1ae0078fcSDexuan Cui /*
2ae0078fcSDexuan Cui  * Hyper-V transport for vsock
3ae0078fcSDexuan Cui  *
4ae0078fcSDexuan Cui  * Hyper-V Sockets supplies a byte-stream based communication mechanism
5ae0078fcSDexuan Cui  * between the host and the VM. This driver implements the necessary
6ae0078fcSDexuan Cui  * support in the VM by introducing the new vsock transport.
7ae0078fcSDexuan Cui  *
8ae0078fcSDexuan Cui  * Copyright (c) 2017, Microsoft Corporation.
9ae0078fcSDexuan Cui  *
10ae0078fcSDexuan Cui  * This program is free software; you can redistribute it and/or modify it
11ae0078fcSDexuan Cui  * under the terms and conditions of the GNU General Public License,
12ae0078fcSDexuan Cui  * version 2, as published by the Free Software Foundation.
13ae0078fcSDexuan Cui  *
14ae0078fcSDexuan Cui  * This program is distributed in the hope it will be useful, but WITHOUT
15ae0078fcSDexuan Cui  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16ae0078fcSDexuan Cui  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17ae0078fcSDexuan Cui  * more details.
18ae0078fcSDexuan Cui  *
19ae0078fcSDexuan Cui  */
20ae0078fcSDexuan Cui #include <linux/module.h>
21ae0078fcSDexuan Cui #include <linux/vmalloc.h>
22ae0078fcSDexuan Cui #include <linux/hyperv.h>
23ae0078fcSDexuan Cui #include <net/sock.h>
24ae0078fcSDexuan Cui #include <net/af_vsock.h>
25ae0078fcSDexuan Cui 
26ac383f58SSunil Muthuswamy /* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some
27ac383f58SSunil Muthuswamy  * stricter requirements on the hv_sock ring buffer size of six 4K pages. Newer
28ac383f58SSunil Muthuswamy  * hosts don't have this limitation; but, keep the defaults the same for compat.
29ae0078fcSDexuan Cui  */
30ae0078fcSDexuan Cui #define PAGE_SIZE_4K		4096
31ae0078fcSDexuan Cui #define RINGBUFFER_HVS_RCV_SIZE (PAGE_SIZE_4K * 6)
32ae0078fcSDexuan Cui #define RINGBUFFER_HVS_SND_SIZE (PAGE_SIZE_4K * 6)
33ac383f58SSunil Muthuswamy #define RINGBUFFER_HVS_MAX_SIZE (PAGE_SIZE_4K * 64)
34ae0078fcSDexuan Cui 
35ae0078fcSDexuan Cui /* The MTU is 16KB per the host side's design */
36ae0078fcSDexuan Cui #define HVS_MTU_SIZE		(1024 * 16)
37ae0078fcSDexuan Cui 
38a9eeb998SSunil Muthuswamy /* How long to wait for graceful shutdown of a connection */
39a9eeb998SSunil Muthuswamy #define HVS_CLOSE_TIMEOUT (8 * HZ)
40a9eeb998SSunil Muthuswamy 
41ae0078fcSDexuan Cui struct vmpipe_proto_header {
42ae0078fcSDexuan Cui 	u32 pkt_type;
43ae0078fcSDexuan Cui 	u32 data_size;
44ae0078fcSDexuan Cui };
45ae0078fcSDexuan Cui 
46ae0078fcSDexuan Cui /* For recv, we use the VMBus in-place packet iterator APIs to directly copy
47ae0078fcSDexuan Cui  * data from the ringbuffer into the userspace buffer.
48ae0078fcSDexuan Cui  */
49ae0078fcSDexuan Cui struct hvs_recv_buf {
50ae0078fcSDexuan Cui 	/* The header before the payload data */
51ae0078fcSDexuan Cui 	struct vmpipe_proto_header hdr;
52ae0078fcSDexuan Cui 
53ae0078fcSDexuan Cui 	/* The payload */
54ae0078fcSDexuan Cui 	u8 data[HVS_MTU_SIZE];
55ae0078fcSDexuan Cui };
56ae0078fcSDexuan Cui 
57ae0078fcSDexuan Cui /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use
5814a1eaa8SSunil Muthuswamy  * a smaller size, i.e. HVS_SEND_BUF_SIZE, to maximize concurrency between the
5914a1eaa8SSunil Muthuswamy  * guest and the host processing as one VMBUS packet is the smallest processing
6014a1eaa8SSunil Muthuswamy  * unit.
61ae0078fcSDexuan Cui  *
62ae0078fcSDexuan Cui  * Note: the buffer can be eliminated in the future when we add new VMBus
63ae0078fcSDexuan Cui  * ringbuffer APIs that allow us to directly copy data from userspace buffer
64ae0078fcSDexuan Cui  * to VMBus ringbuffer.
65ae0078fcSDexuan Cui  */
66ae0078fcSDexuan Cui #define HVS_SEND_BUF_SIZE (PAGE_SIZE_4K - sizeof(struct vmpipe_proto_header))
67ae0078fcSDexuan Cui 
68ae0078fcSDexuan Cui struct hvs_send_buf {
69ae0078fcSDexuan Cui 	/* The header before the payload data */
70ae0078fcSDexuan Cui 	struct vmpipe_proto_header hdr;
71ae0078fcSDexuan Cui 
72ae0078fcSDexuan Cui 	/* The payload */
73ae0078fcSDexuan Cui 	u8 data[HVS_SEND_BUF_SIZE];
74ae0078fcSDexuan Cui };
75ae0078fcSDexuan Cui 
76ae0078fcSDexuan Cui #define HVS_HEADER_LEN	(sizeof(struct vmpacket_descriptor) + \
77ae0078fcSDexuan Cui 			 sizeof(struct vmpipe_proto_header))
78ae0078fcSDexuan Cui 
79ae0078fcSDexuan Cui /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and
80ae0078fcSDexuan Cui  * __hv_pkt_iter_next().
81ae0078fcSDexuan Cui  */
82ae0078fcSDexuan Cui #define VMBUS_PKT_TRAILER_SIZE	(sizeof(u64))
83ae0078fcSDexuan Cui 
84ae0078fcSDexuan Cui #define HVS_PKT_LEN(payload_len)	(HVS_HEADER_LEN + \
85ae0078fcSDexuan Cui 					 ALIGN((payload_len), 8) + \
86ae0078fcSDexuan Cui 					 VMBUS_PKT_TRAILER_SIZE)
87ae0078fcSDexuan Cui 
88ae0078fcSDexuan Cui union hvs_service_id {
89ae0078fcSDexuan Cui 	uuid_le	srv_id;
90ae0078fcSDexuan Cui 
91ae0078fcSDexuan Cui 	struct {
92ae0078fcSDexuan Cui 		unsigned int svm_port;
93ae0078fcSDexuan Cui 		unsigned char b[sizeof(uuid_le) - sizeof(unsigned int)];
94ae0078fcSDexuan Cui 	};
95ae0078fcSDexuan Cui };
96ae0078fcSDexuan Cui 
97ae0078fcSDexuan Cui /* Per-socket state (accessed via vsk->trans) */
98ae0078fcSDexuan Cui struct hvsock {
99ae0078fcSDexuan Cui 	struct vsock_sock *vsk;
100ae0078fcSDexuan Cui 
101ae0078fcSDexuan Cui 	uuid_le vm_srv_id;
102ae0078fcSDexuan Cui 	uuid_le host_srv_id;
103ae0078fcSDexuan Cui 
104ae0078fcSDexuan Cui 	struct vmbus_channel *chan;
105ae0078fcSDexuan Cui 	struct vmpacket_descriptor *recv_desc;
106ae0078fcSDexuan Cui 
107ae0078fcSDexuan Cui 	/* The length of the payload not delivered to userland yet */
108ae0078fcSDexuan Cui 	u32 recv_data_len;
109ae0078fcSDexuan Cui 	/* The offset of the payload */
110ae0078fcSDexuan Cui 	u32 recv_data_off;
111ae0078fcSDexuan Cui 
112ae0078fcSDexuan Cui 	/* Have we sent the zero-length packet (FIN)? */
113ae0078fcSDexuan Cui 	bool fin_sent;
114ae0078fcSDexuan Cui };
115ae0078fcSDexuan Cui 
116ae0078fcSDexuan Cui /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is
117ae0078fcSDexuan Cui  * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here:
118ae0078fcSDexuan Cui  * when we write apps to connect to the host, we can only use VMADDR_CID_ANY
119ae0078fcSDexuan Cui  * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we
120ae0078fcSDexuan Cui  * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY
121ae0078fcSDexuan Cui  * as the local cid.
122ae0078fcSDexuan Cui  *
123ae0078fcSDexuan Cui  * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV:
124ae0078fcSDexuan Cui  * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-
125ae0078fcSDexuan Cui  * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with
126ae0078fcSDexuan Cui  * the below sockaddr:
127ae0078fcSDexuan Cui  *
128ae0078fcSDexuan Cui  * struct SOCKADDR_HV
129ae0078fcSDexuan Cui  * {
130ae0078fcSDexuan Cui  *    ADDRESS_FAMILY Family;
131ae0078fcSDexuan Cui  *    USHORT Reserved;
132ae0078fcSDexuan Cui  *    GUID VmId;
133ae0078fcSDexuan Cui  *    GUID ServiceId;
134ae0078fcSDexuan Cui  * };
135ae0078fcSDexuan Cui  * Note: VmID is not used by Linux VM and actually it isn't transmitted via
136ae0078fcSDexuan Cui  * VMBus, because here it's obvious the host and the VM can easily identify
137ae0078fcSDexuan Cui  * each other. Though the VmID is useful on the host, especially in the case
138ae0078fcSDexuan Cui  * of Windows container, Linux VM doesn't need it at all.
139ae0078fcSDexuan Cui  *
140ae0078fcSDexuan Cui  * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit
141ae0078fcSDexuan Cui  * the available GUID space of SOCKADDR_HV so that we can create a mapping
142ae0078fcSDexuan Cui  * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing
143ae0078fcSDexuan Cui  * Hyper-V Sockets apps on the host and in Linux VM is:
144ae0078fcSDexuan Cui  *
145ae0078fcSDexuan Cui  ****************************************************************************
146ae0078fcSDexuan Cui  * The only valid Service GUIDs, from the perspectives of both the host and *
147ae0078fcSDexuan Cui  * Linux VM, that can be connected by the other end, must conform to this   *
148ae0078fcSDexuan Cui  * format: <port>-facb-11e6-bd58-64006a7986d3, and the "port" must be in    *
149ae0078fcSDexuan Cui  * this range [0, 0x7FFFFFFF].                                              *
150ae0078fcSDexuan Cui  ****************************************************************************
151ae0078fcSDexuan Cui  *
152ae0078fcSDexuan Cui  * When we write apps on the host to connect(), the GUID ServiceID is used.
153ae0078fcSDexuan Cui  * When we write apps in Linux VM to connect(), we only need to specify the
154ae0078fcSDexuan Cui  * port and the driver will form the GUID and use that to request the host.
155ae0078fcSDexuan Cui  *
156ae0078fcSDexuan Cui  * From the perspective of Linux VM:
157ae0078fcSDexuan Cui  * 1. the local ephemeral port (i.e. the local auto-bound port when we call
158ae0078fcSDexuan Cui  * connect() without explicit bind()) is generated by __vsock_bind_stream(),
159ae0078fcSDexuan Cui  * and the range is [1024, 0xFFFFFFFF).
160ae0078fcSDexuan Cui  * 2. the remote ephemeral port (i.e. the auto-generated remote port for
161ae0078fcSDexuan Cui  * a connect request initiated by the host's connect()) is generated by
162ae0078fcSDexuan Cui  * hvs_remote_addr_init() and the range is [0x80000000, 0xFFFFFFFF).
163ae0078fcSDexuan Cui  */
164ae0078fcSDexuan Cui 
165ae0078fcSDexuan Cui #define MAX_LISTEN_PORT			((u32)0x7FFFFFFF)
166ae0078fcSDexuan Cui #define MAX_VM_LISTEN_PORT		MAX_LISTEN_PORT
167ae0078fcSDexuan Cui #define MAX_HOST_LISTEN_PORT		MAX_LISTEN_PORT
168ae0078fcSDexuan Cui #define MIN_HOST_EPHEMERAL_PORT		(MAX_HOST_LISTEN_PORT + 1)
169ae0078fcSDexuan Cui 
170ae0078fcSDexuan Cui /* 00000000-facb-11e6-bd58-64006a7986d3 */
171ae0078fcSDexuan Cui static const uuid_le srv_id_template =
172ae0078fcSDexuan Cui 	UUID_LE(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58,
173ae0078fcSDexuan Cui 		0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3);
174ae0078fcSDexuan Cui 
175ae0078fcSDexuan Cui static bool is_valid_srv_id(const uuid_le *id)
176ae0078fcSDexuan Cui {
177ae0078fcSDexuan Cui 	return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(uuid_le) - 4);
178ae0078fcSDexuan Cui }
179ae0078fcSDexuan Cui 
180ae0078fcSDexuan Cui static unsigned int get_port_by_srv_id(const uuid_le *svr_id)
181ae0078fcSDexuan Cui {
182ae0078fcSDexuan Cui 	return *((unsigned int *)svr_id);
183ae0078fcSDexuan Cui }
184ae0078fcSDexuan Cui 
185ae0078fcSDexuan Cui static void hvs_addr_init(struct sockaddr_vm *addr, const uuid_le *svr_id)
186ae0078fcSDexuan Cui {
187ae0078fcSDexuan Cui 	unsigned int port = get_port_by_srv_id(svr_id);
188ae0078fcSDexuan Cui 
189ae0078fcSDexuan Cui 	vsock_addr_init(addr, VMADDR_CID_ANY, port);
190ae0078fcSDexuan Cui }
191ae0078fcSDexuan Cui 
192ae0078fcSDexuan Cui static void hvs_remote_addr_init(struct sockaddr_vm *remote,
193ae0078fcSDexuan Cui 				 struct sockaddr_vm *local)
194ae0078fcSDexuan Cui {
195ae0078fcSDexuan Cui 	static u32 host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT;
196ae0078fcSDexuan Cui 	struct sock *sk;
197ae0078fcSDexuan Cui 
198ae0078fcSDexuan Cui 	vsock_addr_init(remote, VMADDR_CID_ANY, VMADDR_PORT_ANY);
199ae0078fcSDexuan Cui 
200ae0078fcSDexuan Cui 	while (1) {
201ae0078fcSDexuan Cui 		/* Wrap around ? */
202ae0078fcSDexuan Cui 		if (host_ephemeral_port < MIN_HOST_EPHEMERAL_PORT ||
203ae0078fcSDexuan Cui 		    host_ephemeral_port == VMADDR_PORT_ANY)
204ae0078fcSDexuan Cui 			host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT;
205ae0078fcSDexuan Cui 
206ae0078fcSDexuan Cui 		remote->svm_port = host_ephemeral_port++;
207ae0078fcSDexuan Cui 
208ae0078fcSDexuan Cui 		sk = vsock_find_connected_socket(remote, local);
209ae0078fcSDexuan Cui 		if (!sk) {
210ae0078fcSDexuan Cui 			/* Found an available ephemeral port */
211ae0078fcSDexuan Cui 			return;
212ae0078fcSDexuan Cui 		}
213ae0078fcSDexuan Cui 
214ae0078fcSDexuan Cui 		/* Release refcnt got in vsock_find_connected_socket */
215ae0078fcSDexuan Cui 		sock_put(sk);
216ae0078fcSDexuan Cui 	}
217ae0078fcSDexuan Cui }
218ae0078fcSDexuan Cui 
219ae0078fcSDexuan Cui static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan)
220ae0078fcSDexuan Cui {
221ae0078fcSDexuan Cui 	set_channel_pending_send_size(chan,
222ae0078fcSDexuan Cui 				      HVS_PKT_LEN(HVS_SEND_BUF_SIZE));
223ae0078fcSDexuan Cui 
224ae0078fcSDexuan Cui 	/* See hvs_stream_has_space(): we must make sure the host has seen
225ae0078fcSDexuan Cui 	 * the new pending send size, before we can re-check the writable
226ae0078fcSDexuan Cui 	 * bytes.
227ae0078fcSDexuan Cui 	 */
228ae0078fcSDexuan Cui 	virt_mb();
229ae0078fcSDexuan Cui }
230ae0078fcSDexuan Cui 
231ae0078fcSDexuan Cui static void hvs_clear_channel_pending_send_size(struct vmbus_channel *chan)
232ae0078fcSDexuan Cui {
233ae0078fcSDexuan Cui 	set_channel_pending_send_size(chan, 0);
234ae0078fcSDexuan Cui 
235ae0078fcSDexuan Cui 	/* Ditto */
236ae0078fcSDexuan Cui 	virt_mb();
237ae0078fcSDexuan Cui }
238ae0078fcSDexuan Cui 
239ae0078fcSDexuan Cui static bool hvs_channel_readable(struct vmbus_channel *chan)
240ae0078fcSDexuan Cui {
241ae0078fcSDexuan Cui 	u32 readable = hv_get_bytes_to_read(&chan->inbound);
242ae0078fcSDexuan Cui 
243ae0078fcSDexuan Cui 	/* 0-size payload means FIN */
244ae0078fcSDexuan Cui 	return readable >= HVS_PKT_LEN(0);
245ae0078fcSDexuan Cui }
246ae0078fcSDexuan Cui 
247ae0078fcSDexuan Cui static int hvs_channel_readable_payload(struct vmbus_channel *chan)
248ae0078fcSDexuan Cui {
249ae0078fcSDexuan Cui 	u32 readable = hv_get_bytes_to_read(&chan->inbound);
250ae0078fcSDexuan Cui 
251ae0078fcSDexuan Cui 	if (readable > HVS_PKT_LEN(0)) {
252ae0078fcSDexuan Cui 		/* At least we have 1 byte to read. We don't need to return
253ae0078fcSDexuan Cui 		 * the exact readable bytes: see vsock_stream_recvmsg() ->
254ae0078fcSDexuan Cui 		 * vsock_stream_has_data().
255ae0078fcSDexuan Cui 		 */
256ae0078fcSDexuan Cui 		return 1;
257ae0078fcSDexuan Cui 	}
258ae0078fcSDexuan Cui 
259ae0078fcSDexuan Cui 	if (readable == HVS_PKT_LEN(0)) {
260ae0078fcSDexuan Cui 		/* 0-size payload means FIN */
261ae0078fcSDexuan Cui 		return 0;
262ae0078fcSDexuan Cui 	}
263ae0078fcSDexuan Cui 
264ae0078fcSDexuan Cui 	/* No payload or FIN */
265ae0078fcSDexuan Cui 	return -1;
266ae0078fcSDexuan Cui }
267ae0078fcSDexuan Cui 
268ae0078fcSDexuan Cui static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan)
269ae0078fcSDexuan Cui {
270ae0078fcSDexuan Cui 	u32 writeable = hv_get_bytes_to_write(&chan->outbound);
271ae0078fcSDexuan Cui 	size_t ret;
272ae0078fcSDexuan Cui 
273ae0078fcSDexuan Cui 	/* The ringbuffer mustn't be 100% full, and we should reserve a
274ae0078fcSDexuan Cui 	 * zero-length-payload packet for the FIN: see hv_ringbuffer_write()
275ae0078fcSDexuan Cui 	 * and hvs_shutdown().
276ae0078fcSDexuan Cui 	 */
277ae0078fcSDexuan Cui 	if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0))
278ae0078fcSDexuan Cui 		return 0;
279ae0078fcSDexuan Cui 
280ae0078fcSDexuan Cui 	ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0);
281ae0078fcSDexuan Cui 
282ae0078fcSDexuan Cui 	return round_down(ret, 8);
283ae0078fcSDexuan Cui }
284ae0078fcSDexuan Cui 
285ae0078fcSDexuan Cui static int hvs_send_data(struct vmbus_channel *chan,
286ae0078fcSDexuan Cui 			 struct hvs_send_buf *send_buf, size_t to_write)
287ae0078fcSDexuan Cui {
288ae0078fcSDexuan Cui 	send_buf->hdr.pkt_type = 1;
289ae0078fcSDexuan Cui 	send_buf->hdr.data_size = to_write;
290ae0078fcSDexuan Cui 	return vmbus_sendpacket(chan, &send_buf->hdr,
291ae0078fcSDexuan Cui 				sizeof(send_buf->hdr) + to_write,
292ae0078fcSDexuan Cui 				0, VM_PKT_DATA_INBAND, 0);
293ae0078fcSDexuan Cui }
294ae0078fcSDexuan Cui 
295ae0078fcSDexuan Cui static void hvs_channel_cb(void *ctx)
296ae0078fcSDexuan Cui {
297ae0078fcSDexuan Cui 	struct sock *sk = (struct sock *)ctx;
298ae0078fcSDexuan Cui 	struct vsock_sock *vsk = vsock_sk(sk);
299ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
300ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
301ae0078fcSDexuan Cui 
302ae0078fcSDexuan Cui 	if (hvs_channel_readable(chan))
303ae0078fcSDexuan Cui 		sk->sk_data_ready(sk);
304ae0078fcSDexuan Cui 
305ae0078fcSDexuan Cui 	/* See hvs_stream_has_space(): when we reach here, the writable bytes
306ae0078fcSDexuan Cui 	 * may be already less than HVS_PKT_LEN(HVS_SEND_BUF_SIZE).
307ae0078fcSDexuan Cui 	 */
308ae0078fcSDexuan Cui 	if (hv_get_bytes_to_write(&chan->outbound) > 0)
309ae0078fcSDexuan Cui 		sk->sk_write_space(sk);
310ae0078fcSDexuan Cui }
311ae0078fcSDexuan Cui 
312a9eeb998SSunil Muthuswamy static void hvs_do_close_lock_held(struct vsock_sock *vsk,
313a9eeb998SSunil Muthuswamy 				   bool cancel_timeout)
314a9eeb998SSunil Muthuswamy {
315a9eeb998SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
316a9eeb998SSunil Muthuswamy 
317a9eeb998SSunil Muthuswamy 	sock_set_flag(sk, SOCK_DONE);
318a9eeb998SSunil Muthuswamy 	vsk->peer_shutdown = SHUTDOWN_MASK;
319a9eeb998SSunil Muthuswamy 	if (vsock_stream_has_data(vsk) <= 0)
320a9eeb998SSunil Muthuswamy 		sk->sk_state = TCP_CLOSING;
321a9eeb998SSunil Muthuswamy 	sk->sk_state_change(sk);
322a9eeb998SSunil Muthuswamy 	if (vsk->close_work_scheduled &&
323a9eeb998SSunil Muthuswamy 	    (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
324a9eeb998SSunil Muthuswamy 		vsk->close_work_scheduled = false;
325a9eeb998SSunil Muthuswamy 		vsock_remove_sock(vsk);
326a9eeb998SSunil Muthuswamy 
327a9eeb998SSunil Muthuswamy 		/* Release the reference taken while scheduling the timeout */
328a9eeb998SSunil Muthuswamy 		sock_put(sk);
329a9eeb998SSunil Muthuswamy 	}
330a9eeb998SSunil Muthuswamy }
331a9eeb998SSunil Muthuswamy 
332ae0078fcSDexuan Cui static void hvs_close_connection(struct vmbus_channel *chan)
333ae0078fcSDexuan Cui {
334ae0078fcSDexuan Cui 	struct sock *sk = get_per_channel_state(chan);
335ae0078fcSDexuan Cui 
336b4562ca7SDexuan Cui 	lock_sock(sk);
337a9eeb998SSunil Muthuswamy 	hvs_do_close_lock_held(vsock_sk(sk), true);
338b4562ca7SDexuan Cui 	release_sock(sk);
339ae0078fcSDexuan Cui }
340ae0078fcSDexuan Cui 
341ae0078fcSDexuan Cui static void hvs_open_connection(struct vmbus_channel *chan)
342ae0078fcSDexuan Cui {
343ae0078fcSDexuan Cui 	uuid_le *if_instance, *if_type;
344ae0078fcSDexuan Cui 	unsigned char conn_from_host;
345ae0078fcSDexuan Cui 
346ae0078fcSDexuan Cui 	struct sockaddr_vm addr;
347ae0078fcSDexuan Cui 	struct sock *sk, *new = NULL;
348ac383f58SSunil Muthuswamy 	struct vsock_sock *vnew = NULL;
349ac383f58SSunil Muthuswamy 	struct hvsock *hvs = NULL;
350ac383f58SSunil Muthuswamy 	struct hvsock *hvs_new = NULL;
351ac383f58SSunil Muthuswamy 	int rcvbuf;
352ae0078fcSDexuan Cui 	int ret;
353ac383f58SSunil Muthuswamy 	int sndbuf;
354ae0078fcSDexuan Cui 
355ae0078fcSDexuan Cui 	if_type = &chan->offermsg.offer.if_type;
356ae0078fcSDexuan Cui 	if_instance = &chan->offermsg.offer.if_instance;
357ae0078fcSDexuan Cui 	conn_from_host = chan->offermsg.offer.u.pipe.user_def[0];
358ae0078fcSDexuan Cui 
359ae0078fcSDexuan Cui 	/* The host or the VM should only listen on a port in
360ae0078fcSDexuan Cui 	 * [0, MAX_LISTEN_PORT]
361ae0078fcSDexuan Cui 	 */
362ae0078fcSDexuan Cui 	if (!is_valid_srv_id(if_type) ||
363ae0078fcSDexuan Cui 	    get_port_by_srv_id(if_type) > MAX_LISTEN_PORT)
364ae0078fcSDexuan Cui 		return;
365ae0078fcSDexuan Cui 
366ae0078fcSDexuan Cui 	hvs_addr_init(&addr, conn_from_host ? if_type : if_instance);
367ae0078fcSDexuan Cui 	sk = vsock_find_bound_socket(&addr);
368ae0078fcSDexuan Cui 	if (!sk)
369ae0078fcSDexuan Cui 		return;
370ae0078fcSDexuan Cui 
371b4562ca7SDexuan Cui 	lock_sock(sk);
3723b4477d2SStefan Hajnoczi 	if ((conn_from_host && sk->sk_state != TCP_LISTEN) ||
3733b4477d2SStefan Hajnoczi 	    (!conn_from_host && sk->sk_state != TCP_SYN_SENT))
374ae0078fcSDexuan Cui 		goto out;
375ae0078fcSDexuan Cui 
376ae0078fcSDexuan Cui 	if (conn_from_host) {
377ae0078fcSDexuan Cui 		if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog)
378ae0078fcSDexuan Cui 			goto out;
379ae0078fcSDexuan Cui 
380ae0078fcSDexuan Cui 		new = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
381ae0078fcSDexuan Cui 				     sk->sk_type, 0);
382ae0078fcSDexuan Cui 		if (!new)
383ae0078fcSDexuan Cui 			goto out;
384ae0078fcSDexuan Cui 
3853b4477d2SStefan Hajnoczi 		new->sk_state = TCP_SYN_SENT;
386ae0078fcSDexuan Cui 		vnew = vsock_sk(new);
387ae0078fcSDexuan Cui 		hvs_new = vnew->trans;
388ae0078fcSDexuan Cui 		hvs_new->chan = chan;
389ae0078fcSDexuan Cui 	} else {
390ae0078fcSDexuan Cui 		hvs = vsock_sk(sk)->trans;
391ae0078fcSDexuan Cui 		hvs->chan = chan;
392ae0078fcSDexuan Cui 	}
393ae0078fcSDexuan Cui 
394ae0078fcSDexuan Cui 	set_channel_read_mode(chan, HV_CALL_DIRECT);
395ac383f58SSunil Muthuswamy 
396ac383f58SSunil Muthuswamy 	/* Use the socket buffer sizes as hints for the VMBUS ring size. For
397ac383f58SSunil Muthuswamy 	 * server side sockets, 'sk' is the parent socket and thus, this will
398ac383f58SSunil Muthuswamy 	 * allow the child sockets to inherit the size from the parent. Keep
399ac383f58SSunil Muthuswamy 	 * the mins to the default value and align to page size as per VMBUS
400ac383f58SSunil Muthuswamy 	 * requirements.
401ac383f58SSunil Muthuswamy 	 * For the max, the socket core library will limit the socket buffer
402ac383f58SSunil Muthuswamy 	 * size that can be set by the user, but, since currently, the hv_sock
403ac383f58SSunil Muthuswamy 	 * VMBUS ring buffer is physically contiguous allocation, restrict it
404ac383f58SSunil Muthuswamy 	 * further.
405ac383f58SSunil Muthuswamy 	 * Older versions of hv_sock host side code cannot handle bigger VMBUS
406ac383f58SSunil Muthuswamy 	 * ring buffer size. Use the version number to limit the change to newer
407ac383f58SSunil Muthuswamy 	 * versions.
408ac383f58SSunil Muthuswamy 	 */
409ac383f58SSunil Muthuswamy 	if (vmbus_proto_version < VERSION_WIN10_V5) {
410ac383f58SSunil Muthuswamy 		sndbuf = RINGBUFFER_HVS_SND_SIZE;
411ac383f58SSunil Muthuswamy 		rcvbuf = RINGBUFFER_HVS_RCV_SIZE;
412ac383f58SSunil Muthuswamy 	} else {
413ac383f58SSunil Muthuswamy 		sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE);
414ac383f58SSunil Muthuswamy 		sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE);
415ac383f58SSunil Muthuswamy 		sndbuf = ALIGN(sndbuf, PAGE_SIZE);
416ac383f58SSunil Muthuswamy 		rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE);
417ac383f58SSunil Muthuswamy 		rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE);
418ac383f58SSunil Muthuswamy 		rcvbuf = ALIGN(rcvbuf, PAGE_SIZE);
419ac383f58SSunil Muthuswamy 	}
420ac383f58SSunil Muthuswamy 
421ac383f58SSunil Muthuswamy 	ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb,
422ac383f58SSunil Muthuswamy 			 conn_from_host ? new : sk);
423ae0078fcSDexuan Cui 	if (ret != 0) {
424ae0078fcSDexuan Cui 		if (conn_from_host) {
425ae0078fcSDexuan Cui 			hvs_new->chan = NULL;
426ae0078fcSDexuan Cui 			sock_put(new);
427ae0078fcSDexuan Cui 		} else {
428ae0078fcSDexuan Cui 			hvs->chan = NULL;
429ae0078fcSDexuan Cui 		}
430ae0078fcSDexuan Cui 		goto out;
431ae0078fcSDexuan Cui 	}
432ae0078fcSDexuan Cui 
433ae0078fcSDexuan Cui 	set_per_channel_state(chan, conn_from_host ? new : sk);
434ae0078fcSDexuan Cui 	vmbus_set_chn_rescind_callback(chan, hvs_close_connection);
435ae0078fcSDexuan Cui 
436ae0078fcSDexuan Cui 	if (conn_from_host) {
4373b4477d2SStefan Hajnoczi 		new->sk_state = TCP_ESTABLISHED;
438ae0078fcSDexuan Cui 		sk->sk_ack_backlog++;
439ae0078fcSDexuan Cui 
440ae0078fcSDexuan Cui 		hvs_addr_init(&vnew->local_addr, if_type);
441ae0078fcSDexuan Cui 		hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);
442ae0078fcSDexuan Cui 
443ae0078fcSDexuan Cui 		hvs_new->vm_srv_id = *if_type;
444ae0078fcSDexuan Cui 		hvs_new->host_srv_id = *if_instance;
445ae0078fcSDexuan Cui 
446ae0078fcSDexuan Cui 		vsock_insert_connected(vnew);
447ae0078fcSDexuan Cui 
448ae0078fcSDexuan Cui 		vsock_enqueue_accept(sk, new);
449ae0078fcSDexuan Cui 	} else {
4503b4477d2SStefan Hajnoczi 		sk->sk_state = TCP_ESTABLISHED;
451ae0078fcSDexuan Cui 		sk->sk_socket->state = SS_CONNECTED;
452ae0078fcSDexuan Cui 
453ae0078fcSDexuan Cui 		vsock_insert_connected(vsock_sk(sk));
454ae0078fcSDexuan Cui 	}
455ae0078fcSDexuan Cui 
456ae0078fcSDexuan Cui 	sk->sk_state_change(sk);
457ae0078fcSDexuan Cui 
458ae0078fcSDexuan Cui out:
459ae0078fcSDexuan Cui 	/* Release refcnt obtained when we called vsock_find_bound_socket() */
460ae0078fcSDexuan Cui 	sock_put(sk);
461b4562ca7SDexuan Cui 
462b4562ca7SDexuan Cui 	release_sock(sk);
463ae0078fcSDexuan Cui }
464ae0078fcSDexuan Cui 
465ae0078fcSDexuan Cui static u32 hvs_get_local_cid(void)
466ae0078fcSDexuan Cui {
467ae0078fcSDexuan Cui 	return VMADDR_CID_ANY;
468ae0078fcSDexuan Cui }
469ae0078fcSDexuan Cui 
470ae0078fcSDexuan Cui static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk)
471ae0078fcSDexuan Cui {
472ae0078fcSDexuan Cui 	struct hvsock *hvs;
473ac383f58SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
474ae0078fcSDexuan Cui 
475ae0078fcSDexuan Cui 	hvs = kzalloc(sizeof(*hvs), GFP_KERNEL);
476ae0078fcSDexuan Cui 	if (!hvs)
477ae0078fcSDexuan Cui 		return -ENOMEM;
478ae0078fcSDexuan Cui 
479ae0078fcSDexuan Cui 	vsk->trans = hvs;
480ae0078fcSDexuan Cui 	hvs->vsk = vsk;
481ac383f58SSunil Muthuswamy 	sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE;
482ac383f58SSunil Muthuswamy 	sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE;
483ae0078fcSDexuan Cui 	return 0;
484ae0078fcSDexuan Cui }
485ae0078fcSDexuan Cui 
486ae0078fcSDexuan Cui static int hvs_connect(struct vsock_sock *vsk)
487ae0078fcSDexuan Cui {
488ae0078fcSDexuan Cui 	union hvs_service_id vm, host;
489ae0078fcSDexuan Cui 	struct hvsock *h = vsk->trans;
490ae0078fcSDexuan Cui 
491ae0078fcSDexuan Cui 	vm.srv_id = srv_id_template;
492ae0078fcSDexuan Cui 	vm.svm_port = vsk->local_addr.svm_port;
493ae0078fcSDexuan Cui 	h->vm_srv_id = vm.srv_id;
494ae0078fcSDexuan Cui 
495ae0078fcSDexuan Cui 	host.srv_id = srv_id_template;
496ae0078fcSDexuan Cui 	host.svm_port = vsk->remote_addr.svm_port;
497ae0078fcSDexuan Cui 	h->host_srv_id = host.srv_id;
498ae0078fcSDexuan Cui 
499ae0078fcSDexuan Cui 	return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id);
500ae0078fcSDexuan Cui }
501ae0078fcSDexuan Cui 
502a9eeb998SSunil Muthuswamy static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode)
503a9eeb998SSunil Muthuswamy {
504a9eeb998SSunil Muthuswamy 	struct vmpipe_proto_header hdr;
505a9eeb998SSunil Muthuswamy 
506a9eeb998SSunil Muthuswamy 	if (hvs->fin_sent || !hvs->chan)
507a9eeb998SSunil Muthuswamy 		return;
508a9eeb998SSunil Muthuswamy 
509a9eeb998SSunil Muthuswamy 	/* It can't fail: see hvs_channel_writable_bytes(). */
510a9eeb998SSunil Muthuswamy 	(void)hvs_send_data(hvs->chan, (struct hvs_send_buf *)&hdr, 0);
511a9eeb998SSunil Muthuswamy 	hvs->fin_sent = true;
512a9eeb998SSunil Muthuswamy }
513a9eeb998SSunil Muthuswamy 
514ae0078fcSDexuan Cui static int hvs_shutdown(struct vsock_sock *vsk, int mode)
515ae0078fcSDexuan Cui {
516ae0078fcSDexuan Cui 	struct sock *sk = sk_vsock(vsk);
517ae0078fcSDexuan Cui 
518ae0078fcSDexuan Cui 	if (!(mode & SEND_SHUTDOWN))
519ae0078fcSDexuan Cui 		return 0;
520ae0078fcSDexuan Cui 
521ae0078fcSDexuan Cui 	lock_sock(sk);
522a9eeb998SSunil Muthuswamy 	hvs_shutdown_lock_held(vsk->trans, mode);
523ae0078fcSDexuan Cui 	release_sock(sk);
524ae0078fcSDexuan Cui 	return 0;
525ae0078fcSDexuan Cui }
526ae0078fcSDexuan Cui 
527a9eeb998SSunil Muthuswamy static void hvs_close_timeout(struct work_struct *work)
528a9eeb998SSunil Muthuswamy {
529a9eeb998SSunil Muthuswamy 	struct vsock_sock *vsk =
530a9eeb998SSunil Muthuswamy 		container_of(work, struct vsock_sock, close_work.work);
531a9eeb998SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
532a9eeb998SSunil Muthuswamy 
533a9eeb998SSunil Muthuswamy 	sock_hold(sk);
534a9eeb998SSunil Muthuswamy 	lock_sock(sk);
535a9eeb998SSunil Muthuswamy 	if (!sock_flag(sk, SOCK_DONE))
536a9eeb998SSunil Muthuswamy 		hvs_do_close_lock_held(vsk, false);
537a9eeb998SSunil Muthuswamy 
538a9eeb998SSunil Muthuswamy 	vsk->close_work_scheduled = false;
539a9eeb998SSunil Muthuswamy 	release_sock(sk);
540a9eeb998SSunil Muthuswamy 	sock_put(sk);
541a9eeb998SSunil Muthuswamy }
542a9eeb998SSunil Muthuswamy 
543a9eeb998SSunil Muthuswamy /* Returns true, if it is safe to remove socket; false otherwise */
544a9eeb998SSunil Muthuswamy static bool hvs_close_lock_held(struct vsock_sock *vsk)
545a9eeb998SSunil Muthuswamy {
546a9eeb998SSunil Muthuswamy 	struct sock *sk = sk_vsock(vsk);
547a9eeb998SSunil Muthuswamy 
548a9eeb998SSunil Muthuswamy 	if (!(sk->sk_state == TCP_ESTABLISHED ||
549a9eeb998SSunil Muthuswamy 	      sk->sk_state == TCP_CLOSING))
550a9eeb998SSunil Muthuswamy 		return true;
551a9eeb998SSunil Muthuswamy 
552a9eeb998SSunil Muthuswamy 	if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
553a9eeb998SSunil Muthuswamy 		hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK);
554a9eeb998SSunil Muthuswamy 
555a9eeb998SSunil Muthuswamy 	if (sock_flag(sk, SOCK_DONE))
556a9eeb998SSunil Muthuswamy 		return true;
557a9eeb998SSunil Muthuswamy 
558a9eeb998SSunil Muthuswamy 	/* This reference will be dropped by the delayed close routine */
559a9eeb998SSunil Muthuswamy 	sock_hold(sk);
560a9eeb998SSunil Muthuswamy 	INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout);
561a9eeb998SSunil Muthuswamy 	vsk->close_work_scheduled = true;
562a9eeb998SSunil Muthuswamy 	schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT);
563a9eeb998SSunil Muthuswamy 	return false;
564a9eeb998SSunil Muthuswamy }
565a9eeb998SSunil Muthuswamy 
566ae0078fcSDexuan Cui static void hvs_release(struct vsock_sock *vsk)
567ae0078fcSDexuan Cui {
568b4562ca7SDexuan Cui 	struct sock *sk = sk_vsock(vsk);
569a9eeb998SSunil Muthuswamy 	bool remove_sock;
570ae0078fcSDexuan Cui 
571b4562ca7SDexuan Cui 	lock_sock(sk);
572a9eeb998SSunil Muthuswamy 	remove_sock = hvs_close_lock_held(vsk);
573b4562ca7SDexuan Cui 	release_sock(sk);
574a9eeb998SSunil Muthuswamy 	if (remove_sock)
575a9eeb998SSunil Muthuswamy 		vsock_remove_sock(vsk);
576ae0078fcSDexuan Cui }
577ae0078fcSDexuan Cui 
578ae0078fcSDexuan Cui static void hvs_destruct(struct vsock_sock *vsk)
579ae0078fcSDexuan Cui {
580ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
581ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
582ae0078fcSDexuan Cui 
583ae0078fcSDexuan Cui 	if (chan)
584ae0078fcSDexuan Cui 		vmbus_hvsock_device_unregister(chan);
585ae0078fcSDexuan Cui 
586ae0078fcSDexuan Cui 	kfree(hvs);
587ae0078fcSDexuan Cui }
588ae0078fcSDexuan Cui 
589ae0078fcSDexuan Cui static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
590ae0078fcSDexuan Cui {
591ae0078fcSDexuan Cui 	return -EOPNOTSUPP;
592ae0078fcSDexuan Cui }
593ae0078fcSDexuan Cui 
594ae0078fcSDexuan Cui static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
595ae0078fcSDexuan Cui 			     size_t len, int flags)
596ae0078fcSDexuan Cui {
597ae0078fcSDexuan Cui 	return -EOPNOTSUPP;
598ae0078fcSDexuan Cui }
599ae0078fcSDexuan Cui 
600ae0078fcSDexuan Cui static int hvs_dgram_enqueue(struct vsock_sock *vsk,
601ae0078fcSDexuan Cui 			     struct sockaddr_vm *remote, struct msghdr *msg,
602ae0078fcSDexuan Cui 			     size_t dgram_len)
603ae0078fcSDexuan Cui {
604ae0078fcSDexuan Cui 	return -EOPNOTSUPP;
605ae0078fcSDexuan Cui }
606ae0078fcSDexuan Cui 
607ae0078fcSDexuan Cui static bool hvs_dgram_allow(u32 cid, u32 port)
608ae0078fcSDexuan Cui {
609ae0078fcSDexuan Cui 	return false;
610ae0078fcSDexuan Cui }
611ae0078fcSDexuan Cui 
612ae0078fcSDexuan Cui static int hvs_update_recv_data(struct hvsock *hvs)
613ae0078fcSDexuan Cui {
614ae0078fcSDexuan Cui 	struct hvs_recv_buf *recv_buf;
615ae0078fcSDexuan Cui 	u32 payload_len;
616ae0078fcSDexuan Cui 
617ae0078fcSDexuan Cui 	recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
618ae0078fcSDexuan Cui 	payload_len = recv_buf->hdr.data_size;
619ae0078fcSDexuan Cui 
620ae0078fcSDexuan Cui 	if (payload_len > HVS_MTU_SIZE)
621ae0078fcSDexuan Cui 		return -EIO;
622ae0078fcSDexuan Cui 
623ae0078fcSDexuan Cui 	if (payload_len == 0)
624ae0078fcSDexuan Cui 		hvs->vsk->peer_shutdown |= SEND_SHUTDOWN;
625ae0078fcSDexuan Cui 
626ae0078fcSDexuan Cui 	hvs->recv_data_len = payload_len;
627ae0078fcSDexuan Cui 	hvs->recv_data_off = 0;
628ae0078fcSDexuan Cui 
629ae0078fcSDexuan Cui 	return 0;
630ae0078fcSDexuan Cui }
631ae0078fcSDexuan Cui 
632ae0078fcSDexuan Cui static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
633ae0078fcSDexuan Cui 				  size_t len, int flags)
634ae0078fcSDexuan Cui {
635ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
636ae0078fcSDexuan Cui 	bool need_refill = !hvs->recv_desc;
637ae0078fcSDexuan Cui 	struct hvs_recv_buf *recv_buf;
638ae0078fcSDexuan Cui 	u32 to_read;
639ae0078fcSDexuan Cui 	int ret;
640ae0078fcSDexuan Cui 
641ae0078fcSDexuan Cui 	if (flags & MSG_PEEK)
642ae0078fcSDexuan Cui 		return -EOPNOTSUPP;
643ae0078fcSDexuan Cui 
644ae0078fcSDexuan Cui 	if (need_refill) {
645ae0078fcSDexuan Cui 		hvs->recv_desc = hv_pkt_iter_first(hvs->chan);
646ae0078fcSDexuan Cui 		ret = hvs_update_recv_data(hvs);
647ae0078fcSDexuan Cui 		if (ret)
648ae0078fcSDexuan Cui 			return ret;
649ae0078fcSDexuan Cui 	}
650ae0078fcSDexuan Cui 
651ae0078fcSDexuan Cui 	recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
652ae0078fcSDexuan Cui 	to_read = min_t(u32, len, hvs->recv_data_len);
653ae0078fcSDexuan Cui 	ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read);
654ae0078fcSDexuan Cui 	if (ret != 0)
655ae0078fcSDexuan Cui 		return ret;
656ae0078fcSDexuan Cui 
657ae0078fcSDexuan Cui 	hvs->recv_data_len -= to_read;
658ae0078fcSDexuan Cui 	if (hvs->recv_data_len == 0) {
659ae0078fcSDexuan Cui 		hvs->recv_desc = hv_pkt_iter_next(hvs->chan, hvs->recv_desc);
660ae0078fcSDexuan Cui 		if (hvs->recv_desc) {
661ae0078fcSDexuan Cui 			ret = hvs_update_recv_data(hvs);
662ae0078fcSDexuan Cui 			if (ret)
663ae0078fcSDexuan Cui 				return ret;
664ae0078fcSDexuan Cui 		}
665ae0078fcSDexuan Cui 	} else {
666ae0078fcSDexuan Cui 		hvs->recv_data_off += to_read;
667ae0078fcSDexuan Cui 	}
668ae0078fcSDexuan Cui 
669ae0078fcSDexuan Cui 	return to_read;
670ae0078fcSDexuan Cui }
671ae0078fcSDexuan Cui 
672ae0078fcSDexuan Cui static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
673ae0078fcSDexuan Cui 				  size_t len)
674ae0078fcSDexuan Cui {
675ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
676ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
677ae0078fcSDexuan Cui 	struct hvs_send_buf *send_buf;
67814a1eaa8SSunil Muthuswamy 	ssize_t to_write, max_writable;
67914a1eaa8SSunil Muthuswamy 	ssize_t ret = 0;
68014a1eaa8SSunil Muthuswamy 	ssize_t bytes_written = 0;
681ae0078fcSDexuan Cui 
682ae0078fcSDexuan Cui 	BUILD_BUG_ON(sizeof(*send_buf) != PAGE_SIZE_4K);
683ae0078fcSDexuan Cui 
684ae0078fcSDexuan Cui 	send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL);
685ae0078fcSDexuan Cui 	if (!send_buf)
686ae0078fcSDexuan Cui 		return -ENOMEM;
687ae0078fcSDexuan Cui 
68814a1eaa8SSunil Muthuswamy 	/* Reader(s) could be draining data from the channel as we write.
68914a1eaa8SSunil Muthuswamy 	 * Maximize bandwidth, by iterating until the channel is found to be
69014a1eaa8SSunil Muthuswamy 	 * full.
69114a1eaa8SSunil Muthuswamy 	 */
69214a1eaa8SSunil Muthuswamy 	while (len) {
693ae0078fcSDexuan Cui 		max_writable = hvs_channel_writable_bytes(chan);
69414a1eaa8SSunil Muthuswamy 		if (!max_writable)
69514a1eaa8SSunil Muthuswamy 			break;
696ae0078fcSDexuan Cui 		to_write = min_t(ssize_t, len, max_writable);
697ae0078fcSDexuan Cui 		to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE);
69814a1eaa8SSunil Muthuswamy 		/* memcpy_from_msg is safe for loop as it advances the offsets
69914a1eaa8SSunil Muthuswamy 		 * within the message iterator.
70014a1eaa8SSunil Muthuswamy 		 */
701ae0078fcSDexuan Cui 		ret = memcpy_from_msg(send_buf->data, msg, to_write);
702ae0078fcSDexuan Cui 		if (ret < 0)
703ae0078fcSDexuan Cui 			goto out;
704ae0078fcSDexuan Cui 
705ae0078fcSDexuan Cui 		ret = hvs_send_data(hvs->chan, send_buf, to_write);
706ae0078fcSDexuan Cui 		if (ret < 0)
707ae0078fcSDexuan Cui 			goto out;
708ae0078fcSDexuan Cui 
70914a1eaa8SSunil Muthuswamy 		bytes_written += to_write;
71014a1eaa8SSunil Muthuswamy 		len -= to_write;
71114a1eaa8SSunil Muthuswamy 	}
712ae0078fcSDexuan Cui out:
71314a1eaa8SSunil Muthuswamy 	/* If any data has been sent, return that */
71414a1eaa8SSunil Muthuswamy 	if (bytes_written)
71514a1eaa8SSunil Muthuswamy 		ret = bytes_written;
716ae0078fcSDexuan Cui 	kfree(send_buf);
717ae0078fcSDexuan Cui 	return ret;
718ae0078fcSDexuan Cui }
719ae0078fcSDexuan Cui 
720ae0078fcSDexuan Cui static s64 hvs_stream_has_data(struct vsock_sock *vsk)
721ae0078fcSDexuan Cui {
722ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
723ae0078fcSDexuan Cui 	s64 ret;
724ae0078fcSDexuan Cui 
725ae0078fcSDexuan Cui 	if (hvs->recv_data_len > 0)
726ae0078fcSDexuan Cui 		return 1;
727ae0078fcSDexuan Cui 
728ae0078fcSDexuan Cui 	switch (hvs_channel_readable_payload(hvs->chan)) {
729ae0078fcSDexuan Cui 	case 1:
730ae0078fcSDexuan Cui 		ret = 1;
731ae0078fcSDexuan Cui 		break;
732ae0078fcSDexuan Cui 	case 0:
733ae0078fcSDexuan Cui 		vsk->peer_shutdown |= SEND_SHUTDOWN;
734ae0078fcSDexuan Cui 		ret = 0;
735ae0078fcSDexuan Cui 		break;
736ae0078fcSDexuan Cui 	default: /* -1 */
737ae0078fcSDexuan Cui 		ret = 0;
738ae0078fcSDexuan Cui 		break;
739ae0078fcSDexuan Cui 	}
740ae0078fcSDexuan Cui 
741ae0078fcSDexuan Cui 	return ret;
742ae0078fcSDexuan Cui }
743ae0078fcSDexuan Cui 
744ae0078fcSDexuan Cui static s64 hvs_stream_has_space(struct vsock_sock *vsk)
745ae0078fcSDexuan Cui {
746ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
747ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hvs->chan;
748ae0078fcSDexuan Cui 	s64 ret;
749ae0078fcSDexuan Cui 
750ae0078fcSDexuan Cui 	ret = hvs_channel_writable_bytes(chan);
751ae0078fcSDexuan Cui 	if (ret > 0)  {
752ae0078fcSDexuan Cui 		hvs_clear_channel_pending_send_size(chan);
753ae0078fcSDexuan Cui 	} else {
754ae0078fcSDexuan Cui 		/* See hvs_channel_cb() */
755ae0078fcSDexuan Cui 		hvs_set_channel_pending_send_size(chan);
756ae0078fcSDexuan Cui 
757ae0078fcSDexuan Cui 		/* Re-check the writable bytes to avoid race */
758ae0078fcSDexuan Cui 		ret = hvs_channel_writable_bytes(chan);
759ae0078fcSDexuan Cui 		if (ret > 0)
760ae0078fcSDexuan Cui 			hvs_clear_channel_pending_send_size(chan);
761ae0078fcSDexuan Cui 	}
762ae0078fcSDexuan Cui 
763ae0078fcSDexuan Cui 	return ret;
764ae0078fcSDexuan Cui }
765ae0078fcSDexuan Cui 
766ae0078fcSDexuan Cui static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk)
767ae0078fcSDexuan Cui {
768ae0078fcSDexuan Cui 	return HVS_MTU_SIZE + 1;
769ae0078fcSDexuan Cui }
770ae0078fcSDexuan Cui 
771ae0078fcSDexuan Cui static bool hvs_stream_is_active(struct vsock_sock *vsk)
772ae0078fcSDexuan Cui {
773ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
774ae0078fcSDexuan Cui 
775ae0078fcSDexuan Cui 	return hvs->chan != NULL;
776ae0078fcSDexuan Cui }
777ae0078fcSDexuan Cui 
778ae0078fcSDexuan Cui static bool hvs_stream_allow(u32 cid, u32 port)
779ae0078fcSDexuan Cui {
780ae0078fcSDexuan Cui 	/* The host's port range [MIN_HOST_EPHEMERAL_PORT, 0xFFFFFFFF) is
781ae0078fcSDexuan Cui 	 * reserved as ephemeral ports, which are used as the host's ports
782ae0078fcSDexuan Cui 	 * when the host initiates connections.
783ae0078fcSDexuan Cui 	 *
784ae0078fcSDexuan Cui 	 * Perform this check in the guest so an immediate error is produced
785ae0078fcSDexuan Cui 	 * instead of a timeout.
786ae0078fcSDexuan Cui 	 */
787ae0078fcSDexuan Cui 	if (port > MAX_HOST_LISTEN_PORT)
788ae0078fcSDexuan Cui 		return false;
789ae0078fcSDexuan Cui 
790ae0078fcSDexuan Cui 	if (cid == VMADDR_CID_HOST)
791ae0078fcSDexuan Cui 		return true;
792ae0078fcSDexuan Cui 
793ae0078fcSDexuan Cui 	return false;
794ae0078fcSDexuan Cui }
795ae0078fcSDexuan Cui 
796ae0078fcSDexuan Cui static
797ae0078fcSDexuan Cui int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable)
798ae0078fcSDexuan Cui {
799ae0078fcSDexuan Cui 	struct hvsock *hvs = vsk->trans;
800ae0078fcSDexuan Cui 
801ae0078fcSDexuan Cui 	*readable = hvs_channel_readable(hvs->chan);
802ae0078fcSDexuan Cui 	return 0;
803ae0078fcSDexuan Cui }
804ae0078fcSDexuan Cui 
805ae0078fcSDexuan Cui static
806ae0078fcSDexuan Cui int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable)
807ae0078fcSDexuan Cui {
808ae0078fcSDexuan Cui 	*writable = hvs_stream_has_space(vsk) > 0;
809ae0078fcSDexuan Cui 
810ae0078fcSDexuan Cui 	return 0;
811ae0078fcSDexuan Cui }
812ae0078fcSDexuan Cui 
813ae0078fcSDexuan Cui static
814ae0078fcSDexuan Cui int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target,
815ae0078fcSDexuan Cui 			 struct vsock_transport_recv_notify_data *d)
816ae0078fcSDexuan Cui {
817ae0078fcSDexuan Cui 	return 0;
818ae0078fcSDexuan Cui }
819ae0078fcSDexuan Cui 
820ae0078fcSDexuan Cui static
821ae0078fcSDexuan Cui int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target,
822ae0078fcSDexuan Cui 			      struct vsock_transport_recv_notify_data *d)
823ae0078fcSDexuan Cui {
824ae0078fcSDexuan Cui 	return 0;
825ae0078fcSDexuan Cui }
826ae0078fcSDexuan Cui 
827ae0078fcSDexuan Cui static
828ae0078fcSDexuan Cui int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target,
829ae0078fcSDexuan Cui 				struct vsock_transport_recv_notify_data *d)
830ae0078fcSDexuan Cui {
831ae0078fcSDexuan Cui 	return 0;
832ae0078fcSDexuan Cui }
833ae0078fcSDexuan Cui 
834ae0078fcSDexuan Cui static
835ae0078fcSDexuan Cui int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target,
836ae0078fcSDexuan Cui 				 ssize_t copied, bool data_read,
837ae0078fcSDexuan Cui 				 struct vsock_transport_recv_notify_data *d)
838ae0078fcSDexuan Cui {
839ae0078fcSDexuan Cui 	return 0;
840ae0078fcSDexuan Cui }
841ae0078fcSDexuan Cui 
842ae0078fcSDexuan Cui static
843ae0078fcSDexuan Cui int hvs_notify_send_init(struct vsock_sock *vsk,
844ae0078fcSDexuan Cui 			 struct vsock_transport_send_notify_data *d)
845ae0078fcSDexuan Cui {
846ae0078fcSDexuan Cui 	return 0;
847ae0078fcSDexuan Cui }
848ae0078fcSDexuan Cui 
849ae0078fcSDexuan Cui static
850ae0078fcSDexuan Cui int hvs_notify_send_pre_block(struct vsock_sock *vsk,
851ae0078fcSDexuan Cui 			      struct vsock_transport_send_notify_data *d)
852ae0078fcSDexuan Cui {
853ae0078fcSDexuan Cui 	return 0;
854ae0078fcSDexuan Cui }
855ae0078fcSDexuan Cui 
856ae0078fcSDexuan Cui static
857ae0078fcSDexuan Cui int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk,
858ae0078fcSDexuan Cui 				struct vsock_transport_send_notify_data *d)
859ae0078fcSDexuan Cui {
860ae0078fcSDexuan Cui 	return 0;
861ae0078fcSDexuan Cui }
862ae0078fcSDexuan Cui 
863ae0078fcSDexuan Cui static
864ae0078fcSDexuan Cui int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
865ae0078fcSDexuan Cui 				 struct vsock_transport_send_notify_data *d)
866ae0078fcSDexuan Cui {
867ae0078fcSDexuan Cui 	return 0;
868ae0078fcSDexuan Cui }
869ae0078fcSDexuan Cui 
870ae0078fcSDexuan Cui static void hvs_set_buffer_size(struct vsock_sock *vsk, u64 val)
871ae0078fcSDexuan Cui {
872ae0078fcSDexuan Cui 	/* Ignored. */
873ae0078fcSDexuan Cui }
874ae0078fcSDexuan Cui 
875ae0078fcSDexuan Cui static void hvs_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
876ae0078fcSDexuan Cui {
877ae0078fcSDexuan Cui 	/* Ignored. */
878ae0078fcSDexuan Cui }
879ae0078fcSDexuan Cui 
880ae0078fcSDexuan Cui static void hvs_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
881ae0078fcSDexuan Cui {
882ae0078fcSDexuan Cui 	/* Ignored. */
883ae0078fcSDexuan Cui }
884ae0078fcSDexuan Cui 
885ae0078fcSDexuan Cui static u64 hvs_get_buffer_size(struct vsock_sock *vsk)
886ae0078fcSDexuan Cui {
887ae0078fcSDexuan Cui 	return -ENOPROTOOPT;
888ae0078fcSDexuan Cui }
889ae0078fcSDexuan Cui 
890ae0078fcSDexuan Cui static u64 hvs_get_min_buffer_size(struct vsock_sock *vsk)
891ae0078fcSDexuan Cui {
892ae0078fcSDexuan Cui 	return -ENOPROTOOPT;
893ae0078fcSDexuan Cui }
894ae0078fcSDexuan Cui 
895ae0078fcSDexuan Cui static u64 hvs_get_max_buffer_size(struct vsock_sock *vsk)
896ae0078fcSDexuan Cui {
897ae0078fcSDexuan Cui 	return -ENOPROTOOPT;
898ae0078fcSDexuan Cui }
899ae0078fcSDexuan Cui 
900ae0078fcSDexuan Cui static struct vsock_transport hvs_transport = {
901ae0078fcSDexuan Cui 	.get_local_cid            = hvs_get_local_cid,
902ae0078fcSDexuan Cui 
903ae0078fcSDexuan Cui 	.init                     = hvs_sock_init,
904ae0078fcSDexuan Cui 	.destruct                 = hvs_destruct,
905ae0078fcSDexuan Cui 	.release                  = hvs_release,
906ae0078fcSDexuan Cui 	.connect                  = hvs_connect,
907ae0078fcSDexuan Cui 	.shutdown                 = hvs_shutdown,
908ae0078fcSDexuan Cui 
909ae0078fcSDexuan Cui 	.dgram_bind               = hvs_dgram_bind,
910ae0078fcSDexuan Cui 	.dgram_dequeue            = hvs_dgram_dequeue,
911ae0078fcSDexuan Cui 	.dgram_enqueue            = hvs_dgram_enqueue,
912ae0078fcSDexuan Cui 	.dgram_allow              = hvs_dgram_allow,
913ae0078fcSDexuan Cui 
914ae0078fcSDexuan Cui 	.stream_dequeue           = hvs_stream_dequeue,
915ae0078fcSDexuan Cui 	.stream_enqueue           = hvs_stream_enqueue,
916ae0078fcSDexuan Cui 	.stream_has_data          = hvs_stream_has_data,
917ae0078fcSDexuan Cui 	.stream_has_space         = hvs_stream_has_space,
918ae0078fcSDexuan Cui 	.stream_rcvhiwat          = hvs_stream_rcvhiwat,
919ae0078fcSDexuan Cui 	.stream_is_active         = hvs_stream_is_active,
920ae0078fcSDexuan Cui 	.stream_allow             = hvs_stream_allow,
921ae0078fcSDexuan Cui 
922ae0078fcSDexuan Cui 	.notify_poll_in           = hvs_notify_poll_in,
923ae0078fcSDexuan Cui 	.notify_poll_out          = hvs_notify_poll_out,
924ae0078fcSDexuan Cui 	.notify_recv_init         = hvs_notify_recv_init,
925ae0078fcSDexuan Cui 	.notify_recv_pre_block    = hvs_notify_recv_pre_block,
926ae0078fcSDexuan Cui 	.notify_recv_pre_dequeue  = hvs_notify_recv_pre_dequeue,
927ae0078fcSDexuan Cui 	.notify_recv_post_dequeue = hvs_notify_recv_post_dequeue,
928ae0078fcSDexuan Cui 	.notify_send_init         = hvs_notify_send_init,
929ae0078fcSDexuan Cui 	.notify_send_pre_block    = hvs_notify_send_pre_block,
930ae0078fcSDexuan Cui 	.notify_send_pre_enqueue  = hvs_notify_send_pre_enqueue,
931ae0078fcSDexuan Cui 	.notify_send_post_enqueue = hvs_notify_send_post_enqueue,
932ae0078fcSDexuan Cui 
933ae0078fcSDexuan Cui 	.set_buffer_size          = hvs_set_buffer_size,
934ae0078fcSDexuan Cui 	.set_min_buffer_size      = hvs_set_min_buffer_size,
935ae0078fcSDexuan Cui 	.set_max_buffer_size      = hvs_set_max_buffer_size,
936ae0078fcSDexuan Cui 	.get_buffer_size          = hvs_get_buffer_size,
937ae0078fcSDexuan Cui 	.get_min_buffer_size      = hvs_get_min_buffer_size,
938ae0078fcSDexuan Cui 	.get_max_buffer_size      = hvs_get_max_buffer_size,
939ae0078fcSDexuan Cui };
940ae0078fcSDexuan Cui 
941ae0078fcSDexuan Cui static int hvs_probe(struct hv_device *hdev,
942ae0078fcSDexuan Cui 		     const struct hv_vmbus_device_id *dev_id)
943ae0078fcSDexuan Cui {
944ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hdev->channel;
945ae0078fcSDexuan Cui 
946ae0078fcSDexuan Cui 	hvs_open_connection(chan);
947ae0078fcSDexuan Cui 
948ae0078fcSDexuan Cui 	/* Always return success to suppress the unnecessary error message
949ae0078fcSDexuan Cui 	 * in vmbus_probe(): on error the host will rescind the device in
950ae0078fcSDexuan Cui 	 * 30 seconds and we can do cleanup at that time in
951ae0078fcSDexuan Cui 	 * vmbus_onoffer_rescind().
952ae0078fcSDexuan Cui 	 */
953ae0078fcSDexuan Cui 	return 0;
954ae0078fcSDexuan Cui }
955ae0078fcSDexuan Cui 
956ae0078fcSDexuan Cui static int hvs_remove(struct hv_device *hdev)
957ae0078fcSDexuan Cui {
958ae0078fcSDexuan Cui 	struct vmbus_channel *chan = hdev->channel;
959ae0078fcSDexuan Cui 
960ae0078fcSDexuan Cui 	vmbus_close(chan);
961ae0078fcSDexuan Cui 
962ae0078fcSDexuan Cui 	return 0;
963ae0078fcSDexuan Cui }
964ae0078fcSDexuan Cui 
965ae0078fcSDexuan Cui /* This isn't really used. See vmbus_match() and vmbus_probe() */
966ae0078fcSDexuan Cui static const struct hv_vmbus_device_id id_table[] = {
967ae0078fcSDexuan Cui 	{},
968ae0078fcSDexuan Cui };
969ae0078fcSDexuan Cui 
970ae0078fcSDexuan Cui static struct hv_driver hvs_drv = {
971ae0078fcSDexuan Cui 	.name		= "hv_sock",
972ae0078fcSDexuan Cui 	.hvsock		= true,
973ae0078fcSDexuan Cui 	.id_table	= id_table,
974ae0078fcSDexuan Cui 	.probe		= hvs_probe,
975ae0078fcSDexuan Cui 	.remove		= hvs_remove,
976ae0078fcSDexuan Cui };
977ae0078fcSDexuan Cui 
978ae0078fcSDexuan Cui static int __init hvs_init(void)
979ae0078fcSDexuan Cui {
980ae0078fcSDexuan Cui 	int ret;
981ae0078fcSDexuan Cui 
982ae0078fcSDexuan Cui 	if (vmbus_proto_version < VERSION_WIN10)
983ae0078fcSDexuan Cui 		return -ENODEV;
984ae0078fcSDexuan Cui 
985ae0078fcSDexuan Cui 	ret = vmbus_driver_register(&hvs_drv);
986ae0078fcSDexuan Cui 	if (ret != 0)
987ae0078fcSDexuan Cui 		return ret;
988ae0078fcSDexuan Cui 
989ae0078fcSDexuan Cui 	ret = vsock_core_init(&hvs_transport);
990ae0078fcSDexuan Cui 	if (ret) {
991ae0078fcSDexuan Cui 		vmbus_driver_unregister(&hvs_drv);
992ae0078fcSDexuan Cui 		return ret;
993ae0078fcSDexuan Cui 	}
994ae0078fcSDexuan Cui 
995ae0078fcSDexuan Cui 	return 0;
996ae0078fcSDexuan Cui }
997ae0078fcSDexuan Cui 
998ae0078fcSDexuan Cui static void __exit hvs_exit(void)
999ae0078fcSDexuan Cui {
1000ae0078fcSDexuan Cui 	vsock_core_exit();
1001ae0078fcSDexuan Cui 	vmbus_driver_unregister(&hvs_drv);
1002ae0078fcSDexuan Cui }
1003ae0078fcSDexuan Cui 
1004ae0078fcSDexuan Cui module_init(hvs_init);
1005ae0078fcSDexuan Cui module_exit(hvs_exit);
1006ae0078fcSDexuan Cui 
1007ae0078fcSDexuan Cui MODULE_DESCRIPTION("Hyper-V Sockets");
1008ae0078fcSDexuan Cui MODULE_VERSION("1.0.0");
1009ae0078fcSDexuan Cui MODULE_LICENSE("GPL");
1010ae0078fcSDexuan Cui MODULE_ALIAS_NETPROTO(PF_VSOCK);
1011