Muthuswamy {
464a9eeb998SSunil Muthuswamy 	struct vmpipe_proto_header hdr;
465a9eeb998SSunil Muthuswamy 
466a9eeb998SSunil Muthuswamy 	if (hvs->fin_sent || !hvs->chan)
467a9eeb998SSunil Muthuswamy 		return;
468a9eeb998SSunil Muthuswamy 
469a9eeb998SSunil Muthuswamy 	/* It can't fail: see hvs_channel_writable_bytes(). */
470a9eeb998SSunil Muthuswamy 	(void)hvs_send_data(hvs->chan, (struct hvs_send_buf *)&hdr, 0);
471a9eeb998SSunil Muthuswamy 	hvs->fin_sent = true;
472a9eeb998SSunil Muthuswamy }
473a9eeb998SSunil Muthuswamy 
474ae0078fcSDexuan Cui static int hvs_shutdown(struct vsock_sock *vsk, int mode)
475ae0078fcSDexuan Cui {
476ae0078fcSDexuan Cui 	struct sock *sk = sk_vsock(vsk);
477ae0078fcSDexuan Cui 
478ae0078fcSDexuan Cui 	if (!(mode & SEND_SHUTDOWN))
479ae0078fcSDexuan Cui 		return 0;
480ae0078fcSDexuan Cui 
481ae0078fcSDexuan Cui 	lock_sock(sk);
482a9eeb998SSunil Muthuswamy 	hvs_shutdown_lock_held(vsk->trans, mode);
483ae0078fcSDexuan Cui 	release_sock(sk);
484ae0078fcSDexuan Cui 	return 0;
485ae0078fcSDexuan Cui }
486ae0078fcSDexuan Cui 
487a9eeb998SSunil Muthuswamy static void hvs_close_timeout(struct work_struct *work)
488a9eeb998SSunil Muthuswamy {
489a9eeb998SSunil Muthuswamy 	struct vsock_sock *vsk =
490a9eeb998SSunil Muthuswamy 		container_of(work, struct vsock_sock, close_work.work);
491a9eeb998SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
492a9eeb998SSunil Muthuswamy 
493a9eeb998SSunil Muthuswamy 	sock_hold(sk);
494a9eeb998SSunil Muthuswamy 	lock_sock(sk);
495a9eeb998SSunil Muthuswamy 	if (!sock_flag(sk, SOCK_DONE))
496a9eeb998SSunil Muthuswamy 		hvs_do_close_lock_held(vsk, false);
497a9eeb998SSunil Muthuswamy 
498a9eeb998SSunil Muthuswamy 	vsk->close_work_scheduled = false;
499a9eeb998SSunil Muthuswamy 	release_sock(sk);
500a9eeb998SSunil Muthuswamy 	sock_put(sk);
501a9eeb998SSunil Muthuswamy }
502a9eeb998SSunil Muthuswamy 
503a9eeb998SSunil Muthuswamy /* Returns true, if it is safe to remove socket; false otherwise */
504a9eeb998SSunil Muthuswamy static bool hvs_close_lock_held(struct vsock_sock *vsk)
505a9eeb998SSunil Muthuswamy {
506a9eeb998SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
507a9eeb998SSunil Muthuswamy 
508a9eeb998SSunil Muthuswamy 	if (!(sk->sk_state == TCP_ESTABLISHED ||
509a9eeb998SSunil Muthuswamy 	      sk->sk_state == TCP_CLOSING))
510a9eeb998SSunil Muthuswamy 		return true;
511a9eeb998SSunil Muthuswamy 
512a9eeb998SSunil Muthuswamy 	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
513a9eeb998SSunil Muthuswamy 		hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK);
514a9eeb998SSunil Muthuswamy 
515a9eeb998SSunil Muthuswamy 	if (sock_flag(sk, SOCK_DONE))
516a9eeb998SSunil Muthuswamy 		return true;
517a9eeb998SSunil Muthuswamy 
518a9eeb998SSunil Muthuswamy 	/* This reference will be dropped by the delayed close routine */
519a9eeb998SSunil Muthuswamy 	sock_hold(sk);
520a9eeb998SSunil Muthuswamy 	INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout);
521a9eeb998SSunil Muthuswamy 	vsk->close_work_scheduled = true;
522a9eeb998SSunil Muthuswamy 	schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT);
523a9eeb998SSunil Muthuswamy 	return false;
524a9eeb998SSunil Muthuswamy }
525a9eeb998SSunil Muthuswamy 
526ae0078fcSDexuan Cui static void hvs_release(struct vsock_sock *vsk)
527ae0078fcSDexuan Cui {
528b4562ca7SDexuan Cui 	struct sock *sk = sk_vsock(vsk);
529a9eeb998SSunil Muthuswamy 	bool remove_sock;
530ae0078fcSDexuan Cui 
531b4562ca7SDexuan Cui 	lock_sock(sk);
532a9eeb998SSunil Muthuswamy 	remove_sock = hvs_close_lock_held(vsk);
533b4562ca7SDexuan Cui 	release_sock(sk);
534a9eeb998SSunil Muthuswamy 	if (remove_sock)
535a9eeb998SSunil Muthuswamy 		vsock_remove_sock(vsk);
536ae0078fcSDexuan Cui }
537ae0078fcSDexuan Cui 
538ae0078fcSDexuan Cui static void hvs_destruct(struct vsock_sock *vsk)
539ae0078fcSDexuan Cui {
540ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
541ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
542ae0078fcSDexuan Cui 
543ae0078fcSDexuan Cui 	if (chan)
544ae0078fcSDexuan Cui 		vmbus_hvsock_device_unregister(chan);
545ae0078fcSDexuan Cui 
546ae0078fcSDexuan Cui 	kfree(hvs);
547ae0078fcSDexuan Cui }
548ae0078fcSDexuan Cui 
549ae0078fcSDexuan Cui static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
550ae0078fcSDexuan Cui {
551ae0078fcSDexuan Cui 	return -EOPNOTSUPP;
552ae0078fcSDexuan Cui }
553ae0078fcSDexuan Cui 
554ae0078fcSDexuan Cui static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
555ae0078fcSDexuan Cui 			     size_t len, int flags)
556ae0078fcSDexuan Cui {
557ae0078fcSDexuan Cui 	return -EOPNOTSUPP;
558ae0078fcSDexuan Cui }
559ae0078fcSDexuan Cui 
560ae0078fcSDexuan Cui static int hvs_dgram_enqueue(struct vsock_sock *vsk,
561ae0078fcSDexuan Cui 			     struct sockaddr_vm *remote, struct msghdr *msg,
562ae0078fcSDexuan Cui 			     size_t dgram_len)
563ae0078fcSDexuan Cui {
564ae0078fcSDexuan Cui 	return -EOPNOTSUPP;
565ae0078fcSDexuan Cui }
566ae0078fcSDexuan Cui 
567ae0078fcSDexuan Cui static bool hvs_dgram_allow(u32 cid, u32 port)
568ae0078fcSDexuan Cui {
569ae0078fcSDexuan Cui 	return false;
570ae0078fcSDexuan Cui }
571ae0078fcSDexuan Cui 
572ae0078fcSDexuan Cui static int hvs_update_recv_data(struct hvsock *hvs)
573ae0078fcSDexuan Cui {
574ae0078fcSDexuan Cui 	struct hvs_recv_buf *recv_buf;
575ae0078fcSDexuan Cui 	u32 payload_len;
576ae0078fcSDexuan Cui 
577ae0078fcSDexuan Cui 	recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
578ae0078fcSDexuan Cui 	payload_len = recv_buf->hdr.data_size;
579ae0078fcSDexuan Cui 
580ae0078fcSDexuan Cui 	if (payload_len > HVS_MTU_SIZE)
581ae0078fcSDexuan Cui 		return -EIO;
582ae0078fcSDexuan Cui 
583ae0078fcSDexuan Cui 	if (payload_len == 0)
584ae0078fcSDexuan Cui 		hvs->vsk->peer_shutdown |= SEND_SHUTDOWN;
585ae0078fcSDexuan Cui 
586ae0078fcSDexuan Cui 	hvs->recv_data_len = payload_len;
587ae0078fcSDexuan Cui 	hvs->recv_data_off = 0;
588ae0078fcSDexuan Cui 
589ae0078fcSDexuan Cui 	return 0;
590ae0078fcSDexuan Cui }
591ae0078fcSDexuan Cui 
592ae0078fcSDexuan Cui static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
593ae0078fcSDexuan Cui 				  size_t len, int flags)
594ae0078fcSDexuan Cui {
595ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
596ae0078fcSDexuan Cui 	bool need_refill = !hvs->recv_desc;
597ae0078fcSDexuan Cui 	struct hvs_recv_buf *recv_buf;
598ae0078fcSDexuan Cui 	u32 to_read;
599ae0078fcSDexuan Cui 	int ret;
600ae0078fcSDexuan Cui 
601ae0078fcSDexuan Cui 	if (flags & MSG_PEEK)
602ae0078fcSDexuan Cui 		return -EOPNOTSUPP;
603ae0078fcSDexuan Cui 
604ae0078fcSDexuan Cui 	if (need_refill) {
605ae0078fcSDexuan Cui 		hvs->recv_desc = hv_pkt_iter_first(hvs->chan);
606ae0078fcSDexuan Cui 		ret = hvs_update_recv_data(hvs);
607ae0078fcSDexuan Cui 		if (ret)
608ae0078fcSDexuan Cui 			return ret;
609ae0078fcSDexuan Cui 	}
610ae0078fcSDexuan Cui 
611ae0078fcSDexuan Cui 	recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
612ae0078fcSDexuan Cui 	to_read = min_t(u32, len, hvs->recv_data_len);
613ae0078fcSDexuan Cui 	ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read);
614ae0078fcSDexuan Cui 	if (ret != 0)
615ae0078fcSDexuan Cui 		return ret;
616ae0078fcSDexuan Cui 
617ae0078fcSDexuan Cui 	hvs->recv_data_len -= to_read;
618ae0078fcSDexuan Cui 	if (hvs->recv_data_len == 0) {
619ae0078fcSDexuan Cui 		hvs->recv_desc = hv_pkt_iter_next(hvs->chan, hvs->recv_desc);
620ae0078fcSDexuan Cui 		if (hvs->recv_desc) {
621ae0078fcSDexuan Cui 			ret = hvs_update_recv_data(hvs);
622ae0078fcSDexuan Cui 			if (ret)
623ae0078fcSDexuan Cui 				return ret;
624ae0078fcSDexuan Cui 		}
625ae0078fcSDexuan Cui 	} else {
626ae0078fcSDexuan Cui 		hvs->recv_data_off += to_read;
627ae0078fcSDexuan Cui 	}
628ae0078fcSDexuan Cui 
629ae0078fcSDexuan Cui 	return to_read;
630ae0078fcSDexuan Cui }
631ae0078fcSDexuan Cui 
632ae0078fcSDexuan Cui static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
633ae0078fcSDexuan Cui 				  size_t len)
634ae0078fcSDexuan Cui {
635ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
636ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
637ae0078fcSDexuan Cui 	struct hvs_send_buf *send_buf;
638ae0078fcSDexuan Cui 	ssize_t to_write, max_writable, ret;
639ae0078fcSDexuan Cui 
640ae0078fcSDexuan Cui 	BUILD_BUG_ON(sizeof(*send_buf) != PAGE_SIZE_4K);
641ae0078fcSDexuan Cui 
642ae0078fcSDexuan Cui 	send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL);
643ae0078fcSDexuan Cui 	if (!send_buf)
644ae0078fcSDexuan Cui 		return -ENOMEM;
645ae0078fcSDexuan Cui 
646ae0078fcSDexuan Cui 	max_writable = hvs_channel_writable_bytes(chan);
647ae0078fcSDexuan Cui 	to_write = min_t(ssize_t, len, max_writable);
648ae0078fcSDexuan Cui 	to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE);
649ae0078fcSDexuan Cui 
650ae0078fcSDexuan Cui 	ret = memcpy_from_msg(send_buf->data, msg, to_write);
651ae0078fcSDexuan Cui 	if (ret < 0)
652ae0078fcSDexuan Cui 		goto out;
653ae0078fcSDexuan Cui 
654ae0078fcSDexuan Cui 	ret = hvs_send_data(hvs->chan, send_buf, to_write);
655ae0078fcSDexuan Cui 	if (ret < 0)
656ae0078fcSDexuan Cui 		goto out;
657ae0078fcSDexuan Cui 
658ae0078fcSDexuan Cui 	ret = to_write;
659ae0078fcSDexuan Cui out:
660ae0078fcSDexuan Cui 	kfree(send_buf);
661ae0078fcSDexuan Cui 	return ret;
662ae0078fcSDexuan Cui }
663ae0078fcSDexuan Cui 
664ae0078fcSDexuan Cui static s64 hvs_stream_has_data(struct vsock_sock *vsk)
665ae0078fcSDexuan Cui {
666ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
667ae0078fcSDexuan Cui 	s64 ret;
668ae0078fcSDexuan Cui 
669ae0078fcSDexuan Cui 	if (hvs->recv_data_len > 0)
670ae0078fcSDexuan Cui 		return 1;
671ae0078fcSDexuan Cui 
672ae0078fcSDexuan Cui 	switch (hvs_channel_readable_payload(hvs->chan)) {
673ae0078fcSDexuan Cui 	case 1:
674ae0078fcSDexuan Cui 		ret = 1;
675ae0078fcSDexuan Cui 		break;
676ae0078fcSDexuan Cui 	case 0:
677ae0078fcSDexuan Cui 		vsk->peer_shutdown |= SEND_SHUTDOWN;
678ae0078fcSDexuan Cui 		ret = 0;
679ae0078fcSDexuan Cui 		break;
680ae0078fcSDexuan Cui 	default: /* -1 */
681ae0078fcSDexuan Cui 		ret = 0;
682ae0078fcSDexuan Cui 		break;
683ae0078fcSDexuan Cui 	}
684ae0078fcSDexuan Cui 
685ae0078fcSDexuan Cui 	return ret;
686ae0078fcSDexuan Cui }
687ae0078fcSDexuan Cui 
688ae0078fcSDexuan Cui static s64 hvs_stream_has_space(struct vsock_sock *vsk)
689ae0078fcSDexuan Cui {
690ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
691ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
692ae0078fcSDexuan Cui 	s64 ret;
693ae0078fcSDexuan Cui 
694ae0078fcSDexuan Cui 	ret = hvs_channel_writable_bytes(chan);
695ae0078fcSDexuan Cui 	if (ret > 0)  {
696ae0078fcSDexuan Cui 		hvs_clear_channel_pending_send_size(chan);
697ae0078fcSDexuan Cui 	} else {
698ae0078fcSDexuan Cui 		/* See hvs_channel_cb() */
699ae0078fcSDexuan Cui 		hvs_set_channel_pending_send_size(chan);
700ae0078fcSDexuan Cui 
701ae0078fcSDexuan Cui 		/* Re-check the writable bytes to avoid race */
702ae0078fcSDexuan Cui 		ret = hvs_channel_writable_bytes(chan);
703ae0078fcSDexuan Cui 		if (ret > 0)
704ae0078fcSDexuan Cui 			hvs_clear_channel_pending_send_size(chan);
705ae0078fcSDexuan Cui 	}
706ae0078fcSDexuan Cui 
707ae0078fcSDexuan Cui 	return ret;
708ae0078fcSDexuan Cui }
709ae0078fcSDexuan Cui 
710ae0078fcSDexuan Cui static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk)
711ae0078fcSDexuan Cui {
712ae0078fcSDexuan Cui 	return HVS_MTU_SIZE + 1;
713ae0078fcSDexuan Cui }
714ae0078fcSDexuan Cui 
715ae0078fcSDexuan Cui static bool hvs_stream_is_active(struct vsock_sock *vsk)
716ae0078fcSDexuan Cui {
717ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
718ae0078fcSDexuan Cui 
719ae0078fcSDexuan Cui 	return hvs->chan != NULL;
720ae0078fcSDexuan Cui }
721ae0078fcSDexuan Cui 
722ae0078fcSDexuan Cui static bool hvs_stream_allow(u32 cid, u32 port)
723ae0078fcSDexuan Cui {
724ae0078fcSDexuan Cui 	/* The host's port range [MIN_HOST_EPHEMERAL_PORT, 0xFFFFFFFF) is
725ae0078fcSDexuan Cui 	 * reserved as ephemeral ports, which are used as the host's ports
726ae0078fcSDexuan Cui 	 * when the host initiates connections.
727ae0078fcSDexuan Cui 	 *
728ae0078fcSDexuan Cui 	 * Perform this check in the guest so an immediate error is produced
729ae0078fcSDexuan Cui 	 * instead of a timeout.
730ae0078fcSDexuan Cui 	 */
731ae0078fcSDexuan Cui 	if (port > MAX_HOST_LISTEN_PORT)
732ae0078fcSDexuan Cui 		return false;
733ae0078fcSDexuan Cui 
734ae0078fcSDexuan Cui 	if (cid == VMADDR_CID_HOST)
735ae0078fcSDexuan Cui 		return true;
736ae0078fcSDexuan Cui 
737ae0078fcSDexuan Cui 	return false;
738ae0078fcSDexuan Cui }
739ae0078fcSDexuan Cui 
740ae0078fcSDexuan Cui static
741ae0078fcSDexuan Cui int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable)
742ae0078fcSDexuan Cui {
743ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
744ae0078fcSDexuan Cui 
745ae0078fcSDexuan Cui 	*readable = hvs_channel_readable(hvs->chan);
746ae0078fcSDexuan Cui 	return 0;
747ae0078fcSDexuan Cui }
748ae0078fcSDexuan Cui 
749ae0078fcSDexuan Cui static
750ae0078fcSDexuan Cui int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable)
751ae0078fcSDexuan Cui {
752ae0078fcSDexuan Cui 	*writable = hvs_stream_has_space(vsk) > 0;
753ae0078fcSDexuan Cui 
754ae0078fcSDexuan Cui 	return 0;
755ae0078fcSDexuan Cui }
756ae0078fcSDexuan Cui 
757ae0078fcSDexuan Cui static
758ae0078fcSDexuan Cui int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target,
759ae0078fcSDexuan Cui 			 struct vsock_transport_recv_notify_data *d)
760ae0078fcSDexuan Cui {
761ae0078fcSDexuan Cui 	return 0;
762ae0078fcSDexuan Cui }
763ae0078fcSDexuan Cui 
764ae0078fcSDexuan Cui static
765ae0078fcSDexuan Cui int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target,
766ae0078fcSDexuan Cui 			      struct vsock_transport_recv_notify_data *d)
767ae0078fcSDexuan Cui {
768ae0078fcSDexuan Cui 	return 0;
769ae0078fcSDexuan Cui }
770ae0078fcSDexuan Cui 
771ae0078fcSDexuan Cui static
772ae0078fcSDexuan Cui int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target,
773ae0078fcSDexuan Cui 				struct vsock_transport_recv_notify_data *d)
774ae0078fcSDexuan Cui {
775ae0078fcSDexuan Cui 	return 0;
776ae0078fcSDexuan Cui }
777ae0078fcSDexuan Cui 
778ae0078fcSDexuan Cui static
779ae0078fcSDexuan Cui int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target,
780ae0078fcSDexuan Cui 				 ssize_t copied, bool data_read,
781ae0078fcSDexuan Cui 				 struct vsock_transport_recv_notify_data *d)
782ae0078fcSDexuan Cui {
783ae0078fcSDexuan Cui 	return 0;
784ae0078fcSDexuan Cui }
785ae0078fcSDexuan Cui 
786ae0078fcSDexuan Cui static
787ae0078fcSDexuan Cui int hvs_notify_send_init(struct vsock_sock *vsk,
788ae0078fcSDexuan Cui 			 struct vsock_transport_send_notify_data *d)
789ae0078fcSDexuan Cui {
790ae0078fcSDexuan Cui 	return 0;
791ae0078fcSDexuan Cui }
792ae0078fcSDexuan Cui 
793ae0078fcSDexuan Cui static
794ae0078fcSDexuan Cui int hvs_notify_send_pre_block(struct vsock_sock *vsk,
795ae0078fcSDexuan Cui 			      struct vsock_transport_send_notify_data *d)
796ae0078fcSDexuan Cui {
797ae0078fcSDexuan Cui 	return 0;
798ae0078fcSDexuan Cui }
799ae0078fcSDexuan Cui 
800ae0078fcSDexuan Cui static
801ae0078fcSDexuan Cui int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk,
802ae0078fcSDexuan Cui 				struct vsock_transport_send_notify_data *d)
803ae0078fcSDexuan Cui {
804ae0078fcSDexuan Cui 	return 0;
805ae0078fcSDexuan Cui }
806ae0078fcSDexuan Cui 
807ae0078fcSDexuan Cui static
808ae0078fcSDexuan Cui int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
809ae0078fcSDexuan Cui 				 struct vsock_transport_send_notify_data *d)
810ae0078fcSDexuan Cui {
811ae0078fcSDexuan Cui 	return 0;
812ae0078fcSDexuan Cui }
813ae0078fcSDexuan Cui 
814ae0078fcSDexuan Cui static void hvs_set_buffer_size(struct vsock_sock *vsk, u64 val)
815ae0078fcSDexuan Cui {
816ae0078fcSDexuan Cui 	/* Ignored. */
817ae0078fcSDexuan Cui }
818ae0078fcSDexuan Cui 
819ae0078fcSDexuan Cui static void hvs_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
820ae0078fcSDexuan Cui {
821ae0078fcSDexuan Cui 	/* Ignored. */
822ae0078fcSDexuan Cui }
823ae0078fcSDexuan Cui 
824ae0078fcSDexuan Cui static void hvs_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
825ae0078fcSDexuan Cui {
826ae0078fcSDexuan Cui 	/* Ignored. */
827ae0078fcSDexuan Cui }
828ae0078fcSDexuan Cui 
829ae0078fcSDexuan Cui static u64 hvs_get_buffer_size(struct vsock_sock *vsk)
830ae0078fcSDexuan Cui {
831ae0078fcSDexuan Cui 	return -ENOPROTOOPT;
832ae0078fcSDexuan Cui }
833ae0078fcSDexuan Cui 
834ae0078fcSDexuan Cui static u64 hvs_get_min_buffer_size(struct vsock_sock *vsk)
835ae0078fcSDexuan Cui {
836ae0078fcSDexuan Cui 	return -ENOPROTOOPT;
837ae0078fcSDexuan Cui }
838ae0078fcSDexuan Cui 
839ae0078fcSDexuan Cui static u64 hvs_get_max_buffer_size(struct vsock_sock *vsk)
840ae0078fcSDexuan Cui {
841ae0078fcSDexuan Cui 	return -ENOPROTOOPT;
842ae0078fcSDexuan Cui }
843ae0078fcSDexuan Cui 
844ae0078fcSDexuan Cui static struct vsock_transport hvs_transport = {
845ae0078fcSDexuan Cui 	.get_local_cid            = hvs_get_local_cid,
846ae0078fcSDexuan Cui 
847ae0078fcSDexuan Cui 	.init                     = hvs_sock_init,
848ae0078fcSDexuan Cui 	.destruct                 = hvs_destruct,
849ae0078fcSDexuan Cui 	.release                  = hvs_release,
850ae0078fcSDexuan Cui 	.connect                  = hvs_connect,
851ae0078fcSDexuan Cui 	.shutdown                 = hvs_shutdown,
852ae0078fcSDexuan Cui 
853ae0078fcSDexuan Cui 	.dgram_bind               = hvs_dgram_bind,
854ae0078fcSDexuan Cui 	.dgram_dequeue            = hvs_dgram_dequeue,
855ae0078fcSDexuan Cui 	.dgram_enqueue            = hvs_dgram_enqueue,
856ae0078fcSDexuan Cui 	.dgram_allow              = hvs_dgram_allow,
857ae0078fcSDexuan Cui 
858ae0078fcSDexuan Cui 	.stream_dequeue           = hvs_stream_dequeue,
859ae0078fcSDexuan Cui 	.stream_enqueue           = hvs_stream_enqueue,
860ae0078fcSDexuan Cui 	.stream_has_data          = hvs_stream_has_data,
861ae0078fcSDexuan Cui 	.stream_has_space         = hvs_stream_has_space,
862ae0078fcSDexuan Cui 	.stream_rcvhiwat          = hvs_stream_rcvhiwat,
863ae0078fcSDexuan Cui 	.stream_is_active         = hvs_stream_is_active,
864ae0078fcSDexuan Cui 	.stream_allow             = hvs_stream_allow,
865ae0078fcSDexuan Cui 
866ae0078fcSDexuan Cui 	.notify_poll_in           = hvs_notify_poll_in,
867ae0078fcSDexuan Cui 	.notify_poll_out          = hvs_notify_poll_out,
868ae0078fcSDexuan Cui 	.notify_recv_init         = hvs_notify_recv_init,
869ae0078fcSDexuan Cui 	.notify_recv_pre_block    = hvs_notify_recv_pre_block,
870ae0078fcSDexuan Cui 	.notify_recv_pre_dequeue  = hvs_notify_recv_pre_dequeue,
871ae0078fcSDexuan Cui 	.notify_recv_post_dequeue = hvs_notify_recv_post_dequeue,
872ae0078fcSDexuan Cui 	.notify_send_init         = hvs_notify_send_init,
873ae0078fcSDexuan Cui 	.notify_send_pre_block    = hvs_notify_send_pre_block,
874ae0078fcSDexuan Cui 	.notify_send_pre_enqueue  = hvs_notify_send_pre_enqueue,
875ae0078fcSDexuan Cui 	.notify_send_post_enqueue = hvs_notify_send_post_enqueue,
876ae0078fcSDexuan Cui 
877ae0078fcSDexuan Cui 	.set_buffer_size          = hvs_set_buffer_size,
878ae0078fcSDexuan Cui 	.set_min_buffer_size      = hvs_set_min_buffer_size,
879ae0078fcSDexuan Cui 	.set_max_buffer_size      = hvs_set_max_buffer_size,
880ae0078fcSDexuan Cui 	.get_buffer_size          = hvs_get_buffer_size,
881ae0078fcSDexuan Cui 	.get_min_buffer_size      = hvs_get_min_buffer_size,
882ae0078fcSDexuan Cui 	.get_max_buffer_size      = hvs_get_max_buffer_size,
883ae0078fcSDexuan Cui };
884ae0078fcSDexuan Cui 
885ae0078fcSDexuan Cui static int hvs_probe(struct hv_device *hdev,
886ae0078fcSDexuan Cui 		     const struct hv_vmbus_device_id *dev_id)
887ae0078fcSDexuan Cui {
888ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hdev->channel;
889ae0078fcSDexuan Cui 
890ae0078fcSDexuan Cui 	hvs_open_connection(chan);
891ae0078fcSDexuan Cui 
892ae0078fcSDexuan Cui 	/* Always return success to suppress the unnecessary error message
893ae0078fcSDexuan Cui 	 * in vmbus_probe(): on error the host will rescind the device in
894ae0078fcSDexuan Cui 	 * 30 seconds and we can do cleanup at that time in
895ae0078fcSDexuan Cui 	 * vmbus_onoffer_rescind().
896ae0078fcSDexuan Cui 	 */
897ae0078fcSDexuan Cui 	return 0;
898ae0078fcSDexuan Cui }
899ae0078fcSDexuan Cui 
900ae0078fcSDexuan Cui static int hvs_remove(struct hv_device *hdev)
901ae0078fcSDexuan Cui {
902ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hdev->channel;
903ae0078fcSDexuan Cui 
904ae0078fcSDexuan Cui 	vmbus_close(chan);
905ae0078fcSDexuan Cui 
906ae0078fcSDexuan Cui 	return 0;
907ae0078fcSDexuan Cui }
908ae0078fcSDexuan Cui 
909ae0078fcSDexuan Cui /* This isn't really used. See vmbus_match() and vmbus_probe() */
910ae0078fcSDexuan Cui static const struct hv_vmbus_device_id id_table[] = {
911ae0078fcSDexuan Cui 	{},
912ae0078fcSDexuan Cui };
913ae0078fcSDexuan Cui 
914ae0078fcSDexuan Cui static struct hv_driver hvs_drv = {
915ae0078fcSDexuan Cui 	.name		= "hv_sock",
916ae0078fcSDexuan Cui 	.hvsock		= true,
917ae0078fcSDexuan Cui 	.id_table	= id_table,
918ae0078fcSDexuan Cui 	.probe		= hvs_probe,
919ae0078fcSDexuan Cui 	.remove		= hvs_remove,
920ae0078fcSDexuan Cui };
921ae0078fcSDexuan Cui 
922ae0078fcSDexuan Cui static int __init hvs_init(void)
923ae0078fcSDexuan Cui {
924ae0078fcSDexuan Cui 	int ret;
925ae0078fcSDexuan Cui 
926ae0078fcSDexuan Cui 	if (vmbus_proto_version < VERSION_WIN10)
927ae0078fcSDexuan Cui 		return -ENODEV;
928ae0078fcSDexuan Cui 
929ae0078fcSDexuan Cui 	ret = vmbus_driver_register(&hvs_drv);
930ae0078fcSDexuan Cui 	if (ret != 0)
931ae0078fcSDexuan Cui 		return ret;
932ae0078fcSDexuan Cui 
933ae0078fcSDexuan Cui 	ret = vsock_core_init(&hvs_transport);
934ae0078fcSDexuan Cui 	if (ret) {
935ae0078fcSDexuan Cui 		vmbus_driver_unregister(&hvs_drv);
936ae0078fcSDexuan Cui 		return ret;
937ae0078fcSDexuan Cui 	}
938ae0078fcSDexuan Cui 
939ae0078fcSDexuan Cui 	return 0;
940ae0078fcSDexuan Cui }
941ae0078fcSDexuan Cui 
942ae0078fcSDexuan Cui static void __exit hvs_exit(void)
943ae0078fcSDexuan Cui {
944ae0078fcSDexuan Cui 	vsock_core_exit();
945ae0078fcSDexuan Cui 	vmbus_driver_unregister(&hvs_drv);
946ae0078fcSDexuan Cui }
947ae0078fcSDexuan Cui 
948ae0078fcSDexuan Cui module_init(hvs_init);
949ae0078fcSDexuan Cui module_exit(hvs_exit);
950ae0078fcSDexuan Cui 
951ae0078fcSDexuan Cui MODULE_DESCRIPTION("Hyper-V Sockets");
952ae0078fcSDexuan Cui MODULE_VERSION("1.0.0");
953ae0078fcSDexuan Cui MODULE_LICENSE("GPL");
954ae0078fcSDexuan Cui MODULE_ALIAS_NETPROTO(PF_VSOCK);
955