xref: /kernel/linux/linux-5.10/net/qrtr/af_qrtr.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015, Sony Mobile Communications Inc.
4 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
5 */
6#include <linux/module.h>
7#include <linux/netlink.h>
8#include <linux/qrtr.h>
9#include <linux/termios.h>	/* For TIOCINQ/OUTQ */
10#include <linux/spinlock.h>
11#include <linux/wait.h>
12
13#include <net/sock.h>
14
15#include "qrtr.h"
16
17#define QRTR_PROTO_VER_1 1
18#define QRTR_PROTO_VER_2 3
19
20/* auto-bind range */
21#define QRTR_MIN_EPH_SOCKET 0x4000
22#define QRTR_MAX_EPH_SOCKET 0x7fff
23#define QRTR_EPH_PORT_RANGE \
24		XA_LIMIT(QRTR_MIN_EPH_SOCKET, QRTR_MAX_EPH_SOCKET)
25
26/**
27 * struct qrtr_hdr_v1 - (I|R)PCrouter packet header version 1
28 * @version: protocol version
29 * @type: packet type; one of QRTR_TYPE_*
30 * @src_node_id: source node
31 * @src_port_id: source port
32 * @confirm_rx: boolean; whether a resume-tx packet should be send in reply
33 * @size: length of packet, excluding this header
34 * @dst_node_id: destination node
35 * @dst_port_id: destination port
36 */
37struct qrtr_hdr_v1 {
38	__le32 version;
39	__le32 type;
40	__le32 src_node_id;
41	__le32 src_port_id;
42	__le32 confirm_rx;
43	__le32 size;
44	__le32 dst_node_id;
45	__le32 dst_port_id;
46} __packed;
47
48/**
49 * struct qrtr_hdr_v2 - (I|R)PCrouter packet header later versions
50 * @version: protocol version
51 * @type: packet type; one of QRTR_TYPE_*
52 * @flags: bitmask of QRTR_FLAGS_*
53 * @optlen: length of optional header data
54 * @size: length of packet, excluding this header and optlen
55 * @src_node_id: source node
56 * @src_port_id: source port
57 * @dst_node_id: destination node
58 * @dst_port_id: destination port
59 */
60struct qrtr_hdr_v2 {
61	u8 version;
62	u8 type;
63	u8 flags;
64	u8 optlen;
65	__le32 size;
66	__le16 src_node_id;
67	__le16 src_port_id;
68	__le16 dst_node_id;
69	__le16 dst_port_id;
70};
71
72#define QRTR_FLAGS_CONFIRM_RX	BIT(0)
73
74struct qrtr_cb {
75	u32 src_node;
76	u32 src_port;
77	u32 dst_node;
78	u32 dst_port;
79
80	u8 type;
81	u8 confirm_rx;
82};
83
84#define QRTR_HDR_MAX_SIZE max_t(size_t, sizeof(struct qrtr_hdr_v1), \
85					sizeof(struct qrtr_hdr_v2))
86
87struct qrtr_sock {
88	/* WARNING: sk must be the first member */
89	struct sock sk;
90	struct sockaddr_qrtr us;
91	struct sockaddr_qrtr peer;
92};
93
94static inline struct qrtr_sock *qrtr_sk(struct sock *sk)
95{
96	BUILD_BUG_ON(offsetof(struct qrtr_sock, sk) != 0);
97	return container_of(sk, struct qrtr_sock, sk);
98}
99
100static unsigned int qrtr_local_nid = 1;
101
102/* for node ids */
103static RADIX_TREE(qrtr_nodes, GFP_ATOMIC);
104static DEFINE_SPINLOCK(qrtr_nodes_lock);
105/* broadcast list */
106static LIST_HEAD(qrtr_all_nodes);
107/* lock for qrtr_all_nodes and node reference */
108static DEFINE_MUTEX(qrtr_node_lock);
109
110/* local port allocation management */
111static DEFINE_XARRAY_ALLOC(qrtr_ports);
112
113/**
114 * struct qrtr_node - endpoint node
115 * @ep_lock: lock for endpoint management and callbacks
116 * @ep: endpoint
117 * @ref: reference count for node
118 * @nid: node id
119 * @qrtr_tx_flow: tree of qrtr_tx_flow, keyed by node << 32 | port
120 * @qrtr_tx_lock: lock for qrtr_tx_flow inserts
121 * @rx_queue: receive queue
122 * @item: list item for broadcast list
123 */
124struct qrtr_node {
125	struct mutex ep_lock;
126	struct qrtr_endpoint *ep;
127	struct kref ref;
128	unsigned int nid;
129
130	struct radix_tree_root qrtr_tx_flow;
131	struct mutex qrtr_tx_lock; /* for qrtr_tx_flow */
132
133	struct sk_buff_head rx_queue;
134	struct list_head item;
135};
136
137/**
138 * struct qrtr_tx_flow - tx flow control
139 * @resume_tx: waiters for a resume tx from the remote
140 * @pending: number of waiting senders
141 * @tx_failed: indicates that a message with confirm_rx flag was lost
142 */
143struct qrtr_tx_flow {
144	struct wait_queue_head resume_tx;
145	int pending;
146	int tx_failed;
147};
148
149#define QRTR_TX_FLOW_HIGH	10
150#define QRTR_TX_FLOW_LOW	5
151
152static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb,
153			      int type, struct sockaddr_qrtr *from,
154			      struct sockaddr_qrtr *to);
155static int qrtr_bcast_enqueue(struct qrtr_node *node, struct sk_buff *skb,
156			      int type, struct sockaddr_qrtr *from,
157			      struct sockaddr_qrtr *to);
158static struct qrtr_sock *qrtr_port_lookup(int port);
159static void qrtr_port_put(struct qrtr_sock *ipc);
160
161/* Release node resources and free the node.
162 *
163 * Do not call directly, use qrtr_node_release.  To be used with
164 * kref_put_mutex.  As such, the node mutex is expected to be locked on call.
165 */
166static void __qrtr_node_release(struct kref *kref)
167{
168	struct qrtr_node *node = container_of(kref, struct qrtr_node, ref);
169	struct radix_tree_iter iter;
170	struct qrtr_tx_flow *flow;
171	unsigned long flags;
172	void __rcu **slot;
173
174	spin_lock_irqsave(&qrtr_nodes_lock, flags);
175	if (node->nid != QRTR_EP_NID_AUTO)
176		radix_tree_delete(&qrtr_nodes, node->nid);
177	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
178
179	list_del(&node->item);
180	mutex_unlock(&qrtr_node_lock);
181
182	skb_queue_purge(&node->rx_queue);
183
184	/* Free tx flow counters */
185	radix_tree_for_each_slot(slot, &node->qrtr_tx_flow, &iter, 0) {
186		flow = *slot;
187		radix_tree_iter_delete(&node->qrtr_tx_flow, &iter, slot);
188		kfree(flow);
189	}
190	kfree(node);
191}
192
193/* Increment reference to node. */
194static struct qrtr_node *qrtr_node_acquire(struct qrtr_node *node)
195{
196	if (node)
197		kref_get(&node->ref);
198	return node;
199}
200
201/* Decrement reference to node and release as necessary. */
202static void qrtr_node_release(struct qrtr_node *node)
203{
204	if (!node)
205		return;
206	kref_put_mutex(&node->ref, __qrtr_node_release, &qrtr_node_lock);
207}
208
209/**
210 * qrtr_tx_resume() - reset flow control counter
211 * @node:	qrtr_node that the QRTR_TYPE_RESUME_TX packet arrived on
212 * @skb:	resume_tx packet
213 */
214static void qrtr_tx_resume(struct qrtr_node *node, struct sk_buff *skb)
215{
216	struct qrtr_ctrl_pkt *pkt = (struct qrtr_ctrl_pkt *)skb->data;
217	u64 remote_node = le32_to_cpu(pkt->client.node);
218	u32 remote_port = le32_to_cpu(pkt->client.port);
219	struct qrtr_tx_flow *flow;
220	unsigned long key;
221
222	key = remote_node << 32 | remote_port;
223
224	rcu_read_lock();
225	flow = radix_tree_lookup(&node->qrtr_tx_flow, key);
226	rcu_read_unlock();
227	if (flow) {
228		spin_lock(&flow->resume_tx.lock);
229		flow->pending = 0;
230		spin_unlock(&flow->resume_tx.lock);
231		wake_up_interruptible_all(&flow->resume_tx);
232	}
233
234	consume_skb(skb);
235}
236
237/**
238 * qrtr_tx_wait() - flow control for outgoing packets
239 * @node:	qrtr_node that the packet is to be send to
240 * @dest_node:	node id of the destination
241 * @dest_port:	port number of the destination
242 * @type:	type of message
243 *
244 * The flow control scheme is based around the low and high "watermarks". When
245 * the low watermark is passed the confirm_rx flag is set on the outgoing
246 * message, which will trigger the remote to send a control message of the type
247 * QRTR_TYPE_RESUME_TX to reset the counter. If the high watermark is hit
248 * further transmision should be paused.
249 *
250 * Return: 1 if confirm_rx should be set, 0 otherwise or errno failure
251 */
252static int qrtr_tx_wait(struct qrtr_node *node, int dest_node, int dest_port,
253			int type)
254{
255	unsigned long key = (u64)dest_node << 32 | dest_port;
256	struct qrtr_tx_flow *flow;
257	int confirm_rx = 0;
258	int ret;
259
260	/* Never set confirm_rx on non-data packets */
261	if (type != QRTR_TYPE_DATA)
262		return 0;
263
264	mutex_lock(&node->qrtr_tx_lock);
265	flow = radix_tree_lookup(&node->qrtr_tx_flow, key);
266	if (!flow) {
267		flow = kzalloc(sizeof(*flow), GFP_KERNEL);
268		if (flow) {
269			init_waitqueue_head(&flow->resume_tx);
270			if (radix_tree_insert(&node->qrtr_tx_flow, key, flow)) {
271				kfree(flow);
272				flow = NULL;
273			}
274		}
275	}
276	mutex_unlock(&node->qrtr_tx_lock);
277
278	/* Set confirm_rx if we where unable to find and allocate a flow */
279	if (!flow)
280		return 1;
281
282	spin_lock_irq(&flow->resume_tx.lock);
283	ret = wait_event_interruptible_locked_irq(flow->resume_tx,
284						  flow->pending < QRTR_TX_FLOW_HIGH ||
285						  flow->tx_failed ||
286						  !node->ep);
287	if (ret < 0) {
288		confirm_rx = ret;
289	} else if (!node->ep) {
290		confirm_rx = -EPIPE;
291	} else if (flow->tx_failed) {
292		flow->tx_failed = 0;
293		confirm_rx = 1;
294	} else {
295		flow->pending++;
296		confirm_rx = flow->pending == QRTR_TX_FLOW_LOW;
297	}
298	spin_unlock_irq(&flow->resume_tx.lock);
299
300	return confirm_rx;
301}
302
303/**
304 * qrtr_tx_flow_failed() - flag that tx of confirm_rx flagged messages failed
305 * @node:	qrtr_node that the packet is to be send to
306 * @dest_node:	node id of the destination
307 * @dest_port:	port number of the destination
308 *
309 * Signal that the transmission of a message with confirm_rx flag failed. The
310 * flow's "pending" counter will keep incrementing towards QRTR_TX_FLOW_HIGH,
311 * at which point transmission would stall forever waiting for the resume TX
312 * message associated with the dropped confirm_rx message.
313 * Work around this by marking the flow as having a failed transmission and
314 * cause the next transmission attempt to be sent with the confirm_rx.
315 */
316static void qrtr_tx_flow_failed(struct qrtr_node *node, int dest_node,
317				int dest_port)
318{
319	unsigned long key = (u64)dest_node << 32 | dest_port;
320	struct qrtr_tx_flow *flow;
321
322	rcu_read_lock();
323	flow = radix_tree_lookup(&node->qrtr_tx_flow, key);
324	rcu_read_unlock();
325	if (flow) {
326		spin_lock_irq(&flow->resume_tx.lock);
327		flow->tx_failed = 1;
328		spin_unlock_irq(&flow->resume_tx.lock);
329	}
330}
331
332/* Pass an outgoing packet socket buffer to the endpoint driver. */
333static int qrtr_node_enqueue(struct qrtr_node *node, struct sk_buff *skb,
334			     int type, struct sockaddr_qrtr *from,
335			     struct sockaddr_qrtr *to)
336{
337	struct qrtr_hdr_v1 *hdr;
338	size_t len = skb->len;
339	int rc, confirm_rx;
340
341	confirm_rx = qrtr_tx_wait(node, to->sq_node, to->sq_port, type);
342	if (confirm_rx < 0) {
343		kfree_skb(skb);
344		return confirm_rx;
345	}
346
347	hdr = skb_push(skb, sizeof(*hdr));
348	hdr->version = cpu_to_le32(QRTR_PROTO_VER_1);
349	hdr->type = cpu_to_le32(type);
350	hdr->src_node_id = cpu_to_le32(from->sq_node);
351	hdr->src_port_id = cpu_to_le32(from->sq_port);
352	if (to->sq_port == QRTR_PORT_CTRL) {
353		hdr->dst_node_id = cpu_to_le32(node->nid);
354		hdr->dst_port_id = cpu_to_le32(QRTR_PORT_CTRL);
355	} else {
356		hdr->dst_node_id = cpu_to_le32(to->sq_node);
357		hdr->dst_port_id = cpu_to_le32(to->sq_port);
358	}
359
360	hdr->size = cpu_to_le32(len);
361	hdr->confirm_rx = !!confirm_rx;
362
363	rc = skb_put_padto(skb, ALIGN(len, 4) + sizeof(*hdr));
364
365	if (!rc) {
366		mutex_lock(&node->ep_lock);
367		rc = -ENODEV;
368		if (node->ep)
369			rc = node->ep->xmit(node->ep, skb);
370		else
371			kfree_skb(skb);
372		mutex_unlock(&node->ep_lock);
373	}
374	/* Need to ensure that a subsequent message carries the otherwise lost
375	 * confirm_rx flag if we dropped this one */
376	if (rc && confirm_rx)
377		qrtr_tx_flow_failed(node, to->sq_node, to->sq_port);
378
379	return rc;
380}
381
382/* Lookup node by id.
383 *
384 * callers must release with qrtr_node_release()
385 */
386static struct qrtr_node *qrtr_node_lookup(unsigned int nid)
387{
388	struct qrtr_node *node;
389	unsigned long flags;
390
391	mutex_lock(&qrtr_node_lock);
392	spin_lock_irqsave(&qrtr_nodes_lock, flags);
393	node = radix_tree_lookup(&qrtr_nodes, nid);
394	node = qrtr_node_acquire(node);
395	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
396	mutex_unlock(&qrtr_node_lock);
397
398	return node;
399}
400
401/* Assign node id to node.
402 *
403 * This is mostly useful for automatic node id assignment, based on
404 * the source id in the incoming packet.
405 */
406static void qrtr_node_assign(struct qrtr_node *node, unsigned int nid)
407{
408	unsigned long flags;
409
410	if (node->nid != QRTR_EP_NID_AUTO || nid == QRTR_EP_NID_AUTO)
411		return;
412
413	spin_lock_irqsave(&qrtr_nodes_lock, flags);
414	radix_tree_insert(&qrtr_nodes, nid, node);
415	node->nid = nid;
416	spin_unlock_irqrestore(&qrtr_nodes_lock, flags);
417}
418
419/**
420 * qrtr_endpoint_post() - post incoming data
421 * @ep: endpoint handle
422 * @data: data pointer
423 * @len: size of data in bytes
424 *
425 * Return: 0 on success; negative error code on failure
426 */
427int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
428{
429	struct qrtr_node *node = ep->node;
430	const struct qrtr_hdr_v1 *v1;
431	const struct qrtr_hdr_v2 *v2;
432	struct qrtr_sock *ipc;
433	struct sk_buff *skb;
434	struct qrtr_cb *cb;
435	size_t size;
436	unsigned int ver;
437	size_t hdrlen;
438
439	if (len == 0 || len & 3)
440		return -EINVAL;
441
442	skb = __netdev_alloc_skb(NULL, len, GFP_ATOMIC | __GFP_NOWARN);
443	if (!skb)
444		return -ENOMEM;
445
446	cb = (struct qrtr_cb *)skb->cb;
447
448	/* Version field in v1 is little endian, so this works for both cases */
449	ver = *(u8*)data;
450
451	switch (ver) {
452	case QRTR_PROTO_VER_1:
453		if (len < sizeof(*v1))
454			goto err;
455		v1 = data;
456		hdrlen = sizeof(*v1);
457
458		cb->type = le32_to_cpu(v1->type);
459		cb->src_node = le32_to_cpu(v1->src_node_id);
460		cb->src_port = le32_to_cpu(v1->src_port_id);
461		cb->confirm_rx = !!v1->confirm_rx;
462		cb->dst_node = le32_to_cpu(v1->dst_node_id);
463		cb->dst_port = le32_to_cpu(v1->dst_port_id);
464
465		size = le32_to_cpu(v1->size);
466		break;
467	case QRTR_PROTO_VER_2:
468		if (len < sizeof(*v2))
469			goto err;
470		v2 = data;
471		hdrlen = sizeof(*v2) + v2->optlen;
472
473		cb->type = v2->type;
474		cb->confirm_rx = !!(v2->flags & QRTR_FLAGS_CONFIRM_RX);
475		cb->src_node = le16_to_cpu(v2->src_node_id);
476		cb->src_port = le16_to_cpu(v2->src_port_id);
477		cb->dst_node = le16_to_cpu(v2->dst_node_id);
478		cb->dst_port = le16_to_cpu(v2->dst_port_id);
479
480		if (cb->src_port == (u16)QRTR_PORT_CTRL)
481			cb->src_port = QRTR_PORT_CTRL;
482		if (cb->dst_port == (u16)QRTR_PORT_CTRL)
483			cb->dst_port = QRTR_PORT_CTRL;
484
485		size = le32_to_cpu(v2->size);
486		break;
487	default:
488		pr_err("qrtr: Invalid version %d\n", ver);
489		goto err;
490	}
491
492	if (!size || len != ALIGN(size, 4) + hdrlen)
493		goto err;
494
495	if ((cb->type == QRTR_TYPE_NEW_SERVER ||
496	     cb->type == QRTR_TYPE_RESUME_TX) &&
497	    size < sizeof(struct qrtr_ctrl_pkt))
498		goto err;
499
500	if (cb->dst_port != QRTR_PORT_CTRL && cb->type != QRTR_TYPE_DATA &&
501	    cb->type != QRTR_TYPE_RESUME_TX)
502		goto err;
503
504	skb_put_data(skb, data + hdrlen, size);
505
506	qrtr_node_assign(node, cb->src_node);
507
508	if (cb->type == QRTR_TYPE_NEW_SERVER) {
509		/* Remote node endpoint can bridge other distant nodes */
510		const struct qrtr_ctrl_pkt *pkt;
511
512		pkt = data + hdrlen;
513		qrtr_node_assign(node, le32_to_cpu(pkt->server.node));
514	}
515
516	if (cb->type == QRTR_TYPE_RESUME_TX) {
517		qrtr_tx_resume(node, skb);
518	} else {
519		ipc = qrtr_port_lookup(cb->dst_port);
520		if (!ipc)
521			goto err;
522
523		if (sock_queue_rcv_skb(&ipc->sk, skb)) {
524			qrtr_port_put(ipc);
525			goto err;
526		}
527
528		qrtr_port_put(ipc);
529	}
530
531	return 0;
532
533err:
534	kfree_skb(skb);
535	return -EINVAL;
536
537}
538EXPORT_SYMBOL_GPL(qrtr_endpoint_post);
539
540/**
541 * qrtr_alloc_ctrl_packet() - allocate control packet skb
542 * @pkt: reference to qrtr_ctrl_pkt pointer
543 *
544 * Returns newly allocated sk_buff, or NULL on failure
545 *
546 * This function allocates a sk_buff large enough to carry a qrtr_ctrl_pkt and
547 * on success returns a reference to the control packet in @pkt.
548 */
549static struct sk_buff *qrtr_alloc_ctrl_packet(struct qrtr_ctrl_pkt **pkt)
550{
551	const int pkt_len = sizeof(struct qrtr_ctrl_pkt);
552	struct sk_buff *skb;
553
554	skb = alloc_skb(QRTR_HDR_MAX_SIZE + pkt_len, GFP_KERNEL);
555	if (!skb)
556		return NULL;
557
558	skb_reserve(skb, QRTR_HDR_MAX_SIZE);
559	*pkt = skb_put_zero(skb, pkt_len);
560
561	return skb;
562}
563
564/**
565 * qrtr_endpoint_register() - register a new endpoint
566 * @ep: endpoint to register
567 * @nid: desired node id; may be QRTR_EP_NID_AUTO for auto-assignment
568 * Return: 0 on success; negative error code on failure
569 *
570 * The specified endpoint must have the xmit function pointer set on call.
571 */
572int qrtr_endpoint_register(struct qrtr_endpoint *ep, unsigned int nid)
573{
574	struct qrtr_node *node;
575
576	if (!ep || !ep->xmit)
577		return -EINVAL;
578
579	node = kzalloc(sizeof(*node), GFP_KERNEL);
580	if (!node)
581		return -ENOMEM;
582
583	kref_init(&node->ref);
584	mutex_init(&node->ep_lock);
585	skb_queue_head_init(&node->rx_queue);
586	node->nid = QRTR_EP_NID_AUTO;
587	node->ep = ep;
588
589	INIT_RADIX_TREE(&node->qrtr_tx_flow, GFP_KERNEL);
590	mutex_init(&node->qrtr_tx_lock);
591
592	qrtr_node_assign(node, nid);
593
594	mutex_lock(&qrtr_node_lock);
595	list_add(&node->item, &qrtr_all_nodes);
596	mutex_unlock(&qrtr_node_lock);
597	ep->node = node;
598
599	return 0;
600}
601EXPORT_SYMBOL_GPL(qrtr_endpoint_register);
602
603/**
604 * qrtr_endpoint_unregister - unregister endpoint
605 * @ep: endpoint to unregister
606 */
607void qrtr_endpoint_unregister(struct qrtr_endpoint *ep)
608{
609	struct qrtr_node *node = ep->node;
610	struct sockaddr_qrtr src = {AF_QIPCRTR, node->nid, QRTR_PORT_CTRL};
611	struct sockaddr_qrtr dst = {AF_QIPCRTR, qrtr_local_nid, QRTR_PORT_CTRL};
612	struct radix_tree_iter iter;
613	struct qrtr_ctrl_pkt *pkt;
614	struct qrtr_tx_flow *flow;
615	struct sk_buff *skb;
616	void __rcu **slot;
617
618	mutex_lock(&node->ep_lock);
619	node->ep = NULL;
620	mutex_unlock(&node->ep_lock);
621
622	/* Notify the local controller about the event */
623	skb = qrtr_alloc_ctrl_packet(&pkt);
624	if (skb) {
625		pkt->cmd = cpu_to_le32(QRTR_TYPE_BYE);
626		qrtr_local_enqueue(NULL, skb, QRTR_TYPE_BYE, &src, &dst);
627	}
628
629	/* Wake up any transmitters waiting for resume-tx from the node */
630	mutex_lock(&node->qrtr_tx_lock);
631	radix_tree_for_each_slot(slot, &node->qrtr_tx_flow, &iter, 0) {
632		flow = *slot;
633		wake_up_interruptible_all(&flow->resume_tx);
634	}
635	mutex_unlock(&node->qrtr_tx_lock);
636
637	qrtr_node_release(node);
638	ep->node = NULL;
639}
640EXPORT_SYMBOL_GPL(qrtr_endpoint_unregister);
641
642/* Lookup socket by port.
643 *
644 * Callers must release with qrtr_port_put()
645 */
646static struct qrtr_sock *qrtr_port_lookup(int port)
647{
648	struct qrtr_sock *ipc;
649
650	if (port == QRTR_PORT_CTRL)
651		port = 0;
652
653	rcu_read_lock();
654	ipc = xa_load(&qrtr_ports, port);
655	if (ipc)
656		sock_hold(&ipc->sk);
657	rcu_read_unlock();
658
659	return ipc;
660}
661
662/* Release acquired socket. */
663static void qrtr_port_put(struct qrtr_sock *ipc)
664{
665	sock_put(&ipc->sk);
666}
667
668/* Remove port assignment. */
669static void qrtr_port_remove(struct qrtr_sock *ipc)
670{
671	struct qrtr_ctrl_pkt *pkt;
672	struct sk_buff *skb;
673	int port = ipc->us.sq_port;
674	struct sockaddr_qrtr to;
675
676	to.sq_family = AF_QIPCRTR;
677	to.sq_node = QRTR_NODE_BCAST;
678	to.sq_port = QRTR_PORT_CTRL;
679
680	skb = qrtr_alloc_ctrl_packet(&pkt);
681	if (skb) {
682		pkt->cmd = cpu_to_le32(QRTR_TYPE_DEL_CLIENT);
683		pkt->client.node = cpu_to_le32(ipc->us.sq_node);
684		pkt->client.port = cpu_to_le32(ipc->us.sq_port);
685
686		skb_set_owner_w(skb, &ipc->sk);
687		qrtr_bcast_enqueue(NULL, skb, QRTR_TYPE_DEL_CLIENT, &ipc->us,
688				   &to);
689	}
690
691	if (port == QRTR_PORT_CTRL)
692		port = 0;
693
694	__sock_put(&ipc->sk);
695
696	xa_erase(&qrtr_ports, port);
697
698	/* Ensure that if qrtr_port_lookup() did enter the RCU read section we
699	 * wait for it to up increment the refcount */
700	synchronize_rcu();
701}
702
703/* Assign port number to socket.
704 *
705 * Specify port in the integer pointed to by port, and it will be adjusted
706 * on return as necesssary.
707 *
708 * Port may be:
709 *   0: Assign ephemeral port in [QRTR_MIN_EPH_SOCKET, QRTR_MAX_EPH_SOCKET]
710 *   <QRTR_MIN_EPH_SOCKET: Specified; requires CAP_NET_ADMIN
711 *   >QRTR_MIN_EPH_SOCKET: Specified; available to all
712 */
713static int qrtr_port_assign(struct qrtr_sock *ipc, int *port)
714{
715	int rc;
716
717	if (!*port) {
718		rc = xa_alloc(&qrtr_ports, port, ipc, QRTR_EPH_PORT_RANGE,
719				GFP_KERNEL);
720	} else if (*port < QRTR_MIN_EPH_SOCKET && !capable(CAP_NET_ADMIN)) {
721		rc = -EACCES;
722	} else if (*port == QRTR_PORT_CTRL) {
723		rc = xa_insert(&qrtr_ports, 0, ipc, GFP_KERNEL);
724	} else {
725		rc = xa_insert(&qrtr_ports, *port, ipc, GFP_KERNEL);
726	}
727
728	if (rc == -EBUSY)
729		return -EADDRINUSE;
730	else if (rc < 0)
731		return rc;
732
733	sock_hold(&ipc->sk);
734
735	return 0;
736}
737
738/* Reset all non-control ports */
739static void qrtr_reset_ports(void)
740{
741	struct qrtr_sock *ipc;
742	unsigned long index;
743
744	rcu_read_lock();
745	xa_for_each_start(&qrtr_ports, index, ipc, 1) {
746		sock_hold(&ipc->sk);
747		ipc->sk.sk_err = ENETRESET;
748		ipc->sk.sk_error_report(&ipc->sk);
749		sock_put(&ipc->sk);
750	}
751	rcu_read_unlock();
752}
753
754/* Bind socket to address.
755 *
756 * Socket should be locked upon call.
757 */
758static int __qrtr_bind(struct socket *sock,
759		       const struct sockaddr_qrtr *addr, int zapped)
760{
761	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
762	struct sock *sk = sock->sk;
763	int port;
764	int rc;
765
766	/* rebinding ok */
767	if (!zapped && addr->sq_port == ipc->us.sq_port)
768		return 0;
769
770	port = addr->sq_port;
771	rc = qrtr_port_assign(ipc, &port);
772	if (rc)
773		return rc;
774
775	/* unbind previous, if any */
776	if (!zapped)
777		qrtr_port_remove(ipc);
778	ipc->us.sq_port = port;
779
780	sock_reset_flag(sk, SOCK_ZAPPED);
781
782	/* Notify all open ports about the new controller */
783	if (port == QRTR_PORT_CTRL)
784		qrtr_reset_ports();
785
786	return 0;
787}
788
789/* Auto bind to an ephemeral port. */
790static int qrtr_autobind(struct socket *sock)
791{
792	struct sock *sk = sock->sk;
793	struct sockaddr_qrtr addr;
794
795	if (!sock_flag(sk, SOCK_ZAPPED))
796		return 0;
797
798	addr.sq_family = AF_QIPCRTR;
799	addr.sq_node = qrtr_local_nid;
800	addr.sq_port = 0;
801
802	return __qrtr_bind(sock, &addr, 1);
803}
804
805/* Bind socket to specified sockaddr. */
806static int qrtr_bind(struct socket *sock, struct sockaddr *saddr, int len)
807{
808	DECLARE_SOCKADDR(struct sockaddr_qrtr *, addr, saddr);
809	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
810	struct sock *sk = sock->sk;
811	int rc;
812
813	if (len < sizeof(*addr) || addr->sq_family != AF_QIPCRTR)
814		return -EINVAL;
815
816	if (addr->sq_node != ipc->us.sq_node)
817		return -EINVAL;
818
819	lock_sock(sk);
820	rc = __qrtr_bind(sock, addr, sock_flag(sk, SOCK_ZAPPED));
821	release_sock(sk);
822
823	return rc;
824}
825
826/* Queue packet to local peer socket. */
827static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb,
828			      int type, struct sockaddr_qrtr *from,
829			      struct sockaddr_qrtr *to)
830{
831	struct qrtr_sock *ipc;
832	struct qrtr_cb *cb;
833
834	ipc = qrtr_port_lookup(to->sq_port);
835	if (!ipc || &ipc->sk == skb->sk) { /* do not send to self */
836		if (ipc)
837			qrtr_port_put(ipc);
838		kfree_skb(skb);
839		return -ENODEV;
840	}
841
842	cb = (struct qrtr_cb *)skb->cb;
843	cb->src_node = from->sq_node;
844	cb->src_port = from->sq_port;
845
846	if (sock_queue_rcv_skb(&ipc->sk, skb)) {
847		qrtr_port_put(ipc);
848		kfree_skb(skb);
849		return -ENOSPC;
850	}
851
852	qrtr_port_put(ipc);
853
854	return 0;
855}
856
857/* Queue packet for broadcast. */
858static int qrtr_bcast_enqueue(struct qrtr_node *node, struct sk_buff *skb,
859			      int type, struct sockaddr_qrtr *from,
860			      struct sockaddr_qrtr *to)
861{
862	struct sk_buff *skbn;
863
864	mutex_lock(&qrtr_node_lock);
865	list_for_each_entry(node, &qrtr_all_nodes, item) {
866		skbn = skb_clone(skb, GFP_KERNEL);
867		if (!skbn)
868			break;
869		skb_set_owner_w(skbn, skb->sk);
870		qrtr_node_enqueue(node, skbn, type, from, to);
871	}
872	mutex_unlock(&qrtr_node_lock);
873
874	qrtr_local_enqueue(NULL, skb, type, from, to);
875
876	return 0;
877}
878
879static int qrtr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
880{
881	DECLARE_SOCKADDR(struct sockaddr_qrtr *, addr, msg->msg_name);
882	int (*enqueue_fn)(struct qrtr_node *, struct sk_buff *, int,
883			  struct sockaddr_qrtr *, struct sockaddr_qrtr *);
884	__le32 qrtr_type = cpu_to_le32(QRTR_TYPE_DATA);
885	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
886	struct sock *sk = sock->sk;
887	struct qrtr_node *node;
888	struct sk_buff *skb;
889	size_t plen;
890	u32 type;
891	int rc;
892
893	if (msg->msg_flags & ~(MSG_DONTWAIT))
894		return -EINVAL;
895
896	if (len > 65535)
897		return -EMSGSIZE;
898
899	lock_sock(sk);
900
901	if (addr) {
902		if (msg->msg_namelen < sizeof(*addr)) {
903			release_sock(sk);
904			return -EINVAL;
905		}
906
907		if (addr->sq_family != AF_QIPCRTR) {
908			release_sock(sk);
909			return -EINVAL;
910		}
911
912		rc = qrtr_autobind(sock);
913		if (rc) {
914			release_sock(sk);
915			return rc;
916		}
917	} else if (sk->sk_state == TCP_ESTABLISHED) {
918		addr = &ipc->peer;
919	} else {
920		release_sock(sk);
921		return -ENOTCONN;
922	}
923
924	node = NULL;
925	if (addr->sq_node == QRTR_NODE_BCAST) {
926		if (addr->sq_port != QRTR_PORT_CTRL &&
927		    qrtr_local_nid != QRTR_NODE_BCAST) {
928			release_sock(sk);
929			return -ENOTCONN;
930		}
931		enqueue_fn = qrtr_bcast_enqueue;
932	} else if (addr->sq_node == ipc->us.sq_node) {
933		enqueue_fn = qrtr_local_enqueue;
934	} else {
935		node = qrtr_node_lookup(addr->sq_node);
936		if (!node) {
937			release_sock(sk);
938			return -ECONNRESET;
939		}
940		enqueue_fn = qrtr_node_enqueue;
941	}
942
943	plen = (len + 3) & ~3;
944	skb = sock_alloc_send_skb(sk, plen + QRTR_HDR_MAX_SIZE,
945				  msg->msg_flags & MSG_DONTWAIT, &rc);
946	if (!skb) {
947		rc = -ENOMEM;
948		goto out_node;
949	}
950
951	skb_reserve(skb, QRTR_HDR_MAX_SIZE);
952
953	rc = memcpy_from_msg(skb_put(skb, len), msg, len);
954	if (rc) {
955		kfree_skb(skb);
956		goto out_node;
957	}
958
959	if (ipc->us.sq_port == QRTR_PORT_CTRL) {
960		if (len < 4) {
961			rc = -EINVAL;
962			kfree_skb(skb);
963			goto out_node;
964		}
965
966		/* control messages already require the type as 'command' */
967		skb_copy_bits(skb, 0, &qrtr_type, 4);
968	}
969
970	type = le32_to_cpu(qrtr_type);
971	rc = enqueue_fn(node, skb, type, &ipc->us, addr);
972	if (rc >= 0)
973		rc = len;
974
975out_node:
976	qrtr_node_release(node);
977	release_sock(sk);
978
979	return rc;
980}
981
982static int qrtr_send_resume_tx(struct qrtr_cb *cb)
983{
984	struct sockaddr_qrtr remote = { AF_QIPCRTR, cb->src_node, cb->src_port };
985	struct sockaddr_qrtr local = { AF_QIPCRTR, cb->dst_node, cb->dst_port };
986	struct qrtr_ctrl_pkt *pkt;
987	struct qrtr_node *node;
988	struct sk_buff *skb;
989	int ret;
990
991	node = qrtr_node_lookup(remote.sq_node);
992	if (!node)
993		return -EINVAL;
994
995	skb = qrtr_alloc_ctrl_packet(&pkt);
996	if (!skb)
997		return -ENOMEM;
998
999	pkt->cmd = cpu_to_le32(QRTR_TYPE_RESUME_TX);
1000	pkt->client.node = cpu_to_le32(cb->dst_node);
1001	pkt->client.port = cpu_to_le32(cb->dst_port);
1002
1003	ret = qrtr_node_enqueue(node, skb, QRTR_TYPE_RESUME_TX, &local, &remote);
1004
1005	qrtr_node_release(node);
1006
1007	return ret;
1008}
1009
1010static int qrtr_recvmsg(struct socket *sock, struct msghdr *msg,
1011			size_t size, int flags)
1012{
1013	DECLARE_SOCKADDR(struct sockaddr_qrtr *, addr, msg->msg_name);
1014	struct sock *sk = sock->sk;
1015	struct sk_buff *skb;
1016	struct qrtr_cb *cb;
1017	int copied, rc;
1018
1019	lock_sock(sk);
1020
1021	if (sock_flag(sk, SOCK_ZAPPED)) {
1022		release_sock(sk);
1023		return -EADDRNOTAVAIL;
1024	}
1025
1026	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1027				flags & MSG_DONTWAIT, &rc);
1028	if (!skb) {
1029		release_sock(sk);
1030		return rc;
1031	}
1032	cb = (struct qrtr_cb *)skb->cb;
1033
1034	copied = skb->len;
1035	if (copied > size) {
1036		copied = size;
1037		msg->msg_flags |= MSG_TRUNC;
1038	}
1039
1040	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1041	if (rc < 0)
1042		goto out;
1043	rc = copied;
1044
1045	if (addr) {
1046		/* There is an anonymous 2-byte hole after sq_family,
1047		 * make sure to clear it.
1048		 */
1049		memset(addr, 0, sizeof(*addr));
1050
1051		addr->sq_family = AF_QIPCRTR;
1052		addr->sq_node = cb->src_node;
1053		addr->sq_port = cb->src_port;
1054		msg->msg_namelen = sizeof(*addr);
1055	}
1056
1057out:
1058	if (cb->confirm_rx)
1059		qrtr_send_resume_tx(cb);
1060
1061	skb_free_datagram(sk, skb);
1062	release_sock(sk);
1063
1064	return rc;
1065}
1066
1067static int qrtr_connect(struct socket *sock, struct sockaddr *saddr,
1068			int len, int flags)
1069{
1070	DECLARE_SOCKADDR(struct sockaddr_qrtr *, addr, saddr);
1071	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
1072	struct sock *sk = sock->sk;
1073	int rc;
1074
1075	if (len < sizeof(*addr) || addr->sq_family != AF_QIPCRTR)
1076		return -EINVAL;
1077
1078	lock_sock(sk);
1079
1080	sk->sk_state = TCP_CLOSE;
1081	sock->state = SS_UNCONNECTED;
1082
1083	rc = qrtr_autobind(sock);
1084	if (rc) {
1085		release_sock(sk);
1086		return rc;
1087	}
1088
1089	ipc->peer = *addr;
1090	sock->state = SS_CONNECTED;
1091	sk->sk_state = TCP_ESTABLISHED;
1092
1093	release_sock(sk);
1094
1095	return 0;
1096}
1097
1098static int qrtr_getname(struct socket *sock, struct sockaddr *saddr,
1099			int peer)
1100{
1101	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
1102	struct sockaddr_qrtr qaddr;
1103	struct sock *sk = sock->sk;
1104
1105	lock_sock(sk);
1106	if (peer) {
1107		if (sk->sk_state != TCP_ESTABLISHED) {
1108			release_sock(sk);
1109			return -ENOTCONN;
1110		}
1111
1112		qaddr = ipc->peer;
1113	} else {
1114		qaddr = ipc->us;
1115	}
1116	release_sock(sk);
1117
1118	qaddr.sq_family = AF_QIPCRTR;
1119
1120	memcpy(saddr, &qaddr, sizeof(qaddr));
1121
1122	return sizeof(qaddr);
1123}
1124
1125static int qrtr_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1126{
1127	void __user *argp = (void __user *)arg;
1128	struct qrtr_sock *ipc = qrtr_sk(sock->sk);
1129	struct sock *sk = sock->sk;
1130	struct sockaddr_qrtr *sq;
1131	struct sk_buff *skb;
1132	struct ifreq ifr;
1133	long len = 0;
1134	int rc = 0;
1135
1136	lock_sock(sk);
1137
1138	switch (cmd) {
1139	case TIOCOUTQ:
1140		len = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1141		if (len < 0)
1142			len = 0;
1143		rc = put_user(len, (int __user *)argp);
1144		break;
1145	case TIOCINQ:
1146		skb = skb_peek(&sk->sk_receive_queue);
1147		if (skb)
1148			len = skb->len;
1149		rc = put_user(len, (int __user *)argp);
1150		break;
1151	case SIOCGIFADDR:
1152		if (copy_from_user(&ifr, argp, sizeof(ifr))) {
1153			rc = -EFAULT;
1154			break;
1155		}
1156
1157		sq = (struct sockaddr_qrtr *)&ifr.ifr_addr;
1158		*sq = ipc->us;
1159		if (copy_to_user(argp, &ifr, sizeof(ifr))) {
1160			rc = -EFAULT;
1161			break;
1162		}
1163		break;
1164	case SIOCADDRT:
1165	case SIOCDELRT:
1166	case SIOCSIFADDR:
1167	case SIOCGIFDSTADDR:
1168	case SIOCSIFDSTADDR:
1169	case SIOCGIFBRDADDR:
1170	case SIOCSIFBRDADDR:
1171	case SIOCGIFNETMASK:
1172	case SIOCSIFNETMASK:
1173		rc = -EINVAL;
1174		break;
1175	default:
1176		rc = -ENOIOCTLCMD;
1177		break;
1178	}
1179
1180	release_sock(sk);
1181
1182	return rc;
1183}
1184
1185static int qrtr_release(struct socket *sock)
1186{
1187	struct sock *sk = sock->sk;
1188	struct qrtr_sock *ipc;
1189
1190	if (!sk)
1191		return 0;
1192
1193	lock_sock(sk);
1194
1195	ipc = qrtr_sk(sk);
1196	sk->sk_shutdown = SHUTDOWN_MASK;
1197	if (!sock_flag(sk, SOCK_DEAD))
1198		sk->sk_state_change(sk);
1199
1200	sock_set_flag(sk, SOCK_DEAD);
1201	sock_orphan(sk);
1202	sock->sk = NULL;
1203
1204	if (!sock_flag(sk, SOCK_ZAPPED))
1205		qrtr_port_remove(ipc);
1206
1207	skb_queue_purge(&sk->sk_receive_queue);
1208
1209	release_sock(sk);
1210	sock_put(sk);
1211
1212	return 0;
1213}
1214
1215static const struct proto_ops qrtr_proto_ops = {
1216	.owner		= THIS_MODULE,
1217	.family		= AF_QIPCRTR,
1218	.bind		= qrtr_bind,
1219	.connect	= qrtr_connect,
1220	.socketpair	= sock_no_socketpair,
1221	.accept		= sock_no_accept,
1222	.listen		= sock_no_listen,
1223	.sendmsg	= qrtr_sendmsg,
1224	.recvmsg	= qrtr_recvmsg,
1225	.getname	= qrtr_getname,
1226	.ioctl		= qrtr_ioctl,
1227	.gettstamp	= sock_gettstamp,
1228	.poll		= datagram_poll,
1229	.shutdown	= sock_no_shutdown,
1230	.release	= qrtr_release,
1231	.mmap		= sock_no_mmap,
1232	.sendpage	= sock_no_sendpage,
1233};
1234
1235static struct proto qrtr_proto = {
1236	.name		= "QIPCRTR",
1237	.owner		= THIS_MODULE,
1238	.obj_size	= sizeof(struct qrtr_sock),
1239};
1240
1241static int qrtr_create(struct net *net, struct socket *sock,
1242		       int protocol, int kern)
1243{
1244	struct qrtr_sock *ipc;
1245	struct sock *sk;
1246
1247	if (sock->type != SOCK_DGRAM)
1248		return -EPROTOTYPE;
1249
1250	sk = sk_alloc(net, AF_QIPCRTR, GFP_KERNEL, &qrtr_proto, kern);
1251	if (!sk)
1252		return -ENOMEM;
1253
1254	sock_set_flag(sk, SOCK_ZAPPED);
1255
1256	sock_init_data(sock, sk);
1257	sock->ops = &qrtr_proto_ops;
1258
1259	ipc = qrtr_sk(sk);
1260	ipc->us.sq_family = AF_QIPCRTR;
1261	ipc->us.sq_node = qrtr_local_nid;
1262	ipc->us.sq_port = 0;
1263
1264	return 0;
1265}
1266
1267static const struct net_proto_family qrtr_family = {
1268	.owner	= THIS_MODULE,
1269	.family	= AF_QIPCRTR,
1270	.create	= qrtr_create,
1271};
1272
1273static int __init qrtr_proto_init(void)
1274{
1275	int rc;
1276
1277	rc = proto_register(&qrtr_proto, 1);
1278	if (rc)
1279		return rc;
1280
1281	rc = sock_register(&qrtr_family);
1282	if (rc) {
1283		proto_unregister(&qrtr_proto);
1284		return rc;
1285	}
1286
1287	qrtr_ns_init();
1288
1289	return rc;
1290}
1291postcore_initcall(qrtr_proto_init);
1292
1293static void __exit qrtr_proto_fini(void)
1294{
1295	qrtr_ns_remove();
1296	sock_unregister(qrtr_family.family);
1297	proto_unregister(&qrtr_proto);
1298}
1299module_exit(qrtr_proto_fini);
1300
1301MODULE_DESCRIPTION("Qualcomm IPC-router driver");
1302MODULE_LICENSE("GPL v2");
1303MODULE_ALIAS_NETPROTO(PF_QIPCRTR);
1304